FRACTIONATION OF GLYCERIDES BY LOW-PRESSU RE GAS EXTRACTION

Monoglycerides are important emulsifiers in food industry, cosmetics i ndustry, chemistry and for the production of detergents. They are conv entionally separated from mixtures of partial glycerides by molecular distillation at temperatures above 200-degrees-C with a purity of max. 95%. The yield of monoglycerides is about 60%. An improved process fo r the production of pure monoglycerides was developed. The partial gly cerides are treated with propane as an extractant at 50 bar and temper atures between 40 to 80-degrees-C in a countercurrent column. Due to t he moderate extraction pressure, the process is called ''Low Pressure Gas Extraction''. Monoglycerides are obtained with a purity above 99% at a yield above 95%. Additionally pure diglycerides (above 92%) can b e separated at high yields (above 90%). The process can be applied to all kinds of glycerides as oleates, stearates, cocoates. Comparative d iscussion of mass flow diagrams of conventional glyceride manufacturin g and of the new extractive fractionation demonstrate the advantages o f the new technology.