Encapsulation of phenolics in β-lactoglobulin: Stability, antioxidant activity, and inhibition of advanced glycation end products

β-Lactoglobulin (β-LG) is a whey protein with multiple binding sites for bioactive phenolics. Encapsulation of bioactive components in β-LG could enhance their activity and stability. In this study, vanillic acid (VA), ferulic acid (FA), and quercetin (QT) were encapsulated in β-LG. The resulting complex was studied by fluorescence spectroscopy, isothermal titration calorimetry, molecular docking, and molecular dynamics simulations. The β-LG–tri-ligand complex was successfully formed via an exothermic binding process when the ligands were added in the sequence of FA, QT, and VA, or QT, FA, and VA. The stabilities of the bioactive components in the complex were greatly improved by encapsulation. Molecular dynamics simulations confirmed that the binding of ligand molecules could increase the stability of the β-LG structure and made it more rigid/inflexible. The antioxidant activity and inhibition activity of the β-LG–tri-ligand complex against advanced glycation end products were higher than those of a mixture of FA, QT, and VA. The β-LG–tri-ligand complex shows great potential in functional food applications.