MXPA97006465A - Procedure of extraction of coffee and produ - Google Patents

Abstract

A method is described for the countercurrent extraction of soluble solids. The solids of soluble coffee are extracted from ground coffee and ground in a first extraction stage using a primary extraction liquid at a temperature of 80 ° C to 160 ° C. Then, the solids of soluble coffee are extracted from the partially extracted grindings in a second extraction stage using a secondary extraction liquid at a temperature of 160 ° C to 180 ° C, the coffee beans having at least 25% by weight of soluble solids extracted from the same. The coffee beans obtained from the second extraction stage are drained and thermally hydrolyzed in a hydrolysis stage at a temperature of 160 ° C to 320 ° C, for 1 to 15 minutes. The soluble coffee solids are extracted from the coffee hydrolyzate grains in a third extraction stage using a tertiary extraction liquid at a temperature of 170 ° C to 195 ° C to provide extracted coffee beans and a coffee hydrolysis extract

Description

PROCEDURE FOR EXTRACTION OF COFFEE AND PRODUCT DESCRIPTION OF THE INVENTION This invention relates to a process for the production of a soluble coffee product, which contains hydrolyzed coffee solids. The invention also relates to a soluble coffee product containing hydrolyzed coffee solids. For many consumers, the ideal coffee beverage is made by fermenting roasted and freshly ground coffee beans with hot water; usually at a temperature of 90 ° C to 100 ° C. However, since these conditions produce soluble coffee solids yields of less than 25% it is not commercially viable to produce soluble coffee products under these conditions. Therefore, the most recent technological developments made in the soluble coffee field try to simulate this ideal coffee beverage while obtaining a viable yield. Previous attempts to increase the yield of soluble coffee solids focused on the increase in temperature and pressure of the extraction liquid used to extract the coffee solids from roasted and ground coffee. However, it has been found that, in order to achieve acceptable yields, the temperatures and pressures need to be sufficiently high, so that extensive hydrolysis occurs in the extraction system. This is undesirable since it results in the production of pitches which cause scale and flavors. Attention should then be directed to subject the roasted and ground coffee to extraction under relatively medium conditions and, separately, to subject the partially extracted milling to hydrolysis to increase yields. In this way, the problem of no flavors can be reduced to acceptable levels. For example, U.S. Patent 4,158,067 (Wouda) describes a process wherein the roasted and ground coffee is subjected to a two-stage countercurrent extraction with a separate hydrolysis step between the two extraction stages. Hot water of 60 ° C to 120 ° C is introduced to the second extraction stage while fresh roasted coffee is introduced to the first extraction stage. The extraction liquid that leaves the second extraction stage is introduced to the first extraction stage to extract the ground and roasted fresh coffee. The partially extracted ground coffee leaving the first extraction stage is subjected to thermal hydrolysis at a temperature of 140 ° C to 200 ° C in a separate hydrolysis step before being introduced to the second extraction stage. In this way, the hydrolyzed coffee solids, which are extracted in the second extraction stage, do not pass through the hydrolysis stage and do not undergo any additional extreme conditions. The production of flavors and tars that are otherwise presented is reduced. A further development of this concept is described in European patent 0363529 (Kraft General Foods). In the process described in this patent, partially extracted coffee grinds obtained from a first extraction step are formed in a suspension and subjected to hydrolysis at a temperature of 200 ° C to 260 ° C. The hydrolysis is carried out from 1 to 15 minutes in order to remove at least 50% of manas and to produce a hydrolyzate containing less than 50% of monosaccharides and less than 10% of polysaccharides, which contain more than 6 saccharides in the polysaccharide chain. The hydrolysis is then added to the coffee extracts obtained from the extraction stages. Although this procedure is described to provide good yields, reasonably large quantities of shorter saccharides and chains are produced and lower molecular weights. This significantly alters the taste and feel of beverages produced from the resulting soluble coffee products. Certainly, the flavor profile no longer matches that of fermented coffee. Also, the fermented amount of smaller chain saccharides makes the extract obtained from this procedure behave differently, when compared with normal extracts, during concentration and drying. In particular, the extract has a lower freezing point, which makes drying by freezing more difficult while