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FRANCESCO BIGI
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2023
- Non-thermal techniques and the “hurdle” approach: How is food technology evolving?
[Articolo su rivista]
Bigi, Francesco; Maurizzi, Enrico; Quartieri, Andrea; De Leo, Riccardo; Gullo, Maria; Pulvirenti, Andrea
abstract
Food technology has played a crucial role since the beginning of human civilization. Throughout the centuries, the evolution of food processing has led to an increase of food safety and quality, enhancing the overall quality of human life. Lately, academic research and industries have gained awareness about the impact of conventional preservation technologies like heat sterilization and chemical preservatives on environment and economy, besides the detrimental effects on the organoleptic and nutritional quality of foods. This consciousness oriented the efforts towards more sustainable techniques, paving the way to a new “green era” of food technology.Scope and approach
This work explores seven non-thermal technologies, describing their theoretical principles, mechanism of action, effect on microorganisms, advantages, and limitations. Besides, the concept of hurdle technology to overcome the criticisms related to single processing techniques is highlighted.
Key findings and conclusions
Non-thermal technologies have the potential to substitute conventional techniques for microbial inactivation, improving the safety and quality of food. The efficiency of each technique strongly relies on the process parameters (treatment intensity; exposure time), equipment (geometry; conformation), product (physical state; composition; viscosity; geometry), and microorganism characteristics (strain; concentration; growth phase; resistance mechanisms). In this sense, the hurdle approach allows to overcome the limitations related to the single technologies, broadening their efficiency and application range, and minimizing their impact on food quality. Further studies are recommended to better understand the mechanisms of mutual interaction among these techniques when combined together in specific conditions, in view of their scaling-up for commercial applications.
2023
- Waste Orange Peels as a Source of Cellulose Nanocrystals and Their Use for the Development of Nanocomposite Films
[Articolo su rivista]
Bigi, Francesco; Maurizzi, Enrico; Haghighi, Hossein; Siesler, Heinz Wilhelm; Licciardello, Fabio; Pulvirenti, Andrea
abstract
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Open AccessArticle
Waste Orange Peels as a Source of Cellulose Nanocrystals and Their Use for the Development of Nanocomposite Films
by Francesco Bigi
1 [ORCID] , Enrico Maurizzi
1 [ORCID] , Hossein Haghighi
1 [ORCID] , Heinz Wilhelm Siesler
2 [ORCID] , Fabio Licciardello
1,3 [ORCID] and Andrea Pulvirenti
1,3,* [ORCID]
1
Department of Life Sciences, University of Modena and Reggio Emilia, 42015 Reggio Emilia, Italy
2
Department of Physical Chemistry, University of Duisburg-Essen, 45141 Essen, Germany
3
Interdepartmental Research Centre for the Improvement of Agri-Food Biological Resources (BIOGEST-SITEIA), University of Modena and Reggio Emilia, 42015 Reggio Emilia, Italy
*
Author to whom correspondence should be addressed.
Foods 2023, 12(5), 960; https://doi.org/10.3390/foods12050960
Received: 19 January 2023 / Revised: 16 February 2023 / Accepted: 21 February 2023 / Published: 24 February 2023
(This article belongs to the Special Issue Scientific Breakthroughs to Fruit and Vegetable By-Product Valorization in Food Sector)
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Abstract
To date, approximately 30–50% of food is wasted from post-harvesting to consumer usage. Typical examples of food by-products are fruit peels and pomace, seeds, and others. A large part of these matrices is still discarded in landfills, while a small portion is valorized for bioprocessing. In this context, a feasible strategy to valorize food by-products consists of their use for the production of bioactive compounds and nanofillers, which can be further used to functionalize biobased packaging materials. The focus of this research was to create an efficient methodology for the extraction of cellulose from leftover orange peel after juice processing and for its conversion into cellulose nanocrystals (CNCs) for use in bionanocomposite films for packaging materials. Orange CNCs were characterized by TEM and XRD analyses and added as reinforcing agents into chitosan/hydroxypropyl methylcellulose (CS/HPMC) films enriched with lauroyl arginate ethyl (LAE). It was evaluated how CNCs and LAE affected the technical and functional characteristics of CS/HPMC films. CNCs revealed needle-like shapes with an aspect ratio of 12.5, and average length and width of 500 nm and 40 nm, respectively. Scanning electron microscopy and infrared spectroscopy confirmed the high compatibility of the CS/HPMC blend with CNCs and LAE. The inclusion of CNCs increased the films’ tensile strength, light barrier, and water vapor barrier properties while reducing their water solubility. The addition of LAE improved the films’ flexibility and gave them biocidal efficacy against the main bacterial pathogens that cause foodborne illness, such as Escherichia coli, Pseudomonas fluorescens, Listeria monocytogenes, and Salmonella enterica.
