preservatives- These are food additives that have their own index, which should be on the label of a product. The most common of these at present are benzoic acid (index E 210) and its salts and sorbic acid (index E 200) and its salts, such as sodium sorbate (index E201).

There is an opinion, skillfully fueled by some of the media, that all preservatives are harmful. Actually it is not. For example, the preservative additive E 300 is nothing more than ascorbic acid, that is, pure vitamin C. The head of the laboratory of food additives, Candidate of Medical Sciences A.N. only heat treatment, but also citric acid, salt, sugar (at least 63%), vinegar (acetic acid is a food additive, index E 260), etc. Sugar is harmful for someone, but to argue that the vast majority, especially for children, it is necessary in moderate doses, it is impossible. The same goes for salt. Talk about the carcinogenicity of citric acid is nothing more than a fiction wandering from newspaper to newspaper. And the artificial food additives that are widely used now, in the quantities in which they are used, do not pose a danger to either adults or children. For example, there is a lot of benzoic acid in lingonberries, in cranberries. That is why these berries, picked in the fall, lie quietly all winter and do not deteriorate. Those who are afraid of many years of accumulation of foreign substances in the body should know that scientists whose profession is to study food additives are well aware of how benzoic, sorbic acids and their salts are excreted from the body, as well as some other compounds used today as preservatives.

By adding chemical preservatives to food, you can slow down or completely prevent the development of microflora - bacteria, yeast, as well as extend the safety of products. The effectiveness of the use of chemical preservatives depends on their concentration, nature and acidity of the environment. Perhaps the use of a whole mixture of preservatives. Sulfur dioxide is one of the most common preservatives. Sulfuric acid salts are also used. Sulfur dioxide dissolves well in water, forming sulfurous acid. Sulfur dioxide has an antimicrobial effect. Salts of sulphurous acid and sulfur dioxide block the growth of yeasts, molds and bacteria, they are used to preserve juices, jams and purees. Sulfites are used as a bleaching agent. Sulfites protect peeled potatoes, cut fruits and vegetables from browning. The use of sulfur dioxide is undesirable, due to the fact that it destroys vitamins B 1, biotin.

Sorbic acid (its salts) is also used as a preservative. Sorbic acid is used in the preservation of fruit, vegetable, fish, meat products, as well as margarine. In addition, this acid is also used to treat packaging material.

One of the natural preservatives are benzoic acid and its salts (benzoates), which are part of many fruits. In the manufacture of fruit and berry products, benzoic acid is used. Sodium benzoate is used in the production of canned fish, margarine and beverages.

In the conservation of fish caviar, formaldehyde and urotropine are used.

Organic acids and their salts: formic, citric acids. Formic acid salts are used as salt substitutes. They are used in bread baking, and citric acid is used in margarine products.

Substances used as preservatives and requirements for their quality

Under preservatives understand substances that increase the shelf life of foodstuffs and protect them from spoilage caused by microorganisms.

Chemical preservatives should ensure long-term storage of products without any negative impact on its organoleptic properties, nutritional value and health of the consumer. The effectiveness of the preservative depends on its concentration, pH, and the qualitative composition of the microflora. None of the known preservatives is universal for all foods. Each preservative has its own spectrum of action.

Vitamin C. The antimicrobial effect of preservatives is enhanced in the presence of ascorbic acid. Preservatives can have a bactericidal (destroy, kill microorganisms) or bacteriostatic (stop, slow down the growth and reproduction of microorganisms) action.

One of the main signs of hygienic regulation of chemical preservatives is their use in concentrations that are minimal to achieve a technological effect.

The use of antimicrobial agents at lower doses may promote the growth of microorganisms. This must be taken into account when developing sanitary rules and regulations for food additives and their practical application.

Sulfur compounds. Widespread preservatives include sulfur compounds such as anhydrous sodium sulfite (Na 2 S0 3) or its hydrated form (Na 2 S0 3 7H 2 0), acidic sodium metabisulfate (thiosulfate) (Na 2 S 2 0 3), or sodium hydrosulfite (NaHS0 3). They are highly soluble in water and emit sulfur dioxide (SO 3), which is due to their antimicrobial effect. Sulfur dioxide and the substances that release it mainly inhibit the growth of moulds, yeasts and aerobic bacteria. In an acidic environment, this effect is enhanced. To a lesser extent, sulfur compounds affect the anaerobic microflora. Sulfur dioxide has a high reducing power because it is easily oxidized. Due to these properties, sulfur compounds are strong inhibitors of dehydrogenases, protecting potatoes, vegetables and fruits from non-enzymatic browning. Sulfur dioxide is relatively easy to leave the product when heated or prolonged contact with air. However, it is able to destroy thiamine and biotin and enhance the oxidative breakdown of tocopherol (vitamin E). Sulfur compounds are not advisable to use for canning food, which is the source of these vitamins.

Once in the human body, sulfites are converted into sulfates, which are well excreted in urine and feces. However, a large concentration of sulfur compounds, such as a single oral administration of 4 g of sodium sulfite, can cause toxic effects. The acceptable daily intake level (ADI) for sulfur dioxide, established by the FAO/WHO JECFA, is 0.7 mg per 1 kg of human body weight. Daily consumption of sulphated foods may result in exceeding the allowable daily dose. So, with one glass of juice, about 1.2 mg of sulfurous anhydride is introduced into the human body, 200 g of marmalade, marshmallow or marshmallow - 4 mg, 200 ml of wine - 40 ... 80 mg.

Sorbic acid. It mainly has a fungicidal effect due to its ability to inhibit dehydrogenases and does not inhibit the growth of lactic acid flora, therefore it is usually used in combination with other preservatives, mainly sulfur dioxide, benzoic acid, sodium nitrite. Salts of sorbic acid are widely used.

The antimicrobial properties of sorbic acid do not depend much on the pH value, so it is widely used in the preservation of fruit, vegetables, eggs, flour products, meat, fish products, margarine, cheeses, and wine.

