## 3 Results and Discussion
### Volatile Compound Analyses
#### 3.3.3 Esters  
All the produced wines were exposed to volatile ester analysis. The wine samples presented the most evident differences in the concentration of octanoic acid, ethyl ester, and decanoic acid, ethyl ester (Table 5). It is known that esters not only contribute to the fruity aroma of young wines but also serve as important markers for fruity notes in wines of different ages [68; 69]. Esters have been observed to influence the fruity aroma of wine, even at subthreshold levels, due to their intricate synergistic effects [68; 70; 71], highlighting their significant contribution to the overall aroma of wine. The big difference between the number of esters in each sample and the concentration highlights the crucial role of the yeasts [72]. For instance, octanoic acid, ethyl ester, was not detected in sample Zb-A19Y5, and Ethyl 9-decenoate was not detected in Tc-A9Y1, while the other samples exhibited a high concentration. Additionally, the fact that wines from the two _Z. bailii_ strains showed statistically significant differences can imply intraspecies variability. \begin{table}
\begin{tabular}{c c c c}  & **Zb-A19Y5** & **Tc-A9Y1** & **Zb-K29Y2** \\ \hline Propanoic acid & 3.89 \(\pm\) 0.5 \({}^{\mathrm{a}}\) & 2.77 \(\pm\) 0.42 \({}^{\mathrm{a}}\) & 4.39 \(\pm\) 0.13 \({}^{\mathrm{a}}\) \\ Propanoic acid, 2-methyl- & 4.75 \(\pm\) 0.04 \({}^{\mathrm{b}}\) & 2.34 \(\pm\) 0.45 \({}^{\mathrm{a}}\) & 2.9 \(\pm\) 0.41 \({}^{\mathrm{a}}\) \\ Butanoic acid & 9.84 \(\pm\) 0.28 \({}^{\mathrm{a}}\) & 9.73 \(\pm\) 0.12 \({}^{\mathrm{a}}\) & 8.41 \(\pm\) 0.84 \({}^{\mathrm{a}}\) \\ Pentanoic acid, 3-methyl- & 21.52 \(\pm\) 0.23 \({}^{\mathrm{b}}\) & 9.99 \(\pm\) 1.64 \({}^{\mathrm{a}}\) & 9.54 \(\pm\) 1.08 \({}^{\mathrm{a}}\) \\ Hexanoic acid & 115.65 \(\pm\) 0.56 \({}^{\mathrm{a}}\) & 67.66 \(\pm\) 7.62 \({}^{\mathrm{a}}\) & 144.17 \(\pm\) 26.7 \({}^{\mathrm{b}}\) \\
2-Hexenoic acid & 1.95 \(\pm\) 0.05 \({}^{\mathrm{a}}\) & n.d. \\ Octanoic acid & 184.9 \(\pm\) 3.11 \({}^{\mathrm{b}}\) & 115.68 \(\pm\) 8 \({}^{\mathrm{a}}\) & 176.29 \(\pm\) 22.74 \({}^{\mathrm{a}}\) \\ Nonanoic acid & 2.89 \(\pm\) 0.81 \({}^{\mathrm{a}}\) & 1.91 \(\pm\) 0.11 \({}^{\mathrm{a}}\) & 1.64 \(\pm\) 0.44 \({}^{\mathrm{a}}\) \\ n-Decanoic acid & 65.91 \(\pm\) 4.44 \({}^{\mathrm{b}}\) & 36.64 \(\pm\) 3.33 \({}^{\mathrm{a}}\) & 47.86 \(\pm\) 7.01 \({}^{\mathrm{a}}\) \\ Undecylenic acid & 7.95 \(\pm\) 0.84 \({}^{\mathrm{a}}\) & 6.74 \(\pm\) 2.14 \({}^{\mathrm{a}}\) & n.d. \\ Dodecanoic acid & 8.68 \(\pm\) 1.52 \({}^{\mathrm{a}}\) & 5.45 \(\pm\) 0.38 \({}^{\mathrm{a}}\) & n.d. \\ Tetradecanoic acid & 9.36 \(\pm\) 1.84 \({}^{\mathrm{a}}\) & 6.67 \(\pm\) 0.4 \({}^{\mathrm{a}}\) & 7.27 \(\pm\) 1.2 \({}^{\mathrm{a}}\) \\ Pentadecanoic acid & 2.26 \(\pm\) 0.16 \({}^{\mathrm{a}}\) & 1.41 \(\pm\) 0.01 \({}^{\mathrm{a}}\) & 3.79 \(\pm\) 0.67 \({}^{\mathrm{b}}\) \\ n-Hexadecanoic acid & 236.21 \(\pm\) 9.51 \({}^{\mathrm{b}}\) & 206.62 \(\pm\) 6.86 \({}^{\mathrm{b}}\) & 129.3 \(\pm\) 24.84 \({}^{\mathrm{a}}\) \\ Palmitoleic acid & 4.29 \(\pm\) 0.99 \({}^{\mathrm{a}}\) & 1.62 \(\pm\) 0.24 \({}^{\mathrm{a}}\) & 4.33 \(\pm\) 2.18 \({}^{\mathrm{a}}\) \\ Octadecanoic acid & 135.28 \(\pm\) 15.71 \({}^{\mathrm{a}}\) & 127 \(\pm\) 13.5 \({}^{\mathrm{a}}\) & 74.09 \(\pm\) 13.54 \({}^{\mathrm{a}}\) \\ Oleic Acid & 24.32 \(\pm\) 0.16 \({}^{\mathrm{a}}\) & 21.38 \(\pm\) 2.35 \({}^{\mathrm{a}}\) & 9.98 \(\pm\) 4.87 \({}^{\mathrm{a}}\) \\
9,12-Octadecadienoic acid (Z,Z)- & 2.33 \(\pm\) 0.44 \({}^{\mathrm{a}}\) & 4.56 \(\pm\) 0.98 \({}^{\mathrm{a}}\) & n.d. \\ Benzoic acid, 4-(methylamino)- & 1.12 \(\pm\) 0.24 & n.d. \\ Eicosanoic acid & 4.52 \(\pm\) 0.06 \({}^{\mathrm{a}}\) & 4.59 \(\pm\) 0.22 \({}^{\mathrm{a}}\) & n.d. \\
9-Oxo-1,17-heptadecadioic acid & 50.79 \(\pm\) 3.48 & n.d. \\ Docosanoic acid & n.d. & 4 \(\pm\) 0.14 & n.d. \\
9-Decenoic acid & n.d. & 37.19 \(\pm\) 3.03 \({}^{\mathrm{a}}\) & 30.24 \(\pm\) 4.89 \({}^{\mathrm{a}}\) \\ \end{tabular}
\end{table}