MOF-based nanozyme incorporated composite film with prominent antibacterial activity and multiple functionalities for fruit preservation

The food packaging films with tunable multiple functionalities like sustained antibacterial activity, good light blocking and suitable water vapor permeability present significant practical implications for food preservation. Herein, metal-organic framework (MOF) based nanozyme with oxidase-like activity was constructed simply by chelating platinum ions, named as MOF-Pt. MOF-Pt was then incorporated into the chitosan (CS) film to form the CS-MOF-Pt composite film. Compared to the pure CS film, CS-MOF-Pt film possessed extra excellent antibacterial effect and light blocking abilities in addition to enhanced hydrophobicity with water contact angle from 52.19° to 80.38°. When the CS-MOF-Pt film was used to pack blueberries and cherries, the shelf life of these fruits was obviously prolonged by 4–6 days, with good appearance and minimum weight and polyphenol loss, demonstrating the suitability of the CS-MOF-Pt film for fruit preservation. This study provides a new way for constructing antibacterial food packaging film with multiple functionalities.