Method for producing beverage ingredients

Abstract

The present invention provides a method for processing a beverage ingredient extract, the method comprising the steps of: a. filtering the beverage ingredient extract to obtain a beverage ingredient extract retentate and a beverage ingredient extract permeate; b. raising the pH of the beverage ingredient extract retentate to provide a processed beverage ingredient extract retentate; and c. combining the processed beverage ingredient extract retentate with the beverage ingredient extract permeate to produce a reconstituted ingredient extract.

Description

Technical Field

[0001] The present invention relates to a method for processing a beverage ingredient extract and a beverage ingredient extract obtained by the method. The present invention also relates to a beverage ingredient extract. Background Art

[0002] Instant coffee powder is a soluble coffee powder that consumers particularly like because of its convenience, as it allows for easy and quick preparation of coffee beverages. However, consumers perceive it as having a weaker aroma than freshly brewed coffee products, which are perceived as having a stronger aroma, a fuller taste (less water) and a higher quality.

[0003] The demand for instant coffee powders having a premium perception and higher in-cup quality (eg, having an aroma level comparable to a roasted and freshly ground brew) continues to increase.

[0004] The poor quality perceived by consumers in conventional instant coffee powders is mainly due to the standard processes used to make the soluble coffee powders. These processes usually include multiple steps, each of which can lead to the loss of some of the volatile organic compounds (VOCs), i.e., aroma compounds, that are characteristic of any coffee product.

[0005] The conventional manufacturing process of instant coffee powder is complex and, as mentioned above, includes several steps. The first step is usually to generate an aqueous coffee extract from roasted and ground coffee powder, which is extracted with water at high temperature (e.g., between 100°C-220°C). The resulting just-brewed extract is then sent to an aroma compound recovery step, in which the aroma compounds responsible for the aroma of just-brewed are removed for storage and subsequent addition, thereby adding just-brewed aroma to the final product. The removed extract is concentrated to produce liquid coffee, and once the aroma compounds are added again, it is finally sent to a drying process (freeze drying and / or spray drying) to produce instant coffee powder. High temperatures are usually used to increase the extraction yield of the process, because the extract obtained by high temperature presents a high concentration of molecules with high molecular weight (HMW) compounds (particularly melanoidins), which are directly related to the better cup taste perception of the resulting instant coffee powder when dissolved in water.

[0006] Recent studies have shown that these high molecular weight (HMW) compounds, in particular melanoidins, are also responsible for the binding activity towards volatile organic compounds (VOCs), i.e. aroma compounds of roast and ground coffee extracts. In fact, it has been demonstrated that certain aroma compounds, such as aldehydes, hydroxyphenols, thiols and pyrazines, which play an important role in the aroma perception of any coffee beverage, are bound by high molecular weight (HMW) compounds, such as melanoidins, present in the coffee extract, resulting in a less aromatic and / or stale coffee extract and, therefore, a less aromatic liquid coffee concentrate and / or instant coffee powder.

[0007] Therefore, for the manufacture of high in-cup quality liquid coffee concentrates and / or instant coffee powders, it is crucial to find the right balance between reducing aroma compound binding activity by high molecular weight (HMW) compounds on the one hand and obtaining a high yield of coffee extract on the other hand, which then provides good in-cup taste and aroma.

[0008] Currently, there are few effective solutions to prevent the aroma-HMW compound binding effect, other than limiting or reducing the amount of dry matter extracted (i.e. the yield of the extraction process), resulting in a less cost-effective manufacturing process and liquid coffee concentrate and / or instant coffee powder with poor in-cup quality, with the resulting beverage being perceived as being more watery.

[0009] Other conventional approaches address the problem of low aroma and therefore low quality perceived instant coffee powders using an aroma recovery step, removing aroma compounds from the freshly brewed coffee extract prior to concentration and adding them back prior to the drying process (spray drying or freeze drying). However, the aroma recovery step is a complex and expensive step in the manufacturing process and requires expertise and high power / energy consumption.

[0010] It would therefore be advantageous to provide a method of inhibiting the agonistic effects of HMW compounds while retaining key aroma compounds in the final coffee product.

[0011] It would also be advantageous to provide a method of ensuring that less aroma compounds are bound by HMW compounds, particularly melanoidins, thereby reducing the binding activity between the two species.

[0012] It would also be advantageous to provide a method for improving the quality of instant coffee powder with reduced manufacturing complexity and cost, thereby reducing the aroma compound recovery step or not including an aroma compound recovery step at all.

[0013] It would therefore be advantageous to provide a method that is applicable to any conventional extraction method to produce an aqueous coffee extract (ie, for example, a one stage and / or two stage process).

[0014] It would also be advantageous to provide a liquid coffee concentrate and / or instant coffee powder that has an in-cup mouthfeel comparable to a freshly brewed coffee product and also has an aromatic complexity and level indicative of a freshly brewed beverage.

[0015] It would also be advantageous to provide a method of at least partially releasing bound aroma compounds from HMW compounds in order to improve the in-cup properties of a coffee product (instant coffee powder and / or coffee concentrate) for the preparation of a coffee beverage.

[0016] It is therefore an object of embodiments of the present invention to meet the urgent need for an optimized process for producing high quality instant coffee powder and / or coffee concentrate, and / or to overcome or mitigate at least one problem of the prior art (whether disclosed herein or not). Summary of the invention

[0017] According to a first aspect of the present invention, there is provided a method for processing a beverage ingredient extract, the method comprising the steps of: a) filtering the beverage ingredient extract to obtain a beverage ingredient extract retentate and a beverage ingredient extract permeate; b) raising the pH of the beverage ingredient extract retentate to provide a treated beverage ingredient extract retentate; and c) combining the treated beverage ingredient extract retentate with the beverage ingredient extract permeate to produce a reconstituted ingredient extract.

[0018] The beverage ingredient extract is preferably a coffee extract.

[0019] Without being bound by any theory, it is believed that the step of raising the pH of the beverage ingredient extract retentate, particularly the coffee extract retentate, creates conditions in which phenolic compounds such as hydroxycinnamic acids ("HCA"), including caffeic acid, ferulic acid, and p-coumaric acid, are released from high molecular weight compounds (HMW) such as melanoidins and arabinoxylans in the retentate. The reduction of HCA in the retentate reduces the subsequent binding of aroma compound molecules to HCA compounds, thus providing more aroma composition to the combined extract when the retentate is combined with the permeate, thereby generating a product with more desirable coffee aroma. In other words, it is believed that acidic hydrolysis causes cleavage of aroma (e.g., HCA) compounds and thus reduces π-π interactions. If there are fewer binding partners in the form of HCA on the melanoidins, fewer non-covalent interactions can be formed with flavor enhancers such as FFT or pyrazine.

[0020] In another embodiment, the method may further include the step of filtering the treated beverage ingredient extract retentate for further purification after step b).

[0021] In another embodiment, the method may include the steps of removing aroma volatile compounds from the beverage ingredient extract prior to step a) and re-adding the aroma volatile compounds after step c). Removing the aroma volatile compounds may include stripping and / or steam distillation.

[0022] In some embodiments, step a) may be performed at a temperature in the range of 15°C to 70°C, and may be performed at a pressure in the range of 1 bar to 3 bar.

[0023] Step a) can be carried out with the aid of at least one filter element.

[0024] The at least one filtration member may comprise at least one membrane which may comprise at least one size exclusion cut-off of at least 5 kDa or preferably at least 10 kDa.

[0025] The filtration member may comprise a membrane and / or a sequence of membranes. In a preferred embodiment, the membrane may comprise a size exclusion membrane.

[0026] In some embodiments, the size exclusion membrane may include a size exclusion cutoff of about 50 kDa, 40 kDa, 30 kDa, 20 kDa, 10 kDa, or 5 kDa.

