Mini chamber for storing vegetables and fruits. Refrigeration equipment

Among food products, fresh fruits and vegetables occupy a special place as storage objects. This is primarily due to the fact that complex life processes occur with them, which do not stop at all stages of their storage: on the road, in storage, at home. There are some general patterns that determine the relationship between the preservation of fresh fruits and vegetables with conditions environment... Reasonable regulation to reduce wastage and maintain the quality of fruits and vegetables right up to consumption is at the heart of the work refrigeration equipment (chambers and other installations) for storing vegetables and fruits.

Processes in fruits and vegetables during storage

During storage in fruits and vegetables, various physical and physiological-biochemical processes take place, which have a significant impact on their quality and preservation. These processes are closely related and depend on natural properties fruits and vegetables, the presence of damage, maturity, quality of commodity processing, storage regime and other factors. To a large extent, storage processes are a continuation of the processes occurring in fruits and vegetables during their growth.

But there is also a fundamental difference between them: during growth, along with the decay of organic substances in fruits and vegetables, the synthesis of these substances is carried out, and in the stored objects, their decay and consumption occurs mainly with the release of energy necessary for the vital activity of cells.

Physical processes

The main physical processes occurring in fruits and vegetables when stored in, are moisture evaporation, heat generation, temperature change. The physical process of water evaporation depends on the degree of hydrophilicity of colloids, the anatomical structure and state of the integumentary tissues (thickness and density of the skin, the presence of a wax deposit), the nature and degree of damage, humidity of the surrounding atmosphere, air velocity, storage temperature, degree of maturity, packaging, timing and ways of storing fruits and vegetables and other factors, including the intensity of aerobic respiration, during which water is also formed.

The release of moisture by fruits and vegetables is different in different periods of storage; at the beginning of storage, active evaporation of water is usually observed (post-harvest ripening period), in the middle period it decreases, and at the end of storage it rises again due to the approach of a new growing season. Overripening of fruits is accompanied by increased moisture yield, since as colloids age, their hydrophilicity decreases. Both low humidity and high air temperature increase the evaporation of water. However, in most cases, in practice, wilting of fruits and vegetables is observed, especially at low air humidity and increased ventilation.

Long-term storage of most vegetables and fruits in refrigerators and other equipment at low temperatures, close to 0 ° C, it reduces the intensity of intracellular metabolism, slows down the processes of ripening and overripening, reduces the consumption of reserve substances for respiration, as well as the activity of microorganisms. But the drop in temperature cannot be arbitrary, since at certain low temperatures, fresh fruits and vegetables freeze and may die. The temperature level of the refrigerator compartment should be somewhere close to the freezing point of the tissues of fruits and vegetables. The freezing point of many fruits and vegetables is mainly correlated with their dry matter content and ranges from -1 to -2.5 ° C.

So, the average freezing point:

Potatoes -1.2 ° C;
White cabbage -1.6 ° C;
Carrots and beets -1.6 ° C;
Turnip onions -1.78 ° C;
Apples -2 ° C;
Grapes -3.8 ° C;
Cherries -3.5 ° C.

The freezing process of fruits and vegetables placed in an environment with a negative temperature (below 0 ° C) has some general tendencies. At first, the temperature in fruits and vegetables drops below freezing point, but for some time ice crystals have not yet formed. The so-called tissue hypothermia occurs. In this case, the water of the cell solution freezes.

When water passes into ice, latent heat is released, and the temperature of the tissues immediately rises, reaching a certain higher point (usually up to -0.7, -1.8 ° C), which it holds for some time, and then begins to decrease again. This high point, about which the hypothermia temperature rises, is called the freezing point. It is quite obvious that when storing fresh fruits and vegetables, they should not be allowed to freeze, which leads to the destruction of the tissue structure of the products and, as a result, restrictions on their use.

