JP2002306090A - Curdlan/chitosan-containing composition and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curdlan/chitosan-containing composition having excellent characteristics inherent in the curdlan and the chitosan and capable of easily dispersed into water. SOLUTION: This composition contains the curdlan and the chitosan, preferably in amounts of 70-99 wt.% and 1-30 wt.%, respectively, and forms a complex easily dispersed in water. A method for producing the composition comprises adding a chitosan solution to a curdlan solution, wherein the chitosan solution is obtained by adding an acid to the chitosan to dissolve it, and the curdlan solution is obtained by adding an alkali, preferably having an alkali concentration of 0.1-2.0 N, to the curdlan to dissolve it. Further, a lower alcohol is added to the mixed solution, then the solution is cooled, so that the curdlan/chitosan complex is made to be deposited from the cooled solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a curdlan / chitosan-containing composition and a method for producing the same.

[0002]

2. Description of the Related Art Curdlan has D-glucose of β (1
→ 3) It is a linked nonionic linear polysaccharide. Curdlan is a polysaccharide that is insoluble in water, but is dispersed in water by high-speed stirring. When this dispersion is heated, it swells at about 50 ° C. and increases in viscosity, and further forms a gel when heated. In such gel formation, curdlan gel differs from many other gelling agents in that it is formed only by heating and does not require any other operation, and also has excellent properties of being tasteless, odorless, and colorless. In addition to these excellent properties, curdlan also has a function as a dietary fiber, and is therefore widely used in the fields of the food industry and the like. However, in order to uniformly disperse the curdlan in water as described above, it was necessary to forcibly perform high-speed stirring, which required special equipment. Alternatively, curdlan can be used by dissolving it in trisodium phosphate.
After use, a step of neutralization was required. (JP-A-9-2
JP-A-38653, JP-A-9-266773, JP-A-9-289878, JP-A-10-14541
No.). Therefore, there has been a demand for a curdlan-containing composition that is easily dispersible in water and easily used industrially. on the other hand,
Chitosan is a cationic polymer in which 2-amino-2-deoxy-D-glucose is β (1 → 4) -bonded. Chitosan is also a dietary fiber, and is also said to have an effect of suppressing bacterial growth and an effect of enhancing immunity, and is widely used in fields such as the food industry. However, since chitosan is also insoluble in water and a substance with poor dispersibility, industrial use has not always been easy.

[0003]

Accordingly, an object of the present invention is to provide a curdlan / chitosan-containing composition which has the excellent properties of curdlan and chitosan and is easily dispersible in water. .

[0004]

Means for Solving the Problems As a result of intensive studies in view of the above problems, the present inventor has surprisingly found that when both curdlan and chitosan, both of which are hardly dispersible in water, are used in combination, the easily dispersible water is obtained. The present inventors have found that a curdlan / chitosan-containing composition can be obtained, and have completed the present invention. That is, the present invention provides (1) a composition containing curdlan and chitosan,
(2) The composition according to (1), which is a complex containing curdlan and chitosan, which is easily dispersible in water.
(3) Curdlan 70-99% by weight and chitosan 1-30
(4) a chitosan solution in which an acid is added to dissolve chitosan in a curdlan solution in which curdlan is dissolved by adding an alkali; Is added, and a composition containing curdlan and chitosan is precipitated from the obtained mixed solution, (5) the method for producing the composition according to the above (2), and (5) the alkali concentration of the curdlan solution. Is from 0.1 N to 2.0 N, (6) an alkali is added to a chitosan solution in which chitosan is dissolved by adding an acid, and then curdlan is added to obtain a chitosan solution. Wherein the composition containing curdlan and chitosan is precipitated from the mixed solution.
(7) The production method according to the above (6), wherein the alkali concentration of the curdlan / chitosan mixture after the addition of the curdlan is 0.1 N to 2.0 N, (8) the pH of the chitosan solution
Wherein the alkali is sodium carbonate, potassium carbonate, trisodium phosphate, tripotassium phosphate, sodium hydroxide, potassium hydroxide, or water. (4) or (6) above, which is one or more alkalis selected from the group consisting of ammonium oxide and dimethyl sulfoxide.
(10) The method according to (4) or (6), wherein a lower alcohol is added to a mixed solution containing curdlan and chitosan and cooled to precipitate a composition containing curdlan and chitosan. The production method described above, and (11) the lower alcohol is methanol, ethanol,
One or more of propyl alcohol, butyl alcohol and isopropyl alcohol
The production method according to the above (10), which is a monovalent alcohol.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present specification, the term "composition containing curdlan and chitosan" refers to a mixture containing curdlan and chitosan. The mixture includes, for example, a mixture such as a powder obtained by mixing curdlan and chitosan by physical means, as well as a complex containing curdlan and chitosan. The complex containing curdlan and chitosan refers to a molecular assembly in which curdlan molecules and chitosan molecules are assembled via a chemical bond such as an intermolecular force (eg, hydrogen bond, hydrophobic interaction force). The method for producing curdlan used in the present invention is not particularly limited. For example, Agrobacterium biovar can be prepared using glucose as a raw material.
Can be produced using such microorganisms. Curdlan is available as a commercial product (manufactured by Takeda Pharmaceutical Co., Ltd.). The curdlan used in the present invention may be a purified product, or a culture solution containing curdlan generated by the above microorganisms or the like may be used. When using a culture solution,
The culture solution may be used as it is or as a culture solution concentrated by a centrifuge, or may be used after being diluted with water. After dilution with water, concentration by a centrifuge is particularly preferable because a water-soluble coloring substance can be removed. The compositions according to the invention usually contain 70 to 99% by weight of curdlan, preferably 80 to 90% by weight.

