© Kogbu Kirov Regional Veterinary Laboratory. Kmafanm indicator - as a criterion for product quality

09.06.2017
We are all looking forward to summer, unfortunately it is at this time that the danger of food poisoning increases significantly, as the heat creates favorable conditions for the reproduction of dangerous microorganisms, and food serves as an excellent environment for them. One of the indicators of violation of food storage is QMAFAnM.

QMAFAnM - the number of mesophilic aerobic and facultative anaerobic microorganisms or the total bacterial contamination. This is a criterion that allows you to identify at a temperature of 30 ° C for 48-72 hours all groups of microorganisms growing on certain media. These microorganisms are present always and everywhere (water, air, equipment surface).

This indicator characterizes the total content of microorganisms in the product, it is used everywhere to assess the quality of products, with the exception of those in the production of which special microbial cultures are used (for example, beer, kvass, fermented milk products, etc.). Its control at all technological stages makes it possible to trace how “clean” the raw material goes to production, how the degree of its “purity” changes after heat treatment, and whether the product undergoes re-contamination after heat treatment, during packaging and storage.

The value of the QMAFAnM indicator depends on many factors. The most important are the mode of heat treatment of the product, the temperature regime during its transportation, storage and sale, the humidity of the product and the relative humidity of the air, the presence of oxygen, the acidity of the product, etc.

An increase in QMAFAnM indicates the multiplication of microorganisms, which may include pathogens and microorganisms that cause spoilage of the product (for example, molds); a large number of QMAFAnM most often indicates violations of sanitary rules and the technological regime of production, as well as the timing and temperature regimes of storage, transportation and sale of food products.

How can you protect yourself and your loved ones?

It is very dangerous to buy food in the so-called spontaneous markets, on the street with your hands. Our favorite ready-made salads, which include sausage, mushrooms, cheese and eggs, deteriorate very quickly. Less than half an hour out of the refrigerator is enough for such a product to turn sour and become life-threatening. Cheeses, kefir, yoghurts, sour cream and other dairy derivatives spoil especially quickly in the heat.

It is worth checking not only the release date, but also the tightness of the packaging. Therefore, visit the large city markets, specially equipped for trade. There must be a refrigerator in the outlet; it is impossible for perishable goods to lie on the counter. For all products, the seller is obliged to provide quality certificates, veterinary certificates and conclusions, as well as his own medical book.

Unfortunately, it is difficult to foresee all the cases when you will be sold a low-quality product, but if you take seriously what we eat, most problems can really be avoided.

Hence the conclusion - you need to be able to choose, store and use products correctly!

Deputy Elena Prokopova, Head of the Department of Veterinary Medicine and Risk Analysis of Food Production, Rostov Reference Center of Rosselkhoznadzor

Similar publications: “Department of Veterinary Medicine and Risk Analysis of Food Production”, “Prosperous wintering is the key to the health of marketable fish”, “Production of live marketable fish on the Don has doubled”

According to technical regulations and GOST the requirements for the number of bacteria or QMAFAnM (the number of mesophilic aerobic and facultative anaerobic microorganisms) are as follows:

The highest grade - up to 100 thousand CFU / cm 3;

The first grade - up to 500 thousand CFU / cm 3;

The second grade - from 500 to 4,000 thousand CFU / cm 3;

CFU are colony-forming units, that is, living cells from which a colony can grow on a nutrient medium.

The determination of QMAFAnM is carried out by the following methods:

1. Classic (straight) method: sowing on dense nutrient media.

2. Reductase test- refers to express methods. This test is based on the fact that bacteria, developing in milk, secrete a reductase enzyme that can decolorize organic dyes such as resazurin. The more bacteria in the milk, the more they secrete the enzyme, the faster the discoloration of the milk.

3. By changing the electrical conductivity during the development of microorganisms on a nutrient medium on the device "Buck Truck 4300".

Determination of the number of bacteria in milk by reductase

Sample with resazurin

The method of analysis refers to microbiological. Therefore, when sampling, it is necessary to follow the rules for sampling for microbiological analyzes (GOST R 53430).

