JPS63233768A - Freshness-keeping agent - Google Patents

Abstract

PURPOSE:To obtain a freshness-keeping agent absorbing oxygen and generating carbon dioxide gas in sealed system, capable of keeping the freshness of foods and mitigating the reduction of pressure or shrinkage of a sealed container, by using iron powder, a bicarbonate, etc., as raw materials. CONSTITUTION:(A) More than about 0.5g of iron powder of about >=10 mesh based on 500ml of air to be treated is mixed with (B) about >=0.2g (based on 500ml of air) of preferably powdery bicarbonate such as sodium bicarbonate and potassium bicarbonate, (C) about 5-200pts.wt. of ferrous chloride in terms of anhydride based on 100pts.wt. of the bicarbonate and (D) about 10-500pts.wt. of a 2-8C dicarboxylic acid such as fumaric acid and phthalic acid based on 100pts.wt. of the ferrous chloride. The mixture is sealed in an air-permeable small bag. At least a part of the packaging material of the bag has a Gurley permeability of <=1,000sec/100ml air.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a food freshness-preserving agent, and more specifically, it absorbs oxygen and generates carbon dioxide gas in a sealed system containing food, thereby maintaining the freshness of food. The present invention relates to a food freshness-preserving agent that aims to maintain food freshness and reduce pressure reduction or shrinkage caused by oxygen absorption within a sealed container.

[Conventional technology]

Oxygen absorbers are used as a food preservation technique, and this involves storing food and oxygen absorbers in a sealed bag or container (hereinafter simply referred to as a sealed container or container) with gas barrier properties. It suppresses the oxidation of food and the growth and proliferation of bacteria and mold by making the inside of the sealed system substantially oxygen-free, and is used to preserve a wide range of foods.

However, since the oxygen absorber completely absorbs the oxygen in the sealed container, the amount of gas in the container is reduced to about 415 ml, which is the initial amount, resulting in the container being depressurized or contracted, deformed, and even the food inside deformed. There were cases where external theories were lost.

As a countermeasure for this, for example, Japanese Patent Application Laid-Open No. 55-61914
0-iso-ascorbic acid or its salt,
There are proposals regarding freshness-preserving agents consisting of alkaline substances, deliquescent substances, additives, and copper-based compounds that act as oxidizing agents. This type of freshness preservation agent absorbs oxygen and simultaneously generates carbon dioxide gas, and has the function of hardly changing the total amount of gas in the container, providing a solution to the above problems that occur when only deoxidizing the container. It is something.

However, D-iso-ascorbic acid-based freshness-preserving agents have the disadvantage that the deoxidation rate is extremely slow, especially at low temperatures, compared to oxygen absorbers based on iron powder. The freshness-preserving agent disclosed in Japanese Patent No. 61914 also has the drawback of coexisting with a copper-based compound and being toxic, which is extremely inconvenient for application to foods.

On the other hand, there are also proposals for freshness-preserving agents that have the function of absorbing oxygen and generating carbon dioxide gas for other purposes. For example, JP-A-56-61981 discloses a freshness-preserving agent consisting of an oxygen absorbent, a hygroscopic or deliquescent alkaline earth metal salt, and a hydrogen carbonate;
No. 982 discloses an oxygen absorbent, a hygroscopic substance that becomes acidic when it acts with water, a deliquescent substance that becomes acidic when it acts with water, and a freshness-preserving agent consisting of carbonate and/or hydrogen carbonate, especially JP-A-56-106580 discloses a freshness-preserving agent consisting of an iron-based oxygen absorbent, a hygroscopic or deliquescent alkaline earth metal salt, a hydrogen carbonate, and a solid substance that becomes acidic when it interacts with water. Publication No. 56-148272 proposes a freshness-preserving agent consisting of an iron-based oxygen absorber, a metal halide, a carbonate and/or hydrogen carbonate, a solid substance that becomes acidic when it interacts with water, and an amino acid that has a pH buffering effect. has been done.

Each of the above-mentioned freshness-preserving agents is expected to maintain freshness by imparting carbon dioxide gas generating ability as well as oxygen absorption ability, with the aim of suppressing the growth of mold and bacteria, as well as suppressing the vital functions of fruits and vegetables.

