PREPARATION OF W O FOOD PRODUCT EMULSIONS BY THE MEMBRANE EMULSIFICATION METHOD AND ASSESSMENT OF STABILITY/

High-water-content (40% (w/w)) W/O emulsions from substances containin g fats and oils were prepared at a high emulsification rate by use of a microporous glass membrane, and the stability of emulsions prepared by the membrane emulsification method was assessed. As the indices of stability, variations in dispersed droplet diameter, viscosity, and oi l separation rate over time were used. Even under the experimental con ditions employed, by changing the pore diameter of the membrane, it wa s possible to control dispersed droplet diameter for the most part. Fr om the standpoint of stability, when compared to the stirring emulsifi cation method, variations in dispersed droplet diameter and viscosity of W/O emulsions were confirmed to be more stable, which is an advanta ge of using the membrane emulsification method. As an additional advan tage, the stability of W/O emulsions prepared by the membrane emulsifi cation method was not related to the dispersed droplet diameter size. In addition, with regard to the emulsification rate in this experiment ,the dispersion phase flow rate through the membrane pores resulted in relatively little O/W interfacial tension, and a theory of flow throu gh the membrane was understood. These results indicate that using the membrane emulsification method, it is possible to prepare at a practic al level (high emulsification rate), a more stable, high-water-content W/O emulsion than is possible by means of the existing (stirring emul sification) method.