Abstract: The effect of high relative humidity (HRH) storage on reducing chilling injury of green pepper fruits and its relationship with changes in the antioxidant system were investigated. Fresh green peppers were stored at 4 ℃ in a dry-fog humidity controlled cold room with 96%–99% RH or a common low relative humidity (LRH) cold room with 70%–75% RH for up to 15 days. Every three days during the storage period, changes in chilling injury, quality attributes and antioxidant system parameters were examined. The results showed that HRH storage significantly delayed the increase in chilling injury index, relative electric conductivity and percentage mass loss and the decrease in fruit firmness, and maintained higher levels of chlorophyll, ascorbic acid, total phenolics and total flavonoids. Meanwhile, HRH storage significantly increased the activities of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase, maintained higher scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical, and decreased the accumulation of superoxide anion and hydrogen peroxide. These results suggested that HRH storage could reduce chilling injury of green pepper fruits by maintaining higher antioxidant activity and inhibiting the detrimental effects of reactive oxygen species (ROS).

Key words: green pepper fruit; high relative humidity storage; percentage mass loss; chilling injury; antioxidant activity