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Decaffeinated Teas
Tea from the Camellia Sinensis family contains from 1.6 percent caffeine in Formosa broken leaf type to 4 to 4.5 percent in most other types. According to the U.S. Food & Drug Administration, 97 percent of the 4.5 percent caffeine must be removed in order to label the tea decaffeinated. Some packers label their teas 98 percent caffeine free. These teas, however, have never been decaffeinated but have a naturally low caffeine count. Caffeine-free labels only apply to herbal products, not traditional teas.
There are two sources of decaffeinated tea in the world, both processed by firms in Europe. Decaffeinated tea is found in all leaf grades and a great variety of flavors. There are three processes used to decaffeinate tea: methylene chloride, ethyl acetate and carbon dioxide. The latter two are the only two permitted in the United States. The use of methylene chloride on tea uses the same processing methods as ethyl acetate (see below) but is not allowed for import to the United States. Carbon dioxide is a high pressure, super critical process. Unlike the other two processes mentioned, this process is considered natural and is more gentle to the tea leaves.
Ethyl Acetate Process
The ethyl acetate decaffeination process uses the Haco Method, which is similar to the one used for coffee. Ethyl acetate is derived as a result of the reaction between ethanol and acetic acid. The raw materials are taken from natural origins, such as fruit. This process leaves a maximum carrier residue of 1 ppm or less, and a maximum caffeine residue of .08 percent, dry weight. The tea is 99.9 percent decaffeinated at the end of the process, and has an 8 percent maximum water content when leaving the factory.
Carbon Dioxide Process
Supercritical Carbon Dioxide is the most widely used solvent for decaffeination of food products. The gas is odorless, tasteless and inert. Carbon dioxide processing leaves no toxic residues. In addition, extraction of the caffeine takes place at room temperature which protects product quality by preventing the breakdown of temperature-sensitive components. After extraction occurs, the supercritical fluid turns back into a gas, so no solvent residue remains. The decaffeination processes run under normal, official food control and fully comply with the Swiss and European food laws. |
