Coffee extraction process and coffee product

Abstract

The invention relates to coffee extraction processes and coffee products. The present invention provides an instant coffee composition for forming a coffee beverage wherein the composition comprises at least 6% by weight of an insoluble coffee deposit fraction comprising 1% by weight or less of arabinose when analyzed after acid hydrolysis.

Description

[0001] This application is a divisional application of the Chinese patent application with application number 201980087008.7 filed by the applicant on December 20, 2019 and entitled “Coffee Extraction Process and Coffee Product”. Technical Field

[0002] The present invention relates to a process for extracting roasted and ground coffee with water, in particular, to a process for processing coffee slurry to provide a coffee beverage product with improved flavor and mouthfeel. The present invention also relates to a coffee product obtainable by the process, and an instant coffee composition for forming a coffee beverage. Background Art

[0003] It is well known to extract roast and ground coffee with water to obtain a coffee extract high in coffee solids. Furthermore, it is well known to dry such extracts by spray drying or freeze drying to obtain a soluble beverage powder. The beverage powder can then be reconstituted with hot water at the convenience of the consumer to obtain a coffee beverage. It is desirable for such homemade coffee beverages to have a taste similar to that of coffee shop beverages.

[0004] Industrial production of soluble coffee products is associated with higher temperatures and pressures than coffee shop brewing systems. This allows for higher yields from the coffee beans and therefore higher profitability, but has the side effect that the coffee can take on undesirable processed flavour notes. To avoid this, a number of different technologies are employed, including aroma capture methods, to ensure that flavour molecules are retained from the initial lower temperature extraction step.

[0005] An example of a conventional coffee extraction process involves the following steps. Green coffee beans are roasted to a desired roasting degree and ground to a particle size of 2 to 3 mm. They are subjected to a column extraction process having a first step at about 150°C and a second step at a higher temperature of about 185°C. The coffee extracts washed from the coffee beans in each extraction step are combined, concentrated and dried. The process is semi-continuous, using multiple extraction columns.

[0006] EP0826308 discloses a process for countercurrent extraction of soluble coffee solids. In a first extraction stage, soluble coffee solids are extracted from roasted and ground coffee using a primary extraction liquid at a temperature of 80°C to 160°C. Then in a second extraction stage, soluble coffee solids are extracted from partially extracted grinds using a secondary extraction liquid at a temperature of 160°C to 190°C, the coffee grinds having at least 25% by weight of soluble coffee solids extracted therefrom. The coffee grinds obtained from the second extraction stage are discharged and thermally hydrolyzed at a temperature of 160°C to 220°C for 1 minute to 15 minutes in a hydrolysis stage. In a third extraction stage, soluble coffee solids are extracted from the hydrolyzed coffee grinds using a third extraction liquid at a temperature of 170°C to 195°C to provide extracted coffee grinds and a hydrolyzed coffee extract. A soluble coffee product is obtained containing at least 30% sugars, the sugars comprising less than 1% furfural derivatives, less than 4% monosaccharides, less than 10% oligosaccharides and at least 19% polysaccharides, the sugars having a weight average molecular weight greater than 2000 units and a polydispersity greater than 3.

[0007] EP0916267 discloses a process for continuously extracting water-soluble solids from solid particles containing water-soluble solids (such as roasted and ground coffee) for providing an extract product in one or more extraction stages. In each extraction stage, a slurry containing particles to be extracted and an extract is introduced into an extraction reactor, for example, immediately above a solid-liquid separator, to form an upwardly moving packed bed. Particles are scraped off from the packed bed to define the upper surface of the packed bed. An extraction liquid is introduced into the extraction reactor above the upper surface of the packed bed. A portion of the extraction liquid that percolates through the packed bed to extract water-soluble substances from the particles in the packed bed is obtained to form an extract. The remaining portion of the extraction liquid entrains the particles scraped off from the packed bed to provide a spent particle slurry. The spent particle slurry is removed from the extraction reactor. The extract is removed from below the packed bed, and at least a portion of the extract forms an extract product. The extraction stage can be separated by one or more solubilization stages.

[0008] EP1069830 discloses a process for recovering aroma components from coffee. A slurry of coffee grounds in an aqueous liquid is stripped to strip aroma components from the slurry. The stripping is carried out using a gas in a substantially countercurrent manner to provide an aromatized gas containing aroma components. The aroma components are then collected from the aromatized gas. The aroma components may be added to the concentrated coffee extract prior to drying the extract. The coffee powder produced has greatly increased and improved aroma and flavor and contains higher levels of furans and diketones.

[0009] US3682649 discloses cold water pressure extraction of roasted coffee in whole bean or ground form to obtain a high quality coffee extract and partially extracted coffee that can be further processed. The coffee extract can be dried to obtain high quality soluble coffee. The partially extracted coffee can be further extracted by standard percolation techniques, or can be dried and used as conventional roasted and ground coffee.

[0010] US3652292 discloses the manufacture of instant coffee powder, which comprises soluble coffee solids prepared by extraction as an aqueous medium, to which wet-ground colloidal particles of roasted or extracted roasted coffee are added. The colloidal particles account for about 3% to 40% by weight of the total weight of the coffee product. The colloidal particles are stabilized to prevent flocculation by adjusting the pH to a pH not exceeding 5.2, and the particles are encapsulated in dry soluble coffee solids to form an instant coffee product having a freshly brewed coffee aroma flavor and turbidity.

[0011] EP1795074 relates to a method for providing a concentrated coffee extract that is rich in aroma components released when roasted coffee beans are ground and has a certain amount of coffee oil that can be controlled according to the use and purpose, and to a process for industrially producing the concentrated coffee extract. According to the present invention, the above object is achieved by separating a distillate containing aroma components, a liquid containing coffee oil, and a coffee extract from a slurry obtained by wet grinding roasted coffee beans, and adding back the distillate containing aroma components and the liquid containing coffee oil after concentrating the coffee extract.

[0012] Since the production of liquid (i.e., aqueous) coffee extracts and dried soluble coffee products is associated with flavor differences compared to freshly prepared coffee beverages in a coffee shop environment, there has always been a goal of improving the production methods to achieve improved products. A common approach to improving the flavor of dried soluble coffee products is to add finely ground roasted coffee particles to the coffee extract before drying. The addition of such particles is usually controlled to avoid excessive deposition in the beverage, but generally does have a beneficial effect on the product flavor. The presence of small particles can also contribute to the observed mouthfeel. Summary of the invention

[0013] It would therefore be desirable to provide improved methods for preparing coffee products, improved coffee products and / or to address at least some of the problems associated with the prior art, or at least provide a commercially viable alternative.

[0014] One aspect of the present invention relates to an instant coffee composition for forming a coffee beverage, wherein the composition comprises soluble coffee solids and insoluble coffee solids, the insoluble coffee solids comprising coffee oil and an insoluble coffee sediment fraction, the insoluble coffee sediment fraction being the non-oil portion of the insoluble coffee solids, wherein the composition has a unimodal particle size distribution when analyzed by wet laser diffraction at a concentration of 1.5 wt%, and wherein the composition comprises at least 0.8 wt% coffee oil on a dry weight basis.

