WO2006057398A1

WO2006057398A1 - Method for processing organic matter containing chitin

Info

Publication number: WO2006057398A1
Application number: PCT/JP2005/021845
Authority: WO
Inventors: Hiroyuki Yoshida; Hidemi Nakamura
Original assignee: Osaka Industrial Promotion Organization
Priority date: 2004-11-29
Filing date: 2005-11-29
Publication date: 2006-06-01
Also published as: JP5013878B2; JPWO2006057398A1

Abstract

Disclosed is a method for purifying a chitin which includes a step for processing an organic matter containing a chitin in an acidic aqueous solution in the subcritical or supercritical state. Also disclosed is a method for producing a low molecular weight chitin or a chitin oligosaccharide. Further disclosed is a method for producing a chitosan, a low molecular weight chitosan or a chitosan oligosaccharide which includes deacetylation of the thus-obtained chitin or the like. Still further disclosed is a method for producing a chitin degradation product and/or a protein degradation product which includes a step for processing an organic matter containing a chitin in an acidic aqueous solution in the subcritical or supercritical state.

Description

Specification

Treatment of organic matter containing chitin

Technical field

[0001] The present invention relates to a method for efficiently treating and effectively using an organic substance containing chitin.

More specifically, the present invention relates to a method for efficiently obtaining high-purity chitin and a useful substance by treating an organic substance containing chitin in a subcritical or supercritical state.

Background art

[0002] Chitin and chitosan are increasing in demand as natural substances having various interests / functions. On the other hand, organic waste containing chitin and chitosan, such as power-shelled shrimp shells, is discharged in large quantities from the fish market and processing plants, and the effective treatment of the waste has become a serious issue. Yes. Therefore, methods for producing chitin and chitosan from wastes such as power-shelled shrimp shells have been studied. However, in order to isolate and purify chitin and chitosan from these organic wastes, it is necessary to separate ash, proteins, lipids and pigments from chitin.

[0003] The conventional method requires a multi-step process, a schedule of several days, a large amount of reagents and water, and a large amount of wastewater treatment, which is a large burden in terms of cost. For this reason, the use of wastes containing chitin or chitosan is hardly used.

[0004] On the other hand, methods using subcritical water or supercritical water have been reported so far as methods for treating organic substances and polymer compounds (Japanese Patent Laid-Open Nos. 05-031000 and 11-34 2379). Issue gazette).

[0005] However, obtaining chitin and chitosan with high purity has been difficult.

Disclosure of the invention

Problems to be solved by the invention

The main object of the present invention is to provide a method for obtaining high-purity chitin from an organic substance containing chitin in a small amount of process, in a short time, and at a low cost. Furthermore, the main object is to provide a method for obtaining useful substances from organic substances containing chitin. Means for solving the problem [0007] As a result of intensive studies aimed at solving the above-mentioned problems, the present inventors treated an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state. We have found that chitin can be purified efficiently and with high purity, and have further studied to complete the present invention.

[0008] That is, the present invention relates to the following purification method and production method.

[0009] Item 1: A method for purifying chitin, comprising treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state.

[0010] Preferably, the ash, protein, lipid, and pigment are separated from the chitin by treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state. Purification method of chitin.

[0011] Preferably, the method includes a step of separating ash, protein, lipid, and pigment from chitin in one step by treating an organic substance containing chitin in an acidic aqueous solution in a subcritical or supercritical state. The purification method of chitin.

[0012] The "purification method of chitin" in the present specification can also be referred to as "a method for producing high-purity chitin".

[0013] Item 2: The purification method according to Item 1, wherein an organic substance containing chitin is treated in an acidic aqueous solution in a subcritical state.

[0014] Preferably, the chitin having a step of separating ash, protein, lipid and pigment from the chitin in a single step by treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state. Purification method.

[0015] Item 3: The purification method according to Item 1 or Item 2, wherein an organic substance containing chitin is treated in an acidic aqueous solution in a subcritical state of less than 493K.

[0016] Preferably, the method includes a step of separating ash, protein, lipid, and pigment from chitin in one step by treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state of less than 493K. Purification method of chitin.

Item 4: The purification method according to any one of Items 1 to 3, wherein the acidic aqueous solution is an organic acid aqueous solution.

[0018] Specific embodiments include the purification method according to any one of Items 1 to 3, wherein the acidic aqueous solution is an acetic acid aqueous solution. Item 5: A method for producing chitosan, comprising treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state, and subjecting the treated chitin to deacetylation.

[0020] The embodiment of Item 5 includes a method for producing chitosan characterized in that chitin is purified by the method according to any one of Items 1 to 4 and the purified chitin obtained is deacetylated. . A specific embodiment includes a method for producing chitosan characterized in that an organic substance containing chitin is treated in an acidic aqueous solution in a subcritical state, and the treated chitin is deacetylated.

