Pressing method and pressed coffee tablet for pressurized extraction

Abstract

The invention discloses an industrial process for pressing roasted and ground coffee to obtain pressed coffee tablets (1) suitable for preparing coffee-based beverages, including espresso coffee and similar beverages, by extraction with a pressurized flow having a fluid pressure greater than 5 bar, the method has the advantages in the aspects of size stability, extraction effect, production efficiency and productivity of pressed coffee tablets. The invention further discloses a pressed coffee tablet (1) suitable for preparing coffee-based beverages and exhibiting advantages in the efficiency of extracting coffee by means of a pressurized extraction stream.

Description

Technical Field

[0001] The present invention relates to an industrial production method for preparing pressed tablets for beverages, in particular to roasted and ground coffee tablets for preparing beverages by pressurized flow extraction, and pressed tablets for preparing beverages having the characteristics prepared by the said method. Background Art

[0002] The prior art includes several documents related to methods for producing single - serve pressed coffee (commonly referred to as pressed coffee tablets), which are used to prepare coffee - based beverages. The said documents mention several challenges related to such coffee pressing methods, especially due to the physico - chemical properties of coffee and the relative sizes of the coffee particles to be pressed.

[0003] Pressing a certain quantity of roasted and ground coffee beans presents some challenges, mainly related to the physico - chemical properties of the previously roasted and ground coffee beans, including the release of volatile gases, oils, and the size of the coffee grounds.

[0004] In this context, those skilled in the art are also aware of the fact that there are different types of coffee, including soluble coffee mainly used for making coffee by percolation, and roasted and ground coffee mainly used for making espresso. These two types of coffee have different physico - chemical properties related to the pressing process. Therefore, some of the prior art addresses the problems of pressing soluble coffee tablets or tablets extracted by percolation, that is, extracting by ambient pressure or a fluid pressure greater than ambient pressure but less than 5 bar.

[0005] For example, document EP2154987 B1 discloses a production method for pressed coffee tablets suitable for use in a filter coffee machine, that is, by ambient pressure flow. In this case, the pressing pressure should be between 70 and 130 bar. Before pressing, the relative humidity of the roasted and ground coffee beans is between 2% and 8%. The hardness of the resulting coffee tablets is between 30 - 55 N, and the weight is between 2 - 15 g. The hardness of the coffee tablets is designed to decompose in a specific way at a specific moment.

[0006] The present invention solves the specific problem of pressing coffee tablets for preparing beverages by means of pressurized flow extraction, where the pressure of the extraction fluid is higher than 5 bar, the fluid pressure is optionally between 5 and 20 bar, preferably between 10 and 15 bar.

[0007] The pressing of single - serve roasted and ground coffee is a different and unique problem because it can depend on different characteristics of the roasted and ground coffee beans, including the degree of roasting, residual humidity, particle size, and the relative distribution of particle sizes after the coffee beans are ground. Thus, these characteristics have a relatively important impact on the pressing process.

[0008] In this case, a number of physical parameters can play an important role, both in maintaining the shape of the pressed tablet, promoting or restricting its physical decomposition, and in the process of beverage preparation, including improving the interaction of specific types of coffee with the fluid.

[0009] These several aspects are of particular significance for espresso or similar coffee, in which case the pressed tablet should be impacted by a pressurized fluid with a pressure greater than 5 bar, preferably greater than 10 bar.

[0010] In this case, the particle size, humidity, and roasting degree of the ground coffee beans are all parameters that affect the pressing result.

[0011] The prior art includes references related to the degassing problem, such as reference CA 808588A, which discloses the possibility of producing tablets of roasted and ground coffee beans.

[0012] Document EP0229920 B1 discloses a method for producing coffee tablets by pressing a large number of ground and roasted coffee bean particles with a humidity of at least 3%, especially between 3% and 6%, preferably 4%, and an average particle size between 0.4 mm and 2.0 mm, especially between 0.6 mm and 1.2 mm. The method of pressing the coffee mass is to apply a pressure between 20.7 and 48.3 MPa, preferably 39.5 MPa. The method also includes coating the outside of the pressed tablet with an edible material that can be dispersed in water, wherein the coating includes humidification with an aqueous liquid and application of a dry solid.

[0013] Document WO2004 / 034797A1 discloses a method for producing pressed coffee tablets using a rotary press, including a cooling step before compression.

[0014] Document EP2129232 B1 discloses a method for pressing plant powder, including only one pressing step, which includes a pressing period. The powder used for pressing is roasted and ground coffee with a humidity between 3 and 10% and an average size between 0.2 and 3 mm, preferably between 0.4 and 2 mm.

