In any food cooked and left to cool slowly, at a temperature of +65 to +10 ° C, the microflora rapidly multiplies (approximately, bacteria doubling every 20 minutes). With a rapid decrease in temperature in the body of the product, a rapid reduction in the reproduction of microflora occurs. Microorganisms of different species have different temperature limits of vital activity. With a slow decrease in temperature, traces of vital activity of very many microorganisms appear in the product, while with a fast decrease, many of them simply do not have time to develop. Thanks to this, the shelf life of quick-chilled and quick-frozen products is longer.
When frozen, all water molecules turn into ice crystals, and the faster the process, the smaller the crystals. Thus, only during micro-crystallization, the product molecules are not damaged. As a result, after defrosting, there will be less loss of liquid, the consistency and taste of the product will not change.
Shock freezing systems allow reaching a temperature of -18°C in the body of the product in less than 240 minutes - the maximum time during which it is necessary to carry out the freezing process for micro-crystallization, while maintaining the organoleptic properties of the product unchanged.
Blast chilling differs from shock freezing in the temperature of the product at the exit. During blast freezing (shock freezing) the product comes out with a negative temperature of -10...-20°C, and during blast chilling it is usually +3°C (i.e., the process just ends earlier). In both technologies, the process of lowering the temperature of the product occurs quickly.
Shock chilling can be "soft" (soft) and "hard" (hard). The first option is suitable for delicate and thin products, the second for dense, fatty and large.
In the West, devices for shock freezing are called shock freezers (shock freezer), and for shock cooling blast chillers (blast chiller). For small product capacities (for example, in mini-bakeries), miniature serial samples of batch equipment in the form of shock freezers are used. For industrial production, as a rule, fully automatic equipment of continuous action is used - a shock freezing chamber. Such systems are designed and manufactured for a specific manufacturer.
Advantages of using shock technologies:
1. Due to the longer shelf life, it becomes possible to better plan production, prepare inventory less often repeating the production process. This results in time savings of up to 30%.
2. Due to the long shelf life of products, it makes it possible to save on the purchase of seasonal ingredients (at lower prices and of higher quality (fresh)).
3. Allows you to increase revenue from the sale of weight products (up to 6% increase) due to less weight loss.
4. The use of technology helps to obtain a product that truly meets the standards of the HACCP food safety management system.
5. Allows you to expand the range of products offered.
SHOCK FREEZING OF BAKERY AND CONFECTIONERY PRODUCTS
In the West, frozen bread today occupies about 70-80% of the entire bread market, in Russia - so far only 10-15%. According to experts, the transition of large producers (bakeries) to new technologies and the production of frozen bread for the mass segment can provide an increase in profitability and quality compared to the traditional process. The difference in the production of ordinary and frozen bread is an increase in the costs of freezing and storing products (from 15 to 30%), but a decrease in the costs of returning unsold products from contractors, logistics, damping surges and dips in demand due to long-term storage inventory.
The global market for frozen products is developing much more rapidly than the Russian market, where frozen pastries appeared in the early 90s. For example, in Europe, the production of partially frozen bakery products has become widespread since the 1970s.
The consumers of frozen bakery and confectionery products are the HoReCA sector - cafes, restaurants, the "street food" or street food segment, catering enterprises and individual consumers. The largest part of the sale of frozen bakery products in Russia through retail channels falls on grocery stores, markets and supermarkets.
As experts predict, the demand for such semi-finished products will grow not only in the capital, but also in the regions, and companies offering a wide range of products new to the market will become in demand.
In addition to bread and rolls traditional for the Russian consumer, small-piece products are subjected to shock freezing - rye and wheat buns with various additives, mini-baguettes, classic baguettes of various sizes, almost ready-made dishes from frozen bread (for example, sliced baguette with butter and herbs, baguette with garlic oil), which need only be warmed up before use. Shock freezing is also widely used for products such as bagels, pretzels, pizza, lasagne, sausages in dough, tartlets, flatbread, khachapuri, panini, ciabatta, focaccho, Finnish rye bread, Irish soda, strudel, cheese sticks, pretzels and envelopes with various fillings, cakes, pastries, pies, pancakes, pies, puff pastry (yeast-free and yeast-free), croissants, cheesecakes, muffins (muffins), donuts (donuts), puffs, denishi, cheesecakes, cookies (cookies), etc. d. In total, there are about 300 types of frozen bakery and confectionery products in the world. More than 100 are represented on the Russian market. Only about 10 of them are the most universal and popular, the rest are narrowly focused - for a certain cuisine, for a certain dish, etc.
