Thermal, Morphological and Pasting Properties of Binary Mixtures of Starches

Abstract

Mixtures of different starches can present similar properties of chemically modified starches, lowering the industrial cost, besides to be an alternative to meet the industrial demand and consumption of natural products. Therefore, this study aims to evaluate the thermal, pasting properties and morphological characterisation of the starches from cassava ( Manihot esculenta ), sweet potato ( Ipomoea batatas ) and potato ( Solanum tuberosum ), in their native form and their binary mixture. The starches were isolated from aqueous method. TG/DTG showed the highest thermal stability for potato starch as well as their mixtures with sweet potato and cassava. DSC values showed that the gelatinisation enthalpy of potato starch was higher than cassava and sweet potato starches and the mixtures of the starches were physical with low chemical interaction. The mixture of cassava and potato starches showed the highest viscosity value. Relative crystallinity values were similar for cassava starch and sweet potato and lower for potato starch. The lowest values for roughness were obtained for cassava starch and their blends. The results obtained for the mixtures of starch showed an average of those values found for starches in their native form.