Effect of pressure/heat combinations on blue whiting (Micromesistius poutassou) washed mince:: Thermal and mechanical properties

Washed ground muscle of blue whiting was comminuted at low ionic strength and low temperature, and the batter was subjected to different pressure/heat processings. The functionality induced in the combined processed gels was evaluated by water holding and several rheological and fracture properties and compared to that obtained for traditional heat-induced gel. Ultrastructure was viewed by scanning electron microscopy. Protein denaturation was assessed by differential scanning calorimetry (DSC), and the thermal behavior of pressurized gels revealed that pressure and temperature were interdependent. At nondenaturing temperatures, the higher the pressure, the larger was the protein unfolding effect. At denaturing temperatures, pressure prevented fish protein from subsequent thermal denaturation. DSC demonstrated that pressurized samples underwent both types of pressure effects at the same time. It transmitted a mixed character to the pressure-induced gels, which displayed a rheological behavior intermediate between cold-set and heat-set gels.