JP7462200B2 - Material for packaging fruits and vegetables, method for manufacturing material for packaging fruits and vegetables, packaged fruit and vegetables, and method for preserving freshness of fruits and vegetables - Google Patents

Description

The present invention relates to a fruit and vegetable packaging material suitable for preserving the freshness of fruit and vegetable, a method for producing the fruit and vegetable packaging material, a fruit and vegetable package in which fruit and vegetable are packaged in a packaging container containing the fruit and vegetable packaging material, and a method for preserving the freshness of fruit and vegetable using a packaging container containing the fruit and vegetable packaging material.

Fruits and vegetables, such as vegetables and fruits, are stored in packaging containers made of cardboard, polystyrene foam, etc. at production sites, distribution bases, retail stores, etc., and are distributed between production sites and distribution bases, or between distribution bases and retail stores. This storage and distribution process usually requires a certain amount of time, so there is a strong demand for maintaining the freshness of fruits and vegetables in the packaging containers. One method known for maintaining the freshness of fruits and vegetables in packaging containers is to remove the ethylene that fruits and vegetables emit, thereby suppressing the ripening and aging of the fruits and vegetables.

Specifically, as a method for removing ethylene from a case that contains fruits and vegetables and maintaining the freshness of the fruits and vegetables in the case, for example, a method is known in which a printing ink containing a porous fine powder ethylene adsorbent such as zeolite and hinokitiol or a cyclodextrin inclusion complex of hinokitiol is printed on the inner surface of the case for fruits and vegetables (see Patent Document 1). In the method described in Patent Document 1, the ethylene adsorbent is used for the purpose of removing ethylene from the case, and hinokitiol is used for the purpose of inhibiting the growth of microorganisms in the case.

JP 2002-281894 A

However, the method of preserving the freshness of fruits and vegetables by adsorbing ethylene using an ethylene adsorbent as described in Patent Document 1 has the problem that the amount of ethylene adsorbed by the ethylene adsorbent becomes saturated, and the freshness-preserving ability of the case used to package fruits and vegetables can be significantly impaired in a short period of time.
For this reason, there is a demand for a packaging material for fruits and vegetables that can inhibit the progress of ripening and aging of fruits and vegetables caused by the action of ethylene by a method other than the use of ethylene adsorbents.

In view of the above-mentioned current situation, the present invention aims to provide a fruit and vegetable packaging material that can suppress the progress of ripening and aging of fruit and vegetable caused by the action of ethylene over a long period of time without using an ethylene adsorbent, a method for manufacturing the aforementioned fruit and vegetable packaging material, a fruit and vegetable package in which fruit and vegetable are packaged in a packaging container containing the aforementioned fruit and vegetable packaging material, and a method for preserving the freshness of fruit and vegetable using a packaging container containing the fruit and vegetable packaging material.

The inventors conducted extensive research to find a solution to the above-mentioned problems, and discovered that the above-mentioned problems could be solved by providing a coating made of a composition containing a cyclodextrin inclusion complex (A) in which an inhibitor that inhibits the binding of ethylene to the ethylene receptors present in fruits and vegetables is encapsulated in cyclodextrin, and a matrix component (B), or by using a material impregnated with the aforementioned composition as a packaging material for fruits and vegetables, which led to the completion of the present invention.

That is, the present invention provides
(i) A material for packaging fresh produce, comprising:
The material comprises a coating formed on a substrate and made of a composition including a cyclodextrin inclusion complex (A) and a matrix component (B);
A material, in which an inhibitor that inhibits binding of ethylene to an ethylene receptor in fruits and vegetables is included in the cyclodextrin inclusion complex (A),
(ii) A material for packaging fresh produce, comprising:
the material is a fiber material or a porous material impregnated with a composition containing a cyclodextrin inclusion complex (A) and a matrix component (B);
A material, in which an inhibitor that inhibits binding of ethylene to an ethylene receptor in fruits and vegetables is included in the cyclodextrin inclusion complex (A),
(iii) A material for packaging fresh produce, comprising:
A freshness-preserving sheet for fruits and vegetables, the material being enclosed in a packaging container for the fruits and vegetables,
The freshness-preserving sheet has a freshness-preserving layer formed on a base sheet and made of a composition containing a cyclodextrin inclusion complex (A) and a matrix component (B);
A material, in which an inhibitor that inhibits binding of ethylene to an ethylene receptor in fruits and vegetables is included in the cyclodextrin inclusion complex (A),
(iv) The material for packaging fruits and vegetables according to any one of (i) to (iii), wherein the inhibitor is a compound having one or more unsaturated double bonds;
(v) The packaging material for fruits and vegetables according to (iv), wherein the inhibitor is 1-methylcyclopropene.
(vi) The material for packaging fruits and vegetables according to any one of (i) to (v), wherein the matrix component (B) is shellac.
(vii) The material for packaging fruits and vegetables according to any one of (i) to (vi), wherein the content of the cyclodextrin inclusion complex (A) is 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the matrix component (B);
(viii) A method for producing a packaging material for fruits and vegetables according to any one of (i) to (vii),
A method comprising the steps of: forming a coating on a substrate or a substrate sheet using a liquid composition containing a cyclodextrin inclusion complex (A) and a matrix component (B); or impregnating a fiber material or a porous material with the liquid composition and then solidifying the impregnated liquid composition.
(ix) A fruit and vegetable package in which fruit and vegetables are enclosed in a packaging container,
A fruit and vegetable package comprising the fruit and vegetable packaging material according to any one of (i) to (vii) on at least a portion of the inner surface of a packaging container and/or within the packaging container; and (x) a fruit and vegetable package in which fruit and vegetables are enclosed in a packaging container,
A method for preserving the freshness of fruits and vegetables, comprising gradually releasing the inhibitor from a fruit and vegetable packaging material according to any one of (i) to (vii) in a packaging container;
I will provide a.

