Gamma radiation application to rice: Reduced glycemic index in relation to modified carbohydrate observed in FTIR spectra

Mst Afifa Khatun; Md Razzak; Md Afzal Hossain; Md Ashikur Rahman; Ruhul Amin Khan; Roksana Huque

doi:10.1016/j.crfs.2020.12.002

Gamma radiation application to rice: Reduced glycemic index in relation to modified carbohydrate observed in FTIR spectra

Curr Res Food Sci. 2020 Dec 16:4:11-17. doi: 10.1016/j.crfs.2020.12.002. eCollection 2021.

Authors

Mst Afifa Khatun¹, Md Razzak², Md Afzal Hossain¹, Md Ashikur Rahman¹, Ruhul Amin Khan², Roksana Huque¹

Affiliations

¹ Food Technology Division, Institute of Food and Radiation Biology, Atomic Energy Research Establishment, Dhaka, Bangladesh.
² Institute of Radiation and Polymer Technology, Atomic Energy Research Establishment, Dhaka, Bangladesh.

Abstract

This study was conducted with a popular, low price Bangladesh rice variety BRRI Dhan 29 with a view to possible carbohydrate modification targeting lower glycemic index using gamma radiation application. Irradiation process (5 and 10 kGy at a dose rate of 9.74kGy/h) altered amylose content, amylose/amylopectin ratio, swelling power, and solubility index. FTIR spectroscopy confirmed the changed molecular structures due to radiation application. Treatment with a dose of 5 and 10kGy caused increased amylose and amylose/amylopectin ratio significantly (p < 0.02). The highest amylose content was found in 10 kGy irradiated rice (30.20%) compared to unirradiated one (17.27%). Gamma radiation caused decreased swelling and increased water solubility in rice powder. These features of carbohydrate amendment in irradiated rice lead to reduced glycemic index as investigated with the in vivo experiments. Therefore, this study suggests gamma-irradiated rice (10kGy) is beneficial for diabetic subjects keeping lower blood glucose levels.

Keywords: Amylose; Gamma radiation; Glycemic index; Rice.