Physical Meaning of the Parameters Used for Evaluating Food for the Elderly

Abstract

The physical meaning of the parameters used for evaluating food for the elderly, which were established by Ministry of Health, Labour and Welfare, were investigated with aqueous solutions. The “katasa” parameter based on the shear stress (τb) could not reflect an apparent viscosity of under 500 mPa·s, whereas the parameter was appropriate for a sample of over 500 mPa·s viscosity. This is presumed to be the result of unsteady flow due to the gap between the internal surface of the sample cell and the plunger. A closer correlation to the viscosity could be obtained with the τc5-10 parameter, the force exerted on the plunger divided by the area of the side surface of the plunger. This implies that the stress on the side surface is larger than that on the bottom surface of the plunger.