[0015] Another aspect of the present invention relates to an instant coffee composition for forming a coffee beverage, wherein the composition comprises soluble coffee solids and insoluble coffee solids, the insoluble coffee solids comprising coffee oil and an insoluble coffee sediment fraction, the insoluble coffee sediment fraction being the non-oil portion of the insoluble coffee solids, wherein the composition comprises at least 6 wt % of the insoluble coffee sediment fraction and at least 0.8 wt % of coffee oil on a dry weight basis.

[0016] The present invention also relates to a method for manufacturing a coffee extract product, as well as a coffee extract product obtainable by the method described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The invention will now be further described with reference to the accompanying drawings, in which:

[0019] · Figure 1 A flow chart showing the steps of the present invention.

[0020] · Figure 2 Viscosity graphs of various samples at different shear rates are shown.

[0021] · Figure 3 Sensory data from the trials are shown. DETAILED DESCRIPTION

[0022] According to a first aspect, there is provided a method for producing a coffee extract product, the method comprising:

[0023] (a) providing roast and ground coffee having an average particle size of 100 microns to 600 microns;

[0024] (b) mixing the roast and ground coffee with water to form a first slurry containing 15% to 30% by weight coffee solids,

[0025] (c) passing the first slurry through an aroma separation step to recover a coffee aroma fraction and form a de-aroma slurry;

[0026] (d) conveying the de-aromatherapy slurry to a first filtration device at a temperature of 90° C. to 150° C. to form a first coffee extract and a first filter cake;

[0027] (e) adding water to the first filter cake to form a reconstituted slurry having at least 12% by weight coffee solids;

[0028] (f) heat treating the reconstituted slurry at a temperature of 150° C. to 205° C.;

[0029] (g) then conveying the heat-treated reconstituted slurry to a second filtration device to form a second coffee extract and a second filter cake;

[0030] (h) combining the first coffee extract and the second coffee extract to form a third coffee extract;

[0031] (i) concentrating the third coffee extract to form a fourth coffee extract having 35% to 70% by weight coffee solids;

[0032] (j) adding the coffee aroma fraction to the fourth coffee extract to form a liquid coffee extract product.

[0033] The present invention will now be further described. In the following paragraphs, different aspects of the present invention are defined in more detail. Unless there is a clear contrary description, each aspect so defined can be combined with any one or more other aspects. Specifically, any feature indicated as preferred or advantageous can be combined with any other one or more features indicated as preferred or advantageous.

[0034] The present invention provides methods for making coffee extract products. That is, the present invention provides coffee products obtainable from coffee extracts. Examples of such products include liquid concentrates, such as those sold as bag-in-box coffee products, or soluble coffee products, such as freeze-dried or spray-dried powders or tablets. Both liquid concentrates and soluble coffee products are considered "instant" coffee products because they form a beverage immediately upon addition of water. All of these different product types are well known in the art. Such products can be supplemented by adding a small amount of finely ground roasted and ground coffee to improve flavor or appearance, as is well known in the art.

[0035] This patent application refers to "solids". These are the materials that remain after all the water has been removed. So if you take a coffee beverage and remove the water (by evaporation), you will be left with coffee solids. These coffee solids will include soluble coffee solids and insoluble coffee solids. Insoluble coffee solids will include roasted and ground coffee material as well as coffee oils. A further distinction is made herein to an insoluble coffee sediment fraction, which is the non-oil portion of the insoluble coffee solids.

[0036] The present invention utilizes a new extraction process that can radically change the flavor and taste of instant coffee while still relying solely on water extraction. The key parameters driving these changes are lower extraction and hydrolysis temperatures by using a much finer grind size, but without compromising the yield of the process.

[0037] The present invention has a number of advantages over prior art methods, as will become apparent from the following discussion. One advantage of the process of the present invention is that it can be carried out in a fully continuous manner. This saves the cost and complexity of processing equipment. Another benefit is that it can be operated with lower amounts of water, which is of course environmentally desirable, and also saves a lot of energy when the aim is to provide a liquid concentrate or dry powder, as less water needs to be removed.

[0038] The present invention also uses lower temperatures than conventional temperatures in the initial heat treatment, which helps to restore a more desirable coffee flavor. Since the method has a higher temperature secondary heat treatment, this ensures that high yields are maintained.

[0039] In addition, the present invention provides a coffee product with improved flavor and taste. In particular, the flavor and taste are surprisingly different from products obtained by conventional methods, resulting in a beverage with a richer mouthfeel and better flavor notes.

[0040] The method comprises a number of steps. It will be apparent that a number of these steps must be performed sequentially on a given portion of the material being processed, but it will also be appreciated that these steps may be performed as part of a continuous process, batchwise or a combination of both.

[0041] According to the first step (step (a)), a roasted and ground coffee having an average particle size of 100 to 600 microns, preferably 200 to 600 microns, is provided. The roasted and ground coffee is obtained from coffee beans that have been roasted and ground using techniques recognized in the art. The average particle size is D50, as measured using a Helos dry laser diffractometer under standard measurement conditions.

[0042] The grind size used here is much finer than the grind size used in conventional coffee extraction processes, which typically use a particle size of about 2 mm. The fine particle size allows the formation of a pumpable slurry while increasing the surface area for extraction. Conversely, the energy required to grind the coffee to this size is not too great and does not result in undesirable thermal degradation of the coffee beans during grinding.

[0043] Preferably, the roasted and ground coffee is ground to an average particle size of 200 to 400 microns, more preferably 250 to 350 microns, which is within the range of particle sizes conventionally ground for the production of espresso coffee beverages. This is particularly advantageous because, as explained below, less water needs to be added to prepare the slurry. Furthermore, below 250 microns, filtration becomes more difficult and less efficient. At particle sizes below 100 microns, the particles can clog the filter.

[0044] In another embodiment, it is preferred that the roasted and ground coffee has an average particle size of 400 to 600 microns. This is particularly advantageous for preparing liquid coffee concentrates. This is because for liquid products, it is better to have larger particles to reduce the oil content in the product, because oil causes crema instability in liquids. Larger particle sizes release less oil into the obtained extract.

[0045] According to another step (step (b)), the roasted and ground coffee is mixed with water to form a first slurry containing 15% to 30% by weight of coffee solids. That is, water is added to the coffee beans at a certain ratio so that the coffee beans provide 15% to 30% by weight of the whole mixture, preferably 20% to 25% by weight. The coffee solids include insoluble coffee solids and soluble coffee solids, and some soluble coffee solids will dissolve in the added water. The water of this content provides a pumpable slurry. The amount of water required for the pumpable slurry depends on the size of the grounds used: coarser grounds require more water to achieve pumpability. In the case where the grinding size is about 250 microns, dilution can be easily used to achieve, for example, 25% of solids. In the case where the grinding size is about 100 microns, dilution can be easily used to achieve, for example, 30% of solids. However, at a particle size of 400 microns to 600 microns, it is desirable to add more water, such as to achieve 15% solids.

[0046] According to a further step (step (c)), the first slurry is passed through an aroma separation step to recover a coffee aroma fraction and form a de-aroma slurry. Aroma separation systems are well known in the art of soluble coffee production. An exemplary processing unit is a rotating cone column operable to extract aroma. This involves introducing steam into the slurry which strips aroma from the coffee which can be recovered as an aqueous aroma stream which is stored for later use. Step (c) may be performed under vacuum.

