Effect of UV-C treatment on fruit quality and active oxygen metabolism of postharvest strawberry fruit

Effect of 0, 1.5, 3.0 and 4.5 kJ/m2 UV-C treatment on fruit quality, respiratory, ethylene production, soluble sugars, hexokinase, fructokinase and antioxidant enzymes activities of postharvest strawberry (cv. Fengguan) stored at 10℃ for 12 d was investigated. Results showed that, 3.0 kJ/m2 UV-C treatment significantly inhibited respiration rate and ethylene production, delayed the losing of total titratable acid and vitamin C contents, and maintained higher eating quality. Meanwhile, fruit treated with 3.0 kJ/m2 UV-C exhibiting higher FRK and HXK activities as compared to the other three treated fruits, and promoted the decrease of fructose and glucose during the last period of storage. Results also showed that, UV-C treatment at 3.0 kJ/m2 could maintain higher levels of SOD, CAT, APX and POD activities and inhibit the accumulation of MDA and superoxide anion radical. These results suggest appropriate UV-C treatment (3.0 kJ/m2) can maintain the balance of active oxygen metabolism, thereby effectively inhibiting the peroxidation of lipids and maintain membrane integrity and delaying senescence incidence in postharvest peach fruit. These results also indicate that, 3.0 kJ/m2 UV-C treatment may trigger hexose signaling transduction, regulate the biosynthesis and accumulation of anthocyanin, and finally contribute to red color development in postharvest strawberry fruit. ©, 2015, Chinese Institute of Food Science and Technology. All right reserved.