Stream-specific functional and rheological variability in roller-milled wheat flours: a sustainable approach to cookie quality optimization and flour utilization

Abstract

This study investigated the stream-specific functional, rheological, thermal, and end-product properties of roller-milled wheat flour streams, including break (B1–B4), reduction (C1–C5), and straight-run flour (SRF), to establish structure–function relationships for sustainable flour utilization and cookie quality optimization. Significant variability (p < 0.05) was observed among the streams, with damaged starch (SD) ranging from 3.48% (B1 and C3) to 8.85% (SRF). Reduction streams exhibited higher swelling power (6.94 g g⁻¹ at 98 °C) and solubility (11.64% at 55 °C), while DSC analysis revealed gelatinization temperatures ranging from 60.35 to 70.17 °C and enthalpy values from 4.13 to 8.91 J g⁻¹. Microvisco-amylograph analysis showed considerable variation in pasting behavior, with gelatinization temperatures ranging from 58.5 to 63.9 °C and peak viscosity ranging from 666 to 1032 BU, reflecting differences in starch damage and stream composition. Farinograph properties also varied significantly, with water absorption ranging from 52.0% to 63.9% and dough stability from 0.6 to 18.1 min. Cookie quality differed markedly among streams, where reduction fractions produced higher spread ratios (up to 7.3) and lower hardness (4925 g), while break streams yielded firmer cookie structures. Principal component analysis further confirmed strong relationships among starch functionality, rheology, and cookie-quality attributes. Overall, the findings demonstrate that selective utilization and recombination of milling streams can be strategically used to tailor flour functionality, improve product quality, and support resource-efficient production of application-specific flours for industrial baking applications.