Quality evaluation of flour and biscuits produced from wheat and African Yam Bean Tempeh Flours

Biscuits are foodstuffs that are consumed all over the world as snacks on wide range developing countries where protein and caloric malnutrition are prevalent. There is therefore need to feed on functional foods with improved formulations and substantial health benefits by world nutrition bodies due to different health problems related to food consumption. This study was carried out to evaluate the proximate and functional properties of the flour as well as evaluate the biscuit samples for physical properties, anti-nutrient content, minerals composition and anti-oxidant properties of biscuits produced from wheat flour fortified with African yam bean tempeh flour. The physical parameters varied from 3.12 – 4.22mm, 1.30 –2.81, 4.59 – 6.89g, 1.5 – 2.4mm and 1.25 – 3.65N for diameter, spread ratio, weight, height, and break strength. The proximate composition of the flour varied from 0.05 – 3.46%, 12.6 – 28.74%, 0.84 – 3.18%, 1.37 – 3.76%, 58.64 – 84.74% and 2.22 – 11.4% for ash, protein, crude fiber, crude lipid, carbohydrate and moisture of the flour, respectively. The functional properties ranged from 14.66 – 20.2%, 0.70 – 0.78 (g/ml), 0.71 – 10.57%, 18.08 – 41.03% and 0.71 – 0.74% for water absorption capacity, bulk density, oil absorption capacity, foam capacity and emulsion capacity, respectively. The anti-nutritional properties ranged from 0.067%, – 0.437mg/100g, 0.013 – 0.067%, 0.112 – 0.146%, 0.015 – 0.038%, 0.168 – 0.401, 0.040 – 0.401%, 0.017 – 0.040% for tannin, phytate, saponin, oxalate, alkaloid, phenol and flavonoids, respectively. The anti-oxidant properties were in the range of 0.081 – 0.465%, 0.026 – 0.047%, 0.035 – 0041 mg/100g for scavenging activity, reducing power assay and Beta carotene, respectively. The mineral contents - iron, magnesium, calcium and phosphorus ranged from 4.18 – 13.06, 2.70 – 32.17, 61.04 – 201.42 and 3.76 – 30.42%, respectively. These results suggest that the fortification of wheat flour with Africa yam bean flour can improve the nutritional quality of biscuits.