JP2023146959A - Beer purine body adsorbent - Google Patents

Abstract

To provide a beer purine body adsorbent that contains an acid-treated product of dioctahedral type smectite-based clay and that has excellent adsorption properties for purine bodies and has a small amount of iron ion elution.SOLUTION: The present invention relates to a beer purine body adsorbent that contains an acid-treated product of dioctahedral type smectite-based clay, in which the ratio of BET specific surface area (A) measured by water vapor adsorption method to BET specific surface area (B) measured by nitrogen adsorption method, (A)/(B), is in the range of 0.90 to 2.80, and the amount of iron ions eluted into 0.1 g/L citric acid aqueous solution is 0.15 mg/g or less.SELECTED DRAWING: None

Description

The present invention relates to a purine adsorbent for beer that can adsorb purines such as compounds containing xanthine compounds typified by xanthine and adenine or guanine compounds typified by adenine and guanine as constituent components.

Alcoholic beverages such as beer contain purine, which causes gout and the like, so alcoholic beverages with reduced purine content are on sale.

By the way, xanthine, adenine, guanine, etc. are all compounds having a purine skeleton (collectively, purines). Zeolite, dioctahedral type smectite clay (acid clay), and the like are known as adsorbents for removing these from drinks (Patent Document 1).

However, zeolite is not used industrially because it has poor selectivity for purines and even the active ingredients contained in beverages are adsorbed.

Furthermore, although clay such as acid clay has the advantage of having high selective adsorption to purines and being inexpensive, it has the problem of low filterability. That is, a portion of this type of clay is colloidally dispersed in water, resulting in clogging of the filter during filtration. In order to avoid this, if centrifugation is performed without filtration, the effective ingredients will be lost and the processing cost will also increase.

Furthermore, Patent Document 1 discloses that activated clay obtained by acid-treating acid clay has excellent adsorption properties for caffeine (xanthine compound). Activated clay (Galleon Earth NF-2, Galleonite No. 251, manufactured by Mizusawa Chemical Industry Co., Ltd.) manufactured and sold by Activated Clay has a high adsorption property for caffeine.

Therefore, the present inventors conducted many experiments and studied the adsorption performance of acid-treated products obtained by acid treatment of dioctahedral-type smectite clay. Clay that has not been acid-treated up to this point, but has been acid-treated at a weaker level (hereinafter referred to as weak acid-treated clay), has better adsorption performance than clay that has not been acid-treated (acid clay). Moreover, it has been found that it has excellent filterability and can be easily separated from the solution after adsorption treatment (Patent Document 2).

However, when the above-mentioned weak acid-treated clay is used to remove purines from beer, the beer after adsorption treatment has a metallic taste that was not felt before the adsorption treatment, although the purines have been removed. was there. When we investigated the cause of this, we found that the iron contained in the acid clay before acid treatment was eluted during the acid treatment and was semi-fixed in the clay as exchangeable cations. It was thought that the cause was that it was eluted as iron ions.

Japanese Patent Publication No. 6-142405 JP2017-136584

The object of the present invention is to provide a purine adsorbent for beer containing an acid-treated product of dioctahedral smectite clay, which has excellent adsorption to purines and a small amount of iron ion elution. Our goal is to provide the following.
The purpose of limiting the use of the adsorbent as a purine for beers is that an invention for an adsorbent for purines for liquids other than beer was filed on the same day as the present invention, so it cannot be distinguished from that invention. This is to do so.
Here, the above-mentioned beer refers to a carbonated beverage with a beer-like flavor, and is a fermented beer-taste beverage obtained by fermenting malt, hops, water, etc. as raw materials using yeast. In addition, non-fermented beer-taste drinks, non-alcoholic beer-taste drinks with an alcohol content of less than 1.0 (v/v)%, non-alcoholic beer-taste drinks that do not contain alcohol, and beer flavorings containing esters, higher alcohols, lactones, etc. Contains added carbonated beverages.

The present inventors have conducted many experiments and studied the amount of iron ions eluted from weak acid-treated clay, and found that if the amount of iron ions eluted from the weak acid-treated clay itself is below a specific value, these clays are purine-based. The present inventors have discovered that it has excellent adsorption properties and can reduce the addition of a metallic taste, leading to the completion of the present invention.
Here, although it is possible that the above-mentioned iron ion is divalent or trivalent, in the present invention, the two are not particularly distinguished and are referred to as iron ions.

According to the present invention, there is provided a purine adsorbent for beer containing an acid-treated product of dioctahedral type smectite clay, which has a BET specific surface area (A) measured by a water vapor adsorption method and a BET measured by a nitrogen adsorption method. The ratio (A)/(B) to the specific surface area (B) is in the range of 0.90 to 2.80, and the amount of iron ions eluted into a 0.1 g/L citric acid aqueous solution is 0.15 mg/g or less. Provided is a purine adsorbent for beer, which is characterized by the following.
Here, the amount of iron ions eluted is the amount of iron ions eluted when 1 g of the dioctahedral smectite clay is added to an aqueous citric acid solution having a concentration of 0.1 g/L.
A citric acid aqueous solution having a concentration of 0.1 g/L was used because it showed the same amount of iron ion elution as when beer liquid was used.

In the adsorbent of the present invention,
(1) The acid-treated product of the dioctahedral type smectite clay has been further subjected to iron ion content reduction treatment;
(2) The amount of interlayer water in the acid-treated product of the dioctahedral smectite clay is 30 mg or less per 1 g of adsorbent excluding adsorbed water and interlayer water;
(3) The amount of solid acid with Ho≦-3.0 is in the range of 0.10 to 0.70 mmol/g-dry clay,
(4) The value of BET specific surface area measured by nitrogen adsorption method is in the range of 65 to 400 m ² /g,
(5) The above (A)/(B) is in the range of 1.10 to 2.40;
(6) the purine is a xanthine compound;
is suitable.

Further, according to the present invention, the method for producing beer includes a purine adsorption and removal step of adding the adsorbent and adsorbing and removing purines in the beer. A method is provided.

As shown in the examples below, the adsorbent of the present invention, when used in a small amount, can remove a large amount of purines from a purine-containing solution as well as acid clay or more. It is possible to reduce the addition of metallic taste.

Furthermore, since the adsorbent of the present invention is made of clay treated with a weak acid, it has higher filterability than acid clay and can be easily removed from the solution after the adsorption treatment.

Therefore, the adsorbent of the present invention can be suitably applied to the removal of purines from beers. Further, since the adsorbent of the present invention can reduce the amount of iron ions eluted, the influence on the color and flavor of the beverage can be suppressed.

