JP7165620B2 - trigonelline adsorbent - Google Patents

Description

The present invention relates to novel trigonelline adsorbents.

Trigonelline is contained in coffee beans, some fish and shellfish, etc., is a type of alkaloid having a pyridine ring, and is a compound represented by the following formula.

It is also known that trigonelline is decomposed by heat to produce nicotinic acid, and trigonelline and nicotinic acid are also known as components exhibiting bitterness in coffee (Patent Document 1). In recent years, research results have been reported that trigonelline prevents brain aging and Alzheimer's dementia, and is attracting attention as a so-called functional ingredient (Patent Document 2).

As a method for extracting trigonelline from coffee beans and the like, a method using hot water or the like is known (Patent Document 3). The only known method is a method using an exchange resin (Patent Document 4).
That is, the methods of Patent Documents 3 and 4 are extremely costly to implement industrially, so there is a demand for inexpensive mineral-based adsorbents that adsorb trigonelline. The reality is that it is almost never done.

The inventors of the present invention have studied various mineral adsorbents, but all of them have advantages and disadvantages. It has become. On the other hand, those with high trigonelline desorption ability have extremely low trigonelline adsorption ability. Therefore, it is difficult to reuse trigonelline in any adsorbent.

Japanese Patent Application Laid-Open No. 2010-119386 JP 2018-070464 JP 2018-191543 JP 2013-242284 A

Accordingly, an object of the present invention is to provide a trigonelline adsorbent which is excellent not only in trigonelline adsorption but also in trigonelline desorption.

The inventors of the present invention conducted various studies on trigonelline adsorbents, and found that, among inexpensive mineral-based adsorbents, certain silica-magnesia particles are excellent in both trigonelline-adsorbing and trigonelline-releasing properties. This finding led to the completion of the present invention.

According to the present invention, it is characterized by comprising silica-magnesia composite particles in which silica particles and magnesia particles are integrally combined, and having an anion adsorption capacity represented by the orange II adsorption amount in the range of 18 to 74 mmol/100 g. Provided is a trigonelline adsorbent that
In the present invention, the anion adsorption capacity is measured using a 10 mmol/L orange II aqueous solution.

In the trigonelline adsorbent of the present invention, the silica component and the magnesia component are represented by the following formula:
R=Sm/Mm
In the formula, Sm is the content (% by mass) of the silica component in terms of _SiO2 ,
Mm is the content (% by mass) of the magnesia component in terms of MgO,
It is preferable that the mass ratio (R) represented by is contained at a ratio of 0.1≦R≦3.5.

Further, according to the present invention, there is also provided a method for adsorbing trigonelline, which comprises adding the adsorbent to a trigonelline-containing aqueous solution to adsorb trigonelline.

In the trigonelline adsorption method of the present invention,
(1) adding the adsorbent in an amount of 0.01 part by mass or more per 1 part by mass of trigonelline contained in the aqueous solution;
is preferred.

In the present invention, the trigonelline adsorbent (that is, the used adsorbent) to which trigonelline is adsorbed by the above method is recovered by filtration or the like, and then the adsorbent is mixed with water and stirred to obtain the adsorbent. Trigonelline can be released from the agent.

The trigonelline adsorbent of the present invention consists of silica particles and magnesia particles. Neither silica particles nor magnesia particles have metal ions, such as Al ions, Ca ions, and Fe ions, which can impair the flavor of beverages. Therefore, when the adsorbent of the present invention is added to a trigonelline-containing aqueous solution to adsorb trigonelline, no metal ions are eluted into the aqueous solution. Therefore, when the purpose is to remove trigonelline from a beverage or the like, it is possible to effectively avoid the inconvenience of metal ions being eluted into the beverage and impairing its flavor.

In addition, magnesium silicate cannot be used as a food additive except when used as a filter aid for oils and fats, but the adsorbent of the present invention contains silica and magnesia components approved as food additives. It is an integrated silica-magnesia. Therefore, the present invention is suitably used for removing trigonelline from coffee bean extracts and the like.

Furthermore, the adsorbent of the present invention (hereinafter sometimes referred to as a silica-magnesia-based adsorbent) is excellent in trigonelline adsorption, and is also excellent in desorption. For example, trigonelline is adsorbed. The adsorbed trigonelline can be easily desorbed by collecting the used adsorbent, mixing it with water and stirring.
For example, as shown in Examples described later, activated clay and acid clay have adsorption performance for trigonelline equal to or higher than that of the silica-magnesia-based adsorbent of the present invention. However, minerals such as activated clay and acid clay have remarkably low detachability of trigonelline. Therefore, although trigonelline can be adsorbed and removed from aqueous solutions, it is difficult to desorb and reuse trigonelline. In addition, although silica has remarkably excellent desorption properties for adsorbed trigonelline, it has extremely poor adsorption properties for trigonelline and cannot be industrially used as a trigonelline adsorbent.

