## 3 Results and Discussion
[PERSON] in his research observed an increase in the content of lutein and \(\beta\)-carotene in kale when illuminated with both blue and red light. The maximum accumulation of lutein and \(\beta\)-carotene in fresh kale mass was found at 640 nm and 440 nm, respectively, calculated on a fresh mass basis. However, when converted to dry mass, the maximum lutein content in kale also occurred at 440 nm. [1]. There are no reports in the literature on the content of carotenoids in red clover sprouts, as well as on the impact of PEFs on the content of carotenoids. Therefore, our research can only be compared with the unique research carried out by [PERSON] et al. [25] who studied the effect of PEF on the content \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Treatment** & **UVA** & **Blue** & **Red** & **White** & **PEF 1** & **PEF 2.5** \\ \hline UVA & - & - & - & - & - & - \\ blue & 0.7675 & - & - & - & - & - \\ red & **0.0003** & **0.0002** & - & - & - & - \\ white & **0.0003** & **0.0002** & 1.0000 & - & - & - \\ PEF 1 & **0.0006** & **0.0002** & 0.9915 & 0.9966 & - & - \\ PEF 2.5 & **0.0133** & **0.0011** & 0.2138 & 0.2511 & 0.5309 & - \\ PEF 5 & **0.0156** & **0.0013** & 0.1859 & 0.2194 & 0.4801 & 1.0000 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: \(p\)-Values of [PERSON]’s post hoc tests after one-way ANOVA for lutein with treatments as fixed factors (F = 21.10, \(p<0.05\)). Statistically significant differences are bolded. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Treatment** & **UVA** & **Blue** & **Red** & **White** & **PEF 1** & **PEF 2.5** \\ \hline UVA & - & - & - & - & - & - \\ blue & **0.0015** & - & - & - & - & - \\ red & 0.2638 & **0.0002** & - & - & - & - \\ white & 0.6442 & **0.0287** & **0.0151** & - & - & - \\ PEF 1 & 0.8147 & **0.0163** & **0.0266** & 0.9999 & - & - \\ PEF 2.5 & 0.4240 & 0.0575 & **0.0075** & 0.9996 & 0.9903 & - \\ PEF 5 & 0.9842 & **0.0057** & 0.0755 & 0.9669 & 0.9963 & 0.8470 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: \(p\)-Values of [PERSON]’s post hoc tests after one-way ANOVA for zeaxanthin with treatments as fixed factors (F = 11.07, \(p<0.05\)). Statistically significant differences are bolded. of plant dyes in wheat germ. A 35% increase in the content of carotenoids was observed in the PEF treatment with strength of 6 kV/cm and 50 impulses compared to untreated sprouts [25]. In our experiment, no such significant effect of PEF treatment of red clover seeds on the content of carotenoids was found. Modelling the content of carotenoids in sprouts which are grown in different lighting conditions, especially in ultraviolet radiation with wavelengths up to 400 nm and blue light, forces the plant to adapt to the changes to avoid their harmful effects. Many compounds (e.g., flavonoids as well as carotenoids) can fulfil the role of protection against the harmful effects of UV light [6; 48]. Carotenoids are the auxiliary photoreceptors of chlorophyll and absorb light mainly in the blue region. Cryptochromes are the receptors of blue light in the 390-480 nm range. They stimulate leaf expansion. In the blue and UVA spectrum, phototropins, responsible for plant phototropism, bending of shoots towards the light, opening of stomata and leaf expansion are also photoreceptors in the blue and UVA spectrum [49; 50]. The increase of carotenoids content is plants' response to stress is associated with high irradiance. High exposure does not always lead to the growth of carotenoids, it can sometimes cause photodegradation of pigment particles [1; 51; 52]  
In the presented experiments, we observed that monochromatic blue light increases the content of carotenoids. The positive effect of blue light on the content of these dyes was also observed by other authors [52; 53] Opposite observations were made by [PERSON] et al. [29]. Research on tartary buckwheat sprouts has shown that blue light causes a decrease in the content of carotenoids compared to white light.