Introduction

It has been challenging to select the best method to extract and analyze aroma-active compounds in wine due to high concentration of alcohols in the sample. The objectives of this study were to investigate the applicability of a LiChrolut-EN-based solid-phase extraction (SPE) for wine aroma extraction and to characterize the aroma-active compounds in Merlot wine.

Methods

Volatile compounds in a Merlot wine were extracted with Lichrolut-EN SPE or liquid-liquid extraction (LLE) followed by solvent-assisted flavor evaporation (SAFE). Both extracts were used for aroma extract dilution analysis (AEDA). Selected aroma-active compounds were further quantitated and their odor activity values (OAV) were calculated.

Results

Both SPE and LLE extracts can be used for aroma extract dilution analysis. The odorants with high flavor dilution (FD ≥ 64) values in Merlot wine were ethyl 2-methylpropanoate, ethyl butanoate, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, ethyl hexanoate, ethyl octanoate, 3-methylbutyl acetate, 2/3-methyl-1-butanol, 2-phenylethanol, acetic acid, 2-methylpropanoic acid, butanoic acid, 3-methylbutanoic acid, hexanoic acid, β-damascenone, E-whiskeylactone, γ-nonalactone, 3-(methylthio) propanol, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone, sotolon, vanillin, guaiacol, and eugenol. Quantitative analysis and calculated odor activity value (OAV) suggested that ethyl butanoate, ethyl 2-methylbutanoate, ethyl hexanoate, 3-methylbutyl acetate, ethyl octanoate, ethyl acetate, 2/3-methyl-1-butanol, butanoic acid, 3-methylbutanoic acid, hexanoic acid, β-damascenone, and acetaldehyde could be the major contributors (OAV ≥ 5) to Merlot wine aroma.

Conclusions

Lichrolut-EN SPE was generally comparable with LLE to obtain wine aroma compounds. SPE extract had higher flavor dilution values for esters, and lower for acids and some alcohols than LLE, which is advantageous to study aroma-active compounds in alcoholic beverages due to less interferences from alcohol and acid and improved chromatography. This study confirmed the applicability of LiChrolut-EN SPE as an alternative extraction method for wine aroma characterization to improve laboratory efficiency and minimize the usage of organic solvent.

中文翻译：

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基于LiChrolut-EN的香气提取物稀释分析和气味活度值的美乐葡萄酒中香气化合物的比较表征

介绍

由于样品中酒精含量高，因此选择最佳的方法来提取和分析葡萄酒中的香气活性化合物一直是一项挑战。这项研究的目的是研究基于LiChrolut-EN的固相萃取（SPE）在葡萄酒香气提取中的适用性，以及表征梅乐葡萄酒中的香气活性化合物。

方法

使用Lichrolut-EN SPE或液-液萃取（LLE）萃取梅洛葡萄酒中的挥发性化合物，然后进行溶剂辅助风味蒸发（SAFE）。两种提取物均用于香气提取物稀释分析（AEDA）。进一步对选定的芳香活性化合物进行定量，并计算其气味活性值（OAV）。

结果

SPE和LLE提取物均可用于香气提取物稀释分析。梅乐葡萄酒中具有较高风味稀释度（FD≥64）的气味剂是2-甲基丙酸乙酯，丁酸乙酯，2-甲基丁酸乙酯，3-甲基丁酸乙酯，己酸乙酯，辛酸乙酯，乙酸3-甲基丁酯，2 / 3-甲基-1-丁醇，2-苯基乙醇，乙酸，2-甲基丙酸，丁酸，3-甲基丁酸，己酸，β-大马酮，ê -whiskeylactone，γ-壬内酯，3-（甲硫基）丙醇，4-羟基-2,5-二甲基-3（2 H）-呋喃酮，2-乙基-4-羟基-5-甲基-3（2 H呋喃酮，香,、香兰素，愈创木酚和丁子香酚。定量分析和计算得出的气味活性值（OAV）表明，丁酸乙酯，2-甲基丁酸乙酯，己酸乙酯，乙酸3-甲基丁酯，辛酸乙酯，乙酸乙酯，2 / 3-甲基-1-丁醇，丁酸，3-甲基丁酸酸，己酸，β-大马烯酮和乙醛可能是美乐葡萄酒香气的主要贡献者（OAV≥5）。

结论

Lichrolut-EN SPE通常可与LLE媲美，以获得葡萄酒香气化合物。与LLE相比，SPE提取物的酯类香精稀释值更高，酸和某些醇类的香精稀释值更低，这对研究酒精饮料中的香气活性化合物具有优势，因为其对酒精和酸的干扰较少，并且色谱性能得到了改善。这项研究证实了LiChrolut-EN SPE作为葡萄酒香气表征的另一种提取方法的适用性，以提高实验室效率并最大程度地减少有机溶剂的使用。