Preparation and characterization of modified tapioca starch with epiclorhydrin

Starch is widely used in the food and non-food industry due to unique chemical, physical and structural properties so his production from various sources is growing steadily. Native starch has limitations in food industry applications such as high tendency toward retrogradation, low thermal resistance and shear resistance. Therefore starch is often modified in different ways to change and improve its performance. The aim of this research was to prepare tapioca starch modified with epichlorohydrin and to investigate digestibility, gelatinization, retrogradation, and rheological properties of starches. Digestibility was determined by AOAC 2002.02 method. Differential scanning calorimetry (DSC) was used to characterize the gelatinization and retrogradation properties. Rheological properties were investigated by Brabender Micro Visco-Amylo-Graph. Compared to the native starch, modified tapioca starch had larger digestibility, higher peak viscosity, hot paste viscosity and cold paste viscosity. Lower breakdown values show that modified starch paste is more stable to shearing at high temperatures than native starch paste. Gelatinization temperature of modified tapioca starch was slightly higher than of native starch, while enthalpy of gelatinization was lower. Native tapioca starch had lower tendency to retrograde than modified starch.