Characterization of gelatin-based composite films loaded with polysaccharide and carbon dots from Stropharia rugosoannulata and their application in pork fresh-keeping

In this study, bio-based composite films with enhanced barrier, mechanical, antioxidant and antimicrobial properties were prepared by incorporating Stropharia rugosoannulata waste (SP)-derived polysaccharides (SPP) and carbon dots (SPCDs) as an active substance into gelatin (GEL) matrix, which were evaluated for their potential application in pork preservation. The effects of varying concentrations of SPCDs on the morphology, microstructure, and overall performance of the films were systematically investigated. The findings demonstrated that the addition of SPCDs to the GEL/SPP matrix significantly improved the mechanical strength, water vapor permeability, and ultraviolet light blocking ability of the composite films. Specially, the GEL/SPP/SPCDs composite films containing 3 % carbon dots exhibited radical scavenging rates of 53.74 % for DPPH and 73.19 % for ABTS, along with inhibition rates of 58.37 % for E. coli and 70.25 % for S. aureus. Preservation experiments revealed that the prepared GEL/SPP/SPCDs-3 % films provided superior preservation effect on pork, highlighting their potential as eco-friendly active food packaging materials.