JPH0552200B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a method of hydrolyzing coffee extraction residue material. More particularly, the present invention involves hydrolyzing coffee extraction residue material, such as waste from a commercial coffee extraction system, in a reactor in the presence of an acid catalyst. Although any reactor that provides a short reaction time at a relatively high temperature will suffice, it is advantageous to use a tubular plug flow reactor. The hydrolyzate thus obtained has a degree of polymerization (DP)
A mannan oligomer mixture having a range of 1 to 10 oligomers. The specific conditions chosen for the reactor limit the distribution of mannan oligomers between DP1 and DP about 10. Mannan oligomer hydrolysates are useful, for example, in combination with aqueous extracts of roasted coffee to increase soluble coffee solids content. BACKGROUND OF THE INVENTION It is well known in the art to hydrolyze coffee materials, particularly partially extracted coffee grounds, to obtain increased solids yields. For example, Clough
U.S. Patent No. 2,573,406 by et al. discloses a method for producing soluble coffee, which involves extracting about 20% by weight of coffee at normal pressure and adding a portion of the dregs in a suspension of about 1% sulfuric acid. Hydrolyze for about 1 hour, and the hydrolyzate
This includes adjusting the PH, filtering the hydrolyzate, mixing it with the atmospheric extract, and drying the combined extract. U.S. patent no. Benner et al.
Another similar method described in No. 2,687,355 used phosphoric acid instead of sulfuric acid. In yet another method, described in US Pat. No. 3,224,879 by DiNardo et al., either alkaline or acid hydrolysis was carried out directly in the extraction train of coffee grounds extracted at at least atmospheric pressure. Direct hydrolysis in the extraction train eliminates the separate hydrolysis step of prior art processes and provides the waste coffee grounds material with adsorption of an alkali or acid catalyst. For the methods of Crowe et al. and Bennell et al., relatively low temperature batch hydrolysis takes about 1
It is time consuming and limits the practicality of the method on a commercial scale. Furthermore, both Crow et al. and Bennel et al. are essentially directed to the hydrolyzate resulting from a 1 hour operation at 100°C. Neither disclosure describes the desirability or method of manipulating hydrolysis conditions to affect the composition of the resulting hydrolyzate. Similar deficiencies are known with respect to the Deinaldo disclosure. It is also widely accepted in the art that fibrous materials containing primarily carbohydrate polymers and lignin can be hydrolyzed by acid catalysis under short, high temperature conditions. However, if the fiber material is not relatively pure, the hydrolysis reaction produces undesirable by-products. As such, technologies that primarily deal with acid hydrolysis of fibrous materials are generally limited to the hydrolysis of waste paper and paper by-products or agricultural wastes such as corn husks, rice husks or cobs. For example, U.S. Pat. No. 4,201,596 to Chwch et al. discloses the acid-catalyzed saccharification of fibrous materials in a tubular reactor. The purpose of the Chiarch et al. process is the conversion of cellulose waste materials such as saw dust, wood waste, corn cobs, etc. to glucose, furfural and xylose. Along the same lines, the kinetics of the conversion of cellulose waste to monosaccharides was studied by David R.
David R.Thompson and James E. Gressline
Grethlein) Design and Evaluation of “Plug Flow Reactor for Acid Hydrolysis of Cellulose” “Ind.Eng.
