Effect of high-pressure homogenization on droplet size distributions and rheological properties of model oil-in-water emulsions

Abstract A new ultra high-pressure homogenizer (STANSTED, UK) going up to 350 MPa, was used to realize very fine oil-in-water emulsions. The effect of homogenizing pressure (from 20 to 300 MPa) was studied on model emulsions stabilized by whey proteins. Oil droplet size distributions were measured by laser-light scattering. Rheological properties were characterized with a coaxial cylinder rheometer. The results showed significant modifications in the structure and the texture of emulsions with increasing pressure. Ultra high-pressure homogenizing conditions brought about the high oil content emulsions (>40% w.w.b) from shear-thinning behaviors (at 20 MPa) to Newtonian behaviors (at 300 MPa). Droplet size was reduced with increasing pressure. However, the flow curves could not be fully explained by the droplet size distributions.

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