Enhanced physicochemical properties of chitosan/whey protein isolate composite film by sodium laurate-modified TiO 2 nanoparticles

Polymers Derived from Agro-Industrial Waste in the Development of Bioactive Films in Food

This review explores the potential of biopolymers as sustainable alternatives to conventional plastics in food packaging. Biopolymers derived from plant or animal sources are crucial in extending food shelf life, minimizing degradation, and protecting against oxidative and microbial agents. Their physical and chemical properties, influenced by the raw materials used, determine their suitability for specific applications. Biopolymers have been successfully used in fruits, vegetables, meats, and dairy products, offering antimicrobial and antioxidant benefits. Consequently, they represent a functional and eco-friendly solution for the packaging industry, contributing to sustainability while maintaining product quality.

Milk-derived antimicrobial peptides incorporated whey protein film as active coating to improve microbial stability of refrigerated soft cheese

Nisin is the first FDA-approved antimicrobial peptide and shows significant antimicrobial activity against Gram-positive bacteria, but only a weakly inhibitory effect on Gram-negative bacteria. The aim of this study was to prepare whey protein-based edible films with the incorporation of milk-derived antimicrobial peptides (αs2-casein151-181 and αs2-casein182-207) and compare their mechanical properties and potential application in cheese packaging with films containing nisin. These two antimicrobial peptides showed similar activity against B. subtilis and much higher activity against E. coli than bacteriocin nisin, representing that these milk-derived peptides had great potential to be applied as food preservatives. Antimicrobial peptides in whey protein films caused an increase in film opaqueness and water vapor barrier properties but decreased the tensile strength and elongation at break. Compared to other films, the whey protein film containing αs2-casein151-181 had good stability in salt or acidic solution, as evidenced by the results from scanning electron microscope and Fourier transform infrared spectroscopy. Whey protein film incorporated with αs2-casein151-181 could inhibit the growth of yeasts and molds, and control the growth of psychrotrophic bacteria present originally in the soft cheese at refrigerated temperature. It also exhibited significant inhibitory activity against the development of mixed culture (E. coli and B. subtilis) in the cheese due to superficial contamination during storage. Antimicrobial peptides immobilized in whey protein films showed a higher effectiveness than their direct application in solution. In addition, films containing αs2-casein151-181 could act as a hurdle inhibiting the development of postprocessing contamination on the cheese surface during the 28 days of storage. The films in this study exhibited the characteristics desired for active packaging materials.

Fabricating active Egg Albumin/Sodium Alginate/Sodium Lignosulfonate Nanoparticles film with significantly improved multifunctional characteristics for food packing

In food packaging, sodium lignosulfonate nanoparticles (SLS NPs) showed significant antibacterial properties, antioxidant and UV barrier activities. Herein, the SLS NPs were synthesized via a sustainable green method and were added into egg albumin/sodium alginate mixture (EA/SA) to fabricate a safe, edible EA/SA/SNPs food packaging. A composite film EA/SA/SNP was examined microstructurally and physicochemically. The mechanical characteristics, UV protection, water resistance, and the composite film's thermal stability were all enhanced by the inclusion of SLS NPs, and water vapor permeability reduced by 44 %. This composite film exhibited robust antioxidative properties with DPPH and ABTS free radical scavenging rates reaching 76.84 % and 92.56 %, and effective antimicrobial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) with antibacterial rates reaching 98.25 % and 97.13 % for the positively charged nanoparticles interacting with the cell membrane. Freshness tests showed that the EA/SA/SNPs packaging film could delay the quality deterioration of fresh tomatoes. This composite film can slow down spoilage bacteria proliferation and prolongs food's preservation period by eight days at ambient temperature.

Development of a chitosan and whey protein-based, biodegradable, colorimetric/fluorescent dual-channel monitoring label for real-time sensing of shrimp freshness