<Weak acid treated low iron ion clay>
The adsorbent of the present invention is a beer purine adsorbent containing an acid-treated product of dioctahedral smectite clay and has an iron ion elution amount of 0.15 mg/g or less, or If the amount of iron ions eluted from the acid-treated product exceeds 0.15 mg/g, the acid-treated product may be further treated to reduce the iron ion content to reduce the amount of iron ions eluted to 0.15 mg/g or less. It is obtained by performing acid treatment which is weaker than what is generally called activated clay, or by further performing iron ion content reduction treatment. Therefore, hereinafter, the product after acid treatment or further iron ion content reduction treatment used as a purine adsorbent for beers may be referred to as "weak acid treated low iron ion clay".

The basic purpose of weak acid treatment and iron ion content reduction treatment is to obtain white clay with excellent adsorption performance and filterability for purines by performing weak acid treatment. The purpose of this method is to reduce the amount of iron ions eluted by further performing a treatment to reduce the iron ion content of the acid-treated product when the amount of iron ions eluted exceeds 0.15 mg/g.

Regarding weak acid treatment, JP 2009-072759 by the present applicant discloses that an acid-treated product called semi-active clay obtained by acid-treating dioctahedral clay is used as a catalyst for polylactic acid depolymerization. However, the weak acid treatment used in the present invention is even weaker than this acid treatment.

After acid treatment, the amount of iron ions eluted from clay generally increases. This is because part of the iron contained in the clay skeleton before acid treatment or in iron-containing compounds contained as impurities is dissolved by acid treatment, and a part of it is further transferred between the clay layers as exchangeable cations. This is thought to be due to being fixed. Furthermore, this semi-fixed iron ion cannot be completely removed by washing after acid treatment, and is thought to be eluted into beer due to the action of organic acids contained in beer during purine adsorption treatment of beer. This eluted iron ion is thought to be the cause of the metallic taste in beer.
The amount of iron ions eluted depends on the quality of the clay before acid treatment (iron content in the clay, type and amount of impurities, etc.) and the acid treatment conditions.

If the amount of iron ions eluted from the clay itself after the weak acid treatment is 0.15 mg/g or less, it is not necessary to perform the iron ion content reduction treatment by cation treatment described below. If the amount of iron ions eluted exceeds 0.15 mg/g, the solution after the adsorption treatment will have a metallic taste, so a treatment to reduce the iron ion content by cation treatment as described below is performed. Here, it is preferable that the iron ion elution amount is 0.08 mg/g or less.

The iron ion content reduction treatment in the present invention is not particularly limited as long as the amount of iron ions eluted from the clay after the weak acid treatment can be reduced to a desired concentration. This can be carried out by contacting with an aqueous solution, followed by separation and washing. Through the iron ion content reduction treatment, all or part of the iron ions in the white clay are replaced with cations other than iron, resulting in obtaining iron ion content reduction treated white clay in which the amount of iron ions eluted from the white clay is reduced. be able to.

Cations other than iron ions are not particularly limited as long as they are acceptable as food and drinks, but examples include sodium ions, potassium ions, magnesium ions, calcium ions, and aluminum ions. Among these, sodium ions and potassium ions are preferred.
In the cation treatment, one or more cations other than iron ions can be used.

In the cation treatment, the above-described cations can be added to the clay in the form of salts so that the iron ions and cations in the clay are replaced. The salt formed by the cation may be either an inorganic salt or an organic salt, and examples thereof include sulfate, chloride, gluconate, ascorbate, citrate, and lactate, and sulfate is preferable. It is.
In the cation treatment, one or more types of inorganic salts and organic salts can be used.

In the iron ion content reduction treatment, the cations brought into contact with the clay are preferably in the form of an aqueous solution, and the concentration of the cations can reduce the amount of iron ions eluted from the clay to 0.15 mg/g or less. Although not particularly limited, it is preferably 0.01 to 1000 milliequivalents (hereinafter referred to as "mEq/L"), more preferably 0.1 to 1000 mEq/L, and even more preferably 1 to 1000 mEq. /L concentration. When two or more types of cations or salts are used, the concentration of the cations is preferably such that the sum of the cation concentrations is the above concentration.

In the iron ion content reduction treatment, it is preferable to add an acidic substance so that the pH becomes 5.0 or less. From the viewpoint of efficiency in reducing the iron ion content, the acidic substance is added so that the pH is preferably 3.0 or lower, particularly preferably 2.0 or lower. When the pH is higher than 5.0, the efficiency of reducing the iron ion content becomes poor, and it may not be possible to reduce the iron ion content sufficiently. Although the acidic substance to be added is not particularly limited, it is preferable to use an aqueous sulfuric acid solution that is generally used for acid treatment of clay.

In the iron ion content reduction treatment, the contact time and contact temperature between the clay and cations are not particularly limited as long as the iron ion content in the clay can be reduced to a desired concentration, but the contact time is Preferably for 1 to 48 hours, more preferably for 1 to 24 hours, and the contact temperature is preferably 4 to 50°C, more preferably 10 to 30°C. The weak acid-treated low iron ion clay of the present invention has the following characteristics of the weak acid-treated clay (for example, the BET specific surface area (A) measured by the water vapor adsorption method and the BET specific surface area (B) measured by the nitrogen adsorption method). The iron ion content reduction treatment has a ratio (A)/(B) of 0.90 to 2.80), and the contact time and contact temperature are adjusted appropriately to prevent the iron ion content reduction treatment from becoming a stronger acid treatment than the weak acid treatment. done in a controlled manner.

In the iron ion content reduction treatment, the mixture of clay and cations is subjected to solid-liquid separation treatment to remove iron ions that have been released and eluted from the clay and cations that have not been replaced with iron ions in the clay, and then washed. This is desirable. Examples of the solid-liquid separation treatment include centrifugation and filtration. Washing is not particularly limited as long as it can remove eluted iron ions and cations that have not replaced iron ions in the clay, but it is preferable to wash with pure water two to three times.

In this weak acid-treated low iron ion clay, the level of acid treatment of dioctahedral smectite clay is very low, so the BET specific surface area (A) measured by the water vapor adsorption method and the BET specific surface area (B ) is 0.90 or more, and from the viewpoint of adsorptivity, it is preferably 0.95 or more, more preferably 1.10 or more, particularly preferably 1.20 or more. Moreover, it is 2.80 or less, and from the viewpoint of filterability, preferably 2.40 or less.

