Tight fitting packaging film, raw japanese horseradish product

Abstract

To provide a tight fitting packaging film capable of suppressing the discoloration of appearance and the deterioration of flavor of raw Japanese horseradish during storage in a refrigerator for a long period of time.SOLUTION: A tight fitting packaging film of the present invention has an oxygen permeability of 300 ml / m2 / day or more in an environment of 5°C, and is used for packaging raw Japanese horseradish. Furthermore, when raw Japanese horseradish is packaged, it is preferable that volume difference between a content and a package is 120% or less, and it is preferable that the thickness of the film after packaging measured at 10 arbitrarily selected locations, is 5 to 200 μm.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a cling packaging film and a fresh wasabi product. [Background technology]

[0002] In recent years, the demand for wasabi has been growing along with the growing demand for Japanese food overseas, and this has led to an increase in the demand for fresh wasabi, which has a superior flavor compared to powdered wasabi and paste wasabi. However, there was a problem in that fresh wasabi was not suitable for freezing because the cells were destroyed and the flavor was lost.

[0003] In addition, the most common packaging formats for refrigerated fresh wasabi are wrapped in plastic on a tray or in an aerated bag, but these packaging formats have the problem that water accumulates inside the package and black spots and mold develop within about a week, greatly reducing the product's value. Conversely, packaging formats that allow the product to dry easily and prevent water from accumulating are not suitable for long-term storage or export overseas, as they do not maintain the taste or flavor. There is also the problem that the surface is very uneven, causing the contents to rub against each other and quickly spoil.

[0004] In order to solve the above problems, a method has been known in which vacuum-packaged products using a high-barrier film with low oxygen permeability are stored in a refrigerator for long-term storage (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 62-13882 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the storage period indicated in Patent Document 1 is only for 10 days, which is insufficient considering the time required for export overseas.

[0007] The present invention is intended to solve the above problems, and its object is to provide a tight-fitting packaging film that prevents discoloration of the appearance and deterioration of the flavor of fresh wasabi during long-term refrigerated storage. [Means for solving the problem]

[0008] As a result of earnest efforts to solve the above problems, the inventors of the present invention have discovered that the oxygen permeability is 300 ml / m 2 It was found that if the fresh wasabi is stored in a tightly sealed packaging film with a shelf life of 10 days or more, it can be preserved without losing its flavor or taste even when stored in a refrigerator for a long period of time. Effect of the Invention

[0009] The contact packaging film of the present invention can suppress discoloration of the appearance and deterioration of flavor of fresh wasabi during long-term refrigerated storage. In addition, since fresh wasabi, which is prone to quality deterioration, can be stored for long periods in a refrigerated environment, it is also possible to reduce food waste. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view showing one embodiment of the contact packaging film of the present invention. [Diagram 2] 1 is a schematic cross-sectional view showing a skin pack according to one embodiment of the present invention. [Diagram 3] FIG. 1 is a cross-sectional schematic diagram showing vacuum deep draw packaging according to one embodiment of the present invention. [Figure 4] 1 is a schematic cross-sectional view showing a bag vacuum packaging according to one embodiment of the present invention. [Diagram 5] FIG. 1 is a schematic cross-sectional view showing a shrink package according to one embodiment of the present invention. [Figure 6] FIG. 1 is a schematic cross-sectional view showing one embodiment of a fresh wasabi product obtained using the contact packaging film of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The oxygen permeability of the sealable packaging film of the present invention is 300 ml / m2 at 5°C. 2 / day or more and is used for packaging fresh wasabi. In this specification, the contact packaging film of the present invention may be referred to as the "film of the present invention."

[0012] One embodiment of the contact packaging film of the present invention is shown in Fig. 1. Fig. 1 is a schematic cross-sectional view of a contact packaging film 1. The contact packaging film 1 has a laminated structure of an outer layer 11 / an inner layer 12.

[0013] The oxygen permeability of the film of the present invention is 300 ml / m at 5°C. 2 / day or more, and 400ml / m 2 / day or more, and more preferably 500 ml / m 2 / day or more. Oxygen permeability is 300ml / m 2 / day or more, oxygen permeability is sufficient and the oxygen concentration inside the sealed packaging can be maintained, which makes it possible to suppress the deterioration of flavor of the packaged fresh wasabi due to anaerobic respiration. In addition, although there is no particular upper limit for oxygen permeability, the freshness retention period can be extended by suppressing the respiration rate, and from the perspective of exerting the necessary film strength, a maximum of 6200 ml / m2 at a 5°C environment is set. 2 / day or less, and 3000ml / m 2 / day or less is more preferable, and 1200ml / m 2 / day or less is particularly preferred. The oxygen permeability in the present invention is a value calculated by applying the value measured in accordance with JIS K7126-2 using an oxygen permeability measuring device (product name "OX-TRAN 2 / 20", manufactured by MOCOM) under an atmosphere of temperature 23°C and humidity 65% ​​RH to the slope of a graph showing the temperature dependence of oxygen permeability of known plastic films described in "Agriculture, Fibers and Polymers" (Vol. 49, No. 8, 1993).