[0047] The temperature of the slurry in the aroma separation step can be adjusted as required, but is generally in the range of 70°C to 100°C (such as 90°C to 100°C) at the start of the treatment. The heat treatment (i.e. aroma separation) is preferably carried out for 10 seconds to 2 hours, 1 minute to 25 minutes, preferably 1 minute to 5 minutes. In an alternative embodiment, the duration may be 15 minutes to 25 minutes. Of course, if this is the aroma recovery technology adopted, the temperature can be affected by the addition of steam. The aroma separation can be carried out under vacuum.

[0048] The temperature of the slurry may be raised prior to the aroma separation step by heating the added water before or after forming the slurry. The temperature change may be achieved using heat recovered from other steps of the process, such as by using a conventional heat exchanger. Preferably, the water in step (b) is at a temperature of 80°C to 100°C when mixed with the coffee. This is because adding hot water is cheaper than heating the hot water with the coffee beans or using steam to heat the slurry. If the water is not heated prior to mixing with the coffee, the water is added at a temperature between 15°C and 40°C and the subsequent slurry is heated to 80°C to 100°C. This option has the advantage of improved process simplicity.

[0049] At this point in the process, after step (c), the slurry comprises soluble coffee solids, de-aromatherapy insoluble coffee solids and water.

[0050] According to a further step (step (d)), the de-aroma slurry is conveyed to a first filtration device at a temperature of 90°C to 150°C, preferably 90°C to 120°C and more preferably 90°C to 100°C to form a first coffee extract and a first filter cake. In a preferred embodiment, the de-aroma slurry is conveyed to the first filtration device at a temperature of 140°C to 150°C. Thus, the process separates most of the soluble coffee solids and water from the insoluble coffee solids. The first filtration device can be one of several known filtration systems, including settling tanks, filters and centrifuges. Filters are preferred because they have the ability to process efficiently and continuously and the versatility to handle fine particles. It is most desirable to use a continuous filtration device. This allows efficient separation of insoluble solids from water, and the recovery rate of soluble solids is greater than 90%.

[0051] The coffee solids in the filter cake may be washed or pressed to increase the extraction of soluble coffee solids. The first coffee extract (which is a concentrated coffee liquor) may be stored for later use in the process, or added directly to a later step in the process in a continuous form.

[0052] According to a further step (step (e)), water is added to the first filter cake to form a reconstituted slurry having at least 12% by weight of coffee solids. That is, water is added in an amount necessary to produce a slurry, which typically has a slightly lower solids level than in the first slurry formation step. Preferably, the reconstituted slurry formed in step (e) has 12% to 30% by weight, more preferably 12% to 20% by weight of solids. This solids level is selected to achieve the desired pumpability. Again, reconstitution can be achieved with heated water as desired.

[0053] Preferably the water in step (e) is at a temperature of 80 to 100°C. This is because it is cheaper to add hot water and it also helps to achieve part of the temperatures required in subsequent steps. Heat may be recovered from other steps in the process.

[0054] According to a further step (step (f)), the reconstituted slurry is heat treated at a temperature of 150°C to 205°C, preferably 170°C to 205°C and more preferably 180°C to 205°C. The heating is preferably carried out under high pressure to improve the extraction yield. The preferred pressure is 2 bar to 30 bar, such as 15 bar. The heat treatment is preferably carried out for 5 minutes to 2 hours, preferably 5 minutes to 15 minutes, preferably 5 minutes to 10 minutes. In an alternative embodiment, the duration may be 15 minutes to 25 minutes. During this step, some insoluble coffee solids are hydrolyzed into soluble solids, which can then be recovered. This step can be carried out using a plug flow reactor.

[0055] At this point in the process, the slurry again contains soluble coffee solids, insoluble coffee solids and water. It may be subjected to a flash process where a pressure drop allows any unwanted aroma flavours to be removed.

[0056] According to a further step (step (g)), the heat treated reconstituted slurry is passed to a second filtration device to form a second coffee extract and a second filter cake. The filtration device may be any filtration device as discussed above. This is used to separate the coffee liquor containing dissolved soluble coffee solids from the insoluble coffee solids. The second filter cake may be washed and / or pressed again to recover further coffee extract. The second coffee extract typically has a lower soluble solids concentration than the first coffee extract.

[0057] The second coffee extract, which is a concentrated coffee liquid, may be stored for later use in the process.

[0058] According to a further step (step (h)), the first coffee extract and the second coffee extract are combined to form a third coffee extract. The two coffee extracts are typically combined by simple mixing to provide the third coffee extract.

[0059] According to a further step (step (i)), the third coffee extract is concentrated to form a fourth coffee extract having 35 to 70 wt% coffee solids, preferably 35 to 65 wt% coffee solids and more preferably 40 to 50 wt% coffee solids. When aroma is added in the subsequent step (j), a solids level of 55 to 60% after step (i) is preferred in order to enable dilution to achieve a useful final concentration. This serves to provide a coffee extract suitable for use as a concentrate (i.e. flowable) or for use in a drying process to produce a dry product (i.e. less water removed). Preferably, step (i) is performed in an evaporator unit.

[0060] According to a further step (step (j)), the coffee aroma fraction (from step (c)) is added to the fourth coffee extract to form a liquid coffee extract product. This improves the flavor of the extract without compromising the solids level. The aroma is added after the concentration step to avoid losing a limited amount of aroma from the product. The resulting coffee extract preferably has 35 to 65% by weight and preferably 45 to 65% by weight of coffee solids.

[0061] Preferably, the coffee extract product is a soluble powder. That is, the method further comprises a step (k) of drying the liquid coffee extract product to form a soluble powder. Preferably, the drying step is freeze drying, as this helps to maintain the improved aroma profile of the product. Preferably, the powder product has an average particle size of 200 microns to 3000 microns, more preferably 500 microns to 2000 microns.

[0062] Alternatively, if a liquid coffee concentrate product is desired, the process may include a further step after step (j) and after step (L) in which the extract is diluted to reduce the solids level so that the final product has a soluble solids content of from 25 to 55 wt%, preferably from 25 to 35 wt%. This is a suitable solids level for a liquid concentrate.

[0063] The coffee solids remaining after step (g) can be processed as a waste stream and can be incinerated to provide energy for the process (such as for heating water). Alternatively, the second filter cake can be subjected to an additional high temperature extraction process to obtain an additional coffee extract, which will be combined with the first coffee extract and the second coffee extract in step (h) to form a third coffee extract. Suitable conditions for this additional high temperature processing step are temperatures of 190°C to 215°C. The heat treatment is preferably carried out for 5 minutes to 2 hours, preferably 15 minutes to 25 minutes. This additional step can be carried out using another set of slurry formation and filtration steps, or using conventional extraction techniques.

[0064] Generally speaking, the claimed method involves the use of less water than conventional extraction methods. The use of high solids levels reduces the energy consumption of the associated concentration steps. The process also allows efficient recycling of heat between the different stages by adding water heated at the different stages and heat that can be recovered from the product of the high temperature extraction step.

[0065] Preferably, the method further comprises packaging the coffee extract product.

