Abstract: Moistened black tea is decaffeinated using carbon dioxide as a solvent. The mixture consisting of caffeine, water, aroma constituents and gaseous carbon dioxide obtained in the course of the purification of the carbon dioxide (prior to recirculation of the latter) is removed from the separation tank and separated by raising the temperature at atmospheric pressure into an aqueous caffeine solution and a gaseous aroma fraction. The emanating carbon dioxide transports the aroma components, after a dew point depression by lowering the temperature, to decaffeinated, dried tea, to which the aroma constituents are impregnated.

Abstract: A process is provided for the selective removal of basic materials from plant products, in particular, for removing nicotine from tobacco without materially affecting the content of the other components of the tobacco. Tobacco is traversed with a solvent at high pressure and in a physical state which is either a liquid at a pressure of from about 500-300 atmospheres or a supercritical fluid wherein nicotine and the other components dissolve in the solvent. As the single means of removing substances from the solvent, the solvent is then passed through an acid-containing trap where the solvent is essentially freed of nicotine. The solvent, depleted of nicotine and enriched in the other components, is then recycled to the tobacco to reextract nicotine.

Abstract: A process for the continuous extraction of mixtures of organic substances including high boiling point constituents and/or constituents which do not boil but which melt with at least one solvent in the supercritical state, selected from the group consisting of CO.sub.2, propane, butane, pentane, petroleum ether, water, and having a critical temperature, T.sub.k, and a critical pressure, P.sub.

Abstract: The present invention provides a process for the decaffeination of tea containing 15 to 50% by weight of water with moist carbon dioxide at 255 to 350 bar at 50.degree. to 80.degree. C. in a pressure vessel, subsequent separation of the caffeine from the carbon dioxide with the help of an adsorbent and recycling the caffeine-free carbon dioxide over the already extracted tea, wherein the adsorbent is distributed in the material to be extracted in an amount of from 5 to 40% by weight, referred to the dry weight of the tea.

Abstract: A screen is mounted in an apparatus for contacting particulate solids with a fluid. The apparatus comprises an elongate column for holding a bed of particulate solids for contact with a fluid, the column being designed to be oriented substantially vertically in use and having a fluid inlet near the bottom for admitting a fluid into the column and a fluid outlet near the top for permitting the fluid to exit the column after passing upwardly through a bed of particulate solids in the column. The purpose of the screen is to screen solids from the fluid exiting the column through the fluid outlet. The screen comprises a plurality of vertical screen wires, and the screen is located within the column such that all of the fluid passing through the column passes through the screen and then through the fluid outlet. Each pair of adjacent vertical screen wires defines a substantially vertical screen slot therebetween.

Abstract: By the extraction with CO.sub.2 at 60 to 150 bar and 20.degree. to 70.degree. C., an aroma enriched fraction is taken from the moistened black tea, said fraction being added again to already decaffeinated and dried tea. Decaffeination starts after the aroma fraction has been obtained by pumping carbon dioxide at a pressure of between 150 to 500 bar and a temperature of between 10.degree. to 100.degree. C. through a bulk moistened tea. The solvent charged with caffeine is passed over an adsorber or purified by reduction of density.

Abstract: Method and apparatus for contacting particulate solid matter with a fluid in a pressure vessel through which the fluid continuously moves at high, supercritical, pressure while the particulate solid matter is periodically moved via isolatable pressurizable vessels which are periodically pressurized and de-pressurized to and from the supercritical pressure to facilitate periodic movement of the particulate solids between the pressure vessel and the isolatable pressurizable vessels. A supply of the fluid is maintained at an intermediate pressure at which the fluid exists in both the liquid and gaseous states. The pressurizable vessels are raised to supercritical pressure by first using intermediate pressure fluid in the gaseous state and then in the liquid state, followed by introducing fluid at the supercritical pressure. The vessels are de-pressurized by first venting and then pumping to the intermediate pressure fluid supply.

Abstract: A method of continuously decaffeinating moistened, green coffee solids with supercritical carbon dioxide. Moistened, green coffee beans are moved periodically through an extraction vessel and contacted with continuously flowing supercritical carbon dioxide which extracts caffeine from the moist, green coffee beans. Caffeine is removed from the supercritical carbon dioxide by counter-current contact with wash water in an open vessel. The caffeine-depleted supercritical carbon dioxide is recirculated back to the extraction vessel and the caffeine-bearing wash water is subjected to concentration by reverse osmosis. Acidic, substantially caffeine-free permeate is directed back to the extraction system as wash water, or to moisturize the green coffee beans prior to extraction, or both.