It is presumed that such weak acid-treated low iron ion clay can exhibit excellent adsorption performance for purines by having a BET specific surface area ratio (A/B) within the above range.
That is, as a method for measuring the BET specific surface area, a method using nitrogen (nitrogen method) is generally used, but a method using water vapor (water vapor method) also exists. According to the Clay Handbook (3rd edition), in the nitrogen method, the total external surface area including the end surface per unit mass is measured. Only the external surface area is measured since there is no interlayer penetration at temperature. On the other hand, in the steam method using a polar adsorbate such as water vapor, the adsorbate penetrates sufficiently between the layers of the clay so that the internal surface can be measured. Therefore, the fact that A/B is within the above range means that the micropores are increased by the very weak acid treatment and the interlayers between the three basic layers of smectite clay are expanded. The increase in micropores improves the selective adsorption of purines (especially xanthine compounds such as xanthine), and the expansion of the interlayers between the three basic layers results in appropriate surface hydrophilicity, which improves the adsorption of purines in aqueous and alcoholic solutions. It enhances sexuality. The adsorbent of the present invention (weak acid treated low iron ion clay) having the above A/B value has a well-balanced effect of moderate expansion between the three basic layers and formation of micropores within the layers during the acid treatment process. , is believed to exhibit extremely high selective adsorption to purines.
For example, in the conventionally known activated clay and semi-activated clay obtained by treatment with a strong acid, the spread between the three basic layers increases, and furthermore, the micropores formed between the layers are crushed. Therefore, the value of A/B becomes small, and therefore, the purine adsorption properties become extremely low.

Furthermore, it is presumed that such weak acid-treated low iron ion clay has excellent filterability because it has been acid-treated.
Smectite clay (acid clay) that has not been acid-treated has large interlayers containing cations such as Na between the basic layers, so it exhibits high swelling properties with water and is finely dispersed by swelling. It is thought that filtration performance is poor due to oxidation. In the case of such weak acid-treated low iron ion clay, a part of the base component in the smectite clay reacts with the acid and becomes a kind of binder that is insoluble in water, alcohol, etc. and binds the particles. It is thought that fine dispersion in the solution is suppressed and excellent filterability is exhibited.
Therefore, the weaker the acid treatment, the larger the A/B ratio, which may impair filterability.

Water retained in clay minerals is classified into adsorbed water that adsorbs on particle surfaces, interlayer water that exists in interlayer regions, and structural water that refers to hydroxyl groups within the crystal structure. As a result of studies on interlayer water in weak acid-treated low iron ion clay, the present inventors found that adsorption to purines improves when the amount of interlayer water is within a specific range.
Here, it is known that adsorbed water is desorbed from clay minerals at 60 to 80°C and interlayer water is desorbed from clay minerals at 90 to 150°C. Therefore, the present inventor measured the loss on drying at 80°C (indicating the amount of adsorbed water) and the loss on drying at 150°C (indicating the amount of adsorbed water + interlayer water), respectively, as described in the Examples below. The difference was taken as the amount of interlayer water. The amount of interlayer water is shown as the amount (mg/g) per gram of adsorbent excluding adsorbed water and interlayer water.

The weak acid-treated low iron ion clay used as an adsorbent in the present invention has an interlayer water amount of 30 mg/g or less, preferably 20 mg/g or less, and more preferably 15 mg/g or less.
Further, the amount of interlayer water is preferably 3 mg/g or more, particularly 5 mg/g or more. This is because in order to keep the amount of interlayer water below the above value, treatment must be carried out at high temperatures, which will collapse the micropores formed between the layers, causing the adsorption of purines to become more difficult. This is because it will be damaged.

Although the mechanism by which adsorption improves when the amount of interlayer water is within a certain range is still unclear, water molecules covering purine adsorption sites are removed from the interlayers and micropores within the interlayers. This is thought to be due to the fact that purines were more easily adsorbed.

In addition, even if the adsorbent of the present invention, which has a reduced amount of adsorbed water, absorbs moisture again, the absorbed water will be retained as adsorbed water, so interlayer water will not be newly retained and the adsorption performance will not be impaired. .

The weak acid-treated low iron ion clay used as an adsorbent in the present invention is obtained by a weak acid treatment compared to what is generally called activated clay, so the Na In addition, the decrease in the amount of solid acid caused by the elution of Al and Mg as the acid treatment progresses is suppressed. As a result, it exhibits an amount of solid acid equal to or higher than that of what is generally called activated clay obtained by conventional acid treatment or acid clay that has not been subjected to acid treatment. The weak acid-treated low iron ion clay preferably has a solid acid amount of Ho≦-3.0 in the range of 0.10 to 0.70 mmol/g-dry clay, and contains a large amount of relatively strong solid acids. It means. In other words, the chemical adsorption performance of solid acids on purines has been improved, and as shown in the examples below, when used in small amounts, it can be as good as or equal to conventionally known activated clay or acid clay. Even more purines can be removed from the purine-containing solution.

Here, the solid acid amount is the number of acid sites on the solid surface, and is expressed as the number of acid sites or the number of moles per 1 g of sample. For the strength of a solid acid, Hammett's acidity function Ho is used as an index. By titrating with a base such as an amine using an indicator that changes color with a certain amount of Ho, it is possible to quantify the amount of acid sites with a certain strength or higher.

In addition, since the weakly acid-treated low iron ion clay used as an adsorbent in the present invention has been acid-treated, although weakly, the BET specific surface area by the nitrogen method is improved compared to smectite clay that has not been acid-treated. It is preferably in the range of 65 to 400 m ² /g, particularly preferably in the range of 100 to 400 m ² /g. However, such weak acid-treated low-iron ion clay is considered to exhibit high adsorption, although the BET specific surface area ratio (A/B) is lower than that of smectite clay that has not been acid-treated.

Furthermore, the weak acid-treated low iron ion clay exhibits a unique X-ray diffraction peak derived from the crystal structure of the dioctahedral smectite clay. It has a peak near 2θ=62 degrees (d=1.49 to 1.50 Å).

<Production of weak acid treated low iron ion clay>
Weak acid-treated low iron ion clay having the above-mentioned characteristics is produced by roughly crushing and kneading dioctahedral-type smectite clay, and acid-treating the clay under predetermined conditions using an acid aqueous solution of a predetermined concentration. That is, this weak acid-treated low iron ion clay is obtained in the same manner as the semi-activated clay, but is obtained by acid treatment under milder conditions than the semi-activated clay.

