Human perception of coffee aroma and its odor-active molecules: role of the olfactory threshold and the OBPIIa gene

The olfactory perception of the aroma of both foods and beverages and the individual molecules that compose them is influenced by the olfactory performance of individuals and the genetic factors that contribute to it. Among commonly consumed beverages, coffee is the most popular non-alcoholic one in the world, in accordance with its social significance and functional effects. Recent studies have identified the social and environmental factors that determine whether an individual is a coffee drinker or non-drinker. Knowing the key aroma compounds of coffee, identifying interindividual differences in the number and intensity of odor-active compounds and the factors involved, could be important to understand what guides consumers in their choice of whether or not to drink coffee. In this study, using the coupled Gas Chromatography-Olfactometry technique, the headspace components of roasted coffee beans were separated and evaluated by volunteers. Each participant, genotyped for the rs2590498 (A/G) polymorphism of the OBPIIa gene, was asked to identify and provide a personal evaluation of the pleasantness and intensity of each odor molecule. The results showed that both the ability to perceive odor-active compounds and the intensity with which they are perceived are correlated with the olfactory threshold and the OBP genotype of individuals. The reported pleasantness for the coffee aroma was determined by the hedonic valence attributed to each molecule in terms of pleasantness/unpleasantness. These results could be of great interest to the coffee industry, providing useful information for the development of new blends. In fact, taken together, these findings suggest that the perception of coffee odor is highly subjective due to both physiological and genetic factors.