[0021] Further, in a specific embodiment, (1) by treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state, decomposition of ash, protein, lipid, and pigment in the organic substance is performed. Also included is a method for producing high-purity chitosan, which comprises a step of obtaining chitin by performing in one step, and a step of (2) deacetylating the chitin obtained in (1).

[0022] Item 6: A method for producing low-molecular chitin and Z or chitin oligosaccharide, wherein an organic substance containing chitin is treated in an acidic aqueous solution in a subcritical state or a supercritical state.

[0023] Preferably, the organic material containing chitin is treated in an acidic aqueous solution in a subcritical state.

[0024] Specific embodiments include the production method according to Item 6, wherein the acidic aqueous solution is an organic acid aqueous solution, particularly an acetic acid aqueous solution.

[0025] Item 7: A low molecular weight characterized in that an organic substance containing chitin is treated in an acidic aqueous solution in a subcritical or supercritical state, and the resulting low molecular chitin and Z or chitin oligosaccharide are deacetylated. A method for producing chitosan and Z or chitosan oligosaccharide.

[0026] In the embodiment of Item 7, the method for producing a low-molecular chitosan and Z or chitosan oligosaccharide characterized in that the low-molecular chitin and Z or chitin oligosaccharide obtained by the method of Item 6 are deacetylated. Is included.

Item 8: A method for producing a chitin degradation product and a Z or protein degradation product, which comprises treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state.

[0028] Preferably, the chitin degradation product and the Z or protein degradation product are one or more compounds selected from the group power consisting of amino acids, organic acids, low molecular weight sugars, peptides and low molecular weight water-soluble proteins. [0029] It should be noted that the present invention includes a case where a plurality of one or more methods selected from items 1 to 8 are performed in parallel.

[0030] For example, examples of specific embodiments of the present invention include the following methods.

[0031] Item 9: Purification of chitin and production of low-molecular chitin and Z or chitin oligosaccharide, characterized in that an organic substance containing chitin is treated in an acidic aqueous solution in a subcritical or supercritical state. A method of performing, preferably in one step,

Item 10: Purification of chitin, low molecular chitin, chitin oligosaccharides, chitin degradation products and Z or Z, characterized by treating organic matter containing chitin in an acidic aqueous solution in a subcritical or supercritical state A method for producing a proteolysate, preferably in one step.

Hereinafter, the present invention will be described in detail.

[0033] Organic matter containing chitin

The organic matter targeted by the present invention is not particularly limited as long as it contains chitin, and includes, for example, a biological component itself containing chitin or a processed product thereof, or organic waste.

[0034] Organic waste includes, for example, food processing waste from fish markets and fish processing plants, food waste such as food waste and food residues from homes and schools, and the like.

[0035] Specifically, chitin-containing organic substances include force- and Z or shrimp shells, insect shells and legs, squid shells and shellfish mollusc organs such as shellfish and shellfish, diatoms, fungi, chitin or chitosan. These include microorganisms and bacteria that produce or processed products thereof.

[0036] These organic substances may be used as they are, or may be pulverized to an appropriate size. Also, it may have been pretreated such as drying.

[0037] ^^ is ^^

This invention includes the process of processing the organic substance containing chitin in the acidic aqueous solution of a subcritical state or a supercritical state.

[0038] By treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state, separation of ash content (specifically calcium carbonate), protein, lipid and pigment of chitin power, It is possible to remove the chitin power of ash, proteins, lipids and pigments adhering to chitin in organic substances in one step. Costs and treatment of large amounts of wastewater can be eliminated. In addition, the cost required for processing can be significantly reduced.

[0039] In the present invention, the subcritical state means that the temperature of the solvent is about 433 to 647 K, in particular, about 433 to 523 mm, particularly about 433 to 493 mm, and the pressure force is 0.62 to 22.1. This means that the pressure is about 0.6 MPa, especially about 0.62 to 4. OMPa, especially about 0.62 to 2.32 MPa.

In the present invention, the supercritical state means that the temperature of the solvent is 647 K or more, particularly about 647 K to 673 、, and the pressure is 22. IMPa or more, particularly about 22.1 to 30 OMPa. It means that there is.

[0040] In the present invention, it is particularly preferable to perform the treatment in a subcritical state. Processing in the subcritical state increases the yield of chitin, in other words, the residual rate of chitin, compared to processing in the supercritical state. In particular, the residual ratio of high molecular weight chitin increases.

[0041] Among the subcritical states, the yield of high molecular weight chitin can be further improved by treatment in a relatively low temperature range, preferably a subcritical state of less than 493K (220 ° C). The treatment in the subcritical state at a relatively low temperature raises the residual ratio of the initial molecular weight or high molecular weight chitin with less thermal decomposition of the chitin compared to the treatment in the higher temperature region.

