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_n) were fabricated by transacylation reaction. The results showed that SEP_n was formed by the covalent binding of the carboxyl groups in PGA to the amino groups in SEC through multiple forces. SEP_n-1:1 was determined to be the optimal condition for preparing Cur-loaded emulsions. Additionally, SEP_n-1:1 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_n-1:1 emulsion exhibited excellent gastric stability and higher free fatty acid (FAA) release rates in the small intestine phase compared with that of SEC_con (SEC control sample) and Mixture emulsion, thus leading to the highest bioavailability of Cur (28.57 ± 1.91 %).