PT  - JOURNAL ARTICLE
AU  - H. L. Wildenradt
AU  - V. L. Singleton
TI  - The Production of Aldehydes as a Result of Oxidation of Polyphenolic Compounds and its Relation to Wine Aging
AID  - 10.5344/ajev.1974.25.2.119
DP  - 1974 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 119--126
VI  - 25
IP  - 2
4099  - http://www.ajevonline.org/content/25/2/119.short
4100  - http://www.ajevonline.org/content/25/2/119.full
SO  - Am J Enol Vitic.1974 Jan 01; 25
AB  - 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.