褪黑素对采后红毛丹果实褐变及膜脂代谢和能量代谢的影响  

Effect of Melatonin on Browning,Membrane Lipid and Energy Metabolisms in Postharvest Rambutan Fruit

作　　者：刘士琦 韦东伶 刘家粮 张伟敏[1,2] 张正科 LIU Shiqi;WEI Dongling;LIU Jialiang;ZHANG Weimin;ZHANG Zhengke(School of Food Science and Engineering,Hainan University,Haikou 570228,China;Baoting Research Institute,Hainan University,Baoting 570316,China)

机构地区：[1]海南大学食品科学与工程学院,海南海口570228 [2]海南大学保亭研究院,海南保亭572316

出　　处：《食品科学》2024年第18期207-215,共9页Food Science

基　　金：海南大学红毛丹产业技术体系专项(THAITS-6);国家自然科学基金地区科学基金项目(32060363)。

摘　　要：本实验以采后‘保研7号’红毛丹为对象,使用不同浓度褪黑素溶液浸泡果实15 min,晾干后置于25℃贮藏6 d,研究褪黑素浸泡处理对红毛丹果实褐变的影响。结果显示:不同浓度褪黑素处理均延缓了红毛丹果实的褐变进程,延缓了果皮色度a^(*)值降低,其中以0.125 mmol/L褪黑素处理效果最佳。生理生化分析结果表明,0.125 mmol/L褪黑素处理抑制了果实相对电导率升高和丙二醛积累,并减缓了脂氧合酶、脂肪酶和磷脂酶D活性升高,进而维持了果实细胞膜完整性;0.125 mmol/L褪黑素处理还提高了还原性辅酶(还原型烟酰胺腺嘌呤二核苷酸和还原型黄素二核苷酸)含量,并增强了琥珀酸脱氢酶、细胞色素c氧化酶、H^(+)-ATP酶和Ca^(2+)-ATP酶等能量代谢相关酶活性,维持了较高的ATP和能荷水平,因此改善了果实细胞能量状态。此外,0.125 mmol/L褪黑素处理促进了γ-氨基丁酸(γ-aminobutyric acid,GABA)积累,并能够保持较高的谷氨酸脱羧酶和GABA转氨酶活性,进而有助于提高能量供应水平。综上,褪黑素能够通过调节果实膜脂代谢及能量代谢延缓采后红毛丹果实褐变和衰老。In this study,to investigate the effects of melatonin on pericarp browning in rambutan fruit,postharvest‘Baoyan7’rambutan fruit was immersed in melatonin solutions at varying concentrations for 15 min,air-dried,and then stored at 25℃for 6 days.The results demonstrated that melatonin treatment at each concentration delayed browning and the decline in the chromaticity a^(*)value of rambutan pericarp,with the most pronounced effect being observed at 0.125 mmol/L melatonin.Physiological and biochemical analyses showed that melatonin treatment at 0.125 mmol/L repressed the increase in relative conductivity(RC)and malondialdehyde(MDA)contents,while retarding the increase in lipoxygenase(LOX),lipase(LPS)and phospholipase D(PLD)activities in rambutan fruit during storage,thereby preserving the integrity of the cell membrane.In addition,treatment with 0.125 mmol/L melatonin increased the contents of nicotinamide adenine dinucleotide(NADH)and flavin dinucleotide(FADH2),enhanced the activities of energy metabolism-related enzymes including succinate dehydrogenase(SDH),cytochromic c oxidase(CCO),H^(+)-ATPase and Ca^(2+)-ATPase,and maintained high levels of adenosine triphosphate(ATP)and energy charge,thus improving cellular energy status.Moreover,this treatment enhancedγ-aminobutyric acid(GABA)content,and maintained high activities of glutamate decarboxylase(GAD)and GABA aminotransferase(GABA-T),thus contributing to enhanced cellular energy supply.These findings suggest that melatonin could retard postharvest browning and senescence in rambutan fruit by modulating membrane lipid and energy metabolisms.

关 键 词：红毛丹 褪黑素 褐变 膜脂代谢 能量代谢 

分 类 号：TS255.36[轻工技术与工程—农产品加工及贮藏工程]