ABSTRACT

This work evaluated the quality properties of high-fibre bread with no-added sugar from flour blends of orange fleshed sweet potato, tiger nut, wheat and date fruit. The proximate, functional, physical properties and -carotene of flour and bread was analyzed. The proximate composition, moisture content of the flour ranged from 16.67% (WOTD2) to 18.93% (WOTD5), ash 1.75 (WOTD2) to 2.15 % (WOTDS), crude fibre 2.47 % (WOTD2) to 2.93 % (WOTDS), protein 10.41 % (WOTDS) to 12.16 % (WI), dry matter 81.07 % (WOTDS) to 84.44 % (WI), fat 4.45 % (WOTD5) to 6.67 % (WI), carbohydrate 78.09% (WOTD2) to 80.07 % and energy value 417.77 % (WOTD2) to 401.93 % (WOTD2). Functional properties, bulk density ranged from 0.72 (g/ml) to 0.76 (g/ml), oil absorption capacity 2.75 ml/g (WOTD5) to 2.05ml/g (WOTD2), water absorption capacity 3.10 ml/g (WOTD2) to 3.70ml/g (WOTDS), foam stability 91.17 ml/g (WOTD2) to 94.44 ml/g (WOTD5S), foam capacity 13.64 ml/g (WOTD2) to 16.37ml/g (WOTD5), wettability 41.00s WOTD2 to 56.50s WOTD5, gelatinization temperature 58.43 C WOTD2 to 65.82 C WOTD5 and gelatinization capacity 3.20 % WOTD2 to 4.88 % WOTDS. The B-carotene ranged from 2468.90 (WOTD2) to 5290.80 (WOTD5). In conclusion, the protein, fat and crude fibre contents of both the flour blends increased as orange fleshed sweet potato flour substitution increased. The partial substitution of wheat flour with orange fleshed sweet potato flour considerably improves the physicochemical and physical properties of the flours, especially protein, ash, fiber and energy, as well as functional properties. The values obtained show that the bread are good sources of energy, most nutrients are within range of the Recommended Dietary Allowance.