Volatile components of Zalema white wines

Abstract

The volatile composition of young white wines from Vitis vinifera cv. Zalema, an autochthonous grape variety in Huelva (southern Spain), has been studied by gas chromatography-olfactometry (GC-O) and techniques of quantitative analysis. This is the first time that an olfactometric analysis has been reported in wines made from this grape variety. The quantitative chemical study has shown 71 volatile compounds, of which 23 were in concentrations above their thresholds. On the basis of the odour activity values (OAVs), the most potent odorants were fermentative compounds, mainly fatty acids and their ethyl esters. Two norisoprenoids, β-damascenone and β-ionone, two alcohols (isoamyl alcohol and β-phenylethanol), three volatile thiols, 4-mercapto-4-methyl-2-pentanone, 3-mercaptohexyl acetate and 3-mercapto-1-hexanol, and two carbonyl compounds (acetaldehyde and phenylacetaldehyde) also exhibited OAVs > 1. The GC-O study corroborated these results, showing that five esters (isoamyl acetate, ethyl hexanoate, ethyl butyrate, ethyl isovalerate and ethyl octanoate), isoamyl alcohol and β-damascenone can be considered as the most powerful odorants of Zalema wines.