Selected strains of non-Saccharomyces yeasts have a positive effect on winemaking and, in particular, increase of aromatic complexity of the wine. A mixed microbial culture of non-Saccharomyces and S. cerevisiae species is inoculated due to poorer fermentability of non-Saccharomyces species. The objective of this master's thesis was to investigate the role of non-Saccharomyces yeasts in the production of white wines. We were interested in how individual combinations of successive inoculations of non-Saccharomyces and S. cerevisiae species affect the physicochemical properties, hydroxycinnamic acid (HCA) content and aromatic compounds (thiols, esters) of the wines produced. Sauvignon and Malvasia musts were inoculated successively with different species of non-Saccharomyces yeasts (L. thermotolerans BLF LT7, P. kluyveri FrootZen, K. dobzhanskii Re19L, P. guilliermondii ZIM624, Starmerella sp. 126, T. delbrueckii IVV7) and yeasts of the Saccharomyces genus (S. cerevisiae Zymaflore X5, S. uvarum NO608/1, S. cerevisiae Ca39). Fermentation kinetics and reducing sugars content were monitored gravimetrically during alcoholic fermentation. After completion of alcoholic fermentation, physicochemical analyzes were performed and the content of thiols and esters was determined by GC-MS and the content of HCA by HPLC-DAD. We also performed sensory analysis using the discrimination test method by ranking the samples. The mixed yeast cultures had different fermentation kinetics, the ability to release thiols, and the synthesis of esters during alcoholic fermentation was also different. According to the sensory evaluation, the best evaluated wine was produced with the yeast K. dobzhanskii Re19L in the vinification of must of the Sauvignon variety and with T. delbrueckii IVV7 in the Malvasia variety.
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