Production, extraction and stabilization of lutein from microalga Chlorella sorokiniana MB-1

The efficiencies of extraction and preservation of lutein from microalgae are critical for the success of its commercialization. In this study, lutein was produced by Chlorella sorokiniana MB-1 via semi-batch mixotrophic cultivation. The microalgal biomass with a lutein content of 5.21mg/g was pretreated by bead-beating and high pressure cell disruption methods, and the lutein content was harvested by a reduced pressure extraction method. The effect of pretreatment, pressure, solvent type, extraction time and temperature on lutein recovery was investigated. Using high pressure pretreatment followed by extraction with tetrahydrofuran (THF) as solvent resulted in high lutein recovery efficiencies of 87.0% (20min) and 99.5% (40min) at 850mbar and 25°C. In contrast, using ethanol as the solvent, 86.2% lutein recovery was achieved under 450mbar, 35°C and 40min extraction. The extracted lutein was stabilized in olive oil or sunflower oil with half-lives of 53.1 and 63.8days, respectively.