The Influence of a Novel Chitosan-Based Coating with Natural Antimicrobial Agents on the Storage Properties and Reactive Oxygen Species Metabolism of Harvested Tangelo Fruit

This study investigated the effects of a novel antibacterial film based on chitosan, carboxymethyl cellulose, sodium alginate, tea polyphenols, ascorbic acid, and tangelo peel extract on the postharvest quality and reactive oxygen species metabolism of tangelo fruit during storage. The composite film significantly reduced the fruit decay rate and weight loss, delayed the reduction in total soluble solids and titratable acidity, and retained fruit firmness and the appearance of tangelo fruit during storage. Furthermore, the composite film effectively reduced the fruit respiration rate, inhibited the increase in cell-membrane permeability, markedly reduced the generation of superoxide anion, hydrogen peroxide, and malondialdehyde, and enhanced the activity of the antioxidant enzymes superoxide dismutase, catalase, and ascorbate peroxidase. The composite film also reduced losses of the nonenzymatic antioxidants ascorbic acid and glutathione. Overall, the chitosan-based composite antibacterial film effectively maintained the quality of tangelo fruit during storage, enhanced ROS scavenging capacity and antioxidant properties, and then reduced the rot rate of postharvest tangelo.