To address the growing and urgent need for quick and accurate food spoilage detection systems as well as to reduce food resource wastage, recent research has focused on intelligent bio-labels using pH indicators. Accordingly, we developed a dual-channel intelligent label with colorimetric and fluorescent capabilities using black lycium anthocyanin (BLA) and 9,10-bis(2,2-dipyridylvinyl) anthracene (DSA4P) as colorimetric and fluorescent indicators within a composite film consisting of chitosan (Cs), whey protein (Wp), and sodium tripolyphosphate (STPP). The addition of STPP as a cross-linking agent significantly improved the hydrophobicity, mechanical properties, and thermal stability of the Cs/Wp composite films under low pH conditions. After the incorporation of BLA and DSA4P, the resulting dual-channel intelligent label (Cs/Wp/STPP/BLA/DSA4P) exhibited superior hydrophobicity, as indicated by a water contact angle of 78.03°. Additionally, it displayed enhanced mechanical properties, with a tensile strength (TS) of 3.04 MPa and an elongation at break (EAB) of 81.07 %, while maintaining a low transmittance of 28.48 % at 600 nm. After 25 days of burial in soil, the label was significantly degraded, which showcases its eco-friendly nature. Moreover, the label could visually detect color changes indicating volatile ammonia concentrations (25-25,000 ppm). The color of the label in daylight gradually shifted from brick-red to light-red, brownish-yellow, and finally light-green as the ammonia concentration increased. Correspondingly, its fluorescence transitioned from no fluorescence to green fluorescence with increasing ammonia concentration, gradually intensifying under 365-nm UV light. Furthermore, the label effectively monitored the freshness of shrimp stored at temperatures of 4 °C, 25 °C, and - 18 °C. Thus, the label developed in this study exhibits significant potential for enhancing food safety monitoring.

Effect of tea polyphenols on chitosan packaging for food preservation: Physicochemical properties, bioactivity, and nutrition

Chitosan packaging has been widely studied for food preservation, the application of which is expanded by the incorporation of tea polyphenols. This paper reviews the influence of tea polyphenols incorporation on chitosan-based packaging from the perspectives of physicochemical properties, bioactivity used for food preservation, and nutritional value. The physicochemical properties included optical properties, mechanical properties, water solubility, moisture content, and water vapor barrier property, concluding that the addition of tea polyphenols improved the opacity, water solubility, and water vapor barrier property of chitosan packaging, and the mechanical properties and water content were decreased. The bioactivity used for food preservation, that is antioxidant and antimicrobial properties, is enhanced by tea polyphenols, improving the preservation of food like meat, fruits, and vegetables. In the future, efforts will be needed to improve the mechanical properties of composite film and adjust the formula of tea polyphenols/chitosan composite film to apply to different foods. Besides, the identification and development of high nutritional value tea polyphenol/chitosan composite film is a valuable but challenging task. This review is expected to scientifically guide the application of tea polyphenols in chitosan packaging.

TiO2 loaded on glycidol functionalized poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) nanobiocomposite film for photocatalytic and antibacterial activities

The rapid acceleration of industrialization and urbanization has exacerbated water pollution, which is primarily caused by the presence of highly toxic, non-biodegradable contaminants in industrial waste and effluents. In response to this urgent issue, a novel nanobiocomposite film with titanium dioxide (TiO2) loaded onto a poly(3-hydroxybutyrate-co-18 mol% 3-hydroxyhexanoate) (18PHBH) matrix was developed to serve as an effective dual-function material with photocatalytic and antibacterial properties. Through Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR), Diffuse reflectance ultraviolet-visible (DRUV-Vis), Scanning Electron Microscope (SEM), and X-ray diffraction (XRD) analyses, the physicochemical properties of the TiO2/Gly/18PHBH nanobiocomposite film were exhaustively characterized, revealing effective TiO2 loading and uniform distribution on the film's surface. The film exhibited extraordinary photocatalytic degradation of methylene blue (MB) dye, with the 5TiO2/Gly/18PHBH film demonstrating the greatest efficiency. In addition, antibacterial testing revealed that the film was effective against 99.8 % of Staphylococcus aureus and 96.9 % of Pseudomonas aeruginosa. These results demonstrate the potential of polyhydroxyalkanoate-based films as exceptional nanoparticle matrices and position the 5TiO2/Gly/18PHBH film as a versatile candidate for applications in photocatalysis and antibacterial interventions, providing innovative solutions to critical environmental challenges.

Intelligent biogenic pH-sensitive and amine-responsive color-changing label for real-time monitoring of shrimp freshness

BACKGROUND

This study developed an intelligent, pH-sensitive and amine-responsive colorimetric label based on chitosan, whey protein and thymol blue by controlling the pH value of the film-forming solution. The obtained label was used to monitor shrimp freshness in real time. The results of this study offer a new approach for developing highly intelligent biogenic labels for freshness monitoring during seafood preservation and processing.

RESULTS

The pH 2.0 chitosan-whey protein-thymol blue (CWT-pH 2.0) label exhibited remarkable properties, including the highest tensile strength (5.90 MPa), excellent thermal stability, low water solubility (27.80%) and highly sensitive color responsiveness. The characterization techniques of scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy confirmed the effective immobilization of thymol blue within the film-forming matrix through hydrogen bonding. Furthermore, the CWT-pH 2.0 label demonstrated visible color changes in the presence of volatile ammonia concentrations ranging from 25 to 25 000 ppm. Consequently, the label successfully facilitated real-time monitoring of shrimp freshness during storage at 4 °C. Importantly, the release rate of thymol blue from the label in food simulants was minimal, measuring only 2.53%.

