红毛丹果皮多酚氧化酶的酶促动力学研究

目的]通过对红毛丹果皮多酚氧化酶的酶促动力学研究,寻找影响其催化活性的环境因素。方法]以红毛丹果皮为试验材料,以邻苯二酚为底物,研究不同温度、不同pH、以及EDTA、Vc、亚硫酸氢钠、柠檬酸4种抑制剂和底物浓度对其多酚氧化酶活性的影响。结果]红毛丹果皮多酚氧化酶的最适温度为40℃,最适pH值6.8;EDTA、Vc、NaHSO3、柠檬酸对多酚氧化酶活性表现出较好的抑制效果,其中EDTA的抑制效果较其他3种抑制剂强。结论]利用低温、一定浓度的EDTA、Vc、NaHSO3、柠檬酸等试剂可抑制红毛丹果皮多酚氧化酶的催化活性,延长红毛丹果实的贮藏和运输时间,抑制其褐变;该研究结果为开发利用红毛丹果皮多酚氧化酶提供了理论依据。

Studies on Enzymatic Reaction Kinetics of Nephelium lappaceum Polyphenol Oxidase

Objective] This study aimed to investigate the enzymatic reaction kinetics of polyphenol oxidase in peel of Nephelium lappaceum to explore the environmental factors affecting its catalytic activity.Method] With Nephelium lappaceum peel as the experimental material and catechol as substrate,effects of temperature,pH,four inhibitors(EDTA,Vc,sodium bisulfite and citric acid) and substrate concentration on the activity of polyphenol oxidase were investigated.Result] The optimal temperature for polyphenol oxidase in Nephelium lappaceum peel was 40 ℃,and the optimal pH was 6.8.EDTA,Vc,sodium bisulfite and citric acid all showed ideal inhibitory effects on the activity of polyphenol oxidase;specifically,EDTA had the strongest inhibitory effect.Conclusion] At low temperature,EDTA,Vc,sodium bisulfite and citric acid with certain concentrations can inhibit the catalytic activity of polyphenol oxidase in peel of Nephelium lappaceum,extend the storage and transportation time of Nephelium lappaceum fruit,and inhibit the browning.This study provides theoretical basis for the development and utilization of polyphenol oxidase in peel of Nephelium lappaceum.