II. Basic provisions

From the point of view of protecting products from microbiological spoilage, all products can be divided into two types: products used as raw materials and finished food products.

Due to their high moisture and nutrient content, fruits and vegetables are a good environment for the development of microorganisms that cause their spoilage (rotting, fermentation). Fruits and vegetables, as living organisms, have natural immunity; they are protected from external influences. Before cell sap with nutrients dissolved in it becomes a medium for the development of microorganisms, a number of barriers must be passed:

– a bactericidal cloud created by essential oils and other volatile substances contained in or under the skin;

– a waxy coating on the surface of some fruits, resistant to microorganisms;

– quite durable and thick skin;

– intercellular protopectin, which can be hydrolyzed only under the action of pectolytic enzymes;

– a cell membrane consisting of cellulose and protopectin, and a cytoplasmic membrane.

At the same time, when storing fruits and vegetables, even in the absence of signs of microorganism development, weight loss and a decrease in nutritional value, and sometimes spoilage, occur as a result of biochemical processes with the participation of enzymes. Thus, in order to reliably preserve fruits and vegetables or canned food from them, it is necessary to create conditions under which microorganisms do not develop and enzymes are inactivated. The methods by which such conditions are created can be divided into two groups:

– methods based on the principle of biosis, i.e. maintaining life processes in raw materials and using its natural immunity. In this case, it is important to sort raw materials before storing them and reject damaged items. Conditions that ensure the maintenance of life processes and some limitation of their activity help to prolong storage: laying that provides air access, low room temperature, air humidity that prevents drying, ventilation to remove excess carbon dioxide, ensuring cleanliness in the room, etc.;

– methods based on anabiosis, i.e. suppression, slowdown of the vital activity of microorganisms and metabolic processes in the raw materials themselves. Anabiosis provides cooling to a temperature of –1…–3°C and freezing, when water turns into ice and the supply of nutrients to cells microorganisms due to osmosis stops. Raw materials must be frozen and stored at a temperature of -18...-20°C, then small ice crystals are formed that do not injure the cells of the product, and after defrosting it retains its commercial properties. Some chemical transformations do occur in frozen foods: sucrose inversion and increased acidity, reduced tannins and reduced astringency, and improved natural flavor. Microorganisms enter an anabiotic state (osmoanabiosis) if the environment has high osmotic pressure. It is created by sugar and salt. To reliably preserve products, concentrations of osmotically active substances are used that cause plasmolysis of microbial cells (sugars - 60-70%, salts - 10-12%). Drying also leads to suspended animation of microorganisms – xeroanabiosis. If the moisture content of fruits and vegetables is brought to 8–25%, then microbial cells osmotically give up their moisture and plasmolysis occurs. The vital activity of the fruits and vegetables themselves ceases for the same reason. The advantages of drying as a method of canning include the simplicity of equipment, ease of storage and transportation of the product. However, the natural properties of the product are poorly restored when re-moistened. This disadvantage can be overcome by freeze drying, when moisture passes from a frozen product into a gaseous state under high vacuum conditions. Dried products have high porosity and their original properties are restored when moistened. When storing raw materials in a controlled gas environment, conditions for narcoanabiosis are created. In the absence of regulation of the composition of the gas environment in the food storage room, oxygen is gradually consumed for respiration, carbon dioxide accumulates and anaerobic respiration begins with further accumulation of carbon dioxide and the formation of ethyl alcohol. However, at a carbon dioxide concentration of 10%, the respiration of fruits and microorganisms does not completely stop, but only slows down (narcoanabiosis). The difficulty lies in the fact that different types of stored products require different gas phase compositions. To ensure optimal conditions for each type of product, plant raw materials are stored in films that are selectively permeable to different gases.

To reduce the amount of losses of finished food products due to microbiological spoilage, enterprises take measures in three main areas:

· prevention of food contamination by pathogenic microorganisms;

· creation of conditions that limit the vital activity of microorganisms;

· providing conditions that have a detrimental effect on microorganisms.

The most well-known procedures include: pasteurization and sterilization of food products, cold storage of food products, storage of products in rooms with low humidity.

In addition, practice has shown that strict implementation of a set of veterinary, sanitary and sanitary measures at all stages of food processing provides protection against contamination by pathogenic microorganisms.

In an effort to protect food products from spoilage, in ancient times man developed a method of preserving them (canning) by drying, smoking, salting and fermenting, pickling, and subsequently cooling and freezing, preserving with sugar or using preservatives and heat treatment.
Drying. The preservative effect of drying food products is to remove moisture. When dried, the dry matter content of the product increases, which creates unfavorable conditions for the development of microorganisms.
Increased humidity in the room and air can cause deterioration of dried products - the appearance of mold. Therefore, they must be packaged in containers that exclude the possibility of increasing moisture in the product.

Smoking. This method is used for preparing meat and fish products. It is based on the preservative effect of some components of flue gases, which are obtained during the slow combustion of firewood and hardwood sawdust. The resulting sublimation products (phenols, creosote, formaldehyde and acetic acid) have preservative properties and give smoked meats a specific taste and aroma.
The preservative effect of smoking substances is enhanced by preliminary salting, as well as partial removal of moisture during salting and cold smoking.

Salting. The preservative effect of table salt is based on the fact that when it is concentrated in an amount of 10 percent or more, the vital activity of most microorganisms ceases. This method is used for salting fish, meat and other products.