However, the silica-magnesia-based adsorbent of the present invention not only exhibits high adsorption to trigonelline, but is also excellent in desorption of adsorbed trigonelline. Therefore, the adsorbent of the present invention can be used to collect trigonelline for reuse, which is the greatest advantage of the present invention.

The trigonelline adsorbent of the present invention comprises silica-magnesia composite particles. Silica-magnesia composite particles are substantially formed from silica and magnesia components, which are approved as adsorbents and filter aids for food production. Magnesium) particles are not dissolved in water, but are dispersed as nano-order unit particles (nanoparticles) and homogeneously mixed, and maintains a high adsorption capacity for anionic pigments (orange II) derived from magnesia components. It is a particle that is tightly monolithic so as to be

[Integral Composite and Structure of Silica-Magnesia Composite Particles]
In the present invention, silica (A) and magnesia or its hydrate (B) are homogeneously mixed in the presence of water to form an aqueous slurry (homogeneous mixing), then aged, and water is removed. Thus, the desired silica-magnesia composite particles can be obtained.

That is, silica (silicon dioxide), which is one of the raw materials, is disaggregated into colloidal particles and fine agglomerated particles (primary and secondary particles) in the presence of moisture, for example, by homogenous mixing in water. When magnesia (magnesium oxide) on the other hand is put into water and stirred or pulverized, it hardly dissolves. crystals) are disintegrated or exfoliated to form fine particles of magnesia (magnesium oxide) and/or magnesium oxide hydrate and dispersed in water.

In the aging step, water is removed from the slurry in which these fine particles are uniformly dispersed, and as the solid content concentration increases, the silica particles (A) and the magnesia particles (B) are gradually or rapidly formed. They come close to each other, and without chemical bonding that involves exchange or recombination of atoms, they reach an integrally combined form (completion of integrally combining). That is, the silica-magnesia composite particles of the present invention have an integrated structure so as not to separate by physical means.

The homogenous mixing and aging as described above are performed at 100°C or less, preferably at 50 to 97°C. Performing at 50 to 79°C effectively prevents gelation and enables complex integration in a short time. It is suitable for doing.

Homogenous mixing and aging are generally carried out with stirring in a stirring tank equipped with a stirring blade, but can also be carried out with pulverization or dispersion using a wet ball mill or colloid mill.
Further, it is necessary to carry out homogenous mixing and aging for at least 0.5 hours, although this varies depending on the temperature, the amount of slurry charged, and the like. In addition, the higher the temperature, the higher the fluidity of the nanoparticles and the more efficient the homogenization. Mixing and aging are generally carried out for 1 to 24 hours, particularly 3 to 10 hours.

Moisture removal after aging is carried out by evaporative drying using a spray dryer, slurry dryer, etc., but after dehydration to some extent by means of filtration, centrifugation, etc., it is dried in a box dryer or a band dryer. , a fluid bed dryer or the like may be used for drying. Drying is preferably carried out at a temperature in the range of 110-200°C. At this time, the hydration of the raw material (B) is at least partially or completely eliminated. In addition, from the viewpoint of increasing the particle strength, calcination can be performed in a calcination furnace after drying, and the calcination temperature is in the range of 300 to 830.degree.

As described above, silica-magnesia composite particles having a moisture content of, for example, 10% by mass or less, and having silicon dioxide (silica) particles and magnesia particles, which are raw material particles, closely combined by dehydration, are formed into granules, It can be obtained in the form of powder, cake or nodules. These are pulverized, classified, or molded, if necessary, and used as a particle shape suitable for adsorption of trigonelline, which will be described later.

In the present invention, since the silica component and the magnesia component are integrally combined as described above, the adsorption capacity for the anionic dye (orange II) derived from the magnesia component is maintained high, and the orange II adsorption amount The anion adsorption capacity represented by is in the range of 18 to 74 mmol/100 g. That is, since trigonelline is a bi-charged substance having both a positive charge and a negative charge in one molecule, it exhibits high adsorption to trigonelline due to the above-mentioned anion adsorption ability. For example, when a silica component and a magnesia component form a chemical bond like magnesium silicate, the anion adsorption capacity represented by the orange II adsorption amount is as low as 17 or less, and the trigonelline adsorption is remarkably low. Become.

