Decaffeination is the act of removing caffeine from coffee beans, mate, cocoa, tea leaves and other caffeine containing materials. Caffeine is a bitter white crystalline Xanthine Alkaloid that acts as a Psychoactive Stimulant Drug and a mild Diuretic CoFFEE is an Open source Software for computer supported collaborative learning (CSCL in a digital classroom Mate or maté (\ˈmä-ˌtā\ Spanish and Portuguese: mate, ˈmate is an infusion, containing Stimulants including Cocoa is the dried and fully fermented fatty seed of the cacao tree from which Chocolate is made Tea refers to the cured agricultural product of the leaves leaf buds and internodes of Camellia sinensis, which have been prepared and cured for the market (While caffeine-free soft drinks are occasionally referred to as "decaffeinated," some are better termed "uncaffeinated": prepared via simply omitting caffeine from production. )
In the case of coffee, the decaffeination processes are performed on unroasted (green) beans, but the methods vary somewhat. It generally starts with the steaming of the beans. They are then rinsed in solvent that contains as much of the chemical composition of coffee as possible without also containing the caffeine in a soluble form. A solvent is a liquid or gas that dissolves a solid liquid or gaseous Solute, resulting in a Solution. The process is repeated anywhere from 8 to 12 times until it meets either the international standard of having removed 97% of the caffeine in the beans or the EU standard of having the beans 99. The European Union ( EU) is a political and economic union of twenty-seven member states, located primarily in 9% caffeine free by mass. Coffee contains over 400 chemicals important to the taste and aroma of the final drink; this effectively means that no physical process or chemical reaction will remove only caffeine while leaving the other chemicals at their original concentrations.
Coffea arabica normally contains about half the caffeine of Coffea robusta. Coffea arabica (əˈræbɪkə is a species of Coffee indigenous to Ethiopia and Yemen. Coffea canephora ( Robusta Coffee; syn Coffea robusta) is a Species of Coffee which has its origins in western A Coffea arabica bean containing little caffeine has been found recently in Ethiopia. [1] This may change how low-caffeine coffee is produced in the future. Additionally, genetic engineering technology may be eventually applied to create a "naturally" caffeine-free coffee. But for now, one of several methods to remove the caffeine from caffeine-containing beans is employed.
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Roselius process
The first commercially successful decaffeination process was invented by Ludwig Roselius and Karl Wimmer in 1903. Ludwig Roselius ( June 2 1874 &ndash May 15 1943) was a German Coffee Merchant and founder of the company It involved steaming coffee beans with a brine (salt water) solution and then using benzene as a solvent to remove the caffeine. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6 Coffee decaffeinated this way was sold as Coffee (Kaffee, Koffie etc) HAG (from Kaffee Handels Gesellschaft or Coffee Trading Company) in most of Europe, as Café Sanka in France and later as Sanka brand coffee in the US. This article is about the country For a topic outline on this subject see List of basic France topics. Sanka is a brand of decaffeinated Coffee, sold around the world and was one of the earliest decaffeinated varieties The United States of America —commonly referred to as the Due to health concerns regarding benzene, this process is no longer used commercially and Coffee Hag and Sanka are produced using a different process.
Swiss water process
The Swiss Water Process is a method of decaffeinating coffee beans that was developed by the Swiss Water Decaffeinated Coffee Company. CoFFEE is an Open source Software for computer supported collaborative learning (CSCL in a digital classroom To decaffeinate the coffee bean by the Swiss Water method, a batch of green (unroasted) beans is soaked in hot water, releasing caffeine. Caffeine is a bitter white crystalline Xanthine Alkaloid that acts as a Psychoactive Stimulant Drug and a mild Diuretic This process is done until all the caffeine and coffee solids are released into the water. These beans are then discarded. Next, the water passes through a carbon filter which traps the caffeine molecules but allows the water and the coffee solids to pass through. The caffeine-free water which comes through, known as "flavor-charged" water by the company, is then put in a similar filtration device, and new coffee beans are added. However, since the flavor-charged water cannot remove any of the coffee solids from the new beans, only the caffeine is released. The process repeats, filtering out all the caffeine until the beans are 99. 9% caffeine free. These beans are removed and dried, and thus retain most if not all of their flavour and smell.
Although the process originated in Switzerland in the 1930s, today the world's only Swiss Water decaffeination facility is based near Vancouver, Canada. Vancouver (vænˈkuːvɚ is a coastal Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page [2]
Direct method
In the direct method the coffee beans are first steamed for 30 minutes and then repeatedly rinsed with either methylene chloride or ethyl acetate for about 10 hours. Dichloromethane ( DCM) or methylene chloride is the Chemical compound with the formula CH2Cl2 Ethyl acetate ( systematically, ethyl ethanoate commonly abbreviated EtOAc or EA is the Organic compound with the formula CH3COOCH2CH3 The solvent is then drained away and the beans steamed for an additional 10 hours to remove any residual solvent. Sometimes coffees which are decaffeinated using ethyl acetate are referred to as naturally processed because ethyl acetate can be derived from various fruits or vegetables. However, for the purpose of decaffeination, it is not generally possible to create such a large quantity of ethyl acetate, thus the chemical is synthetically derived.
