关键词: 顶空气相色谱-离子迁移谱, 咖啡, 风味, 挥发性有机物, 指纹图谱

Abstract: In this study, the volatile organic compounds (VOCs) in coffee beans from 8 different geographical origins in the world were fingerprinted by headspace-gas chromatography-ion mobility spectroscopy (HS-GC-IMS). We compared the differences in the VOC fingerprints of these coffee samples using matching matrix and clustering analysis, and we investigated the changes in the VOC fingerprints before and after roasting in the form of data visualization. The results showed that for both raw and roasted coffee powders there were differences in VOCs among geographical origins and there were differences in VOCs between raw and roasted coffee powders from the same geographical origins. According to the fingerprint analysis, three-dimensional principal component analysis (3D-PCA) and matching matrix analysis, when the matching degree was 90%, the differences in the subtle characteristic components in the fingerprints could accurately distinguish raw from cooked coffee powders and discriminate the geographical origins. In conclusion, HS-GC-IMS provides a useful tool for identifying the varietal and geographical origin of coffee beans.

Key words: headspace-gas chromatography-ion mobility spectroscopy, coffee, flavor, volatile organic compounds, fingerprint