Method for producing manninotriose

Abstract

To provide a method for simply producing high-purity manninotriose contained in a soybean-derived solution.SOLUTION: The method according to the present disclosure is a method for producing manninotriose, the method including a filtration step of filtering a liquid containing activated carbon and a soybean-derived solution containing manninotriose through a filtration unit containing activated carbon as a filter medium, and an elution step of eluting manninotriose from the filtration unit after the filtration step.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing manninotriose. [Background technology]

[0002] Manninotriose is a rare oligosaccharide with an α-galactobiose structure, and has been reported to have various physiological activities, such as intestinal regulation and antibacterial activity.

[0003] Manninotriose is known to be produced by the elimination of fructose from the tetrasaccharide stachyose during soybean fermentation, and also by acid hydrolysis of stachyose in soybeans.

[0004] However, obtaining oligosaccharides with an α-galactobiose structure, such as manninotriose, by chemical synthesis is difficult due to the difficulty of stereocontrol of the glycosidic bond, and the purification process is complicated, resulting in expensive oligosaccharides. For this reason, methods for extracting oligosaccharides from natural materials have been developed.

[0005] For example, Patent Document 1 describes that oligosaccharides are purified from a liquid containing proteins, amino acids, ash, and oligosaccharides using a strongly acidic cation exchange resin with a cross-linking degree of 4 to 12%.

[0006] Patent Document 2 also describes that beans are allowed to absorb water so that the moisture content of the beans is 8 to 55% by weight, and then subjected to microwave heating or heat treatment at above 100°C, or subjected to humidified heat treatment at above 100°C so that the moisture content of the beans is a predetermined level, and that γ-glutamyl peptide and / or trisaccharide or higher oligosaccharides are extracted from the beans after the heat treatment using an aqueous solvent. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 62-198694 [Patent Document 2] Japanese Patent Publication No. 2022-179715 Summary of the Invention [Problem to be solved by the invention]

[0008] When manninotriose contained in a soybean-derived solution is extracted using the method described in Patent Document 1, it takes a long time to extract oligosaccharides from a solution containing proteins, amino acids, ash, and oligosaccharides. When manninotriose contained in a soybean-derived solution is extracted using the method described in Patent Document 2, equipment and complicated procedures are required for heat extraction of trisaccharide or higher oligosaccharides. Furthermore, both of the methods described in Patent Documents 1 and 2 merely describe that a mixture of oligosaccharides is obtained, and a step of further purifying the extracted oligosaccharides into manninotriose is required to increase the purity of the resulting manninotriose. Therefore, there is a need for the development of a method for easily producing manninotriose contained in a soybean-derived solution with even higher purity.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for easily producing highly pure manninotriose contained in a soybean-derived solution. [Means for solving the problem]

[0010] That is, the present invention includes the following aspects. [1] A method for producing manninotriose, comprising: a filtration step of filtering a liquid containing activated carbon and a soybean-derived solution containing manninotriose through a filtration section containing activated carbon as a filter material; and an elution step of eluting the manninotriose from the filtration section after the filtration step. [2] The method according to [1], further comprising a mixing step of mixing the activated carbon with the soybean-derived solution containing manninotriose before the filtration step. [3] The method according to [1] or [2], wherein the elution step comprises step (A) of introducing an eluate into the filtration section that elutes components more hydrophilic than manninotriose from the filtration section, thereby eluting components more hydrophilic than manninotriose from the filtration section, and step (B) of introducing, after step (A), an eluate into the filtration section that does not elute components less hydrophilic than manninotriose from the filtration section, thereby eluting the manninotriose from the filtration section. [4] The method according to [3], wherein step (A) is a step of pouring the eluate containing water and at least one selected from the group consisting of methanol, ethanol, and isopropanol into the filtration section to elute components that are more hydrophilic than manninotriose from the filtration section, or a step of pouring water into the filtration section and then pouring the eluate containing water and at least one selected from the group consisting of methanol, ethanol, and isopropanol into the filtration section to elute components that are more hydrophilic than manninotriose from the filtration section. [5] The method according to [3], wherein step (B) is a step of pouring the eluate containing water and at least one selected from the group consisting of methanol, ethanol, and isopropanol into the filtration section to elute the manninotriose from the filtration section. [6] The method according to any one of [1] to [5], wherein the soybean-derived solution is a soybean whey-derived solution. [7] The method according to any one of [1] to [6], wherein the filtration section has a precoat layer of activated carbon. [Effects of the Invention]

