Evaluation of non-Newtonian Viscosities of Liquid Foods in Swallowing Process Using Inclined Flow Channel Instrument

Abstract

AbstractTo evaluate the non-Newtonian viscosities of liquid foods thickened for assistance of swallowing in nursing-care practice, an inclined flow channel instrument was investigated for development into a structurally simple and easy-to-use viscometer. Experimental analysis of the flows of Newtonian and non-Newtonian test liquids in the instrument derived a dimensionless relation expressing changes of the friction coefficient in the flow process which was indicated by the relative flow length, considering the shear rate level in the swallowing process. A methodology to evaluate uniquely the viscosities of liquid foods undergoing the swallowing process was presented using the measurements such as the flow length and velocity in the instrument.