Abstract: In this paper,the crude extracts of Polyphenol Oxidase (PPO) from Apricot kernel were purified by column chromatography stuffed with Sephadex LH-20,and then the inhibition of PPO activity was studied by chemical inhibitors like ascorbic acid,cysteine,citric acid,sodium sulfite and sodium metabisulfite in order to control the enzymatic browning during the industrial processing of Apricot kernel.The results show that all the inhibitors chosen had good inhibitions on the PPO activity within the conditions tested,and there was a good relationship between the dose and its effect.Among the chemical inhibitors,the inhibiting effect of ascorbic acid,cysteine and citric acid on the PPO activity was better than that of sodium sulfite and sodium metabisulfite,which may be used to control the enzymatic browning in Apricot kernel processing industry.

Key words: apricot kernel, polyphenol oxidase, browning, control