Sorbic acid is a low-toxic substance, in the human body it is easily metabolized with the formation of acetic and

B-hydroxybutyric acids. However, there is a possibility of the formation of sorbic acid D-lactone, which has carcinogenic activity.

Benzoic acid. The antimicrobial action of benzoic acid (C 7 H 6 0 2) and its salts - benzoates (C 7 H 5 0 5 Na, etc.) is based on the ability to suppress the activity of enzymes. In particular, the inhibition of catalase and peroxidase accumulates hydrogen peroxide, which inhibits the activity of the microbial cell. Benzoic acid is able to block succinate dehydrogenase and lipase, enzymes that break down fats and starch. It inhibits the growth of yeasts and bacteria of butyric acid fermentation, has little effect on bacteria of acetic acid fermentation, and has very little effect on lactic acid flora and molds.

n-hydroxybenzoic acid and its esters (methyl, ethyl, n-propyl, n-butyl) are also used as preservatives. However, their preservative properties are less pronounced, a negative effect on the organoleptic properties of the product is possible.

Benzoic acid practically does not accumulate in the human body. It is a part of some fruits and berries as a natural compound; esters of n-hydroxybenzoic acid - in the composition of plant alkaloids and pigments. In small concentrations, benzoic acid forms hippuric acid with glycol and is completely excreted in the urine. In high concentrations, the manifestation of the toxic properties of benzoic acid is possible. The permissible daily dose is 5 mg per 1 kg of human body weight.

Boric acid. Boric acid (H 3 B0 3) and borates have the ability to accumulate in the human body, mainly in the brain and nerve tissues, exhibiting high toxicity. They reduce tissue oxygen consumption, ammonia synthesis and adrenaline oxidation. In this regard, these substances are not used in our country.

Hydrogen peroxide. In a number of countries, when preserving milk intended for making cheeses, hydrogen peroxide (H 2 0 2) is used. It should not be present in the finished product. Milk catalase breaks it down.

In our country, hydrogen peroxide is used to bleach slaughterhouse blood. Additionally contribute catalase to remove residual hydrogen peroxide. Catalase is used in the manufacture of roots for various semi-finished products.

Food preservation is one of the main processes in the food industry, widely used to extend shelf life, reduce losses from microbial spoilage and preserve the quality of perishable foods. Canning makes it possible to provide the population with a wide range of food products, regardless of the time and place of production.

Among the various methods of preserving food products (fermentation, pickling, salting, freezing, sterilization, pasteurization, irradiation, etc.), a special place is occupied by the preservation of perishable food raw materials and finished products with the help of chemical preservatives - substances with antimicrobial action.

In the practice of preservation, bactericidal or fungicidal, but more often bacteriostatic or fungistatic properties of chemical preservatives are used. In the first case, bacteria and molds die, in the second, their development slows down. The addition of preservatives at the appropriate concentration ensures the sterility of the product for a certain time, provided that there is no re-contamination or significant change in the environment.

In chemical preservation, the bactericidal (fungicidal) activity of the preservative is usually distinguished, with the concentration and duration of exposure playing a certain role.

The mechanism of antimicrobial action of preservatives is presumably as follows:

Chemicals accumulate on the surface or inside microorganisms as a result of adsorption, normal diffusion and active absorption;

There is a chemical reaction of the preservative with the structural components of the cell or metabolites inside the cell;

The normal activity of the microbial cell is terminated as a result of a change in the chemical reaction of the environment;

There is a gradual or instantaneous inhibition of the biochemical mechanisms of the development of microbes.

These mechanisms are significantly affected by the properties of the medium:

pH of the environment of the preserved product;

partial pressure of oxygen;

The redox potential of the substrate;

Product moisture;

Osmotic pressure;

absorption capacity;

Temperature and relative humidity;

These parameters can affect the antimicrobial activity of substances as a result of improving or worsening the conditions for the vital activity of microorganisms. The effect of preservatives is indirectly affected by the content of vitamins in canned foods. For example, B vitamins can promote the growth of microorganisms.

The antimicrobial action of one substance can be enhanced under certain conditions by the action of another substance. Thus, table salt contributes to better penetration of the preservative through the cell membrane of microorganisms. The combination of chemicals that are weak at elevated pH with organic acids (eg citric, tartaric, malic) increases the preservative effect.

By combining various preservatives, it is possible to significantly enhance the antimicrobial effect in a mixed environment with hydrophilic and lipophilic properties. As a result of the use of preservatives with different solubility or specific effects, the scope of their use is also expanding significantly.

As preservatives, it is allowed to use chemicals that inhibit germination and slow down the development of microorganisms when food is stored fresh.

Preservatives and preservative mixtures may be dissolved in water, ethyl alcohol, glycerin, calcium carbonate, acetic, lactic, tartaric and citric acids and used in this form in production.

The use of preservatives in the food industry cannot be completely excluded, despite their negative effect on any biological objects. However, it must be limited, since their safety can be proven with a certain degree of probability.

The use of preservatives is justified only in cases where a technological economic effect is achieved and if such an effect cannot be achieved by other, for example, physical, methods.

When authorizing the use of a preservative, the minimum concentration of that substance necessary to achieve the desired effect for that product is allowed.

Chemical preservatives are divided into inorganic and organic.

Inorganic preservatives:

Boric acid and its derivatives (borates or borax);

Hydrogen peroxide;

Sulfur dioxide, sulfurous acid, sodium sulfite, sodium and potassium hydrosulfite; pyrosulfite sodium and potassium;

Silver and its compounds (silver chloride, sodium complex with silver chloride, silver sulfate);

Nitrogen oxides;

Nitrogen chloride NCl 3 ;

Chlorine, a mixture of chlorine and nitrosyl chloride (NOCL);

Nitrates and nitrites.

Consider some of the inorganic preservatives most used in the food industry.

