Antioxidant-enriched gluten-free bread made with buckwheat flour: Evaluation of technological and nutritional quality

Background and Objectives Buckwheat is a pseudocereal that has been considered a potential ingredient in bakery products, mainly due to its composition. Many bioactive compounds are found in the outer layers of the grain. This study aimed to produce gluten-free breads using refined buckwheat flour (RBF) and whole-grain buckwheat flour (WBF). Three formulations were developed: F1 (100%-RBF); F2 (70%-RBF and 30%-WBF); and F3 (55%-RBF and 45%-WBF). The flours were evaluated for pasting, thermal, and thermomechanical properties. The breads were characterized for specific volume, color, moisture content, water activity, firmness, total reducing capacity, antioxidant capacity, rutin and quercetin levels, protein content, in vitro protein digestibility, in vitro starch digestibility, and sensory acceptance. Findings RBF presented superior results for pasting and thermomechanical properties, with no significant difference for thermal properties. Breads from formulation F1 had greater specific volume, lower firmness, higher protein digestibility, and better sensory acceptance, when compared to F2 and F3. However, the incorporation of WBF to F2 and F3 led to an increase in rutin and quercetin levels, total reducing capacity, antioxidant capacity, and total protein content. Principal components analysis showed a clear distinction between formulations with and without WBF, and how the parameters evaluated were dependent on the composition of the buckwheat flour used for bread preparation. Conclusions RBF and WBF flours proved to be promising ingredients for the preparation of gluten-free breads with nutritional improvement. Significance and Novelty Data on the use of WBF and nutritional characteristics of breads were obtained. Future studies should evaluate the presence of antinutritional compounds.