1983 年 103 巻 2 号 p. 203-208
Emulsions of a relatively small amount of oleic acid in aqueous glycyrrhizin (GA) solution were investigated by means of turbidity measurement. Oleic acid was easily emulsified in aqueous GA solution by shaking with a reciprocating shaker to give stable o/w emulsions. With increasing GA concentration at a constant pH and ionic strength, the turbidity of emulsion initially increased and then decreased at GA concentrations above its critical micelle concentration. This effect may by attributed to the solubilization of oleic acid by GA solution. The emulsifying power of GA, which was defined as the change of turbidity per unit volume of oleic acid emulsified, was enhanced with rising pH and decreasing ionic strength of GA solution. The dissociation of both GA and oleic acid was considered to play an important role in the emulsification of the system.