Impact of Orange-Flesh Sweet Potato Flour Incorporation on Micronutrient, Physical Characteristics, and Consumer’s Acceptability of Bread

Abstract

Micronutrient contents of composite flour, physical characteristics, and sensory properties of bread from wheat and orange-flesh sweet potato flour blend were carried out. Orange-flesh sweet potato flour was used as a means of biofortification of wheat that produced composite flour at varied ratios. The composite flour samples were used for bread baking, and a control was produced with 100% wheat flour. Composite and control flour were subjected to provitamin A and mineral analyses, and physical characteristics of the dough and sensory properties of the bread samples were also evaluated using standard analytical methods. The values obtained from all analyses evaluated in this work were significantly different (p<0.05). The concentration of β-carotene (Provitamin A) and mineral content of the flour increased with increased addition (10% to 40%) of orange flesh sweet potato flour. Provitamin A content of the flour increased from 5.62 mg/100g to 50.31 mg/100g, calcium 10.99 mg/100 g to 14.88 mg/100g, potassium 310.47 mg/100g to 367.43 mg/100g, and phosphorus increased from 7.24 mg/100 g to 11.57 mg/100 g. On the other hand, magnesium, iron, and zinc decreased gradually from 50.10 to 31.08 mg/100g of magnesium, 3.38 mg/10g to 2.01 mg/100g and 8.01 to 6.87 mg/100 g in the flour samples. The values of physical characteristics of the dough were not the same; loaf volume decreased from 271.08 to 160.43 cm³ while loaf specific volume decreased from 1.39 to 0.71, however, the loaf weight increased from 180.62 to 234.10g as the level of orange flesh sweet potato flour incorporation of increased. In addition, the mean preference scores for sensory properties such as crust colour, taste, and overall acceptability of bread loaves samples were not the same (p>0.05). In all the samples, the composite bread incorporated with 10% orange flesh sweet potato flour having 6.90 mean score was closely related to the control sample in terms of overall acceptability. Indications from quality characteristics and organoleptic properties assessed showed the potential of orange flesh sweet potato flour for improving the nutritional and consumers’ acceptability of bread.