The present study shows that the concentration gap between detection and recognition of aliphatic aldehydes is odorant pair-dependent but at group level spans at least a factor of 100. Nevertheless, single individuals successfully discriminated between certain aldehyde pairs when presented at a factor that was less than 100 above the individual detection thresholds. Even at the lowest concentration, a factor of 3 above the individual detection thresholds, a few of the subjects were able to significantly discriminate some of the odorants.

Furthermore, the results provide evidence of a well developed discrimination ability for aliphatic aldehydes in human subjects and of a significant positive correlation between structural dissimilarity of odorants in terms of differences in carbon chain length and discriminabilty of the odorants for the homologous series of aliphatic aldehydes.