JPS6218217B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an iron-based oxygen absorbent that can be used safely. In recent years, methods have been used to selectively remove oxygen from the atmosphere in which food is packaged in order to prevent the growth of mold and spoilage during the storage period of packaged food. Oxygen absorbers for this purpose have conventionally been organic (ascorbic acid, etc.) and inorganic (iron, hydrosulfite, etc.), but they all have economical, odor, and safety issues. It has poor practicality. Therefore, the present inventors conducted various studies in order to obtain an economical, non-hazardous, safe and effective oxygen absorbent. As a result, by mixing a hygroscopic or deliquescent alkaline earth metal salt with a general iron-based oxygen absorbent, the oxygen absorption rate can be sufficiently increased to prevent food from rotting and deteriorating. It was discovered that a drug can be obtained. However, although the above-mentioned iron-based oxygen absorbent is satisfactory in terms of oxygen absorption ability, it is observed that hydrogen is generated, albeit in a small amount, during oxygen absorption. Therefore, if a large amount of oxygen absorbent is used, hydrogen will be generated in a non-negligible amount, creating a risk of fire, explosion, etc. due to the hydrogen. The present inventors have conducted various studies in order to eliminate the danger caused by hydrogen generation and to find an oxygen absorbent having good oxygen absorption ability, and as a result, they have arrived at the present invention. The present invention comprises (A) an iron-based oxygen absorbent (hereinafter referred to as component (A)), (B) a metal halide (hereinafter referred to as component (B)), and (C) an amino acid having a PH buffering effect (hereinafter referred to as component (C)). ) (D) An oxygen absorbent made of water (hereinafter referred to as component (D)), when it is packaged with food or placed in a container, it should be packaged or placed in a container without generating much hydrogen. By absorbing oxygen, it is possible to preserve food and prevent mold growth and spoilage. The iron-based oxygen absorbent, which is the component (A) of the oxygen absorbent of the present invention, is an iron-based substance that absorbs oxygen by reacting with oxygen in the air and is itself oxidized. Examples include those mainly containing one or more types selected from the following. (a) Iron powders such as reduced iron powder, electrolytic iron powder, and atomized iron powder, and partial oxides of the iron powders. (b) For example, ferrous sulfate, ferrous oxide, ferrous hydroxide
A ferrous compound consisting of iron, etc. (c) For example, iron complex oxides such as triiron tetroxide. (d) Iron compounds consisting of, for example, iron carbide, iron sulfide, iron carbonyl, iron silicon, etc. In the present invention, among the iron-based oxygen absorbents as the component (A) exemplified herein, the iron powders and partial oxides of the iron powders exemplified in (A) are particularly preferred. It is preferably used because it exhibits absorption capacity.
Further, among the iron powders and partial oxides thereof, fine powders having a particle size of less than 80 mesh are particularly preferably used because they have a high oxygen absorption capacity per unit weight. The metal halide as component (B) of the oxygen absorbent of the present invention is, for example, sodium chloride, potassium chloride,
Alkali metal halides such as sodium bromide, potassium bromide, sodium iodide, potassium iodide, sodium fluoride, potassium fluoride, magnesium chloride, calcium chloride, barium chloride, calcium bromide, bromide, etc. Alkaline earth metal halides such as magnesium and barium bromide;
Examples include halides of silver, zinc, aluminum, tin, manganese, iron, cobalt, nickel, copper, etc. Among them, halides of alkali metals and alkaline earth metals are preferred. These salts can be used either in the form of anhydrous salts or various hydrated salts, and can be used alone or in combination of two or more. The amino acid having a PH buffering effect, which is the component (C) of the oxygen absorbent of the present invention, is a component that chemically and/or physically interacts with water vapor in the atmosphere inside the packaging or container.
