Advanced interfacial design of hempseed oil bodies via pH-ultrasound coupling: From molecular rearrangement to emulsion stabilization.

Abstract

A novel pH-ultrasonication approach was developed for effectively extracting hempseed oil bodies (HOBs), and its effects on compositional profile, physicochemical stability, interfacial architecture, and adsorption behavior were systematically investigated. Increasing pH from 7.0 to 10.0 markedly elevated the lipid content of HOBs while reducing protein, moisture, and extraction yield; conversely, the incorporated ultrasonication reversed these trends. HOBs extracted at pH 10.0 exhibited smaller, less-aggregated droplets than those at pH 7.0, whereas ultrasonication impelled further droplet size reduction, especially at 600 W. The physicochemical stability of HOBs was substantially enhanced by moderate sonication, evidenced by reduced creaming indices and EPR signals. Ultrasonication induced protein unfolding (red-shifted fluorescence, α-helix/random coil to β-sheet/β-turn transition) and exposed hydrophobic domains, thereby facilitating diffusion, interfacial penetration, and rearrangement. This yielded a denser, more viscoelastic interfacial membrane with enhanced intermolecular interactions, as reflected by higher interfacial elastic modulus and steeper E-π slopes, ultimately conferring superior stabilization of HOBs.