槲树叶提取液对冷藏期间桃品质及抗氧化系统的影响

以生理成熟期‘新泰红’桃果实为试材,分别用0、2.5、5.0、7.5 g/L槲树叶提取液浸泡果实,以蒸馏水为对照,并于0℃冷藏,测定冷藏期间果实可溶性蛋白等品质指标以及酶活力与活性氧等物质,探讨槲树叶提取液对采后桃果实贮藏品质的影响。结果表明:槲树叶提取液处理能够有效延缓冷藏期间桃果实冷害指数升高以及硬度下降,使整个冷藏期间果实可溶性蛋白、可溶性糖、维生素C含量维持相对较高水平,并且能够有效延缓膜脂过氧化产物(丙二醛)以及活性氧物质(超氧阴离子自由基、过氧化氢和羟基自由基)积累;同时,槲树叶提取液处理还能够显著抑制果实多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)活性,从而延缓冷藏期间桃果实褐变程度。综上所述,槲树叶提取液处理能够缓解冷藏期间桃果实冷害症状,以5.0 g/L槲树叶提取液处理效果最为明显。

Effects of Quercus dentata leaves extract on quality and antioxidant system of peach during cold storage

In this experiment,the peaches(Prunus persica cv.Xintaihong)at physiological maturity were dipped in different concentrations at 0,2.5,5.0,7.5 g/L of Quercus dentata leaves extract with the distilled water as the control.After treatmets,the peaches were stored at 0℃.By measuring the quality indexes such as soluble protein,as well as the enzyme activities and reactive oxygen species,the effects of Quercus dentata leaves extract on the cold storage(0℃)quality of postharvest peach fruit were discussed.The results showed that the extract of Quercus dentata leaves effectively delayed the decline of fruit firmness and chilling injury index during cold storage,maintained high contents of soluble protein,soluble sugar and vitamin C,and delayed the membrane lipid peroxidation produce(MDA)and the accumulation of reactive oxygen species(O2·-,H2O2 and·OH);significantly inhibited the activities of polyphenol oxidase and phenylalanine ammonia-lyase,and delayed the browning of peaches.In a comprehensive view,5.0 g/L Quercus dentata leaves extract could be used to relief the chilling damage of peaches and maintain the storage quality.