Inspired by facial masks: A nanocomposite fresh-keeping paper with moisturizing and antibacterial activities for fruit and vegetable preservation

Inspired by the “moisturizing-antibacterial” efficacy of facial masks, this study for the first time proposes and fabricates a nanocomposite fresh-keeping paper integrating efficient moisturization and synergistic antibacterial activity, aiming to delay post-harvest quality deterioration of fruits and vegetables. Using degradable paper as the substrate, this fresh-keeping paper (P-Car-PDA NPs) with dual moisturizing-antibacterial functions was constructed by loading a nanocomposite coating (CL-Car-PDA NPs). The physicochemical properties and fresh-keeping effects of CL-Car-PDA NPs and P-Car-PDA NPs were systematically investigated. When the volume ratio of Car to PDA NPs was 1:15 ( v /v), the maximum loading efficiency of PDA NPs reached 63.90%. Under simulated cold chain logistics conditions, both CL-Car-PDA NPs and P-Car-PDA NPs could effectively retard the release of Car and exhibit excellent inhibitory activity against Aspergillus niger . CL-Car-PDA NPs demonstrated superior physical barrier properties, washability, and biosafety. Specifically, the viability of mouse mononuclear macrophages treated with CL-Car-PDA NPs reached 94.56%, and no significant differences were observed in the germination rate or average plant height of mung bean sprouts compared with the blank control group. The mechanical properties, water vapor permeability (WVP), and gas selectivity of P-Car-PDA NPs were significantly improved compared with the control group. After 6 days of storage under simulated cold chain logistics, its tensile strength was increased by 520%, while the WVP was decreased by 60.60% relative to the control. Notably, the total migration of P-Car-PDA NPs in four food simulants was below the regulatory threshold of 10 mg/dm 2 . Under simulated cold chain logistics, P-Car-PDA NPs extended the shelf lives of strawberries, blueberries, cherry tomatoes, and Agaricus bisporus to the 8th, 18th, 25th, and 10th days, respectively, which outperformed CL-Car-PDA NPs.