USRE13261E - Schaft - Google Patents

Description

; UNITED STATES" PATENT OFFICE.

J'IOI-IANN FRIEDRICH MEYER, an,

LUDWIG nosELIus, Ann

KARL HEINRICH WIMMER,

F BREMEN, GERMANY, ASSIGNORS TO THE KAFFEE-HANDELS-AKTIENGESELL- SCHAFT, OF BREMEN, GERMANY, A JOINT-STOCK COMPANY OF GERMANY.

PREPARATION 0R TREATMENT OF COFFEE.

Specification of Reissued Letters Patent. Reissued June 27, 1911;

' No Drawing. Original no. 897,840, dated September 1, 1908, Serial no. alaisb. Application for reismi 1 or vapors having an acid filed July 5. 1911}. Serial No. 570,504.

DIVISION A.

MEYER, J r., LUDWIG RosELIUs, and KARL.

HEINRICH WIMM R, subjects of the German Emperor, residmg at Bremen, Germany,

have invented certain new and useful Im-.

provements Relating to the Preparation or Treatment of Coffee, of which the following is a specification.

The present invention has for its object, to deprive coffee beans of caffein, without destroying their other valuable properties. Numerous attempts made for this purpose hav'e been unsuccessful, and especially the treatment of the beans with volatile solvents for 'caifein has produced unsatisfactory results, The reason for failure seems to have been in the cellular tissue or organic structure of the cofi'ee beans, which renders a suflicient penetration of the solvent almost impossible. Moreover, the caifein is contained in the beans in the shape of salts, which are hardly soluble at allin the volatile solvents. Finally there is the defect, that after prolonged treatment of the beans with the solvent itis exceedingly diflicult to remove the solvent completely from the cells, even if tissue of the same, preferably by exposingthem to dry steam of'about 1&2 atmospheres an a closed receptacle.

Subsequently gases or alkaline reaction are introduced into the apparatus, in order to decompose the salts of cafl'ein. Ammonia, sulfurous acid, hydro-chloric acid and simi- -lar chemicals have been found specially suitable for this purpose. The cafi'ein liberated by this treatment can be extracted more .easily than its salts, and in case minute quantities of caifein have remained in the beans after the extraction, they'are volatilized by the subse%uent roastin because at the temperature 0 its freestate is capable of sublimation, although this is not the case with its salts.

"The beans treated asdescribedare, ex-

weak. The boiling roasting co co eaflein in t-racted with a solvent of caffein, preferably one whichdissolves only the latter, but as little as possible of the beans. We have found that benzene (also called benzol) is eminently suitable for this purpose, because an extract made with it leaves on evaporation almost pure caflein. In using other'solvents, such as alcohol or chloroform, it would be necessary, to restore to the cofl'ee-beans the extract, which hasbeen relieved of cafl'ein. Instead of a single solvent, such as benzene, mixtures of volatile solvents, may, of course, be tracting the coifee beans.

The extraction of cafi'ein is veryenergetic and leaves only minute traces while the solvent action of the mixture for other constituents of cofl'ee is comparatively point of the mixture is lower than that ofjthe individual compo nents, and the extraction therefore takes place at a lower temperature.

It is useful to subject the coffee, after extraction, to the influence of dry steam at a pressure of about 1% atmospheres, while keeping the beans continually in motion by stirring, or by causing the apparatus to revolve. An agitation of the beans is useful also during the extraction. In case traces of the extracting liquid remain in the beans in spite of this treatment with steam, these traces may be removed by subjecting the beans alternately to steam of diflerent pressures, or alternately to pressure and vacuum.

employed for ex- This treatment also serves to expel the traces of furfurol contained in the coffee, and ,to relieve the cofl'ee, of this constituent, which recent investigations have shown 'to be injurious.

Example: 100 kilograms of coffee beans are placed in a cylinder with a double jacket, the cylinder is heated indirectly by steam, in order to avoid as much. as possible the condensation of the dry steam to be introduced. Subsequently, been hermetically closed, steam is introduced until the pressure has risen to about 1&2 atmospheres." This pressure is allowed to act for about half an hour, after which gaseous ammonia is admitted. When the'space is'filled with this gas, benzene (or a mixundissolved,

the other constituents of I gmentioned at the beginning of to 3 hours, and the benzene va carry with them any moisture that may be present and also the excess of ammonia;

The heating is then continued-for about 2 v ors thereby produced are condensed in the own manner and re-conducted "into the apparatus. Ifnecessary, the preliminary treatment this specication) is repeated. 7

When the extraction is completed,"the last remnant of the solvent mixture is removed atmospheres has been establishedg iwhich is maintained for about 1 hour while c'onducting steam through the contents and keeping the apparatus in a rotary motion.

What we claim is 1. As a new article of manufacture un broken green coffee beans originally containing caliein but freed-therefrom and if their remaining natural constituents stantially unimpaired 2. As a new article'of manufacture, un broken .cofiee beans 0 'ginally containing cafiein but freed therefrom.

- 3. As a new article of manufacture, un-

cafiein but substantially freed therefrom.,

4. As a new In testimony whereof, we are; our signatures 1n the presence of-two' wltnesses.

101mm FRIEDRICH MEYER, JR; mmwie ROSELIUS. KARL HEINRICH WIMMER.

Witnesses: FREDERICK HOYERMANN, .FRIEDRI H Scrnmvn subbeans originally containingf 'ticle of manufacture, un-' v broken green coffee beans originally contain-; ing caflt'ein but substantially. freed therefrom and having their remaining natural constit' uents substantially unimpaired.

from the beans, by admitting to the extractor-dry steam, until a pressure of about 1%