Bacteria found in food can be both useful for the body and pathogenic - which usually cause food poisoning of varying severity. Beneficial bacteria include probiotics (lacto- and bifidobacteria) and prebiotics. They are mainly found in fermented milk products. Beneficial bacteria stimulate and normalize digestion and metabolic processes in the body,
Bacteria contained in food can be divided into two groups:
Beneficial bacteria include:
Probiotics are useful bacteria for the human body . They include: lactic acid (lacto-) bacteria, bifidobacteria, yeast. In the intestines of a healthy person, there is usually about 1-1.5 kg of probiotics - this amount is a guarantee of the full functioning of all systems and organs, as well as immunity). However, according to statistics, a large part of the healthy microflora in the human body is replaced by pathogenic ones, so in fact only 1/10 of the norm of beneficial bacteria is present .
Functions of probiotics:
Products containing probiotics:
The most effective is the consumption of probiotics, together with prebiotics, which, in turn, are not digested in the intestines, but provide favorable conditions for the growth of healthy microflora.
The main source of lactobacilli for the human body is fermented milk products. It is lactobacilli that are the first bacteria for a newborn, as he receives them from the mother's birth canal.
Functions of lactobacilli:
Products containing lactobacilli
Since lactobacilli are stimulators of lactic acid fermentation, they are used in the production of fermented milk products, so the following are rich in bacteria :
Bifidobacteria are present in the human body in small quantities, they are concentrated mainly in the large intestine, forming the basis of its wall and cavity microflora. These beneficial bacteria suppress the development of putrefactive and disease-causing bacteria in the body.
Functions of bifidobacteria:
Products containing bifidobacteria :
Prebiotics are the remains of nutrients that are not digested by stomach enzymes, because they are not absorbed by the upper parts of the digestive tract, getting to the lower ones, where they are "fed" by probiotics - this has a positive effect not only on the digestive tract, but also on the whole body.
Functions of prebiotics :
Products containing prebiotics :
Harmful bacteria include:
A rod -shaped bacterium (more than 100 species) that lives in the intestines of warm-blooded organisms (animals, humans, birds). It is characterized by resistance to adverse factors, is stored for a long time in water, soil, and on objects. It reproduces at room temperature, but the most favorable temperature is +37ºС. Dies within 15 minutes at +60ºС.
The most vulnerable to contamination are ready meals made from meat, fish, potatoes, salads, etc. Also, very often the source of poisoning is water, the bacterium lives in reservoirs.
This is a putrefactive bacterium . Resistant to drying, high salt concentration, heating up to +65ºС for 30 minutes. It can reproduce at a temperature from +6 to +40ºС, the most favorable — from +20 to +37ºС. The bacterium does not change the organoleptic properties of products during infection.
The main cause of contamination: the use of surfaces and utensils that were used for raw products for slicing ready-made products and vegetables.
A bacterium that lives in water, soil, and food. It reproduces at a temperature of +15ºС, the most optimal — from +37 to +45ºС. Dies in an acidic environment. The stick is resistant to heat.
Prepared meals, in particular meat, are especially vulnerable. To prevent contamination, meals that are prepared in advance must be cooled in time and stored in the refrigerator.
A rod -shaped bacterium that causes salmonellosis is severe food poisoning. The bacterium reproduces at room temperature, and +37ºС is the most favorable. Also, salmonella is resistant to low temperatures, it can survive even at -20ºС. The bacterium reproduces worse in a salty environment, and does not reproduce at all in an acidic environment. It dies when heated to 100ºС instantly, to 60ºС within an hour.
Salmonella bacteria is quite common in nature, it is carried by animals, birds (waterfowl), insects and rodents. Especially vulnerable are meat, dairy products, fish, eggs. Salmonella does not change the properties of contaminated products.
You can prevent contamination of products with bacteria as follows:
A bacterium that causes sore throat, inflammation, purulent skin diseases. It is constantly present on the skin, in the nasal and oral cavities of a person, and in the air. When it gets on food products, the bacterium develops rapidly and releases a large amount of toxin. The most favorable temperature for the development of bacteria is from +30 to +37ºС, however, it retains its viability even at +15-20ºС. Also, staphylococcus is resistant to drying and freezing. The bacterium dies when heated for 30 minutes to +80ºС. However, to neutralize the poison, it is necessary to heat it to +100ºС for 1.5-2 hours. Also, the development of bacteria stops in an acidic environment, but the poison remains.
Various products are susceptible to staphylococcus poison: fish, meat, vegetables, confectionery. The bacterium does not change their organoleptic properties. To prevent contamination of products with staphylococcus, it is necessary to observe the rules of personal hygiene, and also to store products in closed containers at a temperature of +2-4ºС.
The bacterium that causes the most severe food poisoning is botulism. The botulinum bacillus lives in the intestines of animals, humans, fish and birds, and is also present in water bodies, soil, on fruits and vegetables. The bacterium is very resistant to the influence of the external environment: it can develop without air access, it does not die during freezing and canning. However, high temperatures are destructive for botulinus: the bacterium dies when boiled for 15 minutes, when heated for 30 minutes to +80ºС, and meat and fish should be boiled for an hour. Heat treatment of products is the main method of preventing botulism.
The most vulnerable to bacterial contamination are canned foods, in particular, homemade ones: pickled mushrooms and vegetables, canned meat and fish, as well as ham, salted and dried fish. Botulinum does not change the organoleptic properties of products. Rare signs of infection can be: swelling of cans with canned goods, a faint smell of rancid fat, very rarely - softening and discoloration of products.
The main measures to prevent bacterial infection are:
PREMIUM CHAPTERS ▼
Bacteria can get on food products in the following ways:
Bacteria reproduce by fission. Under favorable conditions, the number of bacteria doubles every 20 minutes, that is, in 6 hours one bacterium can grow to about a million. Favorable conditions for the development of bacteria : heat, humidity, nutrient environment. Bacteria cannot multiply without moisture . Contaminated food causes food poisoning of varying severity.
The most vulnerable to bacterial infection are:
Almost all bacteria die when exposed to high temperatures — heat treatment is the main means of preventing food poisoning from contaminated products.