[0066] According to a preferred embodiment of the method, the method comprises:

[0067] (a) providing roast and ground coffee having an average particle size of 200 microns to 600 microns;

[0068] (b) mixing the roast and ground coffee with water to form a first slurry containing 15% to 30% by weight coffee solids,

[0069] (c) passing the first slurry through an aroma separation step to recover a coffee aroma fraction and form a de-aroma slurry;

[0070] (d) conveying the de-aromatherapy slurry to a first filtration device at a temperature of 90° C. to 100° C. to form a first coffee extract and a first filter cake;

[0071] (e) adding water to the first filter cake to form a reconstituted slurry having at least 12% by weight coffee solids;

[0072] (f) heat treating the reconstituted slurry at a temperature of 180° C. to 205° C.;

[0073] (g) then conveying the heat-treated reconstituted slurry to a second filtration device to form a second coffee extract and a second filter cake;

[0074] (h) combining the first coffee extract and the second coffee extract to form a third coffee extract;

[0075] (i) concentrating the third coffee extract to form a fourth coffee extract having 35% to 60% by weight coffee solids;

[0076] (j) adding the coffee aroma fraction to the fourth coffee extract to form a liquid coffee extract product.

[0077] This preferred embodiment is freely combinable with all further features of the first aspect.

[0078] According to a further aspect, there is provided a coffee extract product obtainable by the process described herein.

[0079] The finished instant coffee product exhibits an improved flavor with less process flavor and an improved flavor closer to freshly brewed coffee. Undesirable process sourness produced by processing at higher temperatures is also reduced.

[0080] The inventors have discovered that the above process results in a unique instant coffee product (i.e., liquid coffee concentrate or soluble coffee powder). Specifically, the product has an improved aroma and mouthfeel compared to conventional commercially available coffee products. The inventors have sought to identify the unique properties of the product that result in the observed improvements in aroma and mouthfeel.

[0081] The process results in the presence of an insoluble coffee sediment fraction within the product. This fraction is superficially similar to the roasted and ground coffee additives that are often added to coffee products to improve the flavor of conventional coffee extracts. However, the insoluble coffee sediment fraction is present in the product as a direct result of the process and no additional step of supplementing the coffee extract with roasted and ground coffee is required. Thus, the product of the present invention may be characterized by the presence of an insoluble coffee sediment fraction, which distinguishes it from commercially available coffee products that have not been supplemented with additional roasted and ground coffee.

[0082] Surprisingly, the inventors have found that the insoluble coffee sediment fraction obtained as a direct result of the process is less likely to settle out of the extract than a post-added roast and ground coffee extract. This is observed in the final beverage, where there is significantly less sediment or scum deposited on the walls of the container after the beverage has been swirled in the container.

[0083] The insoluble coffee sediment fraction obtained with the above process further differs from the insoluble coffee sediment fraction observed for coffee with conventional added roasted and ground coffee additives. This is because this fraction has been subjected to a coffee extraction process, exposed to a heated aqueous environment, which changes the balance of carbohydrates in the insoluble coffee material. Thus, the product of the present invention can be characterized by carbohydrate analysis of the insoluble coffee sediment fraction, which is distinguished from commercially available coffee products that have been supplemented with additional roasted and ground coffee.

[0084] Additionally, the process produces a higher oil fraction in the coffee product. This is a result of the finer coffee particle grind size used in the process. Since the finer grind exposes more coffee surface area for extraction, it will be appreciated that a greater amount of oil is released during the extraction process. Thus, the product of the present invention may be characterized by the presence of a higher oil fraction, which is distinguishable from commercially available coffee products obtained by conventional extraction processes.

[0085] According to yet another aspect of the present invention, there is provided an instant coffee composition for forming a coffee beverage.

[0086] Wherein the composition comprises at least 6 wt% of an insoluble coffee sediment fraction, the insoluble coffee sediment fraction comprises 1 wt% or less arabinose when analysed after acid hydrolysis.

[0087] The insoluble coffee sediment fraction is the sediment obtained using the repeated centrifugation process described herein. It represents the solid material (not oil) present in the product that is not soluble in water.

[0088] According to yet another aspect of the present invention, there is provided an instant coffee composition for forming a coffee beverage.

[0089] wherein the composition comprises an insoluble coffee sediment fraction which comprises 1 wt% or less arabinose when analyzed after acid hydrolysis, and

[0090] Wherein the composition comprises at least 0.8 wt% coffee oil, preferably 1 wt% to 5 wt% coffee oil, on a dry weight basis.

[0091] According to yet another aspect of the present invention, there is provided an instant coffee composition for forming a coffee beverage.

[0092] Wherein the composition comprises, by dry weight, at least 6 wt% of an insoluble coffee sediment fraction and at least 0.8 wt% of coffee oil, preferably 1 wt% to 5 wt% of coffee oil.

[0093] According to yet another aspect of the present invention, there is provided an instant coffee composition for forming a coffee beverage.

[0094] wherein the composition comprises at least 6 wt% of an insoluble coffee sediment fraction, the insoluble coffee sediment fraction comprising 1 wt% or less arabinose when analyzed after acid hydrolysis, and

[0095] Wherein the composition comprises at least 0.8 wt% coffee oil, preferably 1 wt% to 5 wt% coffee oil, on a dry weight basis.

[0096] According to yet another aspect of the present invention, there is provided an instant coffee composition for forming a coffee beverage.

[0097] wherein the composition comprises at least 6% by weight of an insoluble coffee sediment fraction, and

[0098] wherein the composition has a monomodal particle size distribution when analyzed by wet laser diffraction at a concentration of 1.5 wt %.

[0099] According to yet another aspect of the present invention, there is provided an instant coffee composition for forming a coffee beverage.

[0100] wherein the composition comprises an insoluble coffee sediment fraction which comprises 1 wt% or less arabinose when analyzed after acid hydrolysis, and

[0101] wherein the composition has a monomodal particle size distribution when analyzed by wet laser diffraction at a concentration of 1.5 wt %.

[0102] According to yet another aspect of the present invention, there is provided an instant coffee composition for forming a coffee beverage.

[0103] wherein the composition has a unimodal particle size distribution when analyzed by wet laser diffraction at a concentration of 1.5 wt %, and

[0104] Wherein the composition comprises at least 0.8 wt% coffee oil, preferably 1 wt% to 5 wt% coffee oil, on a dry weight basis.

[0105] In each of the above aspects relating to instant coffee compositions, the term "instant" encompasses both dry powder products (such as soluble coffee powder) and liquid coffee extracts (e.g. 30% by weight coffee solids (soluble and insoluble) in water). Preferably the composition is dried, more preferably spray-dried or freeze-dried, or vacuum-dried. Such dried products tend to have a longer product life.

[0106] The composition preferably comprises 7.5 to 15 wt% of an insoluble coffee sediment fraction. This amount of insoluble coffee sediment fraction provides a well-balanced flavor without having too much insoluble material which may adversely affect the mouthfeel and may cause undesirable sediment.

[0107] Preferably, the insoluble coffee sediment fraction comprises from 0.5 to 1 wt% arabinose when analysed after acid hydrolysis.

[0108] Preferably, the insoluble coffee sediment fraction comprises less than 5 wt% galactose, preferably 2 to 4 wt% galactose when analysed after acid hydrolysis.

[0109] Preferably, the instant coffee composition comprises at least 1 wt% coffee oil, preferably 1.5 wt% to 5 wt% coffee oil, by dry weight. The increase in oil content improves the mouthfeel of the product. The oil is obtained as a result of the process and has been found to be well distributed within the extract, contributing to an improved mouthfeel without an undesirable oily film being seen in the final beverage.

