Gelatin films incorporated with thymol nanoemulsions: Physical properties and antimicrobial activities

Extension of shelf life of tomato (Solanum lycopersicum L.) by using a coating of polyhydroxybutyrate-carboxymethyl cellulose-pectin-thymol conjugate

This study targets explicitly finding an alternative to petroleum-based plastic films that burden the environment, which is a high priority. Hence, polymeric films were prepared with carboxymethyl cellulose (CMC) (4%), pectin (2%), and polyhydroxybutyrate (PHB) (0.5%) with different concentrations of thymol (0.3%, 0.9%, 1.8%, 3%, and 5%) and glycerol as a plasticizer by solution casting technique. The prepared films were tested for mechanical, optical, antimicrobial, and antioxidant properties. Film F5 (CMC + P + PHB + 0.9%thymol) showed an excellent tensile strength of 15 MPa, Young's modulus of 395 MPa, antioxidant activity (AA) (92%), rapid soil biodegradation (21 days), and strong antimicrobial activity against bacterial and fungal cultures such as Klebsiella pneumoniae, Staphylococcus aureus, Escherichia coli, Aspergillus niger, and Aspergillus flavus. The thymol content increase in films F6 (1.8%), F7 (3%), and F8 (5%) displayed a decrease in mechanical properties due to thymol's hydrophobicity. For shelf life studies on tomatoes, F2, a film without thymol (poor antimicrobial and antioxidant activities), F5 (film with superior mechanical, optical, antimicrobial, and antioxidant properties), and F7 (film with low mechanical properties) were selected. Film F5 coatings on tomato fruit enhanced the shelf life of up to 15 days by preventing weight loss, preserving firmness, and delaying changes in biochemical constituents like lycopene, phenols, and AA. Based on the mechanical, optical, antimicrobial, antioxidant, and shelf life results, the film F5 is suitable for active food packaging and preservation. PRACTICAL APPLICATION: The developed active biodegradable composite can be utilized as a coating to extend the shelf life of fruits and vegetables. These coatings are easy to produce and apply, offering a sustainable solution to reduce food waste. On an industrial scale, they can be applied to food products, ensuring longer freshness without any technical challenges.

New insights into essential oil nano emulsions loaded natural biopolymers recent development, formulation, characterization and packaging applications: A comprehensive review

Customer demand for wholesome diets has spurred researchers to explore preservative-free methods for maintaining food product quality. Nano emulsion-based coatings and films are seen as sustainable solutions for extending the shelf life of fresh produce. These innovations are driving progress in various industries. Nano emulsion techniques offer effective encapsulation of bioactive compounds due to their small droplet size, stability, and enhanced activity. This review highlights the preparation and manufacturing methods of biopolymer-based nano emulsions containing essential oils, which are used as edible coatings and films over the past decade, representing the first comprehensive review paper on this topic to encompass research from the past ten years. The characterization and application of these coatings and films are also discussed. It has been revealed that essential oils can be successfully incorporated into nano emulsion delivery system with different biopolymers. These edible coatings and films help delay or prevent oxidation in various food products, enhancing their quality and safety during storage. They present a green, sustainable, and biodegradable solution for protecting fresh foods in the industry. Essential oil biopolymer nano emulsions not only extend shelf life but also offer protection against hazards, contributing to consumer trust in food safety and quality. This technology holds promise for delivering healthier food options in the marketplace. The current review thus provides an updated overview of the latest literature on EO nano emulsions as active agents in the advancement of edible coatings and films.

Preparation of antibacterial composite film based on arginine-modified chitosan and its application in the preservation of ready-to-eat sea cucumber

An edible composite film was developed and applied for ready-to-eat sea cucumber storage to improve the product quality. The PAC film base is first prepared by mixing 0.5 % glycerin (GL) with 4 % polyvinyl alcohol (PVA) and 1 % arginine-modified chitosan (Arg-CTS) in the same volume. After the addition of nano-ZnO (ZnO) and thymol (Thy) to the PAC film base, the mechanical properties and functions were tested. Compared to the PAC film, the PAC-ZnO-ThyH composite film showed a 1.34-fold increase in the DPPH scavenging rate and a 2.19-fold increase in the ABTS scavenging rate. Contrary to the PAC film, the inhibition zone diameter of Escherichia coli and Staphylococcus aureus significantly increased by 2.35 and 4.08 folds in the PAC-Zno-ThyH film, respectively. After applying the PAC-ZnO-ThyH film to store ready-to-eat sea cucumber for 10 days, there was a significant reduction in weight loss, total volatile basic nitrogen (TVB-N), and lipid oxidation levels to 1.47 and 1.26 folds to the Ctrl group. After preservation, the hardness and chewiness of ready-to-eat sea cucumber were maintained at 1079.62 ± 138.86 N and 913.73 ± 175.79 N, respectively. The novel PAC-ZnO-ThyH composite film can be used as an active food packaging for promising seafood applications.

Application of Natural Functional Additives for Improving Bioactivity and Structure of Biopolymer-Based Films for Food Packaging: A Review

The global trend towards conscious consumption plays an important role in consumer preferences regarding both the composition and quality of food and packaging materials, including sustainable ones. The development of biodegradable active packaging materials could reduce both the negative impact on the environment due to a decrease in the use of oil-based plastics and the amount of synthetic preservatives. This review discusses relevant functional additives for improving the bioactivity of biopolymer-based films. Addition of plant, microbial, animal and organic nanoparticles into bio-based films is discussed. Changes in mechanical, transparency, water and oxygen barrier properties are reviewed. Since microbial and oxidative deterioration are the main causes of food spoilage, antimicrobial and antioxidant properties of natural additives are discussed, including perspective ones for the development of biodegradable active packaging.

