Seabuckthorn (Hippophae rhamnoides L.), a novel seed protein concentrate: isolation and modification by high power ultrasound and characterization for its functional and structural properties

The present work investigated the influence of ultrasonication (US) on the structural and functional properties of Seabuckthorn seed protein concentrate. Ultrasonication was carried out by varying time (0, 5, 15, 25, and 35 min) with a constant power supply of 500 W/cm2.The structural properties were evaluated by FTIR, SDS-PAGE, DLS and FE-SEM. The study revealed that solubility and emulsifying activity index of all the US treated protein concentrates were significantly higher than that of untreated sample and ranged between 7–54% and 13–39%, respectively. The decrease in the percentage of α-helix and increase of β-sheet structure by ultrasonication was confirmed by FTIR. However, SDS-PAGE revealed no change in molecular weight of protein with ultrasonication. The increase in particle size reduction with the increase of US time was confirmed by FE-SEM and DLS. The results of zeta potential revealed that seed protein contains negative charge on its surface and percentage of negative charge increased with ultrasonication duration.