GC-MS/GC-O-MS结合PLSR分析新型青稞白酒的关键香气物质

Analysis of Key Aroma Active Compounds of Novel Qingke Baijiu by GC-MS/GC-O-MS Combined with PLSR

为明晰新型青稞白酒的香气特点,探究不同工艺对酒体风味的影响,以青稞为原料,在清香型白酒工艺基础上引入高温堆积工艺后生产得到一种新型青稞白酒。采用感官定量描述法(quantitative descriptive analysis,QDA)对三个新型青稞白酒原酒样品进行分析,并使用液液萃取法(liquid-liquid extraction,LLE)结合气相色谱-质谱联用仪(gas chromatography-mass spectrometry,GC-MS)以及气相色谱-嗅闻-质谱联用仪(gas chromatographyolfactometry-mass spectrometry,GC-O-MS)对其中香气活性物质进行分析,并采用偏最小二乘回归(partial least squares regression,PLSR)结合分析。三个原酒样品中共检出139种挥发性物质,57种香气化合物,共有11种香气化合物的香气活性值(odor active value,OAV)大于1。经二轮发酵的原酒中挥发性化合物总含量为一轮发酵后原酒的1.4倍,酒的粮香、糟香增加,辛酸乙酯、己酸乙酯、异戊酸乙酯以及愈创木酚是相对应的关键香气化合物。经过高温堆积工艺的原酒糟香、粮香降低,花香更加明显,与未经高温堆积的酒样相比,丁酸乙酯、己酸乙酯、辛酸乙酯的OAV降低,乙酸异戊酯、愈创木酚、4-甲基愈创木酚的OAV升高。高温堆积后乙酸异戊酯浓度提升,酒样花香增强,丁酸、己酸乙酯、辛酸乙酯、癸酸乙酯浓度降低,酒样粮香降低。

A novel Qingke Baijiu was produced by the process of light-aroma Baijiu combined with high-temperature stacking process and using highland barley of Tibet as material.Three kinds of Qingke Baijiu samples were evaluated by quantitative descriptive analysis,and analyzed by liquid-liquid extraction combined with gas chromatography-mass spectrometry and gas chromatography-olfactometry-mass spectrometry and analyzed by partial least squares regression analysis to clarify the aroma characteristic of the novel Qingke Baijiu and to investigate the influence of different manufacturing process.A total of 139 volatile compounds and 57 aroma compounds were detected in three samples,which included 11 aroma active compounds with odor active value(OAV)greater than 1.The total concentration of volatile compounds was 1.4 times higher after secondary fermentation.The sorghum and Zao aromas increased in the samples after secondary fermentation,where ethyl caprylate,ethyl caproate,ethyl isovalerate,and guaiacol were the corresponding key differential compounds.The sorghum and Zao aromas decreased after high-temperature stacking process,while floral aroma increased.Compared with the samples without high-temperature stacking process,the OAV of isoamyl acetate,guaiacol and 4-methylguaiacol increased,while the OAV of ethyl butyrate,ethyl caproate,and ethyl caprylate declined.After high-temperature stacking process,the concentration of isoamyl acetate increased,which lead to stronger floral aroma,and the concentration of butyric acid,ethyl caproate,ethyl caprylate,and ethyl decanoate declined,which lead to weaker sorghum aroma.