Chitosan/alginate/pectin biopolymer-based Nanoemulsions for improving the shelf life of refrigerated chicken breast

This study investigated the use of nanoemulsions and various polymer coatings to enhance the quality and shelf life of chicken breast. This comprehensive study explored the antibacterial activity of essential oils (EOs) against Escherichia coli and Staphylococcus aureus, as well as the characterization of nanoemulsions (Nes) and nanoemulsion-based coatings. The antimicrobial potential of EOs, such as cinnamon, tea tree, jojoba, thyme, and black cumin seed oil, was evaluated against microorganisms, and thyme oil exhibited the highest inhibitory effect, followed by cinnamon and tea tree oil by disk diffusion analysis. The MIC and MBC values of EOs were found between 0.16-2.5 mg/mL and 0.16-5 mg/mL, respectively, while thyme EO resulted in the lowest values showing its antimicrobial potential. Then, the essential oil nanoemulsions (EONe) and their coatings, formulated with thyme oil, alginate, chitosan, and pectin, were successfully characterized. Optical microscope observations confirmed the uniform distribution of droplets in all (EONe), while particle size analysis demonstrated multimodal droplet size distributions. The EONe-chitosan coating showed the highest efficacy in reducing cooking loss, while the EONe-chitosan, EONe-alginate, and EONe-pectin coatings displayed promising outcomes in preserving color stability. Microbial analysis revealed the significant inhibitory effects of the EONe-chitosan coating against mesophilic bacteria, psychrophilic bacteria, and yeasts, leading to an extended shelf life of chicken breast. These results suggest the potential application of thyme oil and NE-based coatings in various industries for antimicrobial activity and quality preservation.

Effect of clove essential oil nanoemulsion on physicochemical and antioxidant properties of chitosan film

This study evaluated the physicochemical and antioxidant properties of clove essential oil (0, 0.2, 0.4, 0.6, 0.8, 1.0 % v/v) nanoemulsion (CEON) loaded chitosan-based films. With the increasing concentrations of the CEON, the thickness, b* and ΔE values of the films increased significantly (P < 0.05), while L* and light transmission dropped noticeably (P < 0.05). The hydrogen bonds formed between the CEON and chitosan could be demonstrated through Fourier-transform infrared spectra, indicating their good compatibility and intermolecular interactions. Furthermore, the added CEON considerably reduced the crystallinity and resulted in a porous structure of the films, as observed through X-ray diffraction plots and scanning electron microscopy images, respectively. This eventually led to a drop in both tensile strength and moisture content of the films. Moreover, the antioxidant properties were significantly enhanced (P < 0.05) with the increase in the amount of clove essential oil (CEO) due to the encapsulation of CEO by the nanoemulsion. Films containing 0.6 % CEO had higher elongation at break, higher water contact angle, lower water solubility, lower water vapor permeability, and lower oxygen permeability than the other films; therefore, such films are promising for application in meat preservation.

Pectin/sodium alginate films tailored with Acetyl-11-keto-beta-boswellic acid for active packaging

The present study aimed to develop food packaging films by using a combination of pectin (PE) and sodium alginate (SA) enriched with Acetyl-11-keto-beta-boswellic acid (AKBA) as a functional or active ingredient. The fabricated films underwent comprehensive evaluation of their morphological, chemical, mechanical, barrier, optical, thermal, antioxidant, and antimicrobial properties. SEM and FTIR analysis showed that AKBA had good compatibility with film-forming components. The AKBA-loaded film samples exhibited a decrease in their barrier properties and tensile strength, but enhancements in both elongation at break and thickness values was observed. With the addition of AKBA, a significant increase (p < 0.05) in the ultraviolet barrier properties of the films and total colour variation (ΔE) was observed. TGA analysis of the films unveiled an improvement in thermal resistance with the incorporation of AKBA. Moreover, the films loaded with AKBA exhibited potent antioxidant activity in the ABTS and DPPH assay methods. Disk diffusion analysis showed the antimicrobial activity of AKBA-loaded films against P. aeruginosa, highlighting the potential of AKBA as a natural antimicrobial agent for the safety of food products. The results demonstrate the practical application of PE and SA active films loaded with AKBA, particularly within the food packaging industry.