Pickling. When fermenting food products, mainly cabbage, cucumbers, tomatoes, watermelons, apples and others, biochemical processes occur in these products. As a result of lactic acid fermentation of sugars, lactic acid is formed, as it accumulates, conditions for the development of microorganisms become unfavorable.
The salt added during fermentation is not decisive, but only helps to improve the quality of the product. To avoid the development of mold and putrefactive microbes, pickled products should be stored at low temperatures in a basement, cellar, or icebox.

Pickling. The preservative effect of pickling food products is based on creating unfavorable conditions for the development of microorganisms by immersing them in a solution of food acid.
Acetic acid is usually used for pickling foods.

Cooling. The preservative effect of cooling is based on the fact that at 0 degrees most microorganisms cannot develop. The shelf life of food products at 0 degrees, depending on the type of product and the relative humidity in the storage area, ranges from several days to several months.

Freezing. The basis for this storage method is the same as for refrigeration. Prepared products are quickly frozen to a temperature of minus 18-20 degrees, after which they are stored at a temperature of minus 18 degrees.
When frozen, the vital activity of microorganisms stops, but when thawed they remain viable.

Canning with sugar. High concentrations of sugar in products of the order of 65-67 percent create unfavorable conditions for the life of microorganisms. When the sugar concentration decreases, favorable conditions are again created for their development, and consequently, spoilage of the product.

Canning using preservatives.
Antiseptics are chemical substances that have antiseptic and preservative properties. They inhibit the processes of fermentation and rotting and, therefore, contribute to the preservation of food products.
These include: sodium benzoate, sodium salicylic acid, aspirin (acetylsalicylic acid). However, it is not recommended to use them at home, since this method of preservation degrades the quality of the products.

Heat Canning. Canning, i.e. preserving food products from spoilage for a long time, is also possible by boiling them in a hermetically sealed container.
The food product to be canned is placed in a tin or glass container, which is then hermetically sealed and heated for a certain time at a temperature of 100 degrees or higher or heated at 85 degrees.
As a result of heating (sterilization) or heating (pasteurization), microorganisms (molds, yeasts and bacteria) die and enzymes are destroyed.
Thus, the main purpose of heat treatment of food products in hermetically sealed containers is to sterilize microorganisms.
Food products in hermetically sealed containers do not undergo changes during the sterilization process, their taste and nutritional value are preserved. With other methods of canning (salting, drying, etc.), products lose their appearance and their nutritional value decreases.

The invention relates to the field of protecting food products from spoilage and can be used to increase the shelf life of sausages, cheeses, fresh and processed meat, fish products, fruits, vegetables, etc. The product for protecting food products from spoilage is a birch bark extract containing a liquid component, in which the birch bark extract dissolves or forms a dispersed system, while the content of the birch bark extract and the liquid component is, wt.%: birch bark extract - 0.01-40, liquid component - 99.99-60. In another embodiment, the product for protecting food products from spoilage is a packaging material containing a base-forming component and a modifier, for which birch bark extract is used in an amount of at least 0.01% by weight of the base-forming component. Protection of food products from spoilage is achieved either by applying the specified agent, which is highly active in inhibiting the growth of various pathogenic microorganisms, on the surface of food products or by packaging the product in packaging material having the same properties. The invention allows to reduce losses of food products during storage and transportation. 3 n. and 4 salary f-ly.

The invention relates to the field of protecting food products from spoilage using organic compounds as preservatives and can be used to increase the shelf life of sausages, cheeses, fresh and processed meat, fish products, fruits, vegetables, etc. by applying a preservative to the surface of food products or by using packaging materials with properties that inhibit the development of pathogenic microorganisms.

Currently, food losses due to spoilage during storage and transportation have increased significantly. This is due both to the deterioration of the environmental situation, which affects the storage conditions of products and the quality of raw materials (contamination with various pathogenic microflora, including spore forms), and to the use of packaging materials, the surface of which becomes contaminated during the manufacturing process and when used for their intended purpose. When packaging materials come into contact with products, pathogenic bacteria, fungi and molds lead to the decomposition of carbohydrates and proteins contained in food products with the formation of substances that not only change the organoleptic properties of the product, but also have toxic properties that often cause severe damage to the human body.

Food products are protected from spoilage using special agents that inhibit the growth of pathogenic microflora. These agents are either introduced into the food product, or treat the surface of the products, or are used to modify packaging materials by treating the external surface of the materials or by introducing them into the base component.

The present invention relates to the protection of food products from spoilage by surface treatment of food products and the use of modified packaging using a new means for protecting food from spoilage.

Good antibacterial protection of food products is provided by antibiotics when used for external processing of packaging materials and/or during the production of packaging materials. However, most antibiotics are toxic (for example, pimaricin, natamycin) and have contraindications for a large number of consumers, and the effectiveness of a particular antibiotic applies only to certain types of pathogenic microorganisms. For example, natamycin inhibits the growth of fungi, mold and yeast (RU 2255615 C2, 2005.07.10.), nisin is more active against spore-forming organisms.

To reduce the limitations associated with antibiotic toxicity, products have been developed using less toxic antibiotics and/or with lower antibiotic content by introducing non-toxic additives with antibacterial, preservative, antioxidant and other properties. Most of the additives used are known as food additives and surfactants (in particular, chelate compounds - EP 0384319 A1, 1990.02.).

An antibacterial agent is known, the bactericidal properties of which are determined only by hop acids or hop resins and/or their derivatives and chelate compounds in an amount of 0.01-5% by weight of the composition (US 6475537, 2002.11.05).

