Major
Chemistry
Faculty Advisor
Kinsel, Mary
Abstract
Coffee is one of the most popular drinks around the world and as such is a very active area of research. This research used HS-SPME - GCMS and HPLC to correlate volatile and nonvolatile coffee components with flavor profiles generated by professional coffee tasters. Coffee was also tasted and ranked by amateur volunteers culled from SIU students and faculty population. Results indicated the professionally established overall coffee scores correlated with coffee cost per ounce, and there were differences between professional and amateur tasters. Professional tasters were trained to recognize subtle differences in flavor attributes such as fruity, floral, and sweet, while amateur tasters were strongly influenced by factors affecting acidity and bitterness. Correlations were observed between the volatile compounds 2,5-dimethylpyrazine, 5-methyl-2-furaldehyde, 2-furanmethanol acetate, guaiacol, 4-ethylguaiacol, p-cyanobenzaldehyde, a cinnamaldehyde derivative, and a 2-methylphenol derivative and several flavor notes including sweet, acidity and bitter rating. The nonvolatile compounds nicotinic acid, trigonelline, chlorogenic acid, and caffeine also exhibited correlations sweet, caramel, and bitter ratings. Future research on this topic should include stable isotope ratio mass spectrometry to determine the proper geographic origins of the coffees from Kroger, Seattle’s Best, Starbucks, and Folgers. This will allow for a comparison across geographic locations. Principle component analysis can also be explored evaluate if groups of two or more volatile and nonvolatile compounds work together synergistically to affect the coffees’ distinct tasting notes.