Fabrication, characterization, and application of pea protein-based edible film enhanced by oregano essential oil (OEO) micro- or nano-emulsion

Pea protein isolate (PPI)-based active films were prepared by incorporating 0.5 %, 1.0 %, or 2.0 % of oregano essential oil (OEO), either in the form of micro-emulsion (MOEO) or nano-emulsion (NOEO). The particle size and polydispersity index of OEO droplets were 2755.00 nm and 0.63 for MOEO, and 256.30 nm and 0.20 for NOEO. The surface and cross-sectional SEM results revealed the presence of holes and internal pores within the film upon the addition of OEO. The molecular interaction between PPI and OEO was confirmed by FTIR. The addition of OEO significantly increased film thickness, decreased water contact angle, and imparted a more yellow color. At a low concentration (0.5 %), the addition of OEO significantly improved the water vapor barrier and mechanical properties of the film. However, at higher concentrations, these film properties were significantly weakened. Additionally, the film antimicrobial properties were assessed after OEO addition. In vitro inhibition zone results indicated that a 2.0 % addition of OEO significantly suppressed the growth of three Salmonella strains [Salmonella Typhimurium (ATCC14028), Salmonella Infantis 94-1, and Salmonella Enteritidis PT-30]. Application of pea protein-based film with 2.0 % OEO on chicken breast demonstrated significant reduction in microbial count. Our results further showed that reducing the particle size of OEO from micrometer-scale to nanometer-scale in the PPI film matrix did not significantly alter film properties or antimicrobial activities. The study demonstrated that the antibacterial film based on pea protein and OEO is an innovative food packing material for prohibiting bacteria growth on poultry products.

Chemical and Structural Engineering of Gelatin-Based Delivery Systems for Therapeutic Applications: A Review

As a biodegradable and biocompatible protein derived from collagen, gelatin has been extensively exploited as a fundamental component of biological scaffolds and drug delivery systems for precise medicine. The easily engineered gelatin holds great promise in formulating various delivery systems to protect and enhance the efficacy of drugs for improving the safety and effectiveness of numerous pharmaceuticals. The remarkable biocompatibility and adjustable mechanical properties of gelatin permit the construction of active 3D scaffolds to accelerate the regeneration of injured tissues and organs. In this Review, we delve into diverse strategies for fabricating and functionalizing gelatin-based structures, which are applicable to gene and drug delivery as well as tissue engineering. We emphasized the advantages of various gelatin derivatives, including methacryloyl gelatin, polyethylene glycol-modified gelatin, thiolated gelatin, and alendronate-modified gelatin. These derivatives exhibit excellent physicochemical and biological properties, allowing the fabrication of tailor-made structures for biomedical applications. Additionally, we explored the latest developments in the modulation of their physicochemical properties by combining additive materials and manufacturing platforms, outlining the design of multifunctional gelatin-based micro-, nano-, and macrostructures. While discussing the current limitations, we also addressed the challenges that need to be overcome for clinical translation, including high manufacturing costs, limited application scenarios, and potential immunogenicity. This Review provides insight into how the structural and chemical engineering of gelatin can be leveraged to pave the way for significant advancements in biomedical applications and the improvement of patient outcomes.

Nanoemulsion-integrated gelatin/bacterial cellulose nanofibril-based multifunctional film: Fabrication, characterization, and application

The current requirements of food safety regulations and the environmental impact stemming from plastic packaging can only be addressed by developing suitable bio-nanocomposite films. Therefore, this study is dedicated to the fabrication of multifunctional film composed of gelatin, bacterial cellulose nanofibrils (BCNF), and black pepper essential oil nanoemulsion (BPEONE) and application for duck meat preservation. BCNF was prepared through ultrasonication of cellulose derived from Komagataeibacter xylinus. BPEONE observed spherical morphology with a diameter ranging from 83.7 to 118 nm. A film matrix containing a higher gelatin proportion than BCNF was more effective in trapping BPEONE. However, increasing the BPEONE fraction showed more surface abrasion and voids in the film morphology. A flexible film with good interaction, crystallinity, and greater thermal stability (421 °C) was developed. Nevertheless, film hydrophobicity (118.89°) declined, resulting in a notable effect on water solubility, swelling, and water vapor permeability. Moreover, the film had improved antibacterial and antioxidant activities, coupled with controlled release characteristics. Consequently, the developed film effectively retarded the lipid oxidation, inhibited microbial growth, and extended the shelf life of duck meat at refrigeration (4 °C) by 3 days, and made the film a promising alternative in the realm of bio-active packaging technology.

Nanoemulsion based edible coatings for quality retention of fruits and vegetables-decoding the basics and advancements in last decade

Fruits and vegetables (F&V) are highly perishable and have important contributions to nutritional and economic sustainability. Although the developing nations have shown an immense increase in the production of horticultural commodities, the post-harvest losses are significant and have an adverse impact on the resources, economy, and environment as well. Nanoemulsion-based carriers are recognized for their diversity, natural origin, and immense potential to restrict losses while boosting the functional attributes of produce. The recent findings attest to nanoemulsions potential for extending the shelf life, managing quality, and reducing the losses of the perishables for sustainable livelihood of the farmers. However, further studies are required to evaluate the biological fate, safety, or potential toxicity of the nanoemulsion-based edible coatings. This review precisely focuses on various matrices used in the production of nanoemulsions, fabrication methods, characterization techniques, and the use of natural emulsifiers instead of chemicals. The future research focus stresses on developing low-cost fabrication techniques for nanoemulsion, improvement of the transmission properties i. e gas transmission rate (GTR), water vapor transmission rate (WVTR), and enhancing the performance of monolayer, bilayer, and other composite nanoemulsion base films. This beyond reducing the postharvest losses shall also restrict burden of the food waste management and related environmental issues at the same time.

