Rheological and Biochemical Characteristics of High-Pressure- and Heat-Induced Gels from Blue Whiting (Micromesistius poutassou) Muscle Proteins

Heat- and high-pressure-induced gels were prepared from blue whiting muscle ( Micromesistius poutassou R.). Minced muscle was homogenized with salt (1% NaCl), and response surface methodology was used to determine the influence of pressure, time, and temperature on the work of penetration. Two combinations of pressure−time−temperature were chosen to give the highest work of penetration, and samples were compared with a heat-induced gel. The following lots were subjected to chemical and rheological analysis: 200 MPa, 3 °C, 10 min (lot L); 375 MPa, 38 °C, 20 min (lot H); and atmospheric pressure, 37 °C, 30 min/90 °C 50 min (lot T). Breaking force, deformation, and cohesiveness were greater in gels of lot L. Hardness and water holding capacity were greatest in gels of lot T. Elasticity was greater in high-pressure-induced gels. The percentage of hydrophobic interactions, essentially linking actin molecules, was greater in gels of lot H than in gels of lots T and L. There were more cross-linkages in the heat-induced gels (lot T).