Oxygen absorber composition and oxygen absorber package

Abstract

The composition contains iron powder (A), an alkali metal halide or alkaline earth metal halide (B), activated carbon (C), and an inorganic powder filler (D), and the inorganic powder filler (D) has an apparent density of 1.10 g / cm 3 excluding the iron powder (A), the alkali metal halide or alkaline earth metal halide (B), and the activated carbon (C). 3 More than 2.90g / cm 3 The oxygen scavenger composition is as follows: wherein the content of the inorganic powder filler (D) is 50 to 300 parts by mass per 100 parts by mass of the iron powder (A).

Description

[Technical Field]

[0001] The present invention relates to an oxygen absorber composition and an oxygen absorber package. [Background technology]

[0002] Oxygen absorbers that utilize the oxidation reaction of iron powder (hereinafter referred to as iron-based oxygen absorbers) have been proposed. Commercially available oxygen absorbers (for example, trade name "AGELESS" manufactured by Mitsubishi Gas Chemical Co., Inc.) are sealed in gas barrier containers together with other items such as food and medicine, and are therefore widely used to remove oxygen from the containers and maintain the quality and freshness of the items.

[0003] Iron-based oxygen absorbers are classified into "moisture-dependent" oxygen absorbers that start absorbing oxygen by utilizing moisture evaporated from the preserved material, etc., and "self-reacting" oxygen absorbers that already contain the moisture necessary for the oxygen absorption reaction of iron in the oxygen absorber composition. "Moisture-dependent" oxygen absorbers are used for foods with a particularly high water content, such as rice cakes and fresh noodles. Recently, cooked rice that can be stored for a long period of time has also become available, and oxygen absorbers that can be used for such foods with high water activity are being developed.

[0004] For example, Patent Document 1 discloses a microwave-resistant cooked rice package in which cooked rice having a viable cell count and pH within a specific range is sealed in a container with low oxygen permeability together with a microwave-resistant oxygen absorber package. Patent Document 1 lists oxygen absorbers whose main ingredient is ascorbic acid or a salt thereof, isoascorbic acid or a salt thereof, or iron powder. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 02-128663 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, the "moisture-dependent" oxygen absorber absorbs oxygen using the moisture evaporated from the preserved food, so it is suitable for foods with high water activity. However, because rice cakes and cooked rice contain a very large amount of moisture, the oxygen absorber package becomes wet with water, which causes a problem in that the original oxygen absorption capacity cannot be fully demonstrated. Therefore, there has been a demand for an oxygen absorber and an oxygen absorber package that can be used for high water activity foods containing a large amount of water and that can maintain their oxygen absorbing capacity even in a wet environment. Therefore, an object of the present invention is to provide an oxygen absorbing composition that can absorb oxygen for a long period of time even when applied to foods with high water activity. [Means for solving the problem]

[0007] That is, the gist of the present invention is as follows. [1] A composition containing iron powder (A), an alkali metal halide or alkaline earth metal halide (B), activated carbon (C), and an inorganic powder filler (D), wherein the inorganic powder filler (D) has an apparent density of 1.10 g / cm 3 excluding the iron powder (A), the alkali metal halide or alkaline earth metal halide (B), and the activated carbon (C). 3 More than 2.90g / cm 3 The oxygen scavenger composition is as follows: wherein the content of the inorganic powder filler (D) is 50 to 300 parts by mass per 100 parts by mass of the iron powder (A). [2] The oxygen absorbing composition according to the above [1], wherein the inorganic powder filler (D) contains at least one selected from the group consisting of metal salts, simple metals, and metal oxides. [3] The oxygen absorbing composition according to the above [1] or [2], wherein the inorganic powder filler (D) is a metal carbonate. [4] The oxygen absorbing composition according to any one of the above [1] to [3], wherein the inorganic powder filler (D) is calcium carbonate. [5] The oxygen absorbing composition according to any one of the above [1] to [4], wherein the inorganic powder filler (D) is at least one selected from the group consisting of heavy calcium carbonate, crushed seashells, calcite, marble, limestone, and precipitated calcium carbonate. [6] The oxygen absorbing composition according to any one of the above [1] to [5], wherein the inorganic powder filler (D) has an average particle size of 10 to 500 μm. [7] The apparent density of the inorganic powder filler (D) is 1.10 g / cm 3 More than 1.50g / cm 3 The oxygen absorbing composition according to any one of the above [1] to [6], which is: [8] The oxygen absorbing composition according to any one of the above [1] to [7], wherein the content of the inorganic powder filler (D) is 105 to 200 parts by mass per 100 parts by mass of the iron powder (A). [9] The oxygen scavenger composition according to any one of the above [1] to [8], wherein the alkali metal halide or alkaline earth metal halide (B) is an alkaline earth metal halide.

[10] The oxygen absorbing composition according to any one of the above [1] to [9], wherein the alkali metal halide or alkaline earth metal halide (B) is at least one selected from the group consisting of calcium chloride, magnesium chloride, magnesium bromide and calcium bromide.

[11] The oxygen absorbing composition according to any one of the above [1] to

[10] , wherein the content of the activated carbon (C) is 0.5 to 5.0 parts by mass per 100 parts by mass of the iron powder (A).

[12] The oxygen absorbing composition according to any one of the above [1] to

[11] , wherein the content of the alkali metal halide or alkaline earth metal halide (B) is 0.3 to 5.0 parts by mass per 100 parts by mass of the iron powder (A).

[13] The oxygen absorbing composition according to any one of the above [1] to

[12] , wherein the content of the alkali metal halide or alkaline earth metal halide (B) is 1.1 to 3.0 parts by mass per 100 parts by mass of the iron powder (A).

[14] An oxygen absorber package comprising the oxygen absorber composition according to any one of [1] to

[13] above and a breathable packaging material containing the oxygen absorber composition.

[15] A method for storing a high-moisture-content food, comprising enclosing the oxygen absorber composition according to any one of [1] to

[13] above or the oxygen absorber package according to

[14] above and the high-moisture-content food in a gas-barrier container.

