WO2002008238A1

WO2002008238A1 - Crystalline mannose and method for production thereof

Info

Publication number: WO2002008238A1
Application number: PCT/JP2001/006384
Authority: WO
Inventors: Satoshi Hanamura; Koji Nishizawa; Yuuichi Sato; Takashi Kawakami; Shigeru Kanazawa
Original assignee: Meiji Seika Kaisha, Ltd.
Priority date: 2000-07-24
Filing date: 2001-07-24
Publication date: 2002-01-31
Also published as: AU2001271080A1

Abstract

A crystalline mannose which contains substantially no organic solvent, has a melting point of 133 to 135 ° as measured by the DSC measurement and has a purity of 96 % or more. The crystalline mannose can be produced by a method which comprises immobilizing mannose isomerase on a carrier having a basic anion exchange group or an adsorptive resin having basic anion exchange function, contacting this enzyme with fructose to convert it into mannose, increasing the purity of mannose to 85 % or more, concentrating the resultant solution so as for the solution to have a Brix of 80 or more, heating the concentrated solution to a temperature of 60 to 90 °, growing crystals at the temperature with or without a seed crystal added, then lowering the temperature of the concentrated solution to a temperature 5 to 20 ° lower than that in the preceding step, and growing crystals at the lowered temperature.

Description

Field of the Invention Crystal mannose and method for producing the same

The present invention relates to crystalline mannose and a method for producing the same. Background art

Mannose is a sugar that can be used in a wide variety of ways. For example, mannose has been reported to have a function of preventing the growth of intestinal harmful Salmonella (PouTtrr, Science, 68, 1357, (1989)), and is expected to be used as a feed additive for poultry and the like. I have. It is also expected to be used as a functional food material and as a raw material for pharmaceuticals such as mannitol.

Japanese Patent Publication No. 11-13787288 discloses a mannose crystal.However, in this method, an organic solvent such as ethanol is used for crystallization. The production required treatment with an organic solvent. Summary of the Invention

The present inventors have now found conditions for efficiently mannose crystallization without using an organic solvent, and have also found that high-purity crystalline mannose can be obtained under these conditions. Further, the present inventors have found conditions for efficiently producing a mannose solution. The present invention is based on such findings.

Further, according to the present invention, there is provided a method for producing crystal mannose, which can efficiently produce high-purity crystal mannose from a mannose solution, and a crystal mannose obtainable by the method.

Further, according to the present invention, there is provided a method for producing a mannose solution using an immobilized enzyme, which can efficiently produce a mannose solution.

The mannose crystal according to the present invention is needle-like, substantially free of an organic solvent, has a melting point of 13 to 13 ° C. by DSC measurement, and has a purity of 96% or more. It is.

Further, the method for producing crystalline mannose according to the first aspect of the present invention,

(a) A mannose solution having a mannose purity of 85% or more is concentrated so that the Brix of the solution is 80 or more, and then the temperature of the concentrated solution is heated to 60 to 90 ° C, and seed crystals are added. Growing the concentrated solution in the temperature range,

(b) Next, a cooling step of lowering the temperature of the concentrated liquid by 5 to 20 ° C from the temperature in the step,

(c) placing the concentrate at a temperature lowered in the cooling step, and growing a crystal;

And then recovering the crystalline mannose.

Further, the method for producing crystalline mannose according to the second aspect of the present invention,

(a ′) concentrating a mannose solution having a mannose purity of 85% or more so that Brix of the solution is 80 or more, and then heating the temperature of the concentrated solution to 60 to 90 ° C.

(b,) a cooling step of lowering the temperature of the concentrated solution by 5 to 20 ° C. below the temperature in the step and causing crystallization.

And then recovering the crystalline mannose.

Further, the method for producing crystalline mannose according to the third aspect of the present invention comprises:

(a) A mannose solution having a mannose purity of 85% or more was concentrated so that the Brix of the solution became 80 or more, and then the temperature of the concentrated solution was heated to 60 to 90 ° C, and seed crystals were added. After, a step of growing a crystal;

(?) Next, the concentrated solution is concentrated under reduced pressure, and the temperature of the concentrated solution is lowered by 5 to 20 ° C. to grow crystals.

