Antioxidant Activities, Nutrient Composition and Sensory Properties of Unripe Plantain-Purple Skinned Sweet Potato Flour Blends

Abstract

The functional properties of plant foods have received much attention in recent times. Therefore, the  present study sought to assess the antioxidant potential and  nutrient composition  of  unripe plantain (UP) and purple skinned sweet potato (PP) composite blends (UP: PP); (100:0, 80:20, 60:40, 40:60, 20:80 and 0:100)  and also to evaluate the sensory properties of the porridge prepared from the blends.  HPLC/DAD analyses revealed the presence of some flavonoids and phenolic acids.  The evaluated antioxidant indices increases progressively as the percentage inclusion of sweet potato increases, and the highest antioxidant activities was recorded for 100% sweet potato. Whereas, the evaluated proximate indices, with exception of moisture content, increases as the inclusion of unripe plantain increases in the blend;  and the highest carbohydrate (78.51%), protein (13.35%), fiber (0.19%) and fat (5.56%) were recorded for 100% unripe plantain. The 100% potato recorded the highest level of Ca, Mg, P and Fe, while the highest level of Na and K was recorded for 100% unripe plantain. The result of the sensory properties of the porridge showed a varied rating with respect to the evaluated sensory parameters; however, better overall acceptability was recorded for porridge from two blends (60UP:40PP, 40UP:60PP).  Result from this investigation showed that combination of these plant foods can be harnessed as functional food, most especially two of the blends; (60UP:40PP, 40UP:60PP) and these could be a valuable blend that could be explored in the management of free radical mediated diseases.

Keywords: Antioxidant potential; Nutritional value; Phenolic composition; Sensory properties; Solanum tuberosum; Musa paradisiacae