[16] A high-moisture-content food package, wherein the oxygen absorber composition according to any one of [1] to

[13] above or the oxygen absorber package according to

[14] above and the high-moisture-content food are enclosed in a gas-barrier container. [Advantages of the Invention]

[0008] According to the present invention, an oxygen absorber composition capable of absorbing oxygen for a long time even when applied to high-moisture-content foods can be provided. Further, according to the present invention, an oxygen absorber package, a method for storing a high-moisture-content food, and a high-moisture-content food package can be provided. [Modes for Carrying Out the Invention]

[0009] Embodiments of the oxygen absorber composition, the oxygen absorber package, the method for storing a high-moisture-content food, and the high-moisture-content food package according to the present invention will be described in detail below. In this specification, the term "A to B" regarding the description of numerical values means "A or more and B or less" (when A < B) or "A or less and B or more" (when A > B). Further, in the present invention, a combination of preferred embodiments is a more preferred embodiment.

[0010] [Oxygen Absorber Composition] The oxygen absorber composition of the present invention contains iron powder (A), a halide of an alkali metal or a halide of an alkaline earth metal (B), activated carbon (C), and an inorganic powder filler (D). The inorganic powder filler (D) excludes iron powder (A), a halide of an alkali metal or a halide of an alkaline earth metal (B), and activated carbon (C), and the apparent density of the inorganic powder filler (D) is 1.10 g / cm 3 or more and 2.90 g / cm 3The oxygen scavenger composition is as follows: wherein the content of the inorganic powder filler (D) is 50 to 300 parts by mass per 100 parts by mass of the iron powder (A). The oxygen absorbing composition of the present invention, having the above-mentioned constitution, can absorb oxygen for a long period of time even when applied to foods with high water activity.

[0011] The reason why the oxygen absorbing composition of the present invention exhibits the above-mentioned effects is not clear, but one possible reason is as follows. It is believed that inorganic powder fillers with a specific range of apparent density can retain an appropriate amount of moisture without excessively retaining moisture evaporated from food. This prevents the oxidation reaction from being inhibited by excess moisture and provides moisture that promotes the oxidation reaction, making it possible to absorb oxygen even in the presence of high water activity foods. Furthermore, it is believed that the halide and activated carbon can supply moisture to the iron powder surface through deliquescence and adsorption / desorption, thereby promoting and sustaining the oxidation reaction. As described above, it is believed that the oxygen absorbing composition of the present invention, having the above-mentioned constitution, can absorb oxygen for a long period of time even when applied to foods with high water activity.

[0012] Each component will be described below. <Iron powder (A)> The oxygen absorbing composition of the present invention contains iron powder. The iron powder contained in the oxygen absorbing composition of the present invention is referred to as "iron powder (A)" (component A). The iron powder (A) in the oxygen scavenger composition of the present invention is a main agent for the oxygen scavenging reaction.

[0013] The iron powder (A) is not particularly limited, but is preferably one with an exposed surface of iron (zero-valent metallic iron), and may have an extremely thin oxide film like a normal metal surface, as long as it does not impair the effects of the present invention. Specifically, reduced iron powder, electrolytic iron powder, atomized iron powder, etc. can be suitably used. Also, crushed or cut products of cast iron, etc. can be used. The iron powder (A) may be one type of iron powder alone, or two or more types of iron powder may be used in combination as needed. These iron powders are readily available commercially and may also be used.

[0014] The iron powder (A) has an average particle size (D50) of, for example, 3000 μm or less, preferably 1000 μm or less, more preferably 500 μm or less, and even more preferably 300 μm or less from the viewpoint of improving contact with oxygen, and preferably 1 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more from the viewpoint of suppressing dust generation. Specifically, the iron powder (A) has an average particle size (D50) of, for example, 1 to 3000 μm, preferably 1 to 1000 μm, more preferably 10 to 500 μm, and even more preferably 20 to 300 μm. Iron powder having an average particle size within the above range can be obtained by appropriately selecting commercially available iron powder, or by classifying the iron powder using a sieve according to the desired average particle size. The average particle size of the iron powder (A) can be measured by the method described in the Examples.

[0015] In addition, the specific surface area of ​​the iron powder (A) is preferably 0.02 m from the viewpoint of oxygen absorption performance. 2 / g or more, more preferably 0.03m 2 / g or more, and from the viewpoint of suppressing the generation of dust, it is preferably 0.40 m 2 / g or less, more preferably 0.15m 2 / g or less, more preferably 0.10m 2 / g or less, and even more preferably 0.07m 2 / g or less, and even more preferably 0.045m 2 Specifically, the specific surface area of ​​the iron powder (A) is preferably 0.02 to 0.40 m 2 / g, more preferably 0.03 to 0.15m 2 / g, more preferably 0.03 to 0.10 m 2 / g, and even more preferably 0.03 to 0.07 m 2 / g, and even more preferably 0.03 to 0.045 m 2 / g. The specific surface area of ​​the iron powder (A) can be measured by the method described in the Examples.

[0016] The content of the iron powder (A) is not particularly limited, but is preferably 15% by mass or more and 75% by mass or less, more preferably 20% by mass or more and 60% by mass or less, and even more preferably 25% by mass or more and 50% by mass or less, in the oxygen absorbing composition.

[0017] <Alkali metal halide or alkaline earth metal halide (B)> The oxygen absorbing composition of the present invention contains an alkali metal halide or an alkaline earth metal halide. The alkali metal halide or alkaline earth metal halide contained in the oxygen absorbing composition of the present invention is referred to as "alkali metal halide or alkaline earth metal halide (B)" (component B), and is also referred to as "halide (B)." The alkali metal halide or alkaline earth metal halide (B) in the oxygen absorber composition of the present invention is a substance that acts catalytically on the oxidation reaction of iron powder and improves the activity of the iron powder. The alkali metal halide or alkaline earth metal halide (B) also plays a role in preventing the water contained in the oxygen absorber composition from evaporating and being lost from the oxygen absorber composition, thereby suppressing the transfer of moisture to the stored item. The halide (B) contained in the oxygen absorbing composition is preferably present on the surface of iron powder, and more preferably contained in the oxygen absorbing composition as halide-coated iron powder. The presence of the halide (B) on the surface of the iron powder makes it easier for moisture to be attracted to the surface of the iron due to the deliquescence phenomenon of the halide (B), thereby improving the oxygen absorption performance.