The dioctahedral smectite clay used as raw material clay is thought to be metamorphosed from volcanic rock or lava under the influence of seawater, and the main component, dioctahedral smectite, consists of a SiO ₄ tetrahedral layer - an AlO ₆ octahedral layer. The basic structure (unit layer) is a three-layer structure (unit layer) consisting of SiO ₄ tetrahedral layers, and these tetrahedral layers and octahedral layers are partially isomorphically substituted with different metals. Between the layers, cations such as Ca, K, Na, etc., hydrogen ions, and water molecules coordinated therewith exist. In addition, Mg and Fe(II) are substituted for part of the Al in the octahedral layer of the basic three-layer structure, and Al is substituted for part of the Si in the tetrahedral layer, so the crystal lattice is negative. It has an electric charge, and this negative charge is neutralized by metal cations and hydrogen ions that exist between the basic layers. Such smectite clays include acid clay, bentonite, fuller's earth, etc., and each exhibits different characteristics depending on the type and amount of metal cations present between the basic layers, the amount of hydrogen ions, etc. For example, bentonite has a large amount of Na ions existing between the basic layers, and therefore the pH of the dispersion suspended in water is high, generally on the high alkaline side, and it also has high swelling properties in water. It also exhibits the property of gelling and solidifying. On the other hand, acid clay has a large amount of hydrogen ions existing between the basic layers, so the pH of the dispersion suspended in water is low, generally on the acidic side, and also exhibits swelling properties in water. However, compared to bentonite, its swelling property is generally low and does not result in gelation.

In the present invention, the dioctahedral type smectite clay used for producing the weak acid-treated low iron ion clay is not particularly limited, and any of the above-mentioned types can be used. In addition, such raw material clay differs depending on the origin of the clay, the place of production, and the place of burial (face) even in the same place of production, but generally it has the following composition in terms of oxides.
SiO ₂ ; 50 to 75% by mass
Al ₂ O ₃ ; 11-25% by mass
Fe ₂ O ₃ ; 2 to 20% by mass
MgO; 2-7% by mass
CaO; 0.1 to 3% by mass
Na ₂ O; 0.1 to 3% by mass
K ₂ O; 0.1 to 3% by mass
Other oxides (TiO ₂ etc.); 2% by mass or less Ig-loss (1050°C); 5-11% by mass

Furthermore, depending on the region of production, the raw clay may contain a large amount of impurities such as quartz. Therefore, it is preferable to subject the above-mentioned dioctahedral type smectite clay to purification operations such as rock and sand separation, buoyancy beneficiation, magnetic beneficiation, water elutriation, elutriation, etc. as necessary to remove as many impurities as possible, and then perform acid treatment. After performing such treatment, by performing acid treatment under mild conditions described below, it is possible to obtain weakly acid-treated clay having A/B within the above range.

The acid treatment is performed by adding raw clay to an acid aqueous solution and mixing and stirring. The acid aqueous solution used in the acid treatment is not particularly limited, but a sulfuric acid aqueous solution is generally used from the viewpoint of cost, environmental impact, and the like.

In addition, as mentioned above, this acid treatment is performed under milder conditions than the acid treatment used to produce conventionally known activated clay or semi-activated clay. For example, when using an aqueous sulfuric acid solution, , the amount of sulfuric acid aqueous solution calculated assuming that the water contained in the raw clay also constitutes the sulfuric acid aqueous solution is 250 to 800 parts by mass per 100 parts by mass of raw clay (as a dry product at 110°C), and the concentration of the sulfuric acid aqueous solution at that time is 1 The acid treatment may be performed under conditions such that the concentration is about 15% by mass. In the acid treatment, heating can be carried out to about 25 to 95°C if necessary. In this way, depending on the composition of the raw materials, the acid concentration of the acid aqueous solution used, the treatment temperature, etc., the specific surface area ratio (A/B) is kept within a predetermined range (about 0.5 to 12 hours, preferably 0. The acid treatment may be performed for about .5 to 8 hours, particularly preferably for about 0.5 to 4 hours).

If the amount of iron ions eluted from the clay itself after the weak acid treatment is 0.15 mg/g or less, there is no need to perform iron ion content reduction treatment by cation treatment. When the above iron ion elution amount exceeds 0.15 mg/g, iron ion content reduction treatment by cation treatment is performed.

In iron ion content reduction treatment, the clay after acid treatment is added to a sulfate aqueous solution containing cations such as sodium sulfate, and by mixing and stirring, the iron ions are replaced with cations such as sodium. It will be done.

By the above acid treatment and iron ion content reduction treatment, the ratio A/B of the BET specific surface area by the nitrogen method and the BET specific surface area by the water vapor method, the amount of solid acid, and the values of the BET specific surface area by the nitrogen method are within the above range. Therefore, the adsorbent of the present invention (low iron ion clay treated with a weak acid) having excellent adsorption performance for purines can be obtained.

Further, the weak acid-treated low iron ion clay obtained by the above-described acid treatment and iron ion content reduction treatment generally has the following chemical composition in terms of oxides.
SiO ₂ ; 50-85% by mass
Al ₂ O ₃ ; 8-23% by mass
Fe ₂ O ₃ ; 1 to 10% by mass
MgO; 1 to 10% by mass
CaO; 0.1 to 2% by mass
Na ₂ O; 0.1 to 3% by mass
K ₂ O; 0.1 to 5% by mass
Other oxides (TiO ₂ etc.); 2% by mass or less Ig-loss (1050°C); 4-9% by mass

After the acid treatment or the iron ion content reduction treatment, it is filtered and washed with water, and then a drying treatment is performed to adjust the amount of interlayer water. The drying process can be performed by any method such as heat drying in an oven, air drying, microwave irradiation, etc. as long as the amount of interlayer water is within a predetermined range.
The drying temperature varies depending on the drying method, but for example, when drying in an oven, the oven temperature is preferably 120°C or higher, and 140°C or higher in order to remove interlayer water from the clay mineral. It is more preferable to Further, in order to prevent the micropores formed between the layers from being crushed, the oven temperature is preferably lower than 200°C, and more preferably lower than 170°C.
The drying time is not particularly limited as long as the amount of interlayer water is within a predetermined range, but in the case of standing to dry in an oven, it is sufficient to dry for about 2 hours or more.

<Purine>
In the present invention, the above-mentioned weak acid-treated low iron ion clay exhibits excellent selective adsorption to purines, that is, compounds having a purine skeleton.

で表され、弱酸処理低鉄イオン白土は、上記のようなプリン骨格を有する化合物、即ち、部分構造としてプリン骨格を有する化合物、及び、かかる化合物の誘導体もしくはかかる化合物から派生する化合物に対して優れた選択的吸着性を示す。 The purine skeleton has the following formula:

The weak acid-treated low iron ion clay is superior to compounds having a purine skeleton as described above, that is, compounds having a purine skeleton as a partial structure, and derivatives of such compounds or compounds derived from such compounds. It exhibits selective adsorption properties.

