# 유중수적형 유화계내에서의 유화안정지수 산출법의 확립

• Chang, Pahn Shick (Department of Food Science and Technology, Seoul National Polytechnic University)
• 장판식 (서울산업대학교 식품공학과)
To evaluate the emulsion stability indices of W/O emulsion system, we developed the simple and sensitive "VOLUMETRIC METHOD". This technique involved the first step of homogenizing the milk fat-water system with Ultra-turrax T25, then the volume of the added water phase was measured immediately. After quiescent incubation in test tubes at room temperature for a desired storage time, the bottom volume of the separated water layer was measured. And then "emulsion stability index(ESI)" was calculated by the following equation : $ESI=(1-V_s/V_a){\times}100$, where $V_a$ means the volume of the added water in the W/O emulsion and $V_s$ represents the volume of the separated water in the W/O emulsion for a desired storage time. The emulsion stability indices of W/O emulsion system at sorbitan trioleate, span 60, and tween 20 were $95.4{\pm}1.8$, $56.1{\pm}2.8$, and $41.6{\pm}2.2$ respectively. Furthermore, the differences between "VOLUMETRIC METHOD" and "Titus et al method" were less than 5.0 of ESI Value.