## 1 Introduction
### Grape and Wine Volatile Compounds
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Terpenoids** & **Benzenoids** & **Sulfur compounds** \\ \multicolumn{2}{c}{linalool} & \multicolumn{1}{c}{zingerone} & methyl mercaptan \\ \multicolumn{2}{c}{nrol} & \multicolumn{1}{c}{zingerol} & ethyl mercaptan \\ \multicolumn{2}{c}{geraniol} & \multicolumn{1}{c}{acetophenone} & dimethyl sulfide \\ \multicolumn{2}{c}{citronellolololol} & \multicolumn{1}{c}{vanillin} & diethyl sulfide \\ \multicolumn{2}{c}{\(\alpha\)-terpineolol} & methyl salicylate & dimethyl disulfide \\ \multicolumn{2}{c}{_cis/trans_ ocimenol} & eugenol & diethyl disulfide \\ \multicolumn{2}{c}{_cis/trans_ linalooloxide (furanic form)} & _cis/trans_ isoequenol} & methyl thioacetate \\ \multicolumn{2}{c}{_cis/trans_ linalooloxide (pyranic form)} & 2-phenylethanol & ethyl thioacetate \\ \multicolumn{2}{c}{hydroxycitronellolol} & benzyl alcohol & 2-mercaptoethanolethanol \\ \multicolumn{2}{c}{8-hydroxydihydrodinalool} & acetovanillone & 2-(methylthio)-1-ethanol \\ \multicolumn{2}{c}{7-hydroxygeraniol} & benzaldehyde & 3-(methylthio)-1-propanol \\ \multicolumn{2}{c}{7-hydroxynerol} & 4-hydroxybenzaldehyde & 4-(methylthio)-1-butanol \\ \multicolumn{2}{c}{_cis/trans_ 8-hydroxylinalool} & 2,4-dimethylbenzaldehyde & 2-furanmethanethiol \\ \multicolumn{2}{c}{diendiol I} & phenylacetaldehyde & benzothiazole \\ \multicolumn{2}{c}{endiolololol} & syringaldehyde & thiazole \\ \multicolumn{2}{c}{diendiol II} & conferaldehyde & 5-(2-hydroxyethyl)-4-methylthiazolo \\ \multicolumn{2}{c}{neroloxide} & sinapaldehyde & 4-methyl-4-mercaptoethanol-2-one \\ \multicolumn{2}{c}{2-exo-hydroxy-1,8-cineol} & proprioisyringone & 3-mercaptoethanolacetate \\ \multicolumn{2}{c}{1,8-cineol} & propriovanillon & _cis/trans_ 2-methylthiophan-3-ol \\ \multicolumn{2}{c}{_cis/trans_ 1,8-terpine} & syringol & 2-methyltetrahydrodrothiophene-3-one \\ \multicolumn{2}{c}{_p_-menthenthetoid I} & coniferl alcohol & _cis/trans_ 2-methyltetrahydrodrothiophene-3-ol \\ \multicolumn{2}{c}{(_E_)-geranic acid} & vanillic alcohol & 3-mercaptoethanol-1-ol \\ \multicolumn{2}{c}{(_E_)-2,6-dimethyl- 6-hydroxyocta-2,7-dienoic acid} & sinapic alcohol & 3-mercaptoethanol-1-ol \\ \multicolumn{2}{c}{(_E_)- and (Z)-sobrerol} & _o_-cymene & 4-mercaptoethanol-4-methylpentan-2-ol \\ \multicolumn{2}{c}{_cis/trans_ rose oxide} & _p_-cymene & 3-mercaptoethanol-3-methylbutan-1-ol \\ \multicolumn{2}{c}{liac alcohols} & guaiacol \\ \multicolumn{2}{c}{triol} & 4-ethylguaiacol \\ \multicolumn{2}{c}{hortienol} & 4-vinylguaiacol \\ \multicolumn{2}{c}{myrcenol} & 4-ethylphenol \\ \multicolumn{2}{c}{limonene} & 4-vinylphenol \\ \multicolumn{2}{c}{\(\beta\)-phellandrene} & methyl anthranilate \\ \multicolumn{2}{c}{\(\beta\)-ocimene} & 2\({}^{*}\)-aminoacetophenone \\ \multicolumn{2}{c}{wine lactone} \\ \hline
**Aliphatic alcohols** & **Acids** & **Sesquierpenes** \\ \multicolumn{2}{c}{1-butanol} & isobutyric acid & rotundone \\ \multicolumn{2}{c}{2-nonanol} & isovaleric acid & farnesol \\ \multicolumn{2}{c}{3-methyl-1-butanol} & acetic acid & germacrene D \\ \multicolumn{2}{c}{2-methyl-1-butanol} & butyric acid & \(\gamma\)-cadinene \\ \multicolumn{2}{c}{isobutanol} & hexanoic acid & \(\alpha\)-ylangene \\ \multicolumn{2}{c}{1-pentanol} & octanoic acid & \(\alpha\)-farmesene \\ \multicolumn{2}{c}{1-hexanol} & decanoic acid & \(\beta\)-farmesene \\ \multicolumn{2}{c}{1-octanol} & hexadecanoic acid & meridolTwenty-four aldehydes (mostly alkyls) were identified in wine; they can form during winemaking or be present in the grapes [28]. For example, glyoxal, methylglyoxal, hydroxypropandial and glycolaldehyde form by microorganisms such as _Saccharomyces cerevisiae_ or _Leuconostoc oenos_, or can form in grapes as a consequence of _Botrytis cinerea_ grape attack [30,31]. In general, C6 aldehydes (hexanal, (_E_)-2-hexenal, and (_Z_)-3-hexenal) and (_Z_)-2-nonenal are responsible for the green, herbaceous, and sometimes bitter aroma of wines [21]. They are mainly due to the enzymatic cleavage of oxidized linoleic and linoleic acid during grape crushing before fermentation [29].