探讨3 ℃冷激处理对冷藏香蕉果实脂氧合酶活性和膜脂脂肪酸的影响及相关生理机理。用3 ℃冷激处理香蕉6 h后置于（8±0.5）℃下贮藏，以不经过冷激处理直接置于（8±0.5）℃的作为对照组。定期测定香蕉果实（8±0.5）℃贮藏期间的冷害指数、细胞膜透性、脂氧合酶活性和膜脂脂肪酸组分。贮藏30 d后置于（20±0.5）℃恒温箱中催熟，观察冷害症状和后熟情况。结果表明：香蕉果肉中含有8种脂肪酸，分别为十三烷酸、十七烷酸、顺-10-十七碳烯酸、反亚油酸、亚油酸、花生酸、γ-亚麻酸和α-亚麻酸。3 ℃冷激处理6 h能够降低香蕉果实的冷害指数、相对电导率、脂氧合酶活性以及十三烷酸、十七烷酸、花生酸等饱和脂肪酸的含量；有效地抑制顺-10-十七碳烯酸、反亚油酸、亚油酸、γ-亚麻酸、α-亚麻酸等不饱和脂肪酸含量的下降，维持较高的膜脂不饱和脂肪酸指数和膜脂脂肪酸不饱和度，从而增强香蕉果实的抗冷性，减少冷害的发生并提高香蕉果实的后熟品质。

The effects of cold-shock treatment (CST) at 3 ℃ on fatty acids present in the membrane lipids and lipoxygenase of cold-stored banana fruits and the related physiological mechanisms were investigated. Banana fruits were treated with cold air at 3 ℃ for 6 h and then stored at 8 ℃ ± 0.5 ℃; the fruits without CST were directly stored at 8 ℃ ± 0.5 ℃ and were used as the control group. The chilling injury index, cell membrane permeability, lipoxygenase activity, and membrane fatty acid composition of banana fruits were measured regularly during the period of storage at 8 ℃ ± 0.5 ℃. After the fruits were stored in a constant temperature oven at 20 ℃ ± 0.5 ℃ for 30 days to accelerate fruit ripening, the conditions of chilling injury and fruit after ripening were observed. Eight fatty acids were identified in the pulp of banana, that is, tridecylic acid, heptadecanoic acid, arachidic acid, cis-10-heptadecenoic acid, trans-linoleic acid, linoleic acid, γ-linolenic acid, and α-linolenic acid. CST at 3 ℃ for 6 h could decrease the chilling injury index, relative conductivity, lipoxygenase activity, and the content of tridecylic acid, heptadecanoic acid, arachidic acid, and other saturated fatty acids (SFAs). Besides, it effectively prevent the decrease in the content of cis-10-heptadecenoic acid, trans-linoleic acid, linoleic acid, γ-linolenic acid, α-linolenic acid and other unsaturated fatty acids (UFSAs). It can also maintain relatively high SFA and UFSA indexes in membrane lipids. Thus, CST enhanced the chilling resistance of banana fruits, reduced the incidence of cold damage, and improved the after-ripening quality of banana fruits.

科技部科技富民强县专项（国科发农[2013]514号）