JP2001017978A - Production of partial hydrolyzate of organic matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration due to secondary hydrolysis and to minimize the contamination of a dialyzate with bacteria by deacidifying an acid- contg. partial hydrolyzate obtained by partially hydrolyzing org. matter with an acid by the use of an ion-exchange membrane electrodialyzer circulating an alkali soln. as a liq. concentrate. SOLUTION: An acid-contg. partial hydrolyzate obtained by partially hydrolyzing org. matter is deacidified as such by using an ion-exchange membrane electrodialyzer 1 circulating an alkali soln. as a liq. concentrate while omitting a stage for neutralizing the acid. For example, as the org. matter, chitin is used when N-acetylchitooligosaccharide is produced, and silk protein is used when silk peptide is produced. Hydrochloric acid, sulfuric acid and especially concd. hydrochloric acid are preferably used as the acid for partial hydrolysis. The degree of partial hydrolysis is appropriately determined in accordance with the use of an object. Further, enzymes, or the like are allowed to act on the obtained partial hydrolyzate if necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a partially hydrolyzed organic substance obtained by partially hydrolyzing an organic substance using an acid such as hydrochloric acid, and more particularly, to chitin or silk protein (silk). A partially hydrolyzed solution of an organic substance such as N-acetylchitooligosaccharide or silk peptide, which is subjected to a deacidification treatment using an ion exchange membrane electrodialysis device. .

[0002]

2. Description of the Related Art N-acetylchitooligosaccharides are oligosaccharides in which two to seven N-acetyl-D-glucosamines are linked by β-1,4 bonds, and have been conventionally used in crustaceans such as crab, shrimp and krill. It is known that it can be obtained by partially hydrolyzing the contained polysaccharide chitin. In addition, similar to fructooligosaccharides and maltooligosaccharides, they are expected to be used as growth promoting factors for bifidobacteria and low-tasting sweeteners. As a method for producing such an N-acetylchitooligosaccharide, the following methods have been conventionally known.

Japanese Patent Application Laid-Open No. Hei 5-320204 discloses an N-
As a method for producing acetyl-chitooligosaccharide, chitosan is decomposed with a chitosanase produced by Bacillus, and the obtained chitooligosaccharide is N-degraded with an acylating agent such as acetic anhydride.
Methods for acetylating and purifying N-acetylchitooligosaccharides using electrodialysis have been described. In this method, chitosan obtained by deacetylating chitin is used as a raw material, chitooligosaccharide is produced by using an enzyme, and the obtained chitooligosaccharide is subjected to a chemical reaction again using an acylating agent such as acetic anhydride and a chemical reaction. This is a method of synthesizing acetylchitooligosaccharides and removing salts by-produced by the synthesis by electrodialysis. However, it can be said that this method is not preferable for use in food applications.

Japanese Patent Publication No. 5-86399 discloses that chitin is partially hydrolyzed with an acid, neutralized with an alkali, and the by-product salt in the neutralized solution is desalted by ion exchange membrane electrodialysis. After that, it is treated with ion exchange resin, dried and powdered.
-A method for producing acetylchitooligosaccharides is described.
In this method, chitin is partially hydrolyzed with an acid and then neutralized with an alkali.However, even if the neutralization reaction is carried out while cooling, it neutralizes the excess acid remaining after the partial hydrolysis. The temperature rise due to the heat of neutralization generated at the time is remarkable, and secondary heat and neutralization of N-
There has been a problem that deacetylation due to partial contact between acetyl-chitooligosaccharide and alkali and decomposition of sugar to produce a colored substance.

[0005] JP-A-2-177864 describes a food containing a hydrolyzate obtained by hydrolyzing silk protein with a strong acid, a strong alkali, or a proteolytic enzyme, and a method for producing the same. This Japanese Patent Laid-Open No. 2-17
As a specific example of hydrolysis using an acid in JP 7864, after adding phosphoric acid to an aqueous solution of silk fibroin and hydrolyzing it, neutralizing it with calcium hydroxide, and filtering off a white precipitate formed, , Freeze-dried to obtain a white powder, but the insoluble calcium phosphate, which is a neutralized salt formed, cannot be completely removed by filtration, and this white powder contains calcium phosphate .

Further, conventionally, as described above, a desalination treatment from a solution of an organic substance or the like is performed through a plurality of cation exchange membranes and anion exchange membranes provided alternately between an anode and a cathode. It is common to use an ion-exchange membrane electrodialysis apparatus that energizes a DC power supply while circulating the liquid to be treated and the concentrate in an ion-exchange membrane dialysis tank that has a liquid-to-be-treated (diluted solution) circulation chamber and a concentrated liquid circulation chamber. Are known. It has also been known that an organic solution and an acid are separated using such an ion exchange membrane electrodialysis apparatus or an electrodialysis apparatus using only an anion exchange membrane.

[0007]

An object of the present invention is to provide an organic substance such as N-acetylchitooligosaccharide or silk peptide formed by partially hydrolyzing an organic substance such as chitin or silk protein using an acid such as hydrochloric acid. The step of neutralizing the acid is omitted from the acid-containing partial hydrolyzate, and the dehydrogenation treatment is performed as it is to prevent deterioration in quality due to secondary hydrolysis due to heat of neutralization and the like. An object of the present invention is to provide a method for producing a partial hydrolyzate of an organic substance such as N-acetylchitooligosaccharide or silk peptide, which can minimize bacterial contamination that occurs.

[0008]

Means for Solving the Problems In producing N-acetylchitooligosaccharides, the present inventors have used a conventional method, that is, chitin is partially hydrolyzed with hydrochloric acid, neutralized with an alkali, and a by-product salt is produced. Was attempted using an ion-exchange membrane electrodialysis device. However, it was found that quality degradation such as secondary hydrolysis due to the heat of neutralization and bacterial contamination in the dialysate occurred. We tried to remove the acid by the ion exchange membrane electrodialysis method by omitting the summation process. However, unlike the removal of the neutralized salt, it was found that the dialysis efficiency gradually decreased even when the same voltage was applied. Was. Then, when electrodialysis was performed using an alkaline solution as a concentrate circulating in the ion exchange membrane electrodialysis tank, it was found that the dialysis efficiency was greatly improved. However, it was also found that there is a possibility that the stainless plate generally used for the cathode is corroded and deteriorated by acid, and that the anion exchange membrane may be deteriorated by strong alkali.

Therefore, when an alkaline solution is used as a concentrate circulating in the ion exchange membrane electrodialysis tank and electrodialysis is performed while controlling the pH of the concentrate, the dialysis efficiency does not decrease, and the electrode and the ion exchange membrane are not degraded. It has been found that a partial hydrolyzate of organic substances such as N-acetyl-chitooligosaccharides and silk peptides having a good composition and excellent microbiological contamination can be obtained without deteriorating erosion of the present invention. It was completed.

That is, the present invention provides an ion exchange membrane which circulates an alkaline solution as a concentrate to an acid-containing partial hydrolyzate obtained by partially hydrolyzing an organic substance such as chitin or silk with an acid such as hydrochloric acid. N-acetyl-chitooligosaccharide or silk, which is subjected to a deacidification treatment using an electrodialysis device or a deacidification treatment using an ion exchange membrane electrodialysis device while controlling the pH value of the concentrated solution. The present invention relates to a method for producing a partial hydrolyzate of an organic substance such as a peptide.

The present invention also relates to a method for producing a partial hydrolyzate of an organic substance as described above, wherein a plurality of cation exchange membranes and anion exchange membranes are used alternately as an ion exchange membrane electrodialysis apparatus. , PH value is controlled by the concentration of the concentrated solution (electrode solution) in the electrode solution tank and the pH of the concentrated solution in the concentrated solution tank
Based on the measured values, the method for producing the partial hydrolyzate of the organic substance, which is performed by automatically flowing the alkaline solution from the alkaline solution tank into the electrode solution tank and the concentrated solution tank,
The present invention relates to a method for producing a partial hydrolyzate of the organic substance having a pH value of 7 to 9.

