Explain Foaming Properties of proteins

To understand the foaming properties of proteins, we need to know some basic aspects of foam foods. Foam foods are usually colloidal dispersion of gas bubbles in a continuous liquid or semisolid phase that contains a soluble surfactant. (Surfactant is a chemical  compound that acts as a surface modifier which reduces the surface tension of the  liquid). A large  variety of food foams produced with proteins,  exist  with widely  differing  textures, such as cakes,  whipped  creams  and toppings,   ice   creams  etc.  In  many  cases,  gas   is    air (occasionally  CO2)  and  the continuous  phase  is   an  aqueous  or suspension   containing  proteins. 

Next, what are the properties basic to  proteins, to be a good foaming agent? A protein must:

• be able to rapidly absorb at the air-water interface during whipping,
• undergo rapid arrangement and rearrangement at the interface, and
• form cohesive viscoelastic film.