Industrial-scale fractionation of fava bean, chickpea, and red lentil: A comparative analysis of composition, antinutrients, nutrition, structure, and functionality

Legumes are emerging as sustainable protein sources that can replace animal proteins and help meet global dietary needs. This study systemically compared the compositional profiles, antinutritional factors, amino acid profiles, protein quality, structural characteristics, and techno-functional properties of fava bean, chickpea, and red lentil flours, along with their dry- and wet-fractionated protein-enriched fractions (PFs). Wet-fractionated PFs exhibited higher protein content (58.36 - 83.79 g/100 g), while dry-fractionated PFs retained more total dietary fibre (7.62 - 14.64 g/100 g). Wet-fractionated fava bean (84.12 %) and red lentil (84.06 %) showed the highest <i>in vitro</i> protein digestibility (IVPD), while dry-fractionated chickpea showed the highest IVPDCAAS at 62.43 %. The protein composition was generally preserved after fractionation, though changes in secondary structure varied depending on legume source. Surface hydrophobicity (H₀ 62,739 - 99,381) increased following wet fractionation. In terms of functionality, wet-fractionated PFs showed the highest water-holding capacity (2.83 g/g, red lentil), foaming capacity (139.1 %, fava bean) and emulsifying capacity (108.1 m²/g, red lentil), but with relatively poor foaming and emulsifying stability. Conversely, dry-fractionated PFs exhibited higher protein solubility, lower least gelation concentration (8-10 %), and superior oil-holding capacity (3.98 g/g, Chickpea), likely due to reduced structural disruption, which limited protein aggregation and denaturation. Despite higher levels of antinutritional factors, dry fractionation emerges as a promising, cost-effective, and sustainable technology to produce legume protein concentrates with improved functionality and nutritional quality comparable to those obtained by wet-fractionated.