Biofortification of maize flour with grain amaranth for improved nutrition

Abstract

Food insecurity and malnutrition remain two major problems in Kenya that cause undernutrition (protein-energy malnutrition) and nutrient deficiencies. In a bid to combat the problem, the government has targeted increased production of the micronutrient (minerals, vitamins) fortified maize flour. This is mostly based on chemical fortificants, which is a short-term measure that targets reducing the level of malnutrition while creating better livelihoods. However, there is need to think about long- term and sustainable strategies. Among the causes that have led to food and nutrition insecurity in the country is the over reliance on maize as the staple food. Other staples in Kenya are sorghum, rice and millet. This study aimed at providing a better and more sustainable approach by fortifying maize based diets with grain amaranth. Maize was procured from National Cereals and Produce Board and processed to refined flour, while amaranth grain that had been toasted at 100ºC for 5 minutes and milled into flour was obtained from Annicos Limited Company, Nairobi. Complementary formulations were then prepared by blending the flours. The refined maize flour was mixed with varying ratios of 0, 20, 30 and 40% of the grain amaranth flour. The proximate composition, mineral content and microbiological analysis of the raw materials and the blends were determined using recognized standard methods, while protein digestibility was determined after enzyme digestion. Nutritional composition of grain amaranth flour differed significantly (p≤0.05) as compared to refined maize flour; amaranth flour was found to be superior in proteins (15.82%), lipids (7.61%), ash (2.54%) and fibre (4.39%), as compared to proteins (6.29%), lipids (1.92%), ash (0.55%) and fibre (0.76%) in refined maize flour. Adding grain amaranth flour to refined maize flour at the different ratios increased the nutrient density significantly (p≤0.05), particularly protein, iron, calcium and zinc. However, it decreased the digestibility of protein significantly (p≤0.05). The results indicate that although adding 40% grain amaranth gave the best results, the most acceptable blend was the 20% grain amaranth addition. They also indicate that “food to food” fortification can be an approach that can be adapted towards meeting the nutrition requirements of the society.

Keywords: Nutrition security, biofortification, amaranth flour, maize flour, optimal blend