Reduction in chilling injury symptoms by hot electrolyzed functional water treatment may function by regulating ROS metabolism in Satsuma orange fruit

This study investigated the effects of electrolyzed functional water (EFW), hot water or hot electrolyzed functional water treatment on the quality of Satsuma orange (Citrus unshiu) during cold storage (2 degrees C) for 60 days, with untreated fruit as the control. In the study, the fruit chilling injury (CI) index, weight loss, total soluble solid, titratable acid, cell membrane permeability, the production of malondialdehyde and superoxide dismutase, peroxidase, catalase activities were assessed. The results showed that the CI index reduced to 37%, 32%, 25%, weight loss decreased 2.06, 2.98, 1.68 g and the fruit maturity decreased to 31.61, 28.57, 26.84 respectively on the 60 day after EFW, hot water, hot EFW treatment, these results were accompanied by the cell membrane permeability reduced to 34.15%, 32.86%, 30.25%, the content of malondialdehyde reduced to 1.37, 1.32, 1.22 ilmol/g, at the same time, the activities of superoxide dismutase, peroxidase and catalase respectively increased to 6.21, 6.49, 7.16 U/mg, 2.92, 3.01, 3.52 U/mg and 82.44, 89.89, 90.88 U/mg. In conclusion, the three treatments played important roles in maintaining the fruit quality by regulating ROS metabolism during cold storage, and hot EFW treatment had the best effect.