Development and characterization of egg white protein-pullulan-pomegranate peel polyphenol composite films for berry fruits preservation

This study developed innovative egg white protein (EWP)-pullulan (Pu) composite films functionalized with pomegranate peel polyphenols (PPP) for sustainable active food packaging applications. A comprehensive evaluation was conducted on their physicochemical and microstructural properties. Incorporation of PPP markedly improved the films' functional properties, reducing swelling capacity and opacity while substantially enhancing mechanical strength. Microstructural analysis revealed a concentration-dependent enhancement in film compactness, with uniform PPP dispersion observed via SEM. The composite films exhibited significant antibacterial efficacy against the common foodborne pathogens <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>. Fruit preservation trials confirmed that the composite films significantly outperformed PVC films in suppressing decay incidence and maintaining titratable acidity levels, highlighting the dual advantage of EWP-Pu-PPP films, including providing multifunctional food protection and promoting environmental sustainability. This research presents a promising strategy for designing high-performance, eco-friendly packaging materials that concurrently address both food spoilage mitigation and waste valorization.