Breathing fruits and vegetables

The breathing process is the main form of interaction with the environment. Breathing objectively reflects the state of fruits and vegetables during a given period of storage. The biological role of respiration is to provide the living tissues of fruits and vegetables with the energy necessary for their vital activity. In the process of breathing, the energy is released, accumulated by fruits and vegetables during their growth and formation in the form of various plastic substances. The consumption of these substances in respiration, along with the evaporation of moisture, is inevitably accompanied by a decrease in the mass of fruits and vegetables, therefore such losses are called natural. They can be reduced by regulating the intensity of respiration and evaporation of moisture, which is of practical importance.

Optimal storage of fruits and vegetables

The conditions under which the quality of fruits and vegetables is maintained in the best condition, and the processes occurring in them, are carried out normally, are called optimal. For every kind and even a separate variety fruits and vegetables exist optimal conditions storage. The storage mode includes the following important factors: temperature, air humidity, air exchange, gas composition and light. The storage temperature for most fruits and vegetables should be around 0 ° C. At low temperatures, the respiration energy of fruits and vegetables is noticeably reduced, and therefore, the consumption of organic matter decreases and moisture loss decreases; in addition, at 0 ° C, the activity of microorganisms is significantly weakened. But this does not mean that you can create an arbitrarily low temperature; the storage temperature level is usually somewhere close to the border, but above the freezing point of tissues.

However, fruits such as lemons, tangerines, bananas, pineapples, potatoes are stored at a temperature significantly higher than the freezing point; bananas - at temperatures from 12 to 16 ° С, and the freezing temperature of their tissues is about -2 ° С. Air humidity significantly affects the preservation of fruits and vegetables. Since fruits and vegetables contain a lot of water, it would be better to store them at an air humidity close to 100%. However, very high air humidity is favorable for the development of microorganisms, and therefore fruits and vegetables have to be stored in refrigeration equipment at relative humidity air in the range from 70 to 95%.

Only vegetable greens, which have a short shelf life, can be stored at a humidity of 97-100% (by continuously spraying it with water). Evaporation of even a small amount of water, about 6-8%, causes their wilting. Therefore, the optimum humidity should be high enough (85-95%). However, some vegetables (onions, garlic) are stored at low air humidity (70-80%). The source of moisture in the storage facilities is the fruits and vegetables themselves, which release moisture into the atmosphere as a result of evaporation and aerobic respiration, as well as air supplied from the outside and some artificial sources (barrels of water, wet tarpaulin, snow brought into the storage facility). Air exchange means ventilation and circulation.

Ventilation is the flow of air into the storage from the outside; circulation - the movement of air inside the store around fruits and vegetables (i.e. internal exchange). Ventilation is necessary to create a certain temperature, humidity and gas composition of the air in the warehouse. Storing fruits and vegetables in warehouses can build up excessive heat and moisture. In addition to breathing and evaporation, sources of heat and moisture are also the soil in some warehouses and the heat released during condensation of moisture as a result of the contact of warm air with a cold roof.

Distinguish between natural ventilation and forced, or mechanical, which also includes active ventilation.

Natural ventilation

Natural ventilation acts according to the law of thermal convection. The air in the mass of potatoes, vegetables and fruits, warming up due to heat release during breathing, expands, becomes easier and, together with water vapor, moves upward and is removed through chimneys or shafts, and cold air, being denser and heavier, penetrates into the storage through supply pipes, doors, hatches, windows and channels. The speed of air movement, and, consequently, the efficiency of ventilation, is the greater, the higher the difference between the temperatures of the outgoing and incoming air and the greater the distance in height between the exhaust pipes or shaft and the inlet.

Forced ventilation

Forced ventilation , carried out with the help of electric fans, including through the mass of products using the method of active ventilation, allows you to regulate the temperature and humidity in large storage facilities more flexibly at a high loading height and more efficiently, taking into account the type of stored products. At the same time, the storage capacity is used more economically, losses are reduced, and the shelf life of vegetables and fruits is lengthened.

Active ventilation

Active ventilation, in essence, means enhanced uniform periodic ventilation (blowing) of the mass of potatoes and vegetables from bottom to top with air at a certain temperature, humidity and speed. In this case, the outside air can be supplied directly to the mass of products, bypassing the storage air, or by mixing them in moderately cold weather (partial recirculation); at very low outdoor air temperatures, ventilation can only be carried out with the storage air (complete recirculation) or by partial mixing of outdoor air, but so that the required temperature of the mixture is maintained.

