紫外发光二极管处理对香菇采后生理特性及贮藏品质的影响OA

To investigate the effects of ultraviolet light-emitting diode(UV-LED)and mercury lamp treatments on the postharvest physiological characteristics and storage quality of shiitake mushrooms(Lentinula edodes),fresh mushrooms were irradiated with either UV-LED(275 nm)or a mercury lamp at a dose of 4 kJ/m2 and then stored at 4℃.The dynamic changes in physicochemical indicators(color,mass loss rate),nutritional components(soluble protein,reducing sugar,free amino acids),bioactive compounds(total flavonoids,total phenols),enzyme activities(polyphenol oxidase(PPO),peroxidase(POD),phenylalanine ammonia-lyase(PAL)),and microbial and sensory qualities of shiitake mushrooms in each group were assessed on days 0,3,6,9,12,15,18,and 21.Two-way analysis of variance(two-way ANOVA)was employed to explore the effects of light source type,storage time,and their interaction on each quality indicator.The results showed that UV-LED treatment significantly enhanced PAL activity,efficiently activating the phenylpropanoid metabolic pathway and thereby increasing the contents of phenolic and flavonoid antioxidants(P<0.05).This treatment also increased PPO and POD activities,enhancing antioxidant defense while limiting enzymatic browning to a low level.Furthermore,UV-LED treatment effectively maintained nutritional components such as free amino acids and reducing sugar,and significantly reduced mass loss rate(P<0.05).In contrast,although mercury lamp treatment exhibited stronger instantaneous sterilization effects in the late storage period due to its wavelength advantage,it induced more severe browning and greater nutrient loss.Therefore,UV-LED treatment prior to cold storage can effectively improve the storage quality of fresh shiitake mushrooms,extending the shelf life to 21 days.