Combined systems of starch and Gleditsia triacanthos galactomannans: Thermal and gelling properties

Abstract

The purpose of the current study was to determine the effect of starch partial substitution by the galactomannans fraction extracted from milled seeds of Gleditsia triacanthos (Gt) on pasting, gelation and textural properties of the combined systems. Corn and wheat starch-gum systems were evaluated at neutral and acid conditions to obtain some practical information on the functionality and potential usefulness of the galactomannans fraction from Gt seeds in starch-based food products. The galactomannans fraction from Gt improved the viscosity profile of the starch combined systems and accelerated the gelation process of these systems during the first hour of cooling. The galactomannans from Gt reduced starch gelatinization enthalpy, indicating that these polysaccharides limited water absorption and interfered with the thermal energy transmission to the granules. The galactomannans of Gt helped to improve the stiffness and to reduce or keep constant the brittleness of the combined starch gels at 7-day storage. Acid condition did not influence the hot paste behavior and cold paste properties at 25 °C of the systems composed of starch and galactomannans fraction from Gt, and practically, pH reduction did not change the gel texture properties. These results have demonstrated that the galactomannans fraction from Gt seeds could become a suitable alternative to be used as a food texture modifier for starch-based products.