stickiness becomes a problem during spray drying. Furthermore, the storage stability of the coffee powders produced from the extract is reduced due to the improved hygroscopicity and lower vitreous transition temperatures. The degree of the problem depends, of course, on the severity of the hydrolysis treatment. Therefore, there is a need for a process for extracting soluble coffee solids, which has good yields, and which provides a soluble coffee product having higher molecular weight saccharides. There is also a need for a soluble coffee containing hydrolyzed coffee solids and higher molecular weight saccharides. Accordingly, in one aspect, this invention provides a method for the countercurrent extraction of soluble coffee solids from coffee beans, the method comprising: extracting soluble coffee solids from fresh coffee beans in a first extraction step using a primary extraction liquid at a temperature of approximately 80 ° C to 160 ° C to provide an extract of primary coffee and partially extracted grains; extract soluble coffee solids from the partially extracted grains in a second extraction stage using a secondary extraction liquid at a temperature of approximately 160 ° C to approximately 190 ° C to provide a secondary coffee extract and coffee beans, the grains of coffee having at least about 25% by weight soluble coffee solids extracted therefrom based on the weight of the roasted and ground dry coffee, the secondary coffee extract being collected or used as the primary extraction liquid. Drain the coffee beans obtained from the second extraction stage and thermally hydrolyze them in a hydrolysis step at a temperature from about 160 ° C to about 220 ° C for about 1 to about 15 minutes, to provide hydrolyzed coffee beans; and extracting the soluble coffee solids from the hydrolyzed coffee beans in a third extraction step using a tertiary extraction liquid at a temperature from about 170 to about 195 ° C to provide extracted coffee beans and a hydrolyzed coffee extract, the Hydrolyzed coffee extract being collected or used as the primary or secondary extraction liquid. Surprisingly, since the hydrolysis occurs, a soluble coffee product can be produced, which has a good aroma and flavor profile, and which contains a polysaccharide distribution that closely resembles that produced through the processes. where there is very little or no hydrolysis. In addition, good yields on the scale of about 45% to about 70% can be obtained. It is also found that very little or no sediment or tar is produced. In addition, the coffee extract obtained from the process can be freeze-dried or aerated without the problems associated with the hydrolyzed extracts. In addition, the coffee powders obtained from the coffee extract have good storage stability. Preferably, the primary extraction liquid enters the first extraction stage at a temperature in the range of about 110 ° C to about 140 ° C. The secondary extraction liquid preferably enters the second extraction stage at a temperature in the range from about 165 ° C to about 180 ° C. The tertiary extraction liquid preferably enters the third extraction stage at a temperature in the range of 175 ° C to about 190 ° C. In the hydrolysis step, the coffee beans are preferably thermally hydrolyzed at a temperature from about 190 ° C to about 210 ° C. In addition, the coffee beans are preferably thermally hydrolyzed by heating the coffee beans using steam. The coffee beans are preferably drained by steaming downwards through them. Preferably, the hydrolyzed coffee extract contains less than about 1% by weight of furfural derivatives, between about 1% and about 6% by weight of monosaccharides and more than about 28% by weight of oligosaccharides and polysaccharides; All percentages based on the dry matter of the hydrolyzed coffee extract. In addition, the heavy average molecular weight of all saccharides in the hydrolyzed coffee extract is preferably greater than about 1500 units with a polydievity of about 2.5 or more. The process may further comprise: draining the coffee beans obtained from the third extraction stage and hydrolyzing them thermally in a second hydrolysis step at a temperature of about 160 ° C to about 220 ° C for about 1 to 15 minutes, to provide grains of secondary coffee hydrolysates; and extracting the soluble coffee solids from the secondary hydrolyzed coffee grains in a fourth extraction step using a fourth extraction liquid at a temperature from about 170 ° C to about 195 ° C to provide extracted coffee bean and a coffee extract. hydrolyzed, the hydrolyzed coffee extract is collected or used as the primary, secondary or tertiary extraction liquid. In another aspect, this invention provides a soluble coffee product, which contains hydrolyzed soluble coffee solids, the soluble coffee product containing at least about 30 wt% saccharide comprising less than about 1 wt% of furfural derivatives, less than about 5% by weight of monosaccharides, less than about 