[0018] The halide (B) is not particularly limited, but is a halide of an alkali metal or a halide of an alkaline earth metal, preferably a halide of an alkaline earth metal.

[0019] The alkali metal halide is preferably at least one selected from the group consisting of alkali metal chlorides, bromides, and iodides, more preferably at least one selected from the group consisting of alkali metal chlorides and bromides, and even more preferably chloride. Among these, from the viewpoints of ease of handling, safety, etc., the alkali metal halide is preferably at least one selected from the group consisting of sodium chloride, potassium chloride, potassium bromide, and sodium bromide, more preferably at least one selected from the group consisting of sodium chloride and potassium chloride, and even more preferably sodium chloride.

[0020] The alkaline earth metal halide is preferably at least one selected from the group consisting of alkaline earth metal chlorides, bromides, and iodides, more preferably at least one selected from the group consisting of alkaline earth metal chlorides and bromides, and even more preferably chlorides. Among these, from the viewpoints of ease of handling, safety, etc., the alkaline earth metal halide is preferably at least one selected from the group consisting of calcium chloride, magnesium chloride, magnesium bromide, and calcium bromide, more preferably at least one selected from the group consisting of calcium chloride and magnesium chloride, and even more preferably calcium chloride. The halide (B) can be used alone or in combination of two or more kinds as required. In addition, the above-mentioned halide (B) is readily available as a commercially available product and can also be used.

[0021] The content of the halide (B) is preferably 0.3 to 5.0 parts by mass, more preferably 0.4 to 4.0 parts by mass, even more preferably 0.5 to 3.0 parts by mass, still more preferably 1.0 to 3.0 parts by mass, even more preferably 1.1 to 3.0 parts by mass, still more preferably 1.1 to 2.5 parts by mass, and even more preferably 1.1 to 2.0 parts by mass, relative to 100 parts by mass of the iron powder (A). By setting the content of the halide (B) within the above range, moisture can be appropriately supplied to the iron powder, and the halide (B) functions as a reaction accelerator, allowing high oxygen absorption performance to be maintained for a long period of time even in the presence of foods with high water activity.

[0022] <Activated carbon (C)> The oxygen absorbing composition of the present invention contains activated carbon. The activated carbon contained in the oxygen absorbing composition of the present invention is referred to as "activated carbon (C)" (component C). The activated carbon (C) in the oxygen scavenger composition of the present invention functions as a reaction accelerator and a water-retaining carrier.

[0023] The activated carbon (C) is not particularly limited, and the raw material may be wood, coconut shell, coal, or the like. However, from the viewpoint of using the oxygen absorbing composition of the present invention for food, one or more types selected from wood and coconut shell are preferred. The properties of the activated carbon (C) are not particularly limited, but from the viewpoint of ease of handling during production of the oxygen absorbing composition, activated carbon in a granular or powder form with high fluidity is preferably used, and activated carbon with a shape close to spherical is more preferred. The activated carbon (C) can be used alone or in combination of two or more types as required. Commercially available activated carbons are readily available and can also be used.

[0024] Furthermore, in terms of ease of handling during the production of the oxygen scavenger composition, the average particle size of the activated carbon (C) in powder form is preferably 0.1 μm or more and 1000 μm or less, more preferably 1 μm or more and 100 μm or less, and even more preferably 1 μm or more and 50 μm or less. As long as the activated carbon particles have a particle size within the above range, they can be used regardless of whether they are primary particles, agglomerated particles, or granulated particles. Activated carbons having a particle size within the above range can be used alone, or multiple types having different particle sizes can be mixed in any ratio. Such activated carbons are readily available commercially and can also be used.

[0025] The content of activated carbon (C) is preferably 0.5 to 5.0 parts by mass, more preferably 0.5 to 4.0 parts by mass, even more preferably 0.5 to 3.0 parts by mass, still more preferably 0.5 to 2.5 parts by mass, even more preferably 0.5 to 2.0 parts by mass, even more preferably 0.5 to 1.8 parts by mass, even more preferably 0.5 to 1.7 parts by mass, and even more preferably 0.5 to 1.5 parts by mass, relative to 100 parts by mass of iron powder (A). By setting the content of activated carbon (C) within the above range, moisture can be retained for a long period of time, thereby exhibiting its function as a reaction accelerator and allowing high oxygen absorption performance to be maintained for a long period of time even in the presence of high water activity foods.

[0026] The content of activated carbon (C) is preferably 0.2 to 3.0 parts by mass, more preferably 0.2 to 2.0 parts by mass, even more preferably 0.2 to 1.5 parts by mass, still more preferably 0.2 to 1.2 parts by mass, still more preferably 0.2 to 1.0 parts by mass, still more preferably 0.2 to 0.8 parts by mass, still more preferably 0.2 to 0.7 parts by mass, and still more preferably 0.2 to 0.6 parts by mass, relative to 100 parts by mass of the oxygen scavenger composition. By setting the content of activated carbon (C) within the above range, moisture can be retained for a long period of time, thereby exhibiting its function as a reaction accelerator and allowing high oxygen absorption performance to be maintained for a long period of time even in the presence of foods with high water activity.

[0027] <Inorganic powder filler (D)> The oxygen scavenger composition of the present invention has an apparent density of 1.10 g / cm 3 More than 2.90g / cm 3 The oxygen absorbing composition of the present invention contains the following inorganic powder filler: The inorganic powder filler contained in the oxygen absorbing composition of the present invention is referred to as "inorganic powder filler (D)" (component D). The inorganic powder filler (D) is an inorganic powder other than the iron powder (A), alkali metal halide or alkaline earth metal halide (B), and activated carbon (C). In other words, the inorganic powder filler (D) is an inorganic powder that is not included in any of the iron powder (A), alkali metal halide or alkaline earth metal halide (B), and activated carbon (C). The inorganic powder filler (D) is an inorganic powder other than the iron powder (A), alkali metal halide or alkaline earth metal halide (B), and activated carbon (C). The content of the inorganic powder filler (D) in the oxygen absorbing composition is 50 to 300 parts by mass relative to 100 parts by mass of the iron powder (A).