The disadvantage of the product is associated with the presence of bitterness and essential components in the hop extract and its components, which affect the organoleptic properties of the composition when used.

There are known antibacterial agents intended for treating the surface of packaging materials, the main components of which are synthetic organic substances, for example, the product of the polymerization of amine and boric acids (JP 2005143402, 2005.06.09), dehydracytic acid and its sodium salt, etc. Dehydracytic acid and its sodium salt are introduced also in the composition of packaging materials, including in the production of sausage casings (RU 2151513 C1, 2000.06.27., RU 2151514 C1, 2000.06.27.), cheese coatings (RU 2170025 C1, 2001.07.10.). To reduce the toxicity of chemical compounds, which include dehydracetic acid and its sodium salt, they are combined with preservatives, which are table salt, and/or food acids, and/or salts of food acid.

The disadvantage of the known products is that, like any synthetic chemical compound, they are toxic. This requires the use of these substances in small doses, which do not achieve the desired food protection effect. In addition, known chemical agents are generally either bactericidal or fungicidal. Dehydracetic acid and its sodium salt have both bactericidal and fungicidal properties, however, a product based on them does not eliminate the problem of reducing the access of air and moisture to the surface of food products through packaging material treated with this product, which is necessary to ensure a long shelf life of products.

A known means for removing chemical and microbiological contaminants from the surface of food products of animal and plant origin by treating their surface. The composition of the product includes food additives (sodium sulfate, carboxylmethylcellulose, propylene glycol), surfactant, sequestrant, dehydrating agent, etc. (RU 2141207 C1, 1999.11.20). The product is used in the form of an aqueous solution with a concentration of 0.05-0.3%.

The disadvantage of the product is the presence of a large number of components necessary for processing food products, as well as low efficiency with a long shelf life of products.

For surface treatment of agricultural and horticultural products, it is known to use strains (RU 2126210 C1, 1999.02.20), immunostimulants and antiseptics obtained from the biomass of microcetes (for example, RU 2249342 C2, 2005.04.10; RU 2222139 C1, 2004.01.27).

The disadvantage of these products is their focus on inhibiting certain types of microorganisms, the lack of protection from moisture and oxygen of the external environment, as well as their high cost, small volume of production and, as a consequence, inaccessibility to most agricultural producers.

As a prototype, a product was selected that is applicable for protecting food products by processing the food product and treating the surface of the packaging material. The product contains low-toxic high-molecular antibiotics, including bacteriocins that inhibit the growth of many types of gram-positive microorganisms (lantibiotics, pediocin, etc.), lytic enzymes (lysozyme) in an amount of 38.5-99.8% of the total weight of the composition and component, selected from the group of hop acids and its derivatives, in the amount of 61.5-0.2% (US 6451365, 2002.09.17).

The main disadvantage of the product is associated with the use of antibiotics - bactericions, the use of which is undesirable for a large part of the population, and its activity in suppressing only certain types of microorganisms. In addition, the bitterness of hop acids and their derivatives changes the organoleptic properties of food products, and due to the high cost of producing bacteria and enzymes, the cost of the composition as a whole is quite high. In addition, when treating the surface of the packaging material with the specified antimicrobial agent, there is no modification of the material giving it properties of reduced water and gas permeability. High gas-water resistance of packaging materials is necessary to reduce product losses due to drying out and the negative impact of environmental humidity on the condition of food products, as well as to inhibit oxidative processes in them. Secondary oxidation products formed during the oxidation process, in particular fat oxidation products, intensify the biopathology of the product during its storage, which negatively affects the quality of the product and its shelf life.

The technical problem solved by the present invention is the development of a non-toxic product for food protection based on a natural substance, which is highly active in suppressing the growth of various pathogenic microorganisms (bacteria, molds and fungi) in a wide temperature range, has antioxidant properties and the ability to protect products from moisture and oxygen contained in the external environment. Another problem solved by the present invention is the development of an effective agent based on a natural substance that has the ability to modify the properties of packaging materials by immobilizing it in the composition of the packaging material.

In accordance with the invention, a means for protecting food products from spoilage, containing a substance with properties aimed at suppressing pathogenic microorganisms, is characterized by the fact that birch bark extract is used as the above-mentioned means in the composition of a liquid component, in which the birch bark extract dissolves or forms a dispersed system, with In this case, the content of birch bark extract and liquid component is, wt.%: birch bark extract - 0.01-40, liquid component - 99.99-60.

Edible fat and/or alcohol can be used as a liquid component.

Wax and/or paraffin can also be used as a liquid component.

There are known means of protecting products from spoilage, which are packaging materials modified with special substances in order to give them increased elasticity, antibacterial, fungicidal and other properties. To give packaging materials the desired properties, they are modified by means compatible with the base component of the material. At the stage of manufacturing packaging materials or before their intended use, special additives are introduced into them, which diffuse during the use of packaging materials onto the surface between the product and the packaging, providing active suppression of microorganisms.

Packaging materials are known from polyolefin modified with zeolite with silver or its compounds (JP 2003321070, 2003.11.11; JP 19950091889, 1995.10.31), dehydracetic acid (RU 2011662 C1, 1994.04.30), calcium hydroxide (JP 2003341713; 2003.12.03 ), lemongrass oil (JP 11293118, 1999.10.26). It is known to use packaging materials made of polyamide modified with copper and zinc ions (WO 2004095935, 2004.11.11), and silver ions (JP 2002128919, 2002.05.09). It is known to use cardboard packaging materials modified with chitosan and shelloc (JP 2003328292, 2003.11.19). It is known to use cellulose packaging materials modified with vinylpyrrolidone (JP 2004154137, 2004.06.03), as well as hop extract, hop acids and their derivatives (US2005031743, 2004.08.26).

