JPH0661462B2 - Method for producing water-insoluble tannin preparation - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a water-insoluble tannin preparation having excellent adsorption performance for proteins, metals and the like.

(Prior Art) Naturally occurring tannin substances are metals, proteins,
It has long been known to adsorb other coloring components.

In the food industry, there are many opportunities to use this tannic substance, and many examples of use are known particularly in the process of manufacturing various beverages. In this case, the tannic substance is mainly used for removing impurities such as proteins or metals that are inconvenient to exist in food.

Of these, protein may be derived from raw materials or may be mixed in during the food manufacturing process, and in the case of brewed beverages, it may be produced by microorganisms. Protein is
Often causes food coloring and spoilage,
In the case of a beverage, quality deterioration such as precipitation and suspension is caused, resulting in a loss of commercial value. For this reason, in the food manufacturing process, a removal method using a tannin substance has been put to practical use together with a method of precipitating by adding a clarifying agent and a method of using a proteolytic enzyme.

On the other hand, metals are often derived from water used for food production, and therefore the content of metals in water greatly affects the quality of products. In particular, iron causes inconvenient coloring and flavor inhibition, so it is removed by filtration with activated carbon, catalytic oxidation, chlorine oxidation, etc. In many cases, the effect is insufficient, and moreover, efficient methods for removing iron are being developed.

The method using a tannin substance is an advantage that the above protein and iron can be removed together, and the tannin preparation is
Since the adsorptivity of this tannin-derived substance is derived from the galloyl group, the tannin component having a galloyl group is bonded to a water-insoluble carrier to be immobilized, thereby improving the ease of handling. For example, JP-B-55-40234, JP-B-55-7225, or JP-B-58.
Japanese Patent No. 24114 proposes a method of removing iron or protein-turbid mother substance or decolorizing using a tannin preparation obtained by binding a tannin component to a water-insoluble hydrophilic polymer such as cellulose powder. There is.

(Problems to be Solved by the Invention) However, the tannin preparations proposed above are preliminarily activated with a cyanogen halide, epichlorohydrin or the like when a spacer such as alkylenediamine or aminoalkanol is bonded to a carrier in the production method thereof. turned into must keep, furthermore, it is necessary to activate either advance even when coupling the carrier and tannins. Therefore, the manufacturing process is very complicated. Further, since cyanogen halide is highly toxic, it has some problems when used in the food manufacturing process. Furthermore, the tannin activity of these tannin preparations was not always satisfactory in their adsorption capacity.

Therefore, the present invention aims to provide a method for producing a tannin preparation having good tannin activity in a simple and safe process.

(Means for Solving the Problem) The method for producing a water-insoluble tannin preparation according to the present invention uses a chloride of gallic acid triacetate, together with a polysaccharide derivative soluble in an organic solvent, as described in claim 1. After reacting in the presence of quinoline in an organic solvent, the reaction solution is dropped into a polar solvent or water to precipitate the reaction product, and only the phenolic hydroxyl group of the obtained reaction product is deacetylated. Alternatively, as described in claim 2, after the acid chloride of gallic acid triacetate and alkylenediamine are mixed to form gallic acid triacetate alkylenediamineamide, the gallic acid triacetate alkylenediamineamide is soluble in an organic solvent. It is reacted with a polysaccharide derivative in the presence of potassium carbonate in an organic solvent, and the reaction solution is placed in a polar solvent or in water. The reaction product is precipitated by dropping, and only the phenolic hydroxyl group of the obtained reaction product is deacetylated.

In the present invention, chloride of gallic acid triacetate is selected as the tannin substance, and this is reacted with the polysaccharide derivative.

On the other hand, as a carrier for the tannin component, a polysaccharide derivative soluble in an organic solvent is used, and carboxymethyl cellulose, carboxyhexyl agarose, carboxyalkylated polysaccharides such as carboxymethyl cross-linked dextran, hydroxypropyl cellulose, hydroxypropyl cross-linked dextran, etc. Examples thereof include acetylated polysaccharides such as hydroxyalkylated polysaccharides, cellulose acetate, and cellulose diacetate.

Regarding the organic solvent for reacting the acid chloride of gallic acid triacetate with the polysaccharide derivative, chloroform, dichloromethane, dichloroethane and acetone are suitable in the invention of claim 1, and the acid chloride of gallic acid triacetate is suitable. The binding is completed by stirring the product and the polysaccharide derivative in the presence of quinoline at 10 ° C. to 60 ° C. for 1 hour to 6 days. In this case, generally, if the reaction time is lengthened, the yield of the reaction product tends to increase.

Further, when alkylenediamine is introduced as a spacer into the reaction between the acid chloride of gallic acid triacetate and the polysaccharide derivative as in the invention described in claim 2, first, the acid chloride of gallic acid triacetate is introduced. The spacer is mixed and stirred to form gallic acid triacetate alkylenediamine amide, and then this gallic acid triacetate alkylenediamine amide is reacted with the polysaccharide derivative in an organic solvent. Here, as the organic solvent used, dimethyl sulfoxide, dimethylformamide, tetrahydrofuran, dioxane, or acetone is suitable, and gallic acid triacetate alkylenediamine amide and the polysaccharide derivative are used in the presence of potassium carbonate. The binding is completed by stirring at -60 ° C for 1 hour to 6 days. Examples of the alkylenediamine used as the spacer include ethylenediamine, hexamethylenediamine, dodecamethylenediamine and the like.

