Freeze-drying, sublimation, molecular or freeze-drying is one way to preserve perishable foods. The shelf life of such products is practically unlimited. The only condition is protection from moisture. Access to light must be gentle, that is, in order to preserve the color, they should be protected from direct sunlight.
What is sublimation
What does sublimated mean? This is the biological material from which water is extracted. The technological process is carried out as follows. Literally, according to the terminology of physicists, lyophilization is the transition of a substance from one state of aggregation to another, without an intermediate stage. The opposite of sublimation, desublimation, can be observed in nature in the form of frost and frost. As an example of sublimation in natural conditions, one can name the evaporation (sublimation) of elemental iodine, a liquid alcohol tincture of which is in every home first-aid kit. Iodine in nature exists only in two states - solid and gaseous, and does not occur in the liquid phase under normal conditions.
The Need for New Methods for the Preservation of Biological Materials
Initially, the need for long-term preservation of products arose among the military and among doctors. It was about preserving donated blood in the form of dry plasma. The creation and preservation of vaccines, sera and blood does not allow the addition of preservatives.
The development of the space industry for the life support of spacecraft required new discoveries in the ways of regenerating water from moisture-containing objects.
Sublimation of berries and other vegetable fruits of the earth
Freeze-dried or freeze-dried, what does it mean for berries, fruits and vegetables? The same as for all of the above. This is the transformation of a solid into a gaseous substance, bypassing the liquid phase. The process is expensive, because it requires a lot of energy. Fruits, vegetables and berries are more than half water. During sublimation in a vacuum chamber, it is completely removed, but first, the fruits are quickly, in shock mode, frozen to a temperature of -100 to -190 degrees Celsius. With a sharp freeze, the intracellular fluid turns into tiny crystals and does not break the cell membranes. During normal freezing, the liquid expands and violates the integrity of the space in which it is enclosed. Sublimated is a product freed from water, but retaining its useful substances and properties. Moreover, with such drying, it completely retains its shape, color and smell.
Characteristic features of molecular drying products
Freeze-dried berries - what is it and how do freeze-dried berries differ from those dried in the traditional way? The fact that they look the same on the outside as fresh. Due to the complete preservation of color and shape, they can be mistaken for synthetic, however, if they are lowered into a cup of water, they will absorb moisture within 10-15 minutes and become juicy, as if they had just been plucked from a bush. At the same time, no dye, preservative or flavoring was added to the product. The weight of the sublime, respectively, is several times less than that of a non-dehydrated product.
The disadvantages of this method of processing include very high energy costs. Firstly, this is the creation of a high vacuum, and secondly, the need for very careful initial processing.
Freeze-dried coffee
At the beginning of the last century, the technology for the production of instant and then freeze-dried coffee was invented.
Produced by sublimation, or freeze-dried coffee, what does this mean? This means coffee made from coffee extract that was first frozen and then dehydrated in a vacuum. Instant coffee is obtained from the extract by evaporation without freezing and without the use of vacuum. Sublimated coffee, or, as it is commonly called, “freeze dry”, is much more expensive than instant coffee. Subsequently, it was from sublimated that they began to make granular. Coffee lovers still prefer natural beans. The fact is that during sublimation or in the manufacture of instant coffee, it largely loses the aroma for which it is so valued. Initially, this technology for processing coffee beans was ordered for the needs of the American army, because in the trenches it is inconvenient to grind grains and brew a drink in a Turk. The need for a product that does not require complex preparation and improves tone was great.
So, freeze-dried coffee, what does that mean? This means that a drink made from beans processed by sublimation still gives vigor, but does not please with an authentic coffee aroma and is quite expensive, although the cheapest and most unpopular varieties are used to produce freeze-dried and instant coffee. The best coffee is sold in beans.
The use of sublimate in cooking
We can make an unambiguous conclusion that sublimated is a product that helps out in many situations and greatly facilitates the solution of many problems. From freeze-dried fruits and berries, you can cook a lot of different dishes. They can be used whole, or you can grind them in a blender and use the powder. They color and flavor creams and biscuits.