CONCLUSION

The CWT-pH 2.0 label exhibits significant potential as a highly intelligent biogenic label for freshness monitoring in seafood preservation and processing. © 2023 Society of Chemical Industry.

Macro and nano level intervention of reinforcing agents for production of novel edible whey composite films and their applications in food systems: A review

Whey protein-based biocomposite films (WBF) are gaining significant importance as edible packaging materials due to their eco-friendly, biodegradable and barrier properties. The review aims to explore the impact of different reinforcing agents on the techno-functional properties of WBF. The incorporation of reinforcing agents, such as polysaccharides, lipids, starch, chitosan, cellulose, essential oils, and hydrocolloid gums, plays a crucial role in shaping the techno-functional properties of WBF. The review article suggests that whey biocomposite films, when strengthened with various additives, have the potential to be used as edible food packaging materials with desirable attributes. However, despite extensive studies, the utilization of WBF in model food systems remains limited, highlighting a significant gap for further exploration. Further research in this domain could potentially unlock new opportunities for utilizing WBF in various model food systems.

Comparative Study of ZnO-and-TiO2-Nanoparticles-Functionalized Polyvinyl Alcohol/Chitosan Bionanocomposites for Multifunctional Biomedical Applications

This study aimed to synthesize chitosan/polyvinyl alcohol (CS/PVA)-based zinc oxide (ZnO) and titanium dioxide (TiO2) hybrid bionanocomposites (BNCs) and observe their comparative accomplishment against the skin cancer cell line, A431, and antioxidant potential. CS was blended with PVA to form polymeric films reinforced with the immobilization of ZnO and TiO2 nanoparticles (NPs), separately. The optimization of the BNCs was done via physicochemical studies, viz. moisture content, swelling ratio, and contact angle measurements. The free radical scavenging activity was observed for 1,1-diphenyl-2-picryl-hydrazyl, and the antibacterial assay against the Escherichia coli strain showed a higher zone of inhibition. Furthermore, the anticancer activity of the synthesized BNCs was revealed against the skin cancer cell line A431 under varying concentrations of 50, 100, 150, 200, and 300 μg/mL. The anticancer study revealed a high percent of cancerous cell inhibition (70%) in ZnO BNCs as compared to (61%) TiO2 BNCs in a dose-dependent manner.

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.

Fabrication and characterization of waste fish scale-derived gelatin/sodium alginate/carvacrol loaded ZIF-8 nanoparticles composite films with sustained antibacterial activity for active food packaging

An environmental-friendly composite films containing waste fish scale-derived gelatin (FSG), sodium alginate (SA) and carvacrol loaded ZIF-8 (CV@ZIF-8) nanoparticles were designed and fabricated to develop active food packaging materials capable of sustained antibacterial activity. The microstructure and physicochemical properties of the FSG/SA/CV@ZIF-8 composite films were investigated. The incorporation of CV@ZIF-8 into FSG/SA matrix significantly enhanced the UV-light blocking and the elongation at break, improved water resistance and reduced water vapor permeability, and improved the thermal stability of composite film. The FSG/SA/CV@ZIF-8 film not only exhibited strong antioxidant activity with DPPH radical scavenging rate of 92.35 %, but also showed the satisfactory and long-acting antibacterial ability against E. coli and S. aureus due to slow release of CV from composite film. Strawberry preservation experiment revealed that FSG/SA/CV@ZIF-8 film decelerated the texture deterioration and retarded the growth of spoilage microorganism, resulting in the prolonged shelf-life of 8 days under ambient condition, indicating its promising application prospect in food preservation packaging.

Chitosan-Based Green Pea (Pisum sativum L.) Pod Extract Gel Film: Characterization and Application in Food Packaging

