The fermented products: wine, yogurt, sauce, fruit,... long since have become popular in the meal of the person. Fermented products are on the rise according to the development of society, especially alcohol – drink popular top in Vietnam. And to produce wine, then fermented occupy factors and the role dark matter, so fermentation in wine production process how? happenings and conditions out? Let's Wine Encyclopedia learn under this article.
The concept and classification of fermentation
Fermentation is the process of exchange of material and transform material, over which the organic matter affected by microbial additions to the fermentation process, thanks to the enzyme's intrinsic them to convert into the products of secondary desire.
Fermented alcohol (ethanol) is the process of fermentation because yeast. During fermentation, yeast metabolism in the environment contain sugar, they ferment and the nutrients needed by the other, thereby creating the specific products primarily in the environment fermented wine.
Classification:
- Classification according to the author: fermented by mold, fermentation by yeast, fermented by bacteria and yeast, fermented by mold and yeast
- Classified by raw material: product fermented from starch, sugar; fermented products from vegetables; fermented products from aquatic products and meat products; fermented milk;...
- Classification according to conditions: fermentation anaerobic and aerobic
- Classify the nature of the final product: based on the nature of products people are divided into: industrial fermentation classic and fermentation technology, modern
More:
The phase chemistry of wine fermentation
Review chemically, the process of ethanol fermentation divided into 2 periods: inspiration and static
Period inspiration: The first time, the reaction occurs in the direction of product formation is glycerol. By this period, the content of acetaldehyde (CH3CHO) has not much to receive Hydrogen of alcoldehydrogenase that hydrogen back trip to phosphoglyceraldehyde form of phosphorus, glyceryl, then phosphorus glyceryl hydrolyzed liberation of phosphoric acid and glyceryl
Period static: At this time the amount of acetaldehyde was formed many, should the hydrogen from the alcohol dehydrogenase to acetaldehyde (CH3CHO) the products are mainly ethanol and CO2.
Happenings of wine fermentation
In the process of alcoholic fermentation, first yeast cells absorb sugar and other nutrients to the surface of them. Then the substance diffuses through a semi-permeable membrane of the cells into the cell.
In the primeval quality of the yeast cells, sugar is converted to alcohol and CO2. Alcohol and CO2 form is escaping from the cells and diffused into the environment, the longer ethanol soluble infinite in water
Conditions of fermentation ethanol
- Anaerobic conditions and PH 4-5
In anaerobic conditions, fermentation alcohol thrive, but the development of yeast is restricted, then the yeast harvest energy to maintain the activities of life.
Thus, when O2 will inhibit ethanol fermentation phenomena inhibit ethanol fermentation under the influence of oxygen is pasteur effect (inhibition of oxygen in the fermentation process). So, in terms of environment, it's anaerobic and ph 4-5, the fermentation of ethanol will occur according to the mechanism of feed reverse cock. When there pasteur effect, the fermentation of ethanol will occur according to the mechanism of pet photos. From there, showed ethanol fermentation must be carried out in anaerobic conditions.
- Temperature and sugar concentration
In addition to ph and anaerobic, temperature and sugar levels also affect the activity of yeast or fermentation. Ethanol fermentation most appropriate at a temperature of 29-32 degrees C. a favorable Environment for the fermentation of ethanol is 10-18% sugar. Yeast capable of fermenting ethanol in the environment solution with 25-30% of the roads, but slow speed. If the concentration of the sugar high will cause osmotic pressure, big destroy mode normal physiology of the yeast, after which time the fermentation lasts, use non-radical way, at the same time ethanol accumulation, which inhibits the activity of yeast. If the environment has high levels of sugar that is too low will not have economic benefits (cost of equipment, labor,...)
- The influence of the concentration of Ethanol and CO2
The concentration of ethanol affect the activity of the yeast, thereby inhibiting fermentation. Some data suggests the possibility of fermentation of yeast slowed down when the environment is the concentration of ethanol is 2% and stopped when the environment is the concentration of ethanol is 5%
The CO2 produced in the process of ethanol fermentation. The storage of CO2 in the environment will inhibit the fermentation of ethanol. The escape of CO2 gas back to intensify the process of ethanol fermentation because of the escaping CO2 gas environment stirred, stretching suspended state of yeast so that speeds up the fermentation.
On this is the basic theory of the process of ethanol fermentation, hope you read the owner more get more knowledge. To have more knowledge about wine, please regularly visit our website of Vietnamese Wine.
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