香菇多酚氧化酶活性测定方法的改进

Improvement of the Determination of Polyphenol Oxidase Activity in Mushroom(Lentinus edodes(Berk.) sing)

对目前香菇多酚氧化酶活性的测定方法进行改进,通过离心消除蛋白质沉淀对反应的不利影响,以及其他因素对酶活力测定的影响,并对该方法进行了重复与再现试验。结果表明,香菇中多酚氧化酶的最佳测定条件为反应液预热温度40℃,添加质量分数20%(W/V)的三氯乙酸,取酶液1 m L,添加浓度0.3 mol/L的邻苯二酚,反应3 min后进行离心,于波长410 nm处测定吸光度。稳定性与再现性试验表明,此方法的重复试验和再现试验的相对标准偏差性均小于5%。

Common methods from literatures for the determination of polyphenol oxidase （PPO） activity in mushroom （Lentinus edodes （Berk.） sing） is improved. Adverse effect of precipitate is removed by centrifugation, at the same time, some factors are also studied, repetition and repeatability tests are conducted. The results show that the optimal conditions for the determination of PPO activity is as follows ： preheating temperature of the reaction is 40 ℃, concentration of trichloroacetic acid is 20% （W/V） , the crude enzyme is 1 mL, pyrocatechol is 0.3 mol/L after incubation for 3 min, the reaction liquid is centrifuged and measured the absorbance at 410 nm. Stability and repeatability rests show that the relative standard deviation of both tests is within 5%.