Contribution of Protein, Starch, and Fiber Composition to the Prediction of Dough Rheology and Baking Quality in U.S. Hard Red Spring Wheat

Wheat end-product quality results from complex interactions among protein, starch, and fiber, further complicated by genetic and environmental variability, especially in commercial samples composed of multiple varieties from diverse regions. Eighteen composite samples of hard red spring wheat (HRSW) were prepared from 755 field samples to simulate commercial grain blending. These composites were analyzed to evaluate the influence of flour composition on product quality. A wide range of flour compositional properties was analyzed and associated with dough and end-product quality traits, as measured by GlutoPeak, Rapid Visco Analyzer, Farinograph, Extensograph, Alveograph, and loaf baking. The results indicated that dough and bread quality are not determined by protein or gluten content alone, but that protein, starch and fiber composition and structural variations play a crucial role. Flours with higher proportions of high-molecular-weight glutenin (HMW-GS) fractions, particularly those rich in Bx and Ax subunits, exhibited greater dough resistance, mixing strength, and bread volume. In contrast, lower-performing samples were characterized by reduced HMW/LMW, polymeric/monomeric protein ratios, and HMW-Bx content. Multivariate modeling showed strong predictive performance for loaf volume (R2 > 0.860) when protein, starch and fiber quality metrics were combined with protein content. These findings provide a data-driven framework for wheat flour classification and optimizing processing formulation.