Chem.Prod.Res.Dev.1979 Volume 18, No. 3 166-169
It is described on page. The authors of the aforementioned paper were particularly interested in the hydrolysis of cellulin-rich materials to monosaccharides. The author only discloses a hydrolysis method to oligomers, much less a specific mixture of oligomers. Another disclosure, US Pat. No. 4,316,747 to Rugg et al., describes a process for the hydrolysis of cellulose waste to glucose in a twin screw extruder using an acid catalyst. Although the technology discloses short-term, high-temperature acid hydrolysis of fairly cellulose-rich materials, the technology is useful for the treatment of non-cellulose-based materials such as coffee extraction residue materials, especially effluents from commercial extraction systems. has not been disclosed. The main hydrolyzable carbohydrate in coffee extraction residue material is mannan and not cellulose. Additionally, the products of mannan hydrolysis are degraded under cellulose hydrolysis conditions, destroying any desired mannan oligomer intermediates produced. One object of the present invention is to provide a method for hydrolyzing coffee brew residue materials in which mannan is the predominant carbohydrate. Another object of the present invention is to provide a method for hydrolyzing coffee extraction residue material to produce a mannan oligomer mixture having oligomers of DP1 to about DP10. A further object of the invention is that DP1 and about DP10
It is an object of the present invention to provide a method for producing a mannan oligomer mixture having a desired distribution of oligomers between DISCLOSURE OF THE INVENTION It has now been found that the objects of the present invention are fulfilled by hydrolyzing coffee extraction residue material in the presence of an acid catalyst. The coffee extraction residue material, preferably the waste from a commercial extraction system, is slurried in water and the PH is adjusted between PH1 and PH4 with an acid catalyst. The slurry is then fed to the reactor at a temperature between 160°C and 260°C for about 6-60 seconds. After discharging the hydrolyzed coffee extract residue material, DP1 - approx.
Separated by a mannan oligomer mixture with oligomers of DP 10. The distribution of mannan oligomers between DP1 and DP10 depends on the specific conditions selected for a given reactor. It is also possible to completely hydrolyze the mannan initially present in the coffee extraction residue to the monosaccharide mannose (hereinafter referred to as mannan oligomers with DP1). The present invention takes advantage of numerous properties of coffee brew residue materials that have not been widely recognized in the art. First, many of the techniques for processing coffee grounds focus on the cellulose content of the grounds and do not emphasize that there is more mannan than cellulose actually present in the grounds. Furthermore, the inventors have unexpectedly found in the present specification that the mannan is substantially hydrolyzed separately from cellulose. In other words, conditions are such that the mannan and cellulose in the coffee material are sufficiently separated to produce an essentially pure mannan hydrolyzate. Finally, mannan does not need to be completely broken down to monosaccharides (although it is possible to do so), which is the goal of many cellulose hydrolysis studies;
It has been found that mannan oligomer solutions can be produced with any desired oligomer distribution between DP1 and about DP10. Before proceeding with a detailed description of the present invention, it is necessary to clarify some related terminology. “Mannan” as used herein broadly refers to
- Refers to any polysaccharide consisting of mannose units. Monotransparent d-mannose is an aldohexose and an isomer of d-glucose, differing simply by the determined spatial arrangement of the hydroxy groups closest to the carbonyl. Mannan, found in coffee extraction residue, has up to 40 d of polysaccharides.
- Contains mannose units. Similarly, "cellulin" broadly refers to a polymer consisting of cellbiose units that are in turn hydrolyzed into two glucose units. Therefore, complete hydrolysis of cellulose yields the monosaccharide glucose. Cellulose is made up of many structural materials in plants. A more complete discussion of cellulose and its properties can be found in J. Conant (J.
Cpnant) and A. Chemistry of Organic Compounds by A. Blatt, Matsuku Milliran Publishing Co., Ltd. 1947
Described on pages 295-299. "Oligomer" shall mean a polymer consisting of a relatively small number of monosaccharides. In particular, oligomer as used herein refers to a polymer consisting of 10 or fewer monosaccharide units. Although strictly speaking, an oligomer typically consists of one or more units, mannose is designated as a DP1 oligomer for convenience. "Degree of Polymerization" or "DP" refers to the number of monosaccharide units of a given oligomer composition. Thus, for example, the mannan oligomer DP4 consists of 4 mannose units. "Coffee extraction residue material" shall mean partially extracted roasted and ground coffee material, preferably extracted at least at normal pressure.
Particularly thermally hydrolyzed coffee to hydrolyze less stable polysaccharides such as arabinogalactan is particularly useful as a coffee extraction residue material. The dross from a commercial extraction system is extracted at atmospheric pressure and thermally partially hydrolyzed.
