Relationships between Binding Quality of Meat and Myofibrillar Proteins

The viscosity change of myosin A concentrated solution with or without other components was measured as the incubation time elapsed at 30°C.

The viscosity of myosin A solution increased, but that of F-actin solution did not. The shear stress at 0.04 sec^?1 was not increased to 1.0 dyne/cm² in the former, but in the latter was below 0.5 dyne/cm².

The viscosity of myosin B solution increased slightly, but that of native tropomyosin-free myosin B solution decreased remarkably. In both the shear stress at 0.04 sec^?1 was greater than or equal to 15 dynes/cm².

The speed of the viscosity increase in the presence of 3 mm pyrophosphate and 3 mm MgCl₂ was higher in concentrated solution of myosin B than in that of native tropomysin-free myosin B. The shear stress at 0.04 sec^?1 after 6 hr at 30°C was 11.5 and 8.2 dynes/cm², respectively.

The effect of native tropomyosin and actin on the viscosity change was discussed.