Self-assembly of β-lactoglobulin and egg white lysozyme as a potential carrier for nutraceuticals

Self-assembly structures of p-lactoglobulin (beta lg) and egg protein lysozyme (Lyso) were developed, using electrostatic interactions between the two oppositely charged proteins. Different beta lg/Lyso concentration ratios were essayed at pH 6.8 to select the optimal ratio for the proteins co-precipitation, which behaviour was then studied at varying pH values. Optimal beta lg/Lyso concentration ratio, prepared at pH 7.5, was selected for protein co-precipitation. As a result, a structure with a mean diameter of 7.1 +/- 2.5 mu m was formed, as indicated by static light scattering. Furthermore, the SEM images showed that beta lg and Lyso self-assembled to form a microsphere. Vitamin D-3, used as a model nutraceutical, was successfully entrapped in the beta lg/Lyso microspheres with an encapsulation efficiency of 90.8 +/- 4.8%. Therefore, the beta lg/Lyso microspheres can serve as a potential food-grade vehicle for bioactives in the formulation of food products and pharmaceuticals. (C) 2014 Elsevier Ltd. All rights reserved.