Physicochemical, bioactive compounds and functional properties of flours from three cultivars of dehydrated cowpea seeds (Vigna unguilata (L.) Walp.)

Cowpea are a strategic food for combatting food insecurity in the face of strong population growth worldwide, as well as for addressing the sustainability challenges in the livestock sector. Thus, this study examined the physicochemical and functional properties as well as the bioactive compounds of three local cowpea cultivar flours (white, red and black). Regarding the proximal composition, the cowpea flours exhibited a neutral pH (between 7.37 - 7.58) and contained higher amounts of protein (> 21.55 %), crude fiber (> 18.58 %), carbohydrate (> 36.14 %) with lower fat content (˂ 1.5 %). White and black cowpea flours displayed higher moisture content than the indicated limit (10 %). Regarding minerals, white and black cowpea flours showed higher potassium, phosphorus, and calcium contents compared to red cowpea flour which also did not contain microelements such as sodium, copper, manganese, zinc and iron in trace states. Moreover, the contents of bioactive compounds such as total polyphenol and tannins were found to be low (˂ 0.06 %) in these flours with a total absence of flavonoids. However, among the anti-nutritional factors, only phytate showed the highest content (> 227 mg/100g) in these cowpea flours. Functional property assessments revealed higher WAC, WSI and HLB values in red and black cowpea flours that varied significantly from 240.57 – 301.04 %, 33.14 – 35.58 % and 3.28 – 4.22, respectively while the bulk density ranged from 0.91 to 1.11 g.cm-3. These results suggest that these dehydrated cowpea flours are promising ingredients for designing nutritionally enhanced foods with low-fat index.