[0014] After fresh wasabi is packaged in the film of the present invention, the volume difference between the contents and the package is preferably 120% or less, more preferably 110% or less. By having a volume difference between the contents and the package of 120% or less, the package adheres sufficiently to the contents, and moisture generated from the fresh wasabi can be prevented from accumulating inside the package.

[0015] Furthermore, the thickness of the film of the present invention, measured after packaging fresh wasabi at 10 randomly selected locations, is preferably 5 to 200 μm, more preferably 10 to 160 μm, and particularly preferably 20 to 120 μm. By having a thickness of 5 μm or more, the strength of the film can be made sufficient. Furthermore, by having a thickness of 200 μm or less, the film has excellent flexibility and excellent conformability to the fresh wasabi.

[0016] The packaging form of fresh wasabi using the film of the present invention is not particularly limited, but from the viewpoint of exerting adhesion to the fresh wasabi, skin pack packaging, bag vacuum packaging, deep draw vacuum packaging, and shrink packaging are more preferable, and skin pack packaging is particularly preferable.

[0017] <Skin pack packaging> One embodiment of the present invention is a skin pack package consisting of a skin pack lid film using the film of the present invention (hereinafter, the skin pack lid film using the film of the present invention may be referred to as the "skin pack lid film of the present invention") and a base material. Figure 2 is a cross-sectional schematic diagram of the skin pack package. In the skin pack package 3, the contents 32 are packaged between the base material 31 and the skin pack lid film 30.

[0018] The film of the present invention used as the skin pack lid material film of the present invention may be a single layer film or may have a laminate structure including an outer layer and an inner layer in this order. In the skin pack lid material film of the present invention, the outer layer is the layer located on the outermost side when the skin pack is formed and is exposed to the outside air. In addition, the inner layer is the layer located on the innermost side when the skin pack is formed in the skin pack lid material film of the present invention and is the layer that adheres to the base material by heat sealing.

[0019] (outer layer) The resin used for the outer layer is not particularly limited, but it is preferably a resin layer mainly composed of a polyolefin resin. In this specification, the resin that is the "main component" in the resin layer (for example, the outer layer, inner layer, intermediate layer described below, adhesive layer, etc.) constituting the film of the present invention refers to the resin that is the largest in mass conversion among the resins constituting the resin layer. By using a resin layer using a polyolefin resin as the outer layer, the heat resistance and elongation of the film are excellent. The polyolefin resin in the outer layer may be used only one type or two or more types.

[0020] In this specification, the polyolefin resin is a polymer (including olefin elastomers) composed of an olefin as an essential monomer component, that is, a polymer containing at least a structural unit derived from an olefin in the molecule (per molecule). The olefin is not particularly limited, but examples thereof include α-olefins such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene.

[0021] Examples of the polyolefin resin include polyethylene resins, polypropylene resins, ionomers, and amorphous cyclic olefin polymers.

[0022] Examples of the polyethylene resin include ethylene homopolymers and ethylene-α-olefin copolymers. Examples of the polyethylene resin include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE). The LDPE is, for example, a low-density polyethylene containing ethylene-derived structural units as a main component and produced by a high-pressure process. The LLDPE is, for example, a low-density polyethylene containing ethylene-derived structural units as a main component and having short chain branches, produced by a medium- or low-pressure process.

[0023] Examples of the α-olefin in the ethylene-α-olefin copolymer include α-olefins having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene (preferably 1-butene, 1-pentene, 1-hexene, and 1-octene, more preferably 1-pentene, 1-hexene, and 1-octene). Only one of the above α-olefins may be used, or two or more of them may be used.

[0024] Examples of the propylene copolymer include a propylene homopolymer (homopolypropylene) and a propylene-α-olefin copolymer.

[0025] Examples of the α-olefin in the propylene-α-olefin copolymer include ethylene and α-olefins having 2 to 20 carbon atoms (excluding propylene), such as 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene. The α-olefins may be used alone or in combination of two or more. The propylene copolymer (propylene-α-olefin copolymer, etc.) may be a block copolymer, a random copolymer, or a graft copolymer.

[0026] The polyolefin resin is not particularly limited, but is preferably a polyolefin resin obtained by polymerization using a metallocene catalyst (metallocene-catalyzed polyolefin resin). As the metallocene catalyst, a known or commonly used metallocene catalyst for olefin polymerization can be used. The polymerization method (copolymerization method) of the polyolefin resin is not particularly limited, and includes known polymerization methods such as a slurry method, a solution polymerization method, and a gas phase method.

[0027] The polyolefin resin contained in the outer layer is preferably a crosslinked polyethylene resin, more preferably a crosslinked product of an ethylene homopolymer or a crosslinked ethylene-α-olefin copolymer.