In general, freshness preserving agents are stored and distributed by sealing the composition in a gas barrier bag after the composition is sealed in a gas barrier bag, and when needed for food preservation, the gas barrier bag is opened and the freshness preserving agent is placed in a small bag. This purpose can be achieved by taking out the food and sealing it together with another gas barrier bag or container. Therefore, in a freshness-preserving agent equipped with a carbon dioxide gas generation function, if water coexists in the composition, the carbon dioxide gas generation function will be expressed during storage and distribution, causing the gas barrier bag to swell and eventually break, resulting in a loss of freshness. The retention agent comes into contact with atmospheric air, absorbs oxygen, and loses its functionality.

Therefore, in the above-mentioned conventional freshness-preserving agents, water is not contained in the freshness-preserving agent composition, and when applied to high-moisture foods, the moisture that evaporates from the food is incorporated into the composition to prevent oxygen absorption and carbon dioxide gas generation. It is practical when used as a freshness-preserving agent that exhibits both functions, but it is not practical when a component is previously impregnated with water into the composition.

Considering the conventional techniques from the above point of view, for example, Japanese Patent Laid-Open No. 56-61981 and Japanese Patent Laid-Open No. 56-10658
The freshness preserving agent disclosed in Publication No. 0 uses a hygroscopic or deliquescent alkaline earth metal salt such as calcium chloride or magnesium chloride, so the composition itself must be mixed and molded in a dry nitrogen atmosphere. This was accompanied by the complexity of not having to do so.

If mixed in the normal atmosphere, moisture from the atmosphere will be absorbed into the composition due to its extremely high hygroscopicity, and the composition will be stored in a small bag, sealed in a gas barrier bag, and carbonated during distribution. Problems such as expansion and bag breakage due to gas generation occur. In addition, in the above composition, when iron powder is used as an oxygen absorbent, the oxygen absorption rate per unit weight of iron powder becomes slow, and in order to make it a practical freshness preserving agent, the amount of iron powder used must be large. It had drawbacks.

Furthermore, JP-A No. 56-61981 and JP-A No. 5
In the case of the freshness preserving agent disclosed in Japanese Patent Publication No. 6-61982, there was a problem in that carbon dioxide gas once generated was reabsorbed into the composition over time. For example, even if the carbon dioxide concentration in the system once reached 14 to 17%, it would drop to 3 to 4% after a few days.

Since the purpose of these techniques is to suppress bacteria and the vital functions of fruits and vegetables, there is no problem in itself, but this composition is not suitable for preventing depressurization or suppressing shrinkage of containers.

The freshness-preserving agent disclosed in JP-A-56-148272 proposes adding an amino acid having a pH buffering effect to the composition. This has led to problems such as the odor of amino acids being transferred to food, and odor generated by decomposed components of amino acids.

In addition, the effect of the freshness-preserving agent disclosed in JP-A-56-148272 on the freshness-preserving function of amino acids increases the amount of carbon dioxide gas generated and reduces the oxygen absorption rate, rather than the hydrogen generation suppressing effect described in the same publication. In experiments conducted by the present inventors, it was confirmed that the present invention has the effect of

[Problem that the invention seeks to solve]

The present invention has been made particularly in view of the problems of the prior art described above.

In a type of freshness-preserving agent that absorbs moisture that evaporates from food and absorbs oxygen and generates carbon dioxide gas, (1) Even if the freshness-preserving agent composition is mixed and prepared in the atmosphere.

During storage and distribution after being sealed in a gas-barrier bag after being sealed in a breathable pouch, carbon dioxide gas is generated in an extremely small amount and there is no risk of bag breakage. Fast (3
) The carbon dioxide concentration in the same series is 10-23% until the package is opened.
(4) No odor during use (1) (5) Low amount of hydrogen generation and no toxicity of the composition itself;
The purpose is to provide a highly safe freshness preserving agent.

