Isolation and Identification of Headspace Volatiles from Brewed Coffee with an On-Column GC/MS Method

Qualitative and quantitative analyses of headspace volatiles of roasted brewed coffee were conducted with use of a direct on-column injection technique. Qualitative analysis was done by gas chromatography/ mass spectrometry (GC/MS). Quantitative analysis was performed by gas chromatography (GC) using an internal standard. Sixty-two volatile compounds were positively identified in the headspace of brewed coffee. The compounds identified included 23 furans, 10 pyrazines, 6 ketones, 5 aldehydes, 3 pyrroles, 3 thiophenes, and 8 miscellaneous compounds such as alcohols, sulfides, and pyridine. The major constituents were 2-methylbutanal (GC area % = 17.7), furan (13.8), and 3-methylbutanal (9.7). Some well-known coffee volatiles such as furfuryl mercaptan were not found in the headspace sample.