Abstract: In order to understand the effects of relative humidity on calcification and reactive oxygen species metabolism of Chinese chestnuts, the changes of moisture, calcification index, superoxide anion free radical (O2－ ·) production rate, H2O2 content, SOD and CAT activities, and the content of MDA (malondialdehyde) of Chinese chestnut stored under different levels of relative humidity such as 50%, 70% and 90% and room temperature (25 ℃) were determined. The results showed water loss and calcification index of Chinese chestnuts stored under high relative humidity (90%) were significantly decreased. Meanwhile, O2－ · production rate, H2O2 and MDA content were significantly lower, while SOD and CAT activities of chestnuts were significantly higher as compared with Chinese chestnuts stored under low relative humidity (50%). These findings reveal that high relative humidity (90%) efficiently inhibits the occurrence of calcification, maintains higher reactive oxygen species scavenging activity and decrease lipid peroxidation in Chinese chestnuts during postharvest storage.

Key words: relative humidity, chestnut, calcification, reactive oxygen species