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Marina COCCHI
Professore Ordinario
Dipartimento di Scienze Chimiche e Geologiche - Sede Dipartimento di Scienze Chimiche e Geologiche
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Pubblicazioni
2024
- Iron nuclearity in mineral fibres: Unravelling the catalytic activity for predictive modelling of toxicity
[Articolo su rivista]
Gualtieri, Alessandro F.; Cocchi, Marina; Muniz-Miranda, Francesco; Pedone, Alfonso; Castellini, Elena; Strani, Lorenzo
abstract
: Chronic inflammation induced in vivo by mineral fibres, such as asbestos, is sustained by the cyclic formation of cytotoxic/genotoxic oxidant species that are catalysed by iron. High catalytic activity is observed when iron atoms are isolated in the crystal lattice (nuclearity=1), whereas the catalytic activity is expected to be reduced or null when iron forms clusters of higher nuclearity. This study presents a novel approach for systematically measuring iron nuclearity across a large range of iron-containing standards and mineral fibres of social and economic importance, and for quantitatively assessing the relation between nuclearity and toxicity. The multivariate curve resolution (MCR) empirical approach and density functional theory (DFT) calculations were applied to the analysis of UV-Vis spectra to obtain information on the nature of iron and nuclearity. This approach led to the determination of the nuclearity of selected mineral fibres which was subsequently used to calculate a toxicity-related index. High nuclearity-related toxicity was estimated for chrysotile samples, fibrous glaucophane, asbestos tremolite, and fibrous wollastonite. Intermediate values of toxicity, corresponding to a mean nuclearity of 2, were assigned to actinolite asbestos, amosite, and crocidolite. Finally, a low nuclearity-related toxicity parameter, corresponding to an iron-cluster with a lower catalytic power to produce oxidants, was assigned to asbestos anthophyllite.
2023
- A Feasibility Study towards the On-Line Quality Assessment of Pesto Sauce Production by NIR and Chemometrics
[Articolo su rivista]
Tanzilli, Daniele; D'Alessandro, Alessandro; Tamelli, Samuele; Durante, Caterina; Cocchi, Marina; Strani, Lorenzo
abstract
The food industry needs tools to improve the efficiency of their production processes by minimizing waste, detecting timely potential process issues, as well as reducing the efforts and workforce devoted to laboratory analysis while, at the same time, maintaining high-quality standards of products. This can be achieved by developing on-line monitoring systems and models. The present work presents a feasibility study toward establishing the on-line monitoring of a pesto sauce production process by means of NIR spectroscopy and chemometric tools. The spectra of an intermediate product were acquired on-line and continuously by a NIR probe installed directly on the process line. Principal Component Analysis (PCA) was used both to perform an exploratory data analysis and to build Multivariate Statistical Process Control (MSPC) charts. Moreover, Partial Least Squares (PLS) regression was employed to compute real time prediction models for two different pesto quality parameters, namely, consistency and total lipids content. PCA highlighted some differences related to the origin of basil plants, the main pesto ingredient, such as plant age and supplier. MSPC charts were able to detect production stops/restarts. Finally, it was possible to obtain a rough estimation of the quality of some properties in the early production stage through PLS.
2023
- A proficient multivariate approach for iron(II) spin crossover behaviour modelling in the solid state
[Articolo su rivista]
Marchi, Lorenzo; Fantuzzi, Simone; Cingolani, Andrea; Messori, Alessandro; Mazzoni, Rita; Zacchini, Stefano; Cocchi, Marina; Rigamonti, Luca
abstract
Iron(ii) bis-pyrazolilpyridyl (bpp-R) complexes [Fe(bpp-R)(2)](X)(2)center dot solvent, R = substituent and X- = anion, can undergo a spin transition from high (S = 2, HS) to low spin (S = 0, LS), being spin crossover (SCO) in the solid state. The distortion of the octahedral coordination environment around the metal centre is governed by crystal packing, i.e. the intermolecular interactions among the substituent R of the bpp-R ligands, the anion X-, and the co-crystallized solvent, and this modulates the SCO behaviour. In this work, an innovative multivariate approach, through the combination of the chemometric tools Principal Component Analysis and Partial Least Squares regression, was applied on the coordination bond distances and angles and selected torsional angles of the available HS structures. The obtained results can efficiently model and rationalize the structural data distinguishing between SCO-active and HS-blocked complexes bearing different R groups, X- anions, and co-crystallized solvents and help predict the spin transition temperature T-1/2.
2023
- An analytical approach based on excitation-emission fluorescence spectroscopy and chemometrics for the screening of prostate cancer through urine analysis: A proof–of–concept study
[Articolo su rivista]
Mustorgi, Eleonora; Durante, Caterina; Malegori, Cristina; Greco, Piergiorgio; Bartoletti, Riccardo; Cocchi, Marina; Casale, Monica
abstract
In the present feasibility study, excitation-emission fluorescence spectroscopy has been investigated, as a rapid
and accurate analytical method for the development of a tentative model for the early screening of prostate
cancer directly through urine analysis in order to provide reliable results while improving patient compliance.
Sixty-nine urine samples (46 samples from patients with histologically proven prostate cancer and 23 from
healthy donors) were provided, by the University of Pisa, Urology Unit. The excitation-emission fluorescence
measurements were performed on centrifugated urine samples at room temperature on a Perkin-Elmer LS55B
luminescence spectrometer and the corresponding data array was analysed with parallel factor analysis
(PARAFAC).
From a synergistic analysis of the obtained results, four main fluorophores, corresponding to four selected
PARAFAC factors, were recognizable in the urine excitation-emission matrices (EEMs) and the respective species
could be potential markers in the differentiation among healthy and cancer samples. PARAFAC results, in terms
of extracted scores, coupled with discriminant algorithms, allowed to develop a first attempt of healthy/cancer
discrimination model. The chemometrics models show promising correlation between some of the depicted
fluorophores and the disease state. However, considering the limited cohort (not only in terms of number but also
of representativeness), this study must be considered as a proof of concept; a more sound and statistically
relevant sampling must be performed in order to consider the confounding factors in the cohort treated and to
develop an analytical approach applicable in real scenarios.
2023
- Class modelling by soft independent modelling of class analogy: why, when, how? A tutorial
[Articolo su rivista]
Vitale, Raffaele; Cocchi, Marina; Biancolillo, Alessandra; Ruckebusch, Cyril; Marini, Federico
abstract
2023
- Clodronate Liposome-Mediated Phagocytic Hemocyte Depletion Affects the Regeneration of the Cephalic Tentacle of the Invasive Snail, Pomacea canaliculata
[Articolo su rivista]
Bergamini, Giulia; Sacchi, Sandro; Ferri, Anita; Franchi, Nicola; Montanari, Monica; Ahmad, Mohamad; Losi, Chiara; Nasi, Milena; Cocchi, Marina; Malagoli, Davide
abstract
After amputation, granular hemocytes infiltrate the blastema of regenerating cephalic
tentacles of the freshwater snail Pomacea canaliculata. Here, the circulating phagocytic hemocytes were chemically depleted by injecting the snails with clodronate liposomes, and the effects on the cephalic tentacle regeneration onset and on Pc-Hemocyanin, Pc-transglutaminase (Pc-TG) and Pc-Allograft Inflammatory Factor-1 (Pc-AIF-1) gene expressions were investigated. Flow cytometry analysis demonstrated that clodronate liposomes targeted large circulating hemocytes, resulting in a transient decrease in their number. Corresponding with the phagocyte depletion, tentacle regeneration onset
was halted, and it resumed at the expected pace when clodronate liposome effects were no longer visible. In addition to the regeneration progress, the expressions of Pc-Hemocyanin, Pc-TG, and Pc-AIF-1, which are markers of hemocyte-mediated functions like oxygen transport and immunity, clotting, and inflammation, were modified. After the injection of clodronate liposomes, a specific computer-assisted image analysis protocol still evidenced the presence of granular hemocytes in the tentacle blastema. This is consistent with reports indicating the large and agranular hemocyte population as the most represented among the professional phagocytes of P. canaliculata and with the hypothesis that different hemocyte morphologies could exert diverse biological functions, as it has been observed in other invertebrates.
2023
- Erratum for a new self‐consistent empirical potential model for multicomponent borate and borosilicate glasses (Journal of the American Ceramic Society, (2022), 105, 12, (7254-7271), 10.1111/jace.18681)
[Articolo su rivista]
Bertani, M.; Pallini, A.; Lodesani, F.; Cocchi, M.; Menziani, M. C.; Pedone, A.
abstract
The manuscript contains a mistake in Equation (6) and an erroneous value of the B-ij term of B-O interaction in Table 2. An additional sentence is needed in paragraph 2.2. These errata acknowledge and correct the mistakes and add the needed information. The corrections do not lead to any changes in the results, discussion, and conclusion.
2023
- Exploring the Effect of Different Storage Conditions on the Aroma Profile of Bread by Using Arrow-SPME GC-MS and Chemometrics
[Articolo su rivista]
Pellacani, Samuele; Cocchi, Marina; Durante, Caterina; Strani, Lorenzo
abstract
: In the present feasibility study, SPME Arrow-GC-MS method coupled with chemometric techniques, was used for investigating the impact of two different storage conditions, namely freezing and refrigeration, on volatile organic compounds (VOCs) of different commercial breads. The SPME Arrow technology was used as it is a novel extraction technique, able to address issues arising with traditional SPME fibers. Furthermore, the raw chromatographic signals were analysed by means of a PARAFAC2-based deconvolution and identification system (PARADISe approach). The use of PARADISe approach allowed for an efficient and rapid putative identification of 38 volatile organic compounds, including alcohols, esters, carboxylic acids, ketones, and aldehydes. Additionally, Principal Component Analysis, applied on the areas of the resolved compounds, was used to investigate the effects of storage conditions on the aroma profile of bread. The results revealed that the VOC profile of fresh bread is more similar to the one of bread stored in the fridge. Furthermore, there was a clear loss of aroma intensity in frozen samples, which could be explained by phenomena related to different starch retrogradation that occurs during freezing and refrigeration. However, considering the limited number of investigated samples, this study must be considered as a proof of concept; a more statistically representative sampling and further examinations of other properties, such as bread texture, need to be performed to better understand whether samples destined for eventual analysis should be frozen or refrigerated.
2023
- Near Infrared and UV-Visible Spectroscopy Coupled with Chemometrics for the Characterization of Flours from Different Starch Origins
[Articolo su rivista]
Pellacani, Samuele; Borsari, Marco; Cocchi, Marina; D'Alessandro, Alessandro; Durante, Caterina; Farioli, Giulia; Strani, Lorenzo
abstract
2023
- Optimization of an analytical method based on SPME-Arrow and chemometrics for the characterization of the aroma profile of commercial bread
[Articolo su rivista]
Pellacani, Samuele; Durante, Caterina; Celli, Silvia; Mariani, Manuel; Marchetti, Andrea; Cocchi, Marina; Strani, Lorenzo
abstract
A SPME-Arrow GC-MS approach, coupled with chemometrics, was used to thoroughly investigate the impact of different types of yeast (sourdough, bear's yeast and a mixture of both) and their respective leaving time (one, three and five hours) on VOCs of commercial bread samples. This aspect is of paramount importance for the baking industry to adjust recipe modifications and production parameters, as well as to meet consumer needs in formulating new products.
A deep learning approach, PARADISe (PARAFAC2-based deconvolution and identification system), was used to analyse the obtained chromatograms in an untargeted manner. In particular, PARADISe, was able to perform a fast deconvolution of the chromatographic peaks directly from raw chromatographic data to allow a putatively identification of 66 volatile organic compounds, including alcohols, esters, carboxylic acids, ketones, aldehydes. Finally, Principal Component Analysis, applied on the areas of the resolved compounds, showed that bread samples differentiate according to their recipe and highlighted the most relevant volatile compounds responsible for the observed differences.
2023
- Real Time Quality Assessment of General Purpose Polystyrene (GPPS) by means of Multiblock-PLS Applied on On-line Sensors Data
[Articolo su rivista]
Strani, Lorenzo; Bonacini, Francesco; Ferrando, Angelo; Perolo, Andrea; Tanzilli, Daniele; Vitale, Raffaele; Cocchi, Marina
abstract
In the petrochemical industry, in order to control the final product quality over time and to detect potential plant
failures, the amount of lab (off-line) analysis performed every day is very demanding in terms of resources and
time. Hence, at/in-line monitoring can be an efficient solution to decrease chemical wastes and operators’ efforts
and to perform a fast detection of deviations from normal operative conditions. Moving toward this
implementation requires both installation of analytical sensors and the development of models capable to predict
in real time the quality parameters of the polymers based on both process and analytical sensors. The primary
aim of the current work has been the development of real time monitoring models by advanced chemometric
tools for the prediction of a General Purpose PolyStyrene (GPPS) quality property, fusing Near Infrared (NIR)
and process sensors data. In the plant considered, in addition to standard process sensors, along the GPPS
production line, operating in continuous, two NIR probes are installed in-line. After the arrangement of the
available data in different blocks, aiming at studying the specific contribution of the two types of sensors and of
the main phases of the process, Multiblock-PLS (MB-PLS) method was employed to fuse the different blocks
and to assess which were the most relevant sensors and plant phases for the prediction of the two quality
parameters. Good prediction performances were achieved, allowing identifying the most significant data blocks
for the GPPS quality prediction. Moreover, prediction errors obtained by models computed without considering
blocks of data belonging to the final stages of the process were similar to those involving all the available data
blocks. Therefore, a good real time assessment of the GPPS quality can be obtained even before the production
is completed, which is very promising in view of minimizing the number of off-line laboratory analyses
2023
- Toward the Non-Targeted Detection of Adulterated Virgin Olive Oil with Edible Oils via FTIR Spectroscopy & Chemometrics: Research Methodology Trends, Gaps and Future Perspectives
[Articolo su rivista]
Ordoudi, S. A.; Strani, L.; Cocchi, M.
abstract
Fourier-Transform mid-infrared (FTIR) spectroscopy offers a strong candidate screening tool for rapid, non-destructive and early detection of unauthorized virgin olive oil blends with other edible oils. Potential applications to the official anti-fraud control are supported by dozens of research articles with a “proof-of-concept” study approach through different chemometric workflows for comprehensive spectral analysis. It may also assist non-targeted authenticity testing, an emerging goal for modern food fraud inspection systems. Hence, FTIR-based methods need to be standardized and validated to be accepted by the olive industry and official regulators. Thus far, several literature reviews evaluated the competence of FTIR standalone or compared with other vibrational techniques only in view of the chemometric methodology, regardless of the inherent characteristics of the product spectra or the application scope. Regarding authenticity testing, every step of the methodology workflow, and not only the post-acquisition steps, need thorough validation. In this context, the present review investigates the progress in the research methodology on FTIR-based detection of virgin olive oil adulteration over a period of more than 25 years with the aim to capture the trends, identify gaps or misuses in the existing literature and highlight intriguing topics for future studies. An extensive search in Scopus, Web of Science and Google Scholar, combined with bibliometric analysis, helped to extract qualitative and quantitative information from publication sources. Our findings verified that intercomparison of literature results is often impossible; sampling design, FTIR spectral acquisition and performance evaluation are critical methodological issues that need more specific guidance and criteria for application to product authenticity testing.
2023
- Tracing the identity of Parmigiano Reggiano “Prodotto di Montagna - Progetto Territorio” cheese using NMR spectroscopy and multivariate data analysis
[Articolo su rivista]
Cavallini, N.; Strani, L.; Becchi, P. P.; Pizzamiglio, V.; Michelini, S.; Savorani, F.; Cocchi, M.; Durante, C.
abstract
Background
Nuclear magnetic resonance (NMR) spectroscopy is one of the well-established tools for food metabolomic analysis, as it proved to be very effective in authenticity and quality control of dairy products, as well as to follow product evolution during processing and storage. The analytical assessment of the EU mountain denomination label, specifically for Parmigiano Reggiano "Prodotto di Montagna - Progetto Territorio" (Mountain-CQ) cheese, has received limited attention. Although it was established in 2012 the EU mountain denomination label has not been much studied from an analytical point of view. Nonetheless, tracing a specific profile for the mountain products is essential to support the value chain of this specialty.
Results
The aim of the study was to produce an identity profile for Parmigiano Reggiano “Prodotto di Montagna - Progetto Territorio” (Mountain-CQ) cheese, and to differentiate it from Parmigiano Reggiano PDO samples (conventional-PDO) using 1H NMR spectroscopy coupled with multivariate data analysis. Three different approaches were applied and compared. First, the spectra-as-such were analysed after proper preprocessing. For the other two approaches, Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) was used for signals resolution and features extraction, either individually on manually-defined spectral intervals or by reapplying MCR-ALS on the whole spectra with selectivity constraints using the reconstructed “pure profiles” as initial estimates and targets. All approaches provided comparable information regarding the samples’ distribution, as in all three cases the separation between the two product categories conventional-PDO and Mountain-CQ could be highlighted. Moreover, a novel MATLAB toolbox for features extraction via MCR-ALS was developed and used in synergy with the Chenomx library, allowing for a putative identification of the selected features.
Significance
A first identity profile for Parmigiano Reggiano “Prodotto di Montagna - Progetto Territorio” obtained by interpreting the metabolites signals in NMR spectroscopy was obtained. Our workflow and toolbox for generating the features dataset allows a more straightforward interpretation of the results, to overcome the limitations due to dimensionality and to peaks overlapping, but also to include the signals assignment and matching since the early stages of the data processing and analysis.
2023
- Weighted multivariate curve resolution – alternating least squares based on sample relevance
[Articolo su rivista]
Ahmad, M.; Vitale, R.; Cocchi, M.; Ruckebusch, C.
abstract
Alternating least squares, within the multivariate curve resolution framework has seen a lot of practical applications and shows its distinction with its relatively simple and flexible implementation. However, the limitations of least squares should be considered carefully when deviating from the standard assumed data structure. Within this work we highlight the effects of noise in the presence of minor components, and we propose a novel weighting scheme within the weighted multivariate curve-resolution-alternating least squares framework, to resolve it. Two simulated and one Raman imaging case is investigated, by comparing the novel methodology against standard multivariate curve resolution-alternating least squares and essential spectral pixel selection. A trade-off is observed between current methods, while the novel weighting scheme demonstrates a balance, where the benefits of the previous two methods are retained.
2022
- A Multiblock Approach to Fuse Process and Near-Infrared Sensors for On-Line Prediction of Polymer Properties
[Articolo su rivista]
Strani, Lorenzo; Vitale, Raffaele; Tanzilli, Daniele; Bonacini, Francesco; Perolo, Andrea; Mantovani, Erik; Ferrando, Angelo; Cocchi, Marina
abstract
Petrochemical companies aim at assessing final product quality in real time, in order to rapidly deal with possible plant faults and to reduce chemical wastes and staff effort resulting from the many laboratory analyses performed every day. In order to answer these needs, the main purpose of the current work is to explore the feasibility of multiblock regression methods to build real-time monitoring models for the prediction of two quality properties of Acrylonitrile-Butadiene-Styrene (ABS) by fusing near-infrared (NIR) and process sensors data. Data come from a production plant, which operates continuously, and where four NIR probes are installed on-line, in addition to standard process sensors. Multiblock-PLS (MB-PLS) and Response-Oriented Sequential Alternation (ROSA) methods were here utilized to assess which of such sensors and plant areas were the most relevant for the quality parameters prediction. Several prediction models were constructed exploiting measurements provided by sensors active at different ABS production process stages. Both methods provided good prediction performances and permitted identification of the most relevant data blocks for the quality parameters’ prediction. Moreover, models built without considering recordings from the final stage of the process yielded prediction errors comparable to those involving all available data blocks. Thus, in principle, allowing final ABS quality to be estimated in real-time before the end of the process itself.
2022
- A new self-consistent empirical potential model for multicomponent borate and borosilicate glasses
[Articolo su rivista]
Bertani, M.; Pallini, A.; Cocchi, M.; Menziani, M. C.; Pedone, A.
abstract
A new self-consistent empirical potential model based on the BMP potential [Bertani et al., Phys. Rev. Mat. 5 (2021) 045602] has been developed for the simulation of multicomponent borate and borosilicate glasses. We exploited the Bayesian optimization approach to create a set of parameters for the B–O interaction, which depends on the glass composition, and in particular on the R = ([A2O]+[AEO])/[B2O3] (A = alkaline and AE alkaline-earth ions) and K = [SiO2]/[B2O3] ratios. The obtained force field (FF) has been applied to several borate and borosilicate glass series containing, as modifier oxide, Na2O, Li2O, CaO, and MgO and tested on experimental data, such as the fraction of BO4 (N4), density, non-bridging oxygen speciation, neutron diffraction spectra, 11B, 29Si, and 17O magic angle spinning nuclear magnetic resonance. A comparison with other interatomic potentials available in literature has also been performed. The results show that the FF reproduces well almost all the abovementioned properties, showing excellent agreement with experimental data in a wide range of compositions.
2022
- A novel proposal to investigate the interplay between the spatial and spectral domains in near-infrared spectral imaging data by means of Image Decomposition, Encoding and Localization (IDEL)
[Articolo su rivista]
Ahmad, Mohamad; Vitale, Raffaele; Silva, Carolina S.; Ruckebusch, Cyril; Cocchi, Marina
abstract
The emergence of new spectral imaging applications in many science fields and in industry has not come to be a surprise, considering the immense potential this technique has to map spectral information. In the case of near-infrared spectral imaging, a rapid evolution of the technology has made it more and more appealing in non-destructive analysis of food and materials as well as in process monitoring applications. However, despite its great diffusion, some challenges remain open from the data analysis point of view, with the aim to fully uncover patterns and unveil the interplay between both the spatial and spectral domains. Here we propose a new approach, called Image Decomposition, Encoding and Localization (IDEL), where a spatial perspective is taken for the analysis of spectral images, while maintaining the significant information within the spectral domain. The methodology benefits from wavelet transform to exploit spatial features, encoding the outcoming images into a set of descriptors and utilizing multivariate analysis to isolate and extract the significant spatial-spectral information. A forensic case study of near-infrared images of biological stains on cotton fabrics is used as a benchmark. The stain and fabric have hardly distinguishable spectral signatures due to strong scattering effects that originate from the rough surface of the fabric and the high spectral absorbance of cotton in the near-infrared range. There is no selective information that can isolate signals related to these two components in the spectral images under study, and the complex spatial structure is highly interconnected to the spectral signatures. IDEL was capable of isolating the stains, (spatial) scattering effects, and a possible drying effect from the stains. It was possible to recover, at the same time, specific spectral regions that mostly highlight these isolated spatial structures, which was previously unobtainable.
2022
- Application of experimental design in HPLC method optimisation for the simultaneous determination of multiple bioactive cannabinoids
[Articolo su rivista]
Durante, C.; Anceschi, L.; Brighenti, V.; Caroli, C.; Afezolli, C.; Marchetti, A.; Cocchi, M.; Salamone, S.; Pollastro, F.; Pellati, F.
abstract
The scientific interest in Cannabis sativa L. analysis has been rapidly increasing in recent years, especially for what concerns cannabinoids, plant secondary metabolites which are well known for having many biological properties. High-performance liquid chromatography (HPLC) is frequently used for both the qualitative and quantitative analysis of cannabinoids in plant extracts from C. sativa and its derived products. Many studies have been focused on the main cannabinoids, such as Delta(9)-tetrahydrocannabinolic acid (Delta(9)-THCA), cannabidiolic acid (CBDA), cannabigerolic acid (CBGA) and their decarboxylated derivatives, such as Delta(9)-tetrahydrocannabinol (Delta(THC)-T-9), cannabidiol (CBD) and cannabigerol (CBG). In addition to the abovementioned compounds, the plant produces other metabolites of the same chemical class, and some of them have shown interesting biological activities.In the light of this, it is important to have efficient analytical methods for the simultaneous separation of cannabinoids, which is quite complex since they present similar chemical-physical characteristics. The present work is focused on the use of the Design of Experiments technique (DoE) to develop and optimise an HPLC method for the simultaneous separation of 14 cannabinoids. Experimental design optimisation was applied by using a Central Composite Face-Centered design to achieve the best resolution with minimum experimental trials. Five significant variables affecting the chromatographic separation, including ammonium formate concentration, gradient elution, run time and flow rate, were studied. A multivariate strategy, based on Principal Component Analysis (PCA) and Partial Least Squared (PLS) regression, was used to define the best operative conditions. The developed method allowed for the separation of 12 out of 14 cannabinoids. Due to co-elution phenomena, HPLC coupled with a triple quadrupole mass analyser (HPLC-ESI-MS/MS) was applied, monitoring the specific transitions of each compound in the multiple reaction monitoring (MRM) mode. Finally, the optimised method was applied to C. sativa extracts having a different cannabinoid profile to demonstrate its efficiency to real samples.The methodology applied in this study can be useful for the separation of other cannabinoid mixtures, by means of appropriate optimisation of the experimental conditions.
2022
- Ceramic polyaniline-carbon composite obtained by ultrasound-assisted sol-gel route: electrochemical performance towards environmental pollutants
[Articolo su rivista]
López-Iglesias, David; Fanelli, Francesca; Marchi, Lorenzo; Alcántara, Rodrigo; Cocchi, Marina; Cubillana-Aguilera, Laura; María Palacios Santander, José; José García-Guzmán, Juan
abstract
A new ceramic carbon polyaniline electrode material, namely Sonogel-Carbonpolyaniline (SNG-C-PANI), was synthesized using high-power ultrasound. The synthesis conditions were optimized by means of a full factorial design. The electroactivity of polyaniline, previously characterized by means of Raman spectroscopy, is retained into
the sonogel matrix. After the synthesis and the subsequent characterization, the electrode material was applied in the electrochemical determination of a benchmark analyte, 4-chloro-3-methylphenol (PCMC), providing excellent figures of merit, e.g high sensitivity (5.19×103±110 μA/mM·cm2) and low limit of detection (0.36 μM), as well as suitable
selectivity and reproducibility (%RSD < 4%). Besides the electroactive surface can be restored by performing a cyclic electrochemical treatment or simple mechanical polishing, minimizing fouling phenomena commonly found in conducting polymer layerbased sensors. The electrochemical detection of other chlorophenols of interest was also
performed, obtaining remarkable analytical results. Finally, the electrochemical sensor was successfully applied in spiked tap water analyses.
2022
- Chemometric-assisted cocrystallization: Supervised pattern recognition for predicting the formation of new functional cocrystals
[Articolo su rivista]
Fornari, Fabio; Montisci, Fabio; Bianchi, Federica; Cocchi, Marina; Carraro, Claudia; Cavaliere, Francesca; Cozzini, Pietro; Peccati, Francesca; Mazzeo, Paolo P.; Riboni, Nicolò; Careri, Maria; Bacchi, Alessia
abstract
Owing to the antimicrobial and insecticide properties, the use of natural compounds like essential oils and their active components has proven to be an effective alternative to synthetic chemicals in different fields ranging from drug delivery to agriculture and from nutrition to food preservation. Their limited application due to the high volatility and scarce water solubility can be expanded by using crystal engineering approaches to tune some properties of the active molecule by combining it with a suitable partner molecule (coformer). However, the selection of coformers and the experimental effort required for discovering cocrystals are the bottleneck of cocrystal engineering. This study explores the use of chemometrics to aid the discovery of cocrystals of active ingredients suitable for various applications. Partial Least Squares–Discriminant Analysis is used to discern cocrystals from binary mixtures based on the molecular features of the coformers. For the first time, by including failed cocrystallization data and considering a variety of chemically diverse compounds, the proposed method resulted in a successful prediction rate of 85% for the test set in the model validation phase and of 74% for the external test set.
2022
- Fast GC E-Nose and Chemometrics for the Rapid Assessment of Basil Aroma
[Articolo su rivista]
Strani, Lorenzo; D'Alessandro, Alessandro; Ballestrieri, Daniele; Durante, Caterina; Cocchi, Marina
abstract
The aim of this work is to assess the potentialities of the synergistic combination of an ultra-fast chromatography-based electronic nose as a fingerprinting technique and multivariate data analysis in the context of food quality control and to investigate the influence of some factors, i.e., basil variety, cut, and year of crop, in the final aroma of the samples. A low = level data fusion approach coupled with Principal Component Analysis (PCA) and ANOVA—Simultaneous Component Analysis (ASCA) was used in order to analyze the chromatographic signals acquired with two different columns (MXT-5 and MXT-1701). While the PCA analysis results highlighted the peculiarity of some basil varieties, differing either by a higher concentration of some of the detected chemical compounds or by the presence of different compounds, the ASCA analysis pointed out that variety and year are the most relevant effects, and also confirmed the results of previous investigations.
2022
- Immune contribution to tentacle regeneration in adult mollusc and cnidarian models
[Abstract in Rivista]
Bergamini, G; Sacchi, S; Ahmad, M; Cocchi, M; Basu, S; Ikmi, A; Malagoli, D
abstract
Histological studies focusing on the early
cephalic tentacle regeneration in P. canaliculata,
have demonstrated that wound closure and
blastema formation took place within 24 h post
amputation (hpa). A Matlab® plugin allowed the
semi-automated identification and quantification of a
phagocytic hemocyte sub-population in the
blastema. Flow cytometry analysis showed that the
injection of the phagocyte-specific drug
Clophosome® (45 µg/g snail) could transiently
remove circulating hemocytes, that recovered the
pre-treatment level within 24 h. Consistently,
histological experiment demonstrated that rare
hemocytes were present in the early regenerating
tentacles of Clophosome®-injected snails
2021
- A Metabolomic Approach to Beer Characterization
[Articolo su rivista]
Cavallini, Nicola; Savorani, Francesco; Bro, Rasmus; Cocchi, Marina
abstract
The consumers’ interest towards beer consumption has been on the rise during the past
decade: new approaches and ingredients get tested, expanding the traditional recipe for brewing
beer. As a consequence, the field of “beeromics” has also been constantly growing, as well as the
demand for quick and exhaustive analytical methods. In this study, we propose a combination of
nuclear magnetic resonance (NMR) spectroscopy and chemometrics to characterize beer. 1H‐NMR
spectra were collected and then analyzed using chemometric tools. An interval‐based approach was
applied to extract chemical features from the spectra to build a dataset of resolved relative
concentrations. One aim of this work was to compare the results obtained using the full spectrum
and the resolved approach: with a reasonable amount of time needed to obtain the resolved dataset,
we show that the resolved information is comparable with the full spectrum information, but
interpretability is greatly improved.