In recent years, the demand for products made from frozen semi-finished products has increased significantly. As for the taste characteristics, according to experts, there is no pronounced difference between bread baked in a bakery or from frozen semi-finished products. As a rule, frozen products are made from natural ingredients without special additives and improvers. With proper observance of the technology for the production of bread from frozen blanks, the products turn out to be more crispy (in comparison with bread produced in the classical way), which makes them especially appetizing. The stereotype that frozen products are obviously of lower quality than fresh ones is no longer so strong. Restaurateurs and their clients are convinced that the "freeze" not only does not betray itself in appearance, but is absolutely identical to fresh counterparts in terms of taste.
What is the attraction of quick-frozen foods? First of all, it's convenient. Convenient for both the consumer and the manufacturer. For the consumer, because such a product requires a minimum of time and labor for its preparation. Is everything ready. And for the manufacturer, such products have a number of advantages. So, the use of frozen semi-finished bakery products in shopping centers does not need to expand the staff at the expense of specialists who carry out the dough process. Also, when using, for example, frozen semi-finished bread, there is practically no unsold goods, since new batches are baked as the previous ones are sold. As a result, hot and fragrant bread is always present in the assortment.
Today, there are three main ways to freeze bakery and confectionery products:
1. Freezing dough pieces.
2. Freezing of partially baked products (part baked). This type is also called the “incomplete baking” production technology.
3. Take bake technology - freezing finished products.
The first way may have options. Here are two of them.
First option. The test piece is allowed to rest a little. Then frozen and stored. Preparation: defrosting (defrosting) for 30 minutes, proofing for 2...4 hours at +20...+25°C and humidity 70...75%, baking for 10...25 minutes.
Second option. After molding, the dough pieces go through the final proofing stage. Then the dough pieces are frozen in a shock freezing chamber at a temperature of -30...-40°C, packed in the so-called "zero chamber" (0°C) and stored at a temperature of -18°C. Further actions with blanks - defrosting for 15-30 minutes. at room temperature, then baking in an oven or combi steamer.
In the second method, the product is baked until 50-90% cooked. The bread is then deep-frozen. Frozen bread is stored at -18°C. Today, many manufacturers use this technology. To make bread, it is taken out of the freezer, thawed and baked in ovens until cooked. Fresh hot bread is ready.
The latest know-how in the production of frozen bakery and confectionery products is the baking of semi-finished products without prior defrosting, which further simplifies the process of preparing products.
In the third method of freezing, the products are brought to readiness by heating in a microwave oven.
The detailed technology for creating a semi-finished product, shock freezing, cooking after storage for each specific type of product is always individual. As a rule, this technology is know-how and organizations using it are very reluctant to share it. The technology for different types of products can differ significantly due to their features.
Depending on the additives used, the shelf life of some products can be up to 1.5 years. With strict observance of technological parameters and careful quality control of raw materials, the resulting semi-finished products from puff pastry can be stored frozen for up to 6 months without the slightest loss of their properties.
Deep freezing is suitable for products prepared according to a wide variety of recipes. Exceptions are butter cakes and products decorated with vegetable cream cream. The fact is that when defrosting, cracks appear on the surface of the cake, and it loses its presentation.
When working with deep-frozen confectionery, it is important to strictly follow the rules of storage and defrosting. It is recommended to defrost products gradually at a temperature of +2...+5°C (in a conventional refrigerator) for 2 hours. The implementation period in the future is 72 hours, provided that the product is stored in the refrigerator. If the storage and defrosting conditions are violated, the product shrinks, the taste quality deteriorates, and in addition, some of its deformation is possible. Note that manufacturers of frozen cakes and pastries also allow other methods of defrosting: at room temperature or in a microwave oven in defrosting mode.
A few words should be said about the features of shock freezing of yeast dough. Keep in mind that too high or too low a quick freeze rate can cause damage to yeast cells, even when specialized yeasts are used. The acceptable freezing technology for yeast dough is determined by professional technologists of the enterprise that manufactures such products. They determine the conditions under which the maximum survival of yeast is maintained.
EQUIPMENT FOR SHOCK FREEZING OF BAKERY AND CONFECTIONERY PRODUCTS
Bakery and confectionery products are frozen at -20 to -70 °C, depending on technological requirements. The duration of the freezing process depends on the size and thermophysical properties of the product and can vary from 15...20 minutes (puff pastry) to 3...4 hours (cake).
Fully automatic blast freezing line consists of the following components
(types of equipment classified by functional purpose):
- Receiving conveyor system with the function of forming the required layout of products on the tape *
- Product rejection system based on vision system
- Thermal insulation chamber made of sandwich panels
- Spiral or multi-tier cold conveyor with possible additional options (e.g. belt cleaning and washing system)
- Refrigeration equipment (air cooler (special heat exchange unit with shock-froster fans), compressor and receiver unit, condenser, oil cooler, etc.)
