JP3189023B2 - Method for purifying arabinogalactan-containing composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial applications]

[0002] The present invention relates to a method for purifying an arabinogalactan-containing composition useful as a food material or an industrial raw material.

[0003]

[Prior art]

[0004] Arabinogalactan is a neutral polysaccharide contained in the xylem and sap of conifers and the like, and usually has a D-galactose-β-1 → 3 bond as a main chain, and has a D1-galactose β1- → 6 bond at position 6. -Galactose oligomer or β1 → 3 linked L
-Has a structure with short side chains of arabinose oligomers.

Conventionally, arabinogalactan has been mainly used as a substitute for gum arabic, but its main uses are as an emulsion stabilizer and a thickener, and it is very useful in food production.

It has been found that arabinogalactan is contained in conifers, some hardwoods, soybeans, and the like.
If they are the main raw materials, resources are abundant, and
Because of the advantage of low raw material prices, several methods for producing arabinogalactan from larch, a kind of softwood, are introduced.

[0007] As an example of the main method, water-soluble components are extracted from larch sawdust and chips with water several to several tens times that of the extract, and after the solid-liquid separation, the extract is treated with activated carbon. After performing ion exchange purification to deodorize, decolorize, and deionize, the mixture is concentrated to obtain an arabinogalactan-containing liquid.

Next, if necessary, a method of obtaining arabinogalactan powder from the arabinogalactan-containing liquid may be carried out by directly pulverizing the arabinogalactan-containing aqueous solution using a spray drier, or by adding alcohol to the concentrated liquid. Arabinogalactan is precipitated by adding a solvent such as the above, and the precipitate is separated from the liquid, dried and powdered.

However, the extract derived from larch contains coloring impurities and odorous components derived from larch, and these substances can be sufficiently removed by repeating precipitation with alcohol, activated carbon and ion exchange resin. Could not be removed.

Several methods have been proposed in the past to solve these problems.

For example, (1) US Pat. No. 3,325,47
No. 3 proposes a method using magnesium oxide as a flocculant, and (2) Japanese Patent Application Laid-Open No. 2-185501 proposes a method using an aluminum compound as a flocculant. In this method, the coloring material is aggregated, and the coloring material remaining after the aggregation and the remaining coloring material are removed by filtration, activated carbon treatment, and ion exchange purification.

[0012]

[Problems to be solved by the invention]

However, the method introduced in the past has various problems, and cannot be said to be a method capable of producing arabinogalactan of good and stable quality as a food material or an industrial raw material. .

For example, the arabinogalactan-containing aqueous solution or powder obtained in the above method (1) or (2) can be obtained by using an aggregating agent, or through various treatment steps using activated carbon or an ion exchange resin. However, it has been considered that the coloring substance cannot be sufficiently removed, and the coloring substance that cannot be completely removed in these steps remains in the arabinogalactan product.

That is, the aqueous solution of the product obtained by the method (1) or (2) has a coloring substance and an odor remaining. The smell gradually returned, and the color became slightly yellower.

As a result, conventional arabinogalactan-containing liquids and powders obtained therefrom have the drawback that, despite their usefulness in food production, their use is limited due to the above problems.

From the above background, the production of arabinogalactan which is free from coloring and odor, has stable quality without color and odor return even after long-term storage, and can be used for a wide range of uses as a food material or industrial material The method was an issue.

[0018]

[Means for Solving the Problems]

The present inventors have conducted intensive studies on a method for purifying an arabinogalactan-containing composition in order to solve the above-mentioned problems. As a result, surprisingly, the present inventors have conducted a simple operation of applying catalytic hydrogenation. The present inventors have succeeded in developing a method capable of refining the arabinogalactan-containing composition extremely effectively, and have completed the present invention.

That is, the first aspect of the present invention is characterized in that an arabinogalactan-containing composition is subjected to catalytic hydrogenation.
This is a method for purifying an arabinogalactan-containing composition.

[0021] Further, a second aspect of the present invention is to purify an arabinogalactan-containing composition, which comprises subjecting an arabinogalactan-containing composition to catalytic hydrogenation, followed by activated carbon treatment and ion exchange purification. Is the way.