で表されるキサンチンの他、ヒポキサンチンを挙げることができる。
キサンチン、ヒポキサンチンおよびキサンチンから派生する化合物を、本明細書では、総じてキサンチン化合物とする。本発明の吸着剤は、キサンチン化合物に対して優れた選択吸着性を示し、キサンチン化合物用吸着剤として好適であり、キサンチン用吸着剤として特に好適である。 One of the purines is the following formula:

In addition to xanthine represented by, hypoxanthine can be mentioned.
Xanthine, hypoxanthine and compounds derived from xanthine are collectively referred to herein as xanthine compounds. The adsorbent of the present invention exhibits excellent selective adsorption for xanthine compounds, is suitable as an adsorbent for xanthine compounds, and is particularly suitable as an adsorbent for xanthine.

There are also adenine and guanine as purines. Examples of compounds derived from adenine or guanine include purine nucleosides (adenosine, guanosine) composed of adenine or guanine and ribose, and purine nucleotides (adenylic acid, guanylic acid) that further contain phosphoric acid as a constituent. Other organic compounds derived from adenine or guanine include, but are not limited to, deoxyguanosine, deoxyguanosine triphosphate, nicotinamide adenine dinucleotide (NAD), and flavin adenine dinucleotide (FAD). , inosine, inosinic acid, and the like. In this specification, the above adenine or guanine and compounds derived from adenine or guanine are collectively referred to as adenine or guanine compounds. The adsorbent of the present invention exhibits selective adsorption for adenine and guanine, and therefore also exhibits excellent selective adsorption for adenine or guanine compounds, and is suitable as an adsorbent for such compounds.

In the present invention, "beer" refers to carbonated drinks with a beer-like flavor, including fermented beer-taste drinks described below, non-fermented beer-taste drinks, and alcoholic beverages with an alcohol content of 1.0 (v/v)%. Includes non-alcoholic beer-taste beverages containing less than 10% alcohol, non-alcoholic beer-taste beverages that do not contain alcohol, and carbonated beverages to which beer flavoring has been added.
In this specification, beer may be a fermented beer-taste beverage obtained by fermenting malt, hops, water, etc. as raw materials using yeast, or a non-fermented beverage that does not undergo a fermentation process. It may be a beer-taste drink. Here, malt refers to the seeds of barley, wheat, rye, oats, oats, pigeons, oats, etc. that have been germinated, dried, and rooted. It may be something.
In one aspect of the present invention, it is preferable to use barley malt. Barley malt is one of the malts most commonly used as a raw material for Japanese beer-taste beverages. There are several types of barley, such as two-rowed barley and six-rowed barley, and any of them may be used. In addition to regular malt, colored malt can also be used. In addition, when using colored malt, different types of colored malt may be used in appropriate combination, or one type of colored malt may be used. The malt ratio (the ratio of all malt used) is preferably 40% by mass or more, more preferably 45% by mass or more, even more preferably 48% by mass or more, even more preferably 50% by mass or more, particularly preferably 55% by mass or more. mass% or more, and even if it is 60 mass% or more, 65 mass% or more, 66 mass% or more, 67 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, or 100 mass% good. By improving the malt ratio, it is possible to produce a beer-taste beverage that has a rich taste derived from malt and a stronger taste of barley. Here, the malt ratio means a value calculated in accordance with the Liquor Tax Law and the Liquor Administration Related Laws and Regulations Interpretation Notice, which is April 1, 2018, as the construction date.
Furthermore, when suppressing the usage ratio of malt, the amount of raw materials other than malt (carbon source, nitrogen source) that can be assimilated by yeast may be increased. Carbon sources of raw materials that can be assimilated by yeast include monosaccharides, disaccharides, trisaccharides, and their sugar solutions, and nitrogen sources include yeast extract, soy protein, malt, soybeans, yeast extract, peas, and wheat. Examples include malt, ungerminated grains, and their decomposed products. Examples of ungerminated grains include ungerminated barley, wheat, rye, oats, oats, pigeons, oats, rice (white rice, brown rice, etc.), corn, corn, potatoes, beans (soybeans, (peas, etc.), buckwheat, sorghum, millet, millet, etc. Furthermore, starches obtained from these grains and extracts thereof may also be used.
Furthermore, the beer-taste beverage of one embodiment of the present invention may be an ale beer-taste beverage brewed through a fermentation process using top-fermenting yeast (such as Saccharomyces), or may be an ale-beer-taste beverage brewed using a bottom-fermenting yeast (such as Saccharomyces). It may also be a lager beer-taste drink or a pilsner beer-taste drink brewed through a fermentation process.

Furthermore, the beer may be an alcohol-containing beer-taste drink with an alcohol content of 1.0 (v/v)% or more, or a non-alcoholic beer-taste drink with an alcohol content of less than 1.0 (v/v)%. It may also be a non-alcoholic beer-taste drink that does not contain alcohol. In this specification, alcohol content means the alcohol content (v/v%) in a beverage, and can be measured by any known method, for example, by using a vibrating density meter. I can do it. Specifically, a sample is prepared by removing carbon dioxide gas from a beverage by filtration or ultrasonication, then the sample is directly flame distilled, the density of the resulting distillate at 15°C is measured, and the analysis method prescribed by the National Tax Agency is determined. Converted using "Table 2 Alcohol Content and Density (15℃) and Specific Gravity (15/15℃) Conversion Table" which is an attached table of (2009 National Tax Agency Directive No. 6, revised June 22, 2007). can be found. If the alcohol content is low, less than 1.0%, a commercially available alcohol measuring device or gas chromatography may be used.

In the carbonated beverage to which the beer flavoring of the present specification is added, beer flavorings include, for example, isoamyl acetate, ethyl acetate, n-propanol, isobutanol, acetaldehyde, ethyl caproate, ethyl caprylate, isoamylpropionate, linalool. , geraniol, citral, 4-vinylguaiacol (4-VG), 4-methyl-3-pentenoic acid, 2-methyl-2-pentenoic acid, 1,4-cineole, 1,8-cineol, 2,3-diethyl -5-methylpyrazine, γ-decanolactone, γ-undecalactone, ethyl hexanoate, ethyl 2-methylbutyrate, ethyl n-butyrate, myrcene, citral, limonene, maltol, ethylmaltol, and phenylacetic acid. In the flavoring treatment, one or more types of beer flavoring can be added to the above-mentioned beers.

A method for producing a fermented beer-taste beverage, which is beer according to one embodiment of the present invention, includes the following steps (1) to (3).
- Step (1): A step of performing at least one of saccharification treatment, boiling treatment, and solid content removal treatment on the raw material to obtain a pre-fermentation liquid.
- Step (2): A step of cooling the pre-fermentation liquid obtained in step (1) to obtain a cooled pre-fermentation liquid.
- Step (3): A step of adding yeast to the cooled pre-fermentation liquid obtained in step (2) and performing alcoholic fermentation.

