## 3 Results
### HPLC-DAD Separation, Identification and Quantitation of Carotenoids  
Table 3 represents the mean concentrations of carotenoids found in commercial SFO, PO, LSO, HO, SO, WO, EVOO and SBO oils, comparative to authentic oils from each category. The retention time and the absorption spectra determined by diode array detection (DAD) were useful for the identification of individual molecules, while the peak intensity values recorded from the UV-VIS spectra were used to calculate the concentration. Concerning the total carotenoid content, a large range of concentrations were noticed, from mean values of 0.092 mg/100 g in SFO, to 0.15 mg/100 g in WO, 0.452 and 0.257 mg/100 g in LSO and PO, respectively, 0.366-0.395 mg/100 g in EVOO, 0.471-0.906 mg/100 g in SO, and 49.470-129.751 mg/100 g in SBO. SBO was, by far, the richest source of these pigments. The univariate one-way ANOVA including [PERSON]'s HSD post-hoc test (Table S5 includes the graphic representations of significant differences) reflected the significance of differences between the oil groups, considering carotenoids; SBO was, by far, the richest source of \(\beta\)-carotene, lutein, zeaxanthin and \(\beta\)-cryptoxanthin, while PO was the richest source of \(\beta\)-carotene epoxide, and SO a source of high \(\beta\)-carotene di  
Figure 3: (**a**) PLSDA score plot for the discriminatory analysis of the eight classes of oils, considering their carotenoid contents. (**b**) Heatmap representing the Euclidian distance using Ward algorithm to identify the similarities between individual oils. was found especially in hempseed and olive oils, while violaxanthinin and auroxanthin were in LSO. Significant differences between the authentic and commercial samples were noticed for LSO, SO, SBO and between extravirgin (EVOO1,3) and virgin (EVOO2,4) olive oil subgroups, in all cases lutein and zeaxanthin being responsible for such differences. Figure 3a represents the PLSDA score plot for the discriminatory analysis considering their carotenoid contents. The heatmap illustrates the similarities between oil samples inside a group and among groups (Figure 3b). The univariate and multivariate analysis confirm the specificity of carotenoid composition for each oil category, as mentioned above. The PLSDA score plot shows in this case a co-variance of 46.3% for the first two components, with good discrimination between SBO and SO oils; the other oil groups showing less differentiation. The VIP scores shows the most significant 15 molecules to differentiate oils: SBO due to \(\beta\)-carotene, lutein, zeaxanthin, \(\beta\)-cryptoxanthin, while luteoxanthin, \(\beta\)-carotene and \(\alpha\)-carotene were specifically representing HO. Meanwhile violaxanthin and auroxanthin were specific to LSO. Comparing the authentic samples with the commercial ones (Figure 3b), the heatmap shows identified distinct differences for sample EVOO3 in the EVOO group, for HO1 and HO2 comparative to the authentic sample HO4. Different concentrations of carotenoids, highly dependent on the botanical and geographical origin of vegetables, were reported in some recent publications [41, 46] and are in agreement with our data.