Indirect method
In the indirect method beans are first soaked in hot water for several hours, essentially making a strong pot of coffee. Then the beans are removed and either methylene chloride or ethyl acetate is used to extract the caffeine from the water—as in other methods, the caffeine can then be separated from the organic solvent by simple evaporation. The same water is recycled through this two-step process with new batches of beans. An equilibrium is reached after several cycles, where the water and the beans have a similar composition except for the caffeine. Solubility equilibrium is any type Chemical equilibrium between solid and dissolved states of a compound at saturation. After this point, the caffeine is the only material removed from the beans, so no coffee strength or other flavorings are lost. Because water is used in the initial phase of this process, sometimes indirect method decaffeination is referred to as "water processed" even though chemicals are used.
CO2/O2 process
This process is technically known as supercritical fluid extraction. A supercritical fluid is any substance at a Temperature and Pressure above its Thermodynamic critical point. With the CO2 process, pre-steamed beans are soaked in a liquid bath of carbon dioxide at 73 to 300 atmospheres. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single After a thorough soaking, the pressure is reduced allowing the CO2 to evaporate, or the pressurized CO2 is run through either water or charcoal filters to remove the caffeine. Charcoal' is the blackish residue consisting of impure Carbon obtained by removing water and other volatile constituents from Animal and Vegetation The carbon dioxide is then used on another batch of beans. [3] This same process can also be done with oxygen (O2). Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the These liquids work better than water because they are kept in supercritical state near the transition from liquid to gas so that they have the high diffusion of gas and the high density of a liquid. A supercritical fluid is any substance at a Temperature and Pressure above its Thermodynamic critical point. This process has the advantage that it avoids the use of potentially toxic solvents. Toxicity is the degree to which a substance is able to damage an exposed organism
Triglyceride process
Green coffee beans are soaked in a hot water/coffee solution to draw the caffeine to the surface of the beans. Next, the beans are transferred to another container and immersed in coffee oils that were obtained from spent coffee grounds.
After several hours of high temperatures, the triglycerides in the oils remove the caffeine - but not the flavor elements - from the beans. (more properly known as, TAG or triacylglyceride) is Glyceride in which the Glycerol is Esterified with three Fatty acids It is the The beans are separated from the oils and dried. The caffeine is removed from the oils, which are reused to decaffeinate another batch of beans. This is a direct contact method of decaffeination.
Decaffeinated tea
Tea may also be decaffeinated, usually by using processes analogous to the Direct Method or the CO2 process as described above. Fermentation (i. e. the process of oxidizing tea leaves to create "black," "red," or "oolong" tea leaves from green leaves) does not affect the amount of caffeine present in the tea, though tea plant species (i. e. Camellia sinensis sinensis vs. Camellia sinensis assamica) may differ in natural caffeine content. Younger leaves and buds contain more caffeine per weight than older leaves and stems. Also certain processes during production might lend a hand in decreasing either the caffeine content directly or simply lowering the rate to which it is released throughout each infusion. Several instances in China where this is evident is in many cooked pu'er teas, as well as more heavily fired Wuyi Mountain oolongs; commonly referred to as 'zhonghuo' (mid-fired) or 'zuhuo' (high-fired)[4]. A generally accepted statistic is that a cup of tea contains 40–50 mg of caffeine, roughly half the content of a cup of coffee. [5] Although a common technique of discarding a short (30–60 second) steep is believed to reduce caffeine content in a subsequent brew by 80–90%, research suggests that a five minute steep yields up to 70% of the caffeine, and a second steep has one third the caffeine of the first (about 23% of the total caffeine in the leaves). [6]
Caffeine content of decaffeinated coffee
Almost all brands of decaffeinated coffee still contain some caffeine. [7] Drinking five to ten cups of decaffeinated coffee could deliver as much caffeine as would one or two cups of regular coffee, according to research at the University of Florida Maples Center for Forensic Medicine. [8] However, in June 2004, a naturally caffeine-free bean was produced. [9]
References
- ^ "Scientists discover decaf coffee bean", Guardian Unlimited, June 24, 2004.
- ^ History of the SWISS WATER Decaffeination Process , Jan 04, 2007
- ^ Coffee Decaffeination. Retrieved on 2007-12-17. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 546 - Gothic War (535–554: The Ostrogoths of King Totila
- ^ Caffeine & Tea, Yishan Teashop, Beijing, May 19, 2008
- ^ Upton Tea Imports (2003). "Tea and Caffeine". Upton Tea Imports Newsletter 16 (1).
- ^ Monique B. Hicks, Y-H. Peggy Hsieh and Leonard N. Bell (1996). "Tea preparation and its influence on methylxanthine concentration (abstract)". Food Research International 29 (3–4).
- ^ "Study: Decaf coffee is not caffeine-free" UPI, October 10, 2006, at ScienceDaily. com. viewed 28/06/2007
- ^ "Study: Decaf coffee is not caffeine-free" October 15, 2006, at ScienceDaily. com. viewed Jan 12, 2008
- ^ "Naturally decaffeinated coffee plant discovered", NewScientist. com, June 23, 2004
- Ramalakshmi K. , Raghavan B. (1999). "Caffeine in coffee: Its removal. Why and how?". Critical Rev. Food Sci. Nutrition 39: 441–456. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
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