[0028] The apparent density of the inorganic powder filler (D) is 1.10 g / cm 3 More than 2.90g / cm 3 The apparent density of the inorganic powder filler (D) is preferably 1.10 g / cm or less. 3 More than 2.50g / cm 3 More preferably, it is 1.10 g / cm or less. 3 More than 2.10g / cm 3 More preferably, it is 1.10 g / cm or less. 3 More than 1.90g / cm 3 and even more preferably 1.10 g / cm or less. 3 More than 1.80g / cm 3 and even more preferably 1.10 g / cm or less. 3 More than 1.50g / cm 3 and even more preferably 1.10 g / cm or less. 3 More than 1.40g / cm 3 and even more preferably 1.20 g / cm or less. 3 More than 1.40g / cm 3and even more preferably 1.25 g / cm or less. 3 More than 1.35g / cm 3 When the apparent density of the inorganic powder filler (D) is within the above range, inhibition of oxidation reaction due to excess moisture can be suppressed, and even when the oxygen absorbing composition is applied to foods with high water activity, oxygen can be absorbed for a long period of time.

[0029] The content of the inorganic powder filler (D) in the oxygen absorber composition is 50 to 300 parts by mass per 100 parts by mass of the iron powder (A). The content of the inorganic powder filler (D) in the oxygen absorber composition is preferably 60 to 300 parts by mass, more preferably 80 to 300 parts by mass, even more preferably 100 to 300 parts by mass, still more preferably 100 to 250 parts by mass, still more preferably 105 to 200 parts by mass, still more preferably 120 to 180 parts by mass, and still more preferably 140 to 160 parts by mass per 100 parts by mass of the iron powder (A). By having the content of the inorganic powder filler (D) in the above range, inhibition of oxidation reactions due to excess moisture can be suppressed, and the oxygen absorber composition can absorb oxygen for a long period of time even when used in foods with high water activity.

[0030] The content of the inorganic powder filler (D) in the oxygen absorber composition is preferably 10 to 100 parts by mass per 100 parts by mass of the oxygen absorber composition. The content of the inorganic powder filler (D) in the oxygen absorber composition is more preferably 20 to 100 parts by mass, even more preferably 30 to 100 parts by mass, still more preferably 35 to 100 parts by mass, even more preferably 35 to 80 parts by mass, still more preferably 40 to 70 parts by mass, still more preferably 45 to 70 parts by mass, and even more preferably 50 to 65 parts by mass per 100 parts by mass of the oxygen absorber composition. By having the content of the inorganic powder filler (D) in the above range, inhibition of oxidation reactions due to excess moisture can be suppressed, and the oxygen absorber composition can absorb oxygen for a long period of time even when used in foods with high water activity.

[0031] The inorganic powder filler (D) is not limited to any particular type as long as it is a powdered inorganic material having the above-mentioned apparent density, but preferably contains at least one selected from the group consisting of metal salts, simple metals, and metal oxides. Metal salts, simple metals, and metal oxides are all preferred as the inorganic powder filler (D). However, metal oxides are more preferred because the small amount of hydroxyl groups present on the surface of the metal oxides may attract moisture from the system. Therefore, the inorganic powder filler (D) preferably contains at least one selected from the group consisting of metal salts, simple metals, and metal oxides, more preferably at least one selected from the group consisting of metal salts and simple metals, and even more preferably contains a metal salt. The inorganic powder filler (D) is more preferably at least one selected from the group consisting of metal salts, metal elements, and metal oxides. Metal salts, metal elements, and metal oxides are all preferred as the inorganic powder filler (D). However, metal oxides are more preferably metal salts or metal elements because the small amount of hydroxyl groups present on the surface of the metal oxides may attract moisture from the system. Therefore, the inorganic powder filler (D) is more preferably at least one selected from the group consisting of metal salts, metal elements, and metal oxides, even more preferably at least one selected from the group consisting of metal salts and metal elements, and even more preferably a metal salt. By using a metal salt, metal element, or metal oxide as the inorganic powder filler, inhibition of the oxidation reaction can be suppressed even in the presence of excess moisture, and the oxygen absorber composition can absorb oxygen for a long period of time even when used in foods with high water activity. This is thought to be due to the filler's resistance to water absorption, which prevents inhibition of the oxidation reaction due to wetting of the oxygen absorber composition even in the presence of excess moisture.

[0032] The metal salt is preferably at least one metal salt selected from the group consisting of metal carbonates, phosphates, nitrates, nitrites, borates, thiocyanates and organic acid salts, and more preferably a metal carbonate. The metal in the metal salt is preferably at least one selected from the group consisting of alkaline earth metals, transition metals, alkali metals and aluminum, more preferably an alkaline earth metal, and even more preferably calcium. Therefore, the metal salt is more preferably at least one metal salt selected from the group consisting of alkaline earth metal carbonates, phosphates, nitrates, nitrites, borates, thiocyanates, and organic acid salts, even more preferably alkaline earth metal carbonates, and even more preferably calcium carbonate. By using calcium carbonate as an inorganic powder filler, inhibition of oxidation reactions can be suppressed, and even when the oxygen absorber composition is applied to high water activity foods, it can absorb oxygen for a long period of time. This is thought to be because calcium carbonate does not easily absorb water, and even in the presence of excess moisture, inhibition of oxidation reactions due to wetting of the oxygen absorber composition can be prevented.

[0033] The metal element is preferably at least one selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 9 elements, Group 10 elements, Group 11 elements, Group 12 elements, and Group 13 elements, more preferably a Group 11 element, and even more preferably copper.

[0034] The metal in the metal oxide is preferably at least one selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 9 elements, Group 10 elements, Group 11 elements, Group 12 elements, and Group 13 elements, more preferably a Group 11 element, and even more preferably copper. Therefore, the metal oxide is more preferably an oxide of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 9 elements, Group 10 elements, Group 11 elements, Group 12 elements, and Group 13 elements, even more preferably an oxide of a Group 11 element, and even more preferably copper oxide.