The disadvantage of the known means of protecting food products, which are packaging materials, is their low efficiency, due to the fact that the packaging materials are modified with means that do not provide comprehensive protection of the products: in addition to inhibiting the growth of pathogenic microflora, the packaging material must prevent the oxidation of products and reliably isolate them from moisture. and oxygen in the environment. In addition, most known packaging materials are modified with synthetic substances, the use of which in food products can negatively affect the human body or, due to the reduction of doses of these substances to reduce the negative impact on humans, is insufficiently effective. In addition, to modify packaging materials, as a rule, several components are used, which complicates their manufacturing technology.

As a prototype of the proposed product, packaging material modified with one substance - a guanidine-containing polymer (WO 03084820, 2003.10.16.) was selected.

The disadvantage of this means, in addition to those listed above and inherent in all known means, is the use of a non-natural substance to modify the packaging material, which is quite labor-intensive to obtain and process the packaging material with it. In addition, guanidine-containing polymers are not compatible with many packaging materials, which narrows their scope of application.

The technical problem solved by the present invention is the development of a means of protecting food products from spoilage in the form of packaging material of various types, modified with a natural substance approved for use as a food additive.

The technical problem solved by the present invention is also the development of a means of protecting food products from spoilage by using a substance that can inhibit the growth of pathogenic microflora, has antioxidant properties and high gas-water impermeability, which slows down the loss of moisture from the product and prevents the access of air and moisture into the food product from the outside environment. The use of such packaging materials makes it possible to increase the protection of food products from spoilage and, consequently, increase the shelf life of products.

In accordance with the invention, the developed means of protecting food products from spoilage, like the well-known one, is a packaging material containing a base-forming component and a modifier that has the ability to suppress pathogenic microorganisms, characterized by the fact that birch bark extract is used as a modifier in an amount of at least 0.01 % by weight of the base-forming component.

It is advisable to use birch bark extract in the form of betulin.

An analysis of the technical solutions presented in this description shows that the known methods of protecting food products from spoilage by packaging products in packaging materials modified with substances with properties aimed at suppressing pathogenic microorganisms have disadvantages. These disadvantages are due to the properties of the substances used to modify packaging materials. The packaging materials used do not provide comprehensive protection for the products.

The technical problem solved by the present invention is the development of a more effective method for protecting food products from spoilage by packaging products in packaging material based on a substance approved for use as a food additive and having properties that help increase the shelf life of various food products.

In accordance with the invention, a method is proposed for protecting food products from spoilage by packaging products in packaging material containing a base-forming component and a modifier that has the ability to suppress pathogenic microorganisms, for which birch bark extract is used in an amount of at least 0.01% by weight of the base-forming component. It is advisable to use birch bark extract in the form of betulin.

The invention is based on the well-known fact that birch bark contains terpenoids that have antimicrobial properties that inhibit the growth of various microorganisms (bacteria, mold, fungi). Birch bark extract contains a set of terpenoids, but more than 70% of the total mass of substances isolated from birch bark is betulin. Betulin is one of the substances with the highest biological activity. The antioxidant, immunostimulating, hepatoprotective and antimicrobial properties of betulin determine recommendations for its use as a biologically active food supplement and the main component of drugs for the treatment of serious diseases. The remaining components of birch bark extract (lupeol, -sitosterol, flavonoids, betulinic acid, betulinic aldehyde, etc.) also have medicinal properties and are used in medications.

In accordance with the present invention, it is proposed to use a natural substance with antimicrobial properties - birch bark extract - to protect various food products from spoilage, and an additional increase in the effectiveness of such a means of protecting products from spoilage is provided by the antioxidant and hydrophobic properties of the extract. This combination of properties useful for protecting food products distinguishes the claimed product from the known ones that are similar in purpose. In addition, the advantage of birch bark extract is the possibility of using it for various methods of protecting products, including applying it in the form of a solution or dispersed system (emulsion or suspension) to the surface of a food product and modifying packaging materials based on collagen, cellulose, and polymers.

One of the most important applications of birch bark extract is its use to increase the shelf life of fruits and vegetables. The antimicrobial properties of birch bark extract suppress the development of pathogenic microorganisms, and its hydrophobic properties, mainly determined by the presence of betulin, help reduce the rate of evaporation of moisture released by fruits and vegetables during respiration. This not only protects the product from drying out, but also reduces the moisture content in the volume occupied by the product, i.e. prevents the development of pathogenic organisms on the surface of the product and on the container where it is contained. Birch bark extract can be applied to fruits and vegetables, to the inner surface of containers, and to packaging or release paper.

Birch bark extract has a property that allows it to be immobilized into high-molecular materials, which include collagen, cellulose, polyolefins, polyvinyl chloride and other polymeric raw materials, which are the main component of packaging material. The base-forming component also includes plasticizers (vegetable oils, polyols, for example, glycerin, sorbitol, polyglycol, as well as mixtures of polyols with water) and modifiers introduced into the base-forming component to give the packaging materials the desired performance characteristics. Due to the immobilization of birch bark extract, the structure of the high-molecular material is modified and its directional change occurs. As a result, packaging materials acquire the properties necessary to increase the shelf life of products: antimicrobial, hydrophobic and antioxidant. Due to syneresis, the plasticizer with birch bark extract is transferred from the bulk of the material to its surface, and since fats and polyols used in the manufacture of packaging materials as plasticizers are limitedly compatible with high-molecular materials, syneresis occurs continuously for a long time, providing protection for products packaged in such material .

