# The Potential of Apulian Olive Biodiversity: The Case of Oliva Rossa Virgin Olive Oil
## 3 Results
### VOOs Characteristics
Although no organoleptic assessment of the oils was carried out in this study, the relationship between phenolic compounds and the sensory features of the product is well known and confirmed by numerous works [5; 44; 52]. \(p\)-HPEA-EDA, also known as olecanthal, have been proved to be the major compound responsible for pungent notes while other secorioid derivatives are more strongly linked to bitterness [44]. Considering the TPC (Table 3), the phenolic profile (Table 4) and the similarities with the data reported for the Coratina cultivar olive oils [11; 28; 53], which are well known to be strongly bitter and pungent, it might be supposed that the VOOs from the Oliva Rossa landrace have noteworthy bitter and pungent notes, although such a hypothesis should be verified by an in-depth study. To date, the few results available in the literature seem to confirm such a hypothesis [24]. The headspace volatile profile of the oils extracted in 2017/2018 is reported in Table 5. \begin{table}
\begin{tabular}{l c c c} \hline \hline
**Compound** & **S2** & **S3** & **S4** \\ \hline
3,4-DHPEA & 0.33 \(\pm\) 0.05 \({}^{\text{a,b}}\) & 0.42 \(\pm\) 0.06 \({}^{\text{a}}\) & 0.25 \(\pm\) 0.07 \({}^{\text{b}}\) \\ \(p\)-HPEA & 0.54 \(\pm\) 0.03 \({}^{\text{b}}\) & 0.54 \(\pm\) 0.02 \({}^{\text{b}}\) & 0.68 \(\pm\) 0.05 \({}^{\text{a}}\) \\ Vanillic acid & 0.19 \(\pm\) 0.02 \({}^{\text{a}}\) & 0.20 \(\pm\) 0.02 \({}^{\text{a}}\) & 0.21 \(\pm\) 0.06 \({}^{\text{a}}\) \\ Syringic acid & 0.44 \(\pm\) 0.03 \({}^{\text{a}}\) & 0.29 \(\pm\) 0.07 \({}^{\text{b}}\) & 0.36 \(\pm\) 0.04 \({}^{\text{a,b}}\) \\
3,4-DHPEA-EDA & 62.35 \(\pm\) 3.29 \({}^{\text{a}}\) & 25.81 \(\pm\) 4.57 \({}^{\text{b}}\) & 17.57 \(\pm\) 1.77 \({}^{\text{c}}\) \\
3,4-DHPEA-EDA-CARB & 1.64 \(\pm\) 0.23 \({}^{\text{b}}\) & 5.65 \(\pm\) 1.04 \({}^{\text{a}}\) & 1.31 \(\pm\) 0.40 \({}^{\text{b}}\) \\ \(p\)-HPEA-EDA & 30.87 \(\pm\) 0.93 \({}^{\text{a}}\) & 13.97 \(\pm\) 0.78 \({}^{\text{c}}\) & 20.76 \(\pm\) 1.40 \({}^{\text{b}}\) \\ Pinoresinol & 13.78 \(\pm\) 0.28 \({}^{\text{a}}\) & 9.90 \(\pm\) 0.69 \({}^{\text{c}}\) & 11.34 \(\pm\) 0.51 \({}^{\text{b}}\) \\ Luteolin & 2.02 \(\pm\) 0.23 \({}^{\text{b}}\) & 6.76 \(\pm\) 0.62 \({}^{\text{a}}\) & 2.35 \(\pm\) 2.15 \({}^{\text{b}}\) \\ \(p\)-HPEA-EA & 9.01 \(\pm\) 0.94 \({}^{\text{a}}\) & 8.63 \(\pm\) 1.68 \({}^{\text{a}}\) & 5.84 \(\pm\) 1.27 \({}^{\text{b}}\) \\ Apigenin & 3.21 \(\pm\) 0.33 \({}^{\text{a}}\) & 3.75 \(\pm\) 1.27 \({}^{\text{a}}\) & 4.31 \(\pm\) 1.50 \({}^{\text{a}}\) \\ \hline Total & 124.38 \(\pm\) 3.80 \({}^{\text{a}}\) & 75.92 \(\pm\) 7.40 \({}^{\text{b}}\) & 64.98 \(\pm\) 5.60 \({}^{\text{b}}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Identified phenolic compounds (mg GAE kg\({}^{-1}\)) of the Oliva Rossa VOOs extracted during fruit ripening in the 2017/2018 harvest season (mean \(\pm\) SD, \(n\) = 3). The volatile compounds found in Oliva Rossa oils were those usually found in good-quality VOOs [4]. The most abundant ones were C5 and C6 aldehydes, alcohols and esters deriving from the well-known lipoxygenase pathway (LOX) [4], together with a remarkable amount of 3-ethyl-1,5-ocadiene. Regardless of the ripening stage of the drupes, (E)-2-hexenal was the most abundant compound. (_E_)-2-hexenal was reported to be strongly correlated with the bitter, almond, green, green apple-like, fatty, almond-like and cut-grass notes of the VOOs [4]. In decreasing order, 3-ethyl-1,5-ocadiene was the following one. It was already detected in VOOs, although generally in quite lower concentrations [35]. The remarkable amount found in Oliva Rossa oils might be a typical trait of this olive landrace. Indeed, 3-ethyl-1,5-ocadiene was already identified as one of the markers for varietal discrimination in Turkish olive oils [54]. It is worthy to note that the results reported here refer to only one crop season and thus further studies are needed to corroborate such evidence. During ripening, significant differences in the volatile profile were observed [4,5].