Whole berries are added to the filling for pies, to cereals, they are used to make healthy drinks. For example, tea with freeze-dried raspberries for colds is much more useful than jam or dried leaves of this plant. In our, Russian natural conditions, it is not so easy to preserve the berries picked in the season. We cannot dry in the sun, as they do in Central Asia - the temperature is not the same, and when cooking compotes or jams, as well as freezing in an ordinary refrigerator, most of the useful substances are lost.
Sublimated berries, fruits and vegetables are very good to use for baby food. They can be ground and introduced into the diet in small portions.
Sublimation - the solution to many problems
Freeze-dried products are suitable for the formation of a dietary table for a variety of diseases. After all, the same rutabagas or pumpkins cannot be found in stores in winter. And such berries as mulberry, honeysuckle, and many other inhabitants of the northern regions will never be able to try, because they are practically not transportable due to their delicate structure. All hope for lyophilization. The sublimated product is a real find for humanity, a gift of science for all people.
Before the phrase "Camping food" has become on a par with the words "pesticides", "domestos" and "mivina", let's quickly understand what the "sublimation process" is.
Vacuum freeze drying is an incredibly effective method of "preserving" products, which is divided into two parts:
- Quick freezing of the product
- Vacuum moisture removal
How does this happen? Instant freezing turns the water inside the cells into ice, and subsequent vacuum drying turns the ice immediately into steam, bypassing heat treatment.
Thus, the product is dehydrated by 95%, but at the same time does not lose color, and retains its beneficial properties and taste. During vacuum drying, the product becomes almost 10 times lighter than the original.
From the Editor:This technique was discovered and patented by the Russian scientist Georgy Vasilyevich Lappa-Starzhenetsky more than 100 years ago. A curious engineer, dismantling his vacuum unit, found a mummified cranberry, washed it and tasted it.
SUDDENLY, she appeared as fresh.
The discoverer was surprised and interested, in connection with which he continued experiments. It turned out that deep flash freezing can be applied to almost any product, be it vegetables, fruits, dairy or meat products.
Years passed before the sublimated method began to be widely used in medicine, the military sphere, astronautics and, in fact, outdoor activities.
What products can be sublimated?
Sublimation can be applied to any product:
- Fruits and vegetables
- Meat and fish
- Soups and cereals
- Mushrooms and any greens
- dairy products
Well, that is, everything that mere mortals usually eat ... Even if they are vegetarians, girls on a diet, or other space creatures.
Freeze-dried food today
Today, sublimates can be found in specialized outdoor stores, like ours, and in the USA and EU countries and in any large supermarket too.
From the Editor:Yes, yes, the phrase "sublimated products" is now found not only in astronauts' rations or polar explorers' backpacks.
Let's define the exact wording just in case:
Freeze-dried food - food subjected to vacuum-freeze drying.
From the Editor:Please note that between sublimation and conventional drying, the difference is the size of an abyss ... This abyss is called "heat treatment", which kills almost all the most useful things in food to death.
Today, freeze-dried products are an ideal meal for a weary traveler, which quickly satisfies hunger and saturates your body with natural beneficial micro and macro elements, vitamins, and generally yummy…
As Winnie the Pooh said: “You can’t break the diet!”
Let's see why we are sure that with sublimates you will be better on a hike / in a cave / on a mountain than without them?
Sublimated products are:
- Complete food unit
- Which weighs almost nothing
- Doesn't take up space
- Very nutritious
- Perfectly stored in any conditions, from -50 to +50
- Shelf life is usually several years
And, more importantly, freeze-dried foods cook very quickly.
All you need is to open the package, pour boiling water over the contents (the required amount of liquid is indicated on the package), move and wait 5-10 minutes.
The recovery time of a freeze-dried product depends on the temperature: the higher, the faster the sublimate ceases to look like cat food and begins to resemble, after all, the same “Paste with salmon”.
Bon appetit! Eat healthy food on vacation, in the mountains, at the office, on a fishing trip or a long journey without extra effort and time.
