抗坏血酸处理抑制李果实冷害作用机理的研究

Study on the Mechanism of Chilling Injury Inhibited by Ascorbic Acid Treatment on Plum Fruits

为寻找减轻李果实冷害的新途径,以新鲜李子为试材,研究李果实经不同浓度的抗坏血酸处理后冷害与酶促褐变机理。结果表明,对照果冷藏12d后,多酚含量和PPO活性都呈现上升趋势,MDA含量和冷害指数开始逐渐提高,说明冷害已经启动。而抗坏血酸处理组延缓了多酚含量的上升趋势,提高了PPO、POD、CAT的活性,外观和内部冷害指数明显降低,SOD活性变化不大。处理1MDA含量明显低于对照,说明用抗坏血酸处理李果实,从外观上明显抑制了李果实冷害的发生。综合内、外两种冷害指数,只有处理1抑制冷害的效果最好,保持了李果实较好的贮藏品质。

In order to develop new methods to reduce the occurrence of chilling injury for plum fruit,using fresh plum as testing material,chilling injury and mechanism of enzymatic browning of plum fruit treated by different concentrations of ascorbic acid were investigated.The results showed that the content of polyphenol and the activity of polyphenol oxidase（PPO） increased,the content of malondialdehyde（MDA） and the index of chilling injury increased gradually when the control fruits stored at low temperature after 12 d,it showed that chilling injury had started at this time.Ascorbic acid treatment delayed increasing of the polyphenol,increased the activity of PPO and peroxidase（POD） and catalase（CAT）,decreased both indexes of chilling injury obviously,the activity of superoxide dismutase（SOD） little changed,the treatment Ⅰin MDA were lower than the control fruits obviously.It showed that ascorbic acid treatment inhibited chilling injury of plum obviously in appearance,and the treatmentⅠinhibited chilling injury effectively and maintained better storage quality of plum fruit in both indexes of chilling injury.