2021
- A New Protocol of Computer-Assisted Image Analysis Highlights the Presence of Hemocytes in the Regenerating Cephalic Tentacles of Adult Pomacea canaliculata
[Articolo su rivista]
Bergamini, Giulia; Ahmad, Mohamad; Cocchi, Marina; Malagoli, Davide
abstract
In humans, injuries and diseases can result in irreversible tissue or organ loss. This wellknown
fact has prompted several basic studies on organisms capable of adult regeneration, such
as amphibians, bony fish, and invertebrates. These studies have provided important biological
information and helped to develop regenerative medicine therapies, but important gaps concerning
the regulation of tissue and organ regeneration remain to be elucidated. To this aim, new models
for studying regenerative biology could prove helpful. Here, the description of the cephalic tentacle
regeneration in the adult of the freshwater snail Pomacea canaliculata is presented. In this invasive
mollusk, the whole tentacle is reconstructed within 3 months. Regenerating epithelial, connective,
muscular and neural components are already recognizable 72 h post-amputation (hpa). Only in
the early phases of regeneration, several hemocytes are retrieved in the forming blastema. In
view of quantifying the hemocytes retrieved in regenerating organs, granular hemocytes present
in the tentacle blastema at 12 hpa were counted, with a new and specific computer-assisted image
analysis protocol. Since it can be applied in absence of specific cell markers and after a common
hematoxylin-eosin staining, this protocol could prove helpful to evidence and count the hemocytes
interspersed among regenerating tissues, helping to unveil the role of immune-related cells in sensory
organ regeneration.
2021
- Analytical Concentrations of Some Elements in Seeds and Crude Extracts from Aesculus hippocastanum, by ICP-OES Technique
[Articolo su rivista]
Durante, C.; Cocchi, M.; Lancellotti, L.; Maletti, L.; Marchetti, A.; Sighinolfi, S.; Tassi, L.; Roncaglia, F.
abstract
The metal content in some samples of horse chestnut seeds (Aesculus hippocastanum) was monitored over time (years 2016, 2017, 2018, 2019) considering the two most common and representative Mediterranean varieties: the pure species (AHP, which gives white flowers) and a hybrid one (AHH, which gives pink flowers). The selected elemental composition of the samples was determined by applying the ICP-OES technique.
Several samples obtained from different preliminary treatments of the peeled seeds were examined, such as: i) floury samples (wild type) mineralized with the wet method; ii) the ashes of both AHP and AHH varieties; iii) the fraction of total inorganic soluble salts (TISS).
Furthermore, the hydroalcoholic crude extracts (as a tincture) were obtained according to the official Pharmacopoeia methods, and the relevant results were compared with those of a commercial sample, an herbal product - food supplement of similar characteristics. The main characteristics of this research work underline that the two botanical varieties give different distinctive characters, due to the Fe content (80.05 vs 1.42 mg / 100 g d.s., for AHP and AHH - wild type flour samples, respectively), along with K, Ca, Mn, Ni and Cu, which are more abundant in the AHP samples. Furthermore, the PCA analysis was applied to the experimental dataset in order to classify and discriminate the samples, in relation to their similar botanical origin, but different for the color of the bloom. These results can be useful for the traceability of raw materials potentially intended for the production of auxiliary systems of pharmacological interest.
2021
- Characterization of Basil Volatile Fraction and Study of its Agronomic Variation by ASCA
[Articolo su rivista]
D'Alessandro, Alessandro; Ballestrieri, Daniele; Strani, Lorenzo; Cocchi, Marina; Durante, Caterina
abstract
Basil is a plant known worldwide for its culinary and health attributes. It counts more
than a hundred and fifty species and many more chemo-types due to its easy cross-breeds. Each species and each chemo-type have a typical aroma pattern and selecting the proper one is crucial for the food industry. Twelve basil varieties have been studied over three years (2018–2020), as have four different cuts. To characterize the aroma profile, nine typical basil flavour molecules have been selected using a gas chromatography–mass spectrometry coupled with an olfactometer (GC–MS/O). The concentrations of the nine selected molecules were measured by an ultra-fast CG e-nose and Principal Component Analysis (PCA) was applied to detect possible differences among the samples.
The PCA results highlighted differences between harvesting years, mainly for 2018, whereas no observable clusters were found concerning varieties and cuts, probably due to the combined effects of the investigated factors. For this reason, the ANOVA Simultaneous Component Analysis (ASCA) methodology was applied on a balanced a posteriori designed dataset. All the considered factors and interactions were statistically significant (p < 0.05) in explaining differences between the basil aroma profiles, with more relevant effects of variety and year.
2021
- Fusing NIR and Process Sensors Data for Polymer Production Monitoring
[Articolo su rivista]
Strani, Lorenzo; Mantovani, Erik; Bonacini, Francesco; Marini, Federico; Cocchi, Marina
abstract
Process analytical technology and multivariate process monitoring are nowadays the most effective approaches to achieve real-time quality monitoring/control in production. However, their use is not yet a common practice, and industries benefit much less than they could from the outcome of the hundreds of sensors that constantly monitor production in industrial plants. The huge amount of sensor data collected are still mostly used to produce univariate control charts, monitoring one compartment at a time, and the product quality variables are generally used to monitor production, despite their low frequency (offline measurements at analytical laboratory), which is not suitable for real-time monitoring. On the contrary, it would be extremely advantageous to benefit from predictive models that, based on online sensors, will be able to return quality parameters in real time. As a matter of fact, the plant setup influences the product quality, and process sensors (flow meters, thermocouples, etc.) implicitly register process variability, correlation trends, drift, etc. When the available spectroscopic sensors, reflecting chemical composition and structure, consent to monitor the intermediate products, coupling process, and spectroscopic sensor and extracting/fusing information by multivariate analysis from this data would enhance the evaluation of the produced material features allowing production quality to be estimated at a very early stage. The present work, at a pilot plant scale, applied multivariate statistical process control (MSPC) charts, obtained by data fusion of process sensor data and near-infrared (NIR) probes, on a continuous styrene-acrylonitrile (SAN) production process. Furthermore, PLS regression was used for real-time prediction of the Melt Flow Index and percentage of bounded acrylonitrile (%AN). The results show that the MSPC model was able to detect deviations from normal operative conditions, indicating the variables responsible for the deviation, be they spectral or process. Moreover, predictive regression models obtained using the fused data showed better results than models computed using single datasets in terms of both errors of prediction and R2. Thus, the fusion of spectra and process data improved the real-time monitoring, allowing an easier visualization of the process ongoing, a faster understanding of possible faults, and real-time assessment of the final product quality.
2021
- Multi-sensor data fusion and parallel factor analysis reveals kinetics of wood weathering
[Articolo su rivista]
Sandak, Jakub; Sandak, Anna; Cocchi, Marina
abstract
Understanding mechanisms of materials deterioration during service life is fundamental for their confident use in the building sector. This work presents analysis of time series of data related to wood weathering acquired at three scales (molecular, microscopic, macroscopic) with different sensors. By using several complementary techniques, the material description is precise and complete; however, the data provided by multiple equipment are often not directly comparable due to different resolution, sensitivity and/or data format. This paper presents an alternative approach for multi-sensor data fusion and modelling of the deterioration processes by means of PARAFAC model. Time series data generated within this research were arranged in a data cube of dimensions samples × sensors × measuring time. The original protocol for data fusion as well as novel meta parameters, such as cumulative nested biplot, was proposed and tested. It was possible to successfully differentiate weathering trends of diverse materials on the basis of the NIR spectra and selected surface appearance indicators. A unique advantage for such visualization of the PARAFAC model output is the possibility of straightforward comparison of the degradation kinetics and deterioration trends simultaneously for all tested materials.
2020
- A metabolomic data fusion approach to support gliomas grading
[Articolo su rivista]
Righi, V.; Cavallini, N.; Valentini, A.; Pinna, G.; Pavesi, G.; Rossi, M. C.; Puzzolante, A.; Mucci, A.; Cocchi, M.
abstract
Magnetic resonance imaging (MRI) is the current gold standard for the diagnosis of brain tumors. However, despite the development of MRI techniques, the differential diagnosis of central nervous system (CNS) primary pathologies, such as lymphoma and glioblastoma or tumor-like brain lesions and glioma, is often challenging. MRI can be supported by in vivo magnetic resonance spectroscopy (MRS) to enhance its diagnostic power and multiproject-multicenter evaluations of classification of brain tumors have shown that an accuracy around 90% can be achieved for most of the pairwise discrimination problems. However, the survival rate for patients affected by gliomas is still low. The High-Resolution Magic-Angle-Spinning Nuclear Magnetic Resonance (HR-MAS NMR) metabolomics studies may be helpful for the discrimination of gliomas grades and the development of new strategies for clinical intervention. Here, we propose to use T2-filtered, diffusion-filtered and conventional water-presaturated spectra to try to extract as much information as possible, fusing the data gathered by these different NMR experiments and applying a chemometric approach based on Multivariate Curve Resolution (MCR). Biomarkers important for glioma's discrimination were found. In particular, we focused our attention on cystathionine (Cyst) that shows promise as a biomarker for the better prognosis of glioma tumors.
2020
- Exploring local spatial features in hyperspectral image
[Articolo su rivista]
Ahmad, Mohamad; Vitale, Raffaele; Silva, Carolina S.; Ruckebusch, Cyril; Cocchi, Marina
abstract
We propose a methodological framework to extract spatial features in hyperspectral imaging
data and establish a link between these features and the spectral regions, capturing the observed structural patterns. The proposed approach consists of five main steps: i) two dimensional Stationary Wavelet Transform (2D-SWT) is applied to a hyperspectral data cube, decomposing each single-channel image with a selected wavelet filter up to the maximum decomposition level; ii) a grey-level co-occurrence matrix is calculated for every 2D-SWT image resulting from stage i); iii) distinctive spatial features are determined by computing morphological descriptors from each grey-level co-occurrence matrix; iv) the morphological descriptors are rearranged in a two dimensional data array; v) this data matrix is subjected to Principal Component Analysis (PCA) for exploring the variability of the aforementioned descriptors across spectral channels. As a result, groups of spectral wavelengths associated to specific spatial features can be pointed out yielding a better understanding and interpretation of the data.
In principle, this information can also be further exploited, e.g. to improve the separation of
pure spectral profiles in a multivariate curve resolution context.
2020
- Multi Way Classification
[Capitolo/Saggio]
Cocchi, Marina; Li Vigni, Mario; Durante, Caterina
abstract
In this Chapter, the state-of-the-art approaches for the classification of multi-way data is presented and discussed. The theoretical basis and applicative guidelines for multilinear (or multi-way) Partial Least Squares Discriminant Analysis (NPLS-DA) and Multi-way Soft Independent Modelling of Class Analogy (NSIMCA) are detailed. Furthermore, two-dimensional linear discriminant analysis (2DLDA) and a proposal for truly multilinear discriminant analysis are illustrated. The truly multi-way methods are compared to unfolding and feature extraction followed by bilinear classification. Practical hints are depicted through discussion of a case of study.
2020
- Organ-specific accumulation of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) in the apple snail Pomacea canaliculata
[Poster]
Fiorino, Roberta; Bergamini, Giulia; Ahmad, Mohamad; Cocchi, Marina; Prina-Mello, Adriele; Malagoli, Davide
abstract
2020
- Preliminary Assessment of Parmigiano Reggiano Authenticity by Handheld Raman Spectroscopy
[Articolo su rivista]
Li Vigni, M.; Durante, C.; Michelini, S.; Nocetti, M.; Cocchi, M.
abstract
Raman spectroscopy, and handheld spectrometers in particular, are gaining increasing attention in food quality control as a fast, portable, non-destructive technique. Furthermore, this technology also allows for measuring the intact sample through the packaging and, with respect to near infrared spectroscopy, it is not affected by the water content of the samples. In this work, we evaluate the potential of the methodology to model, by multivariate data analysis, the authenticity of Parmigiano Reggiano cheese, which is one of the most well-known and appreciated hard cheeses worldwide, with protected denomination of origin (PDO). On the other hand, it is also highly subject to counterfeiting. In particular, it is critical to assess the authenticity of grated cheese, to which, under strictly specified conditions, the PDO is extended. To this aim, it would be highly valuable to develop an authenticity model based on a fast, non-destructive technique. In this work, we present preliminary results obtained by a handheld Raman spectrometer and class-modeling (Soft Independent Modeling of Class Analogy, SIMCA), which are extremely promising, showing sensitivity and specificity of 100% for the test set. Moreover, another salient issue, namely the percentage of rind in grated cheese, was addressed by developing a multivariate calibration model based on Raman spectra. It was possible to obtain a prediction error around 5%, with 18% being the maximum content allowed by the production protocol.
2019
- DATA FUSION APPROACHES IN SPECTROSCOPIC CHARACTERIZATION AND CLASSIFICATION OF PDO WINE VINEGARS
[Articolo su rivista]
Rios-Reina, R.; Callejón, R. M.; Savorani, F.; Amigo, J. M.; Cocchi, M.
abstract
Spain is one of the major producers of high-quality wine vinegars having three protected designations of origin (a.k.a. PDOs): "Vinagre de Jerez", "Vinagre de Condado de Huelva" and "Vinagre de Montilla-Moriles". Their high prices due to their high quality and their high production costs explain the need for developing an adequate quality control technique and the interest in extensive characterization in order to capture the identity of each denomination. In this framework, methodologies based on non-targeted techniques, such as spectroscopies, are becoming popular in food authentication. Thus, for improving vinegar quality assessment, fusion of data blocks obtained from the same samples but different analytical techniques could be a good strategy, since the
quantity and quality of sample knowledge could be enhanced providing new insights into the differentiation of vinegars. Therefore, the aim of this manuscript is the development of a multi-platform methodology and a model able to classify the Spanish wine vinegar PDOs. Sixty-five PDO wine
vinegars were analyzed by four spectroscopic techniques: Fourier transform mid-infrared spectroscopy (MIR), near infrared spectroscopy (NIR), multidimensional fluorescence spectroscopy (EEM) and proton nuclear magnetic resonance (1H-NMR). Two different data fusion strategies
were evaluated: Mid-level data fusion with different preprocessing, and Common Component and Specific Weights analysis multiblock method. Exploratory and classification analysis on the data from individual techniques were also performed and compared with data fusion models. The data fusion models improved the classification, providing a more efficient differentiation, than the models based on single methods, and supporting the approach to combine these methods to achieve synergies for
an optimized PDO differentiation.
2019
- Data Fusion Methodology and Applications
[Curatela]
Cocchi, Marina
abstract
A comprehensive vision of methodologies and data analytics challenges, framing the nature of coupled data and how data fusion can enhance knowledge discovery.
Key Features
● Presents the first comprehensive textbook on data fusion, focusing on all aspects of data-driven discovery
● Includes comprehensible, theoretical chapters written for large and diverse audiences
● Provides a wealth of selected applications for the topics included
Data Fusion Methodology and Applications explores the data-driven discovery paradigm in science and the need to handle large amounts of diverse data. Drivers of this change include the increased availability and accessibility of hyphenated analytical platforms, imaging techniques, the explosion of omics data, and the development of information technology. As data-driven research deals with an inductive attitude that aims to extract information and build models capable of inferring the underlying phenomena from the data itself, this book explores the challenges and methodologies used to integrate data from multiple sources, analytical platforms, different modalities, and varying timescales.
The primary audience consists of graduate students and researchers in chemical, biochemical, and biomedical disciplines where multianalytical platforms are most used (hyphenated instruments, imaging spectroscopies, microarray, sensors, biosensors, etc.) and whose research areas include life science (systems biology, genomics, proteomics, metabolomics), food science (authentication, adulteration, sensory analysis, nutraceuticals), and industrial process monitoring.
2019
- Data Fusion Strategies in Food Analysis
[Capitolo/Saggio]
Biancolillo, Alessandra; Boque´, Ricard; Cocchi, Marina; Marini, Federico
abstract
With the growing availability of high throughput methodologies for food characterization and analysis, more and more data
are being collected on food products that can be used for the authentication of their quality. In this context, the availability of
different multi-block strategies, each with its own peculiarities and providing specific details on the investigated samples,
allows to integrate the information from the different sources into a richer model with great flexibility. The aim of the
present chapter is to present general perspectives on data-fusion, and to briefly discuss the potentialities of this strategy in
the food analysis context. In order to provide an overview on such a wide topic as multi-block analysis, the chapter is
conceptually divided into two parts. The first one, where the subject is approached from a theoretical standpoint (from
Section 1 to Section 3), and a more practical part, in which selected applications of multi-block methods applied to
authenticate or to check quality of foodstuff - such as, e.g., olive oil, wine, beer, vinegar, tea, and dairies - are described
(Section 4). Throughout the text, general advantages and disadvantages of data-fusion strategies are depicted with a slight
deeper attention into few specific methods
2019
- Fused Adjacency Matrices to enhance information extraction: the beer benchmark
[Articolo su rivista]
Cavallini, Nicola; Savorani, Francesco; Bro, Rasmus; Cocchi, Marina
abstract
Multivariate exploratory data analysis allows revealing patterns and extracting information from
complex multivariate data sets. However, highly complex data may not show evident groupings or
trends in the principal component space, e.g. because the variation of the variables are not grouped
but rather continuous. In these cases, classical exploratory methods may not provide satisfactory
results when the aim is to find distinct groupings in the data.
To enhance information extraction in such situations, we propose a novel approach inspired by the
concept of combining weak classifiers, but in the unsupervised context. The approach is based on
the fusion of several adjacency matrices obtained by different distance measures on data from
different analytical platforms. This paper is intended to present and discuss the potential of the
approach through a benchmark data set of beer samples. The beer data were acquired using three
spectroscopic techniques: Visible, near-Infrared and Nuclear Magnetic Resonance.
The results of fusing the three data sets via the proposed approach are compared with those from the
single data blocks (Visible, NIR and NMR) and from a standard mid-level data fusion methodology.
It is shown that, with the suggested approach, groupings related to beer style and other features are
efficiently recovered, and generally more evident.
2019
- Introduction: Ways and Means to deal with data from Multiple Sources
[Capitolo/Saggio]
Cocchi, Marina
abstract
To introduce and frame the content of the following chapters, here the main motivation for using data fusion, the different definitions and the different context of applications are illustrated. The overview follows the most diffuse taxonomy, which classifies the data fusion approaches in low, mid and high-level. At the same time the link between data fusion and multiblock/multiset methods is underlined aiming at furnishing a unified view of the field.
2019
- Performance of modified wood in service - multi-sensor data fusion and its multi-way analysis
[Relazione in Atti di Convegno]
Sandak, Anna; Sandak, Jakub; Cocchi, Marina
abstract
Recent developments in the field of electronic sensors and analytics provide new opportunity for accurate characterization of materials often based on portable and non-destructive methods. By using several complementary techniques, the material description is precise and complete. The data provided by multiple equipment, however, are often not directly comparable due to different resolution, sensitivity and/or data format. The complexity related to the data fusion step and its further interpretation often leads to not complete exploitation of the available data. This paper presents a multi-block approach used for merging experimental data collected by measurement of modified wood in service. Characterization of samples appearance (colour and gloss) is merged with spectral data that decodes information regarding chemical composition. Alternative approaches for data fusion on the low-, mid- and high-levels are introduced, discussed and confronted with the standard approach (single sensor data interpretation). Finally, the trial to analyse the data with multi-way method is presented and interpreted.
2018
- Analisi metabolomica di tessuti, cellule e biofluidi tramite risonanza magnetica nucleare
[Poster]
Mucci, Adele; Cocchi, Marina; Cavallini, Nicola; Righi, Valeria
abstract
Il poster riporta esempi di applicazione della chemiometria all'elaborazione delle informazioni sul metaboloma, ottenute tramite risonanza magnetica nucleare ad alta risoluzione sui tessuti tal quali
2018
- Chemometric methods for classification and feature selection
[Capitolo/Saggio]
Cocchi, Marina; Biancolillo, Alessandra; Marini, Federico
abstract
Classification methods, i.e., the chemometric strategies for predicting a qualitative response, find many applications in the omic sciences, where often data are collected in order to categorize individuals (e.g., according to whether they were treated or administered a placebo or, for instance, depending on if they were healthy or ill). After a brief discussion of the differences between discriminant and modeling approaches, some of the techniques most commonly used in the omic fields are illustrated in greater detail. A part of the chapter is then devoted to illustrating the strategies for identifying the most relevant features in model building through variable selection approaches, and their role in putative biomarker identification. Lastly, the importance of validation is also addressed and a brief guideline of the available strategies is presented.
2018
- Coupling 2D-wavelet decomposition and multivariate image analysis (2D WT-MIA)
[Articolo su rivista]
Li Vigni, Mario; Prats-Montalban, José Manuel; Ferrer, Alberto; Cocchi, Marina
abstract
The use of 2D discrete wavelet transform in the feature enhancement phase of multivariate image analysis is discussed and implemented in a comparative way with respect to previous publications. In the proposed approach, all the resulting subimages obtained by discrete wavelet transform decomposition are unfolded pixel-wise and midlevel data fused to a feature matrix that is used for the feature analysis phase. Congruent subimages can be obtained either by reconstruction of each decomposition block to the original pixel dimensions or by using the stationary wavelet transform decomposition scheme. The main advantage is that all possible relationships among blocks, decomposition levels, and channels are assessed in a single multivariate analysis step (feature analysis). This is particularly useful in a monitoring context where the aim is to build multivariate control charts based on images. Moreover, the approach can be versatile for contexts where several images are analyzed at a time as well as in the multispectral image analysis. Both a set of simple artificial images and a set of real images, representative of the on-line quality monitoring context, will be used to highlight the details of the methodology and show how the wavelet transform allows extracting features that are informative of how strong the texture of the image is and in which direction it varies.
2018
- Development of 87Sr/86Sr maps as targeted strategy to support wine quality
[Articolo su rivista]
Durante, Caterina; Bertacchini, Lucia; Cocchi, Marina; Manzini, Daniela; Marchetti, Andrea; Rossi, Maria Cecilia; Sighinolfi, Simona; Tassi, Lorenzo
abstract
This study summarizes the results obtained from a systematic and long-term project aimed at the development
of tools to assess the provenance of food in the oenological sector. In particular, 87Sr/86Sr isotope ratios were
measured on statistically representative set of soils, vine branches and wines sampled in the production district
of Modena, worldwide known for the Lambrusco wines production. The obtained data were used to build strontium
isotopic maps able to objectively support the Lambrusco PDO wines origin as well as other products of the
Modena district.
Finally, a strong relationship was found between the 87Sr/86Sr isotope ratios of soils and vine branches on a
large scale, highlighting and confirming once more the idea that plants can also represent an optimal sampling
device to support geographical traceability.
2017
- Chemometrics for Food Quality Control and Authentication
[Capitolo/Saggio]
Cocchi, Marina
abstract
The concern of society about food nowadays extends to the several aspects linked to food consumption encompassing nutritional value, health, safety, and quality, as well as ethics, sustainability, tradition, communication, marketing, and so on. The increased information available to the consumers, the awareness of the impact of diet on healthiness, and the issues brought by globalization of the food market on one hand and the institution of the Common Market (European Union (EU) countries) and its regulations on the other hand have progressively changed the leading paradigms in food science and the essential topics for the food industry. Undoubtedly, ‘quality’ is a primary criterion to access the market. However, quality is a multifaceted concept including both aspects, the set of identifiable features of a product and accountability, trustiness linked to it. Thus, quality is usually an integrated measure of several characteristics deliberately produced (sophistication, adulteration, counterfeit, appearance, etc.) or not (purity, contamination, degradation, etc.) and also of the subjective consumer’s perception of the worth of the product (to which issues such as terroir, authenticity, origin, and production practice contribute). In this context, quality control and authentication require a step beyond traditional chemical analysis and characterization, which focuses mainly on single classes of constituents/properties, moving to fingerprinting, fast, nondestructive techniques. In this perspective, the role of chemometrics is of paramount importance to efficiently extract the relevant information and by providing tailored tools that allow exploratory data analysis, graphical representation, and validation of the models during all steps of data processing as well as efficient storage, retrieval, and sharing of information.
2017
- Chemometrics for the Direct Analysis of Solid Samples by Spectroscopic and Chromatographic Techniques
[Capitolo/Saggio]
Dora, Melucci; Cocchi, Marina; Francesca, Corvucci; Michela, Boi; Laura, Tositti; Francesco, de Laurentiis; Alessandro, Zappi; Clinio, Locatelli; Marcello, Locatelli
abstract
The direct chemical analysis allows investigating samples without altering them, keeping the sample available for further analysis. For the qualitative investigation, analytical procedures like gas-chromatography, Raman microscopy, and Infra Red spectroscopy are available; however, the univariate approach is not exhaustive in the case of very complex matrices. The quantitative approach is still an open issue, due to the strong matrix effect hindering the creation of univariate calibration methods in interpolation mode. The multivariate analysis may be the solution.
Three-way Principal Components Analysis (PCA) allows for comprehension of variables influencing classification. The Partial Least Squares regression (PLS) combined with Discriminant Analysis (DA) allows classifying. Multivariate standard addition calibration based on PLS coupled with Net Analyte Signal (NAS) calculation allows bypassing the matrix effect in quantitative analysis.
This Chapter is focused on the issues mentioned above. Three sections will be presented:
SECTION 1: three-way PCA is applied to the discrimination among bacterial species in samples analyzed as such by pyrolysis gas chromatography-mass spectrometry. Applications to timely analysis of pathogenic microbes are foreseen.
SECTION 2 PLS-DA is applied to Raman spectra to discriminate adulterated beeswaxes from natural ones. This procedure may be implemented to prevent possible adulteration of bees’ products.
SECTION 3 PLS-NAS is applied to ATR spectra to quantify biogenic silica in marine sediments. The new method allows to accurately study the time evolution of primary productivity in the Antarctic basins.
2017
- Chemometrics, Bioinformatics
[Capitolo/Saggio]
Durante, Caterina; LI VIGNI, Mario; Cocchi, Marina
abstract
The need to consider variability due to raw materials, seasonality, agricultural practices, and food processing, that are aspects which all play a role in authenticity tasks, justifies the need for chemometrics methods. This chapter presents a few basic chemometrics methods, such as exploratory data analysis, multiway data analysis, and data fusion. New chemometrics methods are continuously being updated and improved upon, two main distinctive characteristics are required: data exploration and graphical representation; and deep model validation through all steps of data processing. This also explains why chemometrics tools based on latent variables, for example, principal component analysis (PCA), soft independent modeling of class analogies (SIMCA), partial least squares (PLS), and PLS discriminant analysis (PLSDA), are still so popular and powerful. Nowadays, there is an established set of chemometric multiway methods and algorithms. The chapter mentions those that can serve the purposes of exploratory data analysis and classification, the tasks most frequently encountered in food authentication.
2017
- Discrimination of glioma brain tumor grades through Multivariate Data Analysis on 1H-HR-MAS NMR ex-vivo spectra
[Abstract in Atti di Convegno]
Cavallini, N.; Righi, V.; Mucci, A.; Valentini, A.; Cocchi, M.
abstract
Gliomas account for about 40% of total primitive brain tumors, and discrimination between high and low glioma grades is a vital diagnostic decision, determining the most effective treatment and having an important impact on patient management and outcome.
In vivo MRS can support the diagnosis of cancer based on MRI, but it can only be used when the molecular markers are well established. Their identification can be derived from the spectroscopic analysis of ex vivo biopsy samples using HR-MAS NMR technique.
45 specimens of brain tissue were obtained from 35 patients diagnosed either with glioma or lymphoma, and analyzed using HR-MAS NMR. With the aim of retrieving as much information as possible, three different pulse sequences were used, giving rise to three spectral datasets.
Multivariate data analysis was performed to identify informative metabolites and their interactions. The key goals were: 1) explore the data; 2) integrate the spectra to enhance information retrieval and interpretability; 3) distinguish among glioma grades III and IV.
After proper alignment [1], the datasets were explored by Principal Component Analysis (PCA). The spectra were integrated using Multivariate Curve Resolution (MCR, [2]) on selected intervals. MCR is a method able to resolve overlapping peaks and separate them, by extracting their “pure” peak shapes and their relative concentration in each sample. The concentration information was used to produce the interval-resolved data, which are in principle a more compact and cleaner version of the original data [3].
Class-modeling (SIMCA) and Discriminant Analysis (PLS-DA) were finally applied to the interval-resolved data considering each sequence dataset both separately and datafused. The differences in performance were assessed.
2017
- Extraction of sensory features from online reviews using text analysis: an example with beer
[Poster]
Cavallini, Nicola; BRO JORGENSEN, Rasmus; Cocchi, Marina
abstract
We probably live in the golden age of food and cooking. Consumers tend nowadays to be more aware about the different aspects regarding food consumption and preparation.
Not only people are encouraged to taste and try new and different products, but also to review them, often by sharing their opinions on specialized social networks.
Users can rate and describe what they did like or not about a kind of food product, sometimes using terms which are very similar or even in common with those used in the field of sensory analysis.
As a part of a project which is based on using analytical chemistry in synergy with advanced data analysis, the idea proposed here is to apply text analysis methods to study how different beer products were rated and reviewed by the users of Ratebeer.com.
