Brief description of cacao research by Kevin Rams as part of the Guiltinan Lab.
The pulp and seeds in the cacao pod are what determine the difference between the classifications of fine aromatic cacao and bulk cacao. The market for fine aromatic cacao is the fastest growing sector of the chocolate industry due to strong demand from Asian consumers. My research is focused on establishing the connection between the genotype of the tree with the volatile profile of the pulp and seeds of the cacao fruit.
The aromatic profile of cacao is composed primarily of esters, secondary alcohols, ketones, and terpenes. The way we perceive these molecules with our sense of smell or taste is not always dependent on the quantity present. Many molecules can be sensed at much lower levels than others. I have been utilizing 2-dimensional gas chromatography to further the level of characterization of the volatiles present in the cacao pulp and seeds. Coupling this analysis with known thresholds for the molecules will allow a targeted approach to determining what combination of volatiles makes the optimum profile.
All plant volatiles are secondary metabolites and have a specific phytochemistry. By determining what metabolites contribute the most to the aroma, the focus of my research can then narrow to the enzymatic pathways which produce those compounds. Some of the pathways have been studied in other horticulturally important crops such as tomato, melon, and grape to give plant breeders genetic markers to improve the flavor; but cacao has not been studied as such. My research will give more insight into the genetics controlling the aromatic profile of cacao allowing cacao breeders to improve the flavor of the existing varieties.