Abstract: A process for decaffeinating green coffee by extraction of the coffee with water and treatment of the aqueous extract with activated carbon whereby the caffeine is largely absorbed by the activated carbon. The resulting caffeine-loaded activated carbon is then treated with a selected acid whereby the caffeine is largely removed from the activated carbon. The carbon is then washed with water until it has pH in the range of 3 to 6, determined by the standard test method for pH of activated carbon (ASTM D 3838-80). The activated carbon is then ready to be reused more than ten times in the process without further treatment.

Abstract: A process for recovering from caffeine-loaded activated carbon by treatment f the loaded carbon with an acid. According to the present invention, activated carbon is treated with a compound having the formula ##STR1## wherein R.sub.1 is methyl, H or Cl, and R.sub.2 is Cl, OH or phenyl.

Abstract: Xanthine stimulants are extracted from a cocoa material containing a fat by adding water to the cocoa material for swelling it with at least 0.1 part by weight of water per part by weight of cocoa. The swollen material is then contacted with a food-acceptable solvent gas which is supercritical in respect to temperature and pressure, after which the solvent gas containing the stimulants is separated from the swollen cocoa material which thereupon has a reduced content of stimulants.

Abstract: A method of extracting caffeine from green coffee beans whereby an essentially caffeine-free supercritical fluid is continuously fed to one end of an extraction vessel containing green coffee beans and caffeine-laden supercritical fluid is continuously withdrawn from the opposite end. A portion of decaffeinated beans is periodically discharged while a fresh portion of undecaffeinated beans is essentially simultaneously charged to the extraction vessel. The caffeine-laden supercritical fluid is fed to a countercurrent water absorber. Supercritical carbon dioxide is the preferred supercritical fluid. The method of the present invention is more efficient than batch processes and produces an improved decaffeinated coffee.

Abstract: This invention relates to a process for recovering caffeine from laden acated carbon by treating the laden activated carbon with an organic acid. In order to achieve good extraction efficiencies, on the one hand, and to avoid problems with the flash point, such as with acetic acid, on the other hand, the process according to the invention is characterized by treating the activated carbon with a mixture comprising at least 65% by weight of acetic acid and at least 2% by weight of citric acid.

Abstract: A method of decaffeination wherein a caffeine-containing coffee extract solution is contacted with caffeic acid in the presence of water. The caffeine and the caffeic acid form an insoluble caffeine/caffeic acid complex wherein the complex is separated from the coffee extract solution.

Abstract: A process is disclosed for removing substantially all of the theobromine normally present in cacao beans. The process includes a water extraction of cacao nibs at from about 45.degree. C. to about 55.degree. C. followed by a series of water extraction steps at from about 90.degree. C. to about 105.degree. C. Theobromine and caffeine are separated in the filtrates and the final methylxanthine extracted fraction is returned to the cacao nibs mass from which a methylxanthine extracted cacao liquor is obtained.

Abstract: An improvement in the process of decaffeinating green coffee at high pressure with moist carbon dioxide gas in the supercritical state. The decaffeination takes place in a heating profile of at least two distinct heating periods for predetermined times. During the first heating period, the temperature is maintained between 40.degree. C. and 70.degree. C. This first period may be conducted in several steps or in a single rising temperature step. In the second heating period, the temperature is maintained above 70.degree. C. but below 85.degree. C. The second heating period constitutes between one-fifth and one-third of the total heating time resulting in a higher quality product with the same quantity of caffeine removed as prior processes run at a single temperature.

Abstract: Mixtures of substances containing organic components are segregated by extraction with a gaseous solvent in high pressure extraction. One additive component is admixed to the charged solvent, whereby the solvent capacity of the solvent is strongly reduced and consequently a precipitation is achieved for at least a portion of the components to be captured as an extract.

Abstract: The present invention relates to a method of separately recovering caffeine and non-caffeine solids adsorbed on activated carbon. Activated carbon containing the adsorbed solids is contacted with an aqueous basic solution to elute the non-caffeine coffee solids. The two components are separated. The activated carbon is subsequently contacted with a concentrated aqueous acidic solution to elute the relatively pure caffeine. The two components are separated. The non-caffeine solids in the basic solution may be re-adsorbed onto the activated carbon. Essentially pure caffeine may be refined from the aqueous acidic solution.

