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 R- and 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 2-hydroxy-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.

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2-羟基-3-甲基丁酸乙酯对映体：葡萄酒中的定量和感官评估

目的：研究葡萄酒中2-羟基-3-甲基丁酸乙酯的化学和感官特性。方法和结果：2-羟基-3-甲基丁酸乙酯最近被鉴定为乳酸菌酯酶活性的潜在标志物。使用手性气相色谱法（γ-环糊精相）在来自不同年份和法国地区的99种葡萄酒中对这种水果酯的对映体进行了定量。分析表明，R和对映异构体主要存在于红葡萄酒和白葡萄酒中，在1993年的红酒中，最大R / S对映体比率为94/6。结果还表明，取决于葡萄的来源，红色葡萄酒中的酯含量要高于白葡萄酒。水中R-型和S-型的检测阈值分别为4 µg / L和1.5 µg / L，在红酒中为51 mg / L和21 mg / L。而且，用葡萄酒中的水平进行的分级测试未显示明显的感官差异。结论：葡萄酒中的浓度大大低于检测阈值，表明这些化合物对水果香气的调制没有直接作用。感官测试中没有显着差异表明，2-羟基-3-甲基丁酸乙酯对红酒的果香没有明显贡献。研究的意义和影响：据我们所知，以前没有研究确定该化合物在葡萄酒中的对映体分布和感官特性。感官测试中没有显着差异表明，2-羟基-3-甲基丁酸乙酯对红酒的果香没有明显贡献。研究的意义和影响：据我们所知，以前没有研究确定该化合物在葡萄酒中的对映体分布和感官特性。感官测试中没有显着差异表明，2-羟基-3-甲基丁酸乙酯对红酒的果香没有明显贡献。研究的意义和影响：据我们所知，以前没有研究确定该化合物在葡萄酒中的对映体分布和感官特性。