RHEOLOGICAL BEHAVIOR OF TOMATO PASTES IN STEADY AND DYNAMIC SHEAR

Abstract

ABSTRACT Tomato pastes (26–30 °Brix) at 40C were highly shear thinning fluids (n = 0.28) with large magnitudes of Casson yield stresses (78–212 Pa). Dynamic shear data revealed weak gel‐like behavior of the pastes: magnitudes of G′ were higher than those of G″, and both increased with oscillatory frequencies. The Cox‐Merz rule was not applicable to the steady and dynamic shear data on the pastes, but the two types of data conformed with the use of shift factor on frequency. Solids and liquid fractions in the pastes were satisfactory for correlating the dynamic properties, consistency index, and Casson yield stress.