Study of the formation mechanisms of some volatile compounds during the aging of sweet fortified wines

Sweet fortified wines, traditionally aged under strong oxidation conditions , have a characteristic aroma. An experimental laboratory study investigate d the aging of red and white sweet fortified wines under various conditions . The formation of various molecules, previously identified as characterist ic of the aroma of this type of wine, was monitored by analysis. The develo pment of these compounds during accelerated aging was affected by oxidation and the color of the wine. Among the molecules studied, sotolon [3-hydroxy -4,5-dimethyl-2(5H)-furanone] was one of the few molecules present in conce ntrations above the perception threshold, in both red and white wines. Buil dup was strongly affected by the presence of oxygen in white wine subjected to accelerated aging. (Ethoxymethyl)furfural, formed from 5-(hydroxymethyl )furfural, and furfural, derived from sugars, are also involved in the arom a of sweet fortified white wines aged in oxygen-free conditions. The substa nces most characteristic of accelerated aging of sweet fortified red wines were 5-(hydroxymethyl)furfural, acetylformoin, and hydroxymaltol, the forma tion of which is affected by oxidation, and dihydromaltol, formed in the ab sence of oxidation.