黄皮多酚氧化酶活性的影响因素分析

Analysis on Effective Elements of Polyphenol Oxidase from Clausena lansium Fruits

研究了pH值、温度、底物浓度及抑制剂等因素对黄皮果实中多酚氧化酶(PPO)活性的影响。结果表明,黄皮PPO具有同工酶,PPO的最佳底物浓度为0.14 mol.L-1,最适pH值为7.0,最适温度为40℃,当温度高于60℃时,PPO的活性明显降低,亚硫酸钠、抗坏血酸、柠檬酸、L-半胱氨酸等4种抑制剂对黄皮PPO的活性表现出不同的抑制作用,抑制效果为亚硫酸钠>抗坏血酸>柠檬酸>L-半胱氨酸,其中,抗坏血酸随着浓度的增加抑制效果越好,抑制率不断升高。

The effects of pH, temperature, substrate concentration and inhibitors on polyphenol oxidase of Clausena lansium fruits were studied in this paper. The results showed that the PPO of Clausena lansium fruits had isozyme, and the best substrate content was 0.14 mol· L^-1, the proper pH was 7.0, the optimum temperature was 40℃ for PPO of Clausena lansium fruits. The activity of PPO decreased significantly when temperature was higher than 60℃. The four inhibitors of sodium sulrite, ascorbic acid, citric acid and L-cysteine had different effects on inhibiting enzymatic browning and the order of inhibiting effect as follow as sodium sulfite 〉 ascorbic acid 〉 citric acid 〉 L-cysteine. With increasing the concentration of ascorbic acid as the effect of inhibiting the better, inhibition rate rising.