Fabrication, characterization and gastrointestinal fate of curcumin-loaded emulsions stabilized by soy protein-based ternary composite nanoparticles.

To design a novel emulsifier capable of enhancing the bioavailability of curcumin (Cur)-loaded emulsions in the gastrointestinal tract, soy protein-based ternary composite nanoparticles (SEP) were fabricated by transacylation reaction. The results showed that SEP was formed by the covalent binding of the carboxyl groups in PGA to the amino groups in SEC through multiple forces. SEP was determined to be the optimal condition for preparing Cur-loaded emulsions. Additionally, SEP had superior emulsifying capacity as formed plastic-state emulsion gel with φ as low as 0.5. Moreover, the rise in oil content promoted the development of gel, thus increasing the apparent viscosity, gel strength, and stability of Cur-loaded emulsions. Furthermore, SEP emulsion exhibited excellent gastric stability and higher free fatty acid (FAA) release rates in the small intestine phase compared with that of SEC (SEC control sample) and Mixture emulsion, thus leading to the highest bioavailability of Cur (28.57 ± 1.91 %).