[0028] The crosslinked polyolefin resin can be obtained by crosslinking an uncrosslinked polyolefin resin by a known or conventional method, such as (i) a method of irradiating the resin with radiation such as electron beams or gamma rays, (ii) a method of mixing a polyethylene organic silane compound and permeating the mixture with water in the presence of a catalyst to cause crosslinking, or (iii) a method of mixing a crosslinking agent (such as an organic peroxide) and heating the mixture.

[0029] The content of the polyolefin resin in the outer layer is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 99% by mass or more, based on the total mass (100% by mass) of the outer layer. The upper limit of the content may be 100% by mass.

[0030] The outer layer may contain other components other than the polyolefin resin within a range that does not impair the effects of the present invention. Examples of the other components include resins other than polyolefin resins, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, flame retardants, fillers, colorants, and antiblocking agents. The content of the other components is preferably 1.0% by mass or less, more preferably 0.7% by mass or less, and particularly preferably 0.5% by mass or less, based on the total mass (100% by mass) of the outer layer. Only one type of the other components may be used, or two or more types may be used.

[0031] The thickness of the outer layer is preferably 60% or more, more preferably 80% or more, of the total thickness of the film. When the thickness of the outer layer is 60% or more of the total thickness of the film of the present invention, the film has excellent heat resistance and elasticity, and can be subjected to higher heat during skin pack packaging, so that the film has particularly excellent follow-up adhesion to fresh wasabi. The upper limit is not particularly limited, but is preferably 95% or less.

[0032] (Inner layer) The inner layer may be any resin having heat sealability, and the resin to be used is not particularly limited, but specifically, it is preferably a resin layer mainly composed of an ethylene-vinyl acetate copolymer. The inner layer may contain only an ethylene-vinyl acetate copolymer (i.e., may consist of an ethylene-vinyl acetate copolymer), or may contain an ethylene-vinyl acetate copolymer and other components. The ethylene-vinyl acetate copolymer may be used alone, or two or more types of ethylene-vinyl acetate copolymers may be used in combination.

[0033] The ethylene-vinyl acetate copolymer can be obtained, for example, by polymerizing ethylene and vinyl acetate under pressure and heat in the presence of a polymerization initiator. The polymerization initiator is not particularly limited, but examples thereof include free radical generators such as peroxides. The free radical generators such as peroxides are not particularly limited, but examples thereof include t-butyl-peroxy-2-ethylhexanoate, t-butyl peroxy acetate, t-butyl peroxy pivalate, di-t-butyl peroxide, etc.

[0034] The content of vinyl acetate in the ethylene-vinyl acetate copolymer is preferably 5 to 30% by mass, more preferably 6 to 25% by mass, and particularly preferably 7 to 20% by mass, based on the total amount of the ethylene-vinyl acetate copolymer. When the content of vinyl acetate units is within the above range, good adhesion to the adherend can be obtained, and good peeling can be facilitated. The content of vinyl acetate in the present invention can be measured by a method in accordance with JIS K 6924-1.

[0035] The content of the ethylene-vinyl acetate copolymer in the inner layer is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, relative to the total mass (100% by mass) of the inner layer, and the upper limit of the content may be 100% by mass.

[0036] Examples of other components other than the ethylene-vinyl acetate copolymer include resins other than the ethylene-vinyl acetate copolymer, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, flame retardants, fillers, colorants, antiblocking agents, etc. The content of the other components is preferably 1.0% by mass or less, more preferably 0.7% by mass or less, and particularly preferably 0.5% by mass or less, based on the total mass (100% by mass) of the inner layer. Only one type of the other components may be used, or two or more types may be used.

[0037] The film of the present invention may have layers (other layers) other than the outer layer and the inner layer as long as the effects of the present invention are exhibited. Examples of the other layers include a layer (intermediate layer) for adjusting the physical properties such as oxygen permeability and flexibility of the film of the present invention, and a layer (adhesive layer) for improving the adhesion between layers.

[0038] The intermediate layer may be a single layer or multiple layers. When there are multiple intermediate layers, the intermediate layers may be the same (e.g., intermediate layers having the same composition and thickness) or different (e.g., intermediate layers having different compositions or thicknesses). The resin used for the intermediate layer is not particularly limited, but a layer using a resin such as a polyamide resin may be used.