In addition, the trigonelline adsorption properties of silica alone and magnesia alone are remarkably low. Therefore, even a mixture obtained by simply dry-mixing silica and magnesia exhibits low adsorption to trigonelline.

Thus, trigonelline can hardly be adsorbed when a silica component or a magnesia component exists alone or in the form of a reactant. A high trigonelline adsorptivity is expressed by integrally complexing such that the adsorption capacity for the anionic dye (orange II) derived from the component is maintained at a high level.
Furthermore, the silica-magnesia composite particles are also excellent in desorption of adsorbed trigonelline. The reason for exhibiting such detachability has not been clarified exactly, but the present inventors presume that it is because trigonelline has both a negative charge and a positive charge. there is That is, it is thought that the anion adsorption ability of the silica-magnesia composite particles causes the adsorption to trigonelline, but since trigonelline also has a positive charge, the adsorption to trigonelline is not high. It is considered that the detachability is high as a result of the fact that it is loosely held in a state in which it is relatively easy to detach.

In the present invention, the mass ratio of the silica component and the magnesia component may be determined as appropriate. 5, particularly preferably 1.3≤R≤3.0, more preferably 1.5≤R<2.5.
R=Sm/Mm
In the formula, Sm is the content (% by mass) of the silica component in terms of _SiO2 ,
Mm is the content (% by mass) of the magnesia component in terms of MgO.

The degree of integral compositing varies depending on the mass ratio (R) of the silica component and the magnesia component in the adsorbent. For example, when the mass ratio is around 2 (R ≈ 2, preferably 1.5 ≤ R < 2.5), the mass ratio of the silica component and the magnesia component is just right for integral compositing. The expressed anion adsorption capacity is as high as 18 mmol/100 g or more, and the degree of monolithic complexation is very high.

As the above mass ratio becomes less than 2 (R<2) and progresses to a relatively magnesia-rich region, many magnesia fine particles, which are abundant, form the entire magnesia matrix phase. It is thought that the silica component is in a dispersed state, that is, the degree of integral composite is considered to be low. Furthermore, when the magnesia component becomes rich and R < 0.1, the anion adsorption capacity represented by the orange II adsorption amount of the silica-magnesia composite particles of the present invention is outside the above range, and as a result Not only is the adsorption capacity lowered, but the magnesia component is unnecessarily hydrated by moisture in the atmosphere over time, and there is a disadvantage that the anion adsorption capacity cannot be maintained within the above range over a long storage period. In particular, the hydration of the magnesia component over time greatly affects the adsorption capacity of the anionic dye (orange II) derived from the magnesia component. Therefore, when the mass ratio (R) does not satisfy the above range, the anion adsorption capacity is lowered due to hydration, and as a result, a high trigonelline adsorption capacity cannot be maintained. In the present invention, the silica component effectively suppresses the hydration of the magnesia component, resulting in high trigonelline adsorption capacity.

Conversely, when the mass ratio exceeds 2 (2<R) and the region is relatively silica-rich, a large number of fine silica particles form an amorphous silica matrix phase throughout. , in which the magnesia component is sparsely dispersed. In particular, when the silica component is large and 3.5<R, the silica component is excessive, and the adsorption capacity for the anionic dye (orange II) derived from the magnesia component is low, resulting in trigonelline adsorption. decreased ability.

Since the silica-magnesia composite particles of the present invention are integrally combined so as to maintain a high adsorption capacity for the anionic dye (orange II) derived from the magnesia component, the anion represented by the orange II adsorption amount The adsorption capacity is 18 mmol/100 g or more, preferably 20 mmol/100 g or more from the viewpoint of trigonelline adsorption capacity, and 74 mmol/100 g or less, particularly 71 mmol/100 g or less from the viewpoint of monolithic complexing. preferred.

As described above, the trigonelline adsorbent of the present invention comprising silica-magnesia composite particles generally has an adsorption amount of trigonelline of about 8 to 15 mg per gram.

In addition, in the silica-magnesia composite particles, the silica component and the magnesia component are not separated from each other and are closely combined, so the pH of the suspension is usually in the range of 6.0 to 10.0. It is in.

Furthermore, the BET specific surface area measured by the nitrogen adsorption method is preferably 100 m ² /g or more, further 500 m ² /g or more, particularly 600 m ² /g or more, in terms of stably adsorbing trigonelline. .

The silica-magnesia composite particles used as the trigonelline adsorbent of the present invention are not particularly limited. It is preferable to granulate into spherical or ellipsoidal particles having a diameter or major axis of 5 μm to 5 mm, or cylindrical particles having a diameter of 0.5 mm or more and an axial length of 50 mm or less for use.
Such silica-magnesia composite particles are commercially available from Mizusawa Chemical Industry Co., Ltd., for example.

