JP2013079217A - Oligoglucosamine that has reduced browning and method of manufacturing the oligoglucosamine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide oligoglucosamine in which mass production can be facilitated, and browning is reduced compared with past oligoglucosamine, and to provide a method of manufacturing the oligoglucosamine.SOLUTION: In steps of manufacturing oligoglucosamine, the pH is regulated to 3.5-4.5 after the dissolving, thereby the oligoglucosamine in which browning is controlled and that has high purity compared with a conventional oligoglucosamine is manufactured, and thereby the problem has been solved.

Description

  The present invention relates to oligoglucosamine with reduced browning and a method for producing the oligoglucosamine.

(Glucosamine)
Glucosamine is a kind of hexosamine produced by hydrolyzing chitin and is a typical natural amino sugar.
Glucosami is generally produced using crab and shrimp shells as raw materials. First, the shell is decalcified with dilute hydrochloric acid aqueous solution and then deproteinized with dilute sodium hydroxide aqueous solution to obtain chitin. Furthermore, chitin can be hydrolyzed with concentrated aqueous hydrochloric acid and then purified to obtain the desired glucosamine.
In addition, oligoglucosamine means that about 2 to 10 glucosamines are polymerized.

  Glucosamine is a constituent sugar of glucosaminoglycan. Glucosaminoglycan is basically a polymer in which glucosamine and glucuronic acid or their isomers galactosamine and iduronic acid are repeated in pairs. This glucosaminoglucan is a proteoglycan that is one of the glycoproteins combined with the core protein. It forms aggregates such as chondroitin sulfate, keratan sulfate, heparin, heparan sulfate, and dermatan sulfate with hyaluronic acid as the axis. It contributes to the strength, flexibility, and elasticity of each organ in combination with collagen fibers, water, etc. in cartilage and cartilage.

Glucosamine, especially oligoglucosamine, not only becomes a component of cartilage, but also has an anti-inflammatory effect via neutrophils and is effective for arthritis, improves blood fluidity, suppresses platelet function and promotes proteloglycan synthesis. Possible skin beautification is recognized.
In particular, the effect of improving blood flow has been confirmed in a short time by ingesting glucosamine orally to a subject (see Non-Patent Document 1).

(N-acetylglucosamine)
The present applicant has succeeded in obtaining a high-purity N-acetylglucosamine crystal by hydrolyzing chitin obtained through an alkali deproteinization step and an acid decalcification step with concentrated hydrochloric acid (see : Patent Document 1). However, the N-acetylglucosamine is almost white, but browning could not be sufficiently suppressed (see paragraph 0016 of Patent Document 1).
In addition, the powder appearance shape of glucosamine is a white crystal. However, the powder appearance shape of conventional oligoglucosamine is light yellow to light brown (see: Table 9 of Non-Patent Document 2).

As described above, glucosamine, particularly oligoglucosamine, is often taken orally as a product in the cosmetics field, food field, medical field, and health food field.
Ingestion of oligoglucosamine with browning does not adversely affect the human body, but gives the impression that the quality of the oligoglucosamine has deteriorated.

(Browning suppression method)
In the food field, several methods for suppressing browning have been reported (Patent Documents 2 to 4).
However, there is no disclosure of a method for producing glucosamine, particularly oligoglucosamine with reduced browning that allows mass production.
Patent Document 4 discloses “a method for suppressing browning of food (soy milk processed beverage) containing reducing sugar (xylo-oligosaccharide) and protein, and preventing browning by reducing the pH of the soy milk processed beverage to 5.5 or less”. doing. Therefore, it is clearly different from the oligoglucosamine of the present invention in which browning is reduced.

JP 2009-167140 A JP 2007-510431 A Japanese Patent Laid-Open No. 9-9862 JP 2006-280274 A

Japanese Journal of Inflammation and Regenerative Medicine 23 (3) 164-169 (2003) New food material effective utilization technology series No.1

  An object of the present invention is to solve the above-described problems. More specifically, an object to be solved is to provide an oligoglucosamine which can be easily mass-produced and has reduced browning as compared with conventional oligoglucosamine and a method for producing the oligoglucosamine.