[0027] In some embodiments, the filter member may include multiple filter members. In another embodiment, the multiple filter devices may include multiple membranes. The multiple membranes may include multiple size exclusion membranes, and the multiple size exclusion membranes may include a combination of different pore sizes, i.e., different cutoff values. The combination of cutoff values ​​may include any combination of the pore size distribution of about 50kDa, 40kDa, 30kDa, 20kDa, 10kDa and / or 5kDa. In a preferred embodiment, at least one size exclusion membrane includes a pore size distribution (or cutoff value) of about 50kDa.

[0028] In some embodiments, performing step b) may include treating the ingredient extract retentate with a pH raising means that can impart a pH value to the extract in the range of 7 to 14, preferably 7 to 13, and more preferably 7 to 11. In some embodiments, the pH is raised to between 7-11 or between 7-10. In particularly preferred embodiments, the pH is raised to between 7 and 9. Although higher pH values ​​release more HCA molecules and potentially prevent more aroma compounds from binding to the retentate, pH values ​​above about 11 may be less desirable in the industry due to cost and processing impacts, so a pH of 11 or less is preferred because it provides excellent results while incurring less potential cost and processing impacts; but in some embodiments, a pH of 11-13 may be used. The pH raising means may be in the form of an alkaline aqueous solution, which may include, for example, an aqueous NaOH solution; and / or a resin; and / or an absorbent treatment; and / or a combination thereof.

[0029] Step b) may comprise treating the ingredient extract retentate with pH increasing means for a period of time in the range of 10 minutes to 180 minutes, preferably in the range of 30 minutes to 100 minutes, more preferably between 30 minutes and 90 minutes, most preferably between 30 minutes and 60 minutes, and may comprise stirring the ingredient extract retentate while treating with said pH increasing means, and preferably also raising the temperature (of the ingredient extract retentate) to a value in the range of 30°C to 120°C, preferably between 60°C and 90°C (while treating with said pH increasing means). In a particularly preferred embodiment, the temperature is about 60°C and the time is about 60 minutes.

[0030] In another embodiment, the method may further include the steps of filtering the beverage ingredient extract permeate at least once after step a) to produce additional extract retentates, and combining one or more additional extract retentates with the beverage ingredient extract retentate before performing step b).

[0031] In some embodiments, each repeated filtration of the beverage ingredient extract permeate may include the use of a filtration member having a reduced pore size compared to any previous filtration step.

[0032] In further embodiments, the method may further comprise the steps of filtering the resulting reconstituted ingredient extract at least once to provide a secondary beverage ingredient permeate and a secondary beverage ingredient retentate, and treating the secondary beverage ingredient retentate with a pH raising means.

[0033] In some embodiments, the beverage ingredient extract may include a primary extract from a primary extraction process of roasted and ground coffee powder, and / or a secondary extract extracted from ground coffee powder produced by the primary extraction process in a secondary extraction process, and / or a tertiary extract extracted from ground coffee powder produced by the secondary extraction process, and / or a combination thereof. The beverage ingredient extract may include a concentration of soluble solids between 2% and 15% by weight. In some embodiments, the beverage ingredient extract may include a concentration of soluble solids between 15% and 80% by weight.

[0034] In some embodiments, the method may further comprise the step of drying the reconstituted ingredient extract to produce a soluble beverage ingredient powder. The drying step may comprise spray drying and / or freeze drying the reconstituted ingredient extract.

[0035] In some embodiments, the beverage ingredient extract may include an extract obtained from a beverage ingredient selected from the group consisting of coffee, cocoa, chicory, tea, and beer.

[0036] In some embodiments, the reconstituted beverage ingredient extract may be converted into a soluble beverage ingredient powder.

[0037] According to a second aspect of the present invention, there is provided a beverage ingredient extract obtained or obtainable by the method of the first aspect of the present invention.

[0038] In some embodiments, the beverage ingredient extract may include a concentration of between about 2% and 15% soluble solids by weight (also referred to as a "diluted" extract).

[0039] In some embodiments, the beverage ingredient extract may include a concentration of between about 15% and 80% soluble solids by weight (also referred to as a "concentrated" extract).

[0040] The beverage ingredient extract of the second aspect of the present invention may include a beverage ingredient selected from the group consisting of coffee, cocoa, chicory, tea and beer.

[0041] According to a third aspect of the present invention, there is provided a coffee extract obtained or obtainable by the method of the first aspect of the present invention.

[0042] According to a fourth aspect of the present invention, there is provided the use of a beverage ingredient extract comprising high molecular weight compounds, wherein the high molecular weight compounds having a molecular weight higher than one or more of the group consisting of 5kDa, 10kDa, 20kDa, 30kDa and 50kDa have been treated in a pH raising step to reduce the binding of aroma compounds to the extract.

[0043] Preferably, the beverage ingredient extract is as described and defined above, and is more preferably a coffee extract.Preferably, at least high molecular weight compounds above 50 kDa have been treated in the pH raising step. DETAILED DESCRIPTION

[0044] In order that the present invention may be more clearly understood, embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0045] Figure 1 A schematic flow chart showing a first embodiment of the method according to the first aspect of the present invention;

[0046] Figure 2 A schematic flow chart showing a second embodiment of the method according to the first aspect of the present invention;

[0047] Figure 3a shows a schematic flow chart of a third embodiment of the method according to the first aspect of the present invention;

[0048] Figure 3b A schematic flow chart showing a fourth embodiment of the method according to the first aspect of the present invention;

[0049] Figure 4a shows a schematic flow chart of a fifth embodiment of the method according to the first aspect of the present invention;

[0050] Figure 4b shows a schematic flow chart of a sixth embodiment of the method according to the first aspect of the present invention;

[0051] Figure 4c A schematic flow chart showing a seventh embodiment of the method according to the first aspect of the present invention;

[0052] Figure 5 shows a schematic flow chart of an eighth embodiment of the method according to the first aspect of the present invention;

[0053] Figure 6 The results of a coffee beverage obtained from a commercially available coffee concentrate according to a reference HMW binding study are shown. 1 H-NMR spectra and reference samples 1 H-NMR spectra, both doped with 2,3-diethyl-5-methylpyrazine;

[0054] Figure 7a and Figure 7b The results of a coffee beverage obtained from a commercially available coffee concentrate adulterated with 2,3-diethyl-5-methylpyrazine before and after pH increase treatment according to a reference HMW binding study are shown. 1 H-NMR spectroscopy;

[0055] Referring to the drawings, like reference numerals refer to like parts.

[0056] definition

[0057] "Beverage ingredient extract" is a solution comprising soluble beverage ingredient compounds extracted from beverage ingredients. This is typically obtained by contacting beverage ingredient powders or granules with water (usually hot water or steam). The yield of soluble beverage ingredient compounds obtained from beverage ingredient powders will vary depending on the temperature and pressure used for extraction. High temperatures may result in high yields, hydrolyzing complex carbohydrates in beverage ingredients into soluble components. Although high yields are obviously desirable for commercial production, they also result in the production of high concentrations of high molecular weight (HMW) compounds. Beverage ingredients may include ingredients selected from roasted and ground coffee, cocoa powder, chicory, tea and / or beer.

[0058] By "high molecular weight compounds" (HMW) is meant compounds present in the beverage ingredient extract having a molecular weight of at least about 5 kDa, such as above 10 kDa, 20 kDa, 30 kDa, preferably 40 kDa, even more preferably 50 kDa.

[0059] By "low molecular weight compounds" (LMW) is meant compounds present in the beverage ingredient extract having a molecular weight of less than about 5 kDa, preferably less than 4 kDa, more preferably less than 1 kDa.