And then recovering the crystalline mannose.

Furthermore, the method for producing crystalline mannose according to the fourth aspect of the present invention comprises:

(α ′) concentrating a mannose solution having a mannose purity of 85% or more such that Brix of the solution is 80 or more, and then heating the temperature of the concentrated solution to 60 to 90 ° C., (T) Next, a step of concentrating the concentrated solution under reduced pressure, lowering the temperature of the concentrated solution by 5 to 20 ° C to cause crystallization, and growing the crystal.

And then recovering the crystalline mannose. Further, the method for producing crystalline mannose according to the fifth aspect of the present invention,

A mannose solution having a mannose purity of 90% or more was concentrated so that the Brix of the solution became 82 or more, and a seed crystal was added as necessary, and the crystal was grown and solidified. Powdering the crystals.

Further, the method for producing a mannose solution according to the present invention comprises:

Mannose isomerase is immobilized on a carrier having a basic anion exchange group, or at least on an adsorption resin having a basic anion exchange ability, is allowed to act on a fructose solution, and fructose is converted into mannose to obtain a mannose solution. It comprises.

The method for producing crystalline mannose according to the present invention described above enables production of crystalline mannose on an industrial scale. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing the activity of an immobilized enzyme of IRA96SB in a long-term continuous reaction examined in Example 2. '

FIG. 2 is a view showing an X-ray diffraction peak of the crystalline mannose obtained in Example 6. Detailed description of the invention

Crystal mannose

The crystalline mannose according to the present invention is acicular and substantially free of organic solvents. Since it does not contain an organic solvent, the crystalline mannose according to the present invention has an advantage that it can be safely and widely used in applications such as foods and feed additives.

The crystalline mannose according to the present invention has a melting point of 133 to 135 ° C. by DSC measurement, a purity of 96% or more, and preferably a purity of 100%. Furthermore, the present inventors performed X-ray diffraction on crystalline mannose obtained from the aqueous solution, A diffraction peak as shown in Example 6 below was obtained. To the knowledge of the present inventors, there have been no reports of X-ray diffraction of crystalline mannose.

Furthermore, the crystal mannose according to the present invention showed a polarized light rotation. Specifically, the optical rotation immediately after dissolution showed [HI] ² % + 24.5, but the optical rotation changed with time, and finally Showed [hi] ² % + 13.9.

Furthermore, the crystalline mannose according to the present invention shows little hygroscopicity. As a result, for example, in the production of food and feed, there is an advantage that the water content of the product can be easily adjusted and diluted. Also, when mixing with other powders, a simple mixing operation may be performed without adjusting the humidity, and the handling becomes easy.

Manufacturing method of crystalline mannose

The above-mentioned crystalline mannose according to the present invention can be preferably produced by the following production method according to the present invention.

(1) Crystallization stock solution

In any of the following methods, a crystallization stock solution containing mannose with high purity is used as a starting material. The mannose purity is advantageously as high as possible, but in the present invention, the purity is preferably 85% or more, more preferably 90 ° or more. Here, the purity of mannose means the weight ratio of mannose in the sugar component in the undiluted crystallization solution.

(2) The method according to the first and second aspects

In the production method according to the first aspect of the present invention, the crystallization stock solution is first concentrated to Brix80 or more. Concentration may be performed by heating or reduced pressure. Then, heat the concentrate to 60-90 ° C and add seed crystals. After the seed crystal is added, the crystal is grown at a temperature of 60 ° C; The crystal is grown preferably for 1 to 12 hours. Once the crystals have grown to some extent, lower the temperature of the concentrate by 5-20 ° C and allow the crystals to grow for 0.5-48 hours. Crystal mannose can be isolated and recovered by a conventional method (for example, by centrifugation) from the concentrate obtained by crystal growth as described above. After the recovery, the crystals can be dried to obtain crystalline mannose. In the production method according to the second aspect of the present invention, a mother nucleus is formed without adding a seed crystal as described above. Specifically, after concentrating to Brix80 or more, heat to 60 ° C to 90 ° C After the above step, the concentrated solution is lowered by 5 to 20 ° C over 0.5 to 24 hours to precipitate microcrystals. This step is preferably 5-20 ° C lower over 5-17 hours. Using these microcrystals as mother nuclei, crystals can be grown for 0.5 to 48 hours. Thereafter, the crystalline mannose is isolated and recovered by a conventional method as described above.