The adsorbent of the present invention can adsorb trigonelline by adding it to an aqueous solution containing trigonelline, for example, an aqueous solution in which trigonelline is extracted by adding it to water in which coffee beans or the like are boiled, and mixing and stirring. .
In addition, the adsorbent of the present invention can be used without any limitation for solutions containing trigonelline compounds bound to various salts such as phosphates and hydrochlorides.

The amount of the adsorbent to be added is generally 0.01 parts by mass or more, particularly in the range of 0.01 to 320 parts by mass, per 1 part by mass of trigonelline contained in the aqueous solution. If the input amount is small, as a matter of course, the adsorption amount of trigonelline becomes insufficient. In addition, if the amount to be charged is larger than necessary, it is disadvantageous in terms of cost.
The concentration of trigonelline in the aqueous solution into which the adsorbent is added can be measured by high performance chromatography or the like.

The time required for the above adsorption varies depending on the amount of the trigonelline-containing aqueous solution and the concentration of trigonelline, but is generally about 0.25 to 24 hours. A lower temperature is sufficient, and no heating or the like is necessary. That is, there is no possibility that trigonelline will deteriorate due to this adsorption. Stirring can also be performed with a normal stirring blade or the like.

As already mentioned, trigonelline adsorbed on the above adsorbents can be easily desorbed.
For example, an adsorbent (spent adsorbent) that is put into a trigonelline-containing aqueous solution and trigonelline is adsorbed is collected by filtration, and the recovered used adsorbent is mixed with water and stirred to remove trigonelline. can be released.
The amount of water to be used for mixing and stirring is not particularly limited, but in general, it is 400 parts by mass or more, particularly 400 parts by mass, per 100 parts by mass of the used adsorbent, in consideration of mixing stirring performance and recovery work after desorption. About 2000 parts by mass may be sufficient.
Stirring for desorption, like adsorption, does not require heating or the like, and can be carried out at 25° C. or lower, particularly at room temperature, and the treatment time is about 0.25 to 24 hours. Furthermore, this stirring can also be performed with a normal stirring blade or the like.
The water used for desorption is preferably pure water, but may be partially or wholly replaced with an aqueous solution of various salts or an organic solvent.
By such desorption, 40% by mass or more of trigonelline adsorbed to the silica-magnesia composite particles can be recovered in water.

Trigonelline desorbed into water as described above can be used as a drug or the like as it is, or it can be used as an isolated compound after being purified by concentration by heating or the like, recrystallization, or the like.

The excellent effects of the present invention will be explained by the following experimental examples.
In addition, each test and physical property measurement performed in the following examples and comparative examples were performed by the following methods.

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

(2) Trigonelline adsorption test The amount (mg) of trigonelline that can be adsorbed by 1 g of adsorbent (anhydrous) from 30 g of trigonelline aqueous solution of 800 ppm was measured by the following method, and the calculated values are shown in Tables 1 and 2.
First, trigonelline (Cayman
Chemical Co.) was dissolved in distilled water to obtain an 800 ppm trigonelline aqueous solution. 30 g of this 800 ppm trigonelline aqueous solution was weighed into a 50 ml centrifuge tube, 1 g of adsorbent (3.3% by mass relative to the liquid) was added, and a shaker (SA300 manufactured by Yamato Scientific Co., Ltd., shaking speed 5) was used. Shake for 2.5 hours.
Next, the supernatant of the liquid was treated with a centrifugal separator (manufactured by Kubota Corporation, 5200) at a centrifugal acceleration of 3000 rpm for 15 minutes and filtered through a filter for HPLC pretreatment (manufactured by Merck, filter pore size 0.20 μm) to obtain a sample liquid. . The obtained sample solution was analyzed by liquid chromatography (HPLC) under the following conditions.
Measuring device: Shimadzu high performance liquid chromatograph Prominece
Column: Shim-pack VP-ODS manufactured by Shimadzu Corporation
Detector: UV
Measurement wavelength: 270 nm
The amount of trigonelline remaining in the sample solution was calculated using a calibration curve prepared in advance showing the relationship between the trigonelline concentration and the area ratio in HPLC analysis, and the value obtained by subtracting the amount of trigonelline before addition of the adsorbent was used as the adsorption amount of trigonelline.

