贮前热处理对青椒冷害、活性氧代谢和膜脂过氧化的影响

Effect of Prestorage Heat Treatment on Chilling Injury, Activated Oxygen Metabolism and Membrane Lipid Peroxidation in Green Pepper Fruits

贮前50℃10min或53℃5min热水浸泡处理极显著降低了2℃贮藏青椒的冷害,显著抑制了膜透性的上升。与对照相比,50℃热处理对青椒SOD活性影响不明显,而53℃热处理显著提高了3、4和5周时SOD的活性。两热处理均极显著提高了青椒CAT和APX活性。两热处理青椒贮藏过程中POD活性变化较小,而对照组青椒POD活性7周时骤然上升。热处理还导致青椒的LOX活性3周后迅速下降。贮前热处理通过提高活性氧清除酶特别是CAT和APX活性,维持活性氧代谢的平衡,降低LOX活性,抑制膜脂过氧化,从而减轻了青椒的冷害。

500℃ hot water dip 10 min or 53℃ 5 min （prestorage heat treatment） significantly alleviated chilling injury and manifestly hindered increase in membrane permeability of pepper fruits stored at 2℃. Compared to control, 50℃ heat treatment had no obvious effect on SOD activity and 53℃ significantly improved SOD activity in 3 W, 4 W and 5 W. Both heat treatments significantly elevated CAT and APX activity and the effect of them in increasing CAT activity was more obvious than SOD. POD activity of fruits heated changed little without abrupt increase happened in control fruits during storage at 2℃. LOX activity in heated fruits declined fast after 3 W during storage. It is suggested that heat treatment maintained balance of activated oxygen metabolism by increasing activated oxygen scavenging enzyme activity, especially the activity of CAT and APX, decreased LOX activity and therefore depressed membrane lipid peroxidation resulting in alleviation of chilling injury in pepper fruits stored at 2℃.