Borax and borates. The preservative effect of boric acid and borates is based on the disruption of phosphate metabolism and the intense blocking of amino acid decarboxylation in the microbial cell. Traces of borates are found not only in soils, mineral waters, rocks, but also in honey, wines, fruits and other plant products. Boric acid and borates are rapidly absorbed by the body, but are slowly excreted. It has been established that the utilization of fats and proteins from products preserved with boric acid is disrupted in the body. In addition, the acid destroys vitamin B 6, as it forms complexes with pyridoxal and pyridoxamine. The FAO-WHO Expert Committee on Food Additives and the Codex Alimentarius Commission consider that the use of boric acid and borax for food preservation is unsafe for human health due to their toxicity. PSP should be no more than 0.1 g per kilogram of body weight.

Hydrogen peroxide has bactericidal properties, especially in the case of an acid reaction of the substrate. It can be used to preserve drinking water, milk, jelly, crabs, beer, as well as an ice additive when transporting marine fish and fermenting dough. Hydrogen peroxide gives the products an unpleasant aftertaste, adversely affects proteins, components of fats and vitamins.

Sulfurous acid and its salts, sulfur dioxide. The non-dissociated part of sulfurous acid has a preservative effect. The lower the pH and the higher the temperature, the stronger the preservative effect of sulfurous acid.

The action of this acid is associated with the dissolution of the lipoprotein complex of the microbial cell and its entry into the plasma. The structure of the plasma envelope changes, and the microorganisms die. In addition, sulfurous acid has reducing properties; is an oxygen acceptor and holds the breath of microorganisms, changing the value of the redox potential. The acid can react with the intermediate products of the vital activity of microorganisms, disrupt the metabolism and thereby cause the death of microorganisms.

The preservative effect of the acid is observed when the product contains 0.1-0.2% sulfur dioxide. The effectiveness of its action depends on the pH value, the chemical composition of the medium, the concentration of microorganisms and temperature. The higher the initial contamination of the product, the more microorganisms survive.

Sulfurous acid and sulfur dioxide are used not only as preservatives, but also as bleaches, as they prevent oxidative changes in fruit and vegetable semi-finished products caused by the enzymatic darkening of phenolic compounds and the destruction of ascorbic acid.

However, SO 2 destroys vitamin B 1, decomposing it into pyrimidine and thiazole. In high doses, SO 2 has a harmful effect on the human body and gives the products a specific smell, which is felt at a concentration of about 5 mg per 100 g of product.

Due to the toxicity of sulfur compounds, sulphated products are used only for processing into such types of products, the technology of which provides for the possibility of heat treatment for the purpose of desulfurization.

From sulphited semi-finished products, where part of the antiseptics is in a bound form, complete removal of SO 2 does not occur, and part of it remains in the product. The content of the residual amount of SO 2 in the product is strictly regulated, and for most products it should not exceed 0.01% by weight of the total amount of the product (bound + free) or 0.02% free.

Salts of sulfurous acid - sulfites and bisulfites - can be used for preserving semi-finished products with a pH of 3.5 and below. Reacting with the organic acids of the fruit, the salts release sulfur dioxide, which is an antiseptic.

To replace one gram of sulfur dioxide, 1.6 g of sodium bisulfite or 1.8 g of potassium bisulfite must be added. Salts must be chemically pure, without any impurities.

Sulfitation is used in the preparation of whole fruits, purees and juices. Whole fruits can be preserved with SO 2 gas or its solutions (wet method). Stone fruits, when preserved with gas, crack, lose their juice, and their consistency becomes very softened. Therefore, wet sulfitation is used for stone fruits and berries. Pome fruits and citrus fruits retain their shape and texture well, they are sulphited with gaseous SO 2 . Gaseous SO 2 is also used for the sulfitation of purees and juices.

Dry sulfitation of pome fruits (fumigation) consists in the use of SO 2 obtained by burning sulfur, or liquid from cylinders. The duration of fumigation is approximately 10-20 hours, depending on the variety and type of fruit.

Sulfur dioxide and sulfites are also used in the production of fruit and berry and grape wines, drinks, fruit vinegars, dried potatoes and vegetables, starch and other products.

MPC, depending on the type of product, varies from 30 to 3000 mg SO 2 per kilogram of product. In such concentrations, due to its volatility and good excretion from the body, SO 2 does not pose a danger to humans. Sulfites accelerate oxidative processes, destroy vitamin E, thiamine and biotin. In the human body, sulfites are oxidized to sulfates and are easily excreted.

A special group of preservatives includes nitrogen oxides, chlorine, nitrosyl chloride, nitrogen chloride, fluorine, silver, ozone, nitrites, nitrates.

Organic chemical preservatives:

Benzoic acid and its salts;

P-hydroxybenzoic acid and its derivatives;

Sorbic acid and its derivatives;

Salicylic acid and its sodium salt;

Formic acid and its sodium, calcium and potassium salts;

Ethyl and propyl esters of p-hydroxybenzoic acid and its salts;

Hexamethylenetetraamine;

Diphenyl, o-phenylphenol and its sodium salt;

Propionate and calcium acetate;

Diethyl ester of pyrocarbonic acid.

Consider the most common organic chemical preservatives.

Benzoic acid and its salts. Benzoic acid C 6 H 5 -COOH is colorless crystals in the form of needles or leaflets. Its density is 1.265 g/cm 3 at 15°C, melting point 122.4°C. The acid is poorly soluble in water, but well - in alcohol and ether.

In a small amount (less than 0.1%), the acid is found in some berries and fruits (blueberries, raspberries, currants, plums), as well as in cloves, anise oil, etc.

The preservative effect of benzoic acid and its salts is based on the suppression of the activity of catalase and peroxidase, as a result of which hydrogen peroxide accumulates in cells. At low concentrations, these preservatives inhibit the growth of aerobic microorganisms. The most active is benzoic acid and its salts at a concentration of 0.1-0.4%.