Analysis progress. Measure 1 cm 3 of a working 0.014% solution of resazurin into a sterile test tube with a sterile pipette, add 10 cm 3 of milk with a sterile pipette. Close the test tube with a sterile rubber stopper, mix by three turns and place in a reducer at a temperature of 37 + 1 ° C. The countdown begins from the moment the test tubes are placed in the reducer.

A preliminary assessment of the results is done after 20 minutes, the final one - after 1.0 hour, then after 1.5 hours.

If after 20 minutes the milk is discolored, then in such milk there are more than 20 million / cm 3 microorganisms, this is class 4 according to the reductase test, the milk is not subject to acceptance, the analysis is stopped at this point. If the milk has any color, continue the analysis.

If after an hour milk is gray-lilac or lilac with a gray tint, then microorganisms in such milk are less than 500 thousand / cm 3 (class 1 according to the reductase test, the first grade of milk according to GOST).

If after an hour lilac milk with a pink tint or pink color, then the microorganisms in such milk are from 500 thousand / cm 3. up to 4 million / cm 3 (class 2 according to the reductase test, the second grade of milk according to GOST).

If after an hour milk is white or pale pink, then microorganisms in such milk are from 4 to 20 million / cm 3 (class 3 according to the reductase test, milk is not subject to acceptance).

The pink ring on the surface is ignored.

If, when the test tubes are kept in the reducer for another half an hour, the milk still remains gray-lilac or lilac in color, then bacteria in such milk are up to 300 thousand / cm 3.

The nature of the microflora of raw milk is assessed by: fermentation, rennet-fermentation test and test for the presence of butyrate bacteria.

Fermentation test

It is carried out to determine the nature of the microflora of raw milk and the quality of milk protein during acid coagulation (mainly in cheese making).

Analysis progress. Pour 20 ml of milk into clean test tubes, rinsed 2-3 times with test milk, close with cotton plugs and place in a reducer at a temperature of 38 + 1 about C.

After 12 hours, good milk remains liquid or the first signs of curdling appear. Poor quality milk gives a swollen clot. The final result is obtained in a day.

1 class- the clot is dense, even, without serum separation. Minor stripes are allowed on the clot. The microflora is lactic acid, the quality of the protein is high.

Grade 2– A clot with streaks and voids filled with serum, poor serum separation, fine-grained clot structure. The microflora is represented by lactic acid microorganisms with a small admixture of gas-forming microflora (mainly yeast). The quality of milk protein is satisfactory.

3rd grade- The clot shrank with copious release of greenish or whitish serum, coarse-grained, gas bubbles in the clot. Microflora - mainly gas-producing bacteria. With a tightened clot, there may be putrefactive microorganisms. The quality of milk protein is poor.

4th grade- The clot is broken, swollen, permeated with gas bubbles. The microflora is mainly gas-forming, butyric bacteria are present, and may be putrefactive. The quality of milk protein is very poor.

Rennet fermentation test

It is carried out to determine the nature of the microflora of raw milk and the quality of milk protein during rennet coagulation (mainly in cheese making). According to the technical regulations, milk for cheese production must have I or II class according to the rennet-fermentation test.

Analysis progress. Pour approximately 30 cm 3 of milk into large test tubes, add 1 cm 3 of a 0.5% solution of rennet (dissolve 0.5 g of rennet in 100 cm 3 of water at a temperature of 30 ° C), mix and put in a thermostat with temperature 37-40 o C.

Benign milk coagulates within 20 minutes, and after 12 hours it gives a dense clot (cheese) with a clear whey. The results of the rennet-fermentation test are evaluated in accordance with table 5.

Table 5 - Evaluation of the results of the rennet-fermentation test

Task 2:

1. Warm up the milk to 30-35 o C. Determine the organoleptic characteristics of milk and the purity group.

2. Cool the milk to 20 o C, determine the titratable and active acidity of the milk. Compare the obtained values ​​with the values ​​given in Table 6.