  In the production process of oligoglucosamine, the inventors adjust the pH to 3.5 to 4.5 after dissolution, thereby suppressing browning and producing high-purity oligoglucosamine compared to conventional oligoglucosamine. The present invention was completed successfully.

That is, the present invention is as follows.
“1. Production method of oligoglucosamine including the following steps:
(1) A step of preparing a 1 to 20% by weight chitosan dispersion;
(2) adding 5.0 to 40.0% acid to the solution of (1) above;
(3) A step of adding chitosanase to the solution of (2) above;
(4) adjusting the solution of (3) above to pH 3.5-4.5;
(5) The process of heating the solution of said (4) at 50-85 degreeC;
(6) A step of drying the solution of (5) above.
2. The method for producing oligoglucosamine according to item 1, further comprising a concentration step after the heating step (5).
3. 3. The method for producing oligoglucosamine according to item 1 or 2, comprising a step of adding activated carbon to 1.0 to 15.0 (w / w)% after the heating step of (5) or before the concentration step. .
4). Oligoglucosamine obtained by the production method according to any one of items 1 to 3.
5. 5. Oligoglucosamine according to item 4 above, wherein the color difference L value is 60 to 100 and / or the color difference WB value is 15 to 100.
6. The oligoglucosamine according to item 4 or 5, wherein the ratio of 1 to 6 sugars to the total sugars is 80 to 98% and / or the ratio of 1 to 8 sugars to the total sugars is 83 to 100%. "

  The oligoglucosamine obtained by the production method of the present invention can be easily mass-produced, has browning suppressed, and has a high purity.

Production example of oligoglucosamine of the present invention Color difference measurement results and sugar composition ratio results for each oligoglucosamine Relationship between added amount of activated carbon and absorbance (decolorization) in 10% oligoglucosamine solution Relationship between activated carbon addition and Brix in 10% oligoglucosamine solution

(Oligoglucosamine with reduced browning and high purity)
The oligoglucosamine of the present invention is less browned than the conventional oligoglucosamine. Specifically, the L value of the color difference of the oligoglucosamine with reduced browning of the present invention is 60 to 100, preferably 70 to 98, more preferably 85 to 96, and / or the WB value of the color difference is 15 to 100. , Preferably 30 to 90, more preferably 50 to 80.
In addition, the oligoglucosamine of the present invention is higher in purity than conventional oligoglucosamine. Specifically, the ratio of 1-6 sugars to total sugars is 80-98%, preferably 81-96%, and / or the ratio of 1-8 sugars to total sugars is 83-100%, preferably Is 85-100%.
In addition, regarding the molecular weight of oligoglucosamine, in general, the weight average molecular weight (calculated by GPC molecular weight measurement using pullulan as a standard product) is 1200 to 2500, preferably 1400 to 2400, more preferably Is 1500 to 2300, and in the case of Mn, it is 350 to 900, preferably 400 to 850, more preferably 500 to 800.
In addition, the viscosity of the 0.5% W / W solution viscosity at 20 ° C. is 20 to 300 mPa · s, more preferably 30 to 250 mPa · s, and further preferably 35 to 200 mPa · s.

(Browning)
Browning generally means that foods turn brown during processing and storage, and is broadly divided into enzymatic browning and non-enzymatic browning, the latter being browning when sugars are heated alone. Some caramelizations and aminocarbonyl reactions, which are chemical reactions that occur between amino compounds and carbonyl compounds, are included.

(Production method of oligoglucosamine with reduced browning and high purity)
The method for producing oligoglucosamine with reduced browning according to the present invention is described below. However, other than adjusting the pH to 3.5 to 4.5 after the dissolution step, it can be changed or omitted as appropriate.
(1) Preparation of chitosan dispersion (2) Dissolution step (3) Enzyme reaction step (4) Adjustment step to pH 3.5 to 4.5 (5) Enzyme deactivation step (6) Activated carbon treatment step (7) Concentration step (8 ) Drying process

(Chitosan used)
The deacetylation rate of chitosan to be used is generally about 70 to 100%, preferably 80 to 100%. Further, those having a weight average molecular weight (calculated by GPC molecular weight measurement using pullulan as a standard product) of about 10,000 to 4,000,000 are used, preferably 3 million or less, more preferably 2 million or less.
The viscosity of the 0.5% W / W solution viscosity at 20 ° C. is 10 to 300 mPa · s, more preferably 250 mPa · s or less, and further preferably 200 mPa · s or less.

