Graduate Institute of Food Science and Technology, National Taiwan University, Taipei 10672, Taiwan.
J Agric Food Chem. 2012 Oct 24;60(42):10696-701. doi: 10.1021/jf3032342. Epub 2012 Oct 11.
Ascorbic acid occurs naturally in many wine-making fruits. The industry also uses ascorbic acid as an antioxidant and color stabilizer in the making of alcoholic beverages including white wine, wine cooler, alcopop, and fruit liqueur. However, the degradation of ascorbic acid itself may cause browning and the deterioration of color quality. This study was aimed to monitor the degradation of ascorbic acid, the formation of degradation products, and the browning in storage of ascorbic acid containing 0-40% (v/v) ethanolic solutions buffered at pH 3.2 as models of alcoholic beverages. The results show that ascorbic acid degradation in the ethanolic solutions during storage follows first-order reaction, that the degradation and browning rates increase with the increase of ethanol concentration, that the activation energy for the degradation of ascorbic acid is in the range 10.35-23.10 (kcal/mol), that 3-hydroxy-2-pyrone is an indicator and a major product of ascorbic acid degradation, and that aerobic degradation pathway dominants over anaerobic pathway in ascorbic acid degradation in ethanolic solutions.
抗坏血酸在许多酿酒水果中天然存在。工业上也使用抗坏血酸作为抗氧化剂和颜色稳定剂，用于制造包括白葡萄酒、酒精度数较低的葡萄酒、酒精饮料、水果利口酒等酒精饮料。然而，抗坏血酸本身的降解可能会导致褐变和颜色质量恶化。本研究旨在监测含 0-40%（v/v）乙醇溶液中抗坏血酸的降解、降解产物的形成以及在 pH 3.2 缓冲的储存过程中的褐变，这些溶液作为酒精饮料的模型。结果表明，储存过程中乙醇溶液中抗坏血酸的降解遵循一级反应，降解和褐变速率随乙醇浓度的增加而增加，抗坏血酸降解的活化能在 10.35-23.10（kcal/mol）范围内，3-羟基-2-吡喃酮是抗坏血酸降解的指示剂和主要产物，并且在乙醇溶液中抗坏血酸的降解中，有氧降解途径占主导地位，而无氧途径则处于次要地位。
