Effects of novel protein extraction methods on structure-functional properties and protein quality of fava bean protein isolates: A comparative study

The effects of deep eutectic solvent (DES)-based protein extraction on structural and functional properties of fava bean protein isolate (FBPI) were determined in comparison to conventional salt and alkaline extraction methods, and the commercial soybean protein isolate (CS-PI) as the standard protein. The protein content of fava bean isolates extracted from DES (DESE-FBPI), alkaline (ALKE-FBPI), and salt (SSE-FBPI) was observed to be similar (∼92 %). FTIR data indicated that all protein isolates had intermolecular β-sheets as protein aggregates, except in DESE-FBPI. Differences in the extraction methods reflected better solubility, foaming and emulsification properties, and gelling capacity by DESE-FBPI than the conventionally extracted counterparts. In terms of protein quality, significantly higher (p < 0.05) in-vitro-protein digestibility corrected amino acid score (IV-PDCAAS) was exhibited by DESE-FBPI (87.24 ± 0.70%) and SSE-FBPI (86.52 ± 0.83%) than the ALKE-FBPI (80.45 ± 0.08%). These results suggest that different extraction methods have a profound impact on protein functionality and quality.