The concept of fermentation has been modified with the passing of time and currently encompasses a large number of processes and various end products, where according to each of them it can be defined in a different way. The term can be applied in very simple processes, as well as on an industrial scale. However, in its definition, two criteria have prevailed, one biochemical and the other microbiological.
From a biochemical point of view, fermentation responds to any process where organic substances undergo chemical changes in order to produce energy, generated exclusively under anaerobic conditions (without the participation of oxygen), since some microorganisms only live in the absence of oxygen.
For its part, from a microbiological perspective, fermentation responds to that process in which microorganisms produce metabolites (enzymes, ethanol, butanol, acetone, organic acids, among others) or biomass (microbial cells), from the use of organic substances, in the absence (anaerobic) or presence of oxygen (aerobic).
An example of this would be the case of yeasts (microscopic fungi) that are used to make bread ferment, they require the presence of sugar or glucose, since it is this that becomes their food and allows them to grow in size..
This is how fermentation is used to create different products, which vary according to the substrate, the microorganism used (such as fungi, bacteria and molds) and the factors that regulate the process.
For many people, the term means only the production of alcohol, where the fermentation of cereals and fruits intervenes, to produce beers and wines respectively, but there are other products that are obtained through this process such as lactic acid, butyric acid and acetic acid (vinegar).
The production of the latter is carried out with a fermentation in the presence of oxygen, despite the fact that most of the processes carried out today are anaerobic.
Also, there are fermented foods, such as yogurt, soy sauce and cheeses.
This is due to the fact that it was discovered that fermentation allows food to last longer and also modify its flavor.
Finally, fermentation has been used for approximately eight thousand years, despite the lack of knowledge at the time of the influence of microorganisms that intervene in its processes.
