WO2011114856A1

WO2011114856A1 - Packing material and package using same

Info

Publication number: WO2011114856A1
Application number: PCT/JP2011/054149
Authority: WO
Inventors: 幹雄田中; 香代子鬼澤
Original assignee: 株式会社クレハ
Priority date: 2010-03-17
Filing date: 2011-02-24
Publication date: 2011-09-22
Also published as: JPWO2011114856A1

Abstract

A package comprising a packing material, which contains a polyglycolic acid-based resin and a basic compound, and an article, which contains a readily oxidizable pigment, said article being packed in said packing material.

Description

Packaging material and package using the same

The present invention relates to a packaging material and a packaging body using the same, and more particularly to an oxygen gas barrier packaging material and a packaging body in which an article to be packaged containing an oxidizable dye is packaged using the packaging material.

Fresh foods such as sashimi and processed foods such as ham have a risk of causing food poisoning due to proliferation of microorganisms if temperature control is mistaken in the distribution process or storage process. For example, in a food that has been deoxygenated by gas-filled packaging, gas replacement packaging, vacuum packaging, or the like with an inert gas (nitrogen, carbon dioxide) in order to extend the shelf life (shelf life), for example, 25 ° C. or more If exposed to a long period of time, anaerobic bacteria such as Clostridium botulinum may grow and cause food poisoning.

In particular, in a package in which food is deoxygenated and packaged using a packaging material having excellent oxygen gas barrier properties (see, for example, JP-A-2008-254765 (Patent Document 1)), oxygen in the package is excluded during packaging. In addition, since there is no oxygen intrusion from outside during storage, the food is less susceptible to oxidative degradation, and it is possible to preserve fresh food for a long period of time. However, in such a package, since anaerobic bacteria grow when deviating from appropriate storage conditions, there is a problem that the risk of food poisoning due to anaerobic bacteria increases.

In order to reduce the risk of food poisoning due to such anaerobic bacteria, in Europe and the United States, gas-filled packaging and gas replacement packaging that mix a small amount of oxygen (volume ratio 3 to 5%) are performed. Has the harmful effects of causing oxidative degradation of the package and promoting the growth of aerobic bacteria.

In vacuum packaging, a method of avoiding the growth of anaerobic bacteria using a packaging material with high gas permeability, such as polyolefin resin packaging material, can be considered, but the oxygen of the packaging material is oxidized by oxygen permeated through the packaging material. Since deterioration occurs, there is a drawback that the antioxidant effect by vacuum packaging is significantly impaired.

JP 2008-254765 A

The present invention has been made in view of the above-described problems of the prior art, and the oxidative deterioration of the package is less likely to occur under appropriate storage conditions. It is an object of the present invention to provide a packaging material that can be easily confirmed by observing the appearance of and a package using the same.

As a result of intensive studies to achieve the above object, the present inventors have found that the oxygen gas barrier property of the packaging material decreases when the polyglycolic acid resin used as the oxygen gas barrier material of the packaging material is hydrolyzed. And the hydrolyzability of the polyglycolic acid resin was found to depend on temperature and time. Furthermore, a package containing an easily oxidizable dye has a predetermined storage condition by utilizing the property of being oxidized and discolored when the oxygen gas barrier property of the packaging material in which it is packaged is reduced. When it deviates, it discovered that the trace could be confirmed easily by the external appearance observation of a to-be-packaged object, and came to complete this invention.

That is, the packaging material of the present invention is a packaging material for packaging an article to be packaged containing an oxidizable dye, and contains a polyglycolic acid resin and a basic compound.

Such a packaging material preferably includes an oxygen gas barrier layer containing the polyglycolic acid resin and a layer containing the basic compound, and includes an oxygen gas barrier layer containing the polyglycolic acid resin. More preferably, the film A and the film B containing moisture are provided in a separated state, and at least one of the oxygen gas barrier layer and the film B contains the basic compound, It is further preferable that the film B includes a layer containing the basic compound.

The package of the present invention comprises a packaging material containing a polyglycolic acid resin and a basic compound, and an article to be packaged containing an oxidizable dye packaged with the packaging material.

As such a package, it is preferable that the packaging material includes an oxygen gas barrier layer containing the polyglycolic acid resin and a layer containing the basic compound, and the packaging material is the polyglycolic acid. A film A comprising an oxygen gas barrier layer containing a resin and a film B containing moisture affixed on the film A, wherein at least one of the oxygen gas barrier layer and the film B is a base It is more preferable that the packaged material is a packaging material in which the packaged material is packaged by the film A, and the film B includes a layer containing the basic compound. preferable.

According to the present invention, the oxidative deterioration of the package is less likely to occur under appropriate storage conditions, and the trace can be easily confirmed by observing the appearance of the package when deviating from the predetermined storage conditions. .

It is a photograph which shows the halftone image which displayed the state after storing the package body obtained in Example 1 and Comparative Example 1 at 10 degreeC on the display. It is a photograph which shows the halftone image which displayed on the display the state of the to-be packaged object after storing the packaging body obtained in Example 1 and Comparative Example 1 at 10 degreeC for 7 days. It is a photograph which shows the halftone image which displayed the state after storing the package body obtained in Example 2 and Comparative Example 2 at 10 degreeC on the display. It is a photograph which shows the halftone image which displayed on the display the state of the to-be packaged object after storing the package body obtained in Example 2 and Comparative Example 2 at 10 degreeC for 7 days. It is a photograph which shows the halftone image which displayed the state after storing the package body obtained in Example 3 and Comparative Example 3 at various temperatures on a display.

Hereinafter, the present invention will be described in detail on the basis of preferred embodiments thereof.

<Packaging material>
First, the packaging material of the present invention will be described. The packaging material of the present invention is for packaging a package containing a pigment that changes color by oxidation (hereinafter, referred to as an “oxidizable pigment”), and contains a polyglycolic acid resin and a basic compound. It is preferable that it comprises a layer containing a polyglycolic acid resin and a layer containing a basic compound. .

Such a packaging material includes an oxygen gas barrier layer containing a polyglycolic acid resin and a basic compound (hereinafter referred to as “first packaging material”), and an oxygen gas barrier layer containing a polyglycolic acid resin. A film A containing water and a film B containing water are separated, and at least one of the oxygen gas barrier layer and the film B contains a basic compound (hereinafter referred to as “first” Second packaging material).

The polyglycolic acid resin (hereinafter abbreviated as “PGA resin”) has the following reaction formula:

It is hydrolyzed by reacting with water as represented by the following, and the hydrolysis rate is faster than that of other polyester resins and is accelerated by a basic compound. Furthermore, a film containing a PGA-based resin is known to have excellent oxygen gas barrier properties. However, when the PGA-based resin is hydrolyzed, the oxygen gas barrier properties are lowered. Moreover, since the hydrolyzability of PGA-type resin depends on temperature and time, the oxygen gas barrier property also depends on temperature and time.

