Myosins from red and white bovine muscles: Part 1—Gel strength (elasticity) and water-holding capacity of heat-induced gels

Abstract

Myosins were isolated from bovine M. masseter (red) and M. cutaneus trunci (white) and characterized in terms of solubility, electrophoretic pattern and susceptibility to tryptic digestion. Dynamic rheological measurements showed that white myosin is generally the superior gel former: gel strength, expressed as storage modulus, is consistently higher (a) at all temperatures above the gel-inducing minimum, (b) in both 0·2 m and 0·6 m NaCl, (c) at all concentrations investigated (≤ 20 mg/ml) and (d) at pH ≥ 5·8. In 0·6 m NaCl at pH < 5·8 red myosin appears to perform better. All gels formed in 0·2 m NaCl lost about 15% liquid on centrifugation; gels in 0·6 m NaCl displayed an inverse relationship between storage modulus and loss of liquid. The gel strength and water-holding capacity of gels made from mixtures of red and white myosin were a linear function of mixture proportions in the case of 0·2 m NaCl; 0·6 m NaCl gave gels with unpredictable properties.