摘要
为防止果蔬褐变需抑制多酚氧化酶的活性。本文用新方法从香蕉皮中提取出多酚氧化酶，用氧电极测出酶催化反应的最佳条件是ｐＨ值为７，温度为２５℃；测定反应活化能等于２３．６ｋＪ·ｍｏｌ－１，米氏常数为１．５８×１０－２ｍｏｌＬ－１。研究了九种抑制剂对酶活性的抑制效果，并进一步研究了肉桂酸抑制剂的抑制动力学及机理，得出肉桂酸为竞争性抑制。用原子吸收光谱测出蕉皮酚酶中含有铜离子，并探讨了铜离子的作用。
In this paper,polyphenoloxidase is isolated from banana peel with two times of cold acetone extracting. Catechol oxidation reaction is used as researching modle. The oxidation is determinded by oxygen electrode method.The results show that the optimum conditions of the catalyzing aCtion with the oxidase are pHat 7,temperature at 25℃.The energy of activation is 23.6 kJ.mol-1,the Michael's constant is 1.58×10-2molL-1.The inhibition effects to the enzyme activity of nine inhibitors are researched.Also,the inhibition kinetics and mechanism of cinnamic acid to the catalyzed oxide reaCtion with the oxidase is researched.The resultsshow that inhibition type of cinnamic acid is competitive inhibition.Atomic absorption speCtrum of banana peel phenoloxidase show the oxidase contains cupric ion.
出处
《华南理工大学学报（自然科学版）》
EI
CAS
CSCD
1994年第2期81-88,共8页
Journal of South China University of Technology(Natural Science Edition)
关键词
多酚氧化酶
反应动力学
催化反应
s:polyphenol oxidase
enzyme inhibitors
reaction kinetics
reaction mechanism
banana/cinnadric acid
