## 3 Results and Discussion
### Volatile Compounds VOCs  
The volatile fraction was analysed by head-space SMPE during the different phases of winemaking, allowing the identification of some classes of compounds (acids, alcohols, esters) present both at packing (Table 10) and at the end of aging (Table 11). The most significant compounds of the individual classes present were phenyl-ethyl alcohol, _iso_-pentyl alcohol and 2 methyl-butanol, which are characterised by spicy and toasted notes and are strongly influenced both by the variety of grapes and the type of aging [23]. The main esters were ethyl octanoate, ethyl decanoate, ethyl hexanoate, isoamyl acetate, ethyl decanoate, which are characterised by fruity-floranl scents. ### Volatile Compounds VOCs  
The volatile fraction was analysed by head-space SMPE during the different phases of winemaking, allowing the identification of some classes of compounds (acids, alcohols, esters) present both at packing (Table 10) and at the end of aging (Table 11). The most significant compounds of the individual classes present were phenyl-ethyl alcohol, _iso_-pentyl alcohol and 2 methyl-butanol, which are characterised by spicy and toasted notes and are strongly influenced both by the variety of grapes and the type of aging [23]. The main esters were ethyl octanoate, ethyl decanoate, ethyl hexanoate, isoamyl acetate, ethyl decanoate, which are characterised by fruity-floranl scents. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Constituents** & **Lr.i. ** & **C** & **CP** & **T** & **TP** & **G** & **GP** \\ \hline acetic acid & 602 & 1.2 \(\pm\) 0.14 a & 1.0 \(\pm\) 0.15 b & 0.8 \(\pm\) 0.13 c & 0.7 \(\pm\) 0.10 c & 1.4 \(\pm\) 0.08 a & 1.3 \(\pm\) 0.12 a  
From tracking to the end of aging these two classes of compounds tended to have an opposite trend, in fact, esters tended to decrease over time, while alcohols/phenols and aldehydes/ketones tended to increase. From the statistical analysis (PCA) (Figure 5) it is possible to note that at the time of racking, the wines were associated in two different groups according to the area of origin; in fact, the wines from the areas of C and G were similar from the aromatic point of view regardless of the protocol adopted, while they differed considerably from the wines from the T area. However, PCA was able to separate C and G wines, too. If we go into more detail regarding the two different groups, it was possible to note that at the end of the alcoholic fermentation there were no differences within the same area between the wines produced with co-inoculation or sequential inoculation, demonstrating that the effect of the area, and on the technology adopted, in these phases, is prevalent. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Constituents** & **L.ri. ** & **C** & **CP** & **T** & **TP** & **G** & **GP** \\ \hline methyl acetate & 528 & 1.0 \(\pm\) 0.02 a & 0.7 \(\pm\) 0.03 c & 0.0 \(\pm\) 0.01 e & 0.9 \(\pm\) 0.04 b & 0.2 \(\pm\) 0.02 d & 0.9 \(\pm\) 0.03 b \\ acetic acid & 602 & 4.2 \(\pm\) 0.52 a & 2.9 \(\pm\) 0.32 b & 3.8 \(\pm\) 0.48 a & 2.2 \(\pm\) 0.52 b & 4.3 \(\pm\) 0.45 a & 2.8 \(\pm\) 0.42 b \\ ethyl acetate & 603 & 5.6 \(\pm\) 0.51 a & 5.8 \(\pm\) 0.48 a & 3.2 \(\pm\) 0.44 c & 4.7 \(\pm\) 0.40 b & 3.8 \(\pm\) 0.50 c & 6.2 \(\pm\) 0.53 a \\
3-methylbutanol & 736 & 7.5 \(\pm\) 0.65 b & 8  
From the hierarchical cluster analysis (Figure 5), it is possible to notice how at the time of racking (t = 1) the wines were associated in two different groups; through the analysis of the PCA (Figure 6) it is possible to note that there were no differences within the same area, at the end of the alcoholic fermentation, between the wines produced with co-inoculation and sequential inoculation. The hierarchical analysis (Figure 5) carried out at the end of aging (t = 6) showed that wines tended to associate in three groups, independent of the area of origin of the grapes, denoting that the wine-making technology had greatly influenced the odorous expression of the wines.