Enhancement of Egyptian soft white cheese shelf life using a novel chitosan/carboxymethyl cellulose/zinc oxide bionanocomposite film

Sustainable production of cellulosic biopolymers for enhanced smart food packaging: An up-to-date review

Biodegradable and sustainable food packaging (FP) materials have gained immense global importance to reduce plastic pollution and environmental impact. Therefore, this review focused on the recent advances in biopolymers based on cellulose derivatives for FP applications. Cellulose, an abundant and renewable biopolymer, and its various derivatives, namely cellulose acetate, cellulose sulphate, nanocellulose, carboxymethyl cellulose, and methylcellulose, are explored as promising substitutes for conventional plastic in FP. These reviews focused on the production, modification processes, and properties of cellulose derivatives and highlighted their potential for their application in FP. Finally, we reviewed the effects of incorporating cellulose derivatives into film in various aspects of packaging properties, including barrier, mechanical, thermal, preservation aspects, antimicrobial, and antioxidant properties. Overall, the findings suggest that cellulose derivatives have the potential to replace conventional plastics in food packaging applications. This can contribute to reducing plastic pollution and lessening the environmental impact of food packaging materials. The review likely provides insights into the current state of research and development in this field and underscores the significance of sustainable food packaging solutions.

Intelligent double-layer film based on gellan gum/modified anthocyanin/curcumin/sodium alginate/zinc oxide for monitoring shrimp freshness

In this study, intelligent double-layer films were prepared using modified black rice anthocyanin (MBRA)-curcumin (CUR)-gellan gum (GG) as the inner indicator layer and sodium alginate (ALG)‑zinc oxide (ZnO) as the outer antimicrobial layer. The bilayer films were successfully prepared, as revealed by scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction measurements. The mechanical characteristics, moisture content, and water vapor resistance of GG-MBRA/CUR1@ALG-ZnO, GG-MBRA/CUR2@ALG-ZnO, and GG-MBRA/CUR3@ALG-ZnO films showed significant enhancement compared to GG-MBRA/CUR3 and ALG-ZnO films. The bilayer films exhibited excellent pH responsiveness and reacted effectively to ammonia. The outer layer significantly improved the antioxidant and antibacterial properties of the inner layer. When the films were applied to shrimp, it was found that the double-layer films not only monitored the freshness of the shrimp in real-time but also were influential in extending the shelf life of the shrimp by about 1 d. Therefore, the double-layer film demonstrated potential as a smart packaging material for real-time monitoring of meat product freshness.

Carboxymethylcellulose/Agar-Based Multifunctional Films Incorporated with Zn-Doped SnO2 Nanoparticles for Active Food Packaging Application

SnO2 and Zn-SnO2 nanoparticles were prepared by chemical precipitation, and the rutile phase of SnO2 was confirmed through X-ray diffraction studies. X-ray photoelectron spectroscopy (XPS) confirmed the doping of SnO2 with Zn and elucidated the surface chemistry before and after doping. The average sizes of SnO2 and Zn-SnO2 nanoparticles determined using TEM were 3.96 ± 0.85 and 3.72 ± 0.9 nm, respectively. UV-visible and photoluminescence spectrophotometry were used to evaluate the optical properties of SnO2 and Zn-SnO2 nanoparticles, and their energy gaps (Eg) were 3.8 and 3.9 eV, respectively. The antibacterial activity of these nanoparticles against Salmonella enterica and Staphylococcus aureus was evaluated under dark and light conditions. Antibacterial activity was higher in light, showing the highest activity (99.5%) against S. enterica. Carboxymethylcellulose (CMC)/agar-based functional composite films were prepared by adding different amounts of SnO2 and Zn-SnO2 nanoparticles (1 and 3 wt % of polymers). The composite film showed significantly increased UV barrier properties while maintaining the mechanical properties, water vapor barrier, and transparency compared to the neat CMC/agar film. These composite films showed significant antibacterial activity; however, the Zn-SnO2-added film showed stronger antibacterial activity (99.2%) than the SnO2-added film (15%).

Packaging films based on biopolymers from seafood processing wastes: Preparation, properties, and their applications for shelf-life extension of seafoods-A comprehensive review

Biopolymers derived from seafood processing byproducts are used to prepare active and biodegradable films as the packaging of food products. These films possess bioactivities to enhance the shelf life of packed foods by proactively releasing antimicrobial/antioxidative agents into the foods and providing sufficient barrier properties. Seafood processing byproducts are an eminent source of valuable compounds, including biopolymers and bioactive compounds. These biopolymers, including collagen, gelatin, chitosan, and muscle proteins, could be used to prepare robust and sustainable food packaging with some antimicrobial agents or antioxidants, for example, plant extracts rich in polyphenols or essential oils. These active packaging are not only biodegradable but also prevent the deterioration of packed foods caused by spoilage microorganisms as well as chemical deterioration. Seafood discards have a promising benefit for the development of environmentally friendly food packaging systems via the appropriate preparation methods or techniques. Therefore, the green packaging from seafood leftover can be better exploited and replace the synthetic counterpart.