This is an example. In commercial coffee extraction systems, coffee is extracted in a multi-stage countercurrent extraction device, where fresh water at a temperature of about 175° C. or higher enters an area containing a large amount of waste coffee (coffee that has undergone maximum extraction). The concentrated coffee extract is drawn from the area containing the freshest coffee. Said coffee clearly undergoes compositional changes during extraction. Table 1 shows the approximate composition of roasted and ground coffee, and Table 2 shows the composition of the dregs obtained from commercial extraction systems. The total percentage of carbohydrates remains approximately constant, but thermally hydrolyzed arabinogalactan appears to be largely removed. Therefore,
A preferred coffee residue material consists of about 45% carbohydrate by weight, more than half of which is mannan.

【table】

Table: For this method, the coffee brew residue material is first slurried in a liquid, typically water, before being charged to a plug flow reactor. The slurry should have between 4% and 20% by weight of dry-based coffee brew residue material to ensure sufficient solids content in the reactor for sufficient hydrolysis. Furthermore, the slurry should be homogeneous, ie the residual material should be distributed fairly evenly. If the slurry is preformed in batches, steps should be taken to ensure uniformity, such as recirculation with a slurry pump. If a different reactor is used, such as an extruder, there is no need to so dilute the slurry. For example, waste from a conventional extraction system, typically containing about 50%-60% by weight liquid, can be fed directly to such an extruder without further dilution. An acid catalyst is then added to the slurry to adjust the PH to the appropriate level. Acid catalyst is typically added between about 0.05% and 2.0% by weight of the slurry. It has been found that a pH of the slurry between 0.5 and 4 is desirable to catalyze the short-term, high-temperature hydrolysis of mannan to mannan oligomers. PH
determines the distribution of different degrees of polymerization of mannan oligomers with a given reaction time and temperature. Lower PH (in combination with higher temperature and possibly longer reaction times) tends to give a lower degree of polymerization of oligomers, and in limited cases, the monosaccharide mannose. Conversely, higher PH results in higher DP
tend to give mannan oligomers. Particular acid catalysts contemplated for use in the present invention include inorganic and organic acids. Strong inorganic acids such as sulfuric acid are particularly suitable for use in the present invention since they require relatively small amounts of acid to reach the desired PH.
Sulfuric acid is easy to precipitate from the final hydrolyzate, and the acid is widely applied in the food industry. phosphoric acid,
Other inorganic acids such as nitric acid and hydrochloric acid, and combinations of acids such as phosphoric acid mixed with sulfuric acid are also suitable. Organic acids such as acetic acid, citric acid, tartaric acid, malonic acid, adipic acid and fumaric acid, alone or in combination, are also suitable as acid catalysts, but
They are generally weaker and require relatively large amounts of organic acids to achieve the desired PH adjustment. After the acid catalyst is added to the slurry, the slurry is charged to a reactor. Suitable continuous reactors include those capable of promoting relatively high temperature, short time reactions, such as single or twin screw extruders or tubular plug flow reactors. A suitable batch reactor is a so-called explosive puffer, which is placed in a reactor in which the coffee extraction residue material is mixed with an acid catalyst and then pressurized by steam.
