JPH05239106A - Production of purified galactomannan - Google Patents

Abstract

PURPOSE:To obtain a purified galactomannan capable of providing its aqueous solution having excellent transparency and viscosity stability, in production of purified galactomannan. CONSTITUTION:An aqueous solution of crude galactomannan and a monosaccharide is adjusted to proper pH and filtered and purified galactomannan is recovered from the filtrate to produce purified galactomannan. By this method, purified galactomannan providing an aqueous solution of galactomannan showing characteristics of high transparency and excellent viscosity stability is obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing purified galactomannan. Galactomannan is a neutral polysaccharide in which a galactose unit is a side chain in a main chain having mannose as a constituent unit, and is mainly contained in the endosperm portion of seeds of legumes in large amounts. Gua gum made from gua beans,
Cod gum made from cod beans and locust bean gum made from locust beans are typical plant gums containing galactomannan as a main component.

Galactomannan, when dissolved in water,
It has an extremely high viscosity, its aqueous solution is stable in a wide pH range, and the stability of the aqueous solution in which salts coexist is also excellent, and it is widely used in various industries such as printing, paste, etc. in addition to the food field. Has been done. However, ordinary galactomannan is contaminated with impurities such as proteins, oils, and fibers contained in the seed coat and germ when extracting from the seed endosperm, so that its aqueous solution is inferior in transparency and quality stability. become. Therefore, in the application of galactomannan that is required to have high purity and high quality such as high transparency of the aqueous solution, it is desired to provide a purified galactomannan satisfying these requirements.

[0003]

2. Description of the Related Art As a method for purifying galactomannan,
After dissolving galactomannan in hot water, insoluble substances such as proteins and fibers are removed by filtration, and water-affinity organic solvents such as methanol, isopropyl alcohol, and acetone are added to the filtrate to precipitate gums, which are squeezed and dehydrated. Then, a method is known in which the dehydrated product is dried and pulverized to obtain purified galactomannan.

[0004]

However, in the galactomannan purification step, the galactomannan sometimes stays in the state of an aqueous solution for about 1 to 2 days during the purification step. There is a phenomenon that the viscosity of the aqueous solution is reduced, and it is difficult to industrially produce a highly viscous type purified galactomannan.

It is known that when galactomannan is newly dissolved in an aqueous solution in which galactomannan of reduced viscosity coexists, the viscosity of the newly dissolved galactomannan rapidly decreases. In order to prevent deterioration, it is necessary to completely clean the inside of the galactomannan continuous purification device currently used at a frequency of once or more per day, which is low in productivity and excessive in its production. It is a cause of requiring labor, and the advent of a more efficient method for producing purified galactomannan without causing a decrease in viscosity is awaited.

[0006]

In view of such circumstances, the inventors of the present invention have diligently studied a method for producing purified galactomannan, and as a result, the viscosity reduction is caused by adding a monosaccharide to crude galactomannan for purification. It has been found that a galactomannan which does not cause trouble can be obtained, which has led to the present invention. The gist of the invention is to remove an insoluble substance from an aqueous solution obtained by adding a monosaccharide to crude galactomannan, and remove the insoluble substance from the filtrate. A method for purifying galactomannan is characterized by recovering galactomannan.

The crude galactomannan used in the practice of the present invention may be a galactomannan-containing seed obtained by roughly removing the seed coat and the germ part and crushing it, or a crushed product roughly purified by removing impurities to some extent. Good. Commercially available products such as guar gum, tara gum and locust bean gum can also be used.

In carrying out the present invention, first, an aqueous solution of crude galactomannan containing a monosaccharide is prepared. As water for dissolving the crude galactomannan, 70
Hot water at ~ 100 ° C is used. The amount of hot water used is 70 to 125 parts per 1 part of crude galactomannan. As a method for dissolving the crude galactomannan in hot water, first, the crude galactomannan powder is sufficiently stirred and dispersed in cold water at about 20 ° C., and the mixture is heated to a predetermined temperature and dissolved while continuing stirring. The method is, or a method of gradually adding and dissolving the crude galactomannan powder while stirring hot water held at a predetermined temperature.

As the monosaccharide used for carrying out the present invention, arabinose, xylose, fructose, galactose, glucose, mannose and the like are preferable. These monosaccharides may be used alone or in combination of two or more. The addition amount of the monosaccharide is preferably 1 to 20% by weight based on the crude galactomannan. If the amount added is larger than this, there is no particular effect, and if the amount added is smaller than this, the viscosity of galactomannan decreases. The monosaccharide may be dissolved in water together with the crude galactomannan, or may be added before or after the dissolution of the crude galactomannan.

