Interfacial interactions in edible emulsion films from whey protein isolate

Interfacial interactions between protein and lipid in edible emulsion films are thought to reduce water vapor permeability (WVP). Films were prepared from whey protein isolate, glycerol and emulsified lipid (triolein or tripalmitin/butterfat blend). The interfacial composition was varied using sodium dodecyl sulfate. Particle size and WVP were determined by laser light scattering and gravimetric methods respectively. Shear treatment significantly reduced the WVP of the protein phase. Interfacial interactions were small in triolein films and were not detected in tripalmitin/butterfat films. WVP did not depend strongly on the physical state of the dispersed phase. The distribution of the lipid droplets within the film is the primary determinant of WVP in the systems studied.