[0110] Preferably, the instant coffee composition has a unimodal particle size distribution when analyzed by wet laser diffraction at a concentration of 1.5 wt% (solids). This is distinguished from products in which roasted and ground coffee is added as a supplement to a soluble coffee powder (typically in a coffee extract prior to drying). In particular, conventional grinding techniques that crack coffee beans typically produce a bimodal distribution based on the cracking of the beans, with the lower peak being produced by the finest cell wall fragments. In contrast, the coffee particles retained after the method of the present invention, or retained in a conventional extract escaping from a percolation column, have a bimodal distribution.

[0111] Preferably, the instant coffee composition also has a D50 of less than 10 microns, preferably 2.5 microns to 7.5 microns, under the same particle measurement. This fine particle size reflects the effect on the extract obtained from the coffee process described above. In fact, the observed particle size distribution is unusual in that the D90 is generally greater than 30 microns, reflecting a wide particle size distribution.

[0112] Preferably, the composition consists of coffee. That is, preferably, the coffee composition does not comprise any non-coffee components or additives.

[0113] Quantification and analysis of the insoluble coffee sediment fraction requires separation of the insoluble coffee solids from the soluble coffee solids. In order to facilitate such an assessment of a liquid coffee product, it is necessary to dry the product into a powder so that the same analysis can be performed.

[0114] In order to separate and quantify the insoluble coffee sediment fraction (also referred to as sediment), 30 grams of a given coffee sample (dry powder) was added to 70 grams of boiling water and vibrated for 2 minutes. The sample was then centrifuged at 10,000 g for 15 minutes. After centrifugation, the supernatant was decanted, and the sediment was redissolved with 70 grams of boiling water, vibrated for 2 minutes, and then centrifuged again under the same conditions as above. The washing process was repeated 3 times for a total of four centrifugation steps. The sediment from the final wash was then freeze-dried, and the sediment percentage was then related to the 30g starting sample (e.g., 1.8g sediment represents 6% by weight insoluble coffee sediment fraction). Before any analysis was performed, the dried sediment sample was homogenized by simple stirring.

[0115] Given the method used to analyse the insoluble coffee sediment fraction, the fraction does not include any coffee oils that may be present, even though these would also be considered insoluble. This is because the oils would be easily separated during the centrifugation step.

[0116] To test the carbohydrates within the separated insoluble coffee sediment fraction, total carbohydrate analysis was performed using high performance anion exchange pulsed amperometric detection (HPAEC-PAD) according to ISO 11292-1995. The sample was prepared by mixing the separated sediment with 50 ml of 1 M HCl and then shaking the sample at 95°C for 150 minutes. Quantification of monosaccharides was usually performed by analyzing external standards of monosaccharides.

[0117] In order to determine the particle size distribution of instant coffee products, a Malvern Mastersizer 3000 with a Hydro MV tank was used for particle size distribution analysis. 1.5 g of sample (± 0.0005 g) was supplemented to 100 g (± 0.05 g) with deionized water boiled at 100°C, stirred for 60 seconds, cooled slightly, and added dropwise to the Malvern cell to achieve a haze of about 10%. The average of 3 readings was taken. Again, in order to facilitate this evaluation of liquid coffee products, it is necessary to dry the product into a powder so that the same analysis can be performed.

[0118] To determine the oil content, a sample of the product is assessed using a Soxtec H6 (if the product is a liquid coffee concentrate, it is first dried). 2 g of the sample is mixed with petroleum ether 40-60, boiled for 2 hours, and then rinsed for approximately 0.5 hours. The resulting condensate is then heated to recover the solvent. Assessing oil levels in this way is well known in the art.

[0119] In some embodiments, the instant coffee composition of the present invention may be blended with conventional coffee obtained by known methods. For example, the product may contain 10% to 100% (such as 20% to 50%) of the coffee described herein blended with the remainder of conventional coffee. While this can be easily achieved for liquid products, soluble products may be formed from mixed liquid extracts or from dry mixtures of different powdered products. This may be advantageous in situations where the mouthfeel and taste benefits of the present invention are to be mitigated to provide a closer conventional beverage experience.

[0120] like Figure 1 As shown in , the method for manufacturing a coffee extract product comprises a number of steps.

[0121] In step (a), roasted and ground coffee having an average particle size of 100 to 600 microns, preferably 200 to 600 microns is provided. Within this range, larger sizes are advantageous for liquid extract products, while smaller sizes are advantageous for dry soluble coffee products.

[0122] In step (b), the roast and ground coffee is mixed with water 5 to form a first slurry 10 containing 15 to 30 wt% coffee solids. The water 5 is added at a temperature of 80 to 100°C and preferably 90 to 95°C. The solids level is determined by the particle size, as the minimum amount of water 5 is used as required to obtain a pumpable slurry 10. The larger the particle size, the more water 5 (lower solids) is required to achieve a pumpable slurry 10.

[0123] In step (c) the first slurry is passed through an aroma separation step to recover a coffee aroma fraction 15 and form a de-aromatised slurry 20. A typical approach to the process involves adding steam to the pumpable slurry 10, wherein the vapour is processed in a rotating cone processing unit.

[0124] In step (d), the de-aroma slurry 20 is conveyed to a first filtration device at a temperature of 90°C to 150°C, such as 90°C to 100°C, to form a first coffee extract 25 and a first filter cake 30. The temperature is maintained from the previous step or may be further increased to increase the extraction yield. The filter cake 30 may be washed and pressed to obtain the maximum possible amount of soluble coffee solids.

[0125] In step (e), water 5 is added to the first filter cake 30 to form a reconstituted slurry 35 having at least 12 wt% coffee solids. The water 5 is preferably hot, and there may be mechanical agitation to break up the first filter cake 30. The amount of water required to reconstitute the slurry tends to be higher than the amount of water required in step (b).

[0126] In step (f), the reconstituted slurry 35 is heat treated at a temperature of 150°C to 205°C, such as 180°C to 205°C, to form a heat treated reconstituted slurry 40. That is, it is pumped through a heat treatment unit, such as a plug flow reactor. The residence time in the heat treatment is typically at least 5 minutes to ensure good extraction.

[0127] In step (g), the heat treated reconstituted slurry 40 is passed to a second filtration device to form a second coffee extract 45 and a second filter cake 50. The second filter cake 50 may be washed and pressed to obtain the maximum possible amount of soluble coffee solids. The temperature in this step may be maintained from the previous step, or may be reduced as heat is recovered for use in step (b), such as to a temperature of 80°C to 100°C.

[0128] The second filter cake 50 may then be combusted in step M to generate heat for the process, or may be subjected to a further high temperature extraction step M to obtain further coffee extract 52 .

[0129] In step (h), the first coffee extract 25 and the second coffee extract 45 are combined to form a third coffee extract 55. Other aqueous coffee extracts, such as further coffee extract 52, may also be added in this step.

[0130] In step (i), the third coffee extract 55 is concentrated to form a fourth coffee extract 60 having 35 to 70 wt % coffee solids, such as 35 to 60 wt % coffee solids.

[0131] In step (j), the coffee aroma fraction 15 is added to the fourth coffee extract 60 to form a liquid coffee extract product 65 .

[0132] The liquid coffee extract product 65 may be processed in step K to form a dry coffee product, such as a soluble coffee powder 70. The liquid coffee extract product 65 may be diluted in step L to form a liquid coffee concentrate 80.

