## 3 Results and Discussion
The concentration of bioactive phenolic compounds, evaluated over the two years, showed a considerable annual variability but highlighted that 'Calatina' has particularly high values of bioactive phenolic compounds when compared with oils obtained from 'Nocellara' (Table 4). The main phenols were the oleupopein derivatives, especially 3,4-DHPEA-EDA (oleacin), while less evident but still significant differences were observed for the ligstroside derivatives such as p-HPEA-EDA (oleocantal) and ligstroside aglycon. The lignans, which include pinoresinol and acetoxypinoresinol, did not show important differences compared to the values observed in virgin olive oils from 'Nocellara'. High concentrations of bioactive phenolic compounds allow the production of extra virgin olive oils characterized by the health claim on phenolic compounds based on reg. EU 432/2012, even in areas characterized by hot and dry climates. Olive oils produced from 'Abunara' trees showed higher phenolic concentrations than oils produced from 'Nocellara' only in 2021 but, in both years, lower phenolic concentrations than the oils obtained from 'Calatina' trees. The highest differences were found in the oleupopein derivatives, mainly in 3,4-DHPEA-EDA (Table 4). \begin{table}
\begin{tabular}{l c c c} \hline \hline  & **Abunara** & **Calatina** & **Nocellara** \\ \hline \hline  & _2020_ & & \\ \hline
3,  
Considering the volatile compounds responsible for the virgin olive oil flavor, with particular emphasis on the compounds deriving from the lipoxygenase pathway, the oils obtained from 'Calatina' trees showed a high content of unsaturated aldehydes at C6. The highest levels were those of the trans-2-hexenal, responsible for the \"cut grass\" sensory note. Despite a relevant annual variability, the concentration of esters, such as hexenyl acetate, associated with the \"floral\" sensory note, was also high in the oils from 'Calatina'. The olive oils produced by 'Abunara' showed the highest amount of trans-2-hexenal in both years of production and the highest concentration of (_Z_)-3-Hexenyl acetate in 2021. The overall aromatic composition of 'Abunara' olive oils indicates that drupes of this cultivar are characterized by high levels of lipoxygenase activity, leading to the production of virgin olive oils with a high level of positive sensory notes such as cut grass and floral (Table 5). \begin{table}
\begin{tabular}{l c c c} \hline \hline  & **Abunara** & **Calatina** & **Nocellara** \\ \hline  & & _2020_ & \\ \hline  & _Aldehydes_ & & \\ Pentanal & 38 \(\pm\) 2.0 a \({}^{\mathrm{z}}\) & 38 \(\pm\) 5.0 a & 30 \(\pm\) 2.0 a \\ (E)-2-Pentenal & 47 \(\pm\) 5.0 a & 16 \(\pm\) 2.0 b & 44 \(\pm\) 2.0 a \\ Hexanal & 645 \(\pm\) 3.0 a & 321 \(\pm\) 7.0 c & 397 \(\pm\) 24 b \\ (E)-2-Hexenal & 13,537 \(\pm\) 96 a & 8946 \(\pm\) 11 b & 8169 \(\pm\) 52 c \\ (E,E)-2.4-Hexadienal & 181 \(\pm\) 1.0 a & 75 \(\pm\) 1.0 c & 82 \(\pm\) 1.0 b \\ Sum of the aldehydes at C5 and at C6 & 14,448 \(\pm\) 96 a & 9396 \(\pm\) 14 b & 8722 \(\pm\) 57 c \\ \multicolumn{3}{c}{_Alcohols_} \\
1-Pentanol & 446 \(\pm\) 5.0 a & 356 \(\pm\) 0.4 b & 309 \(\pm\) 1.4 c \\
1-Penten-3-ol & 137 \(\pm\) 3.0 a & 69 \(\pm\) 4.0 c & 85 \(\pm\) 2.0 b \\ (E)-2-Penten-1-ol & 59 \(\pm\) 1.0 a & 61 \(\pm\) 1.0 a & 55 \(\pm\) 0.1 b \\ (Z)-2-Penten-1-ol & 473 \(\pm\) 4.0 a & 296 \(\pm\) 5.0 b & 312 \(\pm\) 2.0 b \\ \hline \end{tabular}
\end{table} 
Table 5: Volatile composition (\(\mu\)g kg\({}^{-1}\)) of virgin olive oils from ‘Abunara’, ‘Calatina’, and ‘Nocellara del Belice’ olive trees grown as central leaders at 2 \(\times\) 5 m (CLx2, A), free palmette at 3 \(\times\) 5 m (FPx3), globe vase at 4 \(\times\) 5 m (GVx4), and polyconic vase at 5 \(\times\) 5 m (PVx5) in the last two years of trials. Data are expressed as means \(\pm\) standard deviation (n = 12). For each cultivar, data from different planting systems were pooled together.