When the newly gelatin starch is stirred, more swollen granules break and more starch molecules spill causing increase in viscosity or thickness.
In science, viscosity can be conceptualized as quantifying the internal frictional force that arises between adjacent layers of fluid that are in relative motion. For instance, when a fluid is forced through a tube, it flows more quickly near the tube's axis than near its walls. In such a case, experiments show that some stress (such as a pressure difference between the two ends of the tube) is needed to sustain the flow through the tube. This is because a force is required to overcome the friction between the layers of the fluid which are in relative motion: the strength of this force is proportional to the viscosity.
A fluid that has no resistance to shear stress is known as an ideal or inviscid fluid. Zero viscosity is observed only at very low temperatures in superfluids. Otherwise, the second law of thermodynamics requires all fluids to have positive viscosity; such fluids are technically said to be viscous or viscid. A fluid with a high viscosity, such as pitch, may appear to be a solid.
Viscosity is the material property which relates the viscous stresses in a material to the rate of change of a deformation (the strain rate). Although it applies to general flows, it is easy to visualize and define in a simple shearing flow, such as a planar Couette flow.
The viscosity of the cooked starch paste, after cooling to 50°C, is a measure of the retrogradation (setback) produced by cooling. The starch increases in final viscosity to 919 BUHOW CAN YOU REDUCE THE VISCOSITY OF A STARCH?
The viscosity of the starch solution of moderate concentration (5–10%) can be reduced about two orders of magnitude to 100 mPa·s by the ultrasonic irradiation for 30 min. The treated solution can be efficiently powdered by a spray-dryer after the sonication. #BrainlyFast
To read and learn more about this topic, you may click on these following links:WHAT IS STARCH? : WHAT IS STARCH BROKEN DOWN INTO? :