Effects of ⁶⁰Co-γ Ray Irradiation on the Structure and Processing Properties of Gluten Proteins

This study systematically investigated the effects of ⁶⁰Co-γ-ray irradiation on the structural characteristics and processing properties of gluten proteins. Gluten protein samples were irradiated at doses of 0, 1, 3, 5, 7, and 9 kGy. The investigation assessed the free sulfhydryl groups, disulfide bonds, secondary structure, molecular weight distribution, color attributes, water-holding capacity, emulsifying properties, and taste profiles of gluten protein, and the pasting characteristics of the wheat starch-gluten protein reconstituted system under varying irradiation conditions. The results demonstrated that after γ-ray irradiation treatment, the free sulfhydryl group content in wheat gluten protein consistently exceeded that of the control group. Meanwhile, the disulfide bond content decreased gradually from 488.71 μmol·g⁻¹ to 259.21 μmol·g⁻¹. The protein secondary structure exhibited a conversion from α-helix to β-sheet. SDS-PAGE analysis indicated partial degradation or aggregation of proteins. Irradiation improved certain processing properties of wheat gluten protein. Notably, at an irradiation dose of 7 kGy, the L^* value of color raised by 14.61%, water-holding capacity increased by 0.09 g/g, and emulsion activity and stability were enhanced by 1.84-fold and 5.48-fold, respectively. Irradiation exhibited relatively limited effects on the taste of gluten protein and the pasting properties of wheat starch-gluten protein reconstituted systems. The peak viscosity, final viscosity, and breakdown value of reconstituted flours decreased only at the highest irradiation dose of 9 kGy (P<0.05). This study provides a theoretical foundation for the application of irradiation in flour product processing and gluten protein modification.