Germinated Bambara groundnut (Vigna subterranea) flour as an ingredient in wheat bread: Physicochemical, nutritional, and sensory properties of bread

Abstract

Wheat flour (WF) was substituted with germinated Bambara groundnut (Vigna subterranea) flour (GBF) at different proportions (5%, 10%, 15%, 20%, 25%, and 30%) and used in the preparation of bread. The dough mixing, pasting, and gelatinization properties of the blends were evaluated as well as the nutritional quality, in vitro starch digestibility, phytochemical constituents, antioxidant potential, color, texture, and sensory properties of breads. All the wheat dough containing GBF had higher water absorption capacity, gelatinization temperatures, dough development time, low peak, and setback viscosities. The composite breads had significantly higher dietary fiber, minerals, protein digestibility, corrected amino acid scores, resistant starch, slowly digestible starch, total phenolics, total flavonoids, and antioxidant activities and caused significant reduction in rapidly digestible starch content. The addition of up to 15% GBF had no significant impact on the specific volume of wheat bread. Substitution of WF with GBF influenced color and texture properties of bread. Wheat bread supplemented with 20% GBF had significantly higher scores in taste, aroma, and overall acceptability. This study demonstrated the potential of GBF as a functional ingredient in bread making. PRACTICAL APPLICATION: This study provides a suitable possibility of partial substitution of wheat flour with germinated Bambara groundnut, to develop functional and acceptable bread. The dough mixing and pasting results in this study would add to knowledge on the dough handling characteristics as there is limited information regarding the mixing properties of wheat dough with germinated Bambara groundnut.

Keywords: dough properties; germinated Bambara groundnut; nutrient-dense functional bread; starch digestibility.