JPS5820301B2 - Method for manufacturing polyamide-supported adsorbent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an extremely selective method that specifically adsorbs polyphenols, which are cloudy components of plant-based beverages such as beer and wine, and does not cause pH fluctuations in the beverages after adsorption treatment. The present invention provides a method for producing a novel polyamide-supported adsorbent having excellent adsorption performance.

BACKGROUND ART It is widely known that polyphenols are generally produced as by-products of beverages made from plants, such as beer, wine, fruit juice, etc., during their production processes, such as fermentation processes and fruit juice pressing processes.

If these by-product polyphenols are present in excess, they may associate with the proteins contained in the beverage or undergo self-oxidation to form complex multimers, causing cloudiness in the beverage. This may cause unfavorable effects on quality.

In addition, in white grape wine, it is said that the action of enzymes in seeds containing polyphenols causes browning, which is unfavorable in terms of quality.

Excess polyphenols remaining in plant-based beverages can cause turbidity and browning, which can be fatal in terms of quality. have been variously studied.

Conventionally, known adsorbents for removing polyphenols include powders such as polyamide resins and crosslinked polyvinylpyrrolidone, diatomaceous earth, silica gel, and minerals such as bentonite and montmorillonite.

However, these conventionally known adsorbents do not necessarily have a sufficient polyphenol adsorption effect, and when used for beer processing, they also adsorb isotumurone, which is an essential bitter component in beer. They have disadvantages such as removing proteins from the beer or excessively removing proteins from the beer, resulting in poor foam retention, and do not exhibit selective adsorption performance for polyphenols.

As one method for solving this problem, an attempt has been made to support polyamide on silica gel as an adsorbent.

That is, in this method, polyamide is dissolved in hydrochloric acid,
After silica gel is added and stirred, water is added to make the silica gel support the polyamide, but since the hydrochloric acid used in this case is highly concentrated, the subsequent water washing process takes a very long time. By hydrolysis of polyamide.

The defect is that the acid amide bond is easily broken and the adsorption performance for polyphenols is not sufficiently improved.

In view of the above-mentioned shortcomings of the conventional technology, the present inventors have conducted intensive studies on a method of supporting polyamide that has excellent performance in specifically adsorbing polyphenols and does not cause cleavage of acid amide bonds that serve as adsorption seats. layered.

As a result, they discovered that an unexpectedly significant effect can be obtained by using a methanol or/and ethanol solution containing calcium chloride or lithium chloride as a solution for dissolving polyamide, and have arrived at the present invention. .

That is, the gist of the present invention is Jill.

When supporting polyamide on the surface of particles of metal compounds consisting of hydroxides or hydrates of hydroxides or oxides of conium, titanium, or aluminum, polyamide is added to methanol and/or ethanol containing calcium chloride or lithium chloride. The method for producing a polyamide-supported adsorbent is characterized in that the above-mentioned granules are put into a dissolved solution, stirred, and then a poor solvent such as water is added thereto.

The granules used in the method of the present invention are metal compounds consisting of hydrates of hydroxides or oxides of zirconium, titanium, and aluminum.

Such metal compounds have previously been disclosed by the present inventors as polyphenol adsorbents in Japanese Patent Application Nos. 48-55535 and 1982-104651.

These metal compounds exhibit a very specific adsorption effect on orthodiol type phenols among polyphenols, and have superior performance compared to conventionally known adsorbents. later drink p
Since the H fluctuation is somewhat large and there is a possibility of secondary turbidity, there is still room for improvement in this respect.

These drawbacks can be improved by applying the method of the present invention, resulting in less pH fluctuation and excellent adsorption performance.

Specific examples of such metal compounds include ZrO
(OH)2. Zr(OH)4. Zr0-nH2O.

Ti(OH)2. Ti(OH)3. Ti(OH)4. T
iO・nH2O, Al(OH)2. Al(OH)3. A
l(OH)3゜6H20, Al0(OH), Al2O3
・2H20 etc.

All of the metal compounds mentioned above have polyamide supported on their surfaces in the form of particles or powder.

The average particle diameter at this time is preferably in the range of 0.2 to 50μ.

This is because if it is less than 0.2μ, there are operational difficulties, and if it is more than 50μ, the adsorption capacity itself tends to deteriorate.