[0042] On the other hand, the yield of low-molecular chitin, chitin oligosaccharides, chitin degradation products and Z or protein degradation products can be improved by treatment in a subcritical state in a relatively high temperature region.

[0043] Purification of chitin

The present invention provides a method for purifying chitin comprising a step of treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state. By treating in an acidic aqueous solution in a subcritical state or a supercritical state, chitin is efficiently purified and high purity chitin can be produced.

[0044] The ratio between the amount of the organic substance and the amount of the acidic aqueous solution in the treatment of the present invention is a force that can be appropriately set according to the treatment conditions and the like. Usually, the weight of the organic substance Z acidic aqueous solution is about 0.05 to 0.2. is there. [0045] The acidic aqueous solution used in the present invention can be obtained by adding an acid component to the aqueous solution.

[0046] The type of the acid component is not particularly limited, and a strong acid or a weak acid can be used.

[0047] Strong acids include hydrochloric acid, nitric acid, sulfuric acid and the like. Weak acids include acetic acid, lactic acid, and succinic acid

, Organic acids such as malic acid, formic acid, pyroglutamic acid, glycolic acid and succinic acid, and inorganic acids such as phosphoric acid.

[0048] Of these, organic acids such as acetic acid and lactic acid are preferred because they do not corrode the reactor and can be reused by decomposition of proteins during processing.

[0049] Specifically, the treatment by reusing the acid can be performed as follows.

[0050] By treating an organic substance containing chitin in an acidic aqueous solution in a subcritical or supercritical state, ash, proteins, lipids and pigments are separated from the chitin,

In the treatment, an acidic aqueous solution is prepared using an organic acid generated by protein degradation, and an organic substance containing chitin is treated in the subcritical state or supercritical state in the prepared acidic aqueous solution.

[0051] Thereby, chitin can be continuously purified, and high-purity chitin can be continuously produced.

[0052] The concentration of the acidic aqueous solution can be appropriately set according to the processing conditions and the like. For example, in the case of an acetic acid aqueous solution, the stoichiometric molar ratio of the reaction between calcium carbonate and acetic acid that is usually contained in an organic substance is about 1 to 2 or more, and usually about 1 to 2 to 1 to 4. . In particular, a stoichiometric molar ratio as close to 1 to 2 as possible is appropriate.

The processing procedure is not particularly limited and can be set as appropriate. For example, an organic substance containing chitin is added to an acidic aqueous solution, and the resulting solution is prepared and reacted under subcritical or supercritical conditions.

[0054] The treatment time is not particularly limited, but is usually about 1 to 30 minutes, preferably about 1 to about LO.

[0055] After the treatment, separation and purification can be appropriately performed. For example, the organic matter after treatment is separated by filtration into a solid phase containing chitin and an aqueous phase containing degradation products such as amino acids, organic acids, and sugars, and further purified as necessary. Chitin can be isolated.

[0056] Production of chitosan High purity chitosan can be obtained by treating chitin obtained by treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state as described above.

[0057] The method of deacetylation treatment is not particularly limited, and a known method can be appropriately used.

[0058] For example, a method of treating chitin with an alkali or an enzyme can be used. More specifically, the obtained chitin is treated with 30 to 60% high-concentration molten sodium hydroxide solution under a heating and stirring condition of 353 to 393 K for 30 minutes to 5 hours. Cetylation can be performed.

[0059] The degree of deacetylation is not particularly limited, and can be appropriately set for the purpose of obtaining chitosan having desired physical properties.

[0060] By this method, waste containing chitin can be effectively used to produce high-purity chitosan in a short time, in a short time, efficiently and at low cost.

[0061] Production of chitin and / or chitin oligosaccharide

By treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state as described above, it is possible to efficiently produce low-molecular chitin and ζ or chitin oligosaccharide.

[0062] In the present specification, the low molecular chitin means chitin which has become a lower molecule as a result of degradation of chitin contained in an organic substance. Chitin oligosaccharide means an oligosaccharide produced by the decomposition of chitin.

[0063] Low molecular chitin and sputum or chitin degradation products can be isolated by appropriate separation and purification after treatment. For example, the organic substance after the treatment is separated by filtration into a solid phase containing chitin and an aqueous phase containing chitin or chitin oligosaccharide that has been made low-molecular and soluble, and further purified as necessary. The desired substance can be isolated by

[0064] Production of low minute and early chitosan and / or chitosan oligosaccharide

Organic matter containing chitin in acidic solution in subcritical or supercritical state as described above Low molecular chitosan and Z or chitosan oligosaccharide can be obtained by subjecting low molecular chitin and chitin oligosaccharide obtained by treatment with deacetylation treatment.

