JPS621720B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for removing iron from sugar solution. Sugar solution and sugar content are used in soft drinks, fruit juice drinks, lactic acid bacteria drinks, etc., and as raw materials for pharmaceuticals and bread making.
It is also used in the production of various canned syrups, flavored canned foods, various seasonings, and various pickles, but the presence of iron is not desirable in the processing of these foods. In other words, if iron is mixed in with the sugar solution, it will impair the flavor of the food, promote browning and oxidation of the food, and change the color tone of the food.In addition, iron will interact with the coloring agent and reduce the coloring effect. arise. To begin with, the raw materials for these sugars, starch starch, potato starch, and corn starch, contain 20 ppm, 15 ppm, and 25 ppm of iron, respectively, and rice bran, which is usually produced as a by-product using iron machinery, Contains 60ppm iron. Therefore, in the food industry, there is interest in purification treatments such as decolorization of sugar solutions as well as treatments related to iron removal, and activated carbon (granulated carbon) filtration methods and ion exchange resin methods have been used. However, although treatment at low temperatures is preferred in the ion exchange resin method, it is not easy to efficiently remove heavy metals such as iron from viscous sugar solutions, especially at low temperatures. In addition, the ion exchange resin method has problems such as the use of large amounts of acids and alkalis for regeneration treatment. In view of this situation, the present inventors have conducted various studies and have discovered a method for removing iron from sugar solutions that can be universally applied to sugar solutions and does not affect the taste or sugar concentration. That is, according to the present invention, iron in the sugar solution is removed by bringing the sugar solution into contact with a water-insoluble tannin preparation in which a water-insoluble and hydrophilic polymer and a tannin component are covalently bonded. I can do it. The sugar solution used in the present invention is not particularly limited as long as it is used in the fields of food, medicine, etc., but specifically, for example, various starches such as potato starch, corn starch, and Japanese starch. Examples include saccharification solutions, starch syrup, various glucose solutions, isomerized sugar solutions, fructose solutions, saccharification solutions such as white rice bran, and dextrin solutions. These sugar solutions can generally be used with a sugar content of 1 to 50 W/V%, and any sugar solution with an iron content of at least 1 ppm or more can be used for the purpose of iron removal in the present invention. can. The water-insoluble tannin preparation according to the present invention is a substance in which a water-insoluble and hydrophilic polymer (carrier) and a tannin component are bonded by a covalent bond. This substance can be produced by covalently bonding a tannin compound selected from tannins, aminoalkylated tannins, carboxyalkylated tannins, and hydroxyalkylated tannins to a water-insoluble and hydrophilic polymer. The tannin used in the present invention may be pyrogallol tannin or catechol tannin. Examples of pyrogallol tannins include gallic tannin and pentagram tannin, and examples of catechol tannin include tea,
Examples include catechol polymers obtained from cocoa and the like. Furthermore, the tannins do not necessarily have to be purified, and may be impure tannins such as those commercially available as persimmon tannins. In addition, as aminoalkylated tannins, carboxyalkylated tannins, or hydroxyalkylated tannins, tannins are reacted with cyanogen halides (e.g., cyanogen bromide) or epoxy compounds (e.g., epichlorohydrin) to produce cyanogen halide-activated tannins or epoxy compounds. An activated tannin is prepared and then combined with an alkylene diamine (e.g. ethylenediamine, tetramethylene diamine, hexamethylene diamine, dodecamethylene diamine), an aminoalkyl carboxylic acid (e.g. ε-aminocaproic acid), or an aminoalkanol (e.g. 2-aminoethanol). ) is preferably obtained by reacting. The reaction between tannins and cyanogen halides (e.g. cyanogen bromide) can be carried out, for example, in a suitable solvent (e.g. water) at PH
It can be suitably carried out at a temperature of about 8-12°C and about 15-30°C. The reaction of the thus obtained halogenated cyanogen-activated tannin with an alkylene diamine, aminoalkyl carboxylic acid, aminoalkanol, etc. can be carried out, for example, in a suitable solvent (e.g., water) at a pH of about 8.
~12° C., and can be suitably carried out at a temperature of about 15° C. to 30° C. On the other hand, the reaction between tannin and an epoxy compound (eg, epichlorohydrin) can be suitably carried out in a suitable solvent (eg, water) at a pH of about 9 to 14 and a temperature of about 30 to 100°C. The reaction between the epoxy compound-activated tannin thus obtained and alkylene diamine, aminoalkyl carboxylic acid, etc. is preferably carried out in a suitable solvent (e.g., water) at a pH of about 9 to 14 and a temperature of about 30 to 100°C. I can do it. On the other hand, the polymer used in the present invention is