2017
- Resolved NMR spectra of pale beer samples for consumers’ ratings and sensory features prediction
[Poster]
Cavallini, Nicola; Savorani, Francesco; BRO JORGENSEN, Rasmus; Cocchi, Marina
abstract
The consumers’ interest in how food is produced and prepared has increased. Consumers tend nowadays to be more aware about the different aspects regarding food consumption and in line with this trend, new-concept restaurants and food production techiques are created. This phenomenon is driven by high quality standards, and analytical chemistry in synergy with advanced data analysis can be profitably used to build new tools to aid consumers when choosing and pairing foodstuff.
The aim of this work is assessing the linkage between the “objective” analytical chemical information and the “subjective” consumers’ taste. The analytical information is provided by means of Nuclear Magnetic Resonance (NMR) and Visible-NIR spectroscopies, while the information about taste is represented by a set of users’ ratings collected from social network regarding beer quality. In addition, 30 of the available beer samples have also been assesed by a trained sensory panel.
1H-NMR spectra and Visible-NIR spectra were acquired on a set of one hundred beer samples differing by brewery, alcohol content, yeast, brew style, etc. In a fingerprint-approach perspective, a number of latent features and signals related to specific chemical compounds were extracted from the NMR spectra by means of Multivariate Curve Resolution (MCR), which was applied to selected intervals.
A new dataset was assembled using the identified chemical components’ concentrations. These were used in PLS analysis, with which the correlations between the spectral information and the consumers’ ratings were investigated. The prediction performances of the integrated and the original spectral datasets were also compared. PLS and exploratory analysis performed on the NMR datasets also allowed to gain insight into the composition of beer and into the differences among the various beer styles represented in our dataset. PLS regression was also performed using the Visible-NIR spectra, and the results were compared with those obtained from the NMR datasets.
2016
- Analisi multivariata e spettroscopia NIR per la determinazione del grado di contaminazione da aflatossina M1 in latte bovino
[Abstract in Atti di Convegno]
LI VIGNI, Mario; Durante, Caterina; AMIGO RUBIO, JOSE' MANUEL; Cavallini, Nicola; Cocchi, Marina; Rizzi, N
abstract
La contaminazione alimentare da micotossine ha effetti importanti sull’opinione pubblica, come emerge in occasione di notizie relative a sequestri di prodotti contaminate. Queste molecole (potenziali cancerogeni) rappresentano una minaccia diretta alla salute e sicurezza per via della loro presenza ubiquitaria come contaminanti alimentari, siano essi prodotti vegetali ad uso diretto o semilavorati e, attraverso i mangimi, possono contaminare il latte e suoi derivati. La legislazione europea prevede un limite stringente per l’Aflatossina M1 nel latte (50 ppt): i metodi analitici quindi devono garantire elevata sensibilità, ottenuta al prezzo della velocità e semplicità di analisi (cromatografia), problematica parzialmente affrontata dai metodi immunologici (ELISA). In questo lavoro è valutata la fattibilità di un metodo analitico rapido ed efficente per la determinazione di AFM1 nel latte. L’obiettivo è ottenere un metodo rapido e semplice di screening da implementare ad ogni livello della filiera di produzione del latte, per realizzare un controllo interno capillare. Un totale di ottanta campioni di latte sono stati considerati, secondo quatnge di contaminazione: negativi (tossina assente), sotto il limite (20-50 ppt), sopra il limite (50-80 ppt), altamente contaminati (fino a 300 ppt). NIRS è già impiegata in questo contesto per la determinazione di proprietà del prodotto e controllo della qualità, pertanto è stata impiegata come metodo preliminare per la classificazione dei campioni secondo il livello di contaminazione. L’implementazione di un metodo rapido di screening in grado di definire se un campione cade in uno dei quattro gruppi sopracitati può rappresentare un importante vantaggio per ridurre il numero di campioni da sottoporre ad ulteriori accertamenti della contaminazione
2016
- Feature extraction from 1H-NMR spectra for food characterization
[Poster]
Cavallini, Nicola; Savorani, Francesco; Da Silva Friis, Helena; BRO JORGENSEN, Rasmus; Cocchi, Marina
abstract
During the last decade the awareness of consumers and society in general towards all aspects that concern food consumption has strongly increased. This has led to the new-concept restaurants, food production techniques and ways to enjoy and pair foodstuff, having high quality standards as drivers. The present work is part of a larger project, which is based on the fundamental idea of using analytical chemistry and advanced data analysis to build new tools to aid consumers when choosing foodstuff. A first benchmark, here explored, concerns the classification of different types of beer for assessing the linkage between the “objective” chemical analytical information and the “subjective” consumer’s taste.
Analytical data were acquired on a set of one-hundred beer samples differing by brewery, alcohol content, yeast, brew type, etc. In a fingerprint-approach perspective, 1H-NMR spectra were recorded together with NIR, GC-MS and fluorescence spectra, but also the relative sensory and marketing data were collected.
In particular, this work focuses on the analysis of NMR spectra aiming at linking gastronomic preference to feature-based beer patterns. Both fingerprinting and metabolic profiling approaches have been used in unsupervised analysis to reveal similarities and peculiarities among the different types of beer.
Peaks assignment, on the basis of literature references [1, 2, 3] and brewing process knowledge, have also been carried out in order to give “chemical” names to the new variables, to ease the fruition for non-insiders too.
Different chemometric tools (after proper preprocessing) have been applied in both approaches: PCA and ICA for fingerprinting; while a semi-automated strategy has been used for profiling which integrates depicting spectral intervals and decomposition (PCA) / resolution (MCR) techniques to resolve overlapping peaks and finally obtaining a peaks’ features table.
References
[1] I. Duarte, A. Barros, P. S. Belton, R. Righelato, M. Spraul, E. Humpfer, and A. M. Gil, J. Agric. Food Chem., 50(9), 2475–2481 (2002)
[2] A. M. Gil, I. F. Duarte, M. Godejohann, U. Braumann, M. Maraschin, and M. Spraul, Analytica Chimica Acta, 488(1), 35–51 (2003)
[3] L. I. Nord, P. Vaag, and J. Ø. Duus, Anal. Chem., 76(16), 4790–4798 (2004)
2016
- Linking beer preferences to NIR fingerprint by chemometrics
[Abstract in Atti di Convegno]
Cavallini, Nicola; da Silva Friis, Helena; BRO JORGENSEN, Rasmus; Cocchi, Marina
abstract
The awareness of consumers towards all the different aspects that concern food consumption has increased. This has led to new-concept restaurants as well as new food production techniques and ways to enjoy and pair foodstuff, having high quality standards as drivers. The present work is part of a larger project that is based on the fundamental idea of using analytical chemistry and advanced data analysis to build new tools to aid consumers when choosing foodstuff. A first benchmark, here explored, concerns the classification of different types of beer for assessing the linkage between the “objective” analytical chemical information and the “subjective” consumer’s taste.
Analytical data were acquired on a set of one hundred beer samples differing by brewery, alcohol content, yeast, brew type, etc. In a fingerprint-approach perspective 1H-NMR and NIR spectra were recorded together with GC-MS and fluorescence spectra, but also the relative sensory and consumers’ ratings data were collected.
In particular, this work focused on the analysis of the Visible-NIR spectra, also linked to the consumers’ ratings data. Different preprocessing methods (SNV, derivative but also no preprocessing at all) and exploratory analysis techniques allowed highlighting different features linked to the characteristics of beer.
Methods such as Multivariate Curve Resolution (MCR) have been applied to selected spectral intervals in order to extract latent features and signals, which were related to specific compounds or compound families. This also supported an ad hoc variable selection during PLS analysis, with which the correlations between the spectral information and the consumers’ ratings were investigated.
2016
- Multiresolution analysis and chemometrics for pattern enhancement and resolution in spectral signals and images
[Capitolo/Saggio]
Li Vigni, Mario; Cocchi, Marina
abstract
The chapter illustrates the benefits and improvements of the integration of the wavelet transform with multivariate data analysis upon multiresolution analysis. This approach can be used for feature extraction both in signals and images in a broad sense, focusing on the capability to simultaneously accomplish de-noising and feature enhancement / selection. Different contexts are presented, ranging from feature selection applied to spectroscopic signals in classification and regression tasks, to multiresolution multivariate image analysis with special attention to quality monitoring, fault detection and classification. The proposed cases of study cover applications in the food and materials sciences.
2016
- Multivariate data analysis to assess dry powder inhalers performance from powder properties
[Articolo su rivista]
Elia, Andrea; Cocchi, Marina; Cottini, Ciro; Riolo, Daniela; Cafiero, Claudio; Bosi, Roberto; Lutero, Emilio
abstract
The study aimed at investigating the correlations among the physical and bulk properties of carrier based dry powder inhaler formulations and the performance of the powder inhaler device estimated by in-vitro tests for a specific active pharmaceutical ingredient (API), and at obtaining predictive models for the in-vitro performance.
Samples from scale-up process batches having different formulations, process settings and bulk size, were characterized by rheological, density and particle size tests. In vitro performance was evaluated by several parameters obtained by a dosage unit sampling apparatus (DUSA) and a next generation impactor (NGI). Correlations between powder properties and performance propertieswere established using partial least square (PLS)
regression analysis. Variable importance in projection (VIP)was used in order to assess the most influential powder characterization variables to estimate the analytical ones. Particle size, density and rate of flowability are significant for modeling the Delivered Dose of the API and the total quantity of powder related to each dose. Powder characterization variables, describing the degree of cohesiveness and the flow properties of powder, are related
to the total amount of the active ingredient for different formulations. DUSA test variables were satisfactory predicted on the basis of powder characterization variables, while NGI performance variables were predicted with higher error.
2016
- Multiway and multiset methods: ThRee-way methods In Chemistry And Psychology conference, 8th edition, 2015
[Breve Introduzione]
Cocchi, Marina; Marini, Federico
abstract
Multiway and multiset analysis is nowadays well established and the continuously increasing number of papers reporting applications of such approaches indicates that this topic is as well extending to several research fields and becoming used by practitioners besides experts in tensor algebra, data analysis and signal processing. Continuing with the tradition rooted in 1993, the 8th edition of the multidisciplinary conference ThRee-way methods In Chemistry And Psychology (TRICAP) was held in Pecol Val di Zoldo (Italy) from may 31st to june 5th 2015, with the aim of bringing together leading scientists in multiway and multiset data analysis. As usual, the focus was both on the models themselves (including their mathematical basis and algorithms), and on their applications to different fields, with special emphasis on the bridge between modeling/numerical aspects and practical use and implementation to solve real-world issues.
2016
- Spectroscopic Fingerprint of Pale Beers linked to Sensory Analysis and Consumers Preferences
[Poster]
Cavallini, Nicola; Cocchi, Marina; BRO JORGENSEN, Rasmus; da Silva Friis, Helena; Savorani, Francesco
abstract
During the last decade the awareness of consumers and society in general towards all aspects that concern food consumption has strongly increased. Ethics, sustainability, health, safety, quality, tradition are now everyday words, and communication and marketing are following more and more the trends that these terms represent. Research in food chemistry area has mainly focused on chemical analysis and characterization to contribute to fundamental issues such as food safety and quality, nutritional and health requirements.
The present work is part of a larger project, which is aimed to take a step beyond the aforementioned approach. The fundamental idea is to use our analytical chemistry expertise to build new tools to aid consumers when choosing foodstuff (and have proper knowledge of it) and producers to meet consumer expectations, using food quality as a driver.
To this aim the proposal is to use analytical spectroscopy to capture salient features of foodstuff (fingerprint) and build a reference database that can be efficiently searched through multivariate data analysis tools and, be likely in the near future, linked to applications for mobile smart devices implemented for consumers inquires. At the same time consumers’ choice may be oriented by showing how products of similar categories cluster according to different criteria.
As a first benchmark to develop these ideas a survey on beer is presented. One hundred samples of light beer (i.e. no stout or dark beers have been considered) differing by brewery, alcohol content, yeast, brew type, etc., were collected. This work is focused on Vis-NIR, NMR and sensory data, with the aim of establishing a link between the “objective” information of the spectroscopic fingerprint and the “subjective” world of consumers’ assessments. The latter is represented by online beer ratings and for a reduced number of samples by sensory reports made by a panel of experts.
Different combinations of decomposition methods, e.g. PCA, ICA, MCR and clustering (both linear and non-linear methods) were used to extract relevant information and as basis for data-fusion techniques to integrate the chemical information.
PLS regression allowed establishing a link between spectral fingerprint/information and consumer preferences as expressed by ratings (www.ratebeer.com) aroma, appearance, taste, palate, overall. Furthermore, also the mostly used descriptive words used by consumer were codified, based on the approach described in [1]. This part of the work can contribute to build a “beer vocabulary”, which can be very useful to develop further real-life applications.
References:
[1] M. Bevilacqua, Visualization of comprehensive data mining problems in gastronomy, chap. 10,
Development of chemometric approaches for ensuring food quality and safety, Doctoral Thesis, Roma La Sapienza (2014)
2015
- An analytical approach to Sr isotope ratio determination in Lambrusco wines for geographical traceability purposes
[Articolo su rivista]
Durante, Caterina; Baschieri, Carlo; Bertacchini, Lucia; Bertelli, Davide; Cocchi, Marina; Marchetti, Andrea; Manzini, Daniela; Papotti, Giulia; Sighinolfi, Simona
abstract
Geographical origin and authenticity of food are topics of interest for both consumers and producers.
Among the different indicators used for traceability studies, 87Sr/86Sr isotopic ratio has provided excellent
results. In this study, two analytical approaches for wine sample pre-treatment, microwave and low temperature
mineralisation, were investigated to develop accurate and precise analytical method for
87Sr/86Sr determination. The two procedures led to comparable results (paired t-test, with t < tcrit). Furthermore,
the precision of the whole analytical procedure was evaluated by using a control sample (wine
sample), processed during each sample batch (calculated Relative Standard Deviation, RSD%, equal to
0.002%. Lambrusco PDO (Protected Designation of Origin) wines coming from four different vintages
(2009, 2010, 2011 and 2012) were pre-treated according to the best procedure and their isotopic values
were compared with isotopic data coming from (i) soils of their territory of origin and (ii) wines obtained
by same grape varieties cultivated in different districts. The obtained results have shown no significant
variability among the different vintages of wines and a perfect agreement between the isotopic range
of the soils and wines has been observed. Nevertheless, the investigated indicator was not enough powerful
to discriminate between similar products. To this regard, it is worth to note that more soil samples
as well as wines coming from different districts will be considered to obtain more trustworthy results.
2015
- BEER FINGERPRINTING AND MULTIVARIATE DATA ANALYSIS TOWARDS INFORMED TAILORED FOOD CONSUMPTION.
[Abstract in Atti di Convegno]
Cavallini, Nicola; Cocchi, Marina; Bro, Rasmus; Biancolillo, Alessandra; da Silva Friis, Helena
abstract
There is increasing awareness of consumer and society in general towards all aspects, which concern food consumption encompassing ethics, sustainability,health, safety, quality, tradition, communication,marketing, etc. Research in food chemistry area has mainly focused on chemical analysis and characterisation to contribute to fundamental issues such as food safety and quality, nutritional and health requirements. Aim of this work is to go a step beyond that. Could our analytical chemistry expertise be of use and ease in the cultural and gastronomic aspect linked to food consumption? In particular, could we think of developing new tools to aid consumers when choosing foodstuff to have proper knowledge of it, and producers to meet consumer expectations while using food quality as drivers?
To this aim our proposal is to use analytical spectroscopy to capture salient features of foodstuff (fingerprint) and build a reference database that can be efficiently searched through multivariate data analysis tools and linked to apps for mobile smart devices implemented for consumers inquires. At the same time consumer choice may be oriented by showing how products of similar categories cluster according to different criteria. As a first benchmark to develop these ideas we present a survey on beer. Beer is one of the most consumed alcoholic beverages with a highly relevant economic
impact associated. However, our interest is mainly due to the fact that recently the consumers favor more and more artisanal product coming from local brewery and micro- brewery weighting much more the cultural and quality aspects linked to its consumption. This may be a very positive trend in order to prevent alcoholic disorders especially in young.
Several beer samples differing by e.g. yeast, brewtype, brewery, have been collected and NIR, NMR, GCMS fingerprinting together with sensory attribute and merceological parameters have been acquired. Multivariate explorative and clustering tools are employed to group beer according to several search criteria.
2015
- Beer Fingerprinting and Multivariate Data Analysis Towards Informed Tailored Food Consumption
[Poster]
Cavallini, Nicola; Cocchi, Marina; BRO JORGENSEN, Rasmus; Biancolillo, Alessandra; da Silva Friis, Helena
abstract
There is increasing awareness of consumer and society in general towards all aspects, which concern food consumption encompassing ethics, sustainability, health, safety, quality, tradition, communication, marketing, etc. Research in food chemistry area has mainly focused on chemical analysis and characterization to contribute to fundamental issues such as food safety and quality, nutritional and health requirements. Aim of this work is to go a step beyond that. Could our analytical chemistry expertise be of use and ease in the cultural and gastronomic aspect linked to food consumption? In particular, could we think of developing new tools to aid consumers when choosing foodstuff to have proper knowledge of it, and producers to meet consumer expectations while using food quality as drivers?
To this aim our proposal is to use analytical spectroscopy to capture salient features of foodstuff (fingerprint) and build a reference database that can be efficiently searched through multivariate data analysis tools and linked to apps for mobile smart devices implemented for consumers inquires. At the same time consumer choice may be oriented by showing how products of similar categories cluster according to different criteria.
As a first benchmark to develop these ideas we present a survey on beer. Beer is one of the most consumed alcoholic beverages with a highly relevant economic impact associated. However, our interest is mainly due to the fact that recently the consumers favor more and more artisanal product coming from local brewery and micro- brewery weighting much more the cultural and quality aspects linked to its consumption. This may be a very positive trend in order to prevent alcoholic disorders especially in young.
Several beer samples differing by e.g. yeast, brewtype, brewery, etc, have been collected and NIR, NMR, GCMS fingerprinting together with sensory attribute and merceological parameters have been acquired. Multivariate explorative and clustering tools are employed to group beer according to several search criteria.
2015
- DIFFERENT APPROACHES TO THE ANALYSIS OF DESIGNED NIR FINGERPRINTING DATA
[Abstract in Atti di Convegno]
Cocchi, Marina
abstract
The study of treatments effect is a very general issue, which encompasses several research fields from biomedicine, metabolomics to food processing and material science. The main framework is to assess if different treatments (factors), and which, affect the studied system and how. Using Analysis of Variance (ANOVA) has traditionally assessed these questions, however when several parameters are used to characterize the samples groups and, especially in the case of instrumental characterization, it has been demonstrated that coupling ANOVA with multivariate data analysis is far more efficient. In particular, ANOVA Simultaneous Component Analysis (ASCA) and ASCA combined with PARAFAC (PARAFASCA) have been proposed [1-2]. These methods, which are based on fitting a multivariate decomposition model
on each ANOVA term, allows for easy interpretation of the variation induced by the different factors of
the design due to the graphical representation in components space and projection/evaluation of residuals. In particular, ASCA describes each variance contribution with a PCA model, but a contribution d
epending on crossed factors (interactions) may be described more parsimoniously by multiway models like
parallel factor analysis (PARAFAC). In both cases designed data are described in a way that is both parsimonious and focused on the experimental question. The study of thermal treatments changes in moderate range of temperatures for spruce wood has been used as benchmark to illustrate the methodology. According to ISPM-15 standard, all wood materials to be shipped should be heat
treated with specific time-temperature schedules. Thus, it is commercially important to have a fast method to estimate if a wood has been treated or not, to this aim Near Infrared Spectroscopy has been used as fingerprinting technique to evaluate if could be sensible to changes to wood chemical/physic structure
induced by temperature and exposition time. Experiments have been planned according to a design taking into account three factors: temperature, treatment time and time occurred from treatment to the measurement.
2015
- N-way modeling for wavelet filter determination in multivariate image analysis
[Articolo su rivista]
Prats Montalbán, José Manuel; Cocchi, Marina; Ferrer, Alberto
abstract
When trying to analyze spatial relationships in image analysis, wavelets appear as one of the state-of-the-art tools. However, image analysis is a problem-dependent issue, and different applications might require different wavelets in order to gather the main sources of variation in the acquired images with respect to the specific task to be performed. This paper provides a methodology based on N-way modeling for properly selecting the best wavelet choice to use or at least to provide a range of possible wavelet choices (in terms of families, filters, and decomposition levels), for each image and problem at hand. The methodology has been applied on two different data sets with exploratory and monitoring objectives.
2015
- Spectroscopic fingerprinting and Multivariate Data Analysis of Light Beer Towards Informed Tailored Food Consumption
[Poster]
Cavallini, Nicola; Cocchi, Marina; BRO JORGENSEN, Rasmus; Biancolillo, Alessandra; da Silva Friis, Helena
abstract
There is increasing awareness of consumer and society in general towards all aspects, which concern food consumption encompassing ethics, sustainability, health, safety, quality, tradition, communication, marketing, etc. Research in food chemistry area has mainly focused on chemical analysis and characterization to contribute to fundamental issues such as food safety and quality, nutritional and health requirements.
Aim of this work is to go a step beyond the aforementioned approach. Could our analytical chemistry expertise be of use and ease in the cultural and gastronomic aspect linked to food consumption? In particular, could we think of developing new tools to aid consumers when choosing foodstuff (to have proper knowledge of it) and producers to meet consumer expectations while using food quality as a driver?
To this aim the proposal is to use analytical spectroscopy to capture salient features of foodstuff (fingerprint) and build a reference database that can be efficiently searched through multivariate data analysis tools and, likely in the near future, linked to apps for mobile smart devices implemented for consumers inquires. At the same time consumer’s choice may be oriented by showing how products of similar categories cluster according to different criteria.
As a first benchmark to develop these ideas a survey on beer is presented. Beer is one of the most consumed alcoholic beverages with a highly relevant economic impact associated. However, our interest is mainly due to the fact that recently the consumers favor more and more artisanal product coming from local and micro-breweries weighting much more the cultural and quality aspects linked to its consumption. This may be a very positive trend in order to prevent alcoholic disorders especially among young people.
One-hundred samples of light beer (i.e. no stout or dark beers have been considered) differing by brewery, alcohol content, yeast, brew type, etc, have been collected. Visible-NIR (Near-Infra Red), NMR (Nuclear Magnetic Resonance), GCMS (Gas-Chromatography and Mass Spectroscopy) and fluorescence fingerprinting together with sensory attribute and economic parameters have been acquired. Multivariate explorative and clustering tools are employed to group beer according to several search criteria.
2014
- 8th Colloquium Chemometricum Mediterraneum CCMVIII
[Prefazione o Postfazione]
Cocchi, Marina; Marini, Federico
abstract
The 8th edition of Colloquium Chemometricum Mediterraneum (CCMVIII), with the motto: “..dubito ergo indago..“, was held from June 30th to July 3rd 2013 in Bevagna (Italy) in a pleasant medieval environment.
Registered participants were more than one hundred participants, coming from Mediterranean countries, mainly France, Italy and Spain but also Portugal, Algeria and Tunisia, as well as other European countries (Austria, Belgium, Denmark, Germany, Hungary, Netherland, Norway, Portugal, Serbia), South American (Cuba, Brazil, Argentina) and China. This is a sign of how alive, attractive and well established is Chemometrics now in Mediterranean area.
The scientific program comprised six plenary lectures, 38 oral presentations (organized in seven thematic sessions and mostly given by young researchers) and 65 poster communications. The Conference was opened by Prof. Michele Forina, who is one of the founders of the Colloquium and who was also recipient of the Elsevier Chemometrics Lifetime Achievement Award in 2012, with a lecture entitled: "Memories of a resting professor".
2014
- A mid level data fusion strategy for the Varietal Classification of Lambrusco PDO wines
[Articolo su rivista]
Silvestri, Michele; Elia, Andrea; Bertelli, Davide; Salvatore, Elisa; Durante, Caterina; Li Vigni, Mario; Marchetti, Andrea; Cocchi, Marina
abstract
Nowadays the necessity to reveal the hidden information from complex data sets is increasing due to the development of high-throughput instrumentation. The possibility to jointly analyze data sets arising from different sources (e.g. different analytical determinations/platforms) allows capturing the latent information that would not be extracted by the individual analysis of each block of data. Several approaches are proposed in the literature and are generally referred to as data fusion approaches. In this work a mid level data fusion is proposed for the characterization of three varieties (Salamino di Santa Croce, Grasparossa di Castelvetro, Sorbara) of Lambrusco wine, a typical PDO wine of the district of Modena (Italy). Wine samples of the three different varieties were analyzed by means of 1H-NMR spectroscopy, Emission-Excitation Fluorescence Spectroscopy and HPLC-DAD of the phenolic compounds.
Since the analytical outputs are characterized by different dimensionalities (matrix and tensor), several multivariate analyses were applied (PCA, PARAFAC, MCR-ALS) in order to extract and merge, in a hierarchical way, the information present in each data set.
The results showed that this approach was able to well characterize Lambrusco samples giving also the possibility to understand the correlation between the sources of information arising from the three analytical techniques.
2014
- AN ANALYTICAL APPROACH TO THE DEVELOPMENT OF GEOGRAPHICAL TRACEABILITY MODEL OF OENOLOGICAL PRODUCTS
[Poster]
Durante, Caterina; Bertacchini, Lucia; Cocchi, Marina; Manzini, Daniela; Rossi, Maria Cecilia; Camin, F.; Mattivi, F.; Marchetti, Andrea
abstract
Notwithstanding urbanization and globalization, the strengthening consumers interests towards food with a well-defined geographical origin has been kept constant and features such as food authenticity and traceability are becoming peculiar to the entire mankind. This work summarizes the preliminary results of a long term research project [AGER project] focused on the development of geographical traceability models of two typical Italian oenological products, Lambrusco PDO and TRENTODOC, by means of primary and secondary indicators. In particular, this work reviews the adopted strategy and the obtained results as regard the potentiality of primary geographical tracers, i.e. strontium isotopic ratio, 87Sr/86Sr and elemental content. The innovation of the adopted strategy lies in the use of a systematic approach for developing a geographical traceability model, which requires a deep knowledge of the whole matrices that characterised the investigated systems, namely soils, vine branches, grape juices, intermediate products and wines. For these reasons, a statistically representative sampling for Modena and Trento districts was performed and primary indicators were monitored in all the investigated matrices obtaining isotopic maps able to highlight the geographical link between the investigated wines and their territory of provenance.
2014
- EX VIVO HR-MAS NMR, IN VIVO MRS-MRI AND MULTIVARIATE ANALYSIS TO HIGHLIGHT BIOMARKERS IN GLIOMAS
[Abstract in Atti di Convegno]
V., Righi; Schenetti, Luisa; A., Valentini; G., Pavesi; L., Nocetti; Cocchi, Marina; Mucci, Adele
abstract
Gliomas account for about 40% of total primitive brain tumors, and discrimination between high and low glioma grade remains a vital diagnostic decision, determining the most effective treatment and having an important impact on patient management and outcome. The ex vivo HR-MAS NMR spectra provide more details about metabolites than in vivo MRS and permits to produce a metabolic picture of the tissues. Accurate biochemical assignment of metabolites will improve our interpretation of HR-MAS data and the translation of NMR tumor biomarkers to in vivo studies. We developed this project on gliomas with the aim to gain a better insight into the discrimination among different grades and subtypes using ex vivo HR-MAS NMR, in vivo MRS, MRI, clinical data, chemometrics and statistical analysis. We performed experiments on 20 specimen from different grade glioma. After a chemometric analysis some small metabolites such as alanine, lactate, myo-inositol and glycine seems to be able to discriminate between high and low grade glioma. The same chemometric analysis was performed on in vivo MR spectrum. A number of metabolites have been identified as potential biomarkers of tumor type; now we need to combine all the in vivo, ex vivo, histological and clinical data to obtain a unique tumor fingerprints. Results gathered from this study should lead to the development of tools that can facilitate the distinction of tumor types and grade that cannot be readily distinguished by histopathology or by routine neuroimaging.
2014
- FOCUS SULLA SPETTROSCOPIA NIR
[Articolo su rivista]
Cocchi, Marina; Cattaneo, Tiziana
abstract
Si riporta il resoconto del 6° Simposio Italiano di Spettroscopia nel vicino infrarosso che si è svolto lo scorso maggio a Modena. Nell’illustrare i lavori del simposio è dato rilievo allo stato dell’arte delle applicazioni della metodologia NIR di interesse sia per la ricerca
scientifica, sia industriale/commerciale e alla sua sinergia con l’analisi chemiometrica
2014
- Ranking brain areas encoding the perceived level of pain from fMRI data
[Articolo su rivista]
S., Favilla; A., Huber; Pagnoni, Giuseppe; Lui, Fausta; P., Facchina; Cocchi, Marina; Baraldi, Patrizia; Porro, Carlo Adolfo
abstract
Pain perception is thought to emerge from the integrated activity of a distributed brain system, but the relative
contribution of the different network nodes is still incompletely understood.
In the present functional magnetic resonance imaging (fMRI) study,we aimed to identify themore relevant brain
regions to explain the time profile of the perceived pain intensity in healthy volunteers, during noxious chemical
stimulation (ascorbic acid injection) of the left hand. To this end, we performed multi-way partial least squares
regression of fMRI data from twenty-two a-priori defined brain regions of interest (ROI) in each hemisphere, to
build a model that could efficiently reproduce the psychophysical pain profiles in the same individuals; moreover,
we applied a novel three-way extension of the variable importance in projection (VIP) method to summarize each
ROI contribution to the model.
Brain regions showing the highest VIP scores included the bilateral mid-cingulate, anterior and posterior insular,
and parietal operculum cortices, the contralateral paracentral lobule, bilateral putamen and ipsilateral medial
thalamus.Most of these regions, with the exception of medial thalamus,were also identified by a statistical analysis
on mean ROI beta values estimated using the time course of the psychophysical rating as a regressor at the voxel
level.