Special heating of the air to the optimum temperature and humidity or artificial cooling and supply of conditioned air through the ducts can also be used. In addition to temperature, humidity and air exchange, an important factor in the storage regime of fruits and vegetables is the composition of the gaseous environment of the surrounding air, or rather, the content of carbon dioxide, oxygen and nitrogen in it. Light also affects the intensity of enzymatic processes. In the light, for example, the germination of potatoes is enhanced. In addition, the light promotes greening of the tubers and an increase in the solanine content in them. Therefore, fruits and vegetables are usually stored in the dark.

Refrigeration equipment for storing fruits and vegetables.

The company HolodSpetsStroy is engaged in the design and construction of industrial chambers for storing vegetables and fruits using new technologies - we try to maximize the shelf life of "live" goods. To maintain quality and nutritional value fruits and vegetables, we equip the storage facilities with specialized refrigeration equipment.

Vegetable storage

You can order the construction of vegetable stores from us, as ready-made solutions and individually selected for your needs using modern high-quality equipment, which we will specially select for you.

During the development process, all factors affecting the quality of the freshly harvested crop will be taken into account.

The building of the vegetable store is designed depending on the method of storage of products - in bulk or in containers. Any is a complex, responsible process, therefore, it is necessary to entrust the work to experienced specialists and our company always performs the work with high quality.

During the construction of both fruit storage and vegetable storage, another important factor is taken into account - the creation of a favorable microclimate during storage. For this, it is necessary to provide for a ventilation and artificial cold system, select refrigeration equipment with a microclimate control function.

Fruit storage

In the fruit storage that we are planning, you can store apples for up to 12 months, pears for up to 8 months, grapes for up to six months. Our facilities can rightfully be called the latest word in science and technology in the storage of fruits and vegetables. The products are passed through a conveyor, sorted by size, quality and cleaned.

There are 3 types of controlled atmosphere (gaseous environment):

Traditional Controlled Atmosphere - oxygen content 3-4%, and CO2 - 3-5%.
Low oxygen content LO (Low Oxygen) - 2-2.5% oxygen and 1-3% CO2.
Ultra Low Oxygen (ULO). The O2 content in the chamber is less than 1-1.5%, the carbon dioxide content is 0-2%.

We possess various technologies for storing vegetables and fruits in a controlled atmosphere:

The technology for the rapid reduction of oxygen concentration is called RCA (Rapid Controlled Atmosphere) - when the chamber is loaded, the O2 concentration decreases to 2.5-3% in 1-3 days. The so-called ultra-rapid reduction of the oxygen level ILOS (Initial Low Oxygen Stress) occurs in the chamber in a short period of time. In practice, the technology is implemented simultaneously ULO + ILOS for storage the best varieties apples. The oxygen content decreases from 21% to 5% within 8-10 hours from the moment of loading. The composition of the atmosphere is kept at the level of 0.9% - oxygen and 1.2% - carbon dioxide. The atmosphere is controlled by a computerized control system. After 7 months of storage, you can achieve better results on preservation of products in comparison with a traditional atmosphere in a fruit storage.

LECA (Low Ethylene Controlled Atmosphere) is a technology where the ethylene level in the chamber is reduced using a catalytic ethylene converter.

For the design of storage rooms for vegetables and fruits with RGS, the following factors must be taken into account:

ensuring the correct selection of refrigeration equipment (refrigeration capacity, refrigeration circuit, air exchange rate, air cooler surface).
storage of fruits in chambers is carried out at temperatures from 0 to +4, as well as relative humidity of about 90-95%.
the tightness of the chamber must ensure the greatest gas tightness.

