Impact of steam explosion and particle size reduction of wheat bran on quality characteristics of whole wheat dough and cookies

Abstract

Wheat bran possesses beneficial health attributes and offers potential to lower the starch content in baked products. This research examined how steam explosion (SE) treatment and particle size reduction influence both the physicochemical characteristics of resulting wheat bran powder and subsequently, the quality of dough prepared from reconstituted whole wheat flour and cookies made therefrom. Results demonstrated that SE treatment significantly enhanced the contents of total phenolic compounds (up to 28.48 mg/g), total flavonoids (up to 6.48 mg/g), and water-extractable arabinoxylans (up to 22.17%) in the bran powder. Dough formulated with SE-treated bran (SWB) exhibited increased water absorption and solvent retention capacity but lower stability, indicating a modified gluten network. Textural analysis revealed that fine SWB particles (<150 mesh) transformed the dough into a cohesive composite gel with superior springiness and adhesiveness. Corresponding cookies fortified with fine SWB possessed a denser structure, greater hardness, and a substantially lower in vitro starch digestibility. Principal component analysis identified SWB-150 as the optimal formulation, which exhibited a higher relative crystallinity and a protein secondary structure dominated by β-sheets (61.52%). These findings establish a theoretical foundation for developing high-fiber, nutritionally enriched bakery items using modified wheat bran.