Ultrasonic treatment on physicochemical properties of water-soluble protein from Moringa oleifera seed

Effect of ultrasonic power on the structure and functional properties of water-soluble protein extracted from defatted Moringa oleifera seed were explored. The results showed that ultrasonic treatment could reduce β-sheet and β-turn content of water-soluble protein from Moringa oleifera seed (MOWP) and increase the content of random coil and α-helix. Changes in intrinsic fluorescence spectra, surface hydrophobicity (H(0)) and thermal behaviors indicated that ultrasonic had significant effect on the tertiary structure of MOWP. The results of SEM and SDS-PAGE showed that the MOWP was aggregated but not significantly degraded by ultrasound. The solubility, foaming properties and emulsifying properties of MOWP increased firstly and then decreased with the increase of ultrasonic power. Ultrasonic treatment altered the functional properties of MOWP, which might be attributed to the exposure of hydrophilic group and the change of and secondary and tertiary structure.