黑脉羊肚菌多酚氧化酶特性研究
Study on PPO characteristics of M.angusticepes
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摘要: 采用分光光度法420nm下分析黑脉羊肚菌多酚氧化酶(polyphenoloxidase,PPO)特性。以黑脉羊肚菌为原料,经清洗切分后,匀浆、过滤,于4℃,12000r/min条件下离心分离,得到黑脉羊肚菌PPO粗酶液,应用于催化反应,并研究温度、底物浓度和抑制剂等对其活性的影响。结果表明:黑脉羊肚菌PPO的最适温度为30℃,最适pH7.5;其多酚氧化酶酶促褐变反应动力学符合米氏方程,相应动力学参数为Km=0.4769mol/L,Vmax=1.901mol/L;其中,抗坏血酸对黑脉羊肚菌PPO的抑制效果最好,亚硫酸氢钠次之,柠檬酸最弱。Abstract: The object of the study was to analyze the characterization of M.Angusticepes polyphenol oxidase ( PPO) by spectrophotometer method 420nm. The fresh - cut M. Angusticepes was cleaned and cut, smashed and centrifuged at 4℃, 12000r /min. The obtain crude PPO in the supernatant was used to measure the optimal pH, temperature and Kinetic property and inhibition of various chemicals to the enzyme. The results showed that the optimum PPO temperature was 30℃, the optimum pH of PPO was 7.5.The reaction kinetic of enzymatic browning was accordant with Michaelis equation, the Km and Vmax were 0.4769mol /L and 1.901mol /L respectively. Ascorbic acid showed the most effective inhibitory activity, followed by sodium hydrogensulfite, and then citric acid.