When the surface of a food product is treated with birch bark extract and when the packaging material is in close contact with the food product, the birch bark extract passes into a small surface layer of the food product, giving it properties beneficial to the human body, the most important of which are antioxidant, hepatoprotective and immunostimulating. Birch bark extract is a powdery (betulin - crystalline) substance, odorless and tasteless, so it does not change the organoleptic properties of the product.

The minimum amount of birch bark extract (0.01% by weight of the base component of the packaging material or at a density of 0.1 g/m 2 on the surface of the processed product) was determined by its bactericidal effect.

To evaluate the biological activity of the proposed means of protecting products from spoilage, studies were conducted to prove that birch bark extract inhibits the growth of microorganisms. During the research, an emulsion of birch bark extract in vegetable oil was introduced into the cultural medium. The change in the number of colon-forming units was assessed. The results are shown in the table. The number of colony-forming units is taken as 100%. Changes in height are measured from control values.

Research shows that birch bark extract as a means of suppressing pathogenic microorganisms provides an increase in the shelf life of food products by at least 1.7 times when using packaging material containing birch bark extract 1% by weight of the main component. Increasing the content of birch bark extract in the composition of packaging material generally increases the shelf life of food products, but increasing the content of birch bark extract above 10% does not have a significant effect on the increase in its efficiency.

Since the biological activity of birch bark extract manifests itself at temperatures of -20°C - +220°C, it can be used to modify packaging materials in technological processes taking place at room temperatures (surface treatment of food products and packaging materials) and in the production of packaging materials, temperature the regime of which does not lead to loss of bioactivity of birch bark extract.

Packaging material means a material with a polymer, collagen-containing, cellulose (including cardboard) base component. Polymer materials are used in sausage production as sausage casings for packaging meat and fish products, cheeses, dairy products, and some agricultural products that require special measures to ensure their safety for a long time, as well as for the production of containers. Collagen-containing material is used as sausage casings. Cellulose material is used as sausage casings and for packaging various meat, fish and dairy products. Cellulose materials include cardboard, used for the manufacture of specialized containers, as well as paper as packaging materials.

Since terpenoids - the main components of birch bark extract - are insoluble in water, in a number of practical cases, birch bark extract is used in combination with liquid components, when added to which the birch bark extract dissolves or forms a dispersed system (emulsion or suspension), and one of the strong properties of betulin - the property of an emulsifier. The use of birch bark extract as part of a liquid component allows you to evenly apply birch bark extract to the surface of the food product and allows you to ensure uniform distribution of birch bark extract in the working composition used for modifying the material and, consequently, in the modified material.

As a liquid component, you can use edible vegetable and/or animal fats in a liquid state, low molecular weight and high molecular weight alcohols - polyols. When using a specific component, there is an optimal quantitative ratio between it and birch bark extract; in general, the permissible content of birch bark extract is 0.01-40% and, accordingly, the content of the liquid component is 99.99-60%. The amount of 0.01% birch bark extract in the liquid component corresponds to the amount of extract required to obtain its saturated solution in fat at 5°C.

When using birch bark extract to increase the shelf life of fruit and vegetable products, you can use a dispersed system including wax and/or paraffin.

In some cases, it is advisable to use working compositions in the form of water-fat and water-alcohol dispersed systems, while the water content in the dispersed system can vary from 5 to 30% of the total mass. This water content makes it possible to obtain a medium that ensures uniform surface treatment of food products and effectively modifies collagen-containing, cellulose and polymer materials.

The concentration of the extract in the dispersed system for coating the surface of food products is determined by the desired coating density. To protect meat, fish and dairy products, berries, it is advisable to implement a coating density with a birch bark extract content of 0.005-2 g/m2, and to protect fruits and vegetables, the coating density can be 0.005-10 g/m2. The lower limit is determined by the observed positive effect of the extract on the safety of products (cherries - for 5 days, apples - on average for 2 months when stored at a temperature of 16-18 ° C), and the upper limit is determined by economic feasibility.

Surface treatment of collagen-containing and cellulose packaging materials with such a medium does not change such important characteristics as mechanical strength, elasticity, thermal stability in the required temperature range, and in the production of sausages there is no need to change the injection modes recommended by the manufacturer of sausage casings; sausage casings retain their shape when reduced temperature without the formation of broth-fat edema.

The inventive product can be used in any known technology for treating the surface of packaging material: by immersion, irrigation, soaking.

To modify packaging materials by introducing birch bark extract into the composition of the packaging material during its production, birch bark extract can be used both with additives and without additives, introducing it into one of the components provided for by the manufacturing technology of the material and intended to obtain the required physicochemical characteristics .

In the production of modified packaging materials, as well as for surface treatment of packaging materials, you can use solutions, emulsions and suspensions based on fats and alcohols, including polyols. They are introduced into the molding (extrusion) mass as part of additives, for example, as part of a plasticizer or modifier, or immediately before the formation (extrusion) of packaging material in accordance with regulatory technology. Satisfaction of the required parameters for the physical and mechanical properties of packaging materials (tensile strength, elasticity, operational stability, etc.) is ensured with a content of birch bark extract of 0.01-7% relative to the mass of the molding (extrusion) mass.

