Biobased Composite Films for Strawberry Preservation with Bacterial Antifouling and Liquid Resistance

Food safety has always been a major concern of all mankind. Investigating biobased antimicrobial packaging is crucial for enhancing fruit preservation and promoting environmental sustainability. In this study, we developed a multifunctional biobased film with superhydrophobic and antimicrobial properties through the integration of chitosan (CS), resveratrol-encapsulated shellac nanoparticles (RSNPs), and carnauba wax (CW). By harnessing the antimicrobial capabilities of both chitosan and resveratrol, the film demonstrated an impressive antimicrobial efficacy of up to 99.9% against E. coli and S. aureus. The incorporation of RSNPs significantly enhanced the mechanical and UV-resistant properties of the film. Additionally, the hierarchical microstructure and low surface energy of the carnauba wax coating confer exceptional superhydrophobicity (CA > 150°) to the film, effectively minimizing liquid residues and bacterial adhesion on its surface. Our findings indicated that this film inhibits microbial growth, preserves strawberry quality, and prolongs shelf life during storage at both 25 and 4 °C. The findings suggested that the resveratrol-encapsulated shellac chitosan films possess excellent superhydrophobicity, mechanical properties, and antimicrobial performance, making them suitable as biobased antimicrobial packaging for long-term food preservation.