Abstract: A roasted coffee extract decaffeination method providing a soluble coffee of improved flavor is disclosed. A roasted coffee extract is contacted with a caffeine solvent so that caffeine and a lesser amount of non-caffeine solubles is transferred to the solvent. The two liquids are separated and the caffeine solvent is typically concentrated. The concentrated solvent is then contacted with an aqueous caffeic acid suspension so that caffeic acid/caffeine complex crystals grow in the water phase. The complex crystals are filtered and the then at least partially decaffeinated caffeine solvent is separated from the water phase. Contact of the caffeine solvent and an aqueous caffeic acid suspension may be repeated to achieve further decaffeination. Then, the solvent, which contains substantially only non-caffeine solubles, is added to the substantially decaffeinated roasted coffee extract. The caffeine solvent is then stripped from the roasted coffee extract, which is subsequently dried.

Abstract: The process disclosed herein decaffeinates an aqueous caffeine feed solution by contacting it with a multi-phase extractant which comprises a continuous phase of a liquid, water-immiscible, caffeine-specific solvent and discontinuous aqueous phase dispersed therein. The caffeine is selectively extracted from the aqueous feed solution, leaving the solubles necessary for a good testing beverage due to the high combined selectivity of the extractant phases. Very low solvent-to-extract ratios are possible because the multi-phase extractant has a much improved partition coefficient as compared to the water-immiscible solvent.

Abstract: In the decaffeination of green coffee beans with an aqueous medium, caffeine is removed from the aqueous medium which also contain non-caffeine green coffee solids, contact with substantially neutral active carbon. Thereafter the medium may be recycled to extract further amounts of caffeine from the same or another batch of green coffee beans.Other features of the invention are described in the specification.

Abstract: A process for the decaffeination of green coffee beans by the extraction, process stage (a), of soaked green coffee beans with an equilibrium extract of coffee beans, from which extract caffeine has been removed, resulting in caffeine-deficient beans, which are recovered, and an equilibrium extract of the beans, which in a series of successive process stages (b), (c), (d) and (e), is contacted with an adsorbent circulating counter-currently through the same process steps, said adsorbent having a preferential adsorption capacity for caffeine. The equilibrium extract from stage (a) together with solution from stage (e) are contacted in stage (b) with adsorbent from stage (c) with adsorption of caffeine from the solution. The resulting solution is partly returned to stage (a), and partly, in stage (e), contacted with "clean" adsorbent from stage (d). The resulting "clean" solution is contacted, in stage (d) with adsorbent from stage (e) with desorption of caffeine from said adsorbent.

Abstract: In the decaffeination of green coffee beans with an aqueous medium, caffeine is removed from the aqueous medium which also contain non-caffeine green coffee solids, contact with substantially neutral active carbon. Thereafter the medium may be recycled to extract further amounts of caffeine from the same or another batch of green coffee beans.Other features of the invention are described in the specification.

Abstract: A process for extracting bitter principle and tannin from hops, uses ethanol as the extracting agent in a single extraction. By controlling the water content of the ethanol used, the quantity of extracted tannin can be controlled. The tannin component can be separated out of the obtained extract as desired. By treating the extract with water vapor, all the alcohol can be simultaneously expelled and recovered. Ethanol is preferably removed and recovered from the resultant draff by means of the flash desolventizing system (FDS) method.

Abstract: An aqueous coffee extract is decaffeinated with a treated activated carbon. The activated carbon is first contacted with an ethyl cellulose solution in order to adsorb the ethyl cellulose on the carbon. The ethyl cellulose-containing activated carbon is then dried and contacted with an aqueous coffee extract. The substantially decaffeinated extract is subsequently separated from the carbon.

Abstract: The process described herein improves the decaffeination of both wet and dry green coffee beans with a liquid or supercritical carbon dioxide extractant by dissolving dimethyl sulfoxide in the extractant prior to contact with the beans. Rates of extraction are greatly improved, especially in the preferred mode where the dimethyl sulfoxide is employed at near saturation levels.

Abstract: A process for producing a decaffeinated vegetable material, such as coffee or tea in aqueous extract or solid form, for use in preparation of beverages, which comprises:(a) contacting a caffeine-containing composition with a liquid, water-immiscible fatty material which is capable of removing caffeine therefrom;(b) maintaining said vegetable material and said fatty material in contact for a time sufficient to transfer caffeine from said vegetable material to said fatty material; and(c) separating the decaffeinated vegetable material from the caffeine-laden fatty material.Other features of the invention are described in the specification.

