The influence of amaranth substitution on pasting, dough visco-elastic and bread quality properties of Kenyan home baking grade wheat flour

Amaranth and commercial home baking grade wheat flours were analysed for proximate composition, flour particle size distribution and starch swelling power and solubility before being blended in ratios of 10/90 and 15/85 for comparative studies on flour amylographic pasting, dough visco-elastic, bread baking and bread Organoleptic properties. Pure wheat flour developed significantly higher pasting viscosity than pure amaranth flour. This was attributed mainly to the higher swelling power of wheat starch and to the more coarse particle size distribution in the amaranth flour. The amaranth flour absorbed more water than the wheat flour during dough making. This unexpected result appeared to be due to the presence of larger amounts of crude fibre in the amaranth flour which tended to imbibe and retain more water in the dough. Disregarding the fibre content, it was concluded that amaranth flour could be used in making high dry matter content gruels at desired viscosity. The composite flows compared to wheat flour produced doughs with weaker visco-elastic properties. The composite bread obtained had smaller, darker coloured and denser textured leaves than the pure wheat bread. A slightly bitter after-taste mouth sensation was recognizable in the composite bread. It was concluded that amaranth had high potential as a low level partial substitute for wheat in order to increase the nutritiousness of bread and to spread out the utilization of limited available wheat.