几种抑制剂对小麦多酚氧化酶活性抑制效果研究

使用3-吗啉丙磺酸(MOPS)缓冲液从全麦粉中提取多酚氧化酶(PPO),以邻苯二酚为底物,研究不同抑制剂在不同浓度下对PPO的抑制作用。结果表明抑制剂浓度为1.0 mmol/L时,各种抑制剂的作用效果分别为:L-抗环血酸90.6%,L-半胱氨酸86.5%,NaHSO3 84%,曲酸75.5%。L-抗环血酸、L-半胱氨酸、NaHSO3、曲酸几种抑制剂浓度减小抑制作用降低。响应面分析得到的L-抗坏血酸、L-半胱氨酸和NaH-SO3最佳抑制浓度组合为:L-抗坏血酸0.4 mmol/L,L-半胱氨酸0.11 mmol/L,NaHSO3 0.25 mmol/L,抑制作用为82.03%。

Inhibiting Effects of Some Inhibitors on Polyphenol Oxidase Activity in Wheat

The inbihiting effects of several inhibitors on polyphenol oxidase activity in wheat are studied in this paper.The polyphenol oxidase(PPO) is extracted by MOPS buffer from whole wheat and the catechol is used as substrate.The polyphenol oxidase activity is determined by spectrophotometer.When the concentration of the inhibitors is 1.0 mmol/L,the inhibition effects are:L-ascorbic acid 90.6%,L-cysteine 86.5%,NaHSO3 84%,kojic acid 75.5%.In the experiments of L-ascorbic acid,L-cysteine,NaHSO3 and kojic acid,the inhibiting effect decreased as the concentration of them decrease.By response surface analyses,the optimal conditions to achieve the highest degree of inhibiting are found to be that the concentration are L-ascorbic acid 0.4 mmol/L,L-cysteine 0.11 mmol/L,and NaHSO3 0.25 mmol/L.The degree of polyphenol oxidase activity inhibiting is 82.03%.