This work focuses on studying the preparation, characterization (physical, mechanical, optical, and morphological properties as well as antioxidant and antimicrobial activities) and packaging application of chitosan (CH)-based gel films containing varying empty green pea pod extract (EPPE) concentrations (0, 1, 3, and 5% w/w). The experiments revealed that adding EPPE to CH increased the thickness (from 0.132 ± 0.08 to 0.216 ± 0.08 mm), density (from 1.13 ± 0.02 to 1.94 ± 0.02 g/cm³), and opacity (from 0.71 ± 0.02 to 1.23 ± 0.04), while decreasing the water vapour permeability, water solubility, oil absorption ratio, and whiteness index from 2.34 to 1.08 × 10^-10 g^-1 s^-1 pa^-1, from 29.40 ± 1.23 to 18.75 ± 1.94%, from 0.31 ± 0.006 to 0.08 ± 0.001%, and from 88.10 ± 0.43 to 77.53 ± 0.48, respectively. The EPPE films had better tensile strength (maximum of 26.87 ± 1.38 MPa), elongation percentage (maximum of 58.64 ± 3.00%), biodegradability (maximum of 48.61% after 3 weeks), and migration percentages than the pure CH-gel film. With the addition of EPPE, the antioxidant and antibacterial activity of the film improved. SEM revealed that as EPPE concentration increased, agglomerates formed within the films. Moreover, compared to control samples, packing corn oil in CH-based EPPE gel films slowed the rise of thiobarbituric acid and peroxide values. As an industrial application, CH-based EPPE films have the potential to be beneficial in food packaging.

Green synthesized TiO2 nanoparticles: Structural characterization and photoinduced antifungal activity against P. steckii

This study synthesized titanium dioxide (TiO₂ ) nanoparticles (NPs) from mango leaf extract and investigated the features and antibacterial capabilities of three different. The microscopic morphological observation, scanning electron microscopy, and transmission electron microscopy results showed that all three NPs showed agglomeration phenomenon, and the TN-1 sample existed as large agglomerates, whereas the agglomeration phenomenon of TN-3 sample was improved by the modified, without large agglomerates. The biosynthetic TN-2 and TN-3 NPs were spherical and uniform in size, whereas those of the TN-3 sample was the smallest, ranging from 10 to 30 nm. X-ray diffraction and Raman spectroscopy results exhibited that these were highly pure anatase NPs. The result of ultraviolet (UV)-visible-near-infrared spectral analysis showed that the TN-2 and TN-3 samples displayed higher UV absorption properties than the TN-1 samples and were highest in the modified NPs, which was more suitable for preparing chitosan-based nanocomposite material in future experiments and studies. The colony diameters of the TN-1, TN-2, and TN-3 treatment groups were 7.99, 7.80, and 6.86 mm, respectively, after 120 min of UV light induction at a wavelength of 365 nm. Significant differences were evident between the TN-3 and the other two groups (p < 0.05), indicating that the TN-3 sample more effectively inhibited Penicillium steckii than the other TiO₂ NPs. PRACTICAL APPLICATION: Nanomaterials coated film preservation is widely used in fruit and vegetable preservation. In this paper, TiO₂ nanomaterials will be green synthesized using mango leaf and structurally characterized, whereas antibacterial tests will be conducted against the mango fruit-specific bacterium Penicillium steckii, which will provide a theoretical basis for the storage and preservation of mango.

Development of chloramphenicol wound dressing protein-based microparticles in chitosan hydrogel system for improved effectiveness of dermal wound therapy

Skin wounds have been reported to increase the number of microbial colonies susceptible to infection. Treatments using oral antibiotics have been limited due to their toxicity and hydrophobic characteristics. In this study, we developed a formulation of chloramphenicol microparticles (CPL MPs), which was modified into chitosan hydrogel to increase treatment efficiency in targeting infections and creating an optimal environment to support the healing process. CPL MPs were prepared by a cross-linker stabilized method using whey protein (WPI) biopolymer, and the CPL MPs hydrogel was designed using chitosan biopolymer. Based on the result, CPL-loaded MPs showed desired physical and encapsulation characteristics. In the in vitro study, drug release of CPL MPs in simulated wound fluid represented approximately 99.40 ± 7.01 % of the system after 24 h. The antibacterial activity of CPL-loaded MPs formulation (MIC value 12.5 μg/mL, MBC 25 μg/mL) was effective as MIC concentration increased. Furthermore, the formulation of CPL MPs into hydrogel showed a better dermatokinetic profile compared to hydrogel with pure CPL. Interestingly, the antibacterial activity of the ex vivo infection model showed that Staphylococcus aureus activity decreased by up to 99.98 % after 24 h administration of CPL MPs hydrogel when compared to pure-CPL hydrogel and blank hydrogel. These studies have confirmed that incorporating CPL MPs into hydrogel can provide a promising approach to skin infection treatment.

