Preliminary Study on the Mechanism of Enzymatic Browning in Apricot Fruits

Several factors in relation with enzymatic browning,such as browning degree,total phenolics content,PPO activity,phenolic composition and so on were studied in the apricot fruits of Katy,Hongyu and Shannongkaixin2 picked during tree ripe stage.The results were as follows.Firstly,the main factors related to enzymatic browning in apricot fruits varied in different cultivars.The browning degree of Hongyu was the highest,because of the highest PPO activity and chlorogenic acid content.Besides,total phenolics content and PPO activity were positively related with browning degree (r=0.938,0.9944 respectively);except for ferulic acid,the contents of total phenolics and phenolic components in Shannongkaixin2 were the lowest,and these factors led to the lowest browning degree.Secondly,the analysis of phenolic compositions by HPLC revealed that(-)-epicatechin,chlorogenic acid and(+)-catechin were the major phenolic compounds in apricot fruits during tree ripe stage,and the content of(-)-epicatechin was the highest in all three cultivars.