不同添加剂对小麦PPO的抑制和激活效应

Inhibition and Activation Effects of Different Additives on Wheat PPO Activity

通过测定76个小麦品种全麦粉中多酚氧化酶(PPO)在6种化学试剂作用下的酶活性变化情况,比较了这6种化学试剂对PPO的抑制和激活效应,同时分析了添加剂浓度和基因型对抑制激活效应的影响。结果表明:小麦PPO的抑制和激活效应同时受添加剂种类、添加剂浓度和基因型影响;亚硫酸氢钠、铜试剂、谷胱甘肽和维生素C对小麦PPO产生抑制效应,蔗糖和低浓度柠檬酸产生激活效应,而高浓度柠檬酸产生抑制效应,亚硫酸氢钠的抑制效应比维生素C和谷胱甘肽强;维生素C、谷胱甘肽、铜试剂和亚硫酸氢钠的添加浓度与PPO活性呈对数关系;谷胱甘肽和维生素C可考虑作为抑制小麦PPO活性的食品添加剂。

Seventy-six wheat cultivars were selected as the experimental materials,and polyphenol oxidase（PPO）was extracted by citric acid-phosphate buffer from their whole wheat flour.Six chemical reagents selected as PPO inhibitors and activators were put into the enzymical extract,and then PPO activity was determined using spectrophotometer.The results showed that：the inhibition and activation were influenced by kinds,concentration of additives and wheat cultivars;sodium hydrogen sulfite,sodium diethyldithiocarbamate,glutathione and vitamin C had the inhibition on wheat PPO,and the sucrose and lower concentration citric acid had unobvious activation.However,higher concentration citric acid had unobvious inhibition and the inhibition of sodium hydrogen sulfite was stronger than vitamin C and glutathione;it was presented for logarithmic relationship between wheat PPO activities and concentrations of vitamin C,glutathione,sodium diethyldithiocarbamate and sodium hydrogen sulfite;Glutathione and vitamin C could be used as the food additives to inhibit wheat PPO activity.