不同浓度氧贮藏荔枝的几种酶活性变化

THE CHANGES OF ACTIVITIES OF SOME ENZYMES IN LITCHI FRUITS STORED IN DIFFERENT CONCENTRATION OF OXYGEN

在空气和高浓度氧下贮藏荔枝1至2天,果皮和果肉脂氧合酶活性增高;而在低浓度氧下则无此酶活增高。3天后酶活降低,5天后果实酶活很低。三种浓度氧下3天,果皮过氧化物酶活增至最大值,随后则略有降低。在高浓度氧和空气下,果皮多酚氧化酶活性增高,酶活性较低浓度氧的高。在高浓度氧下,黄嘌呤氧化酶活性鞍空气和低浓度氧下的高。几种酶活性增高,可能导致氧化和过氧化作用加剧和引起果皮褐变。

The activities of lipoxygenase in the pericarp and the juice increased during the fruits were stored in air(20%) and higher concentration of oxygen (45% O2) for 1 to 2 days. And then the activities of the enzyme decreased and maintained in lower level from 5th to 7th days. The activity of peroxidase reached to maximum level after storage for 3 days. The increase of the activity of golyphenol oxidase was also observed in the pericarp of fruits stored in air and higher concentration of oxygen. In higher concentration of oxygen, the activity of xanthine oxidase was higher than that in air and lower concentration of oxygen. The results showed that the increase of the activities of these enzymes might promote the oxidation and peroxidation in the tissue of fruit and induce the browning of the pericarp of fruits.