## 3 Results
### HPLC-RF Separation, Identification and Quantification of Tocopherol Isomers  
For tocopherol' quantitation, the HPLC separation with fluorescence (RF) detection allowed the registration of the peak intensities of each type of the four isomers (\(\alpha\), \(\beta\), \(\gamma\), \(\delta\)), comparative to pure standards, as presented in Table 4.  
The total concentration of tocopherols (TOC) ranged from 12.52 mg/100 g (commercial PO1-3) to 178.435 mg/100 g in EVOO2.4. Besides EVOO, the SBO, SO and SFO oils proved to be oils rich in tocopherols. Concomitantly, variations of the four tocopherol isomer levels were noticed in some groups. The SFO oils were characterized by high \(\alpha\)-tocophenols, while SO was rich in \(\gamma\) and \(\delta\)-tocpherols. In the SBO group, the authentic sample had a 1:1 ratio of \(\beta\)- and \(\gamma\)-tocpherols, as major isomers, while the commercial samples showed decreased concentrations.  
The univariate one-way ANOVA including [PERSON]'s HSD post-hoc test (Table S6 including the graphic representations of significant differences) reflected the significance of differences between the oil groups, considering the different tocopherol isomers: \(\alpha\)-tocopherol was dominant in olive oils EVOO and to a lesser extent in SBO, \(\beta\)-tocopherol had the highest level in SBO, and \(\delta\)-tocopherol was dominant in SO samples. Meanwhile in all oils \(\beta\)-tocopherol was commonly found in different concentrations. The PLSDA score plot shows in this case a co-variance of 61.1% for the first two components, with good discrimination between EVOO, SBO and SO oils.  
Figure 4 shows the PLSDA score plot for the discriminatory analysis considering their tocopherol contents, and also the heatmap illustrating the specificity of individual oils and oil categories.  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Mean Values \(\pm\) SD** & \(\alpha\)**-Tocopherol** & \(\beta\)**-Tocopherol** & \(\gamma\)**-Tocopherol** & \(\delta\)**-Tocopherol** \\ \hline SFO1-3 & 50.955 & 2.257 & 4.887 & 0.000 \\ SD & 0.290 & 2.285 & 3.779 & 0.000 \\ aSFO4 & 55.340 & 2.560 & 1.670 & 0.000 \\ \hline PO1-3 & 6.833 & 6.540 & 32.203 & 2.393 \\ SD & 4.923 & 10.375 & 8.394 & 1.315 \\ aPO4 & 11.670 & 3.450 & 32.340 & 2.930 \\ \hline LSO1-2 & 0.835 & 6.375 & 12.270 & 0.385 \\ SD & 0.672 & 1.025 & 4.059 & 0.021 \\ aLSO3 & 1.970 & 6.650 & 13.660 & 0.980 \\ \hline HO1-3 & 4.213 & 2.507 & 35.877 & 1.783 \\ SD & 1.592 & 1.020 & 6.855 & 0.524 \\ aHO4 & 4.430 & 2.890 & 36.440 & 1.980 \\ \hline SO2-3 & 7.725 & 0.000 & 57.955 & 36.390 \\ SD & 1.633 & 0.000 & 2.496 & 9.433 \\ aSO1 & 13.410 & 0.000 & 60.740 & 19.910 \\ \hline WO1-3 & 3.700 & 1.287 & 18.343 & 4.220 \\ SD & 1.854 & 1.118 & 4.148 & 0.944 \\ aWO4 & 3.220 & 1.660 & 17.550 & 3.980 \\ \hline SBO2-4 & 73.943 & 29.207 & 2.887 & 0.000 \\ SD & 33.263 & 18.390 & 1.636 & 0.000 \\ aSBO1 & 23.400 & 42.250 & 42.690 & 0.000 \\ \hline EVOO1,3 & 82.885 & 3.210 & 6.935 & 2.060 \\ SD & 105.366 & 1.089 & 7.969 & 1.923 \\ \hline EVOO2,4 & 154.135 & 10.500 & 13.800 & 0.000 \\ SD & 17.487 & 3.422 & 3.437 & 0.000 \\ \hline \end{tabular}
\end{table}
Table 4: Mean values (mg/100 g) of individual tocopherol isomers separated and identified in commercial and authentic oils. For oil abbreviations, see Table 1.