[0011] According to the present invention, a method for easily producing highly pure manninotriose contained in a soybean-derived solution can be provided. [Brief explanation of the drawings]

[0012] [Figure 1]Figure 1(A) is a representative example of a chromatogram showing the results of subjecting soy whey-derived solution 1 to high-performance liquid chromatography (HPLC). Figure 1(B) is a representative example of a chromatogram showing the results of subjecting the white powder fraction eluted with 10% by mass aqueous ethanol to HPLC. [Figure 2] Figure 2(A) is a representative example of a C-NMR spectrum showing the results of structural analysis (C-NMR) of soy whey-derived solution 1. Figure 2(B) is a representative example of a C-NMR spectrum showing the results of structural analysis (C-NMR) of the white powder eluted with 10% ethanol aqueous solution. Figure 2(C) is a representative example of a C-NMR spectrum showing the results of structural analysis (C-NMR) of a manninotriose sample. [Figure 3] Figure 3(A) is a representative example of a chromatogram showing the results of subjecting soy whey-derived solution 2 to high-performance liquid chromatography (HPLC). Figure 3(B) is a representative example of a chromatogram showing the results of subjecting the white powder fraction eluted with 10% by mass aqueous ethanol to HPLC. DETAILED DESCRIPTION OF THE INVENTION

[0013] In the present invention and this specification, the term "comprises" means that components other than the target component may be included. The term "consisting of" means that components other than the target component are not included in an amount detectable by ordinary chemical analysis. The term "consisting essentially of" means that components other than the target component are not included in a form that exerts a special function (such as a form that completely eliminates the effects of the invention). In this specification, when "comprises," it includes both an embodiment "consisting of" and an embodiment "essentially consisting of."

[0014] In the present invention and this specification, manninotriose refers to a rare oligosaccharide having an α-galactobiose structure represented by the following chemical formula:

[0015] [ka]

[0016] <Manufacturing method of manninotriose> The method for producing manninotriose in this embodiment includes a filtration step in which a liquid containing activated carbon and a soybean-derived solution containing manninotriose is filtered through a filtration section containing activated carbon as a filter material, and an elution step in which the manninotriose is eluted from the filtration section after the filtration step.

[0017] Next, each step of the method for producing manninotriose of this embodiment will be described in detail below.

[0018] ≪Filtration process≫ In the filtration step, a liquid containing activated carbon and a soybean-derived solution containing manninotriose is filtered through a filtration section containing activated carbon as a filter medium.

[0019] [Activated carbon] The activated carbon of this embodiment may be any carbon that can adsorb and elute manninotriose, and preferably has an average particle size of 1 μm to 100 μm. The activated carbon contained in the liquid to be filtered and the activated carbon contained as a filter material in the filtering section may be the same or different.

[0020] [Soybean-derived solution] The soybean-derived solution contains manninotriose. Examples of the soybean-derived solution include solutions containing components extracted from soybeans, more specifically, solutions derived from defatted soybeans, soy milk, tofu, soy protein, natto, miso, soy sauce, tempeh, tofu yo (tofu yo), fermented soybeans, stinky tofu, soybean processing by-products (okara, soybean whey, soy sauce cake), soybean oligosaccharide syrup, etc.

[0021] The soybean-derived solution is not particularly limited as long as manninotriose is dissolved in the solvent, and may contain a specified amount of insoluble components as long as clogging does not occur during the filtration process. For example, a soybean-derived solution derived from a liquid such as soy milk or soy whey may be used as is. In the case of a soybean-derived solution derived from a solid such as defatted soybeans, tofu, or natto, a solution obtained by extracting the solid with water or aqueous ethanol, homogenizing the solid to form a fluid, or pulverizing the solid and mixing it with water or aqueous ethanol may be used.