[0065] The method for the deacetylation treatment is not particularly limited, and a known method can be appropriately used as described above.

[0066] For example, a method of treating low molecular chitin or chitin oligosaccharide with an alkali or an enzyme can be used. More specifically, the obtained low-molecular chitin or chitin oligosaccharide was used for 30 minutes to 5 hours under a heating and stirring condition of 353 to 393 K using a 30 to 60% high-concentration molten sodium hydroxide solution. By performing the processing, deacetylation can be performed.

[0067] The degree of deacetylation is not particularly limited, and can be set as appropriate for the purpose of obtaining low-molecular chitosan or chitosan oligosaccharide having desired physical properties.

[0068] According to this method, waste containing chitin can be effectively used to produce low-molecular chitosan and chitosan oligosaccharide in a short time, with an efficient combing force and a low cost.

[0069] Production of chitin degradation product and / or white degradation product

By treating an organic substance containing chitin in an acidic aqueous solution in a subcritical or supercritical state, a part of chitin and soot or protein can be decomposed to produce a useful substance.

[0070] The chitin degradation product and the koji or protein degradation product mean a compound produced by the degradation of chitin, a compound produced by the protein degradation and the koji or a mixture thereof.

[0071] Examples of specific embodiments of chitin degradation products and sputum or protein degradation products are amino acids, organic acids, low molecular sugars, peptides, and one or more compounds selected from the group power consisting of low molecular weight water-soluble proteins. is there.

[0072] Examples of amino acids generated by degradation include cystine, serine, parin, threonine, daricin, proline, alanine, methionine, histidine, anoleginin, leucine, isoleucine, tyrosine, lysine, ferulalanin, aspartic acid, glutamic acid. Etc. are included.

[0073] Examples of organic acids generated by decomposition include malic acid, succinic acid, lactic acid, formic acid, acetic acid, pyroglutamic acid, and the like. [0074] Examples of low molecular weight saccharides produced by decomposition include low molecular weight chitin, chitin oligosaccharides, glucosamine, erythrose, and the like.

[0075] Examples of other decomposition products include phosphoric acid.

[0076] These decomposition products can be recovered as resources and reused effectively. For example, it can be used as a component of pharmaceuticals, seasonings, health drinks, additives and the like.

[0077] Conventionally, in the treatment of an organic substance containing chitin, a high cost was required for the deproteinization treatment, and the protein was disposed of as it was, but according to this method, a simple and efficient process, In addition to obtaining high-purity chitin, useful substances such as amino acids, organic acids, and low-molecular sugars can also be obtained.

[0078] Effective organic matter II

In the method of the present invention, by treating an organic substance containing chitin in a subcritical state or a supercritical state, the above one or two or more embodiments can be carried out in parallel or in one step.

[0079] For example, by treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state, it is preferable to produce high-purity chitin and low-molecular chitin and Z or chitin oligosaccharides. It can be done in one step.

[0080] Further, by treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state, production of high-purity chitin, low-molecular chitin, chitin oligosaccharides, chitin degradation products, and Z Alternatively, the proteolysate can be produced preferably in one step.

[0081] Furthermore, the processing residue after recovering them can also be used for energy recovery as a raw material for methane fermentation or the like.

[0082] As described above, the method for treating an organic substance of the present invention is accompanied by the acquisition of purified high-purity chitin.

In addition, it has an excellent advantage that other useful substances can be recovered and used.

[0083] In the treatment method of the present invention, various known techniques relating to the production of chitin and chitosan can be added as necessary.

The invention's effect

[0084] The present invention is capable of efficiently purifying chitin from an organic substance containing chitin in a shorter process than conventional methods, in a short time and with low cost, and obtaining high-purity chitin. Has a special effect.

[0085] According to the conventional method, when isolating chitin-containing organic mosquitoes, the decalcification process, the deproteinization process, etc. require a multi-step process and a period of several days! . In addition, a large amount of reagent was consumed, and a large amount of wastewater treatment was required.

On the other hand, according to the present invention, it is possible to efficiently separate chitin-containing ash, proteins, lipids and pigments in a short time in an organic substance containing chitin. In addition, the burden imposed on the use of large amounts of reagents and water and the treatment of large amounts of wastewater can be greatly reduced. Therefore, according to this invention, the cost accompanying the process of the organic substance containing chitin can be reduced significantly.

[0087] Further, according to the present invention, highly purified chitin with high purity can be efficiently produced.

[0088] In particular, by treating in a subcritical state at a relatively low temperature, high molecular weight chitin can be obtained with high purity. Moreover, the yield of low molecular weight chitin and chitin oligosaccharide can also be improved by processing in a relatively high temperature subcritical state.

