Improved protein extraction from Moringa oleifera seeds using deep eutectic solvents: Mechanistic insights and protein characterization

This study employed novel green solvents, deep eutectic solvents (DES), for protein extraction from Moringa oleifera seeds. Two DESs systems including choline chloride-malic acid (ChCl-MA 2 ) and choline chloride-urea (ChCl-U) exhibited the highest protein extraction efficiency, reaching 31.415 % and 31.945 %, respectively. Molecular dynamics (MD) simulation results revealed that the DESs systems showed smaller Root Mean Square Deviation (RMSD), Solvent Accessible Surface Area (SASA), and Radius of Gyration (Rg) values, along with a significant number of hydrogen bonds. The enhanced extraction efficiency of DESs was attributed to the formation of intermolecular hydrogen bonds. Both hydrogen bonding and hydrophobic interactions promoted protein aggregation, thereby stabilizing the protein structure and preserving its integrity. Spectroscopic analyses further indicated that proteins extracted with DESs displayed a more stable and ordered structure. However, DES-extracted proteins exhibited lower surface hydrophobicity (2000–4000) and reduced solubility (40 %–50 %), which significantly compromised their functional properties. Although DES-treated proteins displayed a superior foaming capacity (57.333 %), their emulsifying properties (3.464 m 2 /g and 1.584 m 2 /g, respectively) were comparatively unsatisfactory. In conclusion, DES represent a promising green and efficient extraction method for protein extraction. This work provides valuable insights into DES-mediated protein extraction and offers guidance for the efficient extraction of high-quality proteins from Moringa oleifera seeds.