摘要
由于香蕉加工中的酶褐变主要是多酚氧化酶引起的，因此本文研究了多酚氧化酶的提取及其特性和交联葡聚糖Ｇ－７５（ＳＥＰＨＡＤＥＸＧ－７５）分离纯化；比较了加入ＰＶＰ（聚乙烯吡咯酮）和ＰＥＧ（聚乙二醇）的效果，发现对酶特性有一定的影响。通过差热扫描分析，由ＳＥＰＨＡＤＥＳＧ－７５分离的两种不同形式的多酚氧化酶蛋白的变性温度分别为９３．０３℃和８９．４２℃；最适ｐＨ分别为６．８和５．９．多酚氧化酶与邻－二酚反应产物在λ＝４１４ｎｍ下有最高吸收。
It was well know that browing in barana process was due to polypherol oxidase(PPO).In this paper the extraction. Characteristics and purifcation by sephadex G-75 ofthe PPO were stndied. The effect of PVP and PEG on PPO were compared during the ex-traction. Two type of PPO coenzymes were separated by the sephadex G-75 column andDSC of both shows that proteins were denaturated at respectioely 93.03 ℃ and 89.42 ℃,their optimun pH were respectioely pH 0.8 and5.9.The largest absorbion of the prodnetof the reaction between PPOand catechol was atλ=414nm.
关键词
香蕉
多酚氧化酶
褐变
anana
Polyphenol oxidase(PPO)
Browning
