Rheology and Food Texture : Ⅰ Basic knowledge of Rheology

Abstract

An overview was provided of the concepts of liquid viscosity (shear viscosity) and flow properties, as well as the concept of viscoelasticity and its static and dynamic measurement principles. For static measurements, creep tests, stress relaxation, the Voigt model, the Maxwell model, the relaxation time, and related topics were explained. Regarding dynamic viscoelasticity, the physical meanings of parameters such as storage modulus, loss modulus, loss tangent, complex viscosity, and dynamic viscosity were described. A classification method for food hydrocolloids was also discussed. In addition, the theory of sol-gel transition proposed by Winter and Chambon, and the Cox-Merz empirical rule that relates shear viscosity and complex viscosity were explained. Finally, part of a study on the relationship between the swallowing characteristics and rheological properties of food hydrocolloids was introduced.