Method and apparatus for preparing decaffeinated green coffee bean extract and caffeine using adsorbent resin and dichloromethane, and corresponding use

Abstract

A method for preparing decaffeinated green coffee beans is described. In this case, one method step comprises the extraction of caffeine from green coffee beans by means of an aqueous extract, the other method step comprises the binding of caffeine in the extract to an adsorbent resin, and the other method step comprises the dissolution of caffeine from the caffeine-laden adsorbent resin with dichloromethane (DCM).

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a method for producing decaffeinated green coffee beans. Here, one method step includes extracting caffeine from green coffee beans with an aqueous extract, another method step includes binding the caffeine in the extract to an adsorption resin, and another method step includes dissolving the caffeine from the caffeine-loaded adsorption resin with dichloromethane (DCM).

[0002] The present invention also relates to an apparatus for producing decaffeinated green coffee beans in a method according to the invention. The present invention also relates to an application of an apparatus according to the invention for carrying out a method according to the invention, an application of dichloromethane for removing caffeine from an adsorption resin, and an application of an adsorption resin for adsorbing caffeine from a caffeine-rich aqueous extract in a method for producing decaffeinated green coffee beans.

[0003] Aspects of the present invention are defined in the appended claims; specific term definitions are included in the following description. Details and preferred embodiments of the method according to the invention, the apparatus according to the invention, and the application according to the invention are derived from the appended claims and the following description, respectively. BACKGROUND OF THE INVENTION

[0004] The decaffeination of green coffee beans is a popular method for producing decaffeinated coffee and for producing caffeine or caffeine concentrates. The decaffeination of green coffee beans is usually carried out during an extraction process. Extraction processes can be roughly divided into three different categories with respect to the extraction agent used.

[0005] Decaffeination processes that have long been known are based on extracting caffeine from green coffee beans with organic solvents such as DCM or ethyl acetate.

[0006] Furthermore, decaffeination methods have been developed in which water or an aqueous solution is used as the extraction agent. These include, in particular, the "Swiss Water Decaffeination" method and the "French Water Decaffeination" method.

[0007] Another common extraction agent for the decaffeination of green coffee beans is carbon dioxide in liquid or supercritical form.

[0008] All of the above decaffeination methods are based on the fact that the extraction agent used is suitable for separating or extracting caffeine from green coffee beans. However, green coffee beans contain not only caffeine, but also a large number of other substances, which in particular ensure that coffee has its characteristic flavor. Therefore, a decaffeination method is needed that selectively removes caffeine from green coffee beans such that at least to a large extent the other coffee inclusions remain in the green coffee beans.

[0009] Coffee inclusions can be schematically divided into two categories: Here, the coffee inclusions of the first category consist of polar, water-soluble components; the coffee inclusions of the second category consist of non-polar, water-insoluble substances. Here, although caffeine more precisely belongs to the non-polar substances of the second category, it is characteristic that a non-negligible part of it is also soluble in water.

[0010] Therefore, decaffeination methods in which an organic non-polar solvent, such as DCM or ethyl acetate, is used as the extraction agent are very suitable for removing caffeine from green coffee beans. However, this method also has disadvantages, as long as no specific and costly measures are taken against these disadvantages.

[0011] The first disadvantage is that, in addition to caffeine, other non-polar coffee inclusions are also extracted from the green coffee beans. These particularly include non-polar components, the so-called flavorings or aromatics, which are sometimes also important for the flavor of coffee. That is, the (direct) extraction of caffeine from green coffee beans with an organic non-polar solvent causes other coffee inclusions to be extracted from the green coffee beans in addition to caffeine. Therefore, with regard to maintaining flavor characteristics in the obtained decaffeinated green coffee beans and their subsequent products, this decaffeination method is not as good as a decaffeination method using a highly selective extraction agent, such as liquid carbon dioxide.

[0012] The second disadvantage of decaffeination methods in which an organic solvent, such as DCM or ethyl acetate, is used as the extraction agent and comes into direct contact with the green coffee beans lies in the unfavorable extraction properties of the obtained subsequent products. Here, in particular in subsequent products in the form of a single-portion system, such as coffee capsules, very long extraction times are usually observed, which can cause complete blockage of the coffee machine.

[0013] Another disadvantage lies in the perception of the consumer. Although decaffeination methods in which an organic solvent, such as DCM or ethyl acetate, is used as the extraction agent and comes into direct contact with the green coffee beans are in principle harmless due to the low residual content of the solvent used after roasting, consumers sometimes still have a bad perception of it, which causes disadvantages in the marketing of the product.

[0014] Decaffeination by means of liquid carbon dioxide, while resulting in a coffee product with high flavor quality due to the high selectivity of the extractant for caffeine, also has certain disadvantages. These disadvantages include, in particular, the high energy and cost-intensive consumption required to extract the desired amount of caffeine from green coffee beans. For this reason too, the decaffeination method by means of liquid carbon dioxide is only very rarely carried out on a large scale. Decaffeination by means of supercritical carbon dioxide is also only very rarely carried out because this method is also very cost-intensive.

[0015] The decaffeination process using an aqueous extraction solution mainly extracts polar inclusions from green coffee beans, causing polar coffee inclusions such as acids, minerals, and polar aromatics (e.g., chlorogenic acids, amino acids, sugars, and water-soluble peptides) to transfer into the aqueous extraction solution. Caffeine is extracted from green coffee beans with only low selectivity. Non-polar aromatics, vitamins, lipids, and other characteristic components of green coffee remain largely in the green coffee beans. Thus, in the aqueous extraction method, a mixture of the extracted coffee inclusions is always obtained.

[0016] Currently, essentially two methods are used in the industry to separate caffeine from the aqueous extraction solution.

[0017] The first method consists in subjecting the caffeine-containing aqueous extraction solution to liquid-liquid extraction with an organic solvent such as dichloromethane (DCM). This method is disadvantageous in that the aqueous extraction solution comes into direct contact with the organic solvent such as DCM. DCM is appreciably soluble in water, such that during liquid-liquid extraction, a certain fraction of DCM transfers into the aqueous extraction solution. If this method is carried out in a simple cycle, i.e., after liquid-liquid extraction with DCM, the aqueous extraction solution is again passed through the green coffee beans, the DCM dissolved in the aqueous extraction solution comes into direct contact with the green coffee beans. For the reasons stated above, this is undesirable and disadvantageous. In addition, during liquid-liquid extraction with an organic solvent such as dichloromethane (DCM), a large amount of the solvent is disadvantageously required to sufficiently remove the caffeine from the aqueous extraction solution.

[0018] The second method for removing caffeine from an aqueous extraction solution consists in using an adsorbent to adsorb caffeine from the aqueous extraction solution. For this purpose, known methods particularly utilize activated carbon filters, to which caffeine binds. However, it is particularly disadvantageous here that subsequently, the caffeine can be separated (desorbed) from the adsorbent very poorly or not at all, such that isolating the caffeine or a caffeine extract is difficult or not feasible. In addition, a significant share of other valuable coffee inclusions also binds to the adsorbent material used and is not further utilized, i.e., in particular, not fed back to the decaffeinated green coffee beans. This ultimately results in an unfavorable loss of quality of the obtained decaffeinated green coffee beans. The adsorbent used usually can also only be used once, which is undesirable in economic and ecological terms.

[0019] Methods are known in which an adsorbent material is used to adsorb substances contained in an aqueous extraction liquid. Some of these processes are listed below:

[0020] WO 2014 / 072282 A1 discloses a process for obtaining caffeine and bioactive substances from coffee by bringing a coffee extract into contact with an adsorbent in order to adsorb the caffeine and the bioactive substances, and subsequently obtaining the adsorbed substances by bringing the adsorbent into contact with an aqueous solution, and collecting at least two fractions of the aqueous solution.

[0021] DE 2600492 A1 discloses a method for decaffeinating an aqueous extract of plant material, which is carried out by bringing the extract into contact with a hydrophobic polymer resin having a dipole moment of less than about 2.0 Debye, whereby the caffeine and other soluble constituents are adsorbed by the resin; separating the resin and the decaffeinated extract; and leaching the resin together with the caffeine adhering thereto and other soluble constituents adhering thereto with water in order to remove the caffeine.

[0022] DE 2832267 A1 discloses a method for removing caffeine from green coffee beans, in which the beans are extracted with an aqueous liquid and the obtained extract is treated with a synthetic polymer resin which preferably adsorbs caffeine, characterized in that the synthetic polymer resin to be used is of the type which can be obtained by polymerization or copolymerization of an aromatic ring system and a monomer containing an acid group, and thereby, the ratio of the total adsorption capacity for caffeine to the total ion exchange capacity is also greater than about 1 and less than about 25 and preferably between 5 and 15. A method for regenerating the caffeine-loaded resin is further disclosed, which is characterized in that first, the loaded resin is rinsed with water at a temperature between 0 °C and room temperature in the case of extracting the desired percentage of solids other than caffeine, and then, the loaded resin is rinsed with water at a temperature between 50 °C and 100 °C in the case of extracting the desired percentage of caffeine.

[0023] EP 0 776 607 B1 discloses an application of a caffeine molecularly imprinted polymer for decaffeinating coffee extracts, and a method for extracting caffeine from an aqueous extract obtained from green coffee beans or roasted coffee beans, in which the extract is contacted with the imprinted polymer which has non-covalent recognition sites for caffeine and is capable of selectively removing caffeine from the aqueous extract, thereby removing caffeine from the extract.

[0024] GB 1 488 340 A discloses a method for decaffeinating green coffee by means of an extractant having high specificity for caffeine, wherein the extractant is an aqueous extraction solution containing soluble components other than caffeine in green coffee.

[0025] EP 0 612 744 B1 discloses a method for decaffeinating green coffee and a method for recovering caffeine from caffeine-loaded activated carbon. The recovery of caffeine from caffeine-loaded activated carbon is carried out by contacting the caffeine-loaded activated carbon with methyl ethyl ketone, ethyl acetate, dichloromethane or a mixture composed of methyl ethyl ketone and ethyl acetate.

[0026] FR 2 433 359 A1 discloses a method for decaffeinating green coffee or roasted coffee and a method for removing caffeine from an aqueous coffee extract by means of an adsorption resin, in which other solids extracted from coffee in addition to caffeine are also adsorbed onto the adsorption resin used.

[0027] However, the disclosed water decaffeination methods have certain disadvantages.

[0028] One of these disadvantages is that, in some cases, the adsorbent material has to be manufactured very expensively and resource - consumingly; thus, the process has not been implemented on a large scale so far (see EP 0 776607B1).

[0029] Furthermore, while the disclosed methods or adsorbent materials mentioned are suitable for removing caffeine from aqueous extraction solutions, none of the methods mentioned are sufficient to provide caffeine or a caffeine extract as a valuable product. In particular, (selectively) desorbing the caffeine bound to the adsorbent material is a major challenge. Thus, when treating the adsorbent material as discussed in some cases, the bound caffeine is not selectively removed, but rather a mixture of caffeine and other coffee inclusions is removed. In some methods, resource - consuming and thus inefficient schemes are used, where the adsorbent material is rinsed multiple times with water at different temperatures. Thus, although the rinse fractions obtained in this way have a certain caffeine concentration gradient, such a scheme does not seem suitable for large - scale standards. To date, this renders the aqueous extraction method for separating caffeine from the extract of the adsorbent material disadvantageous.

[0030] Therefore, there is still a need in the industry for a decaffeination method for preparing decaffeinated green coffee beans that is not only efficient but also meets the growing requirements of consumers. Ideally, not only should decaffeinated green coffee beans of high flavor quality be preparable here, but also caffeine or a caffeine extract should be preparable as a product. The main object of the present invention is to provide such a method and a corresponding device for preparing decaffeinated green coffee beans, and to mitigate or eliminate the disadvantages of known methods. Other objects of the present invention are related to the main object; they follow from the following description. Summary of the Invention

[0031] The main object and other objects are achieved by the present invention. The present invention in its various aspects and categories particularly relates to:

[0032] - A method for preparing decaffeinated green coffee beans,

[0033] - A corresponding device for preparing decaffeinated green coffee beans in a method according to the present invention,

[0034] - The application of the device according to the present invention,

[0035] - The application of dichloromethane for removing caffeine from an adsorption resin,

[0036] And

[0037] - The application of an adsorption resin in a specific method for preparing decaffeinated green coffee beans.

[0038] With the aid of the present invention, it has been particularly successful to provide a method which meets the high requirements of the coffee industry and consumers and which also provides high-quality decaffeinated green coffee beans in an efficient and economic manner, which green coffee beans can be further processed into corresponding subsequent products of the same high quality.

[0039] Particular embodiments, aspects or features described or described as preferred in connection with one of the aspects and categories of the present invention respectively also correspondingly or meaningfully apply to the other aspects and categories respectively, and vice versa.

[0040] Unless it is not feasible or otherwise stated in individual cases, the aspects, categories and preferred embodiments of the present invention are suitable for and are designed for combination with other aspects, categories or preferred embodiments of the present invention. The combinations of what are respectively called preferred aspects or embodiments with one another respectively again result in preferred aspects or embodiments of the present invention.

[0041] According to a main aspect of the present invention, the object and problem posed above are achieved by a method for preparing decaffeinated green coffee beans, the method having the following steps:

[0042] (S1) bringing a quantity of caffeinated green coffee beans into contact with an aqueous extractant such that caffeine is extracted from the caffeinated green coffee beans into the extractant,

[0043] (S2) bringing the caffeine-rich aqueous extract obtained in step S1 into contact with an adsorption resin such that the caffeine in the extract binds to the adsorption resin,

[0044] (S3) bringing the adsorption resin loaded with caffeine obtained in step S2 into contact with dichloromethane such that the caffeine dissolves in the dichloromethane.

[0045] The method includes the steps proposed, however other method steps can be carried out before, after or between these steps. A person skilled in the art selects additional steps and / or intermediate steps according to the individual case.

[0046] Decaffeinated green coffee beans are prepared by means of the method according to the present invention. The term "decaffeinated" has its common meaning. Thus, in the present context, the term "decaffeinated green coffee beans" is understood to mean green coffee beans having a caffeine content of less than one gram of caffeine per kilogram of dry coffee mass (see German regulation "KaffeeV 2001"); the caffeine content is reduced here compared to untreated (naturally occurring) green coffee beans. Thus, the green coffee beans subjected to the method have a lower caffeine content after the method has been carried out than before the method according to the present invention was carried out.

[0047] The term "green coffee beans" means coffee beans from which the outer skin and pulp (so-called "pulp") and the parchment and the mucilage (Schleim) thereon have been removed. According to the invention, any green coffee beans (Arabica coffee beans, Robusta coffee beans, etc.) can be used. The green coffee beans can be pre-puffed or non-pre-puffed.

[0048] In this context, the term "aqueous extract" is understood to mean a liquid containing water, preferably consisting of at least 50% by weight, preferably at least 75% by weight of water.

[0049] In the method according to the invention, in step (S1) the aqueous extract is brought into contact with a quantity of caffeine-containing green coffee beans, i.e. into direct contact with the green coffee beans. The contact is effected such that the aqueous extract extracts caffeine from the caffeine-containing green coffee beans. A person skilled in the art can generally select suitable process parameters for this and also for other process steps, in particular temperature, pressure, contact duration, quantity of aqueous extract, etc.

[0050] In this context, the term "extraction" is understood to mean the separation of one or more substances from an extraction material (i.e. in particular from the green coffee beans to be extracted according to the invention) by means of a suitable extractant, in particular by means of an aqueous extract in step (S1).

[0051] In this context, the term "adsorption resin" is understood to mean a polymeric solid that can adsorb substances. In connection with steps (S2) and (S3) of the method according to the invention, this term specifically denotes the following resin: the resin is capable of adsorbing caffeine and, if necessary, other coffee constituents, and of desorbing the bound caffeine again when brought into contact with dichloromethane, such that the caffeine dissolves in the dichloromethane. Such specifically suitable adsorption resins are commercially available and can be identified by a person skilled in the art on the basis of simple common preliminary tests and evaluated with respect to their adsorption or desorption properties.

[0052] The term "caffeine-loaded adsorption resin" means that the adsorption resin is loaded with a quantity of caffeine, i.e. the adsorption resin has adsorbed a quantity of caffeine. Compared with the adsorption resin used in step S2 and brought into contact with the caffeine-rich aqueous extract, the caffeine-loaded adsorption resin obtained in step S2 contains an increased concentration of adsorbed, i.e. adsorption-bound, caffeine. In step (S3), the caffeine dissolves from the loaded adsorption resin into the dichloromethane; thereby the adsorption resin is depleted of the loaded caffeine.

[0053] In order to overcome the above-mentioned disadvantages of the methods for preparing decaffeinated green coffee beans known from the prior art and to provide a particularly efficient method for preparing decaffeinated green coffee beans, the inventors have given extensive consideration and conducted research. Here, the inventors have faced various challenges and had to overcome the prejudices from the prior art.

[0054] In the process of formulating the present invention, the inventors have decided that green coffee beans should not or at least should not be directly contacted with an organic solvent, such as dichloromethane (DCM), within an important range. At the same time, the inventors hope to utilize the solubility of caffeine in dichloromethane in an advantageous manner.

[0055] When striving to avoid the above-mentioned disadvantages of liquid-liquid extraction of caffeine from an aqueous extract with DCM, the inventors use a suitable adsorption resin as a "caffeine reservoir" and, in short, have developed a new and technically advantageous two-stage extraction sequence "liquid-solid" (aqueous extract / adsorption resin) plus "solid-liquid" (loaded adsorption resin / DCM) to remove and obtain caffeine from the aqueous extract. The two-stage extraction sequence corresponds to steps (S2) and (S3) of the method according to the present invention.

[0056] Surprisingly, it has been confirmed that

[0057] i) The adsorption resin can not only bind the caffeine from the caffeine-rich aqueous extract in step (S2) according to the present invention

[0058] but also

[0059] ii) The caffeine can be (selectively) output to dichloromethane in step S3 according to the present invention.

[0060] The present invention particularly utilizes the following technical situation: (different from other polar inclusions in green coffee) caffeine is not only readily soluble in warm water but also readily soluble in dichloromethane. In the method according to the present invention, neither the green coffee beans themselves nor the caffeine-rich aqueous extraction solution is directly contacted with dichloromethane. Thereby, the aqueous extract is completely or at least to a large extent prevented from being contaminated by dichloromethane. This is a particularly important aspect of the present invention, especially with regard to the disadvantage of the residual amount of organic solvent in the coffee product described above.

[0061] Desorbing the caffeine bound to the adsorption resin with dichloromethane in step S3 according to the present invention as defined above also causes the caffeine to be removed or unloaded from the adsorption resin, so that it can be reused in step S2. That is to say, the adsorption resin can be reused (and multiple times) to (selectively) bind caffeine from the aqueous extract and then (selectively) output the caffeine to dichloromethane.

[0062] Advantageously, after selectively desorbing the caffeine bound to the adsorption resin with dichloromethane in step S3, the single or multiple, preferably multiple, particularly preferably all coffee inclusions that are not caffeine and are present in the caffeine-rich aqueous extract obtained in step S1 remain substantially bound to the adsorption resin. Subsequently, after step S3, the adsorption resin is pre-loaded with the single or multiple coffee inclusions that are not caffeine, wherein the coffee inclusions are preferably selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants. Thus, the adsorption resin pre-loaded in this way has an increased selectivity for the adsorption of caffeine from the caffeine-rich aqueous extract when reused (multiple times) in (a renewed) step S2.