The package of the present invention utilizes the fact that the oxygen gas barrier property of the film (layer) containing the PGA resin changes with temperature and time. In addition, since the PGA-based resin is not easily hydrolyzed by moisture in normal air, the first packaging material of the present invention uses moisture contained in the package as water used for hydrolysis, or When the package is stored and distributed under high humidity conditions, moisture in the air is used. On the other hand, in the 2nd packaging material of this invention, the water | moisture content of the said film B is utilized as water used for a hydrolysis. In addition, since PGA-type resin is hard to be hydrolyzed with the water | moisture content in normal air, the oxygen gas barrier property of an oxygen gas barrier layer does not fall easily before the packaging material of this invention (before packaging).

For example, when a packaging material using the first packaging material of the present invention is stored and distributed under high humidity conditions, moisture in the air is supplied to the oxygen gas barrier layer in the process. Moreover, when a package containing moisture is packaged using the first packaging material of the present invention, moisture in the package is supplied to the oxygen gas barrier layer during storage. Furthermore, when storing the package body in which the package is packaged using the second packaging material of the present invention, the film B is pasted on the film A after the package body is packaged with the film A. Thereby, the moisture of the film B is supplied to the oxygen gas barrier layer. The supplied water may react with the PGA resin in the oxygen gas barrier layer depending on the storage temperature and storage time to hydrolyze the PGA resin, and as a result, the oxygen gas barrier property of the oxygen gas barrier layer may be reduced. May decrease. Further, the decrease in oxygen gas barrier properties depends on the storage temperature and storage time of the package. That is, as the storage temperature of the package increases, the PGA resin is easily hydrolyzed, the oxygen gas barrier property is lowered, and the PGA resin is hydrolyzed as the storage time becomes longer at the temperature at which the PGA resin is hydrolyzed. It is easily decomposed and oxygen gas barrier properties are lowered. Furthermore, such a hydrolysis rate is accelerated by the basic compound, and the oxygen gas barrier property is remarkably lowered. And if the oxygen gas barrier property of a packaging material (oxygen gas barrier layer) falls, the to-be-packaged body in a package will be oxidized. The package to be packaged by the packaging material of the present invention contains an easily oxidizable dye, and as described above, the packaging material is discolored due to oxidation when the oxygen gas barrier property of the packaging material is lowered. This makes it possible to easily check the temperature history of the package during storage.

(Polyglycolic acid resin)
There is no restriction | limiting in particular as polyglycolic acid type resin (henceforth "PGA type resin") used for this invention, For example, following formula (1):

A glycolic acid homopolymer consisting only of glycolic acid repeating units represented by the formula (hereinafter referred to as “PGA homopolymer”, including a ring-opened polymer of glycolide which is a bimolecular cyclic ester of glycolic acid). And a polyglycolic acid copolymer containing glycolic acid repeating units (hereinafter referred to as “PGA copolymer”).

The content of the glycolic acid repeating unit in the PGA copolymer is preferably 60% by mass or more. When the content of the glycolic acid repeating unit is less than the lower limit, the crystallinity of the PGA copolymer is lowered, and the oxygen gas barrier property and heat resistance of the resulting packaging material tend to be lowered.

Examples of the repeating unit other than the glycolic acid repeating unit in such a PGA copolymer include the following formulas (2) to (6):

The repeating unit represented by these is mentioned.

In the formula (2), p represents an integer of 1 to 10, and q represents an integer of 0 to 10. In the formula (3), j represents an integer of 1 to 10. In the formula (4), R ¹ and R ² each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and k represents an integer of 2 to 10.

By introducing 1% by mass or more of the repeating units represented by the above formulas (2) to (6), the melting point of the PGA-based resin can be lowered. As a result, the processing temperature can be lowered, and the melting Thermal decomposition during processing can be reduced. Furthermore, it is possible to improve the processability by controlling the crystallization rate of the PGA resin. However, from the viewpoint of crystallinity and hydrolyzability of the PGA resin, the upper limit of the content of the repeating unit represented by the above formulas (2) to (6) is preferably 40% by mass or less.

The PGA homopolymer used in the present invention can be synthesized by dehydration polycondensation of glycolic acid, dealcoholization polycondensation of glycolic acid alkyl ester, ring-opening polymerization of glycolide, and the like. Preferably, it is synthesized by ring-opening polymerization carried out by heating to a temperature of about 120 to 250 ° C. in the presence of a polymerization catalyst such as a tin compound, a titanium compound, an aluminum compound, a zirconium compound or an antimony compound. Is preferred. Such ring-opening polymerization can be carried out by either bulk polymerization or solution polymerization.

In addition, the PGA copolymer can be synthesized by using a comonomer in combination in the polycondensation reaction or the ring-opening polymerization reaction. Such comonomers include ethylene oxalate (ie, 1,4-dioxane-2,3-dione), lactides, lactones (eg, β-propiolactone, β-butyrolactone, β-pivalolactone, γ- Butyrolactone, δ-valerolactone, β-methyl-δ-valerolactone, ε-caprolactone, etc.), carbonates (eg, trimethylene carbonate, etc.), ethers (eg, 1,3-dioxane, etc.), ether esters ( For example, cyclic monomers such as dioxanone), amides (such as ε-caprolactam); hydroxycarboxylic acids such as lactic acid, 3-hydroxypropanoic acid, 3-hydroxybutanoic acid, 4-hydroxybutanoic acid, 6-hydroxycaproic acid, or Its alkyl ester; ethylene glycol, 1 Aliphatic diols such as 1,4-butanediol; succinic acid, and aliphatic dicarboxylic acids or their alkyl esters such as adipic acid. These comonomers may be used individually by 1 type, or may use 2 or more types together. Of these comonomers, a cyclic monomer and a hydroxycarboxylic acid are preferred from the viewpoint that a PGA copolymer that is easy to copolymerize and has excellent physical properties can be obtained.

Such PGA-type resin may be used individually by 1 type, or may use 2 or more types together. The melt viscosity (temperature 270 ° C., shear rate 120 sec ⁻¹ ) of the PGA resin used in the present invention is preferably 300 to 10,000 Pa · s, more preferably 400 to 8,000 Pa · s, and more preferably 500 to 5 1,000 Pa · s is particularly preferable. Furthermore, the melting point of the PGA resin is preferably 200 ° C. or higher, and more preferably 210 ° C. or higher.

In the present invention, such a PGA-based resin may be used alone, but within a range not impairing the object of the present invention, an inorganic filler, other thermoplastic resin, plasticizer, etc. are added to the PGA-based resin. You may use as a mix | blended PGA-type resin composition. In addition, PGA-based resins and PGA-based resin compositions include heat stabilizers, light stabilizers, moisture-proofing agents, waterproofing agents, water repellents, lubricants, mold release agents, coupling agents, oxygen absorbers as necessary. Various additives such as pigments and dyes can be contained.

