Vliv řízené mikrooxidace na technologii bílých vín =:The effect of controlled micro-oxygenation on technology of white wines /

The PhD.-dissertation thesis deals with the effect of microoxidation on white wine technology. The varieties ‚Pinot Blanc‘ and ‚Pinot Gris‘ were used for the experiment in 2016 and 2017. Micro-oxygenation was applied in the first third of the fermentation process and during the maturation of wine. The effect of microoxidation on the course of fermentation was monitored. In micro-oxygenated wines, a statistically significant increase in the number of living yeast was observed immediately after the micro-oxygenation treatment, compared to the control experiment. The increase in cell mass was also observed by measuring the consumption of ammoniacal nitrogen and nitrogen contained in the amino acids. The results of the experiment show a higher consumption of ammonia nitrogen in the micro-oxygenated wine. The amino acid content did not change significantly. During the whole fermentation process, the course of antioxidant activity was monitored. There were no statistically significant differences between micro-oxygenated wines and control, in some cases the antioxidant activity of micro-oxygenated wines was significantly higher. This phenomenon can be explained by the formation of new phenolic compounds, such as gallic acid, which in some cases has been confirmed by HPLC results and theoretically higher production of yeast cell wall breakdown intermediates, which are potent antioxidants. An aromatic profile was determined in the resulting wine by GC analysis and sensory evaluation. Results from GC analysis show higher concentrations of higher alcohols and esters. The results of this experiment from the year 2016 have been successfully published in the reviewed periodical Ciencia e Técnica Vitivinícola: Bozena Prusova, Mojmir Baron, Effect of controlled micro-oxygenation on white wine, Ciencia Téc. Vitiv. 33 (1) 78-89 (2018), DOI: 10.1051/ctv/20183301078