Université Bourgogne Franche-Comté, Institut Agro, Université Bourgogne, INRAE, UMR PAM 1517, Institut Universitaire de la Vigne et du Vin - Jules Guyot, 21000 Dijon, France.
NMR Laboratory, Department of Chemistry, University of Crete, P.O. Box 2208, Voutes Campus, 71003 Heraklion, Crete, Greece.
Food Chem. 2024 Aug 15;449:138944. doi: 10.1016/j.foodchem.2024.138944. Epub 2024 Mar 5.
Sulfite addition is a common tool for ensuring wines' oxidative stability via the activity of its free and weakly bound molecular fraction. As a nucleophile, bisulfite forms covalent adducts with wine's most relevant electrophiles, such as carbonyls, polyphenols, and thiols. The equilibrium in these reactions is often represented as dissociation rather than formation. Recent studies from our laboratory demonstrate, first, the acetaldehyde sulfonate dissociation, and second, the chemical stability of cysteine and epicatechin sulfonates under wine aging conditions. Thus, the objective of this study was to monitor by H NMR the binding specificity of known carbonyl-derived SO binders (acetaldehyde and pyruvic acid) in the presence of S-containing compounds (cysteine and glutathione). We report that during simulated wine aging, the sulfur dioxide that is rapidly bound to carbonyl compounds will be released and will bind to cysteine and glutathione, demonstrating the long-term sulfur dioxide binding potential of S-containing compounds. These results are meant to serve as a complement to existing literature reviews focused on molecular markers related to wines' oxidative stability and emphasize once more the importance of S-containing compounds in wine aging chemical mechanisms.
亚硫酸盐的添加是通过其游离和弱结合的分子部分的活性来确保葡萄酒氧化稳定性的常用工具。作为亲核试剂，亚硫酸盐与葡萄酒中最相关的亲电试剂（如羰基化合物、多酚和硫醇）形成共价加合物。这些反应的平衡通常表示为离解而不是形成。我们实验室的最近研究首先证明了乙醛磺酸盐的离解，其次证明了半胱氨酸和表儿茶素磺酸盐在葡萄酒陈酿条件下的化学稳定性。因此，本研究的目的是通过 H NMR 监测已知羰基衍生的 SO 结合物（乙醛和丙酮酸）在含硫化合物（半胱氨酸和谷胱甘肽）存在下的结合特异性。我们报告说，在模拟葡萄酒陈酿过程中，迅速与羰基化合物结合的二氧化硫将被释放出来，并与半胱氨酸和谷胱甘肽结合，这表明含硫化合物具有长期的二氧化硫结合潜力。这些结果旨在作为对现有文献综述的补充，这些综述侧重于与葡萄酒氧化稳定性相关的分子标记，并再次强调含硫化合物在葡萄酒陈酿化学机制中的重要性。
