## 3 Results and Discussion
### Effect of Illumination Total Phenolic and Protein Content  
The content of total phenolics increased after the illumination with respect to the dark-grown chia microgreens. The analysis did not show the differences between chia microgreens after exposure to light for 24 h and 48 h (Figure 2).  
Figure 1: Total chlorophyll (**a**) and carotenoid (**b**) content in dark-grown chia microgreens and microgreens after exposure to light for 24 and 48 h. Data represent mean values from three experiments with five replicates (n = 15). The error bars show standard deviation (SD). Different letters signify values that are statistically different at \(p\leq\) 0.05 according to [PERSON]’s LSD test.  
Different soluble phenolic content reported in numerous studies have shown that the mechanisms of polyphenol synthesis vary between plant species, raw seeds, and sprouts, and is also affected by different growth conditions, germination processes, and sprout developmental stages [7]. [PERSON] et al. [5] showed that the controlled germination process exhibited a higher content of bioactive compounds (among others, increased total phenolics) in flour from chia seeds. Compared with the content of phenolics in other sprouts, our results showed that the amount of phenolics in illuminated chia microgreens (24 and 48 h) was higher or similar [7; 38; 39]. These variations could be attributed to the different enzymatic activity of hydrolases and polyphenol oxidases [40], de novo synthesis of phenolics, differences in polymerization and oxidation processes, and degradation of free or bound phenolics [41; 42]. The increase of phenolics observed after exposure to light could also be attributed to the development of defense mechanisms as a response to illumination, which activates different metabolic pathways to enhance antioxidant activity in etiolated sprouts. Therefore, illuminated chia microgreens represent a significant source of phenolics and can be considered as an alternative source in diets.  
Under constant-dark conditions, protein content was significantly higher when dark-grown chia microgreens and illuminated microgreens were compared (Figure 2b). Additionally, protein content did not differ between chia microgreens 24 and 48 h after the light treatment. Proteins represent storage for germinating seeds, and, during the germination process, they are hydrolyzed by proteases, which increases their availability for plant growth [6]. The soluble protein content, however, also depends on the balance between synthesis and demand [6]. In a recent work by [PERSON] et al. [43], authors showed that exposure to light impacted protein synthesis in soybean, mung bean, pumpkin, and radish sprouts differently. Namely, dark-grown mung bean sprouts had significantly higher soluble protein content in comparison to corresponding sprouts exposed to light, which is in accordance with our results. This decreased protein content in chia microgreens after light treatment could be explained by the increased degradation of proteins due to higher demand for developmental processes taking part in growing microgreens induced by light and redirecting metabolic pathways towards the synthesis of other secondary metabolites and components involved in photoproduction.