Further, the present invention provides a method for producing a partial hydrolyzate of the organic substance using an ion exchange membrane electrodialysis apparatus provided with a plurality of anion exchange membranes, and a method for controlling a pH value by using a concentrated solution. (Anolyte) pH of concentrated solution in tank
Based on the measured values, the method for producing the partial hydrolyzate of the organic substance, which is performed by automatically flowing the alkaline solution from the alkaline solution tank into the electrode solution tank and the concentrated solution tank,
The control of the pH value is performed by automatically flowing the alkaline solution from the alkaline liquid tank into the pipe near the inlet of the cooler or near the upstream of the cooler based on the measured value of the pH downstream of the cooler. The method for producing the partial hydrolyzate of the organic substance, and the method for controlling the liquid temperature of the concentrated liquid by controlling the temperature of the condenser based on the measured value of the liquid temperature downstream of the cooler. The present invention relates to a production method and a method for producing a partial hydrolyzate of the organic substance having a pH value of 7 to 9.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION As an organic substance in the present invention,
Any organic substance that can be partially hydrolyzed by an acid may be used, and specific examples thereof include polysaccharides and proteins. For example, when N-acetylchitooligosaccharide is produced, poly-β-1,
Chitin having a 4-N-acetyl-D-glucosamine structure is used. Examples of such chitin include those obtained by decalcifying a shellfish exoskeleton as a raw material with a dilute acid, removing the protein with an alkali, washing with water, and drying. can do. In the case of producing a silk peptide, silk or silk protein obtained by removing insoluble components in a diluted alkaline solution from silk or silk is used as an organic substance.

In the present invention, the acid used for the partial hydrolysis may be an acid which can act on an organic substance such as chitin or silk protein to obtain a partial hydrolyzate such as N-acetylchitooligosaccharide or silk peptide. Although any acid can be used, preferred acids include hydrochloric acid and sulfuric acid, particularly concentrated hydrochloric acid. In addition, the degree of partial hydrolysis can be appropriately determined according to the use of the target substance. Further, the partial hydrolyzate obtained according to the present invention can be further reacted with an enzyme or the like, if necessary.

[0015] The ion exchange membrane electrodialysis apparatus used in the present invention is divided into an apparatus having a plurality of cation exchange membranes and an anion exchange membrane alternately and an apparatus having only a plurality of anion exchange membranes. First, an ion exchange membrane electrodialysis apparatus having a plurality of cation exchange membranes and anion exchange membranes alternately will be described with reference to FIG. 1, and then a plurality of anion exchange membranes will be described. An ion exchange membrane electrodialysis device having only a membrane will be described with reference to FIG. In addition,
In the present invention, a liquid containing an acid-containing partial hydrolyzate is referred to as a diluent, and a liquid that receives chloride ions or the like from the diluted liquid by electrodialysis is referred to as a concentrated liquid. May be included, in which case they may be referred to as a concentrated solution (electrode solution) and a concentrated solution (anolyte solution), respectively.

FIG. 1 shows an ion exchange membrane electrodialysis apparatus 1 having a plurality of cation exchange membranes C and anion exchange membranes A. This ion exchange membrane electrodialysis apparatus 1
Ion exchange membrane dialysis tank 2, DC power supply 3, electrode liquid tank 4, concentrate liquid tank 5, dilution liquid tank 6, alkaline liquid tank
, An alkaline liquid automatic injection electromagnetic valve 8, a pH controller 9, a pipe 10 connecting the tanks, and a pipe 10 downstream of the electrode liquid tank 4, the concentrated liquid tank 5, and the dilution liquid tank 6. It comprises three circulation pumps 11 and a concentrated liquid cooler 12 provided downstream of the concentrated liquid tank 5, of which the alkaline liquid tank 7 newly installed by the present inventors and the alkaline liquid tank 7 are provided. Except for the liquid automatic injection electromagnetic valve 8, the pH controller 9, and the concentrated liquid cooler 12, a conventionally known ion exchange membrane electrodialysis apparatus can be used. Examples of the alkaline liquid include a caustic soda solution and a sodium carbonate solution.

The ion exchange membrane dialysis tank 2 includes a metal anode plate 13
From the starting point, the anolyte flow chamber 14, the anion exchange membrane A, the diluent flow chamber 15, the cation exchange membrane C, the concentrate flow chamber 1
6. Anion exchange membrane A, and in the following, a large number of flow chambers and ion exchange membranes are arbitrarily incorporated, and finally, cation exchange membrane C,
Catholyte flow chamber 17 and metal cathode plate 18 are combined in this order, and back plates (not shown) are attached to both ends, and are fastened so as not to leak liquid from the gap. An anode and a cathode of the DC power supply 3 are connected to the metal anode plate 13 and the metal cathode plate 18 of the ion exchange membrane dialysis tank 2, respectively.
A rectifier can be used as the DC power supply device 3. A platinum-plated titanium plate or a platinum-iridium-plated titanium plate is used as an anode. A stainless steel plate or a silver plate is used as a cathode in addition to the anode material. A plate or the like can be used. Further, as the cation exchange membrane C and the anion exchange membrane A, conventionally known ones can be used.

The electrode solution tank 4 is provided with a stirring means and a pH electrode 19 for measuring the pH of the electrolytic solution in the electrode solution tank 4. Based on the pH value measured by the pH electrode 19, the pH is measured. The controller 9 acts on the alkaline liquid automatic injection solenoid valve 8 provided between the alkaline liquid tank 7 such as a caustic soda solution and the electrode liquid tank 4 so that the pH value is set to a fixed value, for example, p.
When the H value drops to 7.0 or lower, preferably to pH 7.3, the alkaline liquid automatic injection solenoid valve 8 automatically opens, and an alkaline liquid such as a caustic soda solution flows into the electrode liquid tank 4 from the alkaline liquid tank 7. On the other hand, when the pH value rises to a certain set value, for example, pH 9.0 or more, preferably pH 8.5, the alkaline liquid automatic injection electromagnetic valve 8 closes, and the alkaline liquid from the alkaline liquid tank 7 to the electrode liquid tank 4 is discharged. The inflow stops. Further, between the electrode solution tank 4 and the ion exchange membrane dialysis tank 2, an ion exchange membrane dialysis tank 2 is provided.
The pipe 10 is disposed so that the concentrated solution (electrode solution) can flow into the anolyte flow chamber 14 and the catholyte flow chamber 17 by the circulation pump 11.
The pipe 10 is provided so that the concentrated solution (electrode solution) that has passed through 4 and the catholyte flow chamber 15 returns to the electrode solution tank 4 and can be circulated. It should be noted that an automatic alkaline liquid injection pump can be used instead of the automatic alkaline liquid electromagnetic valve 8.

As in the case of the electrode solution tank 4, the concentrating solution tank 5 is provided with a stirring means and a pH electrode 19 for measuring the pH of the electrolytic solution in the concentrating solution tank 5. The pH controller 9 acts on the alkaline liquid automatic injection solenoid valve 8 provided between the alkaline liquid tank 7 and the concentrated liquid tank 5 on the basis of the obtained pH value, so that the pH value is a fixed set value, for example, pH 7.0 or less, Preferably, when the pH is lowered to 7.3, the alkaline liquid automatic injection solenoid valve 8 is automatically opened, and the alkaline liquid flows from the alkaline liquid tank 7 into the concentrated liquid tank 5, and conversely, the pH value is kept constant. Set value, eg pH
When the pH rises to 9.0 or more, preferably to 8.5, the alkaline liquid automatic injection solenoid valve 8 closes, and the inflow of the alkaline liquid from the alkaline liquid tank 7 to the concentrated liquid tank 5 is stopped. In addition, piping is provided between the concentrate tank 5 and the ion exchange membrane dialysis tank 2 so that the concentrate can flow into the respective concentrate flow chambers 16 of the ion exchange membrane dialysis tank 2 by the circulation pump 11. 10 is provided, and a pipe 10 is provided so that the concentrated liquid that has passed through the concentrated liquid flow chamber 16 returns to the concentrated liquid tank 5 again and can be circulated.