[0063] Preferably, in the process according to the invention (as described above, preferably as the process referred to as preferred above), in step S3, the caffeine-loaded adsorption resin obtained in step S2 is brought into contact with dichloromethane such that 50% by weight or more, preferably 60% by weight or more, preferably 70% by weight or more, preferably 80% by weight or more, preferably 90% by weight or more, preferably 95% by weight or more, preferably 99% by weight or more of the caffeine bound to the adsorption resin in step S2 is dissolved in the dichloromethane. Here, the statements in weight percentages (% by weight) relate respectively to the total mass of the caffeine bound to the adsorption resin in step S2. A person skilled in the art selects a suitable time period and temperature for step S3 for this purpose.

[0064] Preferably, after contact with dichloromethane according to step S3, the coffee inclusions that are not caffeine and are contained in the caffeine-rich aqueous extract obtained in step S1 remain bound to the adsorption resin in large amounts such that when the adsorption resin obtained in step S3 is reused (multiple times) in the process according to the invention, in step S2, only 15% by weight or less, preferably 10% by weight or less, preferably 5% by weight or less, preferably 1% by weight or less of the same coffee inclusions are bound to the adsorption resin. The statements in weight percentages (% by weight) relate respectively to the total amount of the coffee inclusions that are not caffeine in the caffeine-rich aqueous extract obtained in step S1. A person skilled in the art selects a suitable time period and temperature for step S3 for this purpose.

[0065] Preferably, the share of caffeine in the mixture consisting of all solids bound to the adsorption resin in step S2 is 40% by weight or more, preferably 50% by weight or more, preferably 60% by weight or more, preferably 70% by weight or more, preferably 80% by weight or more, preferably 90% by weight or more, preferably 99% by weight or more. The statements in weight percentages (% by weight) relate respectively to the total mass of all solids adsorbed to the adsorption resin in step S2.

[0066] Preferably, the share of coffee inclusions other than caffeine contained in the caffeine-rich aqueous extract obtained in step S1 in the mixture consisting of all solids adsorbed to the adsorption resin in step S2 is 60% by weight or less, preferably 50% by weight or less, preferably 40% by weight or less, preferably 30% by weight or less, preferably 20% by weight or less, preferably 10% by weight or less, preferably 1% by weight or less. The statements in weight percentages (% by weight) relate respectively to the total mass of all solids adsorbed to the adsorption resin in step S2.

[0067] Advantageously, the adsorption resin obtained after step S3 is rich in coffee inclusions other than caffeine. Compared with the adsorption resin that has not undergone steps S2 and S3, such pre-loaded adsorption resin has an increased adsorption selectivity for caffeine. Using the corresponding pre-loaded adsorption resin can achieve the removal of caffeine from the caffeine-rich aqueous extract obtained in step S1 with particularly high selectivity.

[0068] The aqueous extract is preferably recycled after step S2. Thus, the aqueous extract is preferably used to re-extract (multiple times) caffeine from green coffee beans. Since the aqueous extract contains caffeine and other coffee inclusions after step S1, and since the aqueous extract can transfer a large amount of caffeine to the adsorption resin when in contact with the pre-loaded adsorption resin, but can only transfer a small amount of other (non-caffeine) coffee inclusions to the adsorption resin, relatively few other coffee inclusions are extracted from the green coffee beans when the aqueous extract present after step S2 is reused in (repeated) step S1. This is particularly advantageous. Thus, the method according to the invention is advantageous, wherein an aqueous extract is used in step S1, the aqueous extract being obtained from step S2 of a previously experienced step S1 and S2 of the method and comprising one or more coffee inclusions other than caffeine.

[0069] The method according to the invention enables the preparation of high-quality decaffeinated green coffee beans using a (multi-)recycled aqueous extract. By means of the method according to the invention, the caffeine content of the green coffee beans is significantly reduced. The coffee inclusions, which are particularly important for the flavor and aroma of coffee, remain in the decaffeinated green coffee beans, and it is also possible to avoid contaminating the decaffeinated green coffee beans with dichloromethane during the recycling of the aqueous extract.

[0070] Advantageously, the dichloromethane solution rich in caffeine obtained after step S3 has a high concentration of caffeine and at the same time a low concentration of other coffee inclusions. Because dichloromethane cannot dissolve in significant amounts the polar coffee inclusions that may be extracted by the aqueous extract and bound by the adsorption resin. Therefore, this is particularly important because caffeine and caffeine extracts are also important valuable substances or valuable marketable products (for example, as food additives or for pharmaceutical products). That is to say, the method according to the invention is particularly economical because in a manner that can be well achieved in terms of process technology, not only one, but two high-quality and valuable products can be prepared, namely decaffeinated green coffee beans (the first product) and caffeine or caffeine extracts (the second product).

[0071] Preferably, the method according to the invention is a method carried out continuously or semi-continuously or periodically, in which one or more components are recycled (transported in a loop) and / or reused.

[0072] Preferably, in the method according to the invention, step S1 and / or step S2 and / or step S3 are carried out multiple times, and preferably the adsorption resin is replaced only after one or more of the steps have been carried out multiple times. When step S1 is carried out multiple times, preferably a plurality of batches of freshly supplied green coffee beans containing caffeine are brought into contact with the aqueous extract, so that caffeine is respectively extracted from the green coffee beans containing caffeine into the extract.

[0073] Preferably, in the method according to the invention, step S1 and / or step S2 and / or step S3 are carried out at least twice, preferably at least three times, preferably at least four times, preferably more than four times. In this regard, the adsorption resin is also replaced only after one or more of the steps have been carried out multiple times (twice, three times, four times or more than four times).

[0074] Preferably, in the method according to the invention, all steps S1, S2 and S3 are carried out multiple times (at least twice) successively.

[0075] Preferably, in the method according to the invention, all steps S1, S2 and S3 are carried out at least twice, preferably at least three times, preferably at least four times, preferably more than four times successively.

[0076] In the method according to the invention, when steps S1 and S2, preferably steps S1, S2 and S3 are carried out multiple times (at least twice), preferably the aqueous extract or the treatment product of the aqueous extract is recycled (conveyed in a circuit) one or more times, preferably multiple times (at least twice) after carrying out step S2, and it is used as the aqueous extract for extracting caffeine from the caffeine-containing green coffee beans when step S1 is carried out again (preferably with a fresh batch of caffeine-containing green coffee beans). By carrying out step S2 multiple times (at least twice), a relatively large amount of caffeine and a relatively small amount of coffee inclusions that are not caffeine are removed from the extract obtained in step S1, preferably recycled, and are bound to the (pre-loaded) adsorption resin. Thus, a relatively large amount of coffee inclusions that are not caffeine remain in the aqueous extract and are recycled together with the aqueous extract; thus, such an extract rich in coffee inclusions that are not caffeine has a reduced absorption capacity for coffee inclusions that are not caffeine when contacting the green coffee beans in a new step S1 (compared to an aqueous extract that does not contain such coffee inclusions). Due to the presence of coffee inclusions that are not caffeine, the selectivity of the recycled extract for extracting caffeine is preferably increased (this generally applies to all aspects of the present invention). Therefore, by preferably recycling the aqueous extract or its treatment product multiple times (at least twice) after carrying out step S2, a relatively large amount of caffeine and a relatively small amount of other coffee inclusions that are not caffeine are selectively extracted from the caffeine-containing green coffee beans into the extract each time step S1 is carried out again. Preferably, when step S1 is carried out multiple times (at least twice), no additional amount of coffee inclusions that are not caffeine is extracted from the caffeine-containing green coffee beans into the extract.

[0077] In the method according to the invention, when steps S1, preferably steps S1 and S2, particularly preferably steps S1, S2 and S3 are carried out multiple times (at least twice), preferably the coffee beans are replaced or supplemented with fresh caffeine-containing green coffee beans (periodic charging) after each execution of step S1. That is to say, each time step S1 is carried out again, caffeine is extracted from the caffeine-containing green coffee beans into the extract by means of an aqueous, preferably recycled, particularly preferably recycled multiple times (at least twice) extract.

[0078] In the method according to the present invention, when steps S2 and S3, preferably steps S1, S2 and S3 are carried out multiple times (at least twice), preferably after carrying out step S3, the adsorption resin is reused once or multiple times, preferably multiple times (at least twice). After the first execution of steps S1, S2 and S3, the adsorption resin is already pre-loaded with one or more coffee inclusions that are not caffeine, which are selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants, so as to prevent the corresponding coffee inclusions in the caffeine-containing extract obtained in step S1 from binding to the adsorption resin or making it difficult. In other words: compared with the non-pre-loaded adsorption resin, due to being pre-loaded with adsorbed coffee inclusions that are not caffeine, the selectivity of the adsorption resin for adsorbing caffeine is preferably increased (this generally applies to all aspects of the present invention).

[0079] Therefore, by preferably reusing the adsorption resin multiple times (at least twice) after step S3, caffeine in the caffeine-containing extract obtained in step S1 is bound to the adsorption resin with relatively high selectivity. That is to say, by reusing, preferably reusing multiple times (at least twice) the adsorption resin after step S3, in the second execution of step S2 and each additional execution of step S2, a relatively large amount of caffeine in the aqueous extract has been bound to the adsorption resin together with a relatively small amount of other coffee inclusions that are not caffeine. Preferably, when step S2 is carried out multiple times (at least twice), in the case of reusing the adsorption resin after the respective subsequent step S3, no additional amount of coffee inclusions that are not caffeine in the aqueous extract is bound to the adsorption resin.

[0080] A particularly preferred method according to the present invention is a method for preparing decaffeinated green coffee beans, the method having the following steps:

[0081] (S1) bringing a certain amount of caffeine-containing green coffee beans into contact with an aqueous extract so that caffeine is extracted from the caffeine-containing green coffee beans into the extract,

[0082] (S2) bringing the caffeine-rich aqueous extract obtained in step S1 into contact with an adsorption resin so that the caffeine in the extract binds to the adsorption resin,

[0083] (S3) bringing the adsorption resin loaded with caffeine obtained in step S2 into contact with dichloromethane so that the caffeine dissolves in the dichloromethane.

[0084] Steps S1, S2 and S3 are carried out successively multiple times (at least twice), preferably at least three times, preferably at least four times, preferably more than four times, and preferably after each execution of step S1, the green coffee beans containing caffeine are replaced or supplemented with fresh ones in step 1.

[0085] and / or

[0086] wherein the aqueous extract obtained in step S2 or the processed product of the extract is recycled and used as the aqueous extract when step S1 is carried out again.

[0087] and / or

[0088] wherein preferably, the adsorption resin is reused after step S3 is carried out.

[0089] Preferably, in the method according to the present invention, the aqueous extract obtained in step S2 or the processed product of the extract is recycled multiple times (at least twice), preferably at least three times, preferably at least four times, preferably more than four times, and used as the aqueous extract when step S1 is carried out again.

[0090] Preferably, in the method according to the present invention, after step S3 is carried out, the adsorption resin is reused multiple times (at least twice), preferably at least three times, preferably at least four times, preferably more than four times.

[0091] In summary, the inventors have successfully combined the important advantages of known decaffeination methods with each other without having to bear the corresponding disadvantages existing for individual methods.

[0092] Preferably, in the method according to the present invention (as described above, preferably as the method called preferred above), an adsorption resin pre-loaded with one or more coffee inclusions other than caffeine is used in step S2, and the coffee inclusions are selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants, so as to prevent the corresponding coffee inclusions in the caffeine-containing extract obtained in step S1 from binding to the adsorption resin or making it difficult.

[0093] It has been confirmed that if an adsorption resin pre-loaded with one or more of the above coffee inclusions is used herein, step (S2) is particularly efficient.

[0094] When using such an adsorption resin pre-loaded with one or more of the above coffee inclusions, in step S2, it is prevented that the corresponding (different from caffeine) coffee inclusion in the caffeine-containing extract obtained in step S1 binds (adsorbs) to the adsorption resin or at least significantly makes it difficult. Therefore, the coffee inclusion (at least substantially) remains in the aqueous extract and is preferably reused together with the aqueous extract in step S1. In contrast, caffeine is bound by the adsorption resin in step S2.

[0095] Particularly preferred is the method according to the invention, wherein

[0096] i) In step S1, an aqueous solution is used, the aqueous solution comprising one or more coffee inclusions that are not caffeine, the coffee inclusions being selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants,

[0097] and

[0098] ii) In step S2, an adsorption resin pre-loaded with one or more coffee inclusions that are not caffeine is used, the coffee inclusions being selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants.

[0099] The particularly preferred design has the following effects:

[0100] i) In step S1, caffeine is (selectively) extracted from the caffeine-containing green coffee beans into the aqueous extract, while other water-soluble coffee inclusions that are particularly important for the flavor and aroma of coffee are not extracted or only slightly extracted and thus remain in the decaffeinated green coffee beans,

[0101] and

[0102] ii) In step S2, caffeine is (selectively) bound or adsorbed to the pre-loaded adsorption resin, while other water-soluble coffee inclusions that are particularly important for the flavor and aroma of coffee are not adsorbed or only slightly adsorbed and thus remain in the aqueous extraction solution.

[0103] Particularly preferred is the method according to the invention, the method having the following additional step:

[0104] (Before S2) Prepare or provide an adsorption resin pre-loaded with one or more coffee inclusions that are not caffeine, the coffee inclusions being selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants.

[0105] The step (before S2) preferably includes one or more of the following measures:

[0106] - Preparing or providing an aqueous solution comprising one or more coffee inclusions other than caffeine, said coffee inclusions being selected from acids, minerals, aromatics, compounds convertible into aromatics by the Maillard reaction, and antioxidants; the prepared or provided aqueous solution preferably does not include caffeine or includes less than 300 mg of caffeine per liter of the aqueous solution, preferably less than 100 mg of caffeine per liter of the aqueous solution;

[0107] - Preparing or providing an adsorption resin;

[0108] - Contacting the prepared or provided aqueous solution comprising one or more coffee inclusions other than caffeine, said coffee inclusions being selected from acids, minerals, aromatics, compounds convertible into aromatics by the Maillard reaction, and antioxidants, with the prepared or provided adsorption resin, so as to obtain an adsorption resin pre-loaded with one or more coffee inclusions other than caffeine, said coffee inclusions being selected from acids, minerals, aromatics, compounds convertible into aromatics by the Maillard reaction, and antioxidants.

[0109] Particularly preferably, a pre-loaded adsorption resin is used, which is saturated with one or more coffee inclusions other than caffeine, said coffee inclusions being selected from acids, minerals, aromatics, compounds convertible into aromatics by the Maillard reaction, and antioxidants. Saturation herein means that the pre-loaded saturated adsorption resin cannot further bind the substances mentioned. Preferably, the method according to the invention (as described above, preferably as the method called preferred above), wherein in step S1, as the aqueous extract

[0110] - Using water

[0111] or

[0112] - Using an aqueous solution comprising one or more coffee inclusions other than caffeine, said coffee inclusions being selected from acids, minerals, aromatics, compounds convertible into aromatics by the Maillard reaction, and antioxidants, so as to prevent or make it difficult for the corresponding coffee inclusions in the caffeinated green coffee beans to be extracted into the extract.

[0113] Within the scope of the present invention, the (water-soluble) aromatics and / or compounds convertible into aromatics by the Maillard reaction comprised in the aqueous solution are preferably selected from chlorogenic acids, amino acids, sugars, and water-soluble peptides.

[0114] In a particularly preferred method according to the invention, in step S1, a quantity of green coffee beans containing caffeine is brought into contact with an aqueous extraction liquid, wherein as the aqueous extraction liquid there is used an aqueous solution which comprises single or multiple coffee inclusions other than caffeine, the coffee inclusions being selected from acids, minerals, aromatics, compounds which can be converted into aromatics by the Maillard reaction, and antioxidants. Using such an aqueous solution comprising coffee inclusions causes the corresponding substances in the green coffee beans containing caffeine not to be extracted into the aqueous solution or to be made significantly more difficult. Thus, the green coffee beans are selectively extracted such that caffeine is transferred into the aqueous extraction liquid, whereas other coffee inclusions are not transferred or are only transferred in small amounts into the aqueous extraction liquid.

[0115] Here, the aqueous solution used in step S1 is preferably saturated with one or more of the above-mentioned coffee inclusions.

[0116] Preferably using such an aqueous extraction liquid which comprises single or multiple coffee inclusions and which is preferably saturated with one or more coffee inclusions causes that, when carrying out the extraction in accordance with step S1 of the method according to the invention, (especially in terms of sensory properties) valuable water-soluble coffee inclusions remain in the green coffee beans and are not transferred into the extraction liquid. This causes the obtained decaffeinated green coffee beans to have a particularly high quality.

[0117] The method according to the invention can be carried out continuously, semi-continuously or discontinuously (as a batch process). A continuous or semi-continuous method control in which at least part of the process flow of the method is carried out without interruption over a longer period of time is preferred for industrial purposes.

[0118] In the method according to the invention, method step S1 is preferably carried out semi-continuously (batchwise (halb-kontinuierlich)).

[0119] Particularly preferably, method step S1 is carried out semi-continuously, wherein (i) the aqueous extraction liquid is circulated and brought into contact with the green coffee beans multiple times, (ii) or the aqueous extraction liquid is brought into contact with the green coffee beans, acts for a certain time, and is then only released via the adsorption resin. In a semi-continuous method, the composition of the aqueous extraction liquid used can change to a certain extent. For example, the aqueous extraction liquid used in step S1 can be pure water at the start of the method and can be converted into an aqueous solution comprising single or multiple coffee inclusions (especially the above-mentioned coffee inclusions other than caffeine) when step S1 is carried out multiple times within the scope of the semi-continuous method. As the method continues, the concentration of the single or multiple coffee inclusions mentioned above in the aqueous extraction solution increases.

[0120] Preferably, in the aqueous extraction solution used in step S1, the caffeine content is less than 300 mg per liter of the aqueous extraction solution, and particularly preferably less than 100 mg per liter.

[0121] Particularly preferred is the method according to the invention, wherein in step S1, an aqueous solution comprising one or more coffee inclusions other than caffeine is used as the aqueous extraction solution, and the coffee inclusions are selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants, and the aqueous extraction solution is prepared before the start of step S1. A person skilled in the art can particularly prepare such an aqueous extraction solution by mixing (the above-mentioned) known water-soluble coffee inclusions (other than caffeine) with water; however, an aqueous extraction solution prepared by means of extracting green coffee beans and treating the liquid aqueous extract in a previously performed method according to the invention or other methods can also be used.

[0122] Therefore, in a particularly preferred design of the method according to the invention, the aqueous solution used in step S1 is an aqueous extraction solution obtained from a previously performed method according to the invention, preferably an aqueous extraction solution having a caffeine content of less than 300 mg per liter of the aqueous extraction solution, particularly preferably less than 100 mg per liter of the aqueous extraction solution, and most particularly preferably a caffeine-free aqueous extraction solution.

