title: Degradation of ascorbic acid in ethanolic solutions.
abstract: 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.
authors.affiliation: Graduate Institute of Food Science and Technology, National Taiwan University, Taipei 10672, Taiwan.
authors.forename: Hsin-Yun
authors.initials: HY
authors.lastname: Hsu
authors.forename: Yi-Chin
authors.initials: YC
authors.lastname: Tsai
authors.forename: Chi-Chang
authors.initials: CC
authors.lastname: Fu
authors.forename: James Swi-Bea
authors.initials: JS
authors.lastname: Wu
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry*; D007700:Kinetics; D012996:Solutions
chemical_list: D012996:Solutions; D000431:Ethanol; D001205:Ascorbic Acid