JP2008072916A - Highly dispersible vegetable chitosan and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide vegetable chitosan (highly dispersible vegetable chitosan) having improved dispersability in water, and to provide a method for producing the same. <P>SOLUTION: Highly dispersible vegetable chitosan can be produced efficiently by treating vegetable chitosan with a glycosyltransferase (for example, cyclodextrin glucanotransferase). Enzymatic treatment is, preferably, carried out in the coexistence of a sugar donor. The vegetable chitosan is, preferably, obtained by deacetylating chitin contained in carpophores or mycelia of Basidiomycetes, such as Lentinula edodes, Flammulina velutipes, Agaricus bisporus, Grifola frondosa, Pleurotus eryngii, or Lyophyllum shimeji. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plant chitosan obtained from basidiomycetes and the like. More specifically, the present invention relates to a processed plant chitosan having high dispersibility and a method for producing the same.

Chitosan is a polysaccharide mainly composed of D-glucosamine units, and various functions and functions including physiological activity are utilized in a wide range of fields such as foods, pharmaceuticals and cosmetics. For example, it is known that ingestion of chitosan makes it difficult for cholesterol to be absorbed into the body, and it is expected to help prevent obesity and improve lifestyle-related diseases. It is also used as a material.

Chitosan, which has been produced industrially until now, has a high concentration after isolating chitin (polysaccharide consisting of N-acetyl-D-glucosamine) from shells (cuticle layer) such as crabs. Chitosan produced by deacetylation of chitin by alkali treatment, that is, animal chitosan, is common.

  On the other hand, cell walls of fungi (so-called mushrooms and molds) were known to contain chitin bound to polysaccharides such as cellulose and glucan, but a method for producing chitosan from such chitin was established. Was not. In recent years, however, methods have been developed that can efficiently produce chitosan using basidiomycetes as raw materials (Patent Documents 1 and 2).

  “Plant chitosan” obtained from basidiomycetes and the like can be said to be a unique substance different from animal chitosan which is a homopolymer composed only of glucosamine in that polysaccharides such as glucan are bound. In addition to the unique physical properties and physiological activities different from animal chitosan, that is, the physiological activities inherent to glucan and chitosan, it is said to possess physiological activity as a mixture or heteropolymer of chitosan and glucan.

  In addition, chitosan produced from crab as a raw material has a strange smell and unpleasant peculiar to crab, but chitosan produced from mushroom as a raw material by the method described in the above-mentioned patent document has a preferred fragrance unique to mushrooms. Is included, and there is no off-flavor or unpleasant pity. For these reasons, it is expected that plant chitosan will be widely used in the future.

  However, chitosan as described above (both animal and plant) is soluble in neutral water but soluble in dilute acids (for example, aqueous solutions of organic acids such as citric acid and malic acid). For this reason, when chitosan is added to a food or beverage containing a lot of water, there is a problem that it precipitates and causes solid-liquid separation, which limits the use of chitosan in the field of food and the like.

As a means for avoiding such problems, for example, a method has been proposed in which a solvent is made acidic by adding an organic acid powder together with chitosan into a food to increase the solubility (Patent Document 3). Since the organic acid used can affect the taste, the range of foods that can be used is limited. In addition, it is known that chitosan becomes “water-soluble” by reducing its molecular weight (for example, molecular weight of about 10,000 or less) by chemical treatment using an oxidizing agent or enzymatic treatment using a hydrolase or the like. . However, it is thought that the physiological action as described above is exhibited by the fact that chitosan is a “dietary fiber” insoluble in water. However, such physiological effects cannot be expected.
WO2004 / 033502 JP 2005-029770 A Japanese Patent No. 3313391

  An object of this invention is to provide the vegetable chitosan (highly dispersible vegetable chitosan) improved in the dispersibility to water, and its manufacturing method.

  Highly dispersible plant chitosan can be efficiently produced by enzymatic treatment of plant chitosan with a glycosyltransferase (eg, cyclodextrin glucanotransferase). The enzyme treatment is more preferably performed in the presence of a sugar donor.

  The plant chitosan may be obtained by deacetylating chitin contained in, for example, basidiomycetes shiitake mushroom, enoki mushroom, maitake, eringi, shimeji fruiting body and mycelium. preferable.

