贮藏温度对茄子果实活性氧代谢及细胞壁降解的影响

Effects of Storage Temperature on Active Oxygen Metabolism and Cell Wall Degradation of Postharvest Eggplant Fruits

摘要:

为研究贮藏温度对茄子活性氧代谢及细胞壁降解影响，试验将“上新”茄子在2 ℃、12℃、20 ℃下贮藏12 d，每2 d测定其硬度、超氧阴离子产生速率(O2-)、过氧化氢含量(H2O2)、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、脂氧合酶(LOX)、抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)等酶活性及果胶质、纤维素、木质素含量变化。结果表明，2 ℃时，随着贮藏时间延长，果实SOD、POD、CAT、APX、GR活性不断降低，O2-产生速率及H2O2含量增加，LOX活性上升，加剧膜脂过氧化反应。同时，2 ℃贮藏仅6 d，果实发生木质化现象，硬度升高。贮藏期间细胞壁结构变化与细胞壁物质降解程度有关。12 ℃时，果实硬度下降较慢，抗氧化酶活性逐渐下降。而20 ℃时，果实硬度下降明显，出现腐烂变质，细胞壁降解酶活性增强，细胞壁物质发生降解。综合比较，12 ℃可作为茄子果实短期适宜的贮藏温度。

Abstract:

To investigate the impact of storage temperature on active oxygen metabolism and cell wall degradation of eggplant fruits, “Shangxin” eggplant fruits were stored at 2 ℃, 12 ℃, and 20 ℃ for 12 days. Firmness, superoxide anion (O2-) production rate, peroxide (H2O2) content, and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), lipoxygenase (LOX), ascorbate peroxidase (APX), and glutathione reductase (GR), and pectin, cellulose, and lignin content were measured every two days. The results showed that at 2 ℃, over the storage period, SOD, POD, CAT, APX, and GR activities decreased continuously; the O2- production rate and H2O2 content increased; and LOX activity increased, which accelerated peroxidation of membrane lipids. At the same time, after storage for six days at 2 ℃, the eggplant fruits showed signs of lignification, with increased firmness. During the storage period, changes in the cell wall structure were closely related to the degradation of cell wall materials. At 12 ℃, fruit firmness decreased slowly and antioxidant enzyme activity declined gradually. At 20 ℃, fruit firmness decreased significantly, fruits rotted, the activity of cell wall-degrading enzymes increased, and cell wall degradation occurred. In conclusion, 12 ℃ appears to be an optimal temperature for short-term storage of eggplant fruits.