[0006] Chitosan is obtained, for example, by deacetylating chitin contained in the exoskeleton of invertebrates such as crab and shrimp. In addition, chitosan is available as a commercial product (trade name: Kimitsukitosan, Kimitsu Chemical Industry), and various properties are present depending on differences in the degree of deacetylation, but the present invention is not particularly limited. Can be used. The composition of the present invention usually contains 1 to 30% by weight of chitosan, preferably 10 to 20% by weight.

Production Method 1 One method of producing the composition of the present invention is to add a chitosan solution in which chitosan is dissolved by adding an acid to a curdlan solution in which curdlan is dissolved by adding an alkali. A composition containing curdlan and chitosan is precipitated from the obtained mixture.

The concentration of the curdlan in the curdlan solution is usually 0.1 to 10% (w / v), preferably 0.5 to 5.0.
% (W / v). Examples of the alkali used for dissolving the curdlan include sodium carbonate, potassium carbonate, trisodium phosphate, tripotassium phosphate, sodium hydroxide, potassium hydroxide, ammonium hydroxide, dimethyl sulfoxide, and the like. These may be used alone or in combination of two or more. The concentration of the alkali may be any concentration at which the curdlan can be dissolved. Usually, the alkali concentration in the curdlan solution is 0.1N.
It is used so as to be 2.0 N. To promote dissolution,
Stirring or heating may be performed as necessary. Preferably 4
Dissolve at 0-70 ° C.

[0009] The chitosan concentration in the chitosan solution is usually 0.1 to 5% (w / v), preferably 0.2 to 2.0% (w / v).
/ v). Examples of the acid used for dissolving chitosan include hydrochloric acid, acetic acid, lactic acid, malic acid, tartaric acid, and citric acid. These may be used alone or in combination of two or more. The amount of the acid used may be an amount capable of dissolving chitosan, and varies depending on the concentration of chitosan in the prepared chitosan solution and the type of acid used. For example, in the case of glacial acetic acid, about 1 g of chitosan is used. 0.5 ml may be used, and in the case of citric acid, malic acid or tartaric acid, about 3 g per 1 g of chitosan
May be used. Stirring may be performed as necessary to promote dissolution.

The addition ratio of the chitosan solution to the curdlan solution can be appropriately changed according to the desired properties of the composition. As an index of the addition ratio, a chitosan ratio represented by the following formula may be used. In the formula, chitosan [g] and curdlan [g] each represent a weight as a dry product. Chitosan ratio [%] = chitosan [g] / (curdlan [g] + chitosan [g]) × 100 In order to produce a composition which is uniformly dispersed in water at a low concentration, the chitosan ratio is 10 to 20%. Is preferred. In order to increase the viscosity of the suspension, the chitosan ratio is preferably from 10 to 20%. In order to shorten the time required for making the dispersion have a uniform viscosity, the chitosan ratio is preferably higher, more preferably 10% or more. In order to increase the gel strength, the lower the chitosan ratio, the better, and preferably 10% or less.

