JPH08309181A - Oxygen absorbent - Google Patents

Abstract

PURPOSE: To provide an oxygen absorbent which is safe, hygienic and can absorb oxygen at an adequately high speed. CONSTITUTION: This oxygen absorbent is composed of a main agent consisting mainly of gallic acid, a pH adjusting agent consisting mainly of sodium carbide, and a deliquescent substance such as calcium chloride or a water-absorbing polymer. The deliquescent substance or the water-absorbing polymer absorbs, deliquesces or induces an atmospheric moisture, and supplies the moisture which contributes to a reaction to a reaction system and thereby, displays a remarkably rapid oxygen absorbing capability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen absorbent, and more particularly to an oxygen absorbent suitable for use in packaging foods, drinks such as alcohol and juice.

[0002]

2. Description of the Related Art Conventionally, the presence of oxygen in a package in which foods or the like are packaged has sometimes caused the contents such as foods to be oxidized and deteriorated or discolored. Further, if insects and microorganisms are present in the package, the microorganisms grow and reproduce, causing pollution and decay. In order to solve such a problem, oxygen in the package is removed.

There are several methods for removing oxygen, one is vacuum packaging in which a vacuum is applied during packaging. This vacuum packaging is effective for liquid substances that do not require shape retention. However, vacuum packaging does not remove so-called dissolved oxygen already dissolved in the liquid material. Another way is
In this method, the air in the space inside the package is replaced with a gas containing no oxygen; for example, nitrogen or the like. Since this method can make the pressure inside the package the same as the atmospheric pressure, it is also effective for packaging an article that needs to retain its shape. However, in this gas replacement method, the removal rate of oxygen is not sufficient, and 1-2 vo is present in the space.
Oxygen with a concentration of about 1% remains. Then, similarly to the above, the dissolved oxygen of the liquid material is not removed.

As a further alternative, oxygen absorbers are widely used. As the oxygen absorber, one containing iron powder as a main component and one containing ascorbic acid or a salt thereof as a main component have been put into practical use. What uses iron powder as the main agent is oxygen absorption by the oxidation reaction of iron, and for ascorbic acid-based oxygen absorbers, the consumption of oxygen accompanying the decomposition reaction of ascorbic acid (salt) is the principle of oxygen absorption. Has been done. Since this oxygen absorbent absorbs (consumes) oxygen by the reaction as described above, not only can it absorb oxygen in the space almost completely, but it can also absorb dissolved oxygen dissolved in the liquid substance. There are merits.

As the form of the oxygen absorbent, the respective components are mixed in a powder state or granulated into granules,
It is common to package it in a breathable packaging material.
As another form, a method has been proposed in which each component is dissolved in a solvent such as water to form a solution, and the solution is impregnated into a filter paper or the like for use. There is also a proposal that a resin is mixed (kneaded) with the above-mentioned components and a packaging container is prepared using the resin, or the resin is used for a part of the container, for example, a liner of a cap.

By the way, since the iron-based oxygen absorbent uses iron powder, it has a problem that it cannot be put into the package before the foreign matter inspection because it is caught by the metal detector for the foreign matter inspection. . Similarly, since the metal itself is used, there is a demerit that the package enclosing the oxygen absorbent cannot be heated in a microwave oven.

On the other hand, ascorbic acid-based oxygen absorbers are
The ascorbic acid (salt), iron sulfate, carbonate, and the like, which are components, are mixed with a filler and granulated into granules are commercially available. Since this oxygen absorbent does not use metal powder, there is no problem in using the metal detector or the microwave oven, and there is an advantage that it is more hygienic and safer than metal powder.

[0008]

However, the ascorbic acid-based oxygen absorbent has a problem that the oxygen absorption rate is slower than that of the iron-based oxygen absorbent. If the oxygen absorption rate is slow, the content may be very sensitive to oxygen, and the content may be oxidized or decomposed by oxygen before the oxygen absorbent absorbs oxygen. There is.

For the purpose of improving the oxygen absorption rate of the ascorbic acid-based oxygen absorbent, an invention in which the components (ascorbic acid (salt) and iron sulfate) are used in the form of an aqueous solution as described above (Patent Publication 1) No. 42745) and an invention characterized by adding tocopherol or an organic acid (Japanese Patent Publication No. 3-49315), but a sufficient oxygen absorption rate has not yet been realized.

As described above, the oxygen absorbers that have been conventionally used or proposed have not been satisfactory depending on the application in terms of safety and / or oxygen absorption rate.

Therefore, the present invention provides an oxygen absorbent which is safer and more hygienic than iron-based oxygen absorbents and has a sufficient oxygen absorption rate.

