Decaffeination

The decaffeination process is a process that contained caffeine can be partially or almost completely removed from the coffee beans or tea leaves.

Decaffeination of coffee

In the case of coffee decaffeination process begins with the still green and unroasted beans. In general, it swells the beans on exposure to hot water or steam first. Subsequently, the caffeine contained in the beans is extracted with a solvent. Since in one process run only part of the caffeine contained may be withdrawn, the process must be repeated many times to get to the maximum 0.1 percent residual content prescribed in the EU for decaffeinated coffee. Coffee contains approximately 400 chemical components, which are essential for the flavor and aroma of the brewed beverage. Depending on the decaffeination process, these components are also removed to a greater or lesser extent, which can lead to undesirable changes in taste of the coffee.

The world, researchers in the production of coffee varieties with reduced caffeine content. 2004, a Brazilian research group at genetic experiments with Arabica coffee several variants, which practically did not contain caffeine. Working groups at the Universities of Glasgow, Tokyo and at the Institute Integrated Coffee Technologies in Hawaii researching the manufacture of decaffeinated coffee plants by genetic engineering. In the future it could be possible to dispense with the costly decaffeination completely.

Roselius process

The first commercial process for decaffeination was 1903/1905 developed by Ludwig Roselius and patented. Roselius had a suspicion that his previously deceased father, who was a heavy coffee drinker, had poisoned with caffeine. Therefore, he looked for a way to escape the coffee the caffeine. When Roselius process, the beans are pre-swollen with salt water. As a solvent, the toxic and carcinogenic benzene is used in the extraction is used, which is why this method is now used only very rarely. In this way, decaffeinated coffee was in most parts of Europe as Kaffee Hag, sold in France as Café Sanka and later under the brand Sanka in the USA. Today other decaffeination be used because of the harmful benzene for Coffee HAG and Sanka.

Swiss Water Process (SWP )

At this end of the 1970 years of the Swiss Water Decaffeinated Coffee Company developed method in a first step as long beans are treated with hot water until all the caffeine and other solid ingredients are dissolved out. The beans of this first process step are discarded. The water with the dissolved caffeine and other coffee components then passes through an activated carbon filter, with which the caffeine molecules are removed. The now caffeine-free water are added new coffee beans in a similar filter apparatus. Since the water is already enriched with dissolved coffee solids, only this time the caffeine is released and retained the other flavor constituents with the coffee beans. The process is repeated until the desired degree of decaffeination is obtained. The beans are then dried and are intended to retain most of its taste and aroma, but this is controversial among experts. A disadvantage of the method is the relatively high cost, since the bound with the activated carbon is not caffeine is recovered and may be sold separately. Today, there are few works that use the Swiss Water process, worldwide.

Direct method

After about 30 minutes Einwirkens by steam the beans for 10 hours to be extracted in dichloromethane or ethyl acetate. The extractant (solvent) is then poured off and remainders are ongoing in a further 10 hours drying step away. The complete removal of the solvent is particularly important in dichloromethane, as this is suspected to be carcinogenic. Coffee that is decaffeinated with ethyl acetate, is also sometimes referred to as a naturally decaffeinated coffee as ethyl acetate is also present in various fruits and vegetables. The decaffeination with this method is relatively inexpensive.

Indirect method

In the indirect method, first with hot water all the water-soluble components from the beans removed as during subsequent cooking of coffee. From this solution is then extracted with dichloromethane or ethyl acetate caffeine. Subsequently, the decaffeinated coffee solution is heated with new beans, result of which a solubility equilibrium and only the caffeine is extracted from the beans. This method essentially corresponds to the Swiss -water method, but using a different solvent.

Carbon dioxide method

With steam pretreated coffee beans are in this process at a pressure 73-300 bar with liquid CO2 ( high pressure CO2 is liquid ) rinsed and thus solved the caffeine in the liquid CO2. The carbon dioxide is allowed to evaporate it, it remains the pure caffeine. CO2 is then compressed again, condensed and reused.

Triglyceride method

The unroasted beans are treated in a hot water solution coffee to get the caffeine to the surface of the beans. In a separate vessel, the beans are then immersed for several hours in hot coffee bean oils. The triglycerides contained in the oils to remove the caffeine from the beans, but not the flavor and aroma materials. The beans are then separated and dried by oil.

Caffeine content in decaffeinated coffee

Virtually all decaffeinated coffee still contain residual amounts of caffeine. As decaffeinated coffee may be described in the EU of coffee with a percentage of caffeine less than 0.1 percent. In other countries there are less restrictive rules so that the caffeine content may be higher there. According to the results of the Florida Maples Center for Forensic Medicine ten cups of decaffeinated coffee may contain approximately the same amount as one to two cups of ordinary coffee. The measured caffeine content was 3 to 15.8 mg per cup of decaffeinated espresso and 6 to 6.7 mg per cup of decaf. Nichtentkoffeinierter coffee contains about 85 mg compared to caffeine per cup.

Decaffeination of tea

Decaffeinated tea is usually with the help of Kohlenstoffdioxidverfahrenes already used for coffee. Different types of tea may vary in their caffeine content, also have young leaves and buds have a higher caffeine content per weight than old leaves and stems on. A cup of tea contains about 40 to 50 mg in about half of the Koffeines a cup of coffee.

It is possible to influence the content of tea by a special procedure for brewing. Brews you the same tea several times, the caffeine content reduced significantly. So contained tea in experiments in the second five-minute brewing only a third of the first infusion of caffeine equivalent to 23 percent of the total caffeine contained in the leaves.