National Wine and Grape Industry Centre, Charles Sturt University, Locked Bag 588, Wagga Wagga 2678, Australia.
J Agric Food Chem. 2010 Jan 27;58(2):1004-11. doi: 10.1021/jf903233x.
The stereochemical influence of antioxidant and flavanol compounds on oxidation processes in a model wine system was studied. The diastereoisomers, ascorbic acid and erythorbic acid, were used as antioxidants in a model wine system containing either (+)-catechin or (-)-epicatechin as the oxidizable flavanol compound. Samples were stored at 45 degrees C for a period of 14 days and analyzed by UV/visible spectrometry, CIELab, UPLC-PDA, and LC-MS. The results showed that less brown oxidative coloration occurred for samples with erythorbic acid for a given flavanol compound, while (+)-catechin provided less yellow coloration for a given antioxidant. Although erythorbic acid was degraded faster than ascorbic acid, it was associated with less decay in the accompanying flavanol compound. Xanthylium cation pigments were identified as the major contributor to color development. Furthermore, the production of pigment precursors, previously identified as furanone-substituted flavanols, was confirmed in all cases and their corresponding xanthylium cation pigments were lower in the presence of erythorbic acid than ascorbic acid. The results demonstrate that erythorbic acid is more efficient at minimizing oxidative color development than ascorbic acid in the model wine system.
研究了抗氧化剂和黄烷醇化合物的立体化学影响对模型酒系统中氧化过程的影响。在含有（+）-儿茶素或（-）-表儿茶素作为可氧化黄烷醇化合物的模型酒系统中，使用抗坏血酸和异抗坏血酸作为抗氧化剂。将样品在 45°C 下储存 14 天，并通过 UV/可见光谱法、CIELab、UPLC-PDA 和 LC-MS 进行分析。结果表明，对于给定的黄烷醇化合物，含异抗坏血酸的样品发生的棕色氧化着色较少，而对于给定的抗氧化剂，（+）-儿茶素产生的黄色较少。尽管异抗坏血酸的降解速度快于抗坏血酸，但它与伴随的黄烷醇化合物的降解较少有关。黄嘌呤阳离子色素被确定为显色的主要贡献者。此外，在所有情况下都确认了先前鉴定为呋喃酮取代的黄烷醇的色素前体的产生，并且在异抗坏血酸存在下，它们相应的黄嘌呤阳离子色素低于抗坏血酸。结果表明，在模型酒系统中，异抗坏血酸比抗坏血酸更有效地最小化氧化显色。