In any of the first and second embodiments of the present invention, a needle-like crystal having a purity of 95 or more can be obtained.

(3) The method according to the third and fourth aspects

In the production method according to the third aspect of the present invention, the crystallization stock solution is first concentrated to a Brix of 80 or more. Concentration may be performed by heating or reduced pressure. Then, seed the concentrate. After the seed crystal is added, the crystal is grown at a temperature of 60 ° C to 90 ° C for 0.5 to 24 hours using the seed crystal as a mother nucleus. Preferably from 1 to 12 hours. After the crystals have grown to some extent, the pressure is reduced to an absolute pressure of 40 to 250 mm¾ over 0.5 to 48 hours, preferably 60 to 120 mmHg within 1 to 24 hours. This decompression operation lowers the temperature of the concentrate by 5 to 20 ° C. Thereafter, the crystals are grown for 0.5 to 24 hours. From the concentrate obtained by crystal growth as described above, crystalline mannose is isolated and recovered by a conventional method (for example, by centrifugation). After recovery, the crystals are dried appropriately to obtain crystalline mannose.

According to the fourth aspect of the present invention, a mother nucleus is formed without adding a seed crystal as described above. Specifically, after concentrating to Brix80 or more, after passing through the step of heating to 60 to 90 ° C, the concentrated solution is subjected to 0.5 to 48 hours in absolute pressure of 40 to 250 mmHg, preferably 60 to 120 mHg in 1 to 24 hours. Reduce the pressure so that This decompression operation lowers the temperature of the concentrated liquid by 5 to 20 ° C., and precipitates fine crystals. Using these microcrystals as mother nuclei, crystals can be grown for 0.5 to 24 hours. Thereafter, crystalline mannose can be isolated and recovered in the same manner as above.

In any of the third and fourth embodiments of the present invention, needle-like crystals having a purity of 95% or more can be obtained.

(3) The method according to the fifth aspect

According to a fifth aspect of the present invention, there is provided a method for producing crystalline mannose, which can efficiently produce needle-like crystals having a purity of 90% or more. In the method according to the fifth aspect of the present invention, a crystallization stock solution having a Mannoth purity of 90% or more is first concentrated to a Brix of 82 or more. Concentration may be performed by heating or reduced pressure. Then, if Brix and mannose purity is low, seed crystals are added, and crystal growth and solidification are performed at room temperature for several hours to several weeks, preferably for two days to three weeks. The resulting crystals can then be pulverized to obtain crystalline mannose. For pulverization, a commonly used method such as a cutting machine or a crusher can be used.

Enzymes suitable for mannose production and their immobilization

According to another aspect of the present invention, there is provided an immobilized enzyme suitable for a method for producing mannose from fructose.

The enzyme used in this embodiment is mannose isomerase, and the enzyme is adsorbed on a carrier having a basic anion exchange group or at least an adsorption resin having a basic anion exchange ability. In the present invention, the term “adsorption resin” means a resin having an ion-binding ability as a whole. Conversion of fructose to mannose by mannose isomerase is carried out extremely efficiently by using a carrier having a basic anion exchange group or an adsorption resin having at least a basic anion exchange capacity as the enzyme-immobilized carrier. Is done. Such high efficiency cannot be realized with a carrier having an acidic cation exchange group. Preferred examples of the carrier having a basic anion exchange group or the adsorption resin having at least a basic anion exchange ability include commercially available basic anion exchange resin and chitosan beads.

The mannose isomerase used in this embodiment is not particularly limited, and for example, those derived from the genus Thermomonospora can be used. As a more specific example, a thermomonospora sp. MBL 10003 strain described in Japanese Patent Application Laid-Open No. Hei 11-75853 (Patent Depositary Center for Patent Organisms, National Institute of Advanced Industrial Science and Technology (Tsukuba, Ibaraki, Japan) Higashi 1-chome No. 1 1 Chuo No. 6), Deposit date: May 2, 1997, Accession number: FERMBP— 73632, Original accession number: P-16209) Is mentioned.