Technological refrigeration equipment for controlled atmosphere storage rooms:

RSA nitrogen generator
CO2 carbon dioxide adsorption device (scrubber)
Ethylene converter / purifier
Ventilation and protection in cold rooms
Atmosphere control station (SKA)
Measuring instruments
Optional equipment
Sealed refrigerating chamber with bumpers
Refrigeration system

Cool & Store manufactures and installs refrigerated chambers for storing vegetables and fruits... How to keep freshly harvested fruits and vegetables healthy and fresh? Place in a cool place, of course. What for? And then, that all living processes in tomatoes, apples, carrots and other fruits of our gardening work slow down dramatically when the ambient temperature is below +15 degrees Celsius.

There is also a lower limit of the ambient air temperature, during the passage of which all vegetables and fruits begin to freeze, that is, their organic structure deteriorates. It starts at zero degrees. Thus, refrigerator for storing vegetables and fruits should optimally support the mode 0 / + 10 degrees. In this case, the maximum long-term storage of plant products is guaranteed.

In addition to temperature, an important role in the high-quality storage of vegetables and fruits in the refrigeration chamber is played by such a factor as humidity and the presence of an inflow. fresh air... Here we are helped by special valves that regulate the flow of fresh air, and therefore humidity into the refrigerating chamber. After all, it is no secret that inside any refrigerating chamber the air is dehumidified due to the fact that the moisture contained in it falls out in the form of frost on the internal evaporator (radiator grill) or on the wall of the refrigerator. As a result, if you do not take measures to control and regulate air humidity, inside the refrigerating chamber or even an ordinary household refrigerator, over time, fruits and vegetables dry out, shrivel, giving moisture to dry air.

Refrigerators for storing vegetables and fruits - prices

Like all other medium-temperature refrigerating chambers of our production, cold rooms for storing fruits and vegetables are made of PVC sandwich panels, with a thickness of 32 mm, filled with extruded polyurethane foam, which has a thermal resistance twice as compared to polystyrene foam used in working with metal sandwich panels. This means that the same heat (cold, in this case) saving we obtain with an almost twofold decrease in the thickness of the filling of the walls of the chamber. Prices for refrigerators for fruits and vegetables are determined individually depending on the required dimensions and parameters of the camera.

Refrigerated boxes for fruits and vegetables

Refrigerators for fruits and vegetables are often seen similar to cellars and cellars - that's why we complete our refrigerating chambers special boxes for sorting products stored there. Storage boxes are drawers made of food-grade plastic that are perforated to allow air to move inside them. These boxes allow you to ventilate the vegetables and fruits lying in them and prevent them from suffocating. Thus, purchasing chambers for storing fruits and vegetables from the Cool & Store company, you are guaranteed to provide your "wards" comfortable accommodation and long life!

How to buy a refrigerator for storing vegetables and fruits

Buy a refrigerator for vegetables and fruits in "Cool & Store" as easy as shelling pears. Call us by contact numbers or fill out the contact form on the website, and we will call you back and discuss all the details.

Refrigerators for storing fruits and vegetables provide:

storage chambers with automatic temperature control from –2 to + 7 ° С and relative humidity of 70-95%;
ripening chambers for fruits and vegetables with automatic temperature control from 8 to 20 ° C and relative humidity of 80-90%;
fruit and vegetable processing room (bulkheads, packing and packaging) with automatic temperature control from 12 to 15 ° С without regulation of the relative air humidity;
heating chambers with temperatures from –2 to + 20 ° С;
fumigation chambers (on distribution refrigerators).

Storage chambers capacity - from 50 to 250 tons and more. The storage chambers must be filled within 7-10 days, which will ensure uniform cooling of all fruits. When loading the chambers, the refrigeration equipment must be turned on. Additional loading of fruits and vegetables with a temperature above 8 ° C into chambers with a capacity of up to 200 T is allowed up to 8%, and into chambers over 200 T - 6% of the capacity of the chambers.

The degree of chamber loading influences the relative humidity of the air in it. So, depending on the degree of loading of the chamber in the amount of 100, 50 and 25%, the relative humidity in it will be 86, 78 and 68%, respectively. A decrease in the degree of loading also affects the deterioration of the circulation conditions.

