The purpose of the master's thesis was to preserve the genetic potential for mixed starter culture of apple wine and to determine the effect of the non-Saccharomyces yeast Kregervanrija fluxuum on the physico-chemical and sensory properties of apple wine by micro-fermentations in sterile apple juice. In the microbiological part of the study, yeast and bacteria from eleven spontaneous fermentations of wines from the Koroška region were revitalized in selective solid media. Using the PCR method, we amplified and sequenced the variable part of the ribosomal gene of yeasts and bacteria. Altogether, 71 strains of yeasts and 18 strains of bacteria autochthonous to Koroška region were preserved in the Collection of Industrial Microorganisms. In the second part of the study we followed apple juice microfermentation of mono- and co-cultures of Kregervanrija fluxuum, Saccharomyces uvarum, Dekkera bruxellensis and Oenococcus oeni by detemining cell concentrations of each culture and by the gravimetric method. K. fluxuum reached the stationary phase after 24 hours of fermentation. In the case of a pure culture, its number increased slightly during the entire fermentation of apple juice. In mixed starter culture, immediately after the stationary phase was reached, the number of cells began to decrease and at the end of the fermentation was not detected only in the absence of D. bruxellensis was present throughout the fermentation. Therefore, after completion of the fermentation, physico-chemical parameters of ciders were determined by WineScan and a sensory analysis was conducted. The results showed that during the fermentation of ciders K. fluxuum did not form alcohol, but it contributed to a greater formation of glycerol.
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