## 3 Results
### Effect of PEF Technology on the Phenolic and Tocopherol Composition of VOO  
In the previous sections it has been shown that the application of PEF technology to the industrial production of VOO can increase the oil extraction yield without affecting the VOO trade standards. However, the main objective of our study was to evaluate the possible benefits of the application of PEF technology to increase the functional and organoleptic quality of VOO. In this sense, the profile of phenolic compounds and tocopherols in the oils was analyzed. The phenolic composition of the oils obtained from cultivars 'Manzanilla' and 'Hoijblanca' was clearly different (Table 5). The total phenolic contents of the 'Manzanilla' oils were always quite high, above 500 mg kg\({}^{-1}\), while the phenolic contents of the 'Hoijblanca' oils were extremely low, well below the limit of 250 mg kg\({}^{-1}\) of hydroxytyrosol and derivatives established by the EFSA health claim ([PERSON] et al., 2016). As shown in Table 5, the application of PEF technology in the oil extraction of the 'Manzanilla' cultivar resulted in significantly (\(p\leq 0.05\)) higher contents of phenolic compounds in both the pilot and industrial extraction tests. On the contrary, no positive effect of the PEF treatment was observed on the phenolic content in the oils of the cultivar 'Hoijblanca'. \begin{table}
\begin{tabular}{l l c c c c} \hline  & & **Fruity** & **Bitter** & **Pungent** & **Defects** & **Classification** \\ \hline
1 st pilot tests & Manzanilla Control & 3.8 & 3.8 & 4.2 & 0.0 & Extra virgin \\  & Manzanilla PEF & 4.4 & 4.4 & 5.3 & 0.0 & Extra virgin \\
2 nd pilot tests & Manzanilla Control & 4.4 & 3.3 & 4.8 & 0.0 & Extra virgin \\  & Manzanilla PEF & 4.6 & 4.5 & 5.1 & 0.0 & Extra virgin \\
3 rd pilot tests & Hoijblanca Control & 3.6 & 2.6 & 3.4 & 1.4 (winey) & Virgin \\  & Hoijblanca PEF & 2.8 & 3.1 & 3.8 & 2.2 (winey) & Virgin \\ Industrial tests & Manzanilla Control & 4.3 & 4.85 & 4.7 & 0.00 & Extra virgin \\  & Manzanilla PEF & 4.45 & 4.10 & 5.1 & 0.00 & Extra virgin \\ \hline \end{tabular}
\end{table} 
Table 4: Sensory evaluation of control and PEF oils obtained from ’Manzanilla’ and ’Hoijblanca’ cultivars. \begin{table}
\begin{tabular}{l l c c c c} \hline  & & **Acidity** & **Peroxide Value** & **K\({}_{\text{232}}\)** & **K\({}_{\text{270}}\)** & **Rancimat** \\  & & **(\% Oleic Acid)** & **(meq O\({}_{\text{2}}\) kg\({}^{-1}\))** & **K\({}_{\text{232}}\)** & **K\({}_{\text{270}}\)** & **(h)** \\ \hline
1 st pilot tests & Manzanilla Control & 0.20 & 5.71 & 1.65 & 0.12 & 13.45 \\  & Manzanilla PEF & 0.20 & 5.07 & 1.59 & 0.12 & 14.16 \\
2 nd pilot tests & Manzanilla Control & 0.16 & 6.39 & 1.70 & 0.13 & 12.81 \\  & Manzanilla PEF & 0.16 & 5.33 & 1.66 & 0.13 & 13.71 \\
3 rd pilot tests & Hoijblanca Control & 0.24 & 10.63 & 1.91 & 0.11 & 4.90 \\  & Hoijblanca PEF & 0.22 & 9.80 & 1.86 & 0.11 & 5.13 \\ Industrial tests & Manzanilla Control & 0.37 & 4.51 & 12.85 & 1.52 & 12.85 \\  & Manzanilla PEF & 0.37 & 4.53 & 11.62 & 1.52 & 11.62 \\ \hline \end{tabular}
\end{table} 
Table 3: Trade standards for olive oils from cultivars ’Manzanilla’ and ’Hoijblanca’ extracted with a standard protocol (Control) and by applying pulsed electric field (PEF) technology. In addition to analyzing the final phenolic content of the oils, different trials were conducted to determine the effect of malaxation time, after the application of PEF technology, on the extraction/formation of key phenolic compounds. In this sense, different trials with cultivar 'Manzanilla' were conducted at different malaxation times: 0, 30 and 45 min. Data obtained on the phenolic composition of the oils suggests that the accumulation kinetics of phenolic compounds in the oil are clearly different in PEF-treated olive paste than in control extractions. Figure 1 shows the content of oleacein (3,4-DHPEA-EDA) (Figure 1A) and oleocanthal (p-HPEA -EDA) (Figure 1B), perhaps the two phenolic components with the highest impact on the functional [29] and flavor properties of VOO [30].