Changes in the Molecular Forces and Rheological Properties of Pork Myosin with Sodium Bicarbonate

To investigate how sodium bicarbonate concentrations (0, 10, 20, 30, 40, and 50 mM) modulate the turbidity and molecular interactions of pork myosin, the pH, turbidity, particle size, active and total thiol content, surface hydrophobicity, rheology properties, and chemical forces were analyzed. Results revealed that increasing sodium bicarbonate concentration from 0 to 50 mM significantly elevated (p < 0.05) pH, surface hydrophobicity, apparent viscosity, active thiol content, and storage modulus (G'), while significantly reducing (p < 0.05) turbidity, mean particle size, gel whiteness, and ionic bonding strength. The alkalinization-induced pH reduced protein turbidity and enhanced molecular unfolding, thereby exposing hydrophobic regions and reactive thiol groups; this promoted hydrophobic interactions and facilitated disulfide bond formation during heat-induced gelation. Consequently, higher sodium bicarbonate levels (40 and 50 mM) markedly strengthened intermolecular forces and improved the rheological performance of the resulting myosin gels.