It is. Pressure is rapidly and explosively released to evacuate the contents from the reactor vessel. A mannan oligomer mixture having oligomers ranging from DP1 to about DP10 is then leached from the material so discharged from the reactor vessel. Tubular plug flow reactors are particularly convenient. A tubular plug flow reactor is essentially a cylindrical length of tube in which the reaction takes place. An orifice is placed at the discharge end of the reactor to control the pressure in the reactor as well as the rate of discharge from said reactor. "Plug flow" refers to the rate at which the slurry flows through the reactor. Normally, the fluid exhibits a parabolic velocity distribution with the fluid in the center of the conduit having a higher velocity than the fluid flowing closer to the side walls. In a plug flow reactor, the velocity distribution is flat and is determined by the vessel geometry and fluid properties. High temperatures are achieved in the reactor in any of a number of ways. For example, the slurry may be passed through a heat exchanger before entering the reactor. The temperature is then maintained by insulating the reactor. Alternatively, hot steam is injected directly into the reactor as a means of increasing temperature. Although the steam dilutes the slurry somewhat, such heating is rapid and allows for short reaction times. The selection of the preferred heating method and the dimensions of the reactor and orifice diameters are all within the skill of those skilled in the art based on standard design principles. The conditions maintained within the reactor are of course important in ensuring that essentially only mannan is hydrolyzed and the desired distribution of mannan oligomers is achieved. The reaction temperature should be between 160°C and 260°C, preferably between 190°C and 220°C, in order to hydrolyze the mannan and minimize degradation of the mannan oligomers thus obtained. Such temperatures generally correspond to pressures in the reactor of between 6 and 35 atmospheres, which is approximately the saturation pressure of the water in the slurry charged to the reactor. in general,
Higher temperatures promote the formation of mannan oligomers with a lower degree of polymerization (depending on PH and length of reaction). The converse is also generally true. It has been found that the preferred reaction time is between 6 and 60 seconds. Below about 6 seconds, there are equipment limitations because it is very difficult to heat the slurry and ensure uniformity of the reaction. On the other hand, if the reaction is carried out for much longer than about 60 seconds in the presence of an acid catalyst, the mannan oligomers (and the small amounts of arabinose and galactose present) begin to degrade, producing off-flavors and limiting useful yields, and Makes purification of the hydrolyzate difficult. As mentioned above, the discharge portion of the reactor has an orifice for regulating the pressure within the reactor and regulating the discharge rate. Rapid passage of the slurry through the orifice reduces the pressure until the slurry is at near atmospheric pressure. Such a rapid decrease in pressure causes expansion and evaporative cooling of the slurry, thereby "shutdown" or immediate cessation of the hydrolysis reaction. By stopping the reaction in this way, it is possible to adjust the reaction time very reliably within the abovementioned range of 6 seconds to 60 seconds. Once the slurry is discharged from the tubular plug flow reactor, it is further cooled and then separated into the mannan oligomer solution and the remaining hydrolyzed coffee brew residue material. Also,
Preferably, the discharged slurry is neutralized by known techniques such as acid precipitation with salts, evaporation of volatile acids, or use of ion exchange resins. Neutralization occurs either before or after separation of the mannan oligomer solution and the hydrolyzed coffee brew residue material.
Separation can be accomplished by any method of solid-liquid separation known in the art. For example, the slurry is passed to remove hydrolyzed coffee extraction material therefrom. Alternatively, the slurry can be separated by centrifugation, such as in a basket centrifuge. After separation, the hydrolyzed coffee extract residue is disposed of and most preferably combusted for fuel. According to another aspect of the invention, carbon dioxide gas is used as the acid catalyst. Carbon dioxide is dissolved in the slurry by pressurizing the slurry while stirring the slurry in a carbon dioxide headspace before introducing the slurry into the reactor. The slurry is then charged to the reactor as described above. Alternatively, instead of adding catalyst to the slurry before entering the reactor as described above, carbon dioxide is injected directly into the tubular plug flow reactor where the carbon dioxide gas is dissolved in the slurry and the PH is PH
Reduce it to 4 or less. A surprising aspect of using carbon dioxide is that the injection of gas further reduces the pH of the slurry while catalyzing the high temperature hydrolysis reaction for a short period of time.
