茉莉酸甲酯处理对鲜切紫薯生理生化及品质的影响

Effect of methyl jasmonate(MeJA)on physiological and biochemical changes of fresh-cut purple sweet potatoes

为了研究不同浓度茉莉酸甲酯(methyl jasmonate,MeJA)对鲜切紫薯生理生化品质的影响,用不同浓度(0.15、0.3mmol/L)的茉莉酸甲酯溶液浸泡处理紫薯10min,以蒸馏水处理作对照,然后将其密封后保存在11℃的冷库中。贮藏期间分析测定与生理代谢有关的多酚氧化酶(PPO)、过氧化物酶(POD)和过氧化氢酶(CAT)等活性,并测定了总酚、花青素、类黄酮和还原性谷胱甘肽含量等品质指标。结果表明,与对照相比,MeJA处理可提高鲜切紫薯的PPO、POD和CAT活性,并使总酚和还原性谷胱甘肽含量增加,保持较高的花青素和类黄酮含量,维持鲜切紫薯的色泽。研究结果认为,0.3mmol/LMeJA效果好于0.15mmol/LMeJA。MeJA减缓鲜切紫薯的抗氧化物质的流失以延长货架期,可以作为天然保鲜剂应用在紫薯的实际贮藏中。

Fresh-cut purple sweet potatoes were treated with methyl jasmonate（MeJA.）of different concentrations（0.15,0.3mmol/L）at 11℃ under sealed preservation in order to study effect of various concentrations of MeJA on the physiology and biochemistry of fresh-cut purple sweet potato quality,while the samples with distilled water were observed as a control group.During storage,the physiological metabolism of polyphenol oxidase（PPO）,peroxidase（POD）and catalase（CAT）activities was analyzed,and the quality indicators about phenolic compounds,anthocyanins,flavonoids and reduced glutathione content were determined as well.The results showed that after treatment of fresh-cut purple sweet potatoes by MeJA,PPO,POD and CAT activities could be enhanced gradually compared with control.At the same time,total phenolics and reduced glutathione content increased while anthocyanins and flavonoids maintained in high levels.Moreover,the color of fresh-cut purple sweet potatoes was kept as well.These data suggested that the effect of fresh-cut purple sweet potatoes combined with 0.3mmol/L MeJA was better than that of 0.15mmol/L MeJA.The enhancement of activities of MeJA played an important role in slowing down the degradation of antioxidants and prolonging the shelf-life of fresh-cut purple sweet potatoes.In summary,MeJA might be used as natural preservatives in the practical application of fresh-cut purple sweet potatoes storage and transportation.Fresh-cut purple sweet potatoes with MeJA treatment had good prospects for development.