Dehydration of food is a very common method. This method is used for drying the moisture content in the food products. Because this moisture content helps the microorganisms to grow. Such microorganisms spoil the food. Sun drying is a very basic method of dehydration. But there are also many artificial methods of drying. Hot air is also used to dry the food products. dehydration process is commonly used for fruits, salad, vegetable, in pickle preparation etc.