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.

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.

This study aims to develop an eco-friendly active packaging film to preserve perishable food. The film was prepared using natural polymers like sodium alginate and gelatin. Further, Clove oil was added to these films to improve their antioxidant and antimicrobial properties. The films' transmission was low, i.e., similar to 18.79% in 315-400 nm, lower, i.e., 14.41% in the UV region of 200-400 nm, and lowest, i.e., 12.21% in 200-280 nm with a band gap of similar to 3.52 eV, showing the effectiveness of films in shielding UV light. The films were hydrophilic and showed a low water vapor transmission rate. The packaging films showed thermal stability and reduced swelling. Freeze-thaw and high-temperature annealing significantly improved the film's mechanical properties (Y = 10.39 MPa and sigma = 23.37 MPa). The Chorioallantoic Membrane (CAM) assay in the chick model showed the films' biocompatibility. After 28 days, the films were completely biodegradable in soil, providing a sustainable solution for food packaging. Active packaging film showed significant antibacterial properties against Gram-positive S. aureus (colony-forming unit (CFU) reduced from 92 +/- 4.2 to 3 +/- 0.2, i.e., 96.74 +/- 5.13% inhibition) and Gram-negative E. coli (colony-forming unit reduced from 106 +/- 6 to 95 +/- 4.11, i.e., 96.13 +/- 3.41%). These films showed significant antioxidant activity and effectively delayed the decay of bananas (Musa acuminata), making them a promising solution for food packaging with excellent UV blocking, antimicrobial, and antioxidant properties. [GRAPHICS] .

Excessive use of nondegradable plastics has raised environmental concerns, promoting the development of high-performance and eco-friendly materials. Polysaccharides and proteins, which offer advantages such as affordability and biodegradability, have potential in packaging but are limited in barrier and mechanical properties. Herein, using 30% acetic acid as a solvent for soy protein isolate (SPI) and introducing oxidized arabinogalactan (OAG) into the system, highly transparent (90%) and ultraviolet-shielding SPI/OAG flexible films were successfully prepared via Schiff base chemical cross-linking and hydrogen bond interactions between the components. The synergistic cross-linking of SPI and OAG effectively increased mechanical strength (tensile strength of 6.93 MPa), improved oxygen and water vapor barrier properties, and reduced swelling in the SPI/OAG films. The films exhibited good antioxidant activity (81.75% for ABTS and 85.34% for DPPH), effectively retarded browning and weight loss of strawberry and apple pieces, and were biodegradable in soil. The prepared SPI/OAG films had advantages over existing SPI-based films, including a uniform structure, low oxygen permeability, and excellent sustainability. This research demonstrates that SPI/OAG cross-linked films have strong potential in biodegradable packaging and as a substitute for petroleum-based plastics.

In this paper, pectin-based plastic films were developed by grafting vanillin to pectin chains and introducing Fe3+ ions. The mechanical properties, thermal stability, moisture resistance, UV-light barrier property, biodegrad-ability, and practical application of fabricated plastic film were evaluated. Results confirmed the successful grafting of vanillin and the presence of hydrogen bonds and metal-ligand bonds, giving the plastic film highest fracture stress of 41.68 +/- 4.10 MPa, which was nearly 481.31% enhancement than that of neat pectin film. Additionally, the thermal stability, moisture resistance, and UV-blocking property (200-400 nm) of fabricated plastic film were significantly improved. Moreover, the plastic film exhibited satisfying processability, which can be processed to bag and appearing excellent food preservation ability. After use, the plastic film can be completely biodegradable in soil (degradation time approximate to 7 weeks) and seawater without manual interference. Thus, our proposed pectin-based plastic film can be recommended as a non-polluting and sustainable food packaging substitute.