Quality characteristics and structure-function relationships of peanut proteins from different phase sources by...

For improved utilization of peanut proteins from the emulsion, aqueous, and solid phases obtained via aqueous enzymatic extraction, this study investigated their nutritional, functional, and structural characteristics and interrelationships. Eighteen amino acids were identified, with about 29 % being essential amino acids. Emulsion-phase proteins exhibited more disordered secondary structure, stronger surface hydrophobicity, and a rough microscopic surface, resulting in superior water-holding capacity (5.26 ± 0.06 g/g) and oil-holding capacity (5.94 ± 0.11 g/g), emulsion activity (45.41 ± 0.72 m²/g) and emulsion stability (106.78 ± 2.83 min). Aqueous-phase proteins exhibited smaller hydrodynamic diameter, higher |ζ-potential|, more disordered secondary structure, and a rough microscopic surface, resulting in the highest nitrogen solubility index (52.78 ± 1.76 %) and the best foaming property (78.33 ± 4.71 %). Solid-phase proteins had the strongest foam stability (92.96 ± 5.00 %) and gel strength (31.16 ± 3.46 g) due to their compact microstructure, abundant disulfide bonds, and more ordered secondary structure.