[0039] Examples of the polyamide resin include 4-nylon, 6-nylon, 7-nylon, 11-nylon, 12-nylon, 46-nylon, 66-nylon, 69-nylon, 610-nylon, 611-nylon, 612-nylon, 6T-nylon, 6I nylon, copolymer of 6-nylon and 66-nylon (nylon 6 / 66), copolymer of 6-nylon and 610-nylon, copolymer of 6-nylon and 611-nylon, copolymer of 6-nylon and 12-nylon (nylon 6 / 12), copolymer of 6-nylon and 612 nylon, 6 copolymers of 6-nylon and 6T-nylon, copolymers of 6-nylon and 6I-nylon, copolymers of 6-nylon, 66-nylon and 610-nylon, copolymers of 6-nylon, 66-nylon and 12-nylon (nylon 6 / 66 / 12), copolymers of 6-nylon, 66-nylon and 612-nylon, copolymers of 66-nylon and 6T-nylon, copolymers of 66-nylon and 6I-nylon, copolymers of 6T-nylon and 6I-nylon, copolymers of 66-nylon, 6T-nylon and 6I-nylon, and copolymers of 66-nylon, 6T-nylon and 6I-nylon.

[0040] The intermediate layer may contain other components in addition to the resin. Examples of the other components include antioxidants, ultraviolet absorbers, light stabilizers, lubricants, flame retardants, fillers, colorants, and antiblocking agents. Only one type of each of the other components may be used, or two or more types may be used. The content of the other components in the intermediate layer is preferably 1.0% by mass or less, more preferably 0.7% by mass or less, and more preferably 0.5% by mass or less, based on the total mass (100% by mass) of the intermediate layer.

[0041] The thickness of the intermediate layer is preferably 5 μm or less, more preferably 3 μm or less. By being within the above range, it is possible to ensure oxygen permeability while exhibiting a minimum level of barrier properties.

[0042] The film of the present invention may have an adhesive layer between the outer layer and the inner layer. When the film has the intermediate layer, an adhesive layer may be provided between the outer layer and the intermediate layer, and between the intermediate layer and the inner layer. The adhesive layer may be a single layer or a multilayer. When the film has a plurality of adhesive layers, the adhesive layers may be the same adhesive layer (e.g., adhesive layers having the same composition and thickness) or different adhesive layers (e.g., adhesive layers having different compositions or thicknesses).

[0043] The adhesive layer may be a resin layer containing a resin having known or customary adhesive properties (adhesive resin) that is usually used in laminated films for skin packs. The adhesive resin is not particularly limited, but examples thereof include maleic anhydride-modified polyolefin resins.

[0044] The adhesive layer may contain other components other than the adhesive resin within a range that does not impair the effects of the present invention. Examples of the other components include other resins, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, flame retardants, fillers, colorants, and antiblocking agents. The other components may each be used alone or in combination of two or more. However, from the viewpoint of increasing the adhesion between layers, the content of the other components in the adhesive layer is preferably 1.0% by mass or less, more preferably 0.7% by mass or less, and more preferably 0.5% by mass or less, based on the total mass (100% by mass) of the adhesive layer.

[0045] The film of the present invention can be produced by a known or conventional method, for example, a feed block method in which a resin or a resin composition, which is a material for forming each layer, is melt-extruded using several extruders, a coextrusion T-die method such as a multi-manifold method, or an air-cooled or water-cooled coextrusion inflation method.

[0046] The film of the present invention can also be produced by separately preparing two or more films for constituting any of the layers, laminating these films together using an adhesive by any of the dry lamination method, extrusion lamination method, hot melt lamination method and wet lamination method, and further laminating other layers as necessary so as to form the desired arrangement. In this case, the adhesive used may be one capable of forming the above-mentioned adhesive layer.

[0047] The film of the present invention can also be produced by laminating two or more films, which have been prepared separately in advance as described above, by a thermal lamination method or the like without using an adhesive, and, if necessary, further laminating other layers so as to achieve the desired arrangement.

[0048] The outer layer can be crosslinked by any known or conventional method, either before or after the tubular film is cut open.

[0049] In addition, since the skin pack packaging is a packaging form in which the fresh wasabi is wrapped in the skin pack covering film of the present invention, the base material used is not particularly limited and any known material can be used. Examples of the base material that can be used include cardboard, cardboard, base film, and resin trays.

[0050] <Deep-draw vacuum packaging> Further, one embodiment of the present invention is a deep-draw vacuum package using the film of the present invention. Fig. 3 is a schematic cross-sectional view of the deep-draw vacuum package. In the deep-draw vacuum package 4, the contents 32 are packaged with the base material film 40 and the lid material 41, which are the films of the present invention.

[0051] The film of the present invention used as the base material of the deep drawing vacuum packaging is not particularly limited, but can be the same as the film exemplified as the skin pack lid material of the present invention. Among them, the film of the present invention used for deep drawing vacuum packaging is preferably one having a sealant in the inner layer, and more preferably a single layer from the viewpoint of exhibiting oxygen permeability. In addition, when the film of the present invention used for the deep drawing vacuum packaging has a laminated structure including an outer layer and an inner layer, the outer layer is the layer located on the side that contacts the mold, and the inner layer is the layer located on the innermost side and is the layer that adheres to the lid material.

[0052] In addition, the lid material for the deep drawn vacuum packaging is not particularly limited, but examples thereof include a film similar to the film of the present invention used as the base material for the deep drawn vacuum packaging, a biaxially stretched polypropylene film, a biaxially stretched polyethylene terephthalate film with a metal oxide vapor deposition, and a film laminated with a polyethylene resin.