[0015] Documents EP3081092 B1 and EP2416665 B1 disclose roasted and ground coffee tablets that are also suitable for extracting coffee by drip, i.e., by a water flow under atmospheric pressure. In this case, the tablets are obtained by a method including two compression stages, especially the so-called pre-compression in the first stage with a pressure between 36.1 MPa and 84.8 MPa, and then the compression stage, where the pressure value applied in the pre-compression stage should account for 20% to 100% of the compression pressure. The hardness of the pressed coffee tablets should be greater than 30 N and the friability should be less than 10%.

[0016] The document WO2008 / 123775A1 discloses a method for producing coffee tablets and the coffee tablets obtained by this method. The coffee tablets generally have an irregular shape.

[0017] Regarding the critical period of the method, the documents US 9,474,290 B2 and US 9,756,869 B2 disclose a method for producing roasted and ground coffee tablets in two stages, but it is suitable for extraction in a drip coffee device. That is to say, during the extraction process, the coffee tablets are pressed so that they are easily broken when impacted by hot water under ambient pressure.

[0018] In particular, the method includes a pre-compression step with a pressure between 10.6 MPa and 63.6 MPa, and a compression step with a pressure between 63 and 169.7 MPa. These two steps are carried out in the same pressing die in order to produce tablets with a hardness of at least 30 N. In fact, the greater hardness of the tablets should be associated with the greater brittleness of their structural rupture.

[0019] In addition, the document also discloses that the delay time between pre-compression and main compression is 80 to 900 milliseconds, and the total time from pre-compression to main compression is about 0.1 to 1 second. The set delay time and timing should also be related to minimizing the dimensional changes of the tablets after pressing, including the dimensional changes caused by the expansion of the compacted volume.

[0020] The document WO 2010 / 137965 A1 mentions a capsule that includes 5 to 6.5 grams of roasted and ground coffee beans, and these coffee beans are pressed using a pressing force of 50 to 800 N, preferably 400 to 600 N.

[0021] The document WO 2020 / 089403 A1 discloses a coffee container that includes a roasted and ground coffee cake, which can be pressed by applying a compression force of 0.5 kN to 15 kN, preferably 1 kN to 10 kN.

[0022] The documents WO 2021 / 118376 A1 and WO 2021 / 118377A1 submitted by the applicant of the present invention relate to pressing coffee tablets. In several aspects, the above-mentioned documents mention that the pressing force is between 4 and 6 kN, preferably between 4.5 and 5.5 kN, and thus pressed tablets with a hardness between 10 and 20 N, preferably between 13 and 17 N, can be obtained.

[0023] According to the tests that have been conducted, too much compression force may cause the particles of roasted and ground coffee beans to be crushed, and the hardness of the pressed tablets will be relatively high, which will limit the flow of pressurized fluid through the pressed tablets, thereby reducing the extraction effect. In addition, in industrial production processes, there are several aspects that affect productivity, including production capacity and the scrap rate caused by defects and losses. Summary of the invention

[0024] The object of the present invention is to provide a method for producing pressed coffee tablets for preparing coffee-based beverages, comprising the steps of pressing roasted and ground coffee tablets, so that these pressed coffee tablets have better structural and handling characteristics when preparing coffee-based beverages (including espresso) by pressurized flow.

[0025] Optimal structural properties include resistance to breakage and disintegration, which are detrimental to handling of the tablets, and to minimal dimensional change after compression forces are applied, which are detrimental to subsequent individual packaging of the tablets.

[0026] Optimal operating characteristics include providing sufficient porosity to allow pressurized flow to flow in the direction of the main flow without severe clogging, and increasing the productivity of the process, including increasing yield and reducing waste.

[0027] The object according to the invention is achieved by the method claimed in claim 1 .

[0028] The method according to the invention comprises carrying out pressing cycles in a press continuously without interruption intervals between the cycles, wherein each pressing cycle comprises the steps of claim 1 .

[0029] In particular, it is an object of the present invention to provide a coffee tablet that, when impacted by a stream of added water, better extracts a compressed quantity of coffee.

[0030] A first aspect of the present invention is to provide roasted and ground coffee beans for pressing with a Hauser index of less than 1.30, so that the edible substance, i.e. roasted and ground coffee beans, has good flowability and minimizes its tendency to aggregate into larger sized portions, for example due to the binding effect of coffee oils released during the pressing process. Within this parameter range of the Hausner index, various edible substances with a mass between 5 and 7 g can be conveyed to the various pressing supports of the pressing machine in a more reliable manner and at a relatively high conveying speed.

[0031] The second set of relevant features are the main properties of the obtained coffee tablets for use in the extraction process of espresso or similar coffee.

[0032] In this sense, the hardness of the post-compression coffee tablet is comparable to the degree of comminution of the roasted and ground coffee bean particles initially provided to the compression device, and does not severely limit the path of the liquid through the tablet body.

[0033] According to tests conducted by the applicant, the hardness of the compressed coffee tablet should be between 4N and 30N, preferably between 5N and 20N, and particularly preferably between 6N and 18N.