[0012]

[Means for Solving the Problems] In order to achieve the above object, the present invention comprises a base compound containing gallic acid as a main component, a pH adjusting agent containing sodium carbonate as a main component, and a deliquescent substance. An oxygen absorbent is provided. In this oxygen absorbent, the deliquescent substance is preferably calcium chloride. Further, in order to achieve the above object, the second invention provides an oxygen absorbent comprising a main agent containing gallic acid as a main component, a pH adjusting agent containing sodium carbonate as a main component, and a water-absorbing polymer. To do.

[0013]

In the oxygen absorbent of the present invention, the main component of oxygen absorption is the oxidation of the main agent, and the reaction is promoted by the action of the pH adjusting agent. This reaction is significantly accelerated when the components come into contact in the presence of the solution. The deliquescent substance absorbs water in the atmosphere and deliquesces to give liquid water to the system. Further, in the oxygen absorbent of the present invention using the absorptive polymer, since the absorptive polymer has an action of trying to attract moisture in the atmosphere, appropriate moisture is supplied to the system,
Oxygen is absorbed quickly.

[0014]

Next, embodiments of the present invention will be described. The oxygen absorbent according to the first aspect of the present invention comprises a main agent containing gallic acid as a main component, a pH adjusting agent containing sodium carbonate as a main component, and a deliquescent substance.

Gallic acid is a substance that has long been recognized as an antioxidant added to foods, and its safety has been sufficiently confirmed. In the present invention, the main agent is mainly gallic acid. As an ingredient. Other reducing substances can be added to the main component as needed. Examples of the reducing substance include compounds having an enediol group,
Preferred are ascorbic acids and low molecular weight phenols.

Examples of the ascorbic acids include L-ascorbic acid, D-isoascorbic acid, water-soluble salts such as sodium salts and calcium salts, or derivatives thereof (for example, 6-O-α-D-glycopyranosyl-L).
-Ascorbic acid and the like, which is water-soluble, in which at least one of the 2- and 3-positions is a hydroxyl group.

Further, as the low molecular weight phenols,
Examples include catechol, pyrogallol, and salts or derivatives thereof.

The pH adjusting agent is composed of a basic substance containing sodium carbonate as a main component, and contains, as other components, a hydroxide, a carbonate, a hydrogen carbonate and a phosphate of an alkali metal or an alkaline earth metal. be able to. These may be hydrated salts or anhydrous salts. More specifically, lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, calcium hydroxide, beryllium hydroxide, magnesium hydroxide, strontium hydroxide, barium hydroxide, lithium carbonate, potassium carbonate, magnesium carbonate. ,
Examples thereof include lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium potassium carbonate, potassium magnesium carbonate, sodium phosphate, potassium phosphate, and potassium hydrogen phosphate.

It is necessary that the pH adjusting agent be added in such an amount that it exhibits alkalinity when the oxygen absorbent of the present invention is made into an aqueous solution. Since the absorption may be inhibited, the mixing ratio of the main agent and the pH adjusting agent is preferably 1: 1 (weight ratio) or less.

The deliquescent substance is a substance that deliquesces by absorbing water vapor in the atmosphere, and various known substances can be used, such as aluminum chloride, zinc chloride, calcium chloride,
Iron chloride, beryllium chloride, magnesium chloride, potassium magnesium chloride, magnesium ammonium chloride, lithium chloride, potassium hydrogen sulfate, sodium hydrogen sulfate,
Examples thereof include titanium sulfate, ferric sulfate, manganese sulfate, and their anhydrous or hydrous salts. Among these, it is particularly preferable to use calcium chloride. The amount of deliquescent substance mixed is
It is preferably 0.3 to 1 part by weight with respect to 1 part by weight of the main agent. In addition, even if the deliquescent substance is added to the above amount,
No improvement in reaction rate (oxygen absorption rate) can be expected.

The oxygen absorbent of the present invention can be obtained by mixing the above-mentioned main agent and each agent by a usual method. Further, in order to obtain a powder in which the respective components are more uniformly mixed and contacted with each other, the main agent and the respective drugs are once dissolved in a suitable solvent, preferably water, and the solution is dried by a vacuum freeze-drying method. Oxygen absorber (powder)
Can be obtained.

The above-mentioned oxygen absorbent can be used in the form of powder in a breathable packaging material in the same manner as conventional oxygen absorbents.

If necessary, the oxygen absorbent of the present invention may be mixed with a filler such as activated carbon, zeolite, activated clay, calcium silicate, crystalline cellulose or the like, which serves to provide a reaction site. .

Next, experiments conducted on the oxygen absorption amount and rate of the examples and comparative examples of the present invention will be shown.

First, gallic acid as a main ingredient and anhydrous sodium carbonate as a pH adjuster were mixed at a weight ratio of 1: 1 and calcium chloride as a deliquescent substance was added to 1 part by weight of the main ingredient, respectively. An oxygen absorbent was prepared by adding 0.05 part by weight, 0.1 part by weight, 0.2 part by weight, 0.3 part by weight, and 0.5 part by weight. Then, 5 g of this oxygen absorbent was filled in a pouch made of a single microporous film to prepare an oxygen absorbent package (Examples 1 to 4).