(Basic compound)
The packaging material of the present invention contains a basic compound. This basic compound has an action of promoting the hydrolysis reaction of the PGA-based resin described above, and this action also promotes a reduction in oxygen gas barrier properties of the oxygen gas barrier layer. As a result, oxygen gas easily penetrates into the package, and the oxidizable dye in the package becomes more oxidized and its discoloration becomes prominent, so it is easy to visually check the traces that deviate from the specified storage conditions. It becomes possible to do.

The basic compound used in the present invention is not particularly limited as long as it can accelerate the hydrolysis reaction of the PGA resin. For example, amines such as ammonia, sodium hydroxide, potassium hydroxide, calcium hydroxide, etc. The hydroxide is mentioned.

The content of the basic compound in the packaging material of the present invention is an amount that can promote the hydrolysis reaction of the PGA-based resin and that the discoloration of the package can be sufficiently visually recognized due to the decrease in the oxygen gas barrier property of the oxygen gas barrier layer. There are no particular restrictions. The appropriate content of the basic compound varies depending on the type of the basic compound, the temperature history range monitored by the packaging material of the present invention, and it is difficult to specify precisely. When ammonia or sodium hydroxide is used, the amount is preferably 1.0 × 10 ⁻⁶ to 2.0 mol / cm ³ per cm ^{3 of} the oxygen gas barrier layer. When the content of the basic compound is less than the lower limit, the hydrolysis reaction is hardly promoted, and the effect of adding the basic compound tends to be insufficient. On the other hand, when the content exceeds the upper limit, the PGA-based resin can be obtained in a short time. The hydrolysis reaction is promoted, and even under appropriate storage conditions, the oxygen gas barrier property is lowered and the packaged material may be discolored.

Hereinafter, the first and second packaging materials of the present invention will be described in more detail.

(First packaging material)
The first packaging material of the present invention is a package containing an oxidizable dye and water, or contains an oxidizable dye and is stored and distributed under high humidity conditions (preferably a relative humidity of 90% RH or more). It is for wrapping an object to be packaged (which may contain water), and includes an oxygen gas barrier layer containing the PGA-based resin and the basic compound. Such an oxygen gas barrier layer may be composed of one layer containing a PGA resin and a basic compound, or a layer containing a PGA resin (hereinafter referred to as “PGA resin layer”). It may be composed of two layers including a layer containing a basic compound (hereinafter referred to as “basic compound layer”).

In the first packaging material of the present invention, as a method for producing a single layer oxygen gas barrier layer containing a PGA resin and a basic compound, (i) a composition containing a PGA resin and a basic compound And a method of forming the composition into a film by a known method for producing a PGA-based resin film and stretching it as necessary; (ii) producing a PGA-based resin film by a known method; A method of impregnating a compound and stretching it as necessary; (iii) A method of making a PGA resin stretched film by a known method and then impregnating the film with a basic compound; (iv) A method of producing by a known method A method in which a basic compound (preferably a volatile basic compound) is sprayed and permeated into a PGA-based resin film or a stretched PGA-based resin film; (v) by a known method Examples thereof include a method in which the prepared PGA-based resin film or PGA-based resin stretched film is exposed to a basic compound (preferably volatile basic compound) gas atmosphere to allow the basic compound to permeate the film. In particular, in the methods (iv) and (v), if the PGA resin film (or PGA resin stretched film) is produced, the PGA resin film (or the There is an advantage that a basic compound can be permeated into the PGA-based resin stretched film).

The thickness of such a single-layer oxygen gas barrier layer is preferably 1 to 20 μm, and more preferably 1 to 10 μm. When the thickness of the oxygen gas barrier layer is less than the lower limit, sufficient gas barrier properties tend not to be obtained, and film thickness control during extrusion and film formation tends to be difficult. On the other hand, when the thickness of the oxygen gas barrier layer exceeds the above upper limit, the rigidity of the packaging body increases excessively, and there is a tendency to suffer an economic disadvantage that the amount of packaging material discarded increases.

On the other hand, as a method for producing an oxygen gas barrier layer comprising two layers of a PGA-based resin layer and a basic compound layer, (i) a PGA-based resin film produced by a known method or a PGA-based resin stretched film and a basic compound-containing layer (Ii) A method of coating a basic compound on a PGA resin film or a stretched PGA resin film produced by a known method; (iii) A PGA resin produced by a known method and others A method in which a basic compound (preferably a volatile basic compound) is sprayed on a laminated film of the resin and the basic compound is permeated into at least another resin layer; (iv) a PGA resin prepared by a known method; A laminated film with other resin is exposed to a gas atmosphere of a basic compound (preferably a volatile basic compound) to form a salt on at least the other resin layer. For example, a method of infiltrating the basic compound may be used. As the basic compound-containing film in the method (i), a resin film containing a basic compound can be used. Examples of the method of applying the basic compound in the method (ii) include coating and printing. In the methods (iii) and (iv), there is an advantage that the basic compound can be infiltrated into another resin layer at an appropriate time from before packaging to after packaging after the production of the laminated film. .

In such a two-layered oxygen gas barrier layer, the thickness of the PGA resin layer is preferably 1 to 20 μm, and more preferably 1 to 10 μm. When the thickness of the PGA-based resin layer is less than the lower limit, sufficient gas barrier properties tend not to be obtained, and film thickness control during extrusion and film formation tends to be difficult. On the other hand, when the thickness of the PGA-based resin layer exceeds the upper limit, the rigidity of the packaging body is excessively increased, and there is a tendency to suffer an economic disadvantage that the amount of packaging material discarded increases. The thickness of the basic compound layer is preferably 1 to 1000 μm, more preferably 1 to 500 μm. When the thickness of the basic compound layer is less than the lower limit, the content of the basic compound is decreased, and the hydrolysis reaction of the PGA resin tends not to be sufficiently promoted. On the other hand, when the upper limit is exceeded, the packaging material is discarded. There is a tendency to suffer the economic disadvantage of increasing volume.

In the first packaging material of the present invention, such an oxygen gas barrier layer containing a PGA-based resin and a basic compound may be formed over the entire surface direction of the packaging material, but is excellent in appropriate storage conditions. In view of the fact that it exhibits oxygen gas barrier properties, and if it deviates from that, the wrapping is partially discolored so that oxidative deterioration of the wrapping can be more easily visually recognized. It is preferable that an oxygen gas barrier layer containing a PGA resin and a basic compound is formed, and an oxygen gas barrier layer made of a PGA resin not containing a basic compound is formed in the remaining portion.

Moreover, in the first packaging material of the present invention, it is preferable to provide an inner layer on one surface of the oxygen gas barrier layer in order to avoid contact between the oxygen gas barrier layer and the package. As such an inner layer, in the case where the first package of the present invention uses moisture contained in the package, it has moisture permeability (water vapor permeability) and is made of PGA resin. It is necessary that the effect of the hydrolysis on the deterioration of the oxygen gas barrier property of the first packaging material is small. Examples of the resin constituting the inner layer satisfying such conditions include polyethylene resin, polypropylene resin, ionomer resin, ethylene-vinyl acetate copolymer resin, polyamide resin, polyethylene terephthalate resin, and polylactic acid resin. In addition, since polyolefin resin such as polyethylene resin is relatively difficult to pass moisture, it is preferably used as a thin film or a film perforated by a known method.

