Stability characteristics of O/W emulsions prepared using purified glycyrrhizin or a non-purified glycyrrhizin-rich extract from liquorice root (Glycyrrhiza glabra)

Abstract This study evaluated the stability characteristics of oil-in-water emulsions prepared using purified glycyrrhizin (PG) or a non-purified glycyrrhizin-rich extract from liquorice root (LRE) at equivalent glycyrrhizin concentrations (0.01−0.1%, w/w). PG-stabilized emulsions were sensitive to acidic pH ( 60 °C). These results indicate that the interfacial composition of the two studied systems was different although having similar glycyrrhizin concentration. PG-stabilized droplets consist of glycyrrhizin interfacial layers that are negatively charged and depend exclusively on electrostatic repulsion. LRE-stabilized droplets consist of complex interfacial layers due to the adsorption of various surface-active components, including glycyrrhizin and proteins.