Effect of processing on physicochemical characteristics and bioefficacy of ß-lactoglobulin-epigallocatechin-3-gallate complexes.

ABSTRACT

Varying amounts of epigallocatechin-3-gallate (EGCG) were encapsulated in ß-lactoglobulin (ß-Lg) nanoparticles, either native or processed, denoted as heated or desolvated protein. The stability, physical properties, and bioactivity of the ß-Lg-EGCG complexes were tested. Native ß-Lg-EGCG complexes showed comparable stability and binding efficacy (EGCG/ß-Lg molar ratio of 11) to heated ß-Lg nanoparticles (1% and 5% protein w/w). The sizes of heated and desolvated ß-Lg nanoparticles were comparable, but the latter showed the highest binding affinity for EGCG. The presence of EGCG complexed with ß-Lg did not affect the interfacial tension of the protein when tested at the soy oil-water interface but caused a decrease in dilational elasticity. All ß-Lg complexes (native, heated, or desolvated) showed a decrease in cellular proliferation similar to that of free ECGC. In summary, protein-EGCG complexes did not alter the bioefficacy of EGCG and contributed to increased stability with storage, demonstrating the potential benefits of nanoencapsulation.