Casein micelles voluminosity

The viscosity of milk and milk products is reported to be important in the rate of creaming. The viscosity of milk increases with decrease in temperature because the increased voluminosity of casein micelles temperatures above 65°C increases viscosity due to the denaturation of whey proteins pH an increase or decrease in the pH of milk also causes an increase in casein micelle voluminosity. Fat globules that have undergone cold agglutination may be dispersed due to agitation, causing a decrease in viscosity. 

The ageing at 5°C of whippable emulsions such as ice cream mix will enhance the hydration of milk proteins in the system. This is due to a property of casein micelles in milk. At low temperatures, the hydration or voluminosity of casein increases. The voluminosity is the volume of hydrated protein per gram of protein. This can be studied by analyzing the protein and water content in the sedimented casein pellet after centrifugation of skimmed milk. 

B. Average Size, Size Distribution, and Voluminosity of Casein Micelles 1. Micelle Size... 

Fig. 15. Volume fraction distribution calculated, assuming homogeneous spheres of constant voluminosity, from electron micrographs of casein micelles from three cows (Holt et at., 1978a, and unpublished work by the same authors).

---