Evaluation of zinc oxide nanocomposite with Aloe vera gel for packaging of chicken fillet against Salmonella typhi and Salmonella para typhi A

The growing demand for high food quality has been encouraging researchers in the food industry to apply biodegradable nanocomposites, which provide new opportunities and challenges for the advance of nanomaterials in the food industry. The objective of this study was to estimate the antibacterial activity and cytotoxicity effects of zinc oxide nanocomposite/zeolite (c/Zeo) with Aloe vera gel (AG) and its effect on the shelf life of chicken meat. The ZnONPs/Zeo was assessed using X-ray fluorescence (XRF) and field emission scanning electron microscopy (FE-SEM) analyses. The cytotoxicity effect of ZnONPs/Zeo was assessed by MTT assay. Then, the minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) of ZnONPs/Zeo and ZnONPs/Zeo-AG against Salmonella typhi and Salmonella para typhi A were investigated. Also, the preservative effect of nanocomposites on chicken fillets was evaluated. The results showed that these nanocomposites have the least cytotoxicity effect, resulting in good biocompatibility with the host. The MIC and MBC values of ZnONPs/Zeo-AG were lower than the ZnONPs/Zeo against S. typhi and S. paratyphi A. Both ZnONPs/Zeo-AG and ZnONPs/Zeo caused a significant decrease in the bacterial count of the chicken fillets. So, by spraying on meat, the number of bacteria presented a sharper decline as compared with the control group, resulting in an approximately 3.3 and 3-log10 reduction over 48 h in the ZnONPs/Zeo-AG and ZnONPs/Zeo treatment samples, respectively. In conclusion, antimicrobial packaging with ZnONPs containing A. vera is a beneficial solution for preserving and improving the quality, safety, and shelf life of fresh meat products.

Chitosan Coatings Modified with Nanostructured ZnO for the Preservation of Strawberries

Strawberries are highly consumed around the world; however, the post-harvest shelf life is a market challenge to mitigate. It is necessary to guarantee the taste, color, and nutritional value of the fruit for a prolonged period of time. In this work, a nanocoating based on chitosan and ZnO nanoparticles for the preservation of strawberries was developed and examined. The chitosan was obtained from residual shrimp skeletons using the chemical method, and the ZnO nanoparticles were synthesized by the close-spaced sublimation method. X-ray diffraction, scanning electron microscopy, electron dispersion analysis, transmission electron microscopy, and infrared spectroscopy were used to characterize the hybrid coating. The spaghetti-like ZnO nanoparticles presented the typical wurtzite structure, which was uniformly distributed into the chitosan matrix, as observed by the elemental mapping. Measurements of color, texture, pH, titratable acidity, humidity content, and microbiological tests were performed for the strawberries coated with the Chitosan/ZnO hybrid coating, which was uniformly impregnated on the strawberries' surface. After eight days of storage, the fruit maintained a fresh appearance. The microbial load was reduced because of the synergistic effect between chitosan and ZnO nanoparticles. Global results confirm that coated strawberries are suitable for human consumption.

Chitosan Based Biodegradable Composite for Antibacterial Food Packaging Application

A recent focus on the development of biobased polymer packaging films has come about in response to the environmental hazards caused by petroleum-based, nonbiodegradable packaging materials. Among biopolymers, chitosan is one of the most popular due to its biocompatibility, biodegradability, antibacterial properties, and ease of use. Due to its ability to inhibit gram-negative and gram-positive bacteria, yeast, and foodborne filamentous fungi, chitosan is a suitable biopolymer for developing food packaging. However, more than the chitosan is required for active packaging. In this review, we summarize chitosan composites which show active packaging and improves food storage condition and extends its shelf life. Active compounds such as essential oils and phenolic compounds with chitosan are reviewed. Moreover, composites with polysaccharides and various nanoparticles are also summarized. This review provides valuable information for selecting a composite that enhances shelf life and other functional qualities when embedding chitosan. Furthermore, this report will provide directions for the development of novel biodegradable food packaging materials.

Design and characterization of an antibacterial film composited by hydroxyethyl cellulose (HEC), carboxymethyl chitosan (CMCS), and nano ZnO for food packaging

For food packaging, a novel composite film was prepared by solution casting method using hydroxyethyl cellulose (HEC), carboxymethyl chitosan (CMCS), and zinc oxide nanoparticles as raw materials. The composite film successfully compounded the nanoparticles, as deduced by spectroscopy, crystallography and morphology observation. The addition of CMCS and ZnO enhanced the solvent resistance (the water solubility of the composite film was reduced by 94.3 %) and UV shielding ability (the UV shielding capacity of the composite film was increased by 45.73 %) of the composite film, thus improving the application prospects of the composite film in water-rich foods. In addition, the synergistic effect of CMCS and ZnO helped the composite film to efficiently inhibit the pathogenic bacteria Listeria monocytogenes and Pseudomonas aeruginosa (rate of inhibition>99.99 %) in food. The addition of CMCS and ZnO also significantly improved the elasticity (improve 494.34 %) and maximum load capacity (improve 142.24 %) of the composite film.

The Effect of Active Chitosan Films Containing Bacterial Cellulose Nanofiber and ZnO Nanoparticles on the Shelf Life of Loaf Bread

Due to the disadvantages of synthetic packaging materials such as migration, environmental pollution, lack of easy recycling, and high production costs, natural polymers have received much attention as safe and biodegradable alternatives to plastics. The aim of this study was to investigate the effect of the active film of chitosan (CH) containing bacterial cellulose nanofiber (BCNF) and ZnO nanoparticles (ZnO NPCs) on the shelf life of loaf bread (toast, baguette, and sandwich-type bread). The results showed that ZnO NPCs significantly reduced the thickness and water vapor permeability (WVP) and increased the opacity of films $\left(p<0.05\right)$ . CH-BCNF-ZnO 2% NPCs film had the lowest thickness and WVP and the highest opacity. Differential scanning calorimetric (DSC), thermal gravimetry analysis (TGA), and derivative thermogravimetry (DTG) showed that ZnO NPCs increased the thermal stability of chitosan films. CH-BCNF-ZnO 1% NPCs had the highest melting point (148.66°C) and melting enthalpy (ΔHm). Scanning electron microscopy (SEM) images showed the good distribution of ZnO NPCs in the chitosan film. The higher concentrations of ZnO NPCs formed aggregates in the polymer. ZnO NPCs had a significant effect on the physicochemical properties of bread. The highest moisture content and water activity $\left(a_w\right)$ were observed in CH-BCNF-ZnO 2% toast and control toast, respectively. CH toast showed high ash and insoluble ash. CH baguettes and control baguettes showed the highest pH. As the ZnO NPCs concentration increased, the nanoparticle migration increased. The highest migration was observed in CH-BCNF-ZnO 2% baguette. The highest and lowest hardness was observed in CH-BCNF-ZnO NPCs 2% baguette and CH-BCNF- ZnO NPCs 1% toast bread, respectively. Composite films decreased the microbial population in all bread samples except sandwich-type bread. It can be concluded that BCNF and ZnO NPCs improve the physical properties of chitosan film and can be suggested as active packaging in bread.

