Functional and nutritional properties of acha (digitariaexilis),bambara nut (vigna subterranean), and beetroot (vulgaris ruba)flour blends and physical properties of the biscuits

This study investigated the functional and nutritional properties of acha (Digitaria exilis), bambara groundnut (Vigna subterranea), and beetroot (Beta vulgaris L.) flour blends, as well as the physical properties of biscuits produced from them. Formulations were developed by blending acha flour with varying proportions of bambara groundnut flour (to enhance protein content) and beetroot powder (to increase micronutrient and antioxidant profiles).
Functional property analysis of the composite flours showed significant variations in water absorption capacity, oil absorption capacity, bulk density, and swelling index, which were influenced by the inclusion of bambara groundnut and beetroot. Nutritionally, the addition of bambara groundnut significantly increased the crude protein, ash, and crude fiber content of the flour blends compared to the 100% acha control. Beetroot incorporation significantly boosted the total phenolic content, antioxidant activity, and mineral profile (particularly iron and potassium) of the blends.
Physical evaluation of the baked biscuits revealed that the incorporation of the alternative flours affected the weight, thickness, diameter, and spread ratio. Increasing the level of bambara groundnut and beetroot flours led to a noticeable change in the color profile (L*, a*, b* values) of the biscuits, yielding a darker, more reddish hue. The spread ratio generally decreased as the substitution levels of bambara groundnut and beetroot increased.
Overall, the study demonstrates that a functional, nutrient-dense, and gluten-free biscuit can be successfully produced from acha, bambara groundnut, and beetroot flour blends, offering a promising snack option for protein-energy malnutrition mitigation and health-conscious consumers.