Physico-Chemical Properties of Monodesmoside Saponins of Sapindaceae (Sapindus mukurossi Gaertn) at Air/Water and Oil/Water Interfaces

The surface activity, emulsion stability and foamability for two kinds of monodesmoside saponins of Sapindus mukurossi Gaertn (I and II) and the zeta potentials of emulsions prepared with these saponins in a water/kerosene system were investigated. There were no differences in the surface activity, foamability, emulsion stability or zeta potential of the emulsion droplet between the two kinds of saponins (I and II) of sapindaceae. The surface activity, emulsion stability and foamability of both I and II were higher than those of soyasaponin I (SI). The zeta potential of emulsion droplets prepared with I or II was lower than that prepared with SI. The water separation of both the I and II emulsions by creaming were higher than that of the SI emulsion.