(1) Preparation of chitosan dispersion
In order to prepare a 1 to 20% by weight chitosan dispersion, chitosan is suspended in water, preferably pure water or RO water, to prepare a chitosan dispersion.

(2) Dissolution process
5.0-40.0% acid, preferably hydrochloric acid (35% concentrated hydrochloric acid) is added to the chitosan dispersion of (1) above to dissolve the chitosan in the solution. The amount of hydrochloric acid added is 0.3 to 1.0 mol, preferably 0.4 to 0.9 mol, more preferably 0.5 to 0.8 mol, and the pH of the solution is adjusted to 4.0 to 6.0 with respect to 1 mol of the amino group of chitosan. To do. In this step, chitosan may not be completely dissolved.

(3) Enzyme reaction step In order to decompose chitosan into oligosaccharides, chitosanase is added to the solution after the dissolution step (2). The enzyme reaction time is 4 to 60 hours, and the enzyme reaction temperature is 20 to 45 ° C.
Preferably, the enzyme reaction is carried out while adjusting the pH during the enzyme reaction to 4.5 to 6.0 with hydrochloric acid, preferably 2N hydrochloric acid.
In addition, the addition amount of chitosanase is 5 units per 1 g of a predetermined amount of chitosan. Chitosanase may be added in multiple portions as necessary. In addition, impurities may be removed by performing filtration after completion of the enzyme reaction.

(4) Adjustment step to pH 3.5 to 4.5 Hydrochloric acid, preferably 2N hydrochloric acid, is dropped into the solution after completion of the enzyme reaction of (3) above to adjust to pH 3.5 to 4.5, preferably pH 4.0 to 4.5. To do. In addition, even if it heats a solution by the enzyme deactivation process which is a post process by the process adjusted to this pH 3.5-4.5, browning of oligoglucosamine can be reduced.

(5) Enzyme deactivation step In order to deactivate the enzyme in the solution adjusted to pH 3.5 to 4.5, the solution is heated at 70 to 100 ° C for 10 to 60 minutes. Further, preferably, impurities are removed by performing filtration after completion of heating.

(6) Activated carbon treatment step Preferably, activated carbon is added to the solution after the enzyme deactivation in (5) above. In addition, browning can be reduced more by combining the activated carbon treatment process with pH 3.5-4.5 rather than the adjustment process alone. Further, after completion of the activated carbon treatment step, impurities are removed by filtration.

(7) Concentration step The solution is concentrated for the purpose of efficient drying or to obtain a powder having the desired bulk specific gravity. Therefore, the oligoglucosamine can be powdered without performing this step. The solution is concentrated under reduced pressure using a general evaporator or concentrator.

(8) Drying step Oligoglucosamine powder can be obtained by drying using a drying apparatus such as spray drying or freeze dryer.

  The measuring method of each concentration used in the present invention is as follows. It was also used in the following examples.

(Measurement method of color difference)
The color difference measurement conditions and apparatus used in the present invention are as follows.
Place an O cap on the sample stage, block out the external light, perform zero alignment, and then place a standard white plate on the sample stage to perform standard alignment. Place the oligoglucosamine sample in a φ30 round cell, place it on the sample stage, and measure the color difference.
Color difference measurement condition: Powder reflection measurement Sample type: Powder Sample area: 30mmφ
Sample stand: Powder paste sample stand + round cell O-cap Standard: Standard white plate Color difference measuring device: Colorimetric color difference meter ZE-2000 (Nippon Denshoku Industries Co., Ltd.)

