Microfluidization as Homogenization Technique in Pea Globulin-Based Emulsions

Abstract

The effect of microfluidization pressure (50, 70 and 130 MPa) during emulsification on the properties of native (NP) and soluble thermally aggregated (SA) pea (Pisum sativum L.) globulin-based emulsions at neutral pH was studied. Emulsions were characterized by interfacial protein-adsorption capacity, charge, emulsifying and flocculation properties, and creaming stability. NP- and SA-based emulsions were highly flocculated. Floc size decreased when increasing the microfluidization pressure during emulsification. Shear, turbulence, and collisions due to microfluidization induced modifications in the protein/aggregate association at the O/W interface and decreased the oil droplet size. SA-based emulsions showed higher floc size and smaller oil droplet size and revealed a more effective adsorption of SA at the O/W interface than NP. Creaming stability in NP-based emulsions decreased when increasing microfluidization pressure probably as a consequence of depletion-flocculation phenomena. On the contrary, creaming stability in SA-based emulsions improved when increasing homogenization pressure as a result of the formation of a gel-like network. Microfluidization could be used to modulate the emulsifying properties of pea globulin depending on their initial denaturation state.