摘要
以邻苯二酚为底物,采用紫外分光光度法测定都匀毛尖茶鲜叶多酚氧化酶(PPO)的酶活力,分析了底物浓度、温度和pH值对PPO活力的影响。结果表明,都匀毛尖茶鲜叶PPO的最适pH值为4.0,最适温度为30℃,在一定底物浓度范围内,酶促反应速率随底物浓度的增加而增大,PPO催化的酶促反应符合米氏动力学方程,相应动力学参数K m和v max分别为0.1423 mol·L^-1和7.5301 U·min^-1。
Using catechol as a substrate,the enzyme activity of polyphenol oxidase(PPO)in fresh leaves of Duyun Maojian was detected by ultraviolet spectrophotometry.The effects of substrate concentration,temperature and pH value on the enzyme activity were studied.The results showed that the optimum pH of PPO was 4.0,the optimum reaction temperature was 30℃.The rate of enzymatic reaction was increased along with an increase in substrate concentration in a certain range.The enzymatic browning reaction catalyzed by PPO was in accordance with the Michaelis kinetic equation,and the corresponding kinetic parameters K m and v max were 0.1423 mol·L^-1 and 7.5301 U·min^-1,respectively.
作者
姚玉仙
张明泽
刘丽萍
徐波
YAO Yu-xian;ZHANG Ming-ze;LIU Li-ping;XU Bo(Qiannan Normal University for Nationalities,Guizhou Duyun 558000,China)
出处
《广州化工》
CAS
2020年第13期39-41,共3页
GuangZhou Chemical Industry
基金
贵州省教育厅自然科学基金项目(黔教合KY字[2015]477
黔教合KY字[2019]211)
贵州省普通高校都匀毛尖茶工程研究中心开放基金项目(黔教合KY字[2016]020-01
黔教合KY字[2016]020-02)
黔南州科技计划项目[黔南科合农字(2017)20号
黔南科合农字(2017)22号
黔南民族师范学院校级项目(qnsy201601,qnsy2017001)。
关键词
茶
多酚氧化酶
酶学特性
Camellia sinensis
crude polyphenol oxidase
enzymatic characterization
