生青味缺陷型酱香白酒风味特征分析

为鉴定酱香型白酒中的生青味化合物,建立一种基于感官导向结合代谢组学分析白酒中异嗅味特征成分的方法.利用真空旋转蒸发将样品分成挥发性和难挥发性组分,对具有强烈生青味的挥发性组分进行液液萃取和感官分析,结果表明生青味主要存在于中/碱性组分中;采用气相色谱-质谱联用法对该组分进行检测分析,共定性定量出风味化合物94种,以酯类...

Analysis of Flavor Characteristics of Moutai-aroma Type Baijiu with Green Off-flavor

To identify the green off-flavor compounds in Moutai-aroma type Baijiu, a method involving sensory-guided fractionation and metabolomics was developed for analyzing its characteristic off-flavor compounds. The samples were separated into volatile and non-volatile compounds by vacuum rotary evaporation. Liquid-liquid extraction and sensory analysis were performed on the volatile components with an intense green off-flavor, and the results showed that the green off-flavor compounds mainly existed in the neutral/alkaline components. A total of 94 flavor compounds were qualitatively and quantitatively identified in the volatile components by gas chromatography-mass spectrometry (GC-MS), the predominant ones being esters, alcohols and aromatic compounds. There were significant differences between normal and defective Baijiu as determined by Venn diagram and clustered heatmap analysis. Furthermore, a total of 15 major differential compounds with variable importance in the projection (VIP) > 1 were identified by orthogonal partial least-squares discriminant analysis. Among them, alcohol and ester compounds showed the most significant difference between the two Baijiu samples. Esters including ethyl lactate, ethyl 2-furoate and ethyl DL-2-hydroxycaproate, as well as higher alcohols including isoamyl alcohol, isobutanol and furfural were identified as the major green off-flavor compounds, and also important contributors to the bitterness and astringency of Baijiu. It is worth noting that ethyl 2-furoate and ethyl DL-2-hydroxycaproate were identified in Baijiu with green off-flavor for the first time; however, their flavor characteristics have yet to be further investigated. The results of this study provide a scientific basis for improving the quality of Moutai-aroma type Baijiu and also provide a reference for the analysis of characteristic flavor compounds in foods in the future.