Encapsulation behavior of curcumin in heteroprotein complex coacervates and precipitates fabricated from ?-conglycinin and lysozyme

The associative phase separation of oppositely charged biopolymers produces liquid-like coacervates or solid-like precipitates, whereas the effect of the physical state difference on applications is often overlooked. This study investigated the application of complexes coacervates and precipitates fabricated from beta-conglycinin (beta-CG) and lysozyme (LYS) for the encapsulation of curcumin. The beta-CG-LYS complexes encapsulating curcumin at charge stoichiometric ratios appeared as coacervates at pH 6 and precipitates at pH 7 and 8. The curcumin encapsulation efficiency and loading capacity of these complexes reached 95% and 410-486 mu g/mg. Coacervates and precipitates both significantly improved the curcumin stability when exposed to light and heat treatment. During storage, the curcumin in coacervates had an extremely long half-life value (t1/2), whereas curcumin in the precipitates had a short t1/2. When the coacervates encapsulating curcumin adhered to the bottom of the cuvette, 35.2% of the curcumin was still retained after rinsing with ethanol 30 times. The beta-CG-LYS coacervates were promising carriers to encapsulate functional molecules, which may be used as functional dressings and coatings.

Automated summary

This study investigated the application of complexes coacervates and precipitates fabricated from beta-conglycinin and lysozyme for the encapsulation of curcumin. Both coacervates and precipitates significantly improved the curcumin stability and exhibited different encapsulation efficiency and loading capacity.