When producing packaging material from cardboard, birch bark extract can be introduced into the molding mass before molding or the surface of the cardboard can be treated with a disperse system with birch bark extract.

When synthesizing biodegradable polymeric materials using starch as modifiers, birch bark extract can be introduced into a mixture with starch. At the same time, birch bark extract, which is a natural substance, does not prevent the decomposition of natural polymers introduced into the molding mass, which are exposed to soil microorganisms and contribute to the decomposition of polymer packaging materials.

Tests were conducted to determine the protection of food products from spoilage by treating the surface of products with birch bark extract, which confirmed the effectiveness of the use of birch bark extract. Thus, a solution containing birch bark extract in an amount of 0.01%, corn oil - 99.99%, used to treat the surface of semi-finished meat products, made it possible to increase their shelf life at a temperature of 9°C by 1.5 times.

Treatment of fruits and vegetables with birch bark extract reduces the rate of evaporation of moisture released by fruits and vegetables during respiration. This not only protects the product from drying out, but also reduces the moisture content in the volume occupied by the product, i.e. prevents the development of pathogenic microflora on its surface. There was an increase in the shelf life of expensive piece products (pineapples, melons, mangoes), which were packaged in paper sprayed with birch bark extract.

Potatoes stored in a vegetable storehouse and treated with a water-alcohol disperse system to obtain a coating with an extract density of 0.1-2 g/m 2 were preserved for 2 months longer than in the control installation. The shelf life of apricots in open containers when laying apricots in bulk increased by 14 days when applied with a water-alcohol disperse system with a density of 0.3-1.5 g/m2. When placing apples of various varieties cultivated in central Russia in wooden containers treated with a disperse system containing birch bark extract and vegetable oil, the shelf life at a temperature of 18°C ​​increased by 2 months.

The convenience of transporting the extract and the ease of preparing a working composition with birch bark extract make its use accessible to producers of agricultural products.

Tests have been carried out on a method for protecting food products from spoilage using polymer, collagen-containing and cellulose (including cardboard) modified packaging materials. The shelf life of meat and fish products and cheeses packaged in such packaging material was determined by the presence of pathogenic microorganisms on the surface of the product visually (mold) and by conducting microbiological studies; the shelf life of fruit and vegetable products was determined visually.

Tests have shown an increase in the shelf life of cheeses, meat, fish and fruit and vegetable products packaged in polymer materials by an average of 70% without changing organoleptic properties.

Tests have been carried out on sausages and cheeses in modified collagen and cellulose casings. Due to the increased gas-water impermeability of the casings, the weight loss of semi-smoked sausages, the casings of which were treated with a fat emulsion containing 1% birch bark extract, after 2 months of storage was less than 1%. After 41 days from the start of the experiment, the surface of the experimental sausage loaves was clean, shiny, without a coating of fungal mold; the sausage layer adjacent to the treated casing did not have any foreign taste, odor or color change; experimental samples of sausages had pronounced juiciness. The cheeses retained their excellent appearance for a time exceeding the established shelf life by 1.6 times (for example, Adygei cheese - 58 days after the start of the experiment). The moisture and salt content in the prototypes corresponds to GOST standards for each type of product. Gas-liquid chromatography showed the preservation of unsaturated fatty acids under the casing of sausage products.

Below are examples illustrating methods for modifying packaging materials with the claimed means for protecting food products from spoilage. These materials are intended to implement the declared method of protecting food products. The examples illustrate the industrial applicability of the invention.

A fat emulsion is prepared based on vegetable oil, containing 10-12% birch bark extract and 20% water, for which the vegetable oil is heated to a temperature of 30-35 ° C and the birch bark extract is added to it with stirring. The sausage casing, pre-soaked in water, is immersed in a container with the prepared fat emulsion for 1-2 minutes, then the casing is removed from the emulsion and kept over the container with the emulsion for 3-5 minutes, after which the casing is transferred for extrusion.

The formed sausage loaf, the casing of which has been processed in accordance with example 1, is immersed in a container with esmulsion for 1-2 minutes, then removed from the container, kept above it for 3-5 minutes, after which the sausage loaf is transferred to drying.

A fat suspension is prepared based on vegetable oil, containing 5-10% birch bark extract, for which the vegetable oil is heated to a temperature of 25-30 ° C and the birch bark extract is added to it while stirring. The sausage casing, pre-soaked in water, is immersed in a container with the prepared fat suspension for 1-2 minutes, then the casing is removed from the suspension and kept over the container with the suspension for 3-5 minutes, after which the casing is transferred for extrusion.

A fat suspension is prepared based on vegetable oil, containing 5-10% birch bark extract, for which the vegetable oil is heated to a temperature of 120°C and the birch bark extract is added to it while stirring, after which it is cooled to 40-45°C. The sausage casing is immersed in a container with the prepared fat suspension for 2-5 minutes, then the casing is removed from the suspension and kept over the container with the suspension for 3-5 minutes, after which the casing is transferred for extrusion.

A fat emulsion is prepared based on vegetable oil, containing 15% birch bark extract and 30% water, for which the vegetable oil and water are heated to a temperature of 40-45 ° C and the birch bark extract is added to it with stirring. The formed sausage loaves are hung on sticks and the surface of the sausage is irrigated with the resulting emulsion for 8 minutes.