Development of functional, sustainable pullulan-sodium alginate-based films by incorporating essential oil microemulsion for chilled pork preservation

Developing safe, eco-friendly, and functionally edible packaging materials has attracted global attention. Essential oils, can be incorporated into packaging materials as antioxidant and antibacterial agents. However, their high volatility and discontinuous film matrix issues may cause a rough film surface, limiting the application in food packaging. In this study, thyme essential oil microemulsion (TEO-M) was prepared and incorporated into a pullulan-sodium alginate (PS) film. The TEO-M incorporation endowed the PS film with antioxidant and UV protection properties. The antioxidant activities of the TEO-M-incorporated PS film were significantly better than those of the TEO-C (thyme essential oil coarse emulsion)-incorporated PS film. In comparison to TEO-C, the distribution of TEO-M in the film is more uniform. Lipid oxidation and the growth of microorganisms in chilled pork were inhibited by incorporating TEO-M at a concentration of 50 mg/mL in the PS film (PS-50M). After 10 days of storage at 4 °C, the total viable count (TVC) of chilled pork preserved in the PS-50M material was significantly reduced compared to the control group (P < 0.05). This study shows that incorporating TEO-M in the PS film provides a method for applying essential oils in food packaging, which may have great potential in the food industry.

Recent developments in nanoemulsions against spoilage in cold-stored fish: A review

Nanoemulsion-based technology is developing rapidly in the food industry, especially in the design of delivery systems for bioactive compounds. This review presents an in-depth understanding of the composition, function, antibacterial mechanism and successful application of nanoemulsions as preservative agents against fish spoilage. The results showed that the inclusion of bioactive substances in the food-grade nanoemulsions encapsulation system could improve its stability, control its release, inhibit the microbial growth and reproduction through a variety of targets. These nanoemulsions can inhibit fish spoilage via reducing microbial load and retarding the oxidation of proteins and lipids, thereby maintaining quality attributes of fish. In addition, nanoemulsions could be coupled with vacuum package for enhancing microbial destruction, retaining nutritional value and extending the shelf-life of fish. Accordingly, nanoemulsions are suggested as a promising strategy to inhibit fish spoilage.

Recent advances in the production of bionanomaterials for development of sustainable food packaging: A comprehensive review

Polymers originating from natural macromolecule based polymeric materials have gained popularity due to the demand for green resources to develop unique, eco-friendly, and high-quality biopolymers. The objective of this review is to address the utilization of bionanomaterials to improve food quality, safety, security, and shelf life. Bionanomaterials are synthesized by integrating biological molecules with synthetic materials at the nanoscale. Nanostructured materials derived from biopolymers such as cellulose, chitin, or collagen can be employed for the development of sustainable food packaging. Green materials are cost-effective, biocompatible, biodegradable, and renewable. The interaction of nanoparticles with biological macromolecules must be analyzed to determine the properties of the packaging film. The nanoparticles control the growth of bacteria that cause food spoiling by releasing distinctive chemicals. Bio-nanocomposites and nanoencapsulation systems have been used in antimicrobial bio-based packaging solutions to improve the efficiency of synergism. Nanomaterials can regulate gas and moisture permeability, screen UV radiation, and limit microbial contamination, keeping the freshness and flavor of the food. Food packaging based on nanoparticles embedded biopolymers can alleviate environmental concerns by lowering the amount of packaging materials required and enhancing packaging recyclability. This results in less waste and a more eco-sustainable approach to food packaging. The study on current advances in the production of bionanomaterials for development of sustainable food packaging involves a detailed investigation of the available data from existing literature, as well as the compilation and analysis of relevant research results using statistical approaches.

Recent advances in edible coatings and their application in food packaging

The food packaging industries are facing the challenge of food waste generation. This can be addressed through the use of edible coating materials. These coatings aid in extending the shelf life of food products, reducing waste. The key components of these coatings include food-grade binding agents, solvents, and fillers. The integration of polysaccharide, protein, lipids, bioactive and composite-based materials with edible coating matrix aids to combat substantial post-harvest loss of highly perishable commodities and elevates the quality of minimally processed food. The aim of this review is to introduce the concept of edible coatings and discuss the different coating materials used in the food industry, along with their properties. Additionally, this review aims to classify the coating types based on characteristic features and explore their application in various food processing industries. This review provides a comprehensive overview of edible coatings, including the integration of polysaccharides, proteins, lipids, bioactive, and composite-based materials into the coating matrix. This review also addresses the significant post-harvest loss of highly perishable commodities and emphasizes the enhancement of quality in minimally processed food. Furthermore, the antimicrobial, anti-corrosive, and edible characteristics are highlighted, showcasing their potential applications in different food packaging industries. Moreover, it also discusses the challenges, safety and regulatory aspects, current trends, and future perspectives, aiming to shed light on the commercialization and future investigation of edible coatings.

Insight on Incorporation of Essential Oils as Antimicrobial Substances in Biopolymer-Based Active Packaging

The increasing interest in microbiological food safety requires the development of sensitive and reliable analyses and technologies for preserving food products' freshness and quality. Different types of packaging systems are one of the solutions for controlling microbiological activity in foods. During the last decades, the development of biopolymer-based active packaging with essential oil incorporation systems has resulted in technologies with exceptional application potential, primarily in the food industry. There is no doubt that this principle can facilitate food status monitoring, reduce food waste, extend the shelf life, improve the overall quality of food, or indicate a larger problem during the storage, production, and distribution of foodstuffs. On the other hand, most antimicrobial packaging systems are in the development phase, while the sensitivity, selectivity, complexity, and, above all, safety of these materials are just some of the essential questions that need to be answered before they can be widely used. The incorporation of essential oils as antimicrobial substances in biopolymer-based active packaging holds significant promise for enhancing food safety, extending shelf life, and offering more sustainable packaging solutions. While challenges exist, ongoing research and innovation in this field are likely to lead to the development of effective and environmentally friendly packaging systems with enhanced antimicrobial properties.

