苹果梨中多酚氧化酶抑制剂的抑制效果研究

Single and Combined Inhibitory Effects of Inhibitors against Polyphenol Oxidase from Pingguoli Pear (Pyrus bretchneideri Rehd cv Pingguoli) Fruits

采用匀浆后丙酮抽提法从苹果梨中提取多酚氧化酶。谷胱甘肽为抑制苹果梨中多酚氧化酶的活力的最佳抑制剂。在其浓度为300μmol/L时,多酚氧化酶(PPO)的活力为50%;在其浓度为500μmol/L时,多酚氧化酶(PPO)的活力为零。谷胱甘肽、亚硫酸钠和L-半胱氨酸3种混合抑制剂对苹果梨中多酚氧化酶(PPO)的影响实验结果表明,谷胱甘肽对苹果梨中多酚氧化酶活性影响最大。

Crude polyphenol oxidase （PPO） in Pingguoli pear fruits was prepared through sequential steps of homogenization followed by extraction with acetone. The single inhibitory effects of glutathione, cysteine and sodium sulfite against the enzyme were evaluated according to residue enzyme activity. Subsequently, to obtain the optimal inhibitory effect, the above inhibitors were compounded and the optimal formulation was investigated using orthogonal array design. Results showed that glutathione exhibited a good inhibitory effect against this enzyme with half-inhibitory concentration of 300 μmol/L and maximal inhibitory concentration of 500 μmol/L, which was stronger than that of other two inhibitors.