Our results provide the first rank-ordering of brain regions involved in coding the perceived level of pain. These
findings in amodel of acute prolonged pain confirm and extend previous data, suggesting that a bilateral array of
cortical areas and subcortical structures is involved in pain perception
2013
- Application of data fusion techniques to direct geographical traceability indicators
[Articolo su rivista]
Silvestri, Michele; Bertacchini, Lucia; Durante, Caterina; Marchetti, Andrea; Salvatore, Elisa; Cocchi, Marina
abstract
A hierarchical data fusion approach has been developed proposing multivariate curve resolution (MCR) as a variable reduction tool.
The case study presented concerns the characterization of soil samples of the Modena District. It was performed in order to understand, at a pilot study stage, the geographical variability of the zone prior to planning a representative soils sampling to derive geographical traceability models for Lambrusco Wines. Soils samples were collected from four producers of Lambrusco Wines, located in in-plane and hill areas. Depending on the extension of the sampled fields the number of points collected varies from three to five and, for each point, five depth levels were considered.
The different data blocks consisted of X-ray powder diffraction (XRDP) spectra, metals concentrations relative to thirty-four elements and the 87Sr/86Sr isotopic abundance ratio, a very promising geographical traceability marker.
A multi steps data fusion strategy has been adopted. Firstly, the metals concentrations dataset was weighted and concatenated with the values of strontium isotopic ratio and compressed. The resolved components described common patterns of variation of metals content and strontium isotopic ratio. The X-ray powder spectra profiles were resolved in three main components that can be referred to calcite, quartz and clays contributions. Then, a high-level data fusion approach was applied by combining the components arising from the previous data sets.
The results show interesting links among the different components arising from XRDP, the metals pattern and to which of these 87Sr/86Sr Isotopic Ratio variation is closer. The combined information allowed capturing the variability of the analyzed soil samples.
2013
- Assessing feature relevance in NPLS models by VIP
[Articolo su rivista]
Favilla, Stefania; Durante, Caterina; LI VIGNI, Mario; Cocchi, Marina
abstract
Multilinear PLS (NPLS) and its discriminant version (NPLS-DA) are very diffuse tools to model multi-way data
arrays. Analysis of NPLS weights and NPLS regression coefficients allows data patterns, feature correlation
and covariance structure to be depicted. In this study we propose an extension of the Variable Importance
in Projection (VIP) parameter to multi-way arrays in order to highlight the most relevant features to predict
the studied dependent properties either for interpretative purposes or to operate feature selection. The VIPs
are implemented for each mode of the data array and in the case of multivariate dependent responses considering
both the cases of expressing VIP with respect to each single y-variable and of taking into account
all y-variables altogether.
Three different applications to real data are presented: i) NPLS has been used to model the properties of
bread loaves from near infrared spectra of dough, acquired at different leavening times, and corresponding
to different flour formulations. VIP values were used to assess the spectral regions mainly involved in determining
flour performance; ii) assessing the authenticity of extra virgin olive oils by NPLS-DA elaboration of
gas chromatography/mass spectrometry data (GC–MS). VIP values were used to assess both GC and MS discriminant
features; iii) NPLS analysis of a fMRI-BOLD experiment based on a pain paradigm of acute
prolonged pain in healthy volunteers, in order to reproduce efficiently the corresponding psychophysical
pain profiles. VIP values were used to identify the brain regions mainly involved in determining the pain intensity
profile.
2013
- Classification Methods of Multiway Arrays as a Basic Tool for Food PDO Authentication
[Capitolo/Saggio]
Salvatore, Elisa; Bevilacqua, M.; Bro, R.; Marini, F.; Cocchi, Marina
abstract
Food chain traceability, identification of adulterations, and the control of labeling compliance are topic that require the evaluation of the foodstuff in its entirety: in this respect, more and more researchers are investigating the possibility of using multidimensional or hyphenated techniques for the fingerprinting of the products. However, these techniques produce data structures that are multidimensional as well and that require proper chemometric approaches for data processing (multi-way data analysis).
In this Chapter, the state-of-the-art approaches for the classification of multiway data will be discussed theoretically and compared on case studies coming form the food authenticity context, such as the traceability of extra virgin olive oils of protected denomination of origin and table wines.
2013
- DATA FUSION APPROACH FOR THE VARIETAL CLASSIFICATION OF LAMBRUSCO P.D.O. WINES
[Relazione in Atti di Convegno]
Cocchi, Marina; Silvestri, Michele; Salvatore, Elisa; Elia, A.; Durante, Caterina; Marchetti, Andrea; Papotti, Giulia; Bertelli, Davide; Plessi, Maria
abstract
Owing to the increasing of the throughput of modern analytical techniques and the needs of getting exhaustive information on the peculiarities of similar samples in terms of composition for both authenticity and geographical or varietal origin purposes, it is necessary to extract hidden information from complex data set.
The possibility to jointly analyze data sets arising from different sources (e.g. different analytical determinations/platforms) allows capturing the latent information that would not be extracted by the individual analysis of each block of data. Several approaches are proposed in the literature and are generally referred to as data fusion ones. In this work a hierarchical data fusion is proposed [1,2] for the characterization of three varieties of Lambrusco Wine (Salamino di Santa Croce, Grasparossa di Castelvetro, Sorbara), a typical P.D.O. product of the District of Modena (Italy). In particular, 60 wine samples of the three different varieties were analyzed by means of HPLC-DAD fro the phenolic compounds evaluation, Emission- Excitation Fluorescence Spectroscopy and 1H-NMR.
Since the analytical outputs are characterized by different dimensionality (matrix and tensor), several multivariate analysis were applied (PCA, PARAFAC, MCR-ALS) in order to extract and merge, in a hierarchical way, the information present in each data set.
Results showed that this approach was able to well characterize Lambrusco samples giving also the possibility to understand the correlation between the source of information arising from the three analytical techniques.
2013
- DETERMINATION OF PHENOLIC COMPOUNDS AND AUTHENTICATION OF PDO LAMBRUSCO WINES BY HPLC-DAD AND CHEMOMETRIC TECHNIQUES
[Articolo su rivista]
Salvatore, Elisa; Cocchi, Marina; Marchetti, Andrea; Federico, Marini; Anna De, Juan
abstract
This work proposes a fast and simple method for detection and quantification of phenolic compounds in P.D.O. Lambrusco wines using HPLC-DAD and chemometric techniques.
Samples belonging to three different varieties of Lambrusco (Grasparossa, Salamino and Sorbara) were analyzed to provide a methodology appropriate for routine analysis. Given the high complexity of the sample and the coelution among chromatographic peaks, the use of chemometric techniques to extract the information of the individual eluting compounds was needed. Multivariate Curve Resolution - Alternating Least Squares (MCR-ALS) allowed the
resolution of the chromatographic peaks obtained and the use of this information for the quantification of the phenolic analytes in the presence of interferences. Use of multiset analysis and local rank/selectivity information was proven to be crucial for the correct resolution and quantification of compounds. The quantitative data provided by MCR-ALS about the phenolictargets and additional compounds present in the samples analyzed provided wine composition profiles, which were afterwards used to distinguish among wine varieties. Principal ComponentAnalysis applied to the wine profiles allowed characterizing the wines according to their varieties.
2013
- Exploratory Data Analysis
[Capitolo/Saggio]
LI VIGNI, Mario; Durante, Caterina; Cocchi, Marina
abstract
In the Food research and production field, system complexity is increasing and several new challenges are emerging every day. This implies a urgent necessity to extract information and obtain models capable of inferring the underlying relationships that link all the variability sources which characterize food or its production process (e.g. compositional profile, processing conditions) to very general end-properties of foodstuff, such as the healthiness, the consumer perception, the link to a territory and the effect of the production chain itself on food.
This makes a “deductive”, theory-driven research approach inefficient, since it is often difficult to formulate hypotheses. Explorative Multivariate Data Analysis methods, together with the most recent analytical instrumentation, offer the possibility to come back to an “inductive” data-driven attitude with a minimum of a priori hypotheses, instead helping in formulating new ones from the direct observation of data.
The aim of this Chapter is to offer the reader an overview of the most significant tools which can be used in a preliminary, exploratory phase, ranging from the most classical descriptive statistics methods, to Multivariate Analysis methods, with particular attention to Projection methods. For all techniques, examples are given so that the main advantage of this techniques, that is a direct, graphical representation of data and their characteristics, can be immediately experienced by the reader.
2013
- Geographical traceability based on 87Sr/86Sr indicator: A first approach for PDO Lambrusco wines from Modena
[Articolo su rivista]
Durante, Caterina; Baschieri, Carlo; Bertacchini, Lucia; Cocchi, Marina; Sighinolfi, Simona; Silvestri, Michele; Marchetti, Andrea
abstract
The main goal of this study was to evaluate 87Sr/86Sr ratio in different matrices, namely soils, branches,
and grape juices, of an oenological food chain in order to develop a robust analytical strategy able to link
the investigated food to its territory of origin. The 87Sr/86Sr has been used as traceability marker and several
aspects, affected its variability, i.e. geological features of the investigated area, the bio-available fraction
of elements in the soils and the up-take of the plant, have been taken into account. Optimisation of
an analytical procedure for the separation of Sr from its interferences and investigation of the analytical
performances in terms of precision of used methodology have been carried out as well. This work highlighted
a good match between the isotopic values monitored in the bio-available fraction of soils and
their respective grape juices for almost all the investigated areas. The correlation with food satisfyingly
improves when isotopic relative abundance values of branches vine are considered.
2013
- Near infrared spectroscopy and multivariate analysis to evaluate wheat flour doughs leavening and bread properties
[Articolo su rivista]
LI VIGNI, Mario; COCCHI, Marina
abstract
A mixture design of experiment approach was followed to explore formulation effects on the technological properties of wheat flours optimized for industrial bread-making purposes. Ten different flour mixtures were investigated by means of near infrared spectroscopy (NIRS) to obtain information on flour performance in a critical phase such as dough leavening. For each mixture, a laboratory-scale bread making experiment was carried out according to a standardized recipe and the leavening phase of each dough sample was monitored by means of NIRS at different times. Parallel factor analysis (PARAFAC) was used to highlight the existence of differences among the mixtures on the basis of NIR spectrum variability with respect to the leavening time. Additionally, the relationship among the 3-way NIR dataset and some parameters measured on the baked bread loaves (dimensions, volume, weight) was investigated by means of the n-way extension of partial least squares regression (nPLS), in order to evaluate product properties from its leavening step and mixture formulation. The results give better insight on the relationships among wheat flour formulation and its performance in the leavening phase and as far as some properties of the final product are concerned, thus offering a way to monitor the leavening phase and give information on its influence on the final product properties.
2013
- RP-HPLC and Chemometrics for wheat flour protein characterization in an industrial bread-making process monitoring context
[Articolo su rivista]
LI VIGNI, Mario; Baschieri, Carlo; Marchetti, Andrea; Cocchi, Marina
abstract
In the baking industry, a difficult task is to keep the quality perceived by the consumer as constant as possible, given the inner variability of flour, e.g. due to different wheat mixtures, harvesting time, etc. Here, we evaluated the influence of flour batches properties on bread quality, considering an industrial bread making process. In particular, flour composition in terms of protein fractions (gliadins, glutenins) has been determined by means of RP-HPLC, to assess the inter- and intra-batch variability of flour mixtures deliveries at a baking plant. Multivariate data analysis allowed evaluation of correlation between flour protein composition and technological properties. A great variability within different deliveries of a same flour batch emerged, as well as a considerable seasonal variability. Correlation models among protein sub-fractions, technological properties and bread quality are difficult to establish; however, the role of the protein profile on flour behaviour in bread making could be highlighted.
2013
- Soils sampling planning in traceability studies by means of experimental design approaches
[Articolo su rivista]
Totaro, Sara; Coratza, Paola; Durante, Caterina; Foca, Giorgia; LI VIGNI, Mario; Marchetti, Andrea; Marchetti, Mauro; Cocchi, Marina
abstract
The present research is part of a project dealing with the development of analytical methodologies mainly based on primary indicators, such as isotopic ratio of radiogenic elements, for theauthenticity and geographical traceability of oenological food, typical of the Modena district. In particular, considering the objective of establishing a food-territory link by means of these analytical indicators, it is straightforward how the representativeness of sampling for both food and soils, covers a primary role in the robustness of the traceability models. With the aim of building traceability models for oenological matrices, the issue of selecting a set of representative, informative and different soil samples is tackled. In this case, the goal is not obtaining a set of soil samples uniformly spanning the territory to be investigated, since the planning of a punctual sampling extended in the whole district of Modena is not feasible considering the total number of samples affordable by the study, but rather to choose a representative set of vineyards were to locate the soil samples. Thus, all the vineyard-registered producers of the district of Modena were considered and different variables (geological features of the soils, winegrowing coverage, grapes varieties, yearly productions of the farms, etc.) were handled with Experimental Design (DoE) techniques in order to simultaneously taking into account the different kinds of information for achieving a sustainable and rational site sampling. In particular, D-Optimal Onion design was chosen since it is widely used for mapping and planning purposes, hence it consents to achieve the maximum coverage and uniformity of the selected samples in the whole domain. An efficient mapping of geographical region has been obtained ensuring coverage of farms characterized by main grape production and insisting on soils with different geological features.
2013
- TERROIR DIFFERENTIATION OF LAMBRUSCO PDO WINES BY STRONTIUM ISOTOPIC SIGNATURE
[Relazione in Atti di Convegno]
Baschieri, Carlo; Berni, Alex; Bertacchini, Lucia; Cocchi, Marina; Durante, Caterina; Vigni, M. Li; Manzini, Daniela; Marchetti, Andrea; Sighinolfi, Simona
abstract
The interest of consumers, as well as of producers, toward origin and quality of food has increased over the last years. As regards the oenological field, the quality of wine is in many cases related to the concept of terroir (history, geographical origin, typical raw materials and methods, ecc.). In this context, the assessment of the link between the territory of origin and the food product by means of analytical indicators represents a challenging target, useful for the valorization of the product itself. Among the different indicators used for geographical traceability studies, the 87Sr/86Sr isotopic ratio (Sr-I.R.), has provided excellent results for different types of food.
The present research is part of a project dealing with the development of authenticity and geographical traceability models of PDO Italian wines [1], with particular reference on Lambrusco wines, which are one of the main typical products of the Modena district. The possibility of obtaining reliable traceability models is mainly linked to the capability of monitoring the considered indicator in a representative set of investigated matrices: mainly soil and wines. Thanks to the collaboration with Consorzio Marchio Storico dei Lambruschi Modenesi, it has been possible to measure the Sr-I.R. on a statistically representative set of Lambrusco wines, commercially available and produced in 2010, 2011 and 2012. Furthermore, Sr-I.R. values of wines were compared with the Sr-isotopic ranges of Modena soils, with the aim to verify and establish a link with the respective territory of origin. The selection of representative, informative and different soil samples of the Modena district was accomplished in a previous work by means of Design of Experiment techniques, in order to ensure a sustainable and rational mapping of the investigated geographical area, taking into account properties related to geological features and production variables (grape varietals and produced quantities) [2]. Finally, the Sr-I.R. was also determined on vine branches, collected in proximity of each soil sampling point, since previous researches highlighted an improvement of the correlation with food and a better discriminating power, when considering branches instead of soil [3].
2013
- The impact of chemometrics on food traceability
[Capitolo/Saggio]
Bertacchini, Lucia; Cocchi, Marina; LI VIGNI, Mario; Marchetti, Andrea; Salvatore, Elisa; Sighinolfi, Simona; Silvestri, Michele; Durante, Caterina
abstract
In the last decades, mankind has become totally aware about the importance of food quality: nowadays authentication and traceability are words of general use.
Food authentication verifies how much a food is in accordance with its label description and law and it could be considered a further guarantee for the quality and safety of a foodstuff.
The traceability of food could be considered an essential element in ensuring safety and high quality of food. The synergistic use of instrumental analytical techniques and chemometrics represents a promising way to obtain trustworthy results in the development of authenticity and traceability models. This chapter deals with the potentialities of chemometrics tools in resolving some real issues related to food traceability and authenticity. Particular attention will be paid to the use of some exploratory, classification and discrimination techniques.
In the first part of this chapter, a briefly description of European regulations (Authenticity and Traceability: the European Union point of view), and traceability and authenticity markers (Authenticity and Traceability: a scientific point of view) is reported. The second part is split into two sections: namely Food Authenticity and Food Traceability applications, where the main features and advantages of some chemometrics approaches are presented.
2012
- Characterization of lambrusco wines by means of Sr isotope ratio as provenance marker
[Abstract in Rivista]
Baschieri, Carlo; Bertacchini, Lucia; Cocchi, Marina; Marchetti, Andrea; Durante, Caterina; Bertelli, Davide; Papotti, Giulia; Sighinolfi, Simona
abstract
Recently, geographical origin and authenticity of food are topics of great interest for consumers as well as for producers in the food industry. Furthermore, in the oenological field, these concepts are strictly tied with the quality of food. For different reasons, people are more focused towards food characterized by a well-established geographical origin. In the course of time, the symbiosis of
quality and the geographical origin of products is certainly related to ethics of the producers and the whole determines the reputation of the territory. The present research is part of a project dealing with the development of authenticity and geographical traceability models of Italian wines, with particular reference on Lambrusco wines, which are one of the main typical products of the Modena district. Among the different indicators used for traceability studies, 87Sr, and in particular the 87Sr/86Sr isotopic ratio (I.R.), has provided excellent results for different types of food matrices. Aim of this work is to obtain a reliable fingerprint for Lambrusco
wine on the basis of its 87Sr/86Sr isotopic value, linking it to its territory of provenance. Moreover, different analytical methods for the elimination of matrix interferences, before the Sr/Rb separation on resin, are also tested. In particular, the first method, widely used in literature, consists of the following step: i) ethanol elimination by means of HNO3 addition and ii) sample digestion through microwave assisted in acidic media. While, the second one merely consists in the addition of an aliquot of HNO3. Finally, as a preliminary study, wine samples were pre-treated according to the best procedure and 87Sr/86Sr measurements were accomplished
with an high resolution multicollector inductively coupled plasma mass spectrometry (HR-MC-ICP-MS). The isotopic data of wines were compared with the isotopic range of Modena soils, with the aim to determine a correlation between soil and food, obtaining promising results as far as the potentiality of 87Sr/86Sr as geographical tracer is concerned. To the authors’ knowledge, this is the first report developing an easy analytical methodology for the pretreatment of the studied matrix, obtaining high precision and accuracy measurements, in terms of repeatability, reproducibility and time variability of the monitored indicator.
2012
- Computational Insights into ADAMTS4, ADAMTS5 andMMP13 Inhibitor Selectivity
[Articolo su rivista]
FILOMIA, Federico; SAXENA, PUNEET; DURANTE, Caterina; DE RIENZO, Francesca; COCCHI, Marina; MENZIANI, Maria Cristina
abstract
The results obtained by means of Molecular Dynamicssimulations and Multiway Explorative Data Analysison ADAMTS4, ADAMTS5 and MMP13 complexed with Marimastatand two cis-1(S)2(R)-amino-2-indanol ligands suggestthat determinant characteristics for ligand binding andselectivity among the three enzymes are to be found in thedifferent protein conformation flexibility. Moreover, the role of the TS-domain in the inhibitor binding to ADAMTS enzymeshas been investigated for the first time in this work.The results obtained suggest that the influence of the TSdomainon the S1’ loop fluctuations of ADAMTS4 andADAMTS5 could be exploited for the design of therapeuticsfor chronic osteoarthritis diseases.
2012
- Evaluation of the behaviour of fluorine-containing bioactive glasses: reactivity in a simulated body fluid solution assistedby multivariate data analysis
[Articolo su rivista]
Cocchi, Marina; Durante, Caterina; Lusvardi, Gigliola; Malavasi, Gianluca; Menabue, Ledi
abstract
Potentially bioactive fluorine-containing glassesof formula 46.2SiO224.3Na2O(26.9-x)CaO2.6P2O5xCaF2 [x = (0), 5, 10, 15] have been studied: the study wascarried out as a function of fluorine percentage, dimensionsand time of soaking in SBF. The results are compared tothose obtained in the same conditions for Bioglass 45S5.Due to the high number and different kind of variables/conditions explored by this set of data, the results arerationalized for the first time by means of multivariate dataanalysis (MDA); in this way it is possible to classify thebehaviour of bioglasses toward bioactivity. The presence offluorine does not inhibit the formation of HA; in particular,for a fast bioactivity (in term of HA crystallization) it willbe better to have large particle size or slabs, while for a fastdissolution fine particle sizes should be preferred.
2012
- GENOCOP algorithm and hierarchical grid transformation for image warping of two dimensional gel eletrophoretic maps
[Articolo su rivista]
Emilio, Marengo; Cocchi, Marina; Marco, Demartini; Elisa, Robotti; Daniela, Cecconi; Giorgio, Calabrese
abstract
Hierarchical grid transformation is a powerful approach to SDS 2DPAGE maps warping. The hierarchy of the warping transformation is able to model both global and local deformations of the gels and the algorithm can be stopped when a certain degree of accuracy in the image alignment is obtained. The numerical optimization of the position of the nodes of the grid that are responsible for the image warping is a multivariate task that can be solved efficiently using Genetic Algorithms. The use of Genetic Algorithms ensures that an optimal position of the nodes can be defined with a low computational cost with respect to other methods. The optimal positions of the nodes of the grid can be successfully used for defining a good warping of the gels.
2012
- LF-1H-NMR AND MULTIVARIATE ANALYSIS TO STUDY OENOLOGICAL PRODUCTS UNDER AUTHENTICITY REGULATION
[Abstract in Atti di Convegno]
Elia, A.; LI VIGNI, Mario; Cocchi, Marina; Bro, R.
abstract
The safeguard of food products which undergo European Union authenticity regulations, such as "Protected Designation of Origin" (PDO) or “Protected Geographical Indication” (PGI), is nowadays of increasing relevance, since several EU resolutions have shown an unequivocal intention towards the valorisation of food and oenological products which are typical of a given region, with the twofold aim of defending the producers, who have to undergo stricter regulations so that their product can bear a mark which grants a higher added value, and the consumers, for which the same mark carries with it a concept of higher quality of the product which must correspond to the truth. In an analytical chemistry context, much attention is given to the development of methods of analysis which can characterize in a fast and cheap way the products, giving information on their quality and authenticity.
In the present study, Low-Field 1H Nuclear Magnetic Resonance Relaxometry (LF-1H-NMR) has been used to investigate a product which is typical of Modena (Italy) district, that is Aceto Balsamico Tradizionale di Modena (ABTM, Balsamic vinegar), which is appointed with the “Protected Designation of Origin” (PDO) mark. One of the main advantages of this technique, as reported in literature for food and beverage contexts, is the possibility of analysing the sample “as is” in few seconds and of acquiring insight on the relaxation behaviour. The results, interpreted with a Multivariate Analysis approach, allow a clear classification of products of different commercial classes and differentiation of succedaneum products, which can be of help in verifying the authenticity. In particular, both CPMG relaxation profile curves analysed as raw “fingerprint” signals and the transversal relaxation time T2 of the different components present in the samples obtained by means of the multi-way PowerSlicing approach can be used to elaborate SIMCA classification models which consistently distinguish the two main commercial classes and aging times of ABTM samples and correctly reject succedaneum products such as not PDO balsamic creams.
2012
- Modeling the Binding Affinity of p38a MAPKinase Inhibitors by Partial Least SquaresRegression
[Articolo su rivista]
Basant, Nikita; Durante, Caterina; Cocchi, Marina; Menziani, Maria Cristina
abstract
The p38 mitogen-activated protein kinase is activatedby environmental stress and cytokines andplays a role in transcriptional regulation andinflammatory responses. Factors influencing theactivity and selectivity of the p38a mitogen-activatedprotein kinase inhibitors have been investigatedin this paper by inspecting the bindingorientation and the possible residue-inhibitorinteractions in the binding site. The binding patternof a set of 45 different inhibitors against p38amitogen-activated protein kinase was studiedthrough Molecular Dynamic Simulations of theprotein-inhibitor complexes. Further, Partial LeastSquares regression was used to develop a QuantitativeStructure Activity Relationship model topredict the binding affinities of ligands. Theselected model successfully predicted the test setwith a Root Mean Square Error of Prediction of1.36. The regression coefficients and the VariableImportance in Projection plots highlighted the residue-inhibitor interactions which exhibited thelargest absolute effect on the ligand binding, suchas the van der Waals interaction with LYS50,ILE81, ASP165; electrostatic interactions withSER29, LEU164; hydrogen bonds with MET106;and total energy interaction with SER29 andLEU83.
2012
- NIR SPECTROSCOPY TO EXPLORE WATER STRUCTURE MODIFICATION INDUCED BY FILTRATION PROCESSES
[Relazione in Atti di Convegno]
Cocchi, Marina; Mario Li, Vigni; Stefania, Vero; Tiziana M. P., Cattaneo; Vittorio, Elia
abstract
Studies on very diluted solutions (i.e. containing solutes in concentration below 10-7 M) and pure water subjected to physical treatments have recently highlighted that the structure of water is still an open research field. Although it is well known that the formation of hydrogen bonds is responsible of the great part of peculiar properties of water, as its very high boiling point or its density variation with temperature, results, different from expected, obtained on extremely dilute solutions, perturbed by mechanical treatments and analyzed with calorimetric technique and the formation of nanoclusters obtained by evaporation at room temperature and atmospheric pressure of solutions of NaCl in concentration 10-7 M highlight that not all that concern water is yet clear.In the last years, Near InfraRed (NIR) spectroscopy has been applied to monitor changes in water structure induced by solutes and/or temperature variation with a so great success to suggest the creation of a new research field called Aquaphotomics. So, this technique seems to be the most accredited to approach the study the formation of nanostructures in water. The present study was focused on the study of variations induced by filtration process on pure water analyzed by chemometric analysis of NIR spectra corresponding to the different conditions. In fact, it has been observed that conductivity varies more than expected by sole natural contamination level of distilled water produced by its contact with the ambient atmosphere, and it may be ascribed to the formation of aqueous nanostructures. This hypothesis has been yet recently suggested by the Nobel Laureate Luc Montagnier to explain the effects observed on water undergone filtration and sterilization processes, and by Vittorio Elia who suggested the formation of dissipative structures.
2012
- Sistemi per la Tracciabilità, Autenticità e il Monitoraggio di Processo e Prodotto
[Spin Off]
Cocchi, Marina; Bertacchini, Lucia; Durante, Caterina; Favilla, Stefania; LI VIGNI, Mario; Silvestri, Michele
abstract
2012
- Use of X-Ray Diffraction Technique and Chemometrics to aid Soil Sampling strategies in traceability studies
[Articolo su rivista]
Bertacchini, Lucia; Durante, Caterina; Marchetti, Andrea; Sighinolfi, Simona; Silvestri, Michele; Cocchi, Marina
abstract
Aim of this work is to assess the potentialities of the X-ray powder diffraction technique as fingerprinting technique, i.e. as a preliminary tool to assess soil samples variability, in terms of geochemical features, in the context of food geographical traceability. A correct approach to sampling procedure is always a critical issue in scientific investigation. In particular, in food geographical traceability studies, where the cause–effect relations between the soil of origin and the final foodstuff is sought, a representative sampling of the territory under investigation is certainly an imperative. This research concerns a pilot study to investigate the field homogeneity with respect to both field extension and sampling depth, taking also into account the seasonal variability. Four Lambrusco production sites of the Modena district were considered. The X-Ray diffraction spectra, collected on the powder of each soil sample, were treated as fingerprint profiles to be deciphered by multivariate and multi-way data analysis, namely PCA and PARAFAC. The differentiation pattern observed in soil samples, as obtained by this fast and non-destructive analytical approach, well matches with the results obtained by characterization with other costly analytical techniques, such as ICP/MS, GFAAS, FAAS, etc. Thus, the proposed approach furnishes a rational basis to reduce the number of soil samples to be collected for further analytical characterization, i.e. metals content, isotopic ratio of radiogenic element, etc., while maintaining an exhaustive description of the investigated production areas.
2011
- A classification tool for N-way array based on SIMCA methodology
[Articolo su rivista]
Durante, Caterina; Rasmus, Bro; Cocchi, Marina
abstract
In the literature there are only fewpapers concerned with classification methods for multi-way arrays. The mostcommon procedure, by far, is to unfold the multi-way data array into an ordinary matrix and then to apply thetraditional multivariate tools for classification. As opposed to unfolding the data several possibilities exist forbuilding classification models more directly based on the multi-way structure of the data. As an example, multiwaypartial least squares discriminant analysis has been used as a supervised classification method, anotheralternative that has been investigated is to perform classification using Fisher's LDA or SIMCA on the score matrixfrom e.g. a PARAFAC or a Tucker model. Despite a few attempts of applying such multi-way classificationapproaches, no-one has looked into how such models are best built and implemented.In this work, the SIMCA method is extended to three-way arrays. Included in this work is also actual code thatwill work on general multi-way arrays rather than just three-way arrays. In analogy with two-way SIMCA, adecomposition model is separately built for the multi-way data for each class, using multi-way decompositionmethod such as PARAFAC or Tucker3. In the choice of the best class dimensionality, i.e. number of latent factors,both the results of cross-validation but mainly the sensitivity/specificity values are evaluated. In order toestimate the class limits for each class model, orthogonal and score distances are considered, and differentstatistics are implemented and tested to set confidence limits for these two parameters. Classificationperformance using different definitions of class boundaries and classification rules, including the use of crossvalidatedresiduals and scores is compared.The proposed N-SIMCA methodology and code, besides simulated data sets of varying dimensionality, has beentested on two case studies, concerning food authentication tasks for typical food products.
