Significant research has been devoted to uncovering the chemical composition of the coffee seed, but not to correlating those chemical elements to coffee’s sensory attributes or to genetic traits, agricultural practices, post-harvest techniques, and climate conditions.
The flavor of a cup of coffee is the result of a long chain of chemical transformations from the seed to the cup. Aroma precursors are made and/or transported in the tissue of coffee seeds as the seeds grow and mature. The compounds and metabolites that accumulate during seed development contribute directly or through roasting-induced chemical reactions to the broad spectrum of aromas and flavors in the final cup. Without understanding the connections between quality and coffee chemistry, it is difficult to rigorously improve quality.
World Coffee Research, with Texas A&M University, will evaluate flavor volatiles in coffee and correlate them to chemical compounds in the coffee seed, creating a database of aroma precursors. The project includes protocols for collection of volatile compounds, measurement of compounds and an understanding of compounds that may be precursor volatile compounds based on literature values and preliminary studies using the Aroma Trax System. Using the World Coffee Research Sensory Lexicon, major sensory attributes will be identified and gas chromatography/mass spectroscopy/olfactory techniques will be used to identify the chemical compound responsible for the aroma.
Understanding the molecular basis of coffee quality will allow coffee researchers, breeders, and agronomists to adjust agricultural practices and post-harvest techniques to maximize quality, and will allow breeders to create coffee varieties of the highest quality.