Continuous decaffeination of green coffee

摘要

In a process in which whole or ground beans are extracted in a series of steps with a solvent in which caffeine is preferentially soluble, the improvement comprises:- using as solvent either MEK or methyl acetate; carrying out extn. at the b.pt. of the solvent countercurrently in at least three stages continuously or semicontinuously; supplying the coffee at about its natural water content; using in the last extn. stage solvent contg. 5-10 vol.% water and adding water to first extn. stage in amts. such that no phase sepn. occurs and the solvent withdrawn contains 5-10 vol.% water. - The extrn. may be carried out using an extn. battery or an endless belt which passes through a series of extn. sections where solvent is circulated transversely to the direction of travel of the belt (see AU 402144). - The process does not use toxic chlorinated solvents, requires only simple appts. and processing times are short. (0/0) EPAB- EP-101135 B A process for the decaffeination of green coffee, in which coffee beans, whole or reduced to particles, are extracted in a series of extraction steps with an aqueous organic solvent in which caffeine from the coffee is preferentially soluble, by - selecting as the organic solvent methyl ethyl ketone or methyl acetate, - the extraction temperature being approximately equal to the boiling temperature of the solvent, - the extraction being effected in continuous or semi-continuous countercurrency in at least three extraction sections, - the coffee being supplied to the first extraction section with approximately its natural water content, - the organic solvent being supplied to the last extraction section with a water content of 5-10% by volume, and - water being added to the first extraction section in at most such a quantity that just no segregation occurs, and the solvent enriched with caffeine, ultimately withdrawn from the first section, contains 5-10% by volume of water. - (4pp)