Abstract: The present invention relates to a method for simultaneously recovering in aqueous medium, from a lipid and protein containing biomass, of a lipid fraction and a protein fraction, wherein the method comprises an extraction step to extract the lipid and protein fraction from the biomass, characterised in that the refining step consists of contacting the biomass with a solution of at least one organic acid in water having a pH of between 1 and 6, wherein the concentration of the organic acid is at least 0.1 M, and in that the method further comprises subjecting the thus treated biomass to a phase separation and recovering a first lipid phase containing at least 65% with respect to the total weight of the lipids contained in the biomass and a second phase containing one or more precipitated proteins.