[0060] By "liquid ingredient concentrate" is meant a concentrated solution containing soluble ingredient solids suitable for dilution to obtain a desired beverage. By "liquid coffee concentrate" is meant a concentrated solution containing soluble coffee solids suitable for dilution to obtain a desired beverage. Liquid coffee concentrates are usually sold as so-called bag-in-box products for dilution in vending machines, or dried to produce instant coffee powder to obtain coffee beverages. Liquid coffee concentrates can be obtained by conventional concentration processes applied to aqueous coffee extracts (such as, for example, evaporation, filtration, distillation, cryogenic concentration) and can contain 6 to 80% by weight of coffee solids, preferably 10 to 65% by weight, more preferably 15 to 50% by weight of coffee solids.

[0061] Example 1

[0062] Figure 1 Flowchart showing a first embodiment of the method according to the first aspect of the invention.

[0063] The aqueous coffee extract (1) is filtered to obtain a coffee extract permeate (2) and a coffee extract retentate (3). The coffee extract permeate (2) is stored for further use, while the coffee extract retentate (3) is sent to treatment with pH raising means in the form of an alkaline solution to produce a treated coffee extract (4). The treated coffee extract (4) is then recombined with the coffee extract permeate (2) to produce a reconstituted roasted and ground coffee extract (5). The aqueous coffee extract (1) is provided by conventional methods, for example by contacting roasted and ground instant coffee powder with hot water at a temperature in the range between 100°C and 220°C (or alternatively by cold extraction at less than 100°C, preferably less than 80°C). The extraction is carried out in a conventional extraction vessel (not shown), such as, for example, a packed column containing roasted and ground coffee powder. The extraction may be carried out batchwise or continuously, and multiple columns may be used to increase the extraction yield. Hot water is sent to the column / columns from the top or alternatively from the bottom through the roasted and ground coffee powder. The extraction time varies based on the number of columns used, the grind size of the roasted and ground coffee powder and the desired extraction yield.The content of HMW compounds in the aqueous coffee extract (1) is in the range of 10%-30%, in particular in the range of 10%-25%.

[0064] The aqueous coffee extract (1) is delivered to a filtration device via a conventional piping system (not shown). In some embodiments, the filtration device is in the form of any conventional method for filtering a liquid and generating a retentate fraction (i.e., the fraction retained by the filtration device) and a permeate fraction of the liquid (i.e., the liquid fraction that passes through the filtration device). The filtration method is based on size exclusion: the physical structure of the filtration device allows molecules with a size less than the critical size of the pores of the filtration device to selectively pass through, while cutting off molecules with a size greater than these pores. The filtration device may, for example, comprise a membrane, but any other conventional method that allows separation of liquid fractions based on molecular size is also contemplated herein. For example, sequential ultrafiltration, nanofiltration, osmosis, pervaporation, diafiltration, centrifugation, dialysis, chromatography and resin technology. In a preferred embodiment of the present invention, the filtration device is a membrane filtration system using a membrane with a molecular weight cutoff of about 50 kDa. Under these conditions, compounds with a molecular weight greater than 50 kDa are retained by the membrane (forming the so-called retentate), while compounds with a lower molecular weight can pass through the membrane itself (generating the so-called permeate). The filtration process is carried out at a temperature of 15°C to 70°C and a pressure of 1 bar to 3 bar for a period of 1 hour to 8 hours. From the filtration process, a coffee extract permeate (2) and a coffee extract retentate (3) are obtained. The concentration of HMW compounds in the coffee extract retentate (3) is higher than the concentration of HMW compounds in the aqueous coffee extract (1), specifically, the concentration of HMW compounds in the coffee extract retentate (3) is more than twice the concentration of HMW compounds in the aqueous coffee extract (1), and can be up to 10 times.

[0065] In some embodiments, the membrane cutoff is less than 50 kDa, such as 30 kDa, 20 kDa, 10 kDa, or 5 kDa.

[0066] Figure 1The coffee extract permeate (2) is stored at low temperature and low oxygen conditions to prevent it from becoming stale, while the coffee extract retentate (3) is sent to a pH-raising treatment with an alkaline solution to reduce the affinity of aroma compounds to HMW compounds responsible for the binding activity to aroma compounds present in any coffee extract and in particular in the coffee extract permeate (2) of the present invention. The pH-raising treatment is carried out by adding a solution of sodium hydroxide (NaOH) to the primary coffee extract retentate (3) in a conventional container. The resulting mixture is stirred at a temperature of 30°C to 100°C for a period of 30 minutes to 180 minutes (preferably at 60°C-90°C for 30 minutes-60 minutes). The pH of the sodium hydroxide (NaOH) solution is in the range of 7 to 14, preferably 8 to 11. The concentration of the solution is in the range of 0.5 mol / L to 5 mol / L (5M). Alternative alkaline solutions such as NaHCO3, H2CO3 or KOH may be used. The treated coffee retentate (4) obtained by this alkaline treatment shows a reduced binding activity towards aromatic compounds, i.e. volatile organic compounds (VOCs). Without being bound by theory, it is found that the explanation for this reduced binding activity effect towards HMW compounds after treatment with an alkaline agent lies in the fact that the alkaline environment, the high temperature and the prolonged treatment time favour the breaking of bonds, in particular ester bonds of the phenolic groups which are responsible for the binding effect towards aromatic components and which are present on the spatial arrangement of the long chains of the high molecular weight (HMW) compounds. By reducing the phenolic groups on the spatial arrangement of the long chains of the high molecular weight (HMW) compounds by means of an alkaline treatment, the binding activity with respect to the aromatic compounds in the treated coffee extract (4) is reduced.

[0067] Other alternative pH raising treatments may be used. For example, the pH raising treatment may be performed using ion exchange resins and / or absorbents. The absorbent may be carbon-based, polyacrylate-based, or polystyrene-based. Examples of commercial absorbents include MN 200, MN 202 and AF5. Examples of ion exchange resins include strongly basic or weakly basic anion exchange resins. Preferably, the ion exchange resin is a weakly basic anion exchange resin. The resin may be based on polyacrylate or polystyrene, preferably polyacrylate. The functional group may be selected from amine functional groups, such as primary amine groups, tertiary amine groups and quaternary amine groups and polyamine groups, preferably tertiary amine groups. The pH value of the extract after the pH increase treatment ranges from 7 to 14, preferably from 8 to 11.

[0068] After the pH is raised by alkaline solution, Figure 1The treated coffee extract (4) showed a reduction in the content of said phenolic groups on the spatial arrangement of the long chains of HMW compounds. The values ​​were in the range of 10% to 50% reduction.

[0069] After the pH raising treatment, the pH of the treated coffee extract (4) was in the range of 4.9-5.8 before being subjected to hydrolysis and post-quenching.

[0070] Then Figure 1 The treated coffee retentate (4) is sent through a conventional piping system to be reconstituted with the coffee extract permeate (2) to obtain a reconstituted roasted and ground coffee extract (5) having a phenolic fraction content less than that of the initial aqueous coffee extract (1) and having a reduced binding activity for aroma compounds compared to the aqueous coffee extract (1) itself.

[0071] The roasted and ground coffee extract (5) is now ready for use in conventional manufacturing processes for producing, for example, ready-to-drink products, or alternatively is sent to conventional manufacturing processes for producing liquid coffee concentrates and / or instant coffee powders (not shown). These processes include a step of concentrating the roasted and ground coffee extract (5) to 6 to 80% by weight coffee solids, preferably 10 to 65% by weight, more preferably 15 to 50% by weight coffee. The concentration step is performed using standard and commercially available methods such as, for example, evaporation, cryogenic concentration and centrifugation. The liquid coffee concentrate is then sent to a packaging process for packaging in a bag-in-box package, for example, ready for sale in a vending machine.

[0072] Alternatively, the liquid coffee concentrate is sent to a further drying process, wherein the liquid coffee concentrate is converted into instant coffee powder by conventional spray drying or freeze drying processes.

