Antibacterial drugs in food. Foods and herbs with antibiotic properties

chemical

Most people are familiar with antibiotics as medicines - now, perhaps, you will not find an adult who has not taken antibiotics even once in his life. Also in animal husbandry, but there is a difference. A person takes antibiotics when they have an infectious disease (ideally on the advice of a doctor). Animal too, but already on the recommendation of a veterinarian.

As a rule, antibiotics are unstable compounds that quickly degrade in the environment. This means that the appearance of antibiotics in food products occurs as a result of their special use in growing animals (previously also used for preservation).

It is clear that the foods that are contaminated with antibiotics are exclusively animal products. After the use of antibiotics for a period until the antibiotic is excreted from the body or its concentration falls below the permissible limit, the animal must not be slaughtered for the purpose of using its parts or whole as food. During the same period, it is also forbidden to use products from it (for example, milk cannot even be processed - it must simply be destroyed, as a rule, poured into the ground, sewers, etc.).

A separate problem is the not always justified use of antibiotics in animals. So they can be added to feed to prevent diseases or due to the fact that against the background of certain antibiotics, animals gain weight faster.

In case of non-compliance with the regulations on the use of antibiotics, they can be found in meat, animal milk, chicken eggs, etc. (according to statistics, they are found in 15-20% of all animal products).

The main problem of uncontrolled use of antibiotics in agriculture is the development of resistant microflora. This always happens when any antibiotic is used for a long time in practice. At the same time, the wider the range of application, the faster the resistant strains will appear. Due to the fact that the groups of antibiotics used in the treatment of diseases in humans and in agriculture are the same, residual amounts of antibiotics in food products contribute to the emergence of resistant strains in humans. This leads to the fact that people who use such products develop immunity to taking antibiotics, and in order to obtain the expected effect in the treatment, increasingly stronger drugs are required, the resistance to which is inherited by their children. To date, in our country, most of the pathogens of the most common infections are resistant to drugs such as: biseptol, gentamicin and drugs of the tetracycline group. The situation with penicillin, ampicillin and amoxicillin is ambiguous; only one microorganism, pneumococcus, retains sensitivity to these drugs.

In addition, when the acceptable levels of antibiotics in food products are exceeded, antibiotics can exhibit toxic and allergic properties. Thus, penicillin and tylosin are the most powerful allergens of antibiotics used in animal husbandry. An allergic effect is manifested even in the case of an extremely low content of antibiotics in food products. This contributes to the development of allergic diseases. Over the past 40 years, the number of people with allergic diseases has increased tenfold in Russia, especially among children.

Standards for the following antibiotics have been established in the main food products: levomycetin, tetracycline group, streptomycin, penicillin, grisin, bacitracin. Their content in food products is not allowed (within the limits determined by the relevant methods).

It should be noted that the range of drugs used in the food industry now includes several dozen types of antibiotics, the content of many of them in food products is not standardized. However, current regulations do not allow the retention of residual amounts of used antibiotics in food products.

To date there are no effective control measures foodstuffs for the content of all used antibiotics. This means that the responsibility for compliance with the relevant regulations for the use of antibiotics in agriculture lies entirely with the manufacturer.

However, due to the undeveloped (low) production culture, many manufacturers do not comply with these rules in order to increase the profitability of production. Because at the very least, this requires: the presence of personnel with specialized knowledge and skills; compliance with the necessary hygienic conditions at work, excluding the need for disease prevention with antibiotics; destruction of food products containing antibiotics, etc.

The only possible way out of this situation is to purchase products of animal origin (meat, dairy products, eggs) from trusted reliable manufacturers who, according to their technological cycle, do not use antibiotics on an industrial scale. These producers include small farms with free-range animals and natural feed.

Antibiotics have become a salvation from many dangerous infections, not only for humans, but also for animals. But sometimes we use them in ignorance along with food, and there is no benefit in such a “reception.

The presence of antibiotics in food products is the result of their use in animal husbandry and in the processing of farm products.

Why is it dangerous for a person to eat foods containing antibiotics? How to determine their presence and protect yourself from harmful effects.

Antibiotics tend to become obsolete due to the adaptation of bacteria and microorganisms to the active substance. Often this happens when taking a medication without a doctor's prescription and improper use. An interrupted course of the prescribed drug can play a bad role.

