### Sensory Evaluation of Wine Quality from Individual Variants
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Vintage** & **Variant** & **4-vinylguaiacol \(\pm\) SD** & **4-vinylphenol \(\pm\) SD** & **Sum of VPs \(\pm\) SD** \\ \hline \multirow{4}{*}{2015} & \multicolumn{2}{c}{\(\mathbf{\mu g\ L^{-1}}\)} & \(\mathbf{\mu g\ L^{-1}}\) & \(\mathbf{\mu g\ L^{-1}}\) \\ \cline{2-4}  & WRC & 67.00 \(\pm\) 4.55 a & 286.00 \(\pm\) 9.42 a & 353.00 \(\pm\) 13.95 a \\  & WRO & 28.67 \(\pm\) 3.40 b & 177.00 \(\pm\) 6.98 b & 205.67 \(\pm\) 9.53 b \\  & CHC & 334.67 \(\pm\) 15.15 a & 301.00 \(\pm\) 10.42 a & 635.67 \(\pm\) 16.21 a \\  & CHO & 210.00 \(\pm\) 9.09 b & 213.33 \(\pm\) 8.81 b & 423.33 \(\pm\) 17.78 b \\
2016 & WRC & 26.00 \(\pm\) 0.82 a & 85.00 \(\pm\) 6.16 a & 111.00 \(\pm\) 6.98 a \\  & WRO & 18.00 \(\pm\) 0.82 b & 58.33 \(\pm\) 2.05 b & 76.33 \(\pm\) 2.87 b \\  & CHC & 181.33 \(\pm\) 4.50 a & 176.00 \(\pm\) 5.10 a & 357.33 \(\pm\) 8.81 a \\  & CHO & 164.67 \(\pm\) 6.80 b & 157.67 \(\pm\) 5.19 b & 322.33 \(\pm\) 4.92 b \\
2017 & WRC & 59.00 \(\pm\) 2.16 a & 253.67 \(\pm\) 9.10 a & 312.67 \(\pm\) 8.26 a \\  & WRO & 40.67 \(\pm\) 1.25 b & 192.00 \(\pm\) 6.48 b & 232.67 \(\pm\) 7.32 b \\  & CHC & 268.67 \(\pm\) 8.81 a & 276.00 \(\pm\) 7.48 a & 544.67 \(\pm\) 15.84 a \\  & CHO & 241.67 \(\pm\) 5.73 b & 256.00 \(\pm\) 6.53 b & 497.67 \(\pm\) 6.60 b \\ \hline \hline \end{tabular} Note: Values express the mean \(\pm\) SD; WRC—Welschriesling control variant; WRO—Welschriesling variant with targeted must oxygenation; CHC—Chardonnay control variant; CHO—Chardonnay variant with targeted must oxygenation; VPs—volatile phenolics; \({}^{\rm ab}\)—mean values of individual parameters in columns with different superscript have a statistically significant difference (\(p<0.05\)) between the variants within one variety and one vintage.  
\end{table} 
Table 3: The 4-vinylguaiacol, 4-vinylphenol, and sum of the volatile phenolics content in the experimental variants in vintages 2015–2017. Figure 2: Results of sensory evaluation of individual variants of the Welschriesling and Chardonnay varieties based on the 100-point system according to STN EN ISO 8586, vintages 2015–2017. Note: WRC—Welschriesling control variant; WRO—Welschriesling variant with targeted must oxygenation; CHC—Chardonnay control variant; CHO—Chardonnay variant with targeted must oxygenation. Microorganisms can metabolize the hydroxycinnamic acids in wine to sensory undesirable volatile phenolic substances. Our results have confirmed that by the natural reduction of the hydroxycinnamic acid content in winemaking, it is possible to eliminate oxidative processes during wine maturation and the formation of sensory undesirable volatile phenolic substances. In the variants with targeted oxygenation of the must, the statistically significant lower content of the sum of the hydroxycinnamic acids is of interest, and a significantly lower content of volatile phenolic substances than the control variants were additionally confirmed. The correlation between the contents of the hydroxycinnamic acids and 4-vinylguaiacol (\(\mu\)g L\({}^{-1}\)) with 4-vinylphenol (\(\mu\)g L\({}^{-1}\)) in the targeted oxygenated group of the Chardon-ray variety was determined through regression and correlation analyses. To describe the dependence between the content of the hydroxycinnamic acids and 4-vinylguaiacol (\(\mu\)g L\({}^{-1}\)) with 4-vinylphenol (\(\mu\)g L\({}^{-1}\)) in the targeted oxygenation variant of the Chardon-ray variety, the power regression model (R\({}^{2}\) = 0.748) was chosen. The equation of the model shows that a 1% increase in hydroxycinnamic acids can result in an average increase in the content of volatile substances by 3.6%. In the control group, the power regression model (R\({}^{2}\) = 0.9346) to describe the dependence was chosen. The regression equations are shown in Figure 3. If we compare a targeted oxygenated group with a control group, it shows a significantly higher content of hydroxycinnamic acids in the control variants compared to the targeted oxygenated variants.