Hedonic Judgments of Chemical Compounds Are Correlated with Molecular Size

Manuel Zarzo

doi:10.3390/s110403667

Abstract

Different psychophysical works have reported that, when a wide range of odors is assessed, the hedonic dimension is the most salient. Hence, pleasantness is the most basic attribute of odor perception. Recent studies suggest that the molecular size of a given odorant is positively correlated with its hedonic character. This correlation was confirmed in the present study, but further basic molecular features affecting pleasantness were identified by means of multiple linear regression for the compounds contained in five chemical sets. For three of them, hedonic judgments are available in the literature. For a further two chemical sets, hedonic scores were estimated from odor character descriptions based on numerical profiles. Generally speaking, fairly similar equations were obtained for the prediction of hedonic judgments in the five chemical sets, with R2 values ranging from 0.46 to 0.71. The results suggest that larger molecules containing oxygen are more likely to be perceived as pleasant, while the opposite applies to carboxylic acids and sulfur compounds.

Highlights

Electronic noses are comprised of an array of non-specific chemical sensors that provide a characteristic response pattern for odorous samples
Olfactory perception space is highly dimensional due to the large number of different olfactory receptors involved in odorant recognition [3], it is widely accepted that pleasantness is the most salient dimension when a wide range of smells is assessed at a similar odor intensity
Many psychophysical studies reviewed in the introduction have shown that the hedonic dimension is the most salient when a wide range of smells are assessed, a fundamental question still unsolved in the field of olfaction is what makes an odorant smell pleasant or unpleasant

Summary

Introduction

Electronic noses are comprised of an array of non-specific chemical sensors that provide a characteristic response pattern for odorous samples. With proper calibration, these devices can be used to assess odor intensity [1] and perform discrimination tasks. Plenty of literature is available on this subject (for a review, see [2]), but the prediction of odor character according to molecular structure is Sensors 2011, 11 still a challenge. Olfactory perception space is highly dimensional due to the large number of different olfactory receptors involved in odorant recognition [3], it is widely accepted that pleasantness is the most salient dimension when a wide range of smells is assessed at a similar odor intensity

Methods

Results

Conclusion