High-Speed Observations of the Nucleation of Ice by Power Ultrasound

Bernhard Lindinger, Thomas Kurz, Werner Lauterborn, Malcolm Povey,

and Robert Chivers

CONTENTS

Introduction ........................................................................................................ 613

Ultrasonic Horn Studies ................................................................................... 614

Single-Bubble Cavitation Studies .................................................................... 616

Laser-Induced Cavitation Studies................................................................... 619

Ultrasonic Cold-Stage Studies ......................................................................... 621

Conclusions......................................................................................................... 621

Acknowledgments ............................................................................................. 622

References ........................................................................................................... 622

The crystallization of water to produce ice crystals is important for a wide

range of foods ranging from ice cream to frozen foods. The control of the

crystallization process is one of the major factors affecting the stability and

sensory characteristics of these products. Crystallization can be divided into

two main stages: nucleation and growth. Nucleation can be difficult to

control as under ambient pressure conditions, nucleation can occur at any

temperature between 0 and 2418C. This temperature range is called the

supercooling temperature and in this region water exists in a metastable

state.