Physico-Chemical and Sensory Properties of Bread Prepared from Wheat and Unripe Plantain Composite Flours Fortified with Bambara Groundnut Protein Concentrate

Abstract

Matured, unripe plantain (Musa paradisiaca) fruits from a local cultivar, “Agbagba” were processed into flour. Protein concentrates were prepared from the flour of Bambara groundnut (Vigna subterranean L. Verde) using the alkaline extraction process. Bread was produced from the substitution levels of wheat/plantain/Bambara groundnut protein concentrate (BGPC) flour blends (100 – 30%, 0 – 40% and 0 – 30%), respectively and the physical, chemical and sensory properties of the product evaluated. The result showed that the loaf height, volume and specific volume decreased with an increase in the levels of plantain/BGPC flour blends. Loaf height decreased from 11.2cm (sample A) to 6.2cm (sample G) and loaf volume reduced from 2291.4cm3 to 1238.6cm3 for samples A and G, respectively. There was no significant difference in loaf height up to sample C (20% PF and 10% BGPC) when compared to the control (sample A). Specific volume also reduced with increasing levels of the blends from 6.3cm3/100g to 2.2cm3/100g for samples A and G, respectively. There was a corresponding increase in loaf weight in all samples as the plantain flour and BGPC increased. There was no significant difference in loaf weight up to sample C which also represents 20% PF 10% BGPC when compared to the control (sample A).The protein content in the fortified bread increased progressively from 10.4% (sample A) to 17.3% (sample G). From the result, it was observed that the addition of 10% BGPC in the formulation improved the protein content of the bread to 13.6%. Fat content increased significantly from 0.76% to 2.51% (samples A and F), respectively with increase in the protein concentrate added. Ash, crude fibre and energy values were also observed to increase with increasing addition of BGPC (0.76% - 2.21%, 9.1% - 11.29% and 276.88kcal/100g – 282.43kcal/100g), respectively. The sensory result showed that the bread produced from 15% BGPC and 25% plantain flour was acceptable with respect to flavour, crumb texture and general acceptability.