[0034] In the case of the first embodiment, preferably, the hardness of the coffee tablet is between 4 and 10N, preferably between 5 and 8N, and particularly preferably between 5 and 7N.

[0035] In the case of the second embodiment, preferably, the hardness of the coffee tablet is between 10 and 20N, preferably between 12 and 18N, and particularly preferably between 14 and 18N.

[0036] In the context of the present invention, the compression density of the compressed coffee tablet should be between 0.15 g / ml and 1.0 g / ml, preferably between 0.30 g / ml and 0.75 g / ml. This range corresponds to the most favorable values that allow the pressurized flow to pass through the compressed tablet without the risk of blockage.

[0037] In the context of the present invention, the combination of these two parameters is particularly advantageous.

[0038] Furthermore, it is advantageous that the amount of ground coffee corresponds to granulated coffee, and its particle distribution has at least 90% of the particle sizes between 100 mm and 3000 mm, with at least 85% of the particles having an average size between 250 mm and 2000 mm.

[0039] In particular, it is advantageous that the amount of roasted and ground coffee is between 4 and 8 grams, preferably between 5 and 7 grams, and especially between 5.3 and 6.7 grams.

[0040] The humidity of the compressed tablet is between 1% by weight and 5% by weight, preferably between 2% by weight and 4% by weight.

[0041] A related object of the present invention is to provide coffee tablets with higher dimensional stability, including coffee tablets with a smaller increase in volume after compression, and the value and distribution of the compression force largely determine this performance, and also determine other relevant parameters, which are related to the effect of treating the compressed coffee tablet with a pressurized flow with a flow pressure greater than 5 bar and extracting the coffee tablet.

[0042] In fact, the application of the compression force also has a specific relationship with the compression of roasted and ground coffee beans.

[0043] According to the present invention, the method may include continuously pressing individual amounts of roasted and ground coffee beans by applying a vertically reciprocating force to the roasted and ground coffee beans, the value of the pressing force being between 5 kN and 50 kN.

[0044] The method may include applying a pressing force less than 50 kN, including a first step of pre-pressing with a first pressing force.

[0045] The method may include a first step of pre-pressing with a first pressing force and then a second step of pressing with a second pressing force, wherein the first pressing force is greater than the second pressing force.

[0046] The method may include continuously applying two pressing forces, either of which is less than 40 kN and preferably greater than 5 kN.

[0047] In particular, the method may include a first pressing force of less than 20 kN to reduce the increase in the volume of the coffee tablet after pressing.

[0048] The method may include applying a first pressing force that is at least twice the second pressing force.

[0049] Another object related to the present invention is to provide a pressed coffee tablet containing a given amount of roasted and ground coffee, which has better physical properties in terms of extraction effect and physical stability of the pressed tablet.

[0050] The present invention solves this object by the pressed coffee tablet described in claim 14.

[0051] The pressed coffee tablet is preferably obtained by the method according to claims 1 to 13. Brief Description of the Drawings

[0052] The present invention will be described in more detail below based on preferred embodiments and the accompanying drawings.

[0053] The drawings show in simplified schematic form:

[0054] Figure 1 : The top view and side view of a pressed tablet in the prior art;

[0055] Figure 2 : The flow chart of the pressing method of a pressed tablet in the prior art;

[0056] Figure 3 : The schematic diagram of a press (1) in the method according to the present invention;

[0057] Figure 4 : The side view and top view of a press (1) in the method according to the present invention;

[0058] Figure 5: Flow chart of the method embodiment according to the present invention;

[0059] Figure 6 : Flow chart of the method embodiment according to the present invention;

[0060] Figure 7 : Schematic diagram of the first moment in the pressing method of pressing tablet (1) according to the present invention;

[0061] Figure 8 : Schematic diagram of the second moment in the pressing method of pressing tablet (1) according to the present invention. Detailed implementation mode

[0062] The method according to the present invention refers to the production of pressed coffee tablets (1), which are suitable for preparing coffee-based beverages, especially for the extraction device of espresso beverage preparation equipment.

[0063] The pressing method involves producing pressed coffee tablets (1) from edible substance particles mainly comprising previously ground and roasted coffee beans, that is, the previously ground and roasted coffee beans account for at least most of the total weight of the initial pressing amount (Q i ) of the edible substance.

[0064] The initially provided edible substance for pressing includes one of the following:

[0065] - Roasted and ground coffee beans, including light roast, dark roast or medium roast, or a mixture of at least one of light roast, medium roast and dark roast;

[0066] - A mixture of roasted and ground coffee beans and another granular edible substance.

[0067] In particular, the method includes the step of providing an edible substance, which may include roasted and ground coffee beans, with a mass fraction of at least 75%, preferably at least 85%.

