Optimization of Provitamin A Maize and Iron-Rich Bean-Based Composite Flour for Improved Child Nutrition

Bio-fortification is a strategy that has been proven to not only reduce the prevalence of micronutrient deficiencies, but also to tackle other forms of malnutrition. Therefore, the inclusion of flour from bio-fortified crops as major components of composite flours can significantly alleviate malnutrition. In this study, the effect of replacing white maize with provitamin A bio-fortified maize in a bean-based composite flour was studied. Response surface methodology was used to optimize the nutrient composition and overall sensory acceptability of the composite flour. Design Expert 2018 (Version 12) was used to generate 30 treatments where provitamin A, iron, phytate concentration, and overall acceptability were considered as the response variables. Six locally available cereals and legumes were considered as independent variables and were included in the composite flour at different levels. Bio-fortified maize was included at a level between 50% and 60%, high iron-rich beans at 15%-20%, sesame at 5%-10%, soy at 10%-15%, wheat and sorghum at 5% each. An optimal formulation of the composite was achieved with 57.89% maize, 17.11% beans, 5% sesame flour, 10% soy bean flour, and 5% of each of the wheat and sorghum flour. The respective values for provitamin A, iron, phytate content, and overall acceptability for the optimal formulation were 1.58 μg/g RAE of beta carotene, 6.0 mg/100 g of iron, 54.20 mg/100 g of phytates, and overall acceptability at 7.10 respectively. All models predicting these values were satisfactory and had a nonsignificant lack of fit (p < 0.05). This indicated the suitability of each model in predicting the responses and optimizing the formulation for the production of a quality provitamin A maize-iron bean-based composite flour.