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 I. structure – Functionality relationships

Abstract

The Maillard-type WPI–chitosan conjugate was prepared through dry heating at 60 °C and 75% relative humidity for 72 h at a weight excess of WPI (8.7-fold) relative to CHIT (75% of deacetylation). The focus of the study was the soluble fraction (68% w/w) of the WPI–CHIT conjugate in the pI range of WPI (pH 4.5). SDS-PAGE analysis revealed that 16% of the total WPI was covalently bonded to CHIT. SDS-PAGE and SEC identified a 29% degree of binding for α-lactalbumin. DSC, fluorimetry, and FTIR detected unfolding of globular whey proteins in the conjugate. The conjugate encapsulated 94% of phosphatidylcholine liposomes loaded with fish oil and curcumin, resulting in complex particles. EPRS, DSC, fluorimetry, laser light scattering, tensiometry, and TEM provided insights into the structural and thermodynamic parameters underlying the functionality of the latter: water solubility, protective ability for encapsulated nutraceuticals, and lower foaming ability compared to that of the WPI–CHIT conjugate.