Coalescence and Arrested Coalescence: Some Microscopic Observations and Practical Behavior Relevant to the Design of Ice Cream and Whipped Toppings

R. Hartel
University of Wisconsin-Madison,
United States

Keywords: food, emulsifier, food science


It is well understood that two unprotected fat globules quickly coalesce to minimize surface energy. In some cases, however, there are forces that block that relaxation. The first is a surface coverage of some sort of emulsifier/stabilizer that prevents the two interfaces from interacting. At times, though, we control the surface conditions to initiate coalescence, which is then arrested by the opposing force of an internal crystalline structure. In this case, arrested or partial coalescence leads to formation of a network of interacting fat globule structures of significantly larger size, which influence physical and sensory attributes of various foods. This talk will be a highly pictorial overview of these different conditions, advancing our understanding of these complex phenomena that control the properties of such foods as ice cream and whipped toppings.