IDENTIFICATION OF STIMULI CONTROLLING THE SENSORY EVALUATION OF VISCOSITY II. <i>Oral Methods</i>

Abstract The stimulus associated with oral evaluation of the viscosity of liquid and viscous foods appears to embrace a range of shear rates extending from 10 ‐1 to 1000 s ‐1. The value associated with a particular food depends on its flow characteristics. For liquid foods the stimulus appears to be the shear rate developed at an approximately constant shear stress (∼ 100 dyn cm ‐2 ), whereas for viscous foods it appears to be the shear stress developed at an approximately constant shear rate (∼ 10 s ‐1 ). Additional factors may be involved when evaluating highly viscous non‐Newtonian foods or foods with an oil continuous medium. These are ‘plug flow’ or the spreading coefficient, respectively.