The diluting liquid tank 6 contains a diluting liquid diluted after partial hydrolysis of an organic substance with an acid, and an ion exchange membrane is provided between the diluting liquid tank 6 and the ion exchange membrane dialysis tank 2. A pipe 10 is provided so that the diluent can flow into each diluent flow chamber 15 of the dialysis tank 2 by the circulation pump 11, and the diluent that has passed through the diluent flow chamber 15 is diluted again. A pipe 10 is provided so as to return to the tank 6 and circulate.

When the ion exchange membrane electrodialyzer 1 is started, for example, a caustic soda solution of 5 to 15 W / V% is put in the alkaline solution tank 7 and the electrode solution tank 4 and the concentrated solution tank 5 are provided respectively in them. Water is added until the liquid overflows from the overflow port, and the diluted liquid tank 6 is filled with the diluted liquid diluted after the partial hydrolysis of the organic matter with the acid, and then the three circulation pumps 11 are operated, and the concentrated liquid (electrode liquid) is turned on. ), The concentrated liquid and the diluted liquid are sent to the ion exchange membrane dialysis tank 2 and circulated between the tanks, and the water reduced by circulation is replenished to the electrode liquid tank 4 and the concentrated liquid tank 5 to near the overflow port, respectively. Then, the DC power supply 3 is adjusted to a constant voltage, current is supplied to the anode 13 and the cathode 18, and the deacidification treatment by dialysis is started. After the operation is started, the operation is stopped when the current hardly flows.

When the deoxidation treatment is started using the above-mentioned ion exchange membrane electrodialyzer 1, the partial hydrolyzate of an organic substance such as N-acetylchitooligosaccharide or silk peptide is a non-electrolyte, and the cation exchange membrane C or Although it cannot pass through the anion exchange membrane A, the hydrogen ions derived from the hydrochloric acid in the diluent pass through the cation exchange membrane C and move to the concentrate flow chamber 16 where they react with the hydroxyl ions therein. Then, chloride ions derived from hydrochloric acid in the dilute solution pass through the anion exchange membrane A and move to the concentrated solution flow chamber 16, where they undergo neutralization reaction with sodium ions therein to form sodium chloride. Heat is generated by these reactions, and the heat is generated in the concentrated solution flow chamber 16 where there is no partial hydrolyzate of an organic substance such as N-acetylchitooligosaccharide or silk peptide. Since the liquid is cooled by the concentrated liquid cooler 12 provided downstream of the concentrated liquid tank 5, partial hydrolysis of organic substances such as N-acetylchitooligosaccharides and silk peptides is caused by secondary heat by the heat of reaction. Does not undergo decomposition. Further, the pH of the diluting solution was strongly acidic while hydrochloric acid was present, and the residual amount of chloride ions was 0.08 g / 1.
When the volume reached 00 ml, the pH became about 3,
At 5.4 to 5.6, there is almost no change in pH, and the pH becomes 3
Is a short time that is less than 1/15 of the entire operation time, and the growth of bacteria during operation can be significantly suppressed. In addition, N-
Since acetyl-chitooligosaccharides and the like do not have any partial contact with an alkaline solution, there is no generation of colored substances due to deacetylation or sugar decomposition.

Next, an ion exchange membrane electrodialysis apparatus 31 having only a plurality of anion exchange membranes will be described with reference to FIG. This ion exchange membrane electrodialysis device 31
An anion exchange membrane dialysis tank 32, a DC power supply 33, a concentrate (anolyte) tank 34, a diluent tank 35, an alkaline liquid tank 36 such as a caustic soda solution, an automatic alkaline liquid injection solenoid valve 37, a pH controller 38, a pipe 39 connecting the tanks, a concentrate (anolyte) tank 34, and a diluent tank 35.
And a condenser cooler 41 provided downstream of the concentrate (anolyte) tank 34. Of these, the present invention Except for the alkaline liquid tank 36, the alkaline liquid automatic injection electromagnetic valve 37, the pH controller 38, and the concentrated liquid cooler 41 newly installed by the users, a conventionally known ion exchange membrane electrodialysis apparatus can be used.

The anion exchange membrane dialysis tank 32 has a metal anode plate 42 as a starting point, a concentrate (anolyte) flow chamber 43, an anion exchange membrane A, a diluent flow chamber 44, an anion exchange membrane A, a concentrate A flow chamber 45, an anion exchange membrane A, and a number of the flow chambers and the anion exchange membrane A are arbitrarily assembled in this order, and finally, an anion exchange membrane A, a diluent (catholyte) flow chamber 46, and a metal cathode plate 47. , And apply the back plate 48 to both ends,
It is tightened so that there is no liquid leakage from the gap. The anode and cathode of the DC power supply 33 are connected to the metal anode plate 42 and the metal cathode plate 47 of the anion exchange membrane dialysis tank 32, respectively.

The concentrate (anolyte) tank 34 is provided with stirring means and an electrode 49 for measuring the pH of the electrolyte in the concentrate (anolyte) tank 34. Based on the pH value, a pH controller 38 acts on an alkaline liquid automatic injection solenoid valve 37 provided between the alkaline liquid tank 36 and the concentrated liquid (anolyte) tank 34 so that the pH value is a fixed set value, for example, pH 7.0. Below, preferably pH 7.3
When the temperature drops to below, the alkaline liquid automatic injection solenoid valve 37 is automatically opened, and an alkaline liquid such as a caustic soda solution flows into the concentrated liquid (anolyte) tank 34 from the alkaline liquid tank 36, and conversely, the pH value Is a fixed set point, eg pH
When the pH rises to 9.0 or more, preferably to pH 8.5, the alkaline liquid automatic injection solenoid valve 37 closes, and the inflow of the alkaline liquid from the alkaline liquid tank 36 to the concentrated liquid (anolyte) tank 34 is stopped. . Further, between the concentrate (anolyte) tank 34 and the anion exchange membrane dialysis tank 32, a concentrate (anolyte) flow chamber 43 and a concentrate flow chamber 45 of the anion exchange membrane dialysis tank 32 are provided. A pipe 39 is provided so that the concentrated liquid can flow in by the circulation pump 40.
Also, the concentrate (anolyte) flow chamber 43 and the concentrate flow chamber 4
A pipe 39 is provided so that the concentrate passing through 5 returns to the concentrate (anolyte) tank 34 again and can be circulated. It should be noted that an automatic alkaline liquid injection pump can be used instead of the automatic alkaline liquid injection electromagnetic valve 37.

The diluent tank 35 contains a diluent diluted after partial hydrolysis of an organic substance with an acid. An anion exchange membrane is provided between the diluent tank 35 and the anion exchange membrane dialysis tank 32. The diluent is supplied to the diluent circulation chamber 44 and the diluent (catholyte) circulation chamber 46 of the exchange membrane
A pipe 39 is provided so that the liquid can flow in through the diluent flow chamber 44 and the catholyte flow chamber 4.
A pipe 39 is provided so that the diluent passing through 6 returns to the diluent tank 35 again and can be circulated.

The anode in the anion exchange membrane dialysis tank 32 includes a platinum plate, a platinum-plated titanium plate or a titanium mesh,
An iridium platinum-plated titanium plate, a titanium mesh, a carbon plate, or the like can be used. The cathode can be made of a good conductor and acid-resistant material such as a silver plate. Each liquid flow chamber in the anion exchange membrane dialysis tank 32 is formed by sticking a rubber plate to a hexagonally cut hard vinyl chloride plate so as to make the space area as large as possible so as to prevent leakage of the liquid. Can be manufactured. As the anion exchange membrane to be held between the rubber plates, a strongly basic anion exchange membrane, for example, Selemion “AMV” manufactured by Asahi Glass Co., Ltd. can be used. As the pipe 39, a soft vinyl chloride pipe or the like can be used.

