基于GC-O、OAV及Feller加和模型对酱香型习酒特征香气成分的分析

Identification of Characteristic Aroma Compounds in Soy Sauce Aroma Type Xi Baijiu Using Gas Chromatography-Olfactometry,Odor Activity Value and Feller’s Additive Model

通过气相色谱-质谱联用仪、气相色谱硫磷检测器研究3种酱香型习酒(习酒蓝、习酒印象贵州、习酒银质)中的挥发性香气成分,分别鉴定出99、96、98种香气成分,其中各包含12种含硫化合物。基于气相色谱嗅闻仪和香气活性值(odor activity value,OAV)方法,表明己酸乙酯(OAV:1 720~1 992)、丁酸乙酯(OAV:1 401~1 523)、辛酸乙酯(OAV:218~327)、3-甲基丁酸乙酯(OAV:835~966)、2-正丁基呋喃(OAV:464~719)、2-甲基丙酸乙酯(OAV:146~342)、3-羟基-2-丁酮(OAV:90~117)、丁酸(OAV:71~79)、2-甲基-3-呋喃硫醇(OAV:33~72)、丁醇(OAV:19~37)、苯乙酸乙酯(OAV:90~91)、己醛(OAV:29~33)、2-甲基丙酸(OAV:13~33)、苯乙醛(OAV:16~35)、糠醇(OAV:7~13)等具有较高的数值,说明这些成分是酱香型习酒主要特征性香气成分。通过香气重组、偏最小二乘回归进一步验证、解释习酒中的特征性香气成分与感官属性之间的相关性。最后,利用Feller加和模型研究习酒印象贵州酒中5种含硫化合物和6种酯类化合物之间的感官交互作用,验证酱香型习酒特征香气鉴定的准确性。结果表明,丙硫醇、二甲基三硫醚、2-甲基-3-呋喃硫醇、3-巯基己基乙酸酯、3-巯基-1-己醇都是增强己酸乙酯的香气,而对其他5个酯类化合物则有增强也有掩盖的作用。实验数据解释了香气物质之间的作用机理,有助于通过定向调控提高酱香型习酒的香气质量。

A total of 99, 96 and 98 volatile aroma compounds were identified in three kinds of soy sauce aroma type Xi Baijiu, namely, Xijiulan, Xijiuyinxiangguizhou and Xijiuyinzhi by gas chromatography-mass spectrometry(GC-MS) and gas chromatography-flame photometric detection(GC-FPD), respectively, each including 12 sulfur-containing compounds.As determined by gas chromatography-olfactometry(GC-O), ethyl hexanoate(OAVs of 1 720–1 992), ethyl butanoate(OAVs of 1 401–1 523), ethyl octanoate(OAVs of 218–327), ethyl 3-methylbutanoate(OAVs of 835–966), 2-butylfuran(OAVs of 464–719), ethyl 2-methylpropanoate(OAVs of 146–342), 3-hydroxy-2-butanone(OAVs of 90–117), butanoic acid(OAVs of 71–79), 2-methyl-3-furanethiol(OAVs of 33–72), butanol(OAVs of 19–37), ethyl phenylacetate(OAVs of 90–91), hexanal(OAVs of 29–33), 2-methylpropionic acid(OAVs of 13–33), phenylacetaldehyde(OAVs of 16–35)and furfuryl alcohol(OAVs of 7–13) exhibited much higher odor activity values(OAVs) and aroma intensities(AIs) than the other compounds, which suggested that these aroma compounds were the main characteristic aroma compounds of Xi Baijiu. The correlation between the key aroma compounds and sensory attributes was further verified and explained by aroma recombination combined with partial least squares regression(PLSR). Finally, the perceptual interactions between five sulfur compounds and six esters in Xijiuyinxiangguizhou Baijiu were studied using Feller’s additive model to verify the accuracy of aroma identification of Xi Baijiu. The results showed that propanethiol, dimethyl trisulfide, 2-methyl-3-furanethiol,3-mercaptohexyl acetate and 3-mercaptohexanol all enhanced the aroma of ethyl hexanoate, but enhanced or masked the aroma of the other five esters. The experimental data partly explained the interaction mechanism between aroma compounds, which would be helpful to improve the aroma quality of soy sauce aroma type Xi Baijiu through directional operation.