Preparation of Chitosan Composite Film Loaded with Chlorogenic Acid–Chitosan Oligosaccharide Nanoparticles and Its Application in Preservation of Pleurotus geesteranus

To reduce the environmental impact of plastic packaging in the edible fungi supply chain, this study developed an edible natural chitosan composite film loaded with chlorogenic acid-chitosan oligosaccharide nanoparticles (CGA/COS NPs). The effects of CGA/COS NPs as additives on the structure and overall performances of chitosan-based films were systematically studied, and the application effect of nanoparticles/chitosan (NPs/CS) composite films in the preservation of <i>Pleurotus geesteranus</i> was explored. The results showed that the NPs had good compatibility with the film matrix, filled the voids of the chitosan matrix, enhanced the comprehensive performance of the film, and significantly improved the antioxidant activity of the film (DPPH free radical scavenging activity increased from 16.95% to 76.47%). Among all the films, the 5%NPs/CS composite film performed the best, not only having stronger barrier properties against moisture, oxygen, and ultraviolet rays, but also having the best thermal stability and mechanical properties, which can effectively extend the shelf life of <i>Pleurotus geesteranus</i>. This study developed a high-performance edible composite film, which provides a new path of great value for solving the preservation problem of perishable agricultural products such as <i>Pleurotus geesteranus</i> and promoting the innovative development of the green food packaging industry.