12% by weight of oligosaccharides and less than about 18% by weight of polysaccharides, the total saccharides having a mean weight average weight greater than about 2000 units with a polydispersity of about 3. or more. Preferably, the soluble coffee product contains more than 31% by weight of saccharides. The saccharides preferably comprise less than about 0.C%. weight of furfural derivatives, from about 1 to about 4% by weight of monosaccharides, from about 2 to about 8% by weight of oligosaccharides, and more than about 23% by weight of polysaccharides. In addition, the saccharides preferably have a heavy average molecular weight greater than about 2200 units with a polydispersity of about 3.5 or greater. The embodiments of the invention will now be described by way of example only, with reference to the drawing in which: Figure 1 is a schematic flow diagram of an extraction and hydrolysis process having an individual inlet for extraction liquid; Figure 2 is a schematic flow diagram of an extraction and hydrolysis process having two inlets for the extraction liquid; Figure 3 is a schematic flow diagram of another extraction and hydrolysis process having two inlets for the extraction liquid; Figure 4 is a schematic flow diagram of an extraction and hydrolysis process having 3 inlets for extraction liquid; and Figure 5 is a graph of the molecular weight distribution of the saccharides versus the total weight of the carbohydrate for soluble coffee products produced through conventional extraction procedures and the procedure of example 1. In this specification, the following terms have the following meanings: "monosaccharides" means a carbohydrate that can not be hydrolyzed to a simpler carbohydrate. "oligosaccharides" means a polymerized saccharide having from 2 to 6 monosaccharide units in the chain. "polysaccharide" means a polymerized saccharide having more than 6 monosaccharide units in the chain. "heavy molecular weight" means the weight of the individual molecular weights of the carbohydrate molecules separated by size excision chromatography. "Polydispersity *" means the dispersion of the molecular weight distribution of the carbohydrate molecule and correlates to the ratio of the weight average molecular weight to the number average molecular weight of the carbohydrate molecules separated by size exclusion chromatography. To produce the eoluble coffee product, ground and roasted coffee is subjected to at least one four stage extraction and countercurrent hydrolysis process. In a first stage of extraction, the ground coffee and fresh roast is extracted under relatively moderate conditions, in which there is little or no hydrolysis of the coffee solids. Therefore, in this step, the temperature of the extraction liquid is in the range of about 80 ° C to about 160 ° C. The partially extracted grinds obtained from the first extraction stage are then subjected to extraction in a second extraction stage. In this step, the temperature of the extraction liquid is in the range of about 160 ° C to about 190 ° C so that moderate hydrolysis of the coffee solids can occur. The partially extracted grinds obtained from the second extraction stage must have at least about 25% by weight of coffee eolidoe, in a bake of roasted and ground coffee, which will be extracted from the same. If it has extracted about 25% menoe in pee from coffee eolids, it is found that the finally produced soluble coffee product is sensitive to moisture and temperature. It is believed that this is caused by the over-hydrolysis of heat-sensitive substance. If more than 25% of the coffee solids have been removed, most or all of the heat-sensitive substances are removed. The partially extracted grinds are first drained to remove a greater part of the extraction liquid to avoid the hydrolysis of the soluble coffee solid containing liquid. The drained grinds are then subjected to hydrolysis in a separate hydrolysis step. In this stage, the partially extracted grinds are heated to a temperature of about 160 ° C to about 220 ° C for a time of about 1 minute to about 15 minutes. The hydrolyzed coffee grinds obtained from the hydrolysis stage were then extracted to a third extraction stage. In this step, the temperature of the extraction liquid ranges from about 170 ° C to about 190 ° C so that moderate hydrolysis of the coffee solids is preempted. The conditions in the hydrolysis step and the third extraction step are selected so that the soluble coffee solids in the tertiary extraction liquid emanating from the third extraction stage contains less than about 1% by weight of furfural derivatives, between about 1 and about 6% by weight of monoeaccharide and more than about 30% by weight of oiigo and polysaccharides. All percentages based on the dry matter of the hydrolyzed coffee extract. In addition, the heavy average molecular weight of all er saccharides. the extract is greater than about 1500 units with a polydispersity of about 2.5 c more.