The remaining not destroyed colonies of pathogens develop immunity to this substance. The next time a person becomes ill and needs treatment, a variety of antibiotics are ineffective. The way out of the situation is the use of a new generation drug, the creation of which takes years.

But even a complete rejection of antibiotic treatment does not guarantee that they will not enter the body. A lot of animal products contain these substances, which got into them in different ways.

Which food groups can contain antibacterial drugs?

Domestic farmers regularly use various drugs to prevent pestilence in pets. For treatment, Penicillin, Tetracycline, Levomycetin and many other drugs are used.

What foods contain antibiotics?

• Meat (beef, pork, chicken, etc.);
• Fish and seafood;
• Milk and its derivatives;
• Eggs.

According to GOSTs, a minimum proportion of the content of antibiotics in products of animal origin is allowed. This is such a meager dose that harm to the body is excluded.

The norm indicators are very often exceeded in order to obtain greater profits. The reason is that the use of drugs contributes to the rapid growth and high survival of animals.

in meat

Cows, pigs and other livestock, as well as birds, can suffer from infectious diseases. To avoid epidemics and pestilence, livestock breeders resort to prophylaxis, and most of the drugs are given during the period of active growth.

In order for the meat that goes on sale to deprive most of the antibiotics, you need to follow a certain order. Before slaughter, the animal is protected from drugs for a period of 7-10 days.

Antibiotics are unstable and rapidly decomposing compounds. They do not accumulate, so after 7-10 days they are not in the animal's body. But no one guarantees that this rule is observed as it should be, and the meat that goes on sale will not cause harm.

Buying meat from private farmers is also not an option, since antibiotics can also be used by private farmers. In addition, such products are not always properly checked, especially you should not take meat in spontaneous markets.

How then to reduce the risk of ingestion of antibiotics contained in meat? Partially they can be neutralized by boiling and draining the first broth. Also avoid frequent consumption of certain offal. Know that the highest concentration of this drug is in the liver and kidneys of the animal.

Most antibiotics are used in the cultivation of chickens, so you should give preference to beef. Also, the low content of harmful substances in quail meat.

In seafood and fish

Some people think that there are no antibiotics in seafood and fish, but this is not entirely true.

Fish grown on an industrial scale by various fish farms are also being prevented. They practice feeding, bathing or intra-abdominal administration of Levomycetin, as well as other drugs.

However, there is no guarantee that fish caught in natural waters and not in hatcheries has not been treated. The same goes for seafood, such as shrimp.

In dairy products

Studies have shown that three out of ten samples of dairy products contain traces of antibiotics.

Drugs can pass into milk in two ways:

• from the body of an animal;
• added directly to the product.

During milk processing, antibiotics are used to prevent the growth of bacteria. This measure significantly increases the shelf life of products, but the harm of such milk is obvious.

The largest doses of medicines fall on the spring pasture for pastures as a preventive measure.

in eggs

A large number of chickens on poultry farms is a common cause of foci of poultry infection. Laying hens undergo prophylaxis with the same vitamin-drug complexes.

Eggs containing a large amount of antibiotics have a much longer shelf life. This is beneficial for entrepreneurs, so chickens go through even more unauthorized drug cycles. As a result, harmful substances end up in eggs supplied to supermarkets and the market.

An excellent alternative is quail eggs, which are a valuable dietary product. Quails rarely get sick, have a high survival rate, and their eggs are stored for a long time without drugs. Thus, they are grown with much less medication. It is one of the safest food products of animal origin.

How to determine the presence of antibiotics?

How can the average consumer be sure that the purchased product is safe? The potential harm of meat, fish and eggs cannot be determined without a laboratory.

Here are examples of checking milk that can be done at home:

Of course, these methods will not determine the quantitative content of drugs in milk. But you will be able to identify those brands whose products are most suitable and safe to use.

The Hidden Danger of Foods

If you constantly eat foods with a high content of antibiotics, this can cause great harm to health.

Among the main unwanted effects:

• dysbacteriosis;
• allergic reactions;
• insensitivity to the drug during treatment.

In addition, bacteria that are resistant to antibiotics can be found in animal products. Infection with these microorganisms is dangerous, especially for people with low immunity, including children and pregnant women.

To avoid infection with antibiotic-resistant bacteria, the following precautions should be taken:

Often we do not even know what harm the food we eat is doing. But basic awareness and preventive measures will help minimize the negative impact. It is advisable to purchase food products from trusted manufacturers.

