Stability of corn oil W1/O/W2 multiple emulsions

The corn oil W1/O/W2 multiple emulsions, which were served as fat substitute, were prepared by two-step emulsifying method with two main ingredients including corn oil and biopolymers. The stability of the prepared multiple emulsions were characterized by the centrifugal creaming stability, and their microstructures were determined by microscopic observations. The results show that: 1. The main influential factors on the stability of the multiple emulsions are the emulsification technology of multiple emulsions, the phase ratio between the inner aqueous phase and oil phase, and so on. 2. In the two-step emulsification, the emulsification condition of the second emulsification has much more effect on the stability of the prepared multiple emulsions than that of the first-step emulsification, and the stability of the multiple emulsion increases with the increase of the emulsifying strength and the decrease of the emulsive droplet size. The optimum emulsification conditions found for multiple emulsions are 7200 r·min-1 and 13 min. 3. The main factors affecting the stability of the multiple emulsions are both the volume ratio of water to oil in the primary emulsion and the volume ratio of primary emulsion to outerwater phase. The former affects the stability of the multiple emulsions by changing its viscosity, while the latter effect is the result of the interaction of van der Walls force and electrical repulsion of the droplets. The found optimum volume ratio of water to oil in primary emulsion is 1:4, and that of primary emulsion to outerwater is 1:1.