[0073] Example 2

[0074] See now Figure 2 , which shows a flow chart of a second embodiment of the method according to the first aspect of the present invention.

[0075] In summary, an aqueous coffee extract (21) is filtered to obtain a coffee extract permeate (22) and a coffee extract retentate (23). The coffee extract permeate (22) is stored for later use, and the primary coffee extract retentate (23) is sent to an alkaline solution for pH raising, thereby producing a treated coffee extract (24). The treated coffee extract (24) is sent to a further filtration process to produce a secondary coffee extract retentate (27) and a spent permeate (26). The secondary coffee extract retentate (27) is then recombined with the coffee extract permeate (22) to produce a reconstituted roasted and ground coffee extract (25).

[0076] The detailed process of Example 2 is as follows.

[0077] An aqueous coffee extract (21) provided by a conventional extraction method as described in Example 1 is filtered to produce a coffee extract permeate (22) and a primary coffee extract retentate (23), which is stored for further use. The filtering apparatus is of the type as described for Example 1 and involves a conventional membrane filtration system comprising, for example, a filter membrane having a cut-off value of about 50 kDa. The filtration process is carried out at a temperature of 15°C to 70°C and a pressure of 1 bar to 3 bar for a period of 1 hour to 8 hours. An alternative filtration method as described in Example 1 may be used. The concentration of HMW compounds in the primary coffee extract retentate (23) is higher than the concentration of HMW compounds in the aqueous coffee extract (21), in particular, the concentration of HMW compounds in the primary coffee extract retentate (23) is more than twice (and can be up to 10 times) the content of HMW compounds in the aqueous coffee extract (21).

[0078] In some embodiments, the membrane cutoff is less than 50 kDa, such as about 30 kDa, 20 kDa, 10 kDa, or 5 kDa.

[0079] The primary coffee extract retentate (23) is sent to a pH raising treatment with an alkaline agent, thereby reducing the agonistic effect of the phenolic groups of high molecular weight (HMW) compounds responsible for the binding activity of the aroma compounds in the coffee extract. As described for Example 1, the alkaline treatment comprises:

[0080] i. Adding sodium hydroxide (NaOH) solution to the primary coffee extract retentate (23)

[0081] In, and

[0082] ii. Stir at a temperature of 30°C to 100°C for 30 to 180 minutes.

[0083] The pH of the sodium hydroxide (NaOH) solution is in the range of 7 to 14, preferably 8 to 11 (concentration 0.5 mol / L-5 mol / L).

[0084] Alternative alkaline agents may also be used, as well as alternative resin and / or absorbent treatments as described in Example 1.

[0085] After the pH raising treatment, the pH of the obtained treated coffee extract (24) is in the range of 4.9 to 5.8, followed by post-hydrolysis quenching.

[0086] The treated coffee extract (24) showed reduced binding activity towards aroma compounds.

[0087] The treated coffee extract (24) is then sent to a further filtration process through a conventional piping system to produce a secondary coffee extract retentate (27) and a waste permeate (26) and the secondary coffee extract retentate is separated from the waste permeate, the waste permeate (26) consisting of a fraction of the coffee extract having major compounds with a molecular weight of less than 5 kDa (in the range of low molecular weight (LMW) compounds).

[0088] When the general Figure 2 When the treated coffee extract (24) is sent to a further filtration process, the filtration device may be a conventional membrane with a cut-off value of 1 kDa, but any alternative filtration method is suitable.

[0089] The resulting secondary coffee extract retentate (27) is then reconstituted with the coffee extract permeate (22) to obtain a reconstituted roast and ground coffee extract (25) having a concentration of phenolic groups less than that of the aqueous coffee extract (21) and thus having a reduced binding activity for aroma compounds compared to the aqueous coffee extract (21). In some embodiments, the treated coffee extract (24) is directly added to the coffee extract permeate (22) without passing through a filtration step to separate the spent permeate (26) to produce the reconstituted roast and ground coffee extract (25).

[0090] The reconstituted roast and ground coffee extract (25) is then sent to a conventional manufacturing process for producing a ready-to-drink liquid coffee concentrate and / or an instant coffee powder.

[0091] The concentration process for making liquid coffee concentrate and / or instant coffee powder is carried out as described for Example 1. The liquid coffee concentrate is then sent to a packaging process for packaging in, for example, bag-in-box packaging, or to a drying process (spray drying or freeze drying) for producing instant coffee powder.

[0092] Example 3a

[0093] Figure 3a A schematic flow chart of a third embodiment of the method according to the first aspect of the present invention is shown.

[0094] A two-stage extraction process is applied to roast and ground coffee powder (300). A first extraction is performed to produce a primary aqueous coffee extract (30) and so-called "ground coffee powder grounds". A second extraction is performed on the ground coffee powder grounds to produce a secondary aqueous coffee extract (31). The secondary aqueous coffee extract (31) is then filtered to obtain a coffee extract retentate (33) and a coffee extract permeate (32), the coffee extract retentate (33) being treated according to the first aspect of the invention, as described in Example 1, to produce a treated roast and ground coffee extract (35), which is then reconstituted with the primary aqueous coffee extract (30) to finally obtain a reconstituted roast and ground coffee extract (39).

[0095] In some embodiments, the two-stage extraction process includes an extraction process for producing an aqueous coffee extract, wherein the extraction is performed in two stages at different temperatures. In the first stage, the extraction is performed at a lower temperature. The roasted and ground coffee powder (300) is extracted with water at a temperature in the range of 20°C to 140°C. In the second stage, the roasted and ground coffee powder (also referred to as "ground coffee powder residue") remaining after the first stage is then extracted again with water at a higher temperature in the range of 170°C to 220°C. The extract obtained from the first stage is also referred to as a primary aqueous coffee extract (30), while the extract from the second stage at a higher temperature is also referred to as a secondary aqueous coffee extract (31). The secondary aqueous coffee extract (31) can be characterized based on the chemical components present in the extract. For example, the secondary aqueous coffee extract (31) can be considered to be an extract having a high molecular weight (HMW) compound level in the range of 10%-40%. Similarly, the primary aqueous coffee extract (30) is characterized based on the level of high molecular weight (HMW) compounds of about 5%-20%. Compared with the conventional one-stage extraction process, the two-stage extraction process can increase the extraction yield due to the high content of high molecular weight (HMW) compounds.

[0096] The final reconstituted roast and ground coffee extract (39) showed a reduced binding activity of HMW compounds towards aroma compounds, resulting in a high content of free aroma compounds.

[0097] The final reconstituted roast and ground coffee extract (39) is then sent to a conventional manufacturing process for producing ready-to-drink liquid coffee concentrate and / or instant coffee powder.

[0098] The concentration and packaging steps were performed as described for Example 1.

[0099] Example 3b

[0100] Figure 3b A schematic flow chart of a fourth embodiment of the method according to the first aspect of the present invention is shown.

[0101] A two-stage extraction process is applied to roasted and ground coffee powder (3000). A first extraction is performed to produce a primary aqueous coffee extract (301) and so-called "ground coffee powder grounds". A second extraction is performed on the ground coffee powder grounds to produce a secondary aqueous coffee extract (310). The primary aqueous coffee extract (301) and the secondary aqueous coffee extract (310) are then filtered to obtain a primary coffee extract permeate (320), a secondary coffee extract permeate (321), a primary coffee extract retentate (330), a secondary coffee extract retentate (331). The remaining roasted and ground coffee powder extracted from the second extraction stage (the so-called 'spent ground coffee powder') is discharged or sent to another industrial use. As described in Example 1, the coffee extract retentate (330, 331) is treated according to the first aspect of the present invention to generate primary and secondary processed coffee extracts (340 and 341, respectively), which are then recombined to obtain a recombined processed coffee extract (350). Finally the reconstituted treated coffee extract (350) is added to the primary coffee extract permeate (320) and the secondary coffee extract permeate (321) to obtain a reconstituted roast and ground coffee extract (390).

