Chitosan-based multifunctional hydrogel coatings with dual antibacterial and antioxidant properties are used for preservation and anti-corrosion

at low concentrations. Mechanistic investigations revealed that the antibacterial efficacy originates from a combined action involving bacterial membrane disruption, enhanced permeability and nucleic acid leakage, excessive intracellular ROS generation, oxidative stress imbalance, and effective biofilm destruction. Beyond antimicrobial activity, the coating also displayed strong antioxidant capacity, contributing to the mitigation of oxidative degradation during storage. Preservation performance was validated using fresh produce models, where CTS-ZnO&CA significantly reduced water loss and maintained the appearance quality of intact tomatoes, while effectively suppressing pathogen proliferation and delaying lesion expansion in wound-infected citrus fruits. This study highlights a hydrogel-coating strategy that integrates antimicrobial and antioxidant functions, providing a promising and practical approach for postharvest fruit preservation and anti-corrosion applications.