Another major advantage is the variety of dishes.
Have you ever eaten fondue on a mountainside while enjoying the starry sky? Pfff. Easily. Or like creme brulee in the middle of the desert? Any of your gastronomic fantasies is feasible, as even confectionery can be restored from a sublimated state. Blueberry soup or exotic in the form of Chili con carne will not leave anyone indifferent
Is it really edible?
Nutritionists say freeze-dried food is healthy and safe.
Firstly, sublimates are well absorbed. This means that for a long time there comes a feeling of satiety.
Secondly, since only high quality fresh products are sublimated, this food is rich in vitamins and microelements.
Thirdly, preservatives and dyes are completely absent in it, since there is absolutely no need.
What we have?
Personal experience of eating Trek'n'Eat products while sitting on a damp spot of sushi in the middle of the river, as it were, made it clear that this is the BEST way to eat something HOT and NUTRITIONAL QUICKLY and TASTY.
Now, even on simple trips, a backup menu is always grazing in a backpack and a bonus in the form of something unusual, like an omelette, fondue or blueberry soup.
Post Scriptum, or "What is a reasonable alternative to what?" as Les Poderevyansky said
All the advantages of freeze-dried food are somewhat supported by one single drawback. This is the price. In this regard, not everyone uses it in their travels, preferring the usual drying.
For a smaller price, we get food that is less, but still has the same number of advantages.
That is, it is light, but heavier than freeze-dried products ... not harmful, but not as useful as sublimates are useful ... and it is stored well, but not as well as freeze-dried ...
And it's not bad, but not too good for a long-term subsistence ...
Cooking food for a hike is one of the most important tasks, along with choosing the right equipment. To provide yourself and your friends with delicious, and most importantly, nutritious and healthy food, you need to purchase a full-fledged tourist food, and not a standard set of tins of canned meat. Experienced travelers prefer sets of freeze-dried products to canned food.
Perfect cargo, perfect food
Sublimates are really the best food for a hike. Directly in the process of preparation (sublimation), semi-finished products (for example, tomato paste or processed cheese) and even ready-made dishes (cereals, risotto, scrambled eggs, broth, jam, etc.) dehydrate extremely quickly at very low temperatures. After that, the powders or slices are dried and packaged in sealed bags or containers. The proposed range of products for a hike in the sublime category can surprise even skeptics.
Obvious advantages of sublimated products:
- impressive shelf life - without contact with air and moisture, sublimated products are stored for up to ten years (good news for those who can accidentally repeat the experience of Robinson or, in extreme cases, F. Konyukhov);
- ease of use - no special manipulations or additional heat treatment is required to prepare a complete meal - just add heated water. The manufacturer indicates the exact proportions on vacuum packaging;
- a varied menu - choosing a sublimated diet, you get full portions with the usual tastes and the ability to "mix" the ingredients at your discretion;
- a slight “gain” of equipment - it is quite simple to calculate the exact amount of food for a hike: you need to proceed from the basic energy needs in terms of physical activity (adjusted for the complexity of the route or sport). And if ordinary food for a week trip will need about 7 kg per person, the same amount of calories in terms of sublimates will weigh exactly seven times less - 1 kg!
The only negative is the higher price compared to the traditional "tourist breakfast" in the format of stew or "quick" noodles.
In our online store, you can order sublimated domestic products of excellent quality (Gala-Gala brand) at a cost commensurate with the energy value of dry rations.
Call and order! TC Turin offers a wide range of sublimates, as well as comprehensive assistance in choosing them.
You can fully rely on the impressive experience of our company, which has been cooperating for many years with leading manufacturers of professional equipment and related accessories for tourism and sports. Our catalog contains only proven high-quality goods available for order, pickup (within Moscow) or delivery throughout the Russian Federation. We value every client, we are focused on an individual approach and mutually beneficial cooperation.