[0133] exist Figure 3 In the figure, the current technology is represented by the smallest quadrilateral. The other two quadrilaterals represent different prototypes with 70% current technology products and 30% new technology products. The axes are: positive x (sticky); positive y (turbid); negative x (powdery); negative y (dry).

[0134] In order to further illustrate certain aspects of the present invention, the present invention also specifically provides the following non-limiting embodiments:

[0135] Embodiment 1. An instant coffee composition for forming a coffee beverage,

[0136] wherein the composition comprises at least 6 wt% of an insoluble coffee sediment fraction, said insoluble coffee sediment fraction comprising 1 wt% or less arabinose when analysed after acid hydrolysis.

[0137] Embodiment 2. The instant coffee composition according to embodiment 1, wherein the composition comprises 7.5 wt % to 15 wt % of the insoluble coffee sediment fraction.

[0138] Embodiment 3. The instant coffee composition according to embodiment 1 or embodiment 2, wherein the insoluble coffee sediment fraction comprises 0.5 wt% to 1 wt% arabinose when analyzed after acid hydrolysis.

[0139] Embodiment 4. An instant coffee composition according to any preceding embodiment, wherein the insoluble coffee sediment fraction comprises less than 5 wt% galactose, preferably 2 to 4 wt% galactose, when analysed after acid hydrolysis.

[0140] Embodiment 5. The instant coffee composition according to any preceding embodiment, wherein the instant coffee composition comprises at least 0.8 wt% coffee oil, preferably 1 wt% to 5 wt% coffee oil, based on dry weight.

[0141] Embodiment 6. The instant coffee composition according to any preceding embodiment, wherein the composition has a D50 of less than 10 microns, preferably 2.5 microns to 7.5 microns, when analyzed by wet laser diffraction at a concentration of 1.5 wt%.

[0142] Embodiment 7. The instant coffee composition according to any preceding embodiment, wherein the composition consists of coffee.

[0143] Embodiment 8. The instant coffee composition according to any preceding embodiment, wherein the composition is spray-dried or freeze-dried, or wherein the instant coffee composition is a liquid coffee concentrate.

[0144] Embodiment 9. A method for manufacturing a coffee extract product, the method comprising:

[0145] (a) providing roast and ground coffee having an average particle size of 100 microns to 600 microns;

[0146] (b) mixing the roast and ground coffee with water to form a first slurry containing 15% to 30% by weight coffee solids,

[0147] (c) passing the first slurry through an aroma separation step to recover a coffee aroma fraction and form a de-aroma slurry;

[0148] (d) conveying the de-aromatherapy slurry to a first filtration device at a temperature of 90° C. to 150° C. to form a first coffee extract and a first filter cake;

[0149] (e) adding water to the first filter cake to form a reconstituted slurry having at least 12% by weight coffee solids;

[0150] (f) heat treating the reconstituted slurry at a temperature of 150° C. to 205° C.;

[0151] (g) then conveying the heat-treated reconstituted slurry to a second filtration device to form a second coffee extract and a second filter cake;

[0152] (h) combining the first coffee extract and the second coffee extract to form a third coffee extract;

[0153] (i) concentrating the third coffee extract to form a fourth coffee extract having 35% to 70% by weight coffee solids;

[0154] (j) adding the coffee aroma fraction to the fourth coffee extract to form a liquid coffee extract product.

[0155] Embodiment 10. The method of embodiment 9, wherein the roast and ground coffee has an average particle size of 400 to 600 microns, or wherein the roast and ground coffee has an average particle size of 250 to 400 microns.

[0156] Embodiment 11. The method according to any one of the preceding embodiments, wherein the coffee extract product is a soluble powder, the method further comprising:

[0157] (k) drying the liquid coffee extract product to form a soluble powder.

[0158] Embodiment 12. The method of any preceding embodiment, wherein the liquid coffee extract product has 40% to 50% by weight coffee solids.

[0159] Embodiment 13. The method according to any of the preceding embodiments, wherein the water in step (b) and / or step (e) is at a temperature of 80°C to 100°C.

[0160] Embodiment 14. The method according to any of the preceding embodiments, wherein the reconstituted slurry formed in step (e) has 12 wt % to 30 wt % solids.

[0161] Embodiment 15. A method according to any one of the preceding embodiments, wherein the second filter cake is subjected to an additional high temperature extraction process to obtain an additional coffee extract, which is combined with the first coffee extract and the second coffee extract in step (h) to form the third coffee extract.

[0162] Embodiment 16. The method according to any of the preceding embodiments, wherein step (f) is performed in a plug flow reactor.

[0163] Embodiment 17. The method of any one of the preceding embodiments, wherein step (i) is performed in an evaporator unit.

[0164] Embodiment 18. The method according to any of the preceding embodiments, wherein step (c) is performed under vacuum.

[0165] Embodiment 19. The method of any preceding embodiment, further comprising packaging the coffee extract product.

[0166] Embodiment 20. The method according to any one of the preceding embodiments, wherein the method is a continuous process.

[0167] Embodiment 21. A coffee extract product obtainable by the method according to any one of embodiments 9 to 20.

[0168] Example

[0169] The invention will now be further described with respect to the following non-limiting examples.

[0170] Example 1

[0171] Roasted whole beans were ground to between 200 and 400 μm in a 3-stage roller mill.

[0172] Roast and ground coffee was slurried with water at a ratio of 25% coffee to 75% water at 20°C to 30°C.

[0173] The slurry is fed forward into a heat exchanger and heated to 95°C before moving into a rotating cone where the aroma is stripped from the slurry.

[0174] After exiting the spinning cone, the slurry was fed forward through a heat exchanger, raising the temperature to between 120°C and 150°C for 2 to 5 minutes.

[0175] The slurry is then fed into a filter to separate the coffee liquor from the grinds. The grinds are then subjected to 2 further washing steps at 130°C to 150°C to remove additional solids.

[0176] The grind is then re-slurried with fresh water at a rate of 12% to 17% solids. The resulting slurry is fed forward to the hydrolysis step where it is heated to between 180°C and 205°C (185°C) and held for between 5 minutes and 20 minutes.

[0177] The resulting slurry is then cooled to below 100°C and then passed through a second filtration step, repeating the separation and washing of the first separation step.

[0178] The coffee extracts obtained from each filtration step are combined and concentrated. The aroma compounds stripped from the first slurry are then added to the mixture. The fully combined three components are then freeze dried using conventional methods to obtain a soluble coffee powder.

[0179] The process recovers an incremental yield of 2% roasted coffee relative to current technology, with reduced water usage.

[0180] Example 2

[0181] Arabica and / or Robusta coffee beans were roasted and ground using a 3-stage roller mill to an average particle size of 300 um. The ground coffee was then slurried with water at a ratio of 25% coffee to 75% water at 20°C to 25°C.

[0182] The slurry is fed forward to a heat exchanger and heated to 70°C before moving to a rotating cone where the aroma is stripped from the slurry.

[0183] The slurry was then fed into a filter at a temperature of 95°C to separate the coffee liquor from the grinds. The grinds were then subjected to 2 further washing steps to remove additional solids.

[0184] The grind was then re-slurried with fresh water at a rate of 12% to 17% solids. The resulting slurry was fed forward to the plug flow reactor (hydrolysis step) where it was heated to 170°C and maintained for 5 to 10 minutes.