(3) Trigonelline Desorption Test The weight of the adsorbent (trigoneline-containing adsorbent) remaining after collecting the sample solution in the above adsorption test and the adsorption test solution remaining adhered to the adsorbent were measured. A desorption solvent (water) was added so as to make a total of 31 g including these adsorbents, and the mixture was shaken for 2.5 hours with a shaker (SA300 manufactured by Yamato Scientific Co., Ltd., shaking speed 5). Next, the supernatant of the liquid was treated with a centrifugal separator (manufactured by Kubota Corporation, 5200) at a centrifugal acceleration of 3000 rpm for 15 minutes, and the supernatant was filtered through a filter for HPLC pretreatment (manufactured by Merck, filter pore size: 0.20 μm) to obtain a sample liquid. . The obtained sample solution was analyzed by liquid chromatography (HPLC) under the following conditions.
Measuring device: Shimadzu high performance liquid chromatograph Prominece
Column: Shim-pack VP-ODS manufactured by Shimadzu Corporation
Detector: UV
Measurement wavelength: 270 nm
The amount of trigonelline in the sample solution was calculated using a previously prepared calibration curve showing the relationship between the trigonelline concentration and the area ratio in HPLC analysis. The amount of trigonelline desorbed was obtained by subtracting the amount of trigonelline derived from the adsorption test solution remaining attached to the adsorbent from the amount of trigonelline.

(4) Orange II adsorption capacity The orange II adsorption capacity in this example was calculated by measuring and calculating the number of mmoles of orange II that can adsorb 100 g of a sample from an orange II aqueous solution with a concentration of 10 mmol/L by the following method. First, Orange II (reagent special grade, manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved in water to obtain an aqueous Orange II solution with a concentration of 10 mmol/L. 20 ml of this 10 mmol/L concentration Orange II aqueous solution was weighed into a 50 ml centrifuge tube, 0.20 g of the test powder was added, and the concentration was 7.5 with a shaker (SA300 manufactured by Yamato Scientific Co., Ltd., shaking speed 5). Shake for time. After the end of shaking, let stand for 12 hours or longer. Next, 0.5 mL of the supernatant of the liquid was treated at a centrifugal acceleration of 3000 rpm for 15 minutes in a centrifuge (manufactured by Kubota Co., Ltd. 5200), and diluted 200 times with deionized water. was measured with a spectrophotometer (V-630 manufactured by JASCO Corporation). Then, the amount of Orange II remaining in the sample liquid was calculated using a calibration curve showing the relationship between the Orange II content of the Orange II aqueous solution and the absorbance of light with a wavelength of 484 nm. A value obtained by subtracting this value from the amount of Orange II added to the sample is defined as the amount of Orange II adsorbed.

In Examples and Comparative Examples, the following silica-magnesia preparations (a) to (d) or acid clay, activated clay, and silica gel were used to measure physical properties and perform various tests, and the results are shown in Table 1 or Table 2. .

Example 1: Silica-magnesia formulation (a) manufactured by Mizusawa Chemical Industry Co., Ltd.
Example 2: Silica-magnesia formulation (b) manufactured by Mizusawa Chemical Industry Co., Ltd.
Example 3: Silica-magnesia formulation (c) manufactured by Mizusawa Chemical Industry Co., Ltd.
Example 4: Silica-magnesia formulation (d) manufactured by Mizusawa Chemical Industry Co., Ltd.

Comparative Example 1: Acid clay manufactured by Mizusawa Chemical Industry Co., Ltd. Comparative Example 2: Activated clay manufactured by Mizusawa Chemical Industry Co., Ltd. Comparative Example 3: Silica gel manufactured by Mizusawa Chemical Industry Co., Ltd.

Claims (5)

A trigonelline adsorbent comprising silica-magnesia composite particles in which silica particles and magnesia particles are integrally combined, and having an anion adsorption capacity represented by an orange II adsorption amount in the range of 18 to 74 mmol/100 g. The silica component and the magnesia component are represented by the following formula:
R=Sm/Mm
In the formula, Sm is the content (% by mass) of the silica component in terms of _SiO2 ,
Mm is the content (% by mass) of the magnesia component in terms of MgO,
The trigonelline adsorbent according to claim 1, wherein the mass ratio (R) represented by is contained in a ratio of 0.1 ≤ R ≤ 3.5. A method for adsorbing trigonelline, which comprises adding the adsorbent of claim 1 or 2 to a trigonelline-containing aqueous solution to adsorb trigonelline. The trigonelline adsorption method according to claim 3, wherein the adsorbent is added in an amount of 0.01 parts by mass or more per 1 part by mass of trigonelline contained in the aqueous solution. A trigonelline adsorbent to which trigonelline is adsorbed is recovered by the method according to claim 4, and then the adsorbent is mixed with water and stirred to desorb trigonelline from the adsorbent. Method for recovering trigonelline.