The inner layer may be formed by coextrusion molding together with the oxygen gas barrier layer, or may be formed by laminating an inner layer film on the oxygen gas barrier layer. Alternatively, the oxygen gas barrier layer and the inner layer film may be bonded using an adhesive resin. Further, such an inner layer may be a single layer or a multilayer of two or more layers.

The thickness of such an inner layer is preferably 5 to 50 μm, more preferably 5 to 40 μm. When the thickness of the inner layer is less than the lower limit, the strength of the package is insufficient, and there is a tendency that sufficient sealing strength cannot be obtained when sealing, and when the upper limit is exceeded, the moisture of the packaged product becomes an oxygen gas barrier. In some cases, the PGA-based resin in the oxygen gas barrier layer is not hydrolyzed even if the storage temperature of the package deviates from a predetermined condition without being sufficiently supplied to the layer.

Further, when the first packaging material is for packaging an article to be packaged that contains an easily oxidizable dye and is stored and distributed under high humidity conditions, moisture is supplied from the outside of the package. Therefore, the thickness of the inner layer can be increased. The thickness of such an inner layer is preferably 5 to 150 μm, more preferably 5 to 100 μm. When the thickness of the inner layer is less than the lower limit, the strength of the package is insufficient, and there is a tendency that sufficient sealing strength cannot be obtained when sealing, and when the upper limit is exceeded, the rigidity of the packaging material becomes too large. In addition, there is a tendency to suffer an economic disadvantage of increasing the amount of packaging materials discarded.

In the first packaging material of the present invention, an outer layer may be provided on one surface of the oxygen gas barrier layer in order to increase the strength of the packaging material. Examples of such outer layers include polyamide resin layers, polyester resin layers, polycarbonate resin layers, polystyrene resin layers, polyolefin resin layers, cyclic olefin resin layers, polyurethane resin layers, ionomer resin layers, and polylactic acid. Examples include thermoplastic resin layers such as resin-based resin layers. Among them, polyamide-based resin layers, polyester-based resin layers, polyolefin-based resin layers, and polylactic acid-based resin layers from the viewpoints of transparency, surface hardness, printability, and heat resistance. Is preferred.

The outer layer may be formed by coextrusion with the oxygen gas barrier layer, or may be formed by laminating an outer layer film on the oxygen gas barrier layer. Moreover, you may adhere | attach an oxygen gas barrier layer and the film for outer layers using adhesive resin. Further, such an outer layer may be a single layer or a multilayer of two or more layers.

The thickness of such an outer layer is preferably 1 to 30 μm, and more preferably 1 to 20 μm. When the thickness of the outer layer is less than the lower limit, the strength of the package tends to be insufficient. On the other hand, when the thickness exceeds the upper limit, a decrease in oxygen gas barrier property due to hydrolysis of the PGA-based resin may occur. It becomes difficult to be reflected in the discoloration due to oxidation of, and the hardness of the packaging material tends to increase too much.

(Second packaging material)
The second packaging material of the present invention comprises a film A having an oxygen gas barrier layer containing a PGA-based resin and a film B containing moisture in a separated state, and the oxygen gas barrier layer and the film B At least one of them contains a basic compound.

In the second packaging material of the present invention, when the oxygen gas barrier layer of the film A does not contain the basic compound, the thickness of the oxygen gas barrier layer is preferably 1 to 20 μm, and preferably 1 to 10 μm. Is more preferable. When the thickness of the oxygen gas barrier layer is less than the lower limit, sufficient gas barrier properties tend not to be obtained, and film thickness control during extrusion and film formation tends to be difficult. On the other hand, when the thickness of the oxygen gas barrier layer exceeds the above upper limit, the rigidity of the packaging body increases excessively, and there is a tendency to suffer an economic disadvantage that the amount of packaging material discarded increases. Moreover, as a manufacturing method of such an oxygen gas barrier layer, the manufacturing method of a well-known PGA-type resin film is mentioned. Such an oxygen gas barrier layer containing a PGA-based resin is preferably formed over the entire surface direction of the film A. Thereby, the second packaging material of the present invention exhibits excellent oxygen gas barrier properties under appropriate storage conditions.

On the other hand, when the basic compound is contained in the oxygen gas barrier layer in the film A, the oxygen gas barrier layer may be composed of one layer containing a PGA-based resin and a basic compound. It may consist of two layers of a layer containing a resin (hereinafter referred to as “PGA resin layer”) and a layer containing a basic compound (hereinafter referred to as “basic compound layer”). Regarding the thickness of the oxygen gas barrier layer composed of one layer containing such a PGA-based resin and a basic compound, the effect thereof, and the production method thereof, the case of the oxygen gas barrier layer composed of one layer in the first packaging material The method for producing an oxygen gas barrier layer comprising two layers of a PGA-based resin layer and a basic compound layer, and the thicknesses and effects of the PGA-based resin layer and the basic compound layer are described above. This is the same as the case of the oxygen gas barrier layer consisting of two layers in the first packaging material. Such an oxygen gas barrier layer containing a PGA-based resin and a basic compound may be formed over the entire surface direction of the film A, but exhibits an excellent oxygen gas barrier property under appropriate storage conditions. From the viewpoint that the oxidative deterioration of the package can be more easily visually recognized due to partial discoloration of the package when it deviates from the above, a PGA-based resin and a basic compound in a part of the surface direction of the film A It is preferable that an oxygen gas barrier layer containing a PGA-based resin not containing a basic compound is formed in the remaining portion.

Further, in the film A, it is preferable to provide an inner layer on one surface of the oxygen gas barrier layer in order to avoid contact between the oxygen gas barrier layer and an article to be packaged. As such an inner layer, the resin layer illustrated as an outer layer in said 1st packaging material is mentioned. The thickness of the inner layer is preferably 5 to 150 μm, more preferably 5 to 100 μm. When the thickness of the inner layer is less than the lower limit, the strength of the package is insufficient, and there is a tendency that sufficient sealing strength cannot be obtained when sealing, and when the upper limit is exceeded, the rigidity of the packaging material becomes too large. In addition, there is a tendency to suffer an economic disadvantage of increasing the amount of packaging materials discarded. Examples of the method for producing such an inner layer include the same method as that for the inner layer in the first packaging material.

Furthermore, in the film A, an outer layer may be provided on one surface of the oxygen gas barrier layer in order to increase the strength of the packaging material. As such an outer layer, since the 2nd package of this invention utilizes the water | moisture content in the film B, it needs to have a water permeability. Examples of the outer layer having such moisture permeability include the resin layer exemplified as the inner layer in the first packaging material. The thickness of the outer layer is preferably 1 to 50 μm, more preferably 1 to 30 μm. When the thickness of the outer layer is less than the lower limit, the strength of the package tends to be insufficient. On the other hand, when the upper limit is exceeded, the moisture permeability decreases and the hardness of the packaging material increases or the transparency decreases. There is a tendency. As a manufacturing method of such an outer layer, the same method as the case of the outer layer in said 1st packaging material is mentioned.

