Controlled release and antioxidant activity of chitosan and β-lactoglobulin complex nanoparticles loaded with epigallocatechin gallate

In order to investigate the influence of different embedding methods on the properties and function of polyphenols, the Epigallocatechin gallate (EGCG) loaded chitosan nanoparticles prepared with or without β-lactoglobulin (β-Lg) were obtained by ionic cross linking method. The average particle sizes of EGCG loaded chitosan nanoparticles (EGCG-CS NPs) decreased from 190 nm to 157 nm after adding with β-Lg, whereas the encapsulation efficiency (EE) increased from 59.79 % to 76.29 %. The results of transmission electron microscopy (TEM) showed that the obtained nanoparticles had obvious core-shell structure. The results of simulated gastrointestinal digestion showed that the release rate of EGCG in CS/β-Lg NPs was much lower than that of CS-NPs. Compared with free EGCG, the DPPH and FRAP assay showed that EGCG-CS NPs and EGCG-CS/β-Lg NPs had slow-controlled antioxidant activity. Meanwhile, the study of cellular antioxidant activity (CAA) showed that the EC50 values of EGCG-CS NPs and EGCG-CS/β-Lg NPs were decreased by 8.56 % and 18.35 %, respectively.