Myofibrillar Protein Structure and Gel Properties of Trichiurus Haumela Surimi Subjected to High Pressure or High Pressure Synergistic Heat

The changes in gel properties and myofibrillar protein structure of Trichiurus haumela surimi subjected to high pressure (300-450 MPa; 5 min) or high pressure synergistic heat (90 degrees C; 30 min) treatment were investigated. The results showed that high pressure below 400 MPa could improve the gel properties. The water holding capacity of the 350 MPa group increased by 27.40% compared with the control group. Moreover, the gel strength of surimi gel induced by high pressure of 300 MPa and 350 MPa increased by 38.08% and 40.00%, respectively, and continually increased by 17.86% and 21.00% after further heating. Both of high pressure and heating affected the composition of myofibrillar protein and partially degraded the actin and myosin heavy chain. High pressure reduced the contents of alpha-helix and beta-turn, but increased beta-sheet and random coil in the myofibrillar protein. Subsequent heat treatment converted the partial beta-sheet into the alpha-helix structure. In addition, in the gels of surimi subjected to high pressure, the secondary structure of myofibrillar protein was significantly correlated with the whiteness, gel strength, and texture characteristics of the gels. Collectively, the results supported an optimum pressure of 300-350 MPa for the induction of hairtail surimi gel.