Determination of caffeine content and the volatile compound in some products of roasted and instant coffee in Vietnam

The aims of this study was to evaluate the quality of coffee in Vietnam market.Two methods Soxhlet and supercritical fluid extraction (SFE) were used to investigate the content of caffeine in 15 coffee samples; in which, 8 sample of roasted coffee and 7 sample of instant coffee. –The content of caffeine in 15 samples was different, and dependent on the object of the manufactures; caffeine is in charge of contribution of bitter and alert for customers. The content of caffeine was about 0.3% - 1.79% for the roasted coffee and 0.32% - 0.88% for the instant coffee. This study was also found out the method to extract the volatile compounds by using SDE and SPME. The major volatile compounds were pyrazine, furan, pyrrole, and pyridine. The number of the volatile compounds was 45 and 49 for SDE and SPME, respectively.