You can find open studies of products of different brands on the subject of health safety.

You probably guess that a healthy lifestyle is a life without pills or with a minimum amount of them. Sure, antibiotics can do wonders for fighting off bacteria and disease, but every drug has its own set of side effects, including allergic reactions, headaches, cramps, nausea, and more.

What to do if you do not want to become addicted to pills? Fortunately, there are several "drugs" in nature that will become excellent analogues of antibiotics. And chances are you already have them in your kitchen.

Garlic

Garlic is one of the most powerful natural antioxidants, which is why it is rightfully in the first place. For many years, this aromatic spice has been used for medicinal purposes, and today the scientific world unanimously declares that its effect even exceeds that of many well-known antibiotics.

The secret is in an organosulfur compound found in garlic. In particular, studies have shown that it is able to cope with bacteria that cause food poisoning (Campylobacter jejuni). These bacteria create a protective layer around themselves that is difficult for such popular antibiotics as erythromycin or ciprofloxacin to overcome.

The healing properties of garlic largely depend on its condition. It is recommended to consume one clove of fresh garlic on a daily basis (without cutting, but swallowing it whole, so as not to injure the microflora of the stomach) - this will protect the immune system and activate the bactericidal action.

Citrus

Goweloveit.info cites a study showing that antibiotic-resistant infections cause about 23,000 deaths per year. That is why doctors prescribe antibiotics only as a last resort, knowing full well that they can not only increase the number of bacteria in the body, but lead to the appearance of those that drugs cannot cope with.

You should be aware of vitamin C. This antioxidant helps create an unfavorable environment for the development of bacteria in the body, thus ensuring your safety. We remind you that vitamin C is not only oranges and lemons, but even more bell peppers, broccoli and pineapples.

Apple vinegar

Apple cider vinegar is always worth having in the kitchen - and here's why. It contains a wide range of vitamins, minerals, pectins, amino acids and other elements that have allowed this product to become a real healthy lifestyle trend. Among these amazing compounds, one can also find malic acid, which is an extremely effective remedy against viruses and bacteria.

Separately, apple cider vinegar does not contain harmful chemicals, so it is an excellent astringent that can cope with any kind of infection. How to take: 1 tablespoon of apple cider vinegar + 1 tablespoon of honey + 1 glass of water (half a glass twice a day).

Coconut oil

Coconut oil is rich in fatty acids, but lauric acid is of particular interest in its composition. Once in the body of a person or animal, it turns into monolaurin - an antiviral, antibacterial and antiprotozoal monoglyceride that destroys the shells of viruses, including herpes, influenza, and other pathogenic bacteria.

In order to properly take advantage of the antimicrobial effect of coconut oil, you need to consume 2-3 tablespoons every day. But do not exceed this amount, as increasing the level of fat in the body will also not benefit you.

oregano

Despite the fact that antibiotics help get rid of tuberculosis, diphtheria, and typhoid fever, they have some drawbacks that prevent us from fully relying on these medicines. So, they kill not only bad bacteria, but also good ones, and, in addition, in the future, the body somehow develops immunity to them.

At the same time, in the sense of counteracting harmful bacteria, the most common herbs will be useful, including oregano, basil, rosemary and mustard seeds, which have antibacterial properties. Oregano (or oregano), in particular, contains two antimicrobial compounds at once - carvacrol and thymol. To maximize the beneficial properties, it is better to use oregano oil, which, as scientific experiments have shown, has the highest concentration of these substances.

Honey

If you are not yet using honey to treat a sore throat, then you should definitely give it a try. The antibacterial properties of honey are supported by clinical evidence: studies also confirm that honey is suitable for the treatment of burns, cuts, eczema, yeast and fungal infections and topical application.

But how does it work? Scientists have discovered in honey a type of enzyme responsible for the release of hydrogen peroxide. Most bacteria cannot survive in the presence of this element, so a thick layer of honey will disinfect the wound, speeding up the healing of inflamed areas, and tea with honey instead of sugar will treat the body from the inside.

Is there anything in the world that does not have duality? For example, antibiotics. They allow you to cope with the most terrible diseases, however, sometimes they bring harm. Most likely, you know that you should only take such a medicine when you need it, because otherwise the body may develop resistance to the pills and over time you will not be able to cope with the infection. However, even if you are taking your medications as directed, you are probably overlooking the antibiotic content of some foods. In some, they are added during production, while in others they are present for natural reasons. Check out this list for all the details.

