Re: egg protein vs protein functionality

It's all about orientation. Each protein/fat molecule consists of a 
hydrophillic head and hydrophobic tail. The molecules at an oil-water 
interface orient themselves tail-to-tail and form what is termed a lipid 
bi-layer. It's somewhat hard to describe but it image two rows of frog 
tadpoles. The rows sit one above the other with their tails touching and 
their heads facing in opposite directions. This is what a lipid bi-layer 
looks like. In an emulsion, which takes shear force to accomplish i.e. 
shaking a salad dressing bottle, the proteins coat each fat droplet with 
the tails oriented inward and the head outward this was the fat droplet 
can emulsify or disperse within the rest of the water-soluble ingredients. 
Similarly, in foaming, instead of fat droplet being dispersed, the violent 
action of mixing or blending incorporates tine air pockets into the 
emulsion which are again coated by the protein in the orientation 
mentioned above.