초록 ▼

A simple, reliable process for decaffeinating green coffee beans to a high degree while avoiding denaturation of the green coffee beans includes wetting the green coffee beans to a high water content of 35-50%-wt.; compressing the beans in a pressure chamber for a period of a few minutes to several

A simple, reliable process for decaffeinating green coffee beans to a high degree while avoiding denaturation of the green coffee beans includes wetting the green coffee beans to a high water content of 35-50%-wt.; compressing the beans in a pressure chamber for a period of a few minutes to several hours in an atmosphere comprised of a supercritical fluid which is a gas at STP, at a temperature ranging from 20°to 80°C. under a critical pressure ranging from 75 to 300 bar; decompressing the wetted beans from critical pressure pc to a pressure p for which pc≤p≤1 bar abruptly or in the space of a few minutes, while avoiding freezing the green coffee beans; washing with water or with the supercritical fluid for selective extraction of the caffeine; repeating the process one or more times; centrifuging; drying; and roasting the beans. Further, caffeine is recovered in a known manner from the washing medium.

대표청구항 ▼

Process for decaffeinating green coffee beans, comprising: a. wetting green coffee beans comprised of caffeine with water to provide wetted beans having a water content ranging from 35 to 50 percent by weight and having bean cells containing an aqueous caffeine solution; b. compressing the wetted be

Process for decaffeinating green coffee beans, comprising: a. wetting green coffee beans comprised of caffeine with water to provide wetted beans having a water content ranging from 35 to 50 percent by weight and having bean cells containing an aqueous caffeine solution; b. compressing the wetted beans positioned in a pressure chamber by subjecting the wetted beans to an atmosphere comprised of a supercritical fluid which is a gas under standard conditions of temperature and pressure, under a pressure ranging from 75 to 300 bar and a temperature ranging from 20°to 80°C. for a period ranging from a few minutes to several hours; c. decompressing the wetted beans in the pressure chamber to a pressure p for which critical pressure pc≤p≤1 bar to provide decompressed beans over a period ranging from abruptly to a few minutes under conditions controlled so that expansion cooling of the atmosphere does not freeze the wetted beans; d. washing the decompressed beans with water one or more times to remove the aqueous caffeine solution therefrom as wash water and provide washed beans; e. repeating the steps of compressing, decompressing and washing as a process cycle one or more times; f. centrifuging the washed beans in a centrifuge to remove residual aqueous caffeine solution therefrom and provide pre-dried beans; g. collecting the wash water and the residual aqueous caffeine solution from centrifuging, and recovering the caffeine therefrom in a recovery means; h. drying the pre-dried beans to provide dried beans having a water content suitable for subsequent roasting; and i. roasting the dried beans.