- Intermediate conveyor system* that takes products from the chamber and transports them to the loading device in the packaging machine (feeder)
- Multifunctional control panels with alarm system
- Feeder
- Packaging machine with labeling capabilities
- Intra-factory logistics system (includes a conveyor system for containers (group packaging) and elements of its automation (product counters, robotic arms, palletizers, etc.)
* As additional options, equipment for confectionery production can be supplied with belt cleaning systems, removable crumb trays, protective covers against dust on the product (see more details) can be installed on conveyors, and more powerful refrigeration units can also be used. installations (industrial).
In conveyor systems for lowering products between levels, inclined, steeply inclined, spiral, vertical conveyors, as well as straight (hills), curved and screw gravity descents made of stainless steel are used.
The heat-insulating chamber is made of "sandwich panels". The thermal insulation material can be different: polyurethane foam (PUR), non-flammable polyisocyanurate (PIR), etc. The most commonly used polyurethane foam (PPU). The outer layers of the sandwich panel can be made of galvanized cold rolled steel with various coatings or stainless steel. The design of the joints (thorn-groove connection) of the chamber can be of lock type (with built-in eccentric locks and a deep profile at the ends), profile (with PVC profiles) and lockless types. With any type of chamber, a tight fit of the panels, rigidity of the structure and the absence of cold bridges are ensured. With a lock design, it is easier and faster to assemble the camera. the use of sealants, sealants, "additional" elements and hardware is not required. This reduces installation costs, but the cost of such a camera is higher than without locks. The chambers have reinforced floor panels. As a rule, the floor panel is reinforced with special plywood and corrugated aluminum sheet. In the room, the low-temperature chamber is installed on the air. The chamber must be provided with drainage and a lighting system. The chamber has special windows for the entry and exit of the product. As a rule, the exact location of these windows is determined during installation. In addition to these windows, the chamber must have at least one refrigerating door for service personnel. When designing a shock freezing system, it is necessary to take into account the ease of maintenance of the conveyor and the heat exchange unit, the required installation distances of the heat exchange unit.
A spiral conveyor is most often used as a technological conveyor for a shock freezing chamber for bakery and confectionery products. CJSC "LIPSIA" has vast experience in the production of spiral conveyors (more than a hundred spiral conveyors of various applications have been installed).
As chamber equipment, heat exchange blocks with an increased spacing of fins of the heat exchange surface are used, which makes it possible to increase the operating time of refrigeration units of industrial equipment between defrost cycles (6...8 hours). At the beginning of a shift in a production facility with an automatic system of shock freezing, the chamber is brought to the mode, then a long-term supply of the product flow to the conveyor belt begins, transporting it to the chamber. Thus, between defrost cycles, the mode of the freezing process does not change (remains consistently fast). This explains the higher quality of the frozen product compared to other methods.
Different heat exchange units are used for different products. Sometimes it is necessary to order non-standard heat exchange units (for example, with slowly blowing fans for freezing cream cakes).
An important role in shock freezing is played by the organization of air flows in the refrigerating chamber. To direct the air flow, a special lining made of stainless steel sheet is installed. An improperly designed blast chiller system may not work or may not work efficiently enough.
CJSC "LIPSIA" has a subdivision that is engaged in the design of climate equipment. When creating refrigeration systems, components of various companies are used, depending on the preferences of the Customer. However, to achieve the best result, the company strongly recommends using brands that have been proven over the years - such as: Bitzer (Germany), Güntner (Germany), GEA Goedhart (Netherlands), Thermofin (Germany), Alfa Laval (Sweden), Danfoss (Denmark).
Frozen products can be wrapped in film using flow-pack packaging machines. It is also possible to pack products in various trays with subsequent sealing. With such packaging methods, it is possible to carry out the freezing process of already packaged products. However, this is often not possible due to a number of factors: difficult heat transfer prevents quick freezing, the stickiness of an unfrozen semi-finished product prevents packaging, the quality of the packaging material and printing does not allow maintaining the presentation after the shock freezing process, etc.
Often frozen products are packed in corrugated containers. For example, a given number of frozen pies needs to be packed into a corrugated cardboard box in automatic mode. In this case, a case packer can act as a packaging machine for frozen semi-finished products. This equipment is for group packaging in corrugated boxes. The following operations are performed in automatic mode: forming a box from a blank, grouping and stacking products in a box, closing valves, sealing the box valves with adhesive tape.