[0068] Figure 1 Illustrates an embodiment of the coffee tablet (1) and this pressing method, which has been previously disclosed by the applicant and thus belongs to the part of the prior art.

[0069] The cross-section of the pressed coffee tablet (1) has a total width (D T ) and is substantially symmetric with respect to the central longitudinal axis (XX).

[0070] The pressed coffee tablet (1) can present an upstream-facing part and a downstream-facing part with respect to the mainstream direction, and further present a sandwich part, which is between the upstream-facing part and the downstream-facing part and extends along at least most of the mainstream direction along the total width.

[0071] The pressed coffee tablet (1) may include a downstream-facing portion having a downstream cavity (B) arranged in a centered manner and extending in an arcuate surface along a partial transverse dimension of the downstream-facing portion when viewed in cross-section, such that a peripheral region of the downstream cavity (B) presents a portion extending at least approximately in a plane transverse to an outer peripheral region of the downstream-facing portion.

[0072] As Figure 2 shown, the method according to the prior art generally includes the following successive steps: providing an initial quantity (Q i ) of an edible substance to a pressing container, applying a pressing force (F) to the initial quantity (Q i ) of pressed coffee tablets (1), and discharging it from the pressing container.

[0073] According to the prior art, the hardness of the pressed coffee tablets (1) obtained by the pressing method of the prior art is between 4 and 30 N.

[0074] At the same time, based on further tests, the applicant has determined that, advantageously, the hardness of the obtained coffee tablets (1) is preferably within at least one of the following ranges: between 4 and 10 N, between 10 and 16 N, and between 16 and 22 N, which will be described in further detail below.

[0075] The method includes providing a pressing machine (2) for pressing tablets or similar particulate edible substances.

[0076] The pressing machine (2) presents a plurality of individual collection ports (21) of a pressing die (20) that can interact with pressing punches (22, 23).

[0077] The pressing machine (2) advantageously presents a pressing die (20) that includes at least 10, preferably at least 20, and particularly preferably at least 30 individual collection ports (21) that can be operated by a plurality of compaction punches (22, 23) and is adapted to press at least approximately simultaneously at least a part, preferably a part, of the individual quantities (Q i ) in the individual collection ports (21) of the pressing die (20).

[0078] The pressing machine (2) can be a rotary tablet press, as Figure 3 shown.

[0079] In this case, the press (2) presents a pressing die (20) which includes a plurality of individual collection ports (21) that are operatively associated with pairs of compaction punches (22, 23) arranged in a circle, and a rotor rotatable about a vertical axis. The press (2) can provide motion guides for the top and bottom punches (22, 23) which act together in a coordinated manner to impact each collection port (21) of the pressing die (20) with a pressing force (F). The pressing die (20) can be arranged between top and bottom die guides and configured as a single piece or include a plurality of individual parts or dies.

[0080] The compaction punches (22, 23) can be arranged in pairs, arranged vertically, and configured to reciprocate vertically up and down relative to each other so as to apply the previously determined pressing force (F) to the particulate content within the individual collection ports (21) previously provided to the pressing die (20).

[0081] The method can include the step of pressing a plurality of individual quantities (Q i ), preferably at least approximately simultaneously, where the relative positions of the compaction punches (22, 23) and the moment of application of the pressing force (F) can vary between successive individual collection ports (21) of the pressing die (20).

[0082] Those skilled in the art can find other details of such presses in the prior art and thus no more detailed description is given here.

[0083] In addition, the method further includes providing an individual quantity (Q i ) of an edible substance having a bulk density between 0.250 g / ml and 0.500 g / ml, preferably between 0.300 g / ml and 0.400 g / ml. It has been experimentally determined that, in terms of the reliability and smoothness of adjustment, this numerical range is more favorable for supplying individual quantities (Q i ) of roasted and ground coffee beans of 5 g to 7 g, preferably 5.2 to 6.8 g, and taking into account the particle size value, to a pressing group including the individual collection ports (21) of the pressing die (20).

[0084] In addition, the pressing cycle is adjusted such that the supply quantity of coffee tablets (1) per pressing group, i.e., per press (2), of the press (2) is reduced by at least 10,000 units per hour, preferably by at least 25,000 units per hour for the supply quantity of coffee tablets (1) per pressing group.

[0085] The method according to the invention can include supplying an individual quantity (Q i) Steps of operating the pressing force (F1, F2) and discharging the pressed coffee tablet (1), these steps are at least approximately simultaneous, but are associated with different individual collection ports (21) of the pressing die (20) of the press (2).

[0086] Before the above steps, and before supplying an individual quantity (Q i ) to the individual collection port (21) of the pressing die (20), the method may include at least one of the following:

[0087] - A step of qualitatively or quantitatively characterizing at least one of the following parameters: a parameter related to the degree of roasting, and a parameter related to the coffee particle size;

[0088] - A step of quantitatively analyzing the relative humidity of the roasted and ground coffee beans.