[0053] <Bag vacuum packaging> As one embodiment of the present invention, there is a vacuum bag packaging using the film of the present invention. Fig. 4 is a schematic cross-sectional view of the vacuum bag packaging. In the vacuum bag packaging 5, the contents 32 are packaged in the vacuum bag packaging film 50, which is the film of the present invention. The film of the present invention used for the vacuum bag packaging is not particularly limited, but the same films as those exemplified as the film for the skin pack lid material of the present invention can be used.

[0054] <Shrink packaging> Further, one embodiment of the present invention is shrink packaging using the film of the present invention. Fig. 5 is a cross-sectional schematic diagram of the shrink packaging. The shrink packaging 6 packages the contents 32 with a shrink film 60, which is a film of the present invention. The film of the present invention used for the shrink packaging is not particularly limited, but the same films as those exemplified as the film for skin pack lid material of the present invention can be used.

[0055] <Fresh wasabi products> Furthermore, as one embodiment of the present invention, a fresh wasabi product in which fresh wasabi is tightly packed in the film of the present invention can be mentioned. Specific examples of the fresh wasabi include real wasabi and horseradish. The fresh wasabi is preferably a fruit or vegetable, and is preferably the rhizome of real wasabi or the root of horseradish. Hereinafter, the fresh wasabi product tightly packed in the film of the present invention may be referred to as the "fresh wasabi product of the present invention". The fresh wasabi product of the present invention may contain parts other than the root and rhizome, but it is preferable that it does not contain parts other than the root and rhizome in order to suppress spoilage, discoloration, etc. due to moisture loss.

[0056] One embodiment of the fresh wasabi product of the present invention will be described with reference to Figure 6. The fresh wasabi product 2 of the present invention comprises fresh wasabi 22, a base material 21 having fresh wasabi arranged on one surface thereof, and a film (lid material) 1' adhered to the surface of the fresh wasabi 22 and one surface of the base material 21.

[0057] The fresh wasabi product 2 is preferably in a packaging form in which the surface of the fresh wasabi 22 is covered with the lid material 1', thereby holding the fresh wasabi 22 on the surface of the base material 21. That is, the fresh wasabi 22 is enclosed by the lid material 1' and the base material 21. The lid material 1' is attached to the base material 21 and the fresh wasabi 22 by heating and softening the contact packaging film 1, i.e., it is the attachment of the contact packaging film 1. The fresh wasabi product 2 is obtained by heating and softening the cover film while degassing the space between the film 1 and the surface of the base material 21, with the contact packaging film 1 of the present invention placed so as to cover the surface of the fresh wasabi 22 and the surface of the base material 21. In addition, the inner layer 12 of the contact packaging film 1 of the present invention is heat-sealed to the surface of the base material 21 by heating.

[0058] The film of the present invention is made into a bag of 200 mm x 300 mm, and one stalk of fresh wasabi and 400 ml of outside air are enclosed inside the bag to produce a fresh wasabi product. The fresh wasabi product is then refrigerated for 388 hours (hereinafter, the above storage test may be referred to as the "bag storage test of the present invention"). After this test, the oxygen concentration inside the bag is preferably 5 to 15%, and more preferably 8 to 12%. By making the oxygen concentration after storage 5% or more, the fresh wasabi stored can easily undergo aerobic respiration, and it becomes easy to suppress ethanol production by anaerobic respiration and the associated deterioration in flavor. Furthermore, by making the oxygen concentration 15% or less, the amount of respiration can be suppressed, and the freshness retention period can be extended.

[0059] In addition, the carbon dioxide concentration in the bag after the bag storage test of the present invention is preferably 5% or less, more preferably 4% or less, and particularly preferably 3% or less. By having a carbon dioxide concentration of 5% or less after storage, the stored fresh wasabi is more likely to undergo aerobic respiration, making it easier to suppress ethanol production by anaerobic respiration and the accompanying deterioration in flavor.

[0060] After 8 weeks of refrigerated storage of the fresh wasabi product of the present invention, the ethanol concentration measured by the method described in the Examples below after opening the packaged fresh wasabi is preferably 2000 ppm or less, more preferably 1000 ppm or less, and particularly preferably 500 ppm or less. By having an ethanol concentration of 2000 ppm or less, it becomes easier to suppress flavor deterioration due to ethanol.

[0061] Furthermore, after 8 weeks of refrigerated storage, the number of bacteria in the fresh wasabi product of the present invention, measured immediately after opening using the method described in the Examples below, is preferably 1000 times or less, and more preferably 10,000 times or less, compared to the number of bacteria at the start of refrigerated storage. Having a colony count of 1000 times or less after refrigerated storage makes it easier to inhibit spoilage.

