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In this paper, we demonstrate for the first time the use of gliadin colloid particles (GCPs) as an effective particulate stabilizer of oil-in-water emulsions of natural oils and water. For this purpose, we fabricated GCPs through a facile anti-solvent precipitation procedure and demonstrated their uses in the formation of Pickering emulsions as well as Pickering high internal phase emulsions (HIPEs). We found that unmodified GCPs can produce stable, surfactant-free o/w emulsions with microscale droplet sizes under experimental mixing conditions at pH 4 and above. In contrast, the emulsions were not stable against coalescence at ∼pH 3.0. The microstructures, e.g., interfacial framework, GCPs partition between the continuous phase and interfacial region, and state of the droplets, of Pickering emulsions as a function of pH were visualized by optical microscopy and confocal laser scanning microscopy (CLSM), confirming that in addition to Pickering stabilization, the GCPs-based network and/or dispersed droplets-based network also contributed to the stabilization of the emulsions, in a pH-dependent manner. Clear correlations exist between colloid properties of the GCPs dispersions and the emulsion characteristics. Interestingly, stable surfactant-free Pickering HIPEs were fabricated by a facile shearing emulsification. This study opens a promising route based on Pickering HIPEs to transform liquid oils into viscoelastic emulsion gels with zero trans-fat and less saturated fat. The Pickering HIPEs possess promising potentials to replace solid fat in food formulations, which outline new directions for future fundamental research. [ABSTRACT FROM AUTHOR]

Microstructure heterogeneity of emulsion films impaired their physical performances. This work attempted to fabricate novel high-barrier chitosan (CH) emulsion films by manipulating emulsion's interface architecture via Pickering stabilization approach. Some selected physical properties, including tensile property, water vapor permeability (WVP), and oxygen permeability (OP) as well as the microstructure of the films were evaluated. Film-forming emulsions (FFEs) based on zein/chitosan colloid particles-stabilized Pickering emulsions (ZCCPEs) were extremely stable, evidenced by the similar droplets size and size distribution in the FFEs and film matrix, endowing the films with homogeneous distributions of lipid droplets over their 3D network matrix. Interestingly, emulsion films exhibited excellent oxygen-barrier efficiency, and the OP of the films was decreased by 1−4 orders of magnitude when compared with CH films. This phenomenon may be associated with the novel interfacial architecture of ZCCPEs as well as film microstructure morphology based on ordered assembles of CH matrix and ZCCPEs. A schematic diagram for the formation pathway of ZCCPEs-loaded CH emulsion films was proposed to establish structure-function relationships of the films. This study opens a promising pathway for producing emulsion films with excellent oxygen-barrier capability via Pickering stabilization principle. [ABSTRACT FROM AUTHOR]