Comparative Analysis of Physicochemical and Functional Properties of Dry and Wet Fractionated Red Lentil Proteins

ABSTRACT Plant proteins are increasingly recognized for their role in sustainable diets, with functional properties being critical for food applications. However, the influence of extraction methods on legume proteins remains underexplored. This study compared dry, wet, and mild fractionation for producing protein‐rich red lentil fractions and assessing their nutritional and functional properties. Whole red lentils were tempered to 12% moisture, roller‐milled, and then pin milled to create a fine parent flour (d 90 < 60 μm) suitable for air classification and wet extraction. Air classification at 10,000, 7000, 6000, and 4000 rpm classifier speeds yielded protein‐rich fractions, with the 6000 rpm setting (cut point 22 μm, d 90 ) offering an optimal balance of purity and yield. In wet fractionation, lentil protein isolate (89.2% protein) was produced through alkaline extraction and isoelectric precipitation, while mild extraction produced lentil protein concentrate by just alkaline extraction (64.2% protein). Functional analysis showed wet‐extracted isolates performed better in emulsification, water, and oil absorption, while dry fractionated proteins performed better in foaming, solubility, and gelling. Mild wet‐extracted concentrates demonstrated good emulsification and oil absorption but poor foaming stability. Amino acid analysis showed that red lentil protein isolate had higher concentrations of hydrophobic amino acids, particularly isoleucine, leucine, and phenylalanine compared to dry fractionated samples, which may contribute to its enhanced emulsifying properties. The dry fractionated samples maintained a similar amino acid profile as that of lentil flour, contributing to its native functionality. In conclusion, dry fractionation offers a sustainable, eco‐friendly alternative to wet extraction, preserving native protein integrity while delivering comparable functionality.