JPH0824639A - Oxygen absorbent - Google Patents

Abstract

PURPOSE:To provide a safe and sanitrary oxygen absorbent having a sufficient oxygen absorbing speed. CONSTITUTION:The oxygen absorbent consists of gallic acid and an alkali compd. and, as the alkali compd., sodium carbonate is pref. This oxygen absorbent is accelerated in oxygen absorbing reaction by the presence of water and can be used in an aq. soln. state and a powdery state.

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 preferably used for packaging liquids such as alcoholic drinks and juices.

[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.

In addition, when the above-mentioned oxygen absorber containing metallic iron or an iron compound as a component is applied for the purpose of absorbing oxygen in the space of a container in which sake is packaged, even if this iron is contained in a small amount, When mixed in, there was a problem that the sake discolored.

As described above, the oxygen absorbers that have been used or proposed have not been satisfactory depending on the application in terms of safety and / or oxygen absorption rate. In addition, there is a risk of discoloration due to iron in special applications such as sake packaging, and it is difficult to use iron or iron compounds, and conventional oxygen absorbers cannot be applied.

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. Another object of the present invention is to provide an oxygen absorber which does not use iron or an iron compound and can be applied to the packaging of articles (for example, sake) which may be altered or deteriorated by iron. .

[0013]

That is, the present invention provides an oxygen absorbent comprising gallic acid and an alkali compound in order to achieve the above object. In this oxygen absorbent, the alkali compound is preferably sodium carbonate.

[0014]

In the oxygen absorbent of the present invention, oxygen absorption occurs when the carboxyl group and hydroxyl group of gallic acid are dissociated by the action of the alkaline compound, and the gallic acid from which one or more hydrogen has been released reacts with oxygen. . It is considered that this reaction proceeds with the presence of water, and the reaction is initiated and progressed by absorbing water given in advance or water in the atmosphere.

[0015]

Next, embodiments of the present invention will be described. The oxygen absorbent of the present invention comprises gallic acid and an alkaline compound.

[0016] Gallic acid is the main ingredient of the oxygen absorbent according to the present invention and 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 alkali compound added for causing the oxidation of gallic acid may be any substance which can make the system of the oxygen absorbent of the present invention alkaline, such as alkali metal or alkaline earth metal. Examples include metal hydroxides, carbonates, hydrogen carbonates, and phosphates.
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, sodium carbonate. , Potassium carbonate, magnesium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium potassium carbonate, potassium magnesium carbonate, sodium phosphate, potassium phosphate, potassium hydrogen phosphate. Among these, sodium carbonate can be particularly preferably used, as will be understood from the experiments described below.

It is necessary that the mixing ratio of the alkaline compound to gallic acid is such that it becomes alkaline at least when it is used as an aqueous solution. This is because gallic acid absorbs the oxygen absorbent in an alkaline atmosphere, as can be seen from the experiment described later. For example, sodium carbonate, sodium phosphate, potassium phosphate, etc.
If 1 mol or more is added to 1 mol of gallic acid, the aqueous solution becomes alkaline.

It should be noted that the supply of the alkaline compound in a large excess should be avoided especially when it is used in a powder state or the like. This is because the amount of the main agent (gallic acid) contained in a certain amount of the drug is reduced and the relative oxygen absorption capacity is reduced. Therefore, when using an agent that can be made alkaline by adding equimolar amounts such as sodium carbonate as the alkaline compound, the mixing amount of the alkaline compound is
It is preferably about 1 to 2 mol per 1 mol of gallic acid.

The gallic acid and the alkaline compound may be used in the form of powder in a breathable packaging material as in the case of the conventional oxygen absorbent, or may be dissolved in a suitable solvent such as water. You may impregnate filter paper etc. and use it. Further, it may be granulated by an appropriate granulation method, or may be kneaded with a resin before use.

If desired, 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. . Further, a deliquescent substance such as calcium chloride may be added to obtain the water necessary for the reaction from the atmosphere.

Next, an experiment conducted on the amount and rate of oxygen absorption in Examples and Comparative Examples of the present invention will be shown.