Benzoic acid is effective in an acidic environment, while its inhibitory effect is negligible in neutral and alkaline environments. Therefore, this preservative is recommended for preserving food products having a pH less than 5.

The presence of proteins in the product increases the resistance of microorganisms and reduces the preservative effect of benzoic acid. When added to the product, only a small part of the benzoic acid remains free and acts as a preservative, while the majority binds to proteins.

Benzoic acid and its salts do not have reducing and bleaching properties, so products with these antiseptics are darker than sulphated ones.

Preservative p-hydroxybenzoic acid and its esters. The sodium salt of this acid and its esters are used: methyl (nipagin M), ethyl (nipagin A), n-propyl (nipazole), n-butyl (nipa-butyl), benzyl ester - nipabenzyl. Acid and its esters - of plant origin - are part of alkaloids and pigments. The acid is found in ripened cheese. As a preservative, p-hydroxybenzoic acid is less effective than its esters. Bacteria, molds and yeasts die in a solution of this acid at a concentration of 0.86%. Esters are effective at 0.05-0.1%. The esters are suitable for use in neutral food products. Ethyl and propyl ethers are approved for the preservation of a wide range of food products.

Esters of p-hydroxybenzoic acid are antispasmodics; they inhibit or stimulate the activity of various enzymes; from the human body, the acid is excreted mostly unchanged.

Sorbic acid and its salts.

Sorbic acid (CH 3 -CH=CH-CH=CH-COOH) is a crystalline powder, poorly soluble in water. Salts of sorbic acid (sorbates) have a higher solubility.

Sorbic acid and sorbates inhibit the growth of yeasts and molds; almost no effect on acid-forming and other types of bacteria. Therefore, they are used to preserve only acidic foods or mixed with other antiseptics.

The concentration of sorbic acid in semi-finished products should be 0.05-0.06%, in finished products - less than 0.05%.

Sorbic acid and sorbates in the human body are oxidized, decomposing to CO 2 and H 2 O in the presence of glucose or to acetoacetic acid in the absence of glucose in the composition of the product.

Due to the rapid decomposition, sorbic acid and sorbates do not have a toxic effect on the human body.

In recent years, sorbic acid and its salts have been allowed in almost all countries as a preservative at concentrations of 0.01-1.2% for margarine, cheese, egg yolk, vegetable and fruit, fish and meat products, biscuits, wine and other products. . Sorbic acid is used to impregnate packages used to store margarine, cheese, bread.

Salicylic acid and its sodium salt. Salicylic acid is poorly soluble in water, sodium salt is good. The antimicrobial action is based on the suppression of enzyme activity during the formation of pantothenic acid, inhibition of the activity of pepsin, catalase and pancreatin.

Salicylic acid was previously used on a large scale to preserve cucumbers and other vegetables and fruits. For packaging marmalades and jams, paper impregnated with salicylic acid is widely used. Currently, in most countries, this substance is not used for canning.

Salicylic acid is rapidly absorbed in the intestines and is not excreted from the body for a long time. It can accumulate, which is especially dangerous for children. In a small amount, salicylic acid passes into breast milk. In high concentrations, it causes damage to the mucous membranes, disruption of the central nervous system and blood circulation, hearing disorders and kidney function.

The FAO-WHO Expert Committee on Food Additives considers this preservative hazardous to human health even in small doses and does not recommend the use of salicylic acid as a food preservative.

Antibiotics. To prevent food spoilage, antibiotics are used mainly from the tetracycline group (chlortetracycline and terramycin).

In addition, penicillin, subtillin, streptomycin, chloramphenicol, nisin, etc. have been proposed for preservation.

Antibiotics are used in the following treatments:

Irrigation or immersion of products in a solution of antibiotics (acronization);

Injection of solutions of antibiotics and table salt into the vascular system of animals;

Use of ice containing antibiotics during transportation and storage (mainly for fish);

Additive solutions to various food products (milk, cheese, canned vegetables, juices, beer);

Spraying fresh vegetables.

Acronization is more commonly used. The products are immersed in a solution containing 10-50 mg/l of antibiotic, and kept in it from several minutes to two hours. This method is often used in combination with cooling. The preservation of meat is doubled.

Chlortetracycline is effective against microorganisms. But at the same time, resistant varieties of staphylococci and salmonella may appear.

Antibiotics used as preservatives, as a rule, are partially destroyed during storage or during culinary processing of products.

By resistance to temperature effects, antibiotics are divided into such as:

thermosensitive (penicillin, chlortetracycline);

Heat-resistant (streptomycin, kanamycin);

Moderately persistent (tetracycline, erythromycin, oxytetracycline).

The heat resistance of antibiotics depends on many factors: the pH value, the temperature and duration of the process, the type of heat treatment, the type of proteins and the concentration of antibiotics.

Many countries have abandoned the use of antibiotics as preservatives for hygiene reasons. In a number of countries, the use of nisin is allowed to increase the shelf life of processed cheeses, biscuits, mayonnaise, fillings, ready meals, canned and pickled vegetables, and some dairy products.

In modern stores you can find a large number of products that have a beautiful appearance and pleasant aroma. Keep in mind that many of them contain preservatives. increasing the shelf life of products.

concept

Every product is damaged. In any protein, processes occur that cause the product to be unusable. The change in the chemical composition and structure of a protein is called autolysis. Its final stage is decay, decomposition and further entry into the circulation of substances in nature.

This process will not be as fast if the food is placed in the freezer. But since this is not always obtained, then preservatives are used. These are the components needed to extend the shelf life of products. The process is achieved by suppressing the microflora. Food changes according to taste.

Many products contain some kind of preservative. The definition of this concept is always the same, no matter what substance is in its composition. Previously, only natural additives were used, such as salt, vinegar, sugar. Due to the development of industry, it became necessary to preserve food without changing its taste. Therefore, synthetic preservatives are now used. These are artificial substances that improve the properties of products.

