Physicochemical, Functional and Pasting properties of Orange-Flesh Sweet Potato Starch, Soya bean and Groundnut Flour Complementary Food

Abstract

Complementary food from blends of orange flesh sweet potatoes (Ipomea batata) (OFSP) starch, soybean (Glycine max) and groundnut (Arachis hypogea) flour was formulated and evaluated for physicochemical, functional and pasting properties. The blends of OFSP starch, soybean and groundnut flour were in the ratios of (OFSP:SB:GN): 90:5:5, 85:10:5, 80:15:5, 75:20:5, 70:25:5, 65:30:5, 60:35:5, 55:40:5, 50:45:5 for PSB1 – PSB9, while 100 % OFSP served as control. Standard analytical methods were used for all analysis. pH (4.60 – 5.69), sugar (0.71 - 3.63 %) and amylopectin (70.28 - 85.34 %) increased significantly (P≤0.05) while starch (69.09 - 87.53 %) and amylose (29.97 - 14.65) decreased with increase in soybean flour addition. Carotenoid content (11.08 – 44.60 mg/kg) will meet >200% of recommended Vitamin A requirement for infants. Bulk density, water absorption capacity, swelling power, solubility index and dispersibility ranged respectively from 0.71 - 0.83 g/ml, 0.59 - 1.35, 9.12 - 14.48, 5.57 - 9.45 and 76.00 – 80.00 %. The peak, trough, breakdown, final and setback viscosities varied significantly (P≤0.05) from 127.5 - 7291.0, 95.3 - 4332.0, 32.3 - 2959.0, 129.0 -6159.0 and 33.79 - 1827.0 RVU respectively. Increase in pH and sugar, decrease in starch, bulk density and reduction in viscosities of the complementary food with increase in soybean flour addition is very important in achieving a near neutral and high nutrient dense gruel yet thin enough for infant feeding.