## 3 Results and Discussion
### Sensory Analysis  
Data obtained from one-way ANOVA showed significant differences (\(p<0.05\)) among the eight wine samples for the following attributes: color intensity, body, aftertaste, and persistency (Figure 1). More specifically, wine NS1 was rated to have the lowest color intensity, a scarce body, to be less persistent, and to have a low aftertaste. In relation to agronomic characteristics, this vineyard has the highest yield per vine with respect to all the other samples. This wine was followed by NS3 and NS5. Both wines received a low rating by the panel in relation to persistence and aftertaste. The NS4 sample reached the highest rating in relation to body, persistence, and aftertaste. It is important to underline the fact that this wine, as reported above, was characterized by the highest concentration of VOCs compounds. The CS1 and CS2 wines are characterized by a good color intensity, which was more intense, but not significantly more than the remaining samples. They also showed the highest astringency with respect to the other samples, although, once again, the difference was not statistically significant. The SS1 sample was the least herbaceous and was characterized by a good scent of rose. The quantitative data relating to wine VOCs and sensory data were subjected to principal component analysis in order to extract the most relevant information [32]. As reported in Figure 2, the PC1 explained 34.7% of the total variance, while PC2 explained 19.5%. In the bi-plot, three groups were evident. The first group was represented by samples NS1 and NS5, the second by CS1, CS2, and NS3, and the third group included SS1, NS2, and NS4 samples. The latter group was characterized by the highest VOC content, as reported above, and corresponded with the highest sensory attribute ratings. This group has in common the type of clone, CFC13, and the same rootstock, 1103P. With regard to the second group, formed by CS1, CS2 and NS3 samples, it can be observed that these wines derive from local selections. The first group, composed by NS1 and NS5, is characterized by wines obtained from different clones and different rootstocks, although they are situated in the same quarter of the biplot (Figure 2). Regarding the influence of the choice of rootstocks on the aroma compounds content, the literature is still scarce. However, similar to our results, differences induced by different rootstocks on aroma compounds were observed in potted Sauvignon Blanc and Cabernet-Sauvignon grapevines [48] and in wines obtained from cv. Albarin negro grown in the Asturias [49]. In our case, differences in the VOC content could be better explained by the type of clone. In fact, clones that confer less vigor to the grapevine, such as the CFC13, could promote, directly or indirectly, the synthesis of secondary metabolites. Figure 1: Graphical representation of the sensory profile of Cannonau wine samples. Values indicate the means for each attribute. The F values represent significant differences between the samples in relation to the individual attributes marked with the asterisk * (\(p<0.05\)). NS1-5 = north Sardinian wines; CS1-2 = central Sardinian wines; SSI = south Sardinian wines. OD represents olfactory attributes, while sensory attributes followed by FL (flavor) represent flavor attributes. In the bi-plot, the samples NS4, SS1, and NS2 were correlated to the medium-chain fatty acid esters: ethyl-butanoate, -hexaneoate, -octanoate, and -decanoate, meaning that these wines contained high concentrations of these aromas in comparison with the other samples. This could have increased the fruity and floral notes perceived by the panel, confirming our findings reported above in relation to the VOC content for these wines. The wines NS1 and NS5, in comparison with the other samples, were characterized by hints of prune, which seems to be correlated with the presence of benzaldehyde, methyl 2-hydroxybenzoate, and 2-ethyl-1-hexanol (equivalent sensory terms: bitter almond, sweet, and mild floral, respectively).