Filtration of the crude galactomannan solution is carried out by adjusting the pH of the solution as disclosed in Japanese Patent Publication No. 2-7962.
Adjust to 4.5-6.3 and filter as an aqueous galactomannan solution containing monosaccharides. The filtration is preferably performed at a temperature of 70 ° C or higher. When the temperature is lowered, the viscosity of the galactomannan aqueous solution is increased, the filterability is deteriorated and the filtration rate is decreased, which is not preferable. When filtering, a filter aid such as perlite is added to the galactomannan aqueous solution in an amount of 0.5 to
A method may also be used in which 1.5% is added, a filter layer is sufficiently formed to form a cake layer, and then the filtrate is taken out.

As a method for recovering galactomannan from the aqueous solution obtained by filtering off the impurities thus obtained, a method is used in which a water-affinitive organic solvent such as methanol, isopropyl alcohol, or acetone is added to form a precipitate and the precipitate is recovered. Is used.

[0012]

EXAMPLES The present invention will be described in more detail below with reference to examples. In the examples, the viscosity of the aqueous solution was such that 4.0 g of purified galactomannan was dispersed in 400 ml of deionized water in cold water, and the mixture was stirred at 85 ° C. for 1 hour to dissolve, and the total amount was accurately corrected to 400 g. Is shown as a measured value (cps) at 20 rpm of B type viscometer.

[0013]

Example 1 240 g of crude locust bean gum and 20 g of arabinose were dispersed in 20 liters of water and dissolved by stirring at 85 ° C. for 1 hour. Next, citric acid and sodium dihydrogen phosphate were added to the solution to adjust the pH of the solution to 5.8. Table 1 shows the change in viscosity of the solution when the solution was allowed to stand at 40 ° C. Next, 240g of filter aid perlite was added to the solution after pH adjustment.
Was added and mixed, and pressure filtration was performed with a filter press. Next, the same volume of isopropyl alcohol was added to the filtrate, and the resulting precipitate was squeezed and dehydrated, dried and pulverized to obtain purified locust bean gum. The aqueous solution viscosity (25 ° C) of the obtained purified locust bean gum was 3500 cps. Table 1 shows the time-dependent changes in aqueous solution viscosity (40 ° C.) of the obtained purified locust bean gum when allowed to stand at 40 ° C.

[0014]

Example 2 240 g of crude locust bean and 20 g of xylose were dispersed in 20 liters of water and dissolved by stirring at 85 ° C. for 1 hour. Next, this solution was treated in the same manner as in Example 1 to adjust the pH of the solution to 5.8. Table 1 shows the change in viscosity when the solution was left at 40 ° C. This solution was then added to Example 1
The same procedure was followed to obtain a purified locust bean gum. Aqueous solution viscosity of the obtained refined locust bean gum (25 ℃)
Was 3550 cps. Table 1 shows the time-dependent changes in the aqueous solution (40 ° C.) of the obtained purified locust bean gum left at 40 ° C.

[0015]

Example 3 240 g of crude locust bean gum and 20 g of fructose were dispersed in 20 liters of water and dissolved by stirring at 85 ° C. for 1 hour. Next, the pH of this solution was adjusted to 5.8 in the same manner as in Example 1. Table 1 shows the change in viscosity when the solution was left at 40 ° C. Next, this solution was treated in the same manner as in Example 1 to obtain purified locust bean gum.
Aqueous solution viscosity of the obtained purified locust bean gum (25
C) was 3400 cps. Table 1 shows the time-dependent changes in aqueous solution viscosity (40 ° C.) of the obtained purified locust bean gum when allowed to stand at 40 ° C.

[0016]

Example 4 240 g of crude tara gum and 20 g of arabinose
Was dispersed in 20 liters of water and dissolved by stirring at 85 ° C. for 1 hour. Next, this solution was treated in the same manner as in Example 1 to prepare a solution.
The pH was adjusted to 5.8. Table 1 shows the change in viscosity when the solution was left at 40 ° C. Next, this solution was treated in the same manner as in Example 1 to obtain purified tara gum. The purified cod gum obtained had an aqueous solution viscosity (25 ° C) of 2900 cps. Table 1 shows the time-dependent changes in aqueous solution viscosity (40 ° C.) of the obtained purified tara gum left at 40 ° C.

[0017]

Comparative Example 1 240 g of crude locust bean gum was dispersed in 20 liters of water and dissolved by stirring at 85 ° C. for 1 hour. Next, citric acid and sodium dihydrogen phosphate were added to this solution to adjust the pH of the solution to 5.8. Table 1 shows the change in viscosity of this solution when allowed to stand at 40 ° C. Next, this solution was treated in the same manner as in Example 1 to obtain purified locust bean gum. The obtained purified locust bean gum has an aqueous solution viscosity (25 ° C) of 33.
It was 00 cps. Of the resulting refined locust bean gum
Table 1 shows the changes over time in the viscosity of the aqueous solution (40 ° C.) when allowed to stand at 40 ° C.

