Method for maintaining freshness of fresh fruits, package, and freshness maintaining metal member

Abstract

To provide a vegetable freshness keeping method capable of keeping freshness of a vegetable well.SOLUTION: This vegetable freshness keeping method comprises: a package manufacturing step of manufacturing a package by packing a vegetable and a metal material including at least one of bivalent metal and trivalent metal by a freshness keeping packing member; and a storage step of holding an oxygen concentration within the range of 0.1-12.0 vol.% and a carbon dioxide concentration within the range of 3-30 vol.% in the package 40 hours after manufacturing of the package. In the storage step, a respiratory quotient of the vegetable is 0.5-2.0.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a method for maintaining the freshness of fruits and vegetables, a package, and a freshness-maintaining metal member.

Background Art

[0002] Fruits and vegetables may be stored in the distribution stage without being consumed immediately after harvest. When storing fruits and vegetables, various studies have been conducted on suppressing the deterioration of freshness during storage.

[0003] For example, Patent Document 1 discloses a sheet provided with an undercoat layer composed of at least one selected from an SBR-based emulsion, a vinyl acetate-based emulsion, and an acrylic-based emulsion on one side of paper or paperboard, and a polyvinylidene chloride (PVDC) layer of 2 to 5 g / m 2 thereon, the sheet having a moisture permeability of 20 to 200 g / m 2 ·day, an oxygen permeability of 1000 to 50000 cc / m 2 ·day, and a carbon dioxide permeability of 20000 cc / m 2 ·day or less, and being a freshness-maintaining sheet for fruits, vegetables, and flowers.

[0004] Patent Document 2 discloses a package in which fruits and vegetables including lettuce are stored in a packaging container containing a polymer film, the internal carbon dioxide concentration of the package being 1 to 98% by volume and the internal oxygen concentration being 1 to 19% by volume.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] As described above, fresh produce may be stored in the distribution stage without being immediately consumed after harvest. CA (Controlled Atmosphere) storage and MA (Modified Atmosphere) storage of fresh produce are storage methods for maintaining the quality of fresh produce by storing it under a low oxygen concentration, a high carbon dioxide concentration, etc. However, the inventor has found that, for example, when fresh produce is exposed to an extremely low oxygen concentration for a long period of time, it may cause problems such as abnormal ripening, browning of tissues, and accumulation of acetaldehyde and ethanol in the fresh produce. Due to the above-mentioned problems, discoloration, off-odor, etc. may occur, resulting in a loss of freshness of the fresh produce and it may become unsellable.

[0007] The problem to be solved by one embodiment of the present disclosure is to provide a method for maintaining the freshness of fresh produce, a package, and a freshness-maintaining metal member that can satisfactorily maintain the freshness of fresh produce.

Means for Solving the Problem

[0008] The means for solving the above problem include the following embodiments. <1> A packaging body manufacturing step of manufacturing a packaging body by packaging fresh produce and a metal material containing at least one of a divalent metal and a trivalent metal with a freshness-maintaining packaging member, and a storage step of storing the fresh produce while maintaining the oxygen concentration in the range of 0.1% by volume to 12.0% by volume and the carbon dioxide concentration in the range of 3% by volume to 30% by volume in the packaging body 40 hours after manufacturing the packaging body, wherein in the storage step, the respiratory quotient of the fresh produce is 0.5 to 2.0. A method for maintaining the freshness of fresh produce. <2> The method for maintaining the freshness of fresh produce according to <1>, wherein the metal material includes at least one selected from the group consisting of copper, an alloy containing copper, aluminum, and an alloy containing aluminum. <3> The method for maintaining the freshness of fresh produce according to <1> or <2>, wherein the mass (g) of the metal material with respect to the mass (g) of the fresh produce is 0.00005 to 0.02000. <4> The mass (g) of the metal material with respect to the volume (cm 3 ) of the package is 0.1×10 -4 ~10.0×10 -4 The method for maintaining the freshness of fruits and vegetables according to any one of <1> to <3>. <5> The surface area (cm 3 ) of the metal material with respect to the volume (cm 2 ) of the package is 0.5×10 -4 ~15.0×10 -3 The method for maintaining the freshness of fruits and vegetables according to any one of <1> to <4>. <6> The package manufacturing step is a step of manufacturing the package by packaging the fresh - keeping metal member including the fruits and vegetables and the metal material containing at least one of the divalent metal and the trivalent metal with the fresh - keeping packaging member. The method for maintaining the freshness of fruits and vegetables according to any one of <1> to <5>. <7> The fresh - keeping metal member includes a metal layer made of the metal material on the outermost surface, and the surface area of the metal layer is 70% - 100% with respect to the total surface area of the fresh - keeping metal member. The method for maintaining the freshness of fruits and vegetables according to <6>. <8> The method for maintaining the freshness of fruits and vegetables according to <6> or <7>, wherein at least a part of the fresh - keeping metal member is in contact with the fruits and vegetables. <9> The fresh - keeping packaging member has a carbon dioxide permeability of 4,500 cm 3 / m 2 ·day·atm to 45,000 cm 3 / m 2 ·day·atm, and an oxygen permeability of 1,000 cm 3 / m 2 ·day·atm to 30,000 cm 3 / m 2 ·day·atm. The method for maintaining the freshness of fruits and vegetables according to any one of <1> to <8>. <10> The fresh - keeping packaging member is a polymer film including at least one selected from the group consisting of polyethylene, polypropylene, polymethylpentene, and polyethylene terephthalate. The method for maintaining the freshness of fruits and vegetables according to any one of <1> to <9>. <11> In the freshness-preserving packaging member, the number of holes with a maximum diameter of 50 μm or more is 1 or less per 1 m 2 The method for preserving the freshness of fruits and vegetables according to any one of <1> to <10>, wherein the number of holes with a maximum diameter of 50 μm or more is 1 or less per 1 m. <12> A package including a fruit or vegetable, a metal material containing at least one of a divalent metal and a trivalent metal, and a freshness-preserving packaging member, wherein the fruit or vegetable and the metal material are packaged by the freshness-preserving packaging member. <13> A freshness-preserving metal member including a metal material containing at least one of a divalent metal and a trivalent metal. <14> The freshness-preserving metal member according to <13>, which is a display member for preserving the freshness of fruits and vegetables, and includes a metal layer made of the metal material and an adhesive layer provided on one side of the metal layer. <15> The freshness-preserving metal member according to <13>, which is a member for decorating fruits and vegetables.

Advantages of the Invention

[0009] According to one embodiment of the present disclosure, it is possible to provide a method for preserving the freshness of fruits and vegetables, a package, and a freshness-preserving metal member that can favorably preserve the freshness of fruits and vegetables.

Embodiments for Carrying Out the Invention

[0010] In the present disclosure, a numerical range indicated using "~" indicates a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of another stepwise numerical range, or may be replaced with the value shown in the examples. In the present disclosure, the amount of each component in the material means the total amount of a plurality of substances present in the material when there are a plurality of substances corresponding to each component in the material, unless otherwise specified.

[0011] ≪Method for Preserving Freshness of Fruits and Vegetables≫ The fresh - keeping method of fresh fruits and vegetables of the present disclosure includes a packaging - body manufacturing step of packaging fresh fruits and vegetables and a metal material containing at least one of a divalent metal and a trivalent metal with a fresh - keeping packaging member to manufacture a packaging body, a storage step of storing the fresh fruits and vegetables after manufacturing the packaging body, by maintaining the oxygen concentration in the range of 0.1% by volume to 12.0% by volume and the carbon dioxide concentration in the range of 3% by volume to 30% by volume in the packaging body 40 hours after manufacturing, In the storage step, the respiratory quotient of the fresh fruits and vegetables is 0.5 to 2.0.