High performance biopolymeric packaging films containing zinc oxide nanoparticles for fresh food preservation: A review

Biodegradable food packaging films (FPFs) assembled from sustainable biopolymeric materials are of increasing interest to the food industry due to pollution and health risks resulting from the use of conventional plastic packaging. However, the functional performance of these FPFs is often poorer than that of plastic films, which limits their commercial application. This problem may be partly overcome by incorporating nano-additives like zinc oxide nanoparticles (ZNPs) into the films. The incorporation of ZNPs into FPFs can improve their functional performance. The properties of these films depends on the concentration, dispersion state, and interactions of ZNPs with the biopolymeric matrix in the films. ZNPs-loaded films and coatings are highly effective at preserving a variety of fresh foods. Studies of ZNPs migration through FPFs have shown that the zinc is mainly transported in an ionic form and the amount entering foods is below safety standards. This article reviews recent developments in the design, fabrication, and application of ZNPs-loaded FPFs based on biopolymers, focusing on the impacts of ZNPs on the optical, barrier, mechanical, water sensitivity, and antimicrobial properties of the films. The potential applications of ZNPs-loaded FPFs for fresh food preservation is also discussed.

The use of essential oils in chitosan or cellulose-based materials for the production of active food packaging solutions: a review

In recent decades, interest in sustainable food packaging systems with additional functionality, able to increase the shelf life of products, has grown steadily. Following this trend, the present review analyzes the state of the art of this active renewable packaging. The focus is on antimicrobial systems containing nanocellulose and chitosan, as support for the incorporation of essential oils. These are the most sustainable and readily available options to produce completely natural active packaging materials. After a brief overview of the different active packaging technologies, the main features of nanocellulose, chitosan, and of the different essential oils used in the field of active packaging are introduced and described. The latest findings about the nanocellulose- and chitosan-based active packaging are then presented. The antimicrobial effectiveness of the different solutions is discussed, focusing on their effect on other material properties. The effect of the different inclusion strategies is also reviewed considering both in vivo and in vitro studies, in an attempt to understand more promising solutions and possible pathways for further development. In general, essential oils are very successful in exerting antimicrobial effects against the most diffused gram-positive and gram-negative bacteria, and affecting other material properties (tensile strength, water vapor transmission rate) positively. Due to the wide variety of biopolymer matrices and essential oils available, it is difficult to create general guidelines for the development of active packaging systems. However, more attention should be dedicated to sensory analysis, release kinetics, and synergetic action of different essential oils to optimize the active packaging on different food products. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Preparation of Novel Composites of Polyvinyl Alcohol Containing Hesperidin Loaded ZnO Nanoparticles and Determination of Their Biological and Thermal Properties

Hesperidin (HSP) is considered to be the most effective antimicrobial agent against SARS-CoV2 virus. The HSP was loaded onto ZnO nanoparticles that were successfully incorporated, via the hydrothermal method, into polyvinyl alcohol (PVA) for use as food packaging material. The hydrothermal method enabled the bioactive ZnO-HSP to be homogeneously dispersed in the PVA, which significantly increased the thermal stability of the matrix, while decreasing the softening temperature. The water holding capacity and water solubility of the obtained nanocomposites was reduced compared to the PVA. Finally, the ZnO-HSP antimicrobial agent contributed important antibacterial properties to the PVA and increased its antioxidant capacity against Staphylococcus aureus and Escherichia coli pathogens. In addition, the nanocomposites had no cytotoxic/proliferative effects on cancer cells. All results showed promise that the PVA/ZnO-HSP nanocomposites would be an excellent alternative for food packaging applications.

Novel Features of Cellulose-Based Films as Sustainable Alternatives for Food Packaging

Packaging plays an important role in food quality and safety, especially regarding waste and spoilage reduction. The main drawback is that the packaging industry is among the ones that is highly dependent on plastic usage. New alternatives to conventional plastic packaging such as biopolymers-based type are mandatory. Examples are cellulose films and its derivatives. These are among the most used options in the food packaging due to their unique characteristics, such as biocompatibility, environmental sustainability, low price, mechanical properties, and biodegradability. Emerging concepts such as active and intelligent packaging provides new solutions for an extending shelf-life, and it fights some limitations of cellulose films and improves the properties of the packaging. This article reviews the available cellulose polymers and derivatives that are used as sustainable alternatives for food packaging regarding their properties, characteristics, and functionalization towards active properties enhancement. In this way, several types of films that are prepared with cellulose and their derivatives, incorporating antimicrobial and antioxidant compounds, are herein described, and discussed.

