Recorded on: August 29, 2018
12:00 noon CT
Presenter: Dr. Rich Hartel, Professor, Food Engineering, University of Wisconsin–Madison
In this webinar, the mechanisms that underlie and the parameters that influence partial coalescence of fat globules in ice cream will be discussed, along with the ramifications of high or low partial coalescence on product quality.
To meet the Standard of Identity, ice cream must contain at least 10% milk fat, with some premium products containing upwards of 16-18% fat. The small (1 µm) globules found in ice cream mix undergo changes during freezing, partially coalescing into large (50-100 µm) clusters of fat globules. The individual fat globules begin to share liquid oil under the intense shear forces within the freezer, but full coalescence is prevented by the network of fat crystals contained within each globule. To promote partial coalescence, it is necessary to weaken the fat/serum interface through addition of emulsifiers that displace the milk proteins.