[Means for Solving the Problems] For the above purpose, the present inventors have conducted intensive studies on freshness preserving agents that use iron powder as an oxygen absorber and hydrogen carbonate as a carbon dioxide gas generating agent, and have developed the present invention. I was able to complete it.

That is, the present invention provides (A) iron powder, (B) hydrogen carbonate,
The present invention provides a freshness-preserving agent for high-moisture foods, characterized in that (C) ferrous chloride and (D) C2 to C6 dicarboxylic acid are mixed and then sealed in an air-permeable pouch.

Normally, when iron-based oxygen scavengers coexist with carbon dioxide gas, the oxygen absorption rate decreases significantly. The present inventors conducted a study to increase the oxygen absorption rate in an atmosphere where carbon dioxide gas is generated, and by including ferrous chloride in the composition, it was possible to effectively convert hydrogen carbonate to carbonate without slowing down the oxygen absorption rate. It was confirmed that gas was generated. However, in this composition system,
It has been found that the carbon dioxide gas generated once applied to food is absorbed by the restring composition.

After further investigation, it was discovered that by adding a C3 to C8 dicarboxylic acid to the above composition, the carbon dioxide concentration within the system could be maintained.

In addition, compared to alkaline earth metals such as calcium chloride and magnesium chloride, ferrous chloride has significantly lower hygroscopicity when left in the atmosphere, and even if mixed with other components in the atmosphere, the composition There is little moisture entering the product, and even if carbon dioxide gas is generated during storage and distribution, the gas barrier bag will not break.

The iron powder (A) used in the present invention may be any commercially available powder, but spray iron, sponge iron, electrolytic iron, etc. are particularly preferred. The particle size of the iron powder used is usually preferably 10 mesh or less, particularly preferably 50 mesh or less. The iron powder may contain various impurities and may be made of partial oxides. Furthermore, the oxygen absorption rate can be increased by coating the surface of the iron powder with iron oxide and/or metal halide.

The (B) hydrogen carbonate used in the present invention is preferably an alkali metal bicarbonate, and particularly preferably sodium hydrogen carbonate or potassium hydrogen carbonate.

The hydrogen carbonate is preferably used in the form of a powder in order to improve its mixability with other components, and the particle size is preferably 10 mesh or less.

The ferrous chloride (C) used in the present invention may be anhydrous or hydrated. Usually, anhydrous, dihydrate or tetrahydrate forms are used. Ferrous chloride is preferably a powder with a particle size of 50 mesh or less.

The (D) C2-C8 dicarboxylic acid used in the present invention may be, for example, a saturated aliphatic dicarboxylic acid, an unsaturated aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, or a dicarboxylic acid having a substituent such as a hydroxyl group. These dicarboxylic acids are those having 2 to 8 carbon atoms in order to maintain the carbon dioxide concentration in the sealed container within a desired range. For example, saturated aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, and adipic acid, unsaturated aliphatic dicarboxylic acids such as fumaric acid and maleic acid, oxydicarboxylic acids such as tartaric acid or malic acid, and phthalic acid. Specific examples of preferred dicarboxylic acids include aromatic dicarboxylic acids such as , isophthalic acid and terephthalic acid.

Furthermore, vic-dicarboxylic acid can be mentioned as a particularly preferred dicarboxylic acid among the above dicarboxylic acids.

Specific examples of vic-dicarboxylic acids include fumaric acid, maleic acid, succinic acid, malic acid, tartaric acid, and phthalic acid. Among the vic-dicarboxylic acids, fumaric acid is most preferred. The use of vic-dicarboxylic acid is particularly preferred because the initial concentration of carbon dioxide gas in the sealed system is maintained over a long period of time. The dicarboxylic acid is preferably a powder with a particle size of 50 mesh or less.

In the present invention, other components may be added in addition to the above-mentioned components (A) to (D). For example, by adding a poorly water-soluble filler, it is possible to increase the oxygen absorption rate or the amount of oxygen absorption, and to make the composition easier to handle. Specific examples of the poorly water-soluble filler include activated carbon, zeolite, perlite, diatomaceous earth, activated clay, silica, kaolin, talc, hentonite, and iron oxide. As the poorly water-soluble filler, powder having a particle size of 50 mesh or less is preferably used.