If so, the coffee extract that comes out of the second extraction stage and / or the third can be subjected to vaporization to remove the bad tastes. In addition, if desired, more than one vaporization step can be incorporated into the process; as described in U.S. Patent 5,183,676 (Schlecht); the description of which is incorporated herein by reference. It is also possible to use one or more inlets for the hot extraction liquid in the system. If a single inlet is used, the extraction fluid flows through all extraction stages and leaves the first extraction stage with primary coffee extract. If more than one entry is used, more than one coffee extract leaves the system. For example, the extraction stage may have its own intake of free-flowing extraction liquid and its own output of coffee extract. The extraction stages each can be made from one or more extraction vessels, which can be any suitable extraction vessel; for example fixed bed reactors or continuous countercurrent reactors. The choice and design of the containers is a matter of preference and have no critical impact on the procedure. In addition, if fixed bed reactors are used the extraction liquid can flow up through the reactor or down through the reactor, as desired. The hydrolysis step can also be done in one or more reaction vessels. The hydrolysis reaction vessel may be a fixed bed reactor, an autoclave, a plug flow reactor, an extruder or the like. Again, the design of the hydrolysis reaction vessel is a matter of choice and does not have any critical impact on the process. However, the extraction reaction vessels and the hydrolysis reaction vessels are conveniently bed reactors and identical. This has the advantage that the coffee beans can remain in the same reaction vessel throughout the entire process. The extracts obtained from the process can be processed as desired into soluble coffee powder. Usually, the extracts are divided using steam to remove volatiles with aroma, concentrates and deepuée dried by asperion or frozen. These procedures are well known in the literature and have no critical impact on the invention. The aroma can also be recovered from roasted and ground coffee before any extraction and by any well known method such as gas separation, vaporization, and the like. In addition, the process may include one or more additional hydrolysis and extraction steps to additionally extract soluble coffee solids from the extract coffee grinds emerging from the third extraction stage. This additional hydrolysis and extraction step may conveniently operate at the same conditions as the hydrolysis step and the third step of extraction. In a first specific embodiment illustrated in Figure 1, fresh roasted and ground coffee 4 is introduced in a first extraction stage 2. A secondary coffee extract 24, which leaves a second extraction stage 8, is introduced to the first extraction stage 2 for extracting the soluble coffee solids from the roasted and ground coffee in the first extraction stage 2. The coffee extract introduced, including the soluble coffee solids in the first extraction stage 2, comes out as a coffee extract of exit 22. Extract of coffee from outlet 22 is then subjected to further processing to convert it to a concentrated coffee extract. The temperature of the secondary coffee extract 24 is conveniently in the range of 80 ° C to 160 ° C so that no substantial hydrolysis of the coffee solids is provided in the first extraction step 2. The coffee grinds partially extracted 6 leaving the first extraction stage 4 are transferred to a second extraction stage 8. A tertiary coffee extract 26, which rises from a third extraction stage 18, is introduced in the second extraction stage 8 to extract the soluble coffee solids from the roasted and ground coffee partially extracted in the second extraction stage 2. The coffee extract introduced, including the soluble coffee solids extracted in the second extraction stage 8, leave the secondary coffee extract 24. The temperature of the tertiary coffee extract 26 is conveniently in the range from about 160 ° C to about 190 ° C so that the Moderate hydrolysis of the coffee solids in the second extraction stage 8. The partially extracted coffee grinds 10 leaving the second extraction stage 8 are transferred to a separate hydrolysis stage 12. In this step, at least the % by weight, based on roasted and ground dry coffee, soluble coffee solids are removed from roasted and ground coffee. In the hydrolysis step 12, the partially extracted coffee grinds are drained and then heated to a temperature of about 160 ° C to about 220 ° C. This can be achieved conveniently in a variety of ways. However, the grinding of partially extracted coffee is obtained by forcing steam through them and they are heated by injecting steam at a temperature of 160 ° C to 220 ° C directly into the reaction vessel, which contains the partially extracted coffee grinds. . If it is heated in this way, the heating is extremely fast. However, any suitable heating method can be used. The hydrolyzed coffee mills 14 leaving hydrolysis stage 12 are transferred to the third extraction stage 18. Hot water 28 is introduced, at a temperature of about 170 ° C to about 195 ° C, into the third extraction stage. 18 to extract any remaining solid coffee solids from the hydrolyzed coffee grinds. The temperature of the hot water is such that moderate hydrophobicity of the coffee solids is present in the third extraction stage 18. The extracted coffee grinds 20 leaving the third extraction stage advantageously have 50 to 70% by weight, approximately, based on ground coffee and dry roasting, of soluble coffee solids extracted from them. Another embodiment is illustrated in Figure 2. In Figure 2, the same reference numbers used in Figure 1 are used for the same items. In this embodiment, the fresh roasted and ground coffee 4 is introduced into a first extraction stage 2. Hot water 30 is introduced, at a temperature of about 80 ° C to about 160 ° C in the first extraction stage 2 to extract the Soluble coffee solids from the roasted and ground coffee in the first extraction stage 2. The temperature of the hot water 30 is such that no hydrophobicity of coffee solids is present in the first extraction stage 2. The coffee extract produced in the first stage of extraction it comes out as an extract of exit coffee 22. The commercially extracted coffee grinds 6 leaving the first extraction stage 4 are transferred to a second extraction stage 8. A tertiary coffee extract 26, which comes out of a third extraction stage 18, is introduced to a second extraction stage 8 to extract soluble coffee steeps from the roasted and partially extracted ground coffee in the second extraction stage 2. The coffee extract introduced, including