Interfacial assembly in flaxseed protein and chitosan at oil-water interfaces: Interfacial structure, rheology, and antioxidant properties of Pickering emulsions

This study investigates the interaction mechanisms between flaxseed protein (FP) and chitosan (CS) to develop CS-FP NPs for stabilizing Pickering emulsions. The optimized CS/FP ratio of 1:3 at pH 6.0 produced uniform NPs (362.4 nm) with nearly neutral wettability (∼90°) and improved interfacial activity. Molecular docking analysis indicated that hydrogen bonding, ionic, and hydrophobic interactions were key drivers of complex formation, enhancing FP's interfacial characteristics. Emulsions stabilized by NPs at 3.5% concentration and 50% (v/v) diacylglycerol (DAG) oil showed small droplet sizes (∼10 μm) and excellent storage stability under different conditions. The synergistic interaction between DAG and NPs at the interface reinforced interfacial rigidity and oxidative stability. Overall, this study suggests that the interfacial assembly and stability of flaxseed protein-chitosan systems can be systematically tuned by concentration and ratio, offered insights into the structure-property relationships of protein-polysaccharide and present an eco-friendly approach for developing clean-label Pickering emulsions for functional food purposes.