[0012] By including the above - mentioned configuration, the fresh - keeping method of fresh fruits and vegetables of the present disclosure can maintain the freshness of fresh fruits and vegetables well. The fresh - keeping method of fresh fruits and vegetables of the present disclosure stores the packaging body manufactured in the above - mentioned packaging - body manufacturing step in the above - mentioned storage step in a low - oxygen and high - carbon - dioxide state. Further, in the above - mentioned storage step, since the respiratory quotient of the fresh fruits and vegetables is 0.5 to 2.0 (that is, aerobic respiration), the occurrence of discoloration, abnormal odor, etc. can be suppressed. As a result, the freshness of fresh fruits and vegetables can be maintained well. Each step will be described below.

[0013] <Packaging - body manufacturing step> The packaging - body manufacturing step in the present disclosure is a step of packaging fresh fruits and vegetables and a metal material containing at least one of a divalent metal and a trivalent metal with a fresh - keeping packaging member to manufacture a packaging body.

[0014] By packaging fresh fruits and vegetables with a fresh - keeping packaging member, the carbon dioxide concentration and oxygen concentration in the packaging body can be adjusted well - balanced, and the respiration rate of fresh fruits and vegetables can be suppressed. As a result, the freshness of fresh fruits and vegetables can be maintained well over a long period.

[0015] (Fresh fruits and vegetables) Examples of fresh fruits and vegetables include fruits, vegetables, etc. Examples of fruits include, for example, strawberries, mangoes, avocados, Japanese quince, Japanese pears, apples, American cherries, cherries, Japanese apricots, apricots, plums, peaches, figs, persimmons, kiwifruits, cranberries, grapes, blueberries, blackberries, raspberries, loquats, Japanese medlars, watermelons, melons, papayas, passion fruits, pineapples, citrus fruits, etc., and strawberries are particularly preferred. Examples of vegetables include, for example, spinach, lettuce, cabbage, Chinese cabbage, Komatsuna, Chinese mustard, large leaf, Mizuna, parsley, celery, celeriac, leek, tomato, cherry tomato, eggplant, pumpkin, pepper, cucumber, ginger, cauliflower, broccoli, shungiku, onion, asparagus, aralia, butterbur, burdock, carrot, daikon radish, radish, turnip, yam, sweet potato, potato, taro, lotus root, okra, pumpkin, bitter melon, corn, edamame, green bean, broad bean, snap bean, etc.

[0016] Among the above, as fresh fruits and vegetables, strawberries, mangoes or avocados are preferred, and strawberries are more preferred.

[0017] (Metal material) The metal material in the present disclosure contains at least one of a divalent metal and a trivalent metal. Since the package in the present disclosure contains the metal material in the present disclosure, even if fresh fruits and vegetables are stored in a low-oxygen and high-carbon dioxide state like the storage step in the present disclosure, the occurrence of discoloration and off-odor can be well suppressed. As a result, the freshness of fresh fruits and vegetables can be well maintained. The metal material in the present disclosure may contain at least one selected from the group consisting of a divalent metal, a trivalent metal, and their alloys.

[0018] The divalent metal can be used without particular limitation. The divalent metal is preferably copper, iron, nickel, manganese, tungsten, titanium, silver or zinc, more preferably copper, iron, tungsten or silver, and even more preferably copper.

[0019] The trivalent metal can be used without particular limitation. As the trivalent metal, it is preferably aluminum, palladium, manganese, iron or titanium, more preferably aluminum or iron, and still more preferably aluminum.

[0020] As the alloy containing a divalent metal, brass (Cu60 - 70%·Zn30 - 40%), copper - tungsten (W70%·Cu30%) or gilding metal (Cu85%·Zn15%) is preferable, and brass (Cu60 - 70%·Zn30 - 40%) or copper - tungsten (W70%·Cu30%) is more preferable.

[0021] As the alloy containing a trivalent metal, aluminum - magnesium (Al97%·Mg3%) is preferable.

[0022] In the method for maintaining the freshness of fruits and vegetables of the present disclosure, it is preferable that the metal material contains at least one selected from the group consisting of copper, an alloy containing copper, aluminum, and an alloy containing aluminum.

[0023] (Freshness - maintaining metal member) The freshness - maintaining metal member in the present disclosure contains a metal material containing at least one of a divalent metal and a trivalent metal. The package in the present disclosure includes fruits and vegetables, a metal material containing at least one of a divalent metal and a trivalent metal, and a freshness - maintaining packaging member, and the fruits and vegetables and the metal material are packaged by the freshness - maintaining packaging member. In the package, it is preferable that the metal material exists as a freshness - maintaining metal member containing a metal material containing at least one of a divalent metal and a trivalent metal.

[0024] The package manufacturing process is preferably a process of manufacturing a package by packaging fruits and vegetables and a freshness - maintaining metal member containing a metal material containing at least one of a divalent metal and a trivalent metal with a freshness - maintaining packaging member.

[0025] As aspects of the freshness - maintaining metal member, specifically, aspects such as a display member for maintaining the freshness of fruits and vegetables for displaying specifications of fruits and vegetables, a member for decorating fruits and vegetables, etc. can be mentioned.

[0026] 〔Display member for maintaining the freshness of fruits and vegetables〕 The display member for maintaining the freshness of fruits and vegetables in the present disclosure includes the freshness - maintaining metal member in the present disclosure, and the freshness - maintaining metal member has a shape that is a sheet - like with an adhesive applied on one side. Examples of the display member for maintaining the freshness of fruits and vegetables include labels, seals, tapes, etc.

[0027] 〔Member for decorating fruits and vegetables〕 The member for decorating fruits and vegetables in the present disclosure includes the freshness - maintaining metal member in the present disclosure. Examples of the member for decorating fruits and vegetables include cushioning materials, wires, ribbons, etc.

[0028] The freshness - maintaining metal member in the present disclosure can be used in various aspects without particular limitation. For example, the freshness - maintaining metal member in the present disclosure may be an adhesive seal, a label, a tag, a ribbon, a wire, a cushioning material (such as a fruit cap), a fruit bag, a fruit pack, a sheet, a foil, a crimp, a binding band, a tape, a vinyl tie or a clip.

[0029] From the viewpoint of maintaining the freshness of fruits and vegetables well, the freshness - maintaining metal member includes a metal layer made of a metal material on its outermost surface, and it is preferable that the surface area of the metal layer is 70% - 100% of the total surface area of the freshness - maintaining metal member, more preferably 75% - 99%, and even more preferably 80% - 95%.

[0030] From the viewpoint of maintaining the freshness of fruits and vegetables well, in the method for maintaining the freshness of fruits and vegetables of the present disclosure, it is preferable that at least a part of the freshness - maintaining metal member is in contact with the fruits and vegetables.

[0031] (Freshness - maintaining packaging member) In the packaging body manufacturing process of the present disclosure, a fresh produce and a metal material containing at least one of a divalent metal and a trivalent metal are packaged with a freshness-retaining packaging member to manufacture a packaging body. As the freshness-retaining packaging member, there is no particular limitation as long as it can maintain the oxygen concentration in the range of 0.1% by volume to 12.0% by volume and the carbon dioxide concentration in the range of 3% by volume to 30% by volume in the packaging body 40 hours after manufacturing the packaging body in the subsequent storage process. Examples of the freshness-retaining packaging member include films and the like.

[0032] In the present disclosure, from the viewpoint of suppressing the respiration rate of fresh produce and adjusting the carbon dioxide concentration and oxygen concentration in the packaging body in a well-balanced manner, it is preferable that the freshness-retaining packaging member has a carbon dioxide permeability and an oxygen permeability within a specific range.

