# Evaluation of Probiotic _Saccharomyces boulardii_ Yeast as a Distillery Strain
## 3 Results and Discussion
### HPLC Analysis of Fermented Media
#### 3.2.4 Results of GC Analysis of Molasses Worts and Rye Mashes After Fermentation  
Tables 7 and 8 present selected results of GC analysis of fermented molasses worts and rye mash, crucial for evaluating the distillery potency of _S. boulardii_ yeast. A full set of analysis results is included in the Supplementary Materials. The results of the two-factor analysis of variance (ANOVA) show that both extract content and yeast breed had a significant effect on the concentration of volatile compounds in the attenuated molasses word, with a relationship for the second independent variable tested, i.e., extract content, for only 6 of the 31 compounds determined. In addition, the  
\begin{table}
\begin{tabular}{c c c} \hline \multirow{2}{*}{**Compound**} & \multicolumn{2}{c}{**Yeast**} \\ \cline{2-3}  & **SB** & **ER** & **TD** \\ \hline Maltotriose & 0.75 \(\pm\) 0.01 1  & 0.78 \(\pm\) 0.04 2  & 0.88 \(\pm\) 0.05 3  \\ \hline Maltose & 0.64 \(\pm\) 0.005 4  & 0.58 \(\pm\) 0.05 5  \\ \hline Clitric acid & 0.84 \(\pm\) 0.001 5  & 0.71 \(\pm\) 0.2  & 0.93 \(\pm\) 0.01 6  \\ \hline Glucose & 0.17 \(\pm\) 0.007 7  & 0.11 \(\pm\) 0.007 8  \\ \hline Xylose & 1.32 \(\pm\) 0.02 9  & 1.04 \(\pm\) 0.02  & 1.38 \(\pm\) 0.03  \\ \hline Arabinose & 0.13 \(\pm\) 0.01 1  & 0.15 \(\pm\) 0.002  & 0.17 \(\pm\) 0.05  \\ \hline Succinic acid & 1.68 \(\pm\) 0.002 1  & 1.87 \(\pm\) 0.03  & 1.92 \(\pm\) 0.1 1  \\ \hline Glycerol & 9.94 \(\pm\) 0.006  & 11.73 \(\pm\) 0.23  & 10.8 \(\pm\) 0.04  \\ \hline Acetic acid & 0.13 \(\pm\) 0.0001 2  & 0.34 \(\pm\) 0.0001  & 0.13 \(\pm\) 0.001  \\ \hline Propylene glycol & 0.04 \(\pm\) 0.003 3 [FOOTNO  
interaction between the studied variables proved significant for most of the determined compounds. The results of variance analysis gave rise to [PERSON]'s multiple comparisons test to show which groups differed significantly from each other. The results of the quantitative analysis of volatile compounds and the results of the statistical analysis are presented in Table 7. Over half of the identified compounds were esters, mainly ethyl esters of acetic acid and higher fatty acids. Quantitatively, on the other hand, the highest concentrations were higher alcohols, whose total concentration exceeded that of esters by up to 10 times and ranged from 145.8 mg/L (SB yeast, 10% (\(w/w\)) extract) to 405.6 mg/L (TD yeast, 10% (\(w/w\)) extract). A higher extract content of 17% (\(w/w\)) led to higher concentrations of volatile compounds, compared to a lower extract content of 10% (\(w/w\)), but this relationship only applied to selected compounds and depended on the yeast strain used for fermentation. When analysing the total ester content, which ranged from 14.7 to 48.7 mg/L, the effect of the higher extract on the increase in ester concentration was evident for SB and TD yeast and concerned the ethyl esters of formic, acetic, butyric, isobutyric, and valeric acids. In contrast, an inverse relationship could be observed for the other esters, where higher concentrations of 3-methylbutyl acetate, 2-methylbutyl acetate, 2-phenylethyl acetate, and ethyl octanoate were recorded in the lower-extract molasses sort fermented by SB yeast. Also, the quantitative profile of volatile compounds in words fermented by ER yeast showed variation according to extract content, with smaller differences than for SB and TD yeasts. Of the 30 compounds determined in these samples, only 8 compounds were different, namely, 3-methylbutanal, propyl acetate, 1,1-diethyloxyethane, ethyl butyrate, ethyl isobutyrate, 2-ethylhexanol, phenylacetaldehyde, and ethyl nonanoate. No statistically significant differences were found for the remaining compounds. Of the higher alcohols determined, amyl alcohols, i.e., 3-methyl-1-butanol and 2-methyl-1-butanol, had the highest proportion (60.70-72.10%), while 2-methyl-1-propanol and 2-phenylethylanol accounted for 19.20-24.67% and 7.35-14.82%, respectively. TD yeast showed a high aptitude for synthesising higher alcohols.