Homogenization

Homogenization (or homogenisation) is a term used in many fields such as chemistry, agricultural science, food technology, sociology and cell biology. Homogenization is a term connoting a process that makes a mixture the same throughout the entire substance.

Chemistry

Intensive mixing of mutually insoluble phases (sometimes with addition of surfactants) to obtain a soluble suspension or emulsion.

In science:

• Homogeneous — a mixture that is the same (uniform) throughout.
• Heterogeneous — a mixture consisting of dissimilar elements or parts.

Food technology

One of the oldest applications of homogenization is in milk processing, to prevent or delay natural separation of cream from the rest of the emulsion. The fat in milk normally separates from the water and collects at the top. Homogenization breaks the fat into smaller sizes so it no longer separates, allowing the sale of non-separating 1%, 2%, and whole milk. This is accomplished by forcing the milk at high pressure through small orifices.

Another method of homogenization uses extruders, hammermills, or colloid mills to mill (grind) solids.

Sociology and history

In sociology and history, the term homogenization has largely negative meanings, indicating a drive towards uniformity, militarism, obedience and conformism. This is often superimposed forcibly by the state, but can also be the result of global economic forces (Conversi 2007). The term homogenization has a close relationship to Americanization.

Cell biology

Homogenization is a process that involves breaking apart cells — releasing organelles and cytoplasm. When the purpose is to extract organelles, it is frequently done in two steps; first using a blender to break the tissue up, and then with an ultrasonic or mechanical tissue disruptor. The organelles are then generally separated using differential centrifugation. Depending upon the subcellular fraction wanted, different processes are used to separate them. When the aim is to extract nucleic acids, the tissue is often ground in a mortar and pestle under liquid nitrogen.

Sometimes, however, a much milder procedure is followed, where the aim is to collect whole, intact cells. Homogenized cells must be kept at low temperatures to prevent autolysis and kept in an isotonic solution to prevent osmotic damage.

See also

• Pasteurization

References

Conversi, Daniele 2007 Homogenisation, nationalism and war: Should we still read Ernest Gellner?, Nations and Nationalism, Vol. 13, no 3, 2007, pp. 1–24

External links

• Homogenizing valve and Homogenizing effect - Interactive animated process
• Homogenization Concept The Dynamic High Pressure
• homogenization equipment with detailed description
• explanation of the technology along with theories on how the homogenization mechanism actually works.
• Homogenizing with Blades, Rotors and Pressure homogenizers.
• How Stuff Works - Homogenization and Pasteurization
• High Throughput Homogenization
• Eliminating Cross Contamination During Homogenization