3. Express acidity in grams of lactic acid. Record the results in table 9.

The number of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM). Determination of the number of mesophilic aerobic and facultative anaerobic microorganisms (KMAFAnM or total microbial number, TMC) refers to the assessment of the number of a group of sanitary indicative microorganisms. QMAFAnM includes various taxonomic groups of microorganisms – bacteria, yeasts, molds. Their total number indicates the sanitary and hygienic state of the product, the degree of its contamination with microflora. Optimum temperature for QMAFAnM growth is 35-37оС (under aerobic conditions); the temperature limit of their growth is within 20-45°C. Mesophilic microorganisms live in the body of warm-blooded animals, and also survive in soil, water, and air. The QMAFAnM indicator characterizes the total content of microorganisms in the product. Its control at all technological stages makes it possible to trace how “clean” the raw material goes to production, how the degree of its “purity” changes after heat treatment, and whether the product undergoes re-contamination after heat treatment, during packaging and storage. The QMAFAnM indicator is estimated by the number of mesophilic aerobic and facultative anaerobic microorganisms that have grown in the form of visible colonies on a dense nutrient medium after incubation at 37°C for 24-48 hours. Although the total number of QMAFAnM bacteria cannot directly indicate the presence or absence of pathogenic bacteria in food products, this indicator is quite widely used, for example, in the dairy industry. The indicator QMAFAnM (OMCH) characterizes the sanitary and hygienic regimes of production and storage conditions for dairy products. Products containing a large number of bacteria, even non-pathogenic and not changing their organoleptic characteristics, cannot be considered complete. A significant content of viable bacterial cells in food products (with the exception of those in the production of which sourdough is used) indicates either insufficiently effective heat treatment of raw materials, or poor equipment washing, or unsatisfactory storage conditions for the product. Increased bacterial contamination of the product also indicates its possible deterioration. This indicator is not examined for sour cream and products, cottage cheese and products, liquid sour milk, yogurt.

Determination of the total number of bacteria

Preparation of samples for research. Tenfold dilutions are prepared from milk and other dairy products (according to the generally accepted method). The number of dilutions for each type of product is prepared taking into account the most likely microbial contamination (Table 56).

Table 56

Note. To determine the total number of bacteria, one should choose those dilutions that, when sown on plates, grow at least 50 and no more than 300 colonies.

Sowing.

1 ml of each dilution is added to 2-3 sterile Petri dishes and 12-15 ml of nutrient agar, melted and cooled to 45°C, are poured. Cups are pre-labeled. Immediately after pouring, the contents of the cup are stirred (by slight rotational rocking) to evenly distribute the inoculated material. Crops are placed in a thermostat at 37 ° C for 48 hours.

At the end of the incubation period, the dishes are removed and the number of colonies is counted using a counter. The number of colonies grown on each plate is multiplied by the appropriate dilution. The results obtained for individual dishes are added, divided by the number of dishes and the arithmetic mean is obtained, which is an indicator of the total number of bacteria in 1 g (ml).

The relevant GOSTs regulate the quality of products, which is established according to acceptable indicators: the total number of microbes and coli-titer. An example for two types of products is presented in Table. 57.

Table 57. Indicators of the total number of bacteria and coli-titer in milk

Note. For other dairy products, there is also a GOST stipulating the permissible number of microbes in 1 ml (g) of the product. The letters A and B indicate the category of the product.

In fermented milk products (kefir, curdled milk, cottage cheese, sour cream, etc.) containing abundant specific microflora, the total number of bacteria is not determined, but the composition of the microflora is controlled. To do this, preparations are prepared from fermented milk products and stained with methylene blue. In the field of view of the preparation should be only microorganisms specific to this product. For example, for curdled milk - lactic acid streptococci and sticks; for kefir - lactic acid streptococci and sticks, single yeast. Microscopy reveals spoilage microorganisms (molds and large amounts of yeast).

According to QMAFAnM

But the quality assessment by this indicator has a number of disadvantages:

— anaerobic microorganisms are not taken into account;

— psychrophilic and thermophilic microorganisms are not taken into account;

- gives only a quantitative assessment of the microbiota;

— does not take into account pathogenic microorganisms;

— not applicable for products containing technological microbiota.

Sanitary-indicative microorganisms:

- bacteria of the Enterobacteriaceae family;

- enterococci.

The detection of sanitary indicative microorganisms in any object indicates its contamination with human or animal secretions and the possible presence of pathogenic microorganisms epidemiologically associated with the corresponding excreta.

Detection of bacteria of the group of Escherichia coli (BCG).

Their presence indicates faecal contamination of the object. The quantitative values ​​of this indicator characterize the degree of this pollution. CGB can get into food products with water, dust, through dirty hands, and be carried by insects.