[0022] Furthermore, when the soybean-derived solution contains a large amount of insoluble components, a step of reducing the insoluble components in the soybean-derived solution may be included before the filtration step. By including this step, the filtration rate is less likely to decrease in the filtration step. Methods for reducing the insoluble components in the soybean-derived solution include known methods such as precipitation methods (centrifugation, salting out, acid treatment, organic solvent treatment, etc.), membrane separation methods, and the filtration methods described below.

[0023] Among the above soybean-derived solutions, those derived from liquid substances are preferred from the viewpoint that the filtration rate is less likely to decrease and the soybean-derived solution can be more easily prepared.

[0024] Among the soybean-derived solutions, a soybean whey-derived solution is more preferred from the viewpoint of easily producing highly pure manninotriose from soybean processing by-products of low commercial value. Examples of soybean whey-derived solutions that can be used include the supernatant obtained when soybean milk is separated by adding an acid, and the washing wastewater obtained when defatted soybeans are washed with an acid or alcohol.

[0025] The pH of the soybean whey-derived solution is not particularly limited as long as it does not impair the effects of the present invention, but is preferably 3 to 7, more preferably 4 to 6. When the pH is within the above range, decomposition of manninotriose is less likely to occur.

[0026] In a liquid containing activated carbon and a soybean-derived solution containing manninotriose, the mass of activated carbon is preferably 10.0 or more relative to the mass of manninotriose in the soybean-derived solution, more preferably 15.0 or more, and even more preferably 18.2 or more. When the mass of the activated carbon is equal to or greater than the above lower limit, a sufficient amount of manninotriose in the soybean-derived solution can be adsorbed onto the activated carbon.

[0027] The liquid containing activated carbon and the soybean-derived solution containing manninotriose is preferably mixed before filtration, from the viewpoint of preventing a decrease in the filtration rate. That is, the production method of this embodiment preferably includes a mixing step of mixing activated carbon and the soybean-derived solution containing manninotriose before the filtration step.

[0028] The method and time for mixing the activated carbon with the soybean-derived solution containing manninotriose are not particularly limited as long as a sufficient amount of manninotriose can be adsorbed onto the activated carbon. The mixing time is preferably 1 minute or more, more preferably 3 minutes or more.

[0029] By mixing the activated carbon with the soybean-derived solution in the mixing step, components such as manninotriose contained in the soybean-derived solution are adsorbed to the activated carbon to a greater extent than when the soybean-derived solution is not mixed. Therefore, the mixing step can also be considered an adsorption step in which components such as manninotriose contained in the soybean-derived solution are adsorbed to the activated carbon. Furthermore, in the filtration step, the pores formed by the activated carbon ensure a fluid path, so that the filtration rate is less likely to decrease. That is, in the filtration step, the activated carbon not only retains manninotriose but also serves as a filter aid.

[0030] The liquid containing activated carbon and the soybean-derived solution containing manninotriose preferably further contains a filter aid (excluding the activated carbon) from the viewpoint of preventing a decrease in the filtration rate. The filter aid is not particularly limited as long as it does not impair the effects of the present invention, and a known filter aid can be appropriately selected depending on the particle size, temperature, pressure, etc. of the suspended matter. Known filter aids include, for example, diatomaceous earth, perlite, cellulose, carbon, acid clay, and bentonite, and diatomaceous earth is preferred.

[0031] The mass of the filter aid is not particularly limited, but it is preferable that the mass of the filter aid is 2.5 or more relative to the mass of manninotriose in the soybean-derived solution, more preferably 5.0 or more, and even more preferably 7.5 or more.

[0032] The method for producing manninotriose of this embodiment may include, before the filtration step, a step of adjusting the manninotriose concentration in the soybean-derived solution, or a step of adjusting the amount of activated carbon according to the manninotriose concentration in the soybean-derived solution.