In the system of intra-factory logistics, packaged products are automatically considered, fall into containers, which are then fed to storage (cold storage of finished products) or to refrigerated transport for further shipment to points of sale.
The line described above is fully automatic. However, such lines, due to their high cost, are not widely used in Russia. At most domestic enterprises, shock freezing lines are installed, partially automated (some of the line components are missing) or not automated at all.
Fully non-automated shock freezing line is as follows. Workers transfer ready-to-freeze semi-finished products to trays in tiers of special mobile carts. Then these trolleys are rolled into a shock freezing chamber, where the products are frozen. Appropriate heat-exchange units of the “shock-froster” type are also installed in the chamber. Then the trolleys are again manually removed from the chamber, the products are removed from the trolleys and packaged. Such chambers are intermittent equipment. In contrast to the automatic system, due to the large heat gains during loading and unloading, the chamber takes a long time to enter the mode. Such lines are characterized by low product quality (damage to product tissues by large ice crystals) and a large share of manual labor and, as a result, low profitability of production as a whole. At enterprises with such lines, there is an irrational use of production space, a large payroll, confusion in the organization of intra-factory logistics and shortages of products, a high percentage of defects, downtime due to the "human factor", and dissatisfaction with working conditions. A fully non-automated line is relatively cheap, and therefore, with low productivity (up to 300 kg / h), such equipment is still used.
Advantages of the system of shock freezing of products based on a spiral conveyor:
- Reducing the payroll
- Significant reduction in labor intensity
- Saving production space
- Reducing the number of defective products (excluding the "human factor", rough impact)
- Improving the consumer qualities of the finished product
- Increasing the implementation time (minimizing the development of microflora, eliminating or minimizing the contact of products with people)
- Organization of a continuous technological process
- Reducing freezing time
The transition to full automation of production from the test process to the receipt of products at the warehouse allows enterprises to take one of the leading positions in such important indicators as quality and price.
Shock freezing does not cause changes in the structure and chemical composition of food products. It is based on the features of liquid freezing. The essence of the method is to cool food at a rate at which water microcrystallization occurs. But this is not a simple freezing, because the volume of ice crystals in relation to the initial volume of the liquid substance does not increase. Here the main criterion is the rate of freezing, and not the temperature regime.
The essence of the process of shock freezing
Speaking about this method of preserving products, we are not talking about a set of special technological equipment, but about achieving the result of liquid microcrystallization. Shock freezing includes three stages: cooling, freezing and freezing. The temperature of the chamber reaches -40°C, and due to the ventilation of the evaporator, there is an accelerated movement of air in this chamber. A greater decrease in temperature and an increase in airflow is not advisable, because in this case power is unjustifiably spent, and the products begin to deform. If at the stage of freezing, then the process will be significantly accelerated.The main difference between shock freezing and conventional freezing is explained simply. In the usual, ice crystals are formed, the size of which is larger than the size of a water molecule. Because of this, the moisture that freezes in the product changes the structure of the food and destroys it. Food frozen in the usual way, when defrosted, loses its shape and valuable nutritional qualities. In the process of shock freezing, the resulting ice crystals do not exceed the size of a water molecule. The structure of the product in this case does not suffer, and when defrosted, the beneficial properties of food will not go anywhere.
Advantages of quick freezing
The advantages of shock freezing are obvious. If you freeze cutlets in the usual way, it will take at least 2.5 hours, and with a fast one, 30 minutes will be enough. Shock freezing produces smaller ice crystals. At the same time, the products retain their attractiveness for buyers, since their shape is not affected. Also, the advantage of quick freezing is that there is no weight loss of the product and the development of bacteria. At a high freezing rate, bacteria simply do not have time to develop and leave traces of their vital activity in food. The period of activity of pathogenic bacteria is minimal. In terms of shelf life, quick-frozen foods have a much longer shelf life than foods frozen in a conventional freezer.Any person who manages a public catering enterprise simply cannot but know that the growth and spread of any bacteria, and especially those that are harmful to humans, directly depends on time and temperature. Therefore, it is very important to consider these two factors when determining the quality of any product. For safety, it is necessary to consider not only the sterility of the environment, but also to control the bacterial load.
Everyone is well aware that in production shops, where food is prepared or prepared, the temperature always lies in the range from +25°C to +30°C. But, unfortunately, we also know very well that this temperature is most favorable for the reproduction of various bacteria. Accordingly, their growth and development provokes premature decomposition and spoilage of food.
As you may have guessed, to prevent such a rapid and inconvenient reproduction of bacteria for us at the moment is possible only with the help of shock freezing.