Freeze Drying is based on the ability of ice to evaporate under certain conditions, bypassing the liquid phase. Freeze drying has the following advantages over traditional canning methods:- the need for refrigeration is eliminated, since dry products can be stored at positive temperatures for a long time;
- the mass of products after drying is significantly reduced, therefore, the costs of loading and unloading operations and transportation are reduced;
- the system of implementation is simplified and the terms of their implementation are lengthened;
- taste changes slightly.
- the presence of the main part of moisture in the product (at least 70%) in a solid state of aggregation;
- maintaining a sufficient difference in the partial pressure of water vapor and in the environment.
During the drying process, energy must be continuously supplied to the vaporization zone in an amount sufficient to compensate for the heat of phase transformation. The supply of heat to the vaporization zone becomes more complicated as this zone moves deeper into the product. The resulting layer of dried product resists both the transfer of steam from the vaporization zone to the surface of the product and the transfer of heat from the outside to the vaporization zone.
Currently, the range of products obtained by freeze-drying is quite diverse and can be divided into several groups.
Meat and meat products: beef, lamb, pork, poultry and others are processed raw, pre-cooked or cooked in other ways.
- Dairy products: cottage cheese, milk, etc.
- Egg products: egg white, egg yolk, mixture of protein and
- Vegetables: potatoes, carrots, beets, various types of cabbage, parsley, green peas, zucchini, onions, mushrooms, vegetable first and second courses, etc. - both raw and pre-cooked
- Fruits, berries and products of their processing: apples, apricots, peaches, plums, bananas, strawberries, raspberries, fruit puree, fruit juices, etc.
- Instant tea, coffee, spices.
- The entire technological process for obtaining sublimated products consists of the following main operations:
- selection and preliminary processing of raw materials;
- freezing;
- freeze drying;
- dried food packaging.
The nature and quantitative ratio of the substances that make up the dry residue of the product predetermine the conditions for its drying and subsequent storage. Thus, the temperature of natural products of animal origin at the stage of removing residual moisture should be such that significant denaturation changes in protein substances do not occur during the drying process. The possibility of oxidation of fats, some vitamins and other components of food products determines the need to isolate most dry products from air during storage. The level of reducing substances in products determines the amount of water that should be removed during the drying process to prevent the development of saccharoamine reactions during storage of a dry product. It is also necessary to take into account the bacterial contamination of food products supplied for freeze-drying.
Thus, when selecting raw materials and determining the conditions for its pre-treatment, attention is paid to the following main factors:
- high biological value and optimal organoleptic characteristics;
- the maximum degree of preservation of the structure and initial state of the constituent components (proteins, lipids, vitamins, pigments, volatile substances) during freezing, drying and subsequent storage;
- optimal size and shape;
- low level of lipid fraction oxidation;
- low bacterial load.
The freezing process as the first stage of freeze-drying significantly affects the quality of products, and rapid freezing contributes to the maximum preservation of the original properties of most food products.
Food products, depending on their composition and properties, are frozen in special chambers at atmospheric pressure or directly in a sublimator due to the intensive evaporation of part of the moisture as a result of a continuously increasing vacuum. At the same time, vacuum freezing is unacceptable for freeze-drying of raw meat and fish in pieces, fruit juices, purees, some types of berries and fruits, since this significantly changes the physicochemical and structural properties.
When freezing pasty products (milk, tea, juices, etc.), their subsequent grinding is provided under conditions of negative temperatures. Therefore, it is quite effective to freeze liquid materials in a pulverized state, followed by drying the frozen granules in a thin layer.
When freezing products in special quick freezers, the technological process should be organized so that the product does not thaw before the start of sublimation.
When carrying out the actual freeze-drying to obtain a high-quality product, it is necessary to remove 75-90% of moisture at a negative temperature in the central zone of the product. The rest of the most firmly bound moisture is removed at positive temperatures. The allowable temperature level of the product during the period of sublimation and removal of residual moisture is determined by its properties and the duration of the drying process. Sufficiently high quality food products can be obtained at moderately low sublimation temperatures - from -10 to -30°C. So, when drying most vegetables, a sufficient sublimation temperature is at the level of -10 ° C. When drying berry and fruit juices, due to their high sugar content, the sublimation zone must be maintained at a temperature of -20 to -30°C. The temperature of products of animal origin during the period of sublimation of moisture should not be higher than -15 -20 ° C. The duration of this drying period is 50-60% of the total drying time, and the amount of moisture removed is 40-50%.
