外源一氧化氮对扁豆采后贮藏品质的影响

Effect of Exogenous Nitric Oxide on Postharvest Storage Quality of Hyacinth Bean

为研究一氧化氮(nitricoxide,NO)对扁豆采后贮藏品质的影响,本实验以硝普纳(sodium nitroprusside,SNP)为外源NO供体,采用0.2mmol/L浓度的SNP溶液浸泡处理扁豆10min(以蒸馏水浸泡为对照),分析(20±1)℃和80%~90%相对湿度条件下贮藏期间扁豆腐烂率、锈斑率、硬度、总可溶性固形物(total soluble solid,TSS)质量分数、丙二醛(malondialdehyde,MDA)含量、类黄酮含量、总酚含量、叶绿素含量以及抗氧化酶(过氧化物酶(peroxidase,POD)、多酚氧化酶(polyphenol oxidase,PPO)、苯丙氨酸解氨酶(phenylalanine ammoniase,PAL)、过氧化氢酶(catalase,CAT)和抗坏血酸过氧化物酶(ascorbate peroxidase,APX))活力的变化情况。结果表明,外源NO处理可以抑制扁豆腐烂和锈斑的产生,使扁豆保持较好的光泽和硬度,同时对TSS和叶绿素的降解起到抑制作用,使扁豆保持良好的感官品质。外源NO处理还可以抑制MDA积累,提高总酚和类黄酮的含量。此外,外源NO处理还可以保持扁豆贮藏过程中PAL、CAT和APX活力,抑制组织中POD和PPO活力的增加,从而增强扁豆的抗氧化能力,延缓扁豆成熟衰老。结论:外源NO处理可以延缓扁豆采后成熟衰老,维持扁豆在贮藏期间的生理品质,有效延长扁豆保鲜期。

In order to study the effect of nitric oxide(NO)on the storage quality of hyacinth bean after harvest,sodium nitroprusside(SNP)was used as an exogenous NO donor in this study.Hyacinth bean was soaked in 0.2 mmol/L SNP solution or distilled water as control for 10 min and then stored at(20±1)℃and 80%-90% relative humidity.Decay incidence,rust incidence,hardness,the contents of total soluble solids(TSS),malondialdehyde(MDA),flavonoids,total phenols and chlorophyll,and the activities of antioxidant enzymes(peroxidase(POD),polyphenol oxidase(PPO),phenylalanine ammoniase(PAL),catalase(CAT)and ascorbate peroxidase(APX))were observed during the storage period.The results showed that exogenous NO treatment could inhibit the rot and rust,keep the color and hardness,and inhibit the degradation of TSS and chlorophyll in hyacinth bean,so that hyacinth bean could maintain good sensory quality.Exogenous NO treatment could also prevent the accumulation of MDA and increase the contents of total phenols and flavonoids.In addition,exogenous NO treatment maintained the activities of PAL,CAT and APX during storage,and inhibited the increase in the activities of POD and PPO,thereby enhancing the antioxidant capacity and delaying the maturation and senescence of hyacinth bean.In conclusion,exogenous NO treatment can delay the postharvest maturation and senescence,maintain the physiological quality during storage,and effectively prolong the shelf life of hyacinth bean.