Impact of ultrasonic treatment on an emulsion system stabilized with soybean protein isolate and lecithin: Its emulsifying property and emulsion stability

The present study aims to investigate the impact of ultrasonic treatment on the emulsifying property and emulsion stability of an emulsion system stabilized with soybean protein isolate (SPI) and lecithin. Ultrasonic parameters used were ultrasonic powers of 150, 300, and 450 W and ultrasonic durations of 12 and 24 min. Emulsifying properties of emulsions were all improved with different extents after ultrasonic treatments. The emulsion treated at 150 W & 24 min showing the best emulsifying property and emulsion stability than the rest. However, the higher ultrasonic power of 450 W gave negative effects on emulsion stability, with increased particle size and decreased absolute zeta-potential values due to protein aggregation. Prolonged ultrasonic duration from 12 to 24 min resulted in a more stable emulsion under the ultrasonic power of 150 W. However, for ultrasonic powers of 300 and 450 W, the additional ultrasonic energy from prolonging ultrasonic duration from 12 to 24 min generated negative effects to emulsion stability. (C) 2016 Elsevier Ltd. All rights reserved.