## 3 Results

Table 2: Proximate analysis of the samples, expressed in percentage of dry weight, measured on day 7 and day 14 of the trial, and wild biomass measured upon arrival to the laboratory. Values are presented as mean \(\pm\) standard deviation (\(n\) = 2). Different letters represent statistical differences between treatments (Kruskal–Wallis, \(p\)-value < 0.05). light treatment which shifts towards red (increase in a*) (Figure 5c). The statistical test with ANOVA indicates significant differences in a* (F(4, 40) = 4.767, \(p\)-value = 0.003), with the two NB and blue LED light treatments being significantly higher than VSE and PES. Minor b* fluctuations can be seen but generally decrease, which indicates slight shifts towards blue; however, no statistical differences were found (Figure 5d). The chroma values C* decreased, indicating a reduction in colour intensity (Figure 5e). The Kruskal-Wallis test showed statistical differences (F(4, 40) = 43.713, \(p\)-value = 0.012), with the NB treatment being significantly higher than the other two nutrient media VSE and PES, while significant differences were neither shown for blue LED light or red LED light. Finally, the hue angle (h\({}^{\circ}\)) values remain relatively stable within the red-yellow hues throughout the cultivation of C. _acicularis_ (Figure 5f). The higher values lean towards the red and lower values towards the yellow, with the blue LED light producing the highest variation. Overall, there are no significant differences between week 1 and week 2 for any of the treatments. Figure 5: Colour parameters of cultivated biomass of _Chondracanthus acicularis_ when grown over 14 days. (**a**) \(\Delta\)E-colour variation, (**b**) L*-lightness, (**c**) a*-green-red, (**d**) b*-blue-yellow, (**e**) C*-chromaticity, (**f**) h\({}^{\circ}\)-hue. VSE—Von Stoch Medium; PES—Provasoli Medium, NB—Nutribloom plus®, all grown with white LED light; blue—PES and blue LED light; red—PES and red LED light. Pigments such as phycoerythrin, phycocyanin, and chlorophyll \(a\) play crucial role in the photosynthetic processes and colouration of red seaweed, with variations in their concentrations influenced by environmental factors such as light quality and nutrient availability. It is certainly possible that the concentration of these pigments may be responsible for the colour changes analyzed above. There were significant differences in the phycoerythrin content between the different treatments and between the wild and cultivated biomass (F(5, 12) = 14.127, _p_-value < 0.001), with all the treatments except for the red LED light significantly increasing the concentration of phycoerythrin (Figure 6). The same pattern was observed for phycocyanin, with all treatments producing significantly higher pigment concentrations than the wild biomass, except for PES (F(5,12) = 11.817, _p_-value < 0.001). For chlorophyll \(a\), only the VSE treatment was significantly higher than the wild biomass (F(5,12) = 8.189, _p_-value = 0.001). It is also noteworthy that, generally, the concentration of carotenoids in red seaweeds, primarily lutein and zeaxanthin [37], is low. However, no significant differences in carotenoid levels were observed.