The viscoelastic properties of Japanese rice porridge were measured using a non-rotational concentric cylinder rheometer. The viscosity and shear modulus of rice porridge exponentially increased with an increase in cooked rice concentration (i.e., 10%, 30%, 50%, 70% and 97% rice porridges). A Mooney's type model can be used to reasonably describe the viscosity of rice porridge as a function of the solid volume fraction. Small rice grains made by polishing and grinding produced low viscosity and shear modulus rice porridges. Moreover, the viscosity and shear modulus of rice porridge increased rapidly after cooking owing to an increase in the rice grain volume with water adsorption.

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A new method using a non-rotational concentric cylinder (NRCC) rheometer was used to determine the viscoelasticities of selected viscous liquid foods. The results were compared with those of conventional dynamic viscoelastic measurements. Two two-element models, the Maxwell model and the Voigt model, were used to describe the viscoelastic behavior of model foods measured by the NRCC method, which generates force-time curves. Mayonnaises with 28-36 w/w% water content and the 4 w/w% gelatinized potato starch exhibited Maxwell behavior with convex force-time curves. In contrast, mayonnaises with 20-24 w/w% water content and 5-7 w/w% gelatinized potato starches exhibited Voigt behavior with straight force-time curves. These results were in good agreement with the results given by the dynamic viscoelastic method. The G' value of the Maxwell model-like samples showed frequency dependence, while the G' values of the Voigt model-like samples exhibited less pronounced frequency dependence over the observed range.