S0601-1-5 Effects of Ultrasonic Irradiation on Freezing of Food

Abstract

A method to actively controlling crystallization is one of promising technique for cryopreservation. The object of this paper is to study the effects of ultrasonic irradiation on ice formation during freezing of biological materials with supercooling. In the experiments, agar gel was frozen under irradiation of ultrasound at frequency of 28kHz. The results suggest that higher degree of ultrasonic irradiation can release supercooling state, but also lower degree of ultrasonic irradiation would enhance supercooling dgree during freezing process. It was also found that the size of ice crystal decreased with increasing ultrasonic power under constant supercoling degree. The method to setting sample as possible as near the ultrasonic horn was useful for reducing ice crystal size.