[0102] In some embodiments, the two-stage extraction process comprises an extraction process for producing an aqueous coffee extract, wherein the extraction is performed in two stages at different temperatures, as described in Example 3a. The extract obtained from the first stage is referred to as the primary aqueous coffee extract (301), while the extract from the second stage at a higher temperature is referred to as the secondary aqueous coffee extract (310).

[0103] The filtration device is of the type as described for Example 1 and involves a conventional membrane filtration system comprising, for example, a filtration membrane with a cut-off of about 50 kDa.

[0104] In some embodiments, the membrane cutoff is less than 50 kDa, such as about 30 kDa, 20 kDa, 10 kDa, or 5 kDa.

[0105] exist Figure 3bIn the embodiment shown, the filtration device applied to the primary aqueous coffee extract (301) comprises a membrane filtration cut-off of about 50 kDa, while the secondary aqueous coffee extract (310) is not filtered before being sent to the pH raising treatment. Thus, the pH raising treatment is applied to the entire secondary aqueous coffee extract (310) without previously separating the high molecular weight (HMW) compounds into a secondary coffee extract retentate (not shown).

[0106] After pH-raising treatment with an alkaline agent to reduce the agonistic effect of phenolic groups of high molecular weight (HMW) compounds (responsible for the binding activity of aroma compounds in coffee extract), the resulting reconstituted roasted and ground coffee extract (390) shows reduced binding activity of HMW compounds for aroma compounds, resulting in a high content of free aroma compounds.

[0107] The reconstituted roast and ground coffee extract (390) is then sent to a conventional manufacturing process for producing a ready-to-drink liquid coffee concentrate and / or instant coffee powder.

[0108] The concentration and packaging steps were performed as described for Example 1.

[0109] Example 4a

[0110] Figure 4a A schematic flow chart of a fifth embodiment of the method according to the first aspect of the present invention is shown.

[0111] A two-stage extraction process is applied to roasted and ground coffee powder (400) in the same manner as described above for Example 3a to produce a primary aqueous coffee extract (40) and a secondary aqueous coffee extract (41), which is stored for subsequent use. The secondary aqueous coffee extract (41) is processed according to the first aspect of the invention as described in Example 2. The secondary aqueous coffee extract (41) is filtered to obtain a coffee extract permeate (42) and a coffee extract retentate (43). The coffee extract permeate (42) is stored for subsequent use, and the coffee extract retentate (43) is sent to a treatment with an alkaline solution to produce a treated coffee extract (44). The treated coffee extract (44) is sent to a further filtration process to produce a secondary coffee extract retentate (47) and a spent permeate (46). The secondary coffee extract retentate (47) is then recombined with the coffee extract permeate (42) to obtain a reconstituted roast and ground coffee extract (45), which is added to the primary aqueous coffee extract (40) to provide a final reconstituted roast and ground coffee extract (49).

[0112] The secondary aqueous coffee extract (41) is produced by a conventional two-stage extraction process. First, the roasted and ground coffee powder (400) is extracted with hot water at a first temperature in the range between 20°C and 140°C to produce a primary aqueous coffee extract (40). The roasted and ground powder (ground coffee powder grounds) remaining after the extraction is then extracted again at a higher temperature between 170°C and 220°C to produce a secondary aqueous coffee extract (41). The extraction is carried out in a conventional extraction device (not shown), such as, for example, a packed column containing roasted and ground coffee powder. The extraction can be carried out in batches or continuously, and multiple columns can be used to increase the extraction yield. Hot water is sent to the column / columns from the top of the roasted and ground coffee powder or alternatively from the bottom. The extraction time varies based on the number of columns used, the grind size of the roasted and ground coffee powder and the desired extraction yield. The content of HMW compounds in the secondary aqueous coffee extract (41) ranges from 10% to 40%.

[0113] The secondary aqueous coffee extract (41) is then filtered to produce a coffee extract permeate (42) and a coffee extract retentate (43), which is stored for further use. The filtration apparatus is of the type as described for Example 1 and involves a conventional membrane filtration system, which comprises, for example, a membrane filter having a cut-off of about 50 kDa. The filtration process is carried out at a temperature of 20°C to 70°C and a pressure of 1 bar to 3 bar for a period of 1 hour to 8 hours. Alternative filtration methods as described in Example 1 may be used. The concentration of HMW compounds in the coffee extract retentate (43) is higher than the content of HMW compounds in the secondary aqueous coffee extract (41), specifically, the content of HMW compounds in the coffee extract retentate (43) is more than twice the concentration of HMW compounds in the secondary aqueous coffee extract (41). In some embodiments, the membrane cut-off is less than about 50 kDa, for example 30 kDa, 20 kDa, 10 kDa or 5 kDa.

[0114] The coffee extract retentate (43) is sent to a treatment with an alkaline agent to reduce the concentration and agonism of the phenolic groups on the long chains of the high molecular weight (HMW) compounds responsible for the binding activity to the aroma compounds in the coffee extract. As described for Example 1, the alkaline treatment comprises:

[0115] i. adding a sodium hydroxide (NaOH) solution to the coffee extract retentate (43), and

[0116] ii. Stir at a temperature of 30°C to 100°C for 30 to 180 minutes.

[0117] The pH of the sodium hydroxide (NaOH) solution is in the range of 7 to 14, preferably 8 to 11 (concentration of 0.5 mol / L-5 mol / L). Alternative alkaline agents (e.g., NaHCO3, H2CO3 or KOH) may also be used, as well as alternative resins and / or absorbent treatments as described in Example 1.

[0118] The obtained treated coffee extract (44) showed a pH in the range of 4.9 to 5.8 after quenching and showed a reduced binding activity towards aroma compounds.

[0119] The treated coffee extract (44) is then sent to a further filtration process through a conventional piping system to produce a secondary extract retentate (47) and a waste permeate (46) and the secondary extract retentate is separated from the waste permeate, the waste permeate comprising a fraction of the coffee extract having major compounds with molecular weights less than 5 kDa (within the range of low molecular weight (LMW) compounds).

[0120] Figure 4a The filtration device for the further filtration step is a conventional membrane with a cut-off value of 1 kDa.

[0121] The resulting secondary coffee extract retentate (47) is then reconstituted with the coffee extract permeate (42) to obtain a reconstituted roast and ground coffee extract (45) having a phenolic content less than that of the secondary aqueous coffee extract (41) and therefore having a reduced aroma compound binding activity compared to the secondary aqueous coffee extract (41).

[0122] The reconstituted roast and ground coffee extract (45) is then added to the primary aqueous coffee extract (40) to provide a final reconstituted roast and ground coffee extract (49), which is then sent to a conventional manufacturing process for producing a ready-to-drink liquid coffee concentrate and / or instant coffee powder.

[0123] The concentration and packaging steps were performed using standard and commercially available methods as described for Example 1.

[0124] Example 4b

[0125] Figure 4b A schematic flow chart of a sixth embodiment of the method according to the first aspect of the present invention is shown.

[0126] A three-stage extraction process is applied to roast and ground coffee powder (401).

