Abstract:

In order to establish the optimal conditions for the ultrasonic emulsification of phytosterol using a sucrose ester
emulsifier, we investigated the effect of ultrasonic power, sonication time, phytosterol concentration, ultrasonic frequency,
temperature and sucrose ester concentration on the absorbance of emulsified phytosterol using single factor experiment and
response surface methodology. Results showed that the absorbance value of emulsified phytosterol under the optimized
conditions of ultrasonic treatment for 35 min at 330 W, 28 kHz and 30 ℃, 0.53% phytosterol, and 6% sucrose ester was
experimentally measured as 1.57, which was basically consistent with the theoretically predicted value. The stability of
phytosterol emulsion prepared by the ultrasonic method and hot water bath method was compared. The particle size and
morphology of the phytosterol emulsion obtained in this study indicated better stability and smaller and more uniform
particle size compared with that prepared by hot water bath method as observed through an inverted microscope.

Key words: phytosterol, ultrasonic emulsification, stability, response surface methodology