Nanofiber mats functionalized with Mentha piperita essential oil stabilized in a chitosan-based emulsion designed via an electrospinning technique

A nanostructured device based on poly(vinyl alcohol) (PVA) loaded with a cross-linked chitosan (CH) emulsion, soy lecithin, and peppermint essential oil (Mentha piperita) was designed for topical applications using an electrospinning instrument coupled to a rotary drum collector. Different suspensions were obtained by varying the PVA to emulsion ratio (PVA:Em) 87.5:12.5, 82:18, and 75:25, using a PVA solution as a control. ATR-FTIR spectra confirmed the interactions among the components of the system. Scanning electron microscopy (SEM) of the mats evinced that the aligned fiber diameter decreased with higher proportions of emulsion while dynamic mechanical analysis (DMA) revealed a decrease in the storage modulus. The entrapment of the functionalized emulsions not only improved the elongation of the matrices but also provided them with greater structural integrity compared to the single PVA matrix. The most favorable formulation in terms of mechanical properties was found to be the 82:18 ratio. After 1 h of close contact between the 82:18 matrix and a porcine skin explant, the latter was examined by confocal microscopy, which revealed the localization of the essential oil mainly on the surface of the stratum corneum (SC).However, after 7 h of contact, the distribution of the peppermint EO throughout the viable epidermis was observed, which was further supported by ATR-FTIR studies. Tailored electrospun matrices would have potential applications as devices for topical or transdermal treatments due to their vehiculization role that allows the diffusion of peppermint essential oil as a skin penetration enhancer.

Entrapment of probiotic (Bifidobacterium longum) in bilayer emulsion film with enhanced barrier property for improving viability

The gelatin/gellan gum based-bilayer emulsion film was developed in this work to improve the survivability of Bifidobacterium longum during the storage process. The baobab seed oil (BO) was added to the gelatin (GE) matrix to develop emulsion film as the barrier outer layer. The blueberry anthocyanin extract (BE) was incorporated into the gellan gum (GG)-based inner layer to enhance the viability of B. longum. The SEM and FTIR results revealed that the probiotics were successfully entrapped in BO/BE-loaded bilayer film. The greatest survivability and viable cell numbers of the B. longum during the storage period were observed in the BO/BE loaded bilayer film. Furthermore, the stability of the colorful patterns by electrochemical writing was also evaluated in this work. Finally, the GE/BO-GG/BE/BM maintain satisfactory probiotic viability in steamed bread coating application. Hence, the GE/BO-GG/BE/BM bilayer film could be considered a novel material to deliver and protect the probiotics in food applications.

Effects of grape seed oil nanoemulsion on physicochemical and antibacterial properties of gelatin‑sodium alginate film blends

The present study aimed to evaluate the impact of incorporating grape seed oil (GSO) nanoemulsion (NE) at varying concentrations into the film matrix on the physicochemical and antimicrobial properties of the resulting films. In this study, ultrasonic treatment was used to prepare GSO-NE, and different levels (2, 4, and 6 %) of nanoemulsioned GSO were incorporated into gelatin (Ge)/sodium alginate (SA)-based films to produce films with improved physical and antibacterial properties. The results revealed that incorporation of GSO-NE at 6 % concentration decreased the tensile strength (TS) and puncture force (PF) significantly (p < 0.05). The whiteness index (WI) of the films decreased from 63.4 to 47.79, while the total color change (ΔE) increased significantly (p < 0.05) with the increase in GSO-NE concentration. Thermogravimetric analysis (TGA) results showed that GSO-NE at different concentrations had improved the thermal stability of Ge/SA-based films. The incorporation of GSO-NE into the films led to the formation of a slightly porous structure. The incorporation of GSO-NE at 4 and 6 % concentrations decreased the water vapor permeability (WVP), moisture content (MC) %, and water solubility (WS) % significantly (p < 0.05). All composite films exhibited hydrophobic surfaces with contact angles θ > 90°. Ge/SA/GSO-NE films were found to be effective against both Gram-positive and Gram-negative bacteria. The prepared active films containing GSO-NE had a high potential for preventing food spoilage in food packaging.

Production, characterization, and antimicrobial activity of almond gum/polyvinyl alcohol/chitosan composite films containing thyme essential oil nanoemulsion for extending the shelf-life of chicken breast fillets

In this study, thyme essential oil (TEO) nanoemulsion was immobilized within composite films based on almond gum (AG), polyvinyl alcohol (PVA), and chitosan (CS). The physical, mechanical, water barrier, microstructural and antimicrobial properties of composite films were assessed. Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the intermolecular interactions in the composite film matrix. The results indicated that the incorporation of TEO into the composite films increased thickness, moisture content, and water vapor permeability, while it reduced light transmittance and transparency value. The antimicrobial activity of films against gram-negative and gram-positive bacteria was tested using a disc diffusion method. The effect of composite on the microbiological properties of chicken breast fillets was investigated during refrigerated storage for 21 days. The microbial populations of total mesophilic, psychrotrophic, and lactic acid bacteria of the samples that were coated with the composite containing TEO were lower than the permitted limit after 21 days while for blank samples they were higher than 7 log CFU/g after 7 days which is considered as the maximum acceptable total count limit. Results disclosed that AG/PVA/CS composite films containing TEO nanoemulsion can be applied as eco-friendly active food packaging to enhance the shelf-life of food products.