The precipitation of the composition containing curdlan and chitosan can be carried out by adding a lower alcohol to the above-mentioned mixed solution and cooling it. As the lower alcohol, a monohydric alcohol having 1 to 4 carbon atoms such as methanol, ethanol, propyl alcohol, butyl alcohol and isopropyl alcohol is preferably used. These may be used alone or in combination of two or more. The amount of the lower alcohol used varies depending on the concentrations of the curdlan and chitosan, the type of the lower alcohol used, and the like. For example, in the case of methanol, 1.3 to 2.2 volumes are usually added to 1 volume of the mixed solution. The lower alcohol may be added in multiple portions. For example, the solution is divided into two times, and the first time, 0.3 to 0.7 volumes are added, and the second time, 1.0 to 1.5 volumes are added.
The cooling temperature varies depending on the concentrations of curdlan and chitosan, the type and amount of lower alcohol used, and the like. For example, when the amount of lower alcohol is small, it is necessary to cool to a lower temperature. To one volume of the mixture having a total concentration of curdlan and chitosan of 3% (w / v), add methanol 2
When adding capacity, the cooling temperature is preferably 20 ° C. or lower.

The obtained precipitate may be collected by a conventional method such as centrifugation or filtration, and may be dried and pulverized if desired. The composition of the present invention thus obtained is a complex that is easily dispersible in water.

Production Method 2 Alternatively, an alkali solution is added to a chitosan solution in which chitosan is dissolved by adding an acid, and then curdlan and chitosan are contained from a mixture obtained by adding curdlan. The composition of the present invention can be produced by precipitating the composition.

The chitosan solution may be prepared in the same manner as in the production method 1 above. Examples of the alkali used for the alkali solution include the same alkalis as those exemplified for the dissolution of curdlan in Production Method 1 described above. Usually, the alkali concentration and the amount of the alkali solution may be adjusted so that the alkali concentration in the curdlan / chitosan mixture after the addition of the curdlan is 0.1 N to 2.0 N. The amount of curdlan added can be appropriately changed according to the desired properties of the composition.
In the same manner as described above, the ratio may be determined using the chitosan ratio as an index. When it is desired to increase the gel strength, the curdlan concentration in the mixed solution after the addition of the curdlan is preferably 0.1 to 10%.
(W / v), more preferably 0.5 to 5.0% (w / v). After addition of the curdlan, stirring or heating may be performed to promote the dissolution of the curdlan. Preferably, it is dissolved at 40 to 70 ° C. Precipitation of a complex containing curdlan and chitosan, and subsequent recovery and drying may be performed in the same manner as in Production Method 1. The composition of the present invention thus obtained is a complex that is easily dispersible in water.

The composition of the present invention thus obtained can be prepared into a uniform dispersion by general stirring without using expensive and special suspending equipment such as a high-speed mixer and a homogenizer. Can be. As a result, not only can the cost of the dispersion step be reduced, but also the subsequent degassing step of the dispersion liquid is reduced by reducing the mixing of air into the dispersion liquid due to stirring. You. This dispersion forms a gel by heat similarly to a normal curdlan dispersion. Since the composition of the present invention retains the excellent properties of curdlan, such as film-forming properties, in addition to such gel-forming properties, it can be used in the same manner as curdlan. Further, the curdlan is heated to increase the viscosity by heating as described above, the dispersion of the composition of the present invention,
Since it has a high viscosity even without heating, when the composition is used, it is not necessary to use a thickener even when the prepared solution requires a high viscosity such as noodles or livestock and marine products. .
Further, the composition of the present invention can be used as a viscosity agent. Further, the composition of the present invention has an emulsifying action and can be used as an emulsifier. Since the composition of the present invention is not digested in the human body, it also has a function as dietary fiber (dietary fiber).