<Step (1)>
Step (1) is a step in which various raw materials are subjected to at least one of saccharification treatment, boiling treatment, and solid content removal treatment to obtain a pre-fermentation liquid. For example, when malt is used as various raw materials, various raw materials including water and malt are put into a brewing kettle or a brewing tank, and if necessary, enzymes are added to promote changes in the components derived from the raw materials before fermentation. Agents may also be added.
Examples of the enzyme agent include amylase, protease, deaminase, polyphenol oxidase, glucanase, xylase, pectinase, cellulase, lipase, glucosidase, and the like. In addition, in Article 3 of the Liquor Tax Act and Liquor Administration Related Laws and Regulations Notification (revised June 27, 2018), "7. Articles not handled as raw materials for alcoholic beverages", "(3) During the brewing process for the purpose of streamlining sake brewing, etc. Enzymes that correspond to the following enzymes to be added can be mentioned. By adding these enzyme agents, the component composition of the resulting fermented beer-taste beverage can be efficiently adjusted. As various raw materials other than malt, hops, preservatives, sweeteners, water-soluble dietary fibers, bittering agents or bittering agents, antioxidants, flavors, acidulants, salts, etc. may be added. These may be added before performing the saccharification treatment, may be added during the saccharification treatment, or may be added after the saccharification treatment is completed. Further, these may be added after the next step of alcohol fermentation.

A mixture of various raw materials is heated to undergo saccharification treatment by saccharifying the starch of the raw materials. The temperature and time of the saccharification treatment are adjusted as appropriate, taking into account the type of malt used, the malt ratio, water and other raw materials other than malt, the type and amount of enzymes used, the original extract concentration of the final beverage, etc. It is preferable to do so. In one embodiment of the present invention, the temperature of the saccharification treatment is preferably 55 to 75°C, and the time of the saccharification treatment is preferably 30 to 240 minutes. After the saccharification treatment, filtration is performed to obtain a saccharified liquid.

Note that this saccharified liquid is preferably subjected to a boiling treatment. When performing this boiling treatment, when using hops, bittering agents, etc. as raw materials, it is preferable to add these. Hops, bittering agents, etc. may be added between the start of boiling of the saccharified liquid and before the end of boiling. In addition, instead of the above-mentioned saccharified liquid, a pre-fermentation liquid may be prepared by adding hops, a bittering agent, etc. to a mixture of malt extract and hot water, and boiling the mixture.

In addition, as various raw materials, if malt is not used, liquid sugar containing a carbon source, a nitrogen source as a raw material containing wheat or amino acids other than malt, hops, preservatives, sweeteners, water-soluble dietary fiber, and bittering agents. Alternatively, a pre-fermentation solution can be prepared by mixing bittering agents, antioxidants, fragrances, acidulants, salts, etc. with warm water to prepare a liquid sugar solution, and then boiling the liquid sugar solution. good. When using hops, they may be added before the boiling process, or between the start of boiling the liquid sugar solution and before the end of boiling.

<Step (2)>
Step (2) is a step of cooling the pre-fermentation liquid obtained in step (1) to obtain a cooled pre-fermentation liquid. After the boiling process is completed, the mixture is transferred to a whirlpool and cooled to 0 to 20°C. After cooling, the concentration of the original extract may be adjusted by removing solids such as coagulated proteins. Through such treatment, a cooled pre-fermentation liquid is obtained.

<Step (3)>
Step (3) is a step of adding yeast to the cooled pre-fermentation liquid obtained in step (2) to perform alcoholic fermentation. The yeast used in this step can be selected appropriately considering the type of fermented beer-taste beverage to be produced, the desired flavor, fermentation conditions, etc. Top-fermenting yeast may be used, or bottom-fermenting yeast may be used. It's okay.

Yeast may be added to the raw material as a yeast suspension, or a slurry obtained by concentrating yeast by centrifugation or sedimentation may be added to the pre-fermentation liquid. Alternatively, after centrifugation, the supernatant may be completely removed and added. The amount of yeast added to the stock solution can be set as appropriate, and is, for example, about 5×10 ⁶ cells/mL to 1×10 ⁸ cells/mL.

Conditions such as fermentation temperature and fermentation period when carrying out alcoholic fermentation can be set as appropriate. For example, fermentation may be carried out at 8 to 25° C. for 5 to 10 days. The temperature (increase or decrease in temperature) or pressure of the fermentation liquid may be changed during the fermentation process. The apparent degree of fermentation of a fermented beer-taste beverage can be adjusted by appropriately setting the type, amount, and timing of addition of polysaccharide-degrading enzymes such as transglucosidase. It can also be adjusted by changing the temperature (temperature or temperature drop) or pressure. Further, after completing this step, yeast may be removed using a filter or the like, and additives such as water, flavoring agents, acidulants, and pigments may be added as necessary. After these steps, steps such as a storage step and a filtration step, which are well known to those skilled in the art, may be performed in the production of fermented beer-taste beverages.

<Step (4)>
Step (4) is a purine adsorption/removal step in which purine is adsorbed and removed in order to further reduce the purine content in the method for producing a fermented beer-taste beverage.
In step (4), the adsorbent of the present invention (weak acid treated low iron ion clay) is added to the pre-fermentation solution, fermentation solution, or fermented beer-taste beverage to adsorb and remove purines. As a specific method for adding the adsorbent, it can be added from any pipe provided in the manufacturing process of the fermented beer-taste beverage or from a tank provided in the middle of the pipe. The method of adding the adsorbent is not particularly limited, but, for example, it can be added by providing an addition inlet in a pipe, or it can be added through an addition inlet provided in a tank. The adsorbent may be added as it is, or may be added dissolved in a medium such as degassed water. As a specific adsorption removal method, a known method such as adsorption removal using a filtration filter can be adopted. The purine removal step may be performed, for example, at the same time as step (1), after the end of step (1), at the same time as step (2), after the end of step (2), at the same time as step (3), or at the same time as step (3). ) may be carried out in a storage step or a filtration step, preferably after step (2), more preferably after step (3). Further, the purine removal step may be performed multiple times.

The amount of adsorbent added may be adjusted depending on the purine content of the pre-fermentation solution, fermentation solution, or fermented beer-taste beverage, and is not particularly limited. In addition, the adsorbent can be added continuously or intermittently, but it is added continuously so that the adsorbent has a constant concentration with respect to the flow rate of the pre-fermentation liquid, fermentation liquid, or fermented beer-taste beverage. (proportional addition) is preferable. In the case of proportional addition, the amount of adsorbent added (concentration of adsorbent at the time of contact with pre-fermentation liquid, fermentation liquid, or fermented beer-taste beverage) is calculated using the following formula 1.
Addition amount (ppm) = Addition amount of adsorbent per unit time (g/h)/(Flow rate of pre-fermentation liquid, fermentation liquid, or fermented beer-taste beverage at addition position (HL/h) x 100)...・(Formula 1)

The amount of adsorbent added to the pre-fermentation liquid, fermentation liquid, or fermented beer-taste beverage is, for example, preferably 50 ppm or more, more preferably 60 ppm or more, 70 ppm or more, 80 ppm or more, 90 ppm or more, 100 ppm or more, 120 ppm or more, 140 ppm. Above, 160 ppm or more, 180 ppm or more, 200 ppm or more, 220 ppm or more, 240 ppm or more, 260 ppm or more, 280 ppm or more, 300 ppm or more, and preferably 5000 ppm or less, more preferably 4500 ppm or less, 4000 ppm or less, 3500 ppm or less, 3000 ppm or less , 2500 ppm or less, 2000 ppm or less, or 1500 ppm.

