Caffeine extraction from coffee by solvent treatment - esp. coffee beans without alteration of taste or aroma

摘要

Decaffeination of coffee, esp. raw coffee beans comprises mixing the coffee as extract or beans, with a solvent for the caffeine; and subjecting the mixt. of solvent and coffee, before heat is applied, to a predetermined pressure greater than the vaporising pressure of the solvent at the highest working temp. the pressure being exerted by an inert gas such as nitrogen. Pressurised water may also be introduced into the processing vessel so that it may be used for opening up the raw beans simultaneously with the extraction of the caffeine. The minimum pressure of the inert gas in that case, is set higher than the vaporising pressure of the water. During operation, the pressure is raised and lowered, from and to the minimum, periodically. Quicker and more economical method, handling the beans more gently eliminating losses of coffee extract due to breaking down by the boilding of the solvent at high temp.