Unlocking nutritional and functional insights: exploring the impact of germination time on bean protein isolate

Abstract

SummaryThe study aims to investigate the effect of germination time on kidney bean protein isolate (KBPI), enhancing its nutritional and functional qualities to fill a knowledge gap. Using an alkaline extraction‐isoelectric precipitation strategy, KBPI was extracted with different germination periods (0–72 h). Germination up to 48 h significantly increased GKBPI (germinated kidney bean protein isolate) yield to 44.01%–50.01%, with G48H at 81.20% showing the highest protein recovery at 45 °C. Essential amino acids like valine and threonine were notably retained up to 48 h at 45 °C, preserving GKBPI's nutritional profile. Gelling capacity, protein solubility, foaming and emulsification properties were favourable at 35 °C with 48‐h germinated samples, making GKBPI versatile for food applications. GKBPI also displayed antioxidant activity, with DPPH% values ranging from 20.19% to 24.47%. After 72 h of germination, phytic acid levels decreased by 47.94%, leading to higher in vitro protein digestibility (IVDP) in G48R (germinated kidney bean for 48 h at 35 °C alkali extraction temperature; 82.82%) and G48H (germinated kidney bean for 48 h at 45 °C alkali extraction temperature; 85.55%) due to reduced anti‐nutrients. The study delves into the novelty of germination time's impact on KBPI. Extended germination, up to 48 h, increases protein yield, recovery, IVDP, antioxidant activity and enhances functional properties and reduced anti‐nutrients which indicates that GKBPI has significant potential as an ingredient for various food applications. However, further research is needed for in vitro data, toxins profile and a comprehensive understanding of its practical, economic and health‐related implications.