Chitosan based ZnO nanoparticles loaded gallic-acid films for active food packaging

Sustainable remediation of toxic congo red dye pollution using bio based carbon nanocomposite: Modelling and performance evaluation

Remediation of synthetic dyes found in aqueous environment poses a serious challenge for treatment due to their resistance to chemical and biological degradation. This research study investigated the application of Chitosan-ZnO-Seaweed bio nanocomposite in the remediation of congo red. The novel bionanocomposite was characterised by FTIR, SEM, TEM, EDS and XRD studies. The FTIR spectra and SEM images indicated the adsorption of congo red onto the synthesized bionanocomposite. The batch wise experimental studies were done to explore the influence of process variables on removal of congo red from synthetic wastewater and to determine optimized conditions. Under optimized conditions of pH 3, temperature 40 °C, initial congo red concentration 50 mg/L, bionanocomposite quantity 0.03 g/L and interaction period 30 min, the bionanocomposite removed 95.64% of congo red. Thermodynamic studies were carried out and the parameters, ΔH° and ΔS° were found to be 38.386 kJ/mol and 0.1451 kJ/mol. K, respectively. The isotherm and kinetic study showed that monolayer Langmuir model was obeyed (R2 = 0.968) and the experimental value of congo red adsorption correlated well with pseudo second order model (R2 = 0.9938) respectively. The maximum adsorption capacity was found to be 303.03 mg/g. Protonated amino group of chitosan, hydroxyl group of seaweed accounts for congo red adsorption along with zinc oxide.

Multi-functional nanocellulose based nanocomposites for biodegradable food packaging: Hybridization, fabrication, key properties and application

Nowadays, non-degradable plastic packaging materials have caused serious environmental pollution, posing a threat to human health and development. Renewable eco-friendly nanocellulose hybrid (NCs-hybrid) composites as an ideal alternative to petroleum-based plastic food packaging have been extensively reported in recent years. NCs-hybrids include metal, metal oxides, organic frameworks (MOFs), plants, and active compounds. However, no review systematically summarizes the preparation, processing, and multi-functional applications of NCs-hybrid composites. In this review, the design and hybridization of various NCs-hybrids, the processing of multi-scale nanocomposites, and their key properties in food packaging applications were systematically explored for the first time. Moreover, the synergistic effects of various NCs-hybrids on several properties of composites, including mechanical, thermal, UV shielding, waterproofing, barrier, antimicrobial, antioxidant, biodegradation and sensing were reviewed in detailed. Then, the problems and advances in research on renewable NCs-hybrid composites are suggested for biodegradable food packaging applications. Finally, a future packaging material is proposed by using NCs-hybrids as nanofillers and endowing them with various properties, which are denoted as "PACKAGE" and characterized by "Property, Application, Cellulose, Keen, Antipollution, Green, Easy."

Biosynthesis of MgO Nanoparticles and Their Impact on the Properties of the PVA/Gelatin Nanocomposites for Smart Food Packaging Applications

Fabricating active and intelligent packaging materials has become the highest demand for catering to market needs, especially after the COVID-19 pandemic, for ensuring food safety. Thus, the wider objective of this article was to promote active and smart packaging biofilms possessing antibacterial and humidity-sensing properties for sustainable poly(vinyl alcohol) (PVA)/gelatin (Ge) reinforced with biosynthesized magnesium nanoparticles (MgO NPs) by a solvent-casting route. The UV-visible spectrum has been utilized to determine the optimized biosynthesized MgO NPs and then the nanostructure of optimized MgO NPs investigated by varying techniques such as XRD, SEM-EDX, TEM, FT-IR, and thermogravimetric analysis. Four MgO NPs proportions (i.e., 1, 3, 5, and 10 wt %) were used to fabricate PVA/Ge biofilms. In the biofilms system, the tensile results showcased that the nanocomposite film containing 5 wt % of MgO NPs had the highest tensile strength value (i.e., 22.10 MPs) compared to the other biofilms or the unfilled blank (i.e., 6.30 MPs). Correspondingly, the humidity-sensing data revealed that the PVA/Ge-1% MgO NPs sensor had higher sensitivity over a broad range of relative humidity from (7-97% RH) and at 100 Hz. Additionally, the hydrophobicity of biofilms, measured by water contact angle, UV-stability, and antioxidant and antibacterial properties was also analyzed to possibly use these biofilms in active food packaging with extended shelf life of foodstuffs. However, the PVA/Ge-1% MgO NPs biofilm was predominately found to possess attractive sensing properties and could be considered as a sensor for intelligent food packaging.

Preparation and performance testing of corn starch/pullulan/gallic acid multicomponent composite films for active food packaging

The present study investigated the mechanical characteristics, hydrophobicity, antioxidant and antibacterial properties, FTIR, SEM and XRD of films fabricated with corn starch and pullulan (CS/PUL) by adding different concentrations of Gallic acid (GA) (0%, 0.5%, 1.0%, 1.5% w/v). The mechanical strength and opacity of CS/PUL films were enhanced by the addition of 1.0% GA. The water vapor permeability (WVP) of CS/PUL films was significantly lower in films with GA compared to those without (P < 0.05). The addition of GA, especially at concentrations of 1.0% and 1.5%, resulted in considerably better free radical scavenging activities on DPPH than films without GA (P < 0.05). Interestingly, the highest water contact angle (WCA) value was observed in films with 0.5% GA, indicating stronger hydrophobicity. Furthermore, the antibacterial capabilities of the films, particularly against E. coli and P. aeruginosa, improved with an increase in GA concentration. The results of FTIR, SEM and XRD analyses showed that GA was well distributed in the CS/PUL matrix.

