Myofibrillar protein marination model: a calculation and its mechanism

BACKGROUND The classic diffusion equation and that for osmotic pressure use ion solution, but cannot be applied in a complex food system. The diffusion coefficient ( D e ) is a physical quantity that describes the rate at which a substance diffuses in another medium and is commonly used in diffusion equations. Osmotic pressure ( π ) refers to the pressure generated when solute molecules in a solution diffuse through a semipermeable membrane toward the solvent side. Myofibrillar protein (MP), a main component in salted meat, was investigated in this study. RESULTS The results showed that, D e values in ion solution were always higher (4.00–5.69 × 10 −10 m 2 s −1 ) than those in MP (1.33–1.81 × 10 −11 m 2 s −1 ), but the declining rate was slower at a salt concentration of 40–80 g kg −1 and quicker at 80–160 g kg −1 . π MP (2.84 MPa ) was higher than π ion (2.68 MPa ) only at low contents of salt. When the salt concentration exceeded 40 g kg −1 , π MP was lower than π ion ; π MP increased from 2.84 to 10.08 MPa and π ion increased from 2.68 to 10.40 MPa . CONCLUSION Under low contents of salt, solubility increased and α ‐helix decreased, resulting in partial unfolding of the protein and enhanced binding to and absorption of water. This made the viscosity decrease, thus reducing the declining rate of D e and decreasing π MP . At high contents of salt, aggregation increased viscosity, and thus increased the declining rate of D e and π MP . This would provide a theoretical foundation for the amendment of the classic equations of D e and π MP .