Preparation of Biodegradable Polylactic Acid/Ethyl Cellulose/Zein Composite Film and Its Effect on the Preservation of Chilled Fresh Meat

In this study, composite films consisting of polylactic acid (PLA), ethyl cellulose (EC), and zein were prepared by solution casting method, and their performance and application in chilled fresh meat preservation were investigated. The results showed that the three materials had satisfactory compatibility in the composite film. Addition of EC and zein effectively improved the mechanical properties, thermodynamic properties, surface hydrophilicity, oxygen permeability, and degradation properties of PLA films. When the ratio of PLA to EC was 3:7, the tensile strength and elongation at break reached maximum values of 16.6 MPa and 30.5%, respectively. Moreover, under different conditions, the composite film exhibited better degradability than the PLA film. The composite film with a 3:7 ratio of PLA to EC had the best performance, with a degradation rate of 21.75% after 84 days. Chilled fresh meat wrapped with the composite film showed significantly improved antioxidant, antibacterial, and water-holding properties.