A comprehensive review of food gels: formation mechanisms, functions, applications, and challenges

Gels refer to the soft and flexible macromolecular polymeric materials retaining a large amount of water or biofluids in their three-dimensional network structure. Gels have attracted increasing interest in the food discipline, especially proteins and polysaccharides, due to their good biocompatibility, biodegradability, nutritional properties, and edibility. With the advancement of living standards, people's demand for nutritious, safe, reliable, and functionally diverse food and even personalized food has increased. As a result, gels exhibiting unique advantages in food application will be of great significance. However, a comprehensive review of functional hydrogels as food gels is still lacking. Here, we comprehensively review the gel-forming mechanisms of food gels and systematically classify them. Moreover, the potential of hydrogels as functional foods in different types of food areas is summarized, with a special focus on their applications in food packaging, satiating gels, nutrient delivery systems, food coloring adsorption, and food safety monitoring. Additionally, the key scientific issues for future food gel research, with specific reference to future novel food designs, mechanisms between food components and matrices, food gel-human interactions, and food gel safety, are discussed. Finally, the future directions of hydrogels for food science and technology are summarized.

Edible Films Made of Dried Olive Leaf Extract and Chitosan: Characterization and Applications

Nowadays a possible strategy in food preservation consists of the use of active and functional packaging to improve safety and ensure a longer shelf life of food products. Many studies refer to chitosan-based films because of the already-known chitosan (CH) antibacterial and antifungal activity. In this work, we developed CH-based films containing Dried Olive Leaf Extract (DOLE) obtained by Naviglio extractor, with the aim to investigate the polyphenols yield and the antioxidant activity of this extract entrapped in CH-based-edible films. Olive tree cultivation produces a huge amount of byproducts that are usually simply burned. Phenolic compounds are already studied for their beneficial effects on human health. Some studies reported that phenols isolated from olive leaves have been shown to inhibit the growth of different strains of microorganisms. Thus, the antimicrobial effect of DOLE-containing films against bacterial strains (Salmonella enterica subsp. enterica serovar Typhimurium ATCC^® 14028, Salmonella enteritidis RIVM 706, and Enterococcus faecalis ATCC^® 29212) was tested in vitro. The DOLE component of the films is effective in inhibiting all the bacteria tested in a dose-dependent manner. Thus, it was demonstrated that these edible films can act as active bioplastics when used to wrap hamburgers in substitution for baking paper, which is normally used.

Natural alternatives for processed meat: Legislation, markets, consumers, opportunities and challenges

Consumers' interest in food with less and/or free from synthetic additives has increased considerably in recent years. In this context, researchers and industries have concentrated efforts on developing alternatives to these compounds. Replacing synthetic additives in meat products is a challenge, given their importance for sensory characteristics and food safety. Complementary technologies combined with the replacement and/or reduction of synthetic additives (hurdle technologies) has been studied focusing on the protection and extension of the shelf life of meat products. This review reports alternatives for replacing and/or reducing the use of synthetic additives in meat derivatives, aiming at the development of more natural and simpler meat products, familiar to consumers and considered clean labels.

Citric acid incorporated in a chitosan film as an active packaging material to improve the quality and duration of matured cheese shelf life

Chitosan-based film incorporated with citric acid was prepared by the casting method for application in a Brazilian matured cheese. Three formulations of cheese were processed, with the intention of evaluating the application of a starter culture and the effect of the film in terms of its physiochemical, microbiological, and sensorial characteristics. It was observed by scanning electron microscopy (sem) analysis that the film has a homogeneous appearance, and the crosslinking between citric acid and chitosan was confirmed by the Fourier transform infrared spectroscopy (FTIR) analysis. The cheese with chitosan-based film presented lower weight loss (5.2%) and showed antimicrobial activity against aerobic mesophilic bacteria. All samples showed high rates of sensorial acceptability (>79%), with no significant differences between them. It is apparent that the chitosan film maintained the typical cheese characteristics. Therefore, chitosan and citric acid film can be used to improve the characteristics of matured cheese and extend its shelf life.

Chitosan as a Tool for Sustainable Development: A Mini Review

New developments require innovative ecofriendly materials defined by their biocompatibility, biodegradability, and versatility. For that reason, the scientific society is focused on biopolymers such as chitosan, which is the second most abundant in the world after cellulose. These new materials should show good properties in terms of sustainability, circularity, and energy consumption during industrial applications. The idea is to replace traditional raw materials with new ecofriendly materials which contribute to keeping a high production rate but also reducing its environmental impact and the costs. The chitosan shows interesting and unique properties, thus it can be used for different purposes which contributes to the design and development of sustainable novel materials. This helps in promoting sustainability through the use of chitosan and diverse materials based on it. For example, it is a good sustainable alternative for food packaging or it can be used for sustainable agriculture. The chitosan can also reduce the pollution of other industrial processes such as paper production. This mini review collects some of the most important advances for the sustainable use of chitosan for promoting circular economy. Hence, the present review focuses on different aspects of chitosan from its synthesis to multiple applications.

Occurrence and D-Tryptophan Application for Controlling the Growth of Multidrug-Resistant Non-O157 Shiga Toxin-Producing Escherichia coli in Dairy Products

The objectives of the current study were first to determine the prevalence of non O157:H7E. coli, especially Shiga toxin-producing Escherichia coli (STEC) in retailed milk and dairy products in Egypt. Second, the antimicrobial resistance profiling and virulence genes of the isolated E. coli strains were screened. Third, evaluation of the inhibitory effects of D-tryptophan against E. coli O26:H11 was further performed. The results revealed that 20% (30/150) of the samples were STEC positive, with 64 isolates harboring some virulent genes, such as Stx1, Stx2, eaeA, and hylA. Serological identification revealed four different pathotypes belonging to EPEC, ETEC, EHEC, and EIEC. Antimicrobial susceptibility testing revealed that 100%, 98.44%, 92.19%, 71.87%, 65.63% and 64.06% of the isolates had a resistance against tetracycline, oxacillin, erythromycin, nalidixic acid, sulphamethoxazol, and ampicillin, respectively. D-tryptophan addition (40 mM) to E. coli O26:H11-inoculated soft cheese and ice cream revealed a significant reduction (p < 0.05) in bacterial growth, especially when accompanied with other food stressors. D-Tryptophan is considered as an effective food preservative and as a promising alternative candidate in the dairy industry.

