Preparation, characterization, biological activity of 'Chuju' polysaccharides/chitosan and its application on the preservation of red grapes fruit.

In order to improve the preservation of red grape fruits, 'Chuju' polysaccharides (CCP) were cross-linked with chitosan (CS) to create CCP/CS composites with varying ratios. These composites were comprehensively characterized using FT-IR, C NMR, and SEM, which confirmed a smooth film surface and a uniform distribution of CCP. The composite films demonstrated efficacy in maintaining the quality of red grapes by mitigating shriveling and significantly reducing firmness loss by 22.26 % and vitamin C degradation by 30.39 % in comparison to the untreated control group. Furthermore, the CCP-200 %/CS composite exhibited a markedly enhanced antibacterial effect against Botrytis cinerea, a fungus associated with red grapes, and displayed improved antioxidant activity. Correlation analysis suggests that the preservation mechanism of the CCP/CS composites on red grapes is likely linked to their capacity to inhibit spoilage bacteria and their antioxidant properties. Collectively, these findings indicate that CCP/CS composites may serve as a promising eco-friendly and sustainable alternative for food packaging applications.