Rheological behaviour and certain quality attributes of the dough and bread prepared from the wheat-millet-Bambara flour (WMB) containing mixtures of emulsifiers and/or apple pectin were investigated. WMB was prepared by substituting wheat flour (WF) with 25% millet flour and 25% Bambara flour. Pectin (1.0-2.0 g) and emulsifiers namely sodium stearoyl lactylate (0.25-0.40 g), polysorbate 80 (0.50-0.80 g), and diacetyl tartaric acid ester of monoglycerides (0.10-0.25 g) mixed in different proportions were added to produce dough and bread. Mixolab was utilised to measure the rheological behaviour of dough and bread made from all mixes were analysed for physical characteristics, nutritional composition, and organoleptic properties. A significant increase in dough development time (emulsifier: 65% and pectin: 57.9%) and dough stability (emulsifier: 18.2% and pectin: 35.2%) were observed. Loaf volume, specific volume and proximate composition of the composite bread increased significantly relative to control. Protein content (33%), protein digestibility (85%) and certain essential amino acids (lysine: 54.6%; threonine: 36.4%) increased significantly in the WMB bread compared to the WF bread. Sensory evaluation revealed an above average acceptability for the composite bread samples. Emulsifiers and pectin used in the present study resulted in significant improvement in the dough rheology, as well as in the physical characteristics, the nutritional and sensory attributes of the WMB composite bread. The results of the present study confirm the potential for supplementation and fortification of wheat bread using flours from millet and Bambara sources.
Keywords: Bambara groundnut; Composite flour; Emulsifiers; Mixolab; Pectin; Rheological behaviour; Wheat–millet–Bambara flour.