the soluble coffee solids extracted in the second extraction stage 8, comes out as a secondary coffee extract 32. The temperature of the tertiary coffee extract is conveniently on the scale from about 160 ° C to about 190 ° C so that moderate hydrolysis of the coffee solids in the second extraction stage 8 is pretended. The secondary coffee extract 32 and the coffee extract 22 can be separately processed as It is written in the United States Patent 5, 242,700 iSchlecht), the description of which is incorporated herein by reference. Alternatively, the secondary coffee extract 32 can be combined with n output coffee extract 22 and then subjected to further processing to convert it to a concentrated coffee extract. The partially extracted coffee grinds leaving the second extraction stage 8 are transferred to a hydrolysis step 12 separately and processed as described with reference to Figure 1. Next, the hydrolyzed coffee grinds 14 leaving the hydrolysis step 12, are transferred to the third extraction stage 18 and processed as described above with reference to Figure 1. The extracted coffee grinds coming out of the third extraction stage have from 45% to 70%, approximately , by weight based on roasted and dry ground coffee, solids of soluble coffee extracted from loe miemoe. One more modality is illustrated in Figure 3. In the Figure 3, the same reference numbers used in Figure 1, are used for the same items. In this embodiment, the fresh roasted and ground coffee 4 is introduced to a first extraction stage 2. A secondary coffee extract 24, which leaves the second extraction stage 8, is introduced in the first extraction stage 2 to extract solidity from the coffee. Eoluble coffee from the ground and roasted coffee in the first extraction stage 2. The extracted coffee extract, including the soluble coffee eolids extracted in the first stage of extraction 2, comes out as an extract of coffee of ealida 22. The temperature of the secondary coffee extract 24 is conveniently in the range of 80 ° C to 160 ° C so that no hydrolysis of coffee solids occurs in the first extraction stage 2. The coffee grinds are partially extracted 6 leaving the first extraction stage 4 are transferred to a second extraction stage 8. Hot water 34 is introduced to the second extraction stage 8 to extract soluble coffee solids of the roasted and ground coffee partially extracted in the second extraction stage 2. The temperature of the hot water 34 conveniently ranges from about 160 ° C to about 190 ° C, so that moderate hydrolysis of the coffee solids occurs. in the second extraction stage 8. The hot water and soluble coffee solids extracted in the second extraction stage 8 come out as the secondary coffee extract 24. The partially extracted coffee grinds 10 leaving the second extraction stage 8 they are transferred to a separate hydrolysis step 12 and treated as described above with reference to Figure 1. The hydrolysed grinds are then transferred to a third extraction step. The hot water 28, at a temperature from about 170 ° C to about 195 ° C, is introduced to the third extraction stage 18 to extract any soluble coffee solids remaining from the hydrolyzed coffee grinds. The temperature of the hot water is such that moderate hydrolysis of the coffee solids is present in the third stage of extraction 18. The hot water and solids of soluble coffee extracted in the third stage of extraction 18 ealen as the tertiary coffee ealida 36. Lae grinds of extracted coffee 20 leaving the third extraction stage also have from about 45 to about 70% by weight, based on the roasted and ground coffee, of soluble coffee solids extracted therefrom. The output of tertiary coffee 36 and the extract of coffee from outlet 22 can be processed as described in the patent of United States 5,242,700 (Schlecht). Alternatively, the tertiary coffee outlet 36 can be combined with the coffee extract 22 and then subjected to further processing to convert it into a concentrated coffee extract. A better embodiment is illustrated in Figure 4. In Figure 4, the same reference numbers used in Figures 1 to 3 are used for the same items. In this embodiment, the fresh roasted and ground coffee 4 is introduced to a first extraction stage 2. Hot water 30, at a temperature of about 80 ° C to about 160 ° C, is introduced to the first extraction stage 2 to extract the coffee solids eoluble of the roasted and ground coffee in the first extraction stage 2. The temperature of the hot water 30 is such that substantially no hydrolysis of the coffee solids occurs in the first extraction stage 2. The coffee extract produced in the first extraction stage 2 comes out as an extract of exit coffee 22. The partially extracted coffee grinds 6 leaving the first extraction stage 4 are transferred to the second extraction stage 8. The hot water 34 is introduced. to the second extraction stage 8 to extract the soluble coffee solids of the ground and partially roasted coffee extracted in the second extraction stage 2. The temperature of the hot water 34 is conveniently in the range of about 160 ° C to about 190 ° C so that moderate hydrolysis of the coffee is presented. the coffee solids in the second extraction stage 8. The hot water and soluble coffee solids extracted in the second extraction stage 8 come out as a secondary coffee outlet 32. The partially extracted coffee grinds 10 that come out of the second Extraction step 8 is carried out in a separate hydrolysis stage 12 and treated as described with reference to Figure 1. The hydrolyzed grinds are then transferred to a third extraction stage. Hot water is introduced 28, at a temperature of about 170 ° C to about 195 ° C towards the third extraction stage 18 to extract any remaining soluble coffee solids from the hydrolyzed coffee grinds. The temperature of the hot water is such that it has the moderate hydrolysis of the coffee solids in the third extraction stage 18. The hot water and soluble coffee solids extracted in the third extraction stage 18 come out as the tertiary coffee outlet 36 The extracted coffee grinds coming out of the third extraction stage also have from about 45 to about 70% by weight, based on the roasted and ground coffee, of soluble coffee eolidoe extracted from the same. The secondary coffee outlet 32, the tertiary coffee outlet 36 and the output coffee extract 22 can be processed as described in US Pat. No. 5,242,700 or can be combined into several options and then processed. additional . It has been found that little or no inelaubles or tars are formed during the process, which could otherwise cause fouling problems during the additional processing steps. Also, very few or no hygroscopic fractions are present, which are difficult for spray drying or freezing to become complicated.