[0062] In addition, the fresh wasabi is preferably sterilized before being packaged in the film of the present invention. As the sterilization method, any known or conventional sterilization method for fresh foods can be used, and an example of the sterilization method is immersion in hypochlorous acid water, which can sterilize the fresh wasabi without adversely affecting its flavor.

[0063] The fresh wasabi product of the present invention uses the film of the present invention, which has excellent oxygen permeability, so that the packaged fresh wasabi can suppress the deterioration of flavor caused by anaerobic respiration due to hypoxic conditions and abnormal metabolism (ethanol production) due to anaerobic respiration. In addition, the fresh wasabi product of the present invention has a flexible structure, so that the film itself conforms to the uneven shape of the fresh wasabi surface and adheres closely, suppressing the surface of the fresh wasabi from getting wet with water droplets and spoiling. Furthermore, since the film of the present invention has excellent permeability to gases other than oxygen, it is possible for carbon dioxide produced by the metabolism of fresh wasabi to pass through, and it is possible to suppress the spoilage and discoloration of the fresh wasabi caused by the expansion of the fresh wasabi product during storage and the accompanying water droplets attached to the surface of the fresh wasabi.

[0064] The fresh wasabi product of the present invention thus produced can be stored for a long period of time when refrigerated. EXAMPLES

[0065] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0066] Manufacturing Example 1 (Production of adhesive packaging film) The film was molded so that the outer layer was made of linear polyethylene (PE) and the inner layer was made of ethylene-vinyl acetate copolymer (EVA). The linear polyethylene was crosslinked by irradiating it from the outer layer side with an electron beam at an acceleration voltage of 175 kV and an exposure dose of 150 kGy to produce a film of Production Example 1 with a total thickness of 100 μm.

[0067] Manufacturing Example 2 A monolayer film of Production Example 2 having a total thickness of 100 μm was produced using linear polyethylene (PE).

[0068] Production Example 3 The outer layer is made of linear low-density polyethylene (density: 0.925 g / cm 3 ), as the intermediate layer, saponified ethylene-vinyl acetate copolymer (EVOH) (saponification degree: 38 mol%), as the inner layer, linear low-density polyethylene (density: 0.925 g / cm 3 ), and as the adhesive layer, a maleic anhydride modified polyolefin resin was used, and molded to have a laminated structure of outer layer / adhesive layer / intermediate layer / adhesive layer / inner layer. From the outer layer side, electron beam irradiation was performed under conditions of an acceleration voltage of 175 kV and an exposure dose of 150 kGy to crosslink the linear polyethylene, and a film of Production Example 3 having a laminated structure with a total thickness of 100 μm (thickness ratio: outer layer / adhesive layer / intermediate layer / adhesive layer / inner layer = 30 / 8 / 10 / 8 / 44) was produced.

[0069] Production Example 4 The outer layer was made of polyethylene terephthalate (PBT), the intermediate layer was made of nylon (NY), the inner layer was made of linear low-density polyethylene, and the adhesive layer was made of maleic anhydride-modified polyolefin resin, and the laminated structure was made of outer layer / adhesive layer / intermediate layer / adhesive layer / inner layer. The film of Production Example 4 was produced with a laminated structure having a total thickness of 50 μm (thickness ratio: outer layer / adhesive layer / intermediate layer / adhesive layer / inner layer=5 / 5 / 30 / 5 / 55).

[0070] Example 1 A single stalk of fresh wasabi weighing 31 to 35 g, with a diameter of 20 to 30 mm and a length of 50 to 80 mm was used as an evaluation sample, and the fresh wasabi was skin-packaged using a skin pack packaging machine (product name "Hi-Pack Hyman HI-750", manufactured by Furukawa Seisakusho Co., Ltd.) using the film obtained in Production Example 1 as the skin pack lid material film and a molded tray with a thickness of 600 μm as the base material, to obtain the package of Example 1. <Packaging conditions> Vacuum condition 5 (vacuum time 30 seconds), Film heating temperature: 130℃ or 110℃

[0071] Example 2 The film obtained in Production Example 2 was vacuum molded using an automatic vacuum molding packaging machine (product name "PF-250 type", manufactured by Yoshikawa Kogyo Co., Ltd.) at a molding temperature of 85°C for 2 seconds using a mold with a width of 55 mm, length of 100 mm, and depth of 40 mm. One stick of the above-mentioned fresh wasabi was placed into the molded depression, and the package was vacuum sealed at 135°C for 2 seconds to obtain a package of Example 2 measuring 150 x 230 mm.

[0072] Example 3 The film obtained in Production Example 2 was made into a bag measuring 120 x 200 mm, and one stick of the above-mentioned fresh wasabi was placed inside. The bag was then packaged using a vacuum packaging machine (product name "C200", manufactured by Multivac) under vacuum conditions of 10 mbr or less to obtain the package of Example 3.