Shock freezing products is a technology for fast and efficient cooling of food. Although this technology is considered new today, it has already found its application in many catering establishments.
In the 80s of the 20th century, British scientists proved that if the temperature of a body or substance drops from +75 to +2 and less degrees Celsius for 90 minutes, then such cooling has the right to be called “safe”, that is, all properties are preserved. until defrosting. In 1990, a piece of legislation was passed in the UK requiring only those products to be sold that meet Cook&Chill technology standards.
A little later, these standards appeared in Russia. But the trick of blast freezing is that most intensive chillers can chill products with an initial temperature above this norm, that is, even + 90 ° C.
To increase profits, manufacturers of such equipment are trying to significantly expand the range of their products. Take, for example, a company like Electrolux. It offers several devices that are similar in design: blast chillers, combi steamers, convection ovens. In addition, they all have almost the same control panels. Therefore, you can easily select the device that will be most convenient for your company.
Shock freezing in the restaurant business is called Cook & Chill, while in industrial production it is called CapKold.
Note that a system such as Cook & Chill can also extend the shelf life of some dishes and, accordingly, reduce unwanted costs to zero.
Consider the clear benefits of using Cook&Chill technology in the kitchen.
First of all, this technology outperforms others by saving space. Let's give an example right away: a combi steamer occupies a maximum of 1 square meter, and a shock freezer is approximately 1 to 2 square meters. It is easy to notice, having previously estimated that this equipment really will not take up much space, despite the complexity of its work and the incomprehensibility of the processes occurring inside such cabinets and combi steamers.
The second advantage of this technology is to reduce the loss of raw materials by 10-15 percent. It is interesting that a raw material processing system has been introduced into the devices, which significantly increases labor productivity.
You will be glad to know that the third advantage of Cook&Chill technology is the reduction in the number of staff and, consequently, the reduction in labor costs. This means that by purchasing such equipment, you can not only deprive yourself of constant problems with personnel, but also save on wages for your employees. Also, spending on the purchase of products is significantly reduced, but it becomes possible to expand the range, improve their quality, and many other advantages of this kind.
It is very important to know that blast freezers in some way act as a pasteurizer. We all know that all bacteria that survive in the process of frying, boiling, parks are able to start multiplying again after a certain amount of time. This is where blast chillers come in handy. When food is cooled to a temperature below +6 ° C, bacteria no longer have the opportunity to increase their numbers at such a rate, or rather, at any rate at all.
The operation of shock freezing cabinets has a common principle with the operation of convection ovens. There is only one difference: in convection ovens, powerful fans work, which create a powerful and uniform air flow, and in blast freezers with an all-round flow of hot air, a powerful flow of cold air flows. This is due to the operation of cold generators and fans that circulate air in the refrigeration chamber at a speed of more than 35 m/s. In this way, blast freezers help to cool food and dishes in less than 90 minutes. A scientific fact claims that this method of cooling allows you to “slip through” an unfavorable temperature zone in a very short period of time.
Despite all the above advantages of blast freezers, today there is no universal freezing mode that is ideal for all products or dishes. But, fortunately, shock freezers have several modes that can be easily changed depending on the case. For most modern models, two modes of operation are most characteristic - this is soft and sharp cooling. Let's look at them in detail.
Let's start with mild shock freezing. This mode is intended for products with a soft and delicate texture. Such products include fruits, berries, some types of vegetables. The soft freeze mode includes two stages. At the first stage, the temperature inside the chamber is reduced to zero degrees Celsius. During this stage, the temperature inside the product itself drops to around +20°C. At the second stage of soft shock freezing, the temperature inside the chamber drops sharply to -40 °C. This temperature in the chamber is maintained until the temperature inside the product itself reaches -18°C.
Now about the sharp shock freezing. This blast chilling method is used for products with a dense or hard consistency. These include, for example: fish, chicken, meat. This method consists of only one step - the same as the second step in soft freezing.
Of course, shock freezing is not able to completely destroy all bacteria, but this process reduces the rate of their reproduction to a minimum. Therefore, food service establishments must take into account the fact that for the complete safety of food, they need to use the safest systems for storing or preparing food. For example, dishes such as fried meat, sauces, creams, soups have some peculiarity, due to which bacteria multiply at an incredible rate. Therefore, it is vital to use shock freezing technology to quickly lower the temperature of the product, especially if this product will have to be stored for a long time.
Shock freezing allows you to very, very quickly reduce the temperature of the entire product to more than -17 ° C. However, you should be aware that a regular freezer is not capable of freezing the product so quickly, because this device is only intended for short-term storage of already prepared frozen foods.
