Protein-polyphenol-polysaccharide ternary complex as a multifunctional pickering stabilizer for Lycium barbarum seed oil encapsulation: Antioxidant activity, stable delivery, and mechanisms based on interfacial behaviors.

Abstract

Pickering emulsions present an effective method for delivering functional oils while addressing their inherent water insolubility. However, the stability of these emulsions can be compromised by complex composition of functional oils and their susceptibility to oxidation. This study developed a composite stabilizer consisting of whey protein isolate (WPI), grape seed proanthocyanidins (OPCs), and Lycii fructus polysaccharides (LFP). Alkali-prepared WPI-OPCs were covalently modified with LFP via Maillard reaction, resulting in smaller particles with increased roughness. The conjugate exhibited strong scavenging capabilities, superior emulsifying properties, improved wettability and reduced surface tension, enabling faster adsorption and the formation of a thicker, denser interfacial film with improved resistance. Molecular dynamics simulations suggested hydrogen-bond-related hydration effects and van der Waals interactions may contribute to the superior film properties. Consequently, emulsion containing Lycium barbarum seed oil demonstrated improved stability and oil protection. This study highlights a protein-polyphenol-polysaccharide complex as an effective stabilization approach for food applications.