USRE13263E - Schaft - Google Patents

Description

, JOHANN ILIEDBICH MEYER, m, LUDWIG BQSELIUS,

OI DREMEN, GERMANY, ASSIGNOBS' ,TO THE UNITED STATES PATENT OFFICE.

AND KARL HEINRICH 'WIMMEB, KAFFEE-HANDELS-AKTIENGESELL- m, OI IBEEMEN, GERMANY, A JOINT-STOCK COMPANY OF GERMANY.

PREPARATION OR TREATMENT OF COFFEE.

Specification of Beissued Letters Patent. Reissued June 27 191 1;

In Drawing. Original No. 897,840,6ated September 1, 1908, 'S erial No. 315,180. Application for reissue filed February 17, 1911.

To all whom it may concern:

Be it known that we, J OHANN FRIEDRICH MEYER, Jr., LUDWIG RosnLIUs, and KARL HEINRICH WIMMER, subjects of the German Emperor, residing at Bremen, Germany, have invented certain new and useful Improvements Relating to the Preparation or Treatment of Coffee, of which the following is a, specification.

he present invention is a division of reissue application, filed July 5, 1910, Serial No. 570,504, and has for its object, to deprive coffee beans of caffein, without destroying their other valuable properties. Numerous attempts made for this purpose have been unsuccessful, and especially the treatment 'of the beans with volatile solvents for caffein has produced unsatisfactory results. The reason for failure seems to have been in the cellular tissue or organic structure of the coffee beans, which renders a suflicient penetration 'of the solvent almost impossible.

Moreover, the ca flt'ein is contained in the beans in the shape of salts, which are hardly soluble at all in the volatile solvents. Finally there is the defect, that after prolonged treatment of the beans with the solvent it is exceedingly diflicult to remove the solvent completelyfrom the cells, even if the solvent had penetrated only into the outer cellular layers of the beans.

According to the present invention the coffee beans are first subjected to a preliminary treatment which caus'es the beans to swell and loosens the structure or cellular tissue of the same, preferably by exposing them to dry steam of about 111 -2 atmospheres in a closed receptacle. Subsequently gases or vapors having an acid or alkaline reaction are introduced into the apparatus, in order to decompos'e'the salts of caifein.

Ammonia, sulfurous acid, hydro-chloric DIVISION 0.

Serial No. 609,081.

mained in the beans they are volat-ilized by the subsequent roasting, because at the temperature of roasting cofi'ee cafl'ein inits free state is capable of sublimation, although this is not the case with its salts.

The beans treated as described are extracted with a solvent of cafi'ein, preferably one which dissolves only the latter, but as little as possible of the other constituents of the beans. We have found that benzene (also called benzol) is eminently suitable for this purpose, because an extract made after the extraction,

with it leaves onv evaporation almost pure cafiein. In using other solvents, such as alcohol or chloroform, it would be necessary, to restore to the coffee-beans the extract, which has been relieved of caffein. "Instead of a single solvent, such as benzene, mixtures of volatile solvents, may, of course, be employed for extracting the cofi'ee beans.

The extraction of cafiein is very energetic and leaves only minute traces undissolved, While the solvent action of the mixture for other constituents of cofiee is comparatively Weak. The boiling point of the mixture is lower than that of the individual compo-' nents, and the extraction therefore takes place at a lower temperature.

It is useful to subject the coflee, after extraction, to: the influence of dry steam at a pressure of about 1- 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 different pres sure, or alternately to pressure and vacuum. This treatment also serves to expel the traces of furfurol contained in the' coffee, and to relieve the coffee of this constituent, which recent investigations have shown to be injurious;

Example: kilograms. of coffee beans 1% 2 atmospheres. This pressure is allowed are placed in a cylinder With a double the condensati'oniof the" dry steam to'beintroduced. Subsequently, after the cylinder l1as.beenl1ermetically closed, steam is introduced until the pressure has risen to about to act for about half an hour, after which gaseous ammonia is admitted. When the space is filled with this gas, benzene (or a mixture of'benzeneand'alcoh'ol) is admitted and heated, the immediate effect of this being, that the ,escaping'benzene vapors will carry with them any moisture that may be present and also the excess'of ammonia.

