D-Optimal Mixture Design Applications in the Assessment of Mineral and Antinutritional Contents of Amaranth-Based Blends

Abstract

Malnutrition is becoming more endemic especially in war-ton and highly deprived area of Africa. The amaranth, pumpkin and sunflower flour seed were cleaned, sorted, milled and defatted to obtain defatted flour samples. The amaranth, pumpkin and sunflower seeds were cleaned, sorted, milled and defatted using n-hexane. Optimization of the production of composite flour from defatted amaranth, sorghum, defatted pumpkin and defatted sunflower flour using D-optimal mixture design of Design Expert software with the levels for amaranth (40-60 %), sorghum (10-30 %), pumpkin (20-40 %), and sunflower flour (3-10 %), respectively was carried out. Using D-optimal design, Fourteen (14) runs were generated and the blends were analyzed for mineral composition (sodium, potassium, iron, calcium, and phosphorus) and anti-nutritional factors (phytate, tannin, oxalate, saponin and trypsin), respectively. The response variables were modeled using a linear regression equation. The mineral composition ranged from 5.50-9.82, 335.01-340.84, 10.80-12.15, 73.56-89.16, and 276.82-284.90 mg/100g for sodium, potassium, iron, calcium, and phosphorus. Phytate and tannin content ranged from 0.1-0.22 and 2.70-2.90 mg/100g, respectively. The linear model terms for both mineral and antinutritional factors were significant (p £ 0.05). In conclusion, composite flour from amaranth, sorghum, pumpkin and sunflower flour have substantial mineral profile and controlled antinutritional factors and therefore can be used in the development of nutrient-densed food product such as snack.