Antibacterial oxygen absorber

Abstract

To provide a deoxidant that imparts a space antibacterial to a deoxidant, dose not damage property of an article contacting with flavor of a food product, and heightens storability of a content, in particular, a deoxidant that maintains the antibacterial property not only in a distribution process but also after a commercial product is opened in a home of a consumer.SOLUTION: A deoxidant that is powder containing a plurality of composite particles containing granules which are antioxidant imparted with antibacterial properties and contain an antibacterial agent selected from the group consisting of an oxygen-absorbing composition and an aldehyde compound having a molecular weight of 200 or less, and hydrophilic inorganic particles formed by adhering by forming a layer of a thickness of 1 mm or less on a surface of the granules, the oxygen-absorbing composition contains a liquid agent containing an oxygen absorbing substance, an alkali compound, and a transition metal compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an oxygen scavenger that also has antibacterial properties. [Background technology]

[0002] Oxygen absorbers are known to be used to prevent oxidation of contents. In particular, oxygen absorbers are sometimes sealed inside food packaging containers to preserve food for long periods of time. Oxygen absorbers prevent the growth of aerobic bacteria and mold inside packaging containers during distribution, thereby suppressing food deterioration, providing so-called antibacterial and antifungal effects.

[0003] When a consumer opens a food packaging container, oxygen enters the container, causing the food to deteriorate. Therefore, the combined use of an oxygen scavenger and an antibacterial agent is effective in maintaining the antibacterial and antifungal properties of the container after opening.

[0004] Prior art 1 reports an ethanol vapor-emission type oxygen absorber that has been given the function of evaporating ethanol vapor. However, there is a risk that the characteristic smell of ethanol may be absorbed into food or may be released when the package is opened, impairing the flavor of the food. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6420619 Summary of the Invention [Problem to be solved by the invention]

[0006] The main object of the present invention is to provide a granular oxygen absorber that is endowed with antibacterial and bactericidal properties to enhance the preservation of the contents. In particular, the antibacterial properties are maintained not only during the distribution process but also after the product is opened by the consumer at home. [Means for solving the problem]

[0007] The present invention provides an oxygen scavenger prepared by mixing and granulating a plurality of components, characterized in that the oxygen scavenger is coated with hydrophilic fine particles, the coating layer having a thickness of 1 mm or less, the oxygen scavenger is composed of a porous carrier carrying an oxygen absorbing substance, an alkaline compound, a transition metal compound, and an antibacterial agent, and the antibacterial agent is an aldehyde compound having a molecular weight of 200 or less.

[0008] The aldehyde compound is also characterized in that it is supported on a binder.

[0009] The binder is also characterized by having amphiphilic properties. The binder is preferably polyvinylpyrrolidone, hydroxypropyl cellulose, or hydroxypropyl methyl cellulose.

[0010] The antibacterial agent is selected from the group consisting of (E)-2-hexenal, hexanal, cinnamaldehyde, citral, and decanal.

[0011] The antibacterial agent is added in an amount of 0.01 to 20.0% by mass to impart antibacterial properties.

[0012] The antibacterial agent is added in an amount of 0.1 to 5.0% by mass to impart antibacterial properties. [Effects of the Invention]

[0013] The present invention makes it possible to maintain antibacterial properties not only during distribution but also after the packaging bag is opened. The inventors discovered that by using an antibacterial agent selected from the group consisting of aldehyde compounds with a molecular weight of 200 or less in combination, these antibacterial agents can provide good antibacterial properties within the packaging bag even after it is opened and resealed. [Brief explanation of the drawings]

[0014] [Figure 1] Schematic diagram of an antibacterial oxygen absorber. [Figure 2] Photograph showing the state of the medium at the end of the culture. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, several embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[0016] 1, an antibacterial oxygen absorber 100 according to one embodiment is mainly composed of a porous support, an oxygen absorbing composition supported on the support, a granulated product 10 obtained by granulating a powder containing an antibacterial agent, and hydrophilic inorganic fine particles 20 attached to the surface of the granulated product 10. The number of composite particles contained in the oxygen absorber according to this embodiment may be, for example, 10 or more and 10,000 or less per 1 g of the oxygen absorber.

[0017] The mass of each composite particle constituting the powder of the oxygen absorber 100 may be 0.3 mg or more, or 0.5 mg or more, and may be 10.0 mg or less, or 7.0 mg or less per composite particle. When the composite particles are this small, a higher oxygen absorption capacity tends to be obtained.

