Stretchable, controlled release of active substances, and biodegradable chitosan-polyvinyl alcohol hydrogel film for antibacterial and chilled meat preservation.

In this study, we utilized chitosan (CS) and polyvinyl alcohol (PVA) as the hydrogel matrix to fabricate a multifunctional hydrogel packaging film through the dimethylsulfoxide/hydroxybenzotriazole activation system-mediated. Based on the evaluation of thermal stability and mechanical properties, the optimal polymerization ratio of PVA to CS was determined as 3:1. Hydrogels made of 6 % PVA and 2 % CS have excellent heat resistance and adhesion, with a remarkable breakage elongation of 754.3 %. The cross-linking of PVA, CS, and ε-PL polymers occurred through esterification and amide reactions involving -COOH, -OH, and -NH2. The incorporation of ε-PL improved the thermal stability and strain properties. In vitro antibacterial assays demonstrated that the PVA/CS@ε-PL exhibited remarkable antibacterial efficacy against Staphylococcus aureus and Pseudomonas fluorescein. The PVA/CS@ε-PL-0.144 showed controlled release of ε-PL for over 3 d and extended the shelf life of chilled chicken to 8 d. These findings suggest that PVA/CS@ε-PL-0.144 is a potential antibacterial packaging.