The present invention provides a fruit and vegetable packaging material that can suppress the progress of ripening and aging of fruit and vegetable caused by the action of ethylene over a long period of time without using an ethylene adsorbent, a method for manufacturing the aforementioned fruit and vegetable packaging material, a fruit and vegetable package in which fruit and vegetable are packaged in a packaging container containing the aforementioned fruit and vegetable packaging material, and a method for preserving the freshness of fruit and vegetable using a packaging container containing the fruit and vegetable packaging material.

FIG. 1 is a graph showing the results of a 1-MCP sustained release test under constant humidity conditions for the fruit and vegetable packaging material obtained in the Examples. FIG. 1 is a graph showing the results of a 1-MCP sustained release test in which the fruit and vegetable packaging material obtained in the Examples was subjected to changes in humidity under constant temperature conditions.

<The first packaging material for fruits and vegetables>
The first packaging material for fruits and vegetables comprises a coating formed on a substrate, the coating being made of a composition containing a cyclodextrin inclusion complex (A) and a matrix component (B).
In the cyclodextrin inclusion complex (A), an inhibitor that inhibits the binding of ethylene to ethylene receptors in fruits and vegetables is included in cyclodextrin.

Since the first fruit and vegetable packaging material holds the cyclodextrin inclusion complex (A) in the coating, the first fruit and vegetable packaging material gradually releases the inhibitor from the cyclodextrin inclusion complex (A).
The inhibitor released from the first fruit and vegetable packaging material binds to the ethylene receptors present in the fruit and vegetable, thereby inhibiting the binding of ethylene to the ethylene receptors present in the fruit and vegetable.
As a result, by constructing at least a portion of the packaging container for packaging fruits and vegetables from the first fruit and vegetable packaging material, it is possible to delay the ripening of the fruits and vegetables in the packaging container due to the action of ethylene, so that the freshness of the fruits and vegetables in the packaging container is maintained for a relatively long period of time.

The fruit and vegetable packaging material may be a material that constitutes the whole or part of a packaging container for the fruit and vegetable. The fruit and vegetable packaging material may also be a material that is enclosed in the packaging container together with the fruit and vegetable.
For example, when the packaging container is a bag, a coating film made of a composition containing the cyclodextrin inclusion complex (A) and the matrix component (B) is formed on at least a part of the inner surface of the bag to provide a bag-shaped first fruit and vegetable packaging material. In this case, the bag-shaped packaging container corresponds to the substrate.
Regarding the bag-shaped first fruit and vegetable packaging material described above, the bag may be changed to a box made of corrugated cardboard, wood, or a resin material such as polystyrene foam.
Alternatively, a small piece of film or sheet can be used as a substrate, and a coating made of a composition containing the cyclodextrin inclusion complex (A) and the matrix component (B) can be formed on the film or sheet to form a first material for packaging fresh produce.
Packaging materials comprising a film or sheet strip as a substrate can be used, for example, by being attached to the inside of a packaging container such as a bag or box.

Below, we will explain the required and optional components of the first fruit and vegetable packaging material.

<Substrate>
The substrate is not particularly limited as long as it can support a coating film made of a composition containing the cyclodextrin inclusion complex (A) and the matrix component (B).
The substrate may be an inorganic material such as glass or a metal plate, or an organic material such as a resin film or sheet, wood, paper, or the like.
The substrate may also be a material in which inorganic materials and/or organic materials are laminated.

Examples of resins that may be used to form the substrate include polyolefins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate and polylactic acid, (meth)acrylic resins such as polymethyl methacrylate, polystyrene, polycarbonate resin, polyamide resin, polyacetal resin, FR-AS resin, FR-ABS resin, AS resin, ABS resin, and fluororesins such as polytetrafluoroethylene and polyvinylidene fluoride.

