Homogenization

Name:
Homogenization
Detailed information:
A mechanical process for reducing the size of the fat particles of an emulsion (usually milk) to uniform size, thus creating a colloidal system that is unaffected by gravity. The original diameter of the fat particles (6–10 microns) is reduced to 1–2 microns, with an increase in total surface area of 4–6 times. This is done by passing the milk through a homogenizer (or colloid mill), a machine having small channels, under a pressure of 2000–2500 psi at a speed of approximately 700 ft/sec. This operation not only brings about a permanently stable system, but also changes the properties of the milk in respect to taste, color, and the chemical nature of the protective coating on the fat particles. It also increases its sensitivity to light and its tendency to foam. The forces involved are shear, impingement, distention, and cavitation.See Homogeneous; colloid mill.