Effects of Bambara groundnut and Butternut blending on functional and sensory properties of sorghum flour porridge

Abstract

Food-to-food fortification to refined sorghum flour (SF) for porridge making has an influence on the desirable properties of the porridge. In view of this, the effects of Bambara groundnut (BG) (15%, 25%, 35%) and dried butternut (BU) powder (23%) blending on functional and sensory properties of porridge were investigated using 100%SF as a control. With the blending by BG and BU, water binding capacity (WBC), water solubility index (WSI), oil absorption capacity (OAC) and gel water solubility index (GSI) increased (p < 0.05), whereas swelling power (SP) and gel water absorption index decreased. Blended flours were characterized by low -WBC and -SP, high -WSI, -OAC and -GSI which are desirable for processing of less bulky, nutrient and energy dense, digestible porridge suitable as a weaning food. In the descriptive sensory properties evaluation, overall aroma and after-taste intensity were rated better for the control sorghum porridge (p < 0.05), while texture (roughness/smoothness, firmness, stickiness, and springiness) differences were insignificant (p > 0.05) and specks appearance is very low in all porridges. The porridges color varied significantly (p < 0.05) and less brownness and high yellowness was observed in the blended flours than for the control sorghum flour. Even though improvement in the functional properties with the blending levels at 25% and 35% BG to the sorghum flours was observed, porridge over all aroma and aftertaste was superior for the refined 100% sorghum flour porridge.