The size and shape of the substrate are not particularly limited as long as the desired type of fruit or vegetable can be accommodated in a packaging container provided with the fruit or vegetable packaging material. The size of the substrate is appropriately determined in consideration of the size and weight of the fruit or vegetable to be packaged, the size of the coating film determined in consideration of the freshness-preserving effect, and the like.
Preferred examples of the shape of the substrate include a film, a sheet, a bag, a box, etc. The substrate can also be a support member for stably supporting fruits and vegetables in a box, which is typically used in a box-shaped container for packaging fruits and vegetables and has one or more recesses shaped according to the shape of the fruits and vegetables and is formed so that the fruits and vegetables can be placed in the recesses.

The surface of the substrate may be smooth or may have regular or irregular projections and recesses.
For example, when the substrate is a film or sheet having a smooth surface, the fruit and vegetable packaging material obtained by forming the coating can be rolled up compactly into a roll, which is advantageous in terms of distribution and storage of the fruit and vegetable packaging material.
Furthermore, when the surface of the substrate is provided with projections and recesses, the surface area of the substrate is large, so that the area of the coating supported on the substrate can be easily increased.

<Coating>
The coating supported on the substrate comprises a composition comprising a cyclodextrin inclusion complex (A) and a matrix component (B).
In the composition for forming a coating, the content of the cyclodextrin inclusion complex (A) is not particularly limited as long as it does not impair the object of the present invention. The content of the cyclodextrin inclusion complex (A) in the composition for forming a coating is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 0.5 parts by mass or more and 8 parts by mass or less, per 100 parts by mass of the matrix component (B), from the viewpoints of easiness of forming the coating and suppression of the production cost of the material for packaging fruits and vegetables.
In addition, when the content of the cyclodextrin inclusion complex (A) in the composition for forming the coating is within the above range, it is possible to achieve a good effect of preserving the freshness of the finished product and to easily prevent the coating from cracking or chipping or peeling off from the substrate inside a packaging container in which fruits and vegetables are packaged.

The shape of the coating and the size of the coating, such as thickness and area, are not particularly limited as long as the desired freshness-preserving effect is obtained.
The coating may be formed on the substrate as a single continuous area or as multiple discontinuous areas.
In addition, taking into consideration the design of the packaging container, a coating in the shape of letters, numbers, symbols, and various animals, plants, characters, etc. may be formed on the substrate, or a lattice-like, dot-like, or other pattern may be drawn on the substrate using the coating.

The thickness of the coating is, for example, preferably from 1 μm to 5 mm, more preferably from 5 μm to 3 mm, even more preferably from 10 μm to 1 mm, still more preferably from 50 μm to 0.5 mm, and particularly preferably from 100 μm to 0.3 mm.
If the coating is too thin, it may be difficult to obtain the desired freshness-retaining effect, and if the coating is too thick, the coating may be prone to cracking or chipping due to its lack of flexibility, depending on the type of matrix component (B).

[Cyclodextrin inclusion complex (A)]
The cyclodextrin inclusion complex (A) is a complex in which an inhibitor that inhibits the binding of ethylene to ethylene receptors in fruits and vegetables is included in cyclodextrin.
Hereinafter, the inhibitor that inhibits the binding of ethylene to the ethylene receptors in fruits and vegetables will also be referred to simply as "inhibitor".

The method for producing the cyclodextrin inclusion complex (A) is not particularly limited. The cyclodextrin inclusion complex (A) may be produced by a known method. An example of a known method for producing the cyclodextrin inclusion complex (A) is the method described in JP-A-2002-523337.

[Cyclodextrin]
The cyclodextrin is not particularly limited as long as it can include the inhibitor. The size of the cyclodextrin is appropriately selected according to the size of the inhibitor. As the cyclodextrin, α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, etc. can be used.
The cyclodextrin may be a chemically modified cyclodextrin derivative for the purpose of adjusting the dispersibility of the cyclodextrin inclusion complex (A) in the matrix component (B).
Examples of cyclodextrin derivatives include substituted cyclodextrins in which some of the hydrogen atoms in the hydroxyl groups of cyclodextrin are substituted with alkyl groups such as methyl groups, ethyl groups, and n-propyl groups, or hydroxyalkyl groups such as hydroxymethyl groups, hydroxyethyl groups, and hydroxypropyl groups.
For example, when the inhibitor is 1-methylcyclopropene, the cyclodextrin used is preferably α-cyclodextrin.

[Inhibitors]
As described above, the inhibitor binds to the ethylene receptor present in fruits and vegetables, thereby inhibiting the binding of ethylene to the ethylene receptor present in fruits and vegetables.

As an inhibitor, for example, a compound having one or more unsaturated double bonds is preferred.