Prevalence of Multidrug-Resistant Listeria monocytogenes in Dairy Products with Reduction Trials Using Rosmarinic Acid, Ascorbic Acid, Clove, and Thyme Essential Oils

Continuous monitoring of Listeria spp., particularly Listeria monocytogenes, in foods is a mandatory task for food safety and microbiology sectors. This study aimed to determine the prevalence and antimicrobial resistance patterns of L. monocytogenes in milk and dairy products retailed in Egypt. Furthermore, an experimental trial was conducted to investigate the antilisterial effects of some phytochemicals. A total of 200 samples (market raw milk, Kareish cheese, Damietta cheese, and plain yoghurt, 50 each) were collected and examined for detection of Listeria spp. The results revealed that 8, 12, 1, and 0 samples of market raw milk, Damietta cheese, Kareish cheese, and plain yoghurt were contaminated with Listeria spp., respectively. Antimicrobial sensitivity testing revealed that all L. monocytogenes isolates (15) were resistant to streptomycin and erythromycin. Molecular analysis revealed that 86.67% of L. monocytogenes harbored hylA virulent gene. Use of rosmarinic acid, ascorbic acid, thyme, and clove essential oils significantly ( $P<0.05$ ) reduced L. monocytogenes growth in soft cheese—artificially contaminated with L. monocytogenes throughout a 4-week incubation period. In conclusion, strict hygienic conditions should be adopted during the preparation and distribution of dairy products. In addition, rosmarinic acid, ascorbic acid, clove, and thyme essential oils are good candidates as food preservatives with antilisterial activities.

The Emergence and Impact of Ethylene Scavengers Techniques in Delaying the Ripening of Fruits and Vegetables

As the top grocery list priorities, the primary challenge when purchasing fruits and vegetables from supermarkets is obtaining fresh, minimally processed perishable goods. This source of diet is critical for obtaining vitamins, minerals, antioxidants, and fibres. However, the short shelf life caused by moisture content in rapid deterioration and decay caused by microbial growth, results in unappealing appearances. Fruits and vegetables undergo ripening and eventually the ageing process, in which the tissues of the plants degrade. Even after harvesting, numerous biological processes occur, generating a significant variation of ethylene production along with respiration rates between fruits and vegetables. Thus, the utilization of ethylene scavengers in food packaging or films has been revealed to be beneficial. The synergistic effects of these biomaterials have been demonstrated to reduce microorganisms and prolong the shelf life of greens due to antimicrobial activity, oxygen scavenging capacity, enzyme immobilization, texture enhancers, and nutraceuticals. The current review fills this void by discussing the most recent advances in research on ethylene scavengers and removal mechanisms of ethylene, including oxidation in fruit and vegetable packaging. The application and advantages of ethylene scavengers in packaging are then discussed with the addition of how the efficiency related to ethylene scavengers can be increased through atmospheric packaging tools. In this context, the article discusses characteristics, types of applications, and efficacy of ethylene control strategies for perishable commodities with the inclusion of future implications.

Prevalence of multidrug resistant Salmonella spp. in dairy products with the evaluation of the inhibitory effects of ascorbic acid, pomegranate peel extract, and D-tryptophan against Salmonella growth in cheese

The present study aimed at investigation of the prevalence and antimicrobial susceptibility of Salmonella spp. in the retailed dairies in Egypt. Besides, the inhibitory effects of some natural additives, including, ascorbic acid, pomegranate peel extract, and D-tryptophan against the isolated Salmonella were evaluated using soft cheese as a food matrix. To reach to this end, different Egyptian retail dairy products were investigated; 30 samples of each product were analyzed. Kariesh cheese samples had the highest Salmonella prevalence rate at 16.67%, followed by market raw milk, and bulk tank milk at 6.66% each, and white soft cheese at 3.33%. Serological examination exhibited 5 different Salmonella serotypes, namely S. Enteritidis, S. Typhimurium, S. Virchow, S. Larochelle, and S. Apeyeme. Antimicrobial susceptibility testing indicated that 100% of the isolates possessed resistance to erythromycin, oxacillin, and nalidixic acid. Some isolates of S. Typhimurium and S. Enteritidis were resistant to all 14 examined antibiotics. Isolates of S. Enteritidis obtained in this study were used to contaminate the freshly prepared soft cheese. Treatment of the artificially Salmonella-contaminated soft cheese with pomegranate peel extract, ascorbic acid, and D-tryptophan revealed a significant (P < 0.05) reduction in Salmonella growth in a dose-dependent manner. Therefore, the examined natural additives can be viewed as a promising new line of preservatives for dairy industry.

Behavioral and Molecular Analysis of Antioxidative Potential of Rosmarinic Acid Against Methamphetamine-induced Augmentation of Casp3a mRNA in the Zebrafish Brain

Introduction:

Methamphetamine (MA) acts as a powerful oxidant agent, while Rosmarinic Acid (RA) is an effective herbal antioxidant. Oxidative stress-mediated by MA results in apoptosis, and caspase-3 is one of the critical enzymes in the apoptosis process. MA can epigenetically alter gene regulation. In this paper, to investigate the effects of RA on MA-mediated oxidative stress, changes in the level of casp3a mRNA were demonstrated in zebrafish.

Methods:

The animals were grouped in 3 treatment conditions for the behavioral test: control, MA, MA pretreated by RA, and 6 treatment conditions for the molecular test: control, RA, MA, MA co-treated with RA, MA co-treated with RA/ZnO/chitosan nanoparticle, and ZnO/chitosan nanoparticle. Then molecular and behavioral investigations were carried out, and critical comparisons were made between the groups.

