Amaranth Leaves and Skimmed Milk Powders Improve the Nutritional, Functional, Physico-Chemical and Sensory Properties of Orange Fleshed Sweet Potato Flour

Abstract

Vitamin A deficiency (VAD) and under nutrition are major public health concerns in developing countries. Diets with high vitamin A and animal protein can help reduce the problem of VAD and under nutrition respectively. In this study, composite flours were developed from orange fleshed sweet potato (OFSP), amaranth leaves and skimmed milk powders; 78:2:20, 72.5:2.5:25, 65:5:30 and 55:10:35. The physico-chemical characteristics of the composite flours were determined using standard methods while sensory acceptability of porridges was rated on a nine-point hedonic scale using a trained panel. Results indicated a significant (p < 0.05) increase in protein (12.1 to 19.9%), iron (4.8 to 97.4 mg/100 g) and calcium (45.5 to 670.2 mg/100 g) contents of the OFSP-based composite flours. The vitamin A content of composite flours contributed from 32% to 442% of the recommended dietary allowance of children aged 6–59 months. The composite flours showed a significant (p < 0.05) decrease in solubility, swelling power and scores of porridge attributes with increase in substitution levels of skimmed milk and amaranth leaf powder. The study findings indicate that the OFSP-based composite flours have the potential to make a significant contribution to the improvement in the nutrition status of children aged 6–59 months in developing countries.

Effect of Sieve Particle Size and Blend Proportion on the Quality Properties of Peeled and Unpeeled Orange Fleshed Sweet Potato Composite Flours

“…Among the minerals measured in both peeled and unpeeled OFSP composite flours, K was the predominant, followed by Ca, while the least was Zn. The Fe concentration in 100% peeled OFSP flour was similar to the value reported by Tumuhimbise et al [ 28 ]…”

“…The loose and tapped bulk density of the OFSP composite flours varied between 0.400-0.508 g/mL and 0.605-0.725 g/mL respectively. The tapped bulk density of flour measurements were consistent with the results reported for OFSP flours by Tumuhimbise et al [28], but lower than that values reported by Fana et al [25] In general, the low bulk density of OFSP flours make them a more suitable ingredient for baby food [22].…”

“…Among the minerals measured in both peeled and unpeeled OFSP composite flours, K was the predominant, followed by Ca, while the least was Zn. The Fe concentration in 100% peeled OFSP flour was similar to the value reported by Tumuhimbise et al [28] Table 3). The unpeeled OFSP composite flours had a significantly (p < 0.05) higher ß-carotene, vitamin A, total phenolic, total flavonoid and total antioxidant activity values but lower ascorbic acid content than the corresponding peeled OFSP composite flours.…”

“…WAC describes the ability of flour to absorb water and swell, which is an important determinant of product yield and consistency [28]. The unpeeled OFSP flour had a significantly (p < 0.05) higher WAC (179.5-188.5%) as compared to peeled OFSP flour (156.5-167.0%) and wheat flour which had the lowest levels (82.3 ± 1.51%).…”

“…Retrogradation increases starch resistance to enzymatic hydrolysis, increases the staling rate of bread and affects the stability of other starchy food products [33]. Therefore, the peeled and unpeeled OFSP flours would be suitable in the preparation of infant foods due to their low setback viscosity [28] and could be suitable for cookie development due to their low viscosity. Peak time and pasting temperature obtained for 100% peeled and unpeeled OFSP flours were lower than the values of blanched OFSP flours reported by Jangchud et al [23] The lower peak time and pasting temperature of OFSP flours suggest a shorter cooking time and a lower energy consumption during cooking as compared to wheat flour.…”