[0089] In particular, the method may include characterizing the degree of roasting and the roasting color of the roasted coffee beans, and may also include identifying the type of grinder used and the grinding size, or measuring the particle size distribution.

[0090] The pressed coffee tablet (1) obtained by the method of the present invention can circulate in a pressurized extraction flow with a pressure between 5 bar and 20 bar along the main flow direction perpendicular to the characteristic dimension (D) of the coffee tablet (1), and will not decompose or dissolve when impacted by the pressurized extraction flow.

[0091] In addition, considering the operating speed of the pressing, the step of discharging the pressed coffee tablet (1) from the press (2) should also be regarded as related to other efficiency aspects, especially to reduce the risk of the coffee tablet (1) breaking.

[0092] Figure 4 Schematically shows the discharging arrangement downstream of the discharging port where the pressed coffee tablet (1) is discharged from the press (2).

[0093] After applying the pressing force, the method according to the present invention further includes a discharging step of the pressed coffee tablet (1), and the discharging speed of the coffee tablet (1) is reduced by at least 70%, preferably at least 90% along a 50 cm extension section through the discharging arrangement (4), without colliding with other previously discharged coffee tablets (1).

[0094] The discharging arrangement (4) may include a sliding support member, the extension section of which is at least 0.5 m, preferably at least 1 m, preferably 2 m, to reduce the speed, and preferably can also fix the pressed coffee tablet (1). Preferably, the material and / or surface treatment of the surface of the sliding support member are adapted to provide the said speed reduction and fixation.

[0095] The discharge arrangement (4) can be a horizontally sliding support or a first extension section that is adjacent to the outlet of the press (2) and is inclined upward relative to the outlet of the press (2) - not shown in the figure.

[0096] The discharge arrangement (4) can be operatively associated with a subsequent collection and / or transport station for the coffee tablets (1) - also not shown in the figure.

[0097] Figure 5 and 6 represents a preferred embodiment of the method according to the invention.

[0098] In each pressing cycle, the edible substance to be pressed is supplied by a filling arrangement (30), and the filling arrangement (30) can supply a separate quantity (Q i ) of the edible substance to a plurality of individual collection ports of the pressing die (20), where the plurality of individual collection ports correspond to a part, preferably a smaller part, of the total number of individual collection ports in the pressing die (20).

[0099] According to one aspect, the supply of the separate quantity (Q i ) includes continuously supplying to at least 15, preferably at least 20, individual pressing supports (21) in each pressing cycle, where the time for continuously supplying the separate quantity (Q i ) to the plurality of individual supports (20) is preferably less than 1 second, particularly preferably less than 0.5 second.

[0100] The supply of the separate quantity (Q i ) can include supplying at least approximately simultaneously a part of the plurality of individual pressing supports (21), preferably at least 2, more preferably at least 4, individual pressing supports (21).

[0101] The filling arrangement (30) is operatively connected to a first supply arrangement (31), and the first supply arrangement (31) can collect the edible substance upstream.

[0102] According to one aspect, the collection volume of the first supply arrangement (31) is less than 1 m 3 , preferably less than 0.5 m 3 , where the volume of the first supply arrangement (31) preferably further exhibits an aspect ratio of less than 8:1, preferably less than 5:1.

[0103] In this case, it is advantageous to provide at least one second supply arrangement (32) upstream of the first supply arrangement (31) and to configure the control device of the implementation method such that the supply rate of the second supply arrangement (32) to the first supply arrangement (31) is at least approximately equal to the rate at which the edible substance is discharged from the first supply arrangement (31) into the filling arrangement (30), so that a reference quantity of the edible substance can be maintained in the first supply arrangement (31).

[0104] Given that roasted and ground coffee beans contain oil and some moisture, advantageously, the above characteristics help to reduce the possibility of adhesion and / or partial compaction of the portions downstream of the first supply arrangement (31) due to the weight accumulated at the top of the portions, thereby increasing the difficulty of supplying individual quantities (Q i ).

[0105] The supply of the adjustable individual quantity (Q i ) for pressing is used to supply multiple individual quantities (Q i ) of the edible substance, the total mass of which is between 4.5 and 12.5 g, preferably between 5.0 and 12.0 g.

[0106] The supply of the individual quantity (Q i ) for pressing can be adjusted to one of the following ranges:

[0107] - The mass of the first type of coffee tablet (1) is between 4.8 and 7.2 g;

[0108] - The mass of the second type of coffee tablet (1) is between 8.0 and 12.0 g.

[0109] The supply of the individual quantity (Q i ) for pressing is preferably carried out in a vertical direction to a plurality of corresponding individual collection ports (21) of the pressing die (20). Further preferably, the supply distance above the feed port of each collection port (21) of the pressing die (20) is less than 1 mm, preferably less than 0.5 mm, and the supply of the individual quantity (Q i ) is carried out in the top region of the collection port.

