Development of Micronutrient Rich Functional Gruels Made from Blends of Orange-Fleshed Sweet Potato, Beetroot, and African Yam Bean Flour

Abstract

Non-communicable diseases (NCDs) and micronutrient deficiencies are substantial public health challenges in developing regions. Traditional cereal-based gruels often provide insufficient essential nutrients and have limited capacity to sequester free radicals in the body. This study evaluated the amino acid composition, antioxidant activity, antinutritional factors, phytochemical properties and sensory characteristics of composite gruels produced from orange-fleshed sweet potato (OFSP), beetroot and African yam bean (AYB) flours. Using processing steps that included slicing, blanching, soaking, dehulling and dehydration, eight formulations were developed from locally sourced ingredients in Makurdi, Nigeria. Antioxidant profiles were assessed, and the results were analysed statistically using ANOVA. Sample G, containing 50% OFSP, 10% beetroot and 40% AYB, had high levels of essential amino acids, particularly leucine, lysine and glutamic acid. Samples enriched with beetroot showed stronger phytochemical properties, with Sample A recording the highest flavonoid content and antioxidant activity. Although antinutritional compounds increased with higher AYB inclusion, they remained within acceptable limits. Sensory evaluation indicated good consumer acceptability, with Sample H recording the highest overall acceptability score of 7.15. The findings showed enhanced antioxidant activity, with DPPH values of 20.14-91.71%, FRAP values of 5.76-35.85 μmol Fe(II)/g and ABTS values of 18.14-64.95%. Overall, the beetroot-enriched blends exhibited strong antioxidant activity. These results suggest that blending these ingredients can improve the functionality of gruels and provide a plant-based approach for addressing micronutrient deficiencies and diet-related health concerns in vulnerable populations.