At the start of the ion exchange membrane electrodialysis apparatus, for example, a caustic soda solution of 5 to 15 W / V% is put into the alkaline solution tank 36 and the concentrated solution (anolyte) solution tank 34 is filled with an overflow port provided therein. 0.2% until it overflows
The caustic soda solution is charged, the diluent tank 35 is filled with the diluent diluted after the partial hydrolysis treatment of the organic substance with the acid, and the two circulating pumps 40 are operated, and the concentrated liquid and the dilute liquid are subjected to anion exchange membrane dialysis. The solution is sent to the tank 32 and circulated between the tanks, and the concentrated liquid (anolyte) tank 34 is replenished with the 0.2% caustic soda solution reduced by circulation to the vicinity of the overflow port. The voltage is adjusted, current is supplied to the anode 42 and the cathode 47, and the deacidification treatment by dialysis is started. After the start of the operation, the operation is stopped after confirming that the pH of the diluent has risen from strongly acidic to about pH 6.5. Further, the operation may be stopped when the current hardly flows.

When the deoxidizing treatment is started using the ion exchange membrane electrodialyzer 31, the partial hydrolyzate of an organic substance such as N-acetylchitooligosaccharide or silk peptide is a non-electrolyte. Although it cannot pass through, chloride ions derived from hydrochloric acid in the dilute solution pass through the anion exchange membrane A and move to the concentrated solution flow chamber 45, where they undergo neutralization reaction with sodium ions therein to form sodium chloride. Then, the hydroxide ions in the concentrated solution pass through the anion exchange membrane A and move to the diluent flowing chamber 44, where they react with the hydrogen ions therein to become water. These reactions generate exotherms,
The place where heat is generated due to the neutralization reaction is in the concentrate flow chamber 45 where there is no partial hydrolyzate of organic matter such as N-acetylchitooligosaccharide or silk peptide. 34, it is cooled by the concentrated liquid cooler 41 provided downstream of
Partial hydrolysates of organic substances such as acetylchitooligosaccharides and silk peptides do not undergo secondary hydrolysis.
The pH of the diluted solution is strongly acidic while hydrochloric acid is present. When the residual amount of chloride ions becomes 0.08 g / 100 ml, the pH becomes about 3, and the pH is further reduced to 5.4 to 5.
6, the change in pH almost disappears, and the time when the pH reaches 3 to 5 or more is a short time that is less than 1/15 of the entire operation time, and the proliferation of bacteria during operation can be significantly suppressed. Furthermore, since N-acetylchitooligosaccharides and the like present in the diluted solution have no partial contact with the alkaline solution,
No colored substance is produced due to deacetylation or sugar decomposition.

In the concentrated solution tank 5 of the ion exchange membrane electrodialyzer 1 shown in FIG. 1 and in the concentrated solution (anolyte) tank 34 of the ion exchange membrane electrodialyzer 31 shown in FIG. Instead of controlling the pH value by stirring or the like of the concentrated liquid circulating and flowing from 45, the alkaline solution is supplied from the alkaline solution tank to the vicinity of the inlet of the cooler or based on the measured value of the pH downstream of the cooler. When the pH value is controlled by automatically flowing into a pipe near the upstream of the cooler, more accurate pH control can be performed. Further, simultaneously with the control of the pH value, the temperature of the cooler can be controlled based on the measured value of the liquid temperature downstream of the cooler to control the liquid temperature of the concentrated liquid.

For this pH value control system, for example, a pH value control unit 50 as shown in FIG. 3 can be used. FIG. 4 shows an ion exchange membrane electrodialysis device in which the pH value control unit 50 is applied to the ion exchange membrane electrodialysis tank 2 shown in FIG. An exchange membrane electrodialysis device is shown as FIG. This p
The H value control unit 50 includes the concentrate flow chamber 16,
The concentrated liquid flowing out from 45 is disposed in the middle of the pipe returning to the concentrated liquid tank 5 or the concentrated liquid (anolyte) tank 34, and is provided with a cooler 51 with an alkali liquid inlet, a rectification sensor tank 52, a pH / temperature controller 53, DFC (DIGITAL FLOW) for flow rate adjustment
CONTROLER) valve 54, an electromagnetic valve for cooling water (not shown), a pump 55 for alkaline liquid, and a pipe 56 connecting these. The DFC valve 54 is defined as a binary control valve operated by a digital signal. When the DFC valve is used, the flow of the fluid can be controlled by directly driving the valve with the digital signal from the CPU. In addition, a drain outlet 57 can be provided in the cooler with an alkali liquid inlet or the rectification sensor tank as necessary, for example, when used in a cold region.

The cooler 51 with an alkaline liquid inlet has a concentrate liquid cooler inlet 58 and a concentrate cooler outlet 59, an alkaline liquid inlet 60, a cooling water inlet 61 and a cooling water outlet 62. Instead of disposing the liquid inlet 60 in the cooler main body, it may be provided in a pipe portion near the upstream side of the inlet of the concentrated liquid cooler. The rectification sensor tank 52
Has a concentrate sensor tank inlet 63, a concentrate sensor tank outlet 64, a pH sensor 65, and a thermosensor 67. The pH sensor 65 and the thermosensor 67 may be provided in the pipe 56 downstream of the cooler 51. The pH / temperature controller 53 has a recorder (not shown). In addition, a pH controller and a temperature controller may be separately provided as the pH / temperature controller 53.

Next, the pH value control unit 5
The control of the pH and the liquid temperature using 0 will be described. The acidic concentrated liquid flowing out of the concentrated liquid flow chambers 16 and 45 passes through the cooler 51 with an alkaline liquid inlet and the rectification sensor tank 52 in that order. The acidic concentrated liquid which flows back to the tank 5 or the concentrated liquid (anolyte) tank 34 and flows into the cooler with an alkaline liquid inlet 51 from the concentrated liquid cooler inlet 58 is provided near the concentrated liquid cooler inlet. It is neutralized by the alkaline liquid injected from the alkaline liquid inlet 60. The heat of neutralization generated at that time is cooled by circulating the cooling water from the cooling water inlet 61 to the cooler 51 with an alkaline liquid inlet. The injection amount of the alkaline solution is controlled as follows.

The pH of the concentrated solution circulating in the pH control unit 50 is controlled by a signal from a pH sensor 65 provided in a rectification sensor tank 52, which is sensed by a pH / temperature controller 53 and subjected to arithmetic processing. This is performed by instructing opening and closing of the valve 54 and driving of the alkaline liquid pump 55. In response to an instruction from the controller 53, the alkaline solution pump 55 is driven, the flow rate of the alkaline solution from the alkaline solution tank 66 is adjusted by the DFC valve 54, and a predetermined amount of the alkaline solution required for neutralization is removed from the alkaline solution. The liquid is injected from the liquid inlet 60 into the cooler 51. As shown in FIG. 3, by providing four DFC valves 54, the flow rate can be adjusted more accurately, but an electromagnetic valve can be used instead of the DFC valve.

The temperature of the concentrated liquid circulating in the pH control unit 50 is controlled by a signal from a thermo sensor 67 provided in the rectification sensor tank 52, which is sensed by a pH / temperature controller 53 and subjected to arithmetic processing. The operation is performed by instructing opening and closing of an electromagnetic valve (not shown) of the cooling water circulating through 51. In response to the instruction from the controller 53, the electromagnetic valve of the cooling water opens and closes, the cooling water circulates through the cooler 51, and cools the concentrated solution heated by the heat of neutralization.

Further, in the ion exchange membrane electrodialysis apparatus shown in FIG. 1, the neutralized solution overflowing from the concentrated solution tank 5 is allowed to flow into the polar solution tank 4, but when the pH control unit 50 is used. The concentrated solution tank 68 can be treated alone without causing the overflowed neutralized solution to flow into the electrode solution tank 4. This single treatment is performed in the concentrate tank 6.
If the NaCl solution is put in the tank before starting the operation, about 2%
The dilution water 69 is added so as to be able to maintain the pressure, and the water can be automatically diluted and discharged. The concentration of the NaCl solution can be checked using an electric conductivity meter, but there is almost no change in the concentration during operation.

Next, in order to clarify the characteristics of the present invention, a conventional method of neutralizing an acid hydrolysis solution of an organic substance and then removing a salt from the neutralized substance, and a method of acid hydrolysis of the organic substance The difference in effect from the method of the present invention using the ion exchange membrane electrodialyzer shown in FIG. 1 for directly deoxidizing the material will be described below.

