Pickering emulsions stabilized by native starch granules

The surface properties of native starch, namely rice, waxy maize, wheat and potato starch were characterized by contact angle measurement, zeta-potential, and then the emulsifying ability of these native starch granules was investigated by using liquid paraffin as oil phase and starch granules as sole emulsifier. It was found that emulsions could be prepared by using rice, waxy maize and wheat starch granules as emulsifier, but not potato starch, which had no emulsifying ability even when the concentration of starch granules as high as 15 wt% relative to water phase. Rice starch was the best emulsifier among these native starches. The emulsion stabilized by rice granules proved to be stable to coalescence for several months when the starch concentration was above 3 wt% relative to water phase. With the increasing of the rice starch concentration, the sizes of droplets decreased and the stability of emulsions enhanced. The salt and pH values had no significant influence on the packing structure of native starch granules at interface.