<Experiment 1: Effect of pH> It was tested how the oxygen absorption capacity of gallic acid as the main ingredient of the present invention was affected by pH. First, a 0.1 M gallic acid aqueous solution and a 0.1 N sodium hydroxide aqueous solution were prepared, and the pH of the gallic acid aqueous solution was adjusted to 3.0 to 13.0 by dropping the sodium hydroxide aqueous solution. 10 ml of gallic acid aqueous solution of each pH was measured and impregnated into a cardboard having a size of 10 × 8 cm, the cardboard was placed in a pouch made of an oxygen barrier material containing aluminum foil in the layer constitution, and then 200 ml It was filled with air (oxygen content; 41.8 ml), sealed, and stored at 40 ° C. The oxygen concentration in this pouch was observed over time. The results are shown in Table 1.

[0025]

[Table 1]

As is apparent from the table, the acidic substances having a pH of 3 hardly absorbed oxygen, while the alkaline substances having a pH of 8 or higher showed high oxygen absorption.

<Experiment 2: Oxygen absorption test in solution>
The gallic acid as the main ingredient of the present invention, the alkaline compound and water were mixed and dissolved in the following proportions to obtain the oxygen absorbent of the present invention. Experiment 1 with each oxygen absorber (solution)
Similarly, it is impregnated with a cardboard of a size of 10 × 8 cm, and this cardboard is placed in a pouch made of an oxygen barrier material containing aluminum foil in the layer structure, and then 200 ml of air (oxygen content; 41.8 ml). ) Was filled and sealed, and it preserve | saved at 40 degreeC conditions. The oxygen concentration in this pouch was observed over time. Table 2 shows the results. For comparison, changes in oxygen concentration were measured in the same manner as above except that ascorbic acid or sodium ascorbate was used as the main ingredient. Further, an oxygen absorbent prepared by mixing sodium ascorbate as a main ingredient and ferrous sulfate as an oxidation catalyst, which is disclosed in JP-B-1-42745, was prepared and evaluated in the same manner as above. The results are shown in Table 1.

[0028]

[Table 2]

From these results, it can be seen that the present invention using gallic acid and an alkaline compound, especially sodium carbonate, has an excellent oxygen absorption capacity as compared with the others.

<Experiment 3: Oxygen absorption test in powder state>
Gallic acid as the main agent of the present invention, and an alkaline compound,
The following amount was put in the above-mentioned pouch and shaken well, and then the following amount of water was injected, further 200 ml of air was filled and sealed, and stored at 40 ° C. The oxygen concentration in this pouch was observed over time. The results are shown in Table 3. For comparison, the same as above except that ascorbic acid or sodium ascorbate was used as the main agent,
The change in oxygen concentration was measured. The results are shown in Table 4.

[0031]

[Table 3]

[0032]

[Table 4]

From these results, it is understood that the oxygen absorbent using gallic acid and the alkaline compound, especially sodium carbonate, of the present invention is superior in oxygen absorbing ability to other materials even in the powder state. In particular, the one using sodium carbonate shows a high oxygen absorption capacity even if the amount of water added is small. This indicates that this oxygen absorbent can sufficiently absorb oxygen with very little water.

[0034]

INDUSTRIAL APPLICABILITY As described above, the oxygen absorbent of the present invention has a remarkably high oxygen absorption capacity as compared with the conventional ascorbic acid oxygen absorbent. Therefore, the oxygen absorbent of the present invention is suitable for absorbing oxygen in the space of a package such as a drink containing juice such as vitamin C containing vitamin C or the like, in which the deterioration due to the dissolved oxygen absorbent is observed. Further, the oxygen absorbent of the present invention is excellent in hygiene and safety, and further, since it does not use metallic iron or iron compound, it does not have any influence on an article which may be deteriorated by iron.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location A23L 3/3436 A61J 1/10 B01D 53/14 B A61J 1/00 331 Z

Claims (2)

[Claims] 1. An oxygen absorber comprising gallic acid and an alkaline compound. 2. The alkali compound is sodium carbonate,
The oxygen absorbent according to claim 1.