In the case of a conventional method of neutralizing an acid hydrolyzate of an organic substance and then removing a salt from the neutralized substance, for example, production of N-acetylchitooligosaccharide in which chitin is hydrolyzed with hydrochloric acid, or chitosan is produced. In the case of production of chitin oligosaccharide by hydrolysis with hydrochloric acid, usually 2 to 3 volumes of concentrated hydrochloric acid is added to the raw material, and the mixture is reacted at 30 to 50 ° C for 3 to 6 hours. After the reaction is stopped, the solution is neutralized using caustic soda solution or sodium carbonate solution. In order to suppress the heat of neutralization, even if the neutralization reaction is performed with cooling, secondary decomposition occurs due to heat generation. In addition, elimination of acetyl group or reduction of molecular weight due to contact with alkali is promoted, and a side reaction such as increase of glucosamine occurs, thereby deteriorating quality.

In an industrial apparatus, a cation exchange membrane and an anion exchange membrane are paired with an ion exchange membrane dialysis tank used for removing neutralized salts using an ion exchange membrane electrodialysis apparatus. , 100 pairs or more, sometimes as large as 500 pairs. Although the ion exchange membrane and the liquid circulation chamber are tightened so as not to cause liquid leakage, they are disassembled after use to remove one piece. To wash one sheet, 2-3
It is practically impossible because it takes days, so after use, a method of circulating washing with overflowing water or circulating a dilute acid or dilute alkali and then rinsing thoroughly with water is usually adopted. ing. However, in these washings, since it is impossible to completely wash the tightened portion between the ion exchange membrane and the liquid flow chamber, the number of microorganisms increases using organic substances that cannot be completely washed as a nutrient source. Industrially, the time required to remove the neutralized salt is 20 minutes.
Because the operation is often set close to the time, even if the operation is started with no general viable bacteria in the neutralized salt solution used for the raw material, even if the operation is started, the solution after the neutralized salt is removed About 10
⁶ cfu / ml general viable bacteria are often detected.

On the other hand, the method of the present invention in which an acid is directly removed from an acid hydrolysis solution of an organic substance has an advantage that a step for neutralization can be omitted and, as described above, During the deoxidizing treatment with hydrochloric acid or the like, the quality is not adversely affected. This is supported by the following comparison results. That is, an N-acetyl-chitooligosaccharide hydrochloride solution obtained by hydrolyzing chitin with hydrochloric acid and filtering out insoluble components is sampled in equal amounts, and directly subjected to a deacidification treatment using an ion exchange membrane electrodialyzer shown in FIG. Comparison results of the sugar composition and the like between the method of the present invention and the conventional method of neutralizing with an alkaline solution and then desalting using a conventionally known ion exchange membrane electrodialysis apparatus are as follows, and the content of undesired D-glucosamine is as follows: Even from this, the method of the present invention was clearly superior in quality to the conventional method.

[Comparative Results] Conventional Method of the Present Invention Hydrochloric Acid Concentration in N-Acetylchitooligosaccharide Hydrochloride Solution 4.4N 4.4N Salt Concentration in N-Acetylchitooligosaccharide Neutralized Solution−3.2N After Removal of Acid and Chloride ion 00 sugar composition after removal of neutralized salt (measured by liquid chromatography; weight%) D-glucosamine 8.8 16.4 monosaccharide 23.8 24.1 2 to 5 sugar 47.5 45.5 5 sugars or more 19.9 14.0

Next, the method of the present invention in which the number of living microorganisms in the silk peptide obtained by partially hydrolyzing silk protein with hydrochloric acid and the conventional method of directly deoxidizing treatment and the desalting treatment after neutralization with an alkaline solution are used. And compared. After immersing the silk in a dilute caustic soda solution, water was added and the insoluble matter was filtered to prepare a silk protein. The silk peptide hydrochloride solution obtained by hydrolyzing the silk protein with hydrochloric acid is sampled in the same amount, and is directly deoxidized and purified using an ion exchange membrane electrodialyzer shown in FIG. 1, and neutralized with an alkaline solution. Thereafter, a comparative test was performed on the increase in the number of viable microorganisms during the purification process with the conventional method of desalting and purification using a conventionally known ion exchange membrane electrodialysis device. As is clear from the following comparison results, it was found that the conventional method significantly increased the number of viable bacteria compared to the method of the present invention. The ion-exchange membrane electrodialyzer was used after circulating a 0.1N sodium hydroxide solution and washing while overflowing water until the effluent showed no alkalinity.

[Comparative Results] Present Invention Conventional Method Hydrochloric Acid Concentration in Silk Protein Hydrochloride Solution 3.4N 3.4N Salt Concentration in Solution after Neutralization of Silk Protein−2.9N After Removal of Acid and Removal of Neutralized Salt Chloride ion (g / 100 ml) 0.02 0.08 pH 5.52 5.58 General bacteria count (cfu / ml) 1 × 10 ² or less 3 × 10 ⁴

[0044]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Example 1 (Production of N-acetylchitooligosaccharide) 510 ml of concentrated hydrochloric acid was placed in a 1-liter three-necked flask,
The liquid temperature was adjusted to 30 ° C., and 115 g of chitin was added little by little with stirring. After the chitin was homogeneously mixed in the liquid, hydrolysis was performed at a liquid temperature of 35.0 to 36.5 ° C. for 5 hours. Immediately after the reaction was completed, 600 ml of water was added to stop the reaction,
To this diluted solution, 30 g of purified diatomaceous earth ("Radiolite FNF-A" manufactured by Showa Chemical Co., Ltd.) and 10 g of activated carbon ("SW-50" manufactured by Nimura Chemical Co., Ltd.) were added, stirred and mixed for 15 minutes, and then suction filtered. Then, 100 ml of water was poured into the filtration residue, washed and filtered, and combined with the filtrate to obtain 1200 ml of an N-acetylchitooligosaccharide hydrochloride solution. The hydrochloric acid concentration in this solution was 16.5 W / V% (4.4 N-HCl).

Next, the N-acetylchitooligosaccharide hydrochloride solution was subjected to a desalting treatment using an ion exchange membrane electrodialyzer shown in FIG. As an ion exchange membrane dialysis tank in such an ion exchange membrane electrodialysis apparatus, a DU-Ob type (effective membrane area: 0.21 dm ² , 10 dilution liquid circulation chambers) manufactured by Asahi Glass Co., Ltd. is used, and a cation exchange membrane is used. As C, "Selemion CMV" manufactured by Asahi Glass Co., Ltd. was used. As the anion exchange membrane A, 10 "Seremion AMV" manufactured by Asahi Glass Co., Ltd. were used. In addition, as a DC power supply device, “DC POWER SUPP” manufactured by Nitto Denko Corporation
LY MODEL PS-20; output 30V, 30A "
A platinum-plated titanium plate was used for the anode, and a stainless steel plate was used for the cathode. As the pH controller, "NPH-680D" manufactured by Nissin Chemical Co., Ltd. was used, and as the solenoid valve, "FSS-03TBFC" manufactured by Freon Kogyo Co., Ltd. was used.

The above N-acetylchitooligosaccharide hydrochloride solution was placed in a dilution tank. Water is poured into the concentrated liquid tank and the electrode liquid tank until it overflows from the overflow port, 2 liters of 10 W / V% caustic soda liquid is charged into the caustic soda liquid tank, and the solenoid valve of the pH controller opens at pH 7.3. , 8.5 beforehand. The pumps provided in the pipes communicating with the dilution tank, the concentrated liquid tank and the electrode liquid tank are operated, and the diluted liquid, the concentrated liquid and the concentrated liquid (electrode liquid) are fed into the ion exchange membrane dialysis tank, and the inside of each tank is separated. Circulation was carried out, and the concentrated liquid tank and the electrode liquid tank were replenished with the water reduced by the circulation to near the overflow port, respectively.
Next, the DC power supply was adjusted to a constant voltage of 10 V, and a current was supplied to the anode and the cathode to start the operation.