[0018] The support constituting the granules 10 may be any porous particle capable of supporting the oxygen absorbing composition. Typically, the oxygen absorbing composition is impregnated into the support, thereby supporting the oxygen absorbing material on the support. The support is selected from, for example, activated carbon, zeolite particles, bentonite particles, activated alumina particles, activated clay, calcium silicate particles, and diatomaceous earth.

[0019] The oxygen absorbing composition contains a liquid agent containing an oxygen absorbing substance, an alkaline compound, and a transition metal compound.

[0020] The liquid agent containing the oxygen absorbing substance may be an oxygen absorbing substance that is liquid at room temperature (for example, 5 to 35°C), or may be a solution containing a liquid or solid oxygen absorbing substance. The oxygen absorbing substance is the main component of the oxygen absorbing composition and is a substance that absorbs oxygen. The oxygen absorbing substance may be, for example, a compound that consumes and absorbs oxygen by oxidizing itself. In this embodiment, an oxygen absorbing substance that is liquid at room temperature or dissolved in a solvent can be used.

[0021] Such oxygen-absorbing substances are, for example, one or more compounds selected from the group consisting of glycerin, 1,2-glycol, and sugar alcohols. Specific examples of 1,2-glycols include ethylene glycol and propylene glycol. Specific examples of sugar alcohols include erythritol, arabitol, xylitol, adonitol, mannitol, and sorbitol. When the liquid preparation is a solution of an oxygen-absorbing substance, examples of the solvent in which the oxygen-absorbing substance dissolves include water; lower aliphatic alcohols such as methanol, ethanol, 1-propanol, i2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, and 2-methyl-2-butanol; glycols such as ethylene glycol, propylene glycol, and trimethylene glycol; and phenol. These oxygen-absorbing substances can be used alone or in combination.

[0022] The amount of the oxygen absorbing substance is usually 80 to 200 parts by mass, or may be 100 to 180 parts by mass, per 100 parts by mass of the support. When the amount of the oxygen absorbing substance is within this range, it tends to be easier to obtain an oxygen scavenger with appropriate oxygen absorption capacity.

[0023] The oxygen absorbing substance may require water for the oxygen absorbing reaction. Therefore, even if the oxygen absorbing substance itself is liquid at room temperature, water can be added to the liquid formulation as needed. The amount of water added as needed is usually 0 to 80 parts by mass, or may be 20 to 60 parts by mass, relative to 100 parts by mass of the oxygen absorbing substance. The amount of water is usually 0 to 90 parts by mass, or may be 20 to 70 parts by mass, relative to 100 parts by mass of the support.

[0024] An alkaline compound is a compound that forms an alkaline aqueous solution when dissolved in water. When the oxygen absorbing substance has a hydroxyl group, the alkaline compound ionizes the hydroxyl group, thereby activating the oxygen absorption reaction. In the state of the oxygen absorbing composition, a portion of the alkaline compound is often dissolved in the liquid agent containing the oxygen absorbing substance.

[0025] The alkaline compound may be a hydroxide, carbonate, bicarbonate, triphosphate, or diphosphate of an alkali metal or alkaline earth metal. The alkaline compound may be one or more compounds selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, beryllium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, radium hydroxide, lithium carbonate, sodium carbonate, calcium carbonate, magnesium carbonate, potassium carbonate, potassium bicarbonate, sodium bicarbonate, lithium bicarbonate, trisodium phosphate, trisodium potassium phosphate, dibasic sodium phosphate, and dibasic potassium phosphate.

[0026] The amount of the alkaline compound is usually 100 to 300 parts by mass, or may be 150 to 250 parts by mass, per 100 parts by mass of the support. When the amount of the oxygen absorbing substance is within this range, it tends to be easier to obtain an oxygen scavenger with appropriate oxygen absorption capacity.

[0027] The transition metal compound is a compound containing a transition metal element and is added to promote the oxygen absorption reaction of the oxygen absorbing substance. In the state of the oxygen absorbing composition, the transition metal compound is often dissolved in a liquid containing the oxygen absorbing substance. Specific examples of the transition metal element include iron, cobalt, nickel, copper, zinc, and manganese. The transition metal compound may be, for example, a transition metal halide, sulfate, nitrate, phosphate, carbonate, organic acid salt, oxide, hydroxide, or chelate compound. The transition metal compound may also be a double salt containing a transition metal element. The transition metal compound may be one or more compounds selected from the group consisting of copper(I) chloride, copper(II) chloride, copper(II) sulfate, copper(II) hydroxide, copper(I) oxide, copper(II) oxide, manganese chloride, manganese nitrate, manganese carbonate, and nickel chloride.

