Preserving the Future: The Science of Food Dehydration Dehydration is one of the world’s oldest methods of food preservation, with the principles of this process influencing some of the most modern methods of food science. Read on to discover the ancient history of dried foods. The ancient technique of dehydrating food Drying food in the sun has been going on since the beginning of recorded human history. All you need is direct sunlight for several days and a low-humidity Ancient techniques of dehydrating food, such as sun-drying and smoking, were used to preserve food for long periods by removing moisture and inhibiting bacterial growth. atmosphere of below 20%. How stuff works. “How dehydrated food works.” Accessed 2nd November 2019. Geography plays a crucial role in food preservation methods, which is why sun-dried foods are integral to certain cultures. Historical evidence indicates that Middle Eastern and Oriental cultures p...