Introducing new wheat milling passages to manage the ultra-fine flours of primary streams: Roles of granulation in starchy content

The size distribution of ultra-fine flours (UFF) is crucial for determining the physicochemical properties of the final wheat milling product. To optimize the milling process, new passages with a stack of fine mesh sieves are used. The UFF extracted from both break and reduction passages exhibits a wide range of functionality and physicochemical characteristics, were incorporated into five reconstituted flour blends. By splitting of UFF fraction isolated from primary passages, the quality of baked bread can be modified manually without using any enzymes or chemical improvers. Substituting the default milling stream with 60% of primary UFF increases the availability of starch for gelatinization by shifting the peak temperature to a higher number. This creates stronger starch-gluten network exhibiting increased elasticity. Raised viscoelasticity and hence water absorption value result in higher loaf volume. The infrared spectroscopy analysis revealed a specific peak at 1659 cm⁻¹, associated with water absorption in the amorphous region of starches, which was recorded as the highest intensity for UFF reduction samples. These results were in agreement with imposing a higher starch damage. Furthermore, structural amorphization was also observed based on a broader shallow XRD curve for samples incorporated with UFF of reduction passages due to higher grinding strength generated through the smooth rolls. The lowest polydispersity index content was calculated for break UFF samples and more uniformity in particle size distribution was found. This finding highlighted the effective role of corrugated rolls for producing the certain range of flour granulation.