香蕉皮中多酚氧化酶性质的研究

以邻苯二酚作为底物,采用比色法测定氧化产物的方法对香蕉皮多酚氧化酶(Polyphenol oxidase,PPO)的性质进行研究,以期为防止果蔬褐变和保鲜提供理论依据.结果表明,香蕉皮多酚氧化酶的最适温度为30℃,最适pH值为4.5和5.5,70℃水浴处理5 min完全失去活性,100℃沸水浴处理20 s可以钝化香蕉皮多酚氧化酶的活性.香蕉皮PPO的最适反应底物浓度为0.16mol/L.动力学研究结果表明,香蕉皮PPO的K_m=14.48 mmol/L.v_(max)=O.151 OD_(420)/min.

Study on Characteristics of Polyphenol Oxidase from Banana Peel

In the paper,the characteristics of polyphenol oxidase (PPO) extracted from banana peel with-catechol as solvent,were studied by spectrophotometer to provide the theoretical basis for preventing browning and keeping freshness of fruits and vegetables.The results showed that the optimum temperature was 30℃,the optimum pH of PPO Wag 4.5 to 5.5,which indicated the PPO had isozymes in its mixture.The PPO was inactivated at 70℃ for 5 min and the extinct condition of PPO was 20 s at 100℃.In addition.the optimum reactive substance concentration of PPO of banana peel was 0.16 mol/L. The results of kinetic study showed tha K_m of PPO of banana peel was 14.48 mmoL/L and V_(max) was 0.151 OD_(420)/min.