Biodegradable composite films based on egg white protein and tea polyphenol: Physicochemical, structural and antibacterial properties

Novel types of food packaging materials that exhibit prominent properties and are sufficiently environment-friendly have been continuously designed, reflecting an ongoing trend. This study aimed at preparing and characterizing egg white protein (EWP)-based composite films with and without tea polyphenol (TP) and comparing their physical properties, structural properties, decomposable properties and bacteriostasis. EWP-TP composite films were developed with glycerol as their plasticizer. As indicated by the mechanical results, the composite films exhibited higher elongation at break values (EAB) and tensile strength (TS) than the EWP film without the addition of TP. The structural and morphological properties were not significantly changed since cross-linking and intermolecular interactions were formed between the components in the films to different extents. Moreover, the composite films exhibited excellent antibacterial activities against Escherichia coli and Staphylococcus aureus on chilled pork in the presence of TP. Accordingly, the prepared films might serve as a freshness-keeping material on the application of meat preservation. The result of the biodegradation assessment confirmed that the EWP-TP composite films were considerably degraded and showed the potential applications in food packaging.