Association between human olfactory performance and ability to detect single compounds in complex chemical mixtures

Humans can accurately discern thousands of odorants, although there is a considerable inter-individual varia-bility. Individuals can be classified as normosmic, hyposmic or anosmic, depending on their olfactory sensitivityor blindness. In this research we studied the olfactory sensitivity to banana head-space as a complex odormixture in a group of 53 subjects classified for their olfactory status, by means of the "Sniffin' Sticks" extendedtest. Using the coupled Gas Chromatography-Mass Spectrometry/ Olfactometry (GC–MS/O) technique, the singlecomponents of the bananaflavor mixture were separated, identified and verbally evaluated by each subject. Foreach compound both the“odor type”(i.e., odor quality: fruity,floral, green, etc.) and“odor descriptor”(i.e.,name used by subjects for odor identification) were reported, so that we could identify molecules that weredefined as smelling of banana. The results show that: (a) the threshold olfactory performance is linearly cor-related with the number of odor-active compounds (total or smelling of banana) for each subject; (b) the in-tensity reported by each subject during the sniffing of the pen containing the banana aroma in the identificationtest is positively correlated both with its hedonic valence and the number of odor-active compounds smelling ofbanana. In conclusion, ourfindings show that human perception of single compounds is conditioned by thethreshold olfactory performance of the subject and that his/her ability to detect single molecular components,which smell as the mixture, affects the intensity and hedonism for the complex aroma.