# Effect of Ultrasound on Fermentation of Thick Molasses Worts by Distiller's Yeast
## 3 Results and Discussion
### Wort Analysis
#### 3.2.1 The Influence of Ultrasound Treatment on Sugar Utilisation  
The following table (Table 5) shows the percentage of glucose and fructose utilisation with the concentrations of these sugars before fermentation. The results of using sugars for wort with an initial density of 18 \({}^{\circ}\)Blg (Table 5) show that, regardless of the strain and sonification used, a reduction in glucose concentration of over 99% was observed. As for fructose, the lowest utilisation was observed for the control sample (without sonification) fermented by Thermosacc Dry yeast and was equal to 86.79 \(\pm\) 4.23 g/L. In the case of the other options, for the TD strain and Ethanol Red, more than 92% fructose consumption was observed. The yeast _Saccharomyces cerevisiae_ quickly assimilates both sugars. Hence, the actual consumption degree depends mainly on fermentation duration and possible factors inhibiting yeast metabolisms, such as ethanol concentration, wort density and the content of other metabolites (including organic acids, whose concentration will be discussed later in the article). The initial density of the wort of 18 \({}^{\circ}\)Blg and the sugar concentration of around 120 g/L are certainly not factors limiting the fermentation capacity of the two distiller's yeasts tested, which are also suitable for producing fuel ethanol according to the manufacturer's declaration. As with the 18 \({}^{\circ}\)Blg wort, after 72 h of fermentation, the medium with an initial density of 22 \({}^{\circ}\)Blg showed a glucose utilisation of 96.68 \(\pm\) 2.70% (TD control sample) to 98.82 \(\pm\) 3.35% (for ER u75), and a fructose utilisation of 70.03 \(\pm\) 1.45% (TD control sample) to 87.33 \(\pm\) 3.71% (for ER u75) fructose utilisation. Comparing these series of results with the values after fermentation of wort at 18 \({}^{\circ}\)Blg, it can be seen that some unassimilated sugars remain in the medium after 72 h of fermentation. However, it can be assumed that the lower assimilation of sugars has translated into the efficiency of ethanol formation, which will be discussed later in the article regarding the ethanol production results. While this was not observable for the results of the 18 \({}^{\circ}\)Blg wort trials, in the case of the 22 \({}^{\circ}\)Blg wort, it was observed that the use of ultrasonic treatment significantly \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Extract** & \multicolumn{2}{c}{**18 \({}^{\circ}\)Blg**} & \multicolumn{2}{c}{**22 \({}^{\circ}\)Blg**} & \multicolumn{2}{c}{**24 \({}^{\circ}\)Blg**} \\ \hline  & **Glucose** & **Fructose** & **Glucose** & **Fructose** & **Glucose** & **Fructose** \\ \hline  & & & \multicolumn{3}{c}{**\% of Utilised**} & \\ \hline ER contr & 99.56 \(\pm\) 3.17 & 93.75 \(\pm\) 2.43 & 98.27 \(\pm\) 1.23 & 81.49 \(\pm\) 0.57 & 67.42 \(\pm\) 2.51 & 27.04 \(\pm\) 0.65 \\ \hline ER u50 & 99.36 \(\pm\) 3.15 & 92.67 \(\pm\) 2.69 & 98.60 \(\pm\) 4.02 & 87.33 \(\pm\) 3.71 & 81.13 \(\pm\) 3.17 & 41.03 \(\pm\) 0.98 \\ \hline ER u75 & 99.05 \(\pm\) 3.25 & 94.89 \(\pm\) 1.99 & 98.82 \(\pm\) 3.35 & 83.89 \(\pm\) 2.06 & 81.57 \(\pm\) 1.08 & 47.89 \(\pm\) 1.64 \\ \hline TD contr & 98.33 \(\pm\) 3.07 & 86.79 \(\pm\) 4.23 & 96.68 \(\pm\) 2.70 & 70.03 \(\pm\) 1.45 & 58.05 \(\pm\) 2.46 & 24.45 \(\pm\) 0.42 \\ \hline TD u50 & 99.97 \(\pm\) 3.32 & 92.40 \(\pm\) 2.64 & 96.98 \(\pm\) 4.49 & 76.06 \(\pm\) 2.64 & 66.91 \(\pm\) 2.94 & 37.37 \(\pm\) 1.14 \\ \hline TD u75 & 98.95 \(\pm\) 3.36 & 93.96 \(\pm\) 1.98 & 97.02 \(\pm\) 2.49 & 73.67 \(\pm\) 3.60 & 78.30 \(\pm\) 2.51 & 72.58 \(\pm\) 2.54 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Glucose and fructose utilisation after 72 h of fermentation of 18, 22, and 24 \({}^{\circ}\)Blg worts. (\(p<0.05\)) intensified the utilisation of sugars by Thermosacc Dry yeast, with no statistically significant difference between the sonicated samples differing in the amplitude of the applied ultrasonic treatment (50% and 75%).