Electrospun PLA/ZnO composite films: Enhanced antibacterial properties and application in fresh chicken meat preservation

Biodegradable and environmentally friendly packaging materials are receiving increasing attention in the field of food packaging. However, microbial spoilage remains a major threat to the shelf life of meat. Therefore, the development of degradable packaging materials with superior antibacterial properties is essential for improving meat preservation. In this study, an antibacterial fiber membrane based on polylactic acid (PLA) and zinc oxide nanoparticles (ZnO NPs) was fabricated using electrospinning. Additionally, their potential application in the storage of fresh chicken breast was investigated. The results indicated that when the PLA content was 10 % (w/v), the electrospun membrane exhibited optimal performance with tightly cross-linked fibers. Among the formulations, the membrane containing 1 % ZnO NPs (w/v, PLA/ZnO-1 %) demonstrated superior properties, with 2.95 MPa of tensile strength and 138.73 % of elongation at break, respectively. The thermal stability significantly improved, with the degradation temperature increasing from 175.17 °C in PLA film to 285.67 °C in PLA/ZnO-1 %. Although the additions of ZnO NPs reduced the water contact angle of the PLA films, the different ZnO NPs composite films still exhibited excellent hydrophobicity. Furthermore, the composite film exhibited potent antibacterial activity, as evidenced by inhibition zones of 35.9 mm and 37.4 mm against Pseudomonas fragi and Brochothrix thermosphacta, respectively. Preservation experiments revealed that the films containing 0.5 % and 1 % ZnO NPs extended the cold storage period of chicken meat by 3 days. The PLA/ZnO-1 % composite membrane holds promise for use in meat packaging to enhance preservation and provide antibacterial protection.