Low-concentration CNF stabilized Pickering emulsions: The assisted role of low-concentration gelatin

Pickering stabilizers are usually used in high concentration, especially for polysaccharide particles with relatively poor surface activity, such as nanocellulose. This study investigated the preparation and properties of Pickering emulsions co-stabilized by a low concentration complex system based on the carboxylated cellulose nanofibril (CNF, 0.2 %) and gelatin (G, 0.02 %-0.10 %). As gelatin concentration gradually increased, the turbidity of CNF/G complex increased while the zeta potential slightly decreased due to electrostatic interaction. Especially, introducing gelatin facilitated the formation of a flocculation network structure of the CNF/G complex due to hydrogen bonding and electrostatic adsorption. Introducing low-concentration gelatin solved the issue that low-concentration CNF could not stabilize the emulsion. At low gelatin concentration ranges (0.06 %-0.10 %), CNF/G stabilized emulsions displayed good stability (i.e., storage, pH, ionic strength and centrifugation stabilities), and the rheological properties of emulsions improved as well. The interface adsorption and network structure of CNF/G stabilized Pickering emulsions can be effectively regulated by low-concentration gelatin as assisted role. The present study develops a stable emulsion stabilized by low-concentration polysaccharide/protein complex system.