The film B constituting the second packaging material of the present invention contains moisture, and examples thereof include a substrate film impregnated with moisture. The film B is stored in a state separated from the film A before use (before packaging), and the outer surface (specifically, oxygen) of the film A at the time of use (immediately before use or after packaging). Affixed on the gas barrier layer). Thus, by sticking the film B on the outer surface of the film A, the water in the film B is supplied to the oxygen gas barrier layer of the film A, and the PGA resin can be hydrolyzed.

Moreover, when the said basic compound is contained in the said film B, this film B may consist of two layers, the layer containing a water | moisture content, and a basic compound layer, but from a viewpoint that it can manufacture easily. A single layer containing water and a basic compound is preferable.

As a raw material which comprises the base film used for such a film B, there is no restriction | limiting in particular, if it can contain a water | moisture content, For example, the material containing polysaccharides, such as a cellulose, a cellophane, a polyvinyl alcohol type | system | group Examples thereof include resins, urea resins, polyacrylates and the like. The thickness of such a substrate film is not particularly limited, but is preferably 1 to 2000 μm.

The water content in the film B is not particularly limited as long as the hydrolysis reaction of the PGA resin can be promoted and the oxygen gas barrier property can be lowered when deviating from predetermined storage conditions. The appropriate water content in the film B varies depending on the material of the film B and the method of attaching to the film A, and thus it is difficult to strictly define, for example, 100 per cm ^{3 of the} film B. ˜5000 mg / cm ³ is preferred. When the moisture content is less than the lower limit, the amount of moisture supplied to the oxygen gas barrier layer of the film A is small, and even when the moisture content deviates from the predetermined storage conditions, hydrolysis of the PGA resin hardly occurs. On the other hand, when the upper limit is exceeded, excessive moisture leaks from the film B, resulting in poor appearance of the package, or the film B is easily peeled off from the film A. Tend to be.

The method for attaching the film B according to the present invention is not particularly limited as long as the method can fix the film B to the outer surface of the film A. For example, the film B may be covered with an adhesive-attached film and fixed to the outer surface of the film A, or an adhesive layer may be provided on a part of the surface of the film B that is attached to the film A. The film B imparted with properties may be directly bonded and fixed to the outer surface of the film A. There are no particular restrictions on the adhesive that constitutes the adhesive layer of the film B or the adhesive-attached film. For example, acrylic resin, olefin resin, urethane resin, ethylene-vinyl acetate resin, epoxy resin, Examples of the adhesive include silicone resin. Moreover, it is preferable that the said film with an adhesive agent is colorless and transparent so that the discoloration of a to-be-packaged object can be visually recognized.

In such a film B, a layer (hereinafter referred to as “moisture dissipation prevention”) is provided on the surface opposite to the surface to which the film B is applied so that the water supply to the film A is not hindered. It is preferable to provide a layer. Further, instead of providing such a moisture dissipation prevention layer on the film B in advance, after the film B is attached to the outer surface of the film A, a film having a moisture dissipation prevention layer may be attached on the film B. Alternatively, a film having a moisture dissipation prevention layer and an adhesive layer may be used as the adhesive-attached film. The moisture dissipation prevention layer is preferably colorless and transparent so that discoloration of the package can be visually recognized. There are no particular restrictions on the resin constituting such a moisture dissipation prevention layer. For example, polyethylene resin, polypropylene resin, ethylene-vinyl acetate copolymer resin, polyamide resin, polyethylene terephthalate resin, polycarbonate resin, polylactic acid resin Etc.

(Packaged items)
The packaging material of the present invention is a packaging material for packaging an object to be packaged containing an easily oxidizable pigment. Examples of the oxidizable dye include heme dye and derivatives thereof (eg, myoglobin, hemoglobin, nitrosyl myoglobin), chlorophyll and derivatives thereof, carotenoids (eg, β-carotene, lycopene, cryptoxanthine, astaxanthin), anthocyanins, flavonoids And the like. Also included are natural colorants such as anato dye, turmeric dye, krill dye, gardenia dye, cucumber dye, red cabbage dye, cochineal dye, red pepper dye, tomato dye, red pepper dye, safflower dye, purple potato dye, and lac dye. . Examples of the package containing such an easily oxidizable pigment include, for example, livestock meat (for example, beef, pork, poultry, lamb, salmon), seafood (for example, tuna, bonito, yellowtail, amberjack, Horse mackerel, Thai, other bloody meat, crustacean such as shrimp and crab), vegetables, fruits, salmon, seaweed, and their cooked products (eg seasoned meat, sushi, grilled fish, ham, sausage) , Kamaboko, salad, side dish, juice, soup), raw juices, dairy products (cheese, butter), and pharmaceuticals colored with natural pigments.

In the case of packaging a package containing moisture in the first packaging material of the present invention, the package is not particularly limited as long as it contains moisture, but moisture penetrates the inner layer. In order to sufficiently supply the oxygen gas barrier layer, the water activity (Aw) of the packaged object is preferably 0.90 to 1.00, more preferably 0.95 to 1.00. preferable. The water activity (Aw) is represented by the ratio (Aw = P / P ₀ ) between the water vapor pressure (P) in the sealed container containing the packaged goods and the maximum water vapor pressure (P ₀ ) at that temperature. Is. Examples of packages containing such oxidizable pigments and moisture include livestock meat (eg, beef, pork, poultry, lamb, salmon), fish (eg, tuna, skipjack, yellowtail, amberjack, horse mackerel, Thailand, other bloody meat, shellfish such as shrimp and crab), vegetables, fruits, potatoes, seaweeds, and their cooked products (eg seasoned meat, sushi, grilled fish, ham, sausage, kamaboko , Salads, prepared dishes, soups, etc.), raw juices, foods such as dairy products (cheese, butter), and liquid pharmaceuticals colored with natural pigments.

<Packaging body>
Next, the package of the present invention will be described. The package of the present invention comprises a packaging material containing a PGA-based resin and a basic compound, and an article to be packaged containing an easily oxidizable pigment packaged by the packaging material.

As such a package, the packaging material comprising the first packaging material of the present invention and the packaging material containing the easily oxidizable dye and moisture, or containing the easily oxidizable dye. And stored and distributed under high humidity conditions (relative humidity of 90% RH or higher) (hereinafter collectively referred to as “first package”); What is provided with the to-be packaged object containing the oxidizable pigment | dye packaged with the said film A which comprises a 2 packaging material (henceforth "the 2nd package body") is mentioned.

(First package)
A first package of the present invention includes a packaging material including an oxygen gas barrier layer containing a PGA-based resin and a basic compound, and an article to be packaged containing an oxidizable dye and moisture, Alternatively, it includes an easily oxidizable dye and a packaged article that is stored and distributed under high humidity conditions (relative humidity of 90% RH or more).

