Phytosterol colloidal particles as Pickering stabilizers for emulsions.
Water-insoluble phytosterols were developed into a kind of colloidal particle as Pickering stabilizers for emulsions by a classic anti-solvent method using 100% ethanol as the organic phase to solubilize the phytosterols and whey protein concentrate (WPC) as the emulsifier. The colloidal particles in the dispersion, with morphology of stacked platelet-like sheets, had a mean diameter of 44.7 and 24.7 μm for the volume- and surface-averaged sizes, respectively. The properties and stability of the emulsions stabilized by these colloidal particles were highly dependent upon the applied total solid concentration (c; in the dispersion) and oil fraction (ø). The results indicated that (1) at a low c value (<1.0%, w/v) the emulsions were susceptible to phase separation, even at a low ø of 0.2, (2) at low ø values (e.g., 0.2 or 0.3) and a relatively high c value (1.0%, w/v, or above), a severe droplet flocculation occurred for the emulsions, and (3) when both c and ø were appropriately high, a kind of self-supporting gel-like emulsions could be formed. More interestingly, a phase inversion of the emulsions from the oil-in-water to water-in-oil type was observed, upon the ø increasing from 0.2 to 0.6 (especially at high c values, e.g., 3.0%, w/v). The elaborated Pickering emulsions stabilized by the phytosterol colloidal particles with a gel-like behavior would provide a candidate to act as a novel delivery system for active ingredients.
Research and Development Centre of Food Proteins, Department of Food Science and Technology, and ‡State Key Laboratory of Pulp and Paper Engineering, South China University of Technology , Guangzhou, Guangdong 510640, People's Republic of China.
Fu
F
Liu
Chuan-He
CH
Tang
D003102:Colloids / Q000737:chemistry; D004655:Emulsions / Q000737:chemistry*; D009821:Oils / Q000737:chemistry; D010316:Particle Size; D010840:Phytosterols / Q000737:chemistry*
D003102:Colloids; D004655:Emulsions; D009821:Oils; D010840:Phytosterols