In order to ensure a practical oxygen absorption rate, the iron powder used as component (A) in the present invention is preferably 0.5 g or more per 500 m of applied air, particularly preferably 0.8 g or more and 3 g or less. Component (B) hydrogen carbonate is 0 per 500 m1 of applied air in order to maintain a practical amount of carbon dioxide gas generation.
．． The amount used is 2g or more, preferably 0.4g or more, and 2.0g or less, preferably 1.5g or less.

The amount of ferrous chloride in component (C) is 1 hydrogen carbonate in terms of anhydride.
The amount used is usually 5 to 200 parts by weight, preferably 20 to 100 parts by weight per 00 parts by weight.

The amount of 02 to C6 dicarboxylic acids of component (D) is generally 10 to 500 parts by weight, preferably 30 to 300 parts by weight, per 100 parts by weight of ferrous chloride.

In addition, when using a poorly water-soluble filler, 5% of the total composition
-50% by weight is preferred, and a range of 10-30% by weight is particularly preferably used.

In the present invention, the mixer for mixing each component is not particularly limited, and any mixer that can mix each component uniformly may be used.

After the above ingredients are mixed uniformly, they are wrapped in a pouch sealed by a backing machine by heat sealing the periphery of the breathable packaging material.

In the freshness preserving agent of the present invention, the air permeability of the packaging material surrounding the composition greatly influences the oxygen absorption rate and the amount of carbon dioxide gas generated.

The freshness preserving agent of the present invention exhibits the function of generating carbon dioxide gas as well as absorbing oxygen, so if the packaging material has poor air permeability and the oxygen absorption rate is suppressed, the composition will be affected by carbon dioxide gas and the rate retardation will be further exacerbated. be done.

From the above point of view, it is preferable that at least half of the total area of the packaging material for the freshness-preserving agent has a Gurley air permeability of 1.000 seconds/100 m1 of air or less, and 500 seconds/100 m1 of air or less for the packaging material in the present invention from the above viewpoint. It is particularly preferable to set the value to 100 ml or less of air.

Furthermore, since the freshness-preserving agent of the present invention is applied to high-moisture foods, it is necessary to take measures to prevent the composition from becoming wet and stains caused by the composition from transferring to the packaging material. For this reason, it is preferable to use a water-resistant sheet material as the packaging material.

For example, in the present invention, a paper that has been treated to be water-resistant or water- and oil-resistant, or a microporous membrane and a polyethylene film with holes are laminated, or the paper and the polyethylene film are laminated and then the polyethylene film portion is formed by a method such as laser aperture. Paper with holes, polyethylene fibers such as Tyvek (trade name, manufactured by DuPont), cross-dispersed and heat pressed, and polyolefin fibers such as Aldo (trade name, manufactured by Doha Paper Co., Ltd., manufactured by M). A post-heat-pressed sheet or the like is preferably used. In particular, a pouch using Tyvek or Aldo as part of the packaging material is preferably used because it has extremely good air permeability.

In order to use these sheets as packaging materials for the freshness preserving agent of the present invention, for example, one side of the sheet may be coated with PET (
Polyethylene terephthalate (hereinafter the same)/PE (polyethylene, hereinafter the same) or NY (nylon, hereinafter the same)/PE, etc., with a normal non-breathable film on the other side, the two facing each other, and the composition between them. By arranging the pouch and heat-sealing the periphery, the composition can be stored inside the pouch, resulting in a freshness-preserving agent having air permeability on only one side.

The food intended as a freshness preserving agent in the present invention preferably has a water activity of 0.6 or more, particularly preferably 0.7.
The above-mentioned food starts to function when the water that evaporates from the food when left in a sealed state transfers to the freshness-preserving agent side.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Iron powder (sprayed iron) 1.0g, sodium hydrogen carbonate 1.0g
, 0.6 g of ferrous chloride, 0.4 g of fumaric acid, and 1.0 g of zeolite were mixed together, and a 5 cm x 8 cm rectangular Tyvek and a 5 cm x 8 cm rectangular PET/PE PE surface were combined and the periphery was heat-sealed. A freshness-preserving agent was prepared by sealing the above mixture inside the container. In addition, each component of the composition used powder having a particle size of 50 mesh or less.