The standards include bacteria of the family Enterobacteriaceae as sanitary indicative microorganisms. This family includes many types of non-pathogenic, opportunistic and pathogenic microorganisms, therefore, the detection of more than 10 2 CFU of enterobacteria that are not pathogenic species in 1 g (cm 3) of the product indicates its potential epidemiological danger.

The presence of enterococci, and especially E. faecalis, in the environment and food is indicative of fresh faecal contamination. Usually, their detection in finished products indicates violations of technological production modes.

3. Conditionally pathogenic microorganisms:

- Escherichia coli;

- Staphylococcus aureus;

- bacteria of the genus Proteus;

- Bacillus cereus;

- sulfite-reducing clostridia;

Vibrio parahaemolyticus.

E. coli (Escherichia coli) has a dual meaning as a sanitary indicative and opportunistic microorganism.

Coagulase-positive Staphylococcus aureus (Staphylococcus aureus) is identified as a potentially dangerous microorganism in cooked foods. An increased amount of it in food products is a sign of secondary contamination of the latter. The microorganism enters the products from contaminated equipment, inventory, from the skin, from the nasopharynx of personnel, as well as from sick animals. Staphylococci are characterized by resistance to adverse environmental factors, they multiply intensively at a temperature of 18÷20ºС, slowly - at 5÷6ºС. Able to multiply in concentrated solutions of sugar (up to 60%) and common salt (up to 12÷14%). Remain viable for 6 months when dried. Reproduction of Staphylococcus aureus in food products from 10 6 to 10 9 CFU / g (cm 3), regardless of the initial contamination, leads to the accumulation of enterotoxin.

Of bacteria of the genus Proteus, two species P. vulgaris and P. mirabilis are causative agents of toxicoinfections.

The waxy stick (Vacillus cereus) is extremely widespread in nature, its main habitat is the soil. It is also found in the water of open reservoirs (up to 10 3 ÷10 4 CFU / cm 3), in tap water and in the air. These objects serve as a source of contamination of equipment and apparatus of food industry and public catering enterprises and the contamination of various food products. If B. cereus is detected in an amount of more than 10 3 CFU / g (cm 3) and there is no pathogenic microbiota, this microorganism can be considered the cause of food poisoning.

Sulfite-reducing clostridia are spore-forming anaerobic bacteria, mainly represented by C. perfringens and C. sporogenes. C. perfringens is constantly present in the intestines of humans and animals and is an indicator of faecal contamination. The presence of sulfite-reducing clostridia in the products in an amount of more than 10 2 CFU / g (cm 3) indicates a violation of the sanitary and hygienic regime at work, in particular, poor preparation of equipment, ingress of soil, dirty water, etc., and in addition , for the possible threat of the presence of C.botulinum.

In the soil, indoor dust, C. perfringens is found in almost 100% of the studied samples, in the air of public catering establishments in 10–12% of cases, on catering equipment in almost 30% of cases, and on sanitary clothing of catering workers in 11–19% of cases. . On food, C. perfringens has been found particularly frequently on meat and meat products, which are most implicated in foodborne outbreaks. In addition to intravital contamination of tissues and organs of animals, contamination can occur during butchering carcasses, grinding meat, adding breading and spices, often with a high degree of contamination. During cooking, C. perfringens spores survive and can germinate and multiply to enormous numbers that can cause food poisoning. Spores of C. perfringens may also contain plant products. The critical level of contamination of food products with spores of C. perfringens is considered to be ≥ 10 5 CFU / g (cm 3).

Parahemolytic or halophilic vibrios (Vibrio parahaemolyticus) are widely distributed in the external environment, primarily in coastal sea waters, marine fish and seafood, and in bottom marine sediments. One of the representatives of the genus Vibrio, which includes about 45 species, V. Parahaemolyticus was the cause of numerous outbreaks of gastroenteritis associated with the use of contaminated seafood - frozen, salted, smoked fish, shellfish. The circulation of this microorganism was established according to the scheme sea water - fish - man - sewage - sea water.

4. Pathogenic microorganisms:

- salmonella;

- Listeria monocytogenes;

bacteria of the genus Yersinia.