Shock freezing of products contributes to the formation of ice macrocrystals, which occurs due to powerful and high-speed cooling and maintaining very low temperatures inside the refrigerator compartment itself.
Italian Lainox blast freezers can serve as a good example to get acquainted with similar products. The following features have been included in this equipment by the manufacturer:
1) Freezing, which is monitored by sensors installed in the heated probe so that it can be easily removed from the frozen product;
2) Complete sterilization of the entire surface of the working chamber;
3) Probe with ultraviolet radiation;
4) Output of all data to a personal computer or even to a printer using the support of the HACCP system;
5) Easy programming of various cooling and freezing modes depending on the individual properties of the products;
6) Universal rack. Allows you to install gastronorm containers and baking sheets up to 600x400mm in size;
7) When the temperature of the refrigerated or frozen products reaches -18°C, the cabinet automatically switches to the product storage mode.
Of course, it's not a secret for anyone that today a wide variety of products can be frozen: ready meals, semi-finished products, vegetables, fruits, and even some bakery products. This is convenient not only for the consumer or buyer, but also for the manufacturer himself, because such a convenient method can permanently increase the shelf life of the product, reduce the time of the productive process, and free up a lot of time.
To date, we know only two ways to store finished products:
Placement of the finished product or dish in a heating cabinet or combi oven, where it will be kept hot;
Using technology to lower the temperature in the shortest possible time in the blast freezer
If transportation is required, such a chain of cold should never be interrupted. But due to the fragility of products subjected to shock freezing, the risk of damage is very high. It is for this reason that the vehicle on which the transportation takes place is obliged to ensure the complete safety of the products.
talking about taste characteristics, we can say for sure that experts say that there are absolutely no differences in taste between bread freshly prepared in a bakery and bread subjected to shock freezing.
If this new technology is correctly followed, then some products can turn out to be much tastier than the same ones, but not subject to shock chilling. For example, bread made from frozen blanks is crispier than its brother made in the classical way.
The only problem with blast freezing technology is the survival of yeast cells when the product is deep frozen. The essence of this problem lies in the fact that during sudden cooling, ice crystals form in yeast cells, which tend to group and increase in volume in some cases. Therefore, the membranes of such cells, and the cells adjacent to them, can burst, unable to withstand such a load.
A big plus is that the purchased blast freezer pays off quite quickly, because such devices can be used in various areas of your enterprise. It will be most useful for the activities of your enterprise to use shock freezing cabinets included in combi steamer. In such a case, the prepared dish or product can first be blast frozen and then regenerated in the combi steamer.
You probably want to know how much such a complex, but very easy-to-manufacture device will cost. Try not to draw huge numbers in your mind, more like millions, because such an apparatus as, for example, a shock freezer, will cost no more than 200 thousand, or rather, from 80 to 180 thousand rubles. Therefore, this technology is becoming more and more popular and is used with great pleasure by representatives of the restaurant and food business.
A large number of enterprises have already fully appreciated the advantages and conveniences of shock freezing technology. Many restaurants, cafes, canteens, hospitals, airlines use blast chillers. Of course, only you can fully appreciate the benefits of using shock freezing technology in your enterprise, but we really hope this article will be able to help you. In any case, we wish you success in your endeavors.
Shock freezing as a technology was patented at the beginning of the 20th century. Since then, the method has been actively used in household and industrial equipment. It allows you to keep products tasty and healthy even with large volumes of sales. Today, there is a blast freezer in almost all catering establishments and grocery stores.
The history of the discovery of shock freezing
The Eskimos who lived in northern Canada can be considered the pioneers of shock freezing. The story goes that the American inventor Clarence Birdseye, while on the island of Newfoundland, drew attention to how local fishermen stored their catch. They put the fish on ice, where, under the influence of the Arctic wind, it froze in a matter of minutes. Then the scientist tried dishes prepared from this fish and noted the preservation of not only taste and aromatic qualities, but also useful properties.
Birdseye conducted a series of experiments that scientifically proved that the shock freezing method allows you to preserve vitamins, essential oils, perishable protein and so on in the product. The American founded his own company for the production of equipment, working on the technology peeped from the Eskimos and improved.
A patent for shock freezing was registered in 1925, and five years later, foods frozen in this way appeared in American supermarkets. The industry was rapidly gaining momentum. Depending on the goals and volumes of production, it became possible to purchase various shock freezing devices. First, fish went on sale, then they began to sell meat, minced meat, mushrooms, vegetables and fruits. At first they were considered elite and were distinguished by a high price, but gradually ceased to be such and entered everyday life.