Add this freshness preserving agent to 51% glycerin aqueous solution 10IT11
along with a humidity conditioner made by impregnating 2g of absorbent cotton with
X18ctn KON (polyvinylidene chloride coated stretched nylon, 15μ)/PE (60μ) bags were loaded. The system was sealed with 500 ml of air and left at 25°C, and the gas concentrations (oxygen concentration, carbon dioxide concentration, and hydrogen concentration) in the system were measured over time. During the measurement period, the RH in the system was maintained at 80% by coexisting absorbent cotton impregnated with a 51% aqueous glycerin solution.

The measurement results are shown in Table 1.

Comparative Example 1 In Example 1, fumaric acid was not used as a composition component, and 0.6 g of ferrous chloride was replaced with 0 calcium chloride.
．． A freshness preserving agent was prepared in the same manner as in Example 1, except that 6 g was used, and the same measurements were carried out.

The results are shown in Table 1 as Comparative Example 1 together with Example 1.

Comparative Example 2 A freshness preserving agent was prepared in the same manner as in Example 1 except that fumaric acid was not used as a composition component in Example 1,
Similar measurements were performed. The results are shown in Table 1 as Comparative Example 2 together with Example 1.

Comparative Example 3 0.6 g of ferrous chloride as a composition component in Example 1
A freshness preserving agent was prepared in the same manner as in Example 1, except that 0.6 g of calcium chloride was used instead of 0.6 g, and the same measurements were performed. The results are shown in Table 1 as Comparative Example 3 together with Example 1.

Comparative Example 4 In Example 1, glycine 1 was further added as a composition component.
．． A freshness-preserving agent was prepared in the same manner as in Example 1, except that a composition containing 0 g was used, and the same measurements were carried out.

The results are shown in Table 1 as Comparative Example 4 together with Example 1.

In Table 1, "Example 1" refers to Example 1 as "Ratio 1 to 4."
" represents Comparative Examples 1 to 4.

As is clear from Table 1, in Example 1, the oxygen absorption rate was fast and the carbon dioxide concentration was suitably maintained.

Table 1 Examples 2 to 3 In Example 1, the same tests and measurements as in Example 1 were conducted except that the proportions of each component of the freshness-preserving agent composition were as shown in Table 2.

The results are shown in Table 2.

In Table 2, "Example 2" refers to Example 2, and "Example 3" refers to Example 2.
represents Example 3.

Table 2 Examples 4 to 6 In Example 1, the same tests and measurements as in Example 1 were conducted except that the proportions of each component of the freshness-preserving agent composition were as shown in Table 3.

The results are shown in Table 3.

In addition, in Table 3, "Example 4-6" represents Examples 4-6.

〔Effect of the invention〕

By storing the freshness-preserving agent of the present invention in a sealed container together with foods whose water activity is preferably 0.6 or more, particularly preferably 0.7 or more, oxygen in the system is quickly absorbed and Since the carbon dioxide concentration of the container is maintained at 10-23% until the container is opened, the container maintains its shape when loaded without depressurizing or shrinking, and the food inside remains fresh. Retained.

The freshness-preserving agent of the present invention can be suitably used for products whose appearance is impaired by deformation and compression, such as castella cakes, sponge cakes, manju buns, fresh sweets, and niboshi. In particular, when the outside of a paper box such as castella cake is sealed with a gas barrier film after being stored in a paper box, deoxidation alone may deform the paper box, but the freshness-preserving agent of the present invention can be used very suitably.

Claims (2)

[Claims] (1) (A) Iron powder, (B) hydrogen carbonate, (C) ferrous chloride, and (D) C_2 to C_3 dicarboxylic acids are mixed and then sealed in a breathable pouch. A freshness-preserving agent for high-moisture foods. (2) The air permeability of at least a portion of the packaging material constituting the breathable pouch is Gurley air permeability of 1,000 seconds/100 m of air.
Claims characterized in that the value is 1 or less (1
) The freshness preserving agent described.