Bacteria of the genus Salmonella are currently recognized as indicators for the entire group of pathogenic intestinal bacteria. This is due, firstly, to the availability of effective methods for their detection and, secondly, to the fact that the detection of Salmonella to a certain extent corresponds to the detection of Shigella in the same object, which are much more difficult to isolate methodically than Salmonella.

Currently, regulatory documents standardize the amount of product in g (cm 3), in which the presence of bacteria of the Salmonella genus is unacceptable.

Bacteria of the genus Yersinia, and in particular Y. enterocolitica, are the causes of infectious diseases with a variety of clinical manifestations. Yersiniosis is often misdiagnosed as enterocolitis, food poisoning, scarlet fever, rubella, hepatitis, appendicitis, rheumatism, acute respiratory disease, etc.

The ability to multiply at a temperature of 0÷5ºС in refrigerators, vegetable stores, etc., leads to an increase in their number on contaminated products. Yersinia is not demanding on environmental conditions and actively reproduces in soil and water. The main carriers of these microorganisms are wild rodents and birds. The main way of human infection is alimentary. The infection is transmitted through contaminated food products, more often with their soil and water contamination, less often with animal secretions. Most often, single diseases and group outbreaks arise from the use of infected dairy products and vegetables - cabbage, carrots, onions, etc.

Listeria monocytogenes is the causative agent of a dangerous infectious disease of a zoonotic nature with a predominantly food-borne transmission route. Pathogenic listeria are widespread in nature and are capable of contaminating a variety of products - dairy, meat, fish, eggs, seafood, vegetable raw materials, etc. Regulatory documents establish the mass or volume of the product in which these bacteria should be absent.

Spoilage microorganisms include:

- yeast;

- mold fungi;

- lactic acid bacteria.

Regulatory documents establish quantitative criteria for their content in certain groups of food products. However, the list of this group of microorganisms is incomplete. Thus, the importance of putrefactive bacteria of the genus Pseudomonas as causative agents of spoilage is shown. The microbiological stability of food products during storage must also be assessed by such indicators as QMAFAnM, thermophilic and psychrophilic microorganisms, as well as special types (or genera) of microorganisms - typical spoilage agents. For example, in products intended for storage at temperatures above 30ºС ± 5ºС, the number of thermophiles is determined; for storage at an unregulated temperature of 20ºС ± 5ºС - KMAFAnM; for storage at low temperature - the number of psychrophiles.

6. Microorganisms of starter microbiota and probiotic microorganisms:

- lactic acid and propionic acid bacteria;

- bifidobacteria;

- yeast.

The standard indicators include microorganisms of the starter microbiota and probiotic microorganisms (for products with a normalized level of biotechnogenic microbiota). These indicators include indicators of the quantitative content of lactic acid, propionic acid bacteria, yeast, bifidobacteria and others. The values ​​of these indicators are determined by the specifics of the production of a particular product and its purpose.

Control questions:

1. What document regulates food safety criteria and methods for their determination?

2. What is the basic principle of the HACCP quality control system?

3. List the main provisions of the HACCP control system.

4. The main principle of the international system for assessing the quality of production according to ISO standards?

5. What hazard factors are included in the list of mandatory ones? Where are they listed?

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QMAFAnM Number of mesophilic aerobic and facultative anaerobic microorganisms ( KMAFAnM) or total bacterial contamination is one of the main indicators of the sanitary quality of raw milk. It determines the ways of further processing of milk and affects its cost.
Sanitary-indicative microflora, by the amount of which one can indirectly judge the safety of products and the sanitary condition of the enterprise. A large number of QMAFAnM most often indicates violations of sanitary rules and the technological regime of manufacture, as well as the timing and temperature regimes of storage, transportation and sale of food products
The number of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM) is one of the main indicators of the sanitary state of meat.

High bacterial contamination is a common cause of food poisoning in humans.
E. coli is an opportunistic bacterium (more than 100 species) that lives in the intestines of humans, animals and birds. They are highly resistant to adverse conditions and remain in water, soil, and on objects for a long time. They develop most intensively at a temperature of 37 ° C, but they can also multiply at room temperature. They die at +60 ° C in 15 minutes. Most types of E. coli are safe. However, some types of E. coli produce dangerous toxins during their life (mainly endotoxins), which can lead to poisoning. The most susceptible to this disease are young children, the elderly and debilitated people. This disease occurs in the form of varying severity of enteritis, enterocolitis in combination with a syndrome of general intoxication.