  The highly dispersible vegetable chitosan thus obtained is superior in water dispersibility compared to conventional plant chitosan, and is suitable for use in addition to foods, cosmetics, pharmaceuticals or feeds. It is.

  According to the present invention, it is possible to produce vegetable chitosan having excellent dispersibility in water (improving dispersibility of vegetable chitosan in water), and therefore food, drinks, cosmetics, pharmaceuticals, feeds, etc. This improves the handleability in the manufacturing field, eliminates the problem of solid-liquid separation in the resulting product, and contributes to the expansion of the use of plant chitosan.

  “Plant” chitosan in the present invention refers to chitosan derived from basidiomycetes, actinomycetes, yeast, etc., but is a term for distinguishing from “animal” chitosan derived from conventional crustaceans and the like. Yes, "plant" or "plantiness" should not be interpreted narrowly.

  In the present invention, the term “highly dispersible” means that plant chitosan is more dispersible in water than ordinary plant chitosan. More specifically, for example, a gel-like substance obtained by adding and mixing plant chitosan to water is more stably maintained for a longer time than usual (the degree of separation from water is suppressed). Represents the nature.

  In addition, it is considered that no low molecular weight has occurred in the enzyme treatment in the present invention, and the “high dispersibility” in the present invention is “water solubility” obtained by reducing the molecular weight of chitosan with a hydrolase or the like. Is a distinctive property.

Plant chitosan The “plant chitosan” in the present invention is derived from chitin bound to high molecular polysaccharides such as glucan contained in basidiomycetes, actinomycetes, yeasts, etc. It is obtained by acetylation treatment. As a raw material for plant chitosan, for example, common edible basidiomycetes such as shiitake mushroom, enoki mushroom, maitake, eringi, shimeji are suitable, but are not particularly limited thereto. Examples of such plant chitosan that can be suitably used in the present invention include products such as “chitoglucan” manufactured by Recom Co., Ltd.

  Plant chitosan can be prepared by a known method using the raw materials as described above. For example, in Patent Document 1, if necessary, heat treatment is carried out in a caustic aqueous solution for soot that has been pretreated with cellulase or glucanase, followed by solid-liquid separation, and the resulting solid is dissolved in an organic acid aqueous solution. A method for producing a chitosan-containing polysaccharide by adding an alcohol or adding caustic so as to have a pH of 10 or more to cause precipitation, washing and drying the precipitate is described. In Patent Document 2, basidiomycetes are immersed in an alkaline solution and heated, then basidiomycetes are recovered and the alkaline solution is removed, and the remaining alkali is removed with an organic acid such as acetic acid or a weak acid such as carbonic acid. It describes a method for efficiently obtaining powdered vegetable chitosan by neutralization, washing with pure water, and drying with hot air. Any method described in any of the documents can be suitably used as a method for preparing the vegetable chitosan used in the present invention, but may be prepared by other methods.

The plant chitosan obtained by the method as described above has a chitin / chitosan moiety (a polymer comprising N-acetyl-D-glucosamine and D-glucosamine) and a glucan moiety (
It is presumed that this glucan moiety contains β (1-6) and β (1-4) bonds, but is substantially free of β (1-3) bonds. (See Patent Document 1). In this respect, it is a substance that is distinguished from animal chitosan that does not contain high-molecular polysaccharides other than chitin and chitosan.

  In addition, “chitosan content” of plant chitosan used in the present invention (ratio of deacetylation of glucosamine in chitin / chitosan part), molecular weight (sum of chitin / chitosan part and glucan part), chitin / chitosan part There is no particular limitation on the molar ratio of the glucan to the glucan moiety. About the vegetable chitosan obtained by the above-mentioned method, although it fluctuates also with a raw material and manufacturing conditions, Usually, chitosan content is about 5 to 80 weight%, molecular weight is about 10,000 to 1 million, and a structure The molar ratio is about chitin / chitosan part: glucan part = 1-5: 5-1.

Method for producing highly dispersible plant chitosan <Glycosyltransferase and sugar donor>
The method for producing highly dispersible plant chitosan according to the present invention is characterized by having a step of enzymatically treating plant chitosan with a glycosyltransferase.

