## 2 Results and Discussion
### Total Phenolic Amounts and Targeted Phenolic Analysis  
The phenolic composition of olive oil is very complex and the average concentration of these compounds depends on several factors including maturation stage, part of the fruit, variety, season, packaging, storage, climatologic conditions and the production technology [14]. VOO is well known for its high content of phenolics along with oleic acid and tocopherols that exhibit health-promoting properties [32]. Phenolic compounds influence the sensory properties (flavor, bitterness, _etc._) of olives and the oil, and they protect against oxidative rancidity by acting as antioxidants, which are increasingly being recognized by playing a beneficial role in the diet [33]. Significant differences in total phenols (TPs) content among several HFs of the samples were observed (Table 4). _Oblica_ oil exhibited the highest TPs amount (212.21 mg/kg), while _Levantika_ oil showed the lowest TPs content (144.60 mg/kg). _Lastovka_ oil was quite similar to _Oblica_ oil considering TPs amount (206.09 mg/kg). It is generally accepted that the TP's level varies in the oils obtained from different cultivars and areas. Discrimination among the olive oil samples with the same geographical origin and different cultivars was possible by comparing TPs [32]. Another authors [34] claim that phenolic composition was found to be not useful in discriminating the olive oil samples due to the fact \begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**VOO Sample**} & \multirow{2}{*}{\(\alpha\)**-Tocopherol**} & \multirow{2}{*}{\(\gamma\)**-Tocopherol**} & \multirow{2}{*}{**Chlorophylls**} & \multirow{2}{*}{**Carotenoids**} \\  & & **(mg/kg)** & **(mg/kg)** & **(mg/kg)** \\ \hline _Oblica_ & \(213.24\pm 2.22\)a & \(33.19\pm 1.86\)a & \(4.07\pm 1.21\)a & \(1.89\pm 0.37\)a \\ _Lastovka_ & \(177.82\pm 4.0\)b & \(24.13\pm 1.18\)b & \(4.75\pm 0.61\)a & \(2.06\pm 0.21\)a \\ _Levantinka_ & \(222.0\pm 7.17\)a & \(31.84\pm 2.16\)a & \(3.86\pm 0.85\)a & \(2.00\pm 0.27\)a \\ \hline \end{tabular} All values are expressed as mean of triplicate determinations \(\pm\) SD; the mean values within each column labeled with different letters are significantly different (Tukey’s test, \(p<0.05\)).  
\end{table} 
Table 3: The amount of \(\alpha\)-tocopherol, \(\gamma\)-tocopherol, total chlorophylls and carotenoids of _Oblica_, _Lastovka_ and _Levantinka_ VOOs. that TPs content of the oils was affected not only by the olive cultivars, but also by the climatic and environmental conditions, agronomic practice and the technological process. TPs content ranged from 50 to 1.000 mg/kg, but the values usually amount from 100 to 300 mg/kg [35] that is similar to the values found in the investigated samples. TPs content of the samples in this study could be considered as medium-high levels in accordance with previous reports [23, 32, 34, 36]. Olive oil hydrophilic extracts contain a large number of phenolic compounds including simple phenols, lignans, and secoiridoids, which exhibit antioxidant properties [37]. Among the phenolic compounds found in extra-virgin olive oils, \(o\)-dihydroxyphenolics are very potent antioxidants [38]. Free radicals are generated in the human body through aerobic respiration and exist in different forms, including superoxide, hydroxyl, hydroperoxyl, peroxyl and alkoxyl radicals. Natural antioxidant enzymes in healthy individuals remove these free radicals while dietary antioxidants assist the body in neutralizing free radicals. Therefore, it is important to consume foods with high contents of antioxidants, such as virgin olive oil, to reduce the harmful effects of oxidative stress [39]. Antioxidant activity measured by DPPH assay showed the highest value in hydrophilic fraction of _Oblica_ oil (0.91 mmol TEAC/kg) and statistically significant lowest value in _Levantinka_ oil (0.55 mmol TEAC/kg). The difference in antioxidant activity of tested oils may depend on the total phenol content in the varieties.