Studies on Gape and Heave of Foodstuffs Due to Internal Pressure during Freezing

Freezing of Tuna by CaCl₂ Brine Spray System

Abstract

The purposes of this study are to measure the internal pressure which causes gape and heave of frozen body during the CaCl₂ brine immersion/spray freezing and to forestall these undue defects of frozen foodstuffs by the internal pressure.
The experiments were carried out on freezing of tuna fish. Both of the temperature and the internal pressure of tuna fish were measured and recorded continuously by a temperature sensor and a pressure sensor during the freezing.
The result was that gape and heave of frozen tuna fish are created by the internal pressure during the freezing, and the internal pressure or stress of frozen body was released by thermal equalizing process during freezing. And the methods which are able to prevent gape or heave of frozen body during the CaCl₂ brine spray freezing were found out.