The mineral, essential and non essential amino acids contents and the antioxidant capacity of extruded breakfast cereal from maize grits, partially defatted peanut and beetroot flour blends was investigated. Composite flour blends were prepared from maize, peanuts and beetroot flour in the following proportion A= (100% Maize flour as control), B= (90:0:10), C= (90:10:0), D= (80:10:10), E= (70:20:10), F= (60:30:10), and G= (50:40:10). There was significant difference in the mineral composition of composite flour blends, the values ranged from 6.05-62.32 mg/g, 0.83-4.53 mg/g, 1.03-3.14 mg/g, 163.81-640.03 mg/g for calcium, iron, zinc, potassium respectively. The esstenial amino acids values of the four blends for isoleucine, leucine, lysine, methionine, alanine, threonine, tryptohan and valine ranged from 0.24-1.25, 0.04-1.08, 0.08-0.40, 0.13-0.49, 0.28-0.48, 0.22-0.44, 0.4-0.24 and 0.30-0.69 respectively. There was increase in antioxidant capacity of the sample with beetroot and peanut inclusion. The 2.2 diphenyl 1-1 picryl hydroxyl (DPPH) radical scavenging activity ranged from 4.03-16.83 while the ferric reducing antioxidant power ranged from 15.65-45.53 MgGAE/Mol with trolox equivalent antioxidant capacity was from 10.21-37.01 mmol trolox/Mol and the total phenohic sontent 5.01-22.01 MgGAE/g.