A method for supporting polyamide on such granules is to dissolve polyamide in advance in methanol or/and ethanol containing calcium chloride or lithium chloride to a low concentration solution (preferably 5% by weight or less). This can be easily carried out by preparing the above-mentioned granular material, dispersing it, stirring it, and pouring a poor solvent such as water into the solution until the polyamide is insolubilized.

Thereafter, after filtration by a conventional method, washing with water is repeated as appropriate and drying, a polyamide-supported adsorbent, which is the object of the present invention, is obtained.

The amount of calcium chloride or lithium chloride contained in methanol and/or ethanol is preferably 3% or more.

If it is less than 3%, the polyamide will be difficult to dissolve sufficiently, which is not preferable.

Further, the polyamide concentration was 5% by weight (unless otherwise specified hereinafter, % represents weight percentage.

) or less is desirable; if the concentration is higher than that, the viscosity increases, causing operational inconvenience, and it becomes difficult to obtain uniform support.

In addition, the polyamides applied to this method are as follows:
Most preferred are nylon 6 and nylon 66, but others include nylon 3, nylon 4, nylon 7, nylon 8, nylon 6/10, nylon 10, nylon 11,
Nylon 12 or the like can be similarly applied.

Furthermore, N-substituted nylons such as N-methyl nylon and N-isopropyl nylon can be similarly applied, and N-methyl nylon in particular has an excellent adsorption effect, so it is one of the preferred embodiments of the present invention. be.

The characteristics of the polyamide-supported adsorbent obtained by the method of the present invention are that, compared to the previously proposed method of dissolving it in hydrochloric acid, it can be uniformly supported on the polyamide without causing any chemical changes. Very small voids (pores) are observed on the surface of the supported polyamide.

The fact that the surface of such an adsorbent exhibits porosity has good results in further improving the adsorption performance for polyphenols, and was one of the unexpected results.

In addition, when polyamide is supported on the surface of the granular adsorbent, the dissociation property of the adsorbent surface is adjusted and the molecular weight of the adsorbed material is effectively controlled, resulting in the effect of suppressing the pH fluctuation of the liquid to be treated. be.

In the present invention, it is desirable that the amount of supported polyamide be at least 0.5% based on the original granules.

If it is less than 0.5%, it will be difficult to fully exhibit the above effects.

When the polyamide-supported adsorbent of the present invention obtained in this manner is actually applied to vegetable beverages, these adsorbents can be used alone or in a mixture of two or more in the same form.

Of course, there is no problem in using it in combination with other adsorbents.

It is of course also possible to use it as one component of a sheet structure composed of multi-component materials such as pulp, other adsorbents, filter aids, etc.

Furthermore, regarding the recyclability of the polyamide-supported adsorbent of the present invention, it can be easily regenerated by the method used for conventionally known polyphenol adsorbents.

In addition, the polyamide-supported adsorbent obtained by the method of the present invention can be used not only for the above-mentioned applications in vegetable drinks such as beer and wine, but also in other fields such as gas adsorption in the gas phase and as a cigarette filter. It is also applicable.

Next, the present invention will be described in more detail with reference to Examples.

Example 1 Methanol solution 100 containing 20% calcium chloride
Nylon 6 in CC 1, 0.1, 0.25 respectively
γ crystal alumina (approximately 1
0 μ diameter) was added and dispersed, and while stirring, 500 cc of water was added.

This was separated by filtration, thoroughly washed with water, and dried to obtain the desired polyamide-supported adsorbent.

The thus obtained adsorbent had 0.23%, 0.56%, and 1.08% of nylon 6 attached to the original γ-crystalline alumina, respectively.

Using 1 g of each of these adsorbents, commercially available beer (p
H4,2) After being immersed in 100 cc for 5 minutes, the beer was immediately filtered and the pH, polyphenol adsorption rate, and intumuron adsorption rate of the beer after treatment were measured.

In addition, for comparison, the original γ-crystalline alumina (comparative sample) before supporting nylon 6 was treated with commercially available beer under the same conditions as above, and the pH and polyphenol adsorption rate of beer after treatment were Intumuron adsorption rate was measured.

The results are shown in Table 1.