At the stage of removing residual moisture, the most important factors that ensure the high quality of the product are the duration of exposure to elevated temperature and its maximum value. For each type of food there is a temperature limit of resistance to heat. Within this temperature limit, optimal ratios of product temperature and heating duration can be selected, at which the duration of the drying process will be the shortest with minimal changes in the product. So, depending on the properties of the product and the duration of the drying process, the permissible level of material temperatures during the removal of residual moisture is in the range from 40 to 80°C. The duration of this period is 30-40%, and the amount of moisture removed is 20-30% of its total amount.
Evaluation of the nutritional value of freeze-dried products in terms of organoleptic, physico-chemical indicators, the degree of digestibility and assimilation shows their slight differences from the original products. At the same time, polyunsaturated fatty acids, essential amino acids, vitamins, minerals and other important indicators of the nutritional value of products are quite well preserved. The aroma and taste inherent in the products are also well preserved. At the same time, freeze-dried products have a porous structure and therefore have a high absorption capacity. Dehydrated products of animal and vegetable origin intensively absorb oxygen from the environment, and especially intensively during the initial period of storage. The absorption of gaseous oxygen can lead to the intensive development of oxidative processes, resulting in a decrease in organoleptic characteristics and nutritional value of products.
In addition, freeze-dried products actively adsorb moisture from the environment, which stimulates the development of browning reactions, leading to a decrease in product quality during storage. The adsorption capacity of a product can be reduced by pressing it before packaging. The pressing process must be carried out under conditions that exclude the contact of the product with atmospheric oxygen. Pressing the dried products also makes it possible to increase their bulk density and tare utilization.
Sublimated products must be hermetically sealed immediately upon receipt. Packaging must isolate the product from atmospheric oxygen and light, prevent moisture sorption by the dried product from the environment, protect against mechanical damage, protect against the loss of natural odor and the acquisition of strangers. The most suitable container for these purposes is made of polymeric materials, the main advantages of which are relatively high barrier properties, low weight and rigidity, good appearance, and low cost. The most optimal option in this case are polymer materials based on aluminum foil cached with polymer films. Products should be packaged immediately after drying under reduced oxygen and moisture conditions.
Oxygen is removed from the package by various methods: physical, chemical or biochemical. Of the physical methods in production practice, the most widely used is a single evacuation of a package followed by the introduction of nitrogen into it. Quite effective chemical methods include the removal of oxygen from the package as a result of the reaction of its interaction with hydrogen, proceeding with the participation of a catalyst, which is used as palladium. It is also possible to pack products in special sealed chambers with inert gas, where this is controlled by a microprocessor.
It is now generally accepted that some changes in the properties of the feedstock occur during the freeze-drying process, but these are minimal compared to changes during preservation by other methods.
Sublimation- This is a completely new direction in nutrition. Nutritionists believe that freeze-dried food is digested before reaching the stomach. You fill up with such food very quickly and even after a glass of a cocktail from a mixture of different juices for several hours you feel absolutely cheerful and full. It is curious that the sublimation method itself was developed by the Russian engineer La pas Starzhinetsky more than 100 years ago, in 1904. However, as often happens, it received real recognition, and then wide distribution, not in its homeland, but in America, and much later. In the middle of the XX century.
What is the sublimation process itself? First, it is a deep freeze of products, and any: meat, cottage cheese, butter, vegetables, fruits. Further, in vacuum dryers, moisture is frozen out, which is why the product, without losing its natural taste, becomes almost weightless - ten times lighter than the original one, and its moisture content does not exceed 8%. Freeze-dried food is the perfect option for those who are always on the go. Since such products are stored for a long time and quickly prepared: poured water - and order. The recovery time depends on the temperature: the higher, the faster. Keep in mind that the products retain their taste, color and all their beneficial properties. They do not contain any preservatives or dyes, which is very important for allergy sufferers. And this is their main difference from other fast food products, that is, fast food.
