Impact of environmental factors on the viscosity of starch solutions

Abstract

Use of starch in food products as a functional agent must be preceded by a precise determination of functional properties, solubility, dispersability, thermal stability, compatibility with other food components et al. Has been studied the influence of environmental factors (the mineral salts, pH, presens of sugars) on viscosity of gelatinizat starch solutions of maize, potatoes and soriz. It has been found that the presence of acids (acetic, lactic, citric, oxalic) in solutions increases degree of hydrolysis of the starch and decreases viscosity solutions. Adding salts (NaCl, KCl, CaCl2) lead also to a gradual decrease in viscosity. This effect could be due to increase of the degree of polymerization of the starch macromolecules and the increasing mobility of the gelatinizat starch snippets. The sugars (sucrose, fructose, glucose), at relatively low concentrations (below 20 %) will behave like cosolvent plastifiant forms complex starch-water-sugar and, therefore, increase viscosity solutions of the gelatinizat starch.