[0073] Example 4 A PE film (product name "High Shrink Suntech S Film M910", manufactured by Asahi Kasei Corporation) was made into a bag measuring 140 x 220 mm, one stick of the above-mentioned fresh wasabi was placed inside, and hot air was applied for 30 seconds to obtain a package of Example 4.

[0074] Comparative Example 1 A commercially available OPP film (product name "Spash", manufactured by Mitsui Chemicals Tocello Co., Ltd.) was made into a bag measuring 120 x 160 mm, one stick of the above-mentioned fresh wasabi was placed inside, and the bag was sealed with tape 3 cm from the opening to obtain a package of Comparative Example 1.

[0075] Comparative Example 2 A film of Comparative Example 2 was obtained in the same manner as in Example 1, except that the film obtained in Production Example 3 was used.

[0076] Comparative Example 3 A film of Comparative Example 3 was obtained in the same manner as in Example 3, except that the film obtained in Production Example 3 was used.

[0077] Comparative Example 4 A film of Comparative Example 4 was obtained in the same manner as in Example 3, except that the film obtained in Production Example 4 was used.

[0078] Comparative Example 5 A film of Comparative Example 5 was obtained in the same manner as in Example 2, except that the film obtained in Production Example 3 was used.

[0079] Comparative Example 6 A film of Comparative Example 6 was obtained in the same manner as in Example 2, except that the film obtained in Production Example 4 was used.

[0080] Comparative Example 7 A film of Comparative Example 6 was obtained in the same manner as in Example 4, except that a commercially available high-barrier shrink film (product name "Diamiron S-ZU", manufactured by Mitsubishi Chemical Corporation) was used.

[0081] (evaluation) The packages obtained in the Examples and Comparative Examples were stored at low temperatures of 1 to 10°C for 1 week, 4 weeks, and 8 weeks, and the samples were evaluated as follows, and the results are shown in Table 1. In Table 1, items marked with "-" indicate items that were not evaluated or could not be evaluated.

[0082] (1) Decay and odor The fresh wasabi preserved in the Examples and Comparative Examples was visually and sensorily evaluated for spoilage, shriveling, and unpleasant odors before and after opening, and samples that showed no sign of spoilage, shriveling, or unpleasant odors compared to before the start of the preservation test were rated as ○, samples that showed slight signs of spoilage, shriveling, or unpleasant odors were rated as △, and samples that showed clearly confirmed signs of spoilage, shriveling, or unpleasant odors were rated ×.

[0083] (2) Taste test For the fresh wasabi preserved in the Examples and Comparative Examples, a taste evaluation was carried out by seven evaluators, and with regard to "flavor" and "pungency", the "flavor" and "pungency" before the start of the preservation test were assigned a rating of 5, and the "flavor" and "pungency" were quantified using the following criteria on a 5-point scale from 1 to 5. Samples with average values ​​for "flavor" and "pungency" of 3.0 or more were rated as ○, samples between 2.0 and 3.0 were rated as △, and samples below 2.0 were rated as ×. 5: Has the same flavor and spiciness as fresh wasabi before the storage test began 4: The flavor and spiciness are slightly attenuated compared to the fresh wasabi before the storage test began. 3: Compared to the raw wasabi before the storage test began, the flavor and spiciness seem to have diminished, but it is still commercially viable. 2: Compared to the raw wasabi before the storage test began, the flavor and spiciness can still be felt, but they have diminished to a level that makes them unsuitable for commercialization. 1: Compared to the raw wasabi before the storage test began, the flavor and spiciness have diminished and are no longer noticeable.

[0084] (3) Appearance The fresh wasabi stored in the Examples and Comparative Examples was evaluated for the presence or absence of browning or blackening after opening, and samples with no visible discoloration were rated as ○, samples with slight discoloration were rated as △, and samples with discoloration that was fatal to the product were rated as ×.

[0085] (4) Water droplets inside the packaging Regarding the packages of the Examples and Comparative Examples, those without fogging or water droplets due to water vapor on the inside of the package were rated as ◯, those with fogging on the inside due to water vapor were rated as △, and those with water droplets were rated as ×.

[0086] (5) Swelling of the packaging Volume measurements were carried out for the packages of the Examples and Comparative Examples, and the amount of volume increase when compared to the sum of the volumes of the packaging material alone and the fresh wasabi alone was taken as the gap that occurred between the fresh wasabi in the package and the packaging material. Packages whose volume was 120% or less of the sum of the volumes of the packaging material alone and the fresh wasabi alone were evaluated as ◯, and packages whose volume exceeded 120% were evaluated as ×.

[0087] (6) O2 concentration in the package The film used for the packaging in the Examples and Comparative Examples was made into a bag measuring 200 x 300 mm, the fresh wasabi was placed inside, 400 ml of air was added, and the bag was sealed. The oxygen concentration inside the package was measured by measuring the fluorescent energy emitted from a fluorescent dye sensitive to oxygen using an OXY-1 SMA trace manufactured by PreSens. Values ​​of 5% or more were evaluated as ○, and values ​​less than 5% were evaluated as ×.

