Quality Evaluation and Kinetics of Dependency of Apparent Viscosity of Whole Wheat- Water Yam Flour Mixture on Temperature in Relation to The Cooked Paste

Abstract

In the past, cooked paste commonly called fu-fu from whole wheat flour was well acceptable by African indigenes due to its light weight, fibre composition and other nutrients. However, it is a carbohydrate rich food and contains gluten not acceptable by some individuals’ body systems. Quality evaluation and kinetics of dependency of apparent viscosity of whole wheat-water yam flour mixture on temperature in relation to the cooked paste were investigated. Composite flours (80:20-B, 60:40-C, 50:50-D, 40:60-E, 20:80-F; WYF: WMF-whole wheat meal flours) were formulated from wheat grains and water yam tubers. Samples A (water yam flour (WYF-100%)) and G-commercial whole wheat meal flour (WWF-100%) served as control. Flour samples were subjected to proximate, selected micronutrient, viscous and pasting characteristics analyses, while the cooked paste was evaluated using selected sensory attributes. Crude fat content of flours ranged from 0.19-1.80%, while crude fibre content differed significantly (p< 0.05) and varied between 1.08 and 4.88%. Crude protein content ranged from 2.10-4.50%, while carbohydrate by difference ranged from 61.10-80.10%. Heating temperatures for the flour dispersions ranged from 70-100oC. Sample B had the highest final viscosity among the blended samples. Apparent viscosities of the dispersions increased with increasing temperatures and displayed dilatants fluid behaviour. Sample B had the lowest value of activation energy required to obtain a suitable cooked paste among others. Overall results indicated that sample B could be consumed as an alternative cooked fu-fu to whole wheat flour fu-fu.