Influence du bois sur certaines substances odorantes des vins

Abstract

<p style="text-align: justify;">L'élevage des vins en barriques modifie profondément leur expression aromatique.</p><p style="text-align: justify;">L'étude par chromatographie en phase gazeuse et spectrométrie de masse permet d'identifier plusieurs substances volatiles appartenant à la fraction phénolique des arômes.</p><p style="text-align: justify;">Les vins rouges présentent naturellement une composition complexe en phénols volatils alors que celle des vins blancs est plus simple. L'élevage sous bois entraîne une augmentation notable des phénols déjà présents ainsi que l'apparition de molécules spécifiques au bois dechêne brûlé.</p><p style="text-align: justify;">L'interaction des levures et des bactéries avec le bois est mise en évidence.</p><p style="text-align: justify;">Les vins rouges se caractérisent par une présence parfois abondante d'éthyl phénols, les vins blancs qui ne subissent pas la fermentation malolactique s'en différencient par l'abondancede vinyl phénols.</p><p style="text-align: justify;">L'étude sensorielle de chaque substance permet de démontrer le rôle négligeable de certaines : furfural, méthyl-5-furfural, alcool furfurylique et le rôle exceptionnel joué par d'autres : cis et trans β-méthyl-γ-octalactone, vanilline et dans certains cas éthyl-4-phénol et éthyl-4-gaïacol.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">Wood storage of wines changes profondly their aromatic expression.</p><p style="text-align: justify;">Several volatile substances from wines and oak woods phenolic fraction of aroma are identified by gas chromatography and mass spectrometry. Wood storage increases natural phenols concentration. Simultaneously specific burned wood molecules appear.</p><p style="text-align: justify;">Yeast and bacterial interaction with wood is demonstrated. Ethyl phenols are characteristic of red wines and vinyl phenols of white wines without malolactic fermentation.</p><p style="text-align: justify;">The sensorial analysis of each substance demonstrates the negligible intervention in wine aroma of furfural, 5-methyl-furfural, and furfuryl alcohol, and the important participation of cis and trans β-methyl-γ-octalactone, vanilin 4-ethyl-phenol and 4-ethyl gaïacol.</p>

A Case Study of Selected Volatile Phenols from Brettanomyces and Micronutrients Mn, Fe, Cu, Zn in Chianti Red Wines

“…A report relevant to red Bordeaux wines and published some two decades ago claimed that the aggregate detection threshold of ethylphenols or perception limit (PL) was 426 μg L -1 (Chatonnet, 1992) by employing a panel of twenty tasters that followed a procedure previously constructed by the same laboratory (Boidron, 1988). The two ethylphenols are mostly produced by the yeast Brettanomyces/Dekkera bruxellensis (Dias, 2003).…”

Effect of smoke application to field-grown Merlot grapevines at key phenological growth stages on wine sensory and chemical properties

“…Smoke and liquid smoke flavourings utilised in food processing have been shown to contain compounds including carbonyls, aldehydes, lactones, ketones, furans, pyrans and phenols (Maga 1988a, Guillén et al 1995, Guillén and Manzanos 1996. The volatile phenols guaiacol and 4-methylguaiacol, which derive from the thermal degradation of lignin, are present in smoke and have been reported to exhibit 'smoky', 'phenolic', 'sharp', 'smoked meat' and 'burning' aromas and flavours (Baltes et al 1981, Boidron et al 1988, Maga 1988a, Rocha et al 2004). Guaiacol and 4-methylguaiacol are routinely detected in wines aged in toasted oak barrels at concentrations up to 100 and 20 mg/L, respectively (Pollnitz et al 2004).…”

Variation des composés volatils du bois dans un peuplement mixte de chênes: forte différenciation interspécifique et forte structuration spatiale de la quantité de whisky-lactone

“…They generally have low aroma thresholds so that their sensorial detection takes place at very low concentration in mature beverages [1,5,8,19]. They are responsible for important olfactory notes such as coconut, woody, vanilla, caramel etc.…”

“…They are responsible for important olfactory notes such as coconut, woody, vanilla, caramel etc. Volatile substances content is strongly affected by natural factors as well as by cooperage techniques: seasoning [5,9,15,16,30,34] and toasting [6,10]. Among the natural factors that have been cited are botanical species and local environment, both of which can affect growth (and hence 'grain' = ring width).…”