Fabrication, performance, and potential environmental impacts of polysaccharide-based food packaging materials incorporated with phytochemicals: A review

Although food packaging preserves food's quality, it unfortunately contributes to global climate change since the considerable carbon emissions associated with its entire life cycle. Polysaccharide-based packaging materials (PPMs) are promising options to preserve foods, potentially helping the food industry reduce its carbon footprint. PPMs incorporated with phytochemicals hold promise to address this critical issue, keep food fresh and prolong the shelf life. However, phytochemicals' health benefits are impacted by their distinct chemical structures thus the phytochemicals-incorporated PPMs generally exhibit differential performances. PPMs must be thoughtfully formulated to possess adequate physicochemical properties to meet commercial standards. Given this, this review first-time provides a comprehensive review of recent advances in the fabrication of phytochemicals incorporated PPMs. The application performances of phytochemicals-incorporated PPMs for preserving foods, as well as the intelligent monitoring of food quality, are thoroughly introduced. The possible associated environmental impacts and scalability challenges for the commercial application of these PPMs are also methodically assessed. This review seeks to provide comprehensive insights into exploring new avenues to achieve a greener and safer food industry via innovative food packaging materials. This is paramount to preserve not only food shelf life but also the environment, facilitating the eco-friendly development of the food industry.

A curcumin-crosslinked bilayer film of soy protein isolate and chitosan with enhanced antibacterial property for beef preservation and freshness monitoring

In this study, antibacterial and antioxidant bilayer films were prepared by using curcumin (Cur) crosslinked soy rotein isolate (SPI) and chitosan (CS). Molecular docking simulations and multispectral analysis revealed that hydrogen bonding and hydrophobic interactions were the primary driving forces that promoted the self-assembly of the bilayer films. The tensile strength, the UV-blocking properties and the hydrophobicity was greatly improved of the bilayer antimicrobial films. Moreover, water vapor permeability, thermal shrinkage and opacity were all reduced significantly. In addition, the composite films with curcumin demonstrated effective antioxidant activity and a slow release characteristic. Morphology observation of the bacteria by AFM revealed that the antibacterial bilayer film had a significant damaging effect on the cell structures of S. aureus and E. coli due to the dual antibacterial effect of curcumin and chitosan. SPI + Cur-CS antimicrobial bilayer film effectively inhibited the growth of bacteria and extended the shelf life of beef. According to the findings, SPI + Cur-CS antimicrobial bilayer film can be used as an active package material for beef preservation and freshness monitoring.

ZnO Nanoparticles-Reinforced Chitosan-Xanthan Gum Blend Novel Film with Enhanced Properties and Degradability for Application in Food Packaging

Nations all over the world are imposing ban on single-use plastics, which are difficult to recycle and lead to creations of nonsustainable and nondegradable piles. To match the requirement in the market, suitable food packaging alternatives have to be developed that are biodegradable and environment-friendly. The current work is designed for the fabrication of a novel nanocomposite by blending xanthan gum in a chitosan matrix and reinforcing it with ZnO nanoparticles, through a solution casting method. Surface morphology of the film was investigated through field emission scanning electron microscopy, along with energy-dispersive X-ray spectroscopy mapping, and characterized through thermogravimetric analysis, Fourier transform infrared (FTIR) spectroscopy, mechanical testing, and ultraviolet spectroscopy. FTIR spectroscopy analysis corroborated the interaction between the components and the H-bond formation. Polyelectrolyte complex formation materializes between the oppositely charged chitosan and xanthan gum, and further nanoparticle incorporation significantly improves the mechanical properties. The synthesized nanocomposite was found to have increases in the tensile strength and elongation at break of pure chitosan by up to 6.65 and 3.57 times, respectively. The transmittance percentage of the bionanocomposite film was reduced compared to that of the pure chitosan film, which aids in lowering the oxidative damage brought on by UV radiation in packed food products. Moreover, the film also showed an enhanced barrier property against water vapor and oxygen gas. The film was totally biodegradable in soil burial at the end of the second month; it lost almost around 88% of its initial weight. The fabricated film does not pose a threat to the environment and hence has great potential for application in the future sustainable food packaging industry.

Photodynamic antibacterial chitosan/nitrogen-doped carbon dots composite packaging film for food preservation applications

In this study, we synthesized nitrogen-doped carbon dots (N-CDs) with remarkable photodynamic antibacterial properties by a hydrothermal method. The composite film was prepared by solvent casting method, compounding N-CDs with chitosan (CS). The morphology and structure of the films were analyzed by Fourier-transformed infrared spectroscopy (FTIR), scanning electron microscope (SEM), atomic force microscope (AFM), and transmission electron microscope (TEM) techniques. The films' mechanical, barrier, thermal stability, and antibacterial properties were analyzed. A preservation test of the films was studied on the samples of pork, volatile base nitrogen (TVB-N), total viable count (TVC), and pH were determined. Besides, the effect of film on the preservation of blueberries was observed. The study found that, compared with the CS film, the CS/N-CDs composite film is strong and flexible, with good UV light barrier performance. The prepared CS/7 % N-CDs composites showed high photodynamic antibacterial rates of 91.2 % and 99.9 % for E. coli and S. aureus, respectively. In the preservation of pork, it was found that its pH, TVB-N, and TVC indicators were significantly lower. The extent of mold contamination and anthocyanin loss was less in the CS/3 % N-CDs composite film-coated group, which could greatly extend the shelf life of food.

