基于主成分分析法评价酱香型白酒的不同轮次基酒

为实现酱香型白酒不同轮次基酒的数据化区分和评价,本研究以同一窖池7个轮次的酱香型基酒为对象,使用气相色谱法对样品风味物质进行定量检测,结合主成分分析法进行分析。结果显示,各轮次基酒中总酸含量随轮次数增加而减小,第1轮次酒总酸含量最高,达2.94 g/L,随后一直降低,第6、7轮次酒达到最小值1.51 g/L,总酯含量呈先上升后下降的趋势,由3.57 g/L开始上升,第3轮次总酯含量达到最高值5.14g/L,随后降低至3.10g/L;第1、2轮次酒乙酸、乙酸乙酯和正丙醇含量极高,分别占据14.77%～15.55%、14.16%～22.90%、37.78%～37.98%;主成分分析结果显示,前3个主成分累计贡献率可达到89.30%,综合得分散点图上各轮次酒得到有效区分,第1轮次酒单独占据第1象限,第2轮次酒位于x轴负轴附近,第3～5轮次酒分布较为集中,位于x轴下方、y轴附近,第6、7轮次酒集中于x轴正轴附近,各轮次酒综合评分结果为:4537612。综上所述,利用风味物质的差异性并结合主成分分析法能够准确、快速的对酱香型白酒各轮次基酒进行区别和评价,可以为基酒盘勾、评级提供理论支持。

Evaluation of Different Rounds of Moutai-flavor Baijiu Based on Principal Component Analysis

In order to evaluate and differentiate different rounds of Moutai-flavor Baijiu, the flavor substances from seven rounds of Moutai-flavor Baijiu in the same cellar as the object were detected by gas chromatography and analyzed by principal component analysis. The results showed that the total acid content in crude spirits decreased with the increase of the number of rounds. The total acid content in the first round was the highest, reaching 2.94 g/L, and then decreased all the time, finally reaching the minimum value of 1.51 g/L in the sixth and seventh rounds. The total ester content first increased and then decreased, starting from 3.57 g/L, and the total ester content in the third round reached the highest value of 5.14 g/L, then declined to 3.10 g/L. The content of acetic acid, n-propanol, ethyl acetate, ethyl lactate, acetaldehyde, acetal and other compounds was relatively high in the crude spirits. The contents of acetic acid, ethyl acetate and n-propanol in the first and second crude spirits were extremely high, they accounted for 14.77%~15.55%, 14.16%~22.90% and 37.78%~37.98% respectively. The results of principal component analysis showed that the cumulative contribution rate of the first three principal components could reach 89.3%, and each round of Baijiu could be effectively distinguished on the scatter chart of comprehensive score. The first round of Baijiu alone occupied the first quadrant, the second round of Baijiu was located near the negative axis of X axis, the third to fifth rounds of Baijiu were concentrated, located below X axis and near Y axis, and the sixth and seventh rounds were concentrated near the positive axis of X axis. The comprehensive score of each round of Baijiu was: 4>5>3>7>6>1>2. To sum up, the difference of flavor substances combined with principal component analysis could accurately and quickly distinguish and evaluate the crude spirits of different rounds of Moutai-flavor Baijiu, which could provide theoretical support for the crude spirits'' hooking and rating.