Laboratory for Aroma Analysis and Enology, Aragón Institute of Engineering Research (I3A), Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, Zaragoza, Spain.
J Agric Food Chem. 2009 Aug 26;57(16):7490-8. doi: 10.1021/jf9006483.
The aroma compositions of 25 premium Spanish red wines have been screened by quantitative gas chromatography-olfactometry and have been related to the quality scores of the wines. The study has shown that up to 65 odorants can be present in the aroma profiles of those wines, 32 of which have been detected in less than half of the samples. One new odorant is reported for the first time in wine [(Z)-2-nonenal], and only 11 odorants, most of them weak and infrequent, remain unknown. Quality was not positively correlated with any single compound or with any olfactometric vector built by the summation of odorants with similar odors. However, an olfactometric vector built by the summation of the olfactometric scores of defective odorants, such as 2-methoxy-3,5-dimethylpyrazine, 4-ethylphenol, 3-ethylphenol, 2,4,6-trichloroanisole, and o-cresol was significant and negatively related to quality. Quality could be satisfactorily explained by a simple partial least-squares model (79% explained variance in cross-validation) with just three X-variables: the aforementioned defective vector, a second vector grouping 9 other compounds with negative aroma nuances, and the fruity vector, grouping 15 compounds with fruit-sweet descriptors. This result shows that the quality of these red wines is primarily related to the presence of defective or negative odorants, and secondarily to the presence of a relatively large number of fruit-sweet odorants. Remarkably, only in a few low-quality samples could defective aroma nuances be detected, which suggests that defective and negative odorants exert a strong aroma suppression effect on fruity aroma.
25 款优质西班牙红葡萄酒的香气成分已通过定量气相色谱-嗅觉测量法进行了筛选，并与葡萄酒的质量评分相关联。研究表明，这些葡萄酒的香气特征中可能存在多达 65 种气味物质，其中 32 种气味物质在不到一半的样本中被检测到。有一种新的气味物质首次在葡萄酒中被报道[(Z)-2-壬烯]，只有 11 种气味物质，其中大部分较弱且不常见，仍然未知。质量与任何单一化合物或任何通过将具有相似气味的气味物质相加而构建的嗅觉向量都没有正相关。然而，由缺陷气味物质（如 2-甲氧基-3,5-二甲基吡嗪、4-乙基苯酚、3-乙基苯酚、2,4,6-三氯苯甲醚和邻甲酚）的嗅觉评分相加构建的嗅觉向量与质量显著负相关。通过一个简单的偏最小二乘模型（交叉验证中 79%的解释方差）可以很好地解释质量，该模型仅使用三个 X 变量：上述缺陷向量、第二向量，该向量将 9 种具有负香气细微差别的其他化合物分组，以及水果味向量，将 15 种具有水果甜味描述符的化合物分组。结果表明，这些红葡萄酒的质量主要与缺陷或负气味物质的存在有关，其次与大量具有水果甜味的气味物质的存在有关。值得注意的是，只有在少数低质量的样品中才能检测到缺陷的香气细微差别，这表明缺陷和负气味物质对水果香气有强烈的抑制作用。
