Effect of Electron Beam Irradiation on the Structure, Physicochemical Properties and Cooking Quality of Proso Millet

To investigate the effect of electron beam irradiation (EBI) on the structure, physicochemical properties, this study applied electron beam irradiation at different doses (0, 3, 6, 9, and 12 kGy) to proso millet. The crystalline structure, short-range ordered structure, amylose content, damaged starch content, pasting properties, thermal properties, solubility, swelling power, cooking characteristics, and textural properties of proso millet were measured. The results showed that EBI destroyed the crystalline structure of proso millet. As the irradiation dose increased, the relative crystallinity significantly decreased from 19.46% to 11.76%, accompanied by a reduction in amylose content from 4.93% to 2.25% and an increase in the amylose index from 75.86% to 76.53%. Consistent with these structural alterations, EBI led to a substantial decline in the pasting properties, thermodynamic transition temperature, and swelling power. In contrast, the solubility increased considerably. These changes collectively contributed to an improvement in cooking quality, manifested by a reduction in the hardness and chewiness of the cooked proso millet by 54.93% and 81.02%, respectively, and an 285.44% increase in soluble solid content. EBI effectively improved the processability of proso millet, making it more suitable for making porridges with a thick texture and soft taste. The results revealed the influence of EBI on the quality of proso millet. It provides a scientific basis for the application of EBI in the efficient preservation and high-value processing of grain. Besides, this study is of great practical significance to promote the sustainable development of the proso millet industry.