To obtain an industrially advantageous method for purifying highly unsaturated fatty acid esters from a mixture of fatty acid lower alkyl esters without getting a heat degeneration in a good efficiency.
This method for purifying a highly unsaturated fatty acid esters is to mix and treat by extracting a mixture of fatty acid lower alkyl esters containing unsaturated fatty acid lower alkyl esters having ≥0.4 degree of double bond [number of double bonds in the fatty acid/(carbon number of fatty acid portion-10)] with a hydrocarbon-based solvent and a water soluble solvent, then separate and collect the aqueous solvent layer, then distill off the water soluble solvent therein for raising the content of the unsaturated fatty acid lower alkyl esters having ≥0.4 degree of double bond.
MATSUYOSHI SHIGERU
MORI MASATO
NAKANO YOSHIRO
