Effect of organic solvent on the extraction of lipids from krill powders using a one-step extraction process

A variety of organic solvents were tested using a one-step extraction process to determine the extraction efficiencies and composition of lipids derived from krill powders. Extraction solvents tested included hexane (H), chloroform (C), methyl-tert-butyl ether (MTBE), 3:2 hexane:isopropanol (HI) and 2:1 chloroform:methanol (CM). Extraction efficiency was calculated, and lipid classes (TLC) and fatty acid profiles (FAP) were determined. Lipid extraction efficiencies were best (P < 0.05) with CM (27.90%; P < 0.05), followed by MTBE (15.36%) and H (10.37%), respectively. The lipids extracted using CM also had the greatest concentration of phospholipids (45%) compared to all the other solvents tested (P < 0.05). TLC showed that H:I and H were most effective at extracting triglycerides, CM was the most effective at extracting phospholipids, followed by MTBE, and cholesterol was effectively separated using H. The FAP of the extracted lipids varied based on the polarities of the organic solvents used to separate them, with C effectively concentrating many of the fatty acids tested. Results were influenced by the polarities of the organic solvents and the types of lipid classes present. The results of this study would be useful for those in the krill oil industry when selecting an organic solvent for extracting krill lipids.