Most recently, food scientists have turned to supercritical carbon dioxide as a means of decaffeination. The Swiss Water Process is also used for decaffeination. Similar to decaffeination in coffee, coca tea can be decocainized. In the case of coffee, various methods can be used for decaffeination. This is a direct-contact method of decaffeination. Although, dark roasting is not to be confused with the Decaffeination process. Decaffeination of coffee seeds is done while the seeds are still green. Decaffeination is the process of extracting caffeine from green coffee beans prior to roasting.