[0089] Furthermore, by using the method of the present invention, chitosan, low-molecular chitosan and chitosan oligosaccharide can also be efficiently obtained with organic power including chitin.

[0090] Further, in the treatment in the subcritical state or supercritical state in the present invention, useful substances such as amino acids and organic acids are produced by the decomposition of proteins and the like, and these can be recovered and used. Furthermore, using the recovered organic acid, it is possible to purify chitin and continuously produce the useful substance.

[0091] Further, according to the method of the present invention, by treating an organic substance containing chitin in a subcritical state or a supercritical state, purification of chitin and production of a useful substance can be performed in parallel or It can be done in one step. Furthermore, energy can be used for the residue after treatment.

[0092] As described above, the present invention has an excellent advantage that both high-purity chitin can be obtained and useful resources can be recovered and used together.

[0093] According to the present invention, chitin, chitosan, chitin oligosaccharide, chitosan oligosaccharide, various amino acids

, Organic acids, and useful compounds such as darcosamine from waste organic matter, etc. It becomes possible to produce at a cost. In addition, the present invention can greatly promote the use of organic substances containing chitin.

[0094] As described above, the present invention can be usefully used as an effective treatment technique for organic substances and an efficient production technique for useful substances.

Brief Description of Drawings

[0095] FIG. 1 is a graph showing the relationship between the solid phase remaining rate and the reaction time when a force bishell is treated in an aqueous solvent in a subcritical state.

FIG. 2 is a graph showing the relationship between the calcium carbonate residual rate and the reaction temperature when calcium carbonate is treated in an aqueous solvent in a subcritical state.

FIG. 3 is a graph showing the relationship between chitin residual rate and reaction temperature when chitin is treated in a subcritical water solvent.

FIG. 4 is a graph showing the relationship between calcium carbonate remaining rate and reaction time when calcium carbonate is treated in an aqueous acetic acid solution in a subcritical state.

FIG. 5 is a graph showing the relationship between chitin residual rate and reaction time when chitin is treated in an aqueous acetic acid solution in a subcritical state.

FIG. 6 is a graph showing the relationship between the residual rate of calcium carbonate and the reaction time when calcium carbonate is treated in a subcritical acetic acid solution at a relatively low temperature.

FIG. 7 is a graph showing the relationship between the chitin remaining rate and the reaction time when chitin was treated in a subcritical acetic acid aqueous solution at a relatively low temperature.

FIG. 8 is a graph showing the relationship between the calcium carbonate recovery rate and the reaction temperature when the two-shell shell is treated in a subcritical acetic acid aqueous solution.

FIG. 9 is a graph showing the relationship between the solid phase residual rate and the reaction temperature when the force two-shell is treated in a subcritical acetic acid aqueous solution.

BEST MODE FOR CARRYING OUT THE INVENTION

[0096] Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the present invention is not limited to these Examples and Experimental Examples. This method can also be applied to crustaceans such as shrimp, shrimp, etc., and continuous purification of chitin is possible using a subcritical continuous processing system. [0097] Experimental Example 1

First, for comparison, force-shells were processed according to conventional methods.

[0098] The force-shell used was a sample obtained by pulverizing a freeze-dried product of a snow crab shell with a mini blender.

[0099] First, the force-shell was immersed in a 2 mol / l hydrochloric acid aqueous solution for 1 day. Thereafter, the aqueous hydrochloric acid solution was replaced, and the deashing treatment was performed by immersing for another day. Thereby the force-about 40 of the initial weight of the shell

% Calcium carbonate was removed.

[0100] Next, the protein was boiled for 6 hours with lmol / 1 sodium hydroxide aqueous solution, and the solution was changed and boiled for further 30 hours to perform deproteinization treatment. This removed about 25% of the protein in the initial weight of the force-shell.

[0101] Furthermore, the remaining lipid and dye were removed by heating at ethanol reflux for 6 hours.

[0102] By these multi-step operations, a solid phase corresponding to about 35% of the initial weight of the force-shell was finally left. This remaining solid phase was regarded as chitin produced by the conventional method.

[0103] Experimental Example 2

Next, the force bishell was treated in a subcritical water solvent according to the following procedure while appropriately changing the reaction conditions.

[0104] (Procedure)

As the force-shell, a frozen and dried product of the snow crab shell was crushed with a mini blender and used as a sample. As the water, ultrapure water produced by an ultrapure water production apparatus (Minipure TW-250RU manufactured by Nomura Micro Science Co., Ltd.) was used.

