果酒中多酚氧化酶及其性质的研究

The Study of Polyphenol Oxidase(PPO) In Fruit Wine

对山楂酒中含有的六种分子量不同的多酚在多酚氧化酶作用下 ,测定氧化前后其涩度的变化。发现多酚物质的氧化作用能够加重果酒的苦涩味。并对山楂中的多酚氧化酶进行提取 ,测定其基本特性 ,确定了底物、温度、pH值对其活性的影响 ,并进一步测定其酶动力学曲线 ,发现多酚氧化酶催化的最适温度是 2 5℃ ,其最适pH是 6 5 ,其作用的最适底物是儿茶酚 ,其米氏常数是 1 0 77× 1 0 - 2 M。

We measured the relative astringency(RA)change of six kinds polyphenol contained in haw wine which was oxidased by PPO,The result showed that the oxidation can increased the astringency of the polyphenol strongly A principal characterization of PPO in the fruit wine was described in this paper,the optimum nature polyphenol substrate of PPO was cathechol,and the optimum temperature of PPO was 25℃,the PPO is not resistant to heat,the PPO lost almost all activity at 80℃,the K m of the PPO was 1 077×10 -2 M The V msx was 188 68×10 -3 (△OD/min)