The enzyme can be prepared according to a conventional method. For example, mannose isomerase can be collected from cells and purified. Here, collection and purification can be performed by known methods, for example, sonication of the cells, treatment with a surfactant. The enzyme is extracted from the cells by conducting the treatment. If necessary, it may be concentrated and dried by salting out, solvent precipitation or ultrafiltration. Mannose isomerase can be purified by various methods. For example, the extracted enzyme may be salted out with ammonium sulfate, and then purified by ion exchange chromatography or gel chromatography, and the purified enzyme may be used.

The immobilization of the enzyme on the carrier can be performed by adsorbing the enzyme on the immobilized carrier due to the affinity between the enzyme and the immobilized carrier. Specifically, the immobilization can be carried out by mixing and stirring the solution in which the enzyme is dissolved or suspended, and the immobilizing carrier. The time required for immobilization is generally about 10 minutes to 40 hours, preferably 1 hour to 24 hours. The temperature at the time of immobilization is a temperature at which the activity of the enzyme to be immobilized is not lost, that is, 5 to 60 ° C; preferably 5 to 25 ° C. If necessary, a solution or suspension of the enzyme can be prepared using a buffer. In this case, it is preferable to use a buffer having a pH not losing the activity of the enzyme to be immobilized, ie, about pH 4 to II. Although the type of the buffer is not particularly limited, a phosphate buffer or a tris-chloride buffer can be used.

The immobilized carrier is removed by filtration, etc., and washed as necessary. The washing solution is not particularly limited, but a phosphate buffer or a Tris-HCl buffer can be used. The immobilized enzyme obtained as described above is allowed to act on fructose to produce mannose. It goes without saying that the most suitable reaction condition may be selected according to the reaction substrate, but the reaction temperature is generally 25 to 75 ° C, preferably 30 to 60 ° C. The reaction pH is generally 5 to 11; preferably 6 to 10. The reaction time depends on the amount of the immobilized enzyme used and the substrate concentration, but it is usually preferable to set the reaction time between 3 and 48 hours. From an industrial perspective, it is desirable to convert more than 20% of the fructoses to mannose.

Chromatographic separation

In order to obtain crystalline mannose from the mannose solution obtained by the enzymatic reaction, according to a preferred embodiment of the present invention, a purification operation is performed using various chromatographic separation methods using an ion exchange resin, activated carbon, or the like. As the chromatographic separation method, it is preferable to use a simulated moving bed chromatographic separation generally used for the production of isomerized saccharide and the like. This chromato By the separation operation, a chromatographic fraction having a mannose purity of 85% or more, that is, a crystallization stock solution can be obtained.

The mannose solution used for chromatographic separation means a mixture of mannose and other sugars, and the production method is not specified at all. However, a mannose solution prepared using immobilized enzyme is not used. This is preferable because it is not necessary to perform a pretreatment such as removing an enzyme. Example

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples.

Activity measurement of immobilized enzyme

The activity of the immobilized enzyme shown in the following examples was measured as follows. First, mannose is dissolved in 0.1M phosphate buffer at pH 7.0 to a concentration of 0.2M, and an appropriate amount of immobilized enzyme is added to 100ml of this solution, and the reaction is performed at 50 ° C for 30 minutes. went. Thereafter, the amount of isomerized fructose was determined by the cysteine-carbazole sulfate method, and the amount of enzyme that isomerized lumol of fructose in one minute was defined as one unit (1).

-Purity

The mannose purity shown in the following examples was measured using the HPLC method.

Mannose isomera

The mannose isomerase used in Example 1 below was obtained from Thermomonospora sp. Strain MBL 10003 (FERMP- 16209).