It was a kind of revolution, and not only on an industrial scale, but also at the level of an individual American housewife. Residents of the United States got the opportunity to cook from high-quality semi-finished products preserved by shock freezing. Some half an hour in the oven - and a hearty lunch on the table. In the United States of America, National Frozen Food Day is celebrated on March 6th. On this day in 1930, the first frozen food went on sale in Springfield.
The effectiveness of the technology turned out to be especially significant for the transportation of products, including by rail. Despite the name, this way of preserving useful and gustatory qualities is the most sparing. In addition, unlike various types of canning, salt, sugar, dyes and artificial chemical additives are not used.
The principle of operation of shock freezing
The speed of the process plays a key role in shock freezing. The product is under the influence of a strong flow of cold air, which allows it to pass into a solid state in a matter of minutes, or even seconds. The water or juice in the product during shock freezing is converted into small crystals, and during subsequent defrosting - defrosting - they do not tear the tissue.
The process of shock freezing is three-stage:
- Cooling down to three degrees of heat or zero. Moisture on the surface of the product turns into small crystals that do not exceed the size of a water molecule. The high cooling rate does not promote the development of harmful bacteria. Shock freezing means that the product is intensively blown with cold air, which acts as a coolant in the blast freezer.
- Freezing is carried out when the temperature in the shock freezing chamber drops to five degrees below zero. The product passes into a solid state, while there is no damage to the intercellular membranes.
- Freezing is carried out with a rapid decrease in temperature to minus eighteen degrees. The structure of the product is fixed, now it can be stored for a long time. Further continuation of the temperature decrease is not required.
You can send to the shock freezing chamber not only products as such, but also ready meals. This method of preserving food is used in confectioneries, cafes, restaurants and other catering establishments. Soups, the second, desserts, pastries are placed in the shock freezing apparatus. You can bring the dish to readiness before serving in just a few minutes.
The range of equipment allows you to choose the one that most effectively solves the problems of a particular enterprise. Models have a convenient control panel, a different number of capacity levels for loading products. There are chambers with the ability to adjust the height of the legs, rounded corners for easy cleaning. Consult with experts to choose the best option.
Benefits of shock freezing
As we have already said, shock freezing allows you to keep the product fresh and healthy. Neither the taste, nor the aesthetic appearance, nor the aroma are violated. Large producers freeze fruits and vegetables almost a few hours after harvest, after carefully sorting, cleaning and grinding raw materials. Unlike traditional slow freezing, small crystals form rather than large ones. That is why the chemical composition and structure of the product, which is in the shock freezing refrigerator, is not destroyed.
Another important plus is a significant restriction of bacterial growth. The smaller the portion, the faster the optimum product temperature will be reached. And products that have been in a shock freezer will be stored longer than those that were frozen in the usual way. This is a great option for harvesting for the winter.
The popularity of frozen food for the consumer can be explained as follows:
- Ease of storage.
- Cooking speed as needed.
- No need to waste time cleaning or cutting the product.
- Good taste properties.
- Portion packing of many products.
- Minimum waste, only packaging.
By extending the shelf life of products that have been blast frozen, the company significantly reduces its own costs compared to using traditional freezers. We are talking about, among other things, reducing the production area and reducing the number of staff. Since the process speed is high, the weight loss is also reduced by up to 7%. It can be said that high-quality equipment, for example, a blast freezer, opens up new opportunities for business owners, allowing them to get ahead of competitors.
Let's say it takes about 2.5 hours to freeze cutlets or dumplings in a conventional chamber. While with the use of shock freezing equipment, 20-30 minutes is enough. You can sell products in different cities and even countries. It is interesting that in each country they freeze their own products that are special for the area, climate, and traditions. Efficiency of use and power of the equipment are especially valuable for enterprises with large volumes of food products turnover.
If your company has a blast freezer, remember that this is a complex refrigeration technique. It requires proper care, maintenance and timely repair. It is important to contact only qualified professionals. The technology will make it possible to recoup the cost of purchasing equipment in a short time.
Complete with freezing equipment, you should pay attention to the purchase of a professional combi oven, which will allow you to quickly heat up the product. It is important to understand that repeated shock freezing of the same product is unacceptable.
If earlier frozen products could only be seen in supermarkets, today every housewife freezes everything on her own and leaves everything “until better times”. But the trouble is that not everyone knows the rules for freezing food, how long and under what conditions they can be stored. Some do not even think about how the structure of products changes during freezing, whether they lose their properties, whether they can deteriorate. You will learn about this and more in this article.
How does freezing work?
