鲜枣贮藏易发生霉变、软化、失水萎蔫，鲜食期极短。为探究热空气处理对鲜枣衰老软化及相关酶活性的影响，以临泽小枣为实验材料，采用45 ℃热空气处理2 h，用0.01 mm厚的聚乙烯袋折叠包装，于(0±0.5) ℃下贮藏，每隔10 d测定鲜枣呼吸强度、相对电导率，丙二醛(MDA)、维生素C、可滴定酸(TA)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、脂氧合酶(LOX)和超氧化物歧化酶(SOD)等指标。结果表明，临泽小枣属于呼吸跃变型果实，与CK相比，45 ℃、2 h热空气处理能有效地抑制鲜枣呼吸强度(p<0.05)，诱导LOX和APX活性降低，保持较高的维生素C和TA含量，果肉组织的相对电导率和MDA的含量减少，且差异显著(p<0.05)；同时诱导鲜枣CAT活性下降速度的延缓，推迟SOD活性高峰的出现，保持了酶的活性。综上所述，45 ℃、2 h热空气处理可有效地延缓采后鲜枣果实衰老软化，保持鲜枣的贮藏品质。

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.

甘肃省农业生物技术研究开发项目(GNSW-2014-02)；博士科研启动金；国家自然基金项目(31560029)