Evaluation of Yam Flour as a Partial Substitute for Wheat Flour in Bread Making

Abstract

Wheat is almost the sole crop used for bread production throughout the world. Consequently, the price of wheat is continuously rising especially in developing countries like Ethiopia. However, there are plenty of underutilized crops with potential of at least partially substituting it in bread making. Yam is one of such underutilized crop owing potential of substituting wheat in production of baked food products. Despite their potential, the utilization of such crops in development of baked food products including bread was not common practice. This study was therefore designed in completely randomized design to evaluate yam flour for partial substitution of wheat in bread making. Yam flour partially substituted wheat at 0%–40%, and the effect on flour and bread quality was investigated. Functional properties of composite flour are acceptable enough for bread making potential. The moisture content of fresh bread ranged between 21.07% and 24.02%. The protein (12.71–8.00) and fat (2.87–1.95%) content decreased as yam flour increased from 0% to 40%. Fiber increased from 1.71% to 2.76% with increase in yam flour. The substitutions of wheat with yam flour in bread making can improve Na, Ca, Mg, and Fe contents of bread products. The sensory acceptability was statistically similar with control bread for up to 20% substitution levels. Generally, acceptable bread can be produced by substituting wheat with yam flour as high as 30%. The finding of this study implies that it is important to consider yam flour production and utilization in baked product development in future research and extension activities.