As the compound having one or more unsaturated double bonds, for example, a compound represented by the following formula (1) is preferable.

In the above formula (1), R ¹ , R ² , R ³ , and R ⁴ each independently represent a hydrogen atom or a group represented by the following formula (1a):
-(L) _n -Z ... (1a)
It is a group selected from the group consisting of groups represented by the following formula:
In formula (1a), n is an integer of 0 to 12. L is a divalent group. Examples of the divalent group suitable for L include groups consisting of one or more atoms selected from the group consisting of H, B, C, N, O, P, S, and Si.
The atoms in the divalent group represented by L are bonded to each other by one or more bonds selected from the group consisting of a single bond, a double bond, and a triple bond.
The divalent group represented by L may be linear, branched, or cyclic, or may have a structure that is a combination of these structures.

The number of heteroatoms other than C and H in each of R ¹ , R ² , R ³ and R ⁴ is preferably 0 to 6.
The total number of atoms other than H in each of R ¹ , R ² , R ³ and R ⁴ is preferably 50 or less.

Z in formula (1a) is a monovalent group. Examples of Z include a hydrogen atom, a halogen atom, a cyano group, a nitro group, a nitroso group, an azide group, a chlorine atom, a bromine atom, an iodine atom, an isocyanato group, an isocyanide group, an isothiocyanato group, a pentafluorothio group, and a cyclic group having 3 to 14 members.

R ¹ , R ² , R ³ , and R ⁴ may be the same or different. R ¹ , R ² , R ³ , and R ⁴ may be directly bonded to the cyclopropene ring, or may be bonded to the cyclopropene ring via a linking group such as a heteroatom-containing group.

The cyclic group represented by Z may have a substituent. Examples of the substituent that the cyclic group may have include an alkyl group, an alkenyl group, an acetylamino group, an alkoxy group, an alkoxyalkoxy group, an alkoxycarbonyl group, an alkoxyimino group, a carboxy group, a halogen atom, a halogenated alkoxy group, a hydroxy group, an alkylsulfonyl group, an alkylthio group, a trialkylsilyl group, and a dialkylamino group.
The cyclic group may have two or more substituents. When a plurality of substituents are present, the plurality of substituents may be the same or different.

Examples of R ¹ , R ² , R ³ , and R ⁴ include an aliphatic hydrocarbyl group (aliphatic hydrocarbon group), an aliphatic hydrocarbyloxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylphosphonato group, an alkylphosphato group, an alkylamino group, an alkylsulfonyl group, an alkylcarbonyloxy group, an alkylaminosulfonyl group, a cycloalkylsulfonyl group, a cycloalkylamino group, a heterocyclyl group, an aryl group, an aryloxy group, a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a nitroso group, an isocyanato group, an isocyanide group, an isothiocyanato group, a pentafluorothio group, a mercapto group, an alkylthio group, and an organosilyl group. These groups may further have a substituent.
Furthermore, R ¹ , R ² , R ³ , and R ⁴ may each have one or more ionizable groups such as a carboxy group, a sulfonic acid group, an amino group, etc. These ionizable groups may exist in the form of a salt such as a sodium salt, a potassium salt, a lithium salt, an ammonium salt, an organic amine salt, a chloride, a bromide, an iodide, or a fluoride.

^R3 and ^R4 may combine together to form one group, such as a carbonyl group, a thiocarbonyl group, an alkylidene group, an organoimino group, and the like.

In formula (1), it is preferable that one or more of R ¹ , R ² , R ³ , and R ⁴ are a hydrogen atom. Also, in formula (1), it is preferable that R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrogen atom or a methyl group.
Furthermore, in formula (1), it is also preferable that R ¹ is an alkyl group having 1 to 4 carbon atoms, and R ² , R ³ , and R ⁴ are hydrogen atoms.
The most preferred compound represented by formula (1) is 1-methylcyclopropene.

Other preferred examples of compounds having one or more unsaturated double bonds include, for example, propylene, 1-butene, cis-2-butene, trans-2-butene, isobutene, trans-cyclooctene, cis-trans-1,3-cyclooctadiene, 2,5-norbornadiene, and diazocyclopentadiene.

Among these inhibitors, 1-methylcyclopropene is preferred because the cyclodextrin inclusion complex (A) is easy to prepare and obtain, has a high inhibitory effect on the binding of ethylene to the ethylene receptors in fruits and vegetables, and has good sustained release performance of the inhibitor from the inclusion complex.

[Matrix Component (B)]
The matrix component (B) is not particularly limited as long as it does not flow in the packaging material and can hold the cyclodextrin inclusion complex (A) in a dispersed state in the matrix component (B).
Suitable examples of the matrix component (B) include various resins and waxes that are solid at room temperature. In addition, a cured product of a curable compound that can be cured by energy such as light or heat or by the action of a curing agent such as an acid or a base can be used as the matrix component (B). In other words, a curable compound that gives the matrix component (B) by curing is a precursor of the matrix component (B).

