外源褪黑素对番茄果实品质和挥发性物质的影响

Effects of exogenous melatonin on fruit quality andvolatile compounds of tomatoes

为探究外源褪黑素对番茄果实品质及挥发性物质的影响,以番茄(Solanum lycopersicum)‘航粉高糖’品种为试材,以果实表面喷施蒸馏水为对照(CK),设4个不同浓度褪黑素喷施果实处理,分别为T1(50μmol·L^(-1))、T2(100μmol·L^(-1))、T3(150μmol·L^(-1))、T4(200μmol·L^(-1))。结果表明:(1)100μmol·L^(-1)外源褪黑素处理能显著增加番茄果实中果糖、葡萄糖和可溶性总糖的含量,降低有机酸含量,从而显著提高番茄果实糖酸比。(2)5个处理中共检测出86种挥发性物质,包括12种酮类、32种醛类、14种醇类、4种酯类、13种烃类、7种酚类和4种其他类物质。各处理挥发性物质总数量和总含量依次为:CK(55种,1279.18μg·kg^(-1))、T1(69种,1960.95μg·kg^(-1))、T2(66种,2258.70μg·kg^(-1))、T3(62种,1818.84μg·kg^(-1))、T4(59种,1695.04μg·kg^(-1)),均为醛类含量最高,酚类含量最低,其中100μmol·L^(-1)处理可提高番茄果实中酮类、醛类、醇类和酯类挥发性物质总含量。检测出的挥发性物质共包含10种番茄特征香气成分,100μmol·L^(-1)处理的特征挥发性物质含量最高,为1307.34μg·kg^(-1)。(3)与对照相比,喷施褪黑素提高了番茄果实单果质量以及可溶性固形物、可溶性蛋白、维生素C、番茄红素含量,促进果实对N、K、Mg、Cu、Fe、Zn等矿质元素的吸收。(4)主成分分析表明,各处理的综合得分表现为T2>T1>T3>T4>CK。综上,外源喷施褪黑素可显著提高番茄果实的营养和风味品质,且100μmol·L^(-1)浓度效果最佳。

To explore the effects of exogenous melatonin on tomato fruit quality and volatile compounds,tomato Solanum lycopersicum(‘Hangfen Gaotang’)was used as the test material in this experiment.Spraying distilled water on fruit surface as the control(CK)and four different concentrations of melatonin spraying treatments of T1(50μmol·L^(-1)),T2(100μmol·L^(-1)),T3(150μmol·L^(-1))and T4(200μmol·L^(-1))were set up.The results showed that:(1)100μmol·L^(-1) exogenous melatonin significantly increased the contents of fructose,glucose and total soluble sugar and reduced the content of organic acids in tomato fruit,thereby,the ratio of sugar to acid in tomato fruit was significantly increased.(2)A total of 86 volatile compounds were detected in five treatments,including 12 ketones,32 aldehydes,14 alcohols,4 esters,13 hydrocarbons,7 phenols and 4 other compounds.The total amount and content of volatile compounds in each treatment were as follows:CK-55 types,1279.18μg·kg^(-1),T1-69 types,1960.95μg·kg^(-1),T2-66 types,2258.70μg·kg^(-1),T3-62 types,1818.84μg·kg^(-1),and T4-59 types,1695.04μg·kg^(-1).In every treatment,the content of aldehydes was the highest and the content of phenols was the lowest.The 100μmol·L^(-1) treatment increased the total contents of ketones,aldehydes,alcohols and esters compounds in tomato fruits.All the detected volatile compounds contained 10 kinds of characteristic aroma substances of tomatoes of which 100μmol·L^(-1) melatonin treatment had the highest content(1307.34μg·kg^(-1)).(3)Compared with the control,spraying melatonin increased the single fruit weight,soluble solids,soluble protein,vitamin C and lycopene content of tomato fruit and promoted the absorption of mineral elements such as N,K,Mg,Cu,Fe and Zn in tomato fruits.(4)Principal component analysis showed that the comprehensive score of each treatment was T2>T1>T3>T4>CK.In conclusion,exogenous spraying melatonin significantly improved the nutritional and flavor quality of tomato fruits,and the 100μmol·L^(-1) treatment was the best.