A Study of the Influence of γ-Irradiation on the Composition of Functional Groups on the Surfaces of Oat Grain Shell, Kernel, and Seed Powder

The influence of γ-irradiation dose on the composition of functional groups on the surfaces of oat grain shell, kernel, and seed powder has been studied. As a result of radiolysis, the relative intensity of absorption bands due to vibrations of C=O, C–O–C, and O–H bonds increased, and absorption bands due to unsaturated bonds appeared. At the same time, absorption bands characteristic of oat grain were retained in the IR spectrum of irradiated oats. Therefore, γ-irradiation at a dose of up to 3000 kGy did not lead to the complete destruction of chemical bonds in the structure of compounds contained in oat seeds. The structures of the oat kernel, shell, and whole grain remained visually intact at relatively low radiation doses (up to 600 kGy). However, at higher doses (1700–3000 kGy), oat grains lost their primary hardness and filminess, and the surface continuity of the kernels and whole grains was disturbed. Note that the initial straw yellow color of the whole grains of oat gradually changed in the course of radiolysis first to light brown and then to dark brown with the absorbed dose as a result of the accumulation of various chromophore groups (C=C, C=O) and the auxochrome group OH, which causes a deeper color intensity by enhancing the effects of chromophore groups, in the polymer structure. Changes in the color of oat grains with the dose of γ-irradiation indicate the radiation-induced carbonization and oxidation of grain macromolecules.