客家黄酒发酵过程中挥发性成分分析

Analyzed of Volatile Components in Hakka Rice Wine Fermentation

为了解客家酒发酵过程中的风味物质变化情况,对客家黄酒发酵过程进行分段取样,采用电子鼻与气相色谱-离子迁移谱(Gaschromatography-ion mobility spectroscopy,GC-IMS)技术对不同发酵时期客家黄酒风味物质进行分析,利用主成分分析探寻发酵初期(10 d)、中期(20 d)、后期(30 d)和炙酒后成品的风味物质差异。GC-IMS在4个不同时期客家黄酒中一共检测出107种挥发性物质,定性检出60种已知挥发性组分。发酵前期检出41种,中期检出47种,后期检出54种,炙酒后成品检出59种,其主要成分为酯类、醇类、醛类和酮类物质。随发酵时间的延长挥发性物质种类增多,酯类物质总含量随着发酵试验的延长不断减少,但是酯类物质种类却不断增加;醇类物质含量不断增加,20 d后趋于稳定;醛类和酮类物质含量呈先降低后增加趋势,特别是炙酒后成品醛类和酮类物质显著提升。2-甲基丁酸乙酯在发酵后期消失,3-甲基戊酸乙酯、2-糠酸甲酯、丁醛、3-甲基丁醛、戊醛、糠醛和松油烯在发酵后期检出,2-甲基丁酸甲酯、3-甲基-1-丁醇乙酸酯、2-甲基丁酸丁酯、3-戊醇和2-丁酮等要到炙酒后成品才能检测出。电子鼻和GC-IMS结果表明,发酵10 d的样品与其他样品差异显著,发酵后期与炙酒后成品差异较小。

In order to explore the changes of flavor substances in the brewing process of Hakka rice wine,segmental sampling was conducted during the fermentation process of rice wine.Electronic nose and gas chromatography-ion mobility spectroscopy(GC-IMS)were used to analysize flavor compounds in rice wine at different fermentation stages.Principal component analysis was used to investigate the differences of flavor substances in the early(10d),middle(20d),late(30d)fermentation and processed products.Gc-IMS detected a total of 107 volatile substances in rice wine at four different periods,60 known volatile components were detected,41 were detected in early fermentation,47 were detected in middle fermentation,54 were detected in late fermentation(30 d),and 59 were detected in final rice wine sample.The main components are esters,alcohols,aldehydes and ketones.With the prolongation of fermentation time,volatile substances increased,and the total content of esters decreased with the prolongation of fermentation experiment,but the types of esters increased continuously.Alcohols tended to be stable after increasing for 20 days.The aldehydes and ketones decreased firstly and then increased,especially the aldehydes and ketones increased significantly in final rice wine sample.Ethyl 2-methylbutanoate disappeared in late fermentation.Ethyl 3-methylpentanoate,methyl 2-furoate,butanal,3-methylbutyral,valeral,furfural and p-mentha-1,3-diene were detected in late fermentation.Methyl 2-methylbutanoate,3-methylbutyl acetate,butyl 2-methylbutanoate,3-pentanol and 2-butanone can be detected until final rice wine sample.The results of electronic nose and GC-IMS showed that the composition of the samples after 10 days of fermentation was different from that of other samples,and there was little difference between the finished product after 30 days of fermentation and processed wine.