Características físico-químicas e utilização em alimentos de amidos modificados por tratamento oxidativo

Abstract

The use of modified starches in foods is to improve characteristics that natural starches cannot confer. The objective of this work was to evaluate the physicochemical characteristics of starches from several botanical sources after chemical modification with H2O2 considering technological properties of interest to the food industry. Modified starches were used in dulce de leche and starch gum, and the sensorial acceptance of these products was verified. The chemical treatment included the suspension of the native starches in a 0.01% Fe2SO4, followed by addition of 1.25% H2O2 at pH 3.0 and reaction time of 15 min at 45 degrees C. After this period the starch was recovered by filtration, washed and oven-dried at 45 degrees C for 24 hours. The modified starches had higher expansion, carboxyl content, reducing power and susceptibility to syneresis. There was a decrease in the viscosity peak of the modified starches especially when the samples were analysed at pH 7.0. The sensorial evaluation indicated that dulce de leche produced with the addition of Peruvian carrot modified starch and regular corn acid-modified starch were the preferred samples. The starch gum made with modified starch of Peruvian carrot reached the second position on global preference between the panelists.