Mild temperature-assisted antimicrobial film with self-activating biocatalytic activity for efficient preservation of perishable products

To mitigate the decay of fruits and vegetables caused by food-borne microorganisms, this contribution proposed for the first time a novel mild temperature-assisted nanozyme-based antibacterial packaging system with self-activating behavior (MnHC-CS films) through a demand-oriented tailoring process that involved the construction of hollow carbon-supported Mn3O4 fillers (MnHC) and its incorporation in chitosan (CS) matrix. In this system, the weak acidity of CS film triggers the self-activation of MnHC nanozyme. Leveraging the synergistic effects of the excellent oxidase-like activity and photothermal properties of MnHC, in conjunction with the inherent bacteria trapping and killing capabilities of CS, the MnHC0.20-CS film (The 0.20 represents the amount of MnHC in the film-forming solution) demonstrates remarkable antibacterial and antifungal performances, with high bactericidal rate, short action time, and mild heating temperature. Therefore, the MnHC0.20-CS film showcases excellent preservation capabilities, significantly extending the shelf life of kumquats by approximately 2.3 times. Additionally, this film also boasts enhanced mechanical strength, improved barrier properties, and sufficient safety, paving the way for its practical application. These exceptional features underscore the good potential of MnHC0.20-CS film in effectively safeguarding perishable products.