Abstract
A method with a simple flow instrument (the Bostwick consistometer) was proposed for evaluating the viscosity of non-Newtonian liquid foods. The flows of Newtonian and non-Newtonian test liquids in the consistometer were analyzed as two-dimensional gravity currents. Theoretical equations modified with the two correction factors on the liquid volume and elapsed time for the Bostwick measurements reproduced the flow of these liquids observed in the consistometer. In order to predict the physically defined viscosity from the Bostwick measurement, theoretical equations were developed into the relation between the friction factor and the Reynolds number. Use of the Bostwick consistometer as a rational flow instrument for the liquid foods was discussed in terms of comparison of the viscosity values predicted from Bostwick measurements with those determined with a rotating viscometer.
