Impact of Ultraviolet-C Light on Softening and Senescence During Storage of Peach Fruit

Ultraviolet-C (UV-C), as a physical preservation technology, has the advantages of energy saving, safety, and sanitation and has broad application prospects in fruit storage. In this study, peach cultivated “Xiahui 5” was used as material to investigate the impact of UV-C on the softening, senescence, and postharvest quality of peaches. It was discovered that the application of UV-C postponed the peak of respiration, retarded the loss of firmness, and inhibited ethylene biosynthesis during peach fruit storage. The UV-C treatment led to the inhibition of the growth of soluble pectin content and the reduction of cellulose and hemicellulose content, together with the suppression of the activities of enzymes that break down cell walls. The application of UV-C treatment resulted in an increase in the total phenolic and flavonoid contents of peach fruit, accompanied by a corresponding enhancement in the activities of glutathione reductase (GR), catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD). This contributed to maintain the fruit’s normal redox balance and antioxidant capacity. The application of UV-C treatment resulted in a reduction in malondialdehyde (MDA) content and lipoxygenase (LOX) activity, thereby indicating that the oxidative damage of peach fruit during storage was inhibited by the UV-C. The application of UV-C maintained higher ATP content and induced the increase of cytochrome C oxidase (COX), succinate dehydrogenase (SDH), H⁺K⁺-ATPase, and Ca²⁺-ATPase activities involved in energy metabolism and had a significant impact in maintaining cell energy status. The findings suggest that UV-C treatment postpones peach fruit softening and senescence by maintaining cellular structure and energy homeostasis.