Types of additives

Additives are distributed according to the EU codification system, where each product has an index (E200-E297). Components have different effects on products. Some are used in their composition, while others only process the outer part.

The definition of food preservatives allows you to distribute them into:

• Synthetic.
• Natural.

The second components are also not completely harmless to humans. For example, salt in large quantities still affects the human condition. Therefore, harmless additives are considered those that are used in moderation. This also applies to synthetic components. Some are safe when consumed in moderation.

Harmful Additives

But among the additives there are those substances that cause great harm to humans. In some countries they are outright banned. These include:

• Benzoates (E211, E216, E217). They are found in products sold in plastic containers. Substances can cause bronchial asthma and allergies.
• (dyes) are highly toxic components. They are used to protect against the development of botulism spores, which are considered more dangerous than preservatives.
• Antioxidants (protect products from oxidation). For this, it is safer to use lecithin, tocopherol, citric, ascorbic acid. But there are also synthetic antioxidants that are part of raw smoked sausage, vegetable, butter, dried fruits.

What are they made from?

All preservatives are acids because microbes cannot survive near them. Only they must be approved for use in the food industry. These include acetic acid and salts of benzoic acid. Additives are created by chemical synthesis. This work is performed exclusively under sterile conditions.

Very rarely, manufacturers use only one preservative. Mixtures and preservative components are usually used. Such substances are found in many products that are sold in modern stores.

Natural additives include salt, honey, sugar, vinegar. They are used at home during cooking. But in production, this is unprofitable, because it is difficult to get a neutral taste with them and extend the shelf life. That is why products with preservatives are sold in stores for a long time and do not deteriorate. Buyers only need to choose those products that contain safe additives.

Food additives (there are several hundred of them) are an easy and cheap way to make a product look attractive, enhance flavor and extend its shelf life. According to the International Classification System, food additives are divided into groups according to the principle of action. The group is determined by the first digit after the letter E.
E100 - E182 Dyes. Enhance the color of the product.
E200 - E299 Preservatives. Extend the shelf life of the product.
E300 - E399 Antioxidants. Slow down oxidation, similar in action to preservatives.
E400 - E499 Stabilizers - keep the desired product consistency. Thickeners - increase viscosity.
E500 - E599 Emulsifiers. Maintain a homogeneous mixture of immiscible products such as water and oil.
E600 - E699 Flavor and odor enhancers.
E700 - E899 Reserved numbers.
E900 - E999 Defoamers. Prevent or reduce foam formation.

THE ROLE OF PRESERVATIVES IN THE FOOD INDUSTRY

Preservatives are food additives that increase the shelf life of foods by protecting them from spoilage caused by bacteria, yeasts and molds.

By adding preservatives to food, it is possible to slow down or completely prevent the development of microorganisms and, accordingly, prolong the safety of products. The effectiveness of the use of preservatives depends on their concentration, nature and acidity of the medium.

Preservatives kill bacteria and thus extend the shelf life of foods. A person does not die from eating preservatives, because he has a large mass, and also because preservatives are partially destroyed in the stomach under the influence of hydrochloric acid.

Preservatives can be conditionally divided into two groups: preservatives proper and substances that have a preservative effect. The action of the actual preservatives is directed directly to the cells of microorganisms. Substances with a preservative effect affect microbes by lowering the pH of the medium, water activity and oxygen concentration.

Each preservative has its own spectrum of action. Therefore, the joint use of several preservatives and their combination with physical preservation methods (drying, heating, cooling, etc.) is more effective.

Currently, in order to optimize the positive effect of preservatives, their special balanced mixtures have been developed for each group of food products.

An important condition for the effective use of a preservative is its uniform distribution in the product. The stage of its introduction into food products is determined by the production technology. The best moment is considered immediately after heat treatment and before mixing.

There are many different classifications of preservatives. The simplest: natural and synthetic. Natural preservatives are salt, sugar, vinegar, citric acid, alcohols. In modern production, acid derivatives of organic compounds are used - synthetic preservatives.

On the shelves of stores there are a huge number of food products that smell good and look beautiful. This abundance is provided by a huge number of different preservatives. It is simply impossible to refuse preservatives today. It was they who created this range of food products. Used in all branches of the food industry, they protect a huge number of products. If all preservatives are removed by a strong-willed decision today, then in a few days humanity will simply have nothing to eat.

SUBSTANCES USED AS PRESERVATIVES

Currently, none of the known preservatives is universal for all food products. Each preservative has its own spectrum of action.

The antimicrobial effect of preservatives is enhanced in the presence of ascorbic acid.

Benzoic acid and its salts (benzoates) are one of the natural preservatives found in many fruits. It is used in the manufacture of fruit and berry products. Sodium benzoate is used in the production of margarine, canned fish and drinks.

Preservatives include sulfur compounds such as anhydrous sodium sulfite (Na 2 S0 3) or its hydrated form (Na 2 S0 3 7H 2 0), acidic sodium metabisulfate (thiosulfate) or sodium hydrosulfite (NaHS0 3). These preservatives are highly soluble in water and emit sulfur dioxide (SO 3 ), which is responsible for their antimicrobial action. With one glass of juice, approximately 1.2 mg of sulfurous anhydride is introduced into the human body, and 200 ml of wine contains 40 ... 80 mg of a preservative. Once in the human body, sulfites are converted into sulfates, which are well excreted in the urine.

Sorbic acid (its salts) is also used as a preservative. It is used in the preservation of fruit, vegetable, fish, meat products and margarine. Also, this acid is used to treat packaging material.

Hydrogen peroxide (H 2 0 2) is used in a number of countries in the preservation of milk intended for the manufacture of cheese. In the finished product, this preservative should be absent. Milk catalase breaks it down.

Formic acid (HCOOH) in its organic structure belongs to fatty acids and has a strong antimicrobial effect. It is found in small amounts in plant and animal organisms. At high concentrations, it has a toxic effect, so it is used as a preservative to a limited extent.