Boosting functional properties of active-CMC films reinforced with agricultural residues-derived cellulose nanofibres

The search for packaging alternatives that reduce the presence of non-biodegradable plastics in water is a focus of much research today. This fact, together with the increasing demand for active packaging capable of prolonging the shelf life of foodstuffs and the rise in the use of natural biopolymers such as cellulose, motivate the present work. This work evaluates CMC films loaded with gallic acid reinforced with (ligno)cellulose nanofibres from various agricultural residues as candidates for use in active food packaging. The first stage of the study involved the evaluation of different nanofibres as the reinforcing agent in CMC films. Increasing proportions of nanofibres (1, 3, 5 and 10% w/w) from horticultural residues (H) and nanofibres from vine shoots (V), containing residual lignin (LCNF) and without it (CNF), and obtained by mechanical (M) or chemical (T) pretreatment, were studied. The results of this first stage showed that the optimum reinforcement effect was obtained with 3% H-MCNF or 3% V-MCNF, where up to 391% and 286% improvement in tensile strength was achieved, respectively. These films offered slightly improved UV-light blocking ability (40-55% UV-barrier) and water vapor permeability (20-30% improvement) over CMC. Next, bioactive films were prepared by incorporating 5 and 10% wt of gallic acid (GA) over the optimised formulations. It was found that the joint addition of cellulose nanofibres and GA enhanced all functional properties of the films. Mechanical properties improved to 70%, WVP to 50% and UV light blocking ability to 70% due to the synergistic effect of nanofibres and GA. Finally, the bioactive films exhibited potent antioxidant activity, 60-70% in the DPPH assay and >99% in the ABTS assay and high antimicrobial capacity against S. aureus.

Preparation of a thermosensitive nanofibre membrane for blackberry preservation

Blackberries provide multiple health benefits. However, they deteriorate easily during harvesting, storage, and transportation (temperature-changing). Therefore, to extend their shelf-life under variable temperature conditions, a temperature-sensitive nanofibre-based material with good preservation attributes was developed, composed of polylactic acid (PLA) electrospun fibres, loaded with lemon essential oil (LEO) and covered with poly (N-isopropylacrylamide) (PNIPAAm). Compared with PLA and PLA/LEO nanofibres, PLA/LEO/PNIPAAm exhibited good mechanical properties, oxidation resistance, antibacterial ability, and controlled release of LEO. The PNIPAAm layer prevented rapid LEO release below the low critical solution temperature (32 °C). When the temperature exceeded 32 °C, the PNIPAAm layer underwent a chain-to-globule transition and accelerated LEO release (slower than PLA/LEO). The temperature-controlled release of LEO via PLA/LEO/PNIPAAm membrane prolongs its action time. Therefore, PLA/LEO/PNIPAAm effectively maintained the appearance and nutritive quality of blackberries during variable storage temperatures. Our research demonstrated that active fibre membranes have great potential applications in preserving fresh products.

Metal-Based Nanoparticles in Food Packaging and Coating Technologies: A Review

Food security has continued to be a topic of interest in our world due to the increasing demand for food. Many technologies have been adopted to enhance food supply and narrow the demand gap. Thus, the attempt to use nanotechnology to improve food security and increase supply has emerged due to the severe shortcomings of conventional technologies, which have made them insufficient to cater to the continuous demand for food products. Hence, nanoparticles have been identified to play a major role in areas involving food production, protection, and shelf-life extensions. Specifically, metal-based nanoparticles have been singled out to play an important role in manufacturing materials with outstanding properties, which can help increase the shelf-life of different food materials. The physicochemical and biological properties of metal-based nanoparticles, such as the large surface area and antimicrobial properties, have made them suitable and adequately useful, not just as a regular packaging material but as a functional material upon incorporation into biopolymer matrices. These, amongst many other reasons, have led to their wide synthesis and applications, even though their methods of preparation and risk evaluation remain a topic of concern. This review, therefore, briefly explores the available synthetic methods, physicochemical properties, roles, and biological properties of metal-based nanoparticles for food packaging. Furthermore, the associated limitations, alongside quality and safety considerations, of these materials were summarily explored. Although this area of research continues to garner attention, this review showed that metal-based nanoparticles possess great potential to be a leading material for food packaging if the problem of migration and toxicity can be effectively modulated.