Birch bark extract in an amount of 1% by weight of collagen-containing raw materials is mixed with glycerin and polyethylene glycol (with 7 and 2% content relative to the weight of collagen-containing raw materials, respectively), the resulting mixture is mixed with collagen-containing raw materials and then a sausage casing is formed.

Birch bark extract in an amount of 1% by weight of collagen-containing raw materials is mixed with corn oil, taken at the rate of 8% by weight of collagen-containing raw materials, the resulting mixture is mixed with collagen-containing raw materials and then a sausage casing is formed.

15% of birch bark extract and 85% of sunflower oil are mixed, then approximately the same amount of crushed low-density polyethylene is added to the resulting suspension and mixed, after which the remaining polyethylene is added in accordance with the recipe, mixed with heating and extruded. The suspension makes up 4% by weight of polyethylene.

To produce a three-layer film material, an ethylene copolymer with vinyl acetate and sunflower oil are used as a plasticizer. A suspension is prepared containing betulin - 10% and oil - 90% and this suspension is used to form the inner layer, as in example 8, and the suspension makes up 3% of the extrusion mass of the inner layer. The packaging material is produced by coextrusion using three extruders.

Example 10.

A suspension is prepared containing birch bark extract - 10% and sunflower oil - 90%, starch is added to the suspension in an amount of 25% by weight of the suspension and then the packaging material is formed in accordance with example 8. The suspension makes up 2% of the total weight of starch and polymer raw materials .

Example 11.

Before casting the cardboard web, the pulp mass is irrigated with a suspension containing birch bark extract - 15% and glycerin - 85%. Cardboard is used for storing vegetables and fruits.

Example 12.

The pulp mass is irrigated with an emulsion before casting the cardboard web intended for lamination with a polymer material. To prepare the emulsion, first prepare a suspension with 20% betulin content and 80% animal fat content, then add water in an amount of 25% by weight of the suspension while stirring.

Example 13.

Birch bark extract is mixed with ethyl alcohol, wt.%: birch bark extract - 0.3, ethyl alcohol - 99.7. The result is a solution that is sprayed onto the surface of the cardboard container.

The given examples do not exhaust all possible combinations of technological components used in the manufacture of packaging materials, and recipes for introducing into them the claimed means for protecting products based on birch bark extract. In each of the examples given, instead of birch bark extract, which contains other substances in addition to betulin, only betulin can be used, however, in some cases this is impractical, since isolating betulin from birch bark extract increases the cost of producing packaging materials.

The advantage is that birch bark extract, introduced into the composition of the new packaging material and used as a new means in implementing the method of protecting food products from spoilage, does not have a negative impact on the biosphere.

CLAIM

1. A product for protecting food products from spoilage, containing a substance with properties aimed at suppressing pathogenic microorganisms, characterized in that the above-mentioned substance is birch bark extract as part of a liquid component in which the birch bark extract dissolves or forms a dispersed system, while the content birch bark extract and liquid component is, wt.%: birch bark extract - 0.01 - 40, liquid component - 99.99 - 60.

2. The product according to claim 1, characterized in that edible fat and/or alcohol are used as a liquid component.

3. The product according to claim 1, characterized in that wax and/or paraffin is used as a liquid component.

4. A product according to any one of claims 1-3, characterized in that birch bark extract in the form of betulin is used.

5. A product for protecting food products from spoilage, which is a packaging material containing a base-forming component and a modifier that has the ability to suppress pathogenic microorganisms, characterized in that birch bark extract is used as a modifier in an amount of at least 0.01% by weight of the base-forming component.

6. The product according to claim 5, characterized in that birch bark extract in the form of betulin is used.

7. A method for protecting food products from spoilage, which involves packaging the product in packaging material made in accordance with any of paragraphs 5 and 6.

Canning is the processing of food products in order to protect them from spoilage during long-term storage. Allows you to provide the population with valuable seasonal products (vegetables, fruits, berries) throughout the year; use food products obtained in remote areas of the country (for example, fish); improve the nutrition of the population in the Far North; create food reserves and facilitate supplies for the population (in case of natural disasters) and troops (in wartime).

The canning methods used in modern conditions are presented below.

Based on application temperature levels and modes For the purpose of canning, there is scientific data on the resistance of various types of microorganisms to temperature. So sterilization of products completely destroys microorganisms, including their spores due to fairly intense (above 100 0 C) and prolonged (more than 30 minutes) temperature exposure. Such regimes lead to significant structural changes in the substance of the canned product, changes in its chemical composition, destruction of enzymes and vitamins, and changes in organoleptic properties. However, this method ensures long-term storage of canned food (up to 5 years).

Pasteurization used for inactivation only vegetative forms microorganisms. The effect can be achieved at a lower temperature and less exposure than with sterilization, which makes it possible to almost completely preserve the biological, taste and other natural properties of the product. Mostly liquid products are subject to pasteurization: milk, fruit and vegetable juices. Low pasteurization is carried out at 65 0 C (no more) for 20 minutes, high- with short-term (no more than 1 minute) exposure to a temperature of 85-90 0 C.

Cooling allows you to delay development in the product non-spore-bearing microflora, as well as limit the intensity of autolytic and oxidative processes for up to 20 days. Most often, meat is preserved by cooling (the temperature in the thickness of the product should be in the range of 0-4 0 C). Freezing leads to the formation of ice crystals in cells and an increase in intracellular pressure. When thawing (defrosting), such products differ sharply from fresh ones. To obtain the least change in tissue structure and maximum reversibility, rapid freezing (-6 0 C) is used. Rancidity of fat is prevented by reducing the temperature to –30 0 C.

