Functional Properties, Nutrient Content, Digestibility and Acceptability of Breakfast Cereals Made from Yellow Maize-Soybean Composite and Firm-Ripe Banana Flour

Abstract

Breakfast cereals were produced from blends of yellow maize-Soybean composite and firm-ripe banana flours.  A Composite flour blend was formulated by mixing yellow maize flour and soybean flour in the ratio of 70:30. Then, five samples of breakfast cereals were produced by substituting firm-ripe banana flour with the composite flour at the following ratios: 95:5 =A, 90:10 = B, 85:15 = C, 80:20 = D, 75:25 =E, and a 100% composite flour blend of yellow maize and Soybean flour (100:0 = F) served as a control. The functionality of the flour blends was assessed. The breakfast cereals were assessed of their proximate composition, anti-nutrient content, in-vitro protein and starch digestibility, and sensory qualities using standard methods. Results revealed that, Bulk density of the samples ranged from 0.90-0.97 g/cm3. Foaming capacity increased significantly from 3.28 to 9.83 %, water absorption capacity increased from 2.60 to 2.40 % while oil absorption capacity decreased from 0.68 to 1.10 % with increased in the percentage composition of firm-ripe banana flour in the blend. Swelling capacity and Gelation temperature ranged from 2.16 to 3.33 % and 72.33 to 75.66 ℃ respectively. Values of protein (9.31 – 12.65 %), lipid (3.61 – 4.94 %), ash (3.16 – 4.22 %) and calorie (372.85 – 382.76 kcal/100g) decreased, while fibre (2.90 – 4.53 %) and carbohydrate (53.92 – 75.77 %) increased, with increasing substitution of firm-ripe banana flour. Phytate (0.57 to 15.45 mg/100g), tannin (40.25-82.92 mg/100g), oxalate (5.24-8.84 mg/100g) and saponin (3.92 to 10.28 mg/100g) were within safe-limits. In-vitro protein digestibility increased from 30.87 to 35.95 % showing significant increase (p˂0.05) with increasing substitution of firm-ripe banana flour, while invitro starch digestibility ranged from 31.74 to 16.21 %. Breakfast cereals developed with up to 10% banana flour compared favourably with Control in all sensory attributes assessed and were acceptable by consumers when served with cold milk.