JP2000070000A - Production of d-mannose by acid hydrolysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently obtain high-quality D-mannose in a high yield from a mannan compound obtained from other than the seed of ivory nut. SOLUTION: A mannan compound containing >=40 wt.% D-mannose derived from guar and carob of pulse family and/or tare of the family Actinidiaceae is hydrolyzed with an acid to liberate and form >=50 wt.% mannan compound as a monosaccharide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing D-mannose at a high yield and at a low cost from a mannan compound derived from guar, carob and cod of the legume family.

[0002]

2. Description of the Related Art D-mannose is used as a raw material for producing mannitol and a cultivation raw material for animal cells, which has attracted attention as a pharmaceutical or food additive, and as a feed additive for chicken poultry or a functional food material. It is expected to be used as an application.

At present, D-mannose is available from HSIsbell, Meth.
od in Carbohydrate Chemistry, RLWhistler, MLWo
lfrom Eds, Academic Press, New York, 1962, pp 145
No.-147, which is produced by acid-hydrolyzing a mannan compound present in seeds of elephant palm with sulfuric acid. However, such a production method was not preferable because acid hydrolysis had to be performed under severe conditions (sulfuric acid concentration: 75%), and the steps were complicated and the yield was low. In addition, the raw material elephant palm has a limited supply, and mannose produced by this method is extremely expensive.

In addition to the above-mentioned acid hydrolysis method, a method of producing mannose by isomerizing glucose at a high temperature using molybdate as a catalyst has also been proposed (Japanese Patent Publication No. Sho 6 (1988)).
No. 3-12072). However, this method also has a very low yield of mannose relative to the raw material, and is not suitable for a commercial production method aimed at low cost and mass production.

On the other hand, mannose is produced from fructose by using mannose isomerase, which is an enzyme that interconverts mannose and fructose, and mannose from glucose by combining mannose isomerase and glucose isomerase (an enzyme that interconverts glucose and fructose). Attempts have also been made (Yoshiyuki Takasaki,
"Food Industry" 38, p40-45 (1995)). However, this method has a very low conversion rate from fructose or glucose to mannose, and is not practical in terms of productivity.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the state of the prior art, and has as its object to provide a very mild condition under which a secondary decomposition reaction of a mannan compound obtained from a source other than a seed of a rhododendron hardly occurs. An object of the present invention is to provide a method for producing D-mannose with high purity and high yield efficiently by acid hydrolysis under low temperature.

[0007]

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies on a method for liberating and producing D-mannose in high purity and high yield from a mannan compound derived from guar, carob or cod of the legume family. It has been found that the above object can be achieved by specifying suitable conditions in the acid hydrolysis method, and the present invention has been completed.

That is, the present invention provides an acid hydrolysis of a mannan compound containing at least 40% by weight of D-mannose derived from legume guar, carob, and / or cod cod, and 50% by weight of the mannan compound. As described above, a method for producing D-mannose, characterized in that preferably at least 60% by weight is released as a monosaccharide.

[0009] In the above production method of the present invention, the preferred acid hydrolysis conditions include a solid content of the mannan compound of 3 to 25% by weight, more preferably 5 to 20% by weight, and still more preferably 10 to 20% by weight. The concentration of the acid to be used is 2 to 20% by weight in the case of an organic acid, more preferably 3.5 to 13.0% by weight, and in the case of a mineral acid, 0.5 to 15% by weight based on the dry matter of the mannan compound. , More preferably 1.0 to 10% by weight, and the temperature at the time of acid hydrolysis is 80%.
-160 ° C, more preferably 95-150 ° C, even more preferably 120-150 ° C.