Example 1: Immobilized enzyme

Amberley, a basic anion-exchange resin, was used as an immobilization carrier in 10 ml of an enzyme solution in which an appropriate amount of mannose isomerase derived from Pseudomonas sp. Obtained by culturing in 0.1 M phosphate buffer was dissolved. G IRA96SB (Japanese agency: Organo Corporation, Production: Rohm & Haas) or Diaion HPA25 (Mitsubishi Chemical Corporation), Kittopar BCW3505, BCW2505 (Fujibo Industries, Ltd.) 5 g each In addition, Shake at room temperature for 2 hours. Next, the immobilized carrier was thoroughly washed with a 0.1 M phosphate buffer to prepare four types of immobilized mannose isomerase.

For comparison, acidic cation exchange resin Amberlite IRC50 was used as a carrier for immobilization in 10 ml of an enzyme solution in which an appropriate amount of mannose isomerase derived from Thermomonospora obtained by culturing in 0.1 M phosphate buffer was dissolved. (Japan agency: Organo Co., Ltd., Manufacture: Rohm & Haas Co.) or 5 g of Diaion WK40 (Mitsubishi Chemical Co., Ltd.) was added and shaken at room temperature for 2 hours. Next, the immobilized carrier was thoroughly washed with a 0.1 M phosphate buffer to prepare two types of immobilized mannose isomerase in the same manner as described above.

Next, the enzyme activity of the immobilized mannose isomerase was measured. The results were as shown in Table 1. As shown in the table, those immobilized on the basic anion exchange resin or the adsorption resin had good immobilization rates and activity expression rates. Among them, IRA96SB, HPA25, BCW3505, and BCW2505 showed good results. Table 1

Carrier classification Immobilization rate () Activity expression rate (%)

IRA 96 SB Basic anion exchange resin 97.05.4.1

HPA 25 Basic anion exchange resin 98.0 28.5

B CW 355 Adsorption resin 99.0 0 20.6

B CW 2 5 0 5 Adsorption resin 9 9-0 5 0 .2

I R C 50 Acidic cation exchange resin 0.0 0.00

WK 40 acidic cation exchange resin 0.00.0 0.0 Example 2: Mannose solution production and long-term stability test of immobilized enzyme

The immobilized enzyme of IRA96SB obtained in Example 1 was packed in a jacketed column having an inner diameter of 10 thighs, and a 20% fructose solution adjusted to PH 7.0 was passed at 45 ° C. The flow was performed by appropriately changing the flow rate so that a solution having a mannose purity of 20% and a fructose purity of 80% was obtained. Then, the activity of the immobilized enzyme in a long-term continuous reaction was examined. The results were as shown in Table 2 below and FIG. Table 2

Time (week) Relative activity (2 ^

0 1 0 0. 0

90.2

2 8 8. 9

3 8 3.7

4 7 9.7

5 7 1.2

665.2 As shown in Fig. 1, the half-life of the activity of the immobilized enzyme was 6 weeks, confirming that the enzyme can withstand industrial use.

Example 3: About chromatographic separation

In order to use the 20% mannose purity solution obtained in Example 2 as a crystallization stock solution, that is, to increase the mannose purity, chromatographic separation was performed using a two-component simulated moving bed chromatograph. Separation patterns A, B, and C were performed by changing the stationary phase flow rate, stock solution supply amount, stock solution supply speed, eluent water flow rate, and the like so that the mannose of the sugar composition of the chromatographic separation solution was 85, 90, and 95%. The results were as shown in Table 3 below. As shown in Table 3, a crystallization stock solution having a purity of 85% or more was obtained. Table 3

Separation pattern composition (%)

Mannose Fructose

A 8 5 1 5

B 9 0 1 0

C955 Example 4: Crystallization according to the first embodiment

Crystallization having a sugar composition of 85% mannose and 15 fractions of mannose obtained according to Example 3. Stock solutions were used.

This crystallization stock solution was concentrated to Brix85. After the temperature of the concentrated solution was further increased to 70 ° C., a 1% mannose seed crystal was added to the solid content of the concentrated solution, and the crystal was grown for 12 hours. Next, the concentrated solution was cooled to 60 ° C., and crystals were grown again over 12 hours. The generated crystals were collected using a centrifuge and dried to obtain crystal mannose. The purity of the obtained crystalline mannose was 96%, and the crystal recovery was 25.