In all cases, the soluble coffee product, which is originally obtained, contains less than 1% by weight of furfural derivatives, less than about 4% by weight of mono saccharide, less than about 12% of oligoeaccharide, and at least about 18% by weight of polysaccharides. The total amount of saccharides present is at least about 30% by weight. All percentages are based on the dry weight of the soluble coffee product. In addition, the heavy average molecular weight of the saccharides is greater than about 2000 units with a polydisperity of about 3 or more. Such a soluble coffee product has a good coffee aroma and flavor profile. Also, there are sufficiently small amounts of small saccharides and high amounts of higher saccharides that result in a storage stable powder even under tropical conditions.

EXAMPLE 1 An extraction system made of 7 fixed-bed reactors. The reactors were connected in series so that the roasted and ground coffee entering the system belongs to the first reactor (reactor 1) and continues to the last reactor (reactor 7). The reactors 1 and 2 form a first extraction stage, the reactors 3 and 4 form a second extraction stage, the reactor 5 forms the hydrolysis stage and the reactors 6 and 7 form a third extraction stage. The reactors are also connected so that the extraction liquid enters the extraction system in the reactor 7 and flows through the reactors 6, 4, 3, 2 and 1, in that order, to leave the system in the reactor 1. The extraction liquid does not flow into the reactor 5. Robustoe lightly roasted grains were milled and fed to the reactor 1. Hot water was fed to the reactor 7 at a temperature of 180 ° C. The mass ratio of the coffee extract leaving the reactor 1 to grind the coffee in the reactor 1 is approximately 5: 1. The extraction liquid leaving the reactor 6 and entering the reactor 4 is at a temperature of approximately 170 ° C. The extraction liquid leaving the reactor 3 is subjected to vaporization to remove the bad tastes and is introduced into the reactor 2 at a temperature of approximately 130 ° C. The extraction yield within the grinds after in the reactor 4 is about 40% by weight of the roasted and ground dry coffee. The mills are partially extracted in reactor 5, first drained and then steam is introduced into the reactor to increase the temperature to about 198 ° C for about 6 minutes. The hydrolysis is terminated by rapidly reducing the pressure below 800 kPa to reduce the temperature below 170 ° C. The extraction yield of reactors 6 and 7 ee of approximately 19% by weight, taking the total extraction yield to approximately 59% by weight of roasted and initial dry ground coffee. The coffee extract exiting the reactor 1 is subjected to steam evaporation, evaporation and drying to produce soluble coffee powder in a conventional manner. The collected extract is dried by freezing or spray-dried. No problem arises during the processing, which could indicate that no tars were formed during the extraction and hydrolysis. The soluble coffee powder is analyzed for the saccharide content and made of approximately 32% saccharides. The saccharides are made from about 0.5% furfural derivative about 3.5% monosaccharides, about 10% oligosaccharide; and 21% polyaccharide. All percentages are peeled on a dry basis of soluble coffee powder. The weight average molecular weight of the saccharides is 2500 units with a polydisperity of approximately 4.3. One teaspoon of soluble coffee powder was dissolved in 150 ml of boiled water. Ur. Panel tested the drink and determined that it has a good coffee flavor with a mild, acid and juicy taste. There was also a perceived attenuation of hardness. The molecular weight distributions for a conventional soluble coffee powder produced by a conventional extraction method, involving little or no hydrolysis, and the soluble coffee powder of this example are illustrated in Figure 5. The distributions compare very well; In particular, the weight of coffee produced from coffee extracts having hydrolyzed coffee solids has a sharp peak to lower molecular weight but contains much less saccharides at molecular weights above about 3000.

