What is fermentation?
Fermentation is a natural process that occurs in certain compounds or elements from the action of different actors and that could be simplified as an incomplete oxidation process.
Fermentation is the process that occurs in some foods such as bread, alcoholic beverages, yogurt, etc., and that has as a main agent the yeast or different chemical compounds that supply its action.
To find the origins of the concept of fermentation, we have to go back to the Latin word fermentatĭo.
The term is associated with the verb ferment that, depending on the context, can be a metabolic process to achieve the degradation of a substance, or the action of being disturbed or moved.
Fermentation implies an anaerobic process characteristic of catabolism (a part of the metabolism) that results in the conformation of an organic compound. It is said that this procedure is anaerobic since it does not require oxygen.
It is important to establish that this process was discovered by the French chemist Louis Pasteur (1822 – 1895), also known for having made important advances in the field of chemistry and microbiology such as pasteurization or the germinal theory of what they are. infectious diseases.
When the fermentation takes place, the resulting compound obtains energy despite the lack of oxygen (this is why the process is qualified as anaerobic). Bread, wine, and beer are some of the products of daily consumption that are created from fermentation.
Yeast is a key player in the development of fermentation. This denomination is granted to unicellular fungi that, through fermentation, manage to decompose carbohydrates, sugars, and other substances to generate various compounds.
Types of Fermentation
In addition to all the above, we must make clear that there are different types of fermentation, equally important:
• Alcoholic fermentation. Under this denomination is the process of granting the yeasts anaerobic energy in the absence of oxygen and from glucose. Wine, rice, beer or even milk can be obtained through this procedure which can be, in turn, of two kinds: natural or industrial.
• Lactic fermentation. In this case, it must be stated that bacteria and glucose play a fundamental role in it. And it is that the first are those that carry out this process in which the lactose is partially oxidized to obtain energy. A clear example of this initiative is the acidification of milk.
• Acetic fermentation. In this other case, what happens is that aerobic bacteria are responsible for transforming the so-called ethyl alcohol into what is acetic acid.
• ferrolaic fermentation pcb.
• Butyric fermentation. This other process should be noted that it is defined as the one in which, in the absence of oxygen, the bacteria “Clostridium butyricum”, the amylobacteria, convert what are carbohydrates into butyric acid.
Take the case of wine fermentation. This process has been known for thousands of years: the Greeks, for example, believed that the god Dionysus was responsible for the surprising transformation of the sugars present in the must (juice or grape juice) into alcohol.
Alcoholic fermentation, in short, releases energy by producing carbon dioxide, which ends up displacing oxygen from the receptacles used for the process.
If we refer to a more colloquial use of the notion of fermentation, we must associate it with the exaltation or agitation of the mind. A person who ferments is upset and very nervous for some reason.
For example: “The words of the manager caused a fermentation among the employees, who went on strike almost immediately.”
The fermentation is carried out by different bacteria and microorganisms in anaerobic media, that is, in those that lack air, that is why it is an incomplete oxidation process. The bacteria or microorganisms, as well as the yeasts, feed on some type of natural component and multiply, changing the composition of the initial product.
In the case of the yeasts that are used to make the bread ferment, they require the presence of sugar or glucose since it is this which becomes their food and allows them to grow in size. The same happens with the alcoholic fermentation that gives drinks like wine or beer.
Both in the case of the fermentation that takes place in the food and that which takes place in the beverages, both involve the conversion of sugars into ethanol and this is the reason why fermented foods (such as bread or yogurt) have a particular aroma that comes from the presence of these natural gases.
Depending on the type of product to which reference is made, the fermentation process will be different, requiring a greater or lesser amount of ferment, more or less time of rest, more or less amount of sugars.
The excess of the fermentation process can easily ruin the product since the presence of too much gas causes it to lose its quality as a consumable for the human being.
According to the evolutionary theory about the origin of life on Earth, fermentation is considered to be the oldest energy obtaining process.
On that basis, it is considered that, given the conditions of the primitive Earth, in which there was no free oxygen and where the sun’s rays did not reach the earth’s surface, the first organisms could only obtain the energy of the organic compounds through fermentation.
The fermentation was discovered by Louis Pasteur, who described it as the vie sans l’air (life without air). The typical fermentation is carried out by the yeasts. Also, some metazoans and protists are capable of make it.
Uses of fermentation
The primary industrial benefit of fermentation is the conversion of must into wine, barley into beer and carbohydrates into carbon dioxide to make bread. According to Steinkraus (1995), the fermentation of foods serves 5 general purposes:
Enrichment of the diet through the development of a diversity of flavors, aromas, and textures in food substrates.
Preservation of substantial amounts of food through lactic acid, ethanol, acetic acid and alkaline fermentation.
Enrichment of food substrates with protein, amino acids, essential fatty acids and vitamins.
Detoxification during the process of nutritional fermentation. Decrease in cooking times and fuel requirements.
Nutrients in Fermentation
Fermentation has some exclusive uses for food. It can produce important nutrients or eliminate antinutrients.
Food can be preserved by fermentation, fermentation uses energy from food and can create unsuitable conditions for undesirable organisms. For example, vinegaring the acid produced by the dominant bacterium inhibits the growth of all other microorganisms.
According to the type of fermentation, some products (eg alcohol fusel) can be harmful to health. In alchemy, fermentation is often the same as putrefaction, meaning to allow the decay or natural decomposition of the substance.
From ancient times, the man obtained alcoholic beverages from the fruit juice and honey, but he did not know that they were products of fermentation that some microorganisms made.
The term fermentation is often wrongly used to describe some aerobic oxidation processes involving acetobacteria, which transform alcohol into acetic acid. However, these bacteria, although not fermentative, are used in the industrial production of vinegar.
The CO2 released in the fermentation process of the yeasts, allows the swelling and increase of the bread mass, and the alcohol produced, when evaporated, gives it its characteristic odor.