| Pickering emulsion is the soap-free emulsion stabilized by solid particles, tolerating coalescence, Ostwald ripening, and can be stable for several months or years. Pickering emulsion of food grade is the hot and great challenge of colloid research in the field, the research of Pickering emulsion stabilized by food protein particles is extremely rare. Gliadin is an amphiphilic hydrophobic protein, changing the polarity of the solvent can be triggered by amphiphilic molecules driven self-assembly nano / microscale colloidal particles. In this study, first around gliadin self-assembly reaction expand control gliadin self-assembly laws and interfacial behavior of colloidal particles of controlled way, and to explore new gliadin colloidal particles stabilized Pickering emulsion, high internal phase emulsions(HIPEs) preparation techniques, characterization Pickering emulsions and physical properties and microstructure of HIPE, buliding a clear relationship between the structure and the latex emulsion interface performance.(1) we demonstrate firstly 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. We found that unmodified GCPs can produce stable, surfactant-free o/w emulsions with micro-scale droplet sizes under experimental mixing conditions at pH4.0 and above. In contrast, the emulsions were not stable against coalescence at ~pH3.0. 0.2%(w/v) of GCPs can stabilize emulsions and emulsions can be stabilized by low concentrations of GCPs.The microstructure, e.g., interfacial framework, GCPs partition, 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 framework and/or dispersed droplets-based network also contributed to the stabilization of the emulsions, in a pH-dependent manner.(2) we used chitosan to modify the surface of gliadin, fabricated GP/CH through a facile anti-solvent precipitation procedure, and used GP/CH to fabricate Pickering emulsions and Pickering HIPEs.We solved the problems that gliadin colloidal particles in the coagulation process easily and quickly, limiting the interfacial adsorption. We found that the emulsions stablised by GP/CH were not stable against coalescence at ~pH3.0. Exploration by adjusting the pH and ionic strength, reduce or block a charge, composite colloidal particles control surface wettability, Pickering emulsion obtained has good storage stability.The microstructure, e.g., interfacial framework, GCPs partition, and state of the droplets, of Pickering emulsions were visualized by CLSM, confirming that Pickering stabilization plays the major role. It is proved that GP/CH can be more attracted to the oil-water interface.(3) We used gliadin colloidal particles and gliadin/chitosan composite colloidal particles as Pickering emulsifiers, for the first time prepared Pickering high internal phase emulsion.Pickering high internal phase emulsions(HIPEs) are stable and wealthy viscoelastic semi-solid milk cream, Imparting liquid oils solid fats property.We systematically studied Pickering high internal phase emulsions(HIPEs) microstructure and rheological properties. The results showed that the chitosan modified gliadin colloid particles contribute to the formation of dense interfacial adsorption and membrane protein interface colloid particles, and thus the formation of the centrifugal tolerance, more viscoelastic Pickering high internal phase emulsion.Stable surfactant-free Pickering HIPEs were fabricated by a facile shearing emulsification.This study opens a promising route based on Pickering HIPEs to structure liquid oils into solid-like fats with zero trans-fat and less saturated fat, which outline new directions for future fundamental research. |
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