One reader asked how is caffeine free tea and coffee created, knowing that coffee and tea come naturally caffeinated. I thought this to be a very good point, and at first I wasn’t entirely sure. A little research uncovered plenty of interesting information related to this topic.
Did you know that around 90 percent of Americans consume caffeine in one form or another every single day. More than half of all American adults consume more than 300 milligrams (mg) of caffeine every day, making it America’s most popular drug by far. The caffeine comes in forms of coffee, tea, cola, chocolate, and plenty more.
Caffeine is known medically as ‘trimethylxanthine’, and the chemical formula is C8H10N4O2. When caffeine is isolated in pure form, it is a white crystalline powder that tastes very bitter, and you would never believe it, but the chief source of pure caffeine is the process of decaffeinating coffee and tea.
Decaffeinated coffee is made by washing the caffeine out of the beans in one of two basic ways, both performed long before roasting. In one method, a chemical solvent is used to extract the caffeine. The solvent is completely washed out before the bean is dried. The second method uses water to steam the beans, and then the outer layers, rich in caffeine, are scraped way. There is also one naturally decaffeinated coffee: the Madagascar coffee species mascarocoffea vianneyi which produces decaffeinated beans.
Outside of this species, caffeine occurs naturally in more than 60 plants, including:
* the arabica plant, which produces coffee beans
* the Theobroma cacao tree, which produces the beans that are the primary ingredient in
chocolate.
* kola nuts, which many cola drink products are made with
* the Thea sinensis plant, whose leaves are used for teas
Several methods are used to remove caffeine from its natural sources:
* Methylene chloride processing
* Ethyl acetate processing
* Carbon dioxide processing
* Water processing
Methylene chloride is a chemical used as a solvent to extract caffeine from many raw materials. Molecules of caffeine bond to molecules of methylene chloride. The materials are softened in a water bath or in steam. The next step is to process the materials with methylene chloride by one of two methods:
(1) Using the “direct” method, caffeine is removed by directly soaking the materials in methylene chloride.
(2) Using the “indirect” method, caffeine, which is water soluble, is extracted by soaking the materials in water. Many of the flavors and oils are also extracted during this process, so the solution is treated with methylene chloride and then returned to the material for reabsorption of the flavorings.
Ethyl acetate processed products are referred to as “naturally decaffeinated” because ethyl acetate is a chemical found naturally in many fruits. Caffeine is extracted in the same way as with methylene chloride processing, but ethyl acetate is the solvent.
Carbon dioxide (CO2) can be used to decaffeinate, water-softened materials are pressure cooked with the gas. At high pressures and high temperatures, carbon dioxide is in a supercritical state, acting as both a gas and a liquid. It becomes a solvent which attracts the small caffeine molecules. Since flavor molecules are larger, they remain intact, which is why this process retains the flavor of the material better.
Water as a caffeine extraction is used primarily for coffee decaffeination. The process is similar to that of methylene chloride processing, but no chemicals are used. After the caffeine is leached out of the material by soaking in hot water for a period of time, the solution is then passed through a carbon filter for caffeine removal. The water is then returned to the beans for reabsorption of flavors and oils.
You should also know that caffeine is not removed completely using any of these methods, but under federal regulations in the United States, caffeine levels must not be above 2.5 percent of the product in order for a product to be labeled “decaffeinated.”
Most of the caffeine removed in processing is manufactured for use in other products, such as medicines and soft drinks. For example, less than 5 percent of the caffeine found in cola drinks is actually from the kola nut, and many of the popular high-caffeine soft drinks do not contain kola nut extracts at all. The caffeine content of soft drinks is primarily, and sometimes completely, from the addition of caffeine extracted from decaffeination processes.