2011
- Evolution of 5-(hydroxymethyl)furfural and furfural in the production chain of the aged vinegar Aceto Balsamico Tradizionale di Modena
[Articolo su rivista]
Cocchi, Marina; Durante, Caterina; P., Lambertini; Manzini, Simona; Marchetti, Andrea; Sighinolfi, Simona; Totaro, Sara
abstract
The present investigation focuses on the monitoring of furfurals along the production chain of the agedvinegar Aceto Balsamico Tradizionale di Modena, from the starting raw material to the final product, inorder to control the quality and safety of this food. In particular, the aim of the study is to achieve a reductionin the furfurals content and, therefore, an optimised heating procedure for the starting grape juicewas proposed and compared to that which is currently adopted. 5-(Hydroxymethyl)furfural (HMF) andfurfural were determined by HPLC. Results show that the suggested heating procedure leads to a decreaseof furfurals in the cooked must. In addition, for comparison purposes, HMF and furfural were also measuredduring the ageing phase of the vinegar and in the final marketable products as well.
2011
- Investigation of the applicability of Zernike moments to the classification of SDS 2D-PAGE maps
[Articolo su rivista]
Marengo, E.; Cocchi, Marina; Demartini, M.; Robotti, E.; Bobba, M.; Righetti, P. G.
abstract
The aim of this work is to investigate theperformance of multivariate classification techniques likepartial least squares–discriminant analysis (PLS-DA) andlinear discriminant analysis (LDA) when using Zernikemoments as global image descriptors, in the classificationof sodium dodecyl sulphate (SDS) two-dimensionalpolyacrylamide gel electrophoresis (2D-PAGE) mapsaffected by different levels of deformation. Synthetic setsof images simulating real SDS 2D-PAGE maps wereanalysed in controlled conditions to obtain information onthe robustness and limits of applicability of the classificationtechniques operating on the basis of a given imagedecomposition method.
2011
- Monitoring Flour Performance in Bread Making
[Capitolo/Saggio]
LI VIGNI, Mario; Baschieri, Carlo; Foca, Giorgia; Marchetti, Andrea; Ulrici, Alessandro; Cocchi, Marina
abstract
A methodology to monitor flour performance in industrial bread-making based on evaluation of rheological and chemical properties of flour, as well as near infrared (NIR) spectra, is presented. The approach considers Multivariate Control Charts for both kinds of measurements, developed on flour batches employed in production. It can be adopted at the Millers laboratories, where rheological flours properties are routinely determined, to monitor flour quality; as well as, at the Bakeries plants, where NIR spectra of every flour batch entering the production can be acquired.Moreover, the variation of protein subunits in flour batches is discussed comparatively with flours properties and bread quality. Overall, flour batches leading to lousy performance can be individuated and they also show a non-optimal protein profile.This is of particular interest from the point of view of assessing flour workability and to rationalize it in terms of flour features. Finally, NIR potentiality allows considering on-line implementation in the control of incoming raw materials.
2011
- Optimization of a Dynamic Headspace – Thermal Desorption – Gas Chromatography/Mass Spectrometry procedure for the determination of furfurals in vinegars
[Articolo su rivista]
S., Manzini; Durante, Caterina; Baschieri, Carlo; Cocchi, Marina; Sighinolfi, Simona; S., Totaro; Marchetti, Andrea
abstract
The use of a Dynamic Headspace System (DHS) device combined with a Thermal Desorption Unit (TDU) interfaced to a Gas Chromatography/Mass Spectrometry (GC/MS) system is proposed for the determination of furfurals in oenological products. An experimental design protocol has been employed for the optimization of the instrumental settings concerning DHS and TDU extraction and desorption steps. It has been possible to individuate the following optimized conditions: incubation temperature 40 °C, purge volume 800 mL, dry volume 1500 mL, TDU hold time 5 min and incubation time 10 min. The performance of two different SPE sorbents, namely Tenax TA and Tenax GR used for the furfurals trapping, was investigated too. The developed DHS sampling procedure showed good reproducibility values with a RSD% lower than 10% for all the monitored species. The optimized experimental settings have been used to determine furfurals in several vinegar samples obtained by traditional procedure starting from cooked grape musts, i.e. in Aceto Balsamico Tradizionale di Modena (ABTM). In fact, the control of these species is extremely important for quality and safety issues.
2011
- Optimization of microwave assisted digestion procedure by means of chemometric tools
[Capitolo/Saggio]
Cocchi, Marina; Durante, Caterina; Marchetti, Andrea; LI VIGNI, Mario; Baschieri, Carlo; Bertacchini, Lucia; Sighinolfi, Simona; Tassi, Lorenzo; S., Totaro
abstract
The introduction of microwave (MW) heating devices inthe “chemical laboratory” represents one of the most important andrelevant application that contributes to speed up the “samplepreparation” step and, therefore, dramatically reduces the timeneeded for the analytical response. On the other hand, few andgeneric are the criteria developed to compare analytical dataobtained with conventional sample preparation approach withrespect to the MW one. In fact, when reference materials, RMs, arenot available, or not sufficiently representative of the real matrixunder investigation, it is often difficult to know when the sampledisgregation has come to completeness or if it is still possible tosave more time on the MW heating process. This contribute willdeal with the use of the more innovative Design of Experimentstools to the MW assisted digestion of organic rich matrices focusing on the potentialities of these experimental approaches when developing new disgregation analytical methods. The experimental approach concerns in finding the “optimum process conditions” in terms of solvent reaction mixture and recovery metal content.
2011
- Seeds of Horse Chestnut (Aesculus hippocastanum L.) and Their Possible Utilization for Human Consumption
[Capitolo/Saggio]
Foca, Giorgia; Ulrici, Alessandro; Cocchi, Marina; Durante, Caterina; LI VIGNI, Mario; Marchetti, Andrea; Sighinolfi, Simona; Tassi, Lorenzo
abstract
This chapter appraises the seeds of horse chestnuts (. Aesculus hippocastanum [AH]) and their derived products. Escin, the major bioactive principle in AH seeds, has shown satisfactory evidence of clinically significant activity in the treatment of chronic venous insufficiency, hemorrhoids, postoperative edema, and mammary induration. There is some evidence that various escin molecules, such as saponins and sapogenins, show beneficial effects when administered at the right concentration, exhibiting an ethanol absorption inhibitory effect and hypoglycemic activity in the oral glucose tolerance test in vivo. Horse chestnut extract has a higher antioxidant activity than vitamin E, showing one of the highest "active-oxygen" scavenging abilities compared to other natural products. β-Escin from AH extracts was also tested to evaluate the chemopreventive efficacy of its dietary intake on azoxymethane-induced colonic aberrant crypt foci. The main adverse effects of escins in humans are due to their hemolytic activity. Research efforts in this field are devoted to improving the selectivity for aberrant red corpuscles, promoting the β-escin fraction as a useful candidate agent for exploring new potential antileukemic drugs. Fresh or naturally desiccated seeds are usually treated by long leaching with water or wooden ashes to remove harshness and bitterness. These treatments cause a variation in the molecular structures of escin fractions, reducing the toxicity but maintaining their nutraceutical potential and anti-obesity effects. Alternatively, the slow roasting of nuts makes the escins harmless and the seeds edible. The claimed toxicity of these extracts makes them natural antibacterials, antimicrobials, antivirals, and antifungals, to some extent, that also act as environmentally biocompatible phytotherapeutics.
2010
- Molecular Dynamics Simulations of Sodium Silicate Glasses:Optimization and Limits of the Computational Procedure
[Articolo su rivista]
Pota, Marco; Pedone, Alfonso; Malavasi, Gianluca; Durante, Caterina; Cocchi, Marina; Menziani, Maria Cristina
abstract
The performance of the molecular dynamics (MD) simulations to obtain the structure of silica glasses containing different concentrations of alkali oxides has been tested. An optimal MD simulation procedure (including cooling cycle, MD constants and ensemble used) has been developed by means of experimental design methodologies (DOE), firstly restricting the study to the 30% Na2O silica glass for which experimental data are available to allow the comparison of the results. The optimization procedure led to simulations that well predict experimental density and short-range structure of glasses with different sodium content. On the contrary, the medium-range structure has been badly reproduced and it was not possible to determine a reliable correlation with the parameters of the simulation procedures used. Therefore, the correlation of medium-range properties with the structure has been studied by means of the PLS methods. The results showed to be useful to highlight the relationships among structural elements, such as radial distribution functions of specific bonds and angles, and Qn species, suggesting possible directions in order to improve the force field.
2010
- Towards a routine application of vibrational spectroscopy to the detection of bone fragments in feedingstuffs: Use and validation of a NIR scanning microscopy method
[Articolo su rivista]
D., Pavino; S., Squadrone; Cocchi, Marina; G., Martra; D., Marchis; M. C., Abete
abstract
The possibility to use NIR scanning microscopy for the detection of bone fragments in feedingstuffs has been evaluated analysing sediments derived from commercial feedingstuffs samples spiked with MBM. The method appeared sensitive enough to reveal the presence of bone fragments for MBM concentration in the feedingstuffs as low as 0.05 wt.%. The identification of MBM is done versus vegetable ingredients. The validation test, performed on a series of feedingstuffs spiked at a 0.1 wt.% MBM level (the detection limit reached by the official EU method based on optical microscopy), indicated that sensitivity (100%) and specificity (96.30%) of the investigated method are satisfactory for possible applications in screening procedure. NIR microscopy analyses turned out to be reliable and fast (including a minimal operational time for the analyst) with the additional possibility to obtain a map of the sediment, with indicated the positions of bone fragments, that then could be selectively re-analyzed by NIR spectroscopy for confirmation.
2010
- Wheat flour formulation by mixture design and multivariate study of its technological properties
[Articolo su rivista]
LI VIGNI, Mario; Durante, Caterina; Foca, Giorgia; Ulrici, Alessandro; Birthe Pontoppidan Møller, Jespersen; Rasmus, Bro; Cocchi, Marina
abstract
Wheat flour plays a pivotal role in determining the overall quality of bread (loaf dimensions, crumb texture and consistency). A precise knowledge of flour chemical and technological properties is of paramount importance for the baking industry, to tune the modifications of the recipe and production parameters. However, it is still common to have to deal with an empirical, trial and error-based approach, and generally, time consuming techniques are employed to determine the quality indexes for flour.In the context of an industrial bread-making process, this study addresses the evaluation of the effect of a systematic variation in the mixture composition of wheat flours on their properties. The main objective is to offer this field a more rigorous method to evaluate and improve flour properties, by employing experimental design methodologies and interpreting the results in a multivariate way, instead of the common one variable at a time approach. The results show that a careful planning of flour mixtures when testing new varieties and formulation helps to obtain meaningful and easy-to-understand results as far as their properties are concerned.
2009
- Application of signal processing and experimental design techniques for the minimisation of instrumental noise in the acquisition of FT-NIR spectra of bread wheat samples
[Relazione in Atti di Convegno]
Ulrici, Alessandro; Foca, Giorgia; N., Sinelli; M., Mariotti; LI VIGNI, Mario; Cocchi, Marina; P., Belloni
abstract
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2009
- Different Feature Selection Strategies in the Wavelet Domain applied to NIR-Based Quality Classification Models of Bread Wheat Flours
[Articolo su rivista]
Foca, Giorgia; Cocchi, Marina; LI VIGNI, Mario; R., Caramanico; M., Corbellini; Ulrici, Alessandro
abstract
The Synthetic Quality Index method (Indice Sintetico di Qualità, ISQ) is used in the Italian cereal trade context for the classification of bread wheat in different quality categories, and consists in the assignation by an expert assessor of each wheat sample to the most fitting class, on the basis of parameters reflecting chemical and rheological properties of the flour. The high uncertainty of this procedure has been recently proved by some of us using a panel test, which confirmed a quite large degree of subjectivity in the assignation of samples to the quality classes.However, the results obtained with the panel test allowed to identify samples whose class assignation is sufficiently univocal, to be used for the development of automated classification methods based on NIR spectra. In the present work, multivariate classification models have been calculated using the WPTER algorithm, which aims at selecting — among the wavelet coefficients derived by application of the Wavelet Packet Transform to the analysed NIR spectra — only those features leading to the best possible discrimination among the considered classes. In particular, WPTER has been used following three different strategies to choose the optimal conditions for the development of SIMCA class models. Due to the restricted number of objects, the statistical validity of the models has been evaluated using a newly developed algorithm, which performs a double cross-validation of the SIMCA models, and by comparison with the results obtained by permutation tests.
2009
- Discrimination of Healthy and Neoplastic Human Colon Tissues by ex Vivo HR-MAS NMR Spectroscopy and Chemometric Analyses
[Articolo su rivista]
V., Righi; Durante, Caterina; Cocchi, Marina; C., Calabrese; G., Di Febo; F., Lecce; A., Pisi; V., Tugnoli; Mucci, Adele; Schenetti, Luisa
abstract
The metabolic profile of human healthy and neoplastic colorectal tissues was obtained using ex vivo High-Resolution Magic Angle Spinning (HR-MAS) NMR spectroscopy. Principal Components Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) were applied to NMR data in order to highlight the biochemical differences between healthy and neoplastic colorectal tissues. The synergic combination of ex vivo HR-MAS NMR spectroscopy with Multivariate Data Analysis enables discrimination between healthy and tumoral colorectal tissues and identification of the increase of taurine, acetate, lactate, and lipids, and the decrease of polyols and sugars as tumoral characteristics. Moreover, it was found that macroscopically/histologically normal colorectal tissues, collected at least 15 cm from the adenocarcinoma, are characterized by a metabolic pattern quite similar to that typical of tumoral lesions.It was shown that ex vivo HR-MAS NMR spectroscopy, performed on intact specimens, may be of great potentiality in the clinical evaluation of human neoplastic colorectal tissues and that thebiochemical data represent the molecular basis for an accurate and noninvasive clinical applications of in vivo NMR spectroscopy.
2009
- Hyperspectral image analysis for bread characterization in the baking industry
[Relazione in Atti di Convegno]
LI VIGNI, Mario; J., Manuel Amigo; Ulrici, Alessandro; Foca, Giorgia; Cocchi, Marina; R., Bro; B. P., Møller Jespersen
abstract
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2009
- Mid and Near Infrared Spectroscopy to analyse surface defectiveness in bread
[Relazione in Atti di Convegno]
Foca, Giorgia; LI VIGNI, Mario; Ulrici, Alessandro; Cocchi, Marina
abstract
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2009
- Near Infrared Spectroscopy and Multivariate Analysis methods for monitoring flour performance in an industrial bread-making process
[Articolo su rivista]
LI VIGNI, Mario; Durante, Caterina; Foca, Giorgia; Marchetti, Andrea; Ulrici, Alessandro; Cocchi, Marina
abstract
The present study is aimed at evaluating the possibility to predict bread specifications, for an industrial bread-making process, on the basis of the properties of flour employed in production. The flour delivered at the production plant, of which rheological and chemical properties were available, were analysed by means of Near Infrared Spectroscopy (NIRS). Based on the flour properties and NIR signals, multivariate control charts were constructed in order to detect flour batches leading to a bread with non-optimal behaviour. The results show that it is possible to distinguish flour batches leading to a product with a particularly negative performance, by modelling the properties commonly measured on flours and the acquired Near Infrared signals. In spite of the absence of monitoring of process variables, which could have offered a more sound basis for the interpretation, especially when false positives and negatives are detected, these results are of particular interest from the point of view of raw material evaluation in process monitoring. Also, the potentiality of Near Infrared Spectroscopy allows considering this approach for an on-line implementation in the control of incoming raw materials in this industrial process.
2009
- Study of protein content of wheat flour in relation to technological properties using chromatography, NIRS and chemometrics
[Relazione in Atti di Convegno]
Baschieri, Carlo; LI VIGNI, Mario; Cocchi, Marina; Foca, Giorgia; Marchetti, Andrea; Ulrici, Alessandro
abstract
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2009
- Wheat Flour formulation by Mixture Design and study of its properties and performance
[Relazione in Atti di Convegno]
LI VIGNI, Mario; Cocchi, Marina; Durante, Caterina; Ulrici, Alessandro; Foca, Giorgia; R., Bro; B. P., Møller Jespersen
abstract
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2008
- At-line control of an industrial bread-making process
[Abstract in Atti di Convegno]
LI VIGNI, Mario; Brettagna, B; Cocchi, Marina; DE MARCO, T; Foca, Giorgia; Marchetti, Andrea; Ulrici, Alessandro
abstract
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2008
- At-line monitoring of the leavening process in industrial bread making by near infrared spectroscopy
[Articolo su rivista]
Ulrici, Alessandro; LI VIGNI, Mario; Durante, Caterina; Foca, Giorgia; P., Belloni; B., Brettagna; T., DE MARCO; Cocchi, Marina
abstract
The potential of near infrared (NIR) spectroscopy to characterise doughs for industrial bread making, directly at the production plant, was investigated. Different stages of dough processing have been monitored at-line, employing a Fourier transform-NIR instrument equipped with an optical fi bre. Parallel factors analysis has been used to study the spectral variation throughout the production line, with the aim of acquiring indications on the modifi cations the dough undergoes during the process. Moreover, wavelet interface for linear modelling analysis, which performs variable selection in the wavelet domain, has been employed to explore the possibility of monitoring the leavening step by identifying a relationship between the NIR signal and the leavening phase, considering the leavening time and the total titrable acidity of the dough. Results show that some aspects of the leavening process can be calibrated from the NIR spectra, thus corroborating the fact that the NIR signal is infl uenced by the modifi cations that occur along with the production process.
2008
- Changes in the Chemical Composition of Reduced Cooked Musts During the Heating Process
[Articolo su rivista]
Cocchi, Marina; R., Consonni; Manzini, Simona; Sighinolfi, Simona; M., Grandi; Durante, Caterina; Marchetti, Andrea
abstract
Cooked must is the starting raw material in Aceto Balsamico Tradizionale di Modena (ABTM) production, and the cooking process is a crucial step to ensure quality and safety standards. In particular, the furfural content has to be strictly monitored. In this study, we followed, directly at the production plant, nine cooking processes, differing for grape type and process conditions in order to monitor the actual variability in cooked must reduction. 5-Hydroxymethylfurfural (5-HMF) and furfural contents were determined by high performance liquid chromatography (HPLC) technique and glucose, fructose, and tartaric and malic acids by gas chromatography (GC) technique. Furthermore, some bulk properties, such as the water content, refractive index, density, and total acidity, were also measured. The obtained results show that the product undergoes, in the worse operating conditions, remarkable degradation, leading to extremely high levels of furfurals (5-HMF and furfural), corre- sponding to a water content lower than 40%. On the basis of these results, a first draft of an optimal heating protocol may be suggested in order to guarantee the safety and quality of the final product.
2008
- Controllo di un processo industriale di panificazione mediante NIRS ed analisi multivariata
[Abstract in Atti di Convegno]
LI VIGNI, Mario; Brettagna, B; Cocchi, Marina; DE MARCO, T; Foca, Giorgia; Marchetti, Andrea; Ulrici, Alessandro; Quaglia, L.
abstract
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2008
- Discrimination of healthy and neoplastic human colon tissues by ex vivo HR-MAS NMR spectroscopy and chemometric analyses
[Abstract in Atti di Convegno]
V., Righi; Durante, Caterina; Cocchi, Marina; C., Calabrese; V., Tugnoli; Mucci, Adele; Schenetti, Luisa
abstract
The metabolic profile of human healthy and neoplastic colorectal tissues was obtained using ex vivo High-Resolution Magic Angle Spinning (HR-MAS) NMR spectroscopy. Principal Components Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) were applied to NMR data in order to highlight the biochemical differences between healthy and neoplastic colorectal tissues.
2008
- Metabolic profiles of healthy and neoplastic human colorectal tissues studied by ex vivo HR-MAS MRS
[Relazione in Atti di Convegno]
V., Righi; Mucci, Adele; Schenetti, Luisa; C., Calabrese; Cocchi, Marina; Durante, Caterina; V., Tugnoli
abstract
The metabolic profile of human healthy and neoplastic colorectal tissues was obtained through ex vivo HR-MAS MRS and studied through chemometric analyses.
2008
- Metodi rapidi di valutazione qualitativa del frumento tenero
[Articolo su rivista]
Foca, Giorgia; Ulrici, Alessandro; M., Corbellini; R., Caramanico; M., Lucisano; M. A., Pagani; Cocchi, Marina; Tassi, Lorenzo; G., Boggini
abstract
SommarioNella classificazione di frumenti teneri mediante il metodo ISQ (Indice Sintetico di Qualità), un valutatore esperto classifica ogni campione di grano in diverse categorie qualitative, definite in base ad alcuni parametri chimici e reologici. Le analisi impiegate per la determinazione di tali parametri richiedono lunghi tempi di esecuzione e l’impiego di personale esperto, mentre durante le transazioni commerciali i prodotti devono essere caratterizzati in tempi molto brevi. Per questa ragione, è stato sviluppato un metodo veloce ed automatizzato per la classificazione del frumento, basato sull’accoppiamento della spettroscopia nel vicino infrarosso (NIR) con metodi di analisi multivariata dei dati.SummaryDuring the classification of bread wheats by means of the ISQ method (Synthetic Index of Quality), an expert assessor classifies each wheat sample in different quality categories, defined on the basis of some chemical and rheological parameters. The analyses involved in the determination of such parameters require long times of execution and the employing of skilled personnel, whereas, during the commercial transactions, the products need to be characterized in very short times. For this reason, we developed a fast and automated method of wheat classification based on the coupling of the Near InfraRed spectroscopy (NIR) and multivariate data analysis methods.
2008
- Mitochondrial DNA Haplogroups and Highly Active Antiretroviral Therapy–Related Lipodystrophy
[Articolo su rivista]
Nasi, Milena; Guaraldi, Giovanni; Gabriella, Orlando; Caterina, Durante; Pinti, Marcello; Elisa, Nemes; Nardini, Giulia; Giuseppe, Passarino; Cocchi, Marina; Esposito, Roberto; Mussini, Cristina; Cossarizza, Andrea
abstract
Background. The combination of different point mutations in mitochondrial DNA (mtDNA), which are defined as haplogroups, may cause modification in organelle function and may be involved in several pathologies. We analyzed the distribution of mtDNA polymorphisms in human immunodeficiency virus (HIV)–infected patients with lipodystrophy, a relevant adverse event caused by highly active antiretroviral therapy, and their correlation with metabolic and viroimmunologic parameters. Methods. The frequency of the 9 most common European haplogroups was investigated in 346 white, HIV- infected patients with lipodystrophy. Haplogroups were identified on the basis of classic methods. Statistical analysis was performed with use of 1-way analysis of variance, the x2 test, and principal-components analysis. Results. The distribution of mtDNA haplogroups among patients with lipodystrophy was similar to that among the general European population. We found no differences between patients with different haplogroups with regard to viroimmunologic results (plasma HIV load, CD4+ T cell count, and nadir CD4+ T cell count), glucose data (glucose, insulin, C-peptide, and glycosylated hemoglobin concentrations and insulin resistance), lipid data (levels of triglycerides, total cholesterol, high- and low-density lipoproteins, and apolipoprotein A1 and B), acid-base balance parameters (lactate level and anion gap), or anthropometric measures (weight, body mass index, and waist- to-hip ratio). No differences were observed in trunk fat levels, leg-fat ratio (which was determined by dual-energy X-ray absorptiometry), or exposure to different drug classes. Principal-components analysis confirmed that the spatial distribution of patients belonging to a given haplogroup was not influenced by different clinical parameters. Conclusions. Our study indicates that, in HIV-infected patients with lipodystrophy, mtDNA haplogroups are not related to major metabolic changes or to particular viroimmunologic features.
2008
- Multicomponent analysis in the wavelet domain of highly overlapped electrochemical signals: resolution of quaternary mixtures of chlorophenols using a peg-modified sonogel-carbon electrode
[Articolo su rivista]
J. M., PALACIOS SANTANDER; L. M., CUBILLANA AGUILERA; Cocchi, Marina; Ulrici, Alessandro; I., NARANJO RODRÍGUEZ; Seeber, Renato; J. L., HIDALGO HIDALGO DE CISNEROS
abstract
Chemometricmethods have been applied to resolve mixture of phenols; phenolic compounds are amongst themost interesting chemical species from an environmental viewpoint.However, the number of papers that applymultivariate calibration methods to resolve electroanalytical signals of mixture of phenols is low.In this paper, we propose a new chemometric methodology to resolve, in the wavelet domain, quaternary mixtures of chlorophenols: 4-chloro-3-methylphenol, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol, in a concentration range from 0.05 to 0.25 mg·L−1, using differential pulse adsorptive stripping voltammetry (DPAdSV) as the electrochemical technique, and a new polyethylenglycol-modified Sonogel–Carbon electrode.The results obtained after applying a FastWavelet Transform (FWT)-based feature selection algorithm, coupled with different multivariate calibration methods (multilinear regression-MLR and partial least squares regression-PLS) are compared with those obtained from a direct PLS. Besides, an Orthogonal Signal Correction (OSC)-based Calibration Transfer procedure (OSC-CT) is also applied, as a pre-processing tool, in order to improve the results obtained with the previous techniques.
2008
- Multivariate analysis of analytical signals to decipher relevant chemical information
[Capitolo/Saggio]
Ulrici, Alessandro; Cocchi, Marina; Durante, Caterina; Foca, Giorgia; Marchetti, Andrea; Tassi, Lorenzo
abstract
Two main elements have recently characterized the research in the analytical field: on one hand the huge development of instrumental analysis in the direction of hyphenated techniques and, on the other hand, the huge development and decreasing cost of computers together with the increased capacity of computational tools. Moreover, new issues are presented to the analytical researcher by new regulations that impose to demonstrate that the whole process is under control, e.g. in the industrial/productive context, or in the life science context by the emerging need of systems biology. Thus, the role of chemometrics is more and more increasing and the toolbox of chemometrics-like methods has been progressively enriched.In particular, deciphering signal-fingerprinting of complex matrix samples requires a deeper consideration on the nature of signals feature, and it has to be taken into account that the information pertinent to the problem is mixed with many uninformative sources of variations that may affect part or the whole signal domain. These issues from the data analysis point of view are reflected in a greater complexity of the preprocessing/pretreatment and variable selection steps.The main focus of this chapter will be on feature selection methodology; after a concise review of the main recently proposed feature selection methods, the specific case of feature selection in the wavelet (WT) domain will then be considered. In particular, it will deal with illustration of our recent developed tools for WT-feature selection in regression and classification tasks. The discussion of different applications will be the core of the work, to illustrate the effectiveness of the integration of both basic (simple) and more advanced methodologies together, with a complete strategy embracing data exploration, modelling, data display-interpretation and validation.
2008
- Neoplasms of the gastro-intestinal tract characterized by HR-MAS NMR
[Abstract in Atti di Convegno]
Mucci, Adele; V., Righi; C., Calabrese; Cocchi, Marina; Durante, Caterina; V., Tugnoli; Schenetti, Luisa
abstract
The results of our studies (HR-MAS NMR and statistical analysis) on healthy stomach and colon mucosa, and on gastric and colon adenocarcinomas are presented.
2008
- Three-way principal component analysis of the volatile fraction by HS-SPME/GC of aceto balsamico tradizionale of modena
[Articolo su rivista]
Cocchi, Marina; Durante, Caterina; Grandi, Margherita; Manzini, Daniela; Marchetti, A.
abstract
The present research is aimed at monitoring the evolution of the volatile organic compounds of different samples of Aceto Balsamico Tradizionale of Modena (ABTM) during ageing. The flavouring compounds, headspace fraction, of the vinegars of fourbatterie were sampled by Solid Phase Micro Extraction technique (SPME), and successively analysed by gas chromatography. Obtaining a data set characterized by different sources ofvariability such as, different producers, samples of different age and chromatographic profile. The gas chromatographic signals were processed by a three-way data analysis method (Tucker3), which allows an easy visualisation of the data by furnishing a distinct set of graphs for each source of variability.The obtained results indicate that the samples can be separated according to their age highlighting the chemical constituents, which play a major role for their differentiation. The present study represents an example of how the application of Tucker3 models, on Gas Chromatographic signals may help to follow the transformation processes of food products.
2007
- Caratterizzazione spettroscopica e tecnologica di miscele gluten-free formulate mediante disegno sperimentale
[Relazione in Atti di Convegno]
Ulrici, Alessandro; Foca, Giorgia; Cocchi, Marina; LI VIGNI, Mario; PAGANI M., A; Lucisano, M.
abstract
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2007
- Characterisation and optimisation of gluten-free formulations by multivariate analysis of technological parameters and nir spectra collected on d-optimal designed mixtures
[Relazione in Atti di Convegno]
Foca, Giorgia; Ulrici, Alessandro; Cocchi, Marina; PAGANI M., A; Lucisano, M.
abstract
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2007
- Characterization and discrimination of different aged 'Aceto Balsamico Tradizionale di Modena' products by Head Space mass spectrometry and Chemometrics
[Articolo su rivista]
Cocchi, Marina; Durante, Caterina; Marchetti, Andrea; C., Armanino; M., Casale
abstract
This work can be seen as an attempt to develop an analytical procedure in the context of quality control and authenticity assessment of typical food. To this aim, head-space mass spectrometry (HS-MS) coupled with multivariate data analysis, is proposed as a fast technique for furnishing a clear visualization and a suitable interpretation of the ageing process of ‘Aceto Balsamico Tradizionale di Modena’ (ABTM) and, for classifying products of different age. Considering the complexity of this food matrix, due to its traditional making procedure, the obtained instrumental data have first been analysed by parallel factor analysis (PARAFAC), an extension of principal component analysis to higher order arrays, in order to visualise the ‘natural’ grouping of vinegar samples and to inspect producers similarity/dissimilarity. On the basis of the PARAFAC results a reasonable class partition with respect to ageing was accomplished and both linear discriminant analysis (LDA) and soft independent modelling of class analogy (SIMCA) were applied as classification tools. Furthermore, it has been shown that discrimination on age basis can be improved by using feature selection in the wavelet domain through WPTER algorithm.
