Preparation of PLA/PBAT/Anthocyanins@ZIF-8 Composite Films via Casting Method and Their Antibacterial Activity and Application for Pork Preservation

Pork is highly perishable during storage, leading to enormous economic losses and potential food safety hazards. Anthocyanins (ANTs) possess excellent antioxidant and antibacterial activities, but their poor stability in practical applications limits their industrial application. To address these issues, a novel composite preservation film was prepared by the four-sided applicator solution casting method, using polylactic acid (PLA) and polybutylene adipate-co-terephthalate (PBAT) as matrix materials and ANTs@ZIF-8 as functional filler. Zeolitic imidazolate framework-8 (ZIF-8) encapsulated ANTs to enhance its stability and achieve sustained release, while the PLA/PBAT was selected for its good biodegradability, mechanical and barrier properties. The structure and properties of the PLA/PBAT/ANTs@ZIF-8 composite films were investigated, and the results showed that ANTs@ZIF-8 nanoparticles had stable dispersibility in the matrix, which effectively improved the compatibility between nanoparticles and the film matrix. The prepared composite films exhibited excellent tensile strength (TS), elongation at break (EAB) and water vapor transmission rate (WVTR), as well as good antibacterial activity against E. coli and S. aureus. Furthermore, the practical pork preservation performance of the films was investigated, and the results demonstrated that the composite films could effectively reduce the pH value, water loss, color difference, total volatile basic nitrogen (TVB-N) content and malondialdehyde (MDA) content of fresh pork during storage, successfully extending the shelf life of pork to 12 days. This study develops a multifunctional, biosafe, and biodegradable PLA/PBAT composite film incorporated with ANTs@ZIF-8, providing a feasible strategy and scientific reference for the design and development of high-performance active biodegradable packaging materials.