When we think of alcohol, the first thing that comes to our mind is drink… However, alcohol has better uses and is more than just a drink. Let us find out more about this important thing.
How is alcohol made?
Whether it is made as wine or beer, the method of production is essentially the same. A carbohydrate, such as starch or sugar, is broken down into glucose form and is then mixed with yeast and allowed to ferment for weeks or even months. Catalysts within the yeast then convert the glucose into alcohol and carbon dioxide thereby releasing the energy that the yeast needs in order to survive and grow.
Uses of Some Alcohols
Alcohols are not just drinks but are widely used as solvents. This is because of its ability to dissolve many substances that cannot be dissolved in water. Ethanediol (ethylene glycol), an alcohol, is used as anti-freeze, to prevent water from freezing in car radiators. The sweet tasting glycerol (glycerine) is an alcohol which is made as a by-product of the manufacture of soap from fats or oils. Ethanol has a boiling point which is similar to that of petrol. It burns very well with a clean flame, and can therefore be used as a fuel.
Oxidation of Alcohols
Alcohols react with organic acids to form substances called as esters, which are found in all living organisms. Animal fats and vegetable oils are examples of such esters. Many esters are sweet-smelling chemicals which are widely distributed among fruits. It is these that give a fruit its characteristic smell and flavour. Many esters are manufactured for use as food flavourings, while others are used as solvents. Ethyl ethanoate (also called as Ethyl acetate,the CAS No. is 141-78-6) for example is made from ethanol and ethanoic acid and is a common solvent for paints, glues and nail varnish.
Oxidation of alcohols to organic acids like vinegar is a two-stage process, the intermediate compound being an aldehyde. Methanol, for example, is oxidised to methanal (formaldehyde), and is used to preserve dead biological specimens and organs for use in scientific research. The oxidation of methanal produces methanoic (formic) acid, which is responsible for the stings of ants and nettles.
Naturally decaffeinated coffee may mean a variety of things. Decaffeinated coffee has long been in demand as many people enjoy the taste of coffee, but either can’t or shouldn’t ingest caffeine. There are several processes that can make coffee decaffeinated. Most today use water decaffeination because it is considered to be the healthiest process, which need to use the following materials.
Ethyl acetate is used for a variety of industrial purposes but naturally occurs in some fruits and vegetables. It is combined with water, pressured lightly and heated slightly to extract the caffeine from the beans. Like DCM, the beans are then steamed to remove any excess ethyl acetate and then dried so that they can be stored and roasted. Because it is naturally occurring this process has been deemed safe by the United States and the European Union.
Methyl chloride (DCM) decaffeination uses food grade methylene chloride to draw the caffeine out of the beans. The first phase of the process uses steam and water to open the cell structure of the coffee beans and then DCM to extract it. The beans are then steamed again to remove any residual DCM. The amount of DCM remaining on the beans is controlled by U.S. and European standards. The beans are then dried so that they can be stored and roasted.
The direct method steams the beans for half an hour and then rinses the coffee beans with ethyl acetate or methylene chloride. After the chemicals are drained, the beans are then steamed again. When this process uses ethyl acetate derived from fruit or vegetables, the coffee is said to be naturally decaffeinated.
Instead of steaming the coffee beans, the water method or the indirect method soaks the beans in water. The water is then drained and either ethyl acetate or methylene chloride is added. These chemicals evaporate as the beans undergo intense heat. The beans then take another bath in water that is reused because it is thought to contain the essential flavor and oils of the coffee. This indirect method is often thought preferable for obtaining decaffeinated coffee, though coffee enthusiasts argue that the process compromises taste.
Most coffee companies will now be happy to share information about the process they use to make decaffeinated coffee. Many natural food stores now boast naturally decaffeinated coffees that use either the water or charcoal method. For those who must completely avoid caffeine, it is important to note that decaffeinated coffee contains a residual amount of caffeine. Caffeine is about 97% reduced by decaffeination processes, but decaffeinated coffee is not completely caffeine-free.