Any amino acid can be used as long as it has a pH buffering effect and is normally solid, but amino acids with an isoelectric point (pI value) of 5.0 or more can be particularly preferably used. When an amino acid having such a pI value is used, an oxygen absorbent having good oxygen absorption ability and hydrogen generation suppressing ability can be obtained. Amino acids with a pI value of less than 5.0 have somewhat insufficient hydrogen generation ability. Examples of such amino acids include those mainly containing one or more types selected from the following groups. For example, asparagine, aminobutyric acid, alanine, arginine, isoleucine, ornithine, canavenine, glycine, glutamine, sarcosine,
Cysteine, cystine, serine, thyroxine, tyrosine, tryptophan, threonine, norleucine, valine-histidine, hydroxyproline,
Hydroxylysine, phenylalanine, proline, homoserine, methionine, methylhistidine, lysine, leucine, etc. Water, which is component (D) of the present invention, is an essential component in order to function as an oxygen absorber, and generally water (can be measured as humidity) in the atmosphere in which the oxygen absorber is used. is sufficient, so there is no need to add it. However, when the target atmosphere that requires oxygen absorption is in a very dry state, it is necessary to add it intentionally. As for the method of addition, it is possible to add water to components (A) to (C), to add water to the filler described later, or to separate water from the oxygen absorber and evaporate it from there. Moisture can also be used. Furthermore, it is also possible to utilize the moisture contained in the objects to which the oxygen absorber is applied, such as vegetables, fruits, and other fresh foods. In any case, it is sufficient that the required amount of water is the amount generally required for this type of oxygen absorbent. The oxygen absorbent of the present invention has the above-mentioned components (A) to (D) as essential components, and if any one component is missing, the function as an oxygen absorbent will deteriorate. This situation will be explained below by taking as an example the case where one component is deleted from each of the four components. (A) If the component is missing, no oxygen absorption capacity will be expressed. (B) If the component is missing, the oxygen absorption capacity will be significantly reduced. (C) When a component is missing, hydrogen is generated,
If large quantities of oxygen absorbers are used, hydrogen may accumulate within the packaging, creating a risk of explosion or fire. (D) When a component is missing, only a small amount of oxygen absorption capacity is expressed. The blending ratio of each component in the oxygen absorbent of the present invention is not particularly limited, and may vary depending on the type of food, the amount of water evaporation from the food, the required oxygen absorption rate, etc.
Generally preferred blending ratios are described below, although they can be varied over a fairly wide range. The metal halide that is component (B) is preferably 0.01 to 3 moles, particularly preferably 0.1 mole, per mole of iron powder and/or iron compound that is the main ingredient of the iron-based oxygen absorber that is component (A).
The oxygen absorption capacity is high in the range of ~2 mol. The amount of the amino acid that has a pH buffering effect, which is component (C), varies depending on the blending ratio of components (A) and (B), but preferably the total amount of components (A) and (B). It is determined within the range of 0.001 to 1 part by weight per 1 part by weight. Below this range, the effect of suppressing hydrogen generation is not observed, and when added above this range, the oxygen absorption capacity per weight of the oxygen absorbent decreases significantly, resulting in poor practicality. Component (D), water, does not normally need to be added as described above, but when it is particularly necessary to add it, it is sufficient to add it in the amount generally required for this type of oxygen absorber. The oxygen absorbent of the present invention contains the above-mentioned components (A) to (D) as essential components, but in order to improve the miscibility and mutual dispersibility of each component, a poorly water-soluble material is added. Fillers can also be added. Examples of such poorly water-soluble fillers include activated carbon, diatomaceous earth, acid clay, activated clay, silica, perlite, zeolite, alumina, kaolin, talc,
bentonite, calcium silicate, asbestos,
Powders of poorly water-soluble inorganic or organic substances such as magnesia, silica alumina, alkaline earth metal sulfates, carbonates and silicates, silicon nitride, graphite, aluminum hydroxide, iron oxide and cellulose;