[0033] (Carbon dioxide permeability) The freshness-retaining packaging member in the present disclosure preferably has a carbon dioxide permeability of 4,500 cm 3 / m 2 ·day·atm to 45,000 cm 3 / m 2 ·day·atm, more preferably 7,000 cm 3 / m 2 ·day·atm to 40,000 cm 3 / m 2 ·day·atm, and even more preferably 10,000 cm 3 / m 2 ·day·atm to 35,000 cm 3 / m 2 ·day·atm. The above carbon dioxide permeability means the carbon dioxide permeability at 23 °C and 0% RH. When the carbon dioxide permeability is within the above range, the carbon dioxide increased by the respiration of fresh produce inside the packaging body is released to the outside, and the carbon dioxide concentration is appropriately adjusted. Thereby, the freshness of fresh produce can be maintained well.

[0034] The carbon dioxide permeability of the freshness - maintaining packaging material is measured using a differential pressure method gas permeability measuring device (GTR - 30XA, manufactured by GTR Tech Co., Ltd.) under the environment of 23°C and 0% RH, with the test gas (CO2) being 100% and the test area being 15.2 cm 2 and is the value measured as such.

[0035] (Oxygen permeability) In the freshness - maintaining packaging member of the present disclosure, the oxygen permeability is preferably 1000 cm 3 / m 2 ·day·atm to 30,000 cm 3 / m 2 ·day·atm, more preferably 8,000 cm 3 / m 2 ·day·atm to 25,000 cm 3 / m 2 ·day·atm, and even more preferably 10,000 cm 3 / m 2 ·day·atm to 20,000 cm 3 / m 2 ·day·atm. The oxygen permeability of the freshness - maintaining packaging member means the oxygen permeability at 23°C and 0% RH. When the oxygen permeability is within the above range, the oxygen concentration inside the package can be maintained at a low level, and the respiration of fruits and vegetables can be suppressed. Also, the oxygen reduced by respiration is supplied from the outside to maintain the minimum required oxygen concentration. Moreover, when the oxygen permeability is within the above range, the freshness of fruits and vegetables can be maintained well.

[0036] The above oxygen permeability is measured using a differential pressure method gas permeability measuring device (GTR - 30XA, manufactured by GTR Tech Co., Ltd.) under the environment of 23°C and 0% RH, with the test gas (O2) being 100% and the test area being 15.2 cm 2 and is the value measured as such.

[0037] The freshness - maintaining packaging member has a carbon dioxide permeability of 4,500 cm 3 / m 2 ·day·atm to 45,000 cm 3 / m 2·day·atm, with an oxygen permeability of 1,000 cm 3 / m 2 ·day·atm to 30,000 cm 3 / m 2 ·day·atm is preferred.

[0038] From the perspective of preventing the intrusion of bacteria and the like from the outside, the freshness-keeping packaging member in the present disclosure preferably exhibits excellent gas permeation even without pores. Also, the smaller the number of pores that can cause the intrusion of bacteria and the like from the outside, the more preferable. Specifically, in the freshness-keeping packaging member, it is preferable that the number of pores with a maximum diameter of 50 μm or more is 1 or less per 1 m 2 or less.

[0039] The material of the freshness-keeping packaging member in the present disclosure is not particularly limited, and examples include α-olefin copolymers. Examples of the α-olefin copolymer include polyethylene, polypropylene, polymethylpentene, polyethylene terephthalate, and the like.

[0040] In one embodiment of the present disclosure, the freshness-keeping packaging member contains a polymer having a structural unit derived from 4-methyl-1-pentene (hereinafter also referred to as a 4-methyl-1-pentene-based polymer). The 4-methyl-1-pentene-based polymer has a lower density due to its bulky molecular structure compared to other polyolefins such as polyethylene and polypropylene, and exhibits high gas permeability. Therefore, it can be suitably used as the material of the freshness-keeping packaging member.

[0041] The 4-methyl-1-pentene-based polymer may be a homopolymer consisting only of structural units derived from 4-methyl-1-pentene, or a copolymer containing structural units derived from 4-methyl-1-pentene and structural units derived from components other than 4-methyl-1-pentene. By changing the ratio of the structural unit derived from 4-methyl-1-pentene and the structural unit derived from components other than 4-methyl-1-pentene, the carbon dioxide permeability and oxygen permeability of the freshness-retaining packaging member can be adjusted to a desired range.

[0042] When the 4-methyl-1-pentene-based polymer is a copolymer containing a structural unit derived from a component other than 4-methyl-1-pentene, examples of the component other than 4-methyl-1-pentene preferably include ethylene or an α-olefin having 3 to 20 carbon atoms (excluding 4-methyl-1-pentene).

[0043] Specific examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-eicosene, and the like. Among these, propylene is preferable from the viewpoint of availability, and 1-butene is preferable from the viewpoint of imparting heat sealability at low temperature to the freshness-retaining packaging member.

[0044] The method for synthesizing the 4-methyl-1-pentene-based polymer is not particularly limited, and a known method can be adopted. When a component other than 4-methyl-1-pentene is used in the synthesis of the 4-methyl-1-pentene-based polymer, only one kind or two or more kinds of components other than 4-methyl-1-pentene may be used.

[0045] The freshness-retaining packaging member may include a 4-methyl-1-pentene-based polymer and a polymer other than the 4-methyl-1-pentene-based polymer. By changing the blend ratio of the 4-methyl-1-pentene-based polymer contained in the freshness-retaining packaging member and the polymer other than the 4-methyl-1-pentene-based polymer, the carbon dioxide permeability and oxygen permeability of the freshness-retaining packaging member can be adjusted to a desired range.

[0046] When the freshness-preserving packaging member contains a 4-methyl-1-pentene polymer and a polymer other than the 4-methyl-1-pentene polymer, the polymer other than the 4-methyl-1-pentene polymer is preferably a polyolefin, and more preferably a homopolymer or copolymer of ethylene or an α-olefin having 3 to 20 carbon atoms (excluding 4-methyl-1-pentene).

[0047] Specific examples of the homopolymer or copolymer of an α-olefin having 3 to 20 carbon atoms include homopolymers or copolymers of propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-eicosene, and the like. Among these, from the viewpoint of availability, a homopolymer or copolymer of propylene (propylene-based polymer) is preferable, and from the viewpoint of imparting heat sealability at low temperature to the freshness-preserving packaging member, a homopolymer or copolymer of 1-butene (1-butene-based polymer) is preferable.

[0048] When the freshness-preserving packaging member contains a 4-methyl-1-pentene polymer and a polymer other than the 4-methyl-1-pentene polymer, the method of blending these polymers is not particularly limited, and a known method can be adopted. When the freshness-preserving packaging member contains a 4-methyl-1-pentene polymer and a polymer other than the 4-methyl-1-pentene polymer, only one kind or two or more kinds of polymers other than the 4-methyl-1-pentene polymer may be used.

[0049] The freshness-preserving packaging member may have a single-layer structure or a multilayer structure. For example, while the 4-methyl-1-pentene polymer has excellent gas permeability, it has a high melting point and tends to have insufficient heat sealability at low temperatures. Therefore, in addition to the layer containing the 4-methyl-1-pentene polymer, a laminate provided with a layer having excellent heat sealability at low temperatures may also be used.

[0050] The thickness of the freshness-preserving packaging member is not particularly limited. From the viewpoints of strength and handleability, it may be selected from the range of 10 μm to 100 μm.

[0051] The form of the freshness-preserving packaging member is not particularly limited, but it is preferably a polymer film. The freshness-preserving packaging member is preferably a polymer film containing an α-olefin copolymer.

[0052] The freshness-preserving packaging member is more preferably a polymer film containing at least one selected from the group consisting of polyethylene, polypropylene, polymethylpentene, and polyethylene terephthalate.

[0053] ≪Package≫ The package of the present disclosure includes a fresh fruit and vegetable, a metal material containing at least one of a divalent metal and a trivalent metal, and a freshness-preserving packaging member, and the fresh fruit and vegetable and the metal material are packaged by the freshness-preserving packaging member. The package of the present disclosure is produced by packaging a fresh fruit and vegetable and a metal material containing at least one of a divalent metal and a trivalent metal with a freshness-preserving packaging member. By including the above configuration, the package of the present disclosure can preferably maintain the freshness of fresh fruits and vegetables.