A refrigerator is not needed to store freeze-dried products. They are packaged in a special three-layer material based on aluminum foil, inside - gaseous nitrogen. At the same time, the shelf life, for example, of freeze-dried fruits, berries and vegetables is 2 years, dairy products - 13 months. In America, similar packages can be bought at any major supermarket. We see them much less frequently. Various fruits and berries of about 20 species, including cranberries, peaches, blueberries, lingonberries, quince, apples, strawberries, cherry plums, apricots, black and red currants, plums ...
There are also many vegetables: potatoes, zucchini, tomatoes, carrots, beets, cabbage, onions, peppers, etc. Freeze-dried dairy products - cottage cheese, butter, sour cream, cheese, curdled milk, kefir, are in great demand among buyers who care about their health, yogurt.
The first in the list of freeze-dried products is ... ordinary beetroot juice. Why exactly him? This juice is considered the most useful. And in sublimated form it becomes a real medicine: it prevents the formation of blood clots in the vessels, treats thyroid diseases, restores the intestinal microflora, and increases the body's defenses. If our Olympians leaned on beets, not a single doping control could find fault with their high hemoglobin. Saturating the body with oxygen, having powerful bactericidal and antioxidant properties, red beetroot is useful for absolutely everyone - it relieves children of allergies, helps women easily endure critical days, and makes men real machos. Eat beets as often as possible, it removes radiation and heavy metal salts from the body.
Do you know people who drink beetroot juice regularly? Probably not. The reason is simple - 99% of people simply do not perceive freshly squeezed beetroot juice, it is tasteless. But with sublimated beetroot juice, real miracles happen - after freezing out the moisture in a vacuum chamber, it suddenly becomes very pleasant to the taste. You dissolve a spoon or two of beetroot powder in a glass of water, any juice or kefir - and drink to your health. And after a glass of such juice, you don’t want to eat for several hours.
Yes, if only beets. Celery juice? Parsley? What about nettle? Any of these herbs is a real storehouse of vitamins. According to popular wisdom, a handful of parsley is equal to a handful of gold - it is so rich in vitamins and minerals. Since ancient times, parsley has been used for a general decline in strength, for diseases of the cardiovascular and genitourinary systems, and for diabetes mellitus. The property of parsley to remove toxic substances from the body has always been used for intoxication of the body. Do you want to keep your eyesight? Eat more parsley. And it is better - drink sublimated juice. One spoonful of freeze-dried parsley contains the properties of a whole armful of this wonderful herb.
You will never have ulcers and other stomach diseases if you drink sublimated white cabbage juice as a preventive measure. In addition to ulcers, it easily copes with overweight, bad cholesterol, diseases of the respiratory system, heart and blood vessels. Cabbage provides the body with essential minerals and almost all essential vitamins, and it contains as much vitamin C as oranges and lemons. Cabbage juice is very useful for diabetic patients, and probably everyone knows that it can quickly relieve a hangover syndrome.
No less useful is celery juice mixed with other juices, such as carrot, beet and cabbage. And celery is also called “male grass”, so clearly it contributes to the growth of male power. Celery lovers never have prostatitis.
Nettle juice was a real discovery. Now sublimated nettle can be used all year round, and not only in fragrant green soup, salads, mashed potatoes, but also in vitamin cocktails. Beta-carotene in it is 2 times more than in carrots, and vitamin C is 3 times more than in lemon.
IN TUBE AND TABLETS
- The convenient form in which sublimated products are produced is only one of their advantages.
- According to nutritionists, the list of freeze-dried products can be expanded indefinitely.
- Do not confuse freeze-dried products with dietary supplements (biologically active additives). These are not additives, but food products that have a healing, preventive, restorative and even therapeutic effect.
- Vitamins and other useful substances are ideally absorbed from sublimated products.
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