Further, the third invention is the method for purifying an arabinogalactan-containing composition according to any one of the first and second aspects, wherein the temperature of the catalytic hydrogenation is 50 to 150 ° C.

Further, in the fourth invention, the arabinogalactan-containing composition is an extract derived from larch.
It is a purification method of the arabinogalactan-containing composition according to any one of the third to third aspects.

The arabinogalactan-containing composition used in the present invention is not particularly limited as long as it contains arabinogalactan without containing much impurities and decomposed products, and the raw material and the form of the raw material are not limited. As raw materials, there are conifers such as larch, some broadleaf trees, and other cereals such as soybean, and among them, larch is most advantageously adopted because it has a high arabinogalactan content and is easily extracted. The most preferred is a relatively small form such as chips or sawdust because of easy extraction and economical availability.

The method and conditions for producing the arabinogalactan-containing composition from various raw materials are not particularly limited as to the presence or absence of heating and the pressure, as long as impurities and decomposed products are not generated so much. From the viewpoint of being economically advantageous, immersion / filtration using hot water or cold water, which is a known unit operation, and ordinary extraction operation are most preferable.

In preparing the arabinogalactan-containing composition used in the present invention, a coagulant such as magnesium oxide or an aluminum compound may be used, or the amount of the coloring substance may be reduced by other methods. The processing is not an essential requirement of the present invention, and the effect of the present invention is not impaired even if the processing is not performed.

In practicing the present invention, the arabinogalactan-containing composition is subjected to catalytic hydrogenation. The hydrogenation catalyst used at that time is to hydrogenate the reducing group of the coloring substance in the arabinogalactan-containing composition. Or any substance capable of hydrocracking the substance, regardless of the type.

However, among these catalysts, those which do not significantly decompose arabinogalactan and which contain catalyst poisons contained in the arabinogalactan-containing composition before and during the catalytic hydrogenation treatment, Preferably, the catalyst has some resistance to catalyst poisons generated during the treatment. Examples of such catalysts include various hydrogen storage alloys and nickel-based catalysts such as Raney nickel.

In a preferred embodiment of the catalytic hydrogenation treatment of the present invention, the reaction temperature is 50 to 150 ° C., more preferably 80 to 150 ° C.
It is recommended to carry out the reaction at a temperature of up to 110 ° C., however, depending on the type of catalyst and other conditions, it is also possible to carry out the condition outside this condition.

However, if the reaction temperature is lower than 50 ° C., the hydrogenation reaction or hydrogenolysis reaction of the coloring substance may not proceed sufficiently. Is not preferred because the decomposition of arabinogalactan may be significant.

When the catalytic hydrogenation of the present invention is carried out, the reaction can proceed smoothly by supplying hydrogen to the catalyst surface. Therefore, the reaction is preferably carried out in a hydrogen atmosphere. Hydrogen pressure is 1kg / c
Although feasible if m ² or more, the economic 1-3
00 kg / cm ² is advantageous.

Although the reaction time required for the catalytic hydrogenation treatment of the present invention varies greatly depending on the hydrogenation conditions such as the type and amount of the hydrogenation catalyst, the temperature and pressure, and the solid concentration of the liquid, it cannot be said unconditionally. If various conditions are selected, it is often in the range of about 10 minutes to 2 hours, which is easy to implement.

In practicing the present invention, the arabinogalactan content in the arabinogalactan-containing composition employed is not limited, but it can be prepared economically, and the characteristics of arabinogalactan when it is made into a product. For the reason that the arabinogalactan content is 50% or more, for example, it is most advantageous to employ it.

In practicing the present invention, the concentration of the arabinogalactan-containing composition to be employed is not limited, but is preferably in the range of about 1 to 50% for economical production of the product.

As a preferred embodiment for carrying out the present invention, activated carbon treatment is carried out. There is no particular restriction on the type and production method of the activated carbon that can be employed, and the activated carbon treatment required for activated carbon treatment depends on the activation method and the activation conditions. Although there may be a slight difference in the amount of activated carbon and the conditions under which it is used, any commercially available activated carbon can be used.