Meat

From time to time, cows and chickens can get sick, so they need antibiotics. Unfortunately, in industrial conditions, drugs are often given to healthy animals. As a result, the quality of meat is seriously reduced. In the United States and Canada, for example, antibiotics are given to cattle to encourage weight gain, despite the fact that many countries have long abandoned this practice. Why are antibiotics such a problem? The thing is that in the body of animals, like in humans, bacteria resistant to antibiotics can develop. They then end up in food and cause disease in humans. Because infections are resistant to medications, they can be very difficult to treat. A vicious circle is created. Try to be as gentle as possible with raw meat and cook it thoroughly to kill bacteria. In addition, choose high quality products - in this case, the likelihood that antibiotics are present in them becomes somewhat lower.

Blueberry

Pesticides are often considered a necessary evil because without them, plants would simply be destroyed by pests. Antibiotics are a key ingredient in many pesticides and can lead to serious allergic reactions. Pesticide-treated berries are the main cause of this allergy, however, any other fruit or vegetable can become a threat. People with severe allergies are advised to keep epinephrine on hand at all times, as eating the berries can be deadly. Unfortunately, this is a very real fact: despite all their benefits, blueberries can also be fatal.

Milk

Milk has been constantly criticized in recent years, primarily due to the fact that it contains antibiotics. In fact, only a small proportion of dairy products have excessive levels of antibiotics, yet drugs are still present in many products. Because of this, many people try to give up milk or buy it directly from farmers, without pasteurization or additives. At the same time, experts do not recommend such a solution, because unpasteurized milk can also contain bacteria and infections. This is no less dangerous than drinking milk containing medicines. If you want to be on the safe side, choose foods that are labeled free of antibiotics.

Honey

Antibiotics are regularly used by beekeepers to protect bees and to stimulate their growth. The content of medicines in honey is practically not controlled, which is not very pleasant, considering that many people use honey for medicinal purposes. This product may be contaminated with pesticides, heavy metals and even radioactive substances. By itself, honey is a good natural antibiotic, so powerful that it is being studied as a medicine. Nevertheless, in modern conditions, its production often leads to the fact that useful properties are seriously reduced.

Garlic

Fragrant garlic has long been famous for its ability to fight bacteria. It was even nicknamed "Russian penicillin" during World War II because it was used by doctors who were running out of medicines. Studies have shown that garlic is amazingly beneficial in controlling the levels of Helicobacter pylori bacteria in the digestive tract without completely killing them. Too much of them can cause ulcers, but too little is harmful. Stomach cancer is a very common problem. Eating garlic and onions can reduce the chance of this disease, so try to take care to make your diet more spicy.

Mushrooms

You may find it strange to use mushrooms to fight bacteria. However, mushrooms do have powerful antimicrobial properties. Many antibiotics, such as penicillin, tetracycline, and streptomycin, are made from fungi and molds. Studies have shown that the use of mushrooms can strengthen the protective properties of the body. But remember, not all mushrooms are created equal. For example, shiitake is useful - they are able to fight cancer, destroy various bacteria and viruses, and also allow you to regulate cholesterol levels. Reishi mushrooms are also useful, which have an anti-inflammatory effect.

Cabbage

Red cabbage has powerful anti-inflammatory and anti-cancer properties. In addition, it has antibacterial properties. This product is surprisingly effective in fighting bacteria that even medicines cannot fight. Cabbage juice is also great for ulcers because it is high in lactic acid, which regulates bacterial levels and prevents symptoms from getting worse. Cabbage leaves have been used for centuries to treat mastitis, an inflammation of the breast. This is a really effective tool, although it seems extremely simple.

Onion

Whether raw or cooked, onions are always a great way to spruce up any dish. In addition, this product has powerful antibiotic properties. Be sure to eat onions during cold and flu season. It does not lag behind garlic in its beneficial properties and allows you to protect the body from infections, even the most resistant ones. Studies have shown that onion is an effective remedy for periodontitis. Eat it regularly!

Butter

Butter is sometimes criticized, then again they begin to consider it useful. It is regularly recommended to switch to margarine, and then it turns out that the latter is even more dangerous. In a word, doctors do not have a single opinion on this matter. Butter does contain a lot of nutrients, for example, it has a component that protects against cancer, however, many manufacturers use raw materials that contain antibiotics. As mentioned earlier, cow's milk is quite dangerous. Choose the highest quality butter to prevent problems.

