PHYTOCHEMICAL AND ANTIOXIDANT PROPERTIES OF FLOURS FROM FOUR VARIETIES OF LOCAL COWPEAS AKIDI, APAMA. ORALUDI AND AZUNGWERE

ABSTRACTS This study evaluated the phytochemical composition, antioxidant capacity, and anti-nutritional factors of flours from four Nigerian cowpea (Vigna unguiculata) varieties—Apama, Olaludi, Black Akidi, and Azungwere—with the objective of identifying varietal strengths and their potential applications in food and nutrition. The seeds were dehulled and dried in a hot air oven at 50°C for 24 hours to reduce moisture content. The dried seeds were milled into fine flour passed through a 60-mesh sieve, and stored in airtight containers at room temperature until analysis. Antioxidant activity was assessed using ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays, while phytochemical analyses determined total phenols, flavonoids, anthocyanins, and tannins. Anti-nutritional factors measured included alkaloids, saponins, phytates, and oxalates. Significant varietal differences were observed in both phytochemical composition and antioxidant performance. Olaludi recorded the highest total phenolic (305.05 mg/100 g) and flavonoid (179.84 mg/100 g) contents, resulting in strong FRAP activity at intermediate concentrations, reflecting superior electron-donating potential. Azungwere, with slightly lower total phenols but the highest anthocyanin (4.60 mg/100 g) and tannin (181.14 mg/100 g) levels, exhibited the highest DPPH radical scavenging activity across all concentrations tested, indicating pronounced hydrogen atom transfer capability. Black Akidi demonstrated moderate phytochemical levels and antioxidant activity, while Apama generally showed the lowest phytochemical concentrations and weaker antioxidant performance, coupled with slightly higher anti-nutrient contents. Anti-nutritional factor levels across all varieties were within acceptable ranges for cowpeas, with Olaludi exhibiting the lowest alkaloid and saponin contents.