The polyphenol adsorption rate was determined by Harris' method.
Intumuron adsorption rates are values measured using the isooctane extraction method.

From the results in Table 1, the polyamide-supported adsorbent of the present invention has greatly improved polyphenol adsorption performance compared to the original γ-crystalline alumina, and has a selective adsorption effect with less pH fluctuation and isotumuron adsorption rate. It can be seen that

In addition, the amount of polyamide supported in the present invention is
It can also be seen that in order to better exhibit the desired selective adsorption performance, it is desirable to set the content to 0.5% or more.

Example 2 Ethanol solution 150C containing 30% lithium chloride
5g of nylon 4 was dissolved in e, and ZrO(OH
) Add 20g of 2 and disperse it, stir and add 20g of 2.
Occ of water was gradually added.

This was separated by filtration, thoroughly washed with water, and dried to obtain the desired polyamide-supported adsorbent.

The adsorbent thus obtained is the original ZrO(OH)2
2.36% of nylon 4 was attached to it.

Using 1 g of each of these adsorbents, commercially available beer (p
H4,2) After stirring for 5 minutes in 100 cc, the beer was immediately filtered and the pH, polyphenol adsorption rate, and intumuron adsorption rate of the beer after treatment were measured.

Also, for comparison, the original Zr before supporting nylon 4
O(OH)2 was also treated in the same way, and the same items were measured for the beer after the treatment.

The results are shown in Table 2.

From the results in Table 2, it can be seen that by supporting nylon 4, pH fluctuations in beer before and after treatment are suppressed, and the polyphenol adsorption rate is also significantly improved.

Example 3 Ethanol solution containing 25% calcium chloride 200
N-methyl nylon 6 (methylation degree 15%) and nylon 6 were separately dissolved in CC, and T was added to each solution.
50g of 1(OH)4 was added and dispersed, and 100cc of ethanol was further added thereto, and while stirring, 600cc of water was poured.

This was separated by filtration, thoroughly washed with hot water, and dried to obtain the desired polyamide-supported adsorbent.

The adsorbent thus obtained had 9.3% and 9.0% of N-methylnylon 6 and nylon 6 adhering to Ti(OH)4, respectively.

Using 1 g of each of these adsorbents, commercially available beer (p
H4,2) After being immersed in 100 cc for 5 minutes, it was immediately filtered and the pH, polyphenol adsorption rate, and intumuron adsorption rate of the treated beer were measured.

For comparison, 5 g each of the above N-methyl nylon 6 and nylon 6 were dissolved separately in 200 cc of 8N hydrochloric acid.
50 I of Ti(OH) was added and dispersed in the mixture, and 600 cc of water was added while stirring. After neutralizing this with caustic soda, it was filtered, washed thoroughly with water, and dried. and created an adsorbent.

These comparative samples contained 9.4% and 9.1% of N-methyl nylon 6 and nylon 6, respectively, based on Ti(OH)4.
It was attached.

Commercial beer was treated with these comparative samples, N-methyl nylon 6, and Ti(OH) 4 without nylon 6 under the same conditions as above, and the pH 1 polyphenol adsorption rate and isotumuron of the treated beer were measured.

The measured values are shown in Table 3. From the results shown in Table 3, by supporting N-methyl nylon 6 and nylon 6, it is possible to suppress the pH fluctuation of beer before and after treatment, and at the same time significantly improve the polyphenol adsorption rate, and furthermore, it is possible to significantly improve the isotumuron adsorption rate. It is clear that a selective adsorption effect can be obtained by reducing the amount of water.

Furthermore, when compared with the conventionally attempted hydrochloric acid dissolution method, it can be seen that the method according to the present invention exhibits a particularly excellent adsorption effect in terms of polyphenol adsorption rate.

Claims (1)

[Claims] 1. When supporting polyamide on the surface of granular metal compounds consisting of hydrates of hydroxides or oxides of zirconium, titanium, or aluminum, the polyamide is preliminarily added to methanol and/or ethanol containing calcium chloride or lithium chloride. Prepare a solution in which polyamide is dissolved, add the above granules to it, stir it,
A method for producing a polyamide-supported adsorbent, which comprises adding a poor solvent such as water to the adsorbent.