[0088] (7) CO2 concentration in the package The film used for the packaging in the Examples and Comparative Examples was made into a bag measuring 200 x 300 mm, the fresh wasabi was placed inside, and 50 ml of the gas in the package was sucked into the detector tube using a detector tube (product name "Carbon Dioxide Detector Tube 2H", manufactured by Gastec Corporation) to measure the carbon dioxide concentration in the gas in the bag. Note that, since the gas required for measurement cannot be obtained with vacuum packaging, the concentration was estimated from the results obtained with air-filled packaging and the gap volume of the packaging. The measured values ​​of 5% or less were evaluated as ○, and those exceeding 5% were evaluated as ×.

[0089] (8) Ethanol concentration After opening the packaged fresh wasabi, it was grated with a grater, 1g was weighed into a PET container, and the container was placed in a 120mm x 150mm nylon plastic bag and sealed to trap the gas. After 10 minutes, 100ml of gas from inside the bag was sucked up with an aspirator equipped with a detector tube to measure the ethanol concentration. Measurements below 2000ppm were evaluated as ○, and measurements above 2000ppm were evaluated as ×.

[0090] (9) Number of bacteria After 1 week, 4 weeks, and 8 weeks of storage, fresh wasabi and 10 ml of saline were placed in a sterilized bag immediately after opening the packaging for each condition, and the bacteria on the surface were collected by shaking 20 times in each direction. The bacteria liquid was diluted with saline and dispensed in 100 μl portions onto standard agar medium, and the number of colonies that emerged after leaving it for 48 hours in a constant temperature and humidity chamber at a temperature of 35°C and a humidity of 65% was counted. An increase in bacteria of 1000 times or less from the initial bacteria growth rate was evaluated as ◯, and an increase in bacteria of more than 1000 times was evaluated as ×.

[0091] (10) Film thickness after packaging Ten locations were randomly selected from the packages of the Examples and Comparative Examples, and the film thickness was measured.

[0092] [Table 1]

[0093] The packaging of the embodiment uses a film with sufficient oxygen permeability, which allows the fresh wasabi to maintain aerobic respiration during storage, suppressing flavor deterioration, and also allows the packaging to maintain close contact with the contents without expanding. Therefore, since the packaging is tightly packed around the fresh wasabi, water droplets do not accumulate inside the packaging, suppressing discoloration of the appearance and proliferation of bacteria, and it was confirmed that quality deterioration is suppressed during long-term refrigerated storage. On the other hand, when the packaging is not tightly packed, moisture generated from the fresh wasabi accumulates inside the packaging, and the resulting discoloration of the appearance could not be suppressed (Comparative Example 1). In addition, when a film with insufficient oxygen permeability is used, gas components released by the metabolism of the fresh wasabi cannot be discharged outside the film, and the expansion of the packaging and the resulting spoilage cannot be suppressed (Comparative Examples 2 to 7).

[0094] Variations of the present invention are described below. [Appendix 1] Oxygen permeability is 300ml / m at 5℃ 2 / day or more and is used for packaging fresh wasabi. [Appendix 2] A contact packaging film as described in Appendix 1, in which after packaging fresh wasabi, the volume difference between the contents and the package is 120% or less. [Appendix 3] 3. A contact packaging film according to claim 1 or 2, wherein after packaging fresh wasabi, the film thickness measured at 10 randomly selected locations is 5 to 200 μm. [Appendix 4] A fresh wasabi product in which fresh wasabi is packaged in a tightly sealed packaging film according to any one of appendices 1 to 3. [Appendix 5] A fresh wasabi product according to Appendix 4, wherein the fresh wasabi is real wasabi or horseradish. [Explanation of symbols]

[0095] 1. Cling packaging film 11 Outer layer 12 Inner layer 2. Fresh wasabi products 21 Bottom material 1' Lid material 22 Fresh Wasabi 3. Skin Pack Packaging 30 Skin pack lid film 31 Bottom material 32 Contents 4 Deep-draw vacuum packaging 40 Base film 41 Lid material 5 bags vacuum packaging 50 bags of vacuum film 6. Shrink Wrapping 60 Shrink Film

Claims

1. Oxygen permeability is 300ml / m at 5℃ 2 / day or more and is used for packaging fresh wasabi.

2. 2. The close-contact packaging film according to claim 1, wherein after packaging fresh wasabi, the difference in volume between the contents and the package is 120% or less.

3. 3. The contact packaging film according to claim 1 or 2, wherein the thickness of the film after packaging is measured at 10 randomly selected locations after packaging fresh wasabi, and the thickness is 5 to 200 μm.

4. A fresh wasabi product, comprising fresh wasabi packaged in the tightly sealed packaging film according to claim 1 or 2.

5. 5. The fresh wasabi product according to claim 4, wherein the fresh wasabi is real wasabi or horseradish.

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