Polyvinyl alcohol-based multifunctional hydrogel film: a novel strategy for food preservation packaging

Food spoilage leads to the annual huge wastage of food. There is a pressing need for safe, multifunctional food preservation packaging to curb this wastage and prevent contamination. In this study, we present a novel, cross-linked P-GL hydrogel film with a smooth surface microstructure, derived from polyvinyl alcohol (PVA), gallic acid (GA), and lysozyme (L). This hydrogel film serves as an exceptional packaging material for food preservation, displaying an ability to completely block UV light and efficiently impede the penetration of water vapor and O2. Remarkably, the P-GL hydrogel film exhibits a fracture strength of approximately 37.9 MPa, demonstrating superior water solubility, thermal stability, and mechanical properties. Also, this P-GL hydrogel film can effectively eliminate E. coli and S. aureus. The P-GL hydrogel film has proven to be successful in mitigating the spoilage of blueberries through coating and covering treatments, outperforming commercial plastic wrap. As a result, the shelf life of blueberries can be extended to 20 days. Our work provides innovative insights that could potentially drive the use of safe and multifunctional hydrogel films in the food preservation packaging industry.