Food drying is one of the oldest method of preserving food. In ancient times the sun and the wind would have naturally way dried foods. Evidence shows that Middle East and Oriental cultures actively dried foods in the hot sun: fish, meat, vegetable and fruits were also dried from the earliest times. Also Romans were used to dried vegetables and herbs, also using a special techniques if the areas – where they lived – haven’t enough sunlight for drying.

What is food dehydration technique

Drying basically dehydrates or removes the moisture from the food and this simple action inhibits the growth of bacteria, mold and yeast. Moreover, it slows down the enzyme action without deactivating them. These factors ensure that food does not spoil easily and hence, makes drying an effective food preservation technique.

A factor that helps with drying food is humidity. Since drying involves extracting the moisture from the food items and expelling it into the surrounding air, low humidity will help with the drying process. If the humidity is high, drying will be slower simply because the surrounding air would also be laden with moisture. By increasing the currents or flow of air, one can speed up the drying process.

Since drying reduces the moisture in foods making them lightweight and convenient to store, it can easily be used in place of other food preservation techniques. In fact, one can even use drying along with other food preservation techniques such as freezing or canning, which would make the process of food preservation even better. Moreover, dried foods are good sources of quick energy and wholesome nutrition, since the only thing lost during preservation is moisture.

Many different foods can be prepared by dehydration. Meat has held a historically significant role: for centuries much of the European diet depended on dried meat, also it formed the main protein source for the slaves on the West Indian plantations. Currently popular dried meats include raw ham and bresaola.

Also vegetable, fruits and mushrooms can be dried: fruits are easier to dry than vegetables because moisture evaporates wore easily, and not as much moisture must be removed for the product to keep. Ripe apples, berries, cherries, peaches, apricots, and pears are practical to dry. Vegetables practical to dry include peas, corn, peppers, zucchini, okra, onions, and green beans. Certain foods are not suitable for drying because of their high moisture content: lettuce, melons, and cucumbers are kind of foods that do not dry well.

A special form of dehydration is the Freeze-drying, a process typically used to preserve a perishable material or make the material more convenient for transport. Freeze-drying works by freezing the material and then reducing the surrounding pressure to allow the frozen water in the material to sublimate directly from the solid phase to the gas phase. We’ll going to talk about the freeze-drying on the next post!

Source: http://www.partselect.com/JustForFun/Preserving-Food-by-Drying.aspx

Definition of freeze-drying: https://en.wikipedia.org/wiki/Freeze-drying