Structures, fabrication mechanisms, and emulsifying properties of self-assembled and spray-dried ternary complexes based on lactoferrin, oat β-glucan and curcumin: A comparison study

Protein-polyphenol-polysaccharide non-covalent ternary complexes possess many unique structural and functional properties. However, rare work is available to fabricate the neutral polysaccharide-based ternary complexes. Herein, the ternary complexes composed of lactoferrin (LF), oat β-glucan (OG), and curcumin (Cur) with three binding sequences were successfully developed through self-assembly technique and spray drying technique, respectively. Spray drying could enhance the extent of the intermolecular associations among LF, OG, and Cur, leading to the formation of ternary complexes with smaller particle sizes and lower turbidities. Cur can be loaded in LF-OG complexes to form an amorphous complex through the intermolecular interactions (mainly hydrophobic interactions and hydrogen bonding). The ternary complexes can be used as potential emulsifiers to stabilize oil-in-water Pickering emulsions. The emulsifying capacity (to enhance physical stability) of the complexes was in the order as follows: the spray-dried ternary complexes > the spray-dried LF-OG complexes > the self-assembled ternary complexes > the self-assembled LF-OG complexes. The structural and functional properties (e.g., emulsifying property) of OG-based ternary complexes can be controlled by adjusting the binding sequences. These results will broaden our current understanding of protein-polyphenol-polysaccharide ternary complexes and provide more applications of OG in food, cosmetics, and pharmaceutical industries.