## 3 Results and Discussion
### Phenolic Compounds from Grapes  
Phenolic compounds deriving from grapes contribute significantly to the character and quality of white wine. Hydroxycinnamic acids and flavonoids are involved in the formation and stability of colour, flavan-3-ol monomers and oligomers impart subtle bitterness, while flavan-3-ol polymers (proanthocyanidins i.e., condensed tannins) contribute to astringency. Additionally, phenols act as antioxidants and protect white wines from oxidation, which can otherwise lead to unwanted browning and flavour degradation [37]. The concentrations of phenolic compounds found in the investigated wines are summarized in Table 3. Yeast had a significant effect on specific phenols, while harvest year significantly influenced the levels of nearly all identified phenols except syringic acid. In many cases, the effects of yeast and harvest year interacted. Among hydroxybenzoic acid acids, control SCE-21 wine contained higher concentrations of 4-aminobenzoic and 2,5-dihydroxybenzoic acids, whereas _p_-hydroxybenzoic acid was more abundant in SCE-22 wine. The concentrations of 4-aminobenzoic acid and vanillic acid were higher in 2022, while _p_-hydroxybenzoic acid and protocatechuric acid were more abundant in 2021 wines. Hydrocycinnamic acids displayed significant interactions between yeast and harvest year, with some clear trends emerging. In 2021, SPA-21 wine had higher levels of hydroxycinnamoyllartrates, such as _trans_-caftaric and _trans_-fertaric acid, while control SCE-21 wine had higher concentrations of the identified free forms, including _p_-coumaric, caffeic, and ferulic acid. This pattern could suggest enhanced cinnoxyl esterase activity in _S. paradoxus_. However, this trend was not consistent in 2022. _Trans_-fertaric acid was more abundant in control SCE-22 than in SPA-22 wine, while other phenols from this group did not show significant differences. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & \multicolumn{6}{c}{**Differences in Concentration**} \\ \cline{2-8}
**PR Proteins and Bentonite Dose** & & \multicolumn{3}{c}{**One-Way ANOVA**} & \multicolumn{3}{c}{**Two-Way ANOVA**} \\ \cline{2-8}  & \multicolumn{3}{c}{**2021**} & \multicolumn{3}{c}{**2022**} & & & \\ \cline{2-8}  & **SCE** & **SPA** & **SCE** & **SPA** & **Y** & **H** & **Y**\(\times\)**H** \\ \hline Thuamatin-like proteins 1 & 13.16 & 13.62 & 35.01 & 32.89 & n.s. & **22** & n.s. \\ Thuamatin-like proteins 2 & 12.72 & 13.05 & **16.68 b** & **18.15 a** & **SPA** & **22** & n.s. \\ Thuamatin-like proteins 3 & 12.59 & 13.75 & 16.81 & 17.21 & n.s. & **22** & n.s. \\ Thuamatin-like proteins 4 & 33.33 & 36.72 & 54.83 & 58.60 & **SPA** & **22** & n.s. \\ Chitinases 1 & 30.32 & 28.16 & **69.28 a** & **60.53 b** & **SCE** & **22** & n.s. \\ Chitinases 2 & 23.91 & 23.93 & **57.23 a** & **52.86 b** & n.s. & **22** & n.s. \\ Total thuamatin-like proteins & 71.80 & 77.15 & 123.33 & 126.84 & n.s. & **22** & n.s. \\ Total chitinases & 54.23 & 52.09 & **126.5 a** & **113.4 b** & **SCE** & **22** & n.s. \\ Total PR proteins & 126.03 & 129.24 & 249.9 & 240.2 & n.s. & **22** & n.s. \\ Bentonite dose & 90.00 & 93.33 & 96.67 & 103.3 & n.s. & n.s. \\ \hline \hline \end{tabular} Abbreviations: n.s.--not significant. One-way ANOVA section: different superscript lowercase letters represent statistically significant differences between the two investigated wines determined by one-way ANOVA at \(p<0.05\) for each harvest year separately. Two-way ANOVA section: designations are reported representing yeast (SCE, SPA) and harvest year (21, 22) with higher concentration determined by two-way ANOVA at \(p<0.05\) with yeast (\(\Upsilon\)) and harvest year (H) as factors. Significant differences are highlighted in bold.  
\end{table}