Monthly Archive: September 2014

Freeze dry

At Earth’s surface, escape velocity (the speed needed to leave our planet) is about 11.2 km/s, more than 40 thousand km/h. Many science fiction writers came up with systems could transport personnel and equipment directly from Earth into space without rocket propulsion. Well-known writers such as Arthur C. Clarke and Frank Shätzing have written about the space elevator – whose complex implementation has been an object of study for space agencies. Once built, the economic return of a space elevator would be obvious: reduced transportation costs and the possibility of launching satellites and shuttles simply using centrifugal force. At the moment, to reduce costs we minimise the load carried into orbit.

In the case of space food, a good solution is freeze-drying, which allows us to maintain colour, taste and texture of products that return almost unchanged, after adding water. In particular, Argotec  hose this technique for two reasons. With a shelf-life of over two years at room temperature freeze-dried food can be kept much longer than using simple dehydration techniques. Secondly freeze-drying respects the characteristics of food and nutritional values. Lyophilisation – or freeze drying – is carried out in a vacuum. Foods are frozen quickly at –30, -40 ° C, then pressure is reduced to the point where water in the food sublimates (switching a from solid ice to steam) by heating it to a temperature of 30° C. Stefano Polato, the head of the Space Food Lab at Argotec, explains: “early attempts at freeze-drying

were done to cater for astronauts but this technique is now used on Earth as it holds a number of advantages for big food companies, especially in terms of convenience in storage and healthiness. For Samantha’s products, Argotec has reduced the mass of her bonus food by more than half compared to the initial water content. Several foods can be freeze-dried, for example natural products such as raspberries (link to the post on avamposto42). Other products must be processed before freeze-drying as is often the case for fruits and vegetables. It can be necessary to add sugar or maltodextrin to avoid insoluble lumps that do not rehydrate after adding water. Argotec selected the best natural products, without any additives, for Samantha’s mission.

Antonio Pilello, Argotec

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