THE LIPID TYPE and amount are important in affecting the WVP
of whey protein/lipid emulsion films. The WVP of the emulsion
films decreased in a non-linear fashion as the fat concentration
increased. For certain lipids, such as beeswax and a high-melting
anhydrous milkfat fraction, a critical concentration existed at
which a sharp decrease in film WVP occurred. Carnauba and
candelilla wax formed less effective films than the softer and
more viscoelastic beeswax and milkfat fraction. As these latter
lipid emulsions dried, the lipid droplets inside the emulsion
came together because of shrinkage. These plastic droplets likely
deformed against each other to yield an intact network of fat
within the emulsion film. This network probably provided the
sharp reduction in WVP of the emulsion film.