Cereal Chem 44:333 - 343.  |  VIEW ARTICLE
The Role of Emulsifiers in the Incorporation of Air into Layer Cake Batter Systems.

J. C. Wootton, N. B. Howard, J. B. Martin, D. E. McOsker, and J. Holme. Copyright 1967 by the American Association of Cereal Chemists, Inc. 

Surface-active lipids, which in the bulk state are alpha-tending in crystalline form, have been found to act as enhancers of air incorporation in cake batters when used as shortening emulsifiers. The ability to enhance air incorporation is related to the unique interfacial behavior of these lipids at oil-water boundaries. If the concentration at the interface exceeds the solubility limit, these lipids crystallize in an alpha-tending form. The interfacial film so formed possesses the waxlike properties of the alpha-crystalline phase and, it is suggested, in effect encapsulates the dispersed oil (shortening) droplets within a protective coating. In this way it is possible that the lipids normally detrimental to the foaming properties of soluble proteins are prevented from migrating into the aqueous phase and interfering with air incorporation. The results of this work show that surface-active additives or additive mixtures which are stable in the alpha-crystalline form are valuable as enhancers of air incorporation. Examples of lipids which show this alpha-tendency include the fatty esters of aliphatic diols, mixed acid diglycerides, and hydroxy acid esters of mono- and diglycerides.