Adverse effects of high‐dose gamma irradiation on wheat quality and processing traits

Abstract Background and Objectives Gamma irradiation treatments are an effective option for sterilizing microbes and pests that damage wheat, however irradiation can alter the physical and nutritional properties of foods. In this study seven Australian wheat varieties were subjected to 0, 25, and 50 kGy treatments to examine the influence of high‐dose irradiation on a range of wheat quality traits such as physical processing, protein composition and dough rheology. Findings The traits most significantly affected by high doses of irradiation included flour color, unextractable polymeric protein (UPP), dough extensibility, dough resistance to extension, pasting viscosity, and starch damage. Rheological traits in the irradiated samples were adversely affected to such a high extent that they were not deemed suitable for end‐product processing, including baking. Conclusions High‐dose irradiation, applied at 25 and 50 kGy, was shown to negatively impact most wheat quality traits tested. High‐dose irradiation is not recommended for treating wheat if viscoelastic functionality is required for manufacturing of high‐quality products. Significance and Novelty Irradiation treatments significantly reduced the functionality of wheat quality traits tested. Irradiation significantly affected protein composition and structure, with a substantial reduction to the UPP fraction in wheat varieties tested. This change in protein functionality is likely linked to the decrease in dough viscoelastic properties.