水杨酸对冷藏期枇杷保护酶系统酶活性的影响

目的]研究不同浓度水杨酸(SA)溶液对冷藏期枇杷膜脂过氧化及衰老的影响。方法]以"大五星"枇杷果实为试材,分别用0.1、0.30、.5 g/L的水杨酸(SA)溶液和清水(CK)浸果20 min,果实风干后在4~8℃下贮藏20 d,每隔5 d取样测定果实中丙二醛(MDA)含量及保护酶活性的变化。结果]贮藏20 d后,0.1、0.30、.5 g/L SA处理的枇杷果实MDA含量分别增加了31.30%、38.26%、49.57%,均低于CK(53.04%)。SA处理后,枇杷果实SOD活性的下降幅度小于CK,CAT活性的下降速度低于CK,POD活性低于CK,其中,0.1 g/L SA处理的效果最好。结论]0.1 g/L SA处理可明显提高冷藏期枇杷果实的SOD和CAT活性,抑制POD活性上升,降低MDA含量,延缓果实衰老。

Effect of Salicylic Acid on Enzyme Activities of Protective Enzyme System in Loquat Fruits during Cold Storage

Objective] The aim was to study the effect of salicylic acid(SA) solution with different concn.on the membrane lipid peroxidation and the aging of loquat fruit in cold storage period.Method] With loquat fruits of Dawuxing as tested material,SA solutions with 0.1,0.3,0.5 g/L and water(CK) were used to soak the fruit for 20 min.After air dry,the fruit was stored for 20 d at 4～8 ℃.Every 5 d the sample was selected to detect the change of MDA content and protective enzyme activity.Result] After storage for 20 d,the MDA content in fruit treated by SA at 0.1,0.3,0.5 g/L was increased 31.30%,38.26%,49.57%,and were all lower than that of CK(53.04%).After SA treating,the decreasing amplitude of the SOD activity of fruit was smaller than that of CK,and the decreasing speed was slower than that of CK,by which the POD activity was lower than that of CK. The effect of treatment with 0.1 g/L was the best.Conclusion] The treatment with 0.1 g/L SA could obviously increase the SOD and CAT activities and inhibit the rise of POD activity,decrease the MDA content and delay the fruit aging.