An Investigating of Some Rheological Properties of Garden Cress Seed Mucilage

Rhelogical properties of mucilage extracted from Garden cress (Lepidium sativum L.) seeds as influenced by gum concentration (0.4, 0.6, 0.8 and 1.0 % w/w), temperature (5, 25 and 40? C), as well as pH (2.5, 4, 7 and 10) were investigated. Non-Newtonian shear thinning flow behavour was observed with the Power law model well describing the rheological behavior of the solutions. Increasing the solution concentrations increased the viscosity and pseudoplasticity while an increase in temperature resulted in a decrease in viscosity and pseudoplasticity. A marked dependence of viscosity on pH was also observed. As pH increased from 2.5 to 7, the viscosity increased whearas it started to decrease at pH 10. To study the structural aspects of the mucilage gum it was characterized through FT-IR with the results indicating that Garden cress seed gum contained carboxylic groups on the backbone of its polymer.