Preparation and characterization of chitosan/whey isolate protein active film containing TiO2 and white pepper essential oil

Active packaging films are designed to improve quality and extend the food shelf life by incorporating functional active ingredients into biopolymer films. This study developed a bioactive film based on chitosan (CS) and whey isolated protein (WPI) incorporated with 0.01 wt% TiO2 and 0.1 wt% white pepper essential oil (WPEO). The physicochemical properties of the prepared film were also evaluated comprehensively. The results showed that water solubility and water vapor permeability of the film incorporated with TiO2 and WPEO were 25.09% and 0.0933 g mm m–2 h–1 KPa–1, respectively, which were significantly higher than those of other films (P &lt; 0.05). In addition, the UV barrier properties of films incorporating TiO2 and WPEO have improved. The films were characterized by Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The FTIR results showed interactions between TiO2 and WPEO with CS/WPI compound, and the SEM results indicated a good incorporation of TiO2 into the composite films. The antioxidative and antibacterial properties of films were significantly enhanced by incorporating WPEO. According to results, the developed biocomposite film can be considered as a packaging material.

Bio-nano-composites containing at least two components, chitosan and zein, for food packaging applications: A review of the nano-composites in comparison with the conventional counterparts

Both chitosan and zein are safe industrial biopolymers for the 21St century, respecting environmentally concerns. This review mainly is focused on preparations, properties and applications of a promising food packaging material, chitosan-zein nano-composite (NC). The properties and applications of the NCs were compared with their conventional counterparts. The structure of chitosan- zein composites was proposed. A procedure for preparations of conventional and nano zein-chitosan composites was proposed. The sizes of composites depend on molecular weight of chitosan and zein, the ratio of chitosan/zein, and pH of chitosan-zein solutions. The NCs had superior mechanical, antimicrobial, antioxidant, and barrier properties compared with the conventional ones. The properties of the composites were further improved by introduction of bioactive compounds, fillers or plasticizers. The composites have potential to employ as coatings/packaging materials to protect mushroom, meats, and fresh fruits and vegetables.

Alginate with citrus pectin and pterostilbene as healthy food packaging with antioxidant property

A new type of film packaging made from natural polysaccharide materials, with its environmental safety and friendliness, is considered as a potential substitute for plastics. Novel polysaccharide composite films based upon citrus pectin (CP) and sodium alginate (SA) were successfully prepared and characterized, containing pterostilbene (PTE) at various concentrations (0.2, 0.4, 0.8, 1.6, 3.2 mM). The rheological analysis displayed that all film-forming liquids performed no gelation behavior with G" > G' at low frequency and weak gelation with G" < G' at high frequency. The SA-CP films had good tensile strength (TS) and elongation at break (EB), while adding PTE as an antioxidant to the film reduced both the values. Of note, the SA-CP films with PTE had better moisture resistance than that of the pure SA-CP films, which was related to the changes of its microstructure. The increased roughness of the films containing PTE was observed by microscope. After calcium chloride cross-linking, the water solubility of the films was reduced, while its thermal stability was improved. Notably, the accretion of PTE expressively enhanced the antioxidant properties of the SA-CP films. Thus, the SA-CP composite films containing PTE could be utilized as an excellent antioxidant packaging material.

The Food-Materials Nexus: Next Generation Bioplastics and Advanced Materials from Agri-Food Residues

The most recent strategies available for upcycling agri-food losses and waste (FLW) into functional bioplastics and advanced materials are reviewed and the valorization of food residuals are put in perspective, adding to the water-food-energy nexus. Low value or underutilized biomass, biocolloids, water-soluble biopolymers, polymerizable monomers, and nutrients are introduced as feasible building blocks for biotechnological conversion into bioplastics. The latter are demonstrated for their incorporation in multifunctional packaging, biomedical devices, sensors, actuators, and energy conversion and storage devices, contributing to the valorization efforts within the future circular bioeconomy. Strategies are introduced to effectively synthesize, deconstruct and reassemble or engineer FLW-derived monomeric, polymeric, and colloidal building blocks. Multifunctional bioplastics are introduced considering the structural, chemical, physical as well as the accessibility of FLW precursors. Processing techniques are analyzed within the fields of polymer chemistry and physics. The prospects of FLW streams and biomass surplus, considering their availability, interactions with water and thermal stability, are critically discussed in a near-future scenario that is expected to lead to next-generation bioplastics and advanced materials.

Protein–TiO2: A Functional Hybrid Composite with Diversified Applications

Functionalization of protein-based materials by incorporation of organic and inorganic compounds has emerged as an active research area due to their improved properties and diversified applications. The present review provides an overview of the functionalization of protein-based materials by incorporating TiO2 nanoparticles. Their effects on technological (mechanical, thermal, adsorptive, gas-barrier, and water-related) and functional (antimicrobial, photodegradation, ultraviolet (UV)-protective, wound-healing, and biocompatibility) properties are also discussed. In general, protein–TiO2 hybrid materials are biodegradable and exhibit improved tensile strength, elasticity, thermal stability, oxygen and water resistance in a TiO2 concentration-dependent response. Nonetheless, they showed enhanced antimicrobial and UV-protective effects with good biocompatibility on different cell lines. The main applications of protein–TiO2 are focused on the development of eco-friendly and active packaging materials, biomedical (tissue engineering, bone regeneration, biosensors, implantable human motion devices, and wound-healing membranes), food preservation (meat, fruits, and fish oil), pharmaceutical (empty capsule shell), environmental remediation (removal and degradation of diverse water pollutants), anti-corrosion, and textiles. According to the evidence, protein–TiO2 hybrid composites exhibited potential applications; however, standardized protocols for their preparation are needed for industrial-scale implementation.

