## 3 Results and Discussion
### Variation of Volatile Metabolites Profiles During Sotol Must Fermentation
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline
**Compound** & **RT** & **Flavor** & \multicolumn{4}{c}{**Days of Fermentation**} \\
**(Min)** & **Descriptor \({}^{\star}\)** & **0** & **1** & **2** & **3** & **4** & **5** \\ \hline \hline \multicolumn{2}{c}{Alcohols} & \multicolumn{1}{c}{2-methoxyhypogen1-olololololol}{olololumn{}}{} & 6.86 & Ehrenal, winery & - & 28.11 \(\pm\) 2.38 & - & - & 33.65 \(\pm\) 2.41 & - \\
2-ethylcytokuan-1-olol & 9.64 & - & - & - & - & 18.82 \(\pm\) 0.06 \({}^{\star}\) & 18.43 \(\pm\) 0.35 \({}^{\star}\) & - \\
3-methylbutana-1-ol & 10.81 & Fruity, purgent & - & 90.62 \(\pm\) 5.14 \({}^{\circ}\) & 61.31 \(\pm\) 3.8\({}^{\circ}\) & 57.63 \(\pm\) 12.2\({}^{\star}\) & - & - \\
3-bromogen-ololol & 16.38 & - & - & - & 94.8 \(\pm\) 0.18 & - & - \\
6-amino-2-methylheptana-2-ol & 20.91 & - & 8.81 \(\pm\) 0.23 & - & - & 94.8 \(\pm\) 0.18 & - & - \\  & \multicolumn{1}{c}{} & 22.33 & Green leaves & 35.28 \(\pm\) 0.53 \({}^{\circ}\) & 44.75 \(\pm\) 1.53 \({}^{\circ}\) & 38.69 \(\pm\) 0.37 \({}^{\circ}\) & 36.80 \(\pm\) 12.6\({}^{\circ}\) & 95.96 \(\pm\) 0.18 \({}^{\circ}\) & 29.59 \(\pm\) 0.26 \({}^{\circ}\) \\
**(2R)**-ethyl2-2([1R)-ethylpolydodecus-3-n-1-yl][Hept+5-m-2 ol] & 23.62 & Desel & - & 10.46 \(\pm\) 0.10 \({}^{\circ}\) & 12.94 \(\pm\) 1.58 \({}^{\circ}\) & 18.18 \(\pm\) 0.76 \({}^{\circ}\) & 18.06 \(\pm\) 0.57 \({}^{\circ}\) & - \\ \multicolumn{2}{c}{(+)Alpha-  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Component**} & **RT** & **Flavor** & \multicolumn{6}{c}{**Days of Fermentation**} \\  & **(Guitar)** & **Descriptor** & **0** & **1** & **2** & **3** & **4** & **5** \\ \hline bq(trimethyl(s)ib) oxalate & 18.37 & [PERSON] & 17.99 \(\pm\) 0.58 & - & - & - & - & - \\ ethyl octanoate & 19.88 & Frinity, winery & - & 24.20 \(\pm\) 25.6* & 14.49 \(\pm\) 1.07* & - & - & 17.58 \(\pm\) 0.39* \\ octyl2 -methylropanoate & 23.39 & Vingser & - & 14.45 \(\pm\) 0.82 & - & - & - & - \\ crypt ester & 23.41 & Wray & 14.73 \(\pm\) 1.41 & - & - & - & - & - \\ thameideideide & 34.00/trimethyl(s) ester & 25.45 & 75.12 \(\pm\) 12.80 & - & - & - & - & - \\ butyl octanoate & 26.99 & Creamy & - & 13.35 \(\pm\) 1.21 & - & - & - & - \\ \hline \(\star\)-methyl-23,4,5,6,7-,8-hydroxy-H-in-aden & 22.91 & Frinity & - & 10.49 \(\pm\) 0.42* & 10.53 \(\pm\) 0.56* & 10.19 \(\pm\) 0.26* & - & 10.05 \(\pm\) 0.35* \\ \(\star\)-35-dimethyl-1,2,4-triucination & 26.40 & - & - & - & - & - & 9.83 \(\pm\) 0.15 \\ \(\star\)-methyl-2,5-methylrop-2,5-pentane & 26.82 & - & - & - & 10.65 \(\pm\) 0.38 & - & - \\ Amines & \(\star\)-methyl-2,5-phenyl-2,5-pentane & 26.82 & - & - & - &  
In particular, esters can be considered the most important class of flavor compounds detected during the fermentation of sotol must; namely, butyl isobutyrate was the most abundant ester at the beginning of the process (day zero) and decreased during fermentation until the process was stopped (day five). Bis(trimethylsilyl) oxalate, octyl ester, and butyl octanoate of green, ethereal, and herbal flavor properties were detected only at the start of the process. Meanwhile, ethyl acetate and ethyl octanoate of fruity and sweet flavor characteristics were identified in the middle and the final stages of the fermentation. Finally, ethyl ethanimidate of floral notes was detected only at the end of the sotol must fermentation. These metabolites with pleasant flavor properties are important in the perceived flavor of the final distilled spirit. The origin of these compounds can be attributed to the esterification reactions between organic acids and alcohol during the fermentation and aging process [65]. Among these metabolites, ethyl acetate is the main ester that occurs in fermented products and their distillates, and commonly commercial strains of _Saccharomyces cerevisiae_ give rise to this compound and other acetate esters; however, great interest has emerged in the use of non-_Saccharomyces_ species due their greater potential for the production of novel aromas [66].