The development of biodegradable and recyclable food packaging materials derived from biomass is a promising solution to mitigate resource depletion and minimize ecological contamination. In this study, lignin nanoparticles (LNPs) were effectively produced from bamboo powder using an eco-friendly recyclable acid hydrotrope (RAH) strategy. A sustainable CA/LNPs nanocomposite film was then designed by incorporating these LNPs into a casein (CA) matrix. The LNPs served as nucleation templates, inducing ordered hydrogen bonding and close packing of the CA chains. The addition of 5 wt% LNPs significantly enhanced the mechanical properties of the film, with tensile strength enhanced to 21.42 MPa (219.7 % improvement) and elastic modulus rising to 354.88 MPa (220.3 % enhancement) compared to pure CA film. Notably, the resultant CA/LNPs nanocomposite film exhibited recyclable recasting characteristics, maintaining a reasonable mechanical strength even after three recasting cycles. The incorporation of LNPs also decreased the water solubility of the pure CA film from 31.65 % to 24.81 % indicating some interactions are taking place, while endowing the film with superior UV-blocking ability, achieving nearly complete absorption in the 200-400 nm range. Moreover, the inherent properties of LNPs imparted improved antibacterial and antioxidant activities to the CA/LNPs nanocomposite film. Owing to its comprehensive properties, the CA/LNPs nanocomposite film effectively extended the storage life of strawberries. A soil burial degradation test confirmed over 100 % mass loss within 45 days, highlighting excellent degradability of the films. Therefore, the simple extraction of LNPs and the easily recovery of p-TsOH provide significant promise and feasibility for extending the developed methodologies in this work to rapidly promote the produced films in fields such as degradable and packaging materials.

Due to the serious environmental pollution generated by plastic packaging, chitosan (CS)-based biodegradable films are gradually gaining popularity. However, the limited antioxidant and bacteriostatic capabilities of CS, the poor mechanical properties and water resistance of pure CS films limit their widespread adoption in food packaging. In this study, new multifunctional bioactive packaging films containing monosaccharide-modified CS and polyvinyl alcohol (PVA) were prepared to address the shortcomings of pure CS films. Initially, Maillard reaction (MR) products were prepared by conjugating chitosan with galactose/mannose (CG/CM). The successful preparation of CG/CM was confirmed using UV spectroscopy, fluorescence spectroscopy, fourier transform infrared spectroscopy (FTIR) and high-performance gel permeation chromatography (HPGPC). At an 8 mg/mL concentration, the DPPH radical scavenging activities of CM and CG were 5 and 15 times higher than that of CS, respectively. At the maximum concentration of 200 mu g/mL, both CM and CG exhibited greater inhibitory effects on the growth of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, compared to CS. Additionally, CM and CG demonstrated significantly stronger protection against oxidative damage in Vero cells than CS. These results indicate that CG and CM possess superior antioxidant and antibacterial capabilities in comparison to CS. Then, the effects of the MR on the structures and functional properties of chitosan-based films were extensively examined. Compared with pure CS films, the MR in the CG/CM films significantly changed the film microstructure, enhanced the UV-barrier property and water resistance, and only slightly reduced thermal stability. The MR reduced the tensile strength but increased the elongation at break. Meanwhile, the composite films hold good soil degradation ability. Moreover, the CG/CM films possessed excellent antioxidant and antibacterial properties and demonstrated superior fresh-keeping capacity in the preservation of strawberries and cherry tomatoes (effectively prolonged for at least 2 days or 3-6 days). Our study indicates that CG/CM films can be used as a promising biodegradable antioxidant and antibacterial biomaterial for food packaging.

Food packaging is one of the most commonly used materials today due to its affordability and convenience. However, this type of packaging is challenging to handle after use, leading to significant environmental waste since it is often made from petrochemical polymers that take a long time to decompose. Polyvinyl alcohol (PVA) is a low-cost, safe, and biodegradable polymer with high potential for food packaging, offering a solution to waste issues in the polymer industry. However, its limited hydrophilicity, bactericidal properties, and poor performance in humid conditions hinder its practicality. Enhancing the mechanical properties and water resistance of PVA-based composite films can significantly improve their applicability, particularly in food packaging. In this study, nanocomposite films based on PVA were reinforced with nanocellulose fiber (CNF) and Ag nanoparticles (AgNPs), and cross-linked using citric acid (CA) through the film casting method. The incorporation of CNF and AgNPs improved the structural integrity and thermal stability of the film, while CA crosslinking significantly enhanced water resistance and mechanical properties. The (PVA/CNF/Ag)-CA film exhibited the highest tensile strength (89.44 MPa), Young's modulus (3.29 GPa), and water contact angle (similar to 90 degrees), alongside the lowest water absorption (78.6 %) and a reduced water vapor transmission rate of 6.62 g x h(-1) x m(-2). Compared to pure PVA film, the resulting crosslinked nanocomposite films showed a 32.3 % increase in modulus and a 22.64 % increase in tensile strength. Additionally, the (PVA/CNF/Ag)-CA film exhibited higher thermal stability with 13 % more residue content than uncrosslinked counterparts, reduced moisture absorption, minimal swelling, and water insolubility. However, the CA crosslinking process promoted AgNP aggregation, reducing the antibacterial activity of the (PVA/CNF/Ag)-CA film against Staphylococcus aureus and Escherichia coli, and slowed down its biodegradation in soil. Nevertheless, after seven days of storage under both aerobic and anaerobic conditions, the nanocomposite coatings effectively minimized mass loss and microbial growth on fresh chili peppers. These results highlight the synergistic contribution of CNF/Ag reinforcement and CA crosslinking in enhancing the mechanical strength, thermal stability, and water resistance of PVA-based films for potential food packaging applications.