[0054] The shape of the package is not particularly limited. For example, it may be in a bag shape, a pack shape, a box shape, etc. Within the range where the effects of the present disclosure can be obtained, if necessary, a part of the package may be made of a material other than the freshness-preserving packaging member (for example, a material having a lower carbon dioxide permeability and oxygen permeability than the freshness-preserving packaging member in the present disclosure). From the viewpoint of suppressing the respiration rate of fresh fruits and vegetables and preferably maintaining the freshness of fresh fruits and vegetables, the inside of the package is preferably in a sealed state (substantially free of pores, voids, etc. communicating with the outside). That is, in the package manufacturing process, it is preferable to seal the fresh fruit and vegetable with the above-mentioned freshness-preserving packaging member to manufacture the package.

[0055] The volume of the package is not particularly limited. From the viewpoint of maintaining the freshness of fresh fruits and vegetables well, the volume of the package is 50 cm 3 ~100,000 cm 3 and preferably is, 100 cm 3 ~50,000 cm 3 more preferably is, 1,000 cm 3 ~10,000 cm 3 and even more preferably is.

[0056] The mass (g) of the metal material with respect to the mass (g) of the fresh fruits and vegetables (metal / fresh fruits and vegetables) is preferably 0.00005 to 0.02000, more preferably 0.00010 to 0.01000, and even more preferably 0.00005 to 0.00700.

[0057] The mass (g) of the metal material with respect to the volume (cm 3 ) of the package is preferably 0.1×10 -4 g / cm 3 ~10.0×10 -4 g / cm 3 more preferably is 0.3×10 -4 g / cm 3 ~8.0×10 -4 g / cm 3 even more preferably is 0.5×10 -4 g / cm 3 ~3.0×10 -4 g / cm 3 and even more preferably is.

[0058] The surface area (cm 3 ) of the metal material with respect to the volume (cm 2 ) of the package is preferably 0.5×10 -4 ~15.0×10 -3 more preferably is 0.5×10 -4 ~12.0×10 -3 even more preferably is 0.7×10 -4 ~10.0×10 -3 and even more preferably is.

[0059] <Storage process> In the storage process in the present disclosure, after 40 hours from the production of the package, the fresh fruits and vegetables are stored while maintaining the oxygen concentration in the range of 0.1% by volume to 12.0% by volume and the carbon dioxide concentration in the range of 3% by volume to 30% by volume in the package. In the storage process, the respiratory quotient of the fresh fruits and vegetables is 0.5 to 2.0.

[0060] The method for maintaining the freshness of fresh fruits and vegetables of the present disclosure includes a storage process, so that the package can be stored in a low-oxygen and high-carbon dioxide state (i.e., anaerobic environment). Furthermore, in the storage process, since the respiratory quotient of the fresh fruits and vegetables is 0.5 to 2.0 (i.e., aerobic respiration), the occurrence of discoloration, abnormal odor, etc. can be suppressed. As a result, the freshness of the fresh fruits and vegetables can be maintained well.

[0061] Note that the oxygen concentration and carbon dioxide concentration in the package 40 hours after the production of the package mean the average values of the oxygen concentration and carbon dioxide concentration in the package after 40 hours have elapsed since the production of the package.

[0062] (Oxygen concentration) In the storage process, the oxygen concentration is maintained in the range of 0.1% by volume to 12.0% by volume in the package 40 hours after the production of the package. Thereby, a low-oxygen environment can be obtained, so that the respiration rate of fresh fruits and vegetables can be suppressed. As a result, the freshness of fresh fruits and vegetables can be maintained well. From the same viewpoint as above, it is preferable that the oxygen concentration in the package is 0.2% by volume or more. It is preferable that the oxygen concentration in the package is 10.5% by volume or less, preferably 6.5% by volume or less, and more preferably 3.0% by volume or less.

[0063] (Carbon dioxide concentration) In the storage process, the carbon dioxide concentration is maintained in the range of 3% by volume to 30% by volume in the package 40 hours after the production of the package. As a result, a high-carbon dioxide environment can be obtained, which can suppress the respiration rate of fresh fruits and vegetables. As a result, the freshness of fresh fruits and vegetables can be maintained well. From the same perspective as above, it is preferable that the carbon dioxide concentration in the package is 8% by volume or more, more preferably 11% by volume or more, and even more preferably 15% by volume or more. In the storage process, it is preferable that the carbon dioxide concentration in the package is 28% by volume or less, and more preferably 25% by volume or less. Note that the oxygen concentration and the carbon dioxide concentration can be measured using, for example, CheckPoint3 (MOCON - DANSENSOR).

[0064] In the storage process, it is preferable that the storage temperature is 4°C to 25°C, and more preferably 8°C to 20°C. The storage temperature means the average temperature during the storage process.

[0065] According to the method of the present disclosure, it is also possible to store fresh fruits and vegetables for a long period of time. The storage period may be, for example, 3 days or more, 5 days or more, or 10 days or more.

[0066] As a method of storing the package in an environment at a predetermined temperature, for example, a method of storing the package in a storage with the temperature in the storage set to the predetermined temperature can be mentioned. The storage may involve the transportation of fresh fruits and vegetables.

[0067] (Respiratory quotient) In the storage process, the respiratory quotient of the fresh fruits and vegetables is 0.5 to 2.0. That is, in the storage process, the fresh fruits and vegetables are performing aerobic respiration. As a result, the occurrence of discoloration, off - odor, etc. can be suppressed. As a result, the freshness of the fresh fruits and vegetables can be maintained well. In the present disclosure, the respiratory quotient means the volume ratio of the carbon dioxide emission amount to the oxygen consumption amount until nutrients are decomposed and converted into energy in the living body at a certain time.

[0068] In the storage process, when the respiratory quotient of fresh fruits and vegetables is 0.5 or more, the fresh fruits and vegetables can consume a large amount of oxygen and maintain an aerobic respiration state. From the above perspective, in the storage process, it is preferable that the respiratory quotient of fresh fruits and vegetables is 0.7 or more, and more preferably 0.9 or more. In the storage process, when the respiratory quotient of fresh fruits and vegetables is 2.0 or less, the oxygen consumption can be ensured and the aerobic respiration state can be maintained. From the above perspective, in the storage process, it is preferable that the respiratory quotient of fresh fruits and vegetables is 1.8 or less, and more preferably 1.6 or less.

[0069] The respiratory quotient of fresh fruits and vegetables may be adjusted within a suitable range depending on the type of fresh fruits and vegetables, etc. For example, when the fresh fruit and vegetable is strawberry, the respiratory quotient of strawberry is preferably 0.5 to 2.0, and more preferably 0.8 to 1.8. For example, when the fresh fruit and vegetable is mango, the respiratory quotient of mango is preferably 0.5 to 1.5, and more preferably 0.8 to 1.4.

[0070] The respiratory quotient is expressed as the amount of carbon dioxide emissions / the amount of oxygen consumption. The amount of carbon dioxide emissions and the amount of oxygen consumption can be measured as the change values of the oxygen concentration and carbon dioxide concentration in the package, and can also be calculated from the methods described in, for example, Journal of the Japanese Society for Refrigeration of Foods VOL.22 NO.3 1996 and Journal of the Society of Agricultural and Food Engineers 77(1):19~27,2015. When using the Michaelis Menten equation, it can be calculated, for example, in the following steps. Specifically, it is as follows.

[0071] In the respiration simulation of fresh fruits and vegetables, a model (also referred to as the MM model) based on the Michaelis Menten theory of (1) to (5) is used in the respiration model. In addition, the change in the respiration rate due to the influence of temperature is modeled by the Arrhenius equation in (6). Therefore, the oxygen consumption rate and carbon dioxide generation rate per unit mass of fresh produce are determined by the oxygen concentration, carbon dioxide concentration, and temperature of the gas inside the package. Each parameter of the MM model and the activation energy of the Arrhenius equation are determined based on the experimental results. The experimental method calculates the respiration rate from the time-series changes in the oxygen concentration and carbon dioxide concentration measured using a method with a light-transmissive bag. This calculation may be performed, for example, in Excel, or the parameters of the MM model may be identified from the respiration rate in the gas composition of the measured oxygen concentration values and carbon dioxide concentration values.

