Changes in the Viscosity of Expressible Water in Meat during Heating: Description Based on the Denaturation Kinetics of Water-soluble Proteins

The change in viscosity of expressible water associated with mass transfer during meat cooking was described using dynamic viscoelasticity measurement of meat juice containing 78.9 +/- 5.71 mg/mL of protein. We observed a temperature-dependent decrease in the complex viscosity of meat juice up to 49.4 degrees C; however, the viscosity increased drastically when the temperature exceeded 60 degrees C. This trend was similar to that observed for temperature-dependent denaturation of dissolved water-soluble proteins in the meat, suggesting that the change in viscosity of meat juice is dependent on the denaturation of dissolved water-soluble proteins as well as the temperature. Therefore, a hypothetical new model equation, incorporating the denaturation of water-soluble proteins into Andrade's equation (in order to demonstrate the relationship between liquid temperature and viscosity), enabled the estimation of changes in the viscosity of expressible water in meat associated with mass transfer at an arbitrary temperature during heating.