Short UV-B exposure stimulated enzymatic and nonenzymatic antioxidants and reduced oxidative stress of cold-stored mangoes.
Jiang ZhiFang, Zheng YaoQi, Qiu RongRong, Yang YanJun, Xu MingFeng, Ye Yu, Xu MaoJun
Author Affiliation: Key Laboratory for Quality and Safety of Agricultural Products of Hangzhou City, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China.
Journal of Agricultural and Food Chemistry 63 : 10965-10972
Abstract : The effects of UV-B irradiation on reactive oxygen species (ROS) levels, antioxidant compound contents, antioxidative enzyme activities, and oxidative damage of cold-stored mangoes were examined. Superoxide anion production rate, hydrogen peroxide concentration, ion leakage level and malondialdehyde content of the cold-stored fruit preradiated with 5 KJ m-2 UV-B for 4 h were significantly decreased as compared with control fruit. The activities of ROS generating enzymes remained unchanged in UV-B-irradiated mangoes as compared to the control, but superoxide dismutase and catalase activities, ascorbate and polyphenol contents and antioxidant capacities of the cold-stored mangoes were significantly enhanced by UV-B. The UV-B-enhanced antioxidant compounds and antioxidative enzymes were highly correlated with the reduced-ROS levels in UV-B-irradiated mangoes. The data indicated that a short UV-B exposure reduced oxidative stress and alleviated oxidative damage of the cold-stored mangoes by triggering both enzymatic and nonenzymatic antioxidant systems although ROS generation in the fruit was not affected.