[0072] In the simulation, the Michaelis-Menten (MM) type equation is used as the respiration model. The models at the reference temperature are shown in (1) to (5). Note that the subscript j in the respiration model equation is either oxygen or carbon dioxide. The following shows each equation.

[0073] ·Michaelis Menten (MM), Equation 1

[0074]

Number

[0075] r ref,j : Respiration rate at the reference temperature [m 3 kg -1 s -1 t: Time [s] α j : Maximum reaction rate [m 3 kg -1 s -1 y O2 : Oxygen concentration φ j : Michaelis constant [%]

[0076] ·Michaelis Menten competitive (MMC, competitive inhibition), Equation 2 ​​

[0077] [Number]

[0078] r ref,j : Respiration rate at reference temperature [m 3 kg -1 s -1 t: Time [s] α j : Maximum reaction rate [m 3 kg -1 s -1 y O2 : Oxygen concentration φ j : Michaelis constant [%] y CO2 : Carbon dioxide concentration γ c,j : Inhibition constant [%]

[0079] · Michaelis - Menten uncompetitive (MMU, non - competitive inhibition), Equation 3

[0080] [Number]

[0081] r ref,j : Respiration rate at reference temperature [m 3 kg -1 s -1 t: Time [s] α j : Maximum reaction rate [m 3 kg -1 s -1 y O2 : Oxygen concentration φ j : Michaelis constant [%] y CO2 : Carbon dioxide concentration γ u,j : Non - inhibition constant [%]

[0082] ​​​​·Michaelis Menten non-competitive (MMN, non-competitive inhibition), Equation 4

[0083]

Number

[0084] r ref,j : Respiration rate at reference temperature [m 3 kg -1 s -1 t: Time [s] α j : Maximum reaction rate [m 3 kg -1 s -1 y O2 : Oxygen concentration φ j : Michaelis constant [%] y CO2 : Carbon dioxide concentration γ n,j : Non-inhibition constant [%]

[0085] ·Michaelis-Menten combination of competitive and uncompetitive (MMUN, non-competitive inhibition), Equation 5

[0086]

Number

[0087] r ref,j : Respiration rate at reference temperature [m 3 kg -1 s -1 t: Time [s] α j : Maximum reaction rate [m 3 kg -1 s -1 y O2 : Oxygen concentration φ j : Michaelis constant [%] y​​​​CO2 : Carbon dioxide concentration γ c,j : Inhibition constant [%] t i : At the initial stage, the subscript i is initial (initial). γ n,j : Non-inhibition constant [%]

[0088] · Arrhenius equation (correction of the respiration model by temperature), Equation 6

[0089]

Number

[0090] r j : Respiration rate [m 3 kg -1 s -1 , and the subscript j is either O2 or CO2. t: Time [s] r ref,j : Respiration rate at the reference temperature [m 3 kg -1 s -1 E r,j : Activation energy (respiration rate) [Jmol -1 R: Gas constant [JK -1 mol -1 T F : Temperature of fresh produce [K] T F,ref : Reference temperature of fresh produce [K]

[0091] · (Calculation of respiration rate from measured gas concentration), Equation 7, Using A1, B1, C1, D1 as parameters, fit the concentration on the left side to the measured concentration.

[0092]

Number

[0093] Y O2 : Oxygen concentration [%] ​​​t: Time [s] A1: 32.47007 B1: 0.963 C1: 0.00017 D1: 0

[0094] Equation 8 also performs the same fitting as Equation 7 to determine A1, B1, C1, D1, A2, B2, C2, and D2.

[0095]

Number

[0096] Y CO2 : Carbon dioxide concentration [%] t: Time [s] A2: 312.67 B2: 0.670826 C2: 0 D2: 7.2315503

[0097] (Equation obtained by differentiating Equation 7 with respect to time), Equation 9 (Equation obtained by differentiating Equation 8 with respect to time), Equation 10 Using the predetermined A1, B1, C1, D1, A2, B2, C2, and D2, calculate the change amounts of oxygen concentration and carbon dioxide concentration.

[0098]

Number

[0099]

Number

[0100] (Equation 9 and the equation for calculating the respiration rate from the gas permeability of the package), Equation 11 (Equation 10 and the equation for calculating the respiration rate from the gas permeability of the package), Equation 12

[0101]

Number

[0102] r O2 : Oxygen respiration rate Y O2 : Oxygen concentration [%] t: Time [s] V H : Volume of the mixed gas in the package [m 3 W F : Fresh produce weight [kg], subscript F is for fresh produce (i.e., Fruit) A p : Surface area of the packaging film [m 2 Q O2 : Carbon dioxide permeability [m 3 m -2 atm -1 d -1 y O2 : Oxygen concentration L: Thickness of the packaging film [m] ρ H : Total pressure of the gas in the packaging film [Pa], subscript H is for headspace

[0103]

Number

[0104] r CO2 : Carbon dioxide respiration rate Y CO2 : Carbon dioxide concentration [%] t: Time [s] V H : Volume of the mixed gas in the package [m 3 W F : Fresh produce weight [kg], subscript F is for fresh produce (i.e., Fruit) A p : Surface area of the packaging film [m 2 Q CO2 : Carbon dioxide permeability [m 3 m -2 atm -1 d -1 L: Thickness of the packaging film [m]​​​​​​ ρ H : Total pressure of gas in the packaging film [Pa], subscript H is the headspace

[0105] The respiration rate in each measured concentration value of Formula 11 and Formula 12 is fitted to the respiration rate of the respiration model, and the parameters of each MM type model are identified. The respiratory quotient is the carbon dioxide respiration rate r CO2 divided by the oxygen respiration rate r O2 and defined as the value obtained.

Example

[0106] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to examples. It should be noted that the invention of the present disclosure is not limited to the description of these examples at all.

[0107] Details of the members used in this example are as follows. 〔Freshness-retaining metal member〕 · Copper ribbon Manufactured by Nirako Co., Ltd., brand 110607, width 3.0 mm, thickness 0.1 mm, length 2 cm Surface area of the metal material: 1.2 cm 2 Surface area of the metal layer / total surface area of the freshness-retaining metal member: 1.2 cm 2 · Aluminum foil Manufactured by Daiso Industries Co., Ltd., brand F030, aluminum foil, thickness 11 μm, 7 cm square size Surface area of the metal material: 98 cm 2 Surface area of the metal layer / total surface area of the freshness-retaining metal member: 98 cm 2 · Copper alloy Manufactured by Nirako Co., Ltd., brand 531109, 1 mm diameter, 16 cm length Surface area of the metal material: 5 cm 3 Surface area of the metal layer / total surface area of the freshness-retaining metal member: 5

[0108] 〔Freshness-retaining packaging member〕 · Stretched polypropylene film A Manufactured by Mitsui Chemicals Tohcellulose Co., Ltd., Brand: Spash (NFHC-SP), Thickness: 30 μm · Oriented polypropylene film B Manufactured by Mitsui Chemicals Tohcellulose Co., Ltd., Brand: Spash (NFHC-SP), Thickness: 30 μm · Oriented polypropylene film C Manufactured by Mitsui Chemicals, Inc., Brand: Adfresh (M20), Thickness: 40 μm · 4-Methyl-1-pentene film (4M1P film) A laminate comprising a surface layer (outer side of the bag) containing 90 parts by mass of a propylene-based polymer and 10 parts by mass of a 1-butene-based polymer, an intermediate layer containing 20 parts by mass of a 4-methyl-1-pentene-based polymer, 56 parts by mass of a propylene-based polymer and 24 parts by mass of a 1-butene-based polymer, and a surface layer (inner side of the bag) containing 90 parts by mass of a propylene-based polymer and 10 parts by mass of a 1-butene-based polymer, in this order. The thicknesses of the surface layer (outer side of the bag), the intermediate layer, and the surface layer (inner side of the bag) are 8 μm, 24 μm, and 8 μm (total 40 μm), respectively.

