Structural, physicochemical, and digestive properties of sea buckthorn seeds protein obtained from ultrasound-assisted extraction

This study investigated the effects of ultrasound-assisted treatment with alkaline protease on the structural, physicochemical, and digestive properties of sea buckthorn seed protein (SBSP). Different ultrasound powers (250, 350, 450, 550, 650 W) and times (20, 25, 30, 35, 40 min) were applied to assess these effects. Among these treatments, the ultrasonic treatment of 350 W for 30 min led to an increase in surface hydrophobicity, a significant reduction in average particle size, and enhanced the solubility, emulsifying capacity, and foaming properties of SBSP. Furthermore, the secondary and tertiary structures of SBSP underwent changes during the ultrasound treatment, with a decrease in alpha-helix content and a 17.5% increase in beta-sheet content. X-ray diffraction analysis revealed a reduction in SBSP crystallinity. The in vitro digestibility of the protein was also improved, while the content of undesirable volatile flavor compounds was reduced during extraction. Thus, ultrasound-assisted pretreatment proves to be an effective method for extracting SBSP, improving its functional properties, and providing important implications for the application of SBSP in food products.