The heating is then continued for about 2 to 3 hours, andthe benzene vapors thereby pro.- duced are condensed in the known manner and re-conducted into the apparatus. If

necessary, the preliminary treatment (mentioned atthe beginning 'of this specification) is repeated.

When the extraction is completed, the last remnant of the solvent mixture is removed from the beans, by admitting to the extractor dry steam, until a pressure of about 1% atmospheres has been established, which is -maintained for about 1 hour while conducting steam through the contents and keeping the apparatus in a rotary motion.

. What we claim is x 1. In a process for remoying cafiein from green coffee beans, consisting in first treating the green coffee beans with dry steam in order toloosen the cellular structure, then treating them with gaseous chemicals adapted to liberate the cafiein from its salts, then extracting the caffein with a volatile solvent and finally subjecting the extracted beans to a current ofdry steam, substantially as -de-,

scribed. i

. 2. In a process for removing caffein from I green coffeebeans, consisting in first treating the green coffee beans with dry'steam in ,order to loosen the molecular structure, then ltreating them with gaseous chemicals adapted to liberate the caflein' free from its salts, then extracting the caffein .with. a volatile solvent and finally subjecting the extracted beans to currents of dry steam at different pressures, substantially as described.

3. In a process for remo-ving caffein from green coffee beans, consisting in first treating the green coffee beans with dry steam in order to loosen the molecular structure, then treating them with gaseous chemicals adapted to liberate the caffein from its salts, then extracting the caffein with a volatile solvent and finally subjecting the extracted beans to a current of dry steam, while keeping the beans in motion, substantially as described.

4. In a process for removing caffein from green coffee beans, consisting in first treating the green coffee beans with dry steam and then with gases or vapors having an acid "or alkaline reaction, ,subs'equentlyg e'xtracting them with a volatile solvent and finallyitreating them with a current of steam, while keeping the coffee beans in v1olent motion, subs'tantiallyas: described."

" 5. Th'e' herei n' described improvement in the process for the removal of caffein from green coffee beans, which consists in first treating the green coffee beans with dry steam in order to loosen the cellularstriic- 1 ture, then treating them with gaseous chemiv volatile solvent.

.6. The herein described improvement in the process for the removal of caffein from green coffee beans, which consists in first treating the green coffee beans with dry steam, in order to loosen the cellular structure, then treatin them with gaseous chemicals adapted to liberate the caffein from its salts and then extracting the ca'ffein with a mixture of volatile solvents.

7. The rocess for removing caffein from green co ee beans, which consists infirst treating the green coffee beans with dry steam and then with gases or vapors having an acid or alkaline reaction, subsequently extracting them with a volatile solvent and finally treating them with a current of dry steam, while keeping the cofiee beans in motion, substantially as described. v

8. The recess for removing caffein from green 00 ee beans, which consists in first ture, then treating them with gaseous chemicals adapted to liberate the caffein f r-omits salts, then extracting the caffein witha volaits salts, then-extracting the caffein" with a volatile solvent, subjecting I the extracted beans to currents of dry steam at different pressures and then roasting the beans, substantially as described.

10. The process for removing caffein from green coffee beans, which consist-s in first treating the green coffee beans with dry steam in order to loosen the molecular structure, then treating them with gaseous chemicals'adapted to liberate the caffein from its salts, then extracting the caffein with a volatile solvent, subjecting the extracted beans to a current of dry steam while keeping the the solvent, subjecting the extracted beans beans in motion, and then roasting the beans, substantially as described.

11. The process for removing caifein fromgreen coffee beans, which consists in first,

treating the green coffee beans with dry steam and then with gases or vapors having an acid or alkaline reaction, subsequently extracting them with a volatile solvent,

1 treating them With a current of dry steam While keeping the coffee beans in motion, and then roasting the beans, substantially as described.