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Seven indigenous yeast strains of Saccharomyces paradoxus previously isolated and identified using molecular and physiological methods were tested for their fermentation abilities. Chemical analyses of produced wines showed differences compared with the Saccharomyces cerevisiae strain used as a control. The examined S. paradoxus strains showed good fermentation vigour, ethanol tolerance and difference in the fermentation rate. Four of seven analysed S. paradoxus strains (RO66, RO54, RO11 and RO134) metabolised sugar up to 1 g L-1. The total amount of higher alcohol was lower compared with S. cerevisiae wines. Strain RO83 was able to degrade up to 40% malic acid and can be used for biological deacidification. Sensory evaluation of dry and semidry wines underlined good enological properties and positive influence of tested wine strains on final wine quality. All these properties of S. paradoxus strains pointed out the possibility of their application in wine industry. © 2006 Institute of Food Science and Technology Trust Fund

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Commercial sparkling wine production represents a relatively low but important part of the Croatian wine production, especially in the Zagreb county. This study presents the results of volatile aroma compounds profile and organic acid composition of commercial sparkling wine samples from three vine-growing regions in Zagreb county. In total, 174 volatile aroma compounds were identified, separated between their chemical classes (aldehydes, higher alcohols, volatile phenols, terpenes, C13-norisoprenoids, lactones, esters, fatty acids, sulfur compounds, other compounds, other alcohols). Higher alcohols such as phenylethyl and isoamyl alcohol as well as 2-methyl-1-butanol, and esters such as diethyl succinate, ethyl hydrogensuccinate, and ethyl lactate had the strongest impact on the volatile compounds profile of Zagreb county sparkling wine. The presence of diethyl glutarate and diethyl malonate, compounds whose concentrations are influenced by yeast autolysis or caused by chemical esterification during the ageing process, was also noted. The influence of every single volatile aroma compound was evaluated by discriminant analysis using forward stepwise model. The volatile profiles of traditional sparkling wines from Croatia were presented for the first time. It is hoped the results will contribute to better understanding the quality potential and to evaluate possible differences on the bases of detected aroma concentrations and multivariate analysis.