[0185] The resulting slurry is then cooled to below 100°C and then passed through a second filtration step, repeating the separation and washing of the first separation step.

[0186] The coffee extracts obtained from each filtration step are combined and concentrated. The aroma compounds stripped from the first slurry are then added to the mixture. The fully combined three components are then freeze dried using conventional methods to obtain a soluble coffee powder.

[0187] The product of this example was found to have more body / mouthfeel than products produced using current technology.

[0188] Example 3

[0189] Coffee slurry was prepared as described in Example 1.

[0190] The slurry is fed forward into a heat exchanger and heated to 95°C before moving into a rotating cone where the aroma is stripped from the slurry.

[0191] After exiting the spinning cone, the slurry was fed forward through a heat exchanger, raising the temperature to between 145°C and 150°C for 4 to 5 minutes.

[0192] The slurry was then fed into a filter to separate the coffee liquor from the grinds. The grinds were then subjected to 2 further washing steps at 140°C to remove additional solids.

[0193] The slurry is then fed into a filter, which separates the coffee liquid from the grinds.

[0194] The grind was then re-slurried with fresh water at a rate of 12% to 17% solids. The resulting slurry was fed forward to the plug flow reactor (hydrolysis step) where it was heated to 200°C and maintained for 7 to 10 minutes.

[0195] The resulting slurry is then cooled to below 100°C and then passed through a second filtration step, repeating the separation and washing of the first separation step.

[0196] The coffee extracts obtained from each filtration step are combined and concentrated. The aroma compounds stripped from the first slurry are then added to the mixture. The fully combined three components are then freeze dried using conventional methods to obtain a soluble coffee powder.

[0197] The product of this example was found to have more body / mouthfeel than products produced using current technology.

[0198] Example 4

[0199] Arabica and / or Robusta coffee beans were roasted and ground using a 3-stage roller mill to an average particle size of 400 um. The ground coffee was then slurried with water at a ratio of 15% coffee to 85% water at 20°C to 25°C.

[0200] The rest of the process was carried out as in Example 1.

[0201] The oil content of the obtained product is lower than that of the product of Example 1.

[0202] Example 5

[0203] The samples obtained by the method described herein were evaluated in comparison with a range of commercially available soluble coffee products. From the comprehensive testing it can be seen that the products obtained by this process are novel and can be easily distinguished from products obtained by conventional processes.

[0204] Oil content

[0205]

[0206] *Bean identity of the comparison products is based on educated guesswork

[0207] Examples 7, 8, 9 and 10 were produced according to the methods described herein. Examples 1 to 6 are commercially available products, where 2 and 4 are products supplemented with added roast and ground coffee additives (designated "whole bean instant" in the table).

[0208] It is generally understood that the oil level in Robusta coffee beans is lower than the oil level in Arabica coffee beans. This is reflected in the generally lower oil levels in products containing Robusta coffee beans, including Inventive Example 9. Sample 10 is a dark Brazilian known for its high oil level.

[0209] It can be seen that low oil levels are present in pure instant coffee (i.e., Samples 1, 3, 5, and 6), which have not been supplemented with the roast and ground coffee additive. The oil levels in Samples 2 and 4 are slightly higher due to the oil content of the roast and ground coffee additive, with Sample 2 containing approximately 5% roast and ground coffee and Sample 4 containing more roast and ground coffee.

[0210] Samples 7, 8 and 10 contained high levels of oil due to the fine grinding of the roasted coffee in the new process which releases more oil into the extract.

[0211] It can be seen that conventional soluble coffee products do not contain significant levels of oil. In fact, it is speculated that the oil levels observed for some of these products were subsequently added to the surface of the dry powder to improve its flavor.

[0212] The only prior art products containing high oil levels are the result of adding roasted and ground coffee additives to the product. In contrast, the method described herein achieves high levels of oil even for Robusta coffee bean products.

[0213] Sediment level

[0214] The sediment level is determined by taking 30 grams of a given coffee sample added to 70 grams of boiling water and shaken for 2 minutes. The sample is then centrifuged at 10,000g for 15 minutes. After centrifugation, the supernatant is decanted and the sediment is redissolved with 70 grams of boiling water, shaken for 2 minutes, and then centrifuged again under the same conditions as above. This washing process is repeated 3 times for a total of four centrifugation steps. The sediment from the final wash is then freeze-dried and the sediment percentage is then related to the 30g starting sample (e.g., 1.8g sediment represents a 6% by weight insoluble coffee sediment fraction).

[0215] sample Sediment (wt%) 1 l'Or Intense 5.2 2 Kenco thick 4.7 3 Carte Noir 3.8 4 Kenco Milicano Americano 11.5 5 Nescafé Gold 4.4 6 Nescafé Azera Americano 9.3 7 The sample Robusta of the present invention 11.9 8 Sample Colombian Arabica of the present invention 7.8 9 Sample of the present invention Centrals Arabica 9.2

[0216] Examples 7, 8 and 9 have been produced according to the methods described herein. Examples 1 to 6 are commercially available products, where 4, 5 and 6 are products supplemented with added roast and ground coffee additives.

[0217] It can be seen that all commercially available instant coffee products have a certain level of insoluble coffee sediment fraction. This is expected to be small fragments of coffee cell walls that pass through the extraction system into the coffee extract. The level of insoluble coffee sediment fraction generally increases for those products supplemented with added roast and ground coffee additives.

[0218] It can be seen that the products produced according to the methods described herein all have a significantly higher level of insoluble coffee sediment fraction than an instant coffee product which has not been supplemented with the added roast and ground coffee additive.

[0219] Particle size distribution

[0220]

[0221] Examples 7, 8 and 9 have been produced according to the methods described herein. Examples 1 to 6 are commercially available products, where 4, 5 and 6 are products supplemented with added roast and ground coffee additives.

[0222] The sedimentation quantitative method with multiple centrifugation steps allows the recovery of large quantities of very fine particles.

[0223] The particle size distribution has been measured with a Malvern 3000 after preparing a 1.5% hot brew of the dry product (eg 3 g dry product in 200 ml hot water).

[0224] Three types of sediments can be distinguished:

[0225] Category 1 (L'Or Extra Espresso, Kenco Espresso and Black Card) :

[0226] Unimodal distribution D10: <1.5 μm and D90: <15 μm

[0227] Relatively low amount of sediment < 5.5 wt%

[0228] Very small particle sizes (such as low D90) may reflect the manner in which these particles have escaped from the extraction column into the extract, or mannan that has been deposited in the evaporator.

[0229] Category 2 (Kenco Rice Grain Canno, Nestle Gold Medal and Azera) is clearly different from Category 1 and Category 3

[0230] Bimodal distribution (2 peaks): Peak 1 between 1 μm and 10 μm and Peak 2 between 10 μm and 100 μm.

[0231] Category 3: Samples of the present invention

[0232] Unimodal distribution, but broader than class 1: D10: >1.0 μm and D90: >15 μm, and the amount of sediment is relatively high, such as >7.5 wt%.

[0233] Carbohydrate analysis

[0234] The analysis is of monosaccharides after acid hydrolysis.

[0235]

[0236] Examples 7, 8 and 9 have been produced according to the methods described herein. Examples 1 to 6 are commercially available products, where 4, 5 and 6 are products supplemented with added roast and ground coffee additives.