Examples of the resin as the matrix component (B) include the various synthetic resins exemplified as the resin constituting the substrate, as well as synthetic resins such as shellac, rosin, natural rubber, gelatin, and casein.
Examples of waxes that can be used as the matrix component (B) include carnauba wax, rice wax, candelilla wax, paraffin wax, montan wax, and Fischer-Tropsch wax.
Examples of the precursor of the matrix component (B), which is a curable compound, include epoxy compounds such as bisphenol A type epoxy resins and novolac type epoxy resins, precursors of melamine resins, precursors of alkyd resins, precursors of urethane resins, and various (meth)acrylic monomers.
The curable compound is used, if necessary, together with a curing agent, a polymerization initiator, etc. according to the type of the curable compound.

Among the matrix components (B) described above, shellac is preferred because it is derived from a natural product, is unlikely to cause health damage to humans if the matrix component (B) adheres to fruits or vegetables and is mistakenly eaten, is easy to process to form a coating, and has good sustained release properties of the inhibitor from the coating.

The coating and the composition used to form the coating may contain various additives within the scope of the present invention, such as plasticizers, surfactants, antifoaming agents, antioxidants, ultraviolet absorbers, and colorants.
Furthermore, the coating and the composition used to form the coating may contain an adsorbent capable of adsorbing ethylene, such as silica, zeolite, or activated carbon, in order to further enhance the freshness-preserving effect.

<Method of forming coating>
The method for forming the coating is not particularly limited. For example, a liquid composition containing the cyclodextrin inclusion complex (A) and the matrix component (B) or a precursor of the matrix component (B) is applied onto a substrate, and the applied film is then solidified by means of drying, cooling, heating, exposure, or the like, to form a coating.
More specifically, when the liquid composition contains a solvent, the coating is dried to form a coating. When the liquid composition is a melt containing wax or a low-melting resin, the coating is cooled and solidified to form a coating. When the liquid composition contains a precursor of the matrix component (B), the coating is heated or exposed to light to form a coating.

The method for applying the liquid composition onto the substrate to form the coating is not particularly limited, and examples of the application method include roll coating, curtain flow coating, dip coating, spray coating, and slit die coating.
When forming a coating in the form of letters or a pattern, the coating may be formed by applying a printing method such as inkjet printing or screen printing.

The liquid composition containing the cyclodextrin inclusion complex (A) and the matrix component (B) or the precursor of the matrix component (B) may contain a solvent for the purpose of adjusting the viscosity of the liquid composition. The type of the solvent is not particularly limited as long as it does not have an adverse effect such as causing the inhibitor to be rapidly released from the cyclodextrin inclusion complex (A). The type of the solvent is appropriately selected in consideration of the solubility of the matrix component (B) or the precursor of the matrix component (B).
For example, when the matrix component (B) is shellac, it is preferable to use, as the solvent, an alcohol such as methanol or ethanol, which easily dissolves shellac.

The composition containing the cyclodextrin inclusion complex (A) and the matrix component (B) may be formed into a film by a known film-forming method, and the resulting film may then be laminated onto a substrate as a coating. When laminating the coating onto the substrate, a known adhesive or bonding agent may be used to form an adhesive layer or bonding layer between the substrate and the coating.

In addition, if the film can be stretched, the film containing the cyclodextrin inclusion complex (A) may be stretched. By performing stretching, it may be possible to adjust the sustained release of the inhibitor from the coating made of the film.

In this manner, a first fruit and vegetable packaging material is obtained in which a coating made of a composition containing a cyclodextrin inclusion complex (A) and a matrix component (B) is supported on a substrate.

In the first packaging material for fruits and vegetables, the surface of the coating may be covered with a breathable film or the like for the purpose of controlling the sustained release of the inhibitor from the coating. By appropriately changing the breathability of the breathable film, the sustained release of the inhibitor from the coating can be controlled.
The first fruit and vegetable packaging material may be enclosed in a bag made of the breathable film for the purpose of controlling the sustained release of the inhibitor from the coating.

<Second fruit and vegetable packaging material>
The second packaging material for fruits and vegetables is a material obtained by impregnating a fibrous material or a porous material with a composition containing a cyclodextrin inclusion complex (A) and a matrix component (B).
The composition containing the cyclodextrin inclusion complex (A) and the matrix component (B) is as described above for the first packaging material for fruits and vegetables.

The shape of the second fruit and vegetable packaging material is not particularly limited, and examples of the shape of the second fruit and vegetable packaging material include a bag shape, a box shape, a sheet shape, a thread shape, a string shape, and the like.
For example, when the second fruit and vegetable packaging material is manufactured using paper as the fibrous material, the fruit and vegetable may be packaged by wrapping the fruit and vegetable in paper impregnated with a composition comprising the cyclodextrin inclusion complex (A) and the matrix component (B).