In such a first package, moisture in the package or moisture in a high humidity environment is supplied to the oxygen gas barrier layer, and the PGA resin in the oxygen gas barrier layer can be hydrolyzed. And when the storage condition of the package in such a state deviates from a predetermined condition, the hydrolysis reaction of the PGA resin proceeds and the oxygen gas barrier property is lowered. As a result, external oxygen penetrates into the package and the oxidizable dye in the package is oxidized and discolored.By visually observing the appearance of the package, the package is subjected to predetermined storage conditions. The trace which deviated from can be confirmed easily.

In the first package of the present invention, a package containing water includes an inner layer, the oxygen gas barrier layer disposed on the inner layer, and an outer layer disposed on the oxygen gas barrier layer. When packaging with packaging material, in order to supply moisture in the packaged material to the oxygen gas barrier layer of the packaging material, package the packaged product with a moisture-permeable layer as the inner layer (layer on the packaged product side) There is a need to. In addition, when the first package of the present invention is stored and distributed under high humidity conditions, a layer having moisture permeability is used to supply moisture in a high humidity environment to the oxygen gas barrier layer of the packaging material. However, the inner layer does not have to be moisture permeable.

(Second package)
As a second package of the present invention, a film A having an oxygen gas barrier layer containing a PGA-based resin, an article to be packaged containing an easily oxidizable dye packaged by the film A, and the film A Attached film B containing water and a basic compound (hereinafter referred to as “second package A”); The film A comprising an oxygen gas barrier layer containing a PGA-based resin and a basic compound And an article to be packaged containing the easily oxidizable pigment packaged by the film A, and a film B containing moisture affixed on the film A (hereinafter referred to as “second package B”). Said). Further, the basic compound may be contained in both the oxygen gas barrier layer and the film B.

In the second package A of the present invention, the oxygen gas barrier layer containing the PGA resin is preferably formed over the entire surface direction of the film A. As a result, under appropriate storage conditions, the package is less susceptible to oxidative degradation and can be stored for a long period of time, and the film B can be attached to any position of the film A, easily. It can be handled. In the second package A, the film B may be applied to the entire surface direction of the film A, but the packaged material partially discolors when deviating from appropriate storage conditions. From the viewpoint that the oxidative degradation of the package can be more easily visually recognized, it is preferable that the film A is attached to a part in the surface direction.

On the other hand, in the second package B of the present invention, the oxygen gas barrier layer containing the PGA-based resin and the basic compound may be formed over the entire surface direction of the film A, but under appropriate storage conditions. From the viewpoint of exhibiting excellent oxygen gas barrier properties and, when deviating from that, the wrapping is partially discolored, so that the oxidative deterioration of the wrapping can be more easily recognized. It is preferable that an oxygen gas barrier layer made of a PGA resin not containing a basic compound is formed in the remaining portion. Further, in the second package B, from the viewpoint that the oxidative degradation of the package can be more easily visually recognized because the package is partially discolored when deviating from an appropriate storage condition, an oxygen gas barrier is provided. When the layer is formed over the entire surface direction of the film A, the film B is preferably attached to a part of the surface direction of the film A, and the oxygen gas barrier layer is one of the surface directions of the film A. In the case where the film B is formed, the film B is preferably pasted on the oxygen gas barrier layer.

In the second package of the present invention, by sticking the film B to the outer surface of the film A in this way, the moisture in the film B (in the case of the second package A, further basic compound) is The oxygen gas barrier layer is supplied, and the PGA resin of the oxygen gas barrier layer can be hydrolyzed. And when the storage condition of the package in such a state deviates from a predetermined condition, the hydrolysis reaction of the PGA resin proceeds and the oxygen gas barrier property is lowered. As a result, external oxygen penetrates into the package and the oxidizable dye in the package is oxidized and discolored.By visually observing the appearance of the package, the package is subjected to predetermined storage conditions. The trace which deviated from can be confirmed easily.

In the second packaging body of the present invention, as the film A, a packaging material including an inner layer, the oxygen gas barrier layer disposed on the inner layer, and an outer layer disposed on the oxygen gas barrier layer is used. In this case, in order to supply the moisture of the film B to the oxygen gas barrier layer of the film A, it is necessary to wrap the package with the layer having moisture permeability as an outer layer.

Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples.

Example 1
As the resin for each layer, polyethylene terephthalate resin pellets (“Bellpet IFG-8L” manufactured by Bell Polyester Products Inc .; hereinafter abbreviated as “PET resin”) and nylon resin pellets (“Amilan CM6241FS” manufactured by Toray Industries, Inc.). Hereinafter, abbreviated as “Ny6-66 resin”), PGA homopolymer pellets (manufactured by Kureha Corporation, melt viscosity (temperature 270 ° C., shear rate 120 sec ⁻¹ ): 1600 Pa · s, melting point: 224 ° C.), And a linear low-density polyethylene resin (“moretec 0238CN” manufactured by Idemitsu Petrochemical Co., Ltd., hereinafter abbreviated as “LLDPE resin”), and a polyolefin-based adhesive (Mitsubishi Chemical Corporation) as an adhesive between each layer. PET resin (thickness: 2 μm) // Ny6-66 by coextrusion molding using “Modic F563” manufactured by A multilayer film (film A according to the present invention) made of resin (thickness: 8 μm) // PGA resin (thickness: 3 μm) // LLDPE resin (thickness: 21 μm) was produced. When the oxygen gas permeability at 15 ° C. and 80% RH of this multilayer film was measured according to JIS K7126 (Method B), it was 3.0 cm ³ / (m ² · day · atm).

Further, filter paper (manufactured by Advantech Toyo Co., Ltd., thickness: 170 μm) was cut into 2 cm × 2 cm, and 100 μl of 2.8% by mass of aqueous ammonia (2.3 × 10 ⁻³ mol of ammonia per 1 cm ^{3 of} film B) / Cm ³ ) was dropped and impregnated to produce a film containing water and ammonia (film B according to the present invention).

Next, a three-sided seal is applied using the LLDPE resin layer of the multilayer film (film A) as an inner layer to produce a pouch (inner dimensions: 8 cm × 8 cm), which contains myoglobin (an oxidizable dye) as an article to be packaged The beef minced meat 30g was enclosed and vacuum-packed. Thus, the film (film B) containing the said water | moisture content and ammonia was mounted on the PET resin layer surface of the pouch which vacuum-packed the beef minced meat, and the packing tape made from polypropylene resin (Sekisui Chemical Co., Ltd. 4cm x 4 cm) and bonded and fixed to produce a package of the present invention.

This package was stored in the dark at 10 ° C. The photograph (left side of each set) in FIG. 1A shows the state of the package in each storage time (from the top, day 0, day 3, day 7). Moreover, the photograph on the left side of FIG. 1B shows the state of the beef minced meat taken out by opening the package stored for 7 days. As apparent from the results shown in FIGS. 1A to 1B, no discoloration of beef minced meat was observed even when stored at 10 ° C. for 3 days. The beef minced meat turned greenish brown and was visually confirmed to be inedible.