Nanotechnology in Food and Plant Science: Challenges and Future Prospects

Globally, food safety and security are receiving a lot of attention to ensure a steady supply of nutrient-rich and safe food. Nanotechnology is used in a wide range of technical processes, including the development of new materials and the enhancement of food safety and security. Nanomaterials are used to improve the protective effects of food and help detect microbial contamination, hazardous chemicals, and pesticides. Nanosensors are used to detect pathogens and allergens in food. Food processing is enhanced further by nanocapsulation, which allows for the delivery of bioactive compounds, increases food bioavailability, and extends food shelf life. Various forms of nanomaterials have been developed to improve food safety and enhance agricultural productivity, including nanometals, nanorods, nanofilms, nanotubes, nanofibers, nanolayers, and nanosheets. Such materials are used for developing nanofertilizers, nanopesticides, and nanomaterials to induce plant growth, genome modification, and transgene expression in plants. Nanomaterials have antimicrobial properties, promote plants' innate immunity, and act as delivery agents for active ingredients. Nanocomposites offer good acid-resistance capabilities, effective recyclability, significant thermostability, and enhanced storage stability. Nanomaterials have been extensively used for the targeted delivery and release of genes and proteins into plant cells. In this review article, we discuss the role of nanotechnology in food safety and security. Furthermore, we include a partial literature survey on the use of nanotechnology in food packaging, food safety, food preservation using smart nanocarriers, the detection of food-borne pathogens and allergens using nanosensors, and crop growth and yield improvement; however, extensive research on nanotechnology is warranted.

The characterization of antimicrobial nanocomposites based on chitosan, cinnamon essential oil, and TiO2 for fruits preservation

The freshness and safety of fruits have always been crucial issues in the development of the industry. However, the existing fresh-keeping methods have limited effect, meanwhile, the preservation mechanism of different materials. In this study, Cinnamon essential oil (CEO), TiO_2, and chitosan (CS) were compounded to prepare safe and renewable nanocomposites (CS-T-C) for fruit preservation. The results showed that CEO mainly destroyed the bacterial cell wall through penetration, while TiO₂ is through destruction. The strawberry coated with CS-T-C showed better hardness, lower weight loss and mildew rate, and the shelf-life at 20℃ was extended for four days compared with the control. And all four nanocomposites were not cytotoxic. In summary, nanocomposites can deal with many problems through different mechanisms to maximize the fresh-keeping effect, and the nanocomposites developed in this work might be a good choice for fruit preservation.

Chitosan-Based Antibacterial Films for Biomedical and Food Applications

Antibacterial chitosan films, versatile and eco-friendly materials, have garnered significant attention in both the food industry and medicine due to their unique properties, including biodegradability, biocompatibility, and antimicrobial activity. This review delves into the various types of chitosan films and their distinct applications. The categories of films discussed span from pure chitosan films to those enhanced with additives such as metal nanoparticles, metal oxide nanoparticles, graphene, fullerene and its derivatives, and plant extracts. Each type of film is examined in terms of its synthesis methods and unique properties, establishing a clear understanding of its potential utility. In the food industry, these films have shown promise in extending shelf life and maintaining food quality. In the medical field, they have been utilized for wound dressings, drug delivery systems, and as antibacterial coatings for medical devices. The review further suggests that the incorporation of different additives can significantly enhance the antibacterial properties of chitosan films. While the potential of antibacterial chitosan films is vast, the review underscores the need for future research focused on optimizing synthesis methods, understanding structure-property relationships, and rigorous evaluation of safety, biocompatibility, and long-term stability in real-world applications.

Multifunctional composite coatings with hydrophobic, UV-resistant, anti-oxidative, and photothermal performance for healthcare

Personal protective textiles have attracted extensive interest since Corona Virus Disease 2019 has broken out. Moreover, developing eco-friendly, multifunctional waterproof, and breathable surface is of great importance but still faces enormous challenges. Notably, good hydrophobicity and breathability are necessary for protective textiles, especially protective clothing and face masks for healthcare. Herein, the multifunctional composite coatings with good UV-resistant, anti-oxidative, hydrophobic, breathable, and photothermal performance has been rapidly created to meet protective requirements. First, the gallic acid and chitosan polymer was coated onto the cotton fabric surface. Subsequently, the modified silica sol was anchored on the coated cotton fabric surface. The successful fabrication of composite coatings was verified by RGB values obtained from the smartphone and K/S value. The present work is an advance for realizing textile hydrophobicity by utilizing fluorine-free materials, compared with the surface hydrophobicity fabricated with conventional fluorinated materials. The surface free energy has been reduced from 84.2 to27.6 mJ/m2 so that the modified cotton fabric could repel the ethylene glycol, hydrochloric acid, and sodium hydroxide solutions, respectively. Besides, the composite coatings possesses lower adhesion to deionized water. After 70 cycles of the sandpaper abrasion, the fluorine-free hydrophobic coatings still exhibits good hydrophobicity with WCA of 124.6 ± 0.9°, with overcoming the intrinsic drawback of the poor abrasion resistance of hydrophobic surfaces. Briefly, the present work may provide a universal strategy for rapidly creating advanced protective coatings to meet personal healthcare, and a novel method for detecting RGB values of composite coatings by smartphone.