The fiber material is not particularly limited as long as it can be impregnated with a composition containing the cyclodextrin inclusion complex (A) and the matrix component (B).
The form of the fiber material is not particularly limited, and examples of the fiber material include paper, fabric, knitted material, thread, and string.
The fabric may be a woven fabric or a nonwoven fabric. The weaving method of the woven fabric is not particularly limited.
Examples of fibers that make up the textile material include plant fibers such as wood pulp, cotton, hemp, and coconut fiber; animal fibers such as animal hair such as wool and silk thread; synthetic fibers made of resin such as nylon fiber, polyester fiber, and acrylic fiber; and inorganic fibers such as glass fiber, carbon fiber, and metal fiber.

The porous material is not particularly limited as long as it can be impregnated with a composition containing the cyclodextrin inclusion complex (A) and the matrix component (B).
The shape of the porous material is not particularly limited. Examples of the shape of the porous material include a sheet shape, a plate shape, a box shape, and the like. The second fruit and vegetable packaging material manufactured using a sheet-shaped or box-shaped porous material can be used by being enclosed together with the fruit and vegetable in a packaging container such as a box or a bag.

The porous material may be made of an organic material or an inorganic material. Examples of porous materials made of organic materials include porous bodies made of various resins and porous bodies derived from natural products such as cork and sponge. Examples of porous bodies made of inorganic materials include pumice, porous glass, and porous ceramics.

The above-mentioned fibrous material or porous material is impregnated with a liquid composition containing the cyclodextrin inclusion complex (A) and the matrix component (B) or a precursor of the matrix component (B), and the liquid composition that has permeated the fibrous material or porous material is then solidified by means of drying, cooling, heating, exposure to light, or the like, to obtain a second material for packaging fresh produce.
The method for impregnating the fibrous material or porous material with the liquid composition is not particularly limited. Examples of the impregnation method include a method in which the liquid composition is sprayed or spread on the surface of the fibrous material or porous material and then the liquid composition is allowed to penetrate into the fibrous material or porous material, and a method in which the fibrous material or porous material is immersed in the liquid composition.
From the viewpoint of ease of operation, the impregnation method is preferably a method in which a fiber material or a porous material is immersed in a liquid composition.

In the second fruit and vegetable packaging material, the surface of the fruit and vegetable packaging material may be covered with a breathable film or the like for the purpose of controlling the sustained release of the inhibitor. By appropriately changing the breathability of the breathable film, the sustained release of the inhibitor can be controlled.
The second fruit and vegetable packaging material may be enclosed in a bag made of the breathable film for the purpose of controlling the sustained release of the inhibitor.

<The third type of packaging material for fruits and vegetables>
The third packaging material for fruits and vegetables is a sheet for preserving the freshness of fruits and vegetables, which is enclosed in a packaging container for fruits and vegetables.
The third freshness-preserving sheet as a packaging material for fruits and vegetables comprises a base sheet and a freshness-preserving layer formed on the base sheet and comprising a composition containing a cyclodextrin inclusion complex (A) and a matrix component (B).
The composition containing the cyclodextrin inclusion complex (A) and the matrix component (B) is as described above for the first packaging material for fruits and vegetables.

Examples of materials for the base sheet include the same materials as those for the base material described for the first fruit and vegetable packaging material.
As the base sheet, a paper sheet or a resin sheet is preferable because they are easily available and can be processed.

The third fruit and vegetable packaging material can be manufactured in the same manner as the first fruit and vegetable packaging material, except that a base sheet is used as the base material.

The third packaging material for fruits and vegetables can be used by sealing it inside the packaging container in which the fruits and vegetables are packaged, similar to small pieces of oxygen absorbers and ethanol volatilizers that are widely used for the purposes of preserving the freshness and preserving food.

<Fruit and vegetable packaging>
In fruit and vegetable packages, fruit and vegetables are enclosed in a packaging container.
The packaging container in which the fruit or vegetable is enclosed includes a material for packaging the fruit or vegetable on at least a portion of its inner surface and/or within the packaging container.
Although a single type of fruit or vegetable is often enclosed in a packaging container, two or more types of fruit or vegetable may be enclosed in the same packaging container.