Take a look at this chart from the National Soft Drink Association, the following is the caffeine content in mgs per 12 oz can of soda:
| Afri-Cola | 100.0 |
| Jolt | 71.2 |
| Sugar-Free Mr. Pibb | 58.8 |
| Mountain Dew | 55.0 (no caffeine in Canada) |
| Diet Mountain Dew | 55.0 |
| Kick citrus | 54 (36mg per 8oz can, caffeine from guarana) |
| Mello Yellow | 52.8 |
| Surge | 51.0 |
| Tab | 46.8 |
| Battery energy drink | 140mg/l = 46.7mg/can |
| Coca-Cola | 45.6 |
| Diet Cola | 45.6 |
| Shasta Cola | 44.4 |
| Shasta Cherry Cola | 44.4 |
| Shasta Diet Cola | 44.4 |
| Mr. Pibb | 40.8 |
| OK Soda | 40.5 |
| Dr. Pepper | 39.6 |
| Pepsi Cola | 37.2 |
| Aspen | 36.0 |
| Diet Pepsi | 35.4 |
| RC Cola | 36.0 |
| Diet RC | 36.0 |
| Diet Rite | 36.0 |
| Canada Dry Cola | 30.0 |
| Canada Dry Diet Cola | 1.2 |
| 7 Up | 0 |
By means of comparison, a 7 oz cup of coffee has the following caffeine (mg) amounts, according to Bunker and McWilliams in J. Am. Diet.
| Drip | 115-175 |
| Espresso | 100mg of caffeine |
| 1 serving (1.5-2oz) | |
| Brewed | 80-135 |
| Instant | 65-100 |
| Decaf, brewed | 3-4 |
| Decaf, instant | 2-3 |
| Tea, iced (12 ozs.) | 70 |
| Tea, brewed, imported | 60 |
| Tea, brewed, U.S. | 40 |
| Tea, instant | 30 |
| Mate | 25-150mg |
And for further data and statistics, you can compare these products:
| Cup of coffee | 90-150mg |
| Instant coffee | 60-80mg |
| Tea | 30-70mg |
| Mate | 25-150mg |
| Cola | 30-45mg |
| Chocolate bar | 30mg |
| Stay-awake pill | 100mg |
| Vivarin | 200mg |
| Cold relief tablet | 30mg |
Caffeine is a central nervous system stimulant, having the effect of temporarily warding off drowsiness and restoring alertness. Beverages containing caffeine enjoy great popularity: caffeine is the world’s most widely consumed psychoactive substance. In researching, I also found a website doing the math on how much of your favorite drink it would take to kill you. Entering a fairly generic and safe assumption I put in my drink as Coca-Cola Classic, and a weight of 180 pounds. Turns out it would take 361.32 cans of Coca-Cola Classic before I’d be pushing up daisies. I’m not much of a coffee drinker, but I did also enter 180 pounds consuming a Starbucks Grande Coffee as comparison and it was determined that 33.02 cups here and I’d meet death. I may drink my Cola heavily, but I don’t think I’ll be hitting that mark any time soon.
Sources:
Caffeine Content of Food and Drugs. Nutrition Action Health Newsletter. Center For Science in the Public Interest (December 1996).
Jarvis, Gail The Rise and Fall of Cocaine Cola.
Whats your poison: caffeine. Australian Broadcasting Corporation (1997).
Bolton, Ph.D., Sanford, Gary Null, M.S. (1981). “Caffeine: Psychological Effects, Use and Abuse“.
James, JE, KP Stirling (Sep 1983). “Caffeine: A summary of some of the known and suspected deleterious effects of habitual use”.
Senese, Fred (2005-09-20). How is coffee decaffeinated?.
Kirchheimer “Caffeine Withdrawal Is Real“, CBS News, 30 September 2004.
As an AP english student, (long ago but still valid) I would like to know where are your sources?
I would like to know where you had the time to do all this research!
Ami, I have now supplied sources for the major contributors to this article. Paul, some of us do not have homework any longer and can find time such as that to create articles of this type. In addition, I find myself sleepless some nights which gives me additional time to write. I typically will write several articles in one evening, and then throughout the week I will touch them up and publish them.
[…] There is a mini-theme on coffee this week. Worldwide Success thinks we should just give it up while Sickle’s Insight explains just how decaffinated coffee gets that way. Breastfeeding1-2-3 says a little coffee and a little chocolate are OK for breastfeeding mothers. Wisdom of Healing wonders if we should be taking medications for conditions that are just part of women’s lives. […]