[0127] Generally speaking, a first extraction is performed to produce a primary aqueous coffee extract (440) and a so-called "ground coffee powder grounds" (410). An aroma compound recovery process (900) is applied to the primary aqueous coffee extract (440), and the aroma compounds (not shown) are collected and stored for subsequent reintroduction. The ground coffee powder grounds (410) are subjected to a second extraction to produce a secondary aqueous coffee extract (441) and a secondary ground coffee powder grounds (480). The secondary ground coffee powder grounds (480) are subjected to a third extraction to obtain a tertiary coffee extract (482). Both the primary aqueous coffee extract (440) and the secondary aqueous coffee extract (441) are stored for subsequent use. As described in Example 2, the tertiary aqueous coffee extract (482) is processed according to the first aspect of the present invention. The tertiary aqueous coffee extract (482) is filtered to obtain a coffee extract permeate (442) and a coffee extract retentate (443). The coffee extract permeate (442) is stored for later use, and the coffee extract retentate (443) is subjected to a pH raising process to produce a treated coffee extract (444). The treated coffee extract (444) is sent to an additional filtration process to produce a quaternary coffee extract retentate (447) and a spent permeate (446). The purified coffee extract retentate (447) is then recombined with the coffee extract permeate (442), the primary aqueous coffee extract (440) and the secondary aqueous coffee extract (441) to obtain a final reconstituted roasted and ground coffee extract (449). The aroma compounds collected by the aroma compound recovery process (900) are then reintroduced into the final reconstituted roasted and ground coffee extract (449).

[0128] The detailed process of Example 4b is as follows.

[0129] The secondary aqueous coffee extract (441) and the tertiary aqueous coffee extract (482) are produced by a conventional three-stage extraction process. First, the roasted and ground coffee powder (401) is extracted with hot water at a first temperature in the range between 20°C and 140°C to produce a primary aqueous coffee extract (440). The roasted and ground powder (410) left after the extraction is then extracted again at a higher temperature between 170°C and 220°C to produce a secondary aqueous coffee extract (441) and the resulting secondary ground coffee powder grounds (480), and the resulting secondary ground coffee powder grounds are then subjected to a third extraction at a temperature above 220°C, thereby producing a tertiary aqueous coffee extract (482). The extraction is carried out in a conventional extraction device (not shown), such as, for example, a packed column containing roasted and ground coffee powder. The extraction can be carried out in batches or continuously, and multiple columns can be used to increase the extraction yield. Hot water is fed into the column / columns from the top or alternatively from the bottom through the roasted and ground coffee powder (401). The extraction time varies based on the number of columns used, the grind size of the roasted and ground coffee powder and the desired extraction yield. The content of HMW compounds in the tertiary aqueous coffee extract (482) ranges from 1% to 10%.

[0130] The tertiary aqueous coffee extract (482) is then filtered to produce a coffee extract permeate (442) and a coffee extract retentate (443), which is stored for further use. The filtration apparatus is of the type as described for Example 1 and involves a conventional membrane filtration system, which comprises, for example, a membrane filter having a cut-off of about 10 kDa. The filtration process is carried out at a temperature of 15°C to 70°C and a pressure of 1 bar to 3 bar for a period of 1 hour to 8 hours. Alternative filtration methods as described in Example 1 may be used. The concentration of HMW compounds in the coffee extract retentate (443) is higher than the content of HMW compounds in the secondary aqueous coffee extract (441) and the primary aqueous coffee extract (440), specifically, the content of HMW compounds in the coffee extract retentate (443) is more than twice the concentration of HMW compounds in the secondary aqueous coffee extract (441). In other embodiments, the membrane cut-off may be less than about 30 kDa, 20 kDa, 10 kDa or 5 kDa.

[0131] The coffee extract retentate (443) is sent to a pH raising treatment using an alkaline agent, thereby reducing the concentration and agonism of the phenolic groups on the long chain of the high molecular weight (HMW) compounds responsible for the binding activity to the aroma compounds in the coffee extract. As described for Example 1, the alkaline treatment comprises:

[0132] i. adding a sodium hydroxide (NaOH) solution to the coffee extract retentate (443),

[0133] as well as

[0134] ii. Stir at a temperature of 30°C to 100°C for 30 to 180 minutes.

[0135] The pH of the sodium hydroxide (NaOH) solution is in the range of 7 to 14, preferably 8 to 11 (concentration 0.5 mol / L-5 mol / L). Alternative alkaline agents (such as KOH) may also be used, as well as alternative resins and / or absorbent treatments as described in Example 1.

[0136] The obtained treated coffee extract (444) showed reduced binding activity towards aroma compounds.

[0137] The treated coffee extract (444) is then sent to a further filtration process through a conventional piping system to produce a purified coffee extract retentate (447) and a waste permeate (446) and the purified coffee extract retentate is separated from the waste permeate, the waste permeate comprising a fraction of the coffee extract having major compounds with a molecular weight of less than 5 kDa (within the range of low molecular weight (LMW) compounds).

[0138] Figure 4b The filtration device for the further filtration step to separate the waste permeate (446) is a conventional membrane with a cut-off value of 1 kDa.

[0139] The resulting purified coffee extract retentate (447) is then recombined with the coffee extract permeate (442), the primary aqueous coffee extract (440) and the secondary aqueous coffee extract (441) to obtain a final reconstituted roast and ground coffee extract (449) having a phenolic content less than that of the primary aqueous coffee extract (440) and the secondary aqueous coffee extract (441) and therefore having a reduced aroma compound binding activity compared to the two aqueous coffee extracts (440, 441).

[0140] The final reconstituted roast and ground coffee extract (449) is then sent to a conventional manufacturing process for producing ready-to-drink liquid coffee concentrate and / or instant coffee powder.

[0141] The concentration and packaging steps were performed using standard and commercially available methods as described for Example 1.

[0142] Example 4c

[0143] See also Figure 4c, which shows a flow chart of a seventh embodiment of the method according to the first aspect of the present invention.

[0144] A three-stage extraction process is applied to roasted and ground coffee powder (4010) as described in Example 4b. A primary aqueous coffee extract (4400) and a so-called "ground coffee powder grounds" (4100) are obtained by the first extraction stage. The ground coffee powder grounds (4100) are subjected to a second extraction to produce a secondary aqueous coffee extract (4410) and a secondary ground coffee powder grounds (4800). The secondary ground coffee powder grounds (4800) are subjected to a third extraction to obtain a tertiary aqueous coffee extract (4820) and spent ground coffee powder, the tertiary aqueous coffee extract is collected and the tertiary aqueous coffee extract is stored for subsequent reintroduction. As described in Example 3b, both the primary aqueous coffee extract (4400) and the secondary aqueous coffee extract (4410) are subjected to a filtration process to obtain a primary coffee extract retentate (4430), a secondary coffee extract retentate (4431), a primary coffee extract permeate (4460) and a secondary coffee extract permeate (4461). The primary coffee extract permeate (4460) and the secondary coffee extract permeate (4461) are stored for subsequent use, while the primary coffee extract retentate (4430) and the secondary coffee extract retentate (4431) are treated in a pH raising step according to the first aspect of the present invention, thereby obtaining a treated primary coffee extract (4470) and a treated secondary coffee extract (4471). The treated primary (4470) coffee extract is then combined with the treated secondary coffee extract (4471) to provide a reconstituted treated coffee extract (4435). Finally, a tertiary aqueous coffee extract (4820) is added to the reconstituted treated coffee extract (4435) along with the primary coffee extract permeate (4460) and the secondary coffee extract permeate (4461) to provide a final reconstituted roasted and ground coffee extract (4439).

[0145] Optionally, the primary aqueous coffee extract (4400) may be subjected to an aroma compound recovery step (not shown), and the recovered aroma compounds may be reintroduced into the final reconstituted roast and ground coffee extract (4439).

[0146] As described in Example 4b, a secondary aqueous coffee extract (4100) and a tertiary aqueous coffee extract (4820) are produced by a conventional three-stage extraction process.

[0147] The content of HMW compounds in the tertiary aqueous coffee extract (4820) is in the range of 1% to 10%.

[0148] The filtration device is of the type described for Example 1 and relates to a conventional membrane filtration system comprising, for example, a membrane filter having a cutoff of about 50 kDa. In some embodiments, the membrane cutoff is less than about 50 kDa, such as 30 kDa, 20 kDa, or 10 kDa. In some embodiments, a sequence of membrane filtration is applied with membranes having cutoffs of about 50 KDa, 30 KDa, 20 KDa, 10 KDa, and 5 KDa.