[0035] Thus, a specific example of the inorganic powder filler (D) is preferably at least one selected from the group consisting of alkaline earth metal carbonates, simple Group 11 elements, and oxides of Group 11 elements, more preferably at least one selected from the group consisting of calcium carbonate, copper, and copper oxide, even more preferably at least one selected from the group consisting of calcium carbonate and copper, and still more preferably calcium carbonate.

[0036] As mentioned above, the inorganic powder filler (D) is preferably a metal salt, more preferably a metal carbonate, even more preferably an alkaline earth metal carbonate, and even more preferably calcium carbonate. When the inorganic powder filler (D) is calcium carbonate, the inorganic powder filler (D) is preferably at least one selected from the group consisting of heavy calcium carbonate, crushed shells, calcite, marble, limestone, and precipitated calcium carbonate, and more preferably at least one selected from the group consisting of marble and limestone. The use of marble or limestone as the inorganic powder filler can suppress inhibition of oxidation reactions, allowing the oxygen absorber composition to absorb oxygen for a long period of time even when applied to foods with high water activity. This is thought to be because marble or limestone do not easily absorb water, and therefore, even in the presence of excess moisture, inhibition of oxidation reactions due to wetting of the oxygen absorber composition can be prevented. Examples of marble include Arabescato, Kansui stone, Sivec White, Taiwan White, Bianco Carrara, and Perlino Carro, with Kansui stone being preferred. An example of limestone is Hakuryu crushed stone, and Hakuryu crushed stone is preferred.

[0037] The average particle size of the inorganic powder filler (D) is preferably 10 to 500 μm, more preferably 20 to 500 μm, even more preferably 30 to 500 μm, even more preferably 40 to 500 μm, and even more preferably 50 to 450 μm. When the average particle size of the inorganic powder filler (D) is within the above range, inhibition of the oxidation reaction is suppressed, and the oxygen absorber composition can absorb oxygen for a long period of time even when applied to foods with high water activity. This is thought to be because fillers with an average particle size within the above range are less likely to retain water, and therefore, even in the presence of excess moisture, inhibition of the oxidation reaction due to wetting of the oxygen absorber composition with water can be prevented. The average particle size of the inorganic powder filler (D) is the average particle size (D50) at a cumulative frequency of 50% in the volume-based particle size distribution. More specifically, the average particle size of the inorganic powder filler (D) can be determined by the method described in the Examples.

[0038] <Other ingredients> In addition to the above components, the oxygen scavenger composition of the present invention may contain other components as needed, provided that the effects of the present invention are not impaired. Examples of other components include a flow improver, a catalyst, an odor absorbent, and a heat dispersant.

[0039] <Method of manufacturing oxygen absorbing composition> The method for producing the oxygen scavenger composition of the present invention is not particularly limited, but preferably includes a step of mixing iron powder (A), an alkali metal halide or alkaline earth metal halide (B), activated carbon (C), and an inorganic powder filler (D).

[0040] In order for iron to absorb oxygen, it is necessary to attract moisture to the surface of the iron, and this is achieved by utilizing the deliquescence phenomenon of metal salts. The halide (B) is preferably contained in the oxygen scavenger composition as an aqueous solution in which it is dissolved in water.

[0041] The mixing step may be any of the following: (1) a step of mixing all of the components at once; (2) a step of preparing an aqueous solution by dissolving a halide (B) in water, adding the aqueous solution to a mixture of iron powder (A), activated carbon (C) and inorganic powder filler (D), mixing, and drying; or (3) a step of preparing an aqueous solution by dissolving a halide (B) in water, adding the aqueous solution to iron powder (A), mixing, and drying to obtain a halide-coated iron powder, and further mixing with activated carbon (C) and inorganic powder filler (D). According to the above step (3), the deliquescence phenomenon of the halide (B) makes it easier for moisture to be attracted to the surface of the iron, thereby improving the oxygen absorption performance, and therefore the above step (3) is more preferable.

[0042] The mixing method is not particularly limited, and can be performed by shaking mixing, mixing with a mixer, etc. Specific examples of the mixer include a Nauta mixer (manufactured by Hosokawa Micron Corporation), a conical mixer (manufactured by Ohno Chemical Machinery Co., Ltd.), a vertical granulator (manufactured by Powrex Corporation), a high-speed mixer (manufactured by Earth Technica Corporation), and a granulator (manufactured by Akira Kiko Co., Ltd.).

[0043] Since iron, which is the main component of the oxygen scavenger, reacts with oxygen, the reaction proceeds gradually even during the production of the oxygen scavenger composition. Therefore, mixing is preferably carried out in an inert atmosphere (in the case of a substantially closed system, the system is usually filled with an oxygen-free inert gas (e.g., nitrogen) atmosphere), and heat removal is preferably carried out as appropriate.

[0044] [Oxygen absorber packaging] The oxygen absorber package of the present invention comprises the oxygen absorber composition described above and a breathable packaging material containing the oxygen absorber composition.

[0045] (breathable packaging material) There are no particular restrictions on the breathable packaging material as long as it is a container that is breathable and allows oxygen to pass through. However, since the packaging material contains the oxygen absorbing agent composition and is used together with the preserved item, particularly a food with a high water activity, a bag-like or small pouch-like form is preferred.

[0046] Examples of breathable packaging materials include those formed by bonding two breathable films together to form a bag, those formed by bonding one breathable film and one non-breathable film together to form a bag, and those formed by folding one breathable film and sealing the edges together except for the folded part to form a bag. Alternatively, two non-breathable films may be bonded together to form a bag, and a breathable material such as a thread or a sheet having a breathable cross section may be sandwiched between the bonded portions to provide breathability. Compared to breathable packaging materials made of breathable films, breathable packaging materials obtained by sandwiching a breathable material between non-breathable films are preferred because they can prevent excessive moisture penetration.

[0047] The breathable film may be a single-layer film made of one type of breathable material, or a laminated film made of two or more types of breathable materials. However, a laminated film is preferred because it is necessary to efficiently transmit oxygen, prevent leakage of the oxygen absorbing agent composition, and also moderately suppress the penetration of moisture. Among laminated films, a laminated film having an outer layer made of a thermoplastic resin, an intermediate layer made of paper, aluminum foil or a thermoplastic resin, and an inner layer made of a heat-sealable thermoplastic resin is preferred. Here, the outer layer is located outside the oxygen absorber package and is a layer that comes into contact with the outside air and the preserved item, the inner layer is located inside the oxygen absorber package and is a layer that comes into contact with the oxygen absorber composition, and the intermediate layer is a layer that is located between the outer layer and the inner layer.

