Ethyl 2-hydroxy-3-methylbutanoate enantiomers: quantitation and sensory evaluation in wine

Abstract

Aim:To investigate chemical and sensory characteristics of ethyl 2-hydroxy-3-methylbutanoate in wines. Methods and results:Ethyl 2-hydroxy-3-methylbutanoate has been recently identified as a potential marker of lactic acid bacteria esterase activity. Enantiomers of this fruity ester were quantitated in 99 wines from various vintages and French regions using chiral gas chromatography (γ-cyclodextrin phase). Analyses revealed the predominant presence of the R enantiomer in red and white wines, with a maximum R/S enantiomeric ratio of 94/6 in a 1993 red wine. Results also highlighted greater levels of the ester in red than white wines, depending on grape origin. The detection thresholds of the Rand S-form were estimated at 4 µg/L and 1.5 µg/L in water and 51 mg/L and 21 mg/L in red wine, respectively. Moreover, ranking tests made with levels found in wines did not show significant sensory differences. Conclusion:The concentrations found in wines were considerably below the detection threshold, indicating no direct effect of these compounds on fruity aroma modulation. The absence of significant difference in sensory tests demonstrates that ethyl 2hydroxy-3-methylbutanoate does not contribute significantly to the fruity aroma of red wine.Significance and impact of the study: To our knowledge, no previous research had determined the enantiomeric distribution and the sensory characteristics of this compound in wine.

Distribution and Quantification of Lactic Acid Enantiomers in Baijiu

“…The taste threshold of L-lactic acid was less than that of D-lactic acid, indicating that L-lactic acid is more acidic. This result suggests that the stereochemistry of the molecules has a strong influence on their perception [ 41 , 42 , 43 ].…”

Lignans in Spirits: Chemical Diversity, Quantification, and Sensory Impact of (±)-Lyoniresinol

“…The detection threshold of a compound is the concentration beyond which this molecule is perceived by one half of a panel. In oenology, detection thresholds have been measured, mainly on olfactory compounds, in different matrices such as water, wine, or spirits [29,30,32]. These studies have shown that the nature of the matrix can have a significant impact on the olfactory properties of a compound.…”

“…This enantiomer was quantified in various wines at concentrations higher than this value, demonstrating its contribution to wine bitterness [28]. Yet the sensory properties of a molecule, and in particular its detection threshold, can be strongly influenced by the nature of the matrix from an olfactory or gustatory point of view [29,30,31,32]. Consequently, the contribution of lignans to spirit taste cannot be presumed from the results obtained in wine.…”