[0109] [Measurement and Evaluation] (Carbon dioxide concentration, oxygen concentration) Measured using CheckPoint3 (MOCON-DANSENSOR).

[0110] (Respiratory quotient) The respiratory quotient was measured by the method described in the above item (Respiratory quotient).

[0111] (Acetaldehyde concentration) The acetaldehyde concentration was measured using gas chromatography (manufactured by Nissha FFIS, model: SGEA-P3-C) with a semiconductor gas sensor. The measurement method was a manual gas injection method using a syringe (sample volume: 5 cc / time), and the measurement graph and the display of the measured target gas concentration were performed using SGC measurement analysis software.

[0112] (Discoloration ratio) For the images of fresh produce before storage and after storage taken from above, using the Visual Analyzer IRIS VA400 (manufactured by Alpha mos), the ratio [%] occupied by the following color numbers with respect to the total area of the fresh produce in the taken images was measured as the discoloration ratio.

[0113] Regarding the evaluation of the red - black coloring of strawberries, using the Visual Analyzer IRIS VA400 (manufactured by Alpha mos Japan Co., Ltd.), the ratios occupied by color number "1296" (R:88, G:24, B:8), color number "1297" (R:88, G:24, B:24), color number "1313" (R:88, G:40, B:24), color number "1568" (R:104, G:40, B:8), color number "1808" (R:120, G:24, B:8), color number "1840" (R:120, G:56, B:8), color number "2096" (R:136, G:56, B:8), and color number "2098" (R:136, G:56, B:40) were evaluated. Color numbers "1296", "1297", "1313", "1568", "1808", "1840", "2096", and "2098" indicate red - black colors and represent the discolored parts of strawberries. The larger the sum of the above ratios, the larger the ratio of the discolored part of strawberries.

[0114] Regarding the evaluation of the black - red coloring of mangoes, using the Visual Analyzer IRIS VA400 (manufactured by Alpha mos Japan Co., Ltd.), the ratios occupied by color number "2099" (R:136, G:56, B:56), color number "2116" (R:136, G:72, B:72), and color number "2370" (R:152, G:72, B:40) were evaluated. Color numbers "2099", "2116", and "2370" indicate black - red colors and represent the discolored parts of mangoes. The larger the sum of the above ratios, the larger the ratio of the discolored part of mangoes.

[0115] Regarding the green color evaluation of avocados, the ratio occupied by color number "1091" (R: 72, G: 72, B: 56) was evaluated using a visual analyzer IRIS VA400 (manufactured by Alpha MOS Japan Co., Ltd.). Color number "1091" indicates green and represents the parts of the avocado other than the discolored parts. The larger the sum of the above ratios, the smaller the ratio of the discolored parts of the avocado.

[0116] The change in discoloration ratio was calculated from the obtained color ratios. Change in discoloration ratio of strawberries = (Discoloration ratio of strawberry image after storage) - (Discoloration ratio of strawberry image before storage) [%] Color numbers: "1296" (R: 88, G: 24, B: 8), "1297" (R: 88, G: 24, B: 24), "1313" (R: 88, G: 40, B: 24), "1568" (R: 104, G: 40, B: 8), "1808" (R: 120, G: 24, B: 8), "1840" (R: 120, G: 56, B: 80), "2096" (R: 136, G: 56, B: 8), and "2098" (R: 136, G: 56, B: 40) The larger the change in discoloration ratio, the larger the increase in the discolored part.

[0117] Change in discoloration ratio of mangoes = (Discoloration ratio of mango image after storage) - (Discoloration ratio of mango image before storage) [%] Color numbers: "2099" (R: 136, G: 56, B: 56), color number "2116" (R: 136, G: 72, B: 72), color number "2370" (R: 152, G: 72, B: 40) The larger the change in discoloration ratio, the larger the increase in the discolored part.

[0118] Change in discoloration ratio of avocados = (Discoloration ratio of avocado image after storage) - (Discoloration ratio of avocado image before storage) [%] Color number "1091" (R: 72, G: 72, B: 56) The larger the change in discoloration ratio, the larger the increase in the discolored part. That is, in the case of avocado, the larger the change ratio of discoloration, the greater the reduction in the green part, and the smaller the change ratio of discoloration, the more the green part is maintained.

[0119] (Taste index) For all fruits and vegetables packaged in the package, the taste index was calculated as the sum of the scores for each taste according to Table 1 below, and the total score of all fruits and vegetables was used as the index for each taste. Among the score ranges for each taste, the best score is 3.

[0120]

Table 1

[0121] (Sensory evaluation) ~Appearance~ The appearance of the fruits and vegetables was evaluated by the following method. ·ΔE*ab Photos of the fruits and vegetables before and after the experiment were taken using a Visual Analyzer IRIS VA400 (manufactured by Alpha mos), and the L*a*b* information of each was extracted, and ΔE*ab, which is the color difference, was calculated using the following formula. It can be said that the smaller the value of ΔE*ab, the less the color change.

[0122]

Equation

[0123] Using the obtained ΔE*ab, the appearance of the fruits and vegetables was evaluated according to the following criteria. Among the following criteria, the best rank is 1. 〔Criteria〕 1: No blackening. 2: There is a part that has turned black, although not entirely. 3: Entirely turned black.

[0124] ~Taste~ The taste was evaluated according to the following criteria. Among the following criteria, the best rank is 1. 〔Criteria〕 1: It has a fragrant aroma and tastes delicious. 2: The aroma is mild and the taste is somewhat delicious. 3: It has a fermentation odor and tastes bad.

[0125] <Examples 1 to 3, Comparative Example 1> 〔Conducting the storage test〕 To conduct the storage test, strawberries (variety: Tochiotome, mass: 276 g, number: 17) were prepared. Also, bags were made using the freshness - maintaining packaging members described in Table 2.

[0126] 〔Packaging manufacturing process〕 Into the bags made using the freshness - maintaining packaging members described in Table 2, strawberries and the freshness - maintaining metal members described in Table 2 (total mass: the mass described in Table 2) were placed. Then, the upper part of the bag was tied with a binding band to manufacture the package. The volume of the package was 1500 cm 3 It was. The mass of strawberries per unit volume in the package was 0.184 g / cm 3 It was.

[0127] 〔Storage process〕 The obtained packages were placed on a pallet and stored in a storage at the average temperature described in Table 2 for 3 days. Note that during storage, at least a part of the freshness - maintaining metal member is in contact with the fresh produce. The results of various evaluations and measurements are shown in Table 2.

[0128]

Table 2

[0129] As shown in Table 2, a packaging body manufacturing process of manufacturing a packaging body by packaging fresh fruits and vegetables and a metal material containing at least one of a divalent metal and a trivalent metal with a freshness-keeping packaging member, and after manufacturing the packaging body, in the packaging body 40 hours later, the oxygen concentration is maintained in the range of 0.1% by volume to 12.0% by volume, and the carbon dioxide concentration is maintained in the range of 3% by volume to 30% by volume to store the fresh fruits and vegetables. In the storage step, the respiration quotient of the fresh fruits and vegetables is 0.5 to 2.0. In the examples using the freshness-keeping method of fresh fruits and vegetables, the change ratio of discoloration was low, the taste index was high, and it was excellent in appearance and taste in sensory evaluation. Therefore, the freshness of fresh fruits and vegetables could be maintained well. In addition, since the aldehyde concentration in the examples was low, it is considered that the abnormal odor was suppressed. On the other hand, Comparative Example 1 without a metal material had a high change ratio of discoloration, a low taste index, and was inferior in appearance and taste in sensory evaluation. Therefore, the freshness of fresh fruits and vegetables could not be maintained well. In addition, since the aldehyde concentration in Comparative Example 1 was high, it is considered that the abnormal odor was not suppressed.