Development of an edible food packaging gelatin/zein based nanofiber film for the shelf-life extension of strawberries

An edible food packaging gelatin/zein nanofiber film co-loaded with cinnamaldehyde (CA)/thymol (THY) was developed, which possessed outstanding features conducive to strawberries preservation. Firstly, the synergistic antibacterial behavior of CA and THY was investigated. Then CA and THY were co-loaded into gelatin/zein nanofiber films by electrospinning technology. The addition of CA and THY increased water contact angle to 85.1° after 10 s and decreased the water vapor transmission rate of 3.1×10^-8 g·mm^-1·h^-1·Pa^-1. The tensile strength was 1.30 MPa and the elongation at break was 185%. The nanofiber films exhibited good shielding effect of ultraviolet-visible light and excellent antioxidant capacity with DPPH free radical scavenging percentage of 99.9% in 4 h. The nanofiber films (12.5 mg/mL) could achieve significant inhibition effects on Escherichia coli ATCC 25922 with the bacteriostatic ratio of 67.5%, Staphylococcus aureus ATCC 6538 and Listeria monocytogenes ATCC 19115 with the antibacterial ratios of 100%. A real-time study on the nanofiber films as fruit packaging materials was carried out on strawberries and the packaged strawberries kept their freshness as long as 7 days at room temperature. Therefore, the GZ/CT nanofiber film prepared in this work has good application potential in the field of fruit packaging.

Development and characterization of active packaging based on chitosan/chitin nanofibers incorporated with scallion flower extract and its preservation in fresh-cut bananas

The aim of this study was to develop a novel active packaging using chitosan (CS) and esterified chitin nanofibers (CF) combined with different contents (1, 2 and 4 wt% on CS basis) of scallion flower extract (SFE) to protect banana samples. The addition of CF significantly improved the barrier and mechanical properties of the CS films (p < 0.05) due to hydrogen bonds and electrostatic interactions. Moreover, the addition of SFE not only improved the physical properties of the CS film but also improved the CS film biological activity. The oxygen barrier property and antibacterial ability of CF-4%SFE were approximately 5.3 and 1.9 times higher than those of the CS film, respectively. In addition, CF-4%SFE had strong DPPH radical scavenging activity (74.8 ± 2.3 %) and ABTS radical scavenging activity (84.06 ± 2.08 %). Fresh-cut bananas stored in CF-4%SFE showed less weight loss, starch loss, color and appearance change than those stored in traditional polyethylene film, which indicated that CF-4%SFE was much better at storing fresh-cut bananas than conventional plastic packaging. For these reasons, CF-SFE films have great potential as a candidate to replace traditional plastic packaging and extend the shelf life of packaged foods.

Effect of neutralization treatment on properties of chitosan/bamboo leaf flavonoids/nano-metal oxide composite films and application of films in antioxidation of rapeseed oil

Neutralization treatment improved the slow-release antioxidant food packaging function of chitosan (CS)/bamboo leaf flavone (BLF)/nano-metal oxides composite films. The film cast from the CS composite solution neutralized by KOH solution had good thermal stability. The elongation at break of the neutralized CS/BLF film was increased by about 5 times, which provided the possibility for its packaging application. After 24 h of soaking in different pH solutions, the unneutralized films swelled severely and even dissolved, while the neutralized films maintained the basic structure with a small degree of swelling, and the release trend of BLF conformed to the logistic function (R² ≥ 0.9186). The films had a good ability to resist free radicals, which was related to the release amount of BLF and the pH of the solution. The antimicrobial neutralized CS/BLF/nano-ZnO film, like the nano-CuO and Fe₃O₄ films, were effective in inhibiting the increase in peroxide value and 2-thiobarbituric acid induced by thermal oxygen oxidation of rapeseed oil and had no toxicity to normal human gastric epithelial cells. Therefore, the neutralized CS/BLF/nano-ZnO film is likely to become an active food packaging material for oil-packed food, which can prolong the shelf life of packaged food.

Hybrid materials based on chitosan functionalized with green synthesized copper nanoparticles: Physico-chemical and antimicrobial analysis

Recently, the development of materials with antimicrobial properties has become a challenge under scrutiny. The incorporation of copper nanoparticles (NpCu) into a chitosan matrix appears to represent a viable strategy to contain the particles and prevent their oxidation. Regarding the physical properties, the nanocomposite films (CHCu) showed a decrease in the elongation at break (5 %) and an increase in the tensile strength of 10 % concerning chitosan films (control). They also showed solubility values lower than 5 % while the swelling diminished by 50 %, on average. The dynamical mechanical analysis (DMA) of nanocomposites revealed two thermal events located at 113° and 178 °C, which matched the glass transitions of the CH-enriched phase and nanoparticles-enriched phase, respectively. In addition, the thermogravimetric analysis (TGA) detected a greater stability of the nanocomposites. Chitosan films and the NpCu-loaded nanocomposites demonstrated excellent antibacterial capacity against Gram-negative and Gram-positive bacteria, proved through diffusion disc, zeta potential, and ATR-FTIR techniques. Additionally, the penetration of individual NpCu particles into bacterial cells and the leakage of cell content were verified by TEM. The mechanism of the antibacterial activity of the nanocomposites involved the interaction of chitosan with the bacterial outer membrane or cell wall and the diffusion of the NpCu through the cells. These materials could be applied in diverse fields of biology, medicine, or food packaging.