MA solution was prepared with a concentration of 25 mg/L, and RA solution was prepared by DPPH test with the antioxidant power of about 97%. Each solution was administered by immersing 20 zebrafish for 20 minutes, once per day for 7 days. The level of casp3a mRNA was quantified by using qRT-PCR. One-sided trapezoidal tank diving test was applied to study behavioral alterations.

Results:

The qPCR analysis demonstrated the high potential of RA/ZnO/chitosan in counteracting the MA-mediated elevation in casp3a mRNA level. Based on the diving test results of MA-treated fish, MA was found to be anxiolytic compared to the control. While the resulted diving pattern of the MA-treated animals pretreated by RA was novel and different from both the control and MA-treated groups.

Conclusion:

The potential of RA combined with a suitable nanoparticle against MA-induced oxidative stress was supported. The high efficiency of ZnO/chitosan in increasing RA penetration to the brain cells was evident. MA at a dose of 25 mg/L is anxiolytic for zebrafish. However, the molecular mechanisms involved in these processes should be studied.

Facile synthesis and characterization of chitosan/zinc oxide nanocomposite for enhanced antibacterial and photocatalytic activity

In this report, chitosan/zinc oxide (CS/ZnO) nanocomposite was synthesized using Sida acuta and assessed their antibacterial and photocatalytic properties. The formation of CS/ZnO nanocomposite was preliminary confirmed by colour change and UV-visible spectroscopy. The crystalline peaks related to CS and ZnO in CS/ZnO nanocomposite were demonstrated by XRD. Morphological analysis through FE-SEM and TEM showed a rod like appearance for ZnO NPs and agglomerated grains with rod shaped morphology was observed for the CS/ZnO nanocomposite. The peaks around 400-800 cm^-1 in the IR spectrum of nanocomposite indicated the vibrations of metal-oxygen (ZnO), whereas bands at 1659 cm^-1 and 1546 cm^-1 indicated the presence of amine groups, which confirms the CS in the synthesized CS/ZnO nanocomposite. The CS/ZnO nanocomposite exhibited remarkable growth inhibition activity against B. subtilis and E. coli with 22 ± 0.3 and 16.5 ± 0.5 mm zone of inhibitions. In addition, CS/ZnO nanocomposite treated cotton fabrics also exhibited antibacterial activity against B. subtilis and E. coli. Furthermore, the ZnO NPs and nanocomposite showed time depended photodegradation activity and revealed 76% and 91% decomposition of CR under sunlight irradiation. In conclusion, our study revealed that the functionalization of biopolymer CS to the inorganic ZnO enhances the bio and catalytic properties.

Multifunctional palygorskite@ZnO nanorods enhance simultaneously mechanical strength and antibacterial properties of chitosan-based film

A general and effective strategy was developed for improving simultaneously the mechanical strength and antibacterial performance of biopolymer-based films. The well-dispersed zinc oxide (ZnO) nanoparticles were in-situ loaded on non-toxic natural palygorskite (PAL) nanorod to form an antibacterial PAL@ZnO composite nanorod, which can be embedded into chitosan/gelatin (CS/GL) film to produce the composite films with noticeably enhanced mechanical properties and antibacterial activity against S. aureus and E. coli bacteria (inhibition zones are 21.82 ± 0.95 mm and 16.36 ± 1.64 mm, respectively). The toughness of films enhances to 35.13 ± 0.95 MPa and the moisture uptake decreases to 23.74 ± 0.02% after embedding 3% and 9% of PAL@ZnO, respectively. In addition, incorporating PAL@ZnO nanorods also significantly enhanced the water resistance, and thermal stability of film. This work provides an alternative way for the development of antibacterial films with potential applications in many fields such as food packing.

New Active Packaging Based on Biopolymeric Mixture Added with Bacteriocin as Active Compound

The objective of this work was to develop a chitosan/agar-agar bioplastic film incorporated with bacteriocin that presents active potential when used as food packaging. The formulation of the film solution was determined from an experimental design, through the optimization using the desirability function. After establishing the concentrations of the biopolymers and the plasticizer, the purified bacteriocin extract of Lactobacillus sakei was added, which acts as an antibacterial agent. The films were characterized through physical, chemical, mechanical, barrier, and microbiological analyses. The mechanical properties and water vapor permeability were not altered by the addition of the extract. The swelling property decreased with the addition of the extract and the solubility increased, however, the film remained intact when in contact with the food, thus allowing an efficient barrier. Visible light protection was improved by increased opacity and antibacterial capacity was effective. When used as Minas Frescal cream cheese packaging, it contributed to the increase of microbiological stability, showing a reduction of 2.62 log UFC/g, contributing a gradual release of the active compound into the food during the storage time. The film had an active capacity that could be used as a barrier to the food, allowing it to be safely packaged.

Novel Bio-Based Materials and Applications in Antimicrobial Food Packaging: Recent Advances and Future Trends

Food microbial contamination not only poses the problems of food insecurity and economic loss, but also contributes to food waste, which is another global environmental problem. Therefore, effective packaging is a compelling obstacle for shielding food items from outside contaminants and maintaining its quality. Traditionally, food is packaged with plastic that is rarely recyclable, negatively impacting the environment. Bio-based materials have attracted widespread attention for food packaging applications since they are biodegradable, renewable, and have a low carbon footprint. They provide a great opportunity to reduce the extensive use of fossil fuels and develop food packaging materials with good properties, addressing environmental problems and contributing significantly to sustainable development. Presently, the developments in food chemistry, technology, and biotechnology have allowed us to fine-tune new methodologies useful for addressing major safety and environmental concerns regarding packaging materials. This review presents a comprehensive overview of the development and potential for application of new bio-based materials from different sources in antimicrobial food packaging, including carbohydrate (polysaccharide)-based materials, protein-based materials, lipid-based materials, antibacterial agents, and bio-based composites, which can solve the issues of both environmental impact and prevent foodborne pathogens and spoilage microorganisms. In addition, future trends are discussed, as well as the antimicrobial compounds incorporated in packaging materials such as nanoparticles (NPs), nanofillers (NFs), and bio-nanocomposites.

