Effect of germination on the physicochemical, nutritional, functional, thermal properties and in vitro digestibility of Bambara groundnut flours

The physicochemical, functional, thermal properties and in vitro digestibility of flours from germinated Bambara groundnut (BGN) were monitored over 72 h. In a time dependent manner, germination led to significant (p ≤ 0.05) increases in protein (26.1–28.79 g/100 g), dietary fiber components, digestible starch, in vitro protein digestibility (73.67–88.9%), calcium, magnesium, potassium, total phenolic content, and majority of the amino acids. Germination significantly decreased phytic acid, tannin and trypsin inhibitory activity. Protein solubility, oil and water absorption capacity, foaming capacity, emulsion stability and activity of BGN flour increased significantly with germination. Germination also modified the thermal and pasting properties of the flour. However, scanning electron microscopy did not reveal significant changes in starch granular structure. There were significant decreases in relative crystallinity (57.94–20.92%) as observed from the X-ray diffractograms. This study has demonstrated that germination significantly improved the nutritional, total phenolic content, functional and processing properties of BGN flour. This could encourage its utilization in food product development, particularly as a functional food ingredient.