EXAMPLE 2 The procedure of Example 1 was repeated except that strongly milled Milds grains were milled and fed to reactor 1. Also, in reactor 5, the grains were heated to 192 ° C for about 2 minutes. The net extraction yield of the grains after in the reactor 4 was approximately 30.5% by weight in the dry coffee R &G. The extraction yield in reactors 5 to 7 is approximately 20% by weight, taking the total extraction yield to approximately 50.5% by weight of roasted and ground dry coffee. The soluble coffee powder was analyzed for the eaccharide content and made approximately 34% saccharides. Saccharides ee made up to about 0.4% of furfural derivative, about 2% of monosaccharides, about 7.5% of oligosaccharides and 24% of polysaccharides. All the percentages are given in peeo in a dry baee of coffee powder. The weight average molecular weight of the saccharides is 2400 units with a polydisperity of about 3.8. One tablespoon of soluble coffee powder was dissolved in 150 ml of boiling water. A panel of testers took the drink to determine that it had a good taste of coffee with a mild, acidic and juicy flavor. There was also an attenuation of the hardness.

EXAMPLE 3 The extraction system of example 1 was used, except that the reactors were connected so that the extraction liquid enters the extraction system in the reactor 7 and flows through the reactors 6, 4, 3 in that order and leaves the system after the reactor 3. Fresh extraction liquid was introduced into the reactor 2 and left the seventh in the reactor 1. Therefore, the extraction extractor has two extraction liquid inlets. A strongly toasted mixture of 80% Milds grains and 20% Robueta grains was milled and fed to reactor 1. Hot water was fed at a temperature of 140 ° C to reactor 2. The maeá ratio of the extract elea reactor 1 for grinding coffee is approximately 4.5: 1. The net extraction yield on the extraction step 1 is about 29% by weight on a dry basis. Hot water was fed at 180 ° C to the reactor 7. The mass ratio of the coffee extract leaving the reactor 3 to grind the coffee in the reactor 1 is about 5: 1. The extraction liquid leaving the reactor 6 and entering the reactor 4 is at a temperature of approximately 170 ° C. The extraction liquid that leaves the reactor 3 is subjected to vaporization to remove the bad tastes. The grinds partially extracted in the reactor 5 are first drained and steam is then introduced into the reactor to increase the temperature to about 195 ° C for about 4 minutes. The hydrolysis ends by rapidly reducing the pressure below 800 kPa to reduce the temperature below 170 ° C. The extraction yield for the reactors 3 to 7 ee of approximately 21% in peeo taking the total extraction yield to approximately 50% by weight of the roasted and ground dry coffee. The coffee extracts leaving reactor 1 and reactor 3 are separately processed to soluble coffee powder as described in U.S. Patent 5,242,700 (Schlecht). No problem arises during processing that may indicate that no tar is formed during extraction and hydrolysis. The soluble coffee powder is analyzed for the saccharide content and is approximately equal to that of example 1. The total carbohydrate content is 35%, with 0.6% of furfural derivatives, 3.5% of monosaccharides, 7% of oligosaccharides and 25% of polysaccharide. One tablespoon of soluble coffee powder was dissolved in 150 ml of boiling water. A tested panel tests the drink and determines that it has a good taste with a soft, acid and juicy flavor. There is also an attenuation of hardness.

EXAMPLE 4 The extraction system of example 1 was used except that 10 reactors were used. The reactors were connected in such a way that a first inlet of the extraction liquid enters the extraction manifold in the reactor 10 and flows through the reactors 19 and leaves the system after the reactor 9., while a second inlet of the extraction liquid enters the extraction system in the reactor 7 and flows through the reactors 7, 6, 4, 3, 2 and 1, and leaves the system after the reactor 1. Therefore, The extraction system has two extraction fluid inlets. An average toasted mixture made of 80% Milds and 20% Robusta beans was milled and fed to reactor 1. The extraction in reactors 1 to 7 was carried out as described in example 1. The grinds partially extracted in Reactor 5 was drained and then hydrolysed at 195 ° C using saturated steam for 4 minutes. The hydrolysis was extinguished by rapidly reducing the pressure below 800 kPa to reduce the temperature below 170 ° C. The net extraction yield in reactors 1 to 7 is about 52% by weight of the initial dry roasted and ground coffee. The grinds partially extracted in reactor 8 were first drained and processed as described in example 1, using saturated steam at a temperature of 198 ° C for 6 minutes. Hot water at 180 ° C was fed to the reactor 10 and the hydrolyzed mills in the reactors 19 were removed. The weight ratio of the coffee extract leaving the reactor 9 to grind the coffee in the reactor 1 is about 4: 1. The net extraction yield on the reactors 8 to 10 ee of about 5% in pee in roasted and ground dry coffee, taking the total extraction to approximately 57% of the initial roasted and ground dry coffee. The two extracts obtained from the seventh were mixed and processed together to a soluble coffee powder without problem, indicating very little or no tar formation. The drinks produced from soluble coffee powder do not have bad odors. The soluble coffee powder was analyzed for the saccharide content and made up to about 39% saccharides. The saccharides were made from approximately 0. 2% furfural derivatives, about 4% monosaccharides, about 6% oligosaccharides; and 29% polysaccharides. All percentages are given by weight on a base of soluble coffee powder. The weight average molecular weight of the saccharides is 5000 units with a polydiepersity of approximately 4.3. One tablespoon of soluble coffee powder was dissolved in 150 ml of boiled water. A panel of testers took the drink and determined that it has a good coffee flavor and no poor processing is observed, and has a mild, acidic and juicy flavor. There was also an attenuation of the hardness.