[0105] A reaction tube having SWAGELOK caps attached to both ends of a stainless steel pipe (made of SUS316) having an inner diameter of 6.4 mm, an outer diameter of 9.5 mm, a length of 150 mm, and an internal volume of about 8.0 cm ³ was prepared. The reaction tube was charged with 0.1 or 0.2 g of force-shell and 2 g of water, and after replacing the dissolved oxygen with argon, the reaction tube was closed. The reaction tube was added to a salt bath in which potassium nitrate and sodium nitrate were added at a ratio of 1: 1 and preheated to a predetermined temperature (533 to 593 K), and allowed to stand for a predetermined time (1 to 10 minutes). Thereafter, the reaction tube was quickly taken out from the salt bath and poured into water to quench it.

[0106] The process of centrifuging the sample in the reaction tube at 2500 rpm for 10 minutes and washing with water three times After repeating, it was filtered and separated into an aqueous phase and a solid phase. Next, component analysis was performed for each phase.

[0107] (Measurement method)

Organic acids contained in the aqueous phase as products are analyzed by high-performance liquid chromatographic organic acid analysis system (Shimadzu LC-10A, separation method: ion exclusion chromatograph, detection method: post-column pH buffered conductivity detection method ( column: Shim-pack SCR-102H 2 in series, mobile phase: 5mol / m ³ p- toluenesulfonic acid aqueous solution, flow rate ^{^{1.33 X 10- 8 m 3 / s}} , buffer: 5mol / m ³ p- toluenesulfonic sulfonic acid solution 0.1 mol / m ³ EDTA, 20 mol / m ³ Bis-Tris aqueous solution, detector: Shimazu CD D-6A, column temperature: 318K).

[0108] amino acid concentration in the aqueous phase as a product HPLC system (Shimadzu LC-10A, IS C -07 / S1504 column, mobile phase: four, flow rate ^{^{8.33 X 10- 9 m 3 / s}} , Temperature: 328K ) and using a fluorescence photometer (Shimadzu RF-535), post-column (reagent: two, flow rate: determined by ^{^{5 X 10- 9 m 3 / s}} ).

[0109] The sugar contained in the aqueous phase is a high-performance liquid chromatographic sugar analysis system HSS- 1500 (column: Shodex SUGAR KS-804, mobile phase: water, flow rate 1.0 cm ³ / min, detector, manufactured by JASCO Corporation : Differential refractometer MD-2010 deflection type, column temperature: 313K).

[0110] The total organic carbon content (TOC) in the aqueous phase was measured with a TOC analyzer (Shimadzu TOC-500). According to standard methods, 0.01 cm ³ of water-soluble product was injected into the TOC analyzer. Measurements under conditions of high purity air flow rate ^{^{2.5 X 10- 6 m 3 / s}} , all 25 potassium hydrogen phthalate of Oppm as standard solution of carbon (TC), 250 ppm of bicarbonate as a standard solution of inorganic carbon (IC) This was performed using a mixed solution of sodium and sodium carbonate, and TOC was determined by subtracting IC from TC.

[0111] Calcium ions dissolved in the aqueous phase after decomposition and reaction of calcium carbonate were measured using the SPS7800 ICP plasma emission spectrometer manufactured by Seiko Instruments Inc. (measurement wavelength 393.366). nm).

[0112] In Examples 1 and 2 below, the same measurement method as in this experimental example was used.

[0113] (Result)

Figure 1 shows the results of investigating the relationship between the solid-phase residual rate of the force-shell and the reaction time. Normal temperature 'normal pressure' No reaction occurs with water. However, as shown in FIG. 1, by performing subcritical water treatment at a high temperature of 533 to 593K, the weight of the solid phase decreased with the reaction time. From this, it is considered that deproteinization occurs rapidly under these conditions. However, the solid phase residual ratio is 50% or more, and considering the mass balance estimated from the conventional method (Experimental Example 1), it is considered that calcium carbonate and chitin are decomposed and are highly likely.

[0114] After the reaction was completed, the TOC, IC value, amino acid concentration, and organic acid concentration present in the aqueous phase were measured. As a result, most of the degraded proteins whose IC values were close to 0 were mostly amino acids. As a result, it was hydrolyzed as an organic acid. As amino acids, proline, alanine, methionine, histidine, arginine and the like were produced. Organic acids such as malic acid, succinic acid, lactic acid, formic acid, acetic acid, pyroglutamic acid were produced. In addition, the yields increased with the reaction time, and the yields of alanine and arginine for amino acids and acetic acid and pyroglutamic acid for organic acids were high.

