Separation of monoglycerides, diglycerides, and triglycerides by liquid‐liquid extraction

Summary Ternary‐equilibrium data were obtained at 60°C. for mono‐ and dilaurin, and di‐ and trilaurin with aqueous alcohols. Distribution between phases and solvent selectivity are shown graphically. Variation of solvent polarity by water addition caused a shift in the phase boundary curve so that either Type 1 or Type 2 diagrams could be obtained. Pure mono‐, di‐, and trilaurin mixtures, and commercial monoglycerides were studied as quaternary systems for monoglyceride distribution with 50 wt.‐% aqueous ethanol. Pure and commercial systems showed similar distribution tendencies even with differences in molecular weight and degree of unsaturation. Solvent selectivity data (β) for quaternary systems were predicted from ternary systems studied with a common solvent. Aqueous ethanol will separate mixtures of mono‐, di‐, and triglycerides by selective liquid‐liquid extraction; however the literature favors more complex systems based on two immiscible solvents. Continuous countercurrent extraction of commercial monoglycerides by 40% aqueous ethanol solution in a four‐stage agitated column gave a 15% over‐all stage efficiency. Cooling the extract to 0°C. precipitated 96.6% of the extract solids. Flow diagrams were prepared for batch and continuous extraction processes.