Water‐Thawing of Fish Using Low Frequency Acoustics

Blocks of Pacific cod (plate frozen; 91-mm thickness and 12.7 kg) were thawed in an 18°C circulated water bath and simultaneously exposed to 1500 Hz acoustic energy not exceeding 60 watts. A ceramic transducer was positioned for light contact with a frozen block. A motorized belt moved the block in order to distribute the 239 cm2 transducer over the 1500 cm2 block surface. At 60 watts continuous input to the transducer, the block thawed in 71% less time than water-only controls. Quality analyses indicated that the flesh was not adversely affected by the acoustic waves.