天山雪莲果多酚氧化酶的特性研究

摘要

In this study,with fresh material of Tianshan Yacon,The optimum polyphenol oxidase(PPO),optimum pH,optimum temperature,the fitting of the Michaelis-Menten equation and obtained the Km and Vmax,and explore the different inhibitionagents on PPO activity.Using catechol as substrate,the Km and Vmax were 0.061mol/L,776.4U/g·min respectively.The four inhibitors had different effects on inhibiting enzymatic browning and the inhibiting effect are as follow: citric acid〉L-cysteine〉ascorbic acid〉acetic acid.%以新鲜的天山雪莲果为材料,研究了多酚氧化酶（PPO）的最适pH、最适温度,拟合了米氏方程并求得了Km、Vmax,并探讨了不同抑制剂对PPO的活性影响。结果表明：天山雪莲果多酚氧化酶最适反应pH为6.5,最适温度为45℃;以邻苯二酚为底物,km=0.061mol/L,Vmax=776.4U/min·g;在选定的浓度范围内抑制剂对PPO的抑制作用大小为：NaHSO3﹥L-cys﹥Vc﹥柠檬酸。