## 2 Results and Discussion
### Total Phenolic Content and Phenolic Compounds Determined by LC-DAD  
The obtained results show differences in content of total phenols among tested oils (Table 4), which are probably related to the genetic factors since all the tested oils were obtained from the olive fruits cultivated in the same area, climate conditions and processing techniques. The highest value of total phenols was found in _Leccino_ oil (246.6 mg/kg) and in _Kravvica_ and _Masnjaca_ oils it was about two times lower. These results are in agreement with the findings of other authors [31,32]. For example, the mass fraction of total phenols in the oil samples from the olive fruit mixtures (Istria, Croatia) changed linearly in a strict correlation with fruit mass ratio of _Leccino_ and _Istarska beliica_ cultivars [22]. The \begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**VOO Sample**} & \(\alpha\)**-Tocopherol** & \(\gamma\)**-Tocopherol** & **Chlorophylls** & **Carotenoids** \\  & **(mg/kg)** & **(mg/kg)** & **(mg/kg)** & **(mg/kg)** \\ \hline _Kravvica_ & 176.4 \(\pm\) 0.9 & 33.7 \(\pm\) 0.1 & 4.6 \(\pm\) 0.2 & 1.8 \(\pm\) 0.1 \\ _Masnjaca_ & 223.9 \(\pm\) 0.4 & 36.1 \(\pm\) 0.2 & 4.2 \(\pm\) 0.2 & 2.1 \(\pm\) 0.1 \\ _Leccino_ & 312.4 \(\pm\) 0.3 & 42.5 \(\pm\) 0.1 & 7.3 \(\pm\) 0.6 & 4.2 \(\pm\) 0.1 \\ \hline \end{tabular} All values are expressed as mean of triplicate determinations \(\pm\) SD.  
\end{table} 
Table 3: The values of total phenols, \(\alpha\)-tocopherol, \(\gamma\)-tocopherol, total chlorophylls and carotenoids of _Masnjaca_, _Kravvica_ and _Leccino_ VOOs. amount of phenolic compounds is an important factor in evaluation of the VOO quality because of their involvement in resistance to oxidation and the sharp bitter taste of the oil. The research conducted on olive oil chemical composition highlights that the polyphenols are remarkably variable according to the variety, the agronomic conditions, the state of ripeness and the technology of conservation [33]. According to [PERSON] [34], a wide range of total phenolic content has been reported (50-1,000 mg/kg), but values are usually between 100 and 300 mg/kg, which is similar to the values found in the investigated samples. Antioxidant activity measured with the DPPH antiradical assay also showed the highest value in hydrophilic fraction of _Leccino_ oil (1.3 mmol TEAC/kg) and a statistically significant correlation was found between the total phenolic content and the DPPH values (r\({}^{2}=0.9856,p<0.01\)). LC coupled to DAD was utilized to characterize the polar compounds in _Masnjaca_, _Krvavica_ and _Leccino_ VOOs. The phenolic fraction chromatograms are quite similar for three samples, and Table 5 reports only positively detected phenolic compounds. _Leccino_ and _Masnjaca_ VOOs are characterized by high amount of 3,4-DHPEA-EDA, the dialdehyde form of decarboxymethylelenolic acid linked to hydroxyytrosol (also known as decarboxymethyl oleuropein aglycon). _Krvavica_ VOO contains higher amounts of hydroxyytrosol and tyrosol than _Masnjaca_ and _Leccino_ VOOs and it is the only oil where vanillic acid and _p_-coumaric acid were detected. These results are similar to those reported by several authors for other monovarietal VOOs [12,32]. \begin{table}
\begin{tabular}{c c c} \hline
**VOO sample** & **Total phenols (mg GAE/kg)** & **DPPH (mmol TEAC/kg)** \\ \hline _Krvavica_ & \(121.4\pm 1.9\) & \(0.5\pm 0.0\) \\ _Masnjaca_ & \(143.4\pm 4.9\) & \(0.5\pm 0.0\) \\ _Leccino_ & \(246.6\pm 2.6\) & \(1.3\pm 0.0\) \\ \hline \end{tabular}
\end{table} 
Table 4: Total phenolic content and antioxidant activities (DPPH assay) of hydrophilic fractions of _Masnjaca_, _Krvavica_ and _Leccino_ VOOs. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline  & & **LOD** & **LOQ** & _Masnjaca_ & & _Kravavica_ & & _Leccino_ \\
**No. ** & **Compounds** & **RT** & **(mg/kg)** & **(mg/kg)** & & **(mg/kg)** & & **(mg/kg)** & & **(mg/kg)** \\ \hline  & & & & & **Min** & **Max** & **Mean \(\pm\) SD** & **Min** & **Max** & **Mean \(\pm\) SD** \\ \hline
1.