Environmental issues caused by plastic films promote the development of biodegradability packaging materials. Copper ion-modified nanocellulose films were prepared through a one-pot reaction and systematically investigated their structural characteristics, thermal stability, mechanical properties, antibacterial activity, and biodegradability. The results indicate that the film prepared by co-soaking CNCs and copper in NaOH solution for 12 h has favorable performance. Introduction of copper ions as crosslinkers increases tensile strength of film from 36.8 MPa to 56.4 MPa and water contact angle of film from 46 degrees to 92 degrees. Copper coordination also endows the film excellent antibacterial activity, inhibiting growth of Escherichia coli and Staphylococcus aureus. Moreover, biodegradability tests indicate that although the introduction of copper ions slightly reduce biodegradation rate of films, they could still be decomposed significantly within four weeks as burying in soil. This simple process for preparing cellulosic films with water resistance, thermal stable, antibacterial ability, and biodegradable shows potential application in flexible packaging film.

Transforming waste materials into valuable commodities is a promising strategy to alleviate challenges associated with managing solid waste, benefiting both the environment and human well-being. This study is focused towards harnessing the potential of waste eggshell microparticles (ESMP) (0.10, 0.15, 0.20 g/150 mL) as reinforcing biofiller and orange peel essential oil (OPEO) (14 %, 25 % and 36 %, w/w) as bioactive agent with pectin (2.80, 2.85, 2.90, and 3.00 g/150 mL) to fabricate five different biocomposite films using particle dispersion and solvent casting technique. The addition of ESMP and OPEO progressively increased film thickness and led to variations in transparency. Micromorphological analysis and vibrational spectroscopy indicated hydrophobicity and compactness, as showed by the loss of free O- H bonds, sharpening of aliphatic C- H and stretching of C = C, C- O and C- O- C bonds with increasing filler content. Noticeable improvements in thermal stability and tensile strength were observed, while the flexibility was minimized. The films displayed remarkable barrier properties against hydrological stress, as evidenced by a reduction in water activity, moisture content, water uptake capacity, and solubility. The antioxidant activity against DPPH radicals suggested efficient release of bioactive compounds. Antibacterial assessment revealed inhibitory effect on Staphylococcus aureus and Bacillus cereus. During soil burial, notable weight loss along with shrinkage confirmed the film biodegradability. In conclusion, the pectin-ESMP-OPEO biocomposite films show potential characteristics as food packaging materials, warranting further performance testing on food samples.

In food packaging industry, plastic was the most commonly used material for packaging, which caused serious pollution to the marine and soil environment. The researches on biodegradable films development from biodegradable polymers was arise, which was expected to ensure the quality and safety of food as much as possible. Biodegradable materials for films included polysaccharides and proteins of different biological sources, and synthetic materials. This review discussed the molecular characteristics and film-forming properties of natural polymer materials of polysaccharides from halobios, plant and microorganism, protein from animal, plant, milk. In addition, the effects of polymerization degree, crystallinity, and film-forming process of synthetic materials (polycaprolactone, polyvinyl alcohol, polylactic acid) on film performance was studied. In order to improve the practicality of biodegradable films in food packaging, many methods were explored to enhance the physical performance of the films. The enhancement strategies including: introduction of nanoparticles, chemical modification, and blending with other polymers, which can effectively enhance the mechanical properties and water vapor barrier performance of biodegradable films. Furthermore, it will provide a reference for future research interest that to development biodegradable food packaging films with high mechanical and barrier properties.

The environmental impact of food packaging, transportation and disposal are escalating, contributing significantly to global solid waste. There's an increasing focus by industry and research on seeking new sustainable solutions for waste valorization. This study investigates the isolation process of biopolymers from legumes (lentil) products and fish (gilthead seabream) waste, with the aim of producing composite films. The developed films were characterized for optical, mechanical and water barrier properties, hydrophobicity (via contact angle measurement), moisture content, water solubility, and biodegradability. Results indicated that lentil and fish protein concentrates may be effectively utilized to fabricate biodegradable packaging materials with adequate moisture barrier properties and excellent optical characteristics. The composite materials from lentil proteins and pectin had higher elongation at break compared to the respective value of the films produced using fish protein and gelatin (44.94 +/- 2.81 % and 10.52 +/- 1.21 %, respectively). Regarding the composite animal based film, the WVTR and WVP values were measured at 119.50 +/- 2.90 g x s(-1) x m(-2) and 5.04 +/- 0.06 x 10(-8) x g x m(-1) x s-(1)xPa(-1), respectively. The composite plant based materials had higher WVTR and WVP (139.17 +/- 8.01 g x s(-1) x m(-2) and 7.80 +/- 0.91 x 10(-8) x g x m(-1) x s-(1)xPa(-1), respectively). The composite film of pectin and concentrated lentil protein exhibited hydrophobic behavior (contact angle 98.63 +/- 3.78 degrees), whereas for gelatin and concentrated fish protein films, the contact angle was determined as 57.37 +/- 4.00 degrees, indicating hydrophilic behavior. All produced films biodegraded in <20 days during burial test in soil with high relative humidity (80 %). The results of the study show the utilization of food industry potential waste for producing environmentally friendly packaging materials.