When carrying out the activated carbon treatment of the present invention using commercially available activated carbon, the amount, temperature, treatment time,
There are no special restrictions on the distinction between the batch type and the continuous type.However, if the reduction in color or ultraviolet absorption of the arabinogalactan-containing composition after treatment is used as an index of the degree of treatment, the batch type temperature The amount of activated carbon used at 60 ° C. for about one hour is often about 0.1 to several percent of the weight of the liquid to be treated, and about 1 to 10% of the weight of solids in the liquid to be treated. .

In a preferred embodiment for carrying out the present invention, ion exchange purification is carried out. However, there is no particular restriction on the type and system of ion exchange materials and various conditions which can be employed, and ordinary sugar solutions can be purified. The method and the method used in the process are advantageously employed.

The standard of the ion exchange treatment is to reduce the change in pH and the absorption of ultraviolet rays. However, as an ion exchange material, an ion exchange resin is preferable because of its large exchange capacity and easy availability. Among them, the gel type is more preferable than the porous type, and the gel type is larger than the one having a small degree of crosslinking, because arabinogalactan is hardly adsorbed on the resin.

As described above, by carrying out the present invention, it is highly purified by a simple operation, is clear, has no coloration and odor, and has stable quality without color and odor return even after long-term storage. Although an aqueous solution of the arabinogalactan-containing composition can be obtained, this can be powdered by a known method, if necessary, to obtain a tasteless, odorless, pure white powder.

[0040]

【Example】

Hereinafter, the present invention will be described more specifically with reference to examples, but the technical scope of the present invention is not limited to these examples.

In the following examples,% represents% by weight unless otherwise specified.

[0043]

[Preparation Example 1] Extraction of arabinogalactan from larch

10 kg of Japanese larch sawdust
(Water 30%), add 100 liters of water, temperature 60 ℃
After stirring for 2 hours to extract the water-soluble component, the extraction residue and the extract are separated, and the arabinogalactan-containing composition
That is, larch extract 10 having a concentration (Brix) of 0.75%
1 kg was obtained.

[0045]

Embodiment 1

A larch extract solution obtained in Preparation Example 1 was partially concentrated to a concentration of 10%, and 270 g of the larch extract and 10 g of Raney nickel catalyst were charged into a 500 ml high-pressure reaction vessel.
A hydrogen pressure of kg / cm ² was applied, and the mixture was stirred for 90 minutes while maintaining the temperature at 100 ° C.

After cooling, the reaction solution was taken out of the vessel and the catalyst was separated. Thereafter, 2.5 g of activated carbon (purified Shirasagi, manufactured by Takeda Pharmaceutical Co., Ltd.) was added, and the mixture was stirred at 60 ° C. for 1 hour.

When the obtained activated carbon-treated solution was diluted to 2%, the absorbance at 278 nm was 0.295.

Next, the activated carbon-treated solution was treated with a strongly acidic cation exchange resin [Diaion SK-1 manufactured by Mitsubishi Kasei Kogyo Co., Ltd.]
B] and a column of a strongly basic anion exchange resin [Diaion SA20A, manufactured by Mitsubishi Kasei Kogyo Co., Ltd.] to obtain an arabinogalactan-containing composition of the present invention.

The composition obtained was colorless and odorless, had a pH of 2.5 at the outlet of the ion exchange column, and had an absorbance at 278 nm of 0.162 when diluted to a concentration of 2%.

[0051]

Embodiment 2

Activated carbon (purified Shirasagi, manufactured by Takeda Pharmaceutical Co., Ltd.) was added to the larch extract obtained in Preparation Example 1 in an amount of 1% by weight of the liquid.
%, Stirred at 50 ° C. for 1 hour, filtered off the activated carbon, and then ion-exchange resin [Mitsubishi Kasei Kogyo Co., Ltd.]
Manufactured by Diaion SK-1B and Mitsubishi Kasei Kogyo Co., Ltd.
[Diaion SA10A] to obtain a yellow liquid containing arabinogalactan.

This yellow liquid was concentrated to a concentration of 10%.
70 g and 5 g of Raney nickel catalyst were charged into a high-pressure reactor having a volume of 500 ml, a hydrogen pressure of 9 kg / cm ² was applied, and the mixture was stirred for 90 minutes while maintaining the temperature at 100 ° C.

After the reaction solution was cooled, it was taken out of the vessel and the catalyst was separated, and then treated with activated carbon in the same manner as in Example 1 except that the amount of activated carbon used was changed to 2.0 g.

