杏果实酶促褐变机理的研究初报

以完熟期的凯特、山农凯新2号、红玉为试材,对杏果实中与酶促褐变有关的褐变度、多酚氧化酶(PPO)活性、总酚含量及酚类物质组分等多个因素进行了研究。结果表明:(1)品种不同,影响杏果实酶促褐变的主要因素不同。红玉的褐变程度最高,主要是因为其PPO活性和绿原酸含量最高,并且其褐变度与酚类物质含量及PPO活性均呈极显著正相关(r分别为0.938、0.9944);山农凯新2号总酚含量最低,且除阿魏酸外,各酚类物质组分的含量也都最低,这些因素导致其褐变程度最低。(2)利用高效液相色谱对酚类物质组分进行检测,发现表儿茶素、绿原酸、儿茶素是完熟期杏果实中主要的酚类物质,并且表儿茶素是三个品种中测得的含量最高的酚类物质组分。

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.