PURPOSE: To enable purification simply by water without using a purifying solvent and reduce cost by regulating a reaction mixture to a pH within a neutral region, then adding water, a neutral salt and sucrose, then dissolving the formed precipitates in water and ultrafiltering the resultant solution.
CONSTITUTION: A reaction mixture containing the objective sucrose ester of a fatty acid is regulated to a pH within a neutral region (preferably pH6.2-8.2) and water, a neutral salt and sucrose are then added to form precipitates, which are subsequently dissolved in water. The resultant solution is then ultrafiltered to purify the objective ester. Furthermore, the composition of the above- mentioned reaction mixture is 1.0-80.0% unreacted sucrose, 0.5-10.0% unreacted methyl ester of the fatty acid, 0.05-7.0% catalyst, 1.0-10.0% soap, 0.5-10.0% fatty acid, 15.0-95.0% sucrose ester of the fatty acid and 3.0-30.0% volatiles. Fatty acid radicals mainly contained in the respective above-mentioned methyl ester, soap and fatty acid preferably have 16-22C common saturated fatty acid radicals.
HATAKAWA YOSHIO
NAKAJIMA AKIHIKO