Nanotechnology application in food packaging: A plethora of opportunities versus pending risks assessment and public concerns

Environmental factors, oxidation and microorganisms contamination, are the major causes for food spoilage, which leads to sensory features alteration, loss of quality, production of harmful chemicals and growth of foodborne pathogens capable to cause severe illness. Synthetic preservatives, traditional conserving methods and food packaging (FP), although effective in counteracting food spoilage, do not allow the real-time monitoring of food quality during storage and transportation and assent a relatively short shelf life. In addition, FP may protect food by the spoilage caused by external contaminations, but is ineffective against foodborne microorganisms. FP preservative functionalities could be improved adding edible natural antioxidants and antimicrobials, but such chemicals are easily degradable. Nowadays, thanks to nanotechnology techniques, it is possible to improve the FP performances, formulating and inserting more stable antioxidant/antimicrobial ingredients, improving mechanical properties and introducing intelligent functions. The state-of-the-art in the field of nanomaterial-based improved FP, the advantages that might derive from their extensive introduction on the market and the main concerns associated to the possible migration and toxicity of nanomaterials, frequently neglected in existing reviews, have been herein discussed.

Study on Biodegradable Chitosan-Whey Protein-Based Film Containing Bionanocomposite TiO2 and Zataria multiflora Essential Oil

In our research, a composite film of whey protein isolate (WPI)/chitosan incorporated with TiO2 nanoparticles (NPs) and essential oil of Zataria multiflora (ZEO) was developed. The resulting composite films were evaluated by FTIR, SEM, and XRD, and also the physicochemical characteristics including color, mechanical properties, swelling ratio, and water vapor permeability (WVP) were studied. SEM graphs exhibited that the samples had a uniform and homogeneous structure where TiO2 NPs and ZEO were well dispersed. FTIR and XRD findings also show that the hydrogen bonds and hydrophobic interactions are the main interactions between the composite WPI/chitosan and TiO2. The crystalline nature of the composite samples increased with the increase of NP content. Nevertheless, ZEO had an insignificant effect on the functional groups and the crystallinity of composite samples. The film visual characterization revealed that, by adding and increasing the TiO2 and TiO2-ZEO, sample lightness and opacity significantly increased. Additions of TiO2 remarkably (p<0.05) improved the water vapor and mechanical properties of composite samples, although the loading of ZEO, regardless of TiO2 incorporation, led to a considerable decrement of these properties. Furthermore, composite films containing ZEO combined with 2% of TiO2 compared with 1% of NPs blended with ZEO had strong antimicrobial properties against Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes. Generally, the findings proposed that the addition of TiO2 reinforces the properties of composite films with a synergistic effect of ZEO loading on the antibacterial ability, by which the resulting biodegradable composite samples can be used as a food active packaging material.

Effects of Different TiO2 Nanoparticles Concentrations on the Physical and Antibacterial Activities of Chitosan-Based Coating Film

In this investigation, the effect of different concentrations of titanium dioxide (TiO₂) nanoparticles (NPs) on the structure and antimicrobial activity of chitosan-based coating films was examined. Analysis using scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed that the modified TiO₂ NPs were successfully dispersed into the chitosan matrix, and that the roughness of the chitosan-TiO₂ nanocomposites were significantly reduced. Moreover, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses indicated that the chitosan interacted with TiO₂ NPs and possessed good compatibility, while a thermogravimetric analysis (TGA) of the thermal properties showed that the chitosan-TiO₂ nanocomposites with 0.05% TiO₂ NPs concentration had the best thermal stability. The chitosan-TiO₂ nanocomposite exhibited an inhibitory effect on the growth of Escherichia coli and Staphylococcus aureus. This antimicrobial activity of the chitosan-TiO₂ nanocomposites had an inhibition zone ranging from 9.86 ± 0.90 to 13.55 ± 0.35 (mm). These results, therefore, indicate that chitosan-based coating films incorporated with TiO₂ NPs might become a potential packaging system for prolonging the shelf-life of fruits and vegetables.

