Functional and Pasting Properties of Composite Flour from Wheat, Sweet Potato and Soybean

Abstract— This work was done to ascertain the functional and pasting properties of wheat-soy-sweet potato composite flour. Wheat flour, sweet potato flour and soybean flour blends were prepared in different proportions with completely randomized design resulting to 7 samples including control which is 100% wheat flour. Functional and pasting properties of the composite flours were determined and compared with wheat flour as control. The bulk densities of the flour blends ranged from 0.717 to 0.809 g/mL, there was a significant difference in the water absorption capacity of the flour blends. Oil absorption capacity (OAC) ranged between 0.623 to 0.759 mL/g, least gelation concentration (LGC) of the flour samples ranged from 2.000% to 12.000% while the swelling capacity of different flour blends at temperature 50^oC ranged from 1.32% to 2.006%. Peak viscosity, sample WSO (90% wheat flour: 10% soy bean flour: 0% sweet potato flour) had the highest peak viscosity of 273.075 RVU, sample WOS (90% wheat flour: 0% soy bean flour: 10% sweet potato flour) had the highest trough viscosity (245.915 RVU) while sample WSS (80% wheat flour: 10% soy bean flour: 10% sweet potato flour) had the highest breakdown viscosity value (94.245 RVU) compared to the control sample WOO which had 100% wheat flour. This investigation shows that set back value was highest for sample WSS (80% wheat flour +10% soy bean flour + 10 % sweet potato flour) at 220.325 RVU. Sample SSO (0% Wheat flour: 50% Soybean: 50% Sweet potato flour) had highest pasting temperature of 93.450^oC compared to control flour samples.