2007
- Chemical composition and characterisation of seeds from two varieties (pure and hybrid) of Aesculus hippocastanum
[Articolo su rivista]
Baraldi, Cecilia; Bodecchi, Lidia Maria; Cocchi, Marina; Durante, Caterina; Ferrari, Giorgia; Foca, Giorgia; Grandi, Margherita; Marchetti, Andrea; Tassi, Lorenzo; Ulrici, Alessandro
abstract
Investigations have been conducted on some samples of naturally desiccated horse-chestnuts (Aesculus hippocastanum), representativeof the two most common mediterranean varieties: the pure species (AHP, giving white flowers), and a hybrid (AHH, giving pink flowers).Different experimental techniques have been used to gain more information on morphological structure and chemical composition ofthese complex matrices. Surface analysis by SEM showed no differences in such floured samples (wild type), while thermal behaviour(DSC) outlines some significant differences between them. Chemical composition reveals some differences in residual moisture(AHP = 6.97%; AHH = 6.59%), proteins (AHP = 2.64%; AHH = 1.82%), lipids (AHP = 4.13%; AHH = 5.10%), glucides (AHP =15.2%; AHH = 14.3%), and ashes (AHP = 2.51%; AHH = 2.19%). Most likely, these characters modulate other undifferentiated chemicalparameters, such as cold water solubility (CWS:AHP = 53.9%; AHH = 48.6%), and total inorganic soluble salts (TISS:AHP = 2.18%; AHH = 1.92%). Principal component analysis was applied to differentiate the two horse-chestnuts varieties. In particular,the first principal component effectively distinguish and discriminates AHH and AHP samples in two well-separated categories, giving, atthe same time, some information on the influence of the whole set of chemical compositional parameters.
2007
- Determinazione di acidi e zuccheri presenti negli impasti per la produzione industriale di pane a diversi stadi della lavorazione
[Relazione in Atti di Convegno]
Cocchi, Marina; Foca, Giorgia; LI VIGNI, Mario; Marchetti, Andrea; Tassi, Lorenzo; Ulrici, Alessandro
abstract
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2007
- Efficient variables selection in multivariate analysis of signals by coupling fast wavelet transform and genetic algorithms
[Relazione in Atti di Convegno]
Cocchi, Marina; Durante, Caterina; Foca, Giorgia; LI VIGNI, Mario; Leardi, R; Ulrici, Alessandro
abstract
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2007
- Elaboration and Application of Algorithms Performing Feature Selection in the Wavelet Domain for Analysis of NIR based data
[Relazione in Atti di Convegno]
Cocchi, Marina; Durante, Caterina; LI VIGNI, Mario; Foca, Giorgia; Ulrici, Alessandro
abstract
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2007
- End-use classification of wheat flours after feature selection on NIR spectra
[Relazione in Atti di Convegno]
Foca, Giorgia; Ulrici, Alessandro; Cocchi, Marina; Corbellini, M; Tassi, Lorenzo
abstract
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2007
- HR-MAS NMR e analisi multivariata di neoplasie umane colo-rettali
[Abstract in Atti di Convegno]
V., Righi; Durante, Caterina; Cocchi, Marina; V., Tugnoli; Mucci, Adele; Schenetti, Luisa
abstract
E' riportato uno studio basato sull'applicazione dell'HR-MAS NMR e dell'analisi multivariata a neoplasie umane colo-rettali.
2007
- Monitoraggio multivariato di un processo industriale di panificazione
[Relazione in Atti di Convegno]
Belloni, P; Brettagna, B; Cocchi, Marina; DE MARCO, T; Foca, Giorgia; LI VIGNI, Mario; Marchetti, Andrea; Ulrici, Alessandro
abstract
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2007
- Monitoring an industrial bread making process by means of Near Infrared Spectroscopy and chemometric methods
[Relazione in Atti di Convegno]
P., Belloni; B., Brettagna; Cocchi, Marina; T., De Marco; Durante, Caterina; Foca, Giorgia; LI VIGNI, Mario; Marchetti, Andrea; Ulrici, Alessandro
abstract
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2007
- Monitoring of the leavening process in industrial bread making
[Relazione in Atti di Convegno]
Belloni, P; Brettagna, B; Cocchi, Marina; DE MARCO, T; Foca, Giorgia; LI VIGNI, Mario; Marchetti, Andrea; Ulrici, Alessandro
abstract
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2007
- Multivariate analysis of NIR spectra collected on D-optimal designed gluten-free doughs
[Relazione in Atti di Convegno]
Ulrici, Alessandro; Foca, Giorgia; Cocchi, Marina; PAGANI M., A; Lucisano, M.
abstract
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2007
- Study of the monosaccharides and furfurals evolution during the preparation of cooked grape musts for Aceto Balsamico Tradizionale production
[Articolo su rivista]
Cocchi, Marina; G., Ferrari; Manzini, Daniela; Marchetti, Andrea; Sighinolfi, Simona
abstract
Cooked must is the starting raw material used to produce Aceto Balsamico Tradizionale (ABT). It is obtained from grape musts that are condensed by a gentle simmering in uncovered pans over an open fire. Concentrations of fructose, glucose, furfural and 5-Hydroxymethylfurfural (HMF) during must preparation were evaluated as quality indicator of the final product. High pressure liquid chromatography (HPLC) technique was used for the determination of the analytes content in cooked musts sampled at different time during their preparation. Two varieties of grapes (Trebbiano Montanaro and Salamino), and different cooking apparatus were tested by using vats with different surface/volume ratio. The concentrations of the analytical species were found to be dependent on both the kind of grape and the cooking technology. Sugars concentration increases during cooking following almost a linear trend; on the contrary, furfural compounds, produced by monosaccharides degradation, significantly increase with an exponential trend only in the final step of the process. The analytical method gives good recovery values for all the investigated species, ranging from 91% to 104 %. (c) 2006 Elsevier Ltd. All rights reserved.
2007
- Subject classification obtained by cluster analysis and principal component analysis applied to flow cytometric data
[Articolo su rivista]
Lugli, Enrico; Pinti, Marcello; Nasi, Milena; Troiano, Leonarda; Ferraresi, Roberta; Mussi, Chiara; Salvioli, Gianfranco; Patsekin, V; Robinson, Jp; Durante, Caterina; Cocchi, Marina; Cossarizza, Andrea
abstract
BACKGROUND: Polychromatic flow cytometry (PFC) allows the simultaneous determination of multiple antigens in the same cell, resulting in the generation of a high number of subsets. As a consequence, data analysis is the main difficulty with this technology. Here we show the use of cluster analysis (CA) and principal component analyses (PCA) to simplify multicolor data visualization and to allow subjects' classification. METHODS: By eight-colour cytofluorimetric analysis, we investigated the T cell compartment in donors of different age (young, middle-aged, and centenarians). T cell subsets were identified by combining positive and negative expression of antigens. The resulting data set was organized into a matrix and subjected to CA and PCA. RESULTS: CA clustered people of different ages on the basis of cytofluorimetric profile. PCA of the cellular subsets identified centenarians within a different cluster from young donors, while middle-aged donors were scattered between these groups. These approaches identified T cell phenotypes that changed with increasing age. In young donors, memory T cell subsets tended to be CD127+ and CD95- whereas CD127-, CD95+ phenotypes were found at higher frequencies in people with advanced age. CONCLUSIONS: Our data suggest the use of bioinformatic approaches to analyze large data-sets generated by PFC and to obtain the rapid identification of key populations that best characterize a group of subjects. (c) 2007 International Society for Analytical Cytology.
2006
- Analysis of Sensory data of Aceto Balsamico Tradizionale di Modena (ABTM) of different ageing by application of PARAFAC models.
[Articolo su rivista]
Cocchi, Marina; R., Bro; Durante, Caterina; Manzini, Daniela; Marchetti, Andrea; F., Saccani; Sighinolfi, Simona; Ulrici, Alessandro
abstract
Aceto Balsamico Tradizionale di Modena is a typical Italian food product of protected denomination of origin, obtained by alco- holic fermentation and acetic bio-oxidation of cooked musts, and it is aged for at least 12 years in series of wooden casks. The prod- uct suitable for marketing is qualified by sensory examination on the whole of 13 sensory parameters. In this study, a series of six casks for each of seven different producers have been investigated by an expert Panel of eight judges, aiming at (i) assessing the degree of variability of the different sensorial attributes with samples ageing, and (ii) evaluating the sim- ilarity/dissimilarity among the various parameters together with the degree of agreement of the panellists. Given the three-way nature of the data (samples · panellists · sensory attributes) the PARAFAC method has been used, and a satisfactory model was obtained, highlighting the efficacy of three-way analysis in dealing with the different sources of data variabil- ity, extracting the relevant information and displaying it in a simple and interpretable manner.
2006
- Application of N-PLS to gas chromatographic and sensory data of traditional balsamic vinegars of modena
[Articolo su rivista]
Durante, Caterina; Cocchi, Marina; M., Grandi; Marchetti, Andrea; R., Bro
abstract
The application of multi-way models in food analysis as in many other research fields is rapidly increasing, above all because it can significantly help to improve visualization and interpretation of complex multivariate data characterized by different sources of variability. Furthermore, in food authentication tasks a fingerprinting strategy is frequently applied which requires the direct analysis of complex instrumental data, often obtained by hyphenated analytical techniques, which lead to multi-way data. In this work, the main features and advantages of multi-way regression are presented through the study of the evolution of the sensory and compositional profile during the ageing process of Aceto Balsamico Tradizionale di Modena (ABTM), a typical Italian food product, which represents a very interesting benchmark for testing new analytical methodologies due to its long ageing process and the peculiarity of the traditional making procedure. A series of 6 casks for each of 6 different producers has been characterized through sensory and instrumental analysis of the volatile fraction by head space-solid phase micro extraction/gas chromatography (HS-SPME/GC). The N-PLS method has been used as regression method since many sources of variability have to be taken into account, e.g. different cask series, different samples ageing, different panelists, etc. The validity of this choice is evaluated by comparing with results obtained from unfold-PLS method. Satisfactory regression models were obtained, highlighting the efficiency of the three-way model, which was shown to be more robust and interpretable.
2006
- Applicazione di algoritmi per la selezione di variabili nell’analisi di spettri NIR di prodotti alimentari
[Relazione in Atti di Convegno]
Cocchi, Marina; Ulrici, Alessandro; Foca, Giorgia; Durante, Caterina
abstract
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2006
- Classificazione chemiometrica di spettri NIR di frammenti ossei di specie animali diverse
[Relazione in Atti di Convegno]
Cocchi, Marina; Pavino, D; Ulrici, Alessandro; Foca, Giorgia; Durante, Caterina; Martra, G; Abete, M. C.
abstract
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2006
- Classificazione multivariata sulla base di spettri NIR dei risultati di un panel test per il riconoscimento della classe qualitativa del grano tenero
[Relazione in Atti di Convegno]
Ulrici, Alessandro; Foca, Giorgia; Cocchi, Marina; Corbellini, M; Franchini, Giancarlo; Tassi, Lorenzo
abstract
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2006
- Controllo at-line di impasti per la produzione industriale di pane mediante tecniche analitiche e chemiometriche
[Relazione in Atti di Convegno]
Foca, Giorgia; Ulrici, Alessandro; Cocchi, Marina; Marchetti, Andrea; LI VIGNI, Mario
abstract
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2006
- Durum wheat adulteration detection by NIR spectroscopy multivariate calibration
[Articolo su rivista]
Cocchi, Marina; Durante, Caterina; Foca, Giorgia; Marchetti, Andrea; Tassi, Lorenzo; Ulrici, Alessandro
abstract
In the present work, we explored the possibility of using near-infrared spectroscopy in order to quantify the degree of adulteration of durum wheat flour with common bread wheat flour. The multivariate calibration techniques adopted to this aim were PLS and a wavelet-based calibration algorithm, recently developed by some of us, called WILMA. Both techniques provided satisfactory results, the percentage of adulterant present in the samples being quantified with an uncertainty lower than that associated to the Italian official method. In particular the WILMA algorithm, by performing feature selection, allowed the signal pretreatment to be avoided and obtaining more parsimonious models.
2006
- Elaboration and Application of Algorithms Performing Feature Selection in the Wavelet Domain
[Relazione in Atti di Convegno]
Ulrici, Alessandro; Cocchi, Marina; Foca, Giorgia
abstract
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2006
- Feature selection e classificazione multivariata nel dominio wavelet per la classificazione di spettri NIR di grani di diversa qualità
[Relazione in Atti di Convegno]
Foca, Giorgia; Ulrici, Alessandro; Cocchi, Marina
abstract
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2006
- Modulation of CD38 expression in human longevity: A flow cytometric study
[Abstract in Atti di Convegno]
Lugli, Enrico; Pinti, Marcello; Troiano, Leonarda; Nasi, Milena; Ferraresi, Roberta; Roat, Erika; Durante, Caterina; Cocchi, Marina; Cossarizza, Andrea
abstract
The dynamics of CD38 expression innewborns and young healthy donors hasbeen widely investigated for many years.However, little is known about the modulationof this marker during humanageing. We analyzed the changes inCD38 expression in peripheral bloodlymphocytes (PBL) from subjects whowere centenarians. For this purpose weused polychromatic flow cytometry, apowerful technology that allows the determinationof multiple antigens (in ourcase, up to 8) present in the same cell.Among the subsets within CD4+ andCD8+ T cell populations identified bythis approach, we investigated the expressionof CD38 together with markersrelated to extrathymic T cell differentiation(CD45RA and CCR7), T cell survival(CD127/IL-7rα) and activation/apoptosis(CD95). The groups analysed includedyoung donors (21±2 years old),middle-aged individuals (60±1.5 yearsold) and centenarians.By automatic boolean gating, we identifiedall the possible subsets obtained bythe combination of positive and negativeexpression for each marker indicatedabove. Moreover, we could distinguish betweendim or bright expression of CD38.CD38 expressed by CD4+ T cells doesnot show significant modifications in thethree samples either in of the virgin ormemory subsets.A slight increase in CD38 expressionwas found in PBL CD8+ T cells from centenarians.These CD8+/38dim T cells displayeda CD45RA-/CCR7+ central memoryor CD45RA-/CCR7- effector memoryphenotype. Further, CD38 expressionwas associated with the presence ofCD95 and the absence of CD127/IL-7rα.These results were also confirmed byCluster Analysis (CA) and PrincipalComponent Analysis (PCA) of the highnumber of T cell populations identifiedby flow cytometry. These bioinformatictechniques cluster the individuals accordingto the flow cytometric profile,which confirmed that the subsets with anincreased expression of CD38 (CD38bright) are more frequent in the sampleof centenarians.In conclusion, our data indicate amodulation of CD38 expression in CD8+T cells during human ageing. In particular,the preferential coexpression of thisantigen with CD95 but not CD127/IL-7r_suggests an age-dependent acquisition ofan effector phenotype of CD8+ T cellswhich could, at least in part, explain thechronic pro-inflammatory status presentin centenarians.
2006
- Monitoraggio at-line del processo di lievitazione di impasti per la produzione industriale di pane
[Relazione in Atti di Convegno]
Ulrici, Alessandro; Cocchi, Marina; Marchetti, Andrea; Foca, Giorgia; Durante, Caterina; DE MARCO, T; Brettagna, B; Belloni, P.
abstract
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2006
- Simultaneous determination of sugars and organic acids in aged vinegars and chemometric data analysis
[Articolo su rivista]
Cocchi, Marina; Durante, Caterina; M., Grandi; P., Lambertini; Manzini, Daniela; Marchetti, Andrea
abstract
Aceto Balsamico Tradizionale of Modena (ABTM) is a typical product (PDO denomination) of the province of Modena produced by cooked grape must which undergoes a long ageing period (at least 12 years) in series of wooden casks (batterie). The study of the transformations of this product during ageing is extremely relevant in order to control the authenticity of ABTM towards succedaneous products and mislabelling of age. This paper presents the results of the investigation of sugars and fixed organic acids in ABTM samples of different ages, coming from different batterie. The analytes were simultaneously determined by a gas chromatographic method optimised for this peculiar matrix. The method shows good separation and resolution of the investigated chemical species and allows their determination in the concentration ranges reported in brackets: malic (7.6-15.5 g kg(-1)), tartaric (4.0-9.7 g kg(-1)), citric (0.6-1.5 g kg(-1)) and succinic (0.36-0.62 g kg(-1)) acid and glucose (153-294g kg(-1)), fructose (131-279g kg(-1)), xylose (011-0.39g kg(-1)), ribose (0.078-0.429g kg(-1)), rhamnose (0.061-0.195g kg(-1)), galactose (0.136-0.388g kg(-1)), mannose (0.41-1.46g kg(-1)), arabinose (0.33-1.00g kg(-1)) and sucrose (0.46-6.84g kg(-1)), with mean associated errors ranging from 5 to 19% depending on the analytes. Moreover, the recovery values are always satisfactory, being close to one for most of the analytes. Furthermore, in order to assess the degree of variability of the different analytes content with vinegar ageing and the similarity/dissimilarity among series of casks a three-way data analysis method (Tucker3) is proposed. The chemometric technique applied on the data set shows differences between the samples on the bases of their different ageing period, and between the batterie, which traditionally have an own peculiar production procedure.
2006
- Study of the dependence on temperature and composition of the volumic properties of ethane-1,2-diol+2-methoxyethanol+1,2-dimethoxyethane plus water solvent system and graphical representation in the quaternary domain
[Articolo su rivista]
Ulrici, Alessandro; Cocchi, Marina; Foca, Giorgia; M., Manfredini; Marchetti, Andrea; D., Manzini; Tassi, Lorenzo; S., Sighinolfi
abstract
In this paper, the temperature and composition dependencies of the volumetric behavior are studied for the ethane-1,2-diol + 2-methoxyethanol + 1,2-dimethoxyethane + water quaternary system. Density data were collected at different temperatures ranging from -10 to 80 degrees C and at atmospheric pressure over the whole composition range, 0 :5 x(i)(i = 1, 2, 3,4) <= 1. Moreover, we also made use of the results on the six binary (ij) and four ternary (kij) subsystems studied previously. The excess molar volume (V-E) data have been fitted to an equation derived from the well-known Redlich-Kister equation and some interesting correlations were found. Furthermore, in order to represent in an effective way the behavior of the V-E = V-E(x(i)) function (and of the derived partial molar quantities) in the quaternary domain, a new algorithm has been developed, which gives 3D plots where the dependent function is depicted by means of '' colored slices '' of the tetrahedron corresponding to the investigated composition quaternary domain.
2005
- Application of Gas-Cromatography for the characterization of Traditional Balsamic Vinegar
[Abstract in Atti di Convegno]
Manzini, Daniela; Ulrici, Alessandro; Franchini, Giancarlo; Masino, Francesca; Antonelli, Andrea; Cocchi, Marina
abstract
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2005
- Application of NIR spectroscopy and Principal Component Analysis on the monitoring of PVC industrial process for biomedical application
[Relazione in Atti di Convegno]
Bodecchi, Lidia Maria; Cocchi, M.; Manfredini, Matteo; Marchetti, Andrea
abstract
Application of NIR spectroscopy and Principal Component Analysis on the monitoring of PVC industrial process for biomedical application.
2005
- Application of infrared spectroscopy and multivariate quality-control methods in PVC manufacturing
[Articolo su rivista]
M., Manfredini; Cocchi, Marina; Lm, Bodecchi; G., Ferrari; Marchetti, Andrea; M., Malagoli; F., Galavotti
abstract
This work aims at exploring the potentiality of the Fourier transform IR spectroscopy (FTIR) to study the effects that can be generated on plastic materials based on poly(vinyl chloride) (PVC) used for extra-corporal medical disposables, after industrial processes such as extrusion, sterilization and conservation. In particular, FTIR equipped with a single attenuated total reflection accessory (ATR) mounted on an infrared microscope (Mic-IR) has been used. At the same time, this paper proposes a quality-control method for semi-finished blood circuits´ components, based on the chemometric evaluation of surface-selective spectroscopic signals, i.e. Mic-IR/ATR spectra. Results suggest that IR spectroscopic technique coupled with a multivariate approach might represent a simple and powerful method for quality control of industrial processes.
2005
- Application of multy-way analysis to the study of food products
[Relazione in Atti di Convegno]
Cocchi, Marina; Durante, Caterina; Grandi, Margherita; Manzini, Daniela; Marchetti, Andrea; BRO JORGENSEN, Rasmus
abstract
Application of Multy-Way Analysis to the Study of Food Products.
2005
- Classification of bread wheat flours in different quality categories by a wavelet-based feature selection/classification algorithm on NIR spectra
[Articolo su rivista]
Cocchi, Marina; M., Corbellini; Foca, Giorgia; M., Lucisano; Ma, Pagani; Tassi, Lorenzo; Ulrici, Alessandro
abstract
In the Italian context, bread wheat flour is commercially classified in different quality categories on the basis of a Synthetic Index of Quality (Indice Sintetico di Qualit, ISQ), which is defined by means of specific parameters, i.e., hectolitric weight, falling number, protein content, alveographic indexes (W, P/L) and farinograph stability. The analyses involved in the determination of these parameters are expensive, time consuming and require specialized personnel, thus there is concern to develop alternative methods to be applied during the commercial transactions, when the products need to be characterized in very short times. For this reason, a fast technique such as an automated classification on the basis of NIR spectra acquired on the wheat flour samples could be a very useful tool. In this work, various wheat flour samples belonging to four different ISQ classes have been analysed by means of NIR spectroscopy, and the obtained spectra have been classified both by SIMCA applied to the signals subjected to different pretreatment methods, and by using a wavelet-based feature selection/classification algorithm, called WPTER. Due to the high overlap of the two intermediate quality classes, it was not possible to classify all the data set signals. However, when considering only the two extreme categories, an acceptable degree of class separation can be gained after feature selection by WPTER. Moreover, this approach allowed us to locate the NIR spectral regions that are mainly involved in the assignment of the wheat flour samples to these two quality categories.
2005
- Determination of metal concentration in fat supplements for swine nutrition by atomic absorption spectroscopy
[Articolo su rivista]
Cocchi, Marina; V., Faeti; M., Manfredini; Manzini, Daniela; Marchetti, Andrea; Sighinolfi, Simona
abstract
The presence of some essential and toxic metals in fat supplements for swine diet was investigated. Collected samples represented a relevant production of the Italian industry. In particular, some samples were enriched with antioxidants or waste cooking oils. The method for the determination of Ca, Cu, Cd, Fe, Mg, Mn, Ni, Pb, and Zn in fat samples was developed by means of a certified reference material (CRM 186) and a representative fatty sample (RFS). All samples were digested in closed vessels in a microwave oven and then analyzed by flame atomic absorption or graphite furnace atomic absorption spectrometry. The entire analytical method provided a satisfactory repeatability and reproducibility confirmed by agreement between the experimental recovery data obtained for the CRM 186 sample and, with the method of standard additions, for the RFS material. The samples generally showed a small amount of metals compared with the recommended daily intake for the essential elements. On the other hand, some samples contained a significant concentration, from an analytical point of view, of Cd, Ni, and Pb. Principal component analysis (PCA) was applied to inspect the experimental data obtained from samples analysis. Basically no differences were detected in terms of metal concentration among the fat supplements analyzed.
2005
- Use of multivariate analysis of MIR spectra to study bread staling
[Articolo su rivista]
Cocchi, Marina; Foca, Giorgia; Marchetti, Andrea; Sighinolfi, Simona; Tassi, Lorenzo; Ulrici, Alessandro
abstract
Different kinds of bread, stored at constant temperature and at controlled humidity conditions for a week since their manufacturing date, were analysed by Attenuated Total Reflectance-Fourier Transform InfraRed (ATR-FTIR) spectroscopy. The collected spectra were processed by Principal Component Analysis (PCA), in order to evaluate the changes occurring during bread ageing. For the sake of comparison, the 1060-950 cm(-1) spectral window has been also investigated by curve-fitting methods. It was observed that the first PC increases monotonically with ageing of samples. Furthermore, the more influential variables on PCl correspond to spectral regions where are located stretching and bending bands, which are mainly attributed to typical starch bonds vibrations.
2004
- A chemometric approach to the comparison of different sample treatments for metals determination by atomic absorption spectroscopy in aceto balsamico tradizionale di modena
[Articolo su rivista]
Cocchi, Marina; Franchini, Giancarlo; D., Manzini; Marchetti, Andrea; M., Manfredini; Ulrici, Alessandro
abstract
A comparison of different digestion procedures has been carried out for the analysis of metal concentration in samples of vinegars and Aceto Balsamico Tradizionale of Modena (ABTM) coming from an unique barrel set. In particular, classical wet, dry ashing, and closed vessel microwave digestion procedure have been utilized and compared for each investigated species. In a few cases, direct metal determination on ABTM (without treatment procedure) is proposed as possible alternative to sample manipulation. Flame atomic absorption spectrometry was used for the quantification of iron and zinc, while graphite furnace atomic absorption spectrometry was used for all the other elements (i.e., chromium, manganese, cobalt, nickel, copper, cadmium, and lead). The comparison among the different sample treatments was carried out by the use of statistical and chemometric tools. In particular, principal component analysis and ANOVA approaches were used to discriminate between the diverse analytical methods. Furthermore, for all the dissolving techniques, the analytical metal recovery was always evaluated by the application of the recovery function on the same sample matrix. In general, the recoveries were fairly good, ranging from 90 to 103%, except for Cd and Pb with dry ashing, which showed recovery values close to 55% and 67%, respectively. As regards the metals concentration of the investigated samples, the experimental data reveal for some species the presence of concentration slightly over the legal limit fixed for wine and wine vinegar.
2004
- A study of the dielectric behavior and the liquid structure of a ternary solvent system
[Articolo su rivista]
Cocchi, Marina; Franchini, Giancarlo; Marchetti, Andrea; Pigani, Laura; Seeber, Renato; Tassi, Lorenzo; Ulrici, Alessandro; Zanardi, Chiara; Zannini, Paolo
abstract
The static dielectric constant of the {DMF(1) + ME(2) + DME(3)} ternary mixtures was measured as a function of temperature (25 less than or equal to t/degreesC less than or equal to 80) and composition, over the whole mole fraction range 0 less than or equal to x(1),x(2),x(3) less than or equal to 1. The experimental values were processed by an empirical equation accounting for the dependence epsilon = epsilon(T, phi(i)), where phi(i) is the volume fraction of the components. A comparison between calculated and experimental data shows that this fitting relationship can be effectively employed to predict epsilon values in correspondence to experimental data gaps. Starting from the experimental measurements, some derived quantities such as molar polarisation (P), and excess counterpart (P-E) were obtained. Both the excess properties, epsilon(E) and P-E, take values partly positive and partly negative under all experimental conditions. The values of the excess quantities are indicative of the presence of specific interactions among different components in the mixtures.
2004
- Application of NIR spectroscopy multivariate calibration to the quantification of durum wheat semolina adulteration with bread wheat flour
[Relazione in Atti di Convegno]
Cocchi, Marina; Foca, Giorgia; Marchetti, Andrea; Tassi, Lorenzo; Ulrici, Alessandro
abstract
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2004
- Application of a wavelet-based algorithm on HS-SPME/GC signals for the classification of balsamic vinegars
[Articolo su rivista]
Cocchi, Marina; Durante, Caterina; Foca, Giorgia; Manzini, Daniela; Marchetti, Andrea; Ulrici, Alessandro
abstract
A novel feature selection and classification algorithm (WPTER) based on the wavelet packet transform has been applied to the discrimination of balsamic vinegars, namely the typical made Aceto Balsamico Tradizionale di Modena, which gained the PDO denomination on the year 2000, from the industrial made Aceto Balsamico of the Modena district. All the samples have been characterized on the basis of the gas chromatographic (GC) profiles of the headspace (HS) volatile fraction, sampled by solid phase microextraction (SPME). Good discrimination between the two categories has been obtained both for the calibration and for the test set samples. GC-MS analysis allowed the identification of the peaks lying in the chromatographic regions selected by the algorithm, giving useful suggestions about the compounds which may be worth of further investigation in order to rationalize the chemical transformation occurring during the traditional making procedure. The proposed methodology seems very promising in authentication tasks, coupling some of the advantages of blind analysis with the possibility of acquiring chemical information, and giving, at the same time, very parsimonious multivariate classification models, which can be particularly suitable for data storage and handling.
2004
- Applicazione della calibrazione multivariata su spettri NIR per la quantificazione dell’adulterazione di semola di grano duro con farina di grano tenero
[Relazione in Atti di Convegno]
Cocchi, Marina; Foca, Giorgia; Marchetti, Andrea; Tassi, Lorenzo; Ulrici, Alessandro
abstract
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2004
- Applicazione dell’algoritmo WPTER su spettri NIR di farine di frumento tenero per la classificazione nelle diverse classi di qualità
[Relazione in Atti di Convegno]
Cocchi, Marina; Corbellini, M; Foca, Giorgia; Tassi, Lorenzo; Ulrici, Alessandro
abstract
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2004
- Automated evaluation of food colour by means of multivariate image analysis coupled to a wavelet-based classification algorithm
[Articolo su rivista]
Antonelli, Andrea; Cocchi, Marina; Fava, Patrizia; Foca, Giorgia; Franchini, Giancarlo; Manzini, Daniela; Ulrici, Alessandro
abstract
This paper describes an approach for the colour-based classification of RGB images, taken with a common digital CCD camera oninhomogeneous food matrices. The aimwas that of elaborating a feature selection/classification method independent of the specific food matrixthat is analysed, in the sense that the variables that are the most relevant ones for the classification of the analysed samples are selected in a blindway, with no a priori assumptions on the basis of the nature of the considered food matrix.Aone-dimensional signal describing the colour contentof each acquired digital image, which we have called colourgram, is created as the contiguous sequence of the frequency distribution curves ofthe three red, green and blue colours values, of related parameters (also including hue, saturation and intensity) and of the scores values derivingfrom the PCA analysis of the unfolded 3D image array, together with the corresponding loadings values and eigenvalues. Once a sufficientnumber of digital images has been acquired, the corresponding colourgrams are then analysed by means of a feature selection/classificationalgorithm based on the wavelet transform, wavelet packet transform for efficient pattern recognition (WPTER). This approach was tested ona series of samples of “pesto”, a typical Italian vegetable pasta sauce, which presents high colour variability, mainly due to technologicalvariables (raw materials, processes) and to the degradation of chlorophylls during storage. Good classification results (100% of correctlyclassified objects with very parsimonious models) have been obtained, also in comparison with the visual evaluation results of a panel test.