In a preferred embodiment of the production method of the present invention, a mannan compound is added to water or hot water in which an acid is dissolved and mixed, and the residence time is at least 5 minutes in a closed pressure vessel equipped with a jacket-type stirrer capable of adjusting the temperature. The acid hydrolysis is carried out continuously by holding. Further, in a preferred embodiment of the production method of the present invention, the acid hydrolyzate is neutralized with a neutralizing agent to a pH in the range of 3.5 to 6.0, and the acid used by the neutralizing agent is hardly soluble in water. Is an alkaline agent that produces

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The mannan compound used in the present invention is derived from guar, carob and / or cod of the legume family, and needs to contain 40% by weight or more of D-mannose. If the D-mannose content is less than 40% by weight, the product yield is extremely low, and the production cost is undesirably high. The mannan compound used in the present invention can be obtained, for example, by crushing the endosperm portion of guar, carob or cod seeds, respectively, and using those obtained by removing some or all of proteins, lipids, pigments and the like as necessary. You may. The mannan compound may be used in the form of a strip or a powder, but a strip is preferred in terms of handling.

Examples of the acid used in the present invention include mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid and sulfurous acid, and organic acids such as oxalic acid, citric acid, acetic acid and formic acid. A substance that forms a sparingly soluble salt with an acid upon neutralization with a base,
For example, sulfuric acid that produces barium sulfate by neutralization with barium hydroxide, and oxalic acid that produces calcium oxalate by neutralization with calcium hydroxide or calcium oxide are preferred in terms of the purification load of the acid hydrolyzate with the ion conversion resin. .

In the acid hydrolysis procedure of the present invention, the acid is first dissolved in water or hot water. The acid concentration at this time is 2 to 20% by weight, preferably 3.5 to 13.0% by weight, in the case of an organic acid, and 0.5 to 15% by weight in the case of a mineral acid, based on the dry matter of the mannan compound. , Preferably 1 to 10% by weight.

The concentration of the acid used in the present invention is extremely important for releasing D-mannose from the mannan compound in high purity and high yield. If the acid concentration exceeds the above-mentioned concentration, it is over-decomposed and a large amount of sugars other than D-mannose are produced.
-It is not preferable because it causes a decrease in the mannose yield. On the other hand, when the acid concentration is lower than the above concentration, the time required for acid hydrolysis becomes longer, which is not commercially preferable.

Next, a mannan compound containing D-mannose in an amount of 40% by weight or more is dissolved in an acid in an aqueous solution at a solid concentration of 3 to 25% by weight, preferably 5 to 20% by weight, more preferably 10 to 20% by weight. %, And after sufficiently suspending the suspension, the temperature of the suspension is increased by heating, and the temperature of the suspension is reduced to 80%.
To 160 ° C., preferably 95 to 150 ° C., more preferably 5 minutes while maintaining a constant temperature of 120 to 150 ° C.
The acid hydrolysis is performed for 200 hours, preferably 10 minutes to 80 hours, more preferably 30 minutes to 6 hours.

If the solid concentration of the mannan compound is lower than the above-mentioned concentration, a large amount of energy is required for concentration in a subsequent step, which is not preferable. If the solid content exceeds the above concentration, the fluidity during acid hydrolysis is lost,
It is not preferable because handling becomes difficult by an acid hydrolysis operation, a filtration operation and the like.

Examples of the method of heating and raising the temperature include a direct heating method (for example, a direct steam blow-in type in-line heater) and an indirect heating method, but are not particularly limited as long as the heating can be performed. In addition, any vessel that performs acid hydrolysis can be used as long as it is an acid-resistant, heat-resistant, and / or pressure-resistant open-type or closed-type vessel, but a closed-pressure vessel with a temperature-adjustable jacket-type stirrer is used. This is preferable because the process can be continuously performed. Reaction temperature is a factor that greatly affects the reaction rate. Basically, since the rate of the acid hydrolysis reaction depends on the temperature, for example, generally, when the reaction temperature rises by 10 ° C., the time required for the acid hydrolysis is low so that the reaction rate is accelerated about twice. It becomes longer in the temperature range and becomes shorter as the temperature rises. Therefore, when the acid hydrolysis temperature is lower than the above temperature, the reaction time becomes too long, and the efficiency is deteriorated. When the temperature is higher than the above temperature, the decomposition reaction of the liberated saccharide becomes remarkable, and the color of the acid hydrolysis end solution is colored. This is not preferred because decolorization and / or an increase in the purification load on the ion-exchange resin due to an increase in the amount of the resin are not preferred.