Next, SA-1 was used as an anion exchange resin.
Except for using OA, ion-exchange purification was performed in the same manner as in Example 1,
An arabinogalactan-containing composition of the present invention was obtained which was colorless, odorless and had an absorbance at 278 nm of 0.110 when diluted to a concentration of 2%.

[0056]

Embodiment 3

Larch extract concentrate 5 obtained in Preparation Example 1
While stirring 00 g (12% concentration), 6 g of commercially available polyaluminum chloride powder was added thereto, and the pH was adjusted to 7 with sodium hydroxide.

The generated floc was removed to obtain a slightly yellow transparent liquid.

270 g of this solution was hydrocracked in the same manner as in Example 1, and then used as activated carbon by Nimura Chemical Co., Ltd.
Except that 5 g of Taiko Co., Ltd., and Amberlite IR120B and IRA410 manufactured by Organo were used as the ion-exchange resin, activated carbon treatment and ion exchange purification treatment were performed in the same manner as in Example 1 to obtain a colorless and transparent arabino of the present invention. A galactan-containing composition was obtained.

The absorbance at 278 nm of this solution at a concentration of 2% was 0.071.

[0061]

[Comparative Example 1]

After the same polyaluminum chloride treatment as in Example 2, 5 g of Taiko manufactured by Nimura Chemical Co., Ltd. was used as activated carbon, and Amberlite IR120B and IRA410 manufactured by Organo were used as ion exchange resins. 2
Activated carbon treatment and ion exchange purification treatment were performed in the same manner as in the above to obtain a treatment liquid.

The absorbance at 278 nm of the treated solution at a concentration of 2% was 0.506.

[0064]

Embodiment 4

A commercially available arabinogalactan (trade name ST)
RACTAN, manufactured by CHAMPION Co., Ltd.) as an aqueous solution having a concentration of 40%, and 270 g of the aqueous solution and 10 g of Raney nickel catalyst
Into a 500 ml high pressure reaction vessel,
A hydrogen pressure of m ² was applied and the mixture was stirred for 60 minutes while maintaining the temperature at 90 ° C.

After the reaction solution was cooled, it was taken out of the vessel and the catalyst was separated therefrom.
Activated carbon treatment was performed in the same manner as in Example 1 except that the amount was 1 g using 1PS, and then ion exchange purification was performed as in Example 1.

278 nm at a concentration of 2% of the obtained liquid
Had an absorbance of 0.095.

[0068]

[Comparative Example 2]

A commercially available arabinogalactan (trade name ST)
The absorbance at 278 nm of the aqueous solution at a concentration of 2% (RACTAN, manufactured by CHAMPION) was 2.008.

[0070]

Embodiment 5

The purified arabinogalactan solution obtained in Example 4 was lyophilized into a powder, and subjected to a storage test at a temperature of 60 ° C. for 3 months, but no reversion of color or odor was observed.

The change in absorbance at 278 nm measured with a 2% aqueous solution was as follows.

That is, the absorbance at the start of storage was 0.106,
The absorbance after two months was 0.110, and the absorbance after three months was 0.108.

[0074]

【The invention's effect】

As described above, by carrying out the present invention, it is possible to obtain a highly purified product with a simple operation, no coloration and odor, and stable color and odorless return even after long-term storage. Thus, it is possible to obtain arabinogalactan that can be used for a wide variety of uses as a food material and an industrial raw material.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08B 37/00 C07B 61/00 300 C07B 63/00 C07B 63/02 CA (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] 1. A method for purifying an arabinogalactan-containing composition, comprising subjecting the arabinogalactan-containing composition to a catalytic hydrogenation treatment. 2. A method for purifying an arabinogalactan-containing composition, comprising subjecting an arabinogalactan-containing composition to a catalytic hydrogenation treatment, followed by activated carbon treatment and ion exchange purification. 3. The method for purifying an arabinogalactan-containing composition according to claim 1, wherein the temperature of the catalytic hydrogenation is 50 to 150 ° C. 4. The method for purifying an arabinogalactan-containing composition according to claim 1, wherein the arabinogalactan-containing composition is an extract derived from larch.