Effect of Drum Drying on the Colour, Functional and Pasting Properties of Sweetpotato-based Complementary Food

Abstract

This study was conducted to understand the effect of drum drying on colour, functional and pasting properties of a sweetpotato-based complementary food. Four blends of complementary flours made up of Orange fleshed sweetpotato (OFSP), millet and soybean 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. 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. OFSP flour could be used to develop a complementary food with improved functional and pasting properties, when complemented with millet and soybean flours and processed through drum drying.