摘要
采后的荔枝(Litchi chinensis)果实的果皮和果汁中的抗坏血酸及果汁的谷胱甘肽含量逐渐下降。果皮的谷胱甘肽含量先增多(采后3天)接着减少。超氧物歧化酶活性随采后时间加长而降低。膜脂过氧化产物丙二醛及过氧化物酶活性显著增高。采收7天后果皮中丙二醛含量增加2倍,过氧化物酶活性增高6—7倍,超氧物歧化酶活性只为原来的44％。内源清除活性氧能力的减弱与膜脂过氧化产物的积累表明,荔枝果实的衰老与活性氧的伤害有关。过氧化物酶活性增高可作为果实衰老的一个指标。
The decrease of ascorbic acid content was observed in the pericarp and juice of litchi fruit after picking from 0 to 7 days.Change of glutathione content in juice was similar to the change of ascorbic acid,but it increased in the pericarp within first 3 days after pic- king,and then decreased.During the period of experiment,malondialdehyde,a product of lipid peroxidation,increased significantly,it was 3 times in the 7th day after picking as com- pared with the initial content.The activity of superoxide dismutase decreased as malondi- aldehyde accumulated.A rapid increase of peroxidase activity in pericarp after picking would be associted with the senescence of litchi fruit These results suggest that the senesce- nce of litchi fruit might be damaged by active oxygen.The increase of peroxidase activity and malondialdehyde content may be useful as a detector of fruit senescing.