[0123] Preferred is the method according to the invention (as described above, preferably as the method referred to as preferred above), wherein in step S2

[0124] - using a macroporous adsorption resin selected from polystyrene, polydivinylbenzene, and copolymers thereof with each other and other monomers,

[0125] wherein the macroporous adsorption resin is preferably polystyrene or a copolymer of polystyrene, preferably crosslinked polystyrene, particularly preferably divinylbenzene-crosslinked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene-crosslinked polystyrene,

[0126] and / or (preferably "and")

[0127] - binding at least 90%, preferably at least 95%, and most particularly preferably at least 99% of the caffeine in the extraction solution containing caffeine to the adsorption resin.

[0128] It has been confirmed within the scope of its own experimental studies that the adsorption resin used in step S2 is preferably a macroporous adsorption resin, and the macroporous adsorption resin preferably has an average pore diameter greater than 5 nm. When using a macroporous adsorption resin, not only is caffeine adsorbed particularly efficiently from the aqueous extraction solution containing caffeine, but caffeine is also desorbed particularly efficiently by means of DCM.

[0129] The macroporous adsorption resin is herein selected from polystyrene, polydivinylbenzene, and copolymers thereof with one another and other monomers. Polystyrene, polydivinylbenzene, and copolymers thereof with one another and other monomers are characterized in particular by having good solvent compatibility, and this is the case not only with respect to aqueous extraction solutions, but also with respect to DCM. In addition, the above polymer materials are characterized in that they are thermally stable in a wide temperature range up to 150 °C.

[0130] It has also been shown in experimental studies that polystyrene or copolymers of polystyrene are very durable and stable within the scope of the method according to the invention, in particular within the scope of method steps S2 and S3. Thus, the material can be used multiple times and hardly loses its advantageous properties even by repeatedly performing method step S2 or S3.

[0131] The macroporous adsorption resin preferably used in step S2 is preferably polystyrene or a copolymer of polystyrene, particularly preferably crosslinked polystyrene, particularly preferably divinylbenzene-crosslinked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene-crosslinked polystyrene. In own studies (see examples further below) it has been confirmed that the adsorption resin is particularly well suited for use in the method according to the invention for producing decaffeinated green coffee beans described herein.

[0132] The method according to the invention is of course not limited to the preferred adsorption resins listed herein. The inventors have only determined that the preferred adsorption resins mentioned herein are particularly suitable for binding caffeine in an aqueous extraction solution and then releasing or desorbing it again upon contact with dichloromethane. It can be assumed that other adsorption resins known from the prior art are equally suitable for this. A person skilled in the art can determine by means of suitable preliminary experiments whether other adsorption resins are suitable for use in the method according to the invention. For this purpose, in particular, the adsorption affinity of the material under investigation for caffeine and the desorption characteristics of the bound caffeine upon contact with DCM must be taken into account.

[0133] Preferably, according to step S2 of the present invention, at least 90%, preferably at least 95%, and most preferably at least 99% of the caffeine in the extraction liquid containing caffeine binds to the adsorption resin (the so-called caffeine adsorption value). The amount of caffeine bound to the adsorption resin from the extraction liquid containing caffeine can be determined according to common analytical methods. For this purpose, it is particularly suitable to measure the caffeine content of the extraction liquid containing caffeine before contact with the adsorption resin and re-measure it after contact with the adsorption resin. To achieve the preferred caffeine adsorption value, those skilled in the art will particularly use an appropriate amount of a suitable adsorption resin. Particularly preferably, those skilled in the art will use the macroporous adsorption resin as described above. Those skilled in the art will also change the method parameters in a common manner and particularly set the temperature, pressure, and contact duration of the aqueous extraction liquid with the adsorption resin in a targeted manner. Of course, in the case of a larger amount of green coffee beans, those skilled in the art will also provide a larger amount of a suitable adsorption resin.

[0134] Preferably, according to the method of the present invention (as described above, preferably as the method referred to as preferred above), in step S3

[0135] - perform the contact such that at least 80%, preferably at least 90%, particularly preferably at least 95%, and most preferably at least 99% of the caffeine in the adsorption resin carrying caffeine dissolves into dichloromethane,

[0136] and / or

[0137] - the temperature of the dichloromethane is lower than 35°C, preferably lower than 30°C, and particularly preferably lower than 25°C.

[0138] It has been proven to be particularly advantageous to perform the contact in step S3 such that at least 80%, preferably at least 90%, particularly preferably at least 95%, and most preferably at least 99% of the caffeine in the adsorption resin carrying caffeine dissolves into dichloromethane. For those skilled in the art, suitable analytical methods are known for determining the concentration values of caffeine in dichloromethane listed herein. To set the above values, those skilled in the art select suitable method parameters in a common manner, which particularly include temperature, pressure, contact duration, and the amount of dichloromethane in contact with the adsorption resin carrying caffeine.

[0139] Surprisingly, it has been confirmed that the macroporous adsorption resin preferably used in step S2 is particularly well-suited for selectively releasing the previously adsorbed caffeine to dichloromethane upon contact with dichloromethane in step S3, and the macroporous adsorption resin is selected from polystyrene, polydivinylbenzene, and their copolymers with each other and other monomers.

[0140] The temperature of dichloromethane in step S3 can be varied within a wide range. However, it has been confirmed that good caffeine desorption is usually achieved at temperatures below 35 °C. Therefore, there is no need to heat dichloromethane and work under overpressure. Thus, in the method according to the invention, it is feasible to work with dichloromethane or a dichloromethane solution having a relatively low temperature. Thus, the low temperature of dichloromethane is particularly technically advantageous because dichloromethane has a low boiling point of only 39.8 °C and thus easily volatilizes.

[0141] Preferably, in the method according to the invention (as described above, preferably as the method referred to as preferred above), step S1 is carried out such that at least a predetermined amount of caffeine is extracted from a certain amount of green coffee beans containing caffeine.

[0142] When decaffeinating green coffee beans according to the invention, preferably a target value for the caffeine concentration in the decaffeinated green coffee beans to be prepared is specified. That is to say, in a preferred method according to the invention, the person skilled in the art can determine, before carrying out the method according to the invention, how much caffeine is to be extracted from a certain amount of green coffee beans containing caffeine. For example, the person skilled in the art can, for example, specify that a natural caffeine content of, for example, 1.2% in the green coffee beans containing caffeine present at the start of step S1 should be reduced to a value of at most 0.1% after carrying out step S1. Subsequently, the person skilled in the art can carry out step S1 according to the invention such that the target value selected by him is reached. For this purpose, the person skilled in the art can, in particular, carry out step S1 several times in a semi - continuous method such that the green coffee beans come into contact with the aqueous extraction liquid several times, which causes at least the previously defined, i.e. predetermined, amount of caffeine to be extracted from the green coffee beans containing caffeine into the extraction liquid.

[0143] Preferably, in the method according to the invention (as described above, preferably as the method referred to as preferred above), the decaffeinated green coffee beans obtained in step S1 are dried.

[0144] Drying the decaffeinated green coffee beans is a method step widely used in the preparation of decaffeinated coffee. Since the green coffee beans are not in direct contact with an organic solvent, such as DCM, in step S1, the dried decaffeinated green coffee beans do not contain an organic solvent or contain only a very small amount of an organic solvent. Therefore, the dried decaffeinated green coffee beans can be sold directly without further measures.

[0145] Preferably, in the method according to the invention (as described above, preferably as the method referred to as preferred above), the method comprises, after step S3, an additional step:

[0146] (S4) treating the adsorption resin,

[0147] (S4-1) To remove dichloromethane,

[0148] and / or (preferably "and")

[0149] (S4-2) To regenerate the loading capacity of the adsorption resin for caffeine under the conditions of step S2.

[0150] In step S3 of the method according to the invention, the caffeine-loaded adsorption resin obtained in step S2 is brought into contact with dichloromethane such that caffeine dissolves in dichloromethane. On the one hand, step S3 causes the dissolution of caffeine from the caffeine-loaded adsorption resin, but on the other hand, it also causes the adsorption resin to subsequently be surrounded by dichloromethane. In order to enable the adsorption resin used in step S3 to be reused again in step S2 of the method according to the invention, preferably operating semi-continuously, the dichloromethane is removed from the adsorption resin, preferably completely removed. Thus, direct contact between the aqueous extract and dichloromethane is avoided.

[0151] Treating the adsorption resin according to step S4-1 to (preferably completely) remove dichloromethane preferably includes one or more of the following measures:

[0152] - Treating the adsorption resin with liquid water or an aqueous solution at a water temperature of preferably at least 70 °C, particularly preferably at least 85 °C, such that DCM is removed from the adsorption resin, preferably from the pores of the adsorption resin,

[0153] - Treating the adsorption resin with steam such that DCM is removed from the adsorption resin, preferably from the pores of the adsorption resin.

[0154] Additional measures common in the art or repetition of measures are advantageous in some cases in order to remove dichloromethane from the adsorption resin as completely as possible.

[0155] Particularly preferably, the method according to the invention includes an additional method step S4-2, wherein step S4-2 is used to regenerate the loading capacity of the adsorption resin for caffeine under the conditions of step S2. That is, after step S4-2, the adsorption resin should be ready to be reloaded under the conditions of step S2, thereby (at least approximately) regaining the early loading capacity for caffeine again. Preferably, step S4-2 includes the following measures:

[0156] - Treating the adsorption resin with an aqueous alkaline solution, preferably an aqueous solution containing sodium hydroxide, at a temperature in the range of preferably 60 °C to 80 °C.

[0157] It has been confirmed in one's own research that it is advantageous to regenerate the adsorption resin used, so as to thereby restore or improve the loading capacity of the adsorption resin for caffeine under the conditions of step S2. In particular, when it is confirmed that the adsorption or desorption characteristics of the adsorption resin deteriorate over time, step S4-2 is carried out. Preferably, step S4-2 is carried out at fixed predetermined time intervals or time intervals related to the performance of the adsorption resin. Preferably, an aqueous alkaline solution, preferably an aqueous solution containing sodium hydroxide, has been proven to be suitable in one's own research at a temperature in the range of 60 °C to 80 °C, especially when using the adsorption resins referred to above as preferred (such as pre-loaded and / or macroporous).

[0158] Preferably, according to the method of the present invention (as described above, preferably as the method referred to above as preferred), wherein

[0159] The contact in step S2 includes overflowing the adsorption resin with the caffeine-rich aqueous extract obtained in step S1,

[0160] and / or (preferably "and")

[0161] The subsequent contact in step S3 includes overflowing the adsorption resin loaded with caffeine with dichloromethane.

[0162] Here, the contact in step S2 preferably includes overflowing the adsorption resin with the caffeine-rich aqueous extract obtained in step S1 along a defined first flow direction, and the subsequent contact in step S3 includes overflowing the adsorption resin loaded with caffeine with dichloromethane along a defined second flow direction. Generally, it is advantageous that the second flow direction is the opposite of the first flow direction. In other cases (especially related to the geometry of the adsorption unit), the first flow direction and the second flow direction are the same.

[0163] Preferably, not only the contact in step S2 but also the subsequent contact in step S3 is carried out by overflowing the adsorption resin or the adsorption resin loaded with caffeine accordingly, that is, overflowing with the caffeine-rich aqueous extract obtained in step S1 in step S2 or overflowing with dichloromethane in step S3.

[0164] Herein, the term "overflow" means guiding the solution through the adsorption resin or the adsorption resin loaded with caffeine along a specific flow direction. It has been confirmed that if the adsorption resin or the loaded adsorption resin is overflowed with the corresponding liquid, caffeine not only binds (adsorbs) to the adsorption resin particularly efficiently, but also redissolves (desorbs) from the loaded adsorption resin particularly efficiently.

[0165] In many cases, the contact in step S2 is effected by overflowing the adsorption resin with the caffeine-rich aqueous extract obtained in step S1 in a defined (first) flow direction, while in step S3 the subsequent contact of the caffeine-loaded adsorption resin with dichloromethane is effected in the opposite direction to said flow direction. For example, in the case of an adsorption column filled with adsorption resin arranged vertically, this means that the contact in step S2 (overflowing the adsorption resin with the caffeine-rich aqueous extract obtained in step S1) takes place, for example, from top to bottom, while the subsequent contact in step S3 (overflowing the caffeine-loaded adsorption resin with dichloromethane) takes place in the opposite direction, i.e. from bottom to top.

[0166] Said "countercurrent method" generally helps to desorb caffeine particularly efficiently (selectively), i.e. to redissolve the caffeine adsorbed on the adsorption resin in dichloromethane in step S3.

[0167] Preferably, when carrying out the contact in step S2 by overflowing the adsorption resin with the caffeine-rich aqueous extract obtained in step S1, at least 90%, preferably at least 95%, very particularly preferably at least 99% of the caffeine in the extract containing caffeine binds to the adsorption resin.

[0168] Preferably, when carrying out the contact in step S3 by overflowing the caffeine-loaded adsorption resin with dichloromethane, at least 80%, preferably at least 90%, particularly preferably at least 95%, very particularly preferably at least 99% of the caffeine in the caffeine-loaded adsorption resin dissolves in the dichloromethane.

[0169] Preference is given to a process according to the invention (as described above, preferably as the process called preferred above), in which

[0170] - the progress achieved in the extraction in step S1 and / or the loading of the adsorption resin with caffeine achieved in step S2 is determined,

[0171] and

[0172] as soon as a predetermined progress of the extraction in step S1 is reached and / or as soon as a predetermined loading of the adsorption resin with caffeine is reached in step S2, a transition is made, preferably automatically, from step S2 to step S3.

[0173] The progress achieved in the extraction in step S1 can be determined here by means of measures common in the art. For example, the progress achieved in the extraction in step S1 can be determined from the difference between the caffeine contained in the green coffee beans at the start of step S1 and the caffeine that has been extracted into the aqueous extraction solution or bound to the adsorption resin at a specific time. Alternatively, the progress achieved in the extraction in step S1 can be determined from the time course of the caffeine concentration in the aqueous extraction liquid in contact with the green coffee beans.

[0174] The loading of the adsorption resin with caffeine achieved in step S2 can likewise be determined directly or indirectly by means of measures common in the art. For example, within the scope of indirect determination, the concentration of caffeine in the aqueous extraction liquid can be determined before step S2, i.e., before contact with the adsorption resin, and after step S2, i.e., after contact with the adsorption resin, in order to thereby determine whether the caffeine is still bound to the adsorption resin. If the caffeine is no longer adsorbed (or only slightly adsorbed), the loading is complete (or has progressed to a large extent).

[0175] In the preferred embodiment of the method according to the invention discussed here, a transition is made from step S2 to step S3, preferably automatically, as soon as a predetermined progress in the extraction in step S1 (as described above) is achieved and / or (preferably "and") as soon as a predetermined loading of the adsorption resin with caffeine in step S2 (as described above) is achieved.

[0176] In other words, then preferably, as soon as a predetermined amount of caffeine has been extracted from the green coffee beans and / or a predetermined amount of caffeine has been bound to the adsorption resin, a transition is made from step S2 (loading the adsorption resin with caffeine) to step S3 (unloading the caffeine from the adsorption resin). In this preferred method, a switch is made in an efficient and technically advantageous manner between "liquid-solid" (aqueous extract / adsorption resin) extraction and "solid-liquid" (loaded adsorption resin / DCM) extraction.

[0177] The preferred transition described from step S2 to S3 results in the fact that, when the caffeine loading limit of the adsorption resin is reached, the caffeine contained in the aqueous extraction liquid is no longer recycled and brought into contact with the green coffee beans. More precisely, by switching to step S3, the bound caffeine is desorbed from the adsorption resin, so that the obtained (caffeine-free) adsorption resin is again available for use in step S2.

[0178] Preference is given to the method according to the invention (as described above, preferably as the method called preferred above), in which the aqueous extraction liquid is conveyed in a circuit one or more times, and preferably the caffeine-depleted aqueous extraction liquid obtained in step S2 or a processed product thereof is reused as the aqueous extraction liquid in step S1.

[0179] In this regard, it is particularly preferred that the aqueous extract conveyed one or more times in a circuit comprises, at least after its first cycle, one or more coffee inclusions other than caffeine, said coffee inclusions being selected from acids, minerals, aromatics, compounds convertible into aromatics by the Maillard reaction, and antioxidants.

[0180] By means of one or more preferred recirculations of the aqueous extract ("recirculation" herein means conveyance one or more times in a circuit), the properties of the adsorption resin are particularly advantageously utilized as a "caffeine reservoir", in particular in such a way that the adsorption resin can bind the caffeine in the aqueous extract several times. In particular, it is utilized that the adsorption resin has a high affinity for caffeine, such that the caffeine is (selectively) bound from the aqueous extract to the adsorption resin in step S2. It has been proven that the caffeine adsorption on the adsorption resin is also particularly efficient, and in particular in semi - continuous processes.

[0181] Since the aqueous extract is caffeine - poor after contact with the adsorption resin in step S2, preferably comprising less than 300 mg of caffeine per liter of aqueous solution, particularly preferably less than 100 mg of caffeine per liter of aqueous solution, and most particularly preferably no caffeine, said caffeine - poor aqueous extract is suitable for being reused as the aqueous extract in step S1. Preferably, the caffeine - poor aqueous extract to be reused as the aqueous extract comprises one or more coffee inclusions other than caffeine, said coffee inclusions being selected from acids, minerals, aromatics, compounds convertible into aromatics by the Maillard reaction, and antioxidants, such that the extraction of the corresponding coffee inclusions from the caffeine - containing green coffee beans into the extract is prevented or made difficult. That is to say, the coffee inclusions other than caffeine are preferably not adsorbed by the adsorption resin or are not completely adsorbed by the adsorption resin, preferably because the adsorption resin has already been loaded with said coffee inclusions in a previous step. In this regard, also see the individualized embodiments further above.

[0182] Preferably, the method according to the invention (as described above, preferably as the method called preferred above) has the following steps:

[0183] (S1) bringing a quantity of caffeine - containing green coffee beans into contact with an aqueous extract such that caffeine is extracted from the caffeine - containing green coffee beans into the extract,

[0184] wherein as the aqueous extract in step S1

[0185] - water is used,

[0186] or

[0187] - Use an aqueous solution comprising a single or multiple coffee inclusions that are not caffeine, said coffee inclusions being selected from acids, minerals, aromatics, compounds convertible into aromatics through the Maillard reaction, and antioxidants, such that extraction of the corresponding coffee inclusions in green coffee beans containing caffeine into the extract is prevented or made difficult.

[0188] (S2) Contact the caffeine-rich aqueous extract obtained in step S1 with an adsorption resin such that the caffeine in the extract binds to the adsorption resin.

[0189] Wherein, in step S2, the following adsorption resin is used.

[0190] The adsorption resin is pre-loaded with a single or multiple coffee inclusions that are not caffeine, said coffee inclusions being selected from acids, minerals, aromatics, compounds convertible into aromatics through the Maillard reaction, and antioxidants, such that binding of the corresponding coffee inclusions in the extract containing caffeine obtained in step S1 to the adsorption resin is prevented or made difficult.

[0191] And wherein in step S2

[0192] - Use a macroporous adsorption resin selected from polystyrene, polydivinylbenzene, and copolymers thereof with each other and other monomers.

[0193] Wherein the macroporous adsorption resin is preferably polystyrene or a copolymer of polystyrene, preferably crosslinked polystyrene, particularly preferably divinylbenzene-crosslinked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene-crosslinked polystyrene.

[0194] And / or (preferably "and")

[0195] - Bind at least 90%, preferably at least 95%, most particularly preferably at least 99% of the caffeine in the extract containing caffeine to the adsorption resin.

