# Table Olive Flours\": An Ingredient Rich in Bioactive Compounds?
## 3 Results
### Phenolic Composition  
The phenolic composition of \"table olive flours from cv. Cobrancosa\" was determined by HPLC-DAD. In Figure 2, three chromatographs of the \"green, turning color, and black table olive flours\" are presented.  
In total, nine compounds were identified and quantified, namely: hydroxytyrosol, tyrosol, oleuropein derivatives, chlorogenic acid, verbascoside and one derivative, rutin, luteolin, and apigenin. Table 3 shows the contents of these different compounds in the three \"table olive flours\". The total contents varied between 247 and 404 mg/100 g d.m.  
Of all the compounds identified, hydroxytyrosol was the major compound in all \"table olive flours\", varying between 102 and 223 mg/100 g d.m., suggesting that table olives are generally good sources of this phenol. The \"green table olive flour\" was the one with the highest amount of this compound, followed by the \"turning color table olive flour\" and, finally, the \"black table olive flour\".  
\begin{tabular}{c c c c} \hline \hline \multicolumn{1}{c}{\multirow{2}{*}{**Phenolic Compounds**}} & \multicolumn{3}{c}{**Table Olive Flour**} \\  & **Green** & **Turning Colour** & **Black** & **\(p\)-Value** \\ \hline Hydroxytyrosol & 223 \(\pm\) 11 \({}^{\text{c}}\) & 160 \(\pm\) 27 \({}^{\text{b}}\) & 102 \(\pm\) 4 \({}^{\text{a}}\) & \textless{}0.001 \\ Tyrosol & 83 \(\pm\) 2 \({}^{\text{b}}\) & 56 \(\pm\) 12 \({}^{\text{a}}\) & 44 \(\pm\) 6 \({}^{\text{a}}\) & \textless{}0.001 \\ Chlorogenic acid & ND & 2.1 \(\pm\) 0.4 \({}^{\text{a}}\) & 3.1 \(\pm\) 0.4 \({}^{\text{b}}\) & 0.001 \\ Oleuropein derivatives & 31 \(\pm\) 3 & ND & ND & - \\ Verbascoside derivatives & ND & 10 \(\pm\) 3 \({}^{\text{a}}\) & 12 \(\pm\) 2 \({}^{\text{a}}\) & 0.126 \\ Verbascoside & ND & 20 \(\pm\) 6 \({}^{\text{a}}\) & 27 \(\pm\) 5 \({}^{\text{a}}\) & 0.080 \\ Rutin & 12 \(\pm\) 3 \({}^{\text{a}}\) & 11 \(\pm\) 2 \({}^{\text{a}}\) & 13 \(\pm\) 1 \({}^{\text{a}}\) & 0.108 \\ Luteolin & 49 \(\pm\) 1 \({}^{\text{b}}\) & 46 \(\pm\) 2 \({}^{\text{a,b}}\) & 42 \(\pm\) 3 \({}^{\text{a}}\) & 0.003 \\ Apigenin & 5.4 \(\pm\) 0.2 \({}^{\text{b}}\) & 3.9 \(\pm\) 0.2 \({}^{\text{a}}\) & 4.1 \(\pm\) 0.3 \({}^{\text{a}}\) & \textless{}0.001 \\ \hline Total & 404 \(\pm\) 16 \({}^{\text{c}}\) & 309 \(\pm\) 32 \({}^{\text{b}}\) & 247 \(\pm\) 19 \({}^{\text{a}}\) & \textless{}0.001 \\ \hline \multicolumn{1}{c}{Antioxidant activity} \\ \hline TRC (mg GAE/g extract) & 247.3 \(\pm\) 14.2 \({}^{\text{a}}\) & 302.0 \(\pm\) 41.3 \({}^{\text{b}}\) & 354.4 \(\pm\) 13.9 \({}^{\text{c}}\) & \textless{}0.001 \\ RSA DPPH (\% inhibition) & 90.5 \(\pm\) 0.5 \({}^{\text{b}}\) & 84.8 \(\pm\) 6.7 \({}^{\text{a,b}}\) & 78.1 \(\pm\) 10.2 \({}^{\text{a}}\) & 0.005 \\ RSA ABTS\({}^{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\textThe second major compound observed was tyrosol, ranging from 44 to 83 mg/100 g d.m. The highest value was again obtained in the \"green table olive flour\". No significant differences were detected among the \"turning color\" and \"black table olive\" flours.  
As the third major compound in the different flours, luteolin stood out with a concentration between 42 and 49 mg/100 g d.m. The \"green\" and \"turning color table olive\" flours showed the highest values. On the contrary, oleuppein was not detected.  
Figure 2: Chromatographic profile of the different table olive flours (**A**) Green; (**B**) Turning color; (**C**) Black, obtained by HPLC-DAD. The numbers correspond to the following compounds identified: 1—HydroxyMyrosol; 2—Tynosol; 3—Chlorogenic acid; 4—Oleuppein derivative; 5—Verbascoside derivative; 6—Verbascoside; 7—Rutin; 8—Luteolin; 9—Apigenin.  
Rutin and apigenin were the compounds detected in smaller quantities in the \"table olive flours\". No significant differences were observed between them concerning rutin. However, a higher apigenin value was observed in the \"green table olive flour\" compared to the other two flours.