Examples include granular materials. The amount of the poorly water-soluble filler added is preferably determined within the range of 0.001 to 10 parts by weight per 1 part by weight of the total of components (A) to (C). If it is less than 0.001 part by weight, there will be no effect of improving dispersibility, and if it exceeds 10 parts by weight, the concentration of the active ingredient will be relatively lowered and the oxygen absorption capacity will be lowered, which is not preferable. In addition, if the moisture evaporating from the food or the moisture in the atmosphere is low and the rate of oxygen absorption is slow, the above-mentioned poorly water-soluble filler impregnated with moisture may be added or added to the packaging or container at the same time. By placing it there, you can increase the oxygen absorption rate. The oxygen absorbent of the present invention may be in any form as long as it contains the above components (A) to (D) as essential components. Powder and simply mixed it,
Alternatively, the mixed fine powder may be molded into pellets, beads, rods, blocks, sheets, etc. using a tablet machine, extrusion molding machine, roll molding machine, or the like. During such molding, binders and lubricants commonly used in powder molding can also be used. Such binders include:
For example, starch, carboxymethyl cellulose,
Examples include high molecular weight polymers such as polyvinyl acetate, polyolefin, and polyvinyl alcohol, and examples of lubricants include various stearic acid derivatives. As mentioned above, the oxygen absorbent of the present invention can be used as it is in the form of a powder or molded product, or
It can also be used in a bag made of air-permeable packaging material, such as cellophane, various synthetic resin films, and paper. Here, the material, structure, etc. of the packaging material can be changed in various ways as long as it is breathable. In any case, when using an oxygen absorber, it is desirable to avoid direct contact with the food to prevent contamination of the target food, and either the oxygen absorber or the food, or both, should be covered with a breathable packaging material. It is preferable that When the oxygen absorbent of the present invention is packaged with food or sealed in a container, it absorbs oxygen in the system and prevents the food from being deteriorated by oxygen.
Since hydrogen generation is suppressed, food can be safely preserved without any danger. EXAMPLES Below, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Examples 1 to 15 and Comparative Examples 1 to 4 After thoroughly mixing the components shown in Table 1 under a dry nitrogen atmosphere, the various compositions shown in Table 1 were prepared by filling a perforated polyethylene laminate paper bag. was manufactured. Subsequently, the paper bag was suspended in a glass bottle having an internal volume of about 1 ml and containing 5 ml of water at the bottom, and then the glass bottle was sealed. In addition, only in Example 13, a dry glass bottle with no water coexisting at the bottom was used, and hydrated diatomaceous earth was used as a filler. After 1, 2, and 10 days at room temperature, the amount of absorbed oxygen and amount of hydrogen generated were measured by analyzing the gas composition in the glass bottle.Table 1
The results shown are obtained.

[Table] Compared to Examples 1 to 15, when component (C) is not added (Comparative Example 1), the amount of hydrogen generated is approximately 10 to 20 times that when component (C) is added. When there is no component (A) or component (B) (Comparative Example 2 or 3), the oxygen absorption capacity is extremely low and cannot be put to practical use. Further, when there is no moisture in the atmosphere (Comparative Example 4), the oxygen absorption ability is extremely poor, but the same performance can be improved by adding water to the filler (Example 13). Example 16 and Comparative Example 5 Baumkuchen was mixed with the oxygen absorbent prepared in Example 1 and about 800 ml of air, and a gas barrier film [polypropylene film (18μ)/ethylene vinyl alcohol copolymer film (15μ)]
After sealing and packaging with a three-layer structure of 50μ)/polyethylene film (50μ), a storage test was conducted at room temperature. As a control, a test was also conducted on an air-containing packaged product (Comparative Example 5), and the results shown in Table 2 were obtained.

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Claims (1)

[Claims] An oxygen absorbent characterized by comprising the following components: (A) Iron-based oxygen absorber (B) Metal halide (C) Amino acid with PH buffering effect (D) Water