The fruits and vegetables to be enclosed in the packaging container are not particularly limited. In the present application, the fruits and vegetables include flowers in addition to vegetables and fruits.
When the fruit or vegetable is a vegetable, the vegetable may be any of leafy vegetables, root vegetables, and fruit vegetables. Examples of vegetables include cabbage, Chinese cabbage, Japanese mustard spinach, mizuna, mustard greens, kale, watercress, bok choy, broccoli, cauliflower, radish sprouts, arugula, daikon, turnip, horseradish, celery (white celery), mitsuba, coriander (coriander), parsley, Italian parsley, Japanese parsley, chervil, fennel, dill, carrot, spinach, Swiss chard, okahijiki, amaranth, table bean, and the like. Examples of suitable herbs include lettuce, chrysanthemum, endive, chicory, mugwort, butterbur, Japanese silverleaf, estragon, burdock, Jerusalem artichoke, black gram (bean sprouts), soybeans, mung beans, lentils, chickpeas, shiso, perilla, basil, mint, oregano, lavender, rosemary, lemon balm, sage, marjoram, thyme, green onions, chives, Chinese chives, wild boar, barley (young barley leaves), wheat (young wheat leaves), corn, mulukhiyah, and asparagus.

When the fruit or vegetable to be enclosed in the packaging container is fruit, climatic fruits that generate ethylene themselves during the ripening process are particularly preferred, since the freshness-preserving effect of the fruit or vegetable packaging material is significant.
Examples of climatic fruits include apples, bananas, tomatoes, melons, pears, mangoes, papayas, persimmons, kiwifruit, cherimoyas, avocados, guavas, plantains, plums, peaches, passion fruit, apricots, breadfruit, jackfruit, pawpaws, durians, feijoas, and Indian jujubes.

Non-climate fruits are also suitable for use as the produce enclosed within the packaging container.
Examples of non-climate fruits include grapes, citrus fruits (mandarins, oranges, grapefruit, lemons, limes, etc.), pineapple, cherries, strawberries, lychees, blackberries, blueberries, cranberries, raspberries, pomegranates, loquats, dragon fruit, star fruit, rambutan, and jujubes.

The shape of the packaging container is not particularly limited. The packaging container may be a bag or a box.

<How to keep fruits and vegetables fresh>
The method for preserving the freshness of fruits and vegetables is a method for preserving the freshness of fruits and vegetables by gradually releasing an inhibitor from the first to third fruits and vegetables packaging materials described above in the above-mentioned fruit and vegetable packaging body.
In this freshness-preserving method, the concentration of the inhibitor in the fruit and vegetable package can be controlled by adjusting the total amount of cyclodextrin inclusion complex (A) contained in the fruit and vegetable packaging material or by controlling the environment in which the fruit and vegetable package is placed.
Typically, increasing the temperature of the environment will increase the concentration of inhibitors within the produce package, and increasing the humidity of the environment will increase the concentration of inhibitors within the produce package.

The concentration of the inhibitor in the atmosphere inside the fruit and vegetable package is not particularly limited as long as it does not impair the object of the present invention.
The concentration of the inhibitor in the atmosphere inside the fruit and vegetable package is preferably 0.1 ppm by mass or more, more preferably 0.5 ppm by mass or more, and particularly preferably 1 ppm by mass or more, as the concentration three days after the fruit and vegetable are sealed in the packaging container.
The concentration of the inhibitor in the atmosphere inside the fruit and vegetable package, measured three days after the fruit and vegetable are sealed in the packaging container, may be 20 ppm by mass or more, or 30 ppm by mass or more, but a concentration of 10 ppm by mass or more is sufficient to inhibit the binding of ethylene to the ethylene receptor.

It is also necessary to reduce the concentration of inhibitors contained inside the processed fruit and vegetable packaging to a level that is undetectable at the time of consumption in Japan, and processing conditions that result in a concentration of the ingredient inside the fruit and vegetable packaging of 100 mass ppm or more are undesirable from an economic standpoint.

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

Example 1
A shellac solution was prepared by dissolving 6 g of shellac powder (manufactured by Nippon Shellac Kogyo Kabushiki Kaisha) in 50 mL of ethanol, and then 0.5 mL of the shellac solution was mixed with 30 mg of an α-cyclodextrin inclusion complex of 1-methylcyclopentene (1-MCP) in a 15 mL capped vial to obtain a liquid composition for forming a coating film.
The obtained liquid composition was applied onto a 10 cm square piece of paper using a roller. After application, the applied film was dried to remove the ethanol, and a material for packaging fruits and vegetables comprising a film of shellac and an α-cyclodextrin inclusion complex of 1-MCP on the paper was obtained.

<1-MCP sustained release test under constant humidity conditions>
The obtained fruit and vegetable packaging material was placed in a polystyrene box measuring 22 cm x 18 cm x 17 cm, and a 1-MCP sustained release test was conducted in which the 1-MCP concentration in the internal space was periodically measured by gas chromatography. The 1-MCP concentration was measured every day (24 hours) from 1 day to 30 days after the fruit and vegetable packaging material was sealed in the box. The 1-MCP sustained release test was conducted by storing the fruit and vegetable packaging material at 4°C for 15 days and then at 30°C for 15 days.
The results of the sustained release test are shown in the graph of FIG.

