A majority of households in Sub-Saharan Africa utilize cereal-based flours in the preparation of most of their staples. However, the micronutrient contents of these cereal-based flours are low with higher levels of anti-nutrients. Food to food fortification is being used as an alternative to improve the micronutrient content of the cereal-based flours. This study sought to develop an extruded composite flour using sorghum and maize as the cereal base and baobab, grain amaranth and orange-fleshed sweet potatoes as the fortificants. A completely randomized design in factorial arrangement with ingredient ratio and extrusion as factors and seven levels was used to develop different formulations of the composites. Fortification of sorghum-maize cereal flour blends with amaranth, baobab and orange-fleshed sweet potato powder resulted in a significant (p<0.05) increase in the protein, beta-carotene, iron and zinc contents, on average, 8.99 ± 1.03 g/100g, 895.90 ± 346.85 mg/100g, 11.81 ± 9.73 mg/100g and 1.74 ± 0.18 mg/100g dry weight basis respectively. High grain amaranth levels in the formulations significantly (p<0.05) increased the phytate content whereas tannin content was significantly lower in low sorghum formulations. Conversely, extrusion of the composite flours significantly (p<0.05) reduced protein and beta-carotene contents by 4.7% and 40.9% respectively. Extrusion and its interaction with ingredient ratio significantly (p<0.05) affected the proximate, mineral and anti-nutrient composition of the composite flours. Both the fortificants and extrusion play a role in the reduction of anti-nutrients and therefore future studies should focus on other treatments that can be used together with extrusion to reduce anti-nutrients.

Porridge is a popular cereal flour-based food product for children in Sub-Saharan Africa. Compositing of cereal flours to improve their nutritional composition is done. However, the enrichment of such flours with naturally nutrient-rich plant products is poorly developed. A study was conducted to evaluate the acceptability and sensory attributes of newly formulated extruded composite flours containing maize, sorghum, grain amaranth, baobab and orange-fleshed sweet potatoes. Seven extruded formulations optimized for nutritional composition were developed. Twelve trained panellists evaluated the sensory attributes and overall acceptability of the composite flours determined on a 9point hedonic scale. Formulation of the composite flours significantly (p<0.05) affected scores of colour, flavour and overall acceptability with the mean score ranging between 5.7 and 7.4. There was no significant difference (p>0.05) on overall acceptability between extruded and non-extruded composite flours but extruded flours had significantly higher scores on texture (p<0.05). The comparison of the newly formulated composite flours with the conventional flours showed no significant difference (p>0.05) in the overall acceptability; therefore, they can be potentially adopted. All the sensory attributes contributed to the overall acceptability of the formulations, with mouthfeel and flavour having higher relationship with overall acceptability. It is concluded that these attributes are desirable characteristics of any new naturally fortified cereal formulation.