(Measurement method of Brix)
The Brix measurement conditions and measurement apparatus used in the present invention are as follows.
Wipe the prism surface cleanly, apply tap water, distilled water, ion-exchanged water or ultrapure water so that the prism surface is completely covered, and perform zeroing. Wipe clean with tissue paper, apply the sample solution onto the prism surface, and perform Brix measurement.
Color difference measurement conditions: Measurement range: Brix 0.0-45.0%
Measurement temperature: 5-40 ℃ automatic temperature correction
Environmental temperature: 5 ~ 40 ℃
Color difference measuring device: Digital saccharimeter (concentration meter) palette PR-101α (manufactured by Atago Co., Ltd.)

(Measurement method of absorbance)
The absorbance measurement conditions and measurement apparatus used in the present invention are as follows.
Put a blank sample (pure water or ultrapure water) into a 1cm cell and perform zero adjustment. Thereafter, the oligoglucosamine solution sample is put into a 1 cm cell, and the absorbance at 420 nm is measured.
Absorbance measurement conditions: Measurement wavelength: 420 nm
Light source: WI lamp
Cell length: 1cm cell Absorbance measuring device: U-2900 spectrophotometer (manufactured by HITACHI)

(Measurement method of degree of deacetylation)
Deacetylation degree (DAC degree) is obtained by dissolving a chitosan sample (amorphous chitin or chitosan) in 0.5% (w / w) acetic acid solution to 0.5% (w / w), and toluidine blue solution as an indicator The colloidal titration with an aqueous polyvinyl potassium sulfate solution was used to determine the DAC degree per dry matter.

(Measurement method of viscosity)
Viscosity is obtained by dissolving a chitosan sample (amorphous chitin or chitosan) in 0.5% (w / w) acetic acid solution to 0.5% (w / w), stirring at room temperature for 3 hours, and further using a homogenizer for 2 minutes. Stir. The rotational viscosity (mPa · s) was measured with a B-type viscometer while keeping this solution at 20 ° C. in a thermostatic bath.

(Classification of chitin and chitosan)
In the present invention, the characteristics of each chitosan are expressed as follows.
FM means medium viscosity chitosan (DAC degree 85% or more, 0.5% viscosity 10 to 100 mPa · s).
DAC100 means chitosan (DAC degree 95% or more, 0.5% viscosity 100 mPa · s or less).

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the scope of the present invention is not limited by these Examples.

(Production of oligoglucosamine of the present invention)
The oligoglucosamine of the present invention used in the following examples was produced. The manufacturing method is as follows.

1. Production Example 1 (Lot.1103151)
200 g of DAC 100% chitosan (Lot. No.0715-22) was added to 1800 g of pure water to prepare a 10.0% chitosan dispersion, which was sufficiently stirred with a homogenizer.
Next, 90.6 g of 35% HCl was added to the solution followed by 2 g of chitosanase L (from HBI).
Calculation of the amount of HCI added is as follows.
“Calculation of HCl amount: 0.7 mol of HCl is added to 1 mol of amino group of chitosan (DAC100): DAC100 amount (200 g) / chitosan 1 unit molecular weight (161) × hydrochloric acid molecular weight (36.5) / concentrated hydrochloric acid concentration (35% ) = 200g / 161 × 0.7 × 36.5 / 0.35 = 90.6 ”
Calculation of the amount of added chitosanase L is as follows.
“The predetermined amount of chitosanase L is 5 units to chitosan (g). The enzymatic degradation capacity of chitosanase L is 250 units / g. Therefore, the calculation of the predetermined amount of enzyme is 200 g × 5 units / 250 units / g = 4g (predetermined amount) Note that a predetermined half amount is added. "
Next, 2N HCI was added to the solution to pH 5.33 and stirred most at 40 ° C. (pH 5.62 after completion of stirring). In addition, 2N HCI was added to the solution to pH 5.22.
Next, 2 g of chitosanase L (manufactured by HBI) was added, and enzymatic degradation was performed at 40 ° C. for 26 hours.
Next, the enzyme-decomposed solution was filtered with a filter (ADVANTEC, No. 2).
Next, pH 5.62 of the solution after filtration was adjusted to pH 4.2 by adding 2NHCI.
Next, in order to inactivate the enzyme, the pH adjusted solution was heated at 80 ° C. for 20 minutes.
Next, activated carbon (Carborafin EX) was added to the heated solution (added so as to be 0.25% by weight).
Next, the activated carbon-added solution was stirred for 30 minutes and filtered with a membrane filter (ADVANTEC, A045A047A, 0.45 μm).
Finally, the solution after filtration was spray-dried to obtain oligoglucosamine (yield: 168.8 g, yield: 105.5%).

