Preparation of camellia oil pickering emulsion stabilized by glycated whey protein isolate and chitooligosaccharide: Effect on interfacial behavior and emulsion stability

Camellia oil has a high content of unsaturated fatty acids and active ingredients, but it is unstable during production, storage, and application. Camellia oil Pickering emulsions were prepared by utilizing electrostatic complex of glycosylated whey protein isolate (gWPI) and chitooligosaccharide (COS) as the emulsifier can be used as an effective carrier system. The effects of pH level and biomass concentration on polymer interaction and emulsion stability were systematically studied. The emulsion's interfacial properties and rheological behavior were studied by using an interfacial tensiometer and a rheometer, respectively. The mass ratio of 1:1 (1%) and pH 5.0 were the optimal conditions for protein-COS interactions. Compared with WPI-COS, the content of absorbed protein in the O/W interface of gWPI-COS increased, and the diffusion (kdiff) and rearrangement (kR) rates of proteins in the O/W interface of the gWPI/gWPI-COS significantly improved according to the rheokinetics of protein adsorption at the oil/water interface. Moreover, a higher viscoelasticity in the WPI/gWPI-COS stabilized the emulsion system. Subsequent studies on the stability of the emulsion also showed that the Pickering emulsions stabilized by gWPI-COS had better thermal stability, oxidative stability, resistance to oscillatory shear than gWPI/WPI or WPI-COS emulsion.