As the glycosyltransferase used in the present invention, a glycosyltransferase (EC 2.4) or a hydrolase having a glycosyltransferase activity such as amylase can be used, and an appropriate one is selected according to use conditions and the like. be able to. For example, cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19) is a suitable glycosyltransferase from the viewpoint of a high reaction rate. CGTase may be an enzyme of any origin produced by bacteria such as Bacillus or Klebsiella. For example, the trade name “Contiszyme” (Amano Enzyme ( Product)).

  Moreover, since the dispersibility of the resulting highly dispersible vegetable chitosan tends to be excellent, the enzyme treatment using a glycosyltransferase as described above is more preferably performed in the presence of a sugar donor.

As the sugar donor, for example, starch, a partially decomposed starch (dextrin, amylose, amylopectin, maltose, etc.), cyclodextrin and the like can be used. For example, when CGTase is used as a glycosyltransferase, cyclodextrin is used. It is preferable.

<Enzyme treatment process>
Regarding the enzyme treatment in the present invention, the amount of glycosyltransferase and sugar donor added, and various conditions such as enzyme treatment time and temperature are the kind and chemical properties of the target plant chitosan, and the desired degree of dispersibility. Depending on the nature of the glycosyltransferase used, it can be adjusted appropriately.

For example, a general plant chitosan obtained from a basidiomycete, a dextrin having a weight of about 1 to 10 times that of this plant chitosan, and a CGTase at a rate of 10 to 20 units per 1 g of this dextrin, 2 to 48 By making it react over time, the highly dispersible vegetable chitosan of this invention can be obtained. The enzyme treatment is preferably performed at a temperature in the range of 50 to 60 ° C. by adjusting the pH to a range of 5 to 6 using appropriate reagents. After the enzyme treatment, the enzyme may be deactivated using a known appropriate technique, for example, heating at 90 ° C. or higher for 1 hour.

<Other processes>
The highly dispersible vegetable chitosan produced by the enzyme treatment can be used in various applications while being dispersed in water (in the form of a dispersion), but if necessary, a step for isolation and purification can be performed. After passing, it can be commercialized as a dry powder by freeze drying, hot air drying, spray drying or the like. In such steps such as isolation, purification, and dry powdering, known means can be appropriately used.

Utilization of highly dispersible plant chitosan The highly dispersible plant chitosan according to the present invention can be used not only in various applications where conventional chitosan has been used, but also in conventional chitosan due to problems such as solid-liquid separation. It can also be used in a mode that could not be used.

  For example, oral intake of plant chitosan has a lowering effect on blood pressure, urine sugar level, blood glucose level, uric acid level, total cholesterol level, triglyceride level, etc., and test values for lifestyle diseases such as hypertension and diabetes It has been reported that there is a great effect in improving the above (see Patent Document 1: WO 2004/033502, etc.). In addition, the use of chitosan having a low molecular weight as a moisturizing component or antibacterial component in order to deal with the problem of solubility has also been proposed (see Japanese Patent No. 2507425, Japanese Patent No. 2611956, etc.). ). The highly dispersible vegetable chitosan of the present invention is a suitable product for use in foods, cosmetics, pharmaceuticals, feeds and the like so as to utilize such various effects.

  The highly dispersible vegetable chitosan can be used in combination with various known foods, drinks, cosmetics, pharmaceuticals, feeds, and the like. Moreover, about the method of mix | blending highly dispersible vegetable chitosan with food-drinks, cosmetics, a pharmaceutical, or feed, a well-known mixing | blending means etc. can be used suitably.

  Foods and drinks that can be mixed with highly dispersible vegetable chitosan are not particularly limited, but examples include fruit drinks, oolong tea, green tea, black tea, cocoa, vegetable juice, green juice, soy milk, milk drink, lactic acid Beverages such as beverages, near water, sports drinks and nutritional drinks, Western confectionery such as jelly, pudding and yogurt, Japanese confectionery, seasonings, fish meat, processed fish products, processed livestock products, and the like.

  Examples of pharmaceuticals include, for example, solid preparations such as tablets, pills, powders, granules, capsules, and liquid preparations such as syrups and drinks, fillers, extenders, binders, and excipients. , Disintegrants, disintegration inhibitors, lubricants, sweeteners, flavoring agents, and other known and conventional ingredients. Examples of cosmetics include those such as emulsions, liquids, creams, lotions, and lotions.