Functional insights to the development of bioactive material for combating bacterial infections

The emergence of antibiotic-resistant "superbugs" poses a serious threat to human health. Nanomaterials and cationic polymers have shown unprecedented advantages as effective antimicrobial therapies due to their flexibility and ability to interact with biological macromolecules. They can incorporate a variety of antimicrobial substances, achieving multifunctional effects without easily developing drug resistance. Herein, this article discusses recent advances in cationic polymers and nano-antibacterial materials, including material options, fabrication techniques, structural characteristics, and activity performance, with a focus on their fundamental active elements.

Hyaluronic acid-rich burger separator edible disc prepared from slaughterhouse waste

In this study, the edible films from chicken feet (CF), ovine muscle fascia (MF), and bovine bone gelatin (Gel) were prepared and their characteristics were analyzed, and we also evaluated the sensory quality of raw and cooked hamburgers using the edible films. The quantities of the CF and MF hyaluronic acid were evaluated using colorimetry and spectrophotometry. The CF, MF, and Gel films were prepared by solvent casting method. Results indicated that the concentration of hyaluronic acid in CF (124.11 ppm) was greater than MF (101.11 ppm). The antioxidative property of the CF film (18.47%) was greater than the Gel (1.88%) and MF (Undetectable) film. The CF film was more resistant to water vapor permeability (2.75 × 10-9 g/m.s.pa) than the MF (1.57 × 10-8 g/m.s.pa) and Gel (1.5 × 10-7 g/m.s.pa) films. The Gel film had more appropriate mechanical properties than CF and MF films. The films kept burgers patties independent from one another and prevented them from sticking and freezing together. MF and CF films were able to promote the organoleptic properties of raw and cooked hamburgers in taste and texture.

Designing Deferoxamine-Loaded Flaxseed Gum and Carrageenan-Based Controlled Release Biocomposite Hydrogel Films for Wound Healing

In this study, biocomposite hydrogel films made from flaxseed gum (FSG)/kappa carrageenan (CGN) were fabricated, using potassium chloride as a crosslinker and glycerol as a plasticizer. The composite films were loaded with deferoxamine (DFX), an iron chelator that promotes neovascularization and angiogenesis for the healing of wounds. The properties of the biocomposite hydrogel films, including swelling, solubility, water vapor transmission rate, tensile strength, elongation at break, and Young’s modulus studies, were tested. The films were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). In addition, drug release studies in PBS at pH 7.2 were investigated. In vivo analysis was performed by assessing the wound contraction in a full-thickness excisional wound rat model. Hematoxylin & eosin (H & E) and Masson’s trichome staining were performed to evaluate the effect of the films on wound healing progress. The visual and micro-morphological analysis revealed the homogenous structure of the films; however, the elongation at break property decreased within the crosslinked film but increased for the drug-loaded film. The FTIR analysis confirmed the crosslinking due to potassium chloride. A superior resistance towards thermal degradation was confirmed by TGA for the crosslinked and drug-loaded films. Drug release from the optimum film was sustained for up to 24 h. In vivo testing demonstrated 100% wound contraction for the drug-loaded film group compared to 72% for the pure drug solution group. In light of the obtained results, the higher potential of the optimized biocomposite hydrogel film for wound healing applications was corroborated.

Edible hyaluronic acid-rich burger separator discs prepared from slaughterhouse waste

In this study, edible films from chicken feet extract (CF), ovine muscle fascia extract (MF), and bovine bone gelatin powder (Gel) were prepared and their characteristics were analyzed. We also used the films as separators of burger cuts and evaluated the organoleptic characteristics of cooked burgers. Hyaluronic acid quantities of CF and MF were measured using colorimetric and spectrophotometry. Results indicated that the concentration of hyaluronic acid in CF (124.11 ppm) was greater than MF (101.11 ppm). The antioxidative property of the CF film (18.47%) was greater than the Gel (1.88%) and MF (Undetectable) films. The CF film was more resistant to water vapor permeability (2.75 × 10-9 g/m.s.pa) than the MF (1.57 × 10-8 g/m.s.pa) and Gel (1.5 × 10-7 g/m.s.pa) films. The Gel film had more appropriate mechanical properties than CF and MF films. The films kept burgers patties independent from one another and prevented them from sticking and freezing together. MF and CF films were able to promote the organoleptic properties of cooked burgers in taste and texture.

Bio-Nanocomposite Based on Edible Gelatin Film as Active Packaging from Clarias gariepinus Fish Skin with the Addition of Cellulose Nanocrystalline and Nanopropolis

This study develops bio-nano composite gelatin-based edible film (NEF) by combining nanogelatin, cellulose nanocrystal (CNC), and nanopropolis (NP) fillers to improve the resulting film characteristics. The NEF was characterized in terms of thickness, swelling, pH, water content, solubility, vapor and oxygen permeability, mechanical properties, heat resistance, morphology, transparency, and color. The results showed that the thickness and swelling increased significantly, whilst the pH did not significantly differ in each treatment. The water content and the water solubility also showed no significant changes with loadings of both fillers. At the same time, vapor and oxygen permeability decreased with addition of the fillers but were not significantly affected by the loading amounts. The heat resistance properties increased with the filler addition. Tensile strength and Young’s modulus increased for the films loaded with >3% CNC. The elongation at break showed a significant difference together with transparency and color change. The greater the CNC concentration and NP loading were, the darker the resulting transparency and the color of the NEF. Overall results show a considerable improvement in the properties of the resulting NEFs with the incorporation of CNC and NP fillers.