Abstract: In a process for depurinizing cocoa, green or roasted cocoa beans are extracted with water at a temperature of from 40.degree. to 60.degree. C., the extract is treated with an adsorbent based on desugared and activated carob particles in order to remove the purines therefrom, and the beans are dried and roasted. The dried beans are preferably rehydrated using the depurinized extract after being concentrated and before final roasting.The treated cocoa is useful for the production of beverages containing cocoa and, when the variant with reincorporation of the non-purine solids is applied, for the production of chocolate.

Abstract: A process for extracting caffeine from raw coffee, roast coffee, tea and the like. Super-critical carbon dioxide is used as extracting agent, and ion-exchangers are used to absorb the caffeine, and are subsequently regenerated by use of aqueous regenerating agents.

Abstract: An improved extract decaffeination process. Roast coffee extract is contacted with a water-immiscible organic solvent to form decaffeinated extract and caffeine-containing spent solvent. The spent solvent is contacted with water to form decaffeinated spent solvent and caffeine-containing spent water. The spent water can be concentrated to a caffeine content of from about 7 to about 30% by weight. The caffeine in the concentrated spent water can be crystallized out and then separated from the residual spent water. The noncaffeine solubles present in the residual spent water can then be recovered.

Abstract: A process for the recovery of xanthine stimulants from an aqueous solution containing xanthine stimulants extracted from cocoa material, which comprises contacting the solution with a substantially neutral adsorbent and separating the adsorbent, with the xanthine stimulants adsorbed thereon, from the aqueous solution having a reduced content of xanthine stimulants.

Abstract: A process for removal of caffeine from green coffee beans is disclosed by extraction with an aqueous liquid and preferential adsorption of caffein from the extract by means of a synthetic polymer resin of the type that is obtainable by polymerization or copolymerization of monomers containing aromatic ring systems and acid groups, and whereby the ratio of the total adsorption capacity for caffein to the total ion exchange capacity is larger than about 1 and smaller than about 25.

Abstract: Extraction of caffeine from solutions thereof is accomplished with carbon dioxide under high pressure, using adsorbents which combine a high adsorption capacity for caffeine with such hydrophilic properties that the caffeine-laden adsorbent can be regenerated using water only.

Abstract: A process for the direct decaffeination of aqueous coffee extract solutions by contacting the surface of a thin film of an aqueous coffee extract solution with carbon dioxide under supercritical conditions of temperature and pressure to thereby remove the caffeine into the CO.sub.2 and directly recover the aqueous coffee extract solution substantially free from caffeine. The contacting of the aqueous coffee extract solution and the CO.sub.2 is preferably effected by passing the aqueous coffee extract solution downwardly through a packed column, while passing the CO.sub.2 upwardly in countercurrent contact therewith.

Abstract: A process for extracting caffeine from raw coffee by circulating humid nitrogen oxide N.sub.2 O gas in a hypercritical condition under predetermined pressure and temperature conditions through the raw coffee. Optionally the caffeine is separated from the extractor gas by an ion exchanger such as a three-dimensional cross-linked polysaccharide.

Abstract: Aqueous extracts of roasted coffee are stripped of aroma, concentrated and thereafter decaffeinated by means of contact with a decaffeinating fluid such as liquid or supercritical carbon dioxide. Aroma loss is minimized by using water to remove caffeine and aroma from the CO.sub.2 stream, recovering aromatics from this caffeine-containing aqueous stream and adding-back these aromatics to the decaffeinated extract. Preferably equipment cost is minimized by use of a single pressure vessel to transfer the caffeine from the extract stream to the CO.sub.2 and from the CO.sub.2 to the water stream.

Abstract: The invention involves a process for the decaffeination of coffee, wherein--usually moistened--coffee is exposed to a circulating medium essentially composed of a compressed gas and an entrainer; this medium is subjected to partial condensation of the caffeine containing entrainer, in the absence of decompression; the caffeine is recovered from the condensate by evaporation of the entrainer portion thereof, and the medium is recycled to the coffee for continued extraction of caffeine therefrom.

