Alcoholic fermentation

Alcoholic fermentation is the basis of various food industries - brewing, winemaking, alcohol production. This process is of great importance when baking bread, making sour-milk, diet products. Alcoholic fermentation is the transition of carbohydrates to carbon dioxide, ethyl alcohol and other components. In the process of anaerobic decomposition of more complex substances into simpler ones, energy is released.

The microorganisms-activators of this process are yeast, usually from the genus saccharomycis. In a certain environment, alcohol fermentation can provoke some mold fungi and bacteria. The influence of yeast on the development of the process was established by Pasteur. Subsequently, Buchner, Liebig and Lebedev proved that alcoholic fermentation is possible without their (yeast) participation or even without the use of cell-free enzyme components derived from them. The properties of some pathogenic microorganisms to destroy these or other carbohydrates formed the basis for the process of growing a number of bacterial cultures and identifying pathogens.

Today it is reliably established that the transition of carbohydrates to other components is a series of oxidation-reduction and other reactions occurring consecutively. There are different types of fermentation. With the help of yeast, the process most easily takes place in simple sugars - fructose and glucose.

The latter matter is of particular importance. So, at a souring of cabbage, milk, cucumbers passes or takes place lactic fermentation of glucose. The same process occurs when siloing forages. If the mass for ensiling is not sufficiently sealed, then air penetrates. Under its influence begins oleic acid fermentation. As a result of this process, the food becomes unsuitable for use.

In the production of beer , alcoholic fermentation of glucose is used.

Maltose, sucrose can also be exposed to the process. Preliminary there is their hydrolysis with the help of yeast. Thus, monosugars are formed.

Lactose (milk sugar) can be fermented only by certain yeast species.

Glycogen, starch and other carbohydrates with a more complex structure are not exposed to the process. Preliminarily, they undergo hydrolysis by an enzymatic or acid method. As a result, they lose their stability and are affected by yeast.

The yeast itself is a fairly common substance in nature. They are found on berries, fruits, grapes. In summer, they are common in air and soil.

Yeast is divided into wild and cultured. The latter are called those substances that have a technical application in accordance with one or the other positive quality. For example, the substances used in brewing have the ability to lighten the beer, giving it a flavor and a pleasant taste. Grape shakes form a special bouquet. Bread yeast is valued for its ability to actively propagate, as well as for properties to loosen the dough well. Wild substances also have a weaker ferment ability. They form components that give off an unpleasant smell and taste.

The process of converting sugar into carbon dioxide, ethyl alcohol and other components is quite complex. Together with these substances, fermentation is accompanied by the formation of other by-products. In particular, acetic and succinic acid, acetic aldehyde, glycerin are formed in a certain volume. Fusel oils are also formed . These components are a mixture of isomers from higher alcohols: butyl, isobutyl, amyl and others. In addition, substances are formed which, even in insignificant quantities, can affect the aroma, impart a specific taste to beer, wine and other products.