Fermentation is a process of alcohol production in juice, therefore, before discussing the wine fermentation of grape juice, we need to understand what the fermentation substrate in the fermentation of wine, and everything to do with the wine fermentation process.
Fermentation is the process of energy production in cell anaerobic conditions (without oxygen). In general, fermentation is a form of anaerobic respiration, however, there is a clearer definition which defines fermentation as respiration in an anaerobic environment with no external electron acceptors.Sugar is a common ingredient in fermentation. Some examples of fermentation are ethanol, lactic acid, and hydrogen. However, some other components can also be produced from the fermentation such as butyric acid and acetone. Yeast is known as a material commonly used in fermentation to produce ethanol in beer, wine and other alcoholic beverages. Anaerobic respiration in mammalian muscle during work hard (which does not have an external electron acceptor) can be categorized as a form produces fermentation lactic acid as a by-product. The accumulation of lactic acid is what plays a role in causing fatigue in the muscles.
 |
| Figure 1. Wine Fermentation Process |
(Sumber : http://www.showmewine.org)
Fermentation is the process by which wine grape juice together with other materials that are altered by the biochemical reactions and produce wine yeasts. Materials for fermentation are sugar plus yeast will produce alcohol and CO2. CO2 will be released into the air from a mixture of wine and alcohol will remain in the fermenter. If all the fruit sugar is converted into alcohol or alcohol have reached around 15% is usually the fermentation has been completed or terminated. During the fermentation is often added nitrogen and micronutrients to prevent the production of H2S gas. If this gas appears to be causing an unpleasant smell.
During fermentation, the resulting liquid is called must. In order to prevent the growth of bacteria on the must then stirring. Must begin to bubble on the clock to 8 - 20. The initial phase of this fermentation process in red wine is 5-10 days, white wine 10-15 days. After this initial phase followed the second stage. Adjusting the pH regulated by the addition of acid H2SO4 until the reached 4 - 5 pH.
In the second stage of fermentation, the wine was transferred to a fermenter that should not be any oxygen from entering. At this stage of alcohol will result in higher levels. Depending on the material used, the wine may taste sweeter or alcohol and this will affect the price in the market.
Wine fermentation with yeast immobilized
The use of immobilized cell system with continuous fermentation of wine has become an interesting discussion. These systems not only increase productivity but also improve bioprocess costs. Many types of bioreactors are used in a continuous process, one of which was packed-bed bioreactorsyang popular because of its low operating costs and easy operation. During the fermentation of alcoholic beverages, volatile compounds are also produced with various concentrations. These compounds have an important role in the properties of flavor and sensory.
Yeast Growth
Saccharomyces cerevisiae grown on Yeast extract and extract mold broth in a shaker incubator at a temperature of 300C for 18 hours at 100 rpm. Cells were then harvested and washed by centrifugation for immobilization.
Sel khamir diamobilisasi Yeast cells immobilized with calcium alginate 3 mm (sodium alginate 2% dan CaCl20,1 M) yeast alginate beads are then grown in medium production of ethanol for 24 hours.
Medium ethanol production
Medium composed of (g / l): yeast extract 3; peptone 5; glucose 150 3: MgSO4.7H2O 0,025; KH2PO40,5; CaCl2.2H2O 0,1; (NH4)2PO41; MnSO4.6H2O 0,5; dan Zn(NO3)20,2. was adjusted to 4.5 by adding artart acid 0,1M before sterilize in 1100C 20 minutes.
(Source: http: //id.wikipedia.org/wiki/Fermentasi
http://ptp2007.wordpress.com/2008/02/08/fermentasi-wine/)
BACA JUGA ARTIKEL INI : WINE
0 comments:
Post a Comment