[0237] It can be seen that the insoluble coffee sediment fraction of the product of the invention has a level of arabinose that is generally similar to the arabinose level of a soluble coffee product that has not been supplemented with roast and ground coffee. Typically, it also has a lower level of galactose than a soluble coffee product that has been supplemented with roast and ground coffee.

[0238] Without wishing to be bound by theory, it is believed that the high levels of arabinose in the supplemented product are a result of the presence of unextracted coffee material. In contrast, for the product of the invention, the levels are lower, reflecting the fact that arabinose has been extracted into the soluble coffee fraction by the process of the invention.

[0239] Sensory test

[0240] 2 prototypes of the product of the invention were combined with a product from the current art in a ratio of 30 (POI): 70 (current product). These were then tested in a group with an additional sample of 100% of the current art product. The 3 samples were presented to a sensory panel who were then asked to pair the products based on similarity / difference with the third sample.

[0241] Results show that even at just 30% levels in a blend with the current product, the prototype is perceived as stickier / drier and powderier – all attributes that contribute to mouthfeel / consistency. These levels correlate directly with the tribological data. More oil means more lubrication, which means more mouthfeel / consistency. The effects are shown in Figure 3 middle.

[0242] Collapse temperature

[0243] The crystalline product has a well defined "eutectic" freezing / melting point, which is known as its collapse temperature. When freeze drying a concentrated coffee extract, the extract is heated under vacuum from an initial freezing temperature of about -50°C. This allows the water content to sublime away. The rate of heating depends on the extract, and there is a collapse temperature, above which the product will melt back and be affected. The temperature and pressure can then be increased in subsequent cycles until signs of collapse or melt back are observed, indicating that the product is too hot. The inventors were surprised to find that the collapse temperatures of several samples of the product of the invention were higher than those of their standard coffee product.

[0244] Rheological properties of samples

[0245] 1 Alta Rica 2 Nestle Gold Blend 3 Kenco is really thick 4 Rice Grain Curry 5 Percol 6 Kenco is really thick 7 NGC Colombia 8 NGC Central 9 NGC Robusta 10 NGC Brazil

[0246] Samples were prepared with 10 g of coffee dissolved in 40 g of water at 85° C. Complete dissolution was achieved by stirring at 150 rpm for 2 minutes with a 25 mm stirring bar.

[0247] The rheometer was used with a Discovery HR-2 at a flow rate between 0.01 and 1000 s. -1 These samples were tested in a simple shear sweep between shear rates of 1.0 and 2.0 with a sample volume of 8 ml and a circulating bath set to -4° C. The samples were studied at temperatures of 20° C. and 65° C. and concentrations of 1.5 wt % and 20 wt %.

[0248] The data were then fitted to the Quemada model, which develops insights into fluid rheology based on the theory of internal structural unit (SU) suspensions.

[0249] In concentrated systems, single particles and small flocs can form larger and larger groups, the size of which will depend on the applied shear rate.

[0250] Therefore, since viscosity (η) is a function of structure (η=f(s)), and the structure depends on the applied shear level (since increasing shear rate will only serve to disperse the macro- and meso-structure of the flocs into individual subunits), viscosity can be expressed in terms of packing fraction / compactness, since the more compact the SU, the higher the packing, and therefore the more structure (viscosity) will be present.

[0251] This is because the compactness of the SU will contribute to the leveling of the structure;

[0252]

[0253] where η is the viscosity and Φ is a measure of compactness.

[0254] Figure 2 The results from this measurement are shown. In this graph, important information is provided by the intercepts of the curve with the y-axis, which represent the initial structure of the tested samples. The lines from top to bottom are samples 9, 8, 10, 4, 7, 3, 2, 1, 6, 5.

[0255] We can conclude that at 20 wt% (i.e., concentrated samples) at 65°C (close to the consumption temperature), Sample 4 (rice curry) and Samples 7 to 10 have significantly higher η0. This means that from a microstructural perspective, at lower shear rates (1s -1 ) (the lower shear rates represent those during chewing and reflect the mouthfeel), these samples have more structure relative to the other samples. This means that at these lower shear rates, the compactness of their structural units is higher, i.e., better packing of the structural units.

[0256] The tribology of the samples was also observed. "Tribology is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication and wear." Therefore, the parameters to be noted are μ max , which represents the maximum friction observed for each sample. Since lubricity indicates the mouthfeel here and higher μ max A lower lubricity is indicated which should translate into a lower mouthfeel.

[0257] It is observed that at 65°C (consumption temperature), samples 7, 8, and 10 have significantly lower μ max , indicating lower friction and therefore higher mouthfeel. The exception is Sample 9 (Robusta blend) which has a lower oil content.

[0258] Unless otherwise indicated, all percentages herein are by weight.

[0259] Although preferred embodiments of the present invention have been described in detail herein, those skilled in the art will appreciate that changes may be made therein without departing from the scope of the invention or the appended claims.

Claims

1. An instant coffee composition for forming a coffee beverage, wherein the composition comprises soluble coffee solids and insoluble coffee solids, the insoluble coffee solids comprising coffee oil and an insoluble coffee sediment fraction, the insoluble coffee sediment fraction being the non-oil portion of the insoluble coffee solids, wherein the composition has a unimodal particle size distribution when analyzed by wet laser diffraction at a concentration of 1.5 wt %, and wherein the composition comprises at least 0.8 wt% coffee oil on a dry weight basis.

2. An instant coffee composition for forming a coffee beverage, wherein the composition comprises soluble coffee solids and insoluble coffee solids, the insoluble coffee solids comprising coffee oil and an insoluble coffee sediment fraction, the insoluble coffee sediment fraction being the non-oil portion of the insoluble coffee solids, wherein the composition comprises at least 6 wt% of an insoluble coffee sediment fraction and at least 0.8 wt% of coffee oil on a dry weight basis.

3. The instant coffee composition according to claim 1 or claim 2, wherein the amount of coffee oil is 1 wt% to 5 wt%.

4. An instant coffee composition according to any preceding claim, wherein the composition comprises at least 6 wt% of an insoluble coffee sediment fraction comprising 1 wt% or less arabinose when analysed after acid hydrolysis.

5. An instant coffee composition according to any preceding claim, wherein the composition comprises from 7.5% to 15% by weight of the insoluble coffee sediment fraction.

6. An instant coffee composition according to claim 4, wherein the insoluble coffee sediment fraction comprises 0.5 to 1 wt% arabinose when analysed after acid hydrolysis.

7. An instant coffee composition according to any preceding claim, wherein the insoluble coffee sediment fraction comprises less than 5 wt% galactose, preferably 2 to 4 wt% galactose when analysed after acid hydrolysis.

8. An instant coffee composition according to any preceding claim, wherein the composition has a D50 of less than 10 microns, preferably from 2.5 microns to 7.5 microns when analysed by wet laser diffraction at a concentration of 1.5 wt%.

9. An instant coffee composition according to any preceding claim, wherein the composition has a D90 of greater than 30 microns when analysed by wet laser diffraction at a concentration of 1.5 wt%.

10. An instant coffee composition according to any preceding claim, wherein the composition consists of coffee.

11. An instant coffee composition according to any preceding claim, wherein the composition is spray dried or freeze dried, or wherein the instant coffee composition is a liquid coffee concentrate.

12. An instant coffee composition according to any preceding claim, wherein the product is supplemented by the addition of further finely ground roast and ground coffee.

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