Bacterial cellulose (BC), known for its exceptional physical properties and sustainability, has garnered widespread attention as a promising alternative to petrochemical-based plastic packaging. However, application of BC for packaging remains limited due to its hygroscopic nature, poor food preservation capabilities, and low optical transparency. In this study, a novel in-situ spraying method for chitosan (CS) encapsulation was developed to fabricate BC/CS hybrid structure layer by layer. The resulting composites exhibit effective antimicrobial activity against both Gram-positive and Gram-negative (> 75 %) bacteria, ensuring food preservation and safety. The BC/CS composites were modified through mercerization and heat drying (mBC/CS), transforming the cellulose crystal structure from cellulose I to the more stable cellulose II and inducing the alignment of a compact structure. Following waterborne polyurethane (WPU) coating, the mBC/CS/WPU composites acquired hydrophobic and heat-sealable properties, along with an 80 % reduction in haze and light transmittance exceeding 85 %. Further, they exhibited exceptional mechanical properties, including an ultimate tensile strength exceeding 200 MPa and omnidirectional flexibility. These composites could also preserve the freshness of sliced apples (< 20 % weight loss) and poached chicken (< 3 % weight loss) after one week of storage, comparable to commercial zipper bags, and also prevent food contamination. Notably, the mBC/CS/WPU composites displayed no ecotoxicity during decomposition and degraded completely within 60 days in soil. This study provides a valuable framework for functionalizing BC-based materials, promoting sustainable packaging, and contributing to the mitigation of plastic pollution.

Development of bio-based active packaging systems for lipid stabilization presents critical importance in preserving lipid integrity and ensuring food safety. Zein/citric acid (Z/CA) composite films containing grape seed ethanol extract (GSEE) (0-8% w/w) were prepared by the solvent casting method. The structural, functional, and environmental properties of the films, including physical and chemical properties, mechanical properties, antioxidant capacity, antibacterial activity, oxidation inhibition effect, and biodegradability, were comprehensively characterized and evaluated. Progressive GSEE enrichment significantly enhanced film thickness (p < 0.05), hydrophobicity, and total phenolic content, while increasing water vapor permeability by 61.29%. Antioxidant capacity demonstrated radical scavenging enhancements of 83.75% (DPPH) and 89.33% (ABTS) at maximal GSEE loading compared to control films. Mechanical parameters exhibited inverse proportionality to GSEE concentration, with tensile strength and elongation at break decreasing by 28.13% and 59.43%, respectively. SEM microstructural analysis revealed concentration-dependent increases in surface asperity and cross-sectional phase heterogeneity. Antimicrobial assays demonstrated selective bacteriostatic effects against Gram-negative pathogens. Notably, the composite film containing 6 wt% GSEE had a remarkable restraining effect on the oxidation of lard. The soil degradation experiment has confirmed that the Z/CA/GSEE composite film can achieve obvious degradation within 28 days. The above results indicate that the Z/CA/GSEE composite material emerges as a promising candidate for sustainable active food packaging applications.

The growing demand for sustainable and environment-friendly materials has driven extensive research on biopolymers for applications in agriculture, food science, and environmental remediation. Among these, nanocellulose-hydrogel hybrids (NC-HHs) have gained significant attention as an innovative class of bio-based materials that uniquely combine the remarkable physicochemical properties of nanocellulose with the functional versatility of hydrogels. These hybrids are characterised by exceptional water retention, mechanical strength and biodegradability, enabling advances in precision agriculture, smart food preservation and contaminant remediation. This review provides a comprehensive understanding of the synthesis, properties, and multifunctional applications of NC-HHs, emphasising their innovative role in sustainability. In agriculture, NCHHs enhance soil moisture retention, support plant growth, and serve as carriers for controlled-release fertilizers, optimizing water and nutrient use efficiency. In the food industry, they enable intelligent packaging solutions that extend shelf life, monitor food freshness, and inhibit microbial growth. Additionally, NC-HHs present groundbreaking strategies for environmental remediation by effectively immobilizing pollutants in water and soil. Beyond summarizing recent advances, this review presents an in-depth mechanistic perspective on the interactions between NC and HH, critically evaluating their structure-property relationships, functional adaptability and application-specific performance. By integrating recent advances in nanocellulose functionalisation, polymer chemistry and the development of responsive hydrogels, this review critically examines the key technological innovations and future prospects of NC-HHs, underscoring their transformative potential in addressing global challenges related to food security, environmental sustainability, and sustainable agricultural practices.