[0130] <Example 4, Comparative Example 2> 〔Implementation of storage test〕 To conduct a storage test, a mango (variety: Irwin, mass: 460 g, number: 1) was prepared. In addition, a bag was made using the freshness-keeping packaging member described in Table 3.

[0131] 〔Packaging body manufacturing process〕 Into the bag made using the freshness-keeping packaging member described in Table 3 above, the prepared mango and As a freshness-keeping member Aluminum foil were put in. Then, the upper part of the bag was tied with a binding band to package the mango to manufacture a packaging body. The volume of the packaging body was 500 cm It was. 3 The mass of the mango per unit volume in the packaging body was 0.92 g / cm It was. 3 The volume of the packaging body was 500 cm

[0132] 〔Storage step〕 The obtained package was placed on a pallet and stored in a storage at the average temperature shown in Table 3 for 8 days. During storage, at least a part of the freshness-retaining metal member is in contact with the fresh produce. The results of various evaluations and measurements are shown in Table 3.

[0133]

Table 3

[0134] As shown in Table 3, a package manufacturing step of manufacturing a package by packaging fresh produce and a metal material containing at least one of a divalent metal and a trivalent metal with a freshness-retaining packaging member, and after manufacturing the package, in the package 40 hours later, an oxygen concentration in the range of 0.1% by volume to 12.0% by volume and a carbon dioxide concentration in the range of 3% by volume to 30% by volume are maintained to store the fresh produce. In the storage step, an example using a method for maintaining the freshness of fresh produce in which the respiratory quotient of the fresh produce is 0.5 to 2.0 had a low change ratio of discoloration and was excellent in appearance and taste in sensory evaluation. Therefore, the freshness of the fresh produce could be maintained well. In addition, since the acetaldehyde concentration in the example is low, it is considered that the off-odor is suppressed. On the other hand, Comparative Example 2 that does not contain a metal material had a high change ratio of discoloration and was inferior in appearance and taste in sensory evaluation. Therefore, the freshness of the fresh produce could not be maintained well. In addition, since the acetaldehyde concentration in Comparative Example 3 is high, it is considered that the off-odor is not suppressed.

[0135] <Example 5, Comparative Example 3> 〔Conducting the storage test〕 To conduct the storage test, an avocado (mass: 170 g, number: 1) was prepared. Also, a bag was made using the freshness-retaining packaging member described in Table 4.

[0136] 〔Package manufacturing process〕 An avocado prepared and a copper ribbon as a freshness-retaining member were placed into a bag produced using the freshness-retaining packaging member described in Table 4 above. Then, the upper part of the bag was tied with a binding band to package the avocado, thereby manufacturing a package. The volume of the package was 600 cm 3 . The mass of the avocado per unit volume in the package was 0.283 g / cm 3 .

[0137] 〔Storage process〕 The obtained package was placed on a pallet and stored in a storage at the average temperature described in Table 4 for 6 days. Note that during storage, at least a part of the freshness-retaining metal member is in contact with the fresh produce. The results of various evaluations and measurements are shown in Table 4.

[0138]

Table 4

[0139] As shown in Table 4, a package manufacturing process for manufacturing a package by packaging fresh produce and a metal material containing at least one of a divalent metal and a trivalent metal with a freshness-retaining packaging member, and a storage process for storing the fresh produce while maintaining the oxygen concentration in the range of 0.1% by volume to 12.0% by volume and the carbon dioxide concentration in the range of 3% by volume to 30% by volume in the package 40 hours after manufacturing the package, wherein in the storage process, an example using a method for maintaining the freshness of fresh produce with a respiratory quotient of the fresh produce being 0.5 to 2.0 had a low change ratio of discoloration and was excellent in appearance and taste in sensory evaluation. Therefore, the freshness of the fresh produce could be maintained well. In addition, since the acetaldehyde concentration in the example was low, it is considered that the abnormal odor was suppressed. On the other hand, Comparative Example 3 without a metal material had a high change ratio of discoloration and was inferior in appearance and taste in sensory evaluation. Therefore, the freshness of the fresh produce could not be maintained well. In addition, since Comparative Example 3 has a high acetaldehyde concentration, it is considered that the abnormal odor is not suppressed.

Claims

1. A packaging body manufacturing step of manufacturing a packaging body by packaging a fresh fruit and a metal material containing at least one of a divalent metal and a trivalent metal with a freshness-retaining packaging member; A storage step of storing the fresh fruit by maintaining the oxygen concentration in the range of 0.1% by volume to 12.0% by volume and the carbon dioxide concentration in the range of 3% by volume to 30% by volume in the packaging body 40 hours after manufacturing the packaging body; comprising in the storage step, the respiratory quotient of the fresh fruit is 0.5 to 2.0; the mass (g) of the metal material with respect to the mass (g) of the fresh fruit is 0.00005 to 0.02000; the surface area (cm²) of the metal material with respect to the volume (cm³) of the packaging body is 0.5×10⁻⁴ to 15.0×10⁻³; the divalent metal is at least one selected from the group consisting of copper, iron, nickel, manganese, tungsten, titanium, silver, and zinc, and the trivalent metal is at least one selected from the group consisting of aluminum, palladium, manganese, iron, and titanium. A method for maintaining the freshness of fresh fruits.

2. A packaging body manufacturing step of manufacturing a packaging body by packaging a fresh fruit and a metal material containing at least one of a divalent metal and a trivalent metal with a freshness-retaining packaging member; A storage step of storing the fresh fruit by maintaining the oxygen concentration in the range of 0.1% by volume to 12.0% by volume and the carbon dioxide concentration in the range of 3% by volume to 30% by volume in the packaging body 40 hours after manufacturing the packaging body; comprising in the storage step, the respiratory quotient of the fresh fruit is 0.5 to 2.0; the mass (g) of the metal material with respect to the mass (g) of the fresh fruit is 0.00005 to 0.02000; the packaging body manufacturing step is a step of manufacturing the packaging body by packaging the fresh fruit and a freshness-retaining metal member containing the metal material containing at least one of the divalent metal and the trivalent metal with the freshness-retaining packaging member; the freshness-retaining metal member includes a metal layer made of the metal material on the outermost surface, and the surface area of the metal layer is 70% to 100% of the total surface area of the freshness-retaining metal member; the divalent metal is at least one selected from the group consisting of copper, iron, nickel, manganese, tungsten, titanium, silver, and zinc, and the trivalent metal is at least one selected from the group consisting of aluminum, palladium, manganese, iron, and titanium. A method for maintaining the freshness of fresh fruits.

3. The volume (cm ３ ) of the mass (g) of the metal material for the －４ ~10.0×10 －４ The method for maintaining the freshness of fruits and vegetables according to claim 1 or claim 2, which is

4. The method for maintaining the freshness of fruits and vegetables according to claim 2, wherein at least a part of the freshness-maintaining metal member is in contact with the fruits and vegetables.

5. The freshness-preserving packaging member has a carbon dioxide permeability of 4,500 cm ３ / m ２ ·day·atm to 45,000 cm ３ / m ２ ·day·atm and an oxygen permeability of 1,000 cm ３ / m ２ ·day·atm to 30,000 cm ３ / m ２ ·day·atm. The method for preserving the freshness of fruits and vegetables according to any one of claims 1 to 4

6. The method for maintaining the freshness of fruits and vegetables according to any one of claims 1 to 5, wherein the freshness-maintaining packaging member is a polymer film containing at least one selected from the group consisting of polyethylene, polypropylene, polymethylpentene, and polyethylene terephthalate.

