Decaffeination

Decaffeination is the removal of caffeine from coffee beans, cocoa, tea leaves, and other caffeine-containing materials. While soft drinks which do not use caffeine as an ingredient are sometimes described as 'decaffeinated', they are better termed 'non-caffeinated' because decaffeinated implies that there was caffeine present at one point in time. Decaffeinated drinks contain typically 1–2% of the original caffeine content, and sometimes as much as 20%. Decaffeinated products are commonly termed decaf. Decaffeination is the removal of caffeine from coffee beans, cocoa, tea leaves, and other caffeine-containing materials. While soft drinks which do not use caffeine as an ingredient are sometimes described as 'decaffeinated', they are better termed 'non-caffeinated' because decaffeinated implies that there was caffeine present at one point in time. Decaffeinated drinks contain typically 1–2% of the original caffeine content, and sometimes as much as 20%. Decaffeinated products are commonly termed decaf. Friedlieb Ferdinand Runge performed the first isolation of pure caffeine from coffee beans in 1820. He did this after the poet Goethe requested he perform an analysis on coffee beans after seeing his work on belladonna extract. Though Runge was able to isolate the compound, he did not learn much about the chemistry of caffeine itself, nor did he seek to use the process commercially to produce decaffeinated coffee. The first commercially successful decaffeination process was invented by German merchant Ludwig Roselius and co-workers in 1903 and patented in 1906. In 1903, Ludwig accidentally stumbled upon this method when his freight of coffee beans was soaked in sea water and lost much of its caffeine without losing much taste. This original decaffeination process involved steaming coffee beans with various acids or bases, then using benzene as a solvent to remove the caffeine. Coffee decaffeinated this way was sold as Kaffee HAG after the company name Kaffee Handels-Aktien-Gesellschaft (Coffee Trading Company) in most of Europe, as Café Sanka in France and later as Sanka brand coffee in the US. Café HAG and Sanka are now worldwide brands of Kraft Foods. Because of health concerns regarding benzene (which is recognised today as a carcinogen), benzene is no longer used as a solvent commercially. Since its inception, methods of decaffeination similar to those first developed by Roselius have continued to dominate. While Roselius used benzene, many different solvents have since been tried after the potential harmful effects of benzene were discovered. The most prevalent solvents used to date are dichloromethane and ethyl acetate. Another variation of Roselius' method is the indirect organic solvent method. This is very similar to the process described above, only instead of treating the beans directly, water resulting from the soaking of beans is treated with solvents and the process goes on until equilibrium is reached without caffeine in the beans. This method was first mentioned in 1941, and people have made great efforts to make the process more 'natural' and a true water-based process by finding ways to process the caffeine out of the water in ways that circumvents the use of organic solvents. Another process, known as the Swiss Water Method, uses solely water and osmosis to decaffeinate beans. The use of water as the solvent to decaffeinate coffee was originally pioneered in Switzerland in 1933 and developed as a commercially viable method of decaffeination by Coffex S.A. in 1980. In 1988, the Swiss Water Method was introduced by The Swiss Water Decaffeinated Coffee Company of Burnaby, British Columbia, Canada. Noted food engineer Torunn Atteraas Garin also developed a process to remove caffeine from coffee. Most recently, food scientists have turned to supercritical carbon dioxide as a means of decaffeination. Developed by Kurt Zosel, a scientist of the Max Planck Institute, it uses CO2, heated and pressurized above its critical point, to extract caffeine and could be useful going forward because it circumvents the use of other solvents and their possible effects entirely. In the case of coffee, various methods can be used for decaffeination. These methods take place prior to roasting and may use organic solvents such as methylene dichloride or ethyl acetate, supercritical CO2, or water to extract caffeine from the beans while leaving flavour precursors in as close to their original state as possible. In the direct organic solvent process, unroasted (green) beans are first steamed and then rinsed with a solvent (e.g. methylene dichloride or ethyl acetate). The solvent extracts the caffeine while leaving other constituents largely unaffected. The process is repeated from 8 to 12 times until the caffeine content meets the required standard (97% of caffeine removed according to the US standard, or 99.9% caffeine-free by mass per the EU standard).