Herbs and spices

It turns out that along with spices, you add more than just a wonderful flavor to your food. Spices can slow down the development of microbes. Scientists have found that oregano destroys one hundred percent of the bacteria it comes in contact with. Slightly less effective are thyme, cinnamon, cumin, tarragon. Turmeric, a constant ingredient in curry, is a real star in the spice world for its most impressive antibacterial properties. It's all about the high content of curcumin, which helps the rapid healing of wounds. In addition, curcumin prevents the formation of tumors, has antioxidant and antibacterial properties. Quite an impressive effect for an ordinary seasoning!

Ivanov Vitalik

Detection of antibiotics in food in a school laboratory

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Ministry of Education of the Republic of Bashkortostan

Municipal budgetary educational institution

secondary school №16 r.p. Priyutovo

municipal district Belebeevsky district

Republic of Bashkortostan

Section name: biology

Topic: "Antibiotics in food"

Completed:

Ivanov Vitaly, 10th grade,

MAOU secondary school No. 16

Supervisor:

Ivanova Elena Nikolaevna,

Biology teacher

Belebey

2015

Page

Introduction …………………………………………………………………………3

1. Literature review

1.1. Antibiotics in food …………………………………………………………………………………………………

1.2. Tetracyclines …………………………………………………………….. 5

1. Tetracyclines as organic substances………………………..7

2. Experimental part No. 1.

2.1. Qualitative reaction for the detection of tetracyclines…………………..9

(reaction of identity of tetracycline)

2.2. Preparation of product samples for research…………………10

2.3. Experimental results……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

3. Experimental part No. 2.

3.1. The effect of antibiotics on the properties of the oral fluid………………..12

3.2. Results of the experiment…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

Conclusion ……………………………………………………………………14

Literature ……………………………………………………………………..15

1. Literature review

1. Antibiotics in food

The entry of antibiotics into food products is associated with their use for the treatment, prevention of diseases and stimulation of the growth of farm animals and poultry, as well as the use of antibiotics to extend the shelf life of food products.

Below are the data of the Moscow City Veterinary Laboratory, Federal State Institution "Center for Hygiene and Epidemiology in the City of Moscow", CJSC "ROSTEST" and the results of the dissertation work of Kalnitskaya O.I.

These data allow us to conclude that most often residual amounts of antibiotics are found in poultry meat of imported and domestic production, in imported beef and pork, in by-products, as well as in domestic milk.

Most often (~ 90% of cases of detection of antibiotics in raw materials and livestock products, as well as in fish), tetracycline is detected.

Contamination of fish is associated with its surface treatment with tetracycline.

In recent years, antibiotics at concentrations of 10–100 mg/l have been used as substances that delay the spoilage of many food products during storage: meat, fish, poultry, and even vegetables.

Currently, the allowable daily dose of tetracycline in the EU and the Russian Federation is at the level of 30 micrograms per kg of body weight. In this case, taking into account the average daily consumption of products, the permissible residual amounts of tetracyclines in products will be, respectively:

• Milk - 100 mcg/l
• Muscle tissue - 100 mcg / kg
• Adipose tissue - 10 mcg / kg
• Eggs - 200 mcg / kg
• Liver - 300 mcg / kg
• Kidneys - 600 mcg / kg

However, according to scientists, this can lead to an additional risk of digestive diseases, anemia, dermatitis, allergies and immunodeficiency conditions in children. It is proposed to reduce the allowable daily dose of tetracycline to 3 µg/kg of body weight, and the content in food products to the level of 10 µg/kg (0.01 mg/kg). This will significantly reduce the risk to public health.

1. Tetracyclines

Tetracyclines (English tetracyclines) - a group of antibiotics, similar in chemical structure and biological properties. Representatives of this family are characterized by a common spectrum and mechanism of antimicrobial action, complete cross-resistance, similar pharmacological characteristics. The differences relate to some physico-chemical properties, the degree of antibacterial effect, absorption, distribution, metabolism in the body and tolerability.

Tetracyclines are broad-spectrum antibiotics. Active against most gram-positive and gram-negative microorganisms, affect spirochetes, leptospira, rickettsia, large viruses. They have a bacteriostatic effect.

After oral administration, up to 66% of the dose taken is absorbed.