<1-MCP sustained release test with changing humidity under constant temperature conditions>
The obtained fruit and vegetable packaging material was placed in a polystyrene box measuring 15 cm x 24 cm x 18 cm, and a 1-MCP sustained release test was performed in which the 1-MCP concentration in the internal space was periodically measured by gas chromatography under conditions of a temperature of 30°C and relative humidity of 85%, 75%, 55%, and 40%. The 1-MCP concentration was measured every day (24 hours) from 1 day to 25 days after the fruit and vegetable packaging material was sealed in the box.
The results of the sustained release test are shown in the graph of FIG.

Example 2
A packaging material for fruits and vegetables was prepared and a 1-MCP sustained release test was performed under constant humidity conditions in the same manner as in Example 1, except that the amount of α-cyclodextrin inclusion complex of 1-methylcyclopentene (1-MCP) placed in the vial was changed to 50 mg.
The results of the sustained release test are shown in the graph of FIG.

Example 3
A packaging material for fruits and vegetables was prepared and a 1-MCP sustained release test was conducted under constant humidity conditions in the same manner as in Example 1, except that 20 mg of silica gel powder was charged into a vial together with the α-cyclodextrin inclusion complex of 1-methylcyclopentene (1-MCP).
The results of the sustained release test are shown in the graph of FIG.

Example 4
A packaging material for fruits and vegetables was prepared and a 1-MCP sustained release test was carried out under constant humidity conditions in the same manner as in Example 1, except that the amount of shellac solution charged in the vial was changed to 0.3 mL.
The results of the sustained release test are shown in the graph of FIG.

The graph in FIG. 1 shows that 1-MCP was satisfactorily sustained-released from the fruit and vegetable packaging materials of all Examples.
Furthermore, from the graph in FIG. 1, it can be seen that the higher the temperature, the greater the amount of 1-MCP released from the fruit and vegetable packaging material.

The graph in Figure 2 shows that the higher the humidity of the atmosphere surrounding the fruit and vegetable packaging material, the more likely 1-MCP is to be released from the fruit and vegetable packaging material.

The inhibition of the loss of freshness of fruits and vegetables due to the action of ethylene by a compound such as 1-MCP that binds to the ethylene receptor of a plant is known from documents such as Sitler, E. C.; Serek, M., Inhibitors of ethylene responses in plants at the receptor level: recent developments., Physiologia Plantarum. 1997, 100, 577-582.
Therefore, according to the above embodiment, it can be seen that the fruit and vegetable packaging material described above has the effect of preserving the freshness of the fruit and vegetables.

Claims (7)

A packaging material for fruits and vegetables, comprising:
The material has a coating film formed on a substrate and made of a composition containing a cyclodextrin inclusion complex (A) and a matrix component (B);
In the cyclodextrin inclusion complex (A), an inhibitor that inhibits binding of ethylene to an ethylene receptor in the fruit or vegetable is included in the cyclodextrin,
The material, wherein the matrix component (B) is shellac. A packaging material for fruits and vegetables, comprising:
the material is a fiber material or a porous material impregnated with a composition containing a cyclodextrin inclusion complex (A) and a matrix component (B);
In the cyclodextrin inclusion complex (A), an inhibitor that inhibits binding of ethylene to an ethylene receptor in the fruit or vegetable is included in the cyclodextrin,
The material, wherein the matrix component (B) is shellac. A packaging material for fruits and vegetables, comprising:
The material is a sheet for preserving the freshness of fruits and vegetables, which is enclosed in a packaging container for fruits and vegetables and used,
The freshness-preserving sheet has a freshness-preserving layer formed on a base sheet and comprising a composition containing a cyclodextrin inclusion complex (A) and a matrix component (B);
In the cyclodextrin inclusion complex (A), an inhibitor that inhibits binding of ethylene to an ethylene receptor in the fruit or vegetable is included in the cyclodextrin,
The material, wherein the matrix component (B) is shellac. The packaging material for fruits and vegetables according to any one of claims 1 to 3, wherein the inhibitor is a compound having one or more unsaturated double bonds. The fruit and vegetable packaging material according to claim 4, wherein the inhibitor is 1-methylcyclopropene. A fruit and vegetable package in which fruit and vegetables are enclosed in a packaging container,
A fruit and vegetable package comprising the fruit and vegetable packaging material according to any one of claims 1 to 5 on at least a portion of the inner surface of the packaging container and/or within the packaging container. In a fruit and vegetable package in which fruit and vegetables are sealed in a packaging container,
A method for preserving the freshness of fruits and vegetables, comprising slowly releasing the inhibitor from the fruit and vegetable packaging material according to any one of claims 1 to 5 in the packaging container.

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