Chemical, Pasting and Sensory Characteristics of Ukpo oka - A Steamed Maize Pudding Formulated from Maize and African Yam Bean Flour

Abstract

Studies were conducted on the chemical, functional, pasting and sensory properties of flour blends with ukpo oka formulated from maize- African yam bean flour (AYBF) in order to improve the nutritional content of maize and encourage a wider utilization of the legume, AYB. Supplementation of maize and African yam flour was done in the ratio of 100:0, 50:50, 80:20, 60:40 and 20:80 for maize: African yam bean flour, respectively. Proximate composition, functional properties, pasting properties of the flour blends was determined and sensory attributes of the products were also evaluated. The result showed that supplementation of maize with African yam bean flour significantly increased the protein, ash and fiber content of the flour blends with values ranging from 3.91 - 11.08%, 2.90 - 6.60% and 0.67 - 1.82% for protein, ash and fiber contents, respectively. The protein, ash and fiber contents increased with addition of African yam bean flour while carbohydrate content of maize- African yam bean blends decreased with increase in the level of African yam bean. The values for functional properties ranged from 0.72 – 0.82g/ml, 99.33 – 323.33%, 9.01 – 19.65%, 690.00 - 978.33%, 0.67 – 1.13%, and 0.484 – 1.038% for bulk density, foaming capacity, emulsion capacity, swelling capacity, water absorption capacity and oil absorption capacity, respectively. Values for pasting properties of the flour blends expressed in rapid visco unit (RVU) ranged from 129.25 – 209.40, 22.55 – 67.93, 60.21 – 124.62, 145.25 – 247.67, 83.37 – 84.56, 5.47 – 5.97 and 87.19 – 141.35 for peak viscosity, break down viscosity, set back viscosity, final viscosity, pasting temperature, peak time and trough, respectively. Set back viscosity and final viscosity increased with increase in the levels of African yam bean while break down viscosity decreased with the increase in the levels of African yam bean. The products were highly rated in all sensory attributes evaluated, however, aroma decreased with increase in the levels of AYBF. Product made from flour blend 50:50 was the most preferred in terms of general acceptability.