[0196] (S3) Contact the adsorption resin loaded with caffeine obtained in step S2 with dichloromethane such that the caffeine dissolves in the dichloromethane.

[0197] Wherein in step S3

[0198] - Perform the contact such that at least 80%, preferably at least 90%, particularly preferably at least 95%, most particularly preferably at least 99% of the caffeine in the adsorption resin loaded with caffeine dissolves into the dichloromethane.

[0199] And / or (preferably "and")

[0200] - The temperature of the dichloromethane is below 35 °C, preferably below 30 °C, particularly preferably below 25 °C,

[0201] wherein preferably the aqueous extract is circulated one or more times in a circuit, and the caffeine-depleted aqueous extract obtained in step S2 or a processed product thereof is reused as the aqueous extract in step S1.

[0202] Preferably, the method according to the invention (as described above, preferably as the method referred to as preferred above), wherein the method is a method for preparing decaffeinated green coffee beans and a caffeine concentrate, the method comprising the following additional steps:

[0203] (S5) Obtaining a caffeine concentrate from the solution of caffeine in dichloromethane that exists after step S3, preferably by separating the caffeine.

[0204] Preferably, not only is step (S4) described above carried out, but also step (S5) is carried out; here, the order of steps (S4) and (S5) is arbitrary. However, in individual cases, it is also possible to carry out only step (S5) or only step (S4).

[0205] Therefore, preferably, in the method according to the invention, not only decaffeinated green coffee beans are obtained as a product, but in addition a caffeine concentrate is obtained in step S5. The caffeine concentrate is obtained from the solution of caffeine in dichloromethane that exists after step S3, preferably by separating the caffeine.

[0206] Here, the methods common in the art for separating caffeine from a caffeine-containing dichloromethane solution are known to those skilled in the art. This particularly includes heating such a caffeine-containing dichloromethane solution, or extracting caffeine from the caffeine-containing dichloromethane solution with another extractant. In addition, caffeine can be crystallized out of the caffeine-containing dichloromethane solution by, for example, gradually reducing the content of dichloromethane by applying a vacuum or by heating.

[0207] According to another main aspect of the invention, the above-mentioned object and problem are achieved by a device for preparing decaffeinated green coffee beans in a method according to the invention (preferably in the method referred to as preferred), the device comprising:

[0208] - An extractor that can be filled with a certain amount of green coffee beans, for bringing a certain amount of caffeine-containing green coffee beans into contact with an aqueous extractant,

[0209] - An adsorption unit with an adsorption resin for bringing a caffeine-rich aqueous extract into contact with the adsorption resin, wherein the extractor is connected to the adsorption unit such that the caffeine-rich aqueous extract can be guided from the extractor into the adsorption unit, and wherein preferably an adsorption resin pre-loaded with one or more coffee inclusions other than caffeine is used, the coffee inclusions being selected from acids, minerals, aromatics, compounds convertible into aromatics by the Maillard reaction, and antioxidants.

[0210] - A storage container for the aqueous extract, the storage container for the aqueous extract being connected to the extractor such that the aqueous extract can be guided from the storage container for the aqueous extract into the extractor, and the storage container for the aqueous extract being preferably connected to the extractor such that, after the extraction process, the aqueous extract can be drawn back from the extractor or the adsorption unit into the storage container, preferably from the adsorption unit.

[0211] - A storage container for dichloromethane, the storage container for dichloromethane being connected to the adsorption unit such that dichloromethane can come into contact with the adsorption resin.

[0212] - One or more control devices.

[0213] The control devices are used to control the conveyance of the aqueous extract and / or dichloromethane within the device.

[0214] And / or (preferably "and")

[0215] The control devices are used to automatically switch from step S2 to step S3 as soon as a predetermined progress of the extraction in step S1 is reached and / or as soon as a predetermined loading of the adsorption resin with caffeine is reached in step S2.

[0216] Thus, the device according to the invention comprises an extractor that can be filled with a certain amount of green coffee beans, the extractor being used to bring a certain amount of caffeine-containing green coffee beans into contact with an aqueous extract (in accordance with step S1 of the method according to the invention). Preferably, (the whole of) method step S1 takes place in the extractor filled with a certain amount of green coffee beans, i.e., in the extractor, a certain amount of caffeine-containing green coffee beans is brought into contact with the aqueous extract such that caffeine is extracted from the caffeine-containing green coffee beans into the extract.

[0217] A person skilled in the art selects the extractor in a common manner here and particularly takes into account the characteristics of the extractor that are decisive for ensuring effective contact between the green coffee beans and the aqueous extract. In addition, the characteristics include the shape and size as well as the manner of implementation of the stirring or mixing unit within the extractor.

[0218] Preferably, an extractor fillable with a certain amount of green coffee beans has an inlet for filling with an aqueous extract. The inlet is preferably connected via a pipeline to other equipment elements, such as to a storage container or to the output side of an adsorption unit.

[0219] Preferably, an extractor fillable with a certain amount of green coffee beans has an outlet, and the aqueous extract rich in caffeine can be transferred from the outlet to, for example, another equipment element, such as an adsorption unit, via a pipeline.

[0220] Preferably, an extractor fillable with a certain amount of green coffee beans includes not only an inlet for the aqueous extract but also an outlet for the aqueous extract (as described above).

[0221] Preferably, an extractor fillable with a certain amount of green coffee beans includes an inlet for the green coffee beans and preferably includes an outlet for the decaffeinated green coffee beans separated from the inlet.

[0222] The device according to the invention includes an adsorption unit having an adsorption resin, and the adsorption unit is used to bring the aqueous extract rich in caffeine into contact with the adsorption resin, wherein the extractor is connected to the adsorption unit such that the aqueous extract rich in caffeine can be guided from the extractor into the adsorption unit.

[0223] In the adsorption unit, method steps S2 and S3 preferably occur. The adsorption unit having the adsorption resin is designed such that the adsorption unit

[0224] i) can enable the aqueous extract rich in caffeine obtained in step S1 to come into contact with the adsorption resin, so that the caffeine in the extract binds to the adsorption resin,

[0225] and

[0226] ii) can enable the adsorption resin loaded with caffeine obtained in step S2 to come into contact with dichloromethane, so that the caffeine dissolves in the dichloromethane.

[0227] In the device according to the invention, the extractor is connected to the adsorption unit such that the aqueous extract rich in caffeine can be guided from the extractor into the adsorption unit. The connection between the extractor and the adsorption unit is carried out here, for example, through a suitable pipeline system between the corresponding interfaces (inlet or outlet) of the extractor and the adsorption unit.

[0228] Preferably, the adsorption unit is connected to the extractor such that the aqueous extract rich in caffeine is guided back from the adsorption unit to the extractor. This design is particularly advantageous if the method according to the invention, especially steps S1 and S2, is carried out semi - continuously in a preferred manner.

[0229] Preferably, the adsorption unit is designed such that a preferred method according to the invention can be carried out, in which the aqueous extract is conveyed in a circuit one or more times, and preferably the caffeine-depleted aqueous extract obtained in step S2 or a processed product thereof is reused as the aqueous extract in step S1.

[0230] A person skilled in the art selects the specific design of the adsorption unit according to the requirements of the individual case. The adsorption unit preferably consists of one or more adsorption columns, which are (each) filled with an adsorption resin. For use in step S2 of the method according to the invention, it is preferred that the adsorption resin is pre-loaded with one or more coffee inclusions that are not caffeine, which are selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants.

[0231] In the case where there are a plurality of adsorption columns filled with an adsorption resin in the adsorption unit, it is preferred that the adsorption columns each have an inlet and an outlet and are arranged and connected to each other such that not only the caffeine-rich aqueous extract (in step S1) but also the caffeine-depleted aqueous extract (in step S2) can be guided from the first adsorption column filled with the adsorption resin to the second adsorption column filled with the adsorption resin, etc. The specific design of the adsorption unit and the adsorption columns and the selection of the type and amount of the adsorption resin are preferably matched to the requirements of the individual case. Therefore, the size, volume and number of the adsorption columns and the type and amount of the adsorption resin are preferably matched to the type and amount of the green coffee beans to be decaffeinated and / or the amount of caffeine to be extracted.

[0232] The device according to the invention further comprises a storage container for the aqueous extract, which is connected to the extractor such that the aqueous extract can be guided from the storage container for the aqueous extract into the extractor. Depending on the method stage, the aqueous extract in the storage container for the aqueous extract can have different compositions here, so for example, the content of coffee inclusions and / or caffeine may change during the course of the method. A person skilled in the art matches the design of the storage container for the aqueous extract, in particular the size and shape, to the conditions of the individual case.

[0233] In a preferred design, the device according to the invention is configured to convey the aqueous extract in a circulation loop, wherein the extractor and the adsorption unit and preferably the storage container for the aqueous extract are part of the circulation loop.

[0234] If (preferably in semi-continuous operation) the aqueous extract is conveyed in a circuit one or more times, this preferred design of the device is particularly important, wherein preferably the caffeine-depleted aqueous extract obtained in step S2 or a processed product thereof is reused as the aqueous extract in step S1.

[0235] The device according to the invention further comprises a storage container for dichloromethane, which storage container for dichloromethane is connected to the adsorption unit such that dichloromethane can come into contact with the adsorption resin.

[0236] Preferably, in the device according to the invention, the dichloromethane circulation circuit (caffeine desorption circulation circuit) and the aqueous extraction circulation circuit (caffeine adsorption circulation circuit) coincide only in the region of the adsorption unit, but are structurally separated otherwise. This means that the device elements specifically provided for the dichloromethane circulation circuit, such as the storage container for dichloromethane and the line for leading dichloromethane to the adsorption unit, are structurally separated from the device elements specifically provided for the aqueous extraction liquid, such as an extractor that can be filled with a certain amount of green coffee beans and the storage container for the aqueous extraction liquid and its input and output lines. Therefore, this preferred design is particularly advantageous, because in this way it is ensured that the dichloromethane solution for desorbing the caffeine bound to the adsorption resin does not come into direct contact with the green coffee beans. Of course, the adsorption unit filled with the adsorption resin must be accessible not only for the aqueous extraction liquid but also for dichloromethane here.

[0237] The device according to the invention preferably comprises a switching device configured to switch between the following states:

[0238] - A first operating state, in which the caffeine-rich aqueous extraction liquid obtained in step S1 comes into contact with the adsorption resin in the adsorption unit such that the caffeine in the extraction liquid binds to the adsorption resin,

[0239] and

[0240] - A second operating state, in which the adsorption resin loaded with caffeine comes into contact with dichloromethane such that the caffeine dissolves in the dichloromethane.

[0241] In the first operating state, preferably the aqueous extraction circulation circuit (caffeine adsorption circulation circuit) described above is flowed through.

[0242] In the second operating state, preferably the dichloromethane circulation circuit (caffeine desorption circulation circuit) described above is flowed through.

[0243] Preferably, the method according to the invention is carried out and the device according to the invention is operated such that the first operating state and the second operating state do not exist simultaneously. However, when using a plurality of adsorption columns in the adsorption unit that can be operated independently of one another, it can be advantageous for the first operating state (aqueous extraction circuit or caffeine adsorption circuit) to exist in one or more first adsorption columns, while the second operating state (dichloromethane circuit or caffeine desorption circuit) exists in one or more second adsorption columns. Here, the first adsorption column and the second adsorption column can be operated independently of one another.

[0244] A preferred device according to the invention comprises a separation unit for separating caffeine from a solution of caffeine in dichloromethane, wherein the device is configured to convey dichloromethane from a storage container for dichloromethane to the adsorption unit and from there (after loading dichloromethane with caffeine) to the separation unit. There, the dichloromethane (DCM) is separated from the caffeine and can then (in a purified manner) be reused in step (S3).

[0245] Therefore, the preferred design is particularly (primarily) important for efficiently designing step S3, that is, bringing the caffeine-loaded adsorption resin obtained in step S2 into contact with dichloromethane such that the caffeine dissolves in the dichloromethane. Preferably, the separation unit comprises a container, preferably a stainless-steel container, in which the dichloromethane is evaporated in a controlled manner. Here, the caffeine is transferred to a water reservoir, that is, it redissolves. The evaporated DCM is liquefied again, then purified, and can be reused in step (S3).

[0246] The preferred design is also (secondarily) important for the preferred step S5, namely for obtaining a caffeine concentrate (or caffeine), preferably by separating the caffeine, from the solution of caffeine in dichloromethane that exists after step S3.

[0247] In the device according to the invention, the facility elements for dichloromethane (such as the input and output lines of the storage container for dichloromethane) and the separation unit are preferably separate from the aqueous extraction circuit. The separation unit is preferably designed such that it allows the efficient separation of the caffeine dissolved in dichloromethane from the dichloromethane solution containing caffeine. Thus, the preferred device according to the invention allows the preparation of two high-quality products, namely not only the preparation of decaffeinated green coffee beans but also the preparation of caffeine or a caffeine concentrate (in the separation unit mentioned).

[0248] Preferred is the device according to the invention (as described above, preferably as the device called preferred above), wherein

[0249] - The extractor is filled with green coffee beans,

[0250] - The storage container for the aqueous extract contains the aqueous extract,

[0251] - The storage container for dichloromethane contains a certain amount of dichloromethane,

[0252] and / or (preferably "and")

[0253] - The adsorption resin is a macroporous adsorption resin, and the macroporous adsorption resin is selected from polystyrene, polydivinylbenzene, and copolymers thereof with each other and other monomers,

[0254] wherein the macroporous adsorption resin is preferably polystyrene or a copolymer of polystyrene, preferably cross-linked polystyrene, particularly preferably divinylbenzene cross-linked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene cross-linked polystyrene.

[0255] This preferred device according to the invention is ready for performing the method according to the invention.

[0256] Another aspect of the invention relates to the use of the device according to the invention (as described above, preferably as the preferred device described above) for performing the method according to the invention (as described above, preferably as the preferred method described above). It goes without saying that the device according to the invention is preferably matched to the desired design of the method according to the invention.

[0257] Another aspect of the invention relates to the use of dichloromethane for removing caffeine from an adsorption resin that is loaded with caffeine and other coffee inclusions,

[0258] wherein the adsorption resin is preferably a macroporous adsorption resin (such as the macroporous adsorption resin described above), and the macroporous adsorption resin is selected from polystyrene, polydivinylbenzene, and copolymers thereof with each other and other monomers,

[0259] wherein the macroporous adsorption resin is particularly preferably polystyrene or a copolymer of polystyrene, preferably cross-linked polystyrene, particularly preferably divinylbenzene cross-linked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene cross-linked polystyrene.

[0260] The use of dichloromethane according to the invention is achieved in step S3 of the method according to the invention. The preferred selection of the adsorption resin corresponds to the selection for the method according to the invention; the above embodiments apply correspondingly.

[0261] Preferably, the use according to the invention of dichloromethane for removing caffeine from an adsorption resin carrying caffeine and other coffee inclusions is carried out in a device according to the invention (as described above, preferably as the preferably described device above).

[0262] Another aspect of the invention relates to the use of an adsorption resin for adsorbing caffeine from a caffeine-rich aqueous extract in a method for preparing decaffeinated green coffee beans,

[0263] wherein the adsorption resin is preferably a macroporous adsorption resin selected from polystyrene, polydivinylbenzene and copolymers thereof with each other and other monomers,

[0264] wherein the macroporous adsorption resin is particularly preferably polystyrene or a copolymer of polystyrene, preferably crosslinked polystyrene, particularly preferably divinylbenzene-crosslinked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene-crosslinked polystyrene,

[0265] wherein the adsorption resin carrying caffeine extracted from green coffee beans is treated with dichloromethane such that the caffeine dissolves in the dichloromethane.

[0266] The use according to the invention of the adsorption resin is implemented in steps S2 (adsorption; loading with caffeine) and S3 (treatment with DCM; unloading of caffeine) in the method according to the invention.

[0267] Preferably, the use according to the invention of the adsorption resin is carried out in the method according to the invention (as described above, preferably as the preferably described method above) and / or (preferably "and") in a device according to the invention (as described above, preferably as the preferably described device above).

[0268] Preferred is the use of an adsorption resin according to the invention (as described above, preferably as the preferably described adsorption resin above), wherein an adsorption resin pre-loaded with one or more coffee inclusions other than caffeine is used, the coffee inclusions being selected from acids, minerals, aromatics, compounds convertible into aromatics by the Maillard reaction and antioxidants, such that binding of the corresponding coffee inclusions in the extract containing caffeine obtained in step S1 to the adsorption resin is prevented or made difficult.

[0269] Other preferred or particularly preferred aspects of the present invention are described below. These aspects relate not only to the method according to the invention, but also to the device according to the invention and to the applications according to the invention (such as the applications described above, preferably such as the applications referred to as preferred above). Unless otherwise specified in a particular case, all aspects of the following preferred or particularly preferred aspects apply and are intended for combination with other aspects of the present invention, in particular with those aspects referred to as preferred.

[0270] Preferably, the method for preparing decaffeinated green coffee beans according to the invention (as described above, preferably as the method referred to as preferred above) comprises one or more of the following steps:

[0271] - filling an extractor with green coffee beans, preferably dried green coffee beans,

[0272] - heating the green coffee beans in the extractor, preferably by means of an indirect hood heating device,

[0273] - comminuting and / or additionally heating the green coffee beans by means of direct steam, preferably by means of steam,

[0274] - specifying a defined target temperature for the green coffee beans,

[0275] - setting the previously specified target temperature for the green coffee beans, preferably by adding tempered water, an aqueous solution or steam to set the previously specified target temperature,

[0276] - saturating the green coffee beans with water, preferably saturating the green coffee beans until the limiting water content > 40% by weight, particularly preferably > 50% by weight,

[0277] - guiding a tempered aqueous extract, preferably a tempered aqueous extract from a storage container for the aqueous extract, through the green coffee beans in the extractor / extractors,

[0278] - guiding the caffeine-rich aqueous extract obtained in step S1 of the method according to the invention through a particle filter, a decanter and / or a centrifuge, preferably through a decanter, so that the particles are removed from the aqueous extract,

[0279] - in step S2 of the method according to the invention, guiding the caffeine-rich aqueous extract obtained in step S1, preferably the previously filtered extract, through an adsorption resin so that the caffeine in the aqueous extract (selectively) binds to the adsorption resin,

[0280] - The caffeine-depleted aqueous extract obtained in step S2 of the method according to the invention is recycled to the extractor, and the recycled caffeine-depleted aqueous extract is used to (re)extract caffeine from caffeinated green coffee beans (the same batch of caffeinated green coffee beans as in the previous step S1 or a new batch of caffeinated green coffee beans).

[0281] - The aqueous extract is removed from the extractor / extractors, preferably after a preset extraction time or after a previously preset and reached extraction progress, which is preferably determined by measuring the caffeine concentration in the aqueous extract or by determining the degree of decaffeination of the green coffee beans.

[0282] - The decaffeinated and still moist green coffee beans are transferred from the extractor to a dryer.

[0283] - The moist decaffeinated green coffee beans are dried, preferably in a dryer.

[0284] - The aqueous extract is transferred to a storage container for storing the aqueous extract, preferably after step S2 of the method according to the invention.

[0285] - The aqueous extract is stored in a storage container for storing the aqueous extract, wherein the stored aqueous extract is preferably obtained from step S1 or step S2 of the method according to the invention.

