运输中的机械损伤对贮藏初期苹果活性氧代谢的影响

Influence of Mechanical Stress on the Active Oxygene Metabolism System of Apple during Transportation

通过测定红富士苹果运输损伤后的生理生化变化，发现机械损伤不仅使果实表面出现褐色斑块，果实呼吸强度迅速增加，而且细胞内促进活性氧产生的脂氧合酶的活性增加，果皮增加的幅度高于果肉；具有消除自由基作用的SOD和CAT的活性在损伤后也突然升高，但在损伤后第2～6天活性逐渐下降，同时，损伤后POD活性、MDA含量以及膜透性都有显著的增加，说明机械损伤破坏了膜的完整性、促进了脂质过氧化的产生，导致衰老性状的提前出现。本试验从理论上进一步证明减少运输中的机械损伤对延长贮藏寿命、提高果品品质具有重要的意义。

Treated with mechanical stress (during transportation by truck) for 14 hours, the Fuji apple fruits appeared brown (20%) on the surface. The activity of SOD, CAT and POD, MDA level and electrolytes leakage were investigated. The results showed that the activity of SOD, CAT and POD increased after mechanical stress, and decreased during the storage whereas the control almost kept the same level in the 6 days. The activity of LOX reached its peak in the first day after mechanical stress, and the content of MDA, the electrolytes leakage increased greatly at the same time. The data suggested that mechanical stress during the transportation affected the balance of the free radicals metabolism of apple,the integrity of membrane and made it easy to breakdown and senescence in the storage of apple. It also showed the significance of the package of apple during transportation.