[0110] Particularly advantageously, when the supply of the individual quantity (Q i ) comes from a supply chamber directly connected to at least one, preferably a plurality of individual collection ports (21) of the pressing die (20), the loss of the edible substance of the individual quantity (Q i ) in each pressing cycle can be reduced to less than 5%, preferably less than 3%.

[0111] The object of the present invention is to provide a method for making the pressed coffee tablet (1) have greater mechanical resistance while having flow permeability, suitable for preparing coffee-based beverages, including espresso, by impacting the coffee tablet with a pressurized flow without causing the coffee tablet (1) to break or release its parts.

[0112] As Figure 5 shown, the method according to the present invention comprises providing a previously determined individual quantity (Q i ) to a pressing container (22), the majority of which comprises roasted and ground coffee beans, and applying a pressing force (F) between 5 kN and 50 kN.

[0113] In this case, it should be noted that the pressing force (F), together with other parameters such as the average particle size, relative humidity, largely determines the hardness and porosity of the pressed coffee tablet (1), and thus its permeability.

[0114] Generally speaking, in order to obtain good coffee extraction without causing the pressed coffee tablet (1) to break or disintegrate, on the one hand, it is advantageous to reduce the hardness of the coffee tablet (1) as much as possible while presenting a certain porosity, quantified by the pressing density, to facilitate the passage of the pressurized flow; on the other hand, the hardness is within an interval value sufficient to ensure that the shape is maintained without breaking when impacted by the pressurized flow during the extraction of espresso beverages.

[0115] In this case, according to the tests carried out, using the coffee bean particle size range mentioned in this specification, it is advantageous for the coffee tablet (1) to present a hardness between 4 N and 30 N.

[0116] In the case of the first preferred embodiment, in order to obtain the best extraction effect, the hardness value is experimentally determined to be preferably between 13 N and 25 N, particularly preferably between 16 N and 22 N.

[0117] According to the second embodiment, the hardness value is experimentally determined to be preferably between 4 N and 20 N, particularly preferably between 5 N and 8 N.

[0118] Preferably, the hardness of different coffee tablets is suitable for different extraction fluid pressure values, such as between 5 bar and 10 bar, between 10 bar and 15 bar, between 15 bar and 20 bar.

[0119] In this sense, according to other tests and alternatives to the above embodiments, it is advantageous when the hardness of the pressed coffee tablet (1) is between 4 N and 10 N, between 10 N and 16 N, or between 16 N and 22 N, respectively, for each of the above fluid pressure ranges.

[0120] According to the tests carried out, the above hardness ranges can provide such coffee tablets (1) that, in the case of an extraction stream with a relatively high fluid pressure value, provide better anti - rupture and over - flow capabilities respectively.

[0121] These hardness ranges correspond to the most favorable ranges that ensure the coffee tablets resist external shocks without cracking or releasing their fragments.

[0122] In addition, as mentioned above, a parameter related to the extraction effect of the coffee tablet (1) is the pressing density.

[0123] In this case, experiments have shown that, for the extraction effect, it is particularly favorable that the pressing density of the pressed coffee tablet (1) is between 0.15 g / ml and 1.0 g / ml, preferably between 0.300 g / ml and 0.750 g / ml, and particularly preferably between 0.400 g / ml and 0.600 g / ml. To obtain a better extraction effect, it is further determined that the pressing density value is preferably between 0.400 and 0.600 g / ml, more preferably between 0.350 and 0.550 g / ml.

[0124] Preferably, the weight of the pressed coffee tablet (1) is at least equivalent to 98%, preferably at least 99%, of the initial individual quantity (Q i )

[0125] In addition to hardness and pressing density, the dimensional specifications of the coffee tablet (1) are also relevant aspects for obtaining a good extraction effect of espresso.

[0126] The method includes supplying the coffee tablet (1) such that, after 12 hours of pressing, it exhibits at least one, preferably at least two, of the following:

[0127] - An external volume between 2 and 6 mm3, preferably between 2.5 and 4 mm3,

[0128] - A height between 7 and 13 mm, preferably between 8 and 12 mm, and particularly preferably between 9 and 11 mm, and

[0129] - A diameter between 25 and 45 mm, preferably between 30 and 40 mm.

[0130] The method may include a step of packaging the pressed coffee tablet (1) after the pressing step, where the packaging step is preferably carried out no more than two hours, preferably no more than one hour, after the pressing step in the press (2).

[0131] The compaction step is preferably not carried out in the envelope element and the individual quantity (Q iBefore the associated steps, the individual collection openings (21) of the pressing die (20) are neither packaging elements for the pressed coffee tablets (1) nor collect the packaging elements for the pressed coffee tablets (1).

