Quality Characteristics and Sensory Properties of Bread Elaborated with Flour Blends of Wheat and African Yam Bean

Abstract

This study evaluated quality characteristics and sensory properties of bread elaborated with flour blends of wheat and African yam bean. The wheat flour was procured, while the purchased African yam bean seeds were cleaned, sorted, washed and steeped in 2.5 litres of clean water for 12 h with intermittent changing of soaking water at 3 h intervals, drained, sprayed on moistened jute bag spread on malting table and covered with moistened jute bag. The seeds were germinated for 72 h with occasional sprinkling of water. Thereafter, harvested imbibed seeds were dried in a hot air oven at 60⁰C for 12 h and converted into flour with attrition mill. Wheat flour and African Yam Bean flour were sieved individually with 60 mm mesh size sieve. The flours were blended in the percentage ratios (W: W) of 100:0, 90:10, 80:20 and 70:30 for samples A, B, C and D, respectively. Three grams of yeast (Saccharomyces cerevisiae, Foshan Ceng Goa Food Co. Ltd, De Rich Instant Dry) were dissolved in clean bowl with 30 l of water and 10 g sugar of the stipulated receipe and left for 1 h to activate at ambient temperature (29 ± 1⁰C). The flour blends were evaluated for proximate composition, functional properties and consumer acceptability. Preference ranking tests were conducted to describe and evaluate the acceptability of the bread loaves according to hedonic scale on texture, flavour, colour and overall acceptability using a 9-point, where1 = dislike extremely and 9 = extremely like. The data generated were analyzed statistically using one way analysis of variance and means separated by Tukey test at 5% level of Significance. The results showed that sample D – 30% substituted African yam bean flour had higher swelling index (1.81g/g), water absorption capacity (160.00%), protein content (14.89 %), fat content (2.80%), panelists textural scores (6.55) and the least flavour scores (4.05),colour scores (5.70) and overall acceptability scores (3.85) compared to other samples. There were no statistically significant differences (p > 0.05) in overall acceptability scores of samples B, C and D. The overall acceptability scores showed that samples acceptance decreased with increased levels of substitution with African yam bean seed flour.