小麦多酚氧化酶特性及褐变控制研究

[目的]研究小麦多酚氧化酶(PPO)的特性及其褐变的控制方法,为提高小麦品质提供试验和理论依据。[方法]对洛阳地区5个品种小麦籽粒PPO的催化特性、热稳定性和pH值稳定性等性质进行了研究,同时考察了抑制剂对PPO的褐变抑制作用。[结果]小麦PPO活性的最适温度为40℃,最适pH值为6.0;柠檬酸、抗坏血酸、半胱氨酸等抑制剂均可有效抑制PPO的活性,且随着抑制剂浓度的增大PPO活性降低越明显。[结论]可通过调节合适的温度、pH值和添加一定浓度的抑制剂有效地防止PPO褐变的发生。

Study on Characteristics and Browning Inhibition of Polyphenol Oxidase in Wheat

[Objective] The research aimed to study the characteristics and browning inhibition of Polyphenol oxidase(PPO) and provide the experimental and theoretical basis for the improvement of wheat quality.[Method] Different varieties of wheat seeds in district of Luoyang were applied to extract PPO.The spectrophotometry was used to determine the thermal stability and pH value stability of PPO.In addition,inhibiting effects of inhibitors on PPO were investigated.[Result] The optimum temperature and pH value of the wheat PPO were 40 ℃ and 6.0.Three inhibitors(the citric aid,ascorbic acid,cysteine) reduced the PPO activity effectively,and with increasing concentration of inhibitors,PPO activity decreased obviously.[Conclusion] The browning phenomenon could be prevented effectively through the appropriately adjusting temperature,pH value and certain concentration of inhibitors.