The potential utilization of microparticulated whey protein (MWP) as a fat mimetic in reduced calorie model
sauces and dressingswas examined. The influence of solution composition (pH and salt) and processing (homogenization
and heating) on the properties of MWP (0–20%) suspensions (0.01 M phosphate buffer, pH 6) was
studied. High-pressure homogenization (6000 psi, 1 pass) of MWP suspensions significantly reduced protein
particle size and improved their stability to sedimentation. The lightness and viscosity of the suspensions increased
withMWP concentration, which was attributed to the influence of the protein particles on light scattering
and fluid flow. Thermal treatment (90 °C for 5 min) ofMWP suspensions increased their viscosity,whichwas
associated with increased protein aggregation. Solution pH (2–8) also had an impact on the particle size and microstructure
of theMWP suspensions, which was attributed to changes in particle charge: the chargewent from
negative to positive with decreasing pH, with an isoelectric point around pH 4.5. Addition of calcium chloride
(10 mM) to heated systems did not cause significant changes in suspension rheology, which was attributed to
pre-denaturation of the MWP. Overall, this study highlights conditions where MWP can be used as potential
fat replacers in lowcalorie food emulsions.MWP increases the lightness and viscosity of products, thereby mimicking
some of the desirable characteristics of fat droplets.