2004
- Caratterizzazione chimico-fisica di amidi di varia origine
[Relazione in Atti di Convegno]
Cocchi, Marina; Foca, Giorgia; Franchini, Giancarlo; Marchetti, Andrea; Sighinolfi, Simona; Tassi, Lorenzo; Ulrici, Alessandro
abstract
-
2004
- Chemical durability of PVC based biomedical devices
[Relazione in Atti di Convegno]
Bodecchi, L. M.; Cocchi, M.; Marchetti, Andrea; Manfredini, M.
abstract
Il ruolo delle variabili temperatura e tempo è stato investigato relativamente alle proprietà funzionali di dispositivi disposables per uso biomedicale
2004
- Classification of bread wheats in different baking categories by application of a wavelet-based feature selection/classification algorithm on NIR spectra
[Relazione in Atti di Convegno]
Cocchi, Marina; Corbellini, M; Foca, Giorgia; PAGANI M., A; Lucisano, M; Ulrici, Alessandro
abstract
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2004
- Classification of cereal flours by chemometric analysis of MIR spectra
[Articolo su rivista]
Cocchi, Marina; Foca, Giorgia; M., Lucisano; Marchetti, Andrea; Ma, Pagani; Tassi, Lorenzo; Ulrici, Alessandro
abstract
Different kinds of cereal flours submitted to various technological treatments were classified on the basis of their mid-infrared spectra by pattern recognition techniques. Classification in the wavelet domain was achieved by using the wavelet packet transform for efficient pattern recognition (WPTER) algorithm, which allowed singling out the most discriminant spectral regions. Principal component analysis (PCA) on the selected features showed an effective clustering of the analyzed flours. Satisfactory classification models were obtained both on training and test samples. Furthermore, mixtures of varying composition of the studied flours were distributed in the PCA space according to their composition.
2004
- Classificazione di frumenti teneri in diverse classi di qualità mediante applicazione sugli spettri NIR di un algoritmo di classificazione/selezione di variabili basato sulla trasformata wavelet
[Relazione in Atti di Convegno]
Cocchi, Marina; Corbellini, M; Foca, Giorgia; PAGANI M., A; Lucisano, M; Ulrici, Alessandro
abstract
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2004
- Spettroscopia NIR, un metodo di analisi veloce e promettente
[Articolo su rivista]
M., Lucisano; Cocchi, Marina; M., Corbellini; Ma, Pagani; Ulrici, Alessandro; Foca, Giorgia
abstract
La spettroscopia NIR accoppiata all'analisi chemiometrica dei tracciati spettrali è illustarta com emetodica rapida, efficace e non distruttiva nel controllo di routine di alimenti cerealicoli
2004
- Stabilità termica di dispositivi biomedicali a base PVC
[Relazione in Atti di Convegno]
Bodecchi, L. M.; Cocchi, M.; Ferrari, G.; Manfredini, M.; Marchetti, Andrea
abstract
Stabilità Termica di Dispositivi Biomedicali a Base PVC.
2004
- Thermal Stability and Chemical Durability of PVC-Based Biomedical Devices
[Relazione in Atti di Convegno]
Bodecchi, M.; Cocchi, M.; Manfredini, M.; Marchetti, Andrea
abstract
The role of Analytical Chemistry in the Protection of the Citizen
2004
- Utilizzo del rapporto isotopico Sr87/Sr86 per lo sviluppo di modelli di traciabilità geografica di prodotti alimentari
[Relazione in Atti di Convegno]
Cocchi, Marina; Ferrari, Giorgia; Hoogewerff, J. A.; Manzini, Daniela; Marchetti, Andrea; Sighinolfi, Simona
abstract
Molti paesi europei vantano una notevole tradizione eno-gastronomica, che comprende numerose produzioni di alimenti tipici regionali di alto valore commerciale. Il consumo di tali prodotti si è diffuso largamente negli ultimi anni, e ciò ha indotto l’unione europea a tutelare tali alimenti tramite l’introduzione delle denominazioni di qualità, ossia Specialità Territoriale Garantita” (STG), “Indicazione Geografica Protetta” (IGP) e “Denominazione di Origine Protetta” (DOP).
La diffusione di alimenti tipici regionali ha incrementato notevolmente l’interesse verso lo sviluppo di metodi di tracciabilità, intesa come processo che segue l’alimento durante tutte le fasi della produzione, ossia come un insieme di informazioni sull’origine delle materie prime, sul luogo di produzione e sulle tecniche di produzione che portano all’ottenimento dell’alimento.
Finora la tutela dei prodotti tipici è stata legata, essenzialmente, ad una tracciabilità di tipo cartaceo ma, per individuare imitazioni o frodi legate a prodotti ottenuti in zone diverse da quelle di tutela, sta nascendo la necessità di una tracciabilità “oggettiva” basata, cioè, su criteri oggettivi che fanno riferimento a misure scientifiche .
L’impiego del rapporto isotopico di elementi stabili, unitamente alla concentrazione di metalli ed elementi in tracce può essere usata con successo per l’individuazione dell’origine geografica di un alimento, in quanto questi dati tendono a rimanere maggiormente costanti rispetto a numerosi composti organici che possono essere analogamente utilizzati per lo sviluppo di metodi di tracciabilità.
Tra i prodotti con denominazione DOP si inserisce l’Aceto Balsamico Tradizionale di Modena (ABTM) che rappresenta, probabilmente, uno degli alimenti tipici più conosciuti ed apprezzati dell’universo gastronomico mondiale.
La produzione di questo condimento di antica origine, derivante da mosti cotti di uve selezionate tipiche della provincia di Modena, avviene in botticelle di differenti essenze legnose e di diversa capacità, per fermentazione alcolica ed acetica seguita da una lunga maturazione in cui si verificano processi naturali di invecchiamento.
Dato il lungo periodo di invecchiamento e le peculiarità del processo produttivo, l’ABTM rappresenta una matrice molto interessante da un punto di vista scientifico e può essere considerato un “banco di prova” per lo sviluppo di un modello di tracciabilità.
In questo lavoro sono presentati i risultati di un primo studio pilota volto all’elaborazione di un sistema di tracciabilità per l’ABTM, mediante la determinazione del rapporto isotopico 87Sr/86Sr e della concentrazione degli elementi Ca, Mg, Sr, Cu, Cd, Zn, Fe, Pb.
Per la presente ricerca sono stati individuati alcuni produttori di ABTM, variamente dislocati nella provincia di Modena, i quali rincalzano le botti con mosto proveniente da uve di loro stessa coltivazione e conducono da tempo le batterie selezionate con mosto prodotto nelle loro aziende.
Presso tali produttori, sono state campionate le terre del vigneto, le acque eventualmente usate per l’irrigazione, i mosti cotti e gli aceti invecchiati.
Le tecniche MC-ICP/MS (multi collector ICP/MS), FAAS e GFAAS sono state usate per la misura del rapporto isotopico dello stronzio e per la determinazione della concentrazione totale dei metalli, rispettivamente. I dati ottenuti sono stati successivamente elaborati con tecniche di analisi chemiometrica.
I risultati ottenuti sono estremamente interessanti e promettenti, soprattutto per quanto concerne la possibilità di correlare le caratteristiche delle materie prime (mosti) con la composizione dei terreni di provenienza.
Le misure del rapporto isotopico 87Sr/86Sr hanno evidenziato, infatti, una relazione significativa tra mosti e terreni, correlabile alle diverse zone geologiche che si possono identificare nel territorio modenese.
Questi ri
2003
- Applicazione dell’Algoritmo WPTER per la Classificazione di Spettri MIR di Farine Provenienti da Diversi Careali
[Relazione in Atti di Convegno]
Cocchi, M.; Foca, G.; Marchetti, Andrea; Sighinolfi, S.; Tassi, L.; Ulrici, A.
abstract
l’Algoritmo WPTER è stato utilizzato per la Classificazione di prodotti da forno ottenuti impiegando cereali diversi mediante spettri MIR i
2003
- Applicazione dell’algoritmo WPTER per la classificazione di spettri MIR di farine provenienti da diversi cereali
[Relazione in Atti di Convegno]
Cocchi, Marina; Foca, Giorgia; Marchetti, Andrea; Sighinolfi, Simona; Tassi, Lorenzo; Ulrici, Alessandro
abstract
-
2003
- Characterization of “Aceto Balsamico Tradizionale di Modena” Ageing Process by Application of a Wavelet Based Algorithm on HS-SPME/GC Signals
[Relazione in Atti di Convegno]
Cocchi, Marina; Durante, Caterina; Manzini, Daniela; Marchetti, Andrea
abstract
The aceto balsamico tradizionale di Modena received the PDO certification from the EU two years ago.
2003
- Multicomponent Analysis of Electrochemical Signals in the Wavelet Domain
[Articolo su rivista]
COCCHI, Marina; J. L., Hidalgo Hidalgo De Cisneros; I., Naranjo Rodruguez; J. M., Palacios Santnder; SEEBER, Renato; ULRICI, Alessandro
abstract
Successful applications of multivariate calibration in the field of electrochemistry have been recently reported, using various approaches such as multilinear regression (MLR), continuum regression, partial least squares regression (PLS) and artificial neural networks (ANN). Despite the good performance of these methods, it is nowadays accepted that they can benefit from data transformations aiming at removing baseline effects, reducing noise and compressing the data. In this context the wavelet transform seems a very promising tool. Here, we propose a methodology, based on the fast wavelet transform, for feature selection prior to calibration. As a benchmark, a data set consisting of lead and thallium mixtures measured by differential pulse anodic stripping voltammetry and giving seriously overlapped responses has been used. Three regression techniques are compared: MLR, PLS and ANN. Good predictive and effective models are obtained. Through inspection of the reconstructed signals, identification and interpretation of significant regions in the voltammograms are possible.
2003
- Multivariate calibration of analytical signals by WILMA (wavelet interface to linear modelling analysis)
[Articolo su rivista]
Cocchi, Marina; Seeber, Renato; Ulrici, Alessandro
abstract
A novel algorithm based on coupling of the fast wavelet transform (FWT) with MLR and PLS regression techniques for the selection of optimal regression models between matrices of signals and response variables is presented: wavelet interface to linear modelling analysis (WILMA). The algorithm decomposes each signal into the FWT domain and then, by means of proper criteria, selects the wavelet coefficients that give the best regression models, as evaluated by the leave-one-out cross-validation criterion. The predictive ability of the regression model is then checked by means of external test sets. Moreover, the signals are reconstructed back in the original domain using only the selected wavelet coefficients, to allow for chemical interpretation of the results. The algorithm was tested on different literature data sets: two near-infrared data sets from Kalivas, on which the performances of many calibration algorithms have already been tested, and a data set consisting of lead and thallium mixtures measured by differential pulse anodic stripping voltammetry and giving seriously overlapped responses. Good results were obtained for all the studied data sets; in particular, for the data sets from Kalivas the WILMA models showed improved predictive capability. Copyright
2003
- Viscosimetric properties and internal structure of N,N-dimethylformamede+1,2-dimethoxyethane binary mixtures
[Articolo su rivista]
Cocchi, Marina; M., Manfredini; D., Manzini; Marchetti, Andrea; S., Sighinolfi; Tassi, Lorenzo; Ulrici, Alessandro; M., Vignali; Zannini, Paolo
abstract
The kinematic viscosities (v) of liquid binary mixtures of N,N-dimethylformamide and 1,2-dimethoxyethane were measured at 19 temperatures in the range -10 less than or equal to t / degreesC less than or equal to 80, employing the pure species and 9 their solutions covering the whole miscibility range expressed by the condition 0 less than or equal to x(i) less than or equal to 1. The measured values have been used to test some empirical equations of the type v=v(T), v=v(x(i)), and v=v(T,x(i)), in order to obtain useful correlation models with predictive ability in correspondence of the experimental data gaps. Starting from the experimental data, the excess kinematic viscosities (v(E)) have been calculated. Sign and magnitude of these quantities have been discussed in terms of type and nature of specific intermolecular interactions. Some derived quantities such as thermodynamic parameters of the viscous flow (DeltaG*, DeltaH* and DeltaS*), have been calculated on the basis of Eyring's model. Furthermore, the fluidity of this binary solvent system was analysed and interpreted following Hildebrand and modified-Hildebrand correlation models. (C) 2003 Elsevier Science B.V. All rights reserved.
2002
- Beta-functionalised polythiophenes as microelectrode modifiers in low conductive media
[Articolo su rivista]
Cocchi, Marina; Franchini, Giancarlo; M., Manfredini; Marchetti, Andrea; Pigani, Laura; Seeber, Renato; Tassi, Lorenzo; Ulrici, Alessandro; M., Vignali; Zanardi, Chiara; Zannini, Paolo
abstract
A study on polythiophene coated microelectrodes is reported, the goal being that of checking the capability of these electrochemical systems to work in low conductive media. The possibility of electrochemically p-doping the polymer in the presence of very low concentrations or even in the absence of supporting electrolyte in the solution is ascertained, opening the way to the use of similar systems in pure solvent media. This result is obtained in such conditions that the presence of residual charges - and corresponding counterions - trapped inside the film coating can be reasonably hypothesised.
2002
- Caratterizzazione di farine di frumento mediante analisi PCA di spettri infrarossi
[Articolo su rivista]
Cocchi, Marina; Foca, Giorgia; Marchetti, Andrea; Tassi, Lorenzo; Ulrici, Alessandro
abstract
La qualità risulta essere un criterio fondamentale per la scelta dei prodotti alimentari da parte dei consumatori, pertanto le tecniche anaitiche che si occupano del controllo della composizione chimica degli alimenti e dell'individuazione di eventuali adulterazioni sono in continuo aumento.
2002
- Classificazione di spettri MIR acquisiti su matrici di origine cerealicola mediante l’utilizzo dell’algoritmo WPTER
[Relazione in Atti di Convegno]
Cocchi, Marina; Foca, Giorgia; Marchetti, Andrea; Tassi, Lorenzo; Ulrici, Alessandro
abstract
-
2002
- Determination of carboxylic acids in vinegars and in aceto balsamico tradizionale di modena by HPLC and GC methods
[Articolo su rivista]
Cocchi, Marina; P., Lambertini; Manzini, Daniela; Marchetti, Andrea; Ulrici, Alessandro
abstract
The presence of carboxylic acids in grape products has been investigated for a long time by researchers, from both the qualitative and quantitative points of view. Evaluation of carboxylic acids requires the study and optimization of some operative variables which are strictly related to the matrix. In particular, the determination of organic acids in real matrixes such as Aceto Balsamico Tradizionale of Modena (ABTM; a traditional balsamic vinegar made from cooked grape must) is often difficult because of the presence of numerous interferences that need to be removed by separation techniques. To this aim, in the present work a solid-phase extraction (SPE) method with C18 and NH2 exchangers was used to clean the ABTM samples prior to analysis or further treatments. Both HPLC and GC techniques were used to determine organic acids. The efficiency of these two different analytical techniques in the study of ABTM acidic composition has been evaluated. Both methods separately were not able to supply all the data related to carboxylic acids. In particular, HPLC allows acetic and lactic acids quantification, but gluconic and succinic acids are better determined by GC. As far as tartaric, citric, and malic acids are concerned, both HPLC and GC methods give statistically equivalent results. The variation of the single acidic species composition along a series of casks furnished interesting information regarding the chemical transformations taking place during the aging process of this product.
2002
- Effetti della Sterilizzazione per Irraggiamento sulle Superfici di Materiali Plastici per Uso Bio Medicale
[Relazione in Atti di Convegno]
Cocchi, Marina; Manfredini, Matteo; Marchetti, Andrea
abstract
Comunicazione orale
2002
- Il sistema ternario metanolo + etanolo + 1-propanolo: proprietà volumiche e disegno sperimentale di miscele solventi
[Relazione in Atti di Convegno]
Cocchi, Marina; Foca, Giorgia; Franchini, Giancarlo; Manfredini, Matteo; Manzini, Daniela; Marchetti, Andrea; Tassi, Lorenzo; Ulrici, Alessandro; Vignali, M.
abstract
-
2002
- Temperature and composition dependence of the refractive indices of the 2-chloroethanol + 2-methoxyethanol binary mixtures
[Articolo su rivista]
Cocchi, Marina; M., Manfredini; Marchetti, Andrea; Pigani, Laura; Seeber, Renato; Tassi, Lorenzo; Ulrici, Alessandro; M., Vignali; Zanardi, Chiara; Zannini, Paolo
abstract
AbstractMeasurements of the refractive index n for the binary mixtures 2-chloroethanol + 2-methoxyethanol in the 0 ≤ T/°C ≤ 70 temperature range have been carried out with the purpose of checking the capability of empirical models to express physical quantity as a function of temperature and volume fraction, both separately and together, i.e., in a two independent variables expression. Furthermore, the experimental data have been used to calculate excess properties such as the excess refractive index, the excess molar refraction, and the excess Kirkwood parameter Ag over the whole composition range. The quantities obtained have been discussed and interpreted in terms of the type and nature of the specific intermolecular interactions between the components.
2002
- Viscosity of (ethane-1,2-diol+1,2-dimethoxyethane + water) at temperatures from 263.15 K to 353.15 K
[Articolo su rivista]
Cocchi, Marina; M., Manfredini; Marchetti, Andrea; Pigani, Laura; Seeber, Renato; Tassi, Lorenzo; Ulrici, Alessandro; Zanardi, Chiara
abstract
AbstractThe kinematic viscosity ν for (ethane-1,2-diol + 1,2-dimethoxyethane + water) was measured at 14 different ternary compositions covering the whole miscibility field, and at 19 temperatures in the range 263.15 T / K 353.15. The experimental values were fitted using empirical equations of the type ν = ν (T) and ν = ν (xi), respectively, in order to provide reliable models to account for the behaviour of the system. The excess kinematic viscosity νEhas been determined and interpreted in terms of the type and nature of the interactions among the components of the mixture. Using the experimental ν data, the thermodynamic properties ( ΔG * , ΔH * ,ΔS * ) of the viscous flow have been obtained from the Eyring’s approach and standard thermodynamic equations. Furthermore, excess mixing functions, such asΔG * E , have been determined, and found to evidence the existence of quite strong specific interactions among the components, probably due to the formation of hydrogen bonds and dipolar networks. However, all the calculated excess mixing properties suggest the absence of stable three-component adducts.
2001
- Density and volume properties of the 2-methoxyethanol+1,2-dimethoxyethane + water ternary solvent system at various temperatures
[Articolo su rivista]
Cocchi, Marina; Marchetti, Andrea; Pigani, Laura; Tassi, Lorenzo; Ulrici, Alessandro; G., Vaccari; Zanardi, Chiara
abstract
Densities (rho) of the ternary mixtures 2-methoxyethanol + 1,2-dimethoxyethane + water have been measured at 19 temperatures in the range -263.15 less than or equal toT/K less than or equal to 353.15. The experimental data were processed by empirical relations accounting for the dependence of rho on temperature and ternary composition expressed as mole fraction of the components (0 less than or equal to x(i) less than or equal to 1). All checked equations seem to be suitable for correlation purposes, in order to obtain interpolated values in correspondence to experimental data gaps. Furthermore, the excess molar volume (V-E) has been investigated to make evident the possibility of forming stable solvent-cosolvent adducts. The excess property has been interpreted on the basis of specific intermolecular interactions between the components.
2001
- Mass Transport Properties in Solvent Liquid Mixtures
[Articolo su rivista]
Cocchi, Marina; Manfredini, Matteo; A., Marchetti; Tassi, Lorenzo; Seeber, Renato; A., Ulrici
abstract
The study of mass transport properties, such as density and viscosity of mixed solvent systems (both aquomixed and nonaqueous liquids), have proven to be a very useful tool in investigating specific intermolecular interactions and structural effects in condensed phases of real components. The knowledge of these properties and of some related quantities is of strategic importance for a lot of technical and scientific applications, and the availability of correlation models with temperature and chemical composition, which can be employed both for interpretative and predictive calculations, is extremely useful for chemists, physics, biologists, practising engineers and research workers devoted to material sciences. Here, some of the most significant descriptive relationships will be summarised (together with their graphical representations), and some new concepts will be introduced to reach a better understanding about some Newtonian and pseudo-rheological complex systems. The chosen species for these studies pertain to the class of 1,2-ethanedyil-derivatives, such as 1,2-ethanediol (ED), 2-methoxyethanol (ME), 1,2-dimetho-xyethane (DME), di-ethylen-glycol (DEG), 1,2-propa- nediol (12PD), 2-butanone (MEK), in addition to water (W) and to DMF among other solvents, in order to construct a suitable data-base. Emphasis has been given to some aspects related to the peculiar hydrodynamic behaviour of water and to its binary and ternary mixtures. Furthermore, some aspects of excess mixing properties (YE) of multicomponent solvent systems are focused.
2001
- The 2-Methoxyethanol + 1,2-Dimethoxyethane + Water Ternary System: Static Relative Permittivity from -10 to 80 °C
[Articolo su rivista]
Cocchi, Marina; DE BENEDETTI, Pier Giuseppe; Marchetti, Andrea; Menziani, Maria Cristina; Seeber, Renato; Tassi, Lorenzo; Ulrici, Alessandro
abstract
Static relative permittivities of the 2-methoxyethanol + 1,2-dimethoxyethane + water ternary solvent system were measured as a function of temperature (-10 less than or equal to t/degreesC less than or equal to 80) and of composition, over the whole molar fractions range 0 less than or equal to x(1), x(2), x(3) less than or equal to 1. The experimental values have been used to test some empirical relationships accounting for the dependence of epsilon on T. x(i), and on T, x(i) couples of values. A comparison between calculated and experimental data shows that these relationships can be profitably employed to predict E values in correspondence to experimental data gaps. The excess dielectric permittivity, epsilon (E), assumes, in the most cases, negative values for any compositions of the mixtures. while the values of the excess molar polarization, PE, are positive. The large values of the excess quantities are indicative of the strong specific interactions among similar, as well as different molecules in the mixtures. Discussion of the data in terms of Kirkwood correlation factor also gives information on the short-range intermolecular interactions among the components. suggesting the formation of two-components adducts rather than of than mure complex moieties involving all three molecular species.
2001
- The Ethane-1,2-diol + 2-Methoxyethanol + 1,2-Dimethoxyethane Ternary Solvent System: Density and Volume Proprties at Different Temperatures.
[Articolo su rivista]
Cocchi, Marina; M., Manfredini; Marchetti, Andrea; Sighinolfi, Simona; Tassi, Lorenzo; Ulrici, Alessandro; M., Vignali
abstract
The density of the ethane-1,2-diol+2-methoxyethanol + 1,2-dimethoxyethane ternary mixtures has been measured at different temperatures ranging from-10 to 80° C, and over the whole composition range. The experimental data have been used to check the validity of some relationships accounting for the dependence of the density on temperature and composition, useful to evaluate the behaviour of this property in the whole temperature and composition domains. Starting from the primary data, some derived quantities, such as excess molar volumes, partial molar volumes and partial excess molar volumes, have been obtained. In these mixtures VE is generally negative at all the experimental conditions, showing the greatest deviations along the binary axes corresponding to the binary subsystems. The results are compared and discussed to get light to the changes in molecular association and structural effects in this solvent system.
2001
- WPTER: Wavelet packet transform for efficient pattern recognition of signals
[Articolo su rivista]
Cocchi, Marina; Seeber, Renato; Ulrici, Alessandro
abstract
In the present work, we propose a novel algorithm based on the Wavelet Packet Transform WPT for pattern recognition of signals, which operates both feature selection and classification at the same time: Wavelet Packet Transform for Efficient pattern Recognition of signals WPTER . The distinctive characteristics of WPTER with respect to the previously proposed algorithms for the WPT-based classification of signals consist mainly of two aspects: 1 a Classification Ability criterion is introduced into the procedure for selection of the best discriminant basis; 2 the signals are reconstructed in the original domain by using only the selected wavelet coefficients, which allow for chemical interpretation of the results. The algorithm was first tested on an artificial simulated set of signals, consisting of a number of subsequent peaks, par- tially overlapped to each other, with added noise and baseline drift, simulating a three-class system. Then, it was applied to a data set consisting of X-ray diffractograms on fired tiles subjected to different firing cycles, aiming at discriminating the different firing methods on the basis of the phase composition. In both cases, satisfactory classifications were achieved.
2000
- Density and volumetric properties of ethane-1,2-diol plus di-ethylen-glycol mixtures at different temperatures
[Articolo su rivista]
Cocchi, Marina; Marchetti, Andrea; Pigani, Laura; G., Sanna; Tassi, Lorenzo; Ulrici, Alessandro; G., Vaccari; Zanardi, Chiara
abstract
The density of the ethane-1,2-diol (ED) + di-ethylen-glycol (DEG) binary mixtures has been measured at different temperatures over the complete composition range. The experimental measurements have been used to check the validity of relationships accounting for the dependence of the density on temperature and composition, useful to obtain interpolated values in the correspondence of the experimented data gaps. Starting from the primary data, some derived quantities, such as partial molar volumes, excess and partial excess molar volumes, have been obtained. In these mixtures, V-E presents an S-shaped dependence on composition at each temperature, showing negative values in the ED rich-region and positive values at the opposite extreme. The results are compared and discussed to get light to the: changes in molecular association and structural effects in this solvent system. (C) 2000 Elsevier Science B.V. All rights reserved.
2000
- The ad hoc supermolecule approach to receptor ligand design
[Articolo su rivista]
DE BENEDETTI, Pier Giuseppe; Fanelli, Francesca; Menziani, Maria Cristina; Cocchi, Marina
abstract
Among the ligand design methods based on the theoretical QSAR paradigm, the simple ad hoc supermolecule approach is presented and applied to a highly non-congeneric set of a1-adrenergic receptor antagonists. The performance of the approach is satisfactory and highlights its (semi)quantitative ligand design potentiality.
1999
- Development of Quantitative Structure-Property Relationships (QSPR) using calculated descriptors for the prediction of the physico-chemical properties (nD, r, bp, e and h) of a series of organic solvents.
[Articolo su rivista]
Cocchi, Marina; DE BENEDETTI, Pier Giuseppe; Seeber, Renato; Tassi, Lorenzo; Ulrici, Alessandro
abstract
Quantitative structure-property relationship (QSPR) models were derived for predicting boiling point (at 760 mmHg), density (at 25 °C), viscosity (at 25 °C), static dielectric constant (at 25 °C), and refractive index (at 20 °C) of a series of pure organic solvents of structural formula X-CH2CH2-Y. A very large number of calculated molecular descriptors were derived by quantum chemical methods, molecular topology, and molecular geometry by using the CODESSA software package. A comparative analysis of the multiple linear regression techniques (heuristic and best multilinear regression) implemented in CODESSA, with the multivariate PLS/GOLPE method, has been carried out. The performance of the different regression models has been evaluated by the standard deviation of prediction errors, calculated for the compounds of both the training set (internal validation) and the test set (external validation). Satisfactory QSPR models, from both predictive and interpretative point of views, have been obtained for all the studied properties.
1999
- Kinematic viscosities of ternary mixtures containing ethane-1,2-diol, 2-methoxyethanol and water from-10 degrees C to 80 degrees C
[Articolo su rivista]
Cocchi, Marina; Marchetti, Andrea; G., Sanna; Tassi, Lorenzo; Ulrici, Alessandro; G., Vaccari
abstract
Kinematic viscosities (v) of the ternary ethane-1,2-diol (1) + 2-methoxyethanol (2)+ water (3) solvent system have been measured for 36 ternary mixtures covering the whole miscibility range expressed by the condition 0 <X-1,X-2,X-3 < 1, at 19 temperatures in the range - 10 less than or equal to t (degrees C) less than or equal to 80. The measured values have been used to test some empirical equations of the type v = v(t) and v = v(X-i), in order to provide for useful interpolation procedures to obtain calculated values in correspondence to the experimental data gaps. From the experimental data, the excess kinematic viscosities (v(E)) have been calculated. Sign and magnitude of these quantities have been discussed in terms of type and nature of specific intermolecular interactions. Furthermore, derived quantities such as thermodynamic parameters of the viscous flow (Delta G*, Delta H* and Delta S*), have been analysed on the basis of the Eyring's model. All the investigated excess mixing properties indicate the probable absence of stable three-component adducts in this ternary solvent system. (C) 1999 Elsevier Science B.V. All rights reserved.
1998
- Computer modeling of size and shape descriptors of alpha 1-adrenergic receptor antagonists and quantitative structure-affinity/selectivity relationships
[Articolo su rivista]
Montorsi, Monia; Menziani, Maria Cristina; Cocchi, Marina; Fanelli, Francesca; DE BENEDETTI, Pier Giuseppe
abstract
Computational chemistry and molecular modeling procedures allow us to define and compute ad hoc size and shape descriptors on the different prototropic forms assumed by drugs in biotest solutions. Together with experimental data measured on a well-identified target receptor, these descriptors are essential elements for obtaining simple, consistent, comparable, and easily interpretable theoretical quantitative structure-activity relationship (QSAR) models based on the ligand similarity-target receptor complementarity paradigm. In this context, quantitative size and shape affinity/subtype selectivity relationships have been modeled for a large set of very heterogeneous alpha(1a)-, alpha(1b)-, and alpha(1d)-adrenergic receptor antagonists. The linear QSAR models generated have been validated by predicting both binding affinity and selectivity of a test set of noncongeneric antagonists. The satisfactory results obtained highlight both the simplicity and the versatility of the approach presented.