Propionic acid is widely distributed in nature, being an intermediate link in the Krebs cycle, which provides biological oxidation of proteins, fats and carbohydrates. In a number of European countries, it is added to flour, and in the USA it is used as a preservative in the production of bakery and confectionery products.

Nitrates and nitrites of sodium and potassium (NaN0 3 , KN0 3 , NaN0 2 , KN0 2) are widely used as preservatives in the production of meat and dairy products. In the manufacture of sausages, sodium nitrite is added no more than 50 mg per 1 kg of the finished product, some varieties of cheeses and cheese - no more than 300 mg per 1 liter of milk used. The use of these substances in baby food products is not allowed.

Naphthoquinones are used to stabilize soft drinks and provide suppression of yeast growth. Of these, juglone (5-hydroxy-1,4-naphthoquinone) and plumbagin (2-methyl-5-hydroxy-1,4-naphthoquinone) are the most widely used. These preservatives have low toxicity and have a 100-fold safety threshold.

The choice of preservatives and their dosage depend on the degree of bacterial contamination and the qualitative composition of the microflora; production and storage conditions; the chemical composition of the product and its physico-chemical properties, as well as the expected shelf life.

requirements for preservatives

In any civilized country, the following requirements are imposed on preservatives used in the food industry:
- be harmless to the human body (in the amount of the applied dose) or easily removed from the product before it is eaten;
- be effective in small quantities;
- not to reduce the nutritional value of products and not to give them an extraneous, undesirable taste and smell;
- do not enter into a chemical reaction with the materials from which the equipment or containers are made.

PROPERTIES OF SOME PRESERVATIVES

Preservatives have been used for several millennia. The most ancient natural preservatives are salt, wine, honey, alcohol, vinegar. Currently, synthetic preservatives are more often used in the production of products, as they are more effective and lower cost. According to European standards, a group of preservative additives is labeled from E200 to E299.
E200 Sorbic acid - colorless crystals, t pl. = 134 °С. Contained in rowan juice. The preservative is actively used in almost all branches of the food industry.
E201 Sodium sorbate - used for preserving canned fruits and vegetables, eggs and confectionery, meat and fish products, fruit juices and soft drinks.
E202 Potassium sorbate - white powder or granules. The preservative is used in the production of cheeses, fats, vegetable oils (except olive), margarine, butter, mayonnaise.
E203 Calcium sorbate - used for preserving egg, meat and fish products, fruit and vegetable preserves, fruit and berry juices and soft drinks.
E209 Para-hydroxybenzoic acid heptyl ester. The preservative is not allowed for use in Russia, is in the process of research.
E210 Benzoic acid - colorless crystals, t pl. = 122.4 °С. The preservative is used in the production of dyes, medicinal and aromatic substances, in medicine as an external agent of antimicrobial and fungicidal action. Causes cancerous tumors, allergic reactions.
E211 Sodium benzoate is used in the production of marmalade, marmalade, melange (confectionery), fruit juices, sprat, caviar, semi-finished products.
E213 Calcium benzoate. The preservative is included in the list of food additives that do not have permission for use in the food industry in the Russian Federation.
E214 Para - Hydroxybenzoic acid ethyl ester. Banned in several countries.
E215 Para-hydroxybenzoic acid ethyl ester sodium salt. The preservative is not allowed for use in the food industry in the Russian Federation.
E215 Para - Hydroxybenzoic acid ethyl ester sodium salt. Banned in several countries.
E216 Para - Hydroxybenzoic acid propyl ester.
E218 Para-hydroxybenzoic acid methyl ester. The preservative is not allowed for use in the Russian Federation.
E219 Para-hydroxybenzoic acid methyl ester sodium salt. The preservative is included in the list of food additives that do not have permission for use in Russia.
E220 Sulfur dioxide. The preservative negatively affects the function of the kidneys. Respiratory irritant, may trigger an asthma attack.
E222 Sodium hydrosulfite.
E223 Sodium pyrosulfite. Preservative, antioxidant, bleaching agent. Dangerous for asthmatics.
E224 Potassium pyrosulfite. Dangerous for asthmatics.
E225 Potassium sulfite. preservative, antioxidant. Included in the list of food additives that do not have permission for use in the food industry in the Russian Federation.
E226 Calcium sulfite. Banned in several countries. The preservative is not allowed for use in the food industry in the Russian Federation.
E227 Calcium hydrosulfite. The preservative is not allowed for use in the Russian Federation.
E228 Potassium bisulfite. The preservative is included in the list of food additives that do not have permission for use in Russia.
E230 Diphenyl. Banned in several countries. The preservative is included in the list of food additives that do not have permission for use in the food industry in the Russian Federation.
E231 Ortho-Phenylphenol. The preservative is not allowed for use in the food industry in the Russian Federation.
E232 Ortho-Phenylphenol sodium salt. The preservative is not allowed for use in the Russian Federation.
E233 Tabendazole. Banned in several countries. The preservative is included in the list of food additives that do not have permission for use in Russia.
E234 Lowlands.
E235 Pimaricin, Natamycin. May cause allergic reactions, nausea and diarrhea.
E236 Formic acid. Banned in several countries. The preservative is included in the list of food additives that do not have permission for use in the food industry in the Russian Federation.
E237 Sodium formate. Banned in several countries. The preservative is not allowed for use in the food industry in the Russian Federation.
E238 Calcium formate. Banned in several countries. The preservative is not allowed for use in the Russian Federation.
E239 Hexamethylenetetramine - colorless crystals of sweet taste. Used for preserving fish products. Banned in several countries.
E240 Formaldehyde - in everyday life is known in the form of an aqueous solution of formalin. The preservative is banned in Russia and in a number of countries.
E241 Guaiac resin. The preservative is included in the list of food additives that do not have permission for use in Russia.
E242 Dimethyl dicarbonate.
E249 Potassium nitrite. Possibly a carcinogen. It is forbidden to use in baby food.
Е250 Sodium nitrite - colorless or yellowish crystals. Dissolves in water. The preservative is used in the production of meat products to preserve an attractive pinkish color.
Е251 Sodium nitrate - colorless crystals. Hygroscopic, soluble in water. The preservative is used in the production of meat and sausage products.
E252 Potassium nitrate. There are restrictions on its use in many countries. The preservative is included in the list of food additives that do not have permission for use in the food industry in the Russian Federation.
E260 Glacial acetic acid. Preservative, acidity regulator.
E261 Potassium acetates.
E262 Sodium acetate.
E263 Potassium acetate. Stabilizer, acidity regulator. The preservative is not allowed for use in the food industry in the Russian Federation.
E264 Ammonium acetate. The preservative is not allowed for use in the Russian Federation.
E265 Dehydroacetic acid.
E266 Sodium dehydroacetate.
E270 Lactic acid. It is widely used as a preservative in the manufacture of cheese and a variety of other dairy products.
E280 Propionic acid.
E281 Sodium propionate. The preservative is included in the list of food additives that do not have permission for use in Russia.
E282 Calcium propionate. The preservative is included in the list of food additives that do not have permission for use in the food industry in the Russian Federation.
E283 Potassium propionate. The preservative is not allowed for use in the food industry in the Russian Federation.
E285 Sodium tetraborate.
E290 Carbon dioxide - used in the production of soda, in the carbonation of water, in fire extinguishers.
E296 Malic acid. The preservative is not recommended for use in baby food.
E297 Fumaric acid. Acidity regulator.

