Techniques for food preservation have been
used since prehistoric times. Freeze-drying food items was
first introduced in 1919, but did not come into more comprehensive
industrial use until the 1960s, for example, for
instant coffee, soups, dressings, etc. Dried foods have features
of importance for touristic expeditions to places with an
insufficient local food supply, for example, in the wilderness,
arctic areas, and in connection with sea travel. It is
lighter to carry than food that contains liquid substances.
Drying does not violently heat food, and therefore it saves
many of the nutrients. Dried foods can be reconstituted by
adding water or can often simply be consumed dry