Sonication effect on foam properties of egg white

The aim of this study was to determine the effect of ultrasound treatment on foaming properties of egg white. The samples were sonicated at 20/40 kHz and 180/300 W equipment power (3.7/6.9 W absorbed power) for 30, 45 and 60 minutes. Foam capacity had been increased by 25% due to sonication at 40 kHz and 6.9 W absorbed power for 60 minutes. This phenomenon may be caused by the homogenisation effect of ultrasound and protein exposure of hydrophobic groups that improve the adsorption of protein onto the air/water interfacial molecules. It is found that frequency and duration of the treatment have no significant impact on the changes in foam capacity, only the absorbed power. On the other hand, foam stability had been decreased during the ultrasonic treatment. We can assume that sonication decreases the potential difference between the dispersed particles and the dispersion medium and this may be the cause of the collapse of the foam structure due to ultrasound treatment. In this case frequency, treatment time, and the absorbed power had a significant effect on the stability.