Animals as well as people get sick and have to be treated with antibiotics. Cows give milk all year round, which is unnatural for their biological nature, and it causes inflammation in their body.
One of the serious problems of modern animal husbandry is the disease of milk cows with mastitis. Due to the overcrowding of animals, tightness, there are often various infections that are quickly transmitted from one animal to another. Prevention of animal diseases is also done. So one of the sources of antibiotics in milk is the treatment and prevention of diseases.
Each antibiotic has an average duration of 2 to 3 weeks for its removal from the body (with milk, from tissues, etc.). As a rule, 3-5 days are sufficient for excretion of penicillin from an animal organism, however, in some cases this period can be extended up to 6-11 days for sick animals.
According to sanitary rules, milk from treated cows should be disposed of within 5-10 days (depending on the product used). But with a general lack of milk, when large producers buy literally everything, farmers simply dilute milk from normal cows with milk with antibiotics. Yes, the concentration is lower, but the antibiotics are still there.
In addition to treatment, antibacterials can be used to stimulate animal growth (weight gain increases by 30%). Unscrupulous farmers can add antibiotics to feed for preservation, but this is also illegal. This is the second source of antibiotics in milk.
What antibiotics can be found in milk?
More than 70 types of antibiotics are used in animal husbandry, but the most commonly used antibiotics are long known and inexpensive beta-lactams (penicillins), tetracyclines, sulfonamides, streptomycin, fluoroquinolone derivatives, and levomycetine.
Tetracycline is the cheapest and one of the most dangerous antibiotics with a wide range of antibacterial properties. According to the instructions for use, tetracycline can cause gastritis and proctitis, not to mention loss of appetite. Tetracycline and other drugs of this series can increase the sensitivity of the skin to sunlight (photosensitization). Recently, due to the prevalence of tetracycline resistant strains of microorganisms and frequent side effects, the use of tetracycline for medical purposes has become limited.
What are the risks of antibiotics in milk and foodstuffs for humans?
Of course, when talking about the presence of antibiotics in milk purchased in a store, we are talking about microscopic doses of these substances. But, according to experts, because of the specific features of these drugs, even minimal doses of antibiotics have a negative impact on the intestinal microflora, as well as increase the risk of resistance (or resistance) of pathogens to drugs. All of this ultimately reduces the body's immunity. Prolonged use of foods containing residual amounts of antibiotics can cause adverse effects on human health - allergic reactions, dysbiosis.
For example, tetracycline antibiotics have a cumulative effect. By accumulating in the body, they can have a negative impact on the ears, cause a decrease in platelet count and cause toxic reactions in the liver. Accumulating in bone tissue, tetracyclines can disrupt its formation, especially for children, because they can slow down growth. In adults, regular intake of tetracycline leads to the destruction of teeth.
Streptomycin sulfate has a nephropathic effect and causes central hearing receptor damage.
Fluoroquinolone derivatives in children under 14 years of age accumulate in the cartilage, which leads to skeletal disorders. The paradox is that we drink milk because of the benefits for teeth and bones of calcium, and get the opposite result.
On the shelves of shops you can find milk with different expiration dates - from 2 months to six months. Does this mean that milk with a long shelf life contains antibiotics?
No, in this case the reason is the way the milk is processed and the properties of the packaging.
Heat treatment of milk is pasteurization or sterilization. The purpose of heat treatment is to destroy microorganisms and thus prolong the shelf life of the product. Pasteurization is thermal treatment at temperatures below boiling point or simply heating to below 100°C. In the classical sense, pasteurization of milk is its heating up to 74-76°C with a holding time of 15-20 seconds or instantaneous heating up to 85°C without holding time. In pasteurization die microorganisms that do not form spores, including dysentery, typhus, cholera. Escherichia coli and lactic acid bacteria cannot withstand pasteurization. Disputes that survive the pasteurization during the storage of milk "germinate" - begin to proliferate actively, causing damage to milk.
Sterilization - is the heat treatment of milk at temperatures above 100 ° C. Such heating not only kills microorganisms, but also their spores, due to which milk can be stored for a long time even without a refrigerator. In addition, sterilization can also be performed in different ways: there are simply high-temperature sterilization, there is pressure, where the temperature of food processing is higher. One manufacturer can be more gentle, the other uses pressure sterilization. Hence the differences in shelf life. Why aren't they in a hurry to sterilize all the milk? Because high temperatures lead to significant unwanted changes in milk, including taste changes. Therefore, producers are trying to find a "golden" balance between the duration of storage and preservation of the original properties of milk.
In addition, the shelf life depends on the packaging. The leader here is Tetra-Pack, where products are stored for a very long time. The plastic bottle has a shorter shelf life.
However, some manufacturers provide an extension of the shelf life by adding ... lowland antibiotics. This is the only antibiotic, which is not prohibited by Russian legislation, as it is decomposed by our body. But this does not apply to milk. It is forbidden to add lowland to milk.
Are antibiotics destroyed by boiling milk?
Boiling and sterilization have almost no effect on the antibiotic content of milk. After boiling in milk there is from 90 to 95% of the initial amount of antibiotics, i.e. from 5 to 10% of their amount is destroyed. After sterilization, 92 to 100% of the initial amount of antibiotics remains in the milk. Such data allow to draw conclusions about unsuitability of parameters of boiling and sterilization for destruction of antibiotics in milk.
The greatest decrease in the number of antibiotics in the samples occurs with prolonged pasteurization. Probably, it is connected with the longest influence on antibiotics of high temperature which leads to coagulation of proteins and their settling together with antibiotic on walls of capacities.
Do antibiotics persist in dairy products - dried milk, yogurt, cheese, etc.?
Fortunately for the consumer, it is difficult to make sour milk products out of milk with antibiotics. Microorganisms used in the dairy industry are very sensitive to antibiotics. Their presence in milk leads to technological problems in the dairy enterprise. Antibiotics cause lagging or complete delay of enzymatic processes in the production of cheese, cottage cheese and sour milk drinks. Changes in the ratio of microorganisms in starter have a negative impact on quality, particularly on the appearance of the product (for example, the absence of eyes in cheese).
Most of the antibiotics in liquid milk are transformed into powdered ones. Unfortunately, they are not destroyed by drying. If you make butter out of milk with antibiotics, the antibiotics will remain in it. To a lesser extent, of course. But fat-soluble antibiotics remain there.
That is, in many products made of milk, antibiotics can be present, and in what and danger.
How is the content of antibiotics in foodstuffs and, in particular, in milk controlled in our country?
In animal husbandry more than 70 kinds of antibiotics are used, as it was mentioned earlier, in our country several basic groups are controlled: levomitsetin, streptomycin, tetracycline, sulfonamides, quinolones, nitrofurans and penicillin. The maximum allowable levels of these antibacterials are regulated by SanPiN 18.104.22.1688-01. In addition, levomycetin, streptomycin and tetracycline are regulated by the Technical Regulation of the Customs Union 021/2011
According to the regulations, there is a three-level system of raw milk quality control, designed to prevent the milk of sick animals from getting on the consumer's table. Raw milk should be subject to industrial laboratory control, laboratory safety monitoring in veterinary institutions and quality control when accepted into dairy factories. Ideally, this system should ensure that there is no unsafe milk in the total milk yield, but in practice it can fail.
In addition, as part of the annual veterinary monitoring of veterinary drug residues in food, raw milk is examined for five antibiotic residues (levomycetine, streptomycin, tetracycline, nitrofuran, sulfonamides)