Fruits and vegetables that are most sensitive to insufficient air humidity (with a weak water-holding capacity), it is more expedient to store in smaller chambers located in the middle of the refrigerator circuit and having a smaller surface of the outer fences.

In the absence of special rooms for processing and sorting fruits during the shipment period, it is necessary to select one of the chambers in which the temperature is maintained at 2-6 ° C when preparing batches for shipment to distribution refrigerators and 10-12 ° C for shipment to the retail network.

When shipping fruits to distribution refrigerators, an increase in their temperature during the bulkhead period is allowed only for a short time not higher than 2-4 ° C.

Before shipment to the retail network in the warm season, the temperature of the fruits must be increased gradually over 2-3 days in order to avoid condensation on them. At the same time, the air temperature in the room is maintained at 2-3 ° C above the temperature of the product to be insulated, the relative humidity is 75-80%.

Some fruits and vegetables (pears, tomatoes, etc.) do not ripen during storage, therefore, several days before sale, they are transferred to a room with increased air circulation and kept there for 3-7 days at a temperature of 18-20 ° C and relative humidity 90%.

Refrigerated chambers for vegetables and fruits

The choice of a suitable storage technology ensures that the final product is preserved in its original freshness. Lower storage temperatures provide a longer shelf life. Industrial refrigeration chambers and blast freezers can help you store your products.

You can find out more about refrigeration equipment on our website

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Vadim Grinberg

For people far from understanding modern technologies storage, the concept of "vegetable storage", familiar from childhood, can cause not very pleasant visual and olfactory associations. However, those who are "in the know" are quite obvious about the giant technological leap that has taken place in this area over the past 20-30 years. A modern warehouse for storing vegetables and fruits is equipped with a whole range of engineering systems that make it possible to turn the seemingly simple task of preserving the harvest as long as possible into a high-tech controlled process.

To assess the complexity of this process, it is necessary to at least briefly dwell on what, in fact, tasks have to be solved during storage - what natural processes occurring with fruits and vegetables so longed for in the cold winter time have to be fought.

Plant foods, which include fruits and vegetables, contain 75 to 95% water. From the moment of harvesting, chemical and microbiological processes begin to occur in fruits and vegetables, the nature of which is determined by biological functions. The main physiological process that continues in fruits and vegetables after harvest is respiration. The intensity of respiration and associated metabolic processes depends on the temperature. In particular, the so-called post-harvest ripening is characteristic of fruits and berries, during which, due to the transfer of nutrients from the pulp, seeds are formed. It is accompanied by a decrease in the amount of chlorophyll (gradually disappears green color) and the appearance of other pigments, the accumulation of ethylene, the content of vitamins and moisture decreases. Thus, the possible shelf life of vegetables and fruits is determined mainly by the degree of maturity at harvest.

In practice, there are two degrees of maturity - removable and consumer. Removable maturity is determined by the need for subsequent transportation and storage capabilities, and consumer maturity is determined by suitability for use. From the point of view of the consumer, one of the main processes occurring in fruits and vegetables after harvest is moisture evaporation. Evaporation leads to weight loss and wilting. A noticeable wilting of fruits occurs with a loss of 4–6% moisture, and berries and leafy vegetables - with a loss of 1.5–2%.

Consequently, the main task during storage is reduced to inhibiting physiological and biochemical processes, preventing the development of phytopathogenic microorganisms and reducing moisture loss. One of effective ways to achieve this result - rapid pre-cooling. The rate of this cooling depends on the type of fruits and vegetables. If the removable and consumer maturity coincide, which is typical for berries (including cherries, cherries) and cucumbers, or occurs after a relatively short period, as in apricots, peaches, plums and melons, the cooling process should take no more than 5 hours. And, for example, in winter varieties of apples and pears, which reach consumer maturity during long-term storage, the cooling process can take even a day.

