# Influence of Microbial Treatments on Vine Growth and Must Quality: Preliminary Results
## 2 Results and Discussion
### Aroma Composition
#### 2.4.1 Whole Grapes  
The complete chemical compositions of the headspaces of the whole grapes harvested from both control and treated vines are reported in Table 4. Overall, 19 compounds were identified, mainly belonging to the class of non-terpene derivatives that were higher in the Bioma grapes compared to the control ones. In detail, within this class, 2-octanone was found as the major compound in both the samples, even though it was significantly higher in control grapes (57.0%) than in Bioma ones (28.8%). Besides this molecule, not-negligible amounts of other ketones, including 2-hexanone, 2-heptanone, 6-methyl-5-hepten-2-one, 2-nonanone, and 2-undecanone, were detected, and among these, 2-heptanone was significantly higher in the control grapes, and 2-undecanone prevailed in Bioma sample, while the other showed no significant differences. Ketones were reported by [PERSON] et al. [35] as one of the major chemical classes detected in grape berries, with the continuous presence of 2-octanone in all the investigated varieties. Although no literature studies have suggested the influence of vineyard treatment with these components, the present study emphasized a strong effect of Bioma on the vine metabolic pathways leading to the biosynthesis of these molecules.  
\begin{table}
\begin{tabular}{l c c c c c} \hline \hline \multirow{2}{*}{**Compounds**} & \multirow{2}{*}{**Lri. 1**} & \multirow{2}{*}{**Class**} & \multicolumn{2}{c}{**Relative Abundance (\%) \(\pm\) Standard Deviation**} & \multirow{2}{*}{**Significance Level**} \\ \cline{3-3} \cline{5-6}  & & & **Control Grapes** & & & \\ \hline \hline \multirow{2}{*}{Heptane} & 700 & nt & \(7.2\pm 0.53\)  & \(*\) \\ \hline \hline
2-Hexanone & 790 & nt & \(2.1\pm 0.02\) & \(2.0\pm 0.09\) & n.s. \\ \hline (Z)-3-Hexen-1-ol & 896 & nt & \(0.4\pm 0.11\) & \(1.8\pm 0.11\) & *** \\ \hline
1-Hexanol & 903 & nt & \(2.7\pm 0.28\)  & *** \\ \hline
2-Heptanone & 926 & nt & \(13.7\pm 1.18\)  & ** \\ \hline
1-Octen-3-ol & 976 & nt & \(1.1\pm 0.13\)  & ** \\ \hline
6-Methyl-5-hepten-2- & 986 & nt & \(1.5\pm 0.18\) & \(2.5\pm 1.07\) & n.s. \\ one & 990 & nt & \(57.0\pm 0.11\)  & ** \\ \hline Pseudocumene & 990 & nt & \(1.1\pm 0.11\)  & \(*\) \\ \hline \hline
3-Ethyl-1-hexanol & 1030 & nt & -2,8 & \(1.2\pm 0.17\)  & ** \\ \hline \hline \end{tabular}
\end{table}
Table 4: Complete volatile profile of the whole grape berries.  
While control grape berries were characterized by a prevalence of ketones, those of Bioma showed greater relative amounts of the aliphatic hydrocarbon heptane and f the non-terpene alcohols, particularly represented by 1-hexanol, responsible for fruity, flowery, grassy, and green characters [36].  
[PERSON] et al. indicated this molecule as one of the most abundant alcohols present in mature grape berries, with few differences among different varieties and different vintages. Therefore, the differences highlighted in the present work could probably be linked to an enhanced metabolic activity related to the mycorrhizal fungi treatment [37].  
In addition, Bioma grapes showed consistently higher relative amounts of monoterpene hydrocarbons, the only two components of which were limonene and pseudocumene. Monoterpenes have been widely reported as markers of wine varieties [38]. However, no study has yet investigated the effect of vine treatment on their metabolism. In the present study, the mycorrhizal treatment seemed to be responsible for the increased biosynthesis of those flavor compounds usually associated with a possible improvement of the aroma profile [39].