Abstract: In order to explore the effects of methyl jasmonate (MeJA) treatment on the chilling injury-related physiological factors and nutritional quality of postharvest green bell peppers, freshly harvested bell peppers (cv. ‘Jingtian 3’) were dipped in 30 μmol/L MeJA solution or distilled water as control for 10 min and stored at 4 ℃ after shade drying. During storage, the chilling injury index, mass loss percentage, hardness, soluble solid content, total chlorophyll content, the contents of antioxidant substances such as VC, total phenols and flavonoids and malondialdehyde content of green bell peppers were determined as well as the activities of polyphenol oxidase (PPO), peroxidase (POD), ascorbate peroxidase (APX) and catalase (CAT). The results showed that MeJA treatment significantly inhibited chilling injury of green bell peppers, slowed down the reduction of VC, total phenols and flavonoids, and significantly increased the activities of antioxidant enzymes such as PPO, POD, APX and CAT (P < 0.05, P < 0.01), thus enhancing the antioxidant capacity and slowing down the deterioration of green bell pepper quality. In conclusion, MeJA can reduce chilling injury of green bell peppers, and maintain the physiological quality during cold storage, thereby prolonging the storage life.

Key words: green bell pepper; chilling injury; methyl jasmonate; cold storage; quality