Essential characteristics improvement of metallic nanoparticles loaded carbohydrate polymeric films - A review

Petroleum-based films have contributed immensely to various environmental issues. Developing green-based films from carbohydrate polymers is crucial for addressing the harms encountered. However, some limitations exist on their property, processibility, and applicability that prohibit their processing for further developments. This review discusses the potential carbohydrate polymers and their sources, film preparation methods, such as solvent-casting, tape-casting, extrusion, and thermo-mechanical compressions for green-based films using various biological polymers with their merits and demerits. Research outcomes revealed that the essential characteristics improvement achieved by incorporating different metallic nanoparticles has significantly reformed the properties of biofilms, including crystallization, mechanical stability, thermal stability, barrier function, and antimicrobial activity. The property-enhanced bio-based films made with nanoparticles are potentially interested in replacing fossil-based films in various areas, including food-packaging applications. The review paves a new way for the commercial use of numerous carbohydrate polymers to help maintain a sustainable green environment.

Chitosan-based composite films containing eugenol nanoemulsion, ZnO nanoparticles and Aloe vera gel for active food packaging

Biopolymer-based food packaging films are gaining increasing popularity, as consumers' demands for sustainable alternatives and environmental concerns associated with synthetic plastic packaging grow. In this research work, chitosan-based active antimicrobial films reinforced with eugenol nanoemulsion (EuNE), Aloe vera gel, and zinc oxide nanoparticles (ZnONPs) were fabricated and characterized for their solubility, microstructure, optical properties, antimicrobial and antioxidant activities. The rate of release of EuNE from the fabricated films was also evaluated to determine active nature of the films. The EuNE droplet size was about 200 nm, and they were uniformly distributed throughout the film matrices. Incorporation of EuNE in chitosan drastically improved UV-light barrier property of the fabricated composite film by 3 to 6 folds, while maintaining their transparency. The XRD spectra of the fabricated films showed good compatibility between the chitosan and the incorporated active agents. The incorporation of ZnONPs significantly improved their antibacterial properties against foodborne bacteria and tensile strength about 2-folds, whereas incorporation of EuNE and AVG improved DPPH scavenging activities of the chitosan film up to 95 %, respectively.

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.

Recent Advances in ZnO Nanomaterial-Mediated Biological Applications and Action Mechanisms

In recent years, with the deepening research, metal zinc oxide (ZnO) nanomaterials have become a popular research object in the biological field, particularly in biomedicine and food safety, which is attributed to their unique physicochemical properties such as high surface area and volume ratio, luminescence effect, surface characteristics and biological activities. Herein, this review provides a detailed overview of the ZnO nanomaterial-mediated biological applications that involve anti-bacterial, anti-tumor, anti-inflammation, skin care, biological imaging and food packaging applications. Importantly, the corresponding action mechanisms of ZnO nanomaterials are pointed. Additionally, the structure and structure-dependent physicochemical properties, the common synthesis methods and the biosafety of ZnO nanoparticles are revealed in brief. Finally, the significance and future challenges of ZnO nanomaterial applications are concluded.

'Click' synthesized calcium-chitosan-triazole nanocomplex from CaC2 as an efficient drug carrier, antimicrobial and antioxidant polymer

A calcium-chitosan-triazole nanocomplex (Ca@CS-Tz) was synthesized via the robust copper catalyzed azide-alkyne cycloaddition using calcium carbide (CaC2) as an in-situ source of acetylene. The nanocomplex was characterized by various techniques and it was proved to be an efficient drug carrier with satisfactory antimicrobial and antioxidant properties. Quercetin loaded nanocomplex (encapsulation efficiency- 68.2 ± 1.0 %) was studied for targeted drug release and the drug release after 120 h was found to be 80.7 ± 0.8 % and 8.69 ± 0.5 % at pH 5.0 and 7.4 respectively. On biological evaluation, the nanocomplex showed enhanced antimicrobial activity against gram-negative bacteria Escherichia coli (E. coli), gram-positive bacteria Bacillus subtilis (B. subtilis) and a fungi Aspergillus niger (A. niger). Moreover, the synthesized Ca@CS-Tz nanocomplex also exhibited significant antioxidant property. Herein, the novel results corresponding to the antimicrobial effect on A. niger and drug delivery studies performed using our previously synthesized chitosan triazole (CS-triazole) derivative have also been reported. Finally, the results of the present study were compared to the results obtained to our previously reported derivative. The incorporation of calcium ions into CS-triazole can lead to the utilization of this complex in various other biomedical applications e.g. bone tissue engineering.

High-Performance, Degradable, Self-Healing Bio-Based Nanocomposite Coatings with Antibacterial and Antioxidant Properties

The purpose of this study is to obtain a bio-based coating with good functional activity and self-healing ability, demonstrating its potential in food, materials, and other application fields. Plastic coatings can cause serious environmental pollution. It was a good solution to replace plastic coatings with degradable coatings. However, the development of degradable coatings in the fields of food and materials was limited due to their insufficient antibacterial ability and weak comprehensive properties. Therefore, chitosan nanoparticles (NPs) loaded with gallic acid (GA) were self-assembled with gelatin (GE) to prepare high-performance, degradable, self-healing bio-based nanocomposite coatings with antibacterial and antioxidant properties. The oxygen permeability of GE nanocomposite coatings decreased gradually with the addition of NPs, and the barrier properties increased significantly. At the same time, due to the excellent antioxidant and antibacterial ability of GA, the antioxidant effect of the nanocomposite coatings increased by 119%, and the antibacterial rate against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) increased by 32% and 58%, respectively, compared with the pure GE coatings. In addition, the nanocomposite coatings can be repaired within 24 h after being scratched at room temperature. Finally, GA coated with chitosan nanoparticles can significantly delay the escape of GA, and the retardation of gallic acid release exceeded 89% in simulated solutions after 24 h immersion, extending the service life of the nanocomposite coatings.

