Quality Evaluation of Flour and Crackers Made from Acha and Orange-Fleshed Sweet Potato Composite Flour Supplemented with Fermented Cowpea Flour

Abstract

The present study aimed at evaluating the effects of supplementing 60% acha and 40% orange-fleshed sweet potato (OFSP) composite flour with 0, 10, 20, 30, 40 and 50% fermented cowpea flour on the functional properties of the flour blends and on the proximate composition, mineral content, antinutrients, and sensory characteristics of the crackers made from the blends. The 100% composite of acha and orange-fleshed sweet potato flours served as the control sample. The results obtained showed that all the parameters evaluated varied with the proportion of fermented cowpea flour supplementation. The bulk density increased significantly while the water absorption capacity, oil absorption capacity, pH, wettability, and gelatinization temperature decreased significantly with the increase in fermented cowpea flour supplementation. The moisture and carbohydrate content of the crackers progressively decreased from 8.83% - 8.08% and from 68.34% - 54.33% respectively with increase in cowpea flour supplementation. The ash, fibre, fat and protein contents of the crackers progressively increased from 1.90 - 2.43%, 0.40 – 0.70%, 14.46 – 18.45% and 6.07 – 16.01% respectively with increase in fermented cowpea flour supplementation. The potassium content of the crackers decreased from 87.51 – 68.66 mg/100g while the calcium, magnesium, iron and zinc contents of the crackers increased progressively from 59.16 - 96.61 mg/100g, 12.60 – 36.69 mg/100g, 0.62 – 0.78 mg/100g and 0.78 – 1.08 mg/100g respectively with increase in fermented cowpea flour supplementation. The oxalate and phytate contents of the crackers decreased progressively, while the tannin content increased with increasing fermentation of cowpea flour supplementation. It is evident from the study that acceptable crackers of high nutritional value could be produced from a composite of 60% acha and 40% orange-fleshed sweet potato flour supplemented with 30% fermented cowpea flour. This would increase the utilization of these locally grown crops and reduce wheat importation into the country.