Extension of postharvest shelf life of strawberries (Fragaria ananassa) using a coating of chitosan-whey protein isolate conjugate

Chitosan and whey protein isolate (WPI) conjugate films were prepared as a novel matrix for encapsulating and extending the postharvest shelf life of strawberries. Film forming solutions of chitosan, WPI, and chitosan-WPI conjugate were mixed with glycerol, casted for films at 60 ± 2 °C and assessed for their colour, water vapour and oxygen transfer rate, textural, functional groups and secondary structure, thermal, crystallinity, and antioxidant properties. Chitosan-WPI conjugate films were applied as an edible coating on strawberries, and studied for storage stability at 5 °C and 20 °C by assessing physical and biochemical parameters. A considerable reduction in colour indices, weight loss, pH and titratable acidity, reducing sugars, ascorbic acid, total phenolics, DPPH and ABTS assay was noted in the coated strawberries over the control at both the studied temperatures. The control strawberries had a shelf life of 5 and 3 days, whereas coating enhanced the shelf life of strawberries to 8 and 5 days when stored at 5 °C and 20 °C, respectively.

Effect of chitosan-whey protein isolated coatings incorporated with tarragon Artemisia dracunculus essential oil on the quality of Scomberoides commersonnianus fillets at refrigerated condition

The purpose of present work was to assess the effects of chitosan (CH) coating in combination with whey protein isolated (WPI) and tarragon essential oil (TEO) on the bacterial (total mesophilic (TMC) bacteria and psychrotrophic (PTC) bacteria), physicochemical (total volatile bases- nitrogen (TVB-N), pH, thiobarbituric acid reactive substances (TBARS), free fatty acid (FFA)) and sensory properties of Scomberoides commersonnianus muscle during storage at refrigerator (4 ± 1 °C). The fillet were randomly divided into seven lots and subjected to the following treatments by immersion: chitosan (CH), whey protein isolate (WPI), whey protein isolate- TEO (WPI-TEO), chitosan-TEO (CH-TEO), chitosan-whey protein isolated (CH-WPI), chitosan/whey protwin isolated+ TEO (CH/WPI + TEO) and controls, then stored at 4 °C. Results indicated that incorporation of WPI and TEO into the material coating developed active coatings with good antimicrobial agent growth inhibition activity against TMC and PTC bacteria. The coated samples also retarded the increase in the contents of TVB-N, pH, TBARS and FFA during storage. The score less than critical score of 3 was made at day 8 and 12 for fillet coated with control and coated samples except of fillets coated with chitosan, respectively. These results confirmed that the incorporation of essential oils or other biopolymers into edible coatings may improve the deterioration of chilled seafood.

Development of novel active packaging films based on whey protein isolate incorporated with chitosan nanofiber and nano-formulated cinnamon oil

Active packaging is designed to extend products shelf life by incorporating active components with biological properties in its structure. The main goal of this research was to develop a biodegradable whey protein isolate (WPI)-based film, incorporated with chitosan nanofiber (CSNF) and cinnamon essential oil (CiEO) (both emulsified and Nanostructured lipid carriers (NLC) form). Then, the physicochemical properties of developed bio-nanocomposite were fully characterized. Both water solubility and the water vapor permeability of WPI film decreased significantly (p < 0.05) by incorporating the CSNF into film structure. The good complexation between WPI and CSNF was confirmed by FTIR. Microstructure revealed that the fiber networks were well distributed throughout the films while the morphological heterogeneity and contributed to the reduction of the tensile strength were evident after addition of CiEO. These obtained results from SEM to be quite in accordance with FT-IR findings that confirmed the incorporation of NLCs into bio-nanocomposite structure have been through physical interactions. The film barrier properties to ultraviolet light were increased by adding all of nano-reinforcements. Moreover, the antibacterial activity of resulting films was enhanced by adding CiEO, especially NLC form. This study introduces a novel ecofriendly bio-nano composite in packaging industries for the shelf life extension of different perishable foods.

Preparation and Characterization of Soy Protein Isolate-Based Nanocomposite Films with Cellulose Nanofibers and Nano-Silica via Silane Grafting

