The fact that the method is successful may be explained as follows: Mixing the acid with the egg forms a salt which hydrates the mixture, and thus aids in making favorable conditions for emulsifying the oil as explained in the footnote of a previous page.
"School and Home Cooking"
Carlotta C. Greer
Cheese food U.S.A. "Any mixtures of various lots of cheese and other solids derived from milk with emulsifying agents, coloring matter, seasonings, condiments, relishes and water, heated or not, into a homogeneous mass."
"The Complete Book of Cheese"
Robert Carlton Brown