Optimization of Technological Parameters of the Process of Forming Therapeutic Biopolymer Nanofilled Films

The prospects of using biopolymer nano-containing films for wound healing were substantiated. The main components of biopolymer composites are gelatin, polyvinyl alcohol, glycerin, lactic acid, distilled water, and zinc oxide (ZnO) nanoparticles (NPs). Biopolymer composites were produced according to various technological parameters using a mould with a chrome coating. The therapeutic properties of biopolymer films were evaluated by measuring the diameter of the protective effect. Physico-mechanical properties were studied: elasticity, vapour permeability, degradation time, and swelling. To study the influence of technological parameters of the formation process of therapeutic biopolymer nanofilled films on their therapeutic and physico-mechanical properties, the planning of the experiment was used. According to the results of the experiments, mathematical models of the second-order were built. The optimal values of technological parameters of the process are determined, which provide biopolymer nanofilled films with maximum healing ability (diameter of protective action) and sufficiently high physical and mechanical properties: elasticity, vapour permeability, degradation time and swelling. The research results showed that the healing properties of biopolymer films mainly depend on the content of ZnO NPs. Degradation of these biopolymer films provides dosed drug delivery to the affected area. The products of destruction are carbon dioxide, water, and a small amount of ZnO in the bound state, which indicates the environmental safety of the developed biopolymer film.

Nano-enabled plant-based colloidal delivery systems for bioactive agents in foods: Design, formulation, and application

Consumers are becoming increasingly aware of the impact of their dietary choices on the environment, animal welfare, and health, which is causing many of them to adopt more plant-based diets. For this reason, many sectors of the food industry are reformulating their products to contain more plant-based ingredients. This article describes recent research on the formation and application of nano-enabled colloidal delivery systems formulated from plant-based ingredients, such as polysaccharides, proteins, lipids, and phospholipids. These delivery systems include nanoemulsions, solid lipid nanoparticles, nanoliposomes, nanophytosomes, and biopolymer nanoparticles. The composition, size, structure, and charge of the particles in these delivery systems can be manipulated to create novel or improved functionalities, such as improved robustness, higher optical clarity, controlled release, and increased bioavailability. There have been major advances in the design, assembly, and application of plant-based edible nanoparticles within the food industry over the past decade or so. As a result, there are now a wide range of different options available for creating delivery systems for specific applications. In the future, it will be important to establish whether these formulations can be produced using economically viable methods and provide the desired functionality in real-life applications.

Gelatin from leather waste to tough biodegradable packaging film: One valuable recycling solution for waste gelatin from leather industry

Large amount of gelatin can be extracted from the solid waste in leather industry. The advanced application of such gelatin is always desired by the leather industry, but remains challenging. Considering the urgent requirement of biodegradable plastic film, in this study, the gelatin extracted from waste skin scrap in the leather industry was used to fabricate a waste gelatin-based film with a high gelatin content, excellent mechanical performance, and autonomous biodegradability in natural soil. The film was prepared by introducing covalent bonds and metal-ligand bonds to the gelatin matrix. These covalent bonds, metal-ligand bonds, and inherent hydrogen bonds in the gelatin matrix serve as multiple sacrificial bonds for effective energy dissipation giving the waste gelatin-based film excellent mechanical parameters with the highest fracture stress of ≈ 32 MPa, maximum fracture strain of ≈1.25 mm/mm, and a high Young's modulus of ≈ 471 MPa, which are significantly higher than those of the original gelatin film (fracture stress ≈ 4 MPa, fracture strain ≈ 0.70 mm/mm, and Young's modulus ≈ 22 MPa). Owing to the water resistance of covalent bonds and metal-ligand bonds existed in gelatin matrix, the gelatin film possesses good water resistance. Additionally, after use, the fabricated film can completely biodegrade in natural soil in approximately 7 weeks. This strategy not only provides a valuable recycling solution for the gelatin from the unwelcome solid waste of the leather industry, but it also broadens the range of ecofriendly and cost effective biodegradable films available.

Current Trends in the Utilization of Essential Oils for Polysaccharide- and Protein-Derived Food Packaging Materials

Essential oils (EOs) have received attention in the food industry for developing biopolymer-derived food packaging materials. EOs are an excellent choice to replace petroleum-derived additives in food packaging materials due to their abundance in nature, eco-friendliness, and superior antimicrobial and antioxidant attributes. Thus far, EOs have been used in cellulose-, starch-, chitosan-, and protein-based food packaging materials. Biopolymer-based materials have lower antioxidant and antibacterial properties in comparison with their counterparts, and are not suitable for food packaging applications. Various synthetic-based compounds are being used to improve the antimicrobial and antioxidant properties of biopolymers. However, natural essential oils are sustainable and non-harmful alternatives to synthetic antimicrobial and antioxidant agents for use in biopolymer-derived food packaging materials. The incorporation of EOs into the polymeric matrix affects their physicochemical properties, particularly improving their antimicrobial and antioxidant properties. EOs in the food packaging materials increase the shelf life of the packaged food, inhibit the growth of microorganisms, and provide protection against oxidation. Essential oils also influence other properties, such as tensile, barrier, and optical properties of the biopolymers. This review article gives a detailed overview of the use of EOs in biopolymer-derived food packaging materials. The innovative ways of incorporating of EOs into food packaging materials are also highlighted, and future perspectives are discussed.