The current at the start of operation was 3.5 A,
The operation increased to 9.5 A in 45 minutes after the current supply, and almost stopped after 225 minutes from the current supply. FIG. 6 shows a current curve from the start to the stop of the operation. Upon shutdown, the diluent was reduced to 850 ml and the pH was 5.63.
The pH of the concentrated solution is 7.12, and the pH of the electrode solution is 7.1.
23. The overflow amount of the electrode solution was 2030 ml, the pH was 7.11, and the consumption amount of 10 W / V% caustic soda solution was 1930 ml. During this time, the amount of electricity was 13.4 AH, and the average current was 3.57 A.

Next, the diluting liquid was collected from the diluting tank, and a small amount of the remaining liquid in the piping and the dialysis tank was washed away with water, and combined with the diluting liquid. In 1050 ml of the combined liquid, diatomaceous earth (“Radiolite FNF-A” manufactured by Showa Chemical Co., Ltd.) 6
g, and the mixture was thoroughly mixed and stirred, and then filtered under reduced pressure. The filtrate was spray-dried to obtain 64.5 g of pale yellowish white powder (yield per chitin: 56.1%). When the obtained pale yellowish white powder was analyzed, the total nitrogen was 5.86% by weight, the ignition residue was 1.1% by weight, and the pH of the 5% by weight solution was 5.28. The sugar composition was measured by 8.8% by weight of D-glucosamine and N
-Acetylglucosamine 23.8% by weight, N-acetylchitooligosaccharide (G2-5) 47.5% by weight, N-acetylchitooligosaccharide (G6 ~) 19.9% by weight, N-acetylchito of good quality It was found that an oligosaccharide was obtained.

Example 2 (Production of Silk Peptide) After immersing silk in 0.1 N caustic soda solution, sufficiently washing with 250 g of dried and purified silk protein, 900 ml of 6N hydrochloric acid was added, and the mixture was heated to 85-90 ° C. After heating and stirring for a while to partially hydrolyze while dissolving the silk protein, 300 ml of water was added and cooled, then diatomaceous earth ("Radiolite FNF-A" manufactured by Showa Chemical Co., Ltd.)
15 g and activated carbon (“SW-50” manufactured by Nimura Chemical Co., Ltd.) 90
g of the silk peptide, and the mixture is stirred and filtered by suction, and then filtered by suction while pouring water into the residue.
500 ml were obtained. The hydrochloric acid concentration of this solution was 8.4 W /
V% (3.4N-HCl). This was placed in a diluent tank, and hydrochloric acid was removed by the ion exchange membrane electrodialyzer shown in FIG.

As shown in FIG. 7, the current at the start of operation is
It was 2.3 amps, but after 30 minutes it rose to 8.4 amps, then fell and after 210 minutes the current almost went to zero, so operation was stopped. When the operation was stopped, the diluted solution was reduced to 980 ml, the pH was 5.48, the pH of the concentrated solution was 7.08, and the pH of the concentrated solution (electrode solution) was
Is 7.21, and the overflow amount of the concentrated solution (electrode solution) is 2
At 140 ml, its pH was 7.16 and the consumption of caustic soda (10 W / V%) solution was 1870 ml. During this time, the amount of current was 12.1 AH and the average current was 3.
46A. Next, the diluting solution is collected from the diluting tank, a small amount of the remaining liquid remaining in the piping and the dialysis tank is washed away with water, combined with the diluting solution, and the silk peptide dehydrochlorinated solution 12 is removed.
00 ml were obtained. This solution had a composition of 83.6% by weight of water, 2.19% by weight of total nitrogen, 16.4% by weight of solid content and 0% by weight of chlorine, and had a pH of 5.48 and a general viable cell count of 18 cfu / ml. It was found that a high quality silk peptide could be obtained.

The dehydrochlorinated solution of the silk peptide was heated to 50 ° C., 2.4 g of protease (“Flavyzyme L” manufactured by Novo Nordisk) was added, and the mixture was stirred and reacted at 48 to 50 ° C. for 8 hours. After that, hold at 85 ° C for 10 minutes,
The enzyme was deactivated. The solution was cooled to room temperature, mixed with 20 g of activated carbon (“SW-50” manufactured by Nimura Chemical Co., Ltd.), filtered under reduced pressure, added with a small amount of water to the residue, filtered, combined with the filtrate, and spray-dried. 15.93% by weight of total nitrogen,
The pH of the 0.8 wt%, 5 wt% solution of the residue on ignition is 5.35.
Wherein the peptide composition (molecular weight distribution) determined by high performance liquidography is 100 or less 12.0% by weight, 100%
High-quality silk oligopeptides of 20.0% by weight for ２５０250 and 68.0% by weight of 250 to 500 were obtained.

Example 3 (Production of N-acetylchitooligosaccharide) 450 ml of concentrated hydrochloric acid was placed in a 1-liter three-necked flask,
The liquid temperature was adjusted to 20 ° C., and 200 g of chitin was added little by little while stirring so that the liquid temperature did not exceed 35 ° C. After the chitin was homogeneously mixed in the liquid, the liquid was heated at 35 to 37 ° C. for 5 hours. Decomposition was performed. 800 ml of water immediately after completion of the reaction
Was added to stop the reaction, and purified diatomaceous earth ("Radiolite FNF-A" manufactured by Showa Chemical Co., Ltd.) was added to the diluted solution.
g and activated carbon ("SW-50" manufactured by Nimura Chemical Co., Ltd.) were added and stirred and mixed for 15 minutes, followed by suction filtration, 100 ml of water was poured into the filtration residue, washing and filtration were performed, and combined with the filtrate.
1450 ml of N-acetylchitooligosaccharide hydrochloric acid solution was obtained. The hydrochloric acid concentration in this solution was 16.5 W / V% (4.4
N-HCl).

Next, the N-acetylchitooligosaccharide hydrochloride solution was subjected to a desalting treatment using an ion exchange membrane electrodialyzer shown in FIG. As an anion exchange membrane dialysis tank in such an ion exchange membrane electrodialysis apparatus, a hard vinyl chloride plate is cut into a hexagon so as to have as large a space area as possible, and a rubber plate is attached to the tank to leak liquid. It was prepared to prevent As the anion exchange membrane sandwiched between the rubber plates, five "Selemion AMV" manufactured by Asahi Glass Co., Ltd. were used. Further, as a DC power supply device, “DC POWER SUPPLY MODEL PS” manufactured by Nitto Denko Corporation
-20; output 30V, 30A ", a platinum plate was used for the anode, and a silver plate was used for the cathode. As the pH controller, "NPH-680D" manufactured by Nissin Chemical Co., Ltd.
Type) and FRON INDUSTRY CO., LTD.
-03TBFC ".

The above N-acetylchitooligosaccharide hydrochloric acid solution 1
450 ml is placed in the diluting tank, and the concentrated liquid (anolyte) tank is filled with 1500 ml of 0.2% caustic soda solution.
1500 ml of a 15% caustic soda solution was charged into a caustic soda solution tank. The pumps provided respectively in the pipes communicating with the diluent tank and the concentrate (anolyte) tank are operated to feed the diluent and the concentrate into the ion exchange membrane dialysis tank.
Circulation was performed at a flow rate of 0 ml / min, and the concentrated solution (anolyte) tank was replenished with 0.2% caustic soda solution reduced by circulation to near the overflow port. Then, using a DC power supply, a DC current of 24 volts and 20 amps was applied to the anode and the cathode to start the operation. During the operation, the pH of the concentrated solution (anolyte) is controlled from the caustic soda tank to 15% while controlling the pH so that the pH value can be maintained in the range of 7.3 to 8.5.
% Caustic soda solution was allowed to flow into the concentrate (anolyte) bath.