BGKP Bacteria of the Escherichia coli group (Escherichia coli, Enterococcus, Proteus, Clostridium perfringens, thermophilic, Salmonella).
This group includes more than 100 species of microorganisms that live in the intestines of humans, animals and birds. They are highly resistant to adverse conditions and can be stored for a long time in water, soil, and on objects.
Food poisoning can be caused by a product with a very high contamination (content) of these bacteria or a product in which there are individual representatives of this group that are unsafe for humans. Basically, the presence of BGKP indicates the general sanitary condition of production, including the cleanliness of equipment.
On the other hand, the detection of CGB in the product may indicate incorrect storage conditions.
Thus, we can say that 3 (three) market players are the culprit for the presence and / or growth of this microorganism - the manufacturer, the carrier and the seller. Who is more to blame and who is less is not important from the point of view of the consumer.

From the point of view of the Law "On Protection of Consumer Rights", the extreme party closest to the consumer will be the point of sale, i.e. salesman.
The detection of bacteria of the genus Escherichia in food, water, soil, and equipment indicates fresh fecal contamination, which is of great sanitary and epidemiological significance.
Bacteria of the E. coli group are neutralized by conventional pasteurization methods (65 - 75 ° C).

At 60 ° C, E. coli dies after 15 minutes.

yeast A group of unicellular fungi.
In the course of life, yeast metabolize food components, forming their own specific end products of metabolism. At the same time, the physical, chemical and, as a result, organoleptic properties of the products change - the product deteriorates. Yeast growths on products are often visible to the naked eye as a surface coating (for example, on cheese or meat products) or manifest themselves by starting the fermentation process (in juices, syrups, and even in fairly liquid jams).
Yeasts of the genus Zygosaccharomyces have long been one of the most important spoilage agents in the food industry. Particularly difficult to control them is the fact that they can grow in the presence of high concentrations of sucrose, ethanol, acetic acid, benzoic acid and sulfur dioxide, which are the most important preservatives.
Some types of yeast are facultative and opportunistic pathogens, causing disease in people with weakened immune systems.
Yeasts of the genus Candida are components of the normal human microflora, however, with a general weakening of the body by injuries, burns, surgery, prolonged use of antibiotics, in early childhood and old age, etc., Candida fungi can develop en masse, causing a disease - candidiasis.
Cryptococcus neoformans causes cryptococcosis.
The genus Malassezia in violation of the immune system cause pitiriasis (variegated lichen), folliculitis and seborrheic dermatitis.

mold
mold fungi are the cause of such pathological conditions of the body as allergies, bronchial asthma, dermatitis.
Common fungal mold can cause serious illness and even death in immunocompromised people.

In such patients, mold (more specifically, fungal spores) can cause pulmonary aspergillosis.
The most dangerous mold is the fungus Aspergillus, a constant companion not only of humans, but also of birds, animals, and plants. It can be found everywhere: in soil, ventilation systems, food

Organisms are classified according to their need for oxygen aerobes And anaerobes.
Anaerobic Microorganisms live without access to oxygen, they can be present in hermetically sealed products or products packed under vacuum. They do not need oxygen, strict anaerobes die in the presence of oxygen, it is “contraindicated” for them, while facultative anaerobes survive in the presence of oxygen, but they do not need it. Bright representatives of anaerobes are salmonella (Salmonella) and the causative agent of botulism (Clostridium botulinum). The latter can only develop in sealed packages without oxygen).

Aerobes they cannot live without oxygen, for example, Staphylococcus aureus (Staphylococcus aureus).

The amount of MAPAM can be considered as the total microbial number, i.e. the content of all microorganisms in the product. If you control this indicator at all stages of production, then you can track how “clean” the raw material goes to production, how its “purity” changes after heat treatment, and whether the product undergoes re-contamination after heat treatment and during packaging. After all, microorganisms can get into the product from containers, both bottles and caps.

The problem with bottles for some products can be successfully solved: if PET bottles are “blown” out of preforms immediately before filling with hot steam, this guarantees their purity.

Or you can use hot filling.