[0048] The outer layer is preferably made of a thermoplastic resin, more preferably polyethylene terephthalate or biaxially oriented polypropylene. Furthermore, since the outer layer is laminated to the intermediate layer by heat sealing, it is preferably a two-layer film. Examples of thermoplastic resins used in layers other than polyethylene terephthalate or biaxially oriented polypropylene include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-α-olefin copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, acid-modified polyolefin resin, polyvinyl acetate resin, poly(meth)acrylic resin, and polyvinyl chloride resin, with low-density polyethylene being preferred. The outer layer has a plurality of openings formed by perforation.

[0049] The intermediate layer is preferably made of paper, aluminum foil or a thermoplastic resin, more preferably made of paper or a thermoplastic resin. Examples of paper include water-repellent paper, kraft paper, fine paper (Western paper), and Japanese paper. The thermoplastic resin used in the intermediate layer is preferably a nonwoven fabric, and examples thereof include linear low-density polyethylene (LLDPE) nonwoven fabric, polyethylene terephthalate nonwoven fabric, composite nonwoven fabric (e.g., polyethylene terephthalate-polyethylene sheath-core structure), and TYVEK (registered trademark, manufactured by DuPont-Asahi Flashspun Products Co., Ltd.). The aluminum foil has a plurality of openings formed therein by perforation processing. The inner layer is preferably made of a heat-sealable thermoplastic resin, more preferably linear low-density polyethylene or unstretched polypropylene, and has a plurality of openings formed therein by perforation.

[0050] The air permeability of the breathable packaging material is preferably 1000 seconds / 100 cc or less, more preferably 100 seconds / 100 cc or less, and even more preferably 30 seconds / 100 cc or less, in terms of Gurley air permeability.

[0051] The thickness of the laminated film is preferably 30 μm or more and 300 μm or less, more preferably 40 μm or more and 250 μm or less, in which case the packaging material can maintain its strength and have excellent heat-sealing properties and packaging suitability, compared to thicknesses outside the above range.

[0052] In the case of a breathable packaging material in which two non-breathable films are bonded together to form a bag, and a sheet having breathability in cross section is sandwiched between the bonded portions, the material may have a three-layer structure as described above, and a seal layer may be provided between each layer. Alternatively, the bag may be formed by bonding together the outer edge of a laminate consisting of a non-breathable film, a seal layer, a sheet having breathability in cross section, and another seal layer.

[0053] The material of the non-breathable film is preferably one selected from the group consisting of polyethylene terephthalate, polyamide, polypropylene, polycarbonate and cellophane. The material of the sheet having breathability in cross section is preferably paper or nonwoven fabric. The paper is preferably at least one selected from the group consisting of Japanese paper, rayon-blended Japanese paper, and Western paper, and from the viewpoint of adhesiveness, rayon-blended Japanese paper is more preferable. The nonwoven fabric may be a wet-laid nonwoven fabric, a dry-laid nonwoven fabric, or a spunbonded nonwoven fabric. The nonwoven fabric may be made of polyamide, polyethylene terephthalate, rayon, or the like. The material of the sealing layer may be polyethylene, polyethylene vinyl acetate copolymer, ionomer, polybutadiene, or vinyl chloride.

[0054] [Method for preserving high water activity foods and high water activity food packaging] The oxygen absorber composition and the oxygen absorber package are suitable for preserving foods with high water activity because they can absorb oxygen for a long period of time even if the food to be preserved has high water activity. Therefore, the method for preserving high water activity foods of the present invention is a method for preserving high water activity foods by sealing the oxygen absorber composition or the oxygen absorber package and the high water activity food in a gas barrier container for storage. The method for preserving high water activity foods by sealing the oxygen absorber composition or the oxygen absorber package and the high water activity food in a gas barrier container for storage is also included in the present invention. The high water activity food package of the present invention is a high water activity food package in which the oxygen absorber composition or the oxygen absorber package and a high water activity food are sealed in a gas barrier container. The high water activity food package in which the oxygen absorber composition or the oxygen absorber package and a high water activity food are sealed in a gas barrier container is also included in the present invention.

[0055] There are no restrictions on the high water activity food to be used in the high water activity food preservation method and high water activity food packaging of the present invention, but the effects of the present invention are clearly demonstrated by using a food with a water activity of 0.7 or more. Therefore, the water activity of the high water activity food is preferably 0.7 or more, more preferably 0.8 or more, and even more preferably 0.9 or more. By using the oxygen absorber composition and oxygen absorber package, oxygen can be absorbed for a long period of time even when used to preserve foods with a water activity of 0.7 or more. The moisture content of the high water activity food is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more. The upper limit of the moisture content of the high water activity food is usually 70% by mass or less. By using the oxygen absorber composition and oxygen absorber package, oxygen can be absorbed for a long period of time even when used to preserve foods with a moisture content of 30% by mass or more.

[0056] Specific examples of the high water activity foods include cooked rice, rice cakes, rice flour dumplings, fresh noodles, fresh breadcrumbs, steamed buns, bread, etc., and preferably cooked rice and rice cakes. By using the oxygen absorber composition and the oxygen absorber package, oxygen can be absorbed for a long period of time even when stored together with foods with extremely high water activity such as cooked rice and rice cakes.

[0057] The gas barrier container used in the high water activity food preservation method and high water activity food packaging of the present invention is not particularly limited as long as it is sealable and has substantial gas barrier properties, but from the standpoint of blocking external ventilation, it is preferable that it be made of an impermeable material. Specifically, multilayer sheets and films with laminated structures such as polyethylene terephthalate / aluminum vapor deposition / polyethylene, oriented polypropylene / polyvinyl alcohol / polyethylene, and polyvinylidene chloride coated oriented nylon / polyethylene, as well as nylon-based co-extruded multilayer sheets and films with an oxygen permeability of 0.05 to 20 mL / (m 2 ·24hr·atm) (25℃, 50% RH) laminate can be easily used as a bag or packaging container. In addition to the above, metal cans, glass bottles, plastic containers, etc. can also be used as gas barrier containers.

