1 research outputs found
Protein Nanocage as a pH-Switchable Pickering Emulsifier
Encapsulation
of active compounds in Pickering emulsions using bioderived protein-based
stabilizers holds potential for the development of novel formulations
in the fields of foods and cosmetics. We employ a dodecahedron hollow
protein nanocage as a pH-switchable Pickering emulsifier. E2 protein
nanocages are derived from pyruvate dehydrogenase multienzyme complex
from <i>Geobacillus stearothermophilus</i> which adsorb
at the oil/water interface at neutral and basic pH’s and stabilize
the Pickering emulsions, while in the acidic range, at pH ∼4,
the emulsion separates into emulsion and serum phases due to flocculation.
The observed process is reversible for at least five cycles. Optimal
formulation of a Pickering emulsion composed of rosemary oil, an essential
oil, and water has been achieved by ultrasonication and results in
droplets of approximately 300 nm in diameter with an oil/water ratio
of 0.11 (v/v) and 0.30–0.35% (wt %). Ionic stabilization is
observed for concentrations up to 250 mM NaCl and pH values from 7
to 11. The emulsions are stable for at least 10 days when stored at
different temperatures up to 50 °C. The resulting Pickering emulsions
of different compositions also form a gel-like structure and show
shear thinning behavior under shear stress at a higher oil/water ratio