If the content of MAPAM in the final product exceeds the norm, then this may equally indicate both a violation of sanitary conditions at the production site or a violation of technology, and a violation of the conditions for storage and sale of the product in the distribution network.

Psychrophiles- these are organisms that love low temperatures, usually not higher than 10 0 C
mesophiles- these are organisms that develop at medium temperatures (20-40 0 C)
Thermophiles they can survive at high temperatures (more than 45 0 С)

Number of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM)

Determination of the number of mesophilic aerobic and facultative anaerobic microorganisms (KMAFAnM or total microbial number, TMC) refers to the assessment of the number of a group of sanitary indicative microorganisms. The composition of QMAFAnM includes various taxonomic groups of microorganisms - bacteria, yeasts, mold fungi. Their total number indicates the sanitary and hygienic state of the product, the degree of its contamination with microflora. Optimum temperature for QMAFAnM growth is 35-37 o C (under aerobic conditions); the temperature limit of their growth is within 20-45 ° C. Mesophilic microorganisms live in the body of warm-blooded animals, and also survive in soil, water, and air.

The QMAFAnM indicator characterizes the total content of microorganisms in the product. Its control at all technological stages makes it possible to trace how “clean” the raw material goes to production, how the degree of its “purity” changes after heat treatment, and whether the product undergoes re-contamination after heat treatment, during packaging and storage. The QMAFAnM indicator is estimated by the number of mesophilic aerobic and facultative anaerobic microorganisms that have grown in the form of visible colonies on a dense nutrient medium after incubation at 37 ° C for 24-48 hours.

QMAFAnM is the most widely used microbial safety test. This indicator is used everywhere to assess the quality of products, with the exception of those in the production of which special microbial cultures are used (for example, beer, kvass, fermented milk products, etc.). The value of the QMAFAnM indicator depends on many factors. The most important ones are the mode of heat treatment of the product, the temperature regime during its transportation, storage and sale, the humidity of the product and the relative humidity of the air, the presence of oxygen, the acidity of the product, etc. An increase in QMAFAnM indicates the multiplication of microorganisms, which may include pathogens and microorganisms that cause spoilage of the product (for example, molds).

Although the total number of QMAFAnM bacteria cannot directly indicate the presence or absence of pathogenic bacteria in food products, this indicator is quite widely used, for example, in the dairy industry. The indicator QMAFAnM (OMCH) characterizes the sanitary and hygienic regimes of production and storage conditions for dairy products. Products containing a large number of bacteria, even non-pathogenic and not changing their organoleptic characteristics, cannot be considered complete. A significant content of viable bacterial cells in food products (with the exception of those in the production of which sourdough is used) indicates either insufficiently effective heat treatment of raw materials, or poor equipment washing, or unsatisfactory storage conditions for the product. Increased bacterial contamination of the product also indicates its possible deterioration.

For the consumer, the QMAFAnM (OMCH) indicator characterizes the quality, freshness and safety of food products. At the same time, assessing the quality of a product only by this indicator has a number of disadvantages. Firstly, this is only a general, quantitative assessment of microorganisms, since the study does not take into account pathogenic, conditionally pathogenic, psychrophilic and thermophilic microorganisms. Secondly, the method is unacceptable for products containing technological and specific microflora.

The QMAFAnM indicator also allows assessing the level of sanitary and hygienic conditions in the social sphere at work, it allows you to identify violations of the storage and transportation of the product.

Detection methods

Classic method

The method for determining QMAFAnM by inoculation into agar nutrient media is based on the inoculation of the product or its dilution into a nutrient medium, incubation of the inoculations, and counting of all grown colonies.

There is also a method for determining the MNP (most probable number) QMAFAnM. It is based on inoculation of the product and/or dilutions of a sample of the product into a liquid nutrient medium, incubation of the inoculations, taking into account visible signs of microbial growth, subculture (if necessary) of the culture liquid on agar nutrient media to confirm the growth of microorganisms, counting their number using the MPN table.

Alternative (fast track) methods

For accelerated determination of QMAFAnM in the test sample, it is recommended to use 3M TM Petrifilm Aerobic Count Plate (AC). Petrifilm 3M TM Petrifilm Aerobic Count Plate (AC) contains ready-made nutrient medium, gel (freezing at room temperature) and a tetrazolium indicator, which facilitates the counting of colonies on petrifilm.