The acid chloride of gallic acid triacetate or the reaction product of gallic acid triacetate alkylenediamine amide and the polysaccharide derivative can be easily precipitated by dropping in a polar solvent such as methanol or ethanol or in water. Can be collected by filtration or centrifugation.

Then, by relatively weak deacetylation, only the acetyl group of the phenolic hydroxyl group bond of the reaction product is deacetylated. As the deacetylation method, the reaction product is dissolved in dioxane together with sodium acetate and water and stirred at 40 to 80 ° C. for 0.5 to 4 hours, or the reaction product is organic such as chloroform, dichloromethane, dichloroethane or acetone. It is preferable to adopt a method of dissolving in a solvent and blowing in ammonia gas.

As described above, a water-insoluble tannin preparation having excellent tannin properties can be obtained.

(Example) Below, this invention is demonstrated based on an Example.

Example 1 Cellulose diacetate 1 g (4.21 mM), gallic acid triacetate chloride 1.72 g (5.47 m)
M) and 0.9 ml of quinoline (7.58 mM) were dissolved in 30 ml of anhydrous chloroform, and the mixture was stirred at room temperature for 4 days. Next, the reaction solution was added to methanol to cause precipitation, and the precipitated reaction product was collected by filtration.

Next, 100 mg (0.194 mM) of this reaction product was added to sodium acetate 64.9 mg (0.477 mM) and water 0.2.
Dissolved in 7.5 ml of dioxane with 18 ml of 65
The mixture was stirred at 0 ° C for 2 hours for deacetylation. Furthermore, the reaction product was poured into water, filtered, and washed with methanol to obtain a water-insoluble tannin preparation having a galloyl group.

Example 2 9.44 g of gallic acid triacetate chloride together with 2 g (6.8 mM) of hydroxypropyl cellulose
(30 mM) and 6.4 ml (54 mM) of quinoline were dissolved in 40 ml of anhydrous chloroform, stirred at room temperature for 4 days, the reaction solution was added to methanol, and the precipitate was filtered to obtain a reaction.

Next, this reaction product was dissolved in chloroform and saturated with ammonia gas. After 2 hours, ammonia gas was removed while blowing nitrogen gas. This was concentrated, poured into methanol for precipitation, filtered, and washed with methanol to obtain a water-insoluble tannin preparation having a galloyl group.

[Example 3] Carboxymethyl cellulose methyl ester 358 mg
(0.93 mM), 1 g (2.8 mM) of the amide compound formed by previously reacting gallic acid triacetate chloride with ethylenediamine and 1.54 mg (11.16 mM) of potassium carbonate were dissolved in 25 ml of dioxane. And stirred at 70 ° C. for 18 hours. Next, this reaction solution was added to 1N-hydrochloric acid to generate a precipitate, and the precipitate was filtered and washed with ether.

Further, deacetylation was carried out according to Example 1 to obtain a water-insoluble tannin preparation.

With respect to the water-insoluble tannin preparations obtained in the above examples, the galloyl group substitution degree and the protein adsorption capacity were measured. Of these, the protein adsorption capacity was measured as follows. First, take 10 mg of tannin preparation and use BSA.
(Bovine serum albumin) 0.1mg or 0.5
0.2 M acetate buffer (pH 4.5) 1.6 with mg
It was added to the mixture and stirred at 20 ° C. for 1 hour. At this time, if BSA is 0.1 mg, it is 62.5 ppm, and if BSA is 0.5 mg, it is 312 ppm. This was centrifuged at 3000 rpm for 5 minutes, and the supernatant was subjected to the Bradford method using BIO-RAD reagent (Bradford H., Analytical Bioche.
BSA was quantified according to mistry, Vol 72, P, 248, (1976)), and the protein adsorption capacity was calculated from this value.

As the measurement results are shown in the following table, all showed excellent adsorption performance.

(Effects of the Invention) In the production method according to the present invention, not only the production process is simple, but also no toxic material is used, so that the production method can be applied to food production processes. Further, according to this production method, a substance having a high degree of substitution can be obtained, and therefore, it exhibits excellent adsorption ability and can be applied to a wide range of applications as an adsorbent for proteins and metals.

Claims (4)

[Claims] 1. An acid chloride of gallic acid triacetate is reacted with a polysaccharide derivative soluble in an organic solvent in the presence of quinoline in an organic solvent, and then the reaction solution is added dropwise to a polar solvent or water. A method for producing a water-insoluble tannin preparation, comprising precipitating a reaction product by deacetylation and deacetylating only the phenolic hydroxyl group of the obtained reaction product. 2. A gallic acid triacetate alkylenediamine amide is formed by reacting an acid chloride of gallic acid triacetate with an alkylenediamine, and then the gallic acid triacetate alkylenediamine amide is added together with a polysaccharide derivative soluble in an organic solvent. The reaction is carried out in the presence of potassium carbonate in an organic solvent, and the reaction solution is added dropwise to a polar solvent or water to precipitate the reaction product, and only the phenolic hydroxyl group of the obtained reaction product is deacetylated. A method for producing a water-insoluble tannin preparation characterized by the above. 3. The method for producing a water-insoluble tannin preparation according to claim 1, wherein the deacetylation is performed by dissolving and stirring the reaction product in dioxane together with sodium acetate and water. 4. The production of a water-insoluble tannin preparation according to claim 1 or 2, wherein the deacetylation is carried out by dissolving the reaction product in an organic solvent and blowing it in to saturate it. Law.