LYOPHILIZATION – IN SPACE AND ON EARTH

Lyophilization

Quite a complex technological process of drying products, in which moisture is removed from the frozen product in a vacuum, bypassing the liquefaction process on complex and expensive sublimation machines …

Lyophilization (or sublimation )Is a dehydration process (drying) products by quick freezing in a vacuum, where moisture evaporates, bypassing the liquid phase, and goes into a gaseous state.
Substances are freed from water (or other carrier – solvent) by turning this liquid (along with the product of course) in solid form, by freezing, and water (during lyophilization) turns into steam, when a vacuum is applied to the frozen material, these vapors are removed from the air above the frozen material, without heat.

Essentially: as you know, matter has three states: liquid, solid state, steam. (we do not take plasma into account), under the influence of heat (temperatures) these states are transformed.
Exists “Triple point” with a certain temperature and pressure, in which liquid (water or other solvent carrier) are simultaneously in three states (solid, liquid and vapor) in balance with all their physical states.

For example: water at temperature: 0,01° С and steam pressure 611,73 Pa will move to a point of equilibrium with all three physical states. And (the principle of lyophilization) with a slight decrease in temperature and pressure (or increasing the vacuum) – water turns into steam without turning into a liquid state.

Freeze-dried products are not heat-treated, which is very important for proteins and other unstable substances, eg: drugs, such, like antibodies, semi-synthetic penicillins containing immunological preparations, cephalosporins, serum.

At low temperatures, gradual, very gentle drying, the product does not lose useful properties and taste, and upon rehydration, the appearance restores its original properties!
The sublimation process begins at low temperatures from -70 ° C to -1 ° C. And the raw material is frozen to -40 ° С -70 ° С.
Lyophilization process (sublimation) flows, conditionally, in three steps:
1) Freezing, below temperature, the same triple point of matter, which you already know about. Moreover, the type of freezing is very individual for each substance. – freezing should not destroy the product cells with ice crystals.
2) Then the process takes place in a vacuum., which brings matter closer to its triple point.
Primary drying. Water (or solvent carrier) begins to evaporate and re-solidify on the cold condensation plates of the sublimator at low temperatures. At this stage, about 95% moisture. 3) Secondary drying aims to remove non-frozen water molecules. This is the process of gently heating food (smooth heating), the maximum temperature at the edges can be positive.

Sublimation allows you to preserve all the nutrients of the product, his smell, taste, and also the color, peptide bonds in cells.
Lyophilized products differ in their long shelf life – up to 25 years! Virtually any temperature condition: from -50C to + 50C.
The weight of freeze-dried products may decrease by 100 time (for example: when lyophilizing liquid snail mucus) !

Lyophilized street slime, Mucus pro quality   Freeze-dried snail caviar for dietary supplements MUC IN, quality Mucus pro

In the photo: lyophilized snail mucus Helix aspersa and freeze-dried snail roe from Mucus pro

Any product of animal or vegetable origin or semi-synthetic can be converted into a sublimate, be it dairy products, microorganisms (bacteria, yeast), vaccines and antitoxins, biological reagents and strains, enzymes and vitamins, proteins, fats, blood, protein organisms and substances, oils, fruit, the seeds, plants and their juices.

An additional lyophilization product can be a hydrolate of the sublimated substance.

It is impossible to make a sublimate at home.. Freeze-drying or lyophilization is the industrial drying of products and substances, this requires powerful refrigeration units, and special expensive sublimation machines, in which vacuum and gentle heating of raw materials will be created.

Lyophilization is the most expensive and energy-intensive type of food drying., certainly applicable for especially valuable products and substances, unstable to heat, in which you need to save all properties and elements, and sometimes tissue structure and peptide bonds.
The price of a freeze-dried product is much higher than the price of raw materials, and the freeze drying itself takes from several hours to several days.
The term “lyophilization” – Greek origin (“dissolve (dry) with love”) not too common, more often use “Sublimation”.

Bulova Freeze-dry   

Freeze-dryer “Bulova” on the picture.

The phenomenon of the transition of ice to steam was invented in 1906 year Jacques-Arcier d’Arssoval (electrophysicist) and his assistant Frédéric Bordas at the Biophysics Laboratory of the Collège de France in Paris. IN 1911 Downey Harris and Shackle, employed in the Physiology Laboratory at St. Louis University, developed a freeze-drying method to preserve the rabies virus (this work eventually led to the development of the first rabies vaccine). And already in the USA it was used in the first half of the XX century in the food industry. The first food, which was prepared by sublimation method – there was freeze-dried coffee.

Freeze-drying process was developed as a commercial method, which made it possible to make the whey chemically stable and viable without the need for cooling. Shortly thereafter, cryodessication was applied to penicillin and recognized as an important technique for preserving biological substances.. Since that time, lyophilization began to be used as a method of conservation. Interesting fact: using lyophilization to restore documents, damaged by water.

However, NASA has made freeze drying food – truly space, this method is used to prepare space food for astronauts.
And the most famous space freeze-dried product is freeze-dried on Earth space ice cream, made using a freeze-drying method for astronauts. This is a regular ice cream, from which most of the water (and oxygen) is removed during the freeze-drying process.
By the way, ice cream, specially developed by Whirlpool Corporation for the NASA Apollo program back in 1985, has not been in space, but has become a popular space product on Earth.

 

Freeze dryers Bulova

This is cosmically delicious! And a bonus from Bulova, company – all customers and guests of the company will definitely try ice cream that does not melt and but served chilled.

The Bulova company produces freeze dryers with a capacity of 2.5 kg, 12 kg and 400 kg. We can make an experimental drying of your products and substances, draw up a technological scheme for the sublimation of products.

  iophilized snail mucus Mucus pro

In the photo: freeze-dried snail meat Helix aspersa and liophilized snail slime at the production of Mucus pro

Leave a Reply