Example

A caustic soda aqueous solution was added to the dried enoki and heat-treated, neutralized and washed with water, and then dried with hot air to obtain vegetable chitosan. 970 mL of water was added to 10 g of this vegetable chitosan and 20 g of dextrin (trade name “Paindex # 1” (manufactured by Matsutani Chemical Co., Ltd.), and the dextrin was heated and dissolved at 80 ° C. Next, the solution was cooled to 50 ° C. and pH was adjusted. Was adjusted to 6.0, 300 U of glycosyltransferase (trade name “Contiszyme” manufactured by Amano Enzyme Co., Ltd.) was added, and the reaction was allowed to proceed for 24 hours. The obtained dispersion was used as the product of the present invention.

  As a control, a dispersion was prepared by the same treatment as described above except that “Contiszyme” was not added, and the dispersibility of the product of the present invention and the control product was evaluated. The results are shown in the following table.

  The target product (conventional dispersion of plant chitosan) was separated from water after standing overnight, but the product of the present invention (dispersion of highly dispersible plant chitosan) was very good after standing overnight. The dispersibility was maintained.

1 g of mushroom chitosan (trade name “Kitoglucan” manufactured by Recom Co., Ltd.) and 0.04 mL of cyclodextrin glucanotransferase (trade name “Contiszyme” manufactured by Amano Enzyme Co., Ltd.) were added to 100 mL of ion-exchanged water and dispersed. Hold at 24 ° C. for 24 hours. Thereafter, the enzyme was inactivated by heating at 85 ° C. for 30 minutes, and the obtained dispersion was used as the product of the present invention.

  As a control, a dispersion was prepared by the same treatment as above except that “Contizyme” was not added, and the present invention product and the control product were subjected to the following two comparative tests on dispersibility.

・ Comparative test 1
Each dispersion liquid was put into a 100 mL cylinder, and the separation sedimentation property was examined. The results are shown in the following table. The numerical value indicates the volume (mL) of the gel-like material.

In the control product (conventional plant chitosan dispersion), the plant chitosan settled in a short time, but in the product of the present invention (high dispersion plant chitosan dispersion), slight separation was observed after 24 hours. However, a stable gel-like state was maintained.

・ Comparison test 2
1 g of each dispersion was sampled and placed in a 100 mL cylinder, and 100 mL of ion exchange water was added and shaken well. The results are shown in the following table.

  Even in the state diluted 100 times from the above-mentioned comparative test 1, in the control product, the plant chitosan settled after 3 hours, but in the product of the present invention, the highly dispersible plant chitosan was uniformly dispersed throughout. .

・ Functional beverage 0.01 g of dry powder of the product of the present invention of Example 2, 50 g of plain yogurt (non-fat milk solid content 16%, milk fat content 1%), erythritol 3.7 g, maltitol syrup 1.8 g, “αG sweet PX "(Toyo Seika Co., Ltd.) 0.01g, glucose fructose liquid sugar 2.0g, sugar 1.4g, pectin 0.3g
A strawberry-flavored yogurt drink was prepared by adding water to 0.80 g of strawberry juice (6-fold concentrated) and 0.20 g of fragrance to make water. Precipitation was not observed. This product contains mushroom chitosan having a body fat suppression function and can be suitably used as a functional food.

・ Functional jelly 0.01 g of dry powder of the present invention product of Example 2, 10 g of sugar, 0.02 g of “αG sweet PX”, 0.1 g of apple flavor, 0.001 g of safflower pigment, 0.4 g of acidulant, 4.0 g of gelling agent, vitamin Water was added to 0.06 g of C to make 200 g, and an apple-flavored jelly was prepared. Precipitation was not observed. This product contains mushroom chitosan having a body fat suppression function and can be suitably used as a functional food.

Claims (5)

  A method for producing highly dispersible plant chitosan, comprising a step of enzymatically treating plant chitosan obtained by deacetylating chitin contained in a plant with a glycosyltransferase.   The method for producing a highly dispersible vegetable chitosan according to claim 1, wherein the plant is a fruit body or mycelium of shiitake mushroom, enoki, mushroom, maitake, eringi or shimeji, which are basidiomycetes.   The method for producing highly dispersible vegetable chitosan according to claim 1, wherein the enzyme treatment is performed in the presence of a sugar donor.   A highly dispersible vegetable chitosan obtained by the production method according to claim 1.   A food, drink, cosmetic, pharmaceutical product or feed comprising the highly dispersible vegetable chitosan according to claim 4.