Decaffeination of green coffee - by treating aq. extract with activated carbon, regenerating carbon with acid, and recycling washed carbon

摘要

Cream coffee (I) is decaffeinated as follows: (a) an aq. extract of (I) is treated with activated C (from (c)); (b) the caffeine-laden activated C is treated with an aq. liq. (II) so that most of the caffeine is removed; and (c) the activated C is recycled to step (a) after it has been washed with H2O to pH 3-6 (ASTM D 3838-80). (a) Pref. the extract is typically prepd. by extrn. of (I) with H2O at 50-100 deg.C Activated C has surface area pref. at least 800 m2/g (BET). (b) (II) is suitably one or more acids, including (aq) HOAc, or lactic, glycolic, citric, or benzoic acids, or H3PO4, esp. a liq. contg. 50-85% (65-85) wt.% HOAc and also contg. H2O, citric acid, H3PO4, lactic- or benzoic-acid. Treatment is pref. at not less than 100 (110) deg.C. (c) Washing is pref. to pH 3-5.5.