[0018]

Comparative Example 2 240 g of crude tara gum was dispersed in 20 liters of water and dissolved by stirring at 85 ° C. for 1 hour. Next, this solution was treated in the same manner as in Example 1 to adjust the pH of the solution to 5.8. Table 1 shows the change in viscosity of this solution when allowed to stand at 40 ° C. Next, this solution was treated in the same manner as in Example 1 to obtain purified tara gum. The obtained purified cod gum has an aqueous solution viscosity (25 ° C) of 2700.
It was cps. Table 1 shows the time-dependent changes in aqueous solution viscosity (40 ° C.) of the obtained purified tara gum left at 40 ° C.

[0019]

[Table 1]

[0020]

INDUSTRIAL APPLICABILITY According to the production method of the present invention, by adding a monosaccharide, it is possible to stably produce high-quality purified galactomannan having excellent viscosity stability in the aqueous solution state of galactomannan, high transparency. ..

[Procedure amendment]

[Submission date] May 28, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

[0013]

Example 1 240 g of crude locust bean gum and 20 g of arabinose were dispersed in 20 liters of water and the mixture was heated to 85 ° C.
It was dissolved by stirring for 1 hour. Next, citric acid and sodium dihydrogen phosphate were added to the solution to adjust the pH of the solution to 5.8. Table 1 shows the change in viscosity of the solution when the solution was allowed to stand at 40 ° C. Next, 240 g of perlite as a filter aid was added to and mixed with the solution after pH adjustment, and pressure filtration was performed with a filter press. Next, the same volume of isopropyl alcohol was added to the filtrate, the precipitate formed was squeezed and dehydrated, and dried,
It was crushed to obtain purified locust bean gum. The purified locust bean gum obtained had an aqueous solution viscosity (25 ° C.) of 35.
It was 00 cps.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

[0014]

Example 2 240 g of crude locust bean and 20 g of xylose were dispersed in 20 liters of water and dissolved by stirring at 85 ° C. for 1 hour. Next, this solution was treated in the same manner as in Example 1 to adjust the pH of the solution to 5.8. Add this solution to 4
Table 1 shows the change in viscosity when left at 0 ° C. Next, this solution was treated in the same manner as in Example 1 to obtain purified locust bean gum. The aqueous solution viscosity (25 ° C.) of the obtained purified locust bean gum was 3550 cps.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction content]

[0015]

[Example 3] 240 g of crude locust bean gum and 20 g of fructose were dispersed in 20 liters of water, and the mixture was heated to 85 ° C.
It was dissolved by stirring for 1 hour. Next, this solution was adjusted to pH 5.8 in the same manner as in Example 1. Table 1 shows the change in viscosity when the solution was left at 40 ° C. Next, this solution was treated in the same manner as in Example 1 to obtain purified locust bean gum. The aqueous solution viscosity (25 ° C.) of the obtained purified locust bean gum was 3400 cps.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

[0016]

Example 4 240 g of crude tara gum and 20 g of arabinose were dispersed in 20 liters of water and dissolved by stirring at 85 ° C. for 1 hour. Next, this solution was treated in the same manner as in Example 1 to adjust the pH of the solution to 5.8. This solution at 40 ℃
Table 1 shows the change in viscosity when left to stand. Next, this solution was treated in the same manner as in Example 1 to obtain purified tara gum. The obtained purified cod gum has an aqueous solution viscosity (25 ° C.) of 2900.
It was cps.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

[0017]

Comparative Example 1 240 g of crude locust bean gum was added to 2 parts of water.
It was dispersed in 0 liter and dissolved by stirring at 85 ° C. for 1 hour. Next, citric acid and sodium dihydrogen phosphate were added to this solution to adjust the pH of the solution to 5.8. Table 1 shows the change in viscosity of this solution when allowed to stand at 40 ° C. Next, this solution was treated in the same manner as in Example 1 to obtain purified locust bean gum. The aqueous solution viscosity (25 ° C.) of the obtained purified locust bean gum was 3300 cps.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

[0018]

Comparative Example 2 240 g of crude tara gum was dispersed in 20 liters of water and dissolved by stirring at 85 ° C. for 1 hour. Next, this solution was treated in the same manner as in Example 1 to adjust the pH of the solution to 5.8. Table 1 shows the change in viscosity of this solution when allowed to stand at 40 ° C. Next, this solution was treated in the same manner as in Example 1 to obtain purified tara gum. Aqueous solution viscosity (2
5 ° C.) was 2700 cps.

Claims (2)

[Claims] 1. A method for producing purified galactomannan, which comprises removing insoluble substances by filtration from an aqueous solution obtained by adding a monosaccharide to crude galactomannan, and recovering galactomannan from the filtrate. 2. The method for producing purified galactomannan according to claim 1, wherein the monosaccharide is at least one selected from arabinose, xylose, fructose, galactose, glucose and mannose.