Dual Modification Approach for Tapioca Starch Using Gamma Irradiation and Carboxymethylation

Abstract Native starches are modified to enhance their characteristics in terms of thermal stability, cold water solubility, and bacterial susceptibility, which limit their industrial applications. In this work, dual modification of tapioca starch by gamma irradiation followed by carboxymethylation was carried out, and the modified starch characteristics were examined. Four dosages of gamma irradiation (25, 35, 45, and 60 kGy) were used for the first modification stage, followed by carboxymethylation using different parameters. The required modification of starch was characterized by FTIR, SEM, TGA, and XRD. Experimental findings showed that the dual modification enhanced the thermal stability of the starch. In addition, carboxymethylation impacted starch's morphology and reduced its crystallinity. Furthermore, the dual-modified starches exhibited excellent characteristics and could be used in specific applications, including oil and gas, textile, paper, packaging, 3D printing, cosmetics, and pharmaceutical industries.