Efficacy of a Maillard-type conjugate of whey protein isolate with chitosan as a carrier for a liposomal form of a combination of curcumin and balanced amounts of n-3 and n-6 PUFAs. Part II. Carrier behaviour under simulated in vitro digestion

Abstract

The study evaluated the benefits of using the whey protein isolate (WPI)–chitosan (CHIT) carrier formed via a Maillard reaction step to enhance the bioavailability of a liposomal form of nutraceuticals during in vitro gastrointestinal digestion according to the INFOGEST protocol. Liposomes appeared uniformly released from their hydrolysed complex [WPI–CHIT]–(PC–FO–CUR) during both the gastric (54 ± 9%) and small intestinal (46 ± 7%) stages in vitro. This was due to the initial encapsulation of liposomes (94%) by both WPI and chitosan in the soluble fraction of the Maillard-type conjugate. During the gastric stage, the mucoadhesiveness of the complex was improved by covalently attaching chitosan to thermally denatured WPI. The WPI denaturation was confirmed by DSC. Furthermore, both components aided in maintaining the complex's mucoadhesiveness during the small intestinal stage. Laser light scattering, TEM, EPRS, and tensiometry characterized interactions of hydrolysed complex particles and liposomes with mucin or bile salts in the GIT in vitro.