The effect of infrared radiation on gluten aggregation and pasting properties of wheat flours with different protein content

The aim of this study was to investigate the potential of a designed infrared (IR) assisted ribbon mixer system for thermal modification of wheat flours that had different protein content and intended use (bread, cake, and biscuit wheat flours). Additionally, the effect of IR treatment, which was conducted using five different IR power levels for either short or medium wave IR emitters, on gluten content and quality, gluten aggregation and rheological properties of flours were determined. IR treatment resulted in minor crude protein loss (1–2%) in flours. Moreover, the effect of IR treatment on wet gluten and gluten index values was insignificant for bread and cake wheat flours, while it was significant for biscuit wheat flour. Torque maximum values were not significantly affected from IR treatment regardless of the flour type while the treatment caused a significant decrease in peak maximum time values up to 33%. Besides, the effect of IR treatment on maximum viscosity and breakdown viscosity values was insignificant for all flour types (p > 0.05). It was concluded that IR treatment may cause minor changes in gluten functionality and pasting properties of the flours depending on the type of flour and process conditions.