Complete freezing in refrigerators with low temperatures takes 2-3 hours. With normal freezing Food is frozen in three stages:- From +20 to zero. This stage is called preparatory. Due to the gradual cooling, the product is prepared for freezing.
- From zero to -5 degrees. This is an intermediate stage. Here the temperature fluctuation is insignificant. The main thing at this stage is the process of liquid crystallization in the tissues of the product.
- From 5 to 18 degrees with a minus sign. Final stage. At this stage, everything that did not have time before is frozen.
Food freezing rules
In order not to spoil the product and keep it for a long time, you must follow the simple rules of freezing:- Freezing Products must be fresh. If something has already gone bad, don't expect the freezer to do a miracle. It is better to decide immediately after the purchase what you will cook and what you will leave "until better times."
- Then the product must wash and dry well cut into pieces or boiled.
- Choose suitable dishes or special bags (most importantly, keep food away from air and moisture) and lay out the prepared product in small portions. Why small? If you need to cook ten cutlets, you will not defrost two kilograms of minced meat. Therefore, it is better to divide the products in small portions.
- So that they lose less vitamins and do not get chapped, try prevent too much air from entering the package. But do not fill the containers to the top: when frozen, the products increase in volume and can lift the lid.
Useful properties and freezing
If we talk about frozen cucumber and bought in the winter in a supermarket, then in the first, of course, there are much more useful properties. After all, greenhouse products that are sold out of season are processed and lose most of their properties. But if we compare the product just plucked from the garden and defrosted, then the first, of course, is more useful.Vitamin C is lost the most during freezing. But any other treatment also kills it. Thiamine (vitamin B1) is lost during freezing about 25%, riboflavin (B2) - 4-18%. Freezing does not affect vitamin A in any way, but long-term storage kills it. Therefore, do not keep frozen carrots for too long, cook them.
Shelf life of frozen foods
Nothing lasts forever, including frozen foods. Even with the most proper storage, products will still deteriorate sooner or later. Here is a sample list of frozen food expiration dates:- minced meat - up to 2 months;
- sausages - up to 2 months;
- homemade meat and fish dishes - up to 3-4 months;
- small fish - a maximum of 3 months, large - twice as much;
- rabbit, duck, goose and hare meat - six months;
- turkey and chicken meat - 9 months;
- liver - 3 months;
- milk and dairy products - from six months to a year;
- vegetables - 10-12 months, in soup sets - 6-7 months;
- mushrooms - 5-6 months;
- fruits and berries - up to a year;
- greens - 3-4 months;
- flour products - up to 3 months.
- Before freezing, the product is prepared in such a way that it does not need to be washed after defrosting.
- Freshly prepared dishes should be cooled to room temperature, and only then sent to the freezer.
- Freeze only fresh foods, those that have begun to deteriorate are best cooked immediately.
- For better preservation, food should be frozen quickly.
- The packaging in which this or that product will be stored must be airtight.
- Label each bag with the freeze date so you know when the expiration date is.
- If the food is thawed (due to a power outage), you cannot freeze it a second time. It is better to cook their dishes right away.
Deep frozen products
This term is more common on an industrial scale. Deep frozen products include vegetable products and semi-finished products.You can also find frozen berries, fruits, vegetables, mushrooms and a variety of mixtures in stores. A separate place today is occupied by semi-finished products: cutlets, dumplings, pizza crusts and much more.
Shock freezing: technology
Shock freezing is very different from the one that everyone is used to. There are no separate stages here, the product is cooled very rapidly by lowering the temperature to -30-35 degrees and increasing the air flow. With this technology the product is exposed to frosty air from all sides and freezes much faster.Advantages and disadvantages
Freezers have many advantages:- products lose 2-3 times less useful properties than with conventional freezing;
- the freezing time of products is reduced from 3 to 10 times;
- the production area is reduced by one and a half to two times;
- need less staff by 25-30%;
- pays off more by 15-20%.
"Shock" equipment
For shock freezing, the following freezers are used:- Fluidizing - most often used for freezing chopped vegetable and fruit raw materials.
- Conveyor - used for freezing ready meals.
- Cradle - used for freezing packaged semi-finished products from fish, meat and poultry.
- Spiral - designed for freezing portioned dishes.
Mistresses about freezing
Yana:“When I bought a refrigerator with a freezer, I tried to freeze everything that came to hand. I folded everything in small portions, and thawed it every other day to try it. I liked the most frozen melons and watermelons. Even now, when I defrost them in winter, there is such a smell in the house ... "Nika:
“I am sure that freezing retains more of the health benefits than any other canning method. Therefore, I put everything in my freezer in a row: greens, mushrooms, herbs, fruits, berries. It's incredibly convenient."
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