Examples include water-insoluble and hydrophilic polymers having in their molecules one or more functional groups selected from the group consisting of hydroxyl groups, amino groups, and carboxyl groups. Here, hydrophilicity means that the polymer has the property of being wetted or swollen in water. Examples of water-insoluble and hydrophilic polymers having hydroxyl groups in the molecule include polysaccharides such as cellulose, agarose, and crosslinked dextran, and hydroxyalkylated polysaccharides (e.g., hydroxypropylated crosslinked dextran). Examples include polysaccharides with spacers introduced. Next, water-insoluble and hydrophilic polymers having amino acids in their molecules include, for example, aminoalkylated polysaccharides (e.g., aminoethylated cellulose, aminohexylated cellulose, aminohexylated agarose), aminoaralkylated polysaccharides (e.g. aminobenzylated cellulose); polyacrylamide; aminoalkylated polyacrylamide (e.g. aminoethylated polyacrylamide); p -Porous glass with a spacer introduced therein, such as amidobenzoylaminopropylated porous glass; fibrous scleroproteins, such as wool and silk; having amino groups, such as aminoalkylated wool (e.g., aminohexylated wool) Examples include fibrous scleroproteins with subacer introduced therein. Next, water-insoluble and hydrophilic polymers having a carboxyl group in the molecule include, for example, carboxyalkylated polysaccharides (e.g., carboxymethylated cellulose, carboxyhexylated agarose, carboxypentylated agarose, carboxymethylated crosslinked dextran). Examples include polysaccharides into which a spacer having a carboxyl group has been introduced, such as polysaccharides having a spacer having a carboxyl group, such as polysaccharides having a spacer having a carboxyl group, such as carboxyalkylated polyacrylamide (for example, carboxymethylated polyacrylamide). In order to produce a water-insoluble tannin preparation by covalently bonding a tannin compound as described above to a water-insoluble and hydrophilic polymer, a known method employed for producing an immobilized enzyme by a covalent bonding method [ For example, Chibata (ed.), "Immobilized Enzymes," p11-40, published by Kodansha (March 20, 1975); Yamazaki et al., "Affinity Chromatography," p19-32, published by Kodansha (February 1975). For example, it can be produced by the method described in Japanese Unexamined Patent Publication No. 55-39707. The thus obtained water-insoluble tannin preparation is brought into contact with a sugar solution to remove iron from the sugar solution, which can be carried out by any of the column method, fluidized bed method, or batch method. For example, when carrying out the column method, a column is filled with a water-insoluble tannin preparation, washed with water in an amount approximately 10 times the volume of the column, and then a sugar solution is passed through the column and the sugar solution that has passed through the column is collected. Although the passing rate of the sugar solution can be arbitrarily selected, it is generally desirable that the space velocity (SV) is 5 to 30 (hr ^-1 ).
Further, although the operating temperature can be set arbitrarily, it is generally preferable to carry out the operation at 60°C or lower. When the batch method is used, the water-insoluble tannin preparation can be washed with water of about 10 times the volume of the preparation, and then the sugar solution is added and stirred. The stirring time is preferably about 2 hours, and the operation temperature is preferably 60° C. or lower, as described above. The sugar solution treated by this method can be collected as follows. That is, since water-insoluble tannin preparations precipitate in a relatively short period of time, the supernatant liquid can be collected by decantation, or the sugar solution can be collected by removing the water-insoluble tannin preparations by filtration. Furthermore, once used water-insoluble tannin preparations can be regenerated and reused whether used in the column method or the batch method. Regeneration can be easily carried out by contacting the water-insoluble tannin preparation with a dilute acid solution (for example, 0.5N hydrochloric acid). According to the method of the present invention, by simply bringing various sugar solutions into contact with a water-insoluble tannin preparation, iron dissolved in the sugar solution can be easily removed in a short period of time to less than 0.01 ppm, which is desired as a suitable sugar solution. As a result, it is possible to obtain a sugar solution used in the production of various foods of good quality with excellent aroma, taste, and color tone. The present invention will be explained below with reference to reference examples and examples, but these are not intended to limit the present invention in any way. Reference Example 1 (1) 25 g of Filter Pulp No. 4 (trade name manufactured by Toyoro Paper Co., Ltd.) was immersed in 750 ml of 12% sodium hydroxide solution cooled to 4°C for 30 minutes, and 1.5 g of water was added.
