Abstract:Decay, softening, water loss, and wilting can easily occur during the storage of fresh jujube fruits, resulting in an extremely short storage duration for fresh fruits. In order to investigate the influence of hot-air treatment on the postharvest senescence and softening of fresh jujube and related enzyme activities, ‘Linze Xiaozao’ jujube fruit was used as a test material. It was pre-treated with hot air at 45 ℃ for two hours and then packed into folded polyethylene bags (thickness: 0.01 mm) and stored at (0 ℃±0.5). The respiration intensity, relative conductivity, contents of malondialdehyde (MDA), vitamin C, titratable acid (TA), activities of catalase (CAT), ascorbic acid peroxidase (APX), lipoxygenase (LOX), and superoxide dismutase (SOD), among other indicators of fresh jujube fruits were determined every ten days. The results showed that Linze Xiaozao was a climacteric fruit in a respiration pattern. Compared with CK, the hot-air treatment at 45 ℃ for 2 h could effectively inhibit respiration intensity (p＜0.05), decrease the activities of LOX and APX, and maintain relatively high contents of vitamin C and TA. The relative conductivity and the MDA content of the pulp tissues significantly decreased (p<0.05). However, the rate of the decline of CAT activity of fresh jujube slowed down and the appearance of SOD activity peak was delayed. Besides, the activity of the enzyme was maintained. In conclusion, hot-air treatment at 45 ℃ for two hours could significantly delay the senescence and softening of postharvest jujube fruits and maintain the storage quality.
