This study explored the effect of substituting wheat flour (WF) with distinctive optimal doses of buckwheat flour (BF) corresponding to large, medium, and small particle sizes (PS), previously established based on an optimization process, on composite flour characteristics, dough rheology, and bread quality. The optimal dose for each PS was established in a previous study. The highest value for protein, lipid, mineral, and amino acids was found in the optimal composite flour with medium PS, with significant differences between those with large and small PS. The addition of BF in WF at doses corresponding to each fraction provides optimum rheological properties, with the large and medium PS providing higher performance compared to the small one. The same tendency was observed for volume and texture parameters of bread made from optimal composite flours with medium and large PS, respectively, but the crust and crumb lightness presented lower values than bread with small PS. Regarding the bread nutritional profile, the sample with medium PS possessed the highest protein, lipid, and ash content. Compared to the wheat bread, a considerably higher amino acid content, up to 21.22%, was found in bread made from optimal composite flours with medium and small PS, respectively. The bread samples with medium and large PS, respectively were superior in minerals, the value being up to 2.63 times higher compared to the control. Sensory characteristics results revealed that the bread samples containing 9.13% large and 10.57% medium PS were the most preferred by panelists. The results of this research make an important base to suitably develop wheat-buckwheat bread applications in the future.
Keywords: amino acids; chemical composition; minerals; optimal composite wheat–buckwheat bread; rheological properties; sensory profile.