[0033] [Filtration section] From the viewpoint of achieving a higher purity and recovery rate of the manninotriose produced, it is preferable that the filtration section has a filtration layer (precoat layer) made of activated carbon on a filter material other than activated carbon, i.e., a precoat layer of activated carbon. In addition, in the filtration step, the cake layer formed as the filtration proceeds can also be considered to be included in the filtration section.

[0034] In addition, filter media other than activated carbon may be any filter material that has a collection ability to the extent that activated carbon does not flow out of the filtration section, and examples include filters made of materials such as metal fiber, cellulose, polypropylene, polyester, nylon, glass, cotton, polytetrafluoroethylene, polyphenylene sulfide, membranes, filter cloth, filters made of sintered metal powder, and slit filters.

[0035] In addition, in the filtration section, in order to prevent the filtration rate from decreasing, it is preferable to further contain a filter aid in addition to the above-mentioned filter material. As the filter aid, the same as the above-mentioned filter aid can be used, and diatomaceous earth is preferable.

[0036] The mass of the filter aid that may be contained in the filtration section is not particularly limited, but it is preferable that the mass of the filter aid is 2.5 or more relative to the mass of manninotriose in the soybean-derived solution, more preferably 5.0 or more, and even more preferably 7.5 or more.

[0037] The filtration method used in the filtration step can be appropriately selected from known methods depending on the amount and type of soybean-derived solution. Examples include pressure filtration, reduced pressure filtration, vacuum filtration, natural filtration, centrifugal filtration, etc. Examples of equipment used in these filtration methods include known equipment such as a Buchner funnel, a column packed with filter media, a filter press, a drum-type vacuum filter, and a centrifugal filter.

[0038] The filtration speed in the filtration process can be selected appropriately depending on the filtration method used, but from the viewpoint of further improving the recovery rate of manninotriose, it is preferable that the filtration speed be such that the amount of manninotriose that was not adsorbed by the activated carbon in the mixing process is adsorbed by the activated carbon in the filtration section.

[0039] The filtering step may include a step of forming a precoat layer of activated carbon on a filter material other than activated carbon before introducing a liquid containing activated carbon and a soybean-derived solution containing manninotriose into the filtering section.

[0040] ≪Elution process≫ In the elution step, after the filtration step, manninotriose is eluted from the filtration section.

[0041] The elution step preferably includes the following steps (A) and (B).

[0042] [Process (A)] In step (A), after the filtration step, an eluate for eluting components more hydrophilic than manninotriose is introduced into the filtration section, and components more hydrophilic than manninotriose are eluted from the filtration section.

[0043] In step (A), more preferably, an eluate containing water and at least one selected from the group consisting of methanol, ethanol, and isopropanol is poured into the filtration section to elute components that are more hydrophilic than manninotriose from the filtration section, or, alternatively, water is poured into the filtration section, and then an eluate containing water and at least one selected from the group consisting of methanol, ethanol, and isopropanol is poured into the filtration section to elute components that are more hydrophilic than manninotriose from the filtration section.

[0044] In step (A), more preferably, water is added to the filtration section, and then an eluate containing water and at least one selected from the group consisting of methanol, ethanol, and isopropanol is added to the filtration section to elute components that are more hydrophilic than manninotriose from the filtration section.

[0045] The eluate to be added to the filtration section in step (A) is not particularly limited as long as it can elute components more hydrophilic than manninotriose from the filtration section, and can be selected appropriately. Specifically, one type of eluate may be added, or two or more types of eluate may be added in descending order of hydrophilicity, or eluates may be added with successively decreasing hydrophilicity. Furthermore, in order to increase the purity and recovery rate of manninotriose eluted in step (B) described below, the amount of eluate added, the elution temperature, and the elution pH can be appropriately adjusted.

[0046] As the eluent in step (A), for example, water may be added to the filtration section, and then a 5% by mass aqueous ethanol solution may be added to the filtration section, or a 2.5% by mass aqueous ethanol solution may be added to the filtration section without adding water.