In the purine removal step, the contact time between the pre-fermentation solution, fermentation solution, or fermented beer-taste beverage and the adsorbent can be set arbitrarily, for example, 5 minutes to 7 days, 10 minutes to 3 days, 10 minutes. ~180 minutes, 10~40 minutes, etc. Here, the contact time in the purine removal step is calculated by the following equation 2 when the adsorbent is added through a pipe. Therefore, the contact time can be adjusted by the distance from the adsorbent addition position to the centrifuge, and the flow rate of the pre-fermentation liquid, fermentation liquid, or fermented beer-taste beverage.
Contact time (s) = distance from the adsorbent addition position to the centrifuge (m)/flow rate of pre-fermentation solution, fermentation solution, or fermented beer-taste beverage (m/s) (Formula 2)

Further, purine nucleosidase treatment may be performed before adsorption treatment. In the purine nucleosidase treatment, adenosine and guanosine in the solution are converted into free purine groups by acting purine nucleosidase on the fermentation raw material solution before fermentation or the fermentation solution after fermentation, and this free purine is converted into free purine groups. At least a portion of the groups can be converted to xanthine, which is a free purine group that is not assimilated by yeast.
By performing a purine removal step after this treatment, xanthine among purines can be preferentially adsorbed and removed by the adsorbent of the present invention, resulting in purine removal in the final fermented beer-taste beverage. The body content can be reduced. There is no restriction on the timing of the purine nucleosidase treatment as long as it is performed before the adsorption treatment, for example, at the same time as step (1) or after the completion of step (1), or at the same time as step (3) or after step (3). ) may be carried out after completion of the procedure.

The thus obtained fermented beer-taste beverage is filled into a predetermined container and distributed on the market as a product.
The method of packaging the fermented beer-taste beverage is not particularly limited, and any packaging method well known to those skilled in the art can be used. In the container filling process, the fermented beer-taste beverage is filled into containers and sealed. In the container filling process, containers of any form and material may be used, and examples of containers include cans, bottles, plastic bottles, and barrels, but from the viewpoint of ease of transportation, Cans, bottles, and plastic bottles are preferred.

<Application>
The weak acid-treated low iron ion clay used as an adsorbent in the present invention not only has excellent selective adsorption properties for purines, but also has reduced elution of iron ions that can affect the flavor of beverages, so it is Used as an adsorbent to remove purines. For example, it is added once or multiple times in an amount of 0.001 to 10 parts by mass during or after the manufacturing process of beer. More specifically, the aforementioned weak acid-treated low iron ion clay is adjusted to a powder form with an appropriate average particle size (for example, about 10 to 300 μm), and this is mixed with a beverage. Alternatively, a method of processing the adsorbent into a column or filter and passing the liquid through it can also be adopted; in either method, the adsorbent is separated from the beverage after adsorbing xanthine and the like.

The excellent effects of the present invention will be explained by the following examples.

(1) BET specific surface area (B) by nitrogen adsorption method
Measurement was performed by the nitrogen adsorption method using TriStar 3000 manufactured by Micromeritics, and calculation was performed by the BET method. Note that the pretreatment was performed at 150° C. for 2 hours.

(2) BET specific surface area (A) by water vapor adsorption method
Measurement was performed by water vapor adsorption method using BELSORP MAX manufactured by Bell Japan Co., Ltd., and calculation was performed by BET method. Note that the pretreatment was performed at 150° C. for 2 hours.

(3) Amount of interlayer water Approximately 2 g of adsorbent powder was weighed and left to dry in an oven at 80° C. for 2 hours. Thereafter, it was weighed again to determine the weight loss W ₈₀ (%) on drying at 80° C. on a wet basis.
Approximately 2 g of adsorbent powder was weighed and left to dry in an oven at 150° C. for 2 hours. Thereafter, it was weighed again to determine the weight loss W ₁₅₀ (%) on drying at 150° C. on a wet basis.
The following formula:
W _L = (W ₁₅₀ - W ₈₀ )/(100 - W ₁₅₀ ) x 1000
Accordingly, the amount W _L (mg/g) of interlayer water per 1 g of adsorbent excluding adsorbed water and interlayer water was determined.

(4) Amount of solid acid The amount of solid acid, Ho≦-3.0, was measured by n-butylamine titration method. The sample was previously dried at 150°C for 3 hours before measurement {Reference: "Catalyst" Vol. 11, No. 6, P210-216 (1969)}.

(5) Xanthine adsorption test The xanthine adsorption capacity in this example was calculated by measuring the amount of xanthine (mg) that can be adsorbed by 1 g of adsorbent (anhydrous) from a xanthine solution with a concentration of 5 mg/L using the following method. .
First, distilled water was added to ethanol (99.5) (special grade reagent, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) to prepare a 5 vol% ethanol aqueous solution, and sulfuric acid was added to adjust the pH to 3.4. Xanthine (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was dissolved in the resulting solution to obtain a xanthine solution with a concentration of 5 mg/L.
30 g of this xanthine aqueous solution with a concentration of 5 mg/L was weighed into a 50 ml Erlenmeyer flask and left overnight in a constant temperature bath controlled at 2°C. 0.015 g of adsorbent (0.05% by mass relative to the liquid) was added, and the mixture was returned to the constant temperature bath at 2° C., and stirred for 15 minutes using a magnetic stirrer installed in the constant temperature bath.
Next, the entire amount of the liquid in the flask was transferred to a 50 ml centrifuge tube, and treated with a centrifuge (6000 manufactured by Kubota Corporation) at 3000 rpm for 15 minutes. The supernatant of the treated solution was filtered through a membrane filter with a pore size of 0.45 μm to obtain a sample solution. The absorbance of the sample solution at a wavelength of 267 nm was measured using a spectrophotometer (V-560, manufactured by JASCO Corporation). Then, the residual amount of xanthine in the sample solution was calculated using a previously prepared calibration curve showing the relationship between xanthine concentration and absorbance of 267 nm wavelength light, and the xanthine adsorption rate (%) was calculated from the amount of xanthine before addition of the adsorbent.