Example 5: Crystallization according to the first embodiment

A crystallization stock solution having a sugar composition of mannose 90 ° fructose 10% obtained in Example 3 was used.

This crystallization stock solution was concentrated to Brix83. After heating the temperature of the concentrated solution to 85 ° C, a 1 ° mannose seed crystal was added to the solid content of the concentrated solution, and the crystals were grown for 12 hours. Next, the concentrate was cooled to 65 ° C., and a crystal was grown again over 10 hours. The generated crystals were collected using a centrifuge and dried to obtain crystalline mannose. The purity of the obtained crystalline mannose was 96%, and the crystal recovery was 3.

Example 6: Crystallization according to the first embodiment

The crystallization stock solution having a sugar composition of 95% mannose and 5% fructose obtained in Example 3 was used.

This crystallization stock solution was concentrated to Brix80. After heating the temperature of the concentrate to 60 ° C., a 1% mannose seed crystal was added to the solid content of the concentrate, and the crystal was grown for 10 hours. Next, the concentrate was cooled to 55 ° C., and crystals were grown again over 16 hours. The generated crystals were collected using a centrifuge and dried to obtain crystal mannose. The purity of the obtained crystalline mannose was 100%, and the crystal recovery was 24%. The melting point of the obtained mannose was determined by DSC measurement (DSC measuring apparatus manufactured by Seiko Instruments Inc .: RDC220), and the melting point was 134.5 to 135.0 ° C. Furthermore, diffraction X-rays were measured by a powder X-ray diffraction method using Cu K rays. As a result, a diffraction peak as shown in FIG. 2 was obtained. Example 7: Crystallization according to the first aspect

This crystallization stock solution was concentrated to Brix85. After the temperature of the concentrated solution was further increased to 70 ° C., a 1% mannose seed crystal was added to the solid content of the concentrated solution, and the crystal was grown for 10 hours. Next, the concentrate was cooled to 60 ° C., and crystals were grown again for 16 hours. The generated crystals were collected using a centrifuge and dried to obtain crystal mannose. The purity of the obtained crystalline mannose was 96%, and the crystal recovery was 36%.

Example 8: Crystallization according to the second embodiment

The crystallization stock solution having a sugar composition of 85% mannose and 15% fructose obtained in Example 3 was used.

This crystallization stock solution was concentrated to Brix86. The temperature of the concentrated solution was further increased to 80 ° C, and then cooled to 70 ° C over 10 hours to generate microcrystals. Using these microcrystals as mother nuclei, the crystals were grown for 16 hours. The generated crystals were collected using a centrifuge and dried to obtain crystalline mannose. The purity of the obtained crystalline mannose was 95%, and the crystal recovery was 28%.

Example 9: Crystallization according to the third aspect

This crystallization stock solution was concentrated to Brix85. After the temperature of the concentrated solution was further increased to 70 ° C., a 1% mannose seed crystal based on the solid content of the concentrated solution was added, and the crystal was grown for 10 hours. Then, the solution was decompressed to an absolute pressure of 80 ° C and 55 ° C over 10 hours, and crystals were grown again for 16 hours. The generated crystals were collected using a centrifuge and dried to obtain crystalline mannose. The purity of the obtained crystalline mannose was 96%, and the crystal recovery was 26%. When the melting point of the obtained mannose was determined by DSC measurement, the melting point was around 133 ° C.

Example 10: Crystallization according to the fourth embodiment

Crystallization having a sugar composition of 85% mannose and 15% fructose obtained according to Example 3 Stock solutions were used.

This crystallization stock solution was concentrated to Brix85. Furthermore, after heating the temperature of the concentrated solution to 80 ° C, the pressure was reduced to 80 mmHg and 65 ° C over 10 hours, and microcrystals were generated. Using these microcrystals as mother nuclei, crystals were grown for 16 hours.

The generated crystals were collected using a centrifuge and dried to obtain crystalline mannose. The purity of the obtained crystalline mannose was 95%, and the crystal recovery was 25%. Example 11: Crystallization according to the fifth embodiment

The crystallization stock solution having a sugar composition of 90% mannose and 10% fructose obtained in Example 3 was used.