In addition, the three panelists judged the smell of beef minced meat taken out by opening the package stored for 7 days according to the following criteria.
A: It was almost odorless and edible.
B: Slight odor but edible.
C: Strong odor and inedible.

As a result, all three panelists decided “B”, that is, edible.

Therefore, the number of viable bacteria per 1 g of beef minced meat stored for 7 days was measured by a pour plate method (cultured at 37 ° C. for 48 hours) using a standard agar medium, and it was 4.9 × 10 ⁷ cfu / g. there were. From this result, the beef minced meat stored at 10 ° C. for 7 days reached the initial rotting level (10 ⁷ cfu / g or more), and was confirmed to be inedible. Moreover, although the result of the said visual observation corresponds with this viable cell count measurement result, it turned out that the result of odor determination does not correspond.

From the above results, when the storage temperature of beef minced meat deviates from an appropriate storage temperature (5 ° C. or less), even if the beef minced meat that has reached the initial rotting level is determined to be edible in the odor determination, PGA When the packaging material of the present invention comprising the film A having a resin layer and the film B containing water and ammonia is used, the portion to which the film B is pasted and the beef minced meat in the peripheral portion thereof are discolored to thereby reduce the initial rotting level. It was confirmed that it was easy to see and could prevent accidental eating of foods that had reached the initial level of spoilage.

(Comparative Example 1)
As a resin for each layer, an ultra-low density polyethylene resin (“moretech V0398CN” manufactured by Prime Polymer Co., Ltd., hereinafter abbreviated as “VLDPE resin”), an ionomer resin (“High Milan AM79301” manufactured by Mitsui DuPont Polychemical Co., Ltd.). Polyvinylidene chloride (“FB-2” manufactured by Kureha Co., Ltd .; hereinafter abbreviated as “PVDC resin”), and ethylene-vinyl acetate copolymer resin (“EVAFLEX V5714C” manufactured by Mitsui DuPont Polychemical Co., Ltd.) VLDPE resin (thickness: 3 μm) // ionomer resin (thickness: 21 μm) // PVDC resin (thickness: 7 μm) // EVA resin by coextrusion molding using “EVA resin”) A multilayer film composed of (thickness: 24 μm) was produced. The oxygen gas permeability of this multilayer film at 15 ° C. and 80% RH was measured according to JIS K7126 (Method B) and found to be 6.2 cm ³ / (m ² · day · atm). A package was produced in the same manner as in Example 1 except that this multilayer film was used as film A and an EVA resin layer was used as an inner layer to produce a pouch (inner dimensions: 8 cm × 8 cm).

This package was stored in the dark at 10 ° C. The photograph (right side of each set) in FIG. 1A shows the state of the package in each storage time (from the top, 0th day, 3rd day, 7th day). Moreover, the photograph on the right side of FIG. 1B shows the state of the beef minced meat taken out by opening the package stored for 7 days. As is apparent from the results shown in FIGS. 1A to 1B, no discoloration of the beef minced meat was observed even after storage at 10 ° C. for 7 days, and the appearance was edible.

Moreover, when the three panelists judged the smell of the beef minced meat taken out by opening the package stored for 7 days in the same manner as in Example 1, all three panelists were “B”, that is, acceptable. I decided to eat.

On the other hand, when the number of viable bacteria per 1 g of beef minced meat stored for 7 days was measured in the same manner as in Example 1, it was 5.1 × 10 ⁷ cfu / g. From this result, the beef minced meat stored at 10 ° C. for 7 days reached the initial rotting level (10 ⁷ cfu / g or more), and was confirmed to be inedible. Moreover, it turned out that neither the result of the said visual observation nor an odor determination corresponds with this viable count measurement result.

From the above results, when the storage temperature of beef minced meat deviates from an appropriate storage temperature (5 ° C. or less), when the beef minced meat is stored using a film not including the PGA resin layer, the initial rotting level is reached. Beef minced meat was judged to be edible in both odor determination and appearance observation, and it was found that there is a risk of accidentally eating foods that have reached the initial rot level.

(Example 2)
Cellophane (manufactured by Toyo Corp., thickness: 18 μm) was cut into 2 cm × 2 cm, and 10 μl of 2.8% by mass of aqueous ammonia (2.2 × 10 ⁻³ mol / cm ^{3 of} ammonia per 1 cm ^{3 of} film B) The film containing water and ammonia was produced. A package was produced in the same manner as in Example 1 except that this film was used as the film B.

This package was stored in the dark at 10 ° C. The photograph (left side of each set) of FIG. 2A shows the state of the package in each storage time (from the top, 0th day, 3rd day, 7th day). Moreover, the photograph on the left side of FIG. 2B shows the state of the beef minced meat that has been unpacked after being unpacked for 7 days. As is apparent from the results shown in FIGS. 2A to 2B, no discoloration of beef minced meat was observed even when stored at 10 ° C. for 3 days. However, when stored for 7 days, the part where the film B was applied and its peripheral part The beef minced meat turned greenish brown and visually confirmed to be inedible.

Therefore, when the number of viable bacteria per 1 g of beef minced meat stored for 7 days was measured in the same manner as in Example 1, it was 3.1 × 10 ⁷ cfu / g. From this result, it was found that the beef minced meat stored at 10 ° C. for 7 days reached the initial rotting level (10 ⁷ cfu / g or more) and was inedible. Moreover, although the result of the said visual observation corresponds with this viable cell count measurement result, it turned out that the result of odor determination does not correspond.

(Comparative Example 2)
In the same manner as in Example 2, a film containing water and ammonia (base material: cellophane) was produced. A package was produced in the same manner as in Comparative Example 1 except that this film was used as the film B.

This package was stored in the dark at 10 ° C. The photograph (right side of each set) of FIG. 2A shows the state of the package in each storage time (from the top, 0th day, 3rd day, 7th day). Moreover, the photograph on the right side of FIG. 2B shows the state of the beef minced meat taken out by opening the package stored for 7 days. As is apparent from the results shown in FIGS. 2A to 2B, no discoloration of beef minced meat was observed even after storage at 10 ° C. for 7 days, and the appearance was edible.

On the other hand, when the number of viable bacteria per 1 g of beef minced meat stored for 7 days was measured in the same manner as in Example 1, it was 5.9 × 10 ⁷ cfu / g. From this result, it was found that the beef minced meat stored at 10 ° C. for 7 days reached the initial rotting level (10 ⁷ cfu / g or more) and was inedible. Moreover, it turned out that neither the result of the said visual observation nor an odor determination corresponds with this viable count measurement result.

From the above results, when beef minced meat is stored using a film that does not contain a PGA resin layer at a temperature (10 ° C.) that deviates from an appropriate storage temperature (5 ° C. or less), the beef minced meat that has reached the initial spoilage level However, it was determined that the food was judged to be edible both in the odor determination and in the appearance observation, and it was found that there is a risk of accidentally eating foods that have reached the initial rot level.

