Effect of Thermal Treatment on the Rheological Pattern and Composition of Dry Bean Flour Soluble Extracts

Abstract

Dry bean flour samples with 14% (dry basis) moisture content were exposed to thermal treatment, in sealed cans, at 50", 70", 80", and 9O"C, for various periods. The rheological pattern and composition of their soluble extracts, obtained at pH 10, were determined. Soluble extracts decreased in viscosity with time of treatment, up to a time dependent on temperature, where viscosity became constant. Soluble protein decreased with time of treatment. During the first step of dry bean flour heat treatment, soluble solids other than protein, were constant, then began to increase, promoting viscosity Constance in spite of soluble protein decrease.

Physicochemical, morphological and rheological properties of canned bean pastes “negro Queretaro” variety (Phaseolus vulgaris L.)

“…During heating, the intermolecular forces of the bean pastes are broken, producing in the samples less opposition to the shear. These results are in good agreement with those reported by Gerschenson and Bartholomai (1986). They found that increasing the temperature and decreasing the content of soluble solids in beans flour, a decrease in viscosity was observed.…”

“…They found that increasing the amount of soybean protein and the processing temperature causes that the proteins behaved like a rigid gel. Moreover, Gerschenson and Bartholomai (1986) reported that the changes in the viscosity of canned beans, produced by the heating process, causes protein solubilization. Franco et al (1998) analyzed the viscoelastic behavior and the changes in texture of lupin protein-stabilized emulsions.…”