## 3 Results  
### UV-VIS Spectral Fingerprinting Related to Botanical Origin  
The individual UV-VIS spectra of all oils were recorded and analyzed as a first criteria of oil recognition based on the spectral fingerprint and absorbance intensity (data not shown). The sunflower (SFO) and walnut (WO) oils showed absorbances mainly in the UV region (220-280, 325 nm and 220-280 nm, respectively). The pumpkin oil (PO) group was recognized by VIS intense peaks at 450, 526, 568, 590 and 620 nm, indicating their carotenoid, acylated anthocyanin and chlorophyll content. The spectra of linesed (LSO) and soybean (SO) oils showed higher absorbance at 448 and 443 nm, respectively, as indicators of quinones content. The hempesed (HO) and olive (EVOO) oil groups were characterized by strong absorbance at 668 nm (indicator of chlorophylls). The sea buckthorn (SBO) oils had a unique fingerprint with highest absorbance at 445-470 nm, indicating a rich carotenoid content. These spectra offered a first preliminary information about the specific fingerprints of each oil category and a rough indicator of authenticity [25]. GC-MS Profile, Univariate Analysis and Multivariate Classification of Oils Based on Fatty Acids Composition  
Based on the GC-MS analysis (typical chromatograms of each oil category are presented in Figure S2), the percentages of individual fatty acids (FAs) in all oils were determined, then the average values and standard deviations were calculated for commercial oils and compared to the authentic ones. Table S1 includes the individual fatty acid levels expressed in % of area of the total identified fatty acid areas in the GC-MS chromatograms of oils under investigation. These raw data were processed by one-way ANOVA including the Tukey HSD post-hoc test (Table S2) to evaluate the significance of differences between the oil groups, considering each of the 10 fatty acids separated and identified by GC-MS. The graphic representations of the Tukey HSD statistical differentiations (made by the MetaboAnalyst 5.0 algorithm) are also included in Table S2. The specific unique composition of SBO is clearly observed, significantly different from other oils due to fatty acids C16:1n-7, C18:1n-7, C16:0, and C18:2n-6. The linesed oil (LSO) was significantly different due to the presence of C18:3n-3, the hempesed oil (HO) was differentiated due to its higher content in C18:3n-6 and C20:0, while sunflower oils (SFO) had a significant, higher content of C22:0. Olive oils were differentiated by their higher content of C18:1n-9. Stearic acid (C18:0) was present in all studied oils at different levels and cannot be considered specific, although soybean showed the highest content. The multivariate analysis was applied for complementary information and included PCA (data not shown) and PLSDA. Figure 1 included the PLSDA scores plot and the heatmap graph which evidentiates the specific fingerprints of these oil category (Figure 1). The PLSDA score plot (Figure 1a) shows a co-variance of 45.6% and indicates a good discrimination between groups, and especially between SBO vs. SFO and EVOO. Based on PLSDA loadings, the FAs with higher VIP scores were C20:0 and C18:3n-6 (\(\gamma\)-linelonic acid) as markers for HO, C18:1n-9 for EVOO, C18:2n-6 for WO, C22:0 for SFO, C18:3n-3 for LSO oils. Figure 1b illustrates the heatmap of specific fatty acids characterizing each individual sample. There were identified increased C18:0 levels for commercial SO3 and PO2 samples and C22:0 for SFO1 and SFO2 samples. These levels can be considered potential indicators of adulteration, but such data need further confirmation. Table 2 presents comparatively the mean values and standard deviations (x \(\pm\) SD) registered for the main classes of fatty acids, namely saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids identified in all eight types of oils. Samples SFO, PO, HO, SO and WO showed the highest percentages of C18:2n-6 (58 to 81% of total FAs), while LSO had maximum values of 52-67% of C18:3n-3.