摘要
通过添加Vc和外加磁场处理,研究莲藕多酚氧化酶(PPO)反应动力学的变化规律。以邻苯二酚为底物,莲藕PPO褐变反应动力学符合米氏方程所描述的单底物酶促反应动力学,Km为0.775mol/L,Vmax为11.150U/min。Vc对PPO有较强的抑制作用,反应动力学参数Km为0.081mol/L,Vmax为3.243U/min,呈现反竞争性抑制,表现为褐变出现滞后,随Vc浓度的增大滞后时间逐渐增长,且呈现S型趋势,并建立了相应的反应方程。不同磁场强度下,随着处理时间的变化,PPO活性呈现波动性。3.17A/m磁场强度下处理4h的酶液其反应动力学曲线表现为S型,并建立了相应的反应方程。
The change law of reaction dynamics was experimental studied through adding Vc to lotus root polyphenol-oxidase and dealing with lotus root polyphenol-oxidase （PPO） by magnetic field. The experimental results indicated that the reaction kinetic of enzymatic browning was accordant with Michaelis equation with catechol substrate, which Kr, and Vmax were 0. 775 mol/L and 11. 150 U/rain respectively. Vc had an inhibiting effect on lotus root PPO, which Km and Vmax were 0.081 mol/L and 3.243 U/min respectively. The browning was lagged and the lag time increased gradually with the rise in the concentration of the inhibitors, which was an anticompetitive inhibition. The PPO activity expressed a fluctuation at different magnetic field strengths and times. At 3.17 A/m magnetic field strength for 4 hours, the reaction kinetics curve was a wave-type curve. The kinetic equations were established respectively.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2008年第1期78-81,共4页
Transactions of the Chinese Society for Agricultural Machinery
基金
湖北省科技攻关计划资助项目(项目编号:2006AA201C36)
关键词
莲藕
多酚氧化酶
反应动力学
抑制剂
磁场
Lotus root, Polyphenol-oxidase, Reaction dynamics, Inhibitors, Magnetic field