[0058] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, but includes all aspects encompassed by the concept of the present invention and the scope of the claims, and can be modified in various ways within the scope of the present invention. [Example]

[0059] The present embodiment will be described in detail below using examples and comparative examples, but the present embodiment can be modified as appropriate as long as the effects of the present invention are achieved.

[0060] <Material> The materials used in the examples and comparative examples are shown below. Iron powder: "JIP303-60A", manufactured by JFE Steel Corporation, average particle size 41 μm, specific surface area 0.037 m 2 / g Activated carbon: "A3", manufactured by Osaka Gas Chemicals Co., Ltd., powder form Calcium chloride: Tokuyama Corporation

[0061] [Average particle size of iron powder] The average particle size of the iron powder was measured using a standard sieve conforming to ISO 3310-1:2000 (equivalent to JIS Z8801-1:2006) and was determined as the average particle size at a cumulative frequency of 50% (D50) from the weight fraction based on the size of the sieve openings after vibrating for 5 minutes. [Specific surface area of ​​iron powder] The specific surface area of ​​the above iron powder (unit: m 2 / g) was measured based on the BET multipoint method in accordance with JIS Z8830:2013.

[0062] <Inorganic powder filler> Among the materials used in the examples and comparative examples, the materials used as inorganic powder fillers are shown below. Kansui Stone: "Kansui #50", manufactured by Nitto Funka Kogyo Co., Ltd., marble, calcium carbonate, average particle size 71.1 μm, apparent density 1.29 g / cm 3 Hakuryu crushed stone: "Hakuryu Ichirin", manufactured by Asahi Komatsu Co., Ltd., limestone, calcium carbonate, average particle size 312 μm, apparent density 1.27 g / cm 3 Copper: "Copper, powder", manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., average particle size 19.2 μm, apparent density 2.02 g / cm 3 Copper oxide: "Copper(II) oxide", manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., average particle size 15.7 μm, apparent density 1.90 g / cm 3 Alumina: "Alumina A14", manufactured by Nippon Light Metal Holdings Co., Ltd., average particle size 55 μm, apparent density 0.76 g / cm 3 Silica sand: "Tohoku Silica Sand No. 8" manufactured by Tohoku Silica Sand Co., Ltd., average particle size 120 μm, apparent density 1.03 g / cm 3 Yellow iron oxide: "MTY-80", manufactured by Kanto Denka Finetech Co., Ltd., iron oxyhydroxide (FeOOH), average particle size 4.7 μm, apparent density 0.34 g / cm 3 Magnesium carbonate: "Heavy magnesium carbonate", manufactured by Tomita Pharmaceutical Co., Ltd., average particle size 8.5 μm, apparent density 0.36 g / cm 3 Zinc: "Zinc, powder," manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., average particle size 4.6 μm, apparent density 3.09 g / cm 3

[0063] [Average particle size of inorganic powder filler] The average particle size of the inorganic powder filler was measured as the average particle size (D50) at a cumulative frequency of 50% in the volumetric particle size distribution using a particle size distribution analyzer ("CAMSIZAR" manufactured by Microtrac). The measurement was carried out twice under the following conditions, and the average value was taken as the average particle size of the inorganic powder filler. Refractive index: 1.45 Solvent: Methyl ethyl ketone Shape: non-spherical [Apparent density of inorganic powder filler] According to JIS K6720-2:1999, the inorganic powder filler was placed in a 100 mL container, and the mass was measured and calculated.

[0064] <Production of oxygen absorber composition and oxygen absorber package> Example 1 [1] Production of oxygen scavenger composition Calcium chloride, which is an alkaline earth metal halide, was dissolved in water to prepare a 10% aqueous calcium chloride solution. Next, 100 parts by mass of iron powder and the calcium chloride aqueous solution were mixed so that the amount was 1.25 parts by mass in terms of calcium chloride, and the mixture was dried to prepare calcium chloride-coated iron powder. 101.25 parts by mass of this calcium chloride-coated iron powder, 1.5 parts by mass of activated carbon, and 150 parts by mass of kansui stone as an inorganic powder filler were mixed together to obtain an oxygen absorbing composition.

[0065] [2] Manufacturing of oxygen absorber packaging A polyethylene film was laminated onto a polyethylene terephthalate film and perforated to obtain a breathable film (air resistance 0-500 seconds, measured by the Gurley method (JIS-P8117) using a digital Oken-type testing machine (manufactured by Asahi Seiko Co., Ltd.)). A double-sided packaging material was obtained by overlapping the polyethylene film side of the breathable film with the waterproof paper side of a breathable sheet, in which perforated polyethylene was laminated as a sealing layer to waterproof paper, without bonding them together. The sealing layer side of the breathable sheet of this double-sided packaging material was then overlapped with the sealing layer of a separately prepared non-breathable film, in which polyethylene film was laminated as a sealing layer to a polyethylene terephthalate film, so that the sealing layer was in contact with the sealing layer, and three sides were heat-sealed to obtain a single-sided double-sided packaging bag with one side open. 3.5 g of the oxygen absorber composition was filled between the breathable sheet and the non-breathable film through the opening of the single-sided double-sided packaging bag, and the opening was sealed to obtain an oxygen absorber package (size: 45 mm x 50 mm).

[0066] Examples 2 to 4 and Comparative Examples 1 to 5 An oxygen absorber composition and an oxygen absorber package were produced in the same manner as in Example 1, except that the inorganic powder filler, Kansuiseki, was changed to the filler shown in Table 1.