[0286] - The aqueous extract used in the method according to the invention, especially in steps S1 and S2, is sterilized, preferably by means of PEF treatment (PEF = pulsed electric field).

[0287] - The aqueous extract is sterilized by means of PEF treatment, wherein the aqueous extract is preferably guided in a separate sterilization circulation loop and subjected to PEF treatment within this separate circulation loop.

[0288] - The dissolved free asparagine is removed from the aqueous extract used in the method according to the invention, preferably from the aqueous extract directly before step S1 or directly after step S1 or directly after step S2, preferably by adding an enzyme solution comprising asparaginase.

[0289] By removing free asparagine from the aqueous extraction solution (and thus also from the treated green coffee beans), acrylamide formation can be significantly reduced during subsequent roasting of the decaffeinated green coffee beans prepared by the method according to the invention.

[0290] - Provide one or more column modules filled with an adsorbent resin, which is preferably filled with an adsorbent resin carrying single or multiple coffee inclusions other than caffeine.

[0291] - Periodically regenerate the adsorbent resin, preferably regenerating the adsorbent resin periodically after it is completely saturated with caffeine.

[0292] - Regenerate the adsorbent resin by rinsing with one or more solvents, preferably by rinsing with different solvents in a predetermined order. Particularly preferably, rinse the adsorbent resin with solvents selected from organic solvents, especially dichloromethane and / or alcohol, water, and water vapor.

[0293] - Transfer the caffeine redissolved from the adsorbent resin in DCM in step S3 of the method according to the invention to a separation unit.

[0294] - Process the redissolved caffeine in a caffeine treatment facility so as to obtain caffeine or a caffeine extract.

[0295] - Redissolve the caffeine redissolved in step S3 of the method according to the invention in a dichloromethane solution containing caffeine, wherein the redissolution of caffeine is preferably carried out by liquid-liquid extraction. Particularly preferably, transfer caffeine from the dichloromethane solution containing caffeine to an aqueous solution containing caffeine by redissolution.

[0296] - Treat and / or reuse the water vapor used in the method according to the invention.

[0297] - Treat and / or reuse the dichloromethane used in the method according to the invention.

[0298] - Treat and / or reuse the aqueous extract used in the method according to the invention.

[0299] - Treat and / or reuse the rinse solution used in the method according to the invention.

[0300] - Reuse, preferably reuse multiple times, the aqueous extract used in the method according to the invention.

[0301] - Conduct wastewater treatment on the aqueous extract used in the method according to the invention. The wastewater treatment is preferably carried out only when the aqueous extract cannot or should not be reused in the method according to the invention due to contamination (for example, after being used multiple times in the method according to the invention).

[0302] A preferred method according to the invention for preparing decaffeinated green coffee beans comprises one or more of the following steps, wherein the corresponding state or condition of the adsorbent resin is indicated in brackets:

[0303] i. Prepare or provide a suitable adsorbent resin (adsorbent resin), especially when starting the method.

[0304] ii. The adsorbent resin is saturated or loaded with coffee constituents other than caffeine, especially when starting the method. The saturation or loading is preferably achieved during the continuous operation of the method [adsorbent resin + coffee constituents]; step ii. is preferably carried out before step S2 of the method according to the invention.

[0305] iii. Pass the aqueous caffeine-containing extract through the adsorbent resin pre-saturated with coffee constituents other than caffeine, so that the caffeine in the extract binds to the adsorbent resin [adsorbent resin + coffee constituents + caffeine]. This is preferably carried out in step S2 of the method according to the invention or as step S2.

[0306] iv. Bring the caffeine-loaded adsorbent resin obtained in step iii. into contact with dichloromethane so that the caffeine dissolves in the dichloromethane. The dissolution in dichloromethane is preferably carried out by selectively desorbing the caffeine from the adsorbent resin [adsorbent resin + coffee constituents + DCM]. This is preferably carried out in step S3 of the method according to the invention or as step S3.

[0307] v. Remove the dichloromethane from the adsorbent resin and regenerate the adsorbent resin [adsorbent resin + coffee constituents], preferably after step S3 of the method according to the invention.

[0308] vi. Periodically carry out a thorough cleaning of the adsorbent resin with a sodium hydroxide solution.

[0309] It should be noted that preferably only when starting the method according to the invention, for example in accordance with industrial standards, are method steps i. and ii. mentioned above carried out. If the adsorbent resin is put into operation for the first time, then method steps i. and ii. are especially necessary or meaningful. The method steps in steps iii. to vi. or the state of the adsorbent resin especially relate to the (repeated) execution of the method according to the invention within a continuous or semi-continuous method for producing decaffeinated green coffee beans. In particular, steps iii. to v. are preferably carried out regardless of whether steps i, ii, and vi are carried out or not.

[0310] The selection of a suitable adsorbent resin can be tested by means of preliminary tests in the laboratory and by carrying out experiments at a pilot plant.

[0311] In the method according to the invention, the adsorption resin is preferably rinsed and / or soaked with water from all sides before being put into operation for the first time, preferably for a period of at least one hour. Furthermore, it is preferred that after the rinsing or soaking phase, the adsorption resin is rinsed again with water in order to remove possible production residues (interfering substances). The re - rinsing with water is also used to squeeze out air inclusions from the adsorption resin, in particular from the macropores.

[0312] Preferably, in the method according to the invention, the method has the following (additional) steps:

[0313] ii. The adsorption resin is saturated or loaded with coffee constituents other than caffeine (this step ii is preferably carried out before step S2 of the method according to the invention):

[0314] The loading or saturation of the adsorption resin with coffee constituents other than caffeine can be carried out in at least two different ways:

[0315] In the first variant, the adsorption resin is loaded with coffee constituents in such a way that a previously produced coffee extract (water with added coffee constituents, where the coffee constituents are not caffeine) overflows the adsorption resin, and the coffee constituents contained in the previously produced coffee extract bind to the adsorption resin. This variant is applied especially when a new, not yet loaded adsorption resin is (first) put into operation in order to reduce the adsorption of water - soluble constituents other than caffeine in the aqueous extraction solution onto the adsorption resin.

[0316] The second variant of the saturation or loading of the adsorption resin with coffee constituents lies in treating the adsorption resin saturated or loaded not only with coffee constituents but also with caffeine by means of dichloromethane, such that the caffeine is selectively removed, but at least most of the other coffee constituents remain bound to the adsorption resin. This second variant is carried out especially when step S2 of the method according to the invention has already been carried out. Then, in some cases, it may make sense to condition the adsorption resin before (re)loading it with caffeine from the aqueous extraction solution. The term "conditioning" includes, for example, method steps such as re - hydration by rinsing with water, steam or an aqueous solution.

[0317] Preferably, in the method according to the invention, the method has the following (additional) steps:

[0318] iii. Passing an aqueous extraction solution containing caffeine through the adsorption resin pre - saturated with coffee constituents other than caffeine, such that the caffeine in the extraction solution binds to the adsorption resin (preferably in or as step S2 of the method according to the invention):

[0319] Step iii. During the decaffeination process, the so-called "loading" of the adsorption resin with caffeine is caused.

[0320] It is also possible to additionally load or reload with coffee constituents other than caffeine. This is particularly meaningful if, by means of a periodic radical cleaning of the adsorption resin carried out beforehand, some of the coffee constituents other than caffeine are desorbed (dissolved) from the adsorption resin.

[0321] In step iii., the caffeine-containing aqueous extract guided through the adsorption resin is preferably produced / obtained in the following manner:

[0322] - A certain amount of green coffee beans is provided into the extractor.

[0323] - The extractor filled with a defined amount of green coffee beans is filled with an aqueous extract, preferably an aqueous extract that is caffeine-free or low in caffeine but saturated with other coffee constituents, until the green coffee beans are covered.

[0324] - In the special case of a first extraction where the aqueous extract (saturated with coffee constituents) has not yet been made available, the green coffee beans can be covered with a previously prepared coffee extract or water.

[0325] - The mixture consisting of the green coffee beans and the aqueous extract is homogenized by means of stirring, preferably by means of a stirrer in the extractor, in order to ensure an effective extraction of caffeine from the green coffee beans.

[0326] - The low-caffeine or caffeine-free aqueous extract extracts caffeine from the green coffee beans, such that a caffeine-containing aqueous extract is obtained; this last sub-step is preferably carried out in step S1 of the method according to the invention or as step S1.

[0327] According to step iii., guiding the caffeine-containing aqueous extract through an adsorption resin pre-saturated with coffee constituents other than caffeine such that the caffeine in the extract binds to the adsorption resin preferably includes one or more of the following measures:

[0328] - Guiding the caffeine-containing aqueous extract through one or more adsorption columns filled with the adsorption resin, preferably through at least two adsorption columns filled with the adsorption resin.

[0329] - Guiding the aqueous extract containing caffeine through two adsorption columns filled with adsorption resin, wherein preferably, the first adsorption column filled with adsorption resin is first flowed through by the aqueous extract containing caffeine until the first adsorption column filled with adsorption resin is loaded with caffeine, preferably saturated with caffeine by means of caffeine, and subsequently the second adsorption column also filled with adsorption resin is flowed through by the aqueous extract containing caffeine until the second adsorption column filled with adsorption resin is also loaded with caffeine, preferably saturated with caffeine by means of caffeine,

[0330] - Guiding the aqueous extract containing caffeine through a plurality of adsorption columns filled with adsorption resin connected in series, wherein only one adsorption column or a part of the plurality of adsorption columns filled with adsorption resin connected in series is flowed through by the aqueous extract containing caffeine, while one or more of the other adsorption columns not flowed through and filled with adsorption resin

[0331] i) Flushing with dichloromethane in order to (selectively) desorb caffeine from the adsorption resin, and / or

[0332] ii) Regenerating, preferably by flushing with water, steam and / or a solution containing sodium hydroxide.

[0333] Preferably, the adsorption resin pre-saturated with coffee inclusions other than caffeine is loaded with caffeine, preferably saturated with caffeine, after the end of step iii.

[0334] Preferably, the low-caffeine or caffeine-free aqueous extract obtained also through step iii. is re-guided into an extractor filled with green coffee beans, optionally after further treatment (the further treatment especially includes separation or addition of other components), in order to extract caffeine from the green coffee beans (circulation process).

[0335] Preferably, step iii. is carried out until the desired degree of decaffeination of the green coffee beans is reached. Particularly preferably, step iii. is carried out such that in the adsorption columns filled with adsorption resin used in the method, (multiple times) switching is made between the loading cycle (flowing through the aqueous extract, preferably flowing through in a circulation loop system) and the caffeine desorption and regeneration cycle. That is to say, the adsorption columns filled with adsorption resin can either be in the caffeine adsorption cycle loop (loaded with caffeine) or in the caffeine desorption cycle loop (caffeine dissolved) or in the regeneration cycle loop, and can be transferred from the first cycle loop to any other cycle loop by targeted switching.

[0336] Preferably, according to the method of the present invention, the method preferably has the following (additional) steps:

[0337] iv. Contact the caffeine-loaded adsorption resin obtained in step iii with dichloromethane such that the caffeine dissolves in the dichloromethane. The dissolution in dichloromethane is preferably carried out by selectively desorbing the caffeine from the adsorption resin (preferably in step S3 of the method according to the invention or as step S3):

[0338] Step iv causes the so-called "unloading" of the adsorption resin in the decaffeination process, in particular the unloading (desorption) of the caffeine bound to the adsorption resin. Step iv also enables the adsorption resin to be re-loaded with caffeine.

[0339] The desorption should be carried out as selectively as possible so that preferably only the caffeine is desorbed from the caffeine-loaded adsorption resin obtained in step iii, while the coffee inclusions of the caffeine remain bound to the adsorption resin. In step S3 of the method according to the invention, dichloromethane (DCM) is used to carry out this selective desorption.

[0340] Preferably, the caffeine-loaded adsorption resin obtained in step iii is in an adsorption column. Particularly preferably, the adsorption column filled with the adsorption resin is cooled to a temperature below 25 °C by contacting with an aqueous extract, water or other aqueous solution, preferably by rinsing, before contacting with dichloromethane in step iv.

[0341] Preferably, step iv is carried out by passing DCM through, particularly preferably by passing DCM through in a direction opposite to the flow direction of the aqueous extract passed through the adsorption resin in step iii. However, in specific cases, passing through in the same flow direction is also advantageous.

[0342] Preferably, the method according to the invention has the following (additional) steps:

[0343] v. Remove the dichloromethane from the adsorption resin and / or regenerate the adsorption resin, preferably in step S4 of the method preferably according to the invention or as step S4:

[0344] Preferably, between step iv (caffeine desorption by means of DCM) and re-executing step iii (adsorbing caffeine from the aqueous extract), the dichloromethane is removed from the adsorption resin and / or the adsorption resin is regenerated (step v).

[0345] For example, the (additional) step v. is carried out, in particular removing DCM from the adsorption resin in order to exclude the contamination of the green coffee beans by DCM, so that the adsorption resin can be fully loaded with caffeine again. After step iv., in the adsorption resin, "free" (unadsorbed) DCM is regularly present not only externally but also in the pores of the adsorption resin. In addition, some of the dichloromethane used in step iv. may be adsorbed on the surface of the adsorption resin.

[0346] In order to remove DCM from the adsorption resin, in particular the following measures are available, which can be carried out in any order and with any frequency:

[0347] - Removing the "free" (unadsorbed) DCM that is not present in the pores from the adsorption resin by:

[0348] o Passing water through the adsorption resin,

[0349] - Removing the "free" (unadsorbed) DCM from the pores of the adsorption resin by:

[0350] o Passing water, preferably water having a temperature greater than 50 °C, through the adsorption resin,

[0351] o Passing steam through the adsorption resin,

[0352] - Removing the DCM adsorbed on the surface of the adsorption resin by:

[0353] o Passing water, preferably water having a temperature greater than 50 °C, through the adsorption resin,

[0354] o Passing steam through the adsorption resin.

[0355] Preferably, when removing DCM from the adsorption resin, work with as little water as possible, because water or aqueous solutions may also desorb a part of the coffee inclusions that are not caffeine.

[0356] The adsorption resin is preferably regenerated after multiple cycles, where then preferably DCM is removed from the adsorption resin directly before that. In order to regenerate the adsorption resin, the following measures are available, which can be carried out in any order and with any frequency:

[0357] - Rinsing the adsorption resin with water, an aqueous solution or an aqueous extract,

[0358] - Removing gas inclusions by rinsing the adsorption resin with water, an aqueous solution or an aqueous extract.

[0359] Preferably, the regeneration of the adsorption resin occurs only after DCM has been removed from the adsorption resin (as completely as possible). Particularly preferably, the adsorption resin is rehydrated at the end of step v., and the rehydration is preferably carried out by rinsing the adsorption resin with water, an aqueous solution or an aqueous extract.

[0360] Preferably, the method according to the invention has the following (additional) steps:

[0361] vi. Periodically and radically cleaning the adsorption resin with a sodium hydroxide solution.

[0362] Particularly after performing method steps iii. to v. multiple times, it makes sense to radically clean the adsorption resin with a sodium hydroxide solution in order to restore or permanently maintain the full caffeine loading capacity of the adsorption resin. Description of the Drawings

[0363] The present invention will be described in detail below with reference to the accompanying drawings.

[0364] The accompanying drawings show:

[0365] Figure 1 Shows a schematic configuration of an apparatus for preparing decaffeinated green coffee beans according to the present invention.

[0366] Figure 2 Shows a schematic diagram of (the first) method for preparing decaffeinated green coffee beans according to the present invention.

[0367] Figure 3 Shows a schematic diagram of (the second) method for preparing decaffeinated green coffee beans according to the present invention. Detailed Description

[0368] Figure 1 Exemplarily shows a schematic configuration of a preferred apparatus for preparing decaffeinated green coffee beans according to the present invention. In Figure 1 The apparatus shown herein includes the following elements: an extractor 10, a separator 20, an adsorption unit 30, an adsorption column 31 filled with an adsorption resin, an adsorption resin 32, a reserve container 40 for an aqueous extract, an inlet 50 for an aqueous extract, a caffeine adsorption circulation loop 60 for an aqueous extract, a reserve container 70 for dichloromethane, a caffeine desorption circulation loop for dichloromethane and / or a dichloromethane solution containing caffeine or a regeneration circulation loop 80 for a rinsing solution, a separation unit 90, an inlet 100 for a rinsing solution, and an outlet 110 for a rinsing solution.

[0369] Of course, the apparatus according to the present invention is not limited to that shown in Figure 1The design shown in. The device according to the present invention may for example include additional elements not shown in Figure 1 The arrangement and / or number of the individual elements in the device according to the present invention may also be different from those in the device shown in Figure 1 the device shown in

[0370] In Figure 1 the device shown in is in particular (like any device according to the present invention) suitable and configured for carrying out a method according to the present invention for preparing decaffeinated green coffee beans, said method having the following steps:

[0371] (S1) bringing a quantity of caffeinated green coffee beans into contact with an aqueous extraction liquid such that caffeine is extracted from the caffeinated green coffee beans into the extraction liquid,

[0372] (S2) bringing the caffeine-rich aqueous extraction liquid obtained in step S1 into contact with an adsorption resin such that the caffeine in the extraction liquid binds to the adsorption resin,

[0373] (S3) bringing the adsorption resin loaded with caffeine obtained in step S2 into contact with dichloromethane such that the caffeine dissolves in the dichloromethane.

[0374] In Figure 1 the preferred device shown in for preparing decaffeinated green coffee beans, preferably for preparing decaffeinated green coffee beans in a method according to the present invention comprising steps S1, S2 and S3, comprises:

[0375] - an extractor 10 that can be filled with a quantity of green coffee beans, said extractor being for bringing a quantity of caffeinated green coffee beans into contact with an aqueous extraction liquid,

[0376] - a separator 20 for separating the solid constituent from the aqueous extraction liquid after extracting the caffeinated green coffee beans. The separator does not have to be provided in every device according to the present invention; this correspondingly applies to all device elements not mentioned in the definition of the device according to the present invention in the claims,

[0377] - an adsorption unit 30 having an adsorption resin 32 (in an adsorption column 31, to be described in detail later), said adsorption unit being for bringing the caffeine-rich aqueous extraction liquid into contact with the adsorption resin 32. Here, the extractor is connected to the adsorption unit 30 via Figure 1 the separator 20 such that the caffeine-rich aqueous extraction liquid can be conducted from the extractor 10 into the adsorption unit 30,

[0378] - The adsorption column 31 filled with the adsorption resin 32 in the adsorption unit 30. The adsorption column is configured to guide the aqueous extract through. Preferably, the adsorption resin 32 is a macroporous adsorption resin, and the macroporous adsorption resin is selected from polystyrene, polydivinylbenzene, and copolymers thereof with each other and other monomers, where the macroporous adsorption resin is preferably polystyrene or a copolymer of polystyrene, preferably cross-linked polystyrene, particularly preferably divinylbenzene cross-linked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene cross-linked polystyrene.

[0379] - A storage container 40 for the aqueous extract, which is connected to the extractor 10 such that the aqueous extract can be conducted (according to Figure 1 via the corresponding pipeline) from the storage container 40 for the aqueous extract to the extractor 10.

[0380] - An inlet 50 for the aqueous extract, which is connected to the extractor 10, the adsorption unit 30, and the storage container 40 for the aqueous extract (according to Figure 1 via the corresponding pipeline) such that the aqueous extract can be conducted from the inlet 50 for the aqueous extract to the respective components.