[0047] Examples of components that are eluted in step (A) and have higher hydrophilicity than manninotriose include fructose, glucose, pinitol, sucrose, and salts.

[0048] [Process (B)] In step (B), after step (A), an eluate that does not elute components less hydrophilic than manninotriose from the filtration section is introduced into the filtration section to elute manninotriose.

[0049] In step (B), more preferably, an eluate containing water and at least one selected from the group consisting of methanol, ethanol, and isopropanol is poured into the filtration section to elute manninotriose.

[0050] In step (B), more preferably, an eluate containing water and at least one selected from the group consisting of methanol, ethanol, and isopropanol, the hydrophilicity of which is equal to or lower than that of the eluate in step (A), is poured into the filtration section to elute manninotriose.

[0051] The eluate to be added to the filtration section in step (B) can be appropriately selected as long as it does not elute components less hydrophilic than manninotriose from the activated carbon and can elute manninotriose. Specifically, one type of eluate may be added, or two or more types of eluate may be added in descending order of hydrophilicity, or eluates may be added with successively decreasing hydrophilicity. Furthermore, the amount of eluate added, the elution temperature, and the elution pH can be appropriately adjusted to increase the purity and recovery rate of manninotriose.

[0052] In step (B), the eluate to be introduced into the filtration section may be, for example, a 10% by mass aqueous ethanol solution when the eluate in step (A) is water and a 5% by mass aqueous ethanol solution.

[0053] Furthermore, the eluate to be introduced into the filtration section in step (B) may be, for example, the least hydrophilic eluate among the eluates used in step (A) and the most hydrophilic eluate among the eluates used in step (B). After components more hydrophilic than manninotriose are eluted from the filtration section in step (A) using this eluate, manninotriose may be eluted in step (B). More specifically, when the eluate in step (A) is water and a 5% by mass aqueous ethanol solution, a 5% by mass aqueous ethanol solution and a 10% by mass aqueous ethanol solution may be introduced into the filtration section.

[0054] Components that are not eluted in step (B) and have lower hydrophilicity than manninotriose include, for example, stachyose, proteins, and pigments.

[0055] Methods for confirming the presence and purity of manninotriose in the eluted fraction obtained in step (B) include high performance liquid chromatography (HPLC), gas chromatography, etc. Methods for more specifically identifying the manninotriose contained in the eluted fraction include nuclear magnetic resonance (NMR) and mass spectrometry.

[0056] The purity of manninotriose obtained by the method for producing manninotriose of this embodiment is preferably more than 95%, more preferably 97% or more, and even more preferably 98% or more.

[0057] Furthermore, the method for producing manninotriose of this embodiment may include, after the elution step, a step of drying, crystallizing, concentrating, distilling, etc., the eluted fraction containing manninotriose using a known method. Examples of drying methods that can be used include heat drying, drying under reduced pressure, freeze drying, and spray drying.

[0058] The method for producing manninotriose according to the present embodiment does not require reaction conditions such as high temperature and strong acidity, a purification method using ion exchange resins or the like, or complicated operations, and the production scale can be adjusted according to the purpose, so that highly pure manninotriose can be obtained efficiently. [Example]

[0059] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0060] (Soy whey-derived solution) The soy whey-derived solution was prepared by adding acid to soy milk, adjusting the pH to 4.5, and concentrating the supernatant (provided by Fuji Oil Co., Ltd.). Of the above soy whey-derived solutions, soy whey-derived solution 1 (manninotriose concentration: 4.6% by mass, solid content: 46%, pH 4.5, temperature: 20°C) or soy whey-derived solution 2 (manninotriose concentration: 3.5% by mass, solid content: 52%, pH 4.5, temperature: 20°C) was used.

