Formation of whey protein, pectin, and chlorogenic acid ternary complexes and their application in emulsions

Physicochemical properties, stability, and digestive behavior of lycopene-loaded emulsions prepared by ternary complexes fabricated with different mixing sequences based on whey protein isolate (WPI), high methoxyl pectin (HMP), and chlorogenic acid (CA) were investigated. Spectroscopic and molecular docking analyses confirmed the non-covalent interactions among the compounds within the ternary complexes, as well as the conformational changes in the protein induced by the mixing sequence. The interfacial tension (6.92-9.44 mN/m) influenced by the different mixing sequences of WPI, HMP and CA was HMP-CA-WPI > WPI-CA-HMP > WPI-HMP-CA, and the size of emulsions stabilized by HMP-CA-WPI was approximately 10 nm larger than that of the other two. Complexes with mixing sequence of HMP, CA and WPI outperformed in antioxidant properties (Ferric reducing power absorbance 0.43, ABTS∙ radical scavenging activity 66.04 %), lycopene retention rate (after UV irradiation 85.11 %, after thermal treatment 83.15 %), and storage stability of emulsions than those prepared by WPI-HMP-CA and WPI-CA-HMP. Emulsions stabilized by different ternary complexes showed similar free fatty acid release profiles (39.62 %-41.59 %) and lycopene bio-accessibility (28.87 %-29.94 %) during digestion. This study mat offer novel insights for the rational utilization in emulsions of ternary complexes based on proteins, polysaccharides, and phenolic acids.