Appropriate Ratio Of Wild Yam (D. praehensilis) Flour To Add To Wheat Flour For Breadmaking Process

Abstract

The objective of this work was to find the suitable incorporation ratio of D. praehensilis flour into wheat flour in order to obtain appropriate bread. All incorporation reduced bread making potential as wet gluten, dry gluten, gluten index and gluten water binding capacity. These values decrease significantly from (28.4 % to 21.7 %), (10.3 % to 7.54 %), (95 to 88 %) and (18.1 to 14.16 %) respectively for wet gluten, dry gluten, gluten index and gluten water binding capacity. The yam flour incorporation reduced the dough rising potential and the final bread volume. The specific volume decreased from 3.26 to 1.37 cm3/g. During dough fermentation, highest volume values were ranged from 135.45 cm3 to 100.06 cm3, respectively from control (WF) to WYF-25 flours. Flours damaged starch content increasing from 21.8 % to 28.9 %, was responsible of the Hagberg Falling Number reduction related to increase of amylase’s activities. The Falling Number of composite flours was ranged from 327s to 357s, compared to control flour dough (362s). This induced the increasing of dough hydration from 62 % to 82 %. Increase in dough Tenacity (from 103 to 222 mmH2O) and P/L configuration ratio (from 0.93 to 7.93) were noticed. The sensory evaluation showed that below 10 % of yam flour substitution to wheat flour the final bread crumb colour, aroma, taste, and overall are acceptable by consumers.