[0061] (HPLC analysis conditions) Column: Two columns connected in series: Shodex (registered trademark) SUGAR KS-802 (inner diameter: 8.0 mm, length: 300 mm) and Shodex (registered trademark) SUGAR KS-801 (inner diameter: 8.0 mm, length: 300 mm) Mobile phase: water Flow rate: 0.6mL / min Differential refractive index detector: RI-4030 (product name, manufactured by Jasco) Column temperature: 80℃ Sample injection volume: 20 μL

[0062] ( 13 C-NMR analysis conditions) 13 C-NMR was measured using an NMR instrument (manufactured by Bruker). 13 For identification of the C-NMR spectrum, a commercially available manninotriose standard purchased from Fujifilm Wako Pure Chemical Industries, Ltd. was used.

[0063] [Example 1] In Example 1, 13 trials were performed using soy whey-derived solution 1.

[0064] (mixture) 100 g of activated carbon "Activated Carbon, Powder" (trade name, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., major axis 10-80 μm as confirmed under a microscope) and 1:100 mL of the soy whey-derived solution were placed in a beaker and mixed for 5 minutes using a medicine spoon.

[0065] (filtration) Three sheets of filter paper (FILTER PAPER QUALITATIVE No. 2 (trade name, manufactured by ADVANTEC)) were placed on a Buchner funnel (inner diameter 13.0 cm, height 6.0 cm), and then a mixture of 50 g of activated carbon "Activated Carbon, Powder" (trade name, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., major axis 10-80 μm as confirmed under a microscope) and 25 g of Celite (registered trademark) was poured onto the filter paper. The mixture was then subjected to suction filtration using a suction filtration pump (ASPIRATOR (trade name, manufactured by AS ONE Corporation)) to form a precoat layer of activated carbon. The mixture was then poured into the precoated filtration section and subjected to suction filtration using a suction filtration pump, at a filtration rate of approximately 70 mL / min.

[0066] (elution) The eluate was added to the filtration section in the order of 4 L of water and 3 L of 5% by mass ethanol aqueous solution, and then subjected to suction filtration. Next, 1 L of 10% by mass ethanol aqueous solution was added to the filtration section and subjected to suction filtration, and the fraction eluted with the 10% by mass ethanol aqueous solution was collected. The eluted fraction was freeze-dried to obtain a white powder.

[0067] (Analysis results of white powder) As shown in Figures 1(A) and (B), when soy whey-derived solution 1 and the resulting white powder were each subjected to HPLC, the peak corresponding to manninotriose was confirmed as the main component among the sugar peaks detected in the soy whey-derived solution. As shown in Figures 2(A) to 2(C), the soy whey-derived solution 1, the resulting white powder, and the manninotriose preparation were each 13 C-NMR analysis confirmed that the spectrum of the obtained white powder was similar to that of authentic manninotriose.

[0068] The mass of the resulting white powder was measured, revealing a yield of 1.65±0.23 g. HPLC analysis revealed that the manninotriose purity of the resulting white powder was 97.8±1.18%. Based on the yield and purity results, the recovery rate of manninotriose relative to the mass of manninotriose contained in the soy whey-derived solution was calculated to be 30.8±4.5% by mass.

[0069] [Example 2] In Example 2, three trials were performed using soy whey-derived solution 1.

[0070] (mixture) In the same manner as in Example 1, 100 g of activated carbon was mixed with 100 mL of soybean whey solution.

[0071] (filtration) A precoat layer was formed in the same manner as in Example 1, and the mixture was then filtered under suction.

[0072] (elution) The eluate was poured into the filtration section in the following order: 4 L of water, 2 L of 5% by mass ethanol aqueous solution, and then subjected to suction filtration. Next, the eluate was poured into the filtration section in the following order: 1 L of 5% by mass ethanol aqueous solution, and 1 L of 10% by mass ethanol aqueous solution, and then subjected to suction filtration. 1 L of 5% by mass ethanol aqueous solution and 1 L of 10% by mass ethanol aqueous solution were collected as eluate fractions. The eluate fractions were freeze-dried to obtain a white powder.

[0073] The mass of the resulting white powder was measured, revealing a yield of 2.89±0.56 g. The HPLC analysis results indicated that the manninotriose purity of the resulting white powder was 98.0±0.3%. Based on the yield and purity results, the recovery rate of manninotriose relative to the mass of manninotriose contained in the soy whey-derived solution was calculated to be 54.0±10.7% by mass.

