The standard method of dehydrating vegetables and spices is to place the items on a conveyor belt and run them through an oven at a high temperature for a relatively short time. Between 90% and 95% of the moisture is removed.
Some vegetables are more suited to this form of drying than others. This means that with the addition of water, the product reconstitutes back to its original state more easily. Preferable items include: onions, bell peppers, tomatoes, celery, carrots and mushrooms. Dehydrated items such as peas, corn and green beans do not reconstitute as well as freeze-dried.