In circulating blood, a significant part of tetracyclines (55-65%) binds to plasma proteins.

They penetrate well into various organs and tissues, as well as biological fluids - bile, pleural, synovial, cerebrospinal. Selectively accumulate in bones, liver, spleen, tumors, lymph nodes, teeth (because they form stable complexes with Ca cations 2+ in any bone-forming tissue) and are found in them for a long time. Pass through the placenta into breast milk. They are not metabolized. 10 - 25% of the accepted amount of tetracycline is excreted by the kidneys by glomerular filtration and 20 - 50% - unchanged in the feces.

Tetracyclines have a number of adverse effects:

Fever, angioedema, skin allergic reactions: rash, itching;

Lesions of the gastrointestinal tract in the form of acute inflammation of the mucous membrane of the oral cavity, tongue, rectum. These symptoms are accompanied by dyspeptic disorders: nausea, epigastric pain, vomiting, loss of appetite, diarrhea;

Liver damage, increased blood levels of hepatic transaminases, alkaline phosphatase, bilirubin, creatinine;

Changes in the hematopoietic system: neutropenia, thrombocytopenia, hemolytic anemia;

Reactions from the central nervous system: fainting, headache, vestibular disorders.

1. Tetracyclines as organic substances

The group of tetracyclines includes a number of natural antibiotics, which include tetracycline, oxytetracycline, and semi-synthetic tetracyclines. Tetracycline and oxytetracycline are used both in the form of bases and in the form of salts - hydrochlorides. Tetracycline salts are soluble in water.

From the point of view of pharmaceutical chemistry, tetracyclines belong to a series of partially hydrogenated naphthacene derivatives containing several functional groups (phenolic, enol and alcohol hydroxyls, urea group, aliphatic amino group, oxo group).

Tetracyclines are yellow crystalline solids. The color is due to the presence in their structure of chromophores - systems of conjugated double bonds, including ketone and enol groups, which give tetracyclines the ability to absorb both in the ultraviolet and in the visible regions of the spectrum.

They have amphoteric properties and form salts with organic and inorganic acids, alkali and alkaline earth metals. They form insoluble complexes with multivalent metal cations, boric acid, salts of α-hydroxycarboxylic acids (gluconic, malic, citric, etc.). Under certain conditions, tetracycline solutions fluoresce.

2. Experimental part

2.1. Qualitative reaction for the detection of tetracyclines (reactions of authenticity of tetracycline)

The formation of phenolates.

To 0.01 g of the drug dissolved in 1 ml of water, add 2 drops of a 1% aqueous solution of iron (III) chloride: in the presence of tetracyclines, a brown-red color appears.

Rice. 1. Qualitative reaction with iron (III) chloride

different concentration

2.2. Preparation of product samples for research

Literature analysis allowed us to choose two methods of sample preparation. Both methods have been adapted to the conditions of the school laboratory:

1. Method of express - preparation of samples of muscle tissue samples (Kalnitskaya O.I.). 10 g of the sample was homogenized without preheating in a mortar and 100 ml of distilled water was added. Stirred for 20 min. The sample was then decanted and filtered. The aqueous phase was used to determine the content of tetracycline.

2. According to the "Guidelines for the determination of residual amounts of antibiotics in animal products (approved by the USSR Ministry of Health on June 29, 1984, p. 3049-84)":

A) Samples of milk 100 +/- 0.1 ml, cottage cheese 10.0 g each were added to flasks with a capacity of 500 ml and 100 ml of 0.1 N hydrochloric acid were added. For milk, a 1:2 dilution was obtained.

B) 10 g of chopped muscle tissue or by-products were crushed in a mortar and 100 ml of 0.1 N hydrochloric acid was added. Stirred for 10 min.

The supernatant was decanted and further filtered.

To assess the content of tetracycline, 2 drops of iron(III) chloride solution were added to 1 drop of the obtained extract. The color of the extract was compared with the standards.

2.3. Experimental results

Table. Detection of tetracyclines in food

Tetracycline is found in chicken meat. As a result of cooking meat, its amount in muscle tissue is significantly reduced. Basically, from muscle fibers, the drug, together with muscle juice, passes into the broth, part of the drug is destroyed under the influence of high temperatures. However, cooking should be long, because. there is evidence of how the antibiotic tetracycline is digested from a chicken carcass. After thirty minutes of cooking, it remains in the broiler muscles in the form of traces, and after another 30 minutes it completely passes into the broth.