(Example 3)
Cellophane (manufactured by Toyo Corporation, thickness: 18 μm) was cut into 2 cm × 2 cm, and 10 μl of 0.28% by mass of aqueous ammonia (2.2 × 10 ⁻⁴ mol / cm ^{3 of} ammonia per 1 cm ^{3 of} film B) The film containing water and ammonia was produced. A package was produced in the same manner as in Example 1 except that this film was used as the film B.

The package was stored at 5 ° C, 15 ° C, and 25 ° C in the dark. The photographs in Fig. 3 (left side of each set) show the packaging at each storage temperature (5 ° C, 15 ° C, 25 ° C from the top) and each storage time (4th, 7th, 9th from the left set). It shows the state of the body. Table 1 shows the results of visual observation of these. Moreover, the packaging body of each storage temperature and each storage time was opened, beef minced meat was taken out, and the odor was judged by three panelists in the same manner as in Example 1. The results are shown in Table 1. Further, the number of viable bacteria per 1 g of beef minced meat at each storage temperature and each storage time was measured in the same manner as in Example 1. The results are shown in Table 1.

As is clear from the results shown in FIG. 3 and Table 1, no discoloration of the beef minced meat was observed even after storage for 9 days at 5 ° C., and it was edible in appearance. On the other hand, at 15 ° C. on the seventh day from the start of storage, and at 25 ° C. on the fourth day from the start of storage, the portion where the film B was pasted and the surrounding beef minced meat turned green-brown in color. Thus, it was confirmed that it was inedible. Moreover, the expansion | swelling of the package was observed in 25 degreeC and 7 days or more.

As is clear from the results shown in Table 1, regarding the odor of beef minced meat, at storage temperatures of 5 ° C. and 15 ° C., at least one panelist is “A” or “ B ", that is, edible. In particular, at 5 ° C., all three panelists determined “A” or “B”, ie, edible. On the other hand, at 25 ° C., at least 2 panelists were “B” from the start of storage until the 4th day, that is, edible, but after 3 days from the start of storage, all 3 panelists Was determined to be “C”, that is, inedible.

On the other hand, as is clear from the results shown in Table 1, regarding the number of viable bacteria per 1 g of beef minced meat, when the storage temperature is 5 ° C., the initial corrosion level (10 ⁷ cfu unsuitable for food use even for storage for 9 days). / G or more), but reached the 7th day at 15 ° C and the 4th day at 25 ° C. From this, it was found that when the storage temperature was 5 ° C., both the results of the visual observation and the odor determination were in agreement with the viable cell count measurement results. On the other hand, at 15 ° C. and 25 ° C., it was found that the result of the visual observation coincided with the viable cell count measurement result, but the result of odor determination did not coincide.

(Comparative Example 3)
In the same manner as in Example 3, a film containing water and ammonia (base material: cellophane) was produced. A package was produced in the same manner as in Comparative Example 1 except that this film was used as the film B.

The package was stored at 5 ° C, 15 ° C, and 25 ° C in the dark. The photographs in Fig. 3 (right side of each set) show the packaging at each storage temperature (from the top 5 ℃, 15 ℃, 25 ℃) and each storage time (4th, 7th, 9th from the left set). It shows the state of the body. Table 2 shows the results of visual observation of these. Moreover, the packaging body of each storage temperature and each storage time was opened, beef minced meat was taken out, and the odor was judged by three panelists in the same manner as in Example 1. The results are shown in Table 2. Further, the number of viable bacteria per 1 g of beef minced meat at each storage temperature and each storage time was measured in the same manner as in Example 1. The results are shown in Table 2.

As is apparent from the results shown in FIG. 3 and Table 2, expansion of the package was observed when the storage temperature was 25 ° C. and the storage time was 7 days or longer, but under other storage conditions, No discoloration of the meat was observed, and the appearance was edible.

As is clear from the results shown in Table 2, regarding the odor of beef minced meat, at storage temperatures of 5 ° C. and 15 ° C., at least one panelist is “A” or “ B ", that is, edible. In particular, at 5 ° C., all three panelists determined “A” or “B”, ie, edible. On the other hand, at 25 ° C., at least 2 panelists were “B” from the start of storage until the 4th day, that is, edible, but after 3 days from the start of storage, all 3 panelists Was determined to be “C”, that is, inedible.

On the other hand, as can be seen from the results shown in Table 2, the number of viable bacteria per gram of beef minced meat is shown to be an initial corrosion level (10 ⁷ cfu unsuitable for food use even at storage for 9 days at a storage temperature of 5 ° C. / G or more), but reached the 7th day at 15 ° C and the 4th day at 25 ° C. From this, it was found that when the storage temperature was 5 ° C., both the results of the visual observation and the odor determination were in agreement with the viable cell count measurement results. On the other hand, at 15 ° C. and 25 ° C., it was found that the results of the visual observation and the odor determination did not coincide with the viable cell count measurement results.

From the above results, when beef minced meat is stored using a film that does not contain a PGA resin layer at a temperature (10 ° C.) that deviates from an appropriate storage temperature (5 ° C. or less), the beef minced meat that has reached the initial spoilage level However, in both odor determination and appearance observation, it was determined to be edible, and it was found that there is a risk of accidentally eating food that has reached the initial spoilage level.

As described above, according to the present invention, the oxidative deterioration of the package is less likely to occur under an appropriate storage condition, and the trace is easily confirmed by observing the appearance of the package when deviating from the predetermined storage condition. It is possible to prevent accidental eating of foods that have reached the level of spoilage.

Therefore, since the packaging material of the present invention is suitable for packaging of an article to be discolored due to oxidative degradation, livestock meat, fish meat, vegetables, fruits, potatoes, seaweeds, cooked products thereof, and raw juices It is useful as a packaging material for packaging foods such as dairy products and pharmaceuticals colored with natural pigments.

Claims

A packaging material for packaging an object to be packaged containing an easily oxidizable dye, which contains a polyglycolic acid resin and a basic compound.
The packaging material according to claim 1, comprising a layer containing the polyglycolic acid resin and a layer containing the basic compound.
The packaging material is provided with a state in which a film A including an oxygen gas barrier layer containing the polyglycolic acid resin and a film B containing moisture are separated,
The packaging material according to claim 1 or 2, wherein the basic compound is contained in at least one of the oxygen gas barrier layer and the film B.
The packaging material according to claim 3, wherein the film B includes a layer containing the basic compound.
A package comprising a packaging material containing a polyglycolic acid-based resin and a basic compound, and an article to be packaged containing an oxidizable dye packaged by the packaging material.
The packaging body according to claim 5, wherein the packaging material includes a layer containing the polyglycolic acid resin and a layer containing the basic compound.
The packaging material includes a film A provided with an oxygen gas barrier layer containing the polyglycolic acid resin, and a film B containing water attached on the film A, and the oxygen gas barrier layer and the It is a packaging material containing a basic compound in at least one of the films B,
The package according to claim 5 or 6, wherein the package is packaged by the film A.
The package according to claim 7, wherein the film B includes a layer containing the basic compound.