2. Production Example 2 (Lot. 110301)
450 g of DAC 100% chitosan (Lot. No.0715-22) was added to 3050 g of pure water to prepare a 12.5% chitosan dispersion.
Next, 180 g of 35% HCl, followed by 9 g of chitosanase L (HBI) were added to the solution and stirred. Further, 500 g of pure water was added to make a 10% solution.
Next, enzymatic degradation (pH adjustment, 35% HCl) was performed in a bioreactor (desktop culture device MD-N type 10 L, manufactured by Maruhishi Bioengineering Co., Ltd.) at 40 ° C. for 29 hours. Furthermore, 9 g of chitosanase L (manufactured by HBI) was added, and enzymatic degradation (pH adjustment, 2NHCl) was performed at 40 ° C. for 16 hours.
Next, the enzyme-decomposed solution was filtered with a filter (ADVANTEC, No. 2).
Next, pH 4.81 of the solution after filtration was adjusted with 2NHCI to pH 4.2.
Next, in order to inactivate the enzyme, the pH adjusted solution was heated at 80 ° C. for 20 minutes.
Next, activated carbon (purified white lees) was added to the heated solution (added so as to be 0.25% by weight).
Next, the activated carbon-added solution was stirred for 30 minutes and filtered with a membrane filter (ADVANTEC, A045A047A, 0.45 μm).
Finally, the solution after filtration was spray-dried to obtain oligoglucosamine (yield: 423.8 g, yield: 94.2%).

3. Production Example 3 (Lot. 1104081)
A 100% DAC of chitosan (Lot. No.0715-22) 140 g was added to 6860 g of pure water to prepare a 2% chitosan dispersion.
Next, 35% HCl was added to the solution to adjust the pH to 5.54.
Next, 2.8 g of chitosanase L (manufactured by HBI) was added to the pH-adjusted solution, and enzymatic degradation was performed at 40 ° C. for 6 hours.
Next, the enzyme-decomposed solution was filtered with a filter (ADVANTEC, No. 2). The pH of the solution after filtration was 5.63.
Next, pH 5.63 of the solution after filtration was adjusted with 2NHCI (addition amount was 56 ml) to pH 4.2.
Next, in order to inactivate the enzyme, the pH adjusted solution was heated at 75 ° C. for 20 minutes.
Next, 5000 ml of the solution after enzyme inactivation was filtered with a membrane filter 0.45 μm.
Next, the solution after filtration was concentrated with an evaporator to obtain a concentrate.
The concentrate was then sterilized at 75 ° C. for 20 minutes.
Finally, the concentrate after sterilization was spray-dried to obtain oligoglucosamine (yield: 104 g, yield: 104%).

4). Production Example 4 (Lot. 1104082)
A 100% DAC of chitosan (Lot. No.0715-22) 140 g was added to 6860 g of pure water to prepare a 2% chitosan dispersion.
Next, 35% HCl was added to the solution to adjust the pH to 5.54.
Next, 2.8 g of chitosanase L (manufactured by HBI) was added to the pH-adjusted solution, and enzymatic degradation was performed at 40 ° C. for 6 hours.
Next, the enzyme-decomposed solution was filtered with a filter (ADVANTEC, No. 2). The pH of the solution after filtration was 5.63.
Next, pH 5.63 of the solution after filtration was adjusted with 2NHCI (addition amount was 56 ml) to pH 4.2.
Next, in order to inactivate the enzyme, the pH adjusted solution was heated at 75 ° C. for 20 minutes.
Next, activated carbon (purified white lees) was added to 2000 ml of the solution after enzyme deactivation (added so as to be 0.25% by weight).
Next, the activated carbon-added solution was stirred for 30 minutes and filtered through a membrane filter 0.45 μm.
Next, the solution after filtration was concentrated with an evaporator to obtain a concentrate.
The concentrate was then sterilized at 75 ° C. for 20 minutes.
Finally, the concentrate after sterilization was spray-dried to obtain oligoglucosamine (yield: 24 g, yield: 60%).

