UMR PAM Université de Bourgogne Franche-Comté/Institut Agro Dijon, Institut Universitaire de la Vigne et du Vin, Jules Guyot, 21000Dijon, France.
Research and Innovation Centre, Fondazione Edmund Mach, 38010San Michele all'Adige, Italy.
J Agric Food Chem. 2024 Jan 31;72(4):1885-1893. doi: 10.1021/acs.jafc.2c06690. Epub 2023 Feb 1.
Bisulfite (HSO) is the predominant form of sulfur dioxide, present as free and bound to wine relevant electrophiles under wine acidic pH. While sulfonation reactions of flavanols and thiols have been recently reported as key for wine preservation against oxidation, the transient mechanisms and physicochemical parameters responsible for that remain unknown. In the present study, sulfonation reaction kinetics of thiols and flavanols were monitored under simulated wine aging conditions. The reaction products were then characterized by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, and their chemical stability during time was determined by H NMR spectroscopy. Thiol and flavanol sulfonation reaction yields were both promoted by the presence of iron and oxygen, while their chemical stability was confirmed under the same conditions. The sulfonation derivatives of epicatechin and cysteine were synthesized and quantified in young and aged wines. Higher concentrations were reported for both metabolites in older wines, indicating their participation on the strongly bound sulfur dioxide fraction. These findings offer new prospects for more precise use of sulfur dioxide in winemaking.
亚硫酸氢盐（HSO）是二氧化硫的主要形式，在葡萄酒的酸性 pH 值下，以游离态和结合态存在于与葡萄酒相关的亲电试剂中。虽然黄酮醇和硫醇的磺化反应最近被报道为防止葡萄酒氧化的关键，但仍不清楚导致这种反应的瞬态机制和物理化学参数。在本研究中，在模拟葡萄酒陈酿条件下监测了硫醇和黄酮醇的磺化反应动力学。然后通过液相色谱-串联质谱（LC-MS/MS）分析对反应产物进行了表征，并通过 H NMR 光谱法确定了其在时间过程中的化学稳定性。铁和氧的存在均促进了硫醇和黄酮醇的磺化反应产率，而在相同条件下，其化学稳定性也得到了证实。儿茶素和半胱氨酸的磺化衍生物在年轻和陈酿葡萄酒中被合成并定量。在陈酿葡萄酒中，这两种代谢物的浓度都更高，表明它们参与了与强结合态二氧化硫有关的部分。这些发现为更精确地在酿酒过程中使用二氧化硫提供了新的前景。
