Quality Evaluation of Bread Produced from Wheat, Tiger Nut Residue and Carrot Flour Blends

Abstract

This study evaluated the quality of bread produced from blends of wheat, tiger nut residue and carrot flours. Five formulations were prepared: Sample A contained 100% wheat flour (Control); Sample B had 90% wheat flour, 5% tiger nut residue flour, and 5% carrot flour; Sample C contained 85% wheat flour, 10% tiger nut residue flour, and 5% carrot flour; Sample D had 80% wheat flour, 15% tiger nut residue flour, and 5% carrot flour; while Sample E contained 75% wheat flour, 20% tiger nut residue flour, and 5% carrot flour. Flour and bread samples were subjected to functional, proximate, physical and sensory evaluations using standard methods. Functional properties such as oil absorption (0.60 to 0.70g/g), water absorption (0.40 to 0.55g/g), bulk density (0.59 to 0.71g/ml and swelling capacity (5.80 to 7.60g/ml) varied significantly (p≥0.05) among the samples. Proximate analysis revealed moisture content ranging from 27.20 to 39.58%, crude protein from 10.05 to 16.62%, crude fibre ranging from 0.40 to 2.52% and carbohydrate from 42.66 to 54.20%, with a significant (p≥0.05) decrease in protein and fat content as substitution increased. In terms of the physical properties of the samples, loaf volume and specific loaf volume decreased significantly (p<0.05) from 831.20 to 348.10 cm3 and from 3.50 to 1.05 cm3 respectively with increasing tiger nut residue flour substitution. Sensory evaluation indicated that bread from samples B and C (5 and 10% tiger nut residue levels) were comparable to the control in appearance (8.35 to 7.65), aroma (8.55 to 8.10), taste (8.35 to 7.50) and overall acceptability (8.60 to 8.10), while higher substitution levels (15-20%) adversely affected sensory attributes. The study indicated that partial substitution of wheat flour with up to 10% tiger nut residue flour and 5% carrot flour (sample C) produced nutritionally improved bread with acceptable sensory and physical qualities. This demonstrated the potential of tiger nut residue and carrot flour in value-added bakery products applications, promoting waste utilisation and reducing dependency on imported wheat flour.