[0028] The amount of the transition metal compound is usually 10 to 70 parts by mass, or may be 30 to 50 parts by mass, per 100 parts by mass of the support. When the amount of the transition metal compound is within this range, it tends to be easier to obtain an oxygen scavenger with appropriate oxygen absorption capacity.

[0029] The oxygen absorbing composition may further contain other substances as required. Examples of the other substances include catechol-based compounds. The amount of the other substances depends on the quality of the support. The amount is usually about 30 parts by mass or less per 100 parts by mass.

[0030] The antibacterial agent is an aldehyde compound having a molecular weight of 200 or less, preferably 60 or more and 200 or less, and more preferably 90 or more and 200 or less. Non-limiting examples of aldehyde compounds that can be used include (E)-2-hexenal (molecular weight 98.14), hexanal (molecular weight 100.16), benzaldehyde (molecular weight 106.12), octanal (molecular weight 128.21), cinnamaldehyde (molecular weight 132.16), anisaldehyde (molecular weight 136.15), piperonal (molecular weight 150.13), perillaldehyde (molecular weight 150.22), vanillin (molecular weight 152.15), citral (3,7-dimethyl-2,6-octadienal) (molecular weight 152.23), citronellal (molecular weight 154.25), decanal (molecular weight 156.27), and hydroxycitronellal (molecular weight 172.26). Preferred aldehyde compounds include (E)-2-hexenal, hexanal, cinnamaldehyde, citral, and decanal.

[0031] The antibacterial agent is preferably supported on a binder to provide sustained release. By supporting the antibacterial agent described in the previous section on a binder, the release rate can be reduced at low temperatures, and the sustained release rate can be increased when the oxygen scavenger absorbs oxygen and generates heat. Examples of binders that can be used include gum arabic, polyvinyl alcohol, sodium alginate, gelatin, cellulose, carboxymethyl cellulose, methyl cellulose, polyvinyl pyrrolidone, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, polyvinyl butyral, and ethyl cellulose. Among these, amphiphilic polyvinyl pyrrolidone, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose are particularly suitable.

[0032] The concentration of the antibacterial agent added should desirably be 1 to 20%. If it is less than 1%, the amount of agent evaporated will not be sufficient to exhibit antibacterial properties, and if it is 20% or more, the effect of increasing the amount of agent will not be obtained, and there is a possibility that problems will arise such as a decrease in granule strength and a decrease in granulation ability.

[0033] The particle size (maximum width) of the granulated material 10 before the inorganic fine particles are attached is not particularly limited, but may be, for example, 0.3 to 8.0 mm, or 0.3 mm or more and less than 5 mm.

[0034] Granules 10 comprising a support, an oxygen absorbing composition, and an antibacterial agent can be obtained by granulating a mixture containing the support and the components constituting the oxygen absorbing composition and the antibacterial agent. The components constituting the oxygen absorbing composition may be mixed together or separately. The mixer used for mixing is not particularly limited, and may be, for example, a rotating container mixer such as a cylindrical or V-type mixer, or a fixed container mixer such as a ribbon, horizontal screw, paddle, or planetary motion type mixer. Granulation can be performed, for example, by extrusion granulation using a screen with predetermined openings.

[0035] The hydrophilic inorganic fine particles 20 are water-insoluble particles containing a hydrophilic inorganic substance as a main component. The hydrophilic inorganic fine particles 20 typically contain 50 mass % or more of the hydrophilic inorganic substance based on the total mass of the particles. Examples of the hydrophilic inorganic substance include hydrophilic silicon dioxide, calcium silicate hydrate, magnesium oxide, and aluminum silicate.

[0036] The hydrophilic inorganic microparticles 20 have the property of easily absorbing the oxygen absorbing composition, which can contribute to improving the oxygen absorbing capacity of the oxygen absorber. The degree to which the hydrophilic inorganic microparticles absorb the oxygen absorbing composition can be evaluated by the amount of liquid absorbed by the hydrophilic inorganic microparticles 20. This amount of liquid absorbed is measured by a method in which a test liquid consisting of a liquid agent containing an oxygen absorbing substance and a transition metal compound that constitute the oxygen absorbing composition is absorbed into powder of the hydrophilic inorganic microparticles 20. The test liquid for measuring the amount of liquid absorption contains the liquid agent containing the oxygen absorbing substance and the transition metal compound in the same mass ratio as in the oxygen absorbing composition. The amount of liquid absorbed (liquid absorbed by 1 g of hydrophilic inorganic microparticles 20) measured by this method is When the absorbency (mass of the test liquid absorbed) is 2.0 g / g or more, a high oxygen absorption capacity tends to be obtained. From the same viewpoint, the absorbency may be 2.5 g / g or more, or 3.0 g / g or more. The upper limit of the absorbency is not particularly limited, but may be, for example, 20 g / g or less.

