Study on the characteristics of polyphenol oxidase from 'Angeleno' plum

To reveal the characteristics of polyphenol oxidase(PPO)in ‘Angeleno'plum flesh,the characteristics of polyphenol oxidase of plum were studied in this paper by spectrophotometry,including the effects of pH,temperature,substrate concentration,inhibitor,enzyme storage time on PPO activity.Factors affecting the activity of polyphenol oxidase extracted from plum flesh by spectrophotometer were studied.The results showed that the optimum pH was 5.8and the optimum temperature was 40℃,and the PPO activity was inhibited by99.5%in 3minutes at 90℃.The relationship between catechol substrate concentration and‘Angeleno'pulp flesh PPO activity accorded with Michaelis-Menten equation enzymatic reaction kinetics.Ascorbic acid(Vc)and sodium sulfite were found as the strong inhibitors of theenzyme preparation,0.7mmol/L ascorbic acid and 0.6mmol/L sodium sulfite inhibited the activity of PPO,and the activity of PPO of‘Angeleno'plum flesh supernatant enzymes decreased by 14% at 4℃and stored for 2hours.