## 3 Results
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & EVOO [23] & SAO [16] & AKO [24] & JO \({}^{*}\)[17] \\ \hline \multicolumn{5}{c}{**Fatty Acids (tar/mg/kg)**} \\ \hline
**MUFAs** & e.g., oleic acid: 55–83\% & e.g., oleic acid: 60\% & e.g., oleic acid: 60-71\% & e.g., oleic acid: 10\%; \\ \hline
**PUFAs** & e.g., linoleic acid: 4–20\% & e.g., linoleic acid: 37\% & e.g., linoleic acid: 20–23\% & \\ \hline
**SFAs** & e.g., palmitic acid: 7.5–20\%; & e.g., palmitic acid: 9\% & e.g., palmitic acid: 2.9-3.4\%; & e.g., palmitic acid: 1.2\%; \\ \hline \multicolumn{5}{c}{**Unsaponifiable fraction**} \\ \hline
**Tocopherobs** & 97–785 mg/kg & e.g., \(\alpha\)-tocopherol: 20 mg/kg; & e.g., \(\alpha\)-tocopherol: 14.8–40.4 mg/kg; & \\ e.g., \(\alpha\)-tocopherol: 100–330 mg/kg & \(\beta\)-tocopherol: 2 mg/kg; & \(\gamma\)-tocopherol: 330.8–520.8 mg/kg; & e.g., \(\gamma\)-tocopherol? 9\% \\ \hline \multicolumn{5}{c}{**50–800 mg/kg**} \\
**Phenols (TPC)** & e.g., Tynosol, hydroxypropyl, and & & \\ \multicolumn{5}{c}{secoritoids: ca. 90\%;} \\ \multicolumn{5}{c}{lignants: ca. 10\%} \\ \hline
**Pignents** & 1–20 mg/kg & e.g., \(\beta\)-carotene: 57.2 \(\mu\)g/g & \\ \hline
**Hydrocarbons** & 200–7500 mg/kg & e.g., squalec: 100 mg/g & \\ \hline \multicolumn{5}{c}{**Waxes**} \\ \hline \hline \end{tabular}  
* MOFAs: Mono-Unsaturated Fatty Acids; PUFAs: Poly-Unsaturated Fatty Acids; SFAs: Saturated Fatty Acids.
* JO is composed of almost 98% pure waves (wax esters, free acids, free alcohols, and hydrocarbons), sterols, and vitamins with few triglyceride esters; so, it is widely known as liquid wax rather than oil. It also contains other fat-soluble vitamins such as vitamin A [17].  
\end{table} 
Table 1: Quali-quantitative composition of EVOO, AKO, SAO, and JO. bimodal curve obtained when plotting the H\({}_{\text{p/p}}\) as a function of incubation time at 70 \({}^{\circ}\)C. Figure 2 is reported as a representative example of IT determination. The IT values for all the tested samples are reported in Table 2.  
Higher IT values correspond to enhanced oxidative resistance and thus reduced free radical formation; conversely, smaller IT values indicated the susceptibility to free radical formation and, therefore, reduced oxidative stability of the oil. As reported in Table 2, the IT values calculated for not-irradiated oils suggest that EVOO and JO are more resistant to the formation of free radicals than ASO and AKO. Following the UV irradiation, the IT  
Figure 1: EPR spectra of the PBN spin adducts in EVOO after 30 min of incubation at 70 \({}^{\circ}\)C with the not-irradiated (black line) sample and UV-irradiated ones (30 min: green line; 60 min: blue line; 120 min: red line). Results are reported as means (n = 6). Figure 2: Determination of the induction time (IT) for EVOO (sample not irradiated). Results are reported as means (n = 6). values decrease almost proportionally with irradiation time for all the analyzed oils. Again, EVOO and JO turn out to be the most powerful in terms of antioxidant properties as they displayed the greater IT values after 120 min of UV irradiation. These results indicate that during the UV irradiation treatment, the natural antioxidant agents contained in EVOO and JO samples were more powerful than the AKO and SAO ones, thus not yet being exhausted after 120 min of UV treatment. The slope of the linear portion of the signals as a function of incubation time after the IT could be a simple way to measure the oxidative stability in later stages, when the depletion of oil's antioxidants is happening. In order to confirm the obtained results, the slope of the linear portion of the graphs obtained by plotting the H\({}_{\text{p/p}}\) values as a function of incubation time at 70\({}^{\circ}\) were evaluated. First of all, to better discuss and visualize the obtained data, each tested oil will be reported by itself.