This crystallization stock solution was concentrated to Brix86. Further, a 1% mannose seed crystal with respect to the solid content of the concentrated solution was uniformly dispersed, placed in a sheet-like container, and allowed to grow and solidify at room temperature for one week. The generated crystals were first crushed and then crushed by a crusher to obtain a white crystal powder. The purity of the obtained crystalline mannose powder was 90, and the crystal recovery was 100.

Claims

The scope of the claims

1. Crystalline mannose, needle-like, substantially free of organic solvents, with a melting point of 133-135 ° C as measured by DSC, and a purity of 96% or more.

2. The crystalline mannose according to claim 1, having a purity of 100%.

3. A method for producing crystalline mannose,

(a) A mannose solution having a mannose purity of 85% or more is concentrated so that the Brix of the solution is 80 or more, and then the temperature of the concentrated solution is heated to 60 to 90 ° C, and a seed crystal is added. Growing the concentrated solution in the temperature range,

And then recovering the crystalline mannose.

4. A method for producing crystalline mannose,

(a,) concentrating a mannose solution having a mannose purity of 85% or more so that Brix of the solution becomes 80 or more, and then heating the temperature of the concentrated solution to 60 to 90 ° C.

(b ′) a cooling step of lowering the temperature of the concentrated solution by 5 to 20 ° C. below the temperature in the step, and causing crystallization.

And then recovering the crystalline mannose.

5. A method for producing crystalline mannose,

() Concentrate a mannose solution with a mannose purity of 85% or more so that the Brix of the solution is 80 or more, and then heat the concentrated solution to 60 to 90 ° C and add seed crystals. Growing the crystal, (?) Next, the concentrated solution is concentrated under reduced pressure, and the temperature of the concentrated solution is lowered by 5 to 20 ° C. to grow crystals.

And then recovering the crystalline mannose.

6. A method for producing crystalline mannose,

(,) Concentrating a mannose solution having a mannose purity of 85% or more so that Brix of the solution is 80 or more, and then heating the temperature of the concentrated solution to 60 to 90 ° C;

(?) Next, the concentrated solution is concentrated under reduced pressure, the temperature of the concentrated solution is lowered by 5 to 20 ° C. to cause crystallization, and the crystal is grown.

And then recovering the crystalline mannose.

7. The method for producing crystalline mannose according to claim 5 or 6, wherein the concentration under reduced pressure of (?) Or (?,) Is performed at an absolute pressure of 40 to 250 fractions iHg.

8. Crystalline mannose which is a needle-like crystal having a purity of 95% or more obtained by the method according to any one of claims 3 to 7.

9. Concentrate a mannose solution with a mannose purity of 90% or more so that the Brix of the solution is 82 or more, add seed crystals as needed, grow and solidify the crystals, and then concentrate the obtained crystals. A method for producing a crystalline mannose, comprising pulverizing.

10. A crystalline mannose obtained by the method according to claim 9, which is an acicular crystal having a purity of 90% or more.

1 1. A method for producing a mannose solution,

Mannose isomerase is immobilized on a carrier having a basic anion exchange group, or at least on an adsorption resin having a basic anion exchange ability, and allowed to act on a fructose solution to convert fracose into mannose. A method for producing a mannose solution, comprising obtaining a mannose solution.

12. The method for producing a mannose solution according to claim 11, wherein the mannose isomerase is derived from Pseudomonas spora.

13. The method according to claim 11, further comprising a step of fractionating the obtained mannose solution to a purity of 85% or more by a chromatographic separation method. Manufacturing method.

14. A method for producing crystalline mannose, comprising crystallizing a mannose solution obtained by the method according to claim 13 to obtain crystalline mannose.

15. The method for producing crystalline mannose according to claim 14, wherein the method according to any one of claims 3 to 7 and 9 is performed as a step of crystallizing the mannose solution to obtain crystalline mannose.

16. A food or feed composition comprising the crystalline mannose according to claim 1 or 2.

17. Use of the crystalline mannose according to claim 1 or 2 for producing food or feed.