2022
- The Green Era of Food Packaging: General Considerations and New Trends
[Articolo su rivista]
Maurizzi, Enrico; Bigi, Francesco; Quartieri, Andrea; De Leo, Riccardo; Volpelli, Luisa Antonella; Pulvirenti, Andrea
abstract
Recently, academic research and industries have gained awareness about the economic, environmental, and social impacts of conventional plastic packaging and its disposal. This consciousness has oriented efforts towards more sustainable materials such as biopolymers, paving the way for the “green era” of food packaging. This review provides a schematic overview about polymers and blends of them, which are emerging as promising alternatives to conventional plastics. Focus was dedicated to biopolymers from renewable sources and their applications to produce sustainable, active packaging with antimicrobial and antioxidant properties. In particular, the incorporation of plant extracts, food-waste derivatives, and nano-sized materials to produce bio-based active packaging with enhanced technical performances was investigated. According to recent studies, bio-based active packaging enriched with natural-based compounds has the potential to replace petroleum-derived materials. Based on molecular composition, the natural compounds can diversely interact with the native structure of the packaging materials, modulating their barriers, optical and mechanical performances, and conferring them antioxidant and antimicrobial properties. Overall, the recent academic findings could lead to a breakthrough in the field of food packaging, opening the gates to a new generation of packaging solutions which will be sustainable, customised, and green.
2021
- Characterization of chitosan-hydroxypropyl methylcellulose blend films enriched with nettle or sage leaf extract for active food packaging applications
[Articolo su rivista]
Bigi, F.; Haghighi, H.; Siesler, H. W.; Licciardello, F.; Pulvirenti, A.
abstract
The incorporation of plant leaf extracts into biodegradable food packaging materials is a promising green approach to develop active films with antioxidant and antimicrobial activities. In this context, this study aimed to develop active films based on chitosan/hydroxypropyl methylcellulose blend (CS/HPMC) enriched with sage (SLE) and nettle (NLE) leaf extracts (7.5–15% w/w of biopolymer) to characterize their surface and cross-section morphology, optical, mechanical, water barrier, and antioxidant properties for food packaging applications. Scanning electron microscopy confirmed microstructural integrity and compatibility between CS and HPMC and incorporated leaf extracts. The successful incorporation of plant extracts was confirmed by Fourier transform infrared spectroscopy. Active films showed improvement in UV–Vis light barrier properties (p < 0.05) with opacity value lower than five. Addition of leaf extracts induced a slightly darker color by inducing a green and yellow shade. Addition of NLE increased the water solubility and water vapor permeability compared to the control film (p < 0.05). Total phenolic content and antioxidant activity were increased upon addition of leaf extracts. Overall, CS/HPMC films incorporated with SLE and NLE could be employed as a green alternative for partial substitution of synthetic plastics with antioxidant activity and to prolong the shelf-life of food products.
2021
- Impact of low‐dose gaseous ozone treatment to reduce the growth of in vitro broth cultures of foodborne pathogenic/spoilage bacteria in a food storage cold chamber
[Articolo su rivista]
Bigi, Francesco; Haghighi, Hossein; Quartieri, Andrea; De Leo, Riccardo; Pulvirenti, Andrea
abstract
Cold storage coupled with gaseous ozone represents a potential strategy to reduce
or inhibit the presence of pathogenic and spoilage bacteria in a food storage cold
chamber. This study aims to evaluate the impact of gaseous ozone treatment
(0.05 ppm at exposure times of 30 and 60 min) on the bacterial contamination of
internal surface and air in a cold chamber (3C) intended for food storage. The bacterial
load of internal surfaces was reduced by 0.99 ± 0.24 and 1.35 ± 0.27 log after
30 and 60 min ozone treatment, respectively. Airborne bacterial load was reduced by
0.93 ± 0.24 log after 30 min ozone treatment and became non-detectable after
60 min. Gaseous ozone treatments (0.05 ppm at exposure times of 1, 2, 6, 24,
30, and 48 hr) of the cold chamber were investigated to evaluate the effectiveness of
this technology against Escherichia coli, Listeria monocytogenes, Salmonella enterica
Typhimurium, Campylobacter jejuni, and Pseudomonas fluorescens cultured in broth
cultures. Ozone treatment was effective against C. jejuni since the population at the
highest concentration of inoculum (3.34 log CFU/plate) was reduced by 2.23 log
after 1 hr and it was completely undetectable after 2 hr. S. enterica and E. coli showed
the highest resistance to short ozone treatment since 6 hr treatment did not show
antibacterial activity whereas after 24 hr treatment around 2 log reduction was
observed for both pathogens. Short ozone treatment did not affect L. monocytogenes
viability. P. fluorescens showed high sensitivity to short treatments, with 0.75–1.32
log reductions after 1 hr and further 0.22–0.53 log reductions after 6 hr.
