• high pressure;
  • pressure-assisted thawing;
  • pressure-induced thawing

ABSTRACT: High pressure-assisted thawing (HPAT) and high pressure-induced thawing (HPIT) experiments were performed in agar gel samples at different pressures (50 to 210 MPa) and initial temperatures (−5°C to −20 °C). Lower pressures and temperatures yielded HPAT processes in which the sample temperature increased during pressurization because no melting took place. The complete phase transition occurred during the holding time. Higher temperatures and/or higher pressures yielded HPIT processes in which partial melting occurred during pressure loading, causing the sample temperature to decrease. In practice, whether HPAT or HPIT took place depended on the initial temperature of the sample for a given pressure value. Common situations were nonhomogeneous thawing processes.