Fermentation-derived Aroma Compounds in Varietal Young Wines from South Africa

The volatile composition of 925 single cultivar young Sauvignon blanc, Chardonnay, Pinotage, Merlot, Shirazand Cabernet Sauvignon wines of vintages 2005 to 2007, was determined using gas chromatography – flameionisation detection. Compositional data were compared to published data on young wines from South Africa andother countries. South African young wines analysed in this study had a largely similar volatile composition tothat reported in the literature. Significant between-vintage and between-cultivar differences were observed in thevolatile composition of the wines investigated in this study. The concentration ranges of four compounds in redwines, hexanol, propanol, diethyl succinate and ethyl lactate, and four compounds in white wines, 2-phenylethanol,hexanoic acid, isoamyl acetate and propanol, were not influenced by vintage effects. This finding was interpretedas the first indication that typical concentration ranges for some aroma compounds can be established for SouthAfrican young cultivar wines. A trend was observed in the white wines that the alcohols and their respective acetateesters, as well as fatty acids and their ethyl esters, were responsible for the vintage-related effects. Differences involatile composition between Chardonnay and Sauvignon blanc wines could also largely be explained on the samebasis. Classification models were established to discriminate between individual red wine cultivars and between thetwo white wine cultivars and correct classification rates of respectively, 79 % and 85 % were achieved