OPTIMIZING STEEPING TIME FOR ENHANCED FUNCTIONAL PROPERTIES IN MAIZE–SORGHUM CUSTARD BLENDS

Abstract

The aim of this study was to evaluate the physicochemical, functional and sensory characteristics of starch blends from steeped maize and sorghum. Starch were extracted from maize and sorghum after steeping for 6 and 12h. It was blended in the ratio; 100: 0, 90: 10, 80: 20, 70: 30, 60: 40, 50: 50, 0: 100 and labelled A1, A2, A3, A4, A5, A6, A7, respectively for samples soaked for 6h. While same maize-sorghum blend ratios from 12h soaking were labelled B1, B2, B3, B4, B5, B6 and B7, respectively. Percentage moisture, protein and fat content ranged from 9.60 to 13.04 %, 7.16 to 10.13 % and 3.49 to 4.96 %, respectively, while Percentage Ash, Crude fiber and total carbohydrate ranged from 0.97 to 1.46 %, 0.59 to 2.90 % and 71.46 to 74.84 %, respectively. Energy value of sample A1 was significantly higher (379.36 kcal/100g), followed by samples A2 and A3 with values of 375.05 and 373.10 kcal/100g, respectively. Bulk density, water absorption capacity and swelling index ranged from 1.02 to 1.85 g/ml, 1.70 to 2.70 g/g and 1.10 to 1.30, respectively. Water absorption capacity of samples A1, B1 and B2 were significantly higher, with value of 2.70g/g. Swelling index increase with less soaking time (6h). Calcium (Ca), Potassium (K) and Magnesium (Mg) content of the starch blends ranged from 15.08 to 52.48, 108 72 to 269.30 and 11.68 to 99.00 mg/kg, respectively. Calcium, Magnesium and Iron content increased with increased substitution of sorghum starch. pH and viscosity ranged from 3.41 to 3.77 and 1.390 to 1.514 pas, respectively. pH was relatively higher as soaking time increased. While viscosity of the custard was higher at 6h soaking time. Teaxture, Aroma and Taste score ranged from 5.50 to 6.60, 4.25 to 6.40 and 4.10 to 6.16, respectively. All the samples received equal acceptability, except sample sample B1 which was significantly lower.