Effect of African Yam Bean and Orange Albedo Flour Inclusion on Functional, Proximate, Physical and Sensory Quality of Wheat Bread

Abstract

This study evaluated the effect of African yam bean and orange albedo flour inclusion on the functional properties of wheat-based flour blends and the proximate composition, physical characteristics, and sensory quality of bread prepared from the blends. Five flour formulations were prepared using wheat, African yam bean, and orange albedo flour in ratios of 100:0:0, 80:10:10, 75:15:10, 70:20:10, and 65:25:10, designated as Samples A, B, C, D, and E, respectively. The flour blends were analyzed for its functional properties including bulk density, water absorption capacity, oil absorption capacity, foaming capacity, and swelling capacity. Bread samples prepared using flour blends were evaluated for proximate composition, physical properties (loaf weight, loaf height, loaf volume, specific loaf volume) and sensory attributes using a 9-point hedonic scale. The inclusion of African yam bean and orange albedo flour significantly increased water absorption capacity from 0.40 to 0.65 g/g, foaming capacity from 2.15 to 8.00%, and swelling capacity from 15.30 to 17.61%. Blending of flour showed no significant effect bulk density and oil absorption capacity. Protein content of the bread increased from 9.94% in the control to 16.69% in Sample E (65:25:10), while crude fibre increased from 0.66% (100:0:0) to 0.77% (65:25:10) and crude fat from 0.71% (100:0:0) to 0.91% (65:25:10). Carbohydrate content decreased from 69.29% (100:0:0) to 62.06 (65:25:10) with increasing substitution. Loaf weight increased from 178.21 g to 252.21 g, whereas loaf height decreased from 9.00 cm to 6.20 cm and specific loaf volume decreased from 4.31 to 2.85 cm³/g. Sensory evaluation showed that Sample B had acceptable overall acceptability, with a score of 8.20 compared with 8.45 for the control. Higher substitution levels reduced sensory scores. The 80:10:10 blend produced bread with improved protein content and acceptable sensory quality under the conditions of this study.