Freeze-dried and desiccated are both terms that describe the process of drying food so that it can be preserved. Freeze-dried foods are made by freezing a food item, and then removing any water from the frozen product. Desiccation is the process of removing water from food products by exposing them to heat or dry air. The difference between freeze-dried and desiccated is subtle but important: Freeze-dried foods are more nutritious than those that have been desiccated because they don't lose their nutrients through the heat-drying process.