1998
- Use of the supermolecule approach to derive molecular similarity descriptors for QSAR analysis.
[Articolo su rivista]
Cocchi, Marina; DE BENEDETTI, Pier Giuseppe
abstract
A relevant aspect in quantitative structure-activity (QSAR) and structure-selectivity (QSSR) relationships studies is the choice of the most appropriate molecular descriptors both with respect to the molecular series considered and the known or hypothetical mechanism of drug action. We have recently shown that ad hoc derived size and shape descriptors have been successful to derive QSAR and QSSR models for #a 1-adrenergic antagonists, 5-HT1A serotoninergic receptor ligands and M 1 muscarinic ligands, especially when dealing with non congeneric series of molecules. These de- scriptors describe the size-shape similarity with respect to a reference supermolecule which is obtained by superposition of the most active(selective) and structural different compounds, better if rigids. Molecular similarity indices based on molecular electrostatic potential (MEP) have found, as well, widespread use in the QSAR area. In the present study we extend the use of the supermolecule as a reference structure also in the context of MEP similarity. We have defined an ad hoc MEP similarity index with respect to the supermolecule using the same formalism of Hodgkin and Richards. The MEP of the supermolecule is computed as the average MEP of the compounds defining the supermolecule. A FORTRAN code is implemented to optimize the superposition of the ligands on the reference super- molecule in order to maximize the values of the ad hoc similarity descriptors defined in this study. The performance of the different matching criteria and the different ad hoc molecular similarity indices derived with the supermolecule approach are tested in QSAR modeling of the binding affinity and efficacy of a wide ranging series of M 1 muscarinic ligands previously studied.
1997
- Alpha 1-adrenoceptor subtype selectivity: Molecular modelling and theoretical quantitative structure-affinity relationships
[Articolo su rivista]
DE BENEDETTI, Pier Giuseppe; Fanelli, Francesca; Menziani, Maria Cristina; Cocchi, Marina; R., Testa; A., Leonardi
abstract
This study constitutes a preliminary rationalization, at the molecular level, of antagonist selectivity towards the three cloned alpha 1-adrenergic receptor (alpha 1-AR) subtypes. Molecular dynamics simulations allowed a structural/dynamics analysis of the seven alpha-helix-bundle models of the bovine alpha 1a-, hamster alpha 1b-, and rat alpha 1d-AR subtypes. The results showed that the transmembrane domains of these subtypes have different dynamic behaviours and different topographies of the binding sites, which are mainly constituted by conserved residues. In particular, the alpha 1a-AR binding site is more flexible and topographically different with respect to the other two subtypes. The results of the theoretical structural/dynamics analysis of the isolated receptors are consistent with the binding affinities of the 16 antagonists tested towards the three cloned alpha 1-AR subtypes. Moreover, the theoretical quantitative structure-affinity relationships obtained from the antagonist-receptor interaction models further corroborates the hypothesis that selectivity towards one preferential subtype is mainly modulated by receptor and/or ligand distortion energies. In other words, subtype selectivity seems to be mainly guided by the dynamic complementarity (induced fit) between ligand and receptor. On the basis of the quantitative models presented it is possible to predict both affinities and selectivities of putative alpha 1-AR ligands as well as to estimate the theoretical alpha 1-AR subtype affinities and selectivities of existing antagonists.
1997
- Conformational analysis and theoretical quantitative size and shape-affinity relationships of N-4-protonated N-1-arylpiperazine 5-HT1A serotoninergic ligands
[Articolo su rivista]
Cocchi, Marina; Fanelli, Francesca; Menziani, Maria Cristina; DE BENEDETTI, Pier Giuseppe
abstract
Conformational analysis for 24 arylpiperazines in their neutral and N-4-protonated forms has been performed in the AM1 framework. Both these derivatives and eight reference compounds considered in this study are ligands of the 5-HT1A serotoninergic receptor. Quantum chemical reactivity indices, solvation free energies (AMSOL 5.0) and molecular modelling derived ad hoc size and shape descriptors have been computed and correlated with the literature 5-HT1A binding affinity data values. The quantitative size-shape affinity relationships obtained confirm the validity and versatility of the ad hoc descriptors employed. A different role has been postulated for the neutral and protonated forms of the arylpiperazines considered in the molecular recognition process of the 5-HT1A receptor binding site.
1996
- The Heuristic-Direct approach to Quantitative Structure-Activity Relationship Analysis of Ligand-G Protein Coupled Receptor Complexes
[Capitolo/Saggio]
Menziani, Maria Cristina; Fanelli, Francesca; Cocchi, Marina; DE BENEDETTI, Pier Giuseppe
abstract
The Heuristic-Direct approach to Quantitative Structure-Activity Relationship Analysis of Ligand-G Protein Coupled Receptor Complexes
1995
- Comparative molecular dynamics study of the seven-helix bundle arrangement of G-protein coupled receptors
[Articolo su rivista]
Fanelli, Francesca; Menziani, Maria Cristina; Cocchi, Marina; DE BENEDETTI, Pier Giuseppe
abstract
A comparative molecular dynamics study has been performed on the seven-helix bundle arrangement of seven G-protein coupled receptors (GPCRs). They are hamster alpha(1B)-, human alpha(2)-, beta(2)-adrenergic, human D-2-dopaminergic, human 5-HT1A-serotoninergic, human ml-muscarinic receptors and bovine rhodopsin. Starting from a rhodopsin-like input structure and a bacteriorhodopsin-like input structure, a similar arrangement of the averaged helix bundles was obtained. This may be due to the topography of some fundamental polar positions in both the input structures which is substantially the same and dictates, through the establishment of similar H-bonding networks, the helix-helix packing. By comparing the averaged structures and the packing interaction parameters obtained for the GPCRs considered with that of bacteriorhodopsin, we observe that the GPCRs share a similar packing arrangement of their transmembrane helix bundles which differs from that of bacteriorhodopsin. The results obtained from the quantitative and comparative molecular modelling of the GPCRs constitute an important preliminary step in a general understanding of both structure-function and structure activity-selectivity relationships in these proteins, at the molecular level.
1995
- Prototropic molecular forms and theoretical descriptors in QSAR analysis
[Articolo su rivista]
DE BENEDETTI, Pier Giuseppe; Menziani, Maria Cristina; Cocchi, Marina; Fanelli, Francesca
abstract
Computational chemistry allows us to define and compute ad hoc theoretical reactivity and size-shape descriptors on the different prototropic forms assumed by drugs in pharmacological test solutions. These are essential elements for obtaining simple, consistent, comparable and easily interpretable theoretical QSAR models based on the ligand similarity-target complementarity paradigm. In this context, theoretical QSAR models have been obtained for 34 structurally and pharmacologically (antagonists, partial agonists and full agonists) heterogeneous M(1)-muscarinic ligands and the above concepts have been highlighted.
1995
- Quantitative structure-affinity/selectivity relationship analysis on three-dimensional models of the complexes between the ETA and ETB receptors and C-terminal endothelin hexapeptide antagonists
[Articolo su rivista]
Menziani, Maria Cristina; Cocchi, Marina; Fanelli, Francesca; DE BENEDETTI, Pier Giuseppe
abstract
The application of molecular modelling and regression analysis techniques to the complexes between the ET(A) and ET(B) receptors and a series of C-terminal endothelin hexapeptide antagonists allowed the identification of the structural determinants for recognition and the quantitative elucidation of the receptor structure-affinity/selectivity relationships.
1995
- The Heuristic-Direct Approach to QSAR Analysis of Ligand-G-Protein Coupled Receptor Complexes
[Capitolo/Saggio]
DE BENEDETTI, Pier Giuseppe; Menziani, Maria Cristina; Fanelli, Francesca; Cocchi, Marina
abstract
Not available
1995
- Theoretical QSAR analysis on three dimensional models of the complexes between peptide and non-peptide antagonists with the ETA and ETB receptors
[Capitolo/Saggio]
Menziani, Maria Cristina; Cocchi, Marina; Fanelli, Francesca; DE BENEDETTI, Pier Giuseppe
abstract
Not available
1995
- Theoretical quantitative structure-activity relationship analysis of congeneric and non-congeneric α1-adrenoceptor antagonists: a chemometric study
[Articolo su rivista]
Cocchi, Marina; Menziani, Maria Cristina; Fanelli, Francesca; DE BENEDETTI, Pier Giuseppe
abstract
Molecular orbital calculations (AM1) and molecular modelling procedures (QUANTA/CHARMm) have been performed both on a congeneric (prazosin analogs) and on a non-congeneric series of alpha(1)-adrenergic antagonists. A large variety of theoretical molecular descriptors has been obtained and compared by principal component analysis (PCA). The generating optimal least squares estimations (GOLPE) procedure has been used to derive quantitative structure-activity relationships (QSARs). Good predictive QSAR models with a restricted pool of informative theoretical descriptors have been obtained. These results support the generality of the theoretical QSAR approach proposed; in fact both congeneric and non-congeneric molecular series were satisfactorily modeled. Moreover, the high and well-defined physical information content encoded in the theoretical descriptors considered allows the rationalization of the structural heterogeneity of the molecules examined as differences in the complementary intermolecular interactions of the studied ligands towards their common receptor.
1994
- The heuristic-direct approach to theoretical quantitative structure activity relationship analysis of α1- adrenoceptor ligands
[Articolo su rivista]
Fanelli, Francesca; Menziani, Maria Cristina; Cocchi, Marina; A., Leonardi; DE BENEDETTI, Pier Giuseppe
abstract
The heuristic-direct quantitative structure-activity relationship approach has been applied to fifteen non-congeneric alpha1-adrenergic receptor (alpha1-AR) ligands interacting with the rat alpha1A/D-AR subtype. The good linear correlations, which have been obtained between calculated binding energies and the pharmacological affinities, allow one to predict the pharmacological affinity of new ligands. Moreover, according to the alpha1A/D-receptor model proposed, it has been possible to speculate on the amino acid residues which are mainly involved in the interaction with the ligands. This novel procedure consitutes a powerful tool for the design of new selective leads based on explicit intermolecular interactions and for suggesting site-directed mutagenesis studies, in order to give, iteractively, further support and improvement to the predictive and interpretative aspects of the model.
1994
- Theoretical quantitative size and shape activity and selectivity analyses of 5-HT1A serotonin and α1-adrenergic receptor ligands
[Articolo su rivista]
DE BENEDETTI, Pier Giuseppe; Cocchi, Marina; Menziani, Maria Cristina; Fanelli, Francesca
abstract
Quantum chemical reactivity indices and molecular modelling derived size and shape descriptors have been computed for 18 5-HT1A serotonin and alpha1-adrenergic receptor ligands. The quantitative size shape affinity selectivity relationships obtained support the general validity and versatility of the ad hoc size shape descriptors employed.
1993
- A MOLECULAR-DYNAMICS SIMULATION OF SEQUENCE-DIRECTED RECOGNITION PEPTIDES INTERACTING WITH BIGENDOTHELIN
[Articolo su rivista]
Menziani, Maria Cristina; Cocchi, Marina; DE BENEDETTI, Pier Giuseppe
abstract
Detailed insights into the mechanisms and forces responsible for the highly selective binding of three sequence-directed recognition peptides to bigendothelin are provided by the combined use of computer-aided model building techniques, molecular dynamics simulations and quantitative structure-activity analysis. The relevance of the analysis of the interactions between the peptides during the molecular dynamics simulation to peptide design is highlighted.
1993
- AMINO-ACIDS CHARACTERIZATION BY GRID AND MULTIVARIATE DATA-ANALYSIS
[Articolo su rivista]
Cocchi, Marina; Johansson, E.
abstract
The twenty coded amino acids have been characterized by their interaction energies, calculated by the program GRID, with six different probes mimicking various functional groups which can be involved in peptide-peptide interactions. Principal Component Analysis (PCA) have been used to derive amino acids principal properties and comparing the amino acids classification obtained with the one derived by the previous published amino acids z-scales. Partial Least Squares (PLS) method has been used to test the performance of GRID probe interaction energies and the newly derived principal properties in peptide's QSAR modeling. A better separation of amino acids according to the electronic features of the side chain is obtained. The inhibitory activity of the set of peptides considered has been satisfactorally modelled.
1993
- PLS: Partial Least Squares Projections to Latent Structures
[Capitolo/Saggio]
S., Wold; E., Johansson; Cocchi, Marina
abstract
the work describes the use of chemometrics tools such as PCA, PLS in the context of QSAR analysis employing 3D molecular descriptors derived from codification of molecular interactions terms in molecular modeling of biological molecules
1993
- The heuristic-direct approach to quantitative structure-activity relationship analysis
[Articolo su rivista]
DE BENEDETTI, Pier Giuseppe; Menziani, Maria Cristina; Fanelli, Francesca; Cocchi, Marina
abstract
The heuristic-direct approach to quantitative structure-activity relationship analysis
1993
- Theoretical quantitative structure-activity analysis and pharmacophore modelling of selective non congeneric α1a-adrenergic antagonists
[Articolo su rivista]
DE BENEDETTI, Pier Giuseppe; Cocchi, Marina; Menziani, Maria Cristina; Fanelli, Francesca
abstract
Quantitative structure-activity relationship (QSAR) analysis has been done by making use of theoretical molecular descriptors on 13 non-congeneric alpha1a-adrenoceptor antagonists. Linear QSAR models have been obtained between ad hoc molecular shape and size descriptors, defined with respect to a reference ''super-molecule'', and the antagonistic potency. These results, obtained for a highly non-congeneric set of molecules, increase the potential of this approach and the probability of designing new leads. Finally, the reference supermolecule represents the best three-dimensional complementarity towards the alpha1a-adrenoceptor subtype being modelled by superimposing the two most active and selective alpha1a-antagonists.
1993
- Three dimensional molecular modeling of the α1a-adrenoceptor. Direct 3D-QSAR modeling of selective antagonists
[Capitolo/Saggio]
Fanelli, Francesca; Menziani, Maria Cristina; Cocchi, Marina; DE BENEDETTI, Pier Giuseppe
abstract
three dimensional molecular modeling of the α1a-adrenoceptor. Direct 3D-QSAR modeling of selective antagonists
1992
- CORRELATION AND MULTIVARIATE ANALYSES OF SPECTROSCOPIC AND DIHYDROPTEROATE SYNTHASE INHIBITORY ACTIVITY DATA IN 4-AMINOARYL (MULTISUBSTITUTED ARYL) SULFONES
[Articolo su rivista]
Cocchi, Marina; Iarossi, Dario; Frassineti, Chiara; Menziani, Maria Cristina; DE BENEDETTI, Pier Giuseppe
abstract
Nuclear magnetic resonance (H-1 and C-13), vibrational spectroscopy, and quantum chemical calculations (complete neglect of differential overlap/2 [CNDO/2]) have been used to investigate 20 biologically active title compounds, inhibitors of the dihydropteroate synthase. The data obtained have been comparatively analyzed by correlation and multivariate analyses. The results obtained show that also in the case of multisubstitution the electronic effect can be rationalized in terms of electronic charge perturbations which are transmitted from the multisubstituted aryl ring to the common biofunctional moiety 4-NH2-C6H4-SO2- trough the SO2 group, mainly via hyperconjugation. Good predictions of both spectroscopic and biological data are obtained by the partial least squares method using quantum chemical descriptors.
1992
- ELECTRONIC AND ELECTROSTATIC ASPECTS OF CARBONIC-ANHYDRASE INHIBITION BY SULFONAMIDES
[Articolo su rivista]
Menziani, Maria Cristina; Cocchi, Marina; DE BENEDETTI, Pier Giuseppe
abstract
A theoretical conformational analysis was performed within the AM1 framework for three benzenesulphonamide carbonic anhydrase inhibitors in their neutral and anionic forms. The theoretical reactivity and electrostatic indices obtained are compared with both the enzymic inhibitory potencies and the molecular orbital indices computed using a simple theoretical model of the carbonic anhydrase-sulphonamide complex. Finally, the inhibitory activities of the sulphonamides considered were correlated with the proton exchange and charge transfer propensities of the inhibitors. The role of the zinc ion in the inhibition mechanism seems to be mainly connected with the generation of an electrostatic field which favours the correct orientation of the SO2NH2 group and its anticipated deprotonation.
1992
- Molecular modeling and quantitaive structure activity relationship analysis using theoretical descriptors of 1,4-benzodioxan (WB-4101) related-compounds alpha-1-adrenergic antagonists
[Articolo su rivista]
P., Venturelli; Menziani, Maria Cristina; Cocchi, Marina; Fanelli, Francesca; DE BENEDETTI, Pier Giuseppe
abstract
Quantitative structure-activity relationship analysis using theoretical molecular descriptors was done on a set of 30 1,4-benzodioxan (WB-4101) related compounds which are alpha1-adrenoceptor antagonists. The results obtained confirm quantitatively and in terms of reactivity and molecular shape descriptors, the results of previous qualitative structure-activity relationship studies. It was found that the protonated amine function plays a crucial role in the potency of the alpha1-adrenoceptor antagonism due to a charge reinforced hydrogen bond with a primary nucleophilic site of the receptor. Furthermore, the more electrophilic (high SN1LUMO values) the NH2+ group, the stronger the charge reinforced hydrogen bond with the receptor and the higher the blocking activity. It was also found that the three-dimensional shape of the antagonists is more similar to the shape of the most active reference molecule (WB-4101) the more potent antagonists are. Finally, the reactivity (E(LUMO)) and the ad hoc shape (V(D)(norm)) descriptors were used to obtain a bilinear equation which accounts for about 77% of the total variance in the pharmacological data.
1992
- THEORETICAL VERSUS EMPIRICAL MOLECULAR DESCRIPTORS IN MONOSUBSTITUTED BENZENES - A CHEMOMETRIC STUDY
[Articolo su rivista]
Cocchi, Marina; Menziani, Maria Cristina; DE BENEDETTI, Pier Giuseppe; Cruciani, G.
abstract
Quantum chemical methods and molecular modeling techniques allow the definition of a large number of molecular and local quantities characterizing the reactivity, the shape and the binding properties of a molecule as well as of molecular fragments and substituents. This study is focused on a systematic comparison of the theoretical molecular descriptors with both empirical (Hammett's and Taft's substituent constants, hydrophobic parameter, Verloop's steric parameters etc.) and experimental (substituent induced chemical shifts, molecular weight and molecular refractivity) descriptors. Fifty selected monosubstituted benzenes, including some charged substituents have been computed in the AM1 framework. Several theoretical descriptors have been extracted from the AM1 electronic wavefunction as well as molecular modeling techniques and they have been analyzed by principal component analysis and the partial least squares method. The results obtained are consistent with previous principal component studies concerning empirical descriptors, and highlight the interdependencies among theoretical and empirical molecular descriptors.
1991
- A THEORETICAL-STUDY OF THE STRUCTURE OF BIG ENDOTHELIN
[Articolo su rivista]
Menziani, Maria Cristina; Cocchi, Marina; DE BENEDETTI, Pier Giuseppe; Gilbert, Rg; Richards, Wg; Zamai, M; Caiolfa, Vr
abstract
Protein structure prediction and molecular dynamics simulations have been applied for elaborating the three dimensional structure of Big Endothelin (bigET). BigET is 38-amino acid peptide which is converted, by proteolytic cleavage, into Endothelin, the most potent and long lasting endothelium derived contracting factor identified up to date. The intervention of a specific, yet unknown, protease has been evoked. The determination of bigET tertiary structure will contribute to elucidate its proteolytic conversion. In-vitro experimental data on proteolytic fragmentation of bigET in the presence of known proteases and protein homogenates from endothelial cells have been considered for testing the proposed structure.
1991
- Conformational analysis, molecular modeling and quantitative structure-activity relationships studies of 2,4-diamino-6,7-dimethoxy-2-substituted quinazoline α1-adrenergic antagonists
[Articolo su rivista]
Rastelli, Giulio; Fanelli, Francesca; Menziani, Maria Cristina; Cocchi, Marina; DE BENEDETTI, Pier Giuseppe
abstract
Conformational analysis (AM1), modeling of the molecular shape (QUANTA 3.0) and quantitative structure-activity relationship analysis were done on a set of 16 2,4-diamino-6,7-dimethoxy-2-substituted quinazoline alpha-1-adrenoceptor antagonists (prazosin analogs). The results obtained show that the 2-substituents of the analogs considered are quite flexible. Furthermore, they suggest that, once the electronic requirements of the common quinazoline moiety are satisfied, the binding affinities are modulated by the molecular shape of the quinazoline 2-substituent, through the optimization of both dispersive and steric interactions and the hydrophobic contribution.
1991
- Correlation and Multivariate Analyses of the Spectroscopic Data in 4'-Substituted 4-Nitro-difhenylsulfones
[Articolo su rivista]
Cocchi, Marina; Iarossi, Dario; Frassineti, Chiara; Menziani, Maria Cristina; DE BENEDETTI, Pier Giuseppe
abstract
Molecular descriptors such as quantum chemical indices, substituent constants, substituent chemical shifts values of monosubstituted benzenes, and different data analyses (linear regression, dual substituent parameters, and multivariate analysis) have been comparatively used in order to rationalize the electronic substituent effects and to predict C-13 nuclearmagnetic resonance (NMR) and vibrational spectroscopy (IR) data of the 14 title compounds. The results have been compared with those previously obtained for the biologically active 4'-substituted 4-aminodiphenylsulfones, inhibitors of the dihydropteroate synthase enzyme. Both the 4-nitro and the 4-amino sulfone series show similar transmission of the electronic substituent effects through the C(1)-SO2-C(1') moiety by a hyperconjugative mechanism. Good predictions of the spectroscopic data are obtained with the different models considered. However, the partial least-squares method and principal componenent analysis seem to be the most powerful predictive tools.
1991
- MODEL-CALCULATIONS OF CHEMICAL INTERACTIONS .3. ROTATIONAL ENERGY PROFILES IN SIMPLE MOLECULES - EVALUATION, ADDITIVITY AND ROLE OF BOND BOND, BOND LONE-PAIR AND LONE-PAIR LONE-PAIR INTERACTIONS
[Articolo su rivista]
Rastelli, A; Cocchi, Marina
abstract
Rotational isomerism in ethane, methylamine, methanol, fluoromethylamine, hydrazine, hydroxylamine, hydrogen peroxide and difluorine dioxide has been analysed using basis sets of symmetrically orthogonalized hybrid AOs. Total vicinal delocalization, which has either an exclusive or a relevant role in determining the rotational energy profile, shows good additivity of the effects of individual interactions and invariance with respect to alternative hybridizations of lone pairs. Bond-sigma-lone-pair interactions which obtain maximum stabilization in their anti-periplanar orientations are significant even in anticlinal and syn-periplanar orientations and contribute, in comparison with bond-bond interactions, a much lower differential energy between eclipsed and staggered conformations. This finding explains interesting features of the rotational energy profiles, like the 'unusual' stability of some eclipsed rotamers. Bond-pi-lone-pair interactions are noticeably effective in their syn(anti)-periplanar orientations and are responsible for the stability of the skew forms of HOOH and FOOF; the exceptionally large OF-O(Ip, pi) interaction in difluorine dioxide is shown to be responsible for the unusually short O-O and long O-F bond lengths, in agreement with a previous explanation where the same structural features had been attributed to the large three-centre four-electron character of the FOO systems.
1991
- MOLECULAR-ORBITAL STUDY OF THE NITROGEN BASICITY OF PRAZOSIN ANALOGS IN RELATION TO THEIR ALPHA-1-ADRENOCEPTOR BINDING-AFFINITY
[Articolo su rivista]
DE BENEDETTI, Pier Giuseppe; Menziani, Maria Cristina; Rastelli, Giulio; Cocchi, Marina
abstract
AM1 theoretical molecular descriptors were computed for prazosin analogues (2-substituted 4-amino-6,7-dimethoxy derivatives of quinazoline, quinoline and isoquinoline) and and correlated with both their experimental acidity constants and alpha-1-adrenoceptor binding affinity data values. The results confirm the crucial role of the N1 protonated form of these derivatives for a selective and productive binding interaction with the alpha-1 adrenergic receptor.
1991
- QSAR Analysis Using Theoretical Molecular Descriptors in 2,4-Diamino-6,7-Dimethoxy Quinazoline 1-Adrenoceptor Antagonists.
[Abstract in Atti di Convegno]
DE BENEDETTI, Pier Giuseppe; Menziani, Maria Cristina; Rastelli, Giulio; Cocchi, Marina
abstract
QSAR Analysis,Theoretical Molecular Descriptors,Quinazoline,a1-Adrenoceptor Antagonists.
1991
- Theoretical conformational analysis, electronic structure and molecular modelling studies in dihydropteroate synthase in hibition by multisubstituted s
[Articolo su rivista]
Sokolov, Yu. A.; Menziani, M. C.; Cocchi, M.; De Benedetti, P. G.
abstract
Theoretical conformational analysis (MNDO) has been performed for six selected 4-aminoaryl multisubstituted aryl sulphones (4'-NH2; 2',4'-Cl2; 2',4',6'-Cl3; 2'-OH, 4'-O-; 2'-Cl, 4'-O-; 2'-CH3,4'-O-) which are competitive inhibitors, with respect to the substrate 4-aminobenzoate, of the dihydropteroate synthase. These derivatives show multiple conformational energy minima mainly due to the torsional freedom of the sulphur-carbon bond (θ2) of the substituted aryl ring. The other sulphur-carbon torsional angle considered (θ1), lying on the biofunctional common moiety 4-NH2C6H4SO2, is quite rigid, with the aryl ring perpendicular to the C1-S-C1' plane (θ1=90 °). The most stable conformera for all the derivatives considered are θ1=90 ° and θ2=90 ° (butterfly conformation) and θ1=90 ° and θ2=60 °. The highly active derivatives are, in general, less flexible and the inhibitory potency of the six sulphones considered is rationalized in terms of the electronic features of their common moiety, which do not significantly change among the different conformera of the same derivative. Finally, a good matching was obtained by computer superposition between the substrate 4-NH2C6H4COO- and the biofunctional common moiety 4-NH2C6H4SO2 of the sulphones. © 1991.
1990
- MODEL-CALCULATIONS OF CHEMICAL INTERACTIONS .1. INTRAMOLECULAR INTERACTIONS AND ROTATIONAL BARRIERS
[Articolo su rivista]
Rastelli, A; Cocchi, Marina; Schiatti, E.
abstract
A new method for calculation of rotational barrier and interaction energies is proposed based on introduction of hybrid atomic orbitals in ab-initio calculations
1990
- MODEL-CALCULATIONS OF CHEMICAL INTERACTIONS .2. INTRAMOLECULAR INTERACTIONS AND DOUBLE-BOND PYRAMIDALIZATION IN POLYCYCLIC ALKENES
[Articolo su rivista]
Rastelli, A; Cocchi, Marina; Schiatti, E; Gandolfi, R; Burdisso, M.
abstract
A new method for calculation of rotational barrier and interaction energies is proposed based on introduction of hybrid atomic orbitals in ab-initio calculations
1990
- QSAR analysis in 2,4-diamino-6,7-dimethoxy quinoline derivatives - α1-adrenoceptor antagonists - using the partial least squares (PLS) method and theoretical molecular descriptors
[Articolo su rivista]
Cocchi, Marina; Menziani, Maria Cristina; Rastelli, Giulio; DE BENEDETTI, Pier Giuseppe
abstract
QSAR analysis in 2,4-diamino-6,7-dimethoxy quinoline derivatives - α1-adrenoceptor antagonists - using the partial least squares (PLS) method and theoretical molecular descriptors
1989
- A Theoretical Study of Conformation-Electronic Structure Relationships in Benzensulfonamide Inhibitors of Carbonic Anhydrase Enzyme.
[Articolo su rivista]
DE BENEDETTI, Pier Giuseppe; Menziani, Maria Cristina; Cocchi, Marina; Frassineti, Chiara
abstract
A Theoretical Study of Conformation-Electronic Structure Relationships in Benzensulfonamide Inhibitors of Carbonic Anhydrase Enzyme.
1989
- Comparative QSAR Analysis in Dihydropteroate Synthase Inhibition by Sulphones. Design of Some New Derivatives with Improved Petency.
[Articolo su rivista]
DE BENEDETTI, Pier Giuseppe; Iarossi, Dario; Frassineti, Chiara; Menziani, Maria Cristina; Cocchi, Marina; Cennamo, Carlo
abstract
Comparative QSAR Analysis in Dihydropteroate Synthase Inhibition by Sulphones. Design of Some New Derivatives with Improved Petency.
1989
- Studies of 13C NMR Substituent Chemical Shifts of Disubstituted Benzenes Using Multivariate Data Analysis
[Articolo su rivista]
D., Jonhels; U., Edlund; E., Johansson; Cocchi, Marina
abstract
The non-additivity in the 13C substituent chemical shifts (SCS) of 1,3-and 1,4-disubstituted benzenes has been studied using multivariate data analytical methods. Most of the non-additivity is systematic and can be predicted with high accuracy (0.2 ppm) from carbon shifts of monosubstituted benzenes. This means that no additional substituent effects are needed and that the non-additivity contributions of the SCS are clustered in the same way as previously noticed for 13C SCS in monosubstituted benzenes.
1987
- A Quantum Chemical QSAR Analysis of Carbonic Anhydrase Inhibition by Heterocyclic Sulfonamides.
[Articolo su rivista]
DE BENEDETTI, Pier Giuseppe; Menziani, Maria Cristina; Cocchi, Marina; Frassineti, Chiara
abstract
A Quantum Chemical QSAR Analysis of Carbonic Anhydrase Inhibition by Heterocyclic Sulfonamides.