It is possible to change the situation sufficiently. All of the acid catalysts previously discussed are relatively strong acids, certainly stronger than acids generated from carbon dioxide gas dissolved in a slurry. It has unexpectedly been found that the acids described above, despite their relative weakness, are able to catalyze the hydrolysis of coffee brew residue materials. Using either embodiment, the method provides DP1 - about
Provided is the production of mannan oligomer solutions with oligomers of DP10. Furthermore, the particular conditions chosen for the reactor determine the distribution of mannan oligomers between DP1 and DP about 10. The controlling principle is "severe" conditions, i.e. higher temperature, longer time and lower slurry PH will give the production of oligomers with a lower degree of polymerization (in limited cases, the monosaccharide mannose will be produced). ). Conversely, hydrolysis at lower temperatures, shorter times and higher slurry PH within the range gives solutions with a distribution of oligomers with a higher degree of polymerization. Table 3 shows the distribution of mannan oligomers in the hydrolysis produced under the different conditions indicated. The reactor used was a tubular plug flow reactor with provision for direct injection of steam. The acid catalyst in each case was sulfuric acid and the reaction time was about 6 seconds. The overall yield, based on the starting weight of coffee brew residue material and the amount of oligomer produced, was approximately 30%. The distribution of mannan oligomers was quantified by high performance liquid chromatography (HPLC) and the percentages shown are relative to the total peak area of mannan oligomers.

[Table] As seen in Table 3, higher concentrations of acid catalyst (and lower slurry PH) combined with higher temperature hydrolysis give oligomers with lower degrees of polymerization, whereas oligomers of DP1-DP7 Produced with lower acid catalyst concentrations and lower hydrolysis temperatures. DP1 - approx. DP10 produced by the method of the invention
Mannan oligomer mixtures with oligomers in the range have numerous applications, and the specific distribution of oligomers in the mixture can be varied depending on the particular use. One of the most important uses is the addition of said mixtures to ordinary coffee extracts in order to increase the amount of soluble coffee obtained from roasted and ground starting coffee. The mannan oligomer mixture is itself produced from coffee, and the resulting coffee extract is not particularly different from coffee extract, as conventional extracts typically contain large amounts of mannan oligomers. For this particular application it is preferred to have a large number of mannan oligomers distributed between about DP 1 and DP 6. The mannan oligomer mixture can be added to the conventional coffee extract before drying said extract, or the mannan oligomer mixture can be dried and then mixed with the soluble coffee prepared from the conventional extract. Drying can be by any means known in the art such as freeze drying or spray drying. Alternatively, the mixture can be highly biased towards mannose (“oligomers” of DP1 as defined above), which can then be easily converted in known manner to mannitol, a sweetener widely used in the food industry. Provides an inexpensive source of mannitol, a drug. Other uses of mannan oligomers with oligomers in the range DP1-DP10 include the addition of said mixtures to coffee aqueous extracts used for the decaffeination of coffee beans, for the infiltration of oligomers into coffee beans, and for roasted coffee. Spray dried coffee agglomerates are included along with quenching of the roasting reaction with the mixture to infiltrate the beans with oligomers and a dried mannan oligomer mixture to produce superior agglomerates.
Still other uses of mannan oligomer mixtures having oligomers in the range DP1-DP10 will be apparent to those skilled in the art and are not limited to the applications described herein. The following examples illustrate certain embodiments of the invention.
The examples are not intended to limit the invention beyond the scope of the claims below. Example 1 A series of runs were carried out using essentially the same method but varying the acid catalyst, reaction temperature and reaction time. The method was as follows. Waste coffee grounds from a commercial extraction process were dispersed in water and ground to a particle size well below 0.8 mm (orifice size of a plug flow reactor) using a Gripford W-200 colloid mill to yield 4.68% by weight.
A slurry of solid matter was obtained. The slurry was then placed in the hopper of a plug flow reactor at room temperature and maintained with agitation to prevent settling. The slurry was then pumped into a plug flow reactor having a capacity of approximately 113 ml using a Moyno pump. Just before charging the slurry to the reactor, a pre-weighed amount of
94% by weight sulfuric acid was pumped into the slurry fluid by a small stroke piston pump to obtain the desired acid concentration. The pH of the slurry was adjusted by the amount of sulfuric acid added, and was between PH0.5 and PH4.
