The olfactory masking effect of ethylphenols: Characterization and elucidation of its origin

- Investigation of the masking effect of ethylphenols.
- Use of several psychophysical tests.
- The ethylphenols had a masking effect on wine fruity notes.
- Importance of the central locus in perceiving this masking effect.

To date, most of the sensory studies concerning off-flavors focus on their detection or rejection thresholds. However, both supra and sub-threshold concentrations of off-flavor components may change the perception of odorous mixtures. In this context, the aim of this study was to determine the impact of infra- and supra-threshold concentrations of a wine defect, “Bretty” character (ethylphenols), on the wine fruity note. Techniques used included sensory analysis (odor profiling), psychophysical tests (threshold measurements), and chemical analyses (GCMS). The sensory test panels consisted of wine experts. The results showed that both sub- and supraliminal concentrations of off-flavors could interfere with the perception of fruity notes. In addition, the findings revealed that this wine defect not only changes the hedonic valence of the perception, but also has a masking effect on fruity notes, even at subliminal concentrations. The final experiment demonstrated that the interaction between the perception of ethylphenols and ethyl heptanoate takes place at a central locus in the olfactory system.