Structural and biochemical properties of silver carp surimi as affected by comminution method.

Effects of two typical comminution methods (shearing and blending) on structural and biochemical properties of silver carp surimi were comparatively investigated. Surimi myofibrils in striated appearance were progressively disrupted within 15 min of blending. The myofibrils were completely disintegrated after shearing for 5 min. Surface hydrophobicity of surimi increased and then gradually decreased (p < 0.05) under shearing, while it continuously increased (p < 0.05) under blending. As shearing time was extended, α-helical structure decreased and β-sheet structure increased simultaneously; surface active sulfhydryl content (SH) increased and then decreased (p < 0.05); and intensity of myosin heavy chain (MHC) was gradually reduced. However, secondary structure, MHC intensity and SH were slightly changed as blending time extended. Ca-ATPase activities increased and then declined (p < 0.05) with transition times at 1 min and 5 min under shearing and blending, respectively. Results indicated that shearing disrupted the ultrastructure and changed biochemical properties of surimi more pronouncedly than blending.