Fabrication of polyvinyl alcohol/vanillin/Ti3C2Tx/ZnONPs composite film with excellent antimicrobial properties for pepper preservation

Novel food packaging materials with antimicrobial properties must be developed to ensure that fresh agricultural products are free from microbial contamination during the process from "farm" to "table". Herein, we synthesized an antimicrobial composite packaging film by employing a green in situ synthesis method. The method involves the in situ reduction of zinc oxide nanoparticles (ZnONPs) on the substrate Ti3C2Tx by Lactobacillus plantarum fermentation broth, which was then blended with polyvinyl alcohol and vanillin to obtain the polyvinyl alcohol/vanillin/Ti3C2Tx/ZnONPs (PVA/VAN/T-Z) composite film. The incorporation of crosslinker VAN and antimicrobial material Ti3C2Tx/ZnONPs did not affect the transparency and color of the film, but improved its mechanical strength, hydrophobicity, and antimicrobial ability of the film. Antimicrobial experiments demonstrated that the PVA/VAN/T-Z composite film exhibited significant antimicrobial activity against bacteria (Gram-negative E. coli and Gram-positive S. aureus) and fungi isolated from peppers. Furthermore, pepper preservation experiments demonstrated that the PVA/VAN/T-Z composite film exhibited commendable antimicrobial and preservation performance compared to commercially available film. As a novel antimicrobial packaging material, the multifunctional PVA/VAN/T-Z composite film has a broad application prospect in food preservation.