8 hours and 20 minutes after the start of the operation, it was confirmed that the pH of the diluted solution had risen from strongly acidic to 6.5.
The operation was stopped to obtain 1150 ml of a diluted solution. Residual chlorine ions in the diluted solution were 0.08 g / 100 ml. Activated carbon (5 g) was added to the diluted solution, and the mixture was stirred for 15 minutes, filtered by suction, and the filtrate was spray-dried to obtain 118 g of pale yellowish white powder.
(59% yield from raw material chitin) was obtained. When the obtained pale yellowish white powder was analyzed, total nitrogen was 6.24% by weight,
Hydrogen 2.8% by weight, chlorine 0.68% by weight, ignition residue 0.
The pH of the 85% by weight and 5% by weight solutions was 5.28, and the sugar composition was measured by thin layer chromatography. As a result, N-acetylglucosamine was 40.1% by weight, and dimer N-acetylchitooligosaccharide was obtained. It was 19.5% by weight, 40.4% by weight of trimeric or higher N-acetylchitooligosaccharides and a trace amount of D-glucosamine, indicating that high quality N-acetylchitooligosaccharides were obtained.

Example 4 (Production of N-acetylchitooligosaccharide) 850 ml of concentrated hydrochloric acid was adjusted to 20 ° C., and 400 g of chitin was added little by little while stirring so that the liquid temperature did not become 35 ° C. or higher. After being completely homogenized in hydrochloric acid, hydrolysis was carried out at 35 to 37 ° C. for 4.5 hours.
Immediately after the completion of the reaction, 1600 ml of water was added to stop the reaction, 10 g of purified diatomaceous earth and 20 g of activated carbon were added. After stirring for 15 minutes, suction filtration was performed using filter paper, and 200 ml of water was poured into the residue in the filter. The mixture was washed, filtered, and combined with the filtrate. 2870 ml of the filtrate was transferred to a diluting tank in the same manner as in Example 3, then 3000 ml of a 0.2% caustic soda solution was placed in the concentrate tank, and 3000 ml of a 15% caustic soda solution was placed in the caustic soda tank. . Less than,
The ion exchange membrane electrodialyzer shown in FIG. 2 was operated under the same conditions as in Example 3, and it was confirmed that the pH of the diluent increased from strongly acidic to 6.4 15 hours and 40 minutes after the start of operation. Then, the operation of the apparatus was stopped to obtain 2270 ml of a diluted solution.

Chlorine ions remaining in the diluent were 0.11
g / 100 ml, the result of measurement of the number of general viable cells by the standard agar culture method was 10 cfu / 100 ml or less.
10 g of activated carbon was added to the diluted solution, and the mixture was stirred for 15 minutes, filtered by suction, and the filtrate was spray-dried to give 260 g of pale yellowish white powder.
(65% yield from raw material chitin) was obtained. The analysis value of this powder was 3.4% by weight of hydrogen, 6.22% by weight of total nitrogen, 0.85% by weight of chlorine and 0.88% by weight of the residue on ignition. The sugar composition was determined by thin-layer chromatography. As a result of analysis, 33.7% by weight of N-acetylglucosamine, 20.0% by weight of dimer N-acetylchitooligosaccharide, 46.3% by weight of N-acetylchitooligosaccharide more than trimer, and trace amount of D- It was glucosamine, indicating that high-quality N-acetylchitooligosaccharide was obtained.

Example 5 (Production of N-acetylchitooligosaccharide) 430 liters (L) of concentrated hydrochloric acid was placed in a glass-lined reaction vessel having a capacity of 1500 L, the liquid temperature was adjusted to 30 ° C., and 100 kg of chitin was added with stirring. The chitin was added little by little, and after the chitin was homogeneously mixed in the solution, the solution was hydrolyzed at a solution temperature of 34 to 36 ° C for 5 hours. Immediately after completion of the reaction, the reaction was stopped by adding 700 L of water, and 20 kg of purified diatomaceous earth ("Radiolite FNF-A" manufactured by Showa Chemical Co., Ltd.) was added to the diluted solution.
And activated carbon (“Tyco-SW-50” manufactured by Nimura Chemical Co., Ltd.) 1
After adding 5 kg and stirring and mixing for 15 minutes, the mixture was filtered with a filter press, 200 L of water was poured into the filter residue, washed and filtered, and combined with the filtrate to obtain 1280 L of N-acetylchitooligosaccharide hydrochloride solution. The hydrochloric acid concentration in this solution is 12.
It was 6 W / V% (3.45 N-HCl).

Next, the above-mentioned N-acetylchitooligosaccharide hydrochloride solution was subjected to a desalting treatment using an ion exchange membrane electrodialyzer shown in FIG. As the ion exchange membrane dialysis tank in such an ion exchange membrane electrodialysis apparatus, “DW-3E2 type” manufactured by Nippon Rensui Co., Ltd. (effective membrane area: 79 m ² , 0.
395 m ² × 200 pairs), “Ceremion CMV” manufactured by Asahi Glass Co., Ltd. as the cation exchange membrane C, and “Seremion AM” manufactured by Asahi Glass Co., Ltd. as the anion exchange membrane A.
V "was used for each 200 sheets. A platinum-plated titanium plate was used for the anode, a stainless steel plate was used for the cathode, and "SCA" manufactured by Sansha Electric Co., Ltd. was used as the DC power supply.
26-120-150 VC type; constant voltage 0-120 volts, constant current 0-150 amps ".

In addition, as the electromagnetic conductivity meter converter, "MD-35D type" (measurement range 0
５００500 mS / cm) as the pH / temperature controller “NPH-680D” manufactured by Nissin Chemical Co., Ltd.
As a solenoid valve, "FSS-0" manufactured by Freon Industrial Co., Ltd.
3TBFC ", Elepon Kakoki's" SL-35SFX-PVDF "as an alkaline circulation pump, and DFC Corporation's" D-corp.
FC4D06 type PVC ”and“ α-900 ”manufactured by Hitachi Horiba, Ltd. as pH / ORP indicating converter.
As a temperature controller, "REX-D" manufactured by Rika Kogyo Co., Ltd.
"Type" as a recorder, "SBR-
EY100 type "was used.

The above N-acetylchitooligosaccharide hydrochloride solution 1
280 L (162 kg of HCl) was placed in the dilution tank. In the concentrate tank, 500 L of NaC was used as the concentrate.
Approximately 2% solution contains 200 L of NaCl
2% solution, NaOH 40W for neutralization in caustic soda tank
/ V% solution. The pH control of the concentrated solution circulating in the pH control unit by the pH / temperature controller is performed based on a signal from a pH sensor provided in the rectification sensor tank. The alkaline solution pump is driven at pH 7.3, and the alkaline solution tank is driven. Alkaline solution from DFC
After the flow rate is adjusted by the valve, a predetermined amount of alkaline solution required for neutralization is injected into the cooler from the above-mentioned alkaline solution inlet, and at pH 8.5, the flow rate adjusting DFC valve is closed and the alkaline solution pump is driven. Was set to stop. The temperature control of the circulating concentrate by the pH / temperature controller is performed by a signal from a thermo sensor provided in the rectification sensor tank, and the electromagnetic valve of the cooling water circulating through the cooler opens at 26 ° C. Is performed by instructing the electromagnetic valve to close. In accordance with an instruction from the controller 53, the cooling water electromagnetic valve was set to close.

[0062] dilution tank, respectively to operate the pump provided in a pipe communicating with the concentrated liquid vessel and the electrode solution tank, the dilution at a flow rate of 17.5 m ³ / H, the concentrate flow rate 17.5 m ³ /
At H, the electrode solution was fed into the ion exchange membrane dialysis tank at a flow rate of 1.4 m ³ / H, and circulated between the tanks. Dilution water is added to the concentrated solution tank, and the solution is circulated using an electric conductivity meter while maintaining the conductivity at about 38 mS / cm. The liquid portion that increases due to dilution and overflows does not overflow into the electrode solution tank. And discharged directly as drainage. Next, the DC power supply was adjusted to a constant voltage of 50 V, an electric current was applied to the anode and the cathode to start the operation, and the operation was ended 9 hours later.
NaOH required for neutralization by the end of operation (40 W / V%)
The volume was 448 L (179 kg of NaOH), the pH of the terminal diluent was 5.46, and the final volume of the diluent was 730 L (water permeates and decreases during operation). Table 1 shows the progress of dehydrochlorination.

