Fermentation, alcoholic controlling

The growth of malo-lactic bacteria in wines is favored by moderate temperatures, low acidity, very low levels of S02, and the presence of small amounts of sugar undergoing fermentation by yeast. It is frequently possible to inoculate a wine with a pure culture of a desirable strain of bacteria and obtain the malo-lactic fermentation under controlled conditions. The pure-culture multiplication of the selected strain of bacteria is difficult, however. It is also difficult to control the time of the malo-lactic fermentation—sometimes it occurs when not wanted, and at other times will not go when very much desired. For the home winemaker it is probably most satisfactory to accept the malo-lactic fermentation if it occurs immediately following the alcoholic fermentation. The wines should then be siphoned away from deposits, stored in completely filled containers at cool temperatures, and have added to them about 50 ppm S02. If the malo-lactic fermentation does not take place spontaneously and the wine is reasonably tart, the above described regime of preservation will likely prevent its occurrence. When the malo-lactic transformation takes place in wines in bottles, the results are nearly always bad. The wine becomes slightly carbonated, and the spoiled sauerkraut flavors are emphasized. 

Ethanol Alcohol oxidase, alcohol Alcoholic beverages Fermentation process control, tax regulations... 

Fermentation is the name conventionally attributed to any industrial transformation that involves microorganisms. In TBV production, there are two distinct fermentations alcoholic and acetic the first is carried out by yeasts of different genera and species, the second by AAB. Usually, the two fermentations occur in the same vessel (badessa) and are performed by wild strains without any control. The results are unpredictable sometimes the alcoholic fermentation is inhibited by acetic acid produced by AAB often the acetic acid fermentation, for various reasons, does not occur. To solve the problem, a two-stage fermentation procedure has been suggested the oxidation of ethanol should always follow alcoholic... 

Hydrogen sulfide and methanethiol are directly produced by yeast metabolism. The production of H2S during alcoholic fermentation is controlled by the enzymes responsible for reducing sulfates and biosynthesizing certain sulfur amino acids (cysteine and methionine) (Figure 8.19). Methanethiol is synthesized by yeast from methionine (De Mora et al., 1986). 

For food applications, alcoholic beverages, cosmetics, fragrances and pharmaceutical formulations, fermentation alcohol is preferred. In food applications, such as wine or beer, the fermentation broth is used without any further concentration. In most countries, the price and volume of e. produced by fermentation is government-controlled. E. is used as a ->fuel alternative or additive in some countries. 

Fermentation, an original chemical process that was discovered in ancient times, led to the production of wine and beer. With relatively crude techniques, a simple enzyme contained in yeast was found to catalyze the conversion of sugar into alcohol. Control of the ingredients in the fermentation broth would impact the flavor of the alcohol, and the effectiveness of the conversion was controlled by the length of time the fermentation was allowed to proceed and the temperature of the reaction. 

A fermentation route to 1-butanol based on carbon monoxide employing the anaerobic bacterium, Butyribacterium methjlotrophicum has been reported (14,15). In contrast to other commercial catalytic processes for converting synthesis gas to alcohols, the new process is insensitive to sulfur contaminants. Current productivities to butanol are 1 g/L, about 10% of that required for commercial viabiUty. Researchers hope to learn enough about the bacteria s control mechanisms to be able to use recombinant DNA to make the cells produce more butanol. 

Turanose is readily purified by recrystallization from hot methyl alcohol, in which it is moderately, though slowly, soluble. In preparing the sugar, the first stage of the hydrolysis of melezitose by an acid solution is carried out under well controlled conditions, and is followed by the removal of the D-glucose from its mixture with turanose. This is usually accomplished by a selective fermentation with yeast, but an... 

This gum was the first microbial gum to be used in the food industry. It is produced by the aerobic fermentation of Xanthomonas campestris. A specially selected culture is grown on a carbohydrate-containing nutrient medium with a nitrogen source and other essential elements. The pH, temperature and aeration are controlled carefully. The product is then sterilised and the gum is precipitated with propan-2-ol. Next, the precipitate is washed, then pressed to remove residual alcohol, followed by drying and grinding to the required size. 

Rottenbacher, L., Schofiler, M. and Bauer, W., Mathematical modelling of alcoholic fermentation in a gas/solid bioreactor - combined effects of solids mixing and non-steady-state kinetics. Proceedings of the First IFAC Symposium on Modelling and Control of Biotechnological Processes, Noordwijkerhout, 1985b, 151-157. 

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