Regulations

Codex Alimentarius. Food hygiene. Basic texts. Recommended international technical norms and rules. General principles of food hygiene. 2003.

General characteristics of the food product according to QMAFAnM

Group of microbial contamination	CFU / g (cm 3)	Product condition
	10 3 ÷ 10 4 , ≤ 10 5	Fresh, good quality, shelf stable
	> 10 5 ÷ 10 6	Manufactured or stored in violation of technological or sanitary-hygienic regimes
	> 10 6 ÷ 10 7	Potentially dangerous as a source of pathogenic microorganisms and their toxins
	> 10 7 ÷ 10 8	Damaged, which is confirmed visually (discoloration, odor, mold appearance)

Indicative microbiological values ​​of some products

In 1 sample of light unpasteurized beer - BGKP were found;
- in 1 sample of fish x\c - excess of QMAFAnM;
- in 3 air samples from the refrigeration chamber - an excess of mold CFU was found - the sanitary rating is "bad";
- in 4 samples of dried fish, an excess of mold CFU was found;
- in 4 samples of dried fish, an excess of QMAFAnM was found;
- in 5 samples of drinking water (artesian water bottled through a network of automatic bottling machines for bottling water into consumer containers) - exceeding the TMF.

Determination of the number of mesophilic aerobic and facultative anaerobic microorganisms (KMAFAnM or total microbial number, TMC) refers to the assessment of the number of a group of sanitary indicative microorganisms. QMAFAnM includes various taxonomic groups of microorganisms – bacteria, yeasts, molds. Their total number indicates the sanitary and hygienic state of the product, the degree of its contamination with microflora. Optimum temperature for QMAFAnM growth is 35-37оС (under aerobic conditions); the temperature limit of their growth is within 20-45oC. Mesophilic microorganisms live in the body of warm-blooded animals, and also survive in soil, water, and air. The QMAFAnM indicator characterizes the total content of microorganisms in the product. Its control at all technological stages makes it possible to trace how “clean” the raw material goes to production, how the degree of its “purity” changes after heat treatment, and whether the product undergoes re-contamination after heat treatment, during packaging and storage. The QMAFAnM indicator is estimated by the number of mesophilic aerobic and facultative anaerobic microorganisms that have grown in the form of visible colonies on a dense nutrient medium after incubation at 37°C for 24-48 hours.

QMAFAnM is the most widely used microbial safety test. This indicator is used everywhere to assess the quality of products, with the exception of those in the production of which special microbial cultures are used (for example, beer, kvass, fermented milk products, etc.). The value of the QMAFAnM indicator depends on many factors. The most important are the mode of heat treatment of the product, the temperature regime during its transportation, storage and sale, the humidity of the product and the relative humidity of the air, the presence of oxygen, the acidity of the product, etc. An increase in QMAFAnM indicates the multiplication of microorganisms, which may include pathogens and microorganisms that cause spoilage of the product (for example, molds).

Although the total number of QMAFAnM bacteria cannot directly indicate the presence or absence of pathogenic bacteria in food products, this indicator is quite widely used, for example, in the dairy industry. The indicator QMAFAnM (OMCH) characterizes the sanitary and hygienic regimes of production and storage conditions for dairy products. Products containing a large number of bacteria, even non-pathogenic and not changing their organoleptic characteristics, cannot be considered complete. A significant content of viable bacterial cells in food products (with the exception of those in the production of which sourdough is used) indicates either insufficiently effective heat treatment of raw materials, or poor equipment washing, or unsatisfactory storage conditions for the product. Increased bacterial contamination of the product also indicates its possible deterioration.

For the consumer, the QMAFAnM (OMCH) indicator characterizes the quality, freshness and safety of food products. At the same time, assessing the quality of a product only by this indicator has a number of disadvantages. Firstly, this is only a general, quantitative assessment of microorganisms, since the study does not take into account pathogenic, conditionally pathogenic, psychrophilic and thermophilic microorganisms. Secondly, the method is unacceptable for products containing technological and specific microflora.

The QMAFAnM indicator also allows assessing the level of sanitary and hygienic conditions in the social sphere at work, it allows you to identify violations of the storage and transportation of the product.