Delving into the green extraction of proteins from underutilized lima beans using deep eutectic solvent versus conventional methods: A comprehensive investigation of physicochemical, structural, and functional properties

This study investigated the efficiency of three conventional extraction methods- alkaline extraction, salt extraction, and alkaline solubilization-salt precipitation extraction compared to eco-friendly deep eutectic solvent (DES) for recovering protein from lima beans. DES was formulated with choline chloride: glycerol at 1: 2 M ratio. The physicochemical, structural, functional, thermal, and nutritional properties of the extracted proteins were characterized. Results showed that salt extraction had the highest protein yield (13.00 %) and recovery rate (45.85 %). Structural analysis revealed that deep eutectic solvent preserved the protein conformation compared to conventional solvent treatments. Alkaline extraction demonstrated superior solubility (58.04 %), water holding capacity (3.94 g/g), and foaming activity (42.50 %). Salt extraction demonstrated superior emulsifying activity (7.62 m²/g). DES extraction significantly reduced total phenolic content and enhanced thermal stability of lima bean protein. This study highlights the potential of deep eutectic solvents as sustainable alternatives for extracting protein from lima beans.