Rheological properties of carrot juice concentrate

It's important to know the rheological behaviors of foods for every stage of production and prepare the foods formulation. Rheological properties must be known for such as mixing, pumping, heat exchanging processes and equipment design. The rheological properties appeal to the senses and it also determines the quality of the product. In this study the rheological properties of black and yellow carrot juice were investigated due to their increasing importance both as consumer product and natural coloring agent. Rheological properties of black and yellow carrot juice were studied using rotational viscometer (Brookfield LVDV- II+Pro) at 8, 20, 40 and 55 brix, at 20, 40 and 60 C and at convenient shear rates. The flow characteristics were described by the Power-law model. Flow behavior index for both black and yellow carrot juice was found more than 1. This shows that fluids are dilatant. So, with increasing shear rate, viscosity increases. The effect of temperature was described by Arrhenius equation. The values of activation energy of black and yellow carrot juices were found in the range of 9,41-47,32 kJ/mol and 8,01-28,28 kJ/mol, respectively.