[0115] Next, in order to investigate the influence of the reaction temperature and reaction time on the decomposition of calcium carbonate, the reaction temperature was set to 533 ° C or 563 ° C, and the reaction time was set to 1 minute or 2 minutes. As a result, as shown in Fig. 2, when treated for 2 minutes in a subcritical water solvent at 563 mm, calcium carbonate was hardly decomposed. It is considered that the higher the temperature, the stronger the decomposing power. Therefore, it is considered that calcium carbonate is not decomposed by treatment in a subcritical water solvent of 563 mm or less. Similarly, in order to investigate the effect of reaction temperature and reaction time on the degradation of chitin, the reaction temperature was set to 533 ° C and 563 ° C, and the reaction time was set to 1 minute or 2 minutes. As a result, as shown in Fig. 3, the chitin was hardly decomposed even when treated for 2 minutes in a subcritical water solvent at 563mm. However, since the color has changed to brown, it is presumed that a part of it is thermally decomposed and melanoidin is produced by the Maillard reaction of sugar. In order to produce high-purity chitin, it was found that calcium carbonate and protein had to be separated by chitin, but sufficient results could not be obtained when water was used as a solvent.

[0116] Example 1

Considering the results of Experimental Examples 1 and 2 and the fact that acetic acid is contained in the product in the treatment process and that the reactor is less corrosive when using weak acid, the subcritical treatment is carried out in an acetic acid aqueous solution. Tried to make sense.

[0117] (Procedure)

The force-shell was treated in the subcritical state in the same procedure as in Experimental Example 1 except that an acetic acid aqueous solution was used as the solvent.

[0118] The acetic acid aqueous solution is an acetic acid (special grade reagent manufactured by Wako Pure Chemical Industries, Ltd.) which is prepared with ultrapure water produced by an ultrapure water production apparatus (Minipure 1 TW-250RU manufactured by Nomura Microscience Co., Ltd.) to a predetermined concentration. Was used.

[0119] (Result)

First, in order to investigate the influence of the concentration of aqueous acetic acid solution and the reaction temperature on the decomposition of calcium carbonate, the concentration is about 0.03 times (0.0174 mol / 1) or about 3 times the stoichiometric molar ratio to calcium carbonate. The subcritical reaction was performed in an acetic acid aqueous solution adjusted to a concentration of 1.74 mol / l at a temperature of 563 K, 593 K or 623 K. Figure 4 shows the results of investigating the relationship between the residual rate of calcium carbonate and the reaction time.

[0120] From the results in FIG. 4, when the acetic acid concentration is 0.0174 mol / l, that is, a concentration considerably lower than the chemical reaction stoichiometric molar ratio of 1: 2, the decomposition of calcium carbonate hardly occurs, but the acetic acid concentration is 1.74 mol. / l, that is, when the stoichiometric molar ratio is 1 to 3, it is very short of 1 minute, and even during the reaction time, calcium carbonate decomposes almost completely and dissolves in the aqueous phase as acetic acid lucium. And that was a part of it.

[0121] Next, in order to investigate the influence of the reaction temperature on chitin when an acidic aqueous solution was used as the solvent, an experiment was conducted with the reaction temperature set to 563K, 593Κ or 623Κ. As a result, as shown in Fig. 5, when the acetic acid concentration is 0.174 mol / l, chitin is decomposed by the treatment in an acetic acid aqueous solution in a subcritical state at a temperature of 563 to 623 K. It was obvious that the longer the time, the more the amount of decomposition tends to increase.

[0122] Moreover, when the TOC, IC value, amino acid concentration, and organic acid concentration present in the aqueous phase were measured after the reaction was completed, most of the degraded proteins were hydrolyzed as amino acids and organic acids. I was divided.

[0123] Amino acids are cystine, serine, norine, threonine, glycine, proline, alanine, methionine, histidine, anoleginine, leucine, isoleucine, tyrosine, lysine, and phenenorea. Lanin, aspartic acid, glutamic acid and the like were produced.

[0124] As organic acids, malic acid, succinic acid, lactic acid, formic acid, acetic acid, pyroglutamic acid and the like were produced.

[0125] It was also found that the degradation products contained low-molecular chitin, chitin oligosaccharide, darcosamine, erythrose, phosphoric acid and the like.

Thus, this method was proved to be useful as a method for producing saccharides such as amino acids, organic acids, low-molecular chitin and chitin oligosaccharides, and darcosamine.

[0126] Example 2

In order to obtain high purity and high molecular weight chitin, it is necessary to decompose calcium carbonate and protein and not to decompose chitin. Therefore, the treatment was attempted in an acidic aqueous solution in a subcritical state in a relatively low temperature region.

[0127] (Procedure)

The measurement procedure is 1.74 mol / 1 acetic acid aqueous solution that is about 3 times the chemical reaction stoichiometric molar ratio with respect to calcium carbonate, and the reaction temperature is set at a relatively low temperature in the range of 453 to 523K. A subcritical process was performed in the same manner as in Example 1 except that.

[0128] First, the relationship between the decomposition of calcium carbonate and the reaction temperature was examined. The result is shown in FIG.