The acid hydrolysis reaction time is preferably carried out under the condition that the ratio (decomposition rate) of the total amount of the monosaccharides eluted in the reaction solution with respect to the mannan compound on a dry matter basis is 50% by weight or more. . When the decomposition rate is less than 50%, the production yield is reduced, and it becomes difficult to recover high-purity D-mannose, which is not preferable. The reaction time is usually 5 minutes to 200
The time is shorter as the concentration of the acids or the hydrolysis temperature is higher.

Next, the pH of the solution obtained by acid hydrolysis is adjusted to 3.5 to 3.5 by adding a required amount of a base as a neutralizing agent as it is or by mixing it in a conventional manner.
After neutralization to a range of 6.0, the residue is clarified by a known separation method, for example, diatomaceous earth filtration, centrifugation, membrane filtration, filter press, etc., to remove decomposition residues.

The neutralizing agent is not particularly limited as long as it can neutralize the acid hydrolyzate, but it is preferable to use an alkali agent which forms a salt which is hardly soluble with an acid. The pH can be stopped near its isoelectric point in order to insolubilize the protein-derived eluate mixed in the solution.
A range of 6.0 is preferred. Prior to the filtration of the neutralized solution, a method of cooling the neutralized solution and / or storing the neutralized solution for a certain period of time in order to sufficiently precipitate hardly soluble salts and insolubles may be employed. Further, if necessary, the clarified sugar solution is subjected to a known method, for example, decolorization purification with bone charcoal or activated carbon and / or dialysis, and purification using an ion exchange membrane or an ion exchange resin or the like, whereby the decomposition rate is 50% or more. Can be obtained.

From the solution containing a large amount of useful saccharides thus obtained, a D-mannose-rich liquid fraction can be easily obtained by a further known separation and purification method, and is suitable for the purpose of use. D-mannose can be purified with a high degree of purity.

[0022]

EXAMPLES The present invention will be described with reference to the following examples, but the technical scope of the present invention is not limited by these examples.

Example 1 In a vial bottle having a 200 ml screw cap, 7.5 g of guar spirit (guar soybean endosperm) was added to an aqueous solution in which a predetermined amount of oxalic acid was dissolved, in terms of anhydrous content, so that the total amount became 150 g. This was adjusted to obtain a mannan compound solution having a solid content of 5.0% by weight. This solution was shaken in a shaking thermostat at 95.0 ± 0.2 ° C. and 100 rpm to perform an acid hydrolysis reaction. Reaction 50 hours, 72
After a period of time, sampling was performed, and the collected reaction solution was subjected to Ca (O
H) Adjust the pH to 4.0 with ₂ and centrifuge it for 30 minutes.
After centrifugation at 00 rpm for 10 minutes, the supernatant was HP
The sugar composition was analyzed by LC. The results are shown in Table 1 below.

[0024]

[Table 1]

Example 2 Oxalic acid 1 was added to a 5-liter autoclave equipped with a jacket-type stirrer.
To 3.5 kg of an aqueous solution in which 0 g was dissolved, 200 g of guar spirit was added in terms of anhydrous content, and the total amount was adjusted to 4.0 kg with water. While stirring the solution at a rotation speed of 50 rpm, 4 kg / cm ² of steam was introduced into the jacket, the temperature was raised to 140 ° C, and then the acid hydrolysis reaction was carried out while maintaining the temperature at 140 ° C. On the way, 30 minutes, 60 minutes, 9
Sampling was performed after 0 minutes and 120 minutes, the pH of the collected reaction solution was adjusted to 5.0 using Ca (OH) ₂ , and the product was centrifuged at 3000 rpm for 10 minutes using a centrifuge. The supernatant was analyzed for sugar composition by HPLC. The results are shown in Table 2 below.

[0026]

[Table 2]

Example 3 An aqueous solution in which 5.0% by weight of oxalic acid was added / DS was added, and guar spirit was added to a solid content of 15.0% by weight. The mixture was charged into an autoclave equipped with a stirrer, and the stirring speed was 80 r.p.
The temperature was adjusted to 140 ° C. by indirect heating in a jacket with 4 kg / cm ² of steam at a m.

