Effect of Gamma Irradiation on the Functional and Nutritive Properties of Rice Flours from Different Cultivars

Abstract

ABSTRACT The purpose of this work was to study the effect of minimal doses of γ-irradiation to reduce microbial loads (Co60, doses of 0, 1.5, and 3 kGy) on flour from three rice cultivars with different amylose contents (AC) grown in Argentina: RP2 (AC 25%), Yerua (Y) (AC 19%), and Higokumochi (H) (AC 5%). Studies on some starch characteristics such as digestibility (rate of starch hydrolysis in vitro), gel viscosity and syneresis, and scanning electron microscopy (SEM) were performed. Results showed that γ-irradiation affects rice functional and nutritive characteristics proportionally with the dosage used. With 3 kGy, original digestibility values increased 37.5, 60, and 76%; gel viscosity decreased 52, 77, and 90%; and syneresis increased 0, 193, and 546% on RP2, Y, and H, respectively. Amylopectin was the starch fraction most affected as shown by SEM. Although some of these changes in cultivar attributes might be considered negative for traditional food formulations, they could help in the design of n...