Comparative Characterization of Oil Body Proteins from Hemp, Plum, and Jujube Seed and Their Application in Curcumin-Loaded Artificial Oleosomes

The structural and functional characteristics of oil body proteins (OBPs) isolated from hemp, plum, and jujube seeds were systematically investigated, along with their potential application in constructing curcumin-loaded artificial oleosomes (AOs). OBPs were extracted through alkaline extraction coupled with ultrasonic disruption, followed by comprehensive physicochemical characterization using SDS-PAGE, FTIR spectroscopy, fluorescence spectroscopy, and evaluation of particle size, zeta potential, surface hydrophobicity, solubility, thermal stability, and emulsification properties. Plum seed-derived OBPs were found to demonstrate superior emulsifying capacity and solubility, which were attributed to distinctive structural features, including the following: an elevated random coil content (13%), enhanced surface hydrophobicity (21,781 A.U.), reduced particle size (103 nm), and higher zeta potential (-46 mV). These structural advantages were correlated with improved interfacial adsorption capacity and colloidal stability. When employed in AO fabrication, plum seed OBPs produced curcumin-loaded systems exhibiting maximum encapsulation efficiency (92%), minimal droplet size (5.99 μm), and optimal bio-accessibility (50%) compared to their hemp- and jujube-based counterparts. Furthermore, AOs utilizing plum seed OBPs displayed enhanced antioxidant activity and significantly improved stability. The collective findings establish plum seed OBPs as exceptional natural emulsifiers with strong potential for bioactive compound delivery applications.