[0067] <Excess oxygen absorption performance> The oxygen absorber compositions and oxygen absorber packages obtained in the examples and comparative examples were used to evaluate the excess oxygen absorption performance. The oxygen absorber package (oxygen absorber composition 3.5 g) was placed in an oxygen barrier bag (size 220 mm x 300 mm, oxygen permeability 0.53 mL / (m 2 The oxygen absorber package was placed in an oxygen barrier bag at a pressure of 1000 psi (24h MPa) or less (Mocon method, 20°C, 65% RH), and then 1000 mL of air at 100% RH was placed in the bag. The bag was sealed and stored at 25°C. After confirming that the oxygen concentration in the oxygen barrier bag had fallen below 0.1%, the oxygen absorber package was removed. The oxygen absorber package was then hit with a hammer to pulverize the oxygen absorbing composition contained in the oxygen absorber package until no lumps remained. The oxygen absorber package was then opened, and the oxygen absorber composition was placed on filter paper. Water was added dropwise until the oxygen absorbing composition on the filter paper was completely wet. After the water was added dropwise, the filter paper was left to stand for 60 minutes, and then the oxygen absorbing composition was applied to a cotton cloth (thickness: 80 μm) in a 100 cm 2 The powder was spread over an area of ​​1000 mm, a cotton cloth was placed on top, and the powder was pressed for 10 minutes so that the powder was in complete contact with the cotton cloth, thereby removing the moisture. The moisture content of the oxygen absorbing composition after the moisture removal was calculated using the following formula, and was taken as the saturated moisture content. (Saturated moisture content (%))=[(mass of oxygen absorber composition after moisture removal)−(mass of oxygen absorber composition before water addition)] / (mass of oxygen absorber composition after moisture removal)×100

[0068] An oxygen absorber package was produced in the same manner as in Example 1 using the obtained oxygen absorber composition after removing the water content. The oxygen absorber package was placed in an oxygen barrier bag, which was then filled with 3000 mL of air at 100% RH and sealed. The bag was then stored at 25°C for 3 days, and the amount of oxygen in the oxygen barrier bag was measured after 3 days. The amount of oxygen that was reduced was taken as the excess oxygen absorption performance. The greater the amount of oxygen that was reduced, the better the excess oxygen absorption performance, and the more oxygen can be absorbed even in the presence of a large amount of moisture, which is preferable.

[0069] The amount of oxygen in the oxygen barrier bag was measured using a gas analyzer (MOCON's "Check Mate 3") by inserting a hollow needle at the tip of a sampling silicone tube attached to the gas analyzer into the bag through a sampling rubber sheet (25 mm x 25 mm, 2 mm thick) that had been attached to the oxygen barrier bag in advance, and measuring the oxygen concentration inside the gas barrier bag.

[0070] [Table 1]

[0071] As shown in Table 1, the oxygen absorber compositions and oxygen absorber packages of the examples have excellent excess oxygen absorption performance and can absorb oxygen even in the presence of a large amount of moisture. On the other hand, the oxygen absorber compositions and oxygen absorber packages of the comparative examples, which contain inorganic powder fillers whose apparent densities do not satisfy the specified range, have very low excess oxygen absorption performance, and the oxidation reaction is inhibited by the large amount of moisture, resulting in poor oxygen absorption performance. From the above, it can be seen that the oxygen absorber composition and oxygen absorber package of the present invention can absorb oxygen for a long period of time even when applied to foods with high water activity.

Claims

1. The composition contains iron powder (A), an alkali metal halide or an alkaline earth metal halide (B), activated carbon (C), and an inorganic powder filler (D), The inorganic powder filler (D) is any of the inorganic powder fillers other than the iron powder (A), the alkali metal halide or alkaline earth metal halide (B), and the activated carbon (C), The apparent density of the inorganic powder filler (D) is 1.10 g / cm ３ 2.90g / cm or more ３ is as follows: The oxygen scavenger composition has a content of the inorganic powder filler (D) of 50 to 300 parts by mass per 100 parts by mass of the iron powder (A).

2. 2. The oxygen absorbing composition according to claim 1, wherein the inorganic powder filler (D) contains at least one selected from the group consisting of metal salts, elemental metals, and metal oxides.

3. 3. The oxygen absorbing composition according to claim 1, wherein the inorganic powder filler (D) is a metal carbonate.

4. 3. The oxygen absorbing composition according to claim 1, wherein the inorganic powder filler (D) is calcium carbonate.

5. 3. The oxygen absorbing composition according to claim 1, wherein the inorganic powder filler (D) is at least one selected from the group consisting of heavy calcium carbonate, crushed seashells, calcite, marble, limestone, and precipitated calcium carbonate.

6. 3. The oxygen absorbing composition according to claim 1, wherein the inorganic powder filler (D) has an average particle size of 10 to 500 μm.

7. The apparent density of the inorganic powder filler (D) is 1.10 g / cm ３ 1.50g / cm or more ３ 3. The oxygen scavenger composition according to claim 1, wherein:

8. 3. The oxygen absorbing composition according to claim 1, wherein the content of the inorganic powder filler (D) is 105 to 200 parts by mass per 100 parts by mass of the iron powder (A).

9. 3. The oxygen scavenger composition according to claim 1, wherein the alkali metal halide or alkaline earth metal halide (B) is an alkaline earth metal halide.

10. 3. The oxygen scavenger composition according to claim 1, wherein the alkali metal halide or alkaline earth metal halide (B) is at least one selected from the group consisting of calcium chloride, magnesium chloride, magnesium bromide, and calcium bromide.

11. 3. The oxygen absorbing composition according to claim 1, wherein the content of the activated carbon (C) is 0.5 to 5.0 parts by mass per 100 parts by mass of the iron powder (A).

12. 3. The oxygen scavenger composition according to claim 1, wherein the content of the alkali metal halide or alkaline earth metal halide (B) is 0.3 to 5.0 parts by mass per 100 parts by mass of the iron powder (A).

13. 3. The oxygen scavenger composition according to claim 1, wherein the content of the alkali metal halide or alkaline earth metal halide (B) is 1.1 to 3.0 parts by mass per 100 parts by mass of the iron powder (A).

14. An oxygen absorber package comprising the oxygen absorber composition according to claim 1 and a breathable packaging material containing the oxygen absorber composition.

15. A method for preserving a high water activity food, comprising enclosing the oxygen absorber composition according to claim 1 or the oxygen absorber package according to claim 14 and the high water activity food in a gas barrier container for storage.

16. A high water activity food package comprising the oxygen absorber composition according to claim 1 or the oxygen absorber package according to claim 14 and a high water activity food sealed in a gas barrier container.

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