[0063]

[Table 1]

Next, the diluting solution was collected from the diluting tank, and a small amount of the remaining liquid in the piping and the dialysis tank was flushed with water and combined with the diluting liquid. 10 g of diatomaceous earth (“Radiolite FNF-A” manufactured by Showa Chemical Co., Ltd.) is added to 850 L of the combined liquid.
g, and the mixture was thoroughly mixed and stirred, and then filtered under reduced pressure. 770 L of this filtrate was spray-dried, and 54.3 kg of pale yellowish white powder was obtained.
(54.3% yield based on chitin). When the obtained pale yellowish white powder was analyzed, total nitrogen was 5.82.
Wt%, ignition residue 0.58 wt%, pH of 5 wt% solution
Was 5.41, and the sugar composition was measured by high performance liquid chromatography.
6% by weight, 18.8% by weight of N-acetylglucosamine,
48.3% by weight of N-acetylchitooligosaccharide (G2-5) and 25.3% by weight of N-acetylchitooligosaccharide (G6 ~) indicate that good quality N-acetylchitooligosaccharide was obtained. Was.

[0065]

According to the method of the present invention for producing a partial hydrolyzate of an organic substance such as N-acetylchitooligosaccharide, the deacidification treatment is carried out without neutralizing the acid. One step for summation can be omitted, and quality degradation due to secondary hydrolysis due to heat of neutralization, etc., and elimination of acetyl groups due to partial contact with alkali used for neutralization There is no danger of producing D-glucosamine or reducing the molecular weight. Further, in the present invention, since the deacidification purification treatment can be performed in an acidic region, bacterial contamination generated during purification can be minimized. Furthermore, according to the present invention, deoxidation is performed by using an ion exchange membrane electrodialysis apparatus that circulates an alkaline solution as a concentrated solution, so that deoxidation efficiency is high, and the ion exchange membrane electrodialysis is performed while controlling the pH value. Therefore, there is no deterioration of the electrode and the ion exchange membrane. As described above, according to the present invention, high-quality N-acetylchitooligosaccharides and silk peptides with little bacterial contamination can be produced at an industrial level.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view of an ion exchange membrane electrodialysis apparatus provided with a plurality of cation exchange membranes and anion exchange membranes alternately used in the present invention.

FIG. 2 is a schematic vertical sectional view of an ion exchange membrane electrodialysis apparatus provided with a plurality of anion exchange membranes used in the present invention.

FIG. 3 is a schematic longitudinal sectional view of a pH value control unit used in the present invention.

FIG. 4 is a schematic longitudinal sectional view of another embodiment of an ion exchange membrane electrodialysis apparatus provided with a plurality of cation exchange membranes and anion exchange membranes alternately used in the present invention.

FIG. 5 is a schematic longitudinal sectional view of another embodiment of an ion exchange membrane electrodialysis apparatus provided with a plurality of anion exchange membranes used in the present invention.

FIG. 6 is a diagram showing a current curve from the start to the stop of operation in the first embodiment.

FIG. 7 is a diagram showing a current curve from the start of operation to the stop in Example 2.

[Explanation of symbols]

1,31 ion exchange membrane electrodialysis device 2 ion exchange membrane dialysis tank 3,33 DC power supply 4 electrode solution tank 5 concentrated solution tank 6,35 dilution solution tank 7,36 alkaline solution tank 8,37 alkaline solution automatic injection solenoid valve 8 9,38 pH controller 10,39 Piping 11,40 Circulation pump 12,41 Concentrated liquid cooler 13,42 Metal anode plate 14 Anolyte flow chamber 15,44 Dilution liquid flow chamber 16,45 Concentrate liquid flow chamber 17 Catholyte Distribution chamber 18,47 Metal cathode plate 19,49 pH electrode 32 Anion exchange membrane dialysis tank 34 Concentrated liquid (anolyte) tank 43 Concentrated liquid (anolyte) flow chamber 46 Dilution liquid (catholyte) flow chamber 48 Back plate 50 pH value control unit 51 Cooler with alkaline liquid inlet 52 Rectifier sensor tank 53 pH / temperature controller 54 DFC (DIGITAL FLOW CONTR) for flow rate adjustment
OLER) valve 55 alkaline liquid pump 56 piping 57 drain outlet 58 concentrated liquid cooler inlet 59 concentrated liquid cooler outlet 59 60 alkaline liquid inlet 61 cooling water inlet 62 cooling water outlet 63 concentrated liquid sensor tank inlet 64 concentrated liquid sensor Tank outlet 64 65 pH sensor 66 Alkaline liquid tank 67 Thermosensor 68 Concentrated liquid tank 69 Dilution water C Cation exchange membrane A Anion exchange membrane

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C07H 5/04 C07H 5/04 4H045 C07K 1/12 C07K 1/12 1/24 1/24 C08B 37/08 C08B 37 / 08 F-term (reference) 4B018 MD16 MD17 MD20 MD27 MD74 MD76 MF10 MF12 4C057 AA05 BB02 BB03 BB04 CC03 HH03 4C090 AA06 BA46 BB18 CA31 DA27 4D006 GA17 HA47 JA42C KA02 KB12 KB14 KB30 KD12 KD19 KE15P19 EB15 DB18 EB39 FA11 GA07 GA22 GC05 4H045 AA10 AA20 BA11 BA12 BA13 CA51 EA01 FA16 GA10 HA02

Claims (11)

[Claims] 1. An acid-containing partial hydrolyzate obtained by partially hydrolyzing an organic substance using an acid is subjected to a deacidification treatment using an ion exchange membrane electrodialysis apparatus that circulates an alkaline solution as a concentrate. A method for producing a partial hydrolyzate of an organic substance. 2. An acid-containing partial hydrolyzate obtained by partially hydrolyzing an organic substance using an acid is subjected to deacidification using an ion exchange membrane electrodialysis apparatus while controlling the pH value of the concentrate. A method for producing a partial hydrolyzate of an organic substance, comprising: 3. The organic substance part according to claim 1, wherein the ion exchange membrane electrodialysis apparatus is provided with a plurality of cation exchange membranes and anion exchange membranes alternately. A method for producing a hydrolyzate. 4. The method of controlling the pH value, comprising: transferring an alkaline solution from an alkaline solution tank to the electrode solution tank and the concentrated solution based on the measured values of the pH of the concentrated solution (electrode solution) in the electrode solution tank and the concentrated solution in the concentrated solution tank. The method for producing a partial hydrolyzate of an organic substance according to claim 2 or 3, wherein the method is carried out by automatically flowing the mixture into a tank. 5. The method according to claim 1, wherein the ion exchange membrane electrodialysis apparatus comprises a plurality of anion exchange membranes. 6. The control of the pH value is based on the measured value of the pH of the concentrated liquid in the concentrated liquid (anolyte) tank, and the alkaline solution is automatically flowed from the alkaline liquid tank to the concentrated liquid (anolyte liquid) tank. The method for producing a partial hydrolyzate of an organic substance according to claim 2 or 5, wherein the method is performed. 7. The control of the pH value is based on the measured value of the pH downstream of the cooler, and the alkaline solution is automatically flown from the alkaline liquid tank into the pipe near the inlet of the cooler or near the upstream of the cooler. The method for producing a partial hydrolyzate of an organic substance according to claim 2, wherein the method is carried out by causing the partial hydrolysis. 8. The partial hydrolysis of organic matter according to claim 7, wherein the temperature of the cooler is controlled to control the temperature of the concentrated liquid based on the measured value of the liquid temperature downstream of the cooler. Method of manufacturing a product. 9. The method for producing a partially hydrolyzed organic substance according to claim 2, wherein the pH value is 7 to 9. 10. The method according to claim 1, wherein the organic substance is chitin and the partial hydrolyzate is N-acetylchitooligosaccharide. 11. The method for producing a partial hydrolyzate of an organic substance according to claim 1, wherein the organic substance is silk protein and the partial hydrolyzate is a silk peptide.