[0381] - A storage container 70 for dichloromethane, which is connected to the adsorption unit 30 such that dichloromethane can come into contact with the adsorption resin 32.

[0382] - A separation unit 90 for separating caffeine from the dichloromethane solution.

[0383] - An inlet 100 for the rinsing solution, which is connected to the caffeine desorption circulation loop for dichloromethane and / or the dichloromethane solution containing caffeine (see below for this) or the regeneration circulation loop 80 for the rinsing solution (see below for this) and the adsorption unit 30 such that the rinsing solution can be conducted from the inlet 100 for the rinsing solution to the adsorption unit 30.

[0384] - An outlet 110 for the rinsing solution, which is connected to the caffeine desorption circulation loop for dichloromethane and / or the dichloromethane solution containing caffeine or the regeneration circulation loop 80 for the rinsing solution and the adsorption unit 30 such that the rinsing solution can be exported from the adsorption unit 30 via the outlet 110 for the rinsing solution from the device.

[0385] - One or more conveying devices ( Figure 1 not shown in the figure) for conveying liquids within the device.

[0386] - one or more valve devices for selectively opening and closing pipelines, pipeline sections, and other equipment components ( Figure 1 not shown in

[0387] - one or more control devices ( Figure 1 not shown in

[0388] The control device is used to control the conveyance of the aqueous extract and / or dichloromethane within the equipment (the control device interacts with the conveyance device and the valve device in a conventional manner such that the method according to the invention can be carried out in the equipment according to the invention).

[0389] and / or

[0390] The control device is used to automatically switch from step S2 to step S3 in the method according to the invention as soon as a predetermined progress of the extraction in step S1 is reached and / or as soon as a predetermined loading of the adsorption resin 32 with caffeine is reached in step S2 (the control device interacts with one or more measuring and evaluation devices for determining the progress or loading state of the extraction).

[0391] In Figure 1 the equipment according to the invention shown is configured to convey the aqueous extract in a circulation loop, where the extractor 10, the adsorption unit 30, and the storage container 40 for the aqueous extract are part of the circulation loop (caffeine adsorption circulation loop 60). The storage container can be bypassed alternatively via a bypass pipeline not shown.

[0392] In Figure 1 the equipment according to the invention shown is also configured to convey dichloromethane and / or the dichloromethane solution containing caffeine through the adsorption unit 30, preferably in a circulation loop 80 (here: caffeine desorption circulation loop 80). Here, dichloromethane is conveyed from the storage container 70 for dichloromethane to the adsorption unit 30 and from there to the separation unit 90. The equipment is also configured to convey the flushing solution through the adsorption unit 30 in the circulation loop 80 (here: regeneration circulation loop 80). Here, the flushing solution is introduced into the circulation loop through the inlet 100 and led out through the outlet 110 after the flushing is completed.

[0393] In Figure 1 the equipment according to the invention shown includes a separation unit 90, which is used to separate caffeine from the solution of caffeine in dichloromethane and is configured to convey dichloromethane from the storage container 70 for dichloromethane to the adsorption unit 30 and from there to the separation unit 90.

[0394] In accordance with Figure 1In the device according to the invention, the caffeine adsorption circulation circuit 60 for the aqueous extract configured to convey the aqueous extract in a circulation circuit and the caffeine desorption circulation circuit for dichloromethane and / or the dichloromethane solution containing caffeine or the regeneration circulation circuit for the flushing solution 80 coincide in the region of the adsorption unit 30, but are structurally separated otherwise. Similarly, the device elements specifically provided for the caffeine desorption circulation circuit for dichloromethane and / or the dichloromethane solution containing caffeine or the regeneration circulation circuit 80 for the flushing solution, namely, in particular, the storage container 70 for dichloromethane and the pipeline for guiding dichloromethane to the adsorption unit 30, are structurally separated from the device elements specifically provided for the caffeine adsorption circulation circuit for the aqueous extract, such as the extractor 10 that can be filled with a certain amount of green coffee beans and the storage container 40 for the aqueous extract and their input or output pipelines. Therefore, this design is particularly advantageous because in this way it can be ensured that the dichloromethane solution for desorbing the caffeine bound to the adsorption resin does not come into direct contact with the green coffee beans in the extractor 10.

[0395] In the device according to Figure 1 the invention, the method step S1 of the method according to the invention takes place in the extractor 10, that is, a certain amount of green coffee beans containing caffeine are brought into contact with the aqueous extract so that caffeine is extracted from the green coffee beans containing caffeine into the extract. For this purpose, the extractor 10 is filled with green coffee beans. In addition, the extractor is equipped with an inlet or outlet for introducing or discharging the aqueous extract. Here, the aqueous extract is introduced into the extractor 10 through one or more pipelines in the caffeine adsorption circulation circuit 60 for the aqueous extract, and the pipelines are fed with the aqueous extract from the storage container 40 for the aqueous extract and / or the adsorption unit 30.

[0396] In the device according to Figure 1In the device according to the invention, the method step S2 of the method according to the invention takes place in the adsorption unit 30, i.e., the caffeine-rich aqueous extract obtained in step S1 is brought into contact with the adsorption resin 32 so that the caffeine in the extract binds to the adsorption resin 32. For this purpose, the adsorption column 31 in the adsorption unit 30 is filled with the adsorption resin 32, preferably with an adsorption resin 32 pre-loaded with one or more coffee inclusions other than caffeine, the coffee inclusions being selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants. The caffeine-rich aqueous extract obtained in step S1 is conducted from the extractor 10 via a corresponding pipeline into the adsorption unit 30, where the aqueous extract comes into contact with the adsorption resin 32. The corresponding pipeline in the adsorption unit 30, especially the pipeline between the adsorption columns 31 filled with the adsorption resin 32, ensures here that the caffeine-rich aqueous extract is guided past the adsorption resin 32. Before step S2, the caffeine-rich aqueous extract is depleted of caffeine by contact with the adsorption resin 32; the adsorption resin 32 binds / adsorbs caffeine from the aqueous extract. The caffeine-depleted aqueous extract obtained after step S2 is preferably re-fed to the extractor 10 via a corresponding pipeline in order to be reused there for the method step S1 of the method according to the invention (circulation process via the caffeine adsorption circulation loop 60 for the aqueous extract).

[0397] In the device according to Figure 1 the invention, the method step S3 of the method according to the invention takes place in the adsorption unit 30, i.e., the adsorption resin 32 loaded with caffeine obtained in step S2 is brought into contact with dichloromethane so that the caffeine dissolves in the dichloromethane. The design of the adsorption unit 30 for step S2 applies correspondingly here. In order to bring the dichloromethane into contact with the adsorption resin 32 loaded with caffeine, the dichloromethane is guided from the storage container 70 for dichloromethane via a corresponding pipeline into the adsorption unit 30, where the dichloromethane comes into contact with the adsorption resin 32 loaded with caffeine. The corresponding pipeline in the adsorption unit 30, especially the pipeline between the adsorption columns 31 filled with the adsorption resin 32, ensures here that the dichloromethane is guided past the adsorption resin 32. Before step S3, the adsorption resin 32 loaded with caffeine desorbs caffeine when the dichloromethane is passed through, so that the caffeine dissolves in the dichloromethane and a dichloromethane solution containing caffeine is obtained. The dichloromethane solution containing caffeine obtained after step S3 is preferably conveyed from the adsorption unit 30 to the separation unit 90 via a corresponding pipeline (see Figure 1 the caffeine desorption circulation loop 80).

[0398] In the device according to Figure 1In the device according to the invention, the optional (additional) method step S4 also takes place in the adsorption unit 30, i.e., the adsorption resin 32 is treated to remove dichloromethane and / or to regenerate the loading capacity of the adsorption resin 32 for caffeine under the conditions of step S2. In order to conduct the corresponding (preferably heated aqueous) flushing solution or steam through the adsorption resin 32, the pipeline system of the caffeine desorption circulation loop 80 (here: regeneration circulation loop 80) is preferably used. In this case, the corresponding flushing solution is introduced into the regeneration circulation loop 80 through the inlet 100, conveyed to the adsorption unit 30, and led out of the device through the outlet 110 after completion of the treatment of the adsorption resin 32 for removing dichloromethane and / or regenerating the adsorption resin 32.

[0399] The corresponding (not shown in Figure 1 ) conveying device for conveying liquids within the device, the valve device for selectively opening and closing pipelines, pipeline sections, and other device elements, and the control device for controlling the conveyance of the aqueous extract and / or dichloromethane and / or flushing solution within the device ensure that the caffeine adsorption circulation loop 60 for the aqueous extract and the caffeine desorption circulation loop for dichloromethane and / or the dichloromethane solution containing caffeine or the regeneration circulation loop 80 for the flushing solution are separated from each other. Thus, direct contact between the green coffee beans in the extractor 10 and dichloromethane and / or the flushing solution can be completely or at least largely avoided. Thereby, contamination of the green coffee beans by dichloromethane can be completely or at least largely avoided. This is a particularly decisive aspect of the invention especially in view of the above-described considerations of consumers regarding the residual organic solvents in coffee products.

[0400] At the same time, the aqueous extract can be conveyed in a loop one or more times by means of the device according to Figure 1 the invention, wherein preferably, the caffeine-poor aqueous extract or its treatment product obtained in step S2 is reused as the aqueous extract in step S1. This results in a particularly efficient water decaffeination process.

[0401] Furthermore, the device shown in Figure 1 is exemplary for the application of a suitable adsorption resin as a "caffeine buffer" in the method according to the invention: the "caffeine buffer" has a newly developed and technically advantageous two-stage extraction sequence "liquid-solid" (loading step S2; aqueous extract / adsorption resin) plus "solid-liquid" (unloading step S3; loaded adsorption resin / DCM) to remove and obtain caffeine from the aqueous extract, thereby efficiently preparing high-quality decaffeinated green coffee beans.

[0402] Figure 1 List of reference numerals

[0403] 10 Extractor

[0404] 20 Separator

[0405] 30 Adsorption unit

[0406] 31 Adsorption column filled with adsorption resin

[0407] 32 Adsorption resin

[0408] 40 Reserve container for aqueous extract

[0409] 50 Inlet for aqueous extract

[0410] 60 Caffeine adsorption circulation loop for aqueous extract

[0411] 70 Reserve container for dichloromethane

[0412] 80 Caffeine desorption circulation loop for dichloromethane and / or dichloromethane solution containing caffeine or regeneration circulation loop for flushing solution

[0413] 90 Separation unit

[0414] 100 Inlet for flushing solution

[0415] 110 Outlet for flushing solution

[0416] Figure 2 A first embodiment of a method for preparing decaffeinated green coffee beans according to the present invention is shown in a schematic flow chart. Preferably, the method for preparing decaffeinated green coffee beans according to the present invention is carried out in a device for preparing decaffeinated green coffee beans according to the present invention (as described above, preferably as the preferred device described above), for example in a device according to Figure 1 (see the corresponding description).

[0417] In the first step S1 of the method, a certain amount of caffeinated green coffee beans 201 are brought into contact with an aqueous extract 202, so that caffeine is extracted from the caffeinated green coffee beans 201 into the extract. The aqueous extract 203 rich in caffeine obtained in step S1, i.e., when in contact with the caffeinated green coffee beans 201, is brought into contact with an adsorption resin 204 in the next step S2, so that the caffeine in the aqueous extract 203 rich in caffeine binds to the adsorption resin 204.

[0418] Preferably, the adsorption resin 204 used in step S2 is a macroporous adsorption resin, and the macroporous adsorption resin is selected from polystyrene, polydivinylbenzene, and copolymers thereof with each other and other monomers, wherein the macroporous adsorption resin is preferably polystyrene or a copolymer of polystyrene, preferably cross-linked polystyrene, particularly preferably divinylbenzene-cross-linked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene-cross-linked polystyrene.

[0419] Preferably, the adsorption resin 204 used in step S2 is pre-loaded with one or more coffee inclusions that are not caffeine, and the coffee inclusions are selected from acids, minerals, aromatics, compounds that can be converted into aromatics through the Maillard reaction, and antioxidants, so as to prevent the corresponding coffee inclusions in the caffeine-rich aqueous extract 203 from binding to the adsorption resin 204 or making it difficult.

[0420] Preferably, after the aqueous extract contacts the adsorption resin 204, it re-contacts a certain amount of caffeine-containing green coffee beans 201 as the caffeine-poor aqueous extract 202, so that caffeine is extracted from the caffeine-containing green coffee beans 201 into the extract.

[0421] Particularly preferably, the aqueous extract 202 / 203 is conveyed in a loop one or more times in a continuous or semi-continuous process (aqueous extraction circulation loop 207), wherein preferably, the caffeine-poor aqueous extract 202 or its processed product is used as the aqueous extract one or more times again to extract caffeine from the caffeine-containing green coffee beans 201.

[0422] In another step of the method (corresponding to the specific step S3 of the method according to the present invention), the caffeine-loaded adsorption resin 204 is contacted with dichloromethane 205, so that caffeine dissolves in dichloromethane, and a caffeine-containing dichloromethane solution 206 is obtained (desorbing the caffeine bound to the adsorption resin in the caffeine desorption step 208). The obtained caffeine-containing dichloromethane solution 206 is preferably conveyed to a separation unit (not shown in Figure 2 in order to obtain caffeine or a caffeine concentrate from the caffeine-containing dichloromethane solution 206.

[0423] That is, by means of Figure 2In the method shown, decaffeinated green coffee beans can be obtained as a product (by the method steps in the aqueous extraction circuit 207), and caffeine or a caffeine concentrate can also be obtained (by the method steps in the caffeine desorption step 208). Thus, the method according to the invention is particularly economical because, in a manner that can be readily implemented in terms of process technology, not just one but two high-quality and valuable products can be prepared, namely decaffeinated green coffee beans (the first product) and caffeine or a caffeine extract (the second product).

[0424] The green coffee beans 201 do not come into direct contact with the dichloromethane 205 here. Thereby, contamination of the green coffee beans 201 by the dichloromethane 205 is completely or at least largely avoided. This is a particularly decisive aspect of the invention, especially in view of the considerations of consumers regarding the residual organic solvents in coffee products as described above.

[0425] Figure 3 Another embodiment of the method according to the invention for preparing decaffeinated green coffee beans is shown in the flow chart. Preferably, the method according to the invention for preparing decaffeinated green coffee beans is carried out here in a facility according to the invention for preparing decaffeinated green coffee beans (as described above, preferably as the facility referred to as preferred above), for example in a device according to Figure 1 (see the corresponding description).

[0426] In Figure 3 In the first step 401 of the method shown, the prepared or provided adsorption resin 301 is preloaded, preferably saturated, with one or more coffee inclusions that are not caffeine. Preferably, step 401 is carried out by bringing the prepared or provided aqueous solution comprising one or more coffee inclusions that are not caffeine and are selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants into contact with the prepared or provided adsorption resin 301, such that an adsorption resin 302 preloaded with coffee inclusions is obtained, the adsorption resin being preloaded with one or more coffee inclusions that are not caffeine and are selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants.

[0427] The prepared or provided adsorption resin 301 is preferably a macroporous adsorption resin selected from polystyrene, polydivinylbenzene, and their copolymers with each other and other monomers, wherein the macroporous adsorption resin is preferably polystyrene or a copolymer of polystyrene, preferably crosslinked polystyrene, and particularly preferably divinylbenzene-crosslinked polystyrene, and most preferably non-functionalized, non-ionic divinylbenzene-crosslinked polystyrene.

[0428] In the next step 402 of the method (corresponding to the specific step S2 of the method according to the invention), the adsorption resin 302 pre-loaded with coffee inclusions is brought into contact with the aqueous extract rich in caffeine, wherein the aqueous extract rich in caffeine is obtained by previously bringing the aqueous (not yet rich in caffeine) extract into contact with a certain amount of caffeinated green coffee beans (corresponding to previously performing step S1 of the method according to the invention). By bringing the adsorption resin 302 pre-loaded with coffee inclusions into contact with the aqueous extract rich in caffeine in step 402, the caffeine in the extract is bound to the adsorption resin, so that an adsorption resin 303 loaded with coffee inclusions and caffeine is obtained.

[0429] Preferably, step 402 is carried out one or more times in a continuous or semi-continuous process, particularly preferably frequently, until a predetermined loading of the adsorption resin with caffeine is reached, and very particularly preferably frequently until the adsorption resin is saturated with caffeine. In Figure 3 this, the multiple execution is schematically indicated by the process line with the reference numeral 402 starting from and leading back to the adsorption resin 303 loaded with coffee inclusions and caffeine.

[0430] In the next step 403 of the method, the adsorption resin 303 loaded with coffee inclusions and caffeine is brought into contact with dichloromethane, so that the caffeine dissolves in the dichloromethane, thereby obtaining an adsorption resin 304 loaded with coffee inclusions and rinsed all around with dichloromethane (corresponding to the specific step S3 of the method according to the invention).

[0431] In the next step 404 of the method, the adsorption resin 304 loaded with coffee inclusions and rinsed all around with dichloromethane is treated. Step 404 includes removing dichloromethane and / or (preferably "and") regenerating the loading capacity of the adsorption resin for caffeine to prepare for (a new) method step 402. Preferably, step 404 is carried out such that the adsorption resin is thereby converted into the form 302 loaded with coffee inclusions and can be reused in method step 402, i.e., can be reused to bind the caffeine in the aqueous extract solution containing caffeine. The reuse of the adsorption resin in its form 302 pre-loaded with coffee inclusions in method step 402 is Figure 3 schematically indicated by the process line drawn from the adsorption resin 302 pre-loaded with coffee inclusions at the bottom left upwards to the adsorption resin 303 loaded with coffee inclusions and caffeine.

[0432] Preferably, step 404 includes one or more of the following measures:

[0433] - Treat the adsorption resin with liquid water or an aqueous solution, preferably at a water temperature of at least 70 °C, particularly preferably at least 85 °C, so that DCM is removed from the adsorption resin, preferably from the pores of the adsorption resin.

[0434] - Treat the adsorption resin with steam so that DCM is removed from the adsorption resin, preferably from the pores of the adsorption resin.

[0435] - Treat the adsorption resin with an aqueous alkaline solution, preferably an aqueous solution containing sodium hydroxide, to regenerate the caffeine loading capacity of the adsorption resin.

[0436] In Figure 3 The method shown is exemplary for the inventive use of a suitable adsorption resin as a "caffeine reservoir": the "caffeine reservoir" has a newly developed and technically advantageous two-stage extraction sequence within the scope of the invention to remove and obtain caffeine from an aqueous extract: "liquid-solid" (loading step; method step 402; caffeine-rich aqueous extract / adsorption resin) plus "solid-liquid" (unloading step; method step 403; loaded adsorption resin / DCM).

[0437] Furthermore, in Figure 3 The method shown is exemplary for the case where the adsorption resin is cleared or unloaded of caffeine by desorbing (selectively) the caffeine bound to the adsorption resin with dichloromethane, so that it can be reused for adsorbing caffeine (efficient recycling process). That is, the adsorption resin can be reused (and multiple times) for (selectively) binding caffeine in an aqueous extract and then (selectively) releasing it to dichloromethane. Therefore, the method according to the invention can achieve the efficient preparation of high-quality decaffeinated green coffee beans by utilizing the adsorption and desorption characteristics of the adsorption resin.

