焦香风味特征白酒酿造原料的焙烤工艺条件研究

以大麦和小麦为原料，通过固相微萃取结合气相色谱-质谱联用（SPME-GC-MS）对焙烤处理前后原料的香气成分进行分析，采用主成分分析（PCA）及香气活性值（OAV）评价焙烤工艺条件对原料香气成分的影响。采用焙烤后原料酿造白酒，评价焙烤工艺对白酒风味的影响。结果表明，经过焙烤处理后，原料的焦香风味成分增加15种。PCA结果表明，焙烤原料的主要特征性挥发性物质为醛类、吡嗪类；产生焦香风味物质最多的焙烤条件为温度220 ℃、时间75 min。在此条件下，对焦香风味影响较大的物质（OAV＞5）包括2,5-二甲基吡嗪、2,6-二甲基吡嗪、2-乙基-5-甲基吡嗪和2-乙基-6-甲基吡嗪等；与未焙烤原料制备白酒相比，焦香风味成分含量增加，吡嗪含量较高（20.1 mg/L）。

Baking process of Baijiu-brewing materials with burnt flavor characteristic

Using barley and wheat as raw materials, aroma components of raw materials before and after baking were analyzed by solid phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS), and the effect of baking process conditions on aroma components of raw materials was evaluated by principal component analysis (PCA) and aroma activity value (OAV). Baijiu (Chinese liquor) was brewed by baked raw materials, and the effect of baking process on Baijiu flavor were evaluated. The results showed that the burnt flavor components of raw materials increased by 15 after baking, the results of PCA showed that the main characteristic volatile substances were aldehyde and pyrazine. The baking conditions that produced the most burnt flavor components were as follows: temperature 220 ℃ and time 75 min. Under these conditions, substances with greatest influence (OAV＞5) on burnt flavor included 2,5-dimethylpyazine, 2,6-dimethylpyazine, 2-ethyl-5-methylpyazine and 2-ethyl-6-methylpyrazine. Compared with Baijiu prepared by raw materials without baking, the burnt flavor component increased and pyrazine content was higher (20.1 mg/L).