Thermal study in the interactions of starches blends: Amaranth and achira

Amaranth starch (AmS) and achira starch (AS) were blended at different proportions to evaluate swelling power (SP), thermal (DSC) and morphological (SEM) properties of the starch blends during gelatinization at two solid contents (5 and 40%) and establish their possible interactions. SP in the blends at 5% solids, was lower than that achieved by the native starches due to water competition, although gelatinization temperatures of the blends were related to the values of the individual starches and their proportion within the blends. Deconvolution of the areas of endothermic peaks, allowed to determinate the contribution of each starch, and established a non-additive effect in excess and limited water conditions. Both starches were affected by water competition and granular interactions, due to the differences in gelatinization temperature, granule size, crystallization, and percentage of amylose of each starch. These results suggest a modification in the swelling and gelatinization process explained by the changes in granules disruption of starches.