That is, the first task that needs to be solved, regardless of whether vegetables and fruits are stored in the immediate vicinity of the collection point or transported to the storage location over long distances, is to ensure the possibility of pre-cooling. It can be carried out in ordinary storage chambers with an air exchange rate of 30–40 times per hour, in special pre-cooling chambers with an air exchange rate increased to 60–100 times per hour, in intensive air cooling devices, including tunnel type, as well as with cold water by irrigation or immersion.

The solution to the problem of sufficiently long-term storage of vegetables and fruits, thus, can be developed in two main ways: storage in the immediate vicinity of the place of harvest and storage in the region of consumption. The regions of the most concentrated consumption are megalopolises, where the cost of storage is quite high due to the high rental rates of warehouse space. Nevertheless, this option may well be considered for imported fruits and vegetables purchased in large, including ship, consignments.

However, the most interesting from a commercial point of view is the option of territorial unification of the process of growing, harvesting and subsequent storage. In this case, warehouses for storing vegetables and fruits can be built using one of the relatively inexpensive construction technologies, in particular, using lightweight metal structures or frameless technology. Frame storages are made of pre-fabricated lightweight metal structures. As a rule, sandwich panels are used to create an insulating contour, and a profiled steel sheet is used for external cladding. This design scales relatively easily to allow for more storage.

The use of frameless construction technologies makes it possible to speed up the process of erecting storage facilities through the use of panel molding machines. The structures created as a result of using this technology have high strength, resistance to wind and snow loads. Their significant advantage is also the absence of a strong foundation. Warehouses erected by frameless method can be one- or two-layer, with a layer of insulation between the layers.

In the future, in accordance with the task at hand, options of varying degrees of technological equipment can be selected. This is determined by the type of stored products - homogeneous or in an assortment, the way of storage - in bulk or in packaging containers, the expected shelf life. Accordingly, for long-term storage of different types of products, it is necessary to provide temperature zoning.

The most practical option for storing fruits and vegetables using a refrigeration and ventilation system. Its problems have been considered in sufficient detail in a large number of publications related to the construction and equipment of medium-temperature refrigerated warehouses. At the same time, special technical devices that are used to equip warehouses for storing vegetables and fruits, primarily equipped with systems for organizing a controlled microclimate and a controlled atmosphere, are of great interest. The organization of a controlled atmosphere is a technology that can significantly increase the shelf life of products and maintain their quality. Storage of fruits and vegetables in a controlled gas environment takes place in special vegetable stores, refrigeration chambers, plastic films, plastic containers.

There are also several levels of difficulty in this area. At the first level, a controlled carbon dioxide content is mainly achieved while maintaining the required temperature regime and humidity. In this case, the parameters of the controlled atmosphere approximately correspond to the oxygen content of 3-4% and carbon dioxide in 3-5%, while the oxygen content in the ordinary atmosphere is about 21%, nitrogen - 78%, carbon dioxide 0.03%. Excessive CO2 content leads to a rather rapid deterioration of vegetables and fruits, while, in particular, an unpleasant taste and smell may appear, some fungal formations may develop, and the presentation of preserved fruits and vegetables may deteriorate. The task of absorbing excess carbon dioxide is solved by the use of scrubbers (sometimes called scrubbers). With the help of scrubbers, carbon dioxide and part of the ethylene formed are removed from the refrigerating chambers. The removal method is quite simple and is based on the use of activated carbon, which adsorbs gas molecules. The air from the refrigerating chamber is pumped through the activated carbon using a fan low pressure, which consumes a minimum of electricity, and then comes back.

A more sophisticated system for creating a controlled atmosphere provides for a reduction in the oxygen content to 2–5% and carbon dioxide to 1–3%. This is achieved by displacing them with nitrogen, for which a generator is integrated into the system, which produces it from the ambient air. The nitrogen generator consists of two interchangeable carbon molecular sieve tanks that can adsorb oxygen molecules over a period of time. When one of the tanks is saturated, it automatically switches to the other tank. At this time, the regeneration process takes place in the filled tank.