  Production Example 5 (1103152), Production Example 6 (1103231), Production Example 7 (1103232), and Production Example 8 (1103233) other than the above are shown in FIG.

(Manufacture of conventional oligoglucosamine)
A conventional oligoglucosamine used in the following examples was produced. In the production, the step of adjusting the pH to 4.0 to 4.5 is not performed. The manufacturing method is as follows.

Existing oligoglucosamine (Lot.No.100807)
150% DAC 100% chitosan was added to 7000 L of RO water to prepare a 2% chitosan dispersion.
Next, 35% HCl was added to the solution to adjust the pH to 5.2-5.6.
Next, 3.0 kg of chitosanase L (manufactured by HBI) (5 units per g of chitosan) was added to the pH-adjusted solution, and enzymatic degradation was performed at 40 ° C. for 6 hours.
Next, in order to inactivate the enzyme, the enzyme-decomposed solution was heated at 70 ° C. for 20 minutes.
Next, the enzyme-deactivated solution was filtered with a filtration filter press (pickled diatomaceous earth 120 kg, precoat 2 types each 40 kg, body feed 1 type 40 kg).
Next, the filtered solution was concentrated with an evaporator to obtain a concentrated solution.
The concentrated solution was then filtered through 60 mesh.
The filtered solution was then sterilized at 75 ° C. for 20 minutes.
Finally, the concentrate after sterilization was spray-dried to obtain oligoglucosamine.

(Measure color difference of oligoglucosamine)
The color difference of each oligoglucosamine produced in Example 1 was measured. The color difference measurement results are shown in FIG. In addition, oligoglucosamine whose pH was adjusted to 3.5 was subjected to the same color difference measurement (not shown).
It confirmed that the oligoglucosamine of the manufacture examples 1-8 which adjusted pH to 3.5-4.5 after the melt | dissolution process was able to suppress browning compared with the oligoglucosamine which was not adjusting pH after the conventional melt | dissolution process. Moreover, compared with the oligoglucosamine of manufacture example 3, the oligoglucosamine of manufacture example 4 confirmed that browning could be suppressed further.
In addition, it was confirmed that browning can be suppressed by not performing the concentration step (not applying heat) by setting the initial concentration of chitosan to 10%.
As described above, in the oligoglucosamine production process, the browning of oligoglucosamine can be suppressed by including the step of adjusting the pH to 3.5 to 4.5 and / or the activated carbon treatment step after the dissolution step.

(Measurement of sugar composition ratio of oligoglucosamine)
The method for measuring the sugar composition ratio of oligoglucosamine is as follows.
About 20 mg of chitosan oligosaccharide mixture (manufactured by Biochemical Biotechnology) was weighed, dissolved by adding 1 ml of water, and filtered through a 0.45 μm filter to obtain a standard solution.
The sample is dried at 105 ° C. for 3 hours, 20 mg is weighed, 1 ml of water is added to dissolve, and the solution is filtered through a 0.45 μm filter (ADVANTEC, DISMIC) to obtain a test solution.
Furthermore, HPLC analysis was performed under the following conditions.
<Analysis conditions>
Column: TSK-GEL AMIDE-80 4.6 × 250mm
Mobile phase: Acetonitrile / 250 mM phosphate buffer = 2/3
Flow rate: 0.8ml / min
Temperature: Room temperature Injection volume: 20μl
Detector: Differential refractometer Device: LC-20A manufactured by Shimadzu Corporation or liquid chromatography manufactured by JASCO Corporation <Calculation method>
The peak areas of the oligoglucosamine of each degree of polymerization of the test solution and the standard solution are measured, the content is obtained by the following formula 1, and 1 to 8 sugars are added to obtain the content. In addition, about 7 sugar and 8 sugar, it computed from the standard peak of 6 sugars.

