ES402124A1 - Semicontinuous procedure in countercorrent for decaffearing green beans of coffee. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Semi-continuous countercurrent process for decaffeinating green coffee beans, characterized in that it comprises: (a) steam green, dry coffee beans for a time of 0.25 hours to 1 hour, at a temperature of 104 to 110º c, to provide a moisture content in the grains from 16 to 18%; (b) pre-moistening the green coffee beans previously treated with steam, to provide a moisture content in the beans of 41 to 50% by weight; (c) extract caffeine in countercurrent from green coffee beans previously treated with steam and pre-moistened, introducing a fresh organic solvent extractant of caffeine, at a temperature of 49 to 121ºc and a pressure of 2.1 to 14 kg/cm. Relative, inside the first extraction column of an extraction train comprising a series of extraction columns containing green coffee beans, said first column containing the green coffee beans almost completely extracted from the caffeine and containing the last column of said train green fresh coffee beans not extracted and containing the intermediate columns of said train green coffee beans having progressively more caffeine, passing said solvent, successively, through the series of extraction columns that constitute the extraction train, at a solvent surface velocity, with respect to the green coffee grades, from 0.045 m/minute to 0.3 m/minute, simultaneously, at a solvent exchange rate of 2 kg/kg of coffee/minute at 12 kg/kg of coffee/minute, recirculating through each column a portion of said solvent that previously passed through the column a in question, then separating the solvent from the last column of said extraction train; (d) separating with steam water the residual solvent of the decaffeinated green coffee beans contained in the first column, at a temperature of 104 to 110ºC for a time of 1 to 4 hours; and (e) extracting the decaffeinated green coffee beans from the first separated column with steam. (Machine-translation by Google Translate, not legally binding)