<?xml version='1.0' encoding='UTF-8'?><xml><records><record><source-app name="HighWire" version="7.x">Drupal-HighWire</source-app><ref-type name="Journal Article">17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wildenradt, H. L.</style></author><author><style face="normal" font="default" size="100%">Singleton, V. L.</style></author></authors><secondary-authors></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">The Production of Aldehydes as a Result of Oxidation of Polyphenolic Compounds and its Relation to Wine Aging</style></title><secondary-title><style face="normal" font="default" size="100%">American Journal of Enology and Viticulture</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1974</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1974-01-01 00:00:00</style></date></pub-dates></dates><pages><style  face="normal" font="default" size="100%">119-126</style></pages><doi><style  face="normal" font="default" size="100%">10.5344/ajev.1974.25.2.119</style></doi><volume><style face="normal" font="default" size="100%">25</style></volume><issue><style face="normal" font="default" size="100%">2</style></issue><abstract><style  face="normal" font="default" size="100%">Evidence is presented showing that oxidation of ethanol to acetaldehyde by direct chemical reaction with air occurs at an appreciable rate in wine only by a coupled autoxidation of certain phenolic substances occurring in the wine. The oxidation of vicinal di- and tri-hydroxyphenols like caffeic acid, catechin, or myricetin in 12% ethanol model wine produced acetaldehyde. Similar reaction in aqueous 1-propanol produced propanal showing that the source of the volatile aldehyde is the wine's alcohol. A mechanism is postulated which appears to be general for autoxidation of phenols, ascorbic acid, melanoidins, reductones, enediols, and related compounds whereby the oxidation of the phenol to a quinone (or ascorbic to dehydroascorbic, etc.) coproduces a strong oxidant, probably hydrogen peroxide, which then can oxidize other substances in the wine such as ethanol. Relevance of these findings to wine storage and aging reactions is discussed.</style></abstract></record></records></xml>