The third, the highest from the point of view of technological implementation, the level of creation of a controlled atmosphere provides not only an ultra-low concentration of oxygen (within 1-1.5%) and carbon dioxide (0-2%), but also a decrease in the content released during the ripening of fruits and ethylene vegetables. This scheme requires the use of another class of devices - an ethylene catalytic converter. Ethylene gas is emitted by vegetables and fruits and stimulates their ripening, so control over its content makes it possible to store them for a long period of time.

There are ethylene catalytic converters on the market from many manufacturers. General principle their action is based on forced air recirculation over the catalyst bed stored at elevated temperatures. In the process of catalytic interaction of ethylene with atmospheric oxygen, it decomposes into carbon dioxide and water.

With the help of a converter, a ratio of ethylene to the total volume of air in the chamber of 1/109 can be achieved without the use of toxic chemicals. Thus, the process of purifying the air in refrigerating chambers does not have negative impact on the environment. Equally important is the small amount of energy required to operate the converter. This is achieved through heat recovery in a closed converter and refrigeration chamber system.

However, the actual organization of storage, the process, as a rule, does not end. It is also necessary to provide for the technical stage of imparting marketable qualities to vegetables and fruits, that is, to organize the ripening process immediately before sending the products to retail outlets. Let's look at this process using the example of such a well-known fruit as a banana. These fruits are found in the tropics and subtropics, while industrially grown mainly in South and Central America. Bananas are harvested unripe, and on the way and upon arrival at points of consumption, they ripen in warehouses. Bananas are delivered to Russia by sea by powerful refrigerated vessels, refrigeration units which allow you to keep the fruit in a state of "removable" ripeness during the entire period of transportation. The shelf life can vary from 28 days from the date of collection to 40-50 days. Its increase is achieved through the use of a controlled atmosphere during storage.

In preparation for retail trade, the product is brought to a certain degree of maturity by keeping it in aeration chambers. The ripening process is stimulated by ethylene (as opposed to the storage stage, when the ethylene content, on the contrary, decreases). The ethylene treatment is carried out once.

The process of bringing removed unripe fruits in storages, warehouses or specially equipped chambers to the state of consumer ripeness is called dosing. The ripening regimen can be accelerated (up to 4 days), normal (5-6 days) and slow (8 days). A higher quality of fruit is observed with slow ripening of bananas at low temperatures... In summer and winter, the ripening temperature interval is different. If hypothermia is allowed during ripening, longitudinal streaks appear in green bananas Brown under top layer rind, the rind turns gray. The result of an increase in temperature beyond the optimal range is a softening of the pulp, weak fruit legs, cracked peel and brown spots on the greenish-yellow peel. Also, the period of subsequent storage is significantly reduced.

In the ripening chamber, it is necessary to maintain a high level of humidity - 85–95% to maintain the presentation and prevent the loss of moisture by vegetables and fruits. During this process, both the temperature of the air in the chamber and the temperature of the fruit pulp are controlled (since the fruits generate heat during the ripening process). Optimal ambient temperature for the ripening process: +15 ... + 18 ° С.

Summarizing the above, it can be noted that the technological scheme of a modern high-tech complex for long-term storage of vegetables and fruits should include a stage of accelerated pre-cooling (before storage or before transportation to the storage site). In a multi-purpose (for storage different types vegetables and fruits), the complex should provide storage rooms with automatic temperature control in the range from –2 to +7 ° C with a system for maintaining the required level of air humidity.

If storage is carried out in a controlled atmosphere, then the storage, along with the necessary complex of refrigeration and ventilation equipment, can be equipped with scrubbers, nitrogen generators and ethylene converters. The final stage is important - giving the products a presentation and transferring them from the chilled state in which they were stored to the state that meets the conditions of sale. At the same time, condensation must not form on the food. This operation is carried out in the so-called "heating chambers". In addition, at this stage, the process of ripening fruits and vegetables can be realized, for which the storage is equipped with ripening chambers.

All the processes we have considered require not only expensive equipment, but also the exact observance of all parameters. So, before enjoying the taste and aroma of the just bought "winter" apple, it does not hurt to remember that its appearance on our table was preceded by a complex, very technological and such an important process of preserving the presentation and consumer properties.

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