(6) Iron ion elution test The amount of iron ion elution in this example is the amount (mg) of iron eluted from 1 g of adsorbent (anhydrous) in a citric acid aqueous solution with a concentration of 0.1 g/L. It was measured and calculated according to the method.
First, citric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was dissolved in distilled water to obtain a citric acid aqueous solution with a concentration of 0.1 g/L.
30 g of this citric acid aqueous solution with a concentration of 0.1 g/L was weighed into a 50 ml Erlenmeyer flask and left overnight in a constant temperature bath controlled at 2°C. 0.09 g of adsorbent (0.3% by mass relative to the liquid) was added, and the mixture was returned to the constant temperature bath at 2° C., and stirred for 3 hours using a magnetic stirrer installed in the constant temperature bath.
Next, the entire amount of the liquid in the flask was transferred to a 50 ml centrifuge tube, and treated with a centrifuge (6000 manufactured by Kubota Corporation) at 3000 rpm for 15 minutes. The supernatant of the treated solution was filtered through a membrane filter with a pore size of 0.45 μm to obtain a sample solution. The iron ion concentration in the sample solution was measured using an atomic absorption spectrophotometer (Z-2010, manufactured by Hitachi High-Tech Science Co., Ltd.), and the amount of iron eluted was calculated.

Table 1 shows the physical properties and various adsorption test results for the adsorbent powders shown in the Examples and Comparative Examples below.

(Example 1)
Dioctahedral-type smectite clay produced in Tainai City, Niigata Prefecture was roughly crushed, dried in an oven at 110°C for 12 hours, crushed, and classified to obtain clay powder.
220 mL of a 10% by mass sulfuric acid aqueous solution was placed in a beaker and heated to 90°C. 30 g of the clay powder was added thereto, stirred while maintaining the liquid temperature at 90° C., and acid-treated for 30 minutes. After the acid treatment was completed, the acid treated product was filtered and washed with water.
Furthermore, 220 mL of a sodium sulfate aqueous solution with a concentration of 400 mEq/L, which had been adjusted to pH 1.0 by adding sulfuric acid, was placed in a beaker, the entire amount of the filter cake after washing was added thereto, and the iron ion content was determined by stirring at room temperature for 24 hours. Reduction processing was performed.
After the iron ion content reduction treatment, the iron ion content reduction treated product was filtered and washed with water, and the filtered cake after washing was left to dry in an oven at 150°C for 12 hours, crushed, and classified to obtain adsorbent powder. Ta.

(Example 2)
An adsorbent powder was obtained in the same manner as in Example 1 except that the operation in Example 1 was scaled up 90,000 times.

(Example 3)
An adsorbent powder was obtained in the same manner as in Example 1, except that the sodium sulfate aqueous solution with a concentration of 400 mEq/L was changed to a potassium sulfate aqueous solution with a concentration of 400 mEq/L.

(Example 4)
An adsorbent powder was obtained in the same manner as in Example 1, except that the sodium sulfate aqueous solution with a concentration of 400 mEq/L was changed to an aqueous magnesium sulfate solution with a concentration of 400 mEq/L.

(Example 5)
An adsorbent powder was obtained in the same manner as in Example 1 except that the pH was changed from pH 1.0 to pH 3.0.

(Example 6)
An adsorbent powder was obtained in the same manner as in Example 2, except that the sulfuric acid concentration was changed to 15% by mass, the weight of the added clay was increased 1.5 times, and the sodium sulfate aqueous solution concentration was changed to 450 mEq/L.

(Comparative example 1)
An adsorbent powder was obtained in the same manner as in Example 1 except that the sodium sulfate aqueous solution with a concentration of 400 mEq/L was changed to a sulfuric acid aqueous solution.

(Comparative Example 2) An adsorbent powder was obtained in the same manner as in Example 1, except that distilled water was used instead of a 400 mEq/L aqueous sodium sulfate solution adjusted to pH 1.0.

In the adsorbents of Examples 1 to 6, (A)/(B) was in the range of 0.96 to 2.15, and the adsorption rate of xanthine, a purine, was in the range of 86 to 99%, and iron ion elution was The amount (Fe elution amount) was as small as 0.02 to 0.09 mg/g.
In the adsorbents of Comparative Examples 1 and 2, (A)/(B) was in the range of 1.36 to 1.70, and the xanthine adsorption rate was in the range of 83 to 90%, but the amount of iron ion elution was It was 0.17 to 0.70 mg/g. In addition, the beers whose purines were removed using the adsorbents of Comparative Examples 1 and 2 had a metallic taste.
In addition, 3,000 ppm of the adsorbents of Examples 1, 3, 4, and 5 and Comparative Examples 1 and 2 were added to a fermented beer-taste beverage with a malt ratio of less than 50%, and the mixture was kept at 0 to 4°C for 3 hours. After stirring and contacting, the adsorbent was removed by centrifugation, and the adsorption rate of xanthine and the amount of iron ion elution were calculated. As a result, it was confirmed that, compared to the adsorbents of Comparative Examples 1 and 2, the adsorbents of Examples 1, 3, 4, and 5 had a higher xanthine adsorption rate and a smaller amount of iron ion elution.

Claims (8)

A purine adsorbent for beer containing an acid-treated product of dioctahedral type smectite clay, which has a BET specific surface area (A) measured by a water vapor adsorption method and a BET specific surface area (B) measured by a nitrogen adsorption method. The ratio of (A)/(B) is in the range of 0.90 to 2.80,
A purine adsorbent for beer, characterized in that the amount of iron ions eluted into a 0.1 g/L citric acid aqueous solution is 0.15 mg/g or less. The adsorbent according to claim 1, wherein the acid-treated dioctahedral smectite clay has been further subjected to iron ion content reduction treatment. The adsorbent according to claim 1 or 2, wherein the amount of interlayer water in the acid-treated product of the dioctahedral smectite clay is 30 mg or less per gram of adsorbent excluding adsorbed water and interlayer water. The adsorbent according to claims 1 to 3, wherein the amount of solid acid with Ho≦-3.0 is in the range of 0.10 to 0.70 mmol/g-dry clay. The adsorbent according to any one of claims 1 to 4, which has a BET specific surface area value measured by a nitrogen adsorption method in the range of 65 to 400 m ² /g. The adsorbent according to any one of claims 1 to 5, wherein the ratio (A)/(B) is in a range of 1.10 to 2.40. The adsorbent according to any one of claims 1 to 6, wherein the purine is a xanthine compound. A method for producing beers, comprising a purine adsorption and removal step of adding the adsorbent according to any one of claims 1 to 7 to adsorb and remove purines from the beers. manufacturing method.