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Rheological properties of rehydrated suspensions of freeze dried tomato ketchup were measured by Brabender Viscotron at the temperature range of 30-90℃, at the concentration of 15-50%, and at the shear rate of 0-250sec^(-1). At the shear rate of 0-210sec^(-1), tomato ketchup was found to be a thixotropic food product. The values of flow behavior index, consistency index and yield stress at the shear rate of 0-210sec^(-1), at the temperature of 30℃ and at the concentration of 33%, were 0.2131, 22.5047 Pa sec^(-n),and 8.544 Pa, respectively. It was found that the apparent viscosity model for temperature was expressed by Andrade model and the model for concentration was expressed by Power model, and the model for both temperature and concentration was described by exponential and power models. The activation energies at the concentrations of 15, 20, 30, 33, 40, and 50% were 3.973, 4.985, 5.078, 5.226, 5.357, and 7.655 ㎉/g·mole, respectively. Key words: tomato kechup, viscosity, prediction model.
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