枣果采后转红与褐变的关系研究

On the Relationship between the Reddening and Browning of Jujube after Harvest

本试验以壶瓶枣为试材,研究枣果树上和采后转红机理的异同,通过枣果果皮酚类物质、褐变相关酶及褐变度的分析,探讨采后枣果果皮转红与褐变的关系。结果表明:随着枣果着色面积的增大,树上枣果果皮褐变度变化较小,而采后枣果褐变度显著增大。树上枣果果皮酚类物质含量与PPO活性均呈缓慢增大趋势,而采后枣果果皮酚类物质含量下降,PPO活性增加,采后枣果皮酚类物质与褐变度呈显著负相关(r壶瓶枣=-0.952**),采后枣果果皮PPO活性与褐变度呈显著正相关(r壶瓶枣=0.786*),表明采后枣果转红是酚类物质的氧化作用且PPO是褐变主要酶。

The similarities and differences about coloring in trees and postharvest of Hupingzao jujube are studied. Through total phenol, browning enzymes and browning degree of jujube, the mechanism of the jujube turning red is discussed. The results show that, along with the jujube coloration area's enlarging, the browning degree of the jujube peel in trees is low, but browning degree of the postharvest jujube obviously increases.When in trees total phenol content and the PPO activeness of the jujube peel appear increasing slowly, but when off trees, total phenol content of the jujube peel drops and the PPO activeness increases. Total phenol material and browning degree of the postharvest jujube peel assume a remarkable negative correlation(rHupingzao=-0.952**),while the postharvest jujube fruit peel PPO activeness and browning degree assume remarkable positive correlation (rHupingzao =0.786*) . It suggests that the action of total phenols oxidation causes the reddening after harvest and PPO is essential to result in the browning.