Accordingly, the composition of the present invention comprises a gelling agent (forming agent) [for jelly confectionery, tofu, egg tofu, konjac or shiraki], a thickener [for example, dressing or liquid seasoning (eg, tonkatsu sauce) , Okonomiyaki sauce, grilled meat sauce, white sauce, demiglace sauce, brown sauce, tomato sauce, curry sauce, gratin sauce, white hot water)], quality improvers [eg raw, dried, instant noodles (eg, soba, udon, chinese noodles) (Ramen)), bread, cake, pork / meat / curry bean dough, processed meat (eg, ham, sausage, bacon), processed marine products (eg, kamaboko, chikuwa, Satsuageage, fish sausage) or fried ( For example, beef, chicken, pork,
Oysters, shrimps, croquettes) or nutritional enhancers [for example, for health foods (processed cereals such as corn flakes, tablets with vitamins, drinks)] and the like. Further, by utilizing the above-mentioned film-forming properties, it can be used for edible films, sheet-like foods, skins of shumai, spring rolls or ginger skins. The composition of the present invention is applied to cosmetics / quasi-drugs [packs, toothpastes, etc.]
Pigs, chickens), aquaculture feed (freshwater fish, saltwater fish, shellfish, crustaceans), artificial food, etc.), pharmaceuticals [cholesterol lowering agents,
Anticancer agent etc.]. Further, since the composition of the present invention has high separation resistance, it can be used as a separation reducing agent [additive for fresh concrete, additive for ceramic, etc.] of a hydraulic composition in fluid concrete or the like.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

[0018]

Example 1 Curd Run: Takeda Pharmaceutical Co., Ltd. was used. Chitosan: manufactured by Kurita Industry Co., Ltd. (trade name, Press Aid 1)
01) was dissolved in 1% hydrochloric acid to prepare a chitosan solution,
used. At 60 ° C., curdlan was dispersed in water, dissolved with 30% sodium hydroxide, and adjusted to a final curdlan concentration of 3% and an alkali concentration of 0.6 N, and dissolved. A chitosan solution was added to the curdlan solution so as to have a chitosan ratio shown in Table 1 below.
After adding 0.5 volume of methanol to the volume,
After cooling, a complex containing curdlan and chitosan was precipitated. After adding 1 volume of methanol, the mixture was neutralized with hydrochloric acid and centrifuged. After drying the recovered complex, it was pulverized to obtain a trial product.
The physical properties of the obtained test product (curdlan / chitosan complex) were measured. Table 1 shows these physical properties. In the table, "Concentration required for uniform dispersion (w / v%)" means that 100 ml of water and powder are placed in a 100 ml measuring cylinder, shaken several times in the horizontal direction, and a surface is formed on the supernatant even after 30 minutes. Not the lowest concentration. "3% suspension viscosity" refers to a rotational speed of 12,000 rpm with a juicer mixer (VA-W26 type manufactured by Hitachi, Ltd.).
This is a viscosity measured with a B-type viscometer (No. 3 rotor, 30 rpm, 30 ° C.) after stirring at 0 rpm for 5 minutes × 2 times and degassing. The term "viscosity onset time" refers to a rotational speed of 12,000 with a juicer mixer (VA-W26 type manufactured by Hitachi, Ltd.).
This is the time required for obtaining a uniform viscosity when stirring at high speed at 0 rpm (there is almost no change in viscosity even if the stirring time is extended thereafter). "Gel strength" is the high set gel strength of a 2% suspension and is a rheometer measurement.

[0019]

[Table 1]

As is clear from Table 1, the required concentration of uniform dispersion of the dispersion became lower as the chitosan ratio became higher at a chitosan ratio of 15% or less, but the chitosan ratio was 15%.
Above, the chitosan ratio increased as the ratio increased. The suspension viscosity of the dispersion liquid increased as the chitosan ratio increased when the chitosan ratio was 15% or less.
Above 0%, it was extremely low. The viscosity development time became shorter as the chitosan ratio became higher. Gel strength is
It decreased as the chitosan ratio increased. In this experiment, no precipitation of water-insoluble curdlan and chitosan was observed. When this sample (3%) was stirred and dispersed at room temperature (25 ° C.), it was almost uniformly dispersed. On the contrary,
Curdlan (3%) is not uniform at room temperature,
At 60 ° C., the dispersion was uniform.

