Characterisations of oil-in-water Pickering emulsion stabilized hydrophobic phytoglycogen nanoparticles

The medium-chain triacylglycerol (MCT)-in-water (O/W) Pickering emulsions were prepared using octenyl succinate phytoglycogen nanoparticles as stabilizer. The rheological properties and microstructure of emulsions with O/W ratio of 1 and 0.1 were investigated. All emulsions exhibited the typical pseudoplastic fluid characteristics at shear rates of 1-100 1/s. The modified phytoglycogen nanoparticles stabilized emulsions satisfied the Herschel-Bulkley rheological model. The increase of viscosity was pronounced at 5% of modified phytoglycogen nanoparticles and 50% of MCT fraction for emulsion preparation. The emulsion with high oil phase displayed G' was higher than G'', and both G' and G' were independent of frequency, whereas G' and G'' of low oil concentration emulsion showed ascending tendency with increasing frequency. Microstructure of emulsions revealed that the larger droplet size of O/W emulsion containing high oil phase with gel-like appearance was obtained, indicating that nanoparticles accumulated at the oil-water interface in the form of a barrier layer and a three-dimensional network had been formed. It was concluded that it is possible to employ modified phytoglycogen nanoparticles and high MCT content to produce food-grade Pickering emulsion with good long term stability. (C) 2017 Elsevier Ltd. All rights reserved.