Abstract: An aqueous extract of tea, containing native tea tannins and caffeine, is cooled to provide an aqueous solubles phase containing cold-water soluble components of the extract, including a minor portion of the caffeine, and an insolubles phase containing tea tannins complexed with a major portion of the caffeine. The aqueous solubles phase is separated from the insolubles phase, and the latter is subjected to decaffeination to provide decaffeinated tannins which may then be recombined with the aqueous solubles phase. The resulting treated extract from which the major portion of the caffeine has been removed can be dried or, if desired, subjected to further decaffeination and thereafter dried to provide a cold-water-soluble decaffeinated tea. Further features of the invention are set forth in the following description.

Abstract: Liquid propane, liquid butane or mixtures thereof at a temperature of from 30.degree. C. to 95.degree. C. is employed to selectively remove caffeine from moistened green coffee. The resulting decaffeinated coffee is then roasted and processed to ground or soluble coffee products which will possess the flavor and aroma of comparable non-decaffeinated coffee products.

Abstract: A process for the decaffeination of coffee which comprises contacting the coffee with moist carbon dioxide in the supercritical state to effect removal of caffeine therefrom and recovering a substantially decaffeinated coffee. Preferred conditions for contact of the moist carbon dioxide are a temperature within the range of 40.degree.-80.degree. C., a pressure within the range of 120-180 atmospheres and a contact time of from 5 to 30 hours.

Abstract: Method of removing caffeine from vegetable materials using a solvent containing two components:(a) a first component which is inherently gaseous under operational conditions, and (b) a second component which, by itself, has physical properties such that a mixture of (a) and (b) is liquid at the operating temperature.

Abstract: A lower-grade green coffee bean fraction is moisturized to above 37% by weight and then decaffeinated by extraction with a moist supercritical fluid having a temperature of at least 100.degree. C. This decaffeinated coffee is then combined, either before or after roasting, with a higher-grade coffee fraction. Typically the higher-grade fraction will be coffee which has been decaffeinated by extraction with a moist supercritical fluid at a temperature below about 85.degree. C.

Abstract: Caffeine is extracted from solutions thereof with supercritical carbon dioxide having a density of at least 0.85 g/ml.

Abstract: In the decaffeination of coffee by contacting the coffee with water-moist carbon dioxide above its critical temperature and critical pressure, during the contacting, the coffee is maintained in admixture with an adsorbent for the caffeine for takeup of caffeine from the carbon dioxide by the adsorbent.

Abstract: Aqueous extracts of roasted coffee are stripped of aroma, concentrated and thereafter decaffeinated by means of contact with a decaffeinating fluid such as liquid or supercritical carbon dioxide. Aroma loss is minimized by using water to remove caffeine and aroma from the CO.sub.2 stream, recovering aromatics from this caffeine-containing aqueous stream and adding-back these aromatics to the decaffeinated extract. Preferably equipment cost is minimized by use of a single pressure vessel to transfer the caffeine from the extract stream to the CO.sub.2 and from the CO.sub.2 to the water stream.

Abstract: A caffeine free black tea product is produced by an extraction procedure with a supercritical gas such as carbon dioxide in which first the aromatic content of the tea is extracted with dry gas, then the caffeine content is extracted with wet gas, and finally the decaffeinated tea is reimpregnated with the aromatic content.

Abstract: An aqueous extract of a vegetable material is treated with a view to reducing its caffeine and/or chlorogenic acid content. The treatment is with a solid ligneous adsorbent of vegetable origin in divided form at a temperature of from 0.degree. to 100.degree. C. so as to absorb the caffeine and the chlorogenic acid. Preferably adsorption takes place at a temperature of at most 30.degree. C. and the overall process includes the following subsequent steps:Separating the adsorbent from the aqueous extract,Washing the adsorbent with water at a temperature of from 0.degree. to 30.degree. C. so as to displace the non-specifically associated soluble constituents and combining washing waters with the aqueous extract,Subjecting the adsorbent to lixiviation with hot water at at least 60.degree. C.

Abstract: Aqueous vegetable extracts such as extracts of tea or green or roasted coffee are decaffeinated by permitting caffeine to diffuse through at least one porous, hydrophilic membrane and a water-immiscible solvent phase and into a water phase. The solvent may be either internal to a single membrane or positioned between two spaced-apart membranes.

Abstract: Process for extraction of hops utilizing supercritical gases such as carbon dioxide.

Abstract: Decaffeination of green coffee is achieved by extracting caffeine from either green coffee beans or an aqueous extract of green coffee beans by means of diethyl succinate.