Products sealed in hermetically sealed containers are heated by generators ultra high frequency(UHF) to a boil, while uniform heating of the entire thickness of the product occurs (normal heating occurs due to convection from the periphery to the center), which significantly reduces the canning time.

Preservative action dehydration based on the cessation of the vital activity of microorganisms when the moisture content in food products is less than 15% - they fall into suspended animation. Natural(solar) drying is a lengthy process, so products may be subject to infection and general contamination. A type of natural drying is fish drying. Artificial (chamber) drying jet This method is used for preserving liquid products (milk, eggs, tomato juice). The nozzle sprays the product (particle size 5-125 microns) into a special chamber with moving hot air (90 0 - 150 0 C). The suspension dries instantly and settles in the form of powder in special receivers. Drying spraying And film provides minor changes in the composition of the dried product, which is easily restored. It is carried out in chambers with a rapidly rotating disk, onto which a thin stream of heated air is directed.

Vacuum drying is carried out under vacuum conditions at a low temperature (no more than 50 0 C). At the same time, the preservation of vitamins and the natural taste properties of the dried product are ensured to the greatest extent. Lyophilization(freeze drying) is a modern and promising method of canning, which ensures the most perfect drying with maximum preservation of the natural, nutritional and biological properties of the product. First, a high vacuum is created in the sublimator, moisture is removed from the product by condensation of water vapor, and the product self-freezes (this removes up to 18% of moisture). The remaining moisture is removed during the drying process - the plate on which the food is located is heated, and the ice crystals formed during self-freezing evaporate. Further heating is carried out to 45 0 - 50 0 C. In general, drying lasts about 20 hours. An important property of freeze-dried products is their easy reversibility, i.e. recovery by adding water.

Application ionizing(radurization, radisidation and radappertization) of radiation makes it possible to most fully preserve the natural nutritional and biological properties of products and ensure their long-term, sustainable preservation. A feature of this canning is that it produces a sterilizing effect without increasing the temperature. The doses taken to irradiate products in order to extend their shelf life do not cause the appearance of harmful and toxic substances in them.

Promotion osmotic pressure in the product due to concentrated solutions of sodium chloride or sugar leads to increased removal of water from the microbial cell, its protoplasm undergoes dehydration and plasmolysis. At pickling 8-12% sodium chloride solutions are used, because most microorganisms stop growing at these concentrations. The method has a number of disadvantages:

§ a significant amount of nutrients and extractives (including protein and nitrogen) is lost;

§ the consistency and taste of products deteriorate (corned beef, salted fish, etc.);

§ when soaking, part of the nutrients goes into water.

Sugaring acts in the same way, however, the canning effect is achieved at a sugar concentration of about 60%. The effect can be enhanced by cooking (jam) or pre-pasteurization (fruit and berry syrups). Some yeasts and molds (osmophiles) are resistant to this preservation method.

Changing the pH to 4.5 slows down the development of putrefactive bacteria. Usually food acids (acetic, citric) are used for this. Pickling often combined with pre-pasteurization and salting. Pickling changes pH due to the formation of lactic acid. At the same time, other types of fermentation also take place: alcoholic, acetic acid.

Application chemical substances for canning is limited to government services, because they are not indifferent to the human body. More often than others from antiseptics Benzoic acid is used (jam, marmalade, melange, margarines, fish preserves). Limited use of boric acid and methenamine is allowed only for the preservation of caviar. Sulfurous acid and its preparations are more widely used, for example, sulfitation (grape juice, wine, marmalade, marshmallows, raw and dried potatoes, berries, fruits). The Sanitary Rules list products that are allowed to be preserved with antiseptics, and also indicate the permissible residual quantities (RQ) of preservatives.

The first and main condition for admission antibiotics in the food industry is to exclude the entry of active antibiotics into the consumer’s body (allergic reactions occur, intestinal microflora changes, etc.) as part of the food product used. It is necessary that antibiotics, along with a pronounced antimicrobial effect and low stability in the external environment (during product storage), are easily inactivated during heat treatment, do not change the taste properties of food and are not toxic. Biomycin and terramycin (tetracycline series) best meet the above requirements. They are used for processing perishable products (meat, fish), as well as in cases where the use of other preservation methods is difficult or impossible (transporting meat over long distances and delivering fish from the place of catch to fish factories). In addition to the tetracycline series, nystatin is used (to combat yeast and mold fungi) and nisin (inhibits the growth of staphylococci, streptococci, clostridia). The latter is used in canned vegetables - green peas, tomatoes, processed cheese.

Antioxidants used primarily to prevent fat oxidation. These are ortho-para-dipolyphenols, propyl gallate, butyloxytoluene, etc. Ascorbic acid and its salts have antioxidant properties. Currently, it is used as a synergist of antioxidants in animal fats, rendered fats and margarines, and also as an antioxidant in wine (150 mg/l).

Smoking - combined the impact on the food product of drying, salting, heating and the antiseptic effect of smoke. This method not only preserves, but also improves the taste and aromatic properties of products. There are also special smoking preparations that are applied to the product. It is noteworthy that smoking well masks signs of spoilage of fish.

Preservation. This method is used to produce so-called condoms - non-sterile products placed in a sealed tin container (jar). The preservative effect is achieved through salting, pickling, the action of phytoncides, etc. Preserves are products with a limited shelf life. Condoms should be stored in slightly refrigerated conditions (6 0 – 8 0 C).