About the dangers of preservatives

Most preservatives have a negative effect on the human body. Some of them have a detrimental effect on vitamins: sorbic acid destroys vitamin B12, sulfur dioxide destroys vitamin B1. Many preservatives are mild or pronounced carcinogens: benzoic acid, sodium benzoate, para-hydroxybenzoic acid ethyl ester, orthophenylphenol, formaldehyde. Synthetic preservatives can cause allergies, up to asthma attacks, headaches and nausea, especially in people prone to allergic reactions.

A particularly dangerous group of preservatives are nitrates and nitrites (E250 - sodium nitrite, E251 - sodium nitrate, E252 - potassium nitrate). In the process of processing, minced sausage loses its soft pink color, turning into a gray-brown mass. With the help of nitrates and nitrites, boiled sausage acquires a pleasant color of fresh veal. Nitro additives are also found in smoked fish, sprats, and canned herring. They are also added to hard cheeses. Once in the body, they form new compounds called nitrosamines, which reduce resistance to infections and cause cancer.

Preservative E 211 destroys the liver, disrupts the nervous system, and in combination with vitamin C causes cancer. Some preservatives can interfere with blood pressure.

Preservatives are present in almost all products. In drinks, confectionery, meat and fish products, etc. Milk bought in a store, thanks to preservatives, does not turn sour, but rots. Even fruits, such as citrus fruits, are treated with diphenyl E 230. This food additive is an extremely dangerous and poisonous substance that causes vomiting if accidentally inhaled. Once in the body, this preservative causes cancer, diseases of the kidneys, liver, blood vessels and nervous system.

Preservatives cause great harm to human health due to the fact that they suppress bacteria not only contained in products, but also beneficial bacteria in the human body, which are simply necessary for its normal functioning.

Do not buy products with a long shelf life indicated on the label. This is a sign that there are a lot of preservatives in there. As a rule, these are products brought from distant regions, and even from other countries.
Avoid brightly colored foods.
Avoid yogurt with berries, as they contain a huge amount of preservatives.
Eliminate foods with a high content of preservatives (sausages, cheeses and other gastronomy) from your diet.
Eat organic foods - fresh raw vegetables, fruits and berries.
Wash fruits and vegetables thoroughly, peel them before eating - although their peel contains many vitamins, the greatest amount of nitrates also accumulate there.
To neutralize the harm caused by the use of foods with preservatives, periodically cleanse the body.

Vegetables and fruits purchased at the nearest agricultural market have their own unique taste. And dishes prepared from fresh vegetables, seasoned with fragrant olive oil, in themselves become a storehouse of vitamins. But extraordinarily tasty natural vegetables and fruits quickly lose their original natural appearance, during storage, the aroma begins to be lost, the appearance deteriorates, and the taste leaves much to be desired.

So how can we preserve these delicate sources of vitamins so that we can enjoy a salad that is still tasty and fragrant in winter? For this, food is preserved. Of the physical ways to preserve food, the simplest is freezing. The second simplest method of preservation, known since ancient times, is the use of salt and sugar. Thus, various vegetables are preserved and harvested: cabbage, cucumbers, tomatoes, mushrooms, berries and fruits. Such methods of conservation are very important, as they contribute to the preservation of vitamins and microelements of the raw materials, and, most importantly, they are the most harmless to our body.

Along with the use of the simplest seasonings - sugar and salt, large manufacturers of ready-made food products add preservatives to their recipes that slow down or prevent the development of bacterial microflora. To navigate the vast sea of ​​such E-additives quite freely, we must first consider what they really are and whether they are as dangerous as the media scares us.

Preservatives are food additives E200-E299. Their action is aimed at suppressing, slowing down and preventing the growth of bacteria that cause spoilage of certain foods. In the long list of these additives, there are both useful for our body, for example, ascorbic acid (vitamin C), and harmful and even forbidden additives.

The action of preservatives is aimed at increasing the shelf life of food products. However, preservatives cannot compensate for the poor quality of raw materials, as well as violation of sanitation rules. If the product has already begun to deteriorate, then preservatives will be completely useless. Chemically synthesized preservatives must not be introduced into products such as bread, fresh meat, dietary products and baby food, as well as products that are designated as natural by the manufacturer.

