C6-alcohols as varietal markers for assessment of wine origin

Abstract

A significant part of the compounds present in wines having six carbon atoms, the C 6 -compounds, derive from grape polyunsaturated fatty acids (primarily originated from membrane lipids), namely linoleic and ␣-linolenic acids, through a cascade of enzymatic reactions. This biochemical pathway yield C 6 -aldehydes, which are subsequently reduced to C 6 -alcohols, which can, in turn, be esterified to produce esters. As the C 6compounds derive from varietal precursors, they could hypothetically contribute to judge wine origin and affiliation. In this way, two C 6 -alcohols, (E)-3-hexenol and (Z)-3-hexenol, have been referred as the most important because its ratio can act as an indicator of the variety of origin.This study presents the results, concerning the concentration of the three main C 6 -alcohols, 1-hexanol, (E)-3-hexenol and (Z)-3-hexenol, as well as ratios between them, for 43 monovarietal wines from Vinhos Verdes demarcated region, belonging to six white -Alvarinho (8), Arinto (1), Avesso (9), Azal (1), Loureiro (17) and Trajadura (4) -and three red -Amaral (1), Borraçal (1) and Vinhão (1) -grape varieties. Wines were produced at experimental scale using slightly different winemaking practices and representing various terroirs and vintages, being analyzed after different conservation periods.The results showed that (E)-3-hexenol/(Z)-3-hexenol ratio clearly discriminates Loureiro wines from those of Alvarinho, Avesso and Trajadura. Moreover, 1-hexanol/(E)-3-hexenol and 1-hexanol/(Z)-3-hexenol ratios may also be able to discriminate Vinhos Verdes monovarietal wines, and can act on a second level differentiation. The remaining monovarietal wines produced results which may be observed as indicative, since only one sample of each was analysed.

Sauvignon Blanc Wine: Contribution of Ageing and Oxygen on Aromatic and Non-aromatic Compounds and Sensory Composition : A Review

“…However, many studies report stable alcohol concentrations during the ageing of wines (Marais, 1978;Roussis et al, 2005;2007;Blake et al, 2009). Unlike other higher alcohols, the concentration of hexanol can increase during storage, which is probably due to the oxidation of linoleic and linolenic acids (Oliveira et al, 2006).…”

Microbiological and chemical monitoring of Marsala base wine obtained by spontaneous fermentation during large-scale production

“…MNbw natural Grillo base wine; MCbw-1 conventional Grillo base wine 1; MCbw-2 conventional Grillo base wine 2. * significant differences among attributes of the wines fermentative phase (pressing and maceration) (Oliveira et al 2003) and might positively affect the organoleptic complexity of wines. As detected in other spontaneously fermented wines, high level of esters, mainly acetate ester, were also observed in our samples.…”

Complementary Effect of Blending on the Volatile Composition of Albariño and Loureira White Wines (Vitis vinifera L.) from NW Spain

“…Wine volatile compounds were analysed by GC-MS according to the method proposed by Oliveira et al (2006).…”

“…Rapp et al (1993) showed that the contents of E-3-hexenol and its isomer Z-3-hexenol are the most important analytical parameters to discriminate monovarietal wines of Riesling, Müller-Thurgau, Kerner, Scheurebe, Ehrenfelser and Bacchus. Oliveira et al (2006) concluded that the E-3-hexenol/Z-3-hexenol ratio could discriminate Loureiro clearly from Alvarinho wines from Northern Portugal.…”