Example 2 Curdlan: Alcaligenes faecalis var. Myxogene
s) The curdlan fermented broth obtained by culturing the NTK-u strain (ATCC-21680) in a glucose carbon source medium at pH 6.0 and 32 ° C. for 80 hours was used. Chitosan: a food additive of Kimitsu Chemical Industry Co., Ltd. Grade: A high-viscosity MP (trade name: Kimitukitosan) was dissolved in hydrochloric acid to 1% to prepare a chitosan solution and used. While preparing a chitosan solution so as to have a chitosan ratio shown in Table 2, 30%
Of sodium hydroxide was added to adjust the final alkali concentration to 0.6 N to obtain an alkali solution. A curdlan fermented solution was added to the alkaline solution so as to adjust the curdlan content to 3%, and the curdlan was dissolved at 60 ° C. for 2 hours. 0.5 volume of methanol is added to 1 volume of the mixed solution, and then cooled to 17 ° C., then 1 volume of methanol is added, neutralized with hydrochloric acid, and centrifuged to contain curdlan and chitosan. I got a complex. After drying the complex, it was pulverized to obtain a trial product. The physical properties of the obtained test product (curdlan / chitosan complex) were measured. Table 2 shows these physical properties. The terms in the table are the same as in Table 1. However, the “3% dispersion viscosity” was measured by stirring at room temperature for 5 minutes with a stirrer (paddle blade: 250 rpm) to disperse, and a B-type viscometer (No.
3 rotor, 30 rpm, 30 ° C.).

[0022]

[Table 2]

As is clear from Table 2, the required uniform concentration of the dispersion liquid decreased as the chitosan ratio increased from 0% to 15%, but increased at a chitosan ratio of 20%. The suspension viscosity of the dispersion increased as the chitosan ratio increased from 0% to 15% chitosan ratio, but decreased at a chitosan ratio of 20%. Viscosity development time, as the chitosan ratio increases,
It became shorter. Gel strength decreased with increasing chitosan ratio. However, when the curdlan content was adjusted to be constant, the gel strength did not decrease (data not shown). In this experiment, no precipitation of water-insoluble curdlan and chitosan was observed. When this sample (3%) was stirred and dispersed at room temperature (25 ° C.), it was almost uniformly dispersed. On the other hand, curdlan (3%) was not uniform at room temperature but was uniformly dispersed at 40 to 60 ° C. When the particles in the aqueous dispersion were observed with a microscope, the swelling of the particles was considerably larger than that of the curdlan.

[0024]

As is clear from the above, according to the present invention, a curdlan / chitosan-containing composition having excellent properties of curdlan and chitosan and easily dispersible in water can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) A61K 31/722 A61P 3/06 A61P 3/06 35/00 35/00 37/04 37/04 C09K 3 / 00 103L C09K 3/00 103 A23L 1/04 F-term (reference) 2B150 AA01 AA05 AA07 AB03 AD02 AD04 AE02 BC03 BD10 CD26 DC14 DD22 4B018 MD37 MD41 MD47 MF01 MF02 MF11 4B041 LC04 LD03 LH14 LH18 LP07 LP25 4C083 AA01 EA20 EA23 MA02 MA04 ZB09 ZB26 ZC33

Claims (11)

[Claims] 1. A composition comprising curdlan and chitosan. 2. The composition according to claim 1, which is a water-dispersible complex containing curdlan and chitosan. 3. The composition according to claim 1, comprising 70 to 99% by weight of curdlan and 1 to 30% by weight of chitosan. 4. A curdlan solution in which curdlan is dissolved by adding an alkali, a chitosan solution in which chitosan is dissolved by adding an acid is added, and curdlan and chitosan are contained from the resulting mixture. The method for producing a composition according to claim 2, wherein the composition is precipitated. 5. The method according to claim 4, wherein said curdlan solution has an alkali concentration of 0.1N to 2.0N. 6. An alkali is added to a chitosan solution in which chitosan is dissolved by adding an acid, and then curdlan is added to precipitate a composition containing curdlan and chitosan from the resulting mixture. The method for producing a composition according to claim 2, wherein 7. The method according to claim 6, wherein the alkali concentration of the curdlan / chitosan mixture after the addition of the curdlan is 0.1 N to 2.0 N. 8. The method according to claim 4, wherein the chitosan solution has a pH of 1 to 5. 9. The alkali is one or two selected from the group consisting of sodium carbonate, potassium carbonate, trisodium phosphate, tripotassium phosphate, sodium hydroxide, potassium hydroxide, ammonium hydroxide and dimethyl sulfoxide. The method according to claim 4 or 6, wherein the alkali is the above alkali. 10. The production method according to claim 4, wherein a lower alcohol is added to a mixed solution containing curdlan and chitosan and cooled to precipitate a composition containing curdlan and chitosan. 11. The method according to claim 10, wherein the lower alcohol is one or more monohydric alcohols selected from methanol, ethanol, propyl alcohol, butyl alcohol and isopropyl alcohol.