Decaffeination of aqueous extracts

Claim 1

A method of decaffeinating an aqueous caffeine-containing extract of roasted coffee comprising the steps of: (a) subjecting the extract to a stripping operation in order to remove volatiles and from about 5 to 15% by weight of the extract, (b) condensing the extract strippings of step (a); (c) evaporatively concentrating the stripped extract to a solids concentration between 30% and 50% by weight; (d) condensing the aqueous evaporate of step (c), (e) continuously contacting the concentrated extract in a countercurrent fashion with a decaffeinating fluid at a temperature between 10° C. and 180° C. and a pressure between 50 to 450 atmospheres, said fluid being either a liquid gas or a supercritical fluid at the conditions at which the decaffeination operation is effected; (f) thereafter, contacting the caffeine-containing fluid from step (e) with an aqueous stream containing the condensed evaporate of step (d), at a temperature between 10° C. and 180° C. and a pressure between 50 to 450 atmospheres in order to decaffeinate said fluid; (g) passing the decaffeinated extract of step (e) and the caffeine-containing aqueous stream from step (f) to vent tanks and condensing volatiles exiting the vent tanks; (h) removing caffeine from the aqueous stream of step (f) and combining at least a portion of this decaffeinated liquid with the condensed evaporate of step (d) to form the aqueous stream of step (f); (i) adding condensed strippings from step (b) and condensed volatiles from step (g) back to the decaffeinated extract resulting from step (e).

Claim 2

A method of decaffeinating an aqueous caffeine-containing extract of roasted coffee comprising the steps of: (a) subjecting the extract to a stripping operation in order to remove volatiles and from about 5 to 15% by weight of the extract, (b) condensing the extract strippings of step (a); (c) evaporatively concentrating the stripped extract to a solids concentration between 30% and 50% by weight; (d) condensing the aqueous evaporate of step (c), (e) continuously contacting the concentrated extract in a countercurrent fashion with a decaffeinating fluid at a temperature between 10° C. and 180° C. and a pressure between 50 to 450 atmospheres, said fluid being either a liquid gas or a supercritical fluid at the conditions at which the decaffeination operation is effected; (f) thereafter, contacting the caffeine-containing fluid from step (e) with an aqueous stream containing the condensed evaporate of step (d), at a temperature between 10° C. and 180° C. and a pressure between 50 to 450 atmospheres in order to decaffeinate said fluid; (g) passing the decaffeinated extract of step (e) and the caffeine-containing aqueous stream from step (f) to vent tanks and condensing volatiles exiting the vent tanks; (h) removing caffeine from the aqueous stream of step (f) and combining at least a portion of this decaffeinated liquid with the condensed evaporate of step (d) to form the aqueous stream of step (f); (i) adding condensed strippings from step (b) and condensed volatiles from step (g) back to the decaffeinated extract resulting from step (e).