The reactor consisted of a heating section in which steam was injected directly into the slurry and a reaction section which was essentially a length of tubing. After the slurry entered the reactor, the temperature rose rapidly due to condensation of the steam injected into the slurry. The reactor temperature was varied by varying the vapor pressure with a valve and monitored with a thermocouple. The temperatures and pressures used in this example are shown in Tables 4, 5 and 6. The residence time of the slurry in the reactor could be varied by changing the pumping rate of the Moino pump. After the slurry is passed from the reactor through the reactor orifice, the slurry is reduced to atmospheric pressure,
The corresponding temperature dropped to about 100°C and the reaction was stopped. The slurry and any condensate were further cooled to about room temperature by passing through a water-cooled heat exchanger.
The hydrolyzed slurry was then neutralized with calcium carbonate and the residue was then filtered. The resulting hydrolyzate containing mannan oligomers was analyzed to determine both the composition and the distribution of mannan oligomers between DP about 1 and DP10. The purity of the mannan oligomers in this example and in the following run was typically greater than 80%, indicating that essentially only mannan and very small amounts of cellulose were hydrolyzed. High performance liquid chromatography (H,
P, L, C) and the percentages shown are relative percentages of the total peak area of mannan oligomers. The analysis was carried out on a Waters Carbohydrate Analysis column (Part No. 84038) with a solvent of acrylonitrile/water 70/30. The temperature was maintained at about 17°C and the solvent flow rate was about 2 ml/min. Peaks were monitored with a Waters differential refractive index detector. Table 4 shows the results for sulfuric acid. Table 5 shows the results for phosphoric acid and Table 6 shows the results for acetic acid.

【table】

【table】

TABLE The tests in the above table show that varying distributions of mannan oligomers can be obtained by changing the acid catalyst, reaction temperature and reaction time. There is a general trend towards oligomers with a lower degree of polymerization with increasing acid concentration, increasing temperature and increasing reaction time. Example 2 Carbon dioxide was charged as a gas into the reactor through the same opening used to pump sulfuric acid. The pressure of carbon dioxide was maintained above the pressure of the steam introduced into the reactor by adjusting the control valve on the carbon dioxide cylinder. The amount of carbon dioxide flowing into the reactor could also be varied by opening the valve on the _CO2 regulator. The concentration of carbon dioxide resulting in a PH of about 3.4 was estimated to be about 1% by weight. Different runs were performed with higher and lower carbon dioxide flow rates. The valve on the CO ₂ regulator is about 1/2 of the passage for higher carbon dioxide flow rates.
The effluent leaving the reactor after cooling to room temperature consists of liberated gas bubbles (CO ₂ gas plus hydrolyzate and tailings residue), which for lower carbon dioxide flow rates released about a quarter. Ta. High and low at 240℃
_CO2 flow rate gave comparable oligosaccharide distribution. The results are shown in Table 7 below.

Table 7 The tests in Table 7 show that changes in the distribution of mannan oligomers can be similarly obtained with carbon dioxide as acid catalyst. Example 3 Experiments were run on two modified Wenger single-screw extruders manufactured by the Wenger Manufacturing Company of Sabetha, Kansas, which had a thick consistency (approximately 60-70% moisture).
was used as a high-pressure screw conveyor to hydrolyze commercially produced waste coffee grounds. The tailings (approximately 70% moisture) was placed in a lower circular live bin and was charged to the first extruder (SX-80) via two co-rotating screws.
This first extruder generated high pressure and was used to preheat the slag. The SX-80 product was then charged to a second extruder (SX-110) for further heating. Sulfuric acid was injected into the front section of the SX-110 using a small pump once the tailings reached reaction temperature. The temperature remained constant while the three was in the reaction zone. The material was discharged from the SX-110 through a hydraulically activated orifice, and the mouth of the orifice was hydraulically regulated. Neither temperature nor residence time could be accurately measured. The thermocouple in the extruder appears to read only the temperature of the metal shell. Barrel temperatures ranged from 107°C to about 200°C. Residence time varied due to surging. HPLC analysis again showed the presence of mannan oligomers. The results are shown in Table 8 below.

Table: It was not possible to obtain a range of mannan oligomers between DP 1 and DP about 10, as the adjustment was not precise to the extruder, but it was nevertheless possible to produce a distribution of mannan oligomers. It was hot. Example 4 Hydrolyzate is extracted from the tailings in a plug flush reactor.
