2000 Volume 47 Issue 9 Pages 679-684
Effects of pH on the interfacial activity and the emulsifying ability of Sapindaceae saponin (SS: α-L-arabinopyranosyl (1→3)-α-L-rhamnopyranosyl (1→2)-α-L-arabinopyranoside of hedragenin) and on the creaming stability and the zeta potential of emulsions prepared with SS (0.3mM) in a water/kerosene system were investigated. The interfacial tension increased with an increase in pH from 6 to 8. The emulsifying ability of SS below pH 5 was less than that above pH 5. The creaming stability of SS emulsion lowered at pH below 6. The stability of SS emulsion was lower than that of soyasaponin I (SI) above pH 7, though the droplet size of SS emulsion was smaller than that of SI emulsion. The zeta potential of SS emulsion increased with increasing pH from 6 to 8 and was almost constant above pH 8.5, while it was less than that of SI emulsion in the entire pH range investigated.
