Impact of ethanol on odor detection thresholds relevant to No- and Low-Alcohol (NoLo) wines: a combined sensory and computational approach in simplified static hydroalcoholic model wine.

The effect of ethanol on odor detection thresholds (ODTs) in fully and partially dealcoholized (NoLo) wines remains largely unexplored. This study used a combined sensory and thermodynamic approach in simplified static hydroalcoholic wine model systems at 0, 6, and 12 % v/v ethanol with three aroma compounds. Orthonasal ODTs were measured using a 3-AFC ascending method. NRTL-based thermodynamic modeling was used to derive a volatility enhancement factor (VEF), defined as the volatility ratio between ethanol levels, and to estimate headspace concentrations at ODT. ODTs were significantly increased at 6 and 12 % v/v for all compounds, with no difference between these levels. Relative to 0 % v/v, ODT fold increases ranged from 5.7 to 6.1 for rotundone, 4.2-5.9 for isoamyl acetate, and 9.8-10.8 for 2-phenylethanol. VEFs were compound-dependent, being highest for rotundone (VEF12 → 0 = 86.7), intermediate for isoamyl acetate (5.4), and lowest for 2-phenylethanol (3.4). ODT increases were mainly thermodynamically driven for rotundone, whereas perceptual and ethanol masking effects likely dominated for 2-phenylethanol, with isoamyl acetate intermediate. These results indicate that key aroma compounds remain perceptually relevant in NoLo wines despite substantial volatile losses. More broadly, this approach provides a framework for studying aroma behavior in static hydroalcoholic systems.