The slurry liquid is continuously supplied quantitatively at a flow rate of 30 l / hour, and the residence time of the autoclave is set to 10 times.
Minutes, the effluent from the autoclave is further passed through a heated and heated pipe to maintain a temperature of 140 ° C.
The acid hydrolysis reaction was performed for 20 minutes. The solution after the reaction was adjusted to pH 5.0 with Ca (OH) ₂ , filtered through diatomaceous earth, decolorized with an activated carbon column, and purified with an ion exchange resin to obtain a clear and colorless clear solution. As a result of measuring the purity of D-mannose of the obtained sugar solution by HPLC, 58.2% by weight was obtained.
Met.

Example 4 In the method described in Example 3, the amount of oxalic acid added was 5.0% by weight /
DS was adjusted to 2.7% by weight of sulfuric acid / DS, and Ca (OH)
The same operation as in Example 3 was performed except that BaCO ₃ was changed to ₂ , to obtain a colorless and transparent clear liquid. As a result of measuring the mannose purity of the obtained sugar solution by HPLC, 59.2% by weight was obtained.
Met. The recovered total sugar content and mannose yield relative to the used raw material anhydride were 87.0% by weight in terms of anhydrous content, respectively.
It was 51.5% by weight.

Example 5 An acid hydrolysis reaction was carried out for 120 minutes in the same manner as in Example 2 except that the endosperm portion of tara gum was used instead of guar spirit. The obtained reaction solution was adjusted to pH as in Example 2.
The sugar composition was analyzed by HPLC with respect to the supernatant liquid which had been adjusted and centrifuged. As a result, it was found that 66.8% by weight of mannose, 22.0% by weight of galactose, and 11.2% by weight of other sugars.

Example 6 Acid hydrolysis was carried out for 120 minutes in the same manner as in Example 2 except that the endosperm portion of locust bean gum was used instead of guar spirit. The pH of the obtained reaction solution was adjusted in the same manner as in Example 2, and the centrifuged supernatant was subjected to HPLC.
As a result of analyzing the saccharide composition, it was found to be 73.6% by weight of mannose, 18.3% by weight of galactose, and 8.1% by weight of other saccharides.

[0032]

According to the production method of the present invention, D-mannose can be easily produced from mannan compounds derived from inexpensive raw materials with high purity, efficiently and under mild conditions.

Claims (7)

[Claims] 1. D-mannose derived from guar, carob and / or cod of the legume family is 40% by weight.
A method for producing D-mannose, comprising subjecting the above-mentioned mannan compound to acid hydrolysis with an acid to liberate and produce at least 50% by weight of the mannan compound as a monosaccharide. 2. The solid concentration of the mannan compound is 3 to 25.
2. The method for producing D-mannose according to claim 1, wherein the acid hydrolysis is carried out under a condition in a range of weight%. 3. The method according to claim 1, wherein the acid is an organic acid, and the acid hydrolysis is carried out under the condition that the concentration of the organic acid is in the range of 2 to 20% by weight based on the dry weight of the mannan compound. 3. The method for producing D-mannose according to 2. 4. The method according to claim 1, wherein the acid is a mineral acid, and the acid hydrolysis is carried out under the condition that the concentration of the mineral acid is in the range of 0.5 to 15% by weight based on the dry weight of the mannan compound. 2. The method for producing D-mannose according to 1. 5. The process for producing D-mannose according to claim 1, wherein the acid hydrolysis is carried out at a temperature of 80 ° C. to 160 ° C. 6. The acid hydrolysis is continuously carried out by adding and mixing a mannan compound to water or warm water in which an acid is dissolved, and keeping the mixture in a sealed pressure vessel equipped with a temperature-adjustable jacket stirrer for at least 5 minutes as a residence time. The method for producing D-mannose according to any one of claims 1 to 5, wherein the method is performed. 7. The acid hydrolyzate is a neutralizing agent and has a pH of 3.5 to 7.5.
The neutralizing agent is neutralized to a range of 6.0, and the neutralizing agent is an alkali agent that forms a poorly water-soluble salt with the used acid. A method for producing D-mannose.