Effect of Cold Plasma Treatment on the Packaging Properties of Biopolymer-Based Films: A Review

Biopolymers, like polysaccharides and proteins, are sustainable and green materials with excellent film-forming potential. Bio-based films have gained a lot of attention and are believed to be an alternative to plastics in next-generation food packaging. Compared to conventional plastics, biopolymers inherently have certain limitations like hydrophilicity, poor thermo-mechanical, and barrier properties. Therefore, the modification of biopolymers or their films provide an opportunity to develop packaging materials with desired characteristics. Among different modification approaches, the application of cold plasma has been a very efficient technology to enhance the functionality and interfacial characteristics of biopolymers. Cold plasma is biocompatible, shows uniformity in treatment, and is suitable for heat-sensitive components. This review provides information on different plasma generating equipment used for the modification of films and critically analyses the impact of cold plasma on packaging properties of films prepared from protein, polysaccharides, and their combinations. Most studies to date have shown that plasma treatment effectively enhances surface characteristics, mechanical, and thermal properties, while its impact on the improvement of barrier properties is limited. Plasma treatment increases surface roughness that enables surface adhesion, ink printability, and reduces the contact angle. Plasma-treated films loaded with antimicrobial compounds demonstrate strong antimicrobial efficacy, mainly due to the increase in their diffusion rate and the non-thermal nature of cold plasma that protects the functionality of bioactive compounds. This review also elaborates on the existing challenges and future needs. Overall, it can be concluded that the application of cold plasma is an effective strategy to modify the inherent limitations of biopolymer-based packaging materials for food packaging applications.

Functional property optimization of sodium caseinate-based films incorporating functional compounds from date seed co-products using response surface methodology

Novel sodium caseinate films incorporating furfural and date seed oil (DSO) were produced. The effects of furfural and DSO contents on the functional and physical properties of the composite films were assessed using response surface methodology.

Application of Nanotechnology to Improve the Performance of Biodegradable Biopolymer-Based Packaging Materials

There is great interest in developing biodegradable biopolymer-based packaging materials whose functional performance is enhanced by incorporating active compounds into them, such as light blockers, plasticizers, crosslinkers, diffusion blockers, antimicrobials, antioxidants, and sensors. However, many of these compounds are volatile, chemically unstable, water-insoluble, matrix incompatible, or have adverse effects on film properties, which makes them difficult to directly incorporate into the packaging materials. These challenges can often be overcome by encapsulating the active compounds within food-grade nanoparticles, which are then introduced into the packaging materials. The presence of these nanoencapsulated active compounds in biopolymer-based coatings or films can greatly improve their functional performance. For example, anthocyanins can be used as light-blockers to retard oxidation reactions, or they can be used as pH/gas/temperature sensors to produce smart indicators to monitor the freshness of packaged foods. Encapsulated botanical extracts (like essential oils) can be used to increase the shelf life of foods due to their antimicrobial and antioxidant activities. The resistance of packaging materials to external factors can be improved by incorporating plasticizers (glycerol, sorbitol), crosslinkers (glutaraldehyde, tannic acid), and fillers (nanoparticles or nanofibers). Nanoenabled delivery systems can also be designed to control the release of active ingredients (such as antimicrobials or antioxidants) into the packaged food over time, which may extend their efficacy. This article reviews the different kinds of nanocarriers available for loading active compounds into these types of packaging materials and then discusses their impact on the optical, mechanical, thermal, barrier, antioxidant, and antimicrobial properties of the packaging materials. Furthermore, it highlights the different kinds of bioactive compounds that can be incorporated into biopolymer-based packaging.

Physical, Mechanical, and Water Vapor Barrier Properties of Starch/Cellulose Nanofiber/Thymol Bionanocomposite Films

The application of starch films, such as food packaging materials, has been restricted due to poor mechanical and barrier properties. However, the addition of a reinforcing agent, cellulose nanofibers (CNF) and also thymol, into the films, may improve the properties of films. This work investigates the effects of incorporating different concentrations of thymol (3, 5, 7, and 10 wt.%) on physical, mechanical, water vapor barrier, and antibacterial properties of corn starch films, containing 1.5 wt.% CNF produced using the solvent casting method. The addition of thymol does not significantly affect the color and opacity of the films. It is found that the tensile strength and Young’s modulus of the films decreases from 10.6 to 6.3 MPa and from 436.9 to 209.8 MPa, respectively, and the elongation at break increased from 110.6% to 123.5% with the incorporation of 10 wt.% thymol into the films. Furthermore, the addition of thymol at higher concentrations (7 and 10 wt.%) improved the water vapor barrier of the films by approximately 60.0%, from 4.98 × 10^—9 to 2.01 × 10^—9 g/d.m.Pa. Starch/CNF/thymol bionanocomposite films are also found to exhibit antibacterial activity against Escherichia coli. In conclusion, the produced starch/CNF/thymol bionanocomposite films have the potential to be used as antibacterial food packaging materials.