rapid foam formation. Adsorption is the ability to spontaneously form a very thin layer on a surface. The denatured proteins move to the air/water interface to create the cell walls of the air bubbles. Cell wall formation occurs when the denatured proteins aggregate, forming an extremely thin network or film. Many interactions between the proteins and the interface are involved, including hydrogen bonding, electrostatic interactions, disulfide bonds, and Van der Waals interactions. A cake made with egg yolks would not be as light and airy because they have a lower foaming ability than egg whites. This move, to the air/water interface, by the proteins is also aided by their hydrophobic and hydrophilic part. The hydrophobic moieties orient themselves toward the air while the hydrophilic moieties orient themselves toward the water portion of the interface. The air molecules at the air/water interface interact less with the other molecules that are fully inside the bubble. This lack of interaction causes the air molecules to have excess energy, resulting in surface tension. The presence of egg white proteins at the interface acts as a surfactant which lowers the surface tension and promotes foam development. A foam is a type of emulsion: air in an aqueous solution. If the surface tension was not lowered, the air bubbles would coalescence and the emulsion would separate. The interfacial dilational modulus (E) describes how the egg white proteins or surfactants covering the air/water interface are able to resist deformation from stretching or compression. An elastic and viscosity component are incorporated into the value, which account for the energy that is lost and recovered as a result of deformation. E = dγ/d ln A E: interfacial dilational modulus γ: change in interfacial tension A: change in interfacial area at a constant shape The most stable and voluminous foams are created when the egg white proteins are near their isoelectric points. Protein adsorption is most rapid at the isoelectric point because electrostatic repulsion is reduced for proteins with a neutral net charge. The viscoelasticity of protein foam films is usually at its highest near its isoelectric point. This is why acid is usually added to the cake batter, in order to adjust the pH. The preparation of the batter should be done as quickly as possible. When the foam sits, disproportionation will occur. This is the result of water draining from the foam and collecting at the bottom. The