The Application of Phenolic Acids in The Obtainment of Packaging Materials Based on Polymers-A Review

This article provides a summarization of present knowledge on the fabrication and characterization of polymeric food packaging materials that can be an alternative to synthetic ones. The review aimed to explore different studies related to the use of phenolic acids as cross-linkers, as well as bioactive additives, to the polymer-based materials upon their application as packaging. This article further discusses additives such as benzoic acid derivatives (sinapic acid, gallic acid, and ellagic acid) and cinnamic acid derivatives (p-coumaric acid, caffeic acid, and ferulic acid). These phenolic acids are mainly used as antibacterial, antifungal, and antioxidant agents. However, their presence also improves the physicochemical properties of materials based on polymers. Future perspectives in polymer food packaging are discussed.

Preparation and antibacterial mechanism of cinnamaldehyde/tea polyphenol/polylactic acid coaxial nanofiber films with zinc oxide sol to Shewanella putrefaciens

In this study, the coaxial nanofiber films were prepared by coaxial electrospinning technique with cinnamaldehyde (CMA) and tea polyphenol (TP) as core material and polylactic acid (PLA) as shell material, and to obtain food packaging materials with great physicochemical and antibacterial properties, zinc oxide (ZnO) sol were added into PLA, and ZnO/CMA/TP-PLA coaxial nanofiber films were prepared. Meanwhile, the microstructure and physicochemical properties were determined, and the antibacterial properties and mechanism were investigated with Shewanella putrefaciens (S. putrefaciens) as target. The results show that the ZnO sol makes the physicochemical properties and antibacterial properties of the coaxial nanofiber films improve. Among them, the 1.0 % ZnO/CMA/TP-PLA coaxial nanofibers have smooth and continuous uniform surfaces, and their encapsulation effect on CMA/TP and antibacterial properties are the optimal. The synergistic action of CMA/TP and ZnO sol cause severe depression and folding of the cell membrane of S. putrefaciens, makes cell membrane permeability increase and of intracellular materials spillage, interference the bacteriophage protein expression, and makes macromolecular protein degraded. In this study, the introduction of oxide sols into polymeric shell materials by in-situ synthesis technique can provide theoretical support and methodological guidance for the application of electrospinning technology in the field of food packaging.

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.

A Review on Antimicrobial Packaging for Extending the Shelf Life of Food

Food packaging systems are continually impacted by the growing demand for minimally processed foods, changing eating habits, and food safety risks. Minimally processed foods are prone to the growth of harmful microbes, compromising quality and safety. As a result, the need for improved food shelf life and protection against foodborne diseases alongside consumer preference for minimally processed foods with no or lesser synthetic additives foster the development of innovative technologies such as antimicrobial packaging. It is a form of active packaging that can release antimicrobial substances to suppress the activities of specific microorganisms, thereby improving food quality and safety during long-term storage. However, antimicrobial packaging continues to be a very challenging technology. This study highlights antimicrobial packaging concepts, providing different antimicrobial substances used in food packaging. We review various types of antimicrobial systems. Emphasis is given to the effectiveness of antimicrobial packaging in various food applications, including fresh and minimally processed fruit and vegetables and meat and dairy products. For the development of antimicrobial packaging, several approaches have been used, including the use of antimicrobial sachets inside packaging, packaging films, and coatings incorporating active antimicrobial agents. Due to their antimicrobial activity and capacity to extend food shelf life, regulate or inhibit the growth of microorganisms and ultimately reduce the potential risk of health hazards, natural antimicrobial agents are gaining significant importance and attention in developing antimicrobial packaging systems. Selecting the best antimicrobial packaging system for a particular product depends on its nature, desired shelf life, storage requirements, and legal considerations. The current review is expected to contribute to research on the potential of antimicrobial packaging to extend the shelf life of food and also serves as a good reference for food innovation information.

Preparation and characterization of PVA/arginine chitosan/ZnO NPs composite films

In this study, arginineated chitosan (ACS) was used as a soft brain membrane and chelating agent to synthesize ACS-ZnO NPs, and then ACS and ACS-ZnO NPs were added to a polyvinyl alcohol (PVA) matrix as an antimicrobial agent to form films by casting. The formation and structural morphology of ACS and ACS-ZnO NPs were investigated by applying FTIR, 1H NMR, XRD, EDS, SEM, and TEM techniques, and ACS has shown better water solubility. The cytotoxicity experiments of ACS and ACS-ZnO NPs on A549 cells showed that both had good cytocompatibility. The incorporation of ACS and ACS-ZnO NPs improves the composite film's mechanical properties, water barrier, and oxygen barrier and exhibits excellent antibacterial activities against S. aureus and E. coli. More importantly, in addition to extending the shelf life of cherry tomatoes, the composite film is also biodegradable to some degree. Therefore, polyvinyl alcohol films based on ACS and ACS-ZnO NPs added as antimicrobial agents have great potential for food packaging applications.