7. In the freshness-preserving packaging member, the number of holes having a maximum diameter of 50 µm or more is 1 or less per 1 m ２ The method for preserving the freshness of fruits and vegetables according to any one of claims 1 to 6, wherein the number of holes having a maximum diameter of 50 µm or more is 1 or less per 1 m

8. A packaging body manufacturing step of manufacturing a packaging body by packaging fruits and vegetables and a metal material containing at least one of a divalent metal and a trivalent metal with a freshness-maintaining packaging member; A storage step of storing the fruits and vegetables by maintaining the oxygen concentration in the range of 0.1% by volume to 12.0% by volume and the carbon dioxide concentration in the range of 3% by volume to 30% by volume in the packaging body 40 hours after manufacturing the packaging body; comprising In the storage step, the respiratory quotient of the fruits and vegetables is 0.5 to 2.0; The mass (g) of the metal material relative to the volume (cm ３ ) of the package is 0.1×10 －４ to 10.0×10 －４ and The surface area (cm²) of the metal material with respect to the volume (cm³) of the packaging body is 0.5×10⁻⁴ to 15.0×10⁻³; The method for maintaining the freshness of fruits and vegetables, wherein the divalent metal is at least one selected from the group consisting of copper, iron, nickel, manganese, tungsten, titanium, silver, and zinc, and the trivalent metal is at least one selected from the group consisting of aluminum, palladium, manganese, iron, and titanium.

9. A packaging body manufacturing step of manufacturing a packaging body by packaging fruits and vegetables and a metal material containing at least one of a divalent metal and a trivalent metal with a freshness-maintaining packaging member; A storage step of storing the fruits and vegetables by maintaining the oxygen concentration in the range of 0.1% by volume to 12.0% by volume and the carbon dioxide concentration in the range of 3% by volume to 30% by volume in the packaging body 40 hours after manufacturing the packaging body; comprising In the storage step, the respiratory quotient of the fruits and vegetables is 0.5 to 2.0; The mass (g) of the metal material with respect to the volume (cm ３ ) of the package is 0.1×10 －４ to 10.0×10 －４ and The packaging body manufacturing step is a step of manufacturing the packaging body by packaging the fruits and vegetables and a freshness-maintaining metal member containing a metal material containing at least one of the divalent metal and the trivalent metal with the freshness-maintaining packaging member; The freshness-maintaining metal member includes a metal layer made of the metal material on the outermost surface, and the surface area of the metal layer is 70% to 100% of the total surface area of the freshness-maintaining metal member. The divalent metal is at least one selected from the group consisting of copper, iron, nickel, manganese, tungsten, titanium, silver, and zinc, and the trivalent metal is at least one selected from the group consisting of aluminum, palladium, manganese, iron, and titanium. A method for maintaining the freshness of fruits and vegetables.

10. A packaging body manufacturing step of manufacturing a packaging body by packaging fruits and vegetables and a metal material containing at least one of a divalent metal and a trivalent metal with a freshness-retaining packaging member; A storage step of storing the fruits and vegetables by maintaining the oxygen concentration in the range of 0.1% by volume to 12.0% by volume and the carbon dioxide concentration in the range of 3% by volume to 30% by volume in the packaging body 40 hours after manufacturing the packaging body; including In the storage step, the respiratory quotient of the fruits and vegetables is 0.5 to 2.0; The fruits and vegetables are strawberries, mangoes, or avocados; The surface area (cm2) of the metal material with respect to the volume (cm3) of the packaging body is 0.5×10−4 to 15.0×10−3; The divalent metal is at least one selected from the group consisting of copper, iron, nickel, manganese, tungsten, titanium, silver, and zinc, and the trivalent metal is at least one selected from the group consisting of aluminum, palladium, manganese, iron, and titanium. A method for maintaining the freshness of fruits and vegetables.

11. A packaging body manufacturing step of manufacturing a packaging body by packaging fruits and vegetables and a metal material containing at least one of a divalent metal and a trivalent metal with a freshness-retaining packaging member; A storage step of storing the fruits and vegetables by maintaining the oxygen concentration in the range of 0.1% by volume to 12.0% by volume and the carbon dioxide concentration in the range of 3% by volume to 30% by volume in the packaging body 40 hours after manufacturing the packaging body; including In the storage step, the respiratory quotient of the fruits and vegetables is 0.5 to 2.0; The fruits and vegetables are strawberries, mangoes, or avocados; The packaging body manufacturing step is a step of manufacturing the packaging body by packaging the fruits and vegetables and a freshness-retaining metal member containing a metal material containing at least one of the divalent metal and the trivalent metal with the freshness-retaining packaging member; The freshness-retaining metal member includes a metal layer made of the metal material on the outermost surface, and the surface area of the metal layer is 70% to 100% of the total surface area of the freshness-retaining metal member; The divalent metal is at least one selected from the group consisting of copper, iron, nickel, manganese, tungsten, titanium, silver, and zinc, and the trivalent metal is at least one selected from the group consisting of aluminum, palladium, manganese, iron, and titanium. A method for maintaining the freshness of fruits and vegetables.

12. Fruits and vegetables, a metal material containing at least one of a divalent metal and a trivalent metal, and a freshness-preserving packaging member, and The mass (g) of the metal material with respect to the mass (g) of the fruits and vegetables is 0.00005 to 0.02000, The fruits and vegetables and the metal material are packaged by the freshness-preserving packaging member, The surface area (cm2) of the metal material with respect to the volume (cm3) of the package is 0.5 × 10−4 to 15.0 × 10−3, The divalent metal is at least one selected from the group consisting of copper, iron, nickel, manganese, tungsten, titanium, silver, and zinc, and the trivalent metal is at least one selected from the group consisting of aluminum, palladium, manganese, iron, and titanium. A package.

13. Fruits and vegetables, a metal material containing at least one of a divalent metal and a trivalent metal, and a freshness-preserving packaging member, and The mass (g) of the metal material with respect to the volume (cm ３ 3) of the package is 0.1×10 －４ to 10.0×10 －４ and The fruits and vegetables and the metal material are packaged by the freshness-preserving packaging member, The surface area (cm2) of the metal material with respect to the volume (cm3) of the package is 0.5 × 10−4 to 15.0 × 10−3, The divalent metal is at least one selected from the group consisting of copper, iron, nickel, manganese, tungsten, titanium, silver, and zinc, and the trivalent metal is at least one selected from the group consisting of aluminum, palladium, manganese, iron, and titanium. A package.

14. Fruits and vegetables, a metal material containing at least one of a divalent metal and a trivalent metal, and a freshness-preserving packaging member, and The fruits and vegetables are strawberries, mangoes, or avocados, The fruits and vegetables and the metal material are packaged by the freshness-preserving packaging member, The surface area (cm2) of the metal material with respect to the volume (cm3) of the package is 0.5 × 10−4 to 15.0 × 10−3, The divalent metal is at least one selected from the group consisting of copper, iron, nickel, manganese, tungsten, titanium, silver, and zinc, and the trivalent metal is at least one selected from the group consisting of aluminum, palladium, manganese, iron, and titanium. A package body.

15. It includes a metal material containing at least one of a divalent metal and a trivalent metal. The freshness-retaining metal member includes a metal layer made of the metal material on the outermost surface, and the surface area of the metal layer is 70% to 100% of the total surface area of the freshness-retaining metal member. The divalent metal is at least one selected from the group consisting of copper, iron, nickel, manganese, tungsten, titanium, silver, and zinc, and the trivalent metal is at least one selected from the group consisting of aluminum, palladium, manganese, iron, and titanium. A freshness-retaining metal member for strawberries, mangoes, or avocados.

16. It includes the metal layer made of the metal material and an adhesive layer provided on one side of the metal layer. The freshness-retaining metal member according to claim 15, which is a display member for maintaining the freshness of fruits and vegetables.

17. The freshness-retaining metal member according to claim 15, which is a member for decorating fruits and vegetables.

Images