The time independent rheological properties of low fat sesame paste/date syrup blends as a function of fat substitutes and temperature

The rheological behavior of reduced fat sesame paste/date syrup blends were determined using Brookfield rotational viscometer and the effect of fat replacers with guar gum, xanthan and starch at three substitution levels, and temperatures at 25, 35, 45, and 55 degrees C were investigated. All sesame paste/date syrup blends were found to exhibit non-Newtonian, pseudo-plastic behavior at all temperatures and fat substitute levels. Shear stress versus shear rate data was successfully fitted to the Power-law model. The flow behavior index, n, varied in the range of 0.35-0.51. The consistency coefficient, k, was in the range 108-240.04Pa s(n). In addition, the fat substitutes led to the apparent viscosity increasing for all blends in comparison with the control. An Arrhenius equation was also used to describe the effect of temperature and Ea value appeared in the range of 16010.3-24330.1 J/mol. (c) 2006 Elsevier Ltd. All rights reserved.