茯苓多酚氧化酶酶学特性及褐变抑制  

Enzymatic characteristics and inhibitors of polyphenol oxidase from Poria cocos

作　　者：陈红梅[1] 谢翎[1] 

机构地区：[1]安庆师范学院生命科学学院,安徽安庆246011

出　　处：《食品与发酵工业》2014年第7期84-87,共4页Food and Fermentation Industries

基　　金：安徽省教育厅自然科学(KJ2011B081)项目

摘　　要：以茯苓为供试材料,采用分光光度计法测定多酚氧化酶(PPO)活力,研究pH值、温度、底物浓度以及抑制剂等因素对茯苓PPO活性的影响。结果表明,茯苓PPO最适pH值为6.5,最适温度为35℃,最适底物浓度为0.06 mol/L。PPO酶促反应动力学符合米氏方程,动力学参数Km=0.024 4 mol/L,Vmax=121.95 U/min。NaCl、抗坏血酸、L-半胱氨酸和柠檬酸溶液对茯苓PPO均有抑制作用,随着质量浓度的升高,抑制效果越好;相同质量浓度下,L-半胱氨酸抑制作用最强,其次是抗坏血酸和柠檬酸,最后是NaCl。The enzyme activity of polyphenol oxidase （PPO） from Poria cocos was detected by spectrophotome- try. The effects of pH value, temperature, substrate concentration and inhibitors on PPO activity were studied. The results indicated that the optimum pH value, temperature, and substrate concentration for PPO were 6.5, 35 ℃ , and 0.06 mol/L, respectively. The kinetics of enzyme-catalyzed reaction of PPO complied with the law of Michaclis equa- tion. The Km and Vmax were 0. 024 4 mol/L and 121.95 U/min, respectively. The activity of PPO was inhibited by so- dium chloride, ascorbic acid, L-cysteine and citric acid. The inhibitory effects against PPO activity were increasing with the increasing concentrations. The order of inhibitors showing effects from strong to weak was as follows ： L-L-cys- teine, aseorbie acid, citric acid and sodium chloride.

关 键 词：茯苓 多酚氧化酶 酶学特性 抑制 

分 类 号：O629.8[理学—有机化学]