Stability of Emulsion Prepared with Soybean Phospholipids and Transfer of Phospholipid to Separated Phases

Abstract

Effects of three main components of soybean phospholipids, phosphatidylcholine(PC), phosphatidylethanolamine(PE) and phosphatidylinositol(PI), on the stability of model emulsion were investigated. In relation to the stability, transfer of phospholipids to each phases (emulsion, water and oil) separated during aging and interfacial tension at water kerosine interface were also examined. Comparing the stability against creaming of water-kerosine emulsions prepared with the three phospholipids, PI emulsion was the best and PC emulsion was the worst. Among the emulsions with two or three component systems of PC, PE and PI, better stability was generally observed for the emulsions containing a greater amount of PI or PE. Emulsifiers giving more stable emulsions against creaming showed lower interfacial tensions at the water-kerosine interface. Decrease of the interfacial tension in PC system during aging was very slow, suggesting that PC is adsorbed very slowly to the oil-water interface. Smaller amount of phospholipid transferred gradually to water phase during creaming, and in the oil separating stage of emulsion the most portion of phospholipid transferred to the oil phase.