[0438] Example:

[0439] Example test 1 for steps S2 and S3 of the method according to the invention:

[0440] Contact the caffeine-rich aqueous extract with the adsorption resin or other adsorbent material, and then contact the obtained caffeine-loaded adsorption resin or the obtained other adsorbent material with dichloromethane.

[0441] The following adsorption resins and other adsorbent materials were used:

[0442] [1] A microporous activated carbon-type adsorbent composed of spherical particles of a pyrolyzed styrene-DVB copolymer (AF 5 from Lanxess) AF 5)

[0443] [2]Macroporous, monodisperse, strongly acidic food-grade cation exchange resin based on styrene-divinylbenzene copolymer (S2568H of Lanxess Corporation) S2568H)

[0444] [3]Macroporous adsorption resin without functional groups based on divinylbenzene crosslinked polystyrene (VP OC 1064MD PH of Lanxess Corporation) VP OC 1064MD PH)

[0445] [4]Porous activated carbon (ColorSorb W7 series of Jacobi Corporation) TM W7 series)

[0446] The selection of the adsorption materials in the examples is only exemplary, and other adsorption materials can also be used by those skilled in the art with necessary modifications.

[0447] Example test 1 performed herein illustrates the identification and selection of a particularly suitable adsorption material (i.e., adsorption resin) for performing the method for preparing decaffeinated green coffee beans according to the present invention, wherein the adsorption resin is used in steps S2 and S3 of the method according to the present invention. Unless otherwise specified, the tests are performed identically.

[0448] Loading (adsorbing) caffeine in an aqueous solution by an adsorbent resin and other adsorbing materials:

[0449] In example test 1, different adsorption resins or other adsorption materials were weighed on a magnetic stirrer and mixed with caffeine at a mass ratio of 7.5:1 (15 g of the corresponding adsorption resin or the corresponding other adsorption material per 2 g of caffeine). Water was added to the mixture such that a mixture of a caffeine-containing aqueous extract and the adsorption resin or other adsorption material was obtained. The mixture was stirred and then the aqueous solution was filtered. The (filtered) aqueous solution was studied by HPLC-UV according to or similar to DIN ISO 20481 such that conclusions could be drawn about the adsorption capacity of the adsorbent. Thus, the adsorption performance of the material used (= caffeine adsorption rate: the mass of caffeine adsorbed per unit volume of the adsorption resin or other adsorption material) was determined.

[0450] Dissolving (desorbing) caffeine from the caffeine-loaded adsorbent resin or caffeine-loaded adsorbing material:

[0451] Subsequently, approximately 200 g of dichloromethane (DCM) was added to the adsorption resin or other adsorption material previously loaded with caffeine. The DCM was filtered and the caffeine content of the DCM solution was analyzed by HPLC-UV according to or similar to DIN ISO 20481. Thus, the DCM-caffeine-desorption capacity (the amount of caffeine desorbed by DCM, in %) of the material used could be determined.

[0452] Similarly, the adsorption resin or other adsorbent material previously loaded with caffeine is rinsed with water at 80 °C. The water is filtered and the caffeine content of the aqueous solution is analyzed. Thus, the caffeine desorption rate of the material used (the amount of caffeine desorbed by hydrolysis with water at 80 °C, in %) can be determined.

[0453] Table 1 shows the results of Example Test 1.

[0454] Table 1.

[0455]

[0456] The macroporous adsorption resins [2] and [3] used have the advantageous property that when the adsorption resin previously loaded with caffeine is brought into contact with dichloromethane, a large amount of caffeine is desorbed, such that the caffeine dissolves in the dichloromethane. This follows from the DCM-caffeine-unloading capacity (the amount of caffeine desorbed by DCM; desorbed caffeine [%] in Table 1), which is 57% in the case of adsorption resin [2] and 100% in the case of adsorption resin [3].

[0457] The macroporous adsorption resins [2] and [3] used also bind a sufficient amount of caffeine from the caffeine-rich aqueous extract. This follows from the percentage loading of the adsorption resin with the caffeine used (adsorbed caffeine [%] in Table 1), which is 53% in the case of adsorption resin [2] and 54% in the case of adsorption resin [3]. The adsorption performance ( = caffeine loading capacity: the mass of caffeine adsorbed per unit mass of the adsorption resin or other adsorbent material) was determined to be 7% for adsorption resin [2] and 8% in the case of adsorption resin [3]. Although these values are lower compared to the case of the comparative materials [1] and [4]; however, the DCM-caffeine unloading capacity discussed above is decisive first of all.

[0458] Treatment with water did not achieve a good caffeine unloading capacity; furthermore, treatment with water is not selective.

[0459] Thus, it has been confirmed that it is particularly advantageous to use macroporous adsorption resins (adsorption resins [2] and [3] used) selected from polystyrene, polydivinylbenzene and their copolymers with each other and with other monomers in order to:

[0460] i) bind caffeine from the caffeine-rich aqueous extract,

[0461] and

[0462] ii) desorb caffeine when the adsorption resin previously loaded with caffeine is brought into contact with dichloromethane, such that the caffeine dissolves in the dichloromethane.

[0463] It has also been confirmed that it is completely particularly advantageous to use a macroporous adsorption resin that is non-functionalized and non-ionic divinylbenzene cross-linked polystyrene (the adsorption resin [3] used) so that caffeine is desorbed when the previously caffeine-loaded adsorption resin is contacted with dichloromethane, such that the caffeine dissolves in the dichloromethane, see the 100% DCM-caffeine unloading capacity of adsorption resin [3].

[0464] Furthermore, it has been confirmed that dichloromethane is particularly well-suited for desorbing caffeine from a previously caffeine-loaded adsorption resin. This is a major advantage of the method according to the invention, in particular step S3, compared to methods known from the prior art (see also DE 2600492 A1 and DE 2832267 A1).

[0465] In contrast, water at a temperature of 80 °C has a much poorer performance.

[0466] Example test 2: Adsorbing caffeine on an adsorption resin by contacting a caffeine-rich aqueous extract with the adsorption resin

[0467] The following adsorption resins were used:

[0468] [1] Non-functionalized non-ionic macroporous adsorption resin based on divinylbenzene cross-linked polystyrene ( XFP2700),

[0469] [2] Non-functionalized non-ionic macroporous adsorption resin based on polydivinylbenzene (PuroSorb from Purolite TM PAD500),

[0470] [3] Non-functionalized non-ionic macroporous adsorption resin based on divinylbenzene cross-linked polystyrene (VP OC 1064MD PH from Lanxess ),

[0471] [4] Non-functionalized non-ionic macroporous adsorption resin based on divinylbenzene cross-linked polystyrene (Macronet from Purolite TM MN202),

[0472] [5] Non-functionalized non-ionic macroporous adsorption resin based on polydivinylbenzene (PuroSorb from Purolite TM PAD600),

[0473] [6] Tertiary amino-functionalized basic macroporous adsorption resin based on divinylbenzene cross-linked polystyrene (Macronet from Purolite TMMN102)

[0474] [7]Tertiary amino-functionalized basic macroporous adsorption resin based on divinylbenzene cross-linked polystyrene (Macronet MN150 from Purolite TM MN150)

[0475] [8]Sulfonic acid-functionalized acidic macroporous adsorption resin based on divinylbenzene cross-linked polystyrene (C160H from Purolite C160H)

[0476] [9]Sulfonic acid-functionalized acidic macroporous adsorption resin based on divinylbenzene cross-linked polystyrene (Macronet MN502 from Purolite TM MN502).

[0477] The selection of the adsorption resin in Example Test 2 is only exemplary, and those skilled in the art can also study other adsorption materials in a similar manner.

[0478] In Example Test 2, different adsorption resins were analyzed for their caffeine adsorption performance. Unless otherwise specified, the tests were performed identically. A caffeine-rich aqueous extract with a caffeine concentration of 1500 mg / L was prepared. 40 g of the caffeine-rich aqueous extract was mixed with 1 g or 5 g of the respective adsorption resin, and the resulting mixture of the adsorption resin and the caffeine-rich aqueous extract was incubated for one hour. After the one-hour incubation time, the caffeine content of the aqueous extract was analyzed by HPLC-UV according to or similar to DIN ISO 20481. Then, the corresponding caffeine reduction rate (the amount of caffeine reduction after one hour of incubation of the aqueous extract with the respective adsorption resin, in %) and the caffeine adsorption rate (the mass of caffeine adsorbed per unit mass of the adsorption resin used, in %) were calculated therefrom.

[0479] Table 2 shows the results of the reduction of caffeine content in the aqueous extract (caffeine reduction rate) when using different adsorption resins.

[0480] Table 3 shows the results of the absorption of caffeine from the aqueous extract (caffeine adsorption rate) when using different adsorption resins.

[0481] Table 2.

[0482]

[0483] Table 3.

[0484]

[0485]

[0486] All of the macroporous adsorption resins [1] to [9] used herein are capable of binding a certain amount of caffeine from the aqueous extract rich in caffeine (in accordance with step S2 of the method according to the invention).

[0487] Herein, the caffeine content of the aqueous extract containing caffeine is significantly reduced. The caffeine reduction rate (the amount of caffeine reduction after one hour of incubation of the aqueous extract with the corresponding adsorption resin, in %) is in the range between 20.9% and 48.7% (when using 1 g of each adsorption resin), or in the range between 44.4% and 88.5% (when using 5 g of each adsorption resin).

[0488] Correspondingly, all of the macroporous adsorption resins [1] to [9] used herein are capable of adsorbing a certain amount of caffeine (in accordance with step S2 of the method according to the invention). The caffeine adsorption rate (the mass of caffeine adsorbed per unit mass of the adsorption resin used, in %) is in the range between 1.27% and 2.96% (when using 1 g of each adsorption resin), or in the range between 0.54% and 1.08% (when using 5 g of each adsorption resin).

[0489] It has also been confirmed that it is completely particularly advantageous to use macroporous adsorption resins selected from polystyrene, polydivinylbenzene and their copolymers with each other and other monomers and which are non-functionalized and non-ionic, in order to bind the caffeine in the extract to the adsorption resin upon contact with the aqueous extract rich in caffeine (see the particularly good caffeine reduction rates and caffeine adsorption rates of adsorption resins [1] to [5] respectively).

[0490] Example test 3: Adsorbing caffeine on the adsorption resin by (continuously) passing the aqueous extract rich in caffeine through an adsorption column filled with the adsorption resin

[0491] In example test 3, the "co-extract - caffeine solution" (aqueous extract rich in caffeine; caffeine concentration: see the following table headings) was respectively passed through an adsorption column having a volume of 100 mL (100 mL = column volume, BV), where the adsorption column was filled with the adsorption resin respectively. That is to say, the adsorption resin was flowed through by the aqueous extract containing caffeine. After the co-extract - caffeine solution passed through the adsorption column by 2.5 BV or 5 BV each (i.e., after passing through 250 mL or 500 mL), samples were taken from the passed co-extract - caffeine solution, and the caffeine content of the corresponding samples was analyzed according to or similar to DIN ISO 20481. Then conclusions can be drawn respectively about the following:

[0492] i) The amount of caffeine that has passed through (not adsorbed),

[0493] ii) The amount of caffeine adsorbed on the adsorption resin every 2.5 BV or 5 BV passed through,

[0494] iii) The cumulative amount of caffeine adsorbed on the adsorption resin,

[0495] iv) The caffeine loading of the adsorption resin, in g / l (the mass of caffeine adsorbed per unit volume of the adsorption resin, in g / l), and

[0496] v) The caffeine loading of the adsorption resin, in mol / l (the amount of caffeine adsorbed per unit volume of the adsorption resin, in mol / l)

[0497] The following adsorption resins were used:

[0498] [1] A non-functionalized non-ionic macroporous adsorption resin based on divinylbenzene cross-linked polystyrene (VP OC 1064MD PH from Lanxess) VP OC 1064MD PH)

[0499] [2] A microporous activated carbon-type adsorbent composed of spherical particles of pyrolyzed styrene-DVB copolymer (AF 5 from Lanxess) AF 5)

[0500] [3] A macroporous, monodisperse, strongly acidic food-grade cation exchange resin based on styrene-divinylbenzene copolymer (S2568H from Lanxess) S2568H)

[0501] [4] A macroporous, monodisperse, strongly acidic food-grade cation exchange resin based on styrene-divinylbenzene copolymer (S2568 from Lanxess, in the delivery form of Na S2568, delivery form as Na + )

[0502] [5] A non-functionalized non-ionic macroporous adsorption resin based on divinylbenzene cross-linked polystyrene (Macronet MN270 from Purolite) TM MN270).

[0503] The selection of the adsorption resin in Example Test 3 is only exemplary, and those skilled in the art can also study other adsorption materials in a similar manner.

[0504] Tables 4 to 8 show the corresponding results of Example Test 3 when using adsorption resins [1] to [5].

[0505] Table 4. Guiding co-extract-caffeine solution (caffeine concentration: 642 mg / L) through an adsorption column filled with adsorption resin [1] (column volume = 100 mL = 1 BV)

[0506]

[0507] Table 5. Guiding co-extract-caffeine solution (caffeine concentration: 700 mg / L) through an adsorption column filled with adsorption resin [2] (column volume = 100 mL = 1 BV)

[0508]

[0509]

[0510] Table 6. Guiding co-extract-caffeine solution (caffeine concentration: 2087 mg / L) through an adsorption column filled with adsorption resin [3] (column volume = 100 mL = 1 BV)

[0511]

[0512]

[0513] Table 7. Guiding co-extract-caffeine solution (caffeine concentration: 2820 mg / L) through an adsorption column filled with adsorption resin [4] (column volume = 100 mL = 1 BV)

[0514]

[0515] Table 8. Guiding co-extract-caffeine solution (caffeine concentration: 642 mg / L) through an adsorption column filled with adsorption resin [5] (column volume = 100 mL = 1 BV)

[0516]

[0517] All macroporous adsorption resins [1] to [5] used herein are capable of binding a certain amount of caffeine from the water-containing co-extract rich in caffeine (in accordance with step S2 of the method according to the invention). It has also been confirmed that including the contact of overflowing the adsorption resin with the water-containing extract rich in caffeine along a defined first flow direction (in accordance with step S2 of the method according to the invention) is particularly advantageous.

[0518] It has also been confirmed that it is entirely particularly advantageous to use macroporous adsorption resins selected from polystyrene, polydivinylbenzene and their copolymers with one another and other monomers and which are non-functionalized and non-ionic (adsorption resins [1] and [5] used) in order to bind the caffeine in the extract to the adsorption resin during multiple contacts or during contact by percolation with a caffeine-rich aqueous extract. This is confirmed as follows: a high maximum caffeine loading of 22.261 g / l in the case of adsorption resin [1] and 25.454 g / l in the case of adsorption resin [5] (reached after percolation of 40 BV or 50 BV respectively), and a cumulative amount of caffeine adsorbed on the adsorption resin of 2.226 g when using 100 mL of adsorption resin [1] and 2.545 g when using 100 mL of adsorption resin [5] (reached after percolation of 40 BV or 50 BV respectively).

[0519] It can also be seen from Example Test 3 that at the start of percolation of the co-extract-caffeine solution through the adsorption resin, a large amount of caffeine binds to the adsorption resin and sometimes the caffeine is completely removed from the aqueous solution (see the initial values of the caffeine adsorbed per respective BV in column 4 of Tables 4 to 8). Thus, the partially or completely decaffeinated aqueous solution (caffeine-poor aqueous extract) obtained after contact with the respective adsorption resin can be reused as the aqueous extract in step S1 of the process according to the invention (advantageous recycling process).

[0520] However, depending on the type of adsorption resin used, the adsorption resin becomes saturated (caffeine absorption capacity limit) from a certain amount of bound caffeine. This can also be seen from the increase in the caffeine content of the co-extract-caffeine solution passed through. Thus, in Example Test 3 carried out here, when using 100 mL of adsorption resin [1], the caffeine absorption capacity limit was reached at approximately 35 BV of the co-extract-caffeine solution passed through, since from that moment on, little or no caffeine binds to the adsorption resin and instead the caffeine remains in the co-extract-caffeine solution passed through.

[0521] It follows therefrom that preferably, in the process according to the invention, at saturation, a transition is made from step S2 (loading the adsorption resin with caffeine) to step S3 (unloading by contact with DCM). That is, at the latest when saturated with caffeine, a predetermined loading of the adsorption resin with caffeine is reached.

[0522] Example Test 4: Caffeine is adsorbed on the adsorption resin multiple times by passing a caffeine-rich aqueous extract through an adsorption column filled with an adsorption resin in two loading cycles (two independent adsorption steps) with a caffeine desorption step therebetween

[0523] In Example Experiment 4, adsorption columns each with a volume of 100 mL were filled with adsorption resins. A co-extract-caffeine solution (a caffeine-rich aqueous extract with a caffeine concentration of 4500 mg / l) was passed through the adsorption columns filled with adsorption resins (Cycle 1). The volumetric flow rate of the co-extract-caffeine solution passed through was 5 BV / h. After the co-extract-caffeine solution had passed through the adsorption columns by 2.5 BV or 5 BV respectively, samples were taken from the co-extract-caffeine solution that had passed through, and the caffeine content of the samples was analyzed.

[0524] After completion of the first loading cycle, the caffeine-loaded adsorption columns were rinsed with dichloromethane in order to desorb caffeine from the adsorption columns. The caffeine content in the obtained dichloromethane solution was determined, and the caffeine recovery rate was calculated therefrom.

[0525] Subsequently, the loading cycle described above was repeated (Cycle 2). In the second loading cycle, after the co-extract-caffeine solution had passed through the adsorption columns by 2.5 BV or 5 BV respectively, samples were taken from the co-extract-caffeine solution that had passed through, and the caffeine content of the samples was analyzed. Then conclusions can be drawn respectively regarding the following:

[0526] i) The amount of caffeine adsorbed on the adsorption resin per 2.5 BV or 5 BV passed through,

[0527] ii) The cumulative amount of caffeine adsorbed on the adsorption resin,

[0528] iii) The caffeine loading of the adsorption resin (the mass of caffeine adsorbed per unit volume of the adsorption resin, in g / l), and

[0529] iv) The caffeine recovery rate.

[0530] The following adsorption resins were used:

[0531] [1] A non-functionalized non-ionic macroporous adsorption resin based on divinylbenzene cross-linked polystyrene (VP OC 1064MD PH from Lanxess) VP OC 1064MD PH)

[0532] [2] A non-functionalized non-ionic macroporous adsorption resin based on polydivinylbenzene (PuroSorb PAD600FM from Purolite) TM PAD600FM)

[0533] [3] A non-functionalized non-ionic macroporous adsorption resin based on polydivinylbenzene (PuroSorb PAD500 from Purolite) TM PAD500)

[0534] The selection of the adsorption resin in the examples described is merely exemplary, and other adsorption resins may also be used.

[0535] Tables 9 to 11 show the corresponding results of Example Test 4 when using adsorption resins [1] to [3].