[0149] exist Figure 4c In the embodiment illustrated in FIG. 4 , the filtration device applied to the primary aqueous coffee extract (4400) comprises a filter membrane with a cut-off value of about 50 kDa. No filtration is applied to the secondary aqueous coffee extract (4410) before it is sent to the pH raising treatment. Thus, the pH raising treatment is applied to the entire secondary aqueous coffee extract (4410) without previously separating the high molecular weight (HMW) compounds into a secondary coffee extract retentate (not shown).

[0150] In some embodiments (not shown), the tertiary aqueous coffee extract (4820) is subjected to treatment in accordance with the present invention to provide a tertiary coffee extract permeate and a treated tertiary coffee extract, which are then added to the final reconstituted roast and ground coffee extract.

[0151] The primary coffee extract retentate (4430) and the secondary coffee extract retentate (4431) are sent to a pH raising treatment using an alkaline agent as described in Example 3b to reduce the concentration and agonism of phenolic groups on the spatial arrangement of the long chains of the high molecular weight (HMW) compounds.

[0152] The resulting treated primary coffee extract (4470) is then recombined with the treated secondary coffee extract (4471) into a reconstituted treated coffee extract (4435), and the reconstituted treated coffee extract is added to the primary coffee extract permeate (4460) and the secondary coffee extract permeate (4461) to obtain a final reconstituted roasted and ground coffee extract (4439), which has a phenolic content less than the primary aqueous coffee extract (4400) and the secondary aqueous coffee extract (4410) combined, and therefore has a reduced binding activity for aroma compounds.

[0153] The final reconstituted roast and ground coffee extract (4439) is then sent to a conventional manufacturing process for producing ready-to-drink liquid coffee concentrate and / or instant coffee powder.

[0154] The concentration and packaging steps were performed using standard and commercially available methods as described for Example 1.

[0155] Example 5

[0156] See also Figure 5 , which shows a flow chart of an eighth embodiment of the method according to the first aspect of the present invention.

[0157] The aqueous coffee extract (51) is filtered to obtain a primary coffee extract permeate (52) and a primary coffee extract retentate (53). The primary coffee extract retentate (53) is stored for further use, while the primary coffee extract permeate (52) is sent to a further filtering step to provide a secondary coffee extract retentate (520) and a secondary coffee extract permeate (521), which are stored for further use. The secondary coffee extract permeate (521) is sent to a subsequent filtering step to provide a tertiary coffee extract retentate (522) and a tertiary coffee extract permeate (523). The primary coffee extract retentate (53) and the tertiary coffee extract retentate (522) are then treated with an alkaline solution to produce a treated primary coffee retentate (54) and a treated tertiary coffee retentate (540), respectively. The treated coffee retentate (54, 540) is then recombined with the tertiary coffee extract permeate (523) to produce a reconstituted roast and ground coffee extract (55).

[0158] The filtration sequence of Example 5 is carried out by using a sequence of membranes in order to separate fractions of the initial aqueous coffee extract (51) containing different molecular weight compound ranges, and then the fractions are treated individually according to the method of the present invention based on the relevance and affinity level of each fraction for volatile organic compounds (VOCs), i.e. aroma compounds. For example, a sequence with cut-off values ​​above about 50 kDa (first filter - filtration 1), above about 30 kDa (second filter - filtration 2) and above about 10 kDa (third filter - filtration 3) is used. Membranes with cut-off values ​​lower than the previous one allow separation of fractions of the aqueous coffee extract with HMW compounds of reduced molecular weight. The filtration of each fraction of the extract is carried out on the permeate of the previous filtration step. For example, a 30 kDa cut-off membrane is used on the permeate from the 50 kDa cut-off membrane, and so on.

[0159] The roast and ground coffee extract (55) produced by the process of the present invention has a HMW fraction with reduced binding of aroma compounds compared to the aqueous coffee extract (51 ), and therefore has a higher content of free aroma compounds (VOCs).

[0160] The roasted and ground coffee extract (55) produced by the process of the present invention can be used as it is (e.g. for producing a ready-to-drink product), or sent to a conventional concentration process to obtain a liquid coffee concentrate to be sold as such in bag-in-box packaging or used in a further drying process (spray drying or freeze drying) for the manufacture of an instant coffee powder with an enhanced aroma level.

[0161] Reference HMW Binding Studies

[0162] The present invention is based on the finding that reducing the concentration of phenolic groups on the spatial arrangement of the long chains of said high molecular weight (HMW) compounds (such as, for example, melanoidins) in aqueous coffee extracts is particularly advantageous, since these groups are responsible for binding compounds such as HCA which play an important role in the aroma perception of coffee beverage preparations. This binding activity results in a weaker aroma of the beverage and therefore a poorer in-cup quality perception of the beverage by the consumer.

[0163] The present inventors have studied the effects of coffee on beverage products obtained from commercially available coffee. 1 H-NMR spectroscopy analysis confirmed the binding activity of HMW compounds, e.g. Figure 6 Indicated.

[0164] Sample 1: A beverage preparation obtained from a commercially available coffee concentrate with a concentration of 54 g / L was doped with an aqueous solution of 50 mmol / L of an aroma compound (2,3-diethyl-5-methylpyrazine, earthy flavor).

[0165] Reference Sample 1: A comparative aqueous solution (without coffee) doped with 50 mmol / L of an aromatic compound (2,3-diethyl-5-methylpyrazine, earthy flavor).

[0166] Sample 1 and reference sample 1 were analyzed by NMR spectroscopy for an incubation time of up to 30 minutes in order to verify the binding activity of the phenolic groups of the HMW compounds present in the coffee beverage with respect to the adulterated aroma compound (2,3-diethyl-5-methylpyrazine).

[0167] The resonance signal of HC(6) of sample 1 shows significant line broadening, indicating binding between the compounds, and reduced intensity, compared to the aqueous solution (reference sample 1).

[0168] NMR analysis clearly showed a decrease in free 2,3-diethyl-5-methylpyrazine upon incubation with the beverage preparation indicating that the aroma compounds were bound by the HMW compounds.

[0169] like Figure 7a and Figure 7b As indicated, the same experiment was performed on additional samples obtained with commercially available coffee brew.

[0170] Sample 2: A 54 g / L beverage preparation obtained from a commercially available coffee brew treated with an alkaline aqueous solution at a concentration of 2 g / L was doped with a 50 mmol / L aqueous solution of an aroma compound (2,3-diethyl-5-methylpyrazine, earthy flavor) followed by a pH raising step at 60°C for a period of 30 minutes.

[0171] Reference Sample 2: A beverage preparation concentrated to a concentration of 54 g / L obtained from commercially available coffee was doped with an aqueous solution of 50 mmol / L of an aroma compound (2,3-diethyl-5-methylpyrazine, earthy flavor).

[0172] Sample 2 and Reference Sample 2 were analyzed by NMR spectroscopy to verify the binding activity of the phenolic groups of the HMW compounds present in the coffee beverage with respect to the adulterated aroma compound (2,3-diethyl-5-methylpyrazine).

[0173] Involving untreated reference sample 2 Figure 7a The concentration of HMW compounds was shown to be lower than that of treated sample 2. Figure 7b The concentration of HMW compounds.

[0174] NMR analysis demonstrated the significant impact of the alkaline treatment and thus the importance of the affinity of HMW compounds (particularly melanoidins) for aroma compounds. The recovery of free 2,3-diethyl-5-methylpyrazine increased from 56% before alkaline treatment to 84% after treatment.

