## 3 Results and Discussion
### Chemical Analysis of the Fermentation Liquid Fraction and Coffee Beans
The study  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Compound (Area)** & **0 h** & **8 h** & **19 h** & **24 h** \\ \hline _Organic acid_ (**3**) & & & \\ _Actic acid_ & 5.35 \(\pm\) 0.04 \({}^{\text{a}}\) & 6.03 \(\pm\) 0.86 \({}^{\text{a}}\) & 9.99 \(\pm\) 0.33 \({}^{\text{b}}\) & 9.73 \(\pm\) 0.84 \({}^{\text{b}}\) \\ _Butanac acid_, 3-_methyl_ & 0.33 \(\pm\) 0.03 \({}^{\text{a}}\) & 0.44 \(\pm\) 0.24 \({}^{\text{ab}}\) & 0.58 \(\pm\) 0.08 \({}^{\text{ab}}\) & 0.85 \(\pm\) 0.18 \({}^{\text{b}}\) \\ _Isovaleric acid_ & 0.36 \(\pm\) 0.06 \({}^{\text{a}}\) & 1.39 \(\pm\) 0.18 \({}^{\text{b}}\) & 0.54 \(\pm\) 0.12 \({}^{\text{ac}}\) & 0.77 \(\pm\) 0.04 \({}^{\text{c}}\) \\ _Higher alcohols_ (**7**) & & & \\ _Propumd_, 2-_methyl_ & 0.16 \(\pm\) 0.00 \({}^{\text{a}}\) & 0.13 \(\pm\) 0.00 \({}^{\text{ab}}\) & 0.11 \(\pm\) 0.00 \({}^{\text{b}}\) & 0.11 \(\pm\) 0.02 \({}^{\text{b}}\) \\ _1-Octen_, 3-_ol_ & 0.41 \(\pm\) 0.03 \({}^{\text{a}}\) & 0.29 \(\pm\) 0.05 \({}^{\text{b}}\) & 0.22 \(\pm\) 0.00 \({}^{\text{b}}\) & 0.20 \(\pm\) 0.03 \({}^{\text{b}}\) \\ _2-Hexanol_, 5 _methyl_ & 0.59 \(\pm\) 0.10 \({}^{\text{a}}\) & 0.59 \(\pm\) 0.06 \({}^{\text{a}}\) & 0.46 \(\pm\) 0.05 \({}^{\text{ab}}\) & 0.33 \(\pm\) 0.01 \({}^{\text{b}}\) \\ _1-Butanol_, 3-_methyl_ & - & 0.60 \(\pm\) 0.24 \({}^{\text{a}}\) & 0.28 \(\pm\) 0.00 \({}^{\text{a}}\) & 0.59 \(\pm\) 0.12 \({}^{\text{a}}\) \\ _2-Heptanol_, 3-_methyl_ & - & - & - & 0.13 \(\pm\) 0.03 \\ _I-Butanol_ & 2-_methyl_ & - & - & 0.28 \(\pm\) 0.00 \\ _Phenyleth Alcohol_ & - & - & - & 0.26 \(\pm\) 0.03 \\ _Aldehyde_ (**8**) & & & & \\ _Butanal_, 3 _merged_ & 3.33 \(\pm\) 0.46 \({}^{\text{ab}}\) & 4.39 \(\pm\) 0.33 \({}^{\text{b}}\) & 2.48 \(\pm\) 0.18 \({}^{\text{c}}\) & 1.50 \(\pm\) 0.79 \({}^{\text{c}}\) \\ _Butanal_, 2 _methyl_ & 0.70 \(\pm\) 0.07 \({}^{\text{ab}}\) & 0.76 \(\pm\) 0.07 \({}^{\text{b}}\) & 0.26 \(\pm\) 0.00 \({}^{\text{ac}}\) & 0.39 \(\pm\) 0.00 \({}^{\text{c}}\) \\ _Hexanol_ & 2.01 \(\pm\) 0.32 \({}^{\text{a}}\) & 3.49 \(\pm\) 0.56 \({}^{\text{bc}}\) & 3.97 \(\pm\) 0.52 \({}^{\text{c}}\) & 2.44 \(\pm\) 0.27 \({}^{\text{ab}}\) \\ _Heptanal_ & 0.20 \(\pm\) 0.02 \({}^{\text{a}}\) & 0.07 \(\pm\) 0.01 \({}^{\text{b}}\) & - & - \\ _Berzacetaldehyde_ & 1.06 \(\pm\) 0.06 \({}^{\text{a}}\) & 1.07 \(\pm\)0.03 \({}^{\text{a}}\) & 0.94 \(\pm\) 0.05 \({}^{\text{ab}}\) & 0.81 \(\pm\) 0.02 \({}^{\text{b}}\) \\ _Benzaldehyde_ & 1.56 \(\pm\) 0.06 \({}^{\text{a}}\) & 1.23 \(\pm\) 0.12 \({}^{\text{b}}\) & 0.90 \(\pm\) 0.03 \({}^{\text{c}}\) & 0.89 \(\pm\) 0.06 \({}^{\text{c}}\) \\ _Pentanal_ & 0.61 \(\pm\) 0.06 \({}^{\text{a}}\) & 0.58 \(\pm\) 0.21 \({}^{\text{a}}\) & 0.58 \(\pm\) 0.04 \({}^{\text{a}}\) & 0.49 \(\pm\) 0.04 \({}^{\text{a}}\) \\ _Methanol_ & 0.70 \(\pm\) 0.00 \({}^{\text{a}}\) & 0.79 \(\pm\) 0.22 \({}^{\text{a}}\) & 0.67 \(\pm\) 0.12 \({}^{\text{a}}\) & 0.30 \(\pm\) 0.04 \({}^{\text{b}}\) \\ _Ester_ (**1**) & & & & \\ _Ethyl acetate_ & - & & 0.13 \(\pm\) 0.01 \({}^{\text{a}}\) & 0.25 \(\pm\) 0.00 \({}^{\text{b}}\) \\ _Terpene_ (**2**) & & & & \\ _Lindal_ & 0.65 \(\pm\) 0.00 \({}^{\text{a}}\) & 0.71 \(\pm\) 0.04 \({}^{\text{ab}}\) & 0.95 \(\pm\) 0.00 \({}^{\text{b}}\) & 0.61 \(\pm\) 0.16 \({}^{\text{a}}\) \\ _Limonne_ & - & - & 0.17 \(\pm\) 0.01 & - \\ _Pyrazine_ (**1**) & & & & \\ _2-Isobutyl-3-_ & 0.23 \(\pm\) 0.11 & - & - & - \\ _Letones_ (**1**) & & & & \\ _Accotin_ & 0.47 \(\pm\) 0.05 \({}^{\text{a}}\) & 3.49 \(\pm\) 0.51 \({}^{\text{bc}}\) & 4.15 \(\pm\) 0.08 \({}^{\text{c}}\) & 3.30 \(\pm\) 0.09 \({}^{\text{b}}\) \\ _Hydrocarbons_ (**2**) & & & & \\ _Tonner_ & 0.23 \(\pm\) 0.10 \({}^{\text{a}}\) & 0.22 \(\pm\) 0.01 \({}^{\text{a}}\) & - & - \\ _Nonanne_, 3-_methyl_-_-_ _-_ _propyl_ & 0.27 \(\pm\) 0.00 \({}^{\text{a}}\) & - & - \\ _Furan_ (**1**) & & & & \\ _Furan_, _2-_ _pentyl_ & - & 0.33 \(\pm\) 0.07 \({}^{\text{a}}\) & 0.27 \(\pm\) 0.06 \({}^{\text{a}}\) & 0.15 \(\pm\) 0.03 \({}^{\text{a}}\) \\ \hline \hlinesuggested that the differences observed in the diffusion of compounds in grains may be associated with three processes (i) the parchment layer is a barrier, which \"acts\" as a filter; (ii) the compounds suffered metabolic reactions, decreasing their amount in coffee beans; (iii) there is an interaction between volatiles and yeast, significantly reducing the transfer of these compounds.