2021
- Multivariate exploratory data analysis by PCA of the combined effect of film-forming composition, drying conditions, and UV-C irradiation on the functional properties of films based on chitosan and pectin
[Articolo su rivista]
Bigi, F.; Haghighi, H.; De Leo, R.; Ulrici, A.; Pulvirenti, A.
abstract
The technical features of biodegradable films depend on several manufacturing parameters. Exploiting these films on an industrial basis requires statistical models for the fast and effective evaluation of these parameters. This study analyses the impact of compositional and drying factors on the microstructural and functional properties of films based on chitosan and pectin through a multivariate approach. A total of 32 formulations were developed and the results were analysed through principal component analysis (PCA). Four formulations did not form films due to the photodegradation caused by prolonged UV-C irradiation. Films containing glycerol had a higher elasticity (1.5–39%) than those with propylene glycol or that were not plasticized (1.2–12%). Glycerol increased the thickness of pectin films (56–77 μm). Sodium trimethaphosphate (STMP) enhanced the UV mean absorbance of both pectin and chitosan films (0.7–1.7). In addition, STMP led to an increase of thickness (72–129 μm) and air permeability (38.6 × 103 to 9206.1 × 103 cm3/m2 × day × kPa) of the chitosan films, while CaCl2 led to a decrease of thickness (31–59 μm) and air permeability (23.9 × 103 to 46.8 × 103 cm3/m2 × day × kPa) of the pectin films.
2020
- Combined Effects of Dewatering, Composting and Pelleting to Valorize and Delocalize Livestock Manure, Improving Agricultural Sustainability
[Articolo su rivista]
Ronga, Domenico; Mantovi, Paolo; Pacchioli, Maria Teresa; Pulvirenti, Andrea; Bigi, Francesco; Allesina, Giulio; Pedrazzi, Simone; Tava, Aldo; Dal Prà, Aldo
abstract
An agronomic strategy to mitigate climate change impact can be the build-up of soil
organic carbon. Among agronomic management approaches, the administration of organic fertilizers
like livestock manure represents an eective strategy to increase soil organic carbon. However,
livestock manure usually contains a high amount of water, reducing its sustainable delocalization
and impacting on greenhouse gas emissions and nutrient leaching. Furthermore, the possible
presence of weed seeds and harmful microorganisms could reduce the agronomic value of the
manure. To overcome these issues, the combined eects of dewatering, composting and pelleting
were investigated on livestock manure to produce sustainable organic fertilizers. Our results showed
that composting and pelleting can represent a feasible and sustainable solution to reduce the potential
risks related to the presence of weed seeds and harmful bacteria, concentrating nutrients and allowing
a sustainable valorization and delocalization of the livestock manure. In addition, the processed
manures were assessed as fertilizers in the growing medium (GM), displaying an increase in water
retention and nutrient availability and a decrease of GM temperature and weed seed emergences.
However, further study is needed to validate, both in open field and greenhouse productions,
the eects of the proposed fertilizers in real cropping systems.
2019
- Comprehensive characterization of active chitosan-gelatin blend films enriched with different essential oils
[Articolo su rivista]
Haghighi, Hossein; Biard, Syméon; Bigi, Francesco; DE LEO, Riccardo; Bedin, Elisa; Pfeifer, Frank; Siesler, Heinz Wilhelm; Licciardello, Fabio; Pulvirenti, Andrea
abstract
Natural extracts and plant essential oils (EOs) have long been recognized as valid alternatives to synthetic food additives owing to their proved wide-spectrum antimicrobial capacity. The main aim of this study was to characterize the physical, mechanical, water barrier, microstructural and antimicrobial properties of chitosan-gelatin blend films enriched with cinnamon, citronella, pink clove, nutmeg and thyme EOs. The film microstructure determined by scanning electron microscopy, showed that all active films had heterogeneous surface: in particular, films including cinnamon, nutmeg and thyme EOs showed remarkable pores on the surface. The possible interaction of chitosan-gelatin blend film with incorporated EOs was investigated using Fourier-transform infrared (FT-IR) spectroscopy. Presence of new bands and changes in the FT-IR spectra confirmed intermolecular interactions between the chitosan-gelatin matrix and the EOs. The antimicrobial activity of films was determined using the disk diffusion assay. Active films inhibited the growth of four major food bacterial pathogens including Campylobacter jejuni, Escherichia coli, Listeria monocytogenes and Salmonella typhimurium and, among the tested EOs, thyme was the most effective (p < 0.05). The active films can be considered as effective barriers against UV light. The incorporation of EOs to the chitosan-gelatin film increased thickness, moisture content, water vapor permeability, b* and ΔE* values (p < 0.05) while it decreased L* value, light transparency and opacity (p < 0.05). Overall, the characterization of functional properties revealed that chitosan-gelatin films incorporated with EOs could be used as environmentally friendly active food packaging with antimicrobial properties and potential to extend the shelf-life of food products.