# The Application of Wood Species in Enology: Chemical Wood Composition and Effect on Wine Quality
## 2 Chemical Composition of Wood Species
As shown in Table 2, generally, woods not belonging to genus _Quercus_ do not have either _cis_ or _trans_-\(\beta\)-methyl-\(\gamma\)-octalactone in their composition. Nevertheless, some researchers (68; 84) already found very low concentrations of lactones in false acacia and cherry woods. Furthermore, [PERSON] et al. (85) also detected small quantities of _cis_ and _trans_ forms in chestnut wood. [PERSON] et al. (76) investigated the chemical compounds extracted from oak, chestnut, false acacia, and mulberry woods used to manufacture barrels. According to these researchers, chestnut, false acacia, and oak extracted quantities between 1 and 10 ug/g wood of coniferaldehyde, while very low quantities for mulberry wood were found. Furthermore, higher quantities were quantified for syringaldehyde for the wood species considered (chestnut, false acacia, and oak). For cherry wood, only quantities between 1 and 10 ug/g wood were detected. Lastly, benzaldehyde was only found in cherry woods. These results follow an analogous trend showing by [PERSON] et al. (86). According to these authors sinapaldehyde, coniferaldehyde, and syringaldehyde were found in false acacia, oak, and cherry woods (Table 2). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Wood Species**} \\ \cline{2-7}
**Phenolic** & \multicolumn{3}{c}{**Oak Species**} & \multicolumn{3}{c}{**Fabaceae**} & **Cherry** \\ \cline{2-7}
**Compounds** & _Quercus_ & _Quercus_ & _Quercus_ & _Robinia_ & _Prunus_ & **Reference** \\  & _petraea_ & _alba_ & _pyrenaica_ & _pseudoacacia_ & _ruum_ & **L.** & \\  & & & & **Wild.** & **L.** & & \\ \hline Vescalagin (8) & 12.6–17.6 & 1.23–5.28 & 11.3–14.6 & – & – & \\ Castalagin (8) & 20.1–22.7 & 0.37–0.44 & 15.2–19.7 & – & – & [13](9) \\ Ellagic acid & 2.60–4.42 & 1.90–3.62 & 3.9–20.5 & – & – & \\ \hline Total ellagitannins (10) & – & – & – & – & nd-0.04 & [64; 66; 69] \\ \hline Gallic acid (11) & 70.75 & – & – & 9.61 & nd & \\ Vanillic acid (11) & 2.34 & – & – & nd & 1.86 & \\ Syringic acid (11) & 3.78 & – & – & 0.82 & 3.05 & [79] \\ Ellagic acid (11) & 32.68 & – & – & nd & nd & \\ Protocatechuric (11) aldehyde & nd & – & – & 0.19 & 7.90 & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._
False acacia could be defined by an important concentration of benzene aldehydes, oak, and chestnut, by a great concentration of eugenol, vanillin, methoxyeuenol, syringaldehyde, and \(\alpha\)-terpineol [76]. Furthermore, chestnut is also characterized by a great number of fatty acids and volatile compounds. In addition, mulberry wood contains a very low number of volatile compounds. Vanillin, eugenol, and guaiacol are compounds with a significant role in numerous wine sensory descriptors. These compounds are related to sensory descriptors such as vanilla, smoky, and cloves aromas, respectively. Generally, vanillin is existent in different oak, chestnut, cherry, false acacia, and ash species. Nevertheless, lower values are also found in false acacia and cherry woods [86; 87; 88; 89]. For [PERSON] et al. [22], the guaiacol concentrations in medium-toasted ash woods are considerably higher than those found in the other toasted woods. Other researchers [68; 86] revealed similar concentrations of eugenol detected between different toasted oak wood species and other wood species