[0132] As Figure 6 , Figure 7 and Figure 8 shown, the method of the present invention comprises applying a first pressing force (F1) on an initial quantity (Q i ) and a second pressing force (F2) after the first pressing force (F1).

[0133] According to the tests carried out, it is advantageous that the two pressing forces are applied continuously, in particular the first pressing force (F1) is greater than the second pressing force (F2).

[0134] The pressing step may comprise continuously applying a first pressing force (F1) and a second pressing force (F2) to an individual quantity (Q i ), where the first pressing force (F1) is greater than the second pressing force (F2).

[0135] Furthermore, as a supplement or alternative, the pressing step may comprise continuously applying two pressing forces (F1, F2) such that the ratio between the first and second pressing forces (F1, F2) is greater than 1.50:1, preferably greater than 2:1, and less than 4:1, preferably less than 3:1.

[0136] In this case, it has been proven particularly advantageous that the pressing step comprises applying a first pressing force (F1) of less than 50 kN, preferably equal to or less than 45 kN, and further applying a second pressing force (F2) of less than 20 kN, preferably less than 17 kN, after the application of the first pressing force (F1).

[0137] The tests carried out have further shown that an excessive value of the second pressing force (F2) leads to a "capping" problem, which means that a part of the coffee tablet (1) remains in the respective collection openings (21) of the pressing die (20), thus posing an operating risk to the press (2).

[0138] Applying a second pressing force (F2) of less than 20 kN, preferably less than 17 kN, solves this problem.

[0139] Preferably, the pressing step comprises applying a first pressing force (F1) whose value is between 35 and 45 kN, preferably between 37 and 43 kN, particularly preferably between 38 and 42 kN, and then applying a second pressing force (F2) whose value is less than the first pressing force (F1).

[0140] Preferably, the pressing step includes applying a second pressing force (F2) having a value between 5 and 20 kN, preferably between 7 and 18 kN, particularly preferably between 8 and 16 kN, after previously applying a first pressing force (F1) having a value greater than the second pressing force (F2).

[0141] According to one aspect, the pressing step includes applying the second pressing force (F2) with a delay time relative to the application of the first pressing force (F1) of less than 0.5 s, preferably less than 0.3 s, such that the period of each pressing cycle is less than 1 s, preferably less than 0.7 s.

[0142] The pressing method can include only two pressing forces (F1, F2).

[0143] The method can include three phases of applying the pressing force, whereby preferably the pressing force values of at least two phases are different.

[0144] The method can include applying the pressing force along the central symmetry axis direction of the pressed coffee tablet, this direction being similar to the main flow direction of the pressurizing flow.

[0145] The method can include only applying the pressing force, thereby improving the method efficiency.

[0146] The method does not include a step of degassing the roasted and ground coffee beans before the pressing step.

[0147] The method does not include a step of humidifying the roasted and ground coffee beans before the pressing step.

[0148] The method does not include applying the pressing force to a separate quantity (Q i ) placed on a base element, such as of the container type or of the split base type, the separate quantity (Q i ) being part of a corresponding individual package.

[0149] Lisbon, 15 September 2023.

Claims

1. A method for producing compressed coffee tablets (1) for preparing coffee-based beverages, including espresso, by pressure extraction of a stream, characterized in that, the method comprises the following steps: - providing a press (2) comprising a pressing die (20) having a plurality of individual collection ports (21) operable together with pressing punches (22, 23); - Supply individual quantities (Q i ) of an edible substance having a Hausner index of less than 1.30 to each collection port (21) of the pressing die (20); - Press the individual quantity (Q by applying a reciprocating force with a value between 5 kN and 50 kN in the vertical direction through the pressing stamping machines (22, 23) i ); - discharging the compressed coffee tablets (1) having a hardness between 4 N and 30 N and a pressing density between 0.15 g / ml and 1.0 g / ml.

2. The method according to claim 1, characterized in that, In each pressing cycle, the supply of a separate quantity (Q i ) comprises: continuously supplying, in a vertical direction, at least 10, preferably at least 20, separate collection openings (21) arranged in a common arrangement to the pressing die (20), wherein the continuous supply of the separate quantity (Q i ) to the plurality of separate collection openings (21) of the pressing die (20) in total is preferably less than 1 second, particularly preferably less than 0.5 second.

3. The method according to claim 1 or 2, characterized in that, Separate quantity (Q i ) supply includes: a group of separate collection ports (21) supplied to the pressing die (20) at least approximately simultaneously, including at least 2, preferably at least 4 separate collection ports (21) supplied to the pressing die (20), and corresponding to a part of the multiple separate collection ports (21) of the pressing die (20) of the press (2).