The sugar composition ratio of each oligoglucosamine produced in Example 1 was measured. The measurement result of the sugar composition ratio is shown in FIG.
The oligoglucosamines of Production Examples 1 to 8 whose pH was adjusted to 3.5 to 4.5 after the dissolution step were compared with the ratio of 1 to 6 sugars relative to the total sugar and / or the oligoglucosamine whose pH was not adjusted after the conventional dissolution step. Alternatively, it was confirmed that the ratio of 1 to 8 sugars to the total sugars was high. That is, it was confirmed that the oligoglucosamine of the present invention is higher in purity than the conventional oligoglucosamine.
In addition, the reason for the high purity is the newly found that by adjusting the pH to 3.5 to 4.5 after the dissolution process, it is possible to prevent a decrease in purity in the enzyme deactivation process, concentration process and sterilization process during the manufacturing process. ing.
As described above, oligoglucosamine with reduced browning has a higher ratio of 1-6 sugars to total sugars and / or a ratio of 1-8 sugars to total sugars than conventional oligoglucosamines.

(Examination of the amount of activated carbon added)
The optimum amount of activated carbon added in the production of oligoglucosamine was investigated. Details are as follows.

10 (w / w)% chitosan was dissolved in hydrochloric acid, chitosanase was added, enzymatic decomposition was performed, filtration was performed, and pH was adjusted (4.2) to obtain a 10% oligoglucosamine solution.
After adding 0.025% to 10% activated carbon (purified birch) to the total amount of the solution and stirring at room temperature for 30 minutes, absorbance (Abs. 420 nm) and Brix were measured.
In addition, activated carbon was added in a ratio with respect to the total amount (g) of 10% oligoglucosamine solution as the amount of activated carbon added (%).

FIG. 3 shows the relationship between the amount of activated carbon added and the absorbance (decolorization) in a 10% oligoglucosamine solution.
The absorbance (Abs. 420 nm) decreased according to the amount of activated carbon added, but the amount of decrease in absorbance also decreased in proportion to the increase in the amount added.
Moreover, even if the addition amount of activated carbon was performed once or divided into two steps, if the total amount of addition was the same, no significant change was observed in the absorbance.
FIG. 4 shows the relationship between the amount of activated carbon added to the 10% oligoglucosamine solution and Brix.
Birx decreased according to the amount of activated carbon added.
Based on the above, it was specified that the optimum addition amount of activated carbon in the production of oligoglucosamine was 1.0 to 15.0 (w / w)% of the chitosan dispersion.

  INDUSTRIAL APPLICABILITY The present invention can provide oligoglucosamine that can be easily mass-produced, has browning suppressed, and has high purity.

Claims (6)

A method for producing oligoglucosamine comprising the following steps:
(1) A step of preparing a 1 to 20% by weight chitosan dispersion;
(2) adding 5.0 to 40.0% acid to the solution of (1) above;
(3) A step of adding chitosanase to the solution of (2) above;
(4) adjusting the solution of (3) above to pH 3.5-4.5;
(5) The process of heating the solution of said (4) at 50-85 degreeC;
(6) A step of drying the solution of (5) above.   The method for producing oligoglucosamine according to claim 1, further comprising a concentration step after the heating step (5).   The production of oligoglucosamine according to claim 1 or 2, comprising a step of adding activated carbon to 1.0 to 15.0 (w / w)% after the heating step (5) or before the concentration step. Method.   The oligoglucosamine obtained with the manufacturing method of any one of Claims 1-3. The oligoglucosamine according to claim 4, wherein the L value of the color difference is 60 to 100 and / or the WB value of the color difference is 15 to 100. The oligoglucosamine according to claim 4 or 5, wherein the ratio of 1-6 sugars to total sugars is 80-98% and / or the ratio of 1-8 sugars to total sugars is 83-100%.