Masking Effects on Iso-valeric Acid Recognition by Sub-threshold Odor Mixture

In this study, we employed Sniff Olfactometry (SO) to investigate the psychophysics of masking using brief 70ms stimulations with mixtures of the mal-odorant iso-valeric Acid (IVA) and different masking agents. IVA is a component of human sweat that can overpower its smell and is often associated with unpleasant descriptors such as "gym locker," "smelly feet," "dirty clothes," and so on. Traditionally, high concentrations of pleasant-smelling odorants are used to mitigate the unpleasantness of IVA in situations involving clothing or environments contaminated with IVA. To examine the masking effects of sub-threshold levels of various masking agents (neohivernal, geraniol, florhydral, decanal, iso-longifolanone, methyl iso-eugenol, and s-limonene) on IVA, we conducted experiments using SO to measure the probability of recognizing IVA after 70ms stimulations with headspaces containing mixtures of super-threshold concentrations of IVA and sub-threshold concentrations of IVA-suppressors. The study involved nine subjects, and on average, a single masking agent was found to decrease IVA recognition probability by 14% to 72%. Moreover, a sub-threshold odor mixture consisting of six masking agents demonstrated a substantial decrease in IVA recognition, with a reduction of 96%.PMID:37956399 | DOI:10.1093/chemse/bjad047
Source: Chemical Senses - Category: Biochemistry Authors: Source Type: research