基于HS-GC-IMS对8种咖啡豆烘焙前后挥发性有机物成分分析

利用顶空气相色谱-离子迁移谱（headspace-gas chromatography-ion mobility spectrometer,HS-GC-IMS）对8种咖啡样品烘焙前后挥发性有机物成分（volatile organic compounds,VOCs）进行分析。鉴定出42个VOCs，包含9个醇类、9个醛类、9个酯类、7个酮类、3个酸类、2个呋喃类、2个醚类、1个吡嗪类。咖啡烘焙后总VOCs比烘焙前增加180.47%，其中呋喃类增加2 200%，吡嗪类增加532.39%，酮类增加82.03%，醚类降低45.23%，醇类降低32.35%，酯类降低18.52%，醛类降低17.32%，挥发性酸类降低15.55%。烘焙后咖啡中糠醇、γ-丁内酯、2-乙酰基呋喃等化合物大量增加，而乙醇、二甲基硫醚、乙酸丙酯、乙酸丁酯等化合物减少，使烘焙后的咖啡表现出复杂的气味。

Analysis of Volatile Organic Compounds in 8 Kinds of Coffee Beans before and after Roasting Based on HS-GC-IMS

Volatile organic compounds(VOCs)were analyzed with 8 kinds coffee samples before and after roasting by using headspace-gas chromatography-ion mobility spectrometer(HS-GC-IMS).Forty-two VOCs were identified,including 9 alcohols,9 aldehydes,9 esters,7 ketones,3 acids,2 furans,2 ethers and 1 pyrazine.The total VOCs after coffee roasting increased by 180.47%compared with before.Furan increased by 2 200%,pyrazine by 532.39%,ketones by 82.03%,ethers by 45.23%,alcohols by 32.35%,esters by 18.52%,aldehydes by 17.32%,volatile acids by 15.55%.The content of furfuryl alcohol,gamma-butyrolactone,2-acetylfuran and other compounds increased gaeatly after roasting.Ethanol,dimethyl sulfide,propyl acetate,butyl acetate and other compounds reduced.These changes gave the roasted coffee a complex smell.