Modified\nChitosan-Based Coating/Packaging Composites\nwith Enhanced Antibacterial, Antioxidant, and UV-Resistant Properties\nfor Fresh Food Preservation

Chitosan-based\nbiomass packaging materials are a promising material\nfor food preservation, but their limited solubility, antioxidant capacity,\nUV resistance, and mechanical properties severely restrict their application.\nIn this study, we developed a novel chitosan-based coating/packaging\ncomposite (QCTO) using quaternary ammonium salt and tannic acid (TA)-modified\nchitosan (QCS-TA) and oxidized chitosan (OCS). The introduction of\nquaternary ammonium salt and TA effectively improves the water solubility\nand antibacterial, antioxidant, and UV-resistant properties of chitosan.\nThe Schiff-base bond formed between OCS and QCS-TA, along with the\nTA-mediated multiple interactions, conferred the prepared composite\nfilm with good mechanical properties (69.9 MPa tensile strength) and\ngas barrier performance to water (14.3 g·h<sup>–1</sup>·m<sup>–2</sup>) and oxygen (3.5 g·mm·m<sup>–2</sup>·h<sup>–1</sup>). Meanwhile, the prepared\nQCTO composites demonstrate excellent biocompatibility and safety\nand are applied as coatings for strawberries and bananas as well as\npackaging films for mushrooms. These preservation experiments demonstrated\nthat the prepared composites are able to effectively reduce weight\nloss, prevent microbial growth, maintain color, and significantly\nprolong the shelf life of fresh products (bananas, strawberries, and\nmushrooms extended shelf life by 6, 5, and 6 days, respectively).\nTherefore, the developed QCTO coating/packaging film shows great potential\nfor applications in the field of food preservation and packaging.