[0037] The hydrophilic inorganic fine particles 20 having the above-mentioned average particle size, pore volume, specific surface area and liquid absorption capacity can be produced by a conventional method, or can be obtained by appropriately selecting from commercially available products.

[0038] The oxygen scavenger can be obtained by a method including a step of mixing a granulated powder containing a plurality of granulated materials 10 containing a carrier, an oxygen absorbing composition, and an antibacterial agent with a plurality of hydrophilic inorganic fine particles 20, thereby adhering the hydrophilic inorganic fine particles 20 to the surfaces of the granulated materials 10. By forming a mixed powder in which the granulated material 10 powder and the hydrophilic inorganic fine particles 20 are mixed as a whole, a plurality of hydrophilic inorganic fine particles are adhered to the surfaces of each granulated material. For example, the hydrophilic inorganic fine particles 20 can be adhered to the granulated material 10 by mixing the granulated material 10 with the hydrophilic inorganic fine particles 20 and shaking the resulting mixture.

[0039] The hydrophilic inorganic fine particles 20 attached to the granulated material 10 by the above-described powder-mixing method form a relatively thin layer. In this respect, the form of the oxygen absorber of this embodiment generally differs from tablets having a shell obtained by, for example, tableting. Specifically, the hydrophilic inorganic fine particles 20 attached to the surface of the granulated material 10 can form a layer with a thickness of 1 mm or less, or 0.7 mm or less. The thin layer of the hydrophilic inorganic fine particles 20 can also be confirmed by detecting elements contained in the materials constituting the granulated material 10 (oxygen absorbing substances, alkaline compounds, or transition metal compounds) when the surface of the composite particles is subjected to elemental analysis by energy dispersive X-ray analysis (EDX analysis). Generally, in the case of the oxygen absorber of this embodiment, at least one element contained in the materials constituting the granulated material 10 is often detected at a concentration of 0.05 atomic percent or more, or 0.1 atomic percent or more. On the other hand, when a shell of a certain thickness enclosing the granulated material 10 is formed by tableting, the elements of the materials constituting the granulated material 10 are not substantially detected by EDX analysis.

[0040] An oxygen absorbing package according to one embodiment may be mainly composed of the oxygen absorber according to the above embodiment and a breathable packaging material containing the oxygen absorber. The breathable packaging material may be appropriately selected from those commonly used in the art. Specific examples of breathable packaging materials include bags formed from a substrate made of perforated plastic film, nonwoven fabric, microporous film, paper, or a combination thereof. This oxygen absorber package may be placed in various food packaging containers and used for purposes such as maintaining the freshness of food.

[0041] A food package according to one embodiment includes the oxygen absorber package and a food packaging container in which the oxygen absorber package is enclosed. The food packaging container can be appropriately selected from those commonly used in the food packaging field, and a sealable container is preferred. Examples of food packaging containers include bags, deep-draw packages, tray packages, and stretch packages. [Example]

[0042] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to these examples.

[0043] [Example 1] The raw materials shown in Table 1, i.e., activated carbon, an oxygen absorbing composition containing an oxygen absorbing substance, an alkaline compound, and a transition metal salt, and a binder pre-mixed with an antibacterial agent, were uniformly mixed in a sealed state to obtain a mixture. The obtained mixture was granulated using an extrusion granulator equipped with a screen having a screen hole diameter of 1.0 mm and an opening rate of 22.6%, to obtain a granular product. Next, hydrophilic silicon dioxide was coated as hydrophilic inorganic fine particles 20 to obtain an antibacterial oxygen absorber 100. A schematic diagram is shown in FIG.

[0044] [Table 1]

[0045] [Example 2] An antibacterial oxygen absorber 100 was obtained in the same manner as in Example 1, except that the amount of antibacterial agent added was 0.1.

[0046] [Example 3] An antibacterial oxygen absorber 100 was obtained in the same manner as in Example 1, except that the amount of antibacterial agent added was 5.0.

[0047] [Example 4] An antibacterial oxygen absorber 100 was obtained in the same manner as in Example 1, except that the antibacterial agent was citral.

[0048] [Example 5] An antibacterial oxygen absorber 100 was obtained in the same manner as in Example 1, except that the amount of antibacterial agent added was 20.0.

[0049] [Example 6] An antibacterial oxygen absorber 100 was obtained in the same manner as in Example 1, except that the binder was hydroxypropylmethylcellulose.

