Efficiency of surfactant extraction of pigments from wet and non-disrupted Chlorella sorokiniana produced in a bioenergy façade

Abstract

The efficiency of the extraction of pigments from Chlorella sorokiniana produced in a bioenergy façade (53° 29′ 42'' N 10° 0′ 40'' O) with the surfactant Heptylglycerin was studied. Samples were obtained in monthly intervals between May and November 2022 and microalgae were extracted with surfactant: biomass ratios between 3.2 and 5.9, extraction times down to 1 h and temperatures <60 °C. The pigment content of the microalgae was mainly controlled by PAR and varied by a factor of up to 10 during the study period whereby Carotin, Violaxanthin and Zeaxanthin contents decreased with increase in PAR prevailing during a period of 7 days. Yields of extraction of pigments with Heptylglycerin correlated linearly with their contents in biomass. Maximum yields of up to 360 μg g⁻¹ for Lutein and 1029 μg g⁻¹ for β-Carotin detected, were comparable with more aggressive conditions of pressure liquid and supercritical fluid extraction described in literature. Mean recoveries of Violaxanthin, Zeaxanthin, Lutein, and β-Carotene were 8.1, 29.6, 13.5 and 66.6 %, with standard variations from recoveries of 78, 48, 42 and 38 % due to differences in their location in the cells during study period, respectively. Results indicate that extraction of pigments with Heptylglycerin as solvent is favorable to other methods and can be used effectively for large-scale commercial extraction of carotenoids.