Patterns of odour similarity among carbonyls and their mixtures

Abstract

The odours of five carbonyls: heptanone, octanone, octenal, nonenal and decadienal, and two mixtures of each ketone with each aldehyde, giving 17 sample types in all, were compared using two non-quantitative, non-descriptive procedures: sorting and the method of triads. Each procedure was conducted with a different set of eight completely untrained assessors. After non-metric, multi-dimensional scaling the two procedures gave similar groupings of odours which also agreed well with results obtained previously using only eleven sample types and a much larger number of very experienced assessors. The ketones and aldehydes clustered at opposite poles of the diagrams with the mixtures lying between the positions of their components. It is concluded that the procedures are suitable for use with untrained assessors and large numbers of sample types and the results are robust, especially in the case of the sorting procedure.