Common Beans Reinvented: A Soaking and Germination Approach for GABA Enrichment and Mineral Content
摘要
Legumes like common beans are important in human nutrition and have gained attention due to their rich carbohydrate, protein, and fiber content, along with bioactive compounds like phenolics, phytates, and tannins. Germination enhances the availability of these compounds. This study evaluated the effect of soaking and germination on the chemical composition, phenolic content, and gamma-aminobutyric acid (GABA) and minerals content in Carioca and black common beans (Phaseolus vulgaris). Unsoaked and soaked seeds were incubated under high relative humidity at 25 °C, for 15 h, 24 h, 30 h, 40 h, and 48 h. Chemical analyses included crude protein, lipids, ash, total carbohydrates, mineral composition, phenolic compounds (TPC) (Folin-Ciocalteu), and GABA (GC-MS). Protein content increased during the first 15–24 h of incubation period. Additionally, calcium, iron, and phosphorous were positively correlated, suggesting their concurrent release from phytate complexes through phytic-acid hydrolysis. Soaking alone increased GABA content by over 500% in both bean varieties. Soaked black beans reached GABA of 767.41 µg/g in at 40 h of incubation period. In contrast, TPC decreased by 43.3% in Carioca beans and by 36.8% in black beans mainly due to leaching at soaking. These findings indicate that not only germination but also soaking are cost-effective strategies to enhance the nutritional quality of common beans, improving their chemical composition and bioactive potential. The increase in beneficial compounds supports their use in the development of plant-based food products, offering a natural and nutritious alternative to supplementing human health.