High-pressure-shift freezing: Main factors implied in the phase transition time Original Research Article

We have studied the dynamics of the high-pressure-shift freezing (HPSF) process and the main parameters implied. Conventional freezing experiments at atmospheric conditions and HPSF experiments were carried out at identical temperatures and different pressures and the phase transition times compared. Phase transition times in HPSF experiments were lower than their homologues at atmospheric pressure in all cases. The reduction depends on the pressure and temperature conditions before expansion. These variables are highly involved in the supercooling reached and govern both the percentage of ice formed during the pressure release and the temperature drop in the pressure medium. After expansion, the pressure medium plays a significant role in the heat removal from the sample. Good predictions of plateau times can be made from initial pressure and temperature values, both process parameters that can be readily adjusted in the food industry.