Effect of Non-Thermal Food Processing Techniques on Selected Packaging Materials

In the last decade both scientific and industrial community focuses on food with the highest nutritional and organoleptic quality, together with appropriate safety. Accordingly, strong efforts have been made in finding appropriate emerging technologies for food processing and packaging. Parallel to this, an enormous effort is also made to decrease the negative impact of synthetic polymers not only on food products (migration issues) but on the entire environment (pollution). The science of packaging is also subjected to changes, resulting in development of novel biomaterials, biodegradable or not, with active, smart, edible and intelligent properties. Combining non-thermal processing with new materials opens completely new interdisciplinary area of interest for both food and material scientists. The aim of this review article is to give an insight in the latest research data about synergies between non-thermal processing technologies and selected packaging materials/concepts.

A review: Silver–zinc oxide nanoparticles – organoclay-reinforced chitosan bionanocomposites for food packaging

Research on bionanocomposites has been developed, while its application as food packaging is still being explored. They are usually made from natural polymers such as cellulose acetate, chitosan (CS), and polyvinyl alcohol. Bionanocomposite materials can replace traditional non-biodegradable plastic packaging materials, enabling them to use new, high-performance, lightweight, and environmentally friendly composite materials. However, this natural polymer has a weakness in mechanical properties. Therefore, a composite system is needed that will improve the properties of the biodegradable food packaging. The aim of this mini-review is to demonstrate recent progress in the synthesis, modification, characterization, and application of bionanocomposites reported by previous researchers. The focus is on the preparation and characterization of CS-based bionanocomposites. The mechanical properties of CS-based food packaging can be improved by adding reinforcement from inorganic materials such as organoclay. Meanwhile, the anti-bacterial properties of CS-based food packaging can be improved by adding nanoparticles such as Ag and ZnO.

Synthesis of novel chitosan Schiff base and its ZnO nanocomposite for removal of synthetic dye, antimicrobial, and cytotoxicity activity

In this work, a novel chitosan Schiff base 4-(2-Hydroxyaniline)pent-3-en-2-one chitosan (2-HyA-CS) and its ZnO nanocomposite (2-HyA-CS/ZnO) were sensitized and characterized by appropriate methods; FTIR, XRD, Elemental analysis, SEM, TEM and TGA. The result of characterization methods confirms the preparation of 2-HyA-CS and 2-HyA-CS/ZnO. The SEM images reveal that chitosan, 2-HyA-CS, and 2-HyA-CS/ZnO have a varied roughness and porous surfaces. The reason for this difference was attributed to the formation of Schiff base 2-HyA-CS and the presence of ZnO nanoparticles in 2-HyA-CS/ZnO. The patterns of XRD and FTIR confirm the formation of 2-HyA-CS and 2-HyA-CS/ZnO. The degree of substitution (DS) of modified chitosan 2-HyA-CS was calculated using Elemental analysis and FTIR.ATR, it was found to be 74%. The adsorption efficiency of the produced adsorbents was compared with pure chitosan to remove of Remazol Brilliant Blue R (RBBR) from an aqueous medium and antimicrobial activity. The removal percentage of RBBR by chitosan, 2-HyA-CS, and 2-HyA-CS/ZnO are 47.12%, 91.9%, and 96.56%, respectively with the following order: 2-HyA-CS/ZnO > 2-HyA-CS > chitosan. Their antimicrobial activities were studied against two Gram negative bacteria ( E. coli and P. aeruginosa), two Gram positive bacteria ( S. aureus and B. cereus) and ( C. albicans) as a yeast strain, the inhibitory zone measurements revealed that the activity of 2-HyA-CS/ZnO is excellent and higher than 2-HyA-CS and pure chitosan. The cytotoxicity of the prepared compound 2-HyA-CS and 2-HyA-CS/ZnO along with pure chitosan was estimated against two human cancer cells MCF-7 cells and HepG-2 cells, the result indicates that 2-HyA-CS/ZnO having higher Inhibitory activity against both MCF-7 and HepG-2 cells with 53.5 ± 2.86 and 27.4 ± 1.23 µg/mL respectively and 2-HyA-CS possessing moderate Inhibitory activity against both MCF-7 and HepG-2 cancer cells with IC50 = 216.5 ± 7.48 and 135.6 ± 6.49 µg/ml respectively.

Chitosan based film reinforced with EGCG loaded melanin-like nanocomposite (EGCG@MNPs) for active food packaging

In this study, EGCG loaded melanin-like nanoparticles (EGCG@MNPs) were incorporated into chitosan matrix to prepare an active nanocomposite food packaging film, chitosan-EGCG@MNPs (CH-EM). The influence of EGCG@MNPs on the physical and biological properties of the chitosan film was investigated. The EGCG@MNPs nanoparticles were cross-linked with chitosan through intermolecular hydrogen bonds and uniformly distributed in the matrix. Besides, the incorporation of EGCG@MNPs tremendously improved the solubility, swelling ratio and water vapor barrier properties of the film, and permitted superior ultraviolet rays blocking property. In addition, the mechanical properties, thermal stability and surface hydrophobicity have also been significantly improved. The CH-EM^2.0 nanocomposite films also showed excellent oxidation resistance (58.4 ± 4.4%, DPPH and 92.4 ± 1.3%, ABTS⁺), and strong inhibitory ability against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The experimental results comprehensively showed that the prepared chitosan-EGCG@MNPs nanocomposite film offering excellent potential for eco-friendly active food packaging.