There are various methods of preservation, which are divided into three groups - physical, biological and chemical. The tasks of each of them are to prevent the development of harmful microorganisms in the product, the formation of toxins by them, and to prevent the appearance of mold, unpleasant taste and smell. The best-known methods of physical preservation are heat treatment (sterilization and pasteurization), exposure to cold (refrigeration and freezing), removal of water (drying), and exposure to ionizing radiation. By biological preservation is meant the impact on the food product of harmless cultures of microorganisms in order to prevent the development of undesirable microflora. Chemical preservation methods consist in adding special substances (preservatives) to the products that inhibit the development of microorganisms.

In practice, as a rule, different types of canning are combined. For example, during smoking, they are exposed to smoke, which carries antimicrobial properties, then they are dried and then smoked products are stored at low temperatures.

Quite a lot of preservatives are found in nature: sorbic acid (E200) found in rowan berries, benzoic acid (E210)- in lingonberries, as well as in blueberries, sour milk, cheese and yogurt. As a result of lactic acid and acetic acid fermentation in wines, fermented milk products and pickled vegetables, lactic and acetic acids are formed. Nisin is also found in all types of fermented milk products. (E234), which is produced by lactobacilli of the species Streptococcus lactis. It is used in the production of processed and mature cheeses (in an amount not exceeding 12.5 mg/kg), milk drinks with fillers, curd products and desserts (in an amount not exceeding 10 mg/kg), canned vegetables (in an amount not exceeding 100 mg/kg). kg of marinade), semolina puddings and similar products (in an amount not exceeding 3 mg/kg). For industrial use, such preservatives are obtained synthetically, which are identical to natural ones.

Each preservative has its own spectrum of action, that is, its direct antimicrobial work is aimed at a certain type of bacteria. That is why several preservatives are added to some products at once, which could simultaneously act on different groups of microorganisms.

The use of preservatives has been known for a long time. Until synthetic additives were obtained, they mainly used natural substances - table salt, vinegar, sugar, ethyl alcohol. Such additives, when introduced into food products, change the initial taste, since their dose generally ranges from a few to tens of percent, and the preservative effect is considered as a side effect.

Substances that are actually preservatives - sorbic, benzoic, sulfurous acids (H2SO3), as well as their salts, nitrates (E252), nitrites (E250), lowlands (E234) and many others - are introduced into the food product in much smaller quantities, and, accordingly, do not affect the organoleptic characteristics of finished products.

The main products in which nitrates and nitrites are used are meat products and cheeses. Nitrites added to meat products are converted to nitrates, they contribute to the formation of the desired color and aroma, and also protect against oxidative and bacterial spoilage. Nitrates are used in the production of sausages and various meat products (salted, boiled, smoked, canned). The dose of such a preservative should not exceed 250 mg/kg. Also widely known is the use of nitrates in cheeses in an amount not exceeding 50 mg / kg, in herring, salted sprat and in marinades - in an amount not exceeding 200 mg / kg. The document “Hygienic requirements for the use of food additives”, which regulates the residual amount of nitrites in products (sausage, raw smoked meat products, canned meat, minced meat), states that their maximum amount should not exceed 50 mg / kg.

In winemaking, juice production, sulfurous acid (H2SO3) and its salts are widely used to preserve fruit semi-finished products, in an amount of 10 to 500 g/t of product. For dried fruits, this indicator is slightly reduced - from 0.5 to 2 kg/t. The bactericidal action of sulfurous acid is complemented by its antioxidant properties, which slow down the reactions of enzymatic and non-enzymatic browning. Sulfur dioxide accompanies all wine production processes. In the finished wine products, its content is allowed at a sufficiently high level, which guarantees the safety of the drink and protects it from the negative effects of oxygen. According to the legislation of various European countries, the content of sulfur dioxide in finished wines can range from 200 mg/l to 450 mg/l.

Preservatives based on sorbic and benzoic acids (sorbic acid (E200), benzoic acid (E210), potassium sorbate (E202), calcium sorbate (E203), sodium benzoate (E211)) are widely used in the production of margarines, mayonnaises, sauces and salad dressings, non-alcoholic and low-alcohol drinks, and canning fruits and vegetables. But the range of action of such a preservative does not end there, due to the fact that it does not change the taste of the products at all, and at the same time it perfectly exhibits preservative properties. Sorbic acid and its salts are used to preserve wines, flour, bakery and sugar confectionery products, cheeses, curd products, meat, fish, and seafood. The packaging itself is not an exception, as it often contains a similar preservative to reduce molding processes.

Here are some notable examples of the use of sorbic acid. When processing half-smoked sausages with it, their shelf life increases by 4 times. Instead of 20 days, which is stored for ordinary margarine, when a preservative is added, its shelf life increases to 2 months. And the addition of only 0.2% sorbic acid to butter cream allows you to store cream cakes and pastries from 36 to 120 hours in a refrigerated chamber at a temperature of +2 +8°C. Potassium sorbate is often added to soft drinks. (E202) which increases their shelf life up to 180 days.

The amount of administration of a particular preservative may vary depending on various factors. For example, the more acidic a product is, the less preservative it needs. If the product contains a large amount of water, which contributes to the development of undesirable microorganisms, then, accordingly, a larger amount of preservative is required for its safety. Less preservative is required if a large amount of alcohol, sugar or other natural preservative has already been added to the product.

Nitrates (E252) and nitrites (E250), used in the production of meat products, in addition to preservative properties, have the functions of color stabilizers, so they cannot be completely replaced by other preservatives. As the practice of food production shows, the use of several preservatives in small dosages is more effective than the use of one preservative, but in a large dosage, since they have different effects on microorganisms, and when they are used together, the effect of mutual reinforcement is achieved.

Preservatives are, as a rule, heat-resistant compounds - they are not exposed to high temperatures. But, in any case, with prolonged boiling in a container with an open lid, some of them can still evaporate a little, however, along with the vitamins and microelements necessary for the body.