采用顶空固相微萃取结合气相色谱-质谱联用技术对蒸汽熏醅(120℃,21 h)和传统炭火熏醅(80--90℃,5 d)2种山西老陈醋的香气成分动态分析。结果显示,未熏醋醅中检出48种香气物质,蒸汽熏醅后增加到83种,而炭火熏醅后减少到46种,其中杂环化合物在蒸汽熏醅21 h后增加了27种,炭火熏醅5 d仅增加了2种。在2种熏醅工艺中,随着熏醅时间延长,酸、酯、酮类和醇类化合物总含量均呈现逐渐降低趋势,与熏醅前比,蒸汽熏醅21 h后分别降低了35.72%、68.14%、67.91%和57.87%,炭火熏醅5 d分别降低了67.10%、76.00%、67.12%和71.84%;总杂环和四甲基吡嗪含量均呈现增高趋势,与熏醅前比,蒸汽熏醅21 h后分别增高了21.58倍和56.07倍,炭火熏醅5 d仅增高了0.09倍和0.39倍。蒸汽熏醅相比炭火熏醅不仅极大的缩短熏醅时间,减少香气成分损失,还可以显著提高杂环类香气的生成,此工艺值得推广应用。
This study evaluated the influence of different fumigation processes on aroma compounds of Shanxi aged vinegar. The aroma components of vinegars from steam fumigation(120 ℃ for 21 h) and traditional charcoal fumigation(80–90 ℃for 5 days) were dynamically analyzed by headspace solid phase micro-extraction coupled with gas chromatography-mass spectrometry. The results showed that 48 aroma compounds were identified before fumigation, and 83 compounds were detected after steam fumigation, while the number of compounds detected decreased to 46 after charcoal fumigation. Among them, the number of heterocyclic compounds detected in steam fumigated vinegar increased by 27 and by only 2 in charcoal fumigated vinegar. The amounts of acid, ester, ketone and alcohol compounds were gradually reduced by 35.72%, 68.14%, 67.91% and 57.87% after steam fumigation, and by 67.10%, 76.00%, 67.12% and 71.84% after charcoal fumigation, respectively. The amounts of total heterocyclic compounds and ligustrazine presented a gradual increase by 22. 58 and 57.07 times after steam fumigation, and increased by only 9% and 39% after char coal fumigation, respectively. Compared with charcoal fumigation, steam fumigation not only greatly shortened the fumigation time and reduced the loss of aroma components, but also facilitated the formation of heterocyclic aroma. The steam fumigation technology has a great potential for popularization and application.