[0536] Table 9. Results of Example Test 4 when using adsorption resin [1]

[0537]

[0538]

[0539] Table 10. Results of Example Test 4 when using adsorption resin [2]

[0540]

[0541]

[0542] Table 11. Results of Example Test 4 when using adsorption resin [3]

[0543]

[0544]

[0545] The execution or setting of Example Test 4 corresponds to the method according to the invention, in which steps S2 (caffeine adsorption) and S3 (caffeine desorption) are carried out alternately and successively a plurality of times. It has been confirmed here that carrying out the method according to the invention in particular with the adsorption resins [1] to [3] used here, i.e. macroporous adsorption resins selected from polystyrene, polydivinylbenzene and their copolymers with each other and other monomers and non-functionalized and non-ionic, shows particularly good results.

[0546] In the first and second loading cycles (each according to step S2 of the method according to the invention), a large amount of caffeine in the caffeine-containing extract used may bind to the adsorption resin. Thus, the respective maximum cumulative amounts of caffeine adsorbed on the adsorption resin are 3.89 g (cycle 1) and 3.72 g (cycle 2) when using adsorption resin [1], 4.50 g (cycle 1) and 4.75 g (cycle 2) when using adsorption resin [2], and 4.23 g (cycle 1) and 4.12 g (cycle 2) when using adsorption resin [3]. The corresponding maximum caffeine loadings (total capacities, in g / l) of the adsorption resins are 38.94 g / l (cycle 1) and 37.22 g / l (cycle 2) when using adsorption resin [1], 44.97 g / l (cycle 1) and 47.52 g / l (cycle 2) when using adsorption resin [2], and 42.30 g / l (cycle 1) and 41.18 g / l (cycle 2) when using adsorption resin [3]. Thus, the caffeine adsorption performance in the first and second loading cycles is almost the same. Thus, in the method according to the invention, a suitable adsorption resin can be used multiple times as a "caffeine buffer" in a technically advantageous manner.

[0547] Individual drops in caffeine loading at the end of a particular cycle may be the result of measurement inaccuracies in a complex technical facility with multiple columns.

[0548] The caffeine recovery rate by rinsing the caffeine-loaded adsorption resin with DCM after the first loading cycle (according to step S3 of the method according to the invention) is also a very high value, 93.6% (adsorption resin [1]) and 100% (adsorption resins [2] and [3]). Thus, the caffeine-loaded adsorption resin can be rinsed (contacted) with dichloromethane such that at least 90% of the caffeine in the caffeine-loaded adsorption resin dissolves into the dichloromethane.

[0549] The caffeine recovery rate by rinsing the caffeine-loaded adsorption resin with DCM after the second loading cycle (according to step S3 of the method according to the invention) is a very high value, 82.4% (adsorption resin [1]), 84.7% (adsorption resin [2]), and 88.5% (adsorption resin [3]). In the case of repeatedly performing method steps S2 and S3, the caffeine-loaded adsorption resin can also be rinsed (contacted) a second time with dichloromethane such that at least 80% of the caffeine in the caffeine-loaded adsorption resin dissolves into the dichloromethane.

[0550] Thus, the method according to the invention can be effectively carried out such that not only decaffeinated green coffee beans are obtained as a (separate) product, but also caffeine or a caffeine extract.

[0551] Experimental Example 5: Caffeine is extracted from caffeinated green coffee beans by means of an aqueous extracting solution, so that caffeine in the caffeinated green coffee beans is extracted into the extracting solution, and then the obtained caffeine-rich aqueous extracting solution is contacted with an adsorption resin so that the caffeine in the extracting solution is bound to the adsorption resin, and the adsorption resin loaded with caffeine is contacted with dichloromethane so that the caffeine is dissolved in the dichloromethane.

[0552] Green coffee beans and water in a mass ratio of 1:1.27 are placed in a reactor. The extraction mixture is heated to a temperature of 80° C. by means of a hood-type heating device and stirred over a period of 30 minutes. After 30 minutes of stirring, the obtained extract (liquid phase of the extraction mixture) is separated from the extracted green coffee beans and guided through two adsorption columns connected in series. The adsorption columns have a total volume of 2×400 mL=800 mL (=1 BV) and are each filled with 240 g of a non-functional group-free, nonionic macroporous adsorption resin based on divinylbenzene crosslinked polystyrene (Lanxess Corporation). VPOC 1064MD PH). The volume flow is about 5 BV / h. After being conducted through the adsorption column, the extraction liquid is conducted back into the reactor to the (already partially extracted) green coffee beans remaining there and, after their re-extraction, is conducted from there again through the adsorption column (circulation loop system).

[0553] The caffeine content of the aqueous extract was analyzed both before and after the passage through the adsorption column, after each passage of approximately 5 BV (in a time interval of 30-60 minutes) (see Table 12). From this it was determined that:

[0554] i) the amount of caffeine adsorbed on the adsorption resin per passage through the corresponding BV,

[0555] ii) the cumulative amount of caffeine adsorbed on the adsorption resin, and

[0556] iii) Caffeine loading of the adsorption resin (mass of caffeine adsorbed per unit volume of the adsorption resin, in g / l).

[0557] In addition, samples were taken from the aqueous extract at the beginning and at the end of the experiment (after 6.3 hours) and analyzed for concentrations of some common coffee ingredients (see Table 13).

[0558] After the test, the adsorption column carrying caffeine was rinsed with dichloromethane in order to desorb the caffeine from the adsorption column. The recovery rate in the dichloromethane phase was close to 100%. In addition, the phases were analyzed for chlorogenic acid, asparagine, total dry residue (GTR), ash in GTR, total fat, total protein, and total sugar. The content of chlorogenic acid in the obtained dichloromethane solution was <2 ppm, the content of asparagine was <12.5 ppm, the content of total fat was <0.3 g / 100 mL, the content of total protein was <0.5 g / 100 mL, and the content of total sugar was <0.5 g / 100 mL. The GTR was 1600 mg / L, and the ash in GTR was present at 5.36%.

[0559] After the test, the extracted green coffee beans were separated from the aqueous extract and dried. The caffeine content of the extracted green coffee beans was analyzed and was 0.09%.

[0560] Table 12. Results of Example Test 5 - Caffeine Content of the Aqueous Extract

[0561]

[0562] Table 13. Analysis of the Concentrations of Some Coffee Inclusions in the Aqueous Extract at the Beginning of the Test and at the End of the Test (after 6.3 hours)

[0563]

[0564]

[0565] The test execution or setup of Example Test 5 corresponds to the method according to the invention, wherein steps S1 (extracting caffeine from green coffee beans with an aqueous extract) and S2 (adsorbing the caffeine in the aqueous extract on an adsorption resin) are carried out multiple times and the aqueous extract is conveyed in a loop one or more times. Here, the caffeine-depleted aqueous extract obtained in step S2 or its treatment product is reused as the aqueous extract in step S1.

[0566] The results of Example Test 5 show that decaffeinated green coffee beans with a caffeine content of only 0.09% can be prepared in an efficient manner by means of the method according to the invention. Here, the green coffee beans are advantageously not brought into contact with organic solvents, such as DCM; rather, the caffeine is extracted only by contact with the aqueous extract.

[0567] Furthermore, Example Experiment 5 shows (in accordance with step S2 of the method according to the invention) the efficiency of caffeine adsorption on a macroporous adsorption resin selected from polystyrene, polydivinylbenzene and copolymers thereof with one another and with other monomers, and the macroporous adsorption resin is non-functionalized and non-ionic (see adsorption resin [1] used herein). The adsorption resin used herein is capable of binding a particularly large amount of caffeine in the aqueous extraction solution containing caffeine. For this purpose, in particular, see that the maximum cumulative amount of caffeine adsorbed on the adsorption resin is 14.46 g, and the maximum caffeine loading of the adsorption resin is 18.07 g / l. The decrease in caffeine loading between the time points of 5.8 hours and 6.3 hours of the experiment may be the result of measurement inaccuracies in complex industrial facilities and / or the establishment of equilibrium under experimental conditions.

[0568] Furthermore, the adsorption resin used is capable of selectively binding caffeine in step S2 of the method according to the invention. Here, selectivity means that other coffee inclusions contained in the aqueous extract, such as asparagine, fat, protein, sugar and chlorogenic acid, do not bind to or bind less strongly to the adsorption resin (see the values in Table 13). This is particularly advantageous because the substances important for the sensory quality of coffee remain in the aqueous extract, so that a smaller amount of said substances is also extracted from the coffee beans.

[0569] Furthermore, caffeine is very efficiently and selectively desorbed from the adsorption resin previously loaded with caffeine and other coffee inclusions by means of dichloromethane, such that caffeine dissolves in dichloromethane (in accordance with step S3 of the method according to the invention). The recovery rate of caffeine in the dichloromethane solution is very high and is 90.4%.

[0570] Example Experiment 5 shows that although a certain amount of chlorogenic acid binds to the adsorption resin - see that the content of chlorogenic acid in the aqueous extract at the start of the experiment is 10017 mg / L and the content of chlorogenic acid in the aqueous extract at the end of the experiment after 6.3 hours is 8858 mg / L, however, the amount of chlorogenic acid bound to the adsorption resin does not desorb upon contact with dichloromethane. Only <2 ppm of chlorogenic acid is present in the dichloromethane solution.

[0571] Therefore, the adsorption resin can be (in steps S2 and S3 of the method according to the invention) reused (and repeatedly) for (selectively) binding caffeine from the aqueous extract and then (selectively) releasing it to dichloromethane. Therefore, Example Experiment 5 clearly shows that the present invention particularly utilizes the following technical situation: caffeine has a medium solubility in water (and thus can be efficiently bound by the adsorption resin from the aqueous solution), but is particularly well soluble in dichloromethane (and thus is efficiently released by the adsorption resin to dichloromethane).

[0572] Example experiment 6:

[0573] In Example experiment 6, the method according to Example experiment 5 was repeated a total of 13 times (13 loading and unloading cycles in accordance with steps S2 and S3 of the method according to the invention respectively), and the maximum caffeine loading of the adsorption resin in g / l and the recovery rate of caffeine in the dichloromethane solution in % were determined respectively (see Table 14).

[0574] Table 14.

[0575]

[0576] Here, the recovery rate of caffeine is partly higher than the theoretically possible value of 100%. This may be due to common measurement deviations.

[0577] The tests clearly show that the adsorption resin can be used multiple times for (selectively) binding caffeine from the aqueous extract (in accordance with step S2 of the method according to the invention) and subsequently (selectively) releasing it to dichloromethane (in accordance with step S3 of the method according to the invention).

Claims

1. A method for preparing decaffeinated green coffee beans, The method has the following steps: (S1) Contacting a certain amount of green coffee beans containing caffeine with an aqueous extract so that the caffeine in the green coffee beans containing caffeine is extracted into the extract, (S2) Contacting the caffeine-rich aqueous extract obtained in step S1 with an adsorption resin so that the caffeine in the extract binds to the adsorption resin, (S3) Contacting the adsorption resin carrying caffeine obtained in step S2 with dichloromethane so that the caffeine dissolves in dichloromethane.

2. The method according to claim 1, wherein in step S2, an adsorption resin pre-loaded with one or more coffee inclusions other than caffeine is used, and the coffee inclusions are selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants, so as to prevent the corresponding coffee inclusions in the extract containing caffeine obtained in step S1 from binding to the adsorption resin or making it difficult.

3. The method according to any one of the above claims, wherein in step S1 as the aqueous extract - water is used, or - an aqueous solution containing one or more coffee inclusions other than caffeine is used, and the coffee inclusions are selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants, so as to prevent the corresponding coffee inclusions in the green coffee beans containing caffeine from being extracted into the extract or making it difficult.

4. The method according to any one of the above claims, wherein in step S2 - a macroporous adsorption resin is used, and the macroporous adsorption resin is selected from polystyrene, polydivinylbenzene, and copolymers thereof with each other and other monomers, wherein the macroporous adsorption resin is preferably polystyrene or a copolymer of polystyrene, preferably cross-linked polystyrene, particularly preferably divinylbenzene-cross-linked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene-cross-linked polystyrene, and / or - at least 90%, preferably at least 95%, most particularly preferably at least 99% of the caffeine in the extract containing caffeine binds to the adsorption resin.

5. The method according to any one of the above claims, wherein in step S3 - the contact is carried out so that at least 80%, preferably at least 90%, particularly preferably at least 95%, most particularly preferably at least 99% of the caffeine in the adsorption resin carrying caffeine dissolves into dichloromethane, and / or - the temperature of the dichloromethane is lower than 35 °C, preferably lower than 30 °C, particularly preferably lower than 25 °C.

6. The method according to any one of the above claims, wherein step S1 is carried out so that at least a predetermined amount of caffeine is extracted from a certain amount of green coffee beans containing caffeine, and / or the decaffeinated green coffee beans obtained in step S1 are dried.

7. The method according to any one of the above claims, the method comprising an additional step after step S3: (S4) Treating the adsorption resin, (S4-1) to remove dichloromethane, and / or (S4-2) The loading capacity of the regenerated adsorption resin for caffeine under the conditions of step S2, wherein preferably, in step S4-1, treating the adsorption resin to remove dichloromethane includes one or more of the following measures: - Treating the adsorption resin with liquid water or an aqueous solution preferably at a water temperature of at least 70 °C, particularly preferably at least 85 °C, so that DCM is removed from the adsorption resin, preferably from the pores of the adsorption resin. - Treating the adsorption resin with steam so that DCM is removed from the adsorption resin, preferably from the pores of the adsorption resin. And wherein preferably, in step S4-2, treating the adsorption resin to regenerate the loading capacity of the adsorption resin for caffeine under the conditions of step S2 includes the following measures: - Treating the adsorption resin with an alkaline aqueous solution, preferably an aqueous solution containing sodium hydroxide, preferably at a temperature in the range of 60 °C to 80 °C.

8. The method according to any one of the preceding claims, wherein the contact in step S2 includes overflowing the adsorption resin with the caffeine-rich aqueous extract obtained in step S1, and / or the subsequent contact in step S3 includes overflowing the caffeine-loaded adsorption resin with dichloromethane, wherein preferably, the contact in step S2 includes overflowing the adsorption resin with the caffeine-rich aqueous extract obtained in step S1 along a defined first flow direction, and the subsequent contact in step S3 includes overflowing the caffeine-loaded adsorption resin with dichloromethane along a defined second flow direction.

9. The method according to any one of the preceding claims, wherein - determining the progress achieved in the extraction in step S1 and / or the loading of the adsorption resin with caffeine achieved in step S2, and as long as a predetermined progress of the extraction in step S1 is achieved and / or as long as a predetermined loading of the adsorption resin with caffeine is achieved in step S2, switching, preferably automatically, from step S2 to step S3, and / or - wherein the aqueous extract is conveyed in the circuit one or more times, and wherein preferably, the caffeine-poor aqueous extract obtained in step S2 or its treated product is reused as the aqueous extract in step S1.

10. The method according to any one of the preceding claims, wherein the method is a method for preparing decaffeinated green coffee beans and a caffeine concentrate, and the method further includes the following additional step: (S5) Obtaining a caffeine concentrate from the solution of caffeine in dichloromethane present after step S3, preferably by separating the caffeine.

11. An apparatus for preparing decaffeinated green coffee beans in the method according to any one of the preceding claims, the apparatus comprising: - An extractor (10) that can be filled with a certain amount of green coffee beans, the extractor being used to bring a certain amount of caffeine-containing green coffee beans into contact with an aqueous extract. - An adsorption unit (30) having an adsorption resin (32), the adsorption unit being configured to bring a caffeine-rich aqueous extract into contact with the adsorption resin (32), wherein the extractor is connected to the adsorption unit (30) such that the caffeine-rich aqueous extract can be directed from the extractor (10) into the adsorption unit (30), wherein an adsorption resin pre-loaded with one or more coffee inclusions other than caffeine is used, the coffee inclusions being selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants, - A storage container (40) for an aqueous extract, the storage container for an aqueous extract being connected to the extractor (10) such that the aqueous extract can be directed from the storage container (40) for an aqueous extract into the extractor (10), - A storage container (70) for dichloromethane, the storage container for dichloromethane being connected to the adsorption unit (30) such that dichloromethane can come into contact with the adsorption resin (32), - One or more control devices, the control devices being configured to control the conveyance of the aqueous extract and / or dichloromethane within the apparatus, and / or the control devices being configured to automatically switch from step S2 to step S3 as soon as a predetermined progress of the extraction in step S1 is reached and / or as soon as a predetermined loading of the adsorption resin (32) with caffeine is reached in step S2.

12. The apparatus according to claim 11, - wherein the apparatus is configured to convey the aqueous extract in a circulation loop, wherein the extractor (10) and the adsorption unit (30) and preferably the storage container (40) for the aqueous extract are part of the circulation loop, and / or - the apparatus has a separation unit (90), the separation unit being configured to separate caffeine from a solution of caffeine in dichloromethane, wherein the apparatus is configured to convey dichloromethane from the storage container (70) for dichloromethane to the adsorption unit (30) and from there to the separation unit (90).

13. The apparatus according to any one of claims 11 to 12, wherein - the extractor (10) is filled with green coffee beans, - the storage container (40) for the aqueous extract contains an aqueous extract, - the storage container (70) for dichloromethane contains a quantity of dichloromethane, and / or - the adsorption resin (32) is a macroporous adsorption resin, the macroporous adsorption resin being selected from polystyrene, polydivinylbenzene, and copolymers thereof with one another and other monomers, wherein the macroporous adsorption resin is preferably polystyrene or a copolymer of polystyrene, preferably crosslinked polystyrene, particularly preferably divinylbenzene-crosslinked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene-crosslinked polystyrene.

14. Use of an apparatus according to any one of claims 11 to 12 for carrying out a method according to any one of claims 1 to 9.

15. Use of dichloromethane, wherein the dichloromethane is used to remove caffeine from an adsorption resin carrying caffeine and other coffee inclusions, wherein the adsorption resin is preferably a macroporous adsorption resin, and the macroporous adsorption resin is selected from polystyrene, polydivinylbenzene and copolymers thereof with each other and other monomers, wherein the macroporous adsorption resin is particularly preferably polystyrene or a copolymer of polystyrene, preferably crosslinked polystyrene, particularly preferably divinylbenzene crosslinked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene crosslinked polystyrene, and / or wherein the application is carried out in the apparatus according to any one of claims 11 to 13.

16. Use of an adsorption resin, wherein the adsorption resin is preferably a macroporous adsorption resin, and the macroporous adsorption resin is selected from polystyrene, polydivinylbenzene and copolymers thereof with each other and other monomers, wherein the macroporous adsorption resin is particularly preferably polystyrene or a copolymer of polystyrene, preferably crosslinked polystyrene, particularly preferably divinylbenzene crosslinked polystyrene, and most particularly preferably non-functionalized, non-ionic divinylbenzene crosslinked polystyrene, the adsorption resin is used to adsorb caffeine in an aqueous extract rich in caffeine in a method for preparing decaffeinated green coffee beans, wherein the adsorption resin carrying caffeine extracted from green coffee beans is treated with dichloromethane so that the caffeine dissolves in the dichloromethane, the adsorption resin is preferably used in the method according to any one of claims 1 to 10 and / or in the apparatus according to any one of claims 11 to 13.

17. Use of the adsorption resin according to claim 16, wherein an adsorption resin pre-loaded with one or more coffee inclusions that are not caffeine is used, and the coffee inclusions are selected from acids, minerals, aromatics, compounds that can be converted into aromatics by the Maillard reaction, and antioxidants, so as to prevent or make it difficult for the corresponding coffee inclusions in the extract containing caffeine obtained in step S1 to bind to the adsorption resin.

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