# The Application of Wood Species in Enology: Chemical Wood Composition and Effect on Wine Quality
## 3 Impact of Wood Species on Wine Chemical Composition
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Volatile Compounds** & **Wine Characteristics** & **French Oak** & **American Oak** & **Reference** \\ \hline _New oak barrels_ & & & \\ Alcohols \(\times\) 10\({}^{-3}\) & & \(\sim\)325 & \(\sim\)325 & \\ Acids \(\times\) 10\({}^{-1}\) & & \(\sim\)200 & \(\sim\)200 & \\ Esters \(\times\) 10\({}^{-2}\) & & \(\sim\)40 & \(\sim\)40 & \\ Furfuryl \(\times\) 10\({}^{-1}\) & & \(\sim\)140 & \(\sim\)120 & \\ Guaiacol & Monastrell wine aged for & \(\sim\)10 & \(\sim\)10 & \\
4-Methyl guaiacol & 6 months & \(\sim\)10 & \(\sim\)25 & \\
4-Ethyl phenol & & \(\sim\)300 & \(\sim\)320 & \\
4-Ethyl guaiacol & & \(\sim\)25 & \(\sim\)10 & \\ _Trans_-oak lactone & & \(\sim\)40 & \(\sim\)25 & \\ _cis_-oak lactone & & \(\sim\)125 & \(\sim\)400 & \\ Vanillin & & \(\sim\)200 & \(\sim\)175 & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Wine volatile compounds (\(\mu\)g/L) aged in oak barrels with different utilization times. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Volatile Compounds** & **Wine Characteristics** & **French Oak** & **American Oak** & **Reference** \\ \hline _Oak barrels used twice_ & & & & \\  Furfural & & 771 & & \\ 5-Methyl furfural & & 135 & & \\ 5-Hydroxymethyl & & 0.02 & & \\  furfural & & 3714 & & \\  Furfuryl alcohol & & 374 & & \\ _Cs_-oak lactone & & 79 & & \\ _Trans_-oak lactone & & 73 & & \\ \(\gamma\)-Nonalactone & & 2.6 & & \\ \(\gamma\)-Butryrolactone & & 49,930 & & \\  Springaldehyde & & 312 & & \\  Coniferaldehyde & & 40 & & \\  Vanillin & Blend wine of Tempranillo & 89 & & \\  Acetovanillone & (60\%), Cabernet Sauvignon & 114 & & [105] \\ \(\beta\)-Ionone & (20\%), and Garnacha (20\%) & 0.16 & & \\  Eugenol & aged for 12 months & 20 & & \\  Guaiacol & & 8.8 & & \\ 4-Methyl guaiacol & & 0.06 & & \\  Phenol & & 15.52 & & \\ \(m\)-Cresol & & 0.8 & & \\ \(p\)-Cresol & & 0.19 & & \\ 4-Ethyl phenol & & 656 & & \\ 4-Ethyl guaiacol & & 87 & & \\ 2-Phenyl ethanol & & 2051 & & \\  Ethyl butyrate & & 517 & & \\  Ethyl hexanoate & & 206 & & \\  Ethyl octanoate & & 246 & & \\  Ethyl decanoate & & 9 & & \\  Ethyl lactate & & 31,198 & & \\ \hline _Oak barrels used 3 times_ & & & & \\  Alcohols \(\times\)\(10^{-3}\) & & \(\sim\)350 & \(\sim\)325 & \\  Acids \(\times\)\(10^{-1}\) & & \(\sim\)240 & \(\sim\)225 & \\  Esters \(\times\)\(10^{-2}\)- & & \(\sim\)40 & \(\sim\)40 & \\  Furfuryl \(\times\)\(10^{-1}\) & & \(\sim\)125 & \(\sim\)120 & \\  Guaiacol & Monastrell wine aged for 6 & \(\sim\)10 & \(\sim\)10 & [106] \\ 4-Methyl guaiacol & months & \(\sim\)10 & \(\sim\)10 & \\ 4-Ethyl phenol & & \(\sim\)60 & \(\sim\)175 & \\ 4-Ethyl guaiacol & & nd & \(\sim\)5 & \\ _Trans_-oak lactone & & \(\sim\)20 & \(\sim\)5 & \\ _Cs_-oak lactone & & \(\sim\)75 & \(\sim\)100 & \\  Vanillin & & \(\sim\)60 & \(\sim\)75 & \\ \hline _Oak barrels used 5 times_ & & & & \\  Furfural & & 89–206 & 70–110 & \\ 5-Methyl furfural & & 4.0–5.0 & 5–13 & \\  Furfuryl alcohol & & 516–620 & 115–447 & \\ _Cs_-oak lactone & & 44–89 & 100–151 & \\ _Trans_-oak lactone & & 28–51 & 20–37 & \\ \(\gamma\)-Butryrolactone & & 18,200–19,300 & 17,900–18,100 & \\ \(\gamma\)-Nonalactone & & 1.6–2.6 & 1.8–2.6 & \\  Ethyl butyrate & & 225–270 & 246–272 & [103] \\  Ethyl hexanoate & 59\%) aged for 12 months & 264–294 & 292–313 & \\  Ethyl octanoate & & 349–353 & 345–355 & \\  Ethyl decanoate & & 85–89 & 91–106 & \\  Isoamyl acetate & & 276–296 & 245–338 & \\  Ethyl lactate & & 26,200–34,500 & 14,700–17,500 & \\  Vanillin & & 25–35 & 9–25 & \\  Syringaldehyde & & 5–7 & 1–4 & \\  Coniferaldehyde & & 17–20 & 15–18 & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: _Cont._Besides oak wood, other species like cherry (_Prunus avium_), false acacia (_Robinia pseudoacacia_), mulberry (_Morus alba_ L. and _Morus nigra_ L.), or ash (_Fraximus excelsior_) are increasingly considered for winemaking, and they are investigated in numerous studies [65; 66; 74; 76; 77], due to their lower costs, or due to their distinctive sensory contribution [85].