## 3 Results
### Total Fatty Acid and TAG Profiles  
The culture of diatoms under Blue LED light resulted in cells with a higher total fatty acid content (Figure 7a). Regarding cells composition in terms of individual fatty acid relative abundance (Figure 7b), the diatom cells grown under Red LED illumination, when compared with the cells cultivated under full light spectrum, showed lower contents of 16:0 (palmitic acid), 16:1 (palmitoleic acid) and 18:4 (stearidonic acid, SDA) fatty acids and higher contents in 16:3 (hexadecatrienoic acid) and 20:5 (eicosapentaenoic acid, EPA). Blue monochromatic LED illumination promoted the production of 16:1 and a decrease of EPA cell content, in comparison with the cultures grown under RGB LED illumination. This fatty acid remodeling resulted in significantly lower saturated fatty acid (SFA) and _MUFA_ contents in the cells grown under monochromatic Red LED illumination, when compared to the cells grown under full spectrum illumination (Figure 7d). Comparing also with the RGB LED exposed cultures, these same cultures presented significantly higher _PUFA_  
Figure 4: Canonical Analysis of Principal (CAP) components of the _P. tricornutum_ cultures (\(N=5\)) subjected to the three light treatments, having as basis the full Kaustky fluorescence profile at the end of the 96 h exposure period (100% classification efficiency). Figure 3: Kautsky transient light curves (**a**), phenomological energy fluxes ((**b**), absorbed (ABS/CS), trapped (TR/CS), transported (ET/CS) and dissipated (DI/CS) energy fluxes and oxidized reaction centers (RC/CS) and active oxygen evolving complexes (**c**) in the _P. tricornutum_ cultures (N = 5) subjected to the three light treatments at the end of the 96 h exposure period (average \(\pm\) standard error, letters denote significant differences between light treatments at \(p<0.05\)). and unsaturated fatty acid (UFA) contents. Regarding the cells cultivated under Blue LED illumination, their _PULFA_ cellular content showed a significant decrease. These alterations combined resulted in differences in _IA_ and _IT_ (Figure 7c). Figure 5: Pigments profiles (**a**), total chlorophyll (**b**) and total carotenoids (**c**) contents of the _P. tricor-nutum_ cultures (\(N=5\)) subjected to the three light treatments at the end of the 96 h exposure period (average \(\pm\) standard error, letters denote significant differences between light treatments at \(p<0.05\)). Figure 6: Canonical Analysis of Principal (CAP) components of the _P. tricornutum_ cultures (\(N=5\)) subjected to the three light treatments, having as basis the full pigment profile at the end of the 96 h exposure period (93.3% classification efficiency). Regarding the atherogenicity capacity of the cultures in preventing the appearance of micro- and macro-coronary diseases, it was found that the cells grown under monochromatic Red LED illumination are favored in this regard showing a significantly lower \(IA\) value, when compared with both RGB and Blue LED exposed cells. On the other hand, blue light exposure seems to favor the thrombogenicity ability of the culture's fatty acid profile, presenting a higher \(IT\) value. As previously computed for the photochemical and pigment data, the fatty acid profiles of the samples were also analyzed in a multivariate canonical approach in order to evaluate if these fatty acid traits are efficient descriptors of the cells culture light conditions (Figure 8). Once again, a clear separation of the samples grown under different light qualities is observed, with the overall canonical analysis presenting a classification efficiency of the samples of 93.3%, having as basis the cells fatty acid profiles. Figure 7: Total fatty acid content (**a**) and profile (**b**), indexes of atherogenicity (\(IA\)) and thrombogenicity (\(IT\)) (**c**) and fatty acid unsaturation classes (**d**) of the \(P\).