酸处理对采后荔枝果皮色泽与生理活性的影响

以淮枝果实为试材,研究了酸处理对新鲜荔枝及冷藏过程中果实的果皮色泽、pH值、组织相对电导率、花色素苷含量、多酚氧化酶(PPO)、过氧化物酶(POD)的影响。试验结果表明:酸处理使新鲜荔枝果实的色泽鲜艳,但并不能增加花色素苷的含量,同时,显著抑制PPO、POD酶活性(p<0.05);2%酸处理加速了冷藏果实的褪色与褐变,花色素苷含量较快下降,而4%酸处理2min的果实在冷藏过程中,果皮pH值缓慢升高,色泽指标及花色素苷含量维持在较高水平,PPO、POD酶活性明显低于对照,果实不表现明显冷害症状。

Study on Acid Treatment Effects on Pericarp Color and Physiological Characteristics of Litchi Fruit

The effects of acid treatment on pericarp color, pH, relative permeability of membrane, anthocyanin content,polyphenol oxidase(PPO) and peroxidase (POD) in litchi fruit were studied in this paper.The results showed that acid dippingcould make fresh fruits more colorful, but did not increase the content of anthocyanin at the same time. The activities of PPO andPOD were inhibited significantly by acid treatment. During cold storage, fruits treated by 2% acid browned faster than control,but fruits treated by 4% acid for 2 minutes remained the color index values and anthocyanin content, the activities of PPO andPOD were much lower than these of control. More important, the fruits treated by acid did not show chilling injury.