[0050] [Example 7] An antibacterial oxygen absorber 100 was obtained in the same manner as in Example 1, except that the binder was polyvinylpyrrolidone.

[0051] [Example 8] An antibacterial oxygen absorber 100 was obtained in the same manner as in Example 1, except that the amount of antibacterial agent added was 0.01.

[0052] [Example 9] An antibacterial oxygen absorber 100 was obtained in the same manner as in Example 1, except that no binder was added.

[0053] [Example 10] An antibacterial oxygen absorber 100 was obtained in the same manner as in Example 1, except that the binder was polyvinyl butyral.

[0054] [Comparative Example 1] An oxygen scavenger was obtained in the same manner as in Example 1, except that no antibacterial agent was added.

[0055] (Filling of granulated material) 3.0 g of the oxygen absorbers prepared in Examples 1 to 10 and Comparative Example 1 were filled into a 60 mm x 60 mm package formed by a laminate consisting of polyethylene terephthalate / polyethylene / paper / polyethylene / and having through holes.

[0056] (Save test) A 12 μm thick polyethylene terephthalate film with aluminum oxide vapor deposition was bonded to a 30 μm thick polyethylene film using a urethane adhesive to form a heat-sealed layer. The heat-sealed layers were then placed facing each other to obtain a pouch with internal dimensions of 10 cm x 25 cm. Potato dextrose medium was then prepared in a 5 cm diameter circular dish, and Aspergillus niger was added at a concentration of 1.0 x 10 2 A bacterial solution containing a bacterial solution at a concentration of 1000 cfu / ml was applied to the sample, and the sample was placed in a pouch together with the small bags of Examples 1 to 10 and Comparative Example 1.

[0057] The medium contained in the pouch was cultured at 10°C for one week, after which the pouch was opened. After remaining open for approximately two hours, the opening was heat sealed again and cultured for one week at 10°C. After culture, the pouch was opened and kept open for approximately two hours, then resealed and cultured for another week at 10°C.

[0058] The state of the medium at the end of each culture was evaluated for antifungal activity. Level 1 was when no Aspergillus niger growth was visually observed, level 2 when slight growth was visually observed, level 3 when growth was visually observed but judged to be insufficient, and level 4 when growth was visually recognized and judged to be sufficient. Figure 2 shows the visually observed states of levels 1 to 4.

[0059] Table 2 shows the antifungal evaluation results for Examples 1 to 10 and the Comparative Example. When opened after one week, no mold growth was observed in any of the petri dishes. Meanwhile, in the systems to which the antibacterial agent was added, antifungal properties were observed even after two weeks (after resealing), whereas mold growth was observed in the comparative example to which no antibacterial agent was added. After further storage for three weeks, no antibacterial properties were exhibited in the cases without binder, those with 0.01 parts by mass of antibacterial agent added, and those in which the binder was polyvinyl butyral. From the above, it was confirmed that when the antibacterial agent is supported by an amphiphilic binder, hydroxypropyl cellulose, hydroxypropyl methylcellulose, or polyvinylpyrrolidone, the agent is released gradually even after opening, and antibacterial properties are maintained for a long period of time.

[0060] [Table 2] [Explanation of symbols]

[0061] 10 Granulated materials 20 Hydrophilic inorganic fine particles 100 Antibacterial oxygen absorber

Claims

1. An oxygen scavenger obtained by mixing and granulating a plurality of components, the oxygen absorber is coated with hydrophilic fine particles, The thickness of the coating layer is 1 mm or less, the oxygen scavenger comprises a porous carrier carrying an oxygen absorbing substance, an alkaline compound, a transition metal compound, and an antibacterial agent; An antibacterial oxygen absorber characterized in that the antibacterial agent is an aldehyde compound having a molecular weight of 200 or less.

2. 2. The antibacterial oxygen absorber according to claim 1, wherein the aldehyde compound is supported on a binder.

3. 3. The antibacterial oxygen absorber according to claim 2, wherein the binder has amphiphilic properties.

4. 4. The antibacterial oxygen absorber according to claim 2, wherein the binder is made of any one of polyvinylpyrrolidone, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose.

5. The antibacterial oxygen scavenger according to any one of claims 1 to 4, wherein the antibacterial agent is selected from the group consisting of (E)-2-hexenal, hexanal, cinnamaldehyde, citral, and decanal.

6. 6. The antibacterial oxygen absorber according to claim 1, wherein the amount of the antibacterial agent added is 0.01 to 20.0% by mass.

7. 7. The antibacterial oxygen absorber according to claim 1, wherein the amount of the antibacterial agent added is 0.1 to 5.0% by mass.

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