FORMULATION AND CHARACTERIZATION OF SWEETPOTATO-BASED COMPLEMENTARY FOOD
To promote the utilization of orange-fleshed sweetpotato (OFSP) and to aid with the eradication of vitamin A deficiency in Nigeria, a sweetpotato-based complementary food was developed. Four blends of complementary flours made up of OFSP, millet and soyabean flours were formulated based on the nutrient strength of the individual flours. The functional, pasting properties and colour of the flour blends before and after drum drying was determined. The most preferred formulation determined through sensory evaluation was assessed for some nutrients and microbial safety. Colour intensity (ΔE) and saturation (ΔC) of formulated products increased after drum drying. Water absorption capacity (WAC) of formulations ranged from 152.5 to 216.7%, swelling index (SI) from 6.65 to 7.73, bulk density (BD) from 0.787 to 0.827 g/ml and solubility from 17.78 to 20.32%. Drum drying conditions used reduced the WAC, SI, BD and solubility of the formulations. Though the drum drying conditions used did not reduce the pasting temperature, it was able to reduce the peak time and further reduce the peak viscosity, breakdown and setback viscosities. The most preferred formulation was the blend with 50% OFSP, 15% Millet and 35% Soyabean flours. It had significantly (p<0.05) higher protein (16.96%) and β-carotene (0.53 mg/100g) content than the control complementary foods, which are maize-based. Ash and fat were comparable to that of a commercial complementary food. In addition, it had a significantly higher iron and potassium content compared with two commercial complementary foods. Yeast and mould was <3 log10 cfu/g, Total Plate Count, <5 log10 cfu/g, while E. coli and S. aureus had no counts. This complementary food when promoted and utilised could support efforts to reduce vitamin A deficiency in Nigeria and also enhance the use of OFSP to help achieve food and nutrient security.