As a result, it was found that even at a temperature close to the lower limit of the subcritical state of 453 mm, calcium carbonate was decomposed by 90% or more in a short reaction time of 1 minute.

[0130] Further, the relationship between the chitin residual rate and the reaction temperature was examined. The results are shown in FIG.

[0131] As a result, as shown in FIG. 7, in the subcritical state where the temperature is relatively low,

About 80% or more of chitin remained undecomposed, and it became a component.

[0132] Next, the relationship between the calcium carbonate recovery from the force shell and the reaction temperature was examined. The results are shown in FIG. As a result, it was found that the recovery rate of calcium carbonate does not depend on the temperature when the treatment was carried out under conditions of acetic acid concentration of 1.74 mol / l and reaction time of 1 minute and changing the temperature from 453 to 493K. Furthermore, judging from the removal amount of calcium carbonate obtained by the conventional method (Experimental Example 1), under this condition, the calcium carbonate contained in the force-shell is almost completely decomposed, and calcium acetate is contained in the aqueous phase. As it melted, it became a component.

[0133] Furthermore, in order to investigate the relationship between the solid-phase residual rate from the force-shell and the reaction temperature, 1.74 mol / l vinegar The treatment was carried out by setting the temperature in the range of 453 to 523 K using an acid aqueous solution. Figure 9 shows the measurement results.

As a result, when the reaction temperature was changed from 45 3 to 493 K under the constant conditions of acetic acid concentration 1.74 mol / l and reaction time 1 minute, the residual solid phase obtained by the conventional method (Experimental Example 1) Judging from the amount, in addition to calcium carbonate, it was found that the proteins, lipids and pigments contained in the force-shell were separated from the chitin! /.

[0135] The residual solid phase was about 40% of the initial weight regardless of the treatment temperature, but when the obtained solid phase was further treated with hydrochloric acid, it was found to contain 3-5% calcium carbonate by ICP analysis. Wakata. This value is similar to the carbonated lucium contained in commercially available chitin (manufactured by the conventional method), and corresponds to the difference from the solid phase residual rate when no calcium carbonate is contained. From this, it was found that very high purity chitin was obtained by the present invention.

[0136] Further, when the reaction time is lengthened, the residual rate of calcium carbonate is further reduced, and after 10 minutes, when there is no calcium carbonate, that is, a solid phase residual rate equivalent to 100% pure chitin is obtained. It was. From this fact, it was confirmed that chitin with very high purity was obtained by the present invention.

[0137] Furthermore, unlike the case where water was used as the solvent, only acetic acid and glycine were detected in the aqueous solution after the completion of the reaction, so some of the organic acids produced by protein hydrolysis were A salt is formed by the reaction with calcium carbonate contained in the shell, and some of the amino acids are further reacted and decomposed by calcium ions and carbon dioxide produced by the reaction of acetic acid and calcium carbonate. Conceivable.

[0138] As shown by the comparative power between the above examples and experimental examples, by using an acidic aqueous solution activated in a subcritical state, simultaneous decalcification, decolorization, and deproteinization of organic matter containing chitin Was able to be carried out easily with a reaction time as short as 1 minute, and it was remarkable that organic matter containing chitin could be carried out at a lower cost and at a lower cost than conventional methods.

[0139] By using acetic acid, which is a weak acid, it is possible to produce high-purity chitin without using a strong acid or a strong base. On the contrary, acetic acid remaining after the reaction can be reused as a component of the acidic aqueous solution.

. Four

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Claims

The scope of the claims

[1] A method for purifying chitin, comprising treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state.

[2] The purification method according to [1], wherein the organic substance containing chitin is treated in an acidic aqueous solution in a subcritical state.

[3] The purification method according to claim 1, wherein the organic matter containing chitin is treated in an acidic aqueous solution in a subcritical state of less than 493K.

[4] The purification method according to [1], wherein the acidic aqueous solution is an organic acid aqueous solution.

[5] A method for producing chitosan, comprising treating an organic substance containing chitin in an acidic aqueous solution in a subcritical or supercritical state, and deacetylating the treated chitin.

[6] A method for producing low-molecular chitin and Z or chitin oligosaccharide, characterized by treating an organic substance containing chitin in an acidic aqueous solution in a subcritical or supercritical state.

[7] A low molecular weight chitosan and Z characterized in that an organic substance containing chitin is treated in an acidic aqueous solution in a subcritical or supercritical state, and the resulting low molecular chitin and Z or chitin oligosaccharide is deacetylated. Or the manufacturing method of chitosan oligosaccharide.

[8] A method for producing a chitin degradation product and a Z or protein degradation product comprising treating an organic substance containing chitin in an acidic aqueous solution in a subcritical state or a supercritical state.