Encapsulation in β-lactoglobulin-chlorogenic acid complexes enhances digestibility and enzyme inhibitory activity of curcumin

Polyphenols could effectively prevent and alleviate many chronic diseases. However, the low solubility, poor stability, and bioaccessibility of certain bioactive ingredients have limited the development of functional foods. In this study, ultrasonication, free radical and their combination (ultrasonication/free radical) were used to prepare R-lactoglobulin (LG)-chlorogenic acid (CA) complexes. The complex was used as a shell to encapsulate curcumin (Cur), forming a ternary complex through anti-solvent method. Moreover, the digestive properties of the delivery system were evaluated by in vitro digestion simulation. Encapsulation by LG/LG-CA resulted in a controlled release of Cur which decreased Cur release in the oral and gastric phases while increased Cur release in intestinal digestion phase. In addition, LG-CA-Cur complex significantly inhibited the enzymatic activity of alpha-amylase and alpha-glucosidase. These findings indicated the potential of LG-CA complexes as an efficient carrier for Cur delivery and could be further used to develop functional dairy products with hypoglycemic activity.