RESUMEN
Sweet fortified wines, traditionally aged under strong oxidation conditions, have a characteristic aroma. An experimental study investigated the aging of white sweet fortified wines under various conditions. The development of various molecules, previously identified as characteristic of the aroma of this type of wine, was monitored by analysis. The development of these compounds during accelerated aging was affected by oxidation and the color of the wine. Aging in oak containers, variable storage temperatures, and variable modes of oxidation affect the formation of many of the volatile compounds responsible for the aging aroma of vins doux naturels (fortified wines). Furfural (1), 5-ethoxymethylfurfural (2), and sotolon (3) always reach concentrations above their perception thresholds in wood-aged wines, especially when new oak is used. The isomers of methyl-gamma-octalactone (4 and 5) are reliable indicators of aging in oak. Among the many identifiable volatile phenols, only the vanillin (7) content increases with aging, particularly if the container is made of wood and there is a high degree of oxidation. This molecule frequently reaches and even exceeds its perception threshold. We show here that vanillin and isomers of methyl-gamma-octalactone have a major impact on the aromas of fortified wines.
Asunto(s)
Manipulación de Alimentos , Odorantes , Vino/análisis , Benzaldehídos/análisis , Color , Eugenol/análisis , Furaldehído/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Fenoles/análisisRESUMEN
Sweet fortified wines, traditionally aged under strong oxidation conditions, have a characteristic aroma. An experimental laboratory study investigated the aging of red and white sweet fortified wines under various conditions. The formation of various molecules, previously identified as characteristic of the aroma of this type of wine, was monitored by analysis. The development 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 concentrations above the perception threshold, in both red and white wines. Buildup 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 aroma of sweet fortified white wines aged in oxygen-free conditions. The substances most characteristic of accelerated aging of sweet fortified red wines were 5-(hydroxymethyl)furfural, acetylformoin, and hydroxymaltol, the formation of which is affected by oxidation, and dihydromaltol, formed in the absence of oxidation.
Asunto(s)
Furanos/síntesis química , Vino , Oxidación-Reducción , VolatilizaciónRESUMEN
Toasting changes both the quantity and the quality of the extractable substances in the oak wood of barrels used for the aging of fine wines and spirits. Mastery and repeatability of toasting are vital in the production of quality barrels to be used for the aging of wines and spirits. In this study, we show that it is possible for a given cooperage to differentiate barrel toasting levels by analyzing a certain number of volatile and semivolatile compounds resulting from the thermal degradation of oak. Toasted wood components, which can be extracted by the wines or spirits during the aging process, are normally analyzed after the wood has soaked in standard alcoholic solutions and can be used to control the intensity of the wood toasting. The results of the comparative analysis presented in this work show that headspace analysis with a microextractive method using a stationary polydimethylsiloxane type phase is a promising technique for analyzing toasted oak wood from barrels. It is easier to use than the traditional maceration and extraction method and provides similar information.
Asunto(s)
Conservación de Alimentos , Aceites Volátiles/análisis , Vino/normas , Madera , Cromatografía de Gases , Calor , Humanos , VolatilizaciónRESUMEN
Toasting wood to be used in barrels for aging wine produces a great number of volatile and odiferous compounds. Three new volatile odorous compounds in toasted oak were identified. Analysis by high-performance gas chromatography of toasted oak extracts, combined with olfactory detection, enabled various chromatographic peaks with these specific aromas to be isolated. These same odors were simultaneously studied by heating glucose both with and without proline and phenylalanine. Aromatic compounds of interest were identified thanks to a combination of gas chromatography and both mass and infrared spectrometry. An analysis RMN was also used. Hydroxymaltol, 2,5-furanedicarbaldehyde, and furylhydroxymethyl ketone have been detected in extract of toasted oak wood. These molecules may be formed by direct pyrolysis of sugar or Maillard reactions. The acetylformoine was not detected in extract of toasted oak wood, whereas it was detected in heated extracts of various sugars and sugars mixtures with amino acids.