Green and Healthier Alternatives to Chemical Additives as Cheese Preservative: Natural Antimicrobials in Active Nanopackaging/Coatings

The side effects and potential impacts on human health by traditional chemical additives as food preservatives (i.e., potassium and sodium salts) are the reasons why novel policies are encouraged by worldwide public health institutes. More natural alternatives with high antimicrobial efficacy to extend shelf life without impairing the cheese physicochemical and sensory quality are encouraged. This study is a comprehensive review of emerging preservative cheese methods, including natural antimicrobials (e.g., vegetable, animal, and protist kingdom origins) as a preservative to reduce microbial cheese contamination and to extend shelf life by several efforts such as manufacturing ingredients, the active ingredient for coating/packaging, and the combination of packaging materials or processing technologies. Essential oils (EO) or plant extracts rich in phenolic and terpenes, combined with packaging conditions and non-thermal methods, generally showed a robust microbial inhibition and prolonged shelf life. However, it impaired the cheese sensory quality. Alternatives including EO, polysaccharides, polypeptides, and enzymes as active ingredients/nano-antimicrobials for an edible film of coating/nano-bio packaging showed a potent and broad-spectrum antimicrobial action during shelf life, preserving cheese quality parameters such as pH, texture, color, and flavor. Future opportunities were identified in order to investigate the toxicological effects of the discussed natural antimicrobials' potential as cheese preservatives.

Green-based active packaging: Opportunities beyond COVID-19, food applications, and perspectives in circular economy-A brief review

The development of biodegradable packaging, based on agro-industrial plant products and by-products, can transform waste into products with high added value and reduce the use of conventional nonrenewable packaging. Green-based active packaging has a variety of compounds such as antimicrobials, antioxidants, aromatics, among others. These compounds interact with packaged products to improve food quality and safety and favor the migration of bioactive compounds from the polymeric matrix to food. The interest in the potential hygienic-sanitary benefit of these packages has been intensified during the COVID-19 pandemic, which made the population more aware of the relevant role of packaging for protection and conservation of food. It is estimated that the pandemic scenario expanded food packaging market due to shift in eating habits and an increase in online purchases. The triad health, sustainability, and circular economy is a trend in the development of packaging. It is necessary to minimize the consumption of natural resources, reduce the use of energy, avoid the generation of waste, and emphasize the creation of social and environmental values. These ideas underpin the transition from the emphasis on the more subjective discourse to the emphasis on the more practical method of thinking about the logic of production and use of sustainable packaging. Presently, we briefly review some trends and economic issues related to biodegradable materials for food packaging; the development and application of bio-based active films; some opportunities beyond COVID-19 for food packaging segment; and perspectives in circular economy.

Recent Applications of Biopolymers Derived from Fish Industry Waste in Food Packaging

Fish waste is attracting growing interest as a new raw material for biopolymer production in different application fields, mainly in food packaging, with significant economic and environmental advantages. This review paper summarizes the recent advances in the valorization of fish waste for the preparation of biopolymers for food packaging applications. The issues related to fishery industry waste and fish by-catch and the potential for re-using these by-products in a circular economy approach have been presented in detail. Then, all the biopolymer typologies derived from fish waste with potential applications in food packaging, such as muscle proteins, collagen, gelatin, chitin/chitosan, have been described. For each of them, the recent applications in food packaging, in the last five years, have been overviewed with an emphasis on smart packaging applications. Despite the huge industrial potential of fish industry by-products, most of the reviewed applications are still at lab-scale. Therefore, the technological challenges for a reliable exploitation and recovery of several potentially valuable molecules and the strategies to improve the barrier, mechanical and thermal performance of each kind of biopolymer have been analyzed.

The Effect of Molecular Weight on the Antimicrobial Activity of Chitosan from Loligo opalescens for Food Packaging Applications

The growing requirement for sustainable processes has boosted the development of biodegradable plastic-based materials incorporating bioactive compounds obtained from waste, adding value to these products. Chitosan (Ch) is a biopolymer that can be obtained by deacetylation of chitin (found abundantly in waste from the fishery industry) and has valuable properties such as biocompatibility, biodegradability, antimicrobial activity, and easy film-forming ability. This study aimed to produce and characterize poly(lactic acid) (PLA) surfaces coated with β-chitosan and β-chitooligosaccharides from a Loligo opalescens pen with different molecular weights for application in the food industry. The PLA films with native and depolymerized Ch were functionalized through plasma oxygen treatment followed by dip-coating, and their physicochemical properties were assessed by Fourier-transform infrared spectroscopy, X-ray diffraction, water contact angle, and scanning electron microscopy. Their antimicrobial properties were assessed against Escherichia coli and Pseudomonas putida, where Ch-based surfaces reduced the number of biofilm viable, viable but nonculturable, and culturable cells by up to 73%, 74%, and 87%, respectively, compared to PLA. Biofilm growth inhibition was confirmed by confocal laser scanning microscopy. Results suggest that Ch films of higher molecular weight had higher antibiofilm activity under the food storage conditions mimicked in this work, contributing simultaneously to the reuse of marine waste.