It was prepared by hydrolysis with 0.05% sulfuric acid at 220°C and a residence time of about 7 seconds. The hydrolyzate was concentrated in vacuo to approximately 22% solids by weight and extracted.
Regular coffee extract at 22% by weight (approximately 25%
solid matter). The mixture was spray dried in a Niro spray dryer with an inlet temperature of approximately 160°C and an outlet temperature of 80°C. A control consisting of a normally prepared coffee extract was spray dried under the same conditions and both samples were
% level (1 g per 100 c.c. of hot water) and sampled. No major differences in product taste were observed. The product containing the hydrolyzate was more cloudy with some suspended solids and in that respect more similar to home brewed coffee.

Claims (1)

[Scope of Claims] 1. A method for producing mannan oligomers having a degree of polymerization of 1 to about 10 by hydrolyzing a coffee extraction residue material, wherein the coffee extraction residue material is extracted at normal pressure, and then thermally extracted. Consists of coffee grounds that have been hydrolyzed and most of the arabinogalactan has been removed.
The method comprises: (a) slurrying the coffee brew residue material in a liquid to produce a slurry containing from 4% to 60% by weight of the residue material on a dry basis; and (b) adjusting the pH of the slurry. (c) adding enough acid catalyst to the slurry to adjust the PH between 0.5 and 4; (c) heating the slurry at a temperature between 160°C and 260°C;
s - 60 s to hydrolyze the mannan by passing it through the reactor at a pressure between 6 and 35 atm, and (d) draining the slurry from the reaction vessel through an orifice to quickly reduce the pressure to normal pressure. (e) neutralize the discharged slurry, and (f) separate mannan oligomers with a degree of polymerization of 1 to about 10 from the hydrolyzed coffee extraction residue material to obtain a product with a purity of 80% or more. A method for producing a mannan oligomer, comprising the steps of: producing a mannan oligomer. 2 said slurry comprises from about 4% to about 20% by weight of residual material on a dry basis, and said step (c)
The method according to claim 1, wherein the reactor is a tubular progflow reactor. 3. The method according to claim 2, wherein mannan oligomers having a degree of polymerization of 1 to 10 are separated from the hydrolyzed coffee extraction residue material as an aqueous solution. 4 The acid catalyst is sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, acetic acid,
The method of claim 1 selected from the group consisting of citric acid, tartaric acid, maleic acid, adipic acid, fumaric acid and combinations thereof. 5 The temperature in the tubular plug flow reactor is 190℃-
The method according to claim 2, wherein the temperature is 220°C. 6. The method according to claim 1, wherein the reactor in step (c) is an extruder. 7. The method of claim 1, wherein nitric acid is added to the slurry as an acid catalyst at between 0.05% and 0.5% by weight of the slurry. 8 Hydrolyze the coffee extraction residue material to a degree of polymerization of 1
~ about 10 mannan oligomers, the method comprising: (a) slurrying the coffee brew residue material in a liquid to produce a slurry comprising from 4% to 60% by weight of the residue material on a dry basis; (b) the slurry at a temperature between 160°C and 260°C;
react in the reactor while simultaneously injecting carbon dioxide as an acid catalyst so that the pH is below about 4 seconds - 60 seconds; (d) The slurry is discharged from the reaction vessel through an orifice and the pressure is rapidly reduced to atmospheric pressure. (e) separating a mannan oligomer solution having oligomers having a degree of polymerization of 1 to about 10 from the hydrolyzed coffee extract residue material. 9. The method of claim 8, wherein the slurry is between 4% and 20% by weight on a dry basis and the reactor of step (b) is a tubular plug flow reactor. 10. The method according to claim 8, wherein the reactor in step (b) is an extruder. 11. The method according to claim 1 or 8, wherein the liquid for producing the slurry is water. 12. The method according to claim 3 or 8, which further comprises drying a mannan oligomer solution containing oligomers having a degree of polymerization of 1 to 10.