白酒中吡嗪类化合物分析及与酯的感知交互作用

Analysis of Pyrazines in Baijiu and Their Perceptual Interactions with Esters

摘要:

采用液相色谱-质谱联用法（Liquid Chromatography-tandem Mass Spectrometry, LC-MS/MS）结合多元统计分析对12种香型白酒中的18种吡嗪类化合物进行分析，并用S型曲线、Feller加和模型、香气活度值（Odor Activity Value, OAV）法和σ-τ模型研究三甲基吡嗪与乙酸乙酯、丁酸乙酯、己酸乙酯和乳酸乙酯之间的感知交互作用。LC-MS/MS方法在检测范围内线性关系良好（R2≥0.995），检出限为0.69~43.47 μg/L，定量限为2.10~95.21 μg/L，日内精密度≤4.71%、日间精密度≤4.11%，加标回收率82.22%~103.71%。酱香型白酒吡嗪总量最高，为10 411.71~32 628.30 μg/L，其次是兼、芝麻和董香型白酒，四甲基吡嗪和三甲基吡嗪是白酒中含量最高的2种吡嗪类化合物。正交偏最小二乘判别分析（Orthogonal Partial Least Squares Discriminant Analysis, OPLS-DA）模型可对12种香型白酒进行大致分类，变量重要性投影值（Variable Importance in the Projection, VIP）分析筛选出9种关键差异吡嗪类化合物，2-甲基吡嗪的VIP值最高，为1.33。感知交互作用的研究结果表明三甲基吡嗪与乙酸乙酯、丁酸乙酯和己酸乙酯之间存在加成或协同作用，与乳酸乙酯之间是掩盖作用。该研究可为白酒的风味品质调控提供理论参考。

Abstract:

Eighteen pyrazines in 12 aromatic Baijiu were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with multivariable statistical analysis,, and the perceptual interactions among trimethylpyrazine and ethyl acetate, ethyl butyrate, ethyl hexanoate, and ethyl lactate were investigated using the S-curve method, Feller's additive model, odor activity value (OAV) method, and σ-τ model. The LC-MS/MS method showed good linear relationships within the detection ranges (R2≥0.995), with the limits of detection being 0.69~43.47 μg/L, the limits of quantification being 2.10~95.21 μg/L, the intra-day precision ≤ 4.71%, the inter-day precision ≤ 4.11%, and the spiking recoveries being 82.22%~103.71%. Sauce-flavor baijiu samples had the highest total contents of pyrazines (10 411.71~32 628.30 μg/L), followed by Jian-flavor baijiu, Sesame-flavor baijiu, and Dong-flavor baijiu. Tetramethylpyrazine and trimethylpyrazine were the two kinds of pyrazines with the highest contents in baijiu. The orthogonal partial least squares discriminant analysis (OPLS-DA) model could roughly classify the 12 flavor baijiu, and the variable importance in the projection (VIP) analysis allowed 9 key differential pyrazines to be screened out, with 2-methylpyrazine having the highest VIP value (1.33). The results of perceptual interactions showed that there was an additive or synergistic effect between trimethylpyrazine and ethyl acetate, ethyl butyrate or ethyl hexanoate, with a masking effect occurring between trimethylpyrazine and ethyl lactate. This study can provide a theoretical reference for regulating flavor quality of baijiu.