Fabrication and characterization of acid soluble collagen stabilized Pickering emulsions

The objective of present study was to assess the feasibility of using acid soluble collagen as stabilizer to fabricate stable oil-in-water (O/W) Pickering emulsions. The effect of acid soluble collagen concentrations, pH values and ionic strengths on the particle size distribution, rheological properties and Turbiscan stability of emulsions was investigated. Atomic force microscopy (AFM) observation showed that the acid soluble collagen exhibited thread-like structure, the length reached 600-900 nm and the diameter was in about 20 nm. The concentration of acid soluble collagen significantly affected the stability of Pickering emulsions. The results indicated that when the concentration was lower than 0.1 wt%, phase separation of Pickering emulsion occurred. With increased concentration of acid soluble collagen varying from 0.01 to 1.5 wt%, the stability of Pickering emulsions was improved, accompanied with a diminution in droplet sizes. Rheological results showed that the obtained Pickering emulsion exhibited gel-like structure, and the increase of acid soluble collagen concentrations contributed to larger elastic modulus (G') and viscosity modulus (G '') of emulsions, which was beneficial for the stability of emulsions. In addition, ionic strengths and pH values also affected the physical properties of Pickering emulsions. These novel findings in this work could extend the knowledge about acid soluble collagen as potential edible Pickering stabilizer.