Extraction of Bio-pigments from the Green Microalgae Chlorella pyrenoidosa under Different Solvent Ratios

Nowadays, the use of microalgae biomass is evolving rapidly for their various applications such as food, pharmaceutical, and cosmetics. One of the essential compounds in microalgae that have good perspectives in the market is pigment since it can be used as a natural colorant in food or cosmetics. However, the extraction of bio-pigments from the green microalgae Chlorella pyrenoidosa under different solvent ratios is still rarely reported. Therefore, this study aims to investigate the bio-pigment potential from C. pyrenoidosa extracted under different ethanol ratios. The algae-to-ethanol ratios of 1:5, 1:7.5, and 1:10 were employed in this study. Overall, C. pyrenoidosa contains total chlorophyll content much higher than carotenoids due to the fact that C. pyrenoidosa is the autotrophic microorganism that performs photosynthesis. The total chlorophyll content decreased with an increase in ethanol ratio, i.e., 134.47, 133.74, and 129.46 μg/mL at the ratio of 1:5, 1:7.5, and 1:10, respectively. In contrast, the carotenoid content slightly increased with an increase in ethanol ratio, i.e., 86.64, 87.08, 88.45 μg/mL at the ratio of 1:5, 1:7.5, and 1:10, respectively. The main chlorophyll compounds in the ethanol extract with the algae-to-ethanol molar ratio of 1:5 were identified as chlorophyll c (47.09 μg/mL), followed by chlorophyll b (38.50 μg/mL), chlorophyll a (28.67 μg/mL), and chlorophyll d (20.23 μg/mL).