## 3 Results and Discussion
### Relevance for the Production of Volatile Compounds during Alcoholic Fermentation
#### 3.3.2 Thiamine Influence on Wine Volatile Compounds  
Out of the 31 analyzed, 11 volatile compounds were significantly influenced by the initial thiamine concentration in the synthetic must medium (Table 7, Figure 2D-F). Fatty Acids, Fatty Alcohols, and Fatty Acid Ethyl Esters (FAEEs)  
Interestingly, amongst those affected compounds, a noticeable impact of the initial thiamine on fatty acids and derivatives appeared here: 5 of the 13 fatty acids, fatty alcohols, \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Compound (\(\upmu\)g/L)**} & \multicolumn{3}{c}{**Initial Thiamine Concentration (\(\upmu\)g/L)**} \\ \cline{2-3}  & **0** & **50** & **250** \\ \hline
1-Butanol & 255.5 \(\pm\) 60.25 \({}^{\text{a}}\) & 193 \(\pm\) 89 \({}^{\text{ab}}\) & 152.67 \(\pm\) 69.36 \({}^{\text{b}}\) \\ Decanoic acid & 1400.25 \(\pm\) 235.59 \({}^{\text{a}}\) & 1463.75 \(\pm\) 198.13 \({}^{\text{a}}\) & 1966.78 \(\pm\) 343.87 \({}^{\text{b}}\) \\
1-Decanol & 15.59 \(\pm\) 3 \({}^{\text{a}}\) & 17.71 \(\pm\) 1.72 \({}^{\text{a}}\) & 23.29 \(\pm\) 4.47 \({}^{\text{b}}\) \\
3-Ethoxy-1-propanol & 2002.12 \(\pm\) 328.39 \({}^{\text{a}}\) & 1375.25 \(\pm\) 200.96 \({}^{\text{b}}\) & 1027 \(\pm\) 263.77 \({}^{\text{b}}\) \\ Ethyl benzaldehyde & 2.89 \(\pm\) 0.35 \({}^{\text{a}}\) & 2.74 \(\pm\) 0.45 \({}^{\text{a}}\) & 3.49 \(\pm\) 0.33 \({}^{\text{b}}\) \\ Ethyl decanoate & 19.62 \(\pm\) 4.72 \({}^{\text{a}}\) & 23.75 \(\pm\) 4.3 \({}^{\text{a}}\) & 37.33 \(\pm\) 11.79 \({}^{\text{b}}\) \\ Ethyl laurate & 2.67 \(\pm\) 0.93 \({}^{\text{a}}\) & 3.36 \(\pm\) 0.7 \({}^{\text{a}}\) & 5.1 \(\pm\) 1.28 \({}^{\text{b}}\) \\ Isovaleric acid & 2944.5 \(\pm\) 235.19 \({}^{\text{a}}\) & 2973.38 \(\pm\) 282.2 \({}^{\text{a}}\) & 3434.78 \(\pm\) 455.67 \({}^{\text{b}}\) \\ Phenyl ethyl acetate & 2.67 \(\pm\) 0.67 \({}^{\text{a}}\) & 3.6 \(\pm\) 0.61 \({}^{\text{a}}\) & 8.1 \(\pm\) 3.15 \({}^{\text{b}}\) \\ Phenyl ethyl alcohol & 20,728.25 \(\pm\) 4410.14 \({}^{\text{a}}\) & 21,323.5 \(\pm\) 4424.84 \({}^{\text{a}}\) & 35,286 \(\pm\) 9176.91 \({}^{\text{b}}\) \\ \hline \hline \end{tabular} Note: different letters in the same line indicate significant differences between conditions (Scherer–Ray–Hare and Dunn tests, \(p<0.05\)).  
\end{table} 
Table 7: Thiamine-dependent volatile contents in the final wines. and FAEEs indeed displayed significant (\(p<0.05\)) dose-related variations in their contents (Table 7, Figure 2D). Surprisingly, only the longer medium-chain fatty acids (MCFAs) that were analyzed here exhibited a significant dependence towards the initial thiamine in the medium, since solely decanoic acid (C10), decanol, ethyl decanoate, and ethyl laurate (C12) were affected here. Those compounds were associated with increases alongside the initial thiamine concentration in the medium (Figure 2D), and the results appear consistent with previous findings by [PERSON] during the alcoholic fermentation of _S. cerevisiae_[38]. On the other hand, butanol and ethoxy propanol were associated with notable decreases in concentrations when increasing the initial thiamine, in accordance with previous findings by [PERSON] [38]. Interestingly, out of those five significantly impacted compounds, solely ethoxy propanol was present in concentrations above its 100 \(\upmu\)g/L detection threshold [52], suggesting that the initial thiamine might contribute to modulating the sensory profiles of wines. Higher Alcohols, Higher Aldehydes, Fusel Acids, and Associated Esters (Ehrlich Pathway)  
Besides the influence held by the vitamin on fatty acid metabolism, an impact of the initial thiamine concentration in the synthetic must medium on higher alcohols, higher aldehydes, and their derivative esters appeared here (Table 7, Figure 2E), since 5 of those compounds out of their total 10 displayed significant (\(p<0.05\)) variations in regard to thiamine contents. As such, a clear increase in the final concentrations of phenyl ethyl alcohol, phenyl ethyl acetate, and isovaleric acid appeared when raising thiamine doses (Figure 2E).