[0074] [Example 3] In Example 3, three trials were performed using soy whey-derived solution 2.

[0075] (mixture) In the same manner as in Example 1, 100 g of activated carbon and 100 mL of soybean whey solution 2 were mixed.

[0076] (filtration) A precoat layer was formed in the same manner as in Example 1, and the mixture was then filtered under suction.

[0077] (elution) The eluate was added to the filtration section in the order of 4 L of water and 3 L of 5% by mass ethanol aqueous solution, and then subjected to suction filtration. Next, 1 L of 10% by mass ethanol aqueous solution was added to the filtration section and subjected to suction filtration, and the fraction eluted with the 10% by mass ethanol aqueous solution was collected. The eluted fraction was freeze-dried to obtain a white powder.

[0078] (Analysis results of white powder) As shown in Figures 3(A) and (B), when soy whey-derived solution 2 and the resulting white powder were each subjected to HPLC, the peak corresponding to manninotriose was confirmed as the main component among the sugar peaks detected in the soy whey-derived solution.

[0079] The mass of the resulting white powder was measured, revealing a yield of 2.36±0.08 g. Furthermore, HPLC analysis revealed that the manninotriose purity of the resulting white powder was 95.3±1.2%. Based on the yield and purity results, the recovery rate of manninotriose relative to the mass of manninotriose contained in the soy whey-derived solution was calculated to be 59.3±1.8% by mass.

[0080] [Comparative Example 1] In Comparative Example 1, one trial was performed using soybean whey-derived solution 1.

[0081] (filtration) A precoat layer was formed in the same manner as in Example 1, except that only soy whey-derived solution 1 was used without mixing activated carbon with soy whey-derived solution 1, and then soy whey-derived solution 1 was suction filtered.

[0082] (elution) 4 L of water was poured into the filtration section and subjected to suction filtration, but the filtration section became clogged and the dissolution rate was extremely slow, and it took a day to filter 4 L of water.

[0083] From the above results, it was revealed that by using the production method of this embodiment, manninotriose contained in a soybean-derived solution can be obtained with high purity and in a simple manner. [Industrial Applicability]

[0084] According to the present invention, a method for easily producing highly pure manninotriose contained in a soybean-derived solution can be provided.

Claims

1. a filtration step of filtering a liquid containing activated carbon and a soybean-derived solution containing manninotriose through a filtration section containing activated carbon as a filter material; an elution step of eluting the manninotriose from the filtration section after the filtration step; A method for producing manninotriose, comprising the steps of:

2. The method according to claim 1, further comprising a mixing step of mixing the activated carbon with the soybean-derived solution containing manninotriose before the filtering step.

3. The elution step includes a step (A) of introducing an eluate for eluting components more hydrophilic than manninotriose from the filtration section into the filtration section, thereby eluting components more hydrophilic than manninotriose from the filtration section; a step (B) after the step (A) of introducing an eluate that does not elute components less hydrophilic than manninotriose from the filtration section into the filtration section, thereby eluting the manninotriose from the filtration section; 3. The method of claim 1 or 2, comprising:

4. The method according to claim 3, wherein step (A) is a step of pouring the eluate containing water and at least one selected from the group consisting of methanol, ethanol, and isopropanol into the filtration section to elute components that are more hydrophilic than manninotriose from the filtration section, or a step of pouring water into the filtration section and then pouring the eluate containing water and at least one selected from the group consisting of methanol, ethanol, and isopropanol into the filtration section to elute components that are more hydrophilic than manninotriose from the filtration section.

5. The method according to claim 3, wherein step (B) is a step of pouring the eluate containing water and at least one selected from the group consisting of methanol, ethanol, and isopropanol into the filtration section to elute the manninotriose from the filtration section.

6. 3. The method of claim 1 or 2, wherein the soy-derived solution is a soy whey-derived solution.

7. The method according to claim 1 or 2, wherein the filtration section has a precoat layer of activated carbon.

Images