Next, the oxygen absorbent package was placed in a pouch made of a packaging material composed of polyethylene terephthalate / aluminum foil / unstretched polypropylene, and 500 ml of air and 2 ml of water were added and sealed. It was stored at a temperature of ° C. The oxygen concentration in the pouch was measured over time. The results are shown in Table 1.

For comparison, an oxygen absorption prepared in the same manner except that a deliquescent substance was not added in a control group (Comparative Example 1) and sodium L-ascorbate (L-AANa) was used in place of gallic acid. The oxygen concentrations of the agents (Comparative Examples 2 to 7), the oxygen absorbent containing only gallic acid (Comparative Example 8) and the oxygen absorbent containing only L-AANa (Comparative Example 9) were also measured. The results are shown in Table 1.

[0028]

[Table 1]

As is clear from the table, the oxygen absorbent using gallic acid has a faster oxygen absorption rate than the oxygen absorbent using ascorbic acid, and the oxygen absorbing agent containing calcium chloride in an amount of 30% or more has a higher oxygen absorption rate. It turns out to be particularly fast.

Next, the oxygen absorbent according to the second aspect of the present invention will be explained. The oxygen absorbent according to the second aspect of the present invention comprises a main agent containing gallic acid as a main component, a pH adjusting agent containing sodium carbonate as a main component, and an oxygen absorbent containing a water-absorbing polymer.

The oxygen absorbent according to the present invention is characterized in that a water-absorbing polymer is used in place of the deliquescent substance of the oxygen absorbent according to the first invention.
As the regulator, the one used in the oxygen absorbent according to the first invention can be used as it is.

The water-absorbent polymer is capable of absorbing and retaining tens to thousands of times its own weight of water (or an aqueous solution), and various types are commercially available. For example, polyacrylic acid salt-based, polymethacrylic acid salt-based, vinyl alcohol-based respective copolymerized systems, maleic acid (or its salt) -based respective copolymerized systems, starch-based respective copolymerized systems, polyvinyl alcohol-based, polyvinylpyrrolidone System, ethylene /
Maleic acid (or its salt) copolymerization system, isobutylene /
Maleic acid (or its salt) copolymer system, styrene / maleic acid (or its salt) copolymer system, starch / acrylonitrile hydrolyzable product system, alginate (sodium salt, potassium salt, calcium salt, etc.) system, etc. Resin can be used.

The amount of the water-absorbent polymer mixed is preferably 0.05 to 1 part by weight with respect to 1 part by weight of the main agent.

The method of producing and using the oxygen absorbent can be carried out in the same manner as in the first invention described above. The same applies to other additives.

Next, an experiment conducted on the oxygen absorption amount and rate of Examples and Comparative Examples of the present invention will be shown. First, a mixture of gallic acid as a main agent and sodium carbonate as a pH adjuster at a weight ratio of 1: 1 was added with 0.05 parts of a polyacrylate water-absorbing polymer per 1 part by weight of the main agent.
By weight addition, an oxygen absorbent was obtained (Example 6). For comparison, a control group (Comparative Example 10) in which no water-absorbing polymer was added, one in which a water-absorbing polymer was added using sodium L-ascorbate as a main component (Comparative Example 11),
And a compound containing no water-absorbent polymer (Comparative Example 12) were prepared using sodium L-ascorbate as the main component. Then, 0.3 g of each of these oxygen absorbents was filled in a pouch made of a single microporous film to prepare an oxygen absorbent package.

Next, the oxygen absorbent package was put into a pouch made of a packaging material composed of polyethylene terephthalate / aluminum foil / unstretched polypropylene, and 200 ml of air and 2 ml of water were added and sealed. It was stored at a temperature of ° C. The oxygen concentration in the pouch was measured over time. Table 2 shows the results.

[0037]

[Table 2]

As is apparent from the table, the oxygen absorbent using gallic acid has a higher oxygen absorption rate than the oxygen absorbent using ascorbic acid, and the oxygen absorbent using the water-absorbing polymer has a higher oxygen absorption rate. I understand.

[0039]

As described above, the oxygen absorbent of the present invention can exhibit a remarkably fast oxygen absorbing ability by utilizing the moisture of the atmosphere. In addition, since the oxygen absorbent of the present invention uses a substance that is safe for food hygiene, it is safer and more hygienic than the iron-based oxygen absorbent.

Claims (3)

[Claims] 1. An oxygen absorber comprising a main agent containing gallic acid as a main component, a pH adjusting agent containing sodium carbonate as a main component, and a deliquescent substance. 2. The oxygen absorbent according to claim 1, wherein the deliquescent substance is calcium chloride. 3. An oxygen absorbent comprising a main agent containing gallic acid as a main component, a pH adjusting agent containing sodium carbonate as a main component, and a water-absorbing polymer.