Cereal Chem 38:294 - 305.  |  VIEW ARTICLE

Bubble Mechanics in Thick Foams and Their Effects on Cake Quality.

A. R. Handleman, J. F. Conn, and J. W. Lyons. Copyright 1961 by the American Association of Cereal Chemists, Inc. 

Characteristics of finished cakes are compared with those predicted by a theoretical treatment of properties of the batter which would affect the growth and movement of bubbles. Surface tensions, viscosities, and yield values were measured in several white and yellow cake batters, and the rates of bubble-to-bubble gas diffusion were observed in sequential photomicrographs of a single field of each batter. It was observed that, in batters prepared with unemulsified shortening, bubble-to-bubble diffusion was extremely slow, and leavening gas was evolved into only a small percentage of the bubbles. As predicted by the mathematics, when a given amount of gas is evolved into a small number of bubbles, a large proportion attain critical buoyancy and rise. These cakes had lower volumes, indicating that a significant proportion of the gas was lost, presumably by this mechanism. Where diffusion was more rapid and involved larger numbers of bubbles, volumes were higher. In a case where the yield and viscosity values were high, even the tendency to layer (larger cells to accumulate nearer the surface) was minimized.