STUDY ON RHEOLOGICAL PROPERTIES OF SOY PROTEINS

The rheological properties of soy proteins were investigated respectively using a capillary rheometry and a Brabender torque rheometry. The capillary rheometrical measurements show that soy protein is a typical pseudoplastic fluid in the normal processing ranges, and the value of flow behavior index is in the range of 0.2 ~ 0.6 . The apparent viscosity decreases with increasing shear rate, decreases with increasing moisture content, and decreases with increasing temperature before protein denaturation; while as temperature exceedes 110 ℃~120 ℃, the apparent viscosity increases. The dynamic rheometrical measurements show that the dynamic rheological properties are greatly influenced by temperature time history, especially in 120 ℃. The rheological torque increases with increasing protein content, and decreases with increasing moisture content.