Common bean (Phaseolus vulgaris L.) seed germination improves the essential amino acid profile, flavonoid content and expansion index

Common bean (Phaseolus vulgaris L.) is one of the most important grain legume foods for the human diet. Common bean seed is gaining attention due to its content of secondary metabolites with positive effects on human health. The present work analysed the effect of common bean germination on the essential amino acid profile, active compound content, and expansion index after extrusion processing. The content of tryptophan (Trp) in raw common bean (RCB) and in germinated common bean (GCB) seeds was 6.1 and 7.9 mg center dot g-1 of protein, respectively. The limiting amino acids in RCB were sulphur amino acids and Trp, and in GCB only the sulphur amino acids were the limiting amino acids. The germination process in beans increases the levels of quercetin and kaempferol and allows the synthesis of daidzein and genistein, and significantly increases the expansion index after extrusion processing. The germination of common bean could be used as a strategy to improve nutritional, nutraceutical, and processing properties.