# Olive Oil (Royal Cultivar) from Mill Obtained by Short Time Malaxation and Early Ripening Stage
## 2 Materials and Methods
### Phenolic Compounds  
Phenolic compounds are crucial in VOO due to their large antioxidant activity, which contributes to the typical bitter taste of the oils and especially to their shelf life [29]. For the phenolic profiling, ten compounds were evaluated, including the aglycones from ligtroside (p-HPEA-EA) and oleupropein (3,4-DHPEA-EA), along with their decarboxymethylal forms (p-HPEA-EDA and 3,4-DHPEA-EDA, respectively), the major phenolic compounds of the oils, as shown in Table 4. However, behind 3,4-DHPEA-EA and p-HPEA-EA there is a set of phenols, and we have not been able to discriminate between the closed monoaldehyde form of oleupropein aglycone and the open aldehyde form. Table 4 presents the individual content of phenolic compounds determined by HPLC (mg/kg) and the total phenols determined by HPLC (mg/kg), which is the sum of the individual phenolic compounds. The total content of phenolic compounds, primarily secoriridoids, decreased by 11% after vertical centrifugation of the oil for 30 min of malaxing. An analysis of individual phenolic compounds showed that luteolin, hydroxytyrosol, and lignans did not suffer significant variations through centrifugation. On the other hand, tyrosol, vainillinic acid, ferulic acid, p-coumaric acid, and secoriridoids had a significant decrease during centrifugation. This reduction can be attributed to the migration of the hydrophilic phenols from the oil to the water and to the increased level of dissolved oxygen in the olive oil during centrifugation, which can lead to oxidation reactions in the phenolic compounds [30; 31]. \begin{table}
\begin{tabular}{l c c c c c} \hline \hline  & **Trial 1 (15 min)** & \multicolumn{3}{c}{**Trial 2 (30 min)**} & \multirow{2}{*}{**\(p\)-Value**} & \multirow{2}{*}{**Fisher’s LSD**} \\ \hline  & **Decanter** & **Centrifuge** & **Decanter** & **Centrifuge** & \\ \hline Palmitic acid C16:0 & 14.40 \(\pm\) 0.19 a  & 14.47 \(\pm\) 0.03 a  & 14.16 \(\pm\) 0.02 b  & 14.28 \(\pm\) 0.16 a,b  & 0.0667 & 0.24 \\ Palmitoleic acid C16:1 & 1.27 \(\pm\) 0.03 a,b  & 1.29 \(\pm\) 0.00 b  & 1.23 \(\pm\) 0.00 a,b  & 0.0833 & 0.04 \\ Heptadecanoic acid C17:0 & 0.04 \(\pm\) 0.00 & 0.04 \(\pm\) 0.00 & 0.04 \(\pm\) 0.00 & 0.04 \(\pm\) 0.00 & \\ Heptadecenoic acid C17:1 & 0.09 \(\pm\) 0.00 & 0.09 \(\pm\) 0.00 & 0.09 \(\pm\) 0.00 & 0.09 \(\pm\) 0.00 & \\ Stearic acid C18:0 & 1.41 \(\pm\) 0.02 a,b  & 1.43 \(\pm\) 0.00 b  & 1.39 \(\pm\) 0.00 b  & 1.39 \(\pm\) 0.00 b  & 75.77 \(\pm\) 0.06 b  & 74.92 \(\pm\) 1.18 a,b  & 0.0690 & 1.95 \\ Linoleic acid C18:2 & 8.88 \(\pm\) 0.06 a  & 8.72 \(\pm\) 0.19 a  & 6.56 \(\pm\) 0.08 c,b  & 0.0000 & 0.26 \(\pm\) 0.00 & 0.26 \(\pm\) 0.00 & \\ Arachidic acid C20:0 & 0.04 \(\pm\) 0.02 & 0.04 \(\pm\) 0.02 & 0.05 \(\pm\) 0.00 & 0.05 \(\pm\) 0.01 & \\ Eicosenic acid C20:1 & 0.32 \(\pm\) 0.00 & 0.32 \(\pm\) 0.00 & 0.32 \(\pm\) 0.00 & 0.32 \(\pm\) 0.00 & \\ Behenic acid C22:0 & 0.08 \(\pm\) 0.00 & 0.08 \(\pm\) 0.00 & 0.08 \(\pm\) 0.00 & 0.08 \(\pm\) 0.00 & \\ Lignocic acid C24:0 & 0.06 \(\pm\) 0.00 & 0.06 \(\pm\) 0.00 & 0.06 \(\pm\) 0.00 & 0.06 \(\pm\) 0.00 & \\ SFA & 16.03 \(\pm\) 0.21 a  & 16.12 \(\pm\) 0.03 a  & 15.77 \(\pm\) 0.0A clear increase is observed with the malaxation time, going from 96.99 mg/kg to 138.86 mg/kg when the time increases from 15 min to 30 min, although the variation is different for each phenolic compound; for example, a clear increase in oleacein is seen but not in oleocanthal. Similar results have been reported by other authors who studied malaxation on separately ground samples [23; 32; 33]. However, [PERSON] et al. [34] found that malaxation time did not significantly affect phenolic content. Comparing our results with those obtained by [PERSON] et al. [3] for the same cultivar, \"Royal de Cazorla\", our values of the total content of phenolic compounds are lower, 156 mg/kg compared to 290 mg/kg; however, we must take into account that they worked at a laboratory scale and their value is an average of three crop seasons. On the other hand, [PERSON] et al.