Zinc oxide nanoparticles: potential effects on soil properties, crop production, food processing, and food quality

The use of zinc oxide nanoparticles (ZnO NPs) is expected to increase soil fertility, crop productivity, and food quality. However, the potential effects of ZnO NP utilization should be deeply understood. This review highlights the behavior of ZnO NPs in soil and their interactions with the soil components. The review discusses the potential effects of ZnO NPs on plants and their mechanisms of action on plants and how these mechanisms are related to their physicochemical properties. The impact of current applications of ZnO NPs in the food industry is also discussed. Based on the literature reviewed, soil properties play a vital role in dispersing, aggregation, stability, bioavailability, and transport of ZnO NPs and their release into the soil. The transfer of ZnO NPs into the soil can affect the soil components, and subsequently, the structure of plants. The toxic effects of ZnO NPs on plants and microbes are caused by various mechanisms, mainly through the generation of reactive oxygen species, lysosomal destabilization, DNA damage, and the reduction of oxidative stress through direct penetration/liberation of Zn2+ ions in plant/microbe cells. The integration of ZnO NPs in food processing improves the properties of the relative ZnO NP-based nano-sensing, active packing, and food/feed bioactive ingredients delivery systems, leading to better food quality and safety. The unregulated/unsafe discharge concentrations of ZnO NPs into the soil, edible plant tissues, and processed foods raise environmental/safety concerns and adverse effects. Therefore, the safety issues related to ZnO NP applications in the soil, plants, and food are also discussed.

Polysaccharide-Based Packaging Functionalized with Inorganic Nanoparticles for Food Preservation

Functionalization of polysaccharide-based packaging incorporating inorganic nanoparticles for food preservation is an active research area. This review summarizes the use of polysaccharide-based materials functionalized with inorganic nanoparticles (TiO2, ZnO, Ag, SiO2, Al2O3, Fe2O3, Zr, MgO, halloysite, and montmorillonite) to develop hybrid packaging for fruit, vegetables, meat (lamb, minced, pork, and poultry), mushrooms, cheese, eggs, and Ginkgo biloba seeds preservation. Their effects on quality parameters and shelf life are also discussed. In general, treated fruit, vegetables, mushrooms, and G. biloba seeds markedly increased their shelf life without significant changes in their sensory attributes, associated with a slowdown effect in the ripening process (respiration rate) due to the excellent gas exchange and barrier properties that effectively prevented dehydration, weight loss, enzymatic browning, microbial infections by spoilage and foodborne pathogenic bacteria, and mildew apparition in comparison with uncoated or polysaccharide-coated samples. Similarly, hybrid packaging showed protective effects to preserve meat products, cheese, and eggs by preventing microbial infections and lipid peroxidation, extending the food product’s shelf life without changes in their sensory attributes. According to the evidence, polysaccharide-hybrid packaging can preserve the quality parameters of different food products. However, further studies are needed to guarantee the safe implementation of these organic–inorganic packaging materials in the food industry.

Recent Advances in the Development of Smart and Active Biodegradable Packaging Materials

Interest in the development of smart and active biodegradable packaging materials is increasing as food manufacturers try to improve the sustainability and environmental impact of their products, while still maintaining their quality and safety. Active packaging materials contain components that enhance their functionality, such as antimicrobials, antioxidants, light blockers, or oxygen barriers. Smart packaging materials contain sensing components that provide an indication of changes in food attributes, such as alterations in their quality, maturity, or safety. For instance, a smart sensor may give a measurable color change in response to a deterioration in food quality. This article reviews recent advances in the development of active and smart biodegradable packaging materials in the food industry. Moreover, studies on the application of these packaging materials to monitor the freshness and safety of food products are reviewed, including dairy, meat, fish, fruit and vegetable products. Finally, the potential challenges associated with the application of these eco-friendly packaging materials in the food industry are discussed, as well as potential future directions.

Polysaccharides-based bio-nanostructures and their potential food applications

Polysaccharides are omnipresent biomolecules that hold great potential as promising biomaterials for a myriad of applications in various biotechnological and industrial sectors. The presence of diverse functional groups renders them tailorable functionalities for preparing a multitude of novel bio-nanostructures. Further, they are biocompatible and biodegradable, hence, considered as environmentally friendly biopolymers. Application of nanotechnology in food science has shown many advantages in improving food quality and enhancing its shelf life. Recently, considerable efforts have been made to develop polysaccharide-based nanostructures for possible food applications. Therefore, it is of immense importance to explore literature on polysaccharide-based nanostructures delineating their food application potentialities. Herein, we reviewed the developments in polysaccharide-based bio-nanostructures and highlighted their potential applications in food preservation and bioactive "smart" food packaging. We categorized these bio-nanostructures into polysaccharide-based nanoparticles, nanocapsules, nanocomposites, dendrimeric nanostructures, and metallo-polysaccharide hybrids. This review demonstrates that the polysaccharides are emerging biopolymers, gaining much attention as robust biomaterials with excellent tuneable properties.

Antimicrobial activities of chitosan/titanium dioxide composites as a biological nanolayer for food preservation: A review

Packaging is an integral part of food industry that preserves the properties of food during storage. Food spoilage caused by foodborne microorganisms is a public health problem that imposes a significant burden on the healthcare systems. Moreover, packaging based on artificial and chemical materials such as plastic is destructive to the environment. Chitosan can be categorized as an active food packaging material because of its inherent antimicrobial properties and capacity to carry various active components. Combining chitosan and metallic nanoparticles can be used as a practical approach in antimicrobial packaging systems. This strategy has advantages of thermal stability, barrier properties, antioxidant and antimicrobial packaging. Titanium dioxide is one of these nanoparticles that plays a photocatalytic role by releasing reactive oxygen species, thereby leading to the destruction of microorganisms' cell wall and extension of food shelf life. This review elaborates on the antimicrobial applications of chitosan/titanium dioxide nanoparticles films in food packaging systems.