For this reason, it is better not to eat the broth after boiling the chicken.

Samples of milk and cottage cheese contained minimal amounts of tetracycline. It is known that during the heat treatment of milk, due to the partial coagulation of proteins and the formation of salts, a precipitate forms on the surface of the vats - milk stone (burnt). There is an opinion that its formation contributes to the reduction of residual amounts of antibiotics in milk, which partially denature and form protein-salt complexes deposited on the walls of the apparatus.

The sour cream we studied contained tetracycline. Antibiotics are added to sour cream to increase the shelf life of a product for which thermal sterilization cannot be used.

It is worth noting that if the norms for the content of tetracycline are reduced to 10 μg/kg (l), then many of the samples we studied will exceed these norms.

3.1. The effect of antibiotics on the properties of the oral fluid

Goal of the work: study of the effect of antibiotics on the ability of saliva enzymes to hydrolytically degrade starch.

Information. Antibiotics are capable of exerting a selective toxic effect on microorganisms and cells in small doses. Antibiotics sold in pharmacies, as well as nicotine and hyperacidity, cause a decrease in the activity of salivary amylase enzymes to hydrolytic breakdown of starch.

Equipment from the kit:test tubes 2 pcs., 50 ml beaker, test tube stand.

Office equipment:mortar and pestle, marker.

Reagents and materials:iodine solution, starch solution, warm clean water, saliva solution, antibiotic solution (1 tablet per 20 ml of pure water).

Progress

1. Number the tubes.
2. Pour ¼ of the starch solution into the first test tube, add the same amount of saliva solution and 2-3 drops of iodine solution. Mix the contents of the tube. Place the tubes in a glass of warm water for 10 minutes, then observe the color change.
3. Pour the starch solution into the second test tube for ¼ volume, add the same amount of saliva solution, then the same amount of antibiotic solution and 2-3 drops of iodine solution. Mix the contents of the tube. Place the tubes in a glass of warm water for 10 minutes, then observe the color change. Note the rate of change in the blue color of the solution in both tubes.

3.2. Processing of results and conclusions.

Rice. 2. 1 test tube - qualitative reaction for starch

2 tube - amylase + starch solution + iodine

3 tube - amylase + starch solution + tetracycline + iodine

Conclusion:

The antibiotic tetracycline reduces the activity of the enzyme amylase in the oral fluid. All this leads to an increase in the presence of food in the digestive tract, a feeling of heaviness,enhances the slagging of the body. If the lump of food quickly leaves the oral cavity, in the future it will cause fermentation in the gastrointestinal tract (GIT), resembling moonshine, with the release of substances that poison the body and a violation of the absorption process.

Conclusion.

1. Based on the analysis of the literature, it was concluded that animal products - meat and dairy, may contain residual amounts of antibiotics, usually tetracycline.
2. Methods for the determination of tetracycline were selected, studied, mastered and modified in accordance with the capabilities of the school laboratory. The most sensitive and simple reagent for express analyzes was chosen - iron(III) chloride.
3. Methods for the extraction of tetracycline from muscle tissue, milk and dairy products have been mastered. Samples are homogenized and tetracycline is extracted with water (muscle tissue samples) or hydrochloric acid solution (milk and dairy products).
4. The analysis of products purchased in R.P. stores was carried out. Sheltered and regularly used by us. It has been established that poultry meat, milk, sour cream and cottage cheese contain tetracyclines.
5. It has been shown that heat treatment of meat containing tetracycline by boiling for 1 hour makes it possible to reduce the amount of tetracycline to a safe level. In this case, the antibiotic passes into the broth.
6. It has been proven that tetracycline affects the activity of the enzyme amylase in human oral fluid.

Literature

Kalnitskaya O.I. "Veterinary and sanitary control of residual quantities of antibiotics in raw materials and products of animal origin". Dis. ... doc. vet. Sciences: M, 2010.

Melentieva G.A., Antonova L.A. Pharmaceutical chemistry. M.: "Medicine", 1993. - 479p.

Tyukavkina N.A., Luzin A.P., Zurabyan S.E. Organic chemistry. M.: "Medicine", 1998. - 496 p.

Pharmaceutical Chemistry: Textbook / Ed. A.P. Arzamastsev. M.: "GEOTAR-Media", 2005.-640s.