A whole potato, sliced pieces (right), and dried sliced pieces (left)

Drying is a method of food preservation that works by removing water from the food, which prevents the growth of microorganisms and decay. Drying food using the sun and wind to prevent spoilage has been known since ancient times. Water is usually removed by evaporation (air drying, sun drying, smoking or wind drying) but, in the case of freeze-drying, food is first frozen and then water is removed by sublimation.

Bacteria and micro-organisms within the food and from the air need the water in the food to grow. Drying effectively prevents them from surviving in the food. It also creates a hard outer-layer, helping to stop micro-organisms from entering the food.

[edit] Food types

A collection of dried mushrooms.

Many different foods are prepared by dehydration. Good examples are meat such as prosciutto (a.k.a. Parma ham), bresaola, and beef jerky. Dried and salted reindeer meat is a traditional Sami food. First the meat is soaked / pickled in saltwater for a couple of days to guarantee the conservation of the meat. Then the meat is dried in the sun in spring when the air temperature is below zero. The dried meat can be further processed to make soup.

Fruits change character completely^{[clarification needed]} when dried: the plum becomes a prune, the grape a raisin; figs and dates are also transformed.

Drying is rarely used for vegetables for use in the household, however dehydrated vegetables are often found in commercially packaged meals as well as meals made for backpackers^[1], hunters, military, etc. The exception to this rule are bulbs, such as garlic and onion, which are often dried. Also chilis are frequently dried. Edible and psilocybin mushrooms, as well as other fungi, are also sometimes dried for preservation purposes, to affect the potency of chemical components, or so they can be used as seasonings.

For centuries, much of the European diet depended on dried cod, known as salt cod or bacalhau (with salt) or stockfish (without). It formed the main protein source for the slaves on the West Indian plantations, and was a major economic force within the triangular trade. Dried shark meat, known as Hákarl, is a delicacy in Iceland.

[edit] Methods

There are many different methods for drying, each with their own advantages for particular applications; these include:

• Bed dryers
• Fluidized bed dryers
• Freeze Drying
• Shelf dryers
• Spray drying
• Sunlight
• Commercial food dehydrators
• Household oven

[edit] See also

• Dried fruit
• Meat extract
• Bouillon cube
• Instant soup
• Instant noodles

[edit] References

[edit] External links