The mixture was stirred at 60°C for 30 minutes. Add 250ml of epichlorohydrin to this, stir at 60°C for 30 minutes, and collect the activated cellulose by filtration.
Washed thoroughly with water. Add the obtained epichlorohydrin-activated cellulose to hexamethylene diamine solution 1 (6.25 g of hexamethylene diamine dissolved in water and adjust the pH to 11),
The mixture was stirred at ℃ for 2 hours. The produced aminohexylcellulose was collected by filtration, thoroughly washed with water, and then suspended in 1.25% of 0.25N sodium hydroxide solution. Add epichlorohydrin to this suspension.
After adding 125 ml and stirring at 60°C for 30 minutes, the solid content was collected by filtration and thoroughly washed with water to obtain epichlorohydrin-activated aminohexylcellulose. (2) Dissolve 31.2g of five-fold tannin in 500ml of water,
After adding 125 ml of 0.1N sodium carbonate aqueous solution, the pH was adjusted to 7.0 with sodium hydroxide aqueous solution. Add water to this solution to make a total volume of 1, and
Suspend 200 g (wet weight) of epichlorohydrin-activated aminohexyl cellulose obtained in (1),
The mixture was stirred at 45°C for 2.5 hours. After the reaction is complete, the solid content is collected by filtration, and water and 30%
By washing thoroughly with acetone water, 193 g (wet weight) of a water-insoluble tannin preparation was obtained. This wet sample was further freeze-dried to obtain 36.5 g of a dry powder product. Reference Example 2 (1) 10g of Cellulose Powder C (trade name manufactured by Toyoro Shisha Co., Ltd.) in 500ml of 25% sodium hydroxide aqueous solution
ml for 30 minutes at 25°C, and then thoroughly washed with water. 25g of the resulting alkali-treated cellulose
(wet amount) in 0.1M sodium bicarbonate aqueous solution
It was suspended in 200ml and the pH was adjusted to 11.5. 2.0 g of cyanogen bromide was added to this suspension to activate cellulose (the pH was always 11 during the activation reaction).
~11.5 and the reaction temperature was not allowed to exceed 30°C. ). After about 8 minutes, the activated cellulose was collected by filtration and washed with a pre-cooled 0.1M aqueous sodium bicarbonate solution and water.
The obtained cyanogen bromide-activated cellulose was dissolved in an aqueous solution containing 57.5 g of hexamethylene diamine (PH
10) Suspend in 250 ml and react at 25°C for 2 hours. After the reaction was completed, the solid content was collected by filtration and washed with a 0.1M aqueous sodium bicarbonate solution and water to obtain aminohexylated cellulose. (2) Dissolve five-fold tannin in water at a ratio of 5%,
The 500ml was adjusted to pH 11.5. Add 2.0g of cyanogen bromide to this solution at 20°C, and at the same temperature, pH11~
The reaction was carried out for 8 minutes while maintaining the temperature at 11.5. The resulting cyanogen bromide-activated pentad tannin solution was added to the aminohexylated cellulose obtained in (1) above, and the mixture was heated at 25°C.
The mixture was reacted for 2 hours. After the reaction, the solid content was collected by filtration and thoroughly washed with a 0.1 M aqueous sodium bicarbonate solution and water to obtain 32.3 g (wet weight) of a water-insoluble tannin preparation. This wet sample was further freeze-dried to obtain 14.6 g of a dry powder product. Reference Example 3 15 g of epoxy-activated Sepharose 6B (trade name, manufactured by Pharmacia) was sequentially washed with 500 ml of water, 500 ml of 0.5M aqueous sodium chloride solution, and 500 ml of water. To this, add a solution of 1g of five-fold tannin dissolved in 100ml of 0.1M sodium bicarbonate aqueous solution,
After adjusting the pH to 10.5 with sodium hydroxide, 37℃
The reaction was allowed to occur while shaking for 26 hours. After the reaction is complete,
Filter out the solid content, add 1 part water, and carbonate buffer (PH10).
By sequentially washing with 500 ml and water 1,
40 g (wet weight) of a water-insoluble tannin preparation was obtained. This wet sample was further freeze-dried to obtain 8 g of a dry powder product. Experimental Example 1 1 g (dry powder) of each of the water-insoluble tannin preparations prepared by the methods of Reference Examples 1 and 2 was swollen with distilled water, and then added to a column with an inner diameter of 1.5 cm (column volume;
12 ml), and 100 ml of distilled water was poured down the column to wash it. A glucose solution (concentration: 30%) containing ferrous ammonium sulfate containing 3 ppm of iron ions was allowed to flow down through this column at a rate of SV = 15 (hr ^-1 ). The effluent was fractionated into 100 ml portions, and the iron contained in each fraction was measured. The results are shown in Table 1, and it was confirmed that all water-insoluble tannin preparations according to the present invention adsorbed iron well.
The determination of iron was carried out by both atomic absorption method and colorimetric method using α,α'-dipyridyl.