[0175] Example 6—Binding Study of Example 4c

[0176] Table 1 below shows that the recovery (% of free key aroma compound 2,3-diethyl-5-methylpyrazine) of several final reconstituted roast and ground coffee extracts prepared according to the present invention as in Example 4c increases when different processing conditions are applied to the primary aqueous extract, the secondary aqueous extract and the tertiary aqueous extract.

[0177] Each of the primary aqueous coffee extract, the secondary aqueous coffee extract and / or the tertiary aqueous coffee extract prepared according to Example 4c was subjected to a sequence of filtration membranes using cut-off values ​​of 50 kDa, 30 kDa, 10 kDa and 5 kDa (hereinafter referred to as "total treated") or a single membrane of 50 kDa (hereinafter referred to as "single fraction treated").

[0178] The resulting fractionated retentate of each aqueous coffee extract was subjected to a pH raising treatment according to the invention to a pH of 13 as described in Example 4c.

[0179] Furthermore, an aqueous solution of 2,3-diethyl-5-methylpyrazine at a concentration of 5.15 mol / L was used as a reference sample. It is believed that the pyrazine is also a key aroma compound responsible for earthy notes in coffee brew. After treatment according to the first aspect of the invention, the treated primary coffee extract, the treated secondary coffee extract and the treated tertiary coffee extract were doped with the aqueous pyrazine solution in order to obtain the same concentration as the reference sample (5.15 mol / L).

[0180] After incubation at room temperature for 30 minutes, 1 The concentration (%) of free pyrazine was determined by H-NMR.

[0181] The increase in recovery (%) was determined by comparison with the recovery of pyrazines in an untreated final roast and ground coffee extract (hereinafter referred to as 'untreated final extract' or 'untreated FE') obtained by combining the primary, secondary and tertiary aqueous coffee extracts of Example 4c without any pH raising treatment, which represents conditions of maximum pyrazine binding (and therefore minimum free aroma compound binding - least conducive to providing aroma complexity and effective in-cup performance)).

[0182] Table 1 - Extracts of Example 4c treated according to the invention and with the same concentration as the reference sample compared to untreated extracts The recovery rate of the extract doped with pyrazine at the same concentration in No. 1 increased by %.

[0183]

[0184] Each reconstituted roast and ground coffee extract treated according to the first aspect of the invention showed a significant increase in the % recovery of free pyrazines compared to the untreated final extract, confirming that treatment of the retentate at any stage of a one-stage, two-stage or higher stage extraction process ensures a reduction in the binding of aroma compounds by HMW compounds. Particularly effective was the treatment of HMW compounds above 50 kDa (i.e. using a filter with a cut-off of 50 kDa), suggesting that those HMW compounds have a disproportionate effect on the binding of free aroma compounds in extracts not treated according to the invention.

[0185] Sample No. 7 includes a combined primary extract, a secondary extract, and a tertiary extract, each of which is produced by filtering through a sequence of filter membranes using cutoff values ​​of 50 kDa, 30 kDa, 10 kDa, and 5 kDa, and combining the resulting fractions, and then processing the combined retentate with a pH-raising treatment according to the present invention. Sample No. 7 shows an increase of 21% in free pyrazine, which provides good in-cup performance for the resulting instant coffee.

[0186] Even using only a single membrane with a cut-off of 50 kDa to process the coffee extract retentate resulted in a significant reduction in the overall binding in the final reconstituted roast and ground coffee extracts (samples Ref 4 and 8).

[0187] Example 7—Binding Study of Example 4c

[0188] The process of Example 6 was repeated, but the pH of the resulting >50 kDa fractionated retentate of each aqueous coffee extract was raised to a pH of 8, 9, 10, 11 or 12. This resulted in less release of pyrazine than at pH 13. pH 8, 9 and 10 showed <5% recovery compared to pH 13; pH 11 showed about 20% recovery of pyrazine compared to pH 13; and pH 12 showed about 90% recovery of pyrazine compared to pH 13. Although this resulted in a retentate with more bound aroma compounds than raising the pH to 13, the process performed at pH 7-12, and particularly at 7-10, is more manageable on an industrial scale when considering cost and processing issues, and still provides more release of aroma compounds and subsequent beneficial improvement in the aroma of the final coffee product compared to not raising the pH of the extract retentate, and therefore the process of the present invention can be performed by raising the pH of the extract retentate to any value between pH 7-13, depending on the final application.

[0189] The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the present invention as defined in the appended claims.

Claims

1. A method for processing a coffee extract, the method comprising the following steps: a. filtering the coffee extract to obtain a coffee extract retentate and a coffee extract permeate, the filtration being based on size exclusion having a size exclusion cutoff of at least 10 kDa; b. raising the pH of the coffee extract retentate to between 7 and 14 to provide a treated coffee extract retentate; as well as c. combining the treated coffee extract retentate with the coffee extract permeate to produce a recombinant coffee extract.

2. The method according to claim 1, wherein the method further comprises the step of filtering the treated coffee extract retentate for further purification after step b).

3. The method according to claim 1 or 2, wherein the method further comprises the following steps: Aromatic volatile compounds are removed from the coffee extract before step a) and are added to or combined with the recombinant coffee extract after step c).

4. The method of claim 3, wherein removing the aromatic volatile compounds comprises steam stripping and / or steam distillation.

5. The method according to claim 1, wherein step a) is performed at a temperature ranging from 20°C to 100°C.

6. The process according to claim 1, wherein step a) is carried out at a pressure in the range of 1 bar to 3 bar.

7. The method according to claim 1, wherein step a) is performed with the aid of at least one filtration membrane.

8. The method of claim 1, wherein said raising said pH comprises treating said coffee extract retentate with an aqueous alkaline solution and / or a resin and / or an absorbent and / or a combination thereof.

9. The method of claim 1, wherein performing step b) comprises treating the coffee extract retentate with pH raising means for a period of 10 minutes to 180 minutes.

10. The method of claim 1, wherein performing step b) comprises raising the temperature of the coffee extract retentate to 30°C to 100°C while simultaneously raising the pH.

11. The method according to claim 1, wherein the method further comprises the following steps: The coffee extract permeate is filtered at least once after step a) to produce a further extract retentate, and at least one further extract retentate is combined with the coffee extract retentate before performing step b).

12. The method of claim 11, wherein each repeated filtering of the coffee extract permeate comprises using a filter member having a reduced size exclusion cutoff as compared to any previous filter.

13. The method according to claim 1, wherein the method further comprises the following steps: The resulting reconstituted ingredient extract is filtered at least once to provide a secondary coffee permeate and a secondary coffee retentate, and the pH of the secondary coffee retentate is raised.

14. The method according to claim 1, wherein the coffee extract comprises a primary extract from a primary extraction process of roasted and ground coffee powder, and / or a secondary extract extracted in a secondary extraction process from ground coffee powder residues produced by the primary extraction process, and / or a tertiary extract extracted from ground coffee powder residues produced by the secondary extraction process, and / or a combination thereof.

15. The method of claim 1, wherein the coffee extract comprises a concentration of soluble solids between 2% and 15% by weight.

16. The method of claim 1, wherein the coffee extract comprises a concentration of soluble solids between 15% and 80% by weight.

17. The method of claim 1, wherein the method further comprises the step of drying the reconstituted coffee extract to produce a soluble coffee powder.

18. The method according to the preceding claim 1, wherein the reconstituted coffee extract is a soluble coffee powder.

19. Coffee extract obtainable or obtainable by the process according to claim 1.

20. The coffee extract of claim 19, comprising a concentration of soluble solids between 2% and 15% by weight.

21. The coffee extract of claim 19, comprising a concentration of soluble solids between 15% and 80% by weight.

22. Use of a coffee extract according to claim 19, wherein high molecular weight compounds above at least 10 kDa, 20 kDa, 30 kDa and / or at least 50 kDa have been treated in a pH raising step to reduce the binding of aroma compounds to the extract.

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