Claims (10)

1. A method for countercurrent extraction of soluble coffee solids from coffee beans, the process is characterized in that it comprises: extracting soluble coffee solids from fresh coffee beans in a first extraction stage using a primary extraction liquid at a temperature from about 80 ° C to about 160 ° C, to provide an extract of primary coffee and partially extracted grinds; extract the soluble coffee solids from the partially extracted grinds in a second extraction step using a secondary extraction liquid at a temperature from about 160 ° C to about 190 ° C, to provide an extract of secondary coffee and grind coffee, the milling of coffee having at least about 25% by weight of soluble coffee solids extracted therefrom based on the weight of the roasted and ground dry coffee, the secondary coffee extract being collected or used as the primary extraction liquid; draining the coffee beans obtained from the second extraction and hydrolyzing them thermally in a hydrolysis step at a temperature from about 160 ° C to about 220 ° C, for about 1 to 15 minutes to provide hydrolyzed coffee beans; and extracting soluble coffee solids from the hydrolyzed coffee beans in a third extraction step using a tertiary extraction liquid at a temperature from about 170 ° C to about 195 ° C to provide extracted coffee beans and a hydrolyzed coffee extract, the hydrolyzed coffee extract being collected or used as the primary or secondary extraction liquid.

2. The method according to claim 1, characterized in that the primary extraction liquid enters the first extraction stage at a temperature in the range from about 110 ° C to about 140 ° C.

3. The method according to claim 1 or 2, characterized in that the secondary extraction liquid enters the second extraction stage at a temperature in the range from approximately 165 ° C to approximately 180 ° C.

4. The process according to claims 1 to 3, characterized in that the tertiary extraction liquid enters the third extraction stage at a temperature in the range from about 175 ° C to about 190 ° C.

5. The process according to any of claims 1 to 4, characterized in that in the hydrolysis step, the coffee bean is thermally hydrolyzed at a temperature of about 190 ° C to about 210 ° C.

6. The process according to any of claims 1 to 5, characterized in that the coffee beans are drained by forcing them through steam downwards through them and are thermally hydrolyzed by heating using steam.

7. The process according to any of claims 1 to 7, characterized in that the hydrolyzed coffee extract leaving the first extraction stage contains less than about 1% by weight of furfural derivatives, from about 1% to about 6% by weight of monosaccharide and more than about 28% by weight of oligoeaccharides and polysaccharides; all percentages based on the dry matter of the hydrolyzed coffee extract.

8. The process according to claim 7, characterized in that the heavy average molecular weight of all the saccharides in the hydrolyzed coffee extract is greater than about 1500 units with a polydispersity of about 2.5 or more.

9. The process according to any of claims 1 to 8, characterized in that it comprises: draining the coffee beans obtained from the third extraction stage and hydrolyzing them thermally in a second hydrolysis stage at a temperature of about 160 ° C to about 220 ° C, for about 1 to about 15 minutes to provide secondary hydrolyzed coffee beans; and extracting soluble coffee solids from the hydrolyzed coffee beans in a fourth extraction step using a fourth extraction liquid at a temperature from about 170 ° C to about 195 ° C to provide extracted coffee beans and a hydrolyzed coffee extract, the hydrolyzed coffee extract being collected or used as the primary, secondary or tertiary extraction liquid.

10. A soluble coffee product, which contains hydrolyzed soluble coffee solids, the soluble coffee product containing at least about 30 wt% of saccharides, comprising less than about 1 wt% of furfural derivatives, less than about 5 wt% weight of monosaccharides, less than about 12% by weight of oligosaccharides, and at least about 18% by weight of polysaccharides, the saccharides having a weight average molecular weight greater than about 2000 units with a polydispersity of above about 3.