## 3 Results and Discussion
### Grape Phenolic Compounds  
The effects of the two investigated yeasts on grape phenolic compounds are reported in Table 14. Among hydroxybenzoic acids, the most significant differences were observed for 2,5-dihydroxybenzoic acid, followed by \(p\)-hydroxybenzoic acid, both found in higher concentrations in the control _SCE_ wine. Both free forms of hydroxycinnamic acids and their esters with tartaric acid were significantly affected, but with opposite directions. Free \(p\)-coumaric and caffe acid were found in higher concentrations in _SCE_, while all three major hydroxycinnamoyl tartrates, _trans_-cafaric, _trans_-fertaric, and _trans_-coutaric acid, were more abundant in _LEV_ wine. Such results imply distinct differences between the activity of certain enzymes between the two yeasts, such as higher activity of cinnaryl esterases responsible for the release of free hydroxycinnamic acids from their tartrate esters [54] in _S. cerevisiae_, as well as different activity of decarboxylases that catalyze the transformation of free \(p\)-coumaric and ferulic acid into 4-vinylphenols [42; 55]. Besides that, the differential adsorption of grape phenols on the surface of yeast cells between different yeasts observed previously [56] could have also had an effect. _Trans_-resveratrol, a stilbene important because of its known antioxidant activity, was less abundant in _LEV_, while among flavanols, quercetin showed a higher concentration in this wine. From the group of flavan-3-ols, only procyanidin B1 and epigallocatechin showed significant differences, with a higher amount of the former found in _LEV_ wine and that of the latter in _SCE_ wine. Catechol had almost double the concentration in control _SCE_ compared to _LEV_ wine. The total phenolic content was slightly higher in the _LEV_ treatment wine, implying a possibility of a higher degree of adsorption of phenols, including large molecules such as tannins, on _S. cerevisiae_ yeast cells. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Phenolic Compounds** & **F-Ratio** & \multicolumn{2}{c}{**Treatment**} \\ \hline  & & _SCE_ & _LEV_ \\ \hline _Hydroxyleneoic acid derivatives_ & & & \\
2,5-Dihydroxybenzoic acid & 100.993 & 0.715 \(\pm\) 0.077 a & 0.262 \(\pm\) 0.009 b \\ \(p\)-Hydroxyleneoic acid & 10.571 & 0.439 \(\pm\) 0.077 a & 0.293 \(\pm\) 0.012 b \\ Protocatechuic acid & 0.639 & 0.565 \(\pm\) 0.058 & 0.668 \(\pm\) 0.214 \\ Vanillic acid & 0.424 & 0.106 \(\pm\) 0.022 & 0.096 \(\pm\) 0.012 \\ Syringic acid & 0.221 & 0.422 \(\pm\) 0.128 & 0.370 \(\pm\) 0.145 \\ _Hydroxcyclinumic acid derivatives_ & & & \\ \(p\)-Coumaric acid & 493.014 & 1.27 \(\pm\) 0.04 a & 0.44 \(\pm\) 0.05 b \\ _trans_-Cafaric acid & 138.458 & 0.179 \(\pm\) 0.032 b & 0.804 \(\pm\) 0.086 a \\ _trans_-Coutaric acid & 31.520 & 0.491 \(\pm\) 0.072 b & 0.797 \(\pm\) 0.061 a \\ Caffeic acid & 27.638 & 2.24 \(\pm\) 0.11 a & 1.75 \(\pm\) 0.12 b \\ _trans_-Fertaric acid & 12.844 & 2.45 \(\pm\) 0.19 b & 2.85 \(\pm\) 0.04 a \\ Ferulic acid & 5.108 & 0.498 \(\pm\) 0.040 & 0.601 \(\pm\) 0.067 \\ _Other acids_ & & & \\
4-Aminobenzoic acid & 4.055 & 0.066 \(\pm\) 0.009 & 0.082 \(\pm\) 0.011 \\ _Stilbenes_ & & & \\ _trans_-Resveratrol & 30.043 & 0.115 \(\pm\) 0.008 a & 0.080 \(\pm\) 0.007 b \\ _cis_-Resveratrol & 6.092 & 0.026 \(\pm\) 0.014 & 0.053 \(\pm\) 0.013 \\ _Flatum_-_3-_ols_ & & & \\ Procyanidin B1 & 32.423 & 1.33 \(\pm\) 0.28 b & 2.73 \(\pm\) 0.32 a \\ Epigallocatechin & 10.543 & 0.019 \(\pm\) 0.005 a & 0.005 \(\pm\) 0.005 b \\ Epicatechin & 3.120 & 0.245 \(\pm\) 0.068 & 0.360 \(\pm\) 0.091 \\ Gallocatechin & 2.120 & 0.188 \(\pm\) 0.010 & 0.159 \(\pm\) 0.032 \\ Catechin & 1.117 & 1.41 \(\pm\) 0.14 & 1.23 \(\pm\) 0.25 \\ Procyanidin B2 + B4 & 0.425 & 0.158 \(\pm\) 0.055 & 0.239 \(\pm\) 0.207 \\ \hline \hline \end{tabular}
\end{table}