4. The method according to claims 1-3, characterized in that, Supplying a separate quantity (Q i ) for pressing, including supplying a particulate edible substance having at least one of the following: - the Hausner index is between 1.1 and 1.35, preferably between 1.15 and 1.30, particularly preferably between 1.20 and 1.25; - the compression index is between 10% and 30%, preferably between 15% and 25%.

5. The method according to any one of claims 1-4, characterized in that, Separate quantity (Q i ) for pressing, the supply of which comprises supplying particulate edible substances having a particle size of at least one of the following: - the average size of most of the particles is between 0.3 and 1.0 mm, preferably between 0.3 and 0.8 mm; -D v10 has an average particle size of 100 microns or less, D v90 has an average particle size between 700 microns and 1 mm, preferably between 750 and 950 microns.

6. The method according to any one of claims 1-5, characterized in that, The pressing step includes continuously applying a first pressing force (F1) and a second pressing force (F2) to the separate quantity (Q i ), where the first pressing force (F1) is greater than the second pressing force (F2). and / or the pressing step comprises continuously applying two pressing forces (F1, F2) such that the ratio between the first and second pressing forces (F1, F2) is greater than 1.50:1, preferably greater than 2:1, and less than 4:1, preferably less than 3:

1.

7. The method according to any one of claims 1-6, characterized in that, the pressing step comprises applying a first pressing force (F1) of less than 50 kN, preferably equal to or less than 45 kN, and / or the pressing step comprises applying a second pressing force (F2) of less than 20 kN, preferably less than 17 kN.

8. The method according to any one of claims 1-4, characterized in that, the pressing step comprises applying a first pressing force (F1) between 35 and 45 kN, preferably between 37 and 43 kN, particularly preferably between 38 and 42 kN, and then applying a second pressing force (F2) having a value less than the value of the first pressing force (F1).

9. The method according to any one of claims 1-8, characterized in that, the pressing step comprises applying a second pressing force (F2) between 5 and 20 kN, preferably between 7 and 18 kN, particularly preferably between 8 and 16 kN, and applying a first pressing force (F1) having a value greater than the value of the second pressing force (F2) before that.

10. The method according to any one of claims 1-9, characterized in that, the application of the second pressing force (F2) is delayed by less than 0.5 s, preferably less than 0.3 s, relative to the application of the first pressing force (F1), such that the period of the pressing cycle is less than 1 s, preferably less than 0.6 s.

11. The method according to any of the preceding claims, characterized in that, The pressing cycle is adjusted such that the productivity of the pressed coffee tablets (1) supplied by the press (2) reaches at least 10,000 units per hour per pressing group, preferably at least 25,000 units per hour per pressing group.

12. The method according to any one of the preceding claims, characterized in that The pressing step does not include the time for maintaining a reduced pressing volume for a separate quantity (Q i ) by the pressing stamping machines (22, 23), so that the impact time of the pressing force (F; F1, F2) on the separate quantity (Q i ) of the edible substance is less than 0.5 seconds, preferably less than 0.2 seconds.

13. The method according to any one of the preceding claims, characterized in that the method comprises supplying the coffee tablets (1) after 12 hours of pressing, which have a corresponding dimensional change parallel to the pressing direction, such as height, and this change is less than 10%, preferably less than 7%, and / or The humidity of the said individual quantity (Q i ) is less than 3% by weight, preferably between 1.5% and 3% by weight, and particularly preferably between 2.0% and 2.8% by weight.

14. A pressed coffee tablet (1) for the preparation of an espresso beverage, characterized in that the pressed coffee tablet (1) has a humidity between 0.3% by weight and 3% by weight, a pressing density between 0.15 g / ml and 1.00 g / ml, and a hardness between 4 N and 30 N, such that the coffee tablet (1) is suitable for the passage of a pressurized extraction stream with a fluid pressure between 5 and 20 bar.

15. The pressed coffee tablet according to claim 14, characterized in that the pressed coffee tablet (1) has at least one of the following: - a humidity between 0.5% by weight and 2.7% by weight, preferably between 0.7% by weight and 2.6% by weight; - a hardness between 4 N and 22 N, preferably in at least one of the following ranges: between 4 N and 10 N, between 10 N and 16 N, and between 16 N and 22 N; - a brittleness less than 10%, preferably less than 8%; - a pressing density between 0.300 and 0.750 g / ml, preferably between 0.400 and 0.600 g / ml; - with a volume between 250 mm 3 and 450 mm 3 , preferably between 300 and 400 mm 3 ; - presents at least one, preferably two, of the following dimensions: Overall height (H T ) is between 5 mm and 12 mm, preferably between 7 mm and 10 mm, and the characteristic dimension (D) is between 30 mm and 44 mm, preferably between 32 mm and 40 mm; - an aspect ratio of width to height between 1:1 and 5:1, preferably between 2:1 and 3.5:1, and thus preferably when there are no right-angled edges at the periphery of the coffee tablet (1). Lisbon, 15 September 2023.

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