Milk was heated to 200 C for 3 min in sealed inverted-Y-shaped glass vials and reacted with a glutaraldehyde solution at that temperature. Electron microscopy of the metal-shadowed and negatively stained samples revealed that casein micelles in the milk did not disintegrate extensively at the high-temperature used but, rather, became enlarged. Some of them were found to be either clustered or distorted.
Harwalkar, V. R.; Allan-Wojtas, Paula; and Kalab, Miloslav
"Effect of Heating to 200 C on Casein Micelles in Milk: A Metal Shadowing and Negative Staining Electron Microscope Study,"
2, Article 7.
Available at: http://digitalcommons.usu.edu/foodmicrostructure/vol8/iss2/7