Abstract: The effect of cold shock treatment at 0 ℃  for 4 or 12 h on the quality and antioxidant defense system of hot peppers at room temperature (22 ℃ was explored. The results showed that cold shock treatment at 0 ℃  for 4 h could result in a decrease of disease incidence in hot peppers by 20% after 16 days of storage at room temperature, and an increase of chlorophyll, vitamin C and soluble protein contents in pericarps by 66.7%, 17.6% and 11.3%, respectively, as well as the inhibition of soluble sugar when compared with the control group. Moreover, cell membrane permeability of pericarps revealed a reduction by 20.9% for the hot peppers treated with cold shock at 0 ℃ for 4 h. However, the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in the hot peppers treated with cold shock at 0 ℃ for 4 h were higher than those in the control group. On the other hand, cold shock treatment at 0 ℃ for 12 h exhibited an opposite effect in comparison with the cold shock treatment for 4 h. Therefore, the appropriate duration of cold shock treatment could reduce the disease occurrence of hot peppers after harvest, attenuate the deterioration of hot pepper quality and prolong the storage and transportation time of hot peppers at room temperature. These actions can be helpful for improving disease resistance and postponing the maturation and senescence of hot peppers.

Key words: hot pepper, quality, cold shock treatment, storage at room temperature