Laboratory for Aroma Analysis and Enology, Department of Analytical Chemistry, Faculty of Sciences, Instituto Agroalimentario de Aragón (IA2-Unizar-CITA), Universidad de Zaragoza, 50009 Zaragoza, Spain.
Molecules. 2022 May 10;27(10):3056. doi: 10.3390/molecules27103056.
Strecker aldehydes (SA) can be formed in wine from the degradation of Strecker and, to a lesser degree, via the oxidation of higher alcohols. The objective of this article is to assess the magnitude of the differences introduced by wine compositional factors other than amino acids and Fe, in the accumulation of SA during oxidation. Eight red, two rosé and two white wines were oxidized. The accumulation of SA was analyzed. Whites and rosés presented negative accumulations for isobutyraldehyde, and in general, these wines accumulated smaller concentrations of the other SA than red wines. Only methional and phenylacetaldehyde were accumulated in all of the wines during oxidation. 2-methylbutanal and 3-methylbutanal were accumulated in 9 out of the 12 wines, whereas isobutyraldehyde was accumulated only in 5 out of the 12. 2-methylbutanal was, on average, the least accumulated aldehyde. Methional was the aldehyde formed most homogenously. Most of the observed differences can be attributed to three factors: the pH, oxidation time and native levels of Strecker aldehydes. The influence of pH was particularly intense in the cases of phenylacetaldehyde and methional. An independent test using synthetic wines with Strecker amino acids and 4-methylcatechol with different pHs (4.2, 3.5 and 2.8) was carried out in order to verify the higher pH value, the greater accumulation in SA after oxidation process. The results strongly suggest the important role played by pH in the accumulation of SA in wine oxidation.
斯特雷克醛（SA）可以在葡萄酒中由斯特雷克降解形成，在一定程度上也可以通过高级醇的氧化形成。本文的目的是评估除氨基酸和铁以外的葡萄酒成分因素对 SA 在氧化过程中积累的差异程度。对 8 款红葡萄酒、2 款桃红葡萄酒和 2 款白葡萄酒进行了氧化处理。分析了 SA 的积累情况。白葡萄酒和桃红葡萄酒的异丁醛出现负积累，一般来说，与红葡萄酒相比，这些葡萄酒积累的其他 SA 浓度较小。在氧化过程中，只有甲硫醛和苯乙醛在所有葡萄酒中都有积累。除了异丁醛外，2-甲基丁醛和 3-甲基丁醛在 12 款葡萄酒中的 9 款中都有积累，而只有 5 款葡萄酒中有异丁醛积累。2-甲基丁醛是平均积累最少的醛。甲硫醛是形成最均匀的醛。大多数观察到的差异可以归因于三个因素：pH 值、氧化时间和斯特雷克醛的天然水平。pH 值对苯乙醛和甲硫醛的影响尤其强烈。为了验证较高的 pH 值会导致氧化后 SA 积累增加，进行了使用含有斯特雷克氨基酸和不同 pH 值（4.2、3.5 和 2.8）的 4-甲基儿茶酚的合成葡萄酒的独立测试。结果强烈表明 pH 值在葡萄酒氧化过程中 SA 积累中起重要作用。
