Nutritional composition and functional properties of maize – soya bean composite flour

The functional properties, proximate, mineral and anti-nutritional composition of maize/soya bean composite flour blends were investigated. The maize flour (MF) was blend with soya bean flour (SF) in the ratios of 90:10,80:20, 70:30, 60:40 and 50:50 (MF: SF) respectively. The flour blends were analyzed using Standard methods. The range in functional properties of the blends were, bulk density, (0.90 ±0.09 - 0.94 ±0.12g/mL), swelling capacity, (1.79 ±1.68 - 2.29 ±1.22%), pH (5.18 ±0.29 - 6.76 ± 0.48) and water absorption capacity (11.96 ±0.18 - 16.22 ±0.11%). The proximate composition of blend shows that the protein content of the samples increased steadily with increased substitution with soya bean flour 79.13 ±0.10 % in 90:10 and 63.66 ±0.34 % in 50:50 sample ratios while carbohydrate and fiber decreased, fat, and ash increased with increase in soya bean flour addition. The mineral composition of the blends also showed that potassium, phosphorous, iron, zinc and magnesium was increasing, while the anti-nutrient gradually decreased as shown in the following ranges, phytate (0.36 ± 0.01- 1.23 ± 0.01 mg/100g), oxalate (0.10 ± 0.01-0.31 ± 0.01 mg/100g.) and tannin (0.02 ± 0.01- 0.18 ± 0.00 mg/100g) respectively. The study showed that the nutritional value and functional properties of maize flour can be drastically improved by supplementing the flour with adequately processed Soya bean flour. Swelling capacity, water absorption capacity, pH, protein, ash, phosphorus, potassium, calcium, iron, zinc and magnesium contents of the composite blends increased significantly with increased supplementation with soya bean flour. Compositing maize and soya bean flour has resulted in decreased anti-nutrient content of the composite flour samples. Soya beans can effectively be used in locally formulated weaning foods as an acceptable protein supplements. The processes, parameters and formulation developed through this study has successfully produced a high protein energy weaning food with acceptable functional characteristic as well as excellent nutritional quality.