Soy protein isolate (SPI) has attracted considerable attention in the field of packaging technology due to its easy processability, biodegradability, and good film-forming characteristics. However, SPI-based films often suffer from inferior mechanical properties and high moisture sensitivity, thus restricting their practical application. In the present study, herein, a biobased nanocomposite film was developed by cross-linking SPI matrix from the synergistic reinforcement of cellulose nanofibers (CNF) and nano-silica (NS) particles. First, we functionalized the CNF with NS using a silane agent (KH560) as an efficient platform to enhance the interfacial interaction between SPI and CNF/NS, resulting from the epoxy-dominated cross-linking reaction. The chemical structure, thermal stability, and morphology of the resultant nanocomposite films were comprehensively investigated via Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). These results supported successful surface modification and indicated that the surface-tailored CNF/NS nanohybrid possesses excellent adhesion with SPI matrix through covalent and hydrogen-bonding interactions. The integration of CNF/NS into SPI resulted in nanocomposite films with an improved tensile strength (6.65 MPa), representing a 90.54% increase compared with the pristine SPI film. Moreover, the resulting composites had a significantly decreased water vapor permeation and a higher water contact angle (91.75°) than that of the unmodified film. The proposed strategy of synergistic reinforcements in the biobased composites may be a promising and green approach to address the critical limitations of plant protein-based materials in practical applications.

Cheese Whey Processing: Integrated Biorefinery Concepts and Emerging Food Applications

Cheese whey constitutes one of the most polluting by-products of the food industry, due to its high organic load. Thus, in order to mitigate the environmental concerns, a large number of valorization approaches have been reported; mainly targeting the recovery of whey proteins and whey lactose from cheese whey for further exploitation as renewable resources. Most studies are predominantly focused on the separate implementation, either of whey protein or lactose, to configure processes that will formulate value-added products. Likewise, approaches for cheese whey valorization, so far, do not exploit the full potential of cheese whey, particularly with respect to food applications. Nonetheless, within the concept of integrated biorefinery design and the transition to circular economy, it is imperative to develop consolidated bioprocesses that will foster a holistic exploitation of cheese whey. Therefore, the aim of this article is to elaborate on the recent advances regarding the conversion of whey to high value-added products, focusing on food applications. Moreover, novel integrated biorefining concepts are proposed, to inaugurate the complete exploitation of cheese whey to formulate novel products with diversified end applications. Within the context of circular economy, it is envisaged that high value-added products will be reintroduced in the food supply chain, thereby enhancing sustainability and creating "zero waste" processes.

Antimicrobial Nanoparticles Incorporated in Edible Coatings and Films for the Preservation of Fruits and Vegetables

Edible coatings and films (ECF) are employed as matrixes for incorporating antimicrobial nanoparticles (NPs), and then they are applied on the fruits and vegetables to prolong shelf life and enhance storage quality. This paper provides a comprehensive review on the preparation, antimicrobial properties and mechanisms, surface and physical qualities of ECF containing antimicrobial NPs, and its efficient application to vegetables and fruits as well. Following an introduction on the properties of the main edible coating materials, the preparation technologies of ECF with NPs are summarized. The antimicrobial activity of ECF with NPs against the tested microorganism was observed by many researchers. This might be mainly due to the electrostatic interaction between the cationic polymer or free metal ions and the charged cell membrane, the photocatalytic reaction of NPs, the detachment of free metal ion, and partly due to the antimicrobial activity of edible materials. Moreover, their physical, mechanical and releasing properties are discussed in detail, which might be influenced by the concentration of NPs. The preservation potential on the quality of fruits and vegetables indicates that various ECF with NPs might be used as the ideal materials for food application. Following the introduction on these characteristics, an attempt is made to predict future trends in this field.

Mango leaf extract incorporated chitosan antioxidant film for active food packaging

Health hazards associated with usage of plastic films for food preservation demands for development of active films from non-toxic and antioxidant rich bio-sources. The reported work highlights the development, characterization and application studies of chitosan films enhanced for their antioxidant activity by mango leaf extract (MLE) incorporation. Effect of MLE variation (1-5%) on the morphology, optical nature, water exposure and mechanical characteristics of the chitosan-MLE composite films was studied. Increase in the MLE concentration resulted in films with increased thickness and decreased moisture content. Contact angle, water solubility and vapor permeability analysis demonstrated the reduced hydrophilicity and water vapor penetrability of the films due to MLE inclusion. MLE films possessed better tensile strength (maximum of 23.06 ± 0.19 MPa) with reduced elongation ratio than the pure chitosan film (18.14 ± 0.72 MPa). Antioxidants assessment in terms of total phenolic content, DPPH radical scavenging, ferric reducing power and ABTS radical scavenging showed improved antioxidant activity with the incremental amounts of MLE in the chitosan films. Microscopic studies revealed the smooth, compact and dense nature of the MLE-chitosan films favouring low oxygen transport rates. Application studies to cashew nuts preservation for 28 days storage indicated 56% higher oxidation resistance for the 5% MLE film than a commercial polyamide/polyethylene film. Results highlight the potential and promising nature of MLE impregnated chitosan films as suitable alternative for active packaging films for food preservation.