[Table] Experimental Example 2 1 g of the water-insoluble tannin preparation (dry powder) prepared by the method of Reference Example 1 was swollen with distilled water, packed into a column (column volume: 12 ml), and washed with distilled water. An isomerized sugar solution containing 5 ppm of ferrous sulfate as iron ions was flowed through this column at a rate of SV=15 (hr ^-1 ). The effluent was fractionated into 100ml portions and the iron adsorption capacity of the water-insoluble tannin preparation was measured. The results are shown in Table 2, and it was confirmed that the iron adsorption amount of this tannin preparation was about 3 mg as iron ions per gram.

[Table] Experimental Example 3 After washing the column used in Experimental Example 2 with distilled water, 100 ml of 0.2N hydrochloric acid was flowed down at SV=10 (hr ^-1 ), and the column was regenerated by further washing with water. Thereafter, a re-adsorption test was conducted in exactly the same manner as in Experimental Example 2.
The results are shown in Table 3, and the iron adsorption capacity did not decrease at all even after the regeneration treatment.

[Table] Example 1 30 g of water-insoluble 10% solid wet immobilized tannin prepared by the method of Reference Example 1 was packed into a column with a jacket tube (column volume: 60 ml), washed with water,
3 of each of the three types of starch saccharification solutions obtained by saccharifying white bran starch at a flow rate of 600 ml/hr (SV=10) at ℃ was allowed to flow down. The PH, iron content, and glucose content of the saccharified solution before and after treatment were measured to examine the treatment effects. The physical properties of this saccharified solution were also shown. As shown in the table below,
All iron in the saccharification solution could be removed very significantly.

[Table] Example 2 30 g of water-insoluble 10% solid wet immobilized tannin prepared by the method of Reference Example 1 was packed into a column with a jacket tube (column volume: 60 ml), washed with water,
3 of the starch saccharified liquid obtained by saccharifying white bran starch at a flow rate of 600 ml/hr (SV=10) at ℃ was allowed to flow down.
The PH and iron content of the saccharified liquid before and after passing through the column were measured to examine the treatment effects.

【table】

[Table] As shown in the table above, the iron concentration in the sugar solution was able to be significantly lowered. Example 3 30 g of water-insoluble 10% solids fixed tannin prepared by the method of Reference Example 2 was washed with water, filtered,
After thoroughly draining the water, 10% solids dextrin solution 3 heated to 95°C was added, stirred at 95°C for 15 minutes, and then filtered. When we measured the iron concentration before and after immobilized tannin treatment, it was 86 ppb before treatment and after treatment.
It was 3ppb.

Claims (1)

[Claims] 1. Removing iron from a sugar solution by bringing the sugar solution into contact with a water-insoluble tannin preparation in which a water-insoluble and hydrophilic polymer and a tannin component are covalently bonded. Characteristic sugar solution purification method. 2. The water-insoluble tannin preparation consists of a polymer having in its molecule one or more functional groups selected from the group consisting of hydroxyl groups, amino groups, and carboxyl groups, and tannins, aminoalkylated tannins, carboxyalkylated tannins, and hydroxyalkylated tannins. The purification method according to claim 1, wherein the tannin compound selected from the group is a substance bound by a covalent bond. 3. Claim 1, wherein the sugar solution is a saccharified solution of various starches, starch syrup, various glucose solutions, isomerized sugar solution, fructose solution, saccharified solution such as white rice bran, or dextrin solution.
The purification method described in Section 2 or Section 2.