What is fermentation, surely every person imagines. One has only to leave milk, fruit juice, compote or soup warm for a while, and bubbles begin to appear on the surface, and the product itself appears sour. Humanity has long learned to benefit from this chemical process, receiving new products with its help. Today we want to tell you more about fermentation. This is a really interesting topic, especially since the practical value is beyond doubt.
a brief description of
After we understand what is at stake, a scientific definition should be given. So, fermentation is a rather complicated (with all its apparent simplicity) chemical reaction. It lies in the fact that the sugar contained in the product is converted to ethyl alcohol, lactic acid. The latter depends on the initial product, as well as the family of bacteria involved in this process. However, the result of this process cannot always be predicted, especially if it occurs under natural conditions. It will be predictable only in case of strict observance of technological conditions.
Convert carbohydrates to alcohol
This type of reaction is used in the production of wines and apple cider vinegar, in the preparation of yeast dough, etc. Thus, this is a process that occurs due to the activity of a number of microorganisms. In the process of their life, carbon dioxide and ethyl alcohol are actively formed. Of course, not only this, in laboratory conditions it is possible to determine the release of carboxylic acids and other alcohols. Rosy bread and aromatic wine, healthy apple cider vinegar - these are all products that we get thanks to the yeast bacteria of the genus Saccharomyces.
Lactic acid fermentation
Useful yogurt, delicious cottage cheese and excellent cheese - all these products give us milk fermentation. It does not occur by itself, but also as a result of the vital activity of bacteria. In this case, lactic acid bacteria are responsible for turning milk into new products . Speaking in scientific terms, this is the conversion of sugars to lactic acid, while we get a small amount of hydrogen and pyruvic acid. In this case, two groups of bacteria are distinguished: coccal and rod-shaped bacteria.
The first group is homoenzymatic: lactic streptococcus, creamy and thermophilic streptococcus. The second group is atypical bacteria, they are permanent residents of our intestines. In the process of their life, not only lactic, but also acetic acid is formed.
Butyric acid fermentation
This chemical process is very similar to those described above. The only difference is that the microorganisms that provide this process belong to a different species. Butyric acid fermentation is caused by anaerobic bacteria. They turn many carbohydrates, as well as higher alcohols, into butyric acid. This forms a mixture of gases. It is usually carbon dioxide and hydrogen.
The optimum temperature at which this fermentation reaction proceeds is +30 - +40 degrees. At the same time, the process goes well with a neutral reaction. It can also go in an acidic environment, but in this case, butyl alcohol and acetone accumulate.
The benefits and harms of butyric acid fermentation
Fermentation is not always a useful and necessary reaction. In particular, butyric acid, which is characterized by a bitter taste and pungent odor, is released as a result of this process. But the esters have a pleasant smell of flowers and fruits. This is the reason that they are widely used in the production of various essences for the confectionery and perfumery industries. However, in an economy, butyric acid fermentation most often causes damage, since it is it that usually causes the death of potatoes and vegetables, and the bloating of cheeses. Canned food explodes because of it, milk and sour cream rancid.
Other types of fermentation
In fact, there are a lot of them. All chemical reactions that occur with the conversion of sugars during the life of bacteria are fermentation. The result is the formation of carbon dioxide, alcohols and the complete conversion of the initial product.
Protein fermentation exists in nature. Putrefactive anaerobic bacteria are able to ferment not only carbohydrates, but also proteins, due to which they are real orderlies of our planet. Organics break down to amino acids. In nature, such a cycle of matter is of tremendous importance.
The next type is propionic acid fermentation. Some bacteria from the genus Propionibacterium cause it. As a result of their vital activity, propionic and acetic acids are formed. A lot of acids in production are formed precisely by these processes. For example, oxalic acid, which turns into succinic. However, many moldy fungi ferment sugar with the formation of citric acid. A significant part of the citric acid that is obtained in production is precisely the result of the cultivation of molds.
Thus, it is obvious that fermentation is an important chemical reaction that proceeds almost everywhere, both according to our will (in industrial production) and by a random combination of factors (suitable temperature, nutrient medium). Being able to control these processes, we can turn them for good, while preventing fermentation where it is not needed and stimulating it, where it will bring tangible benefits.