Caffeine removal from raw coffee - by extn. with supercritical carbon di:oxide super-satd. with water

摘要

Raw coffee is decaffeinated by extn. with moist, supercritical CO2, super-satd. with 0.5-5 wt.% of water, opt. followed by treatment with water, esp. with water contg. natural coffee aromas. The water content for the extn. is adjusted by the amt. of water corresp. to the super-satn. of the CO2 used, and is brought to 1-2 wt.%. Extn. in the first stage is with CO2 super-satd. with water, at 200-350 (235) bars, and 40-80 (60)deg.C, and is followed by treatment at 70-90 (75-80) deg.C with water enriched with natural coffee aromas; treatment with water may be in countercurrent to the extn. --The fluid CO2 in supercritical state has been loaded to a negligible extent with caffeine at the start of extn., and is recycled. -