JP2023150881A - Freshness holding bag, package, and freshness holding method - Google Patents

Abstract

To provide a technique capable of effectively holding freshness of garden stuff.SOLUTION: A freshness holding bag 100 comprises: a bag main body 10 which is formed in a cylindrical shape by sticking both ends of a synthetic resin film, then closing one end, and stores garden stuff; and a back lining part 20. The back lining part 20 comprises a communication region 30 for communicating the outside and inside of the bag main body 10, and satisfies the following condition a. (Condition a) When a dyeing solution including an organic solvent and mineral oil is brought into contact with an external part end part of the bag main body 10 of the communication region 30, and when measuring a period (t seconds) required for the dyeing solution to reach an inside part end part of the bag main body 10 of the communication region 30 from the outside part end part of the bag main body 10 of the communication region 30 by capillarity, t is 0.6 to 3.SELECTED DRAWING: Figure 1

Description

The present invention relates to a freshness preservation bag, a package, and a freshness preservation method.

Vegetables, fruits, and other fruits and vegetables continue to have a respiratory effect even after they are harvested. Therefore, during storage, distribution, or preservation after harvesting, the fruits and vegetables consume energy through their own respiration, causing deterioration in freshness. Therefore, as a method for maintaining the freshness of fruits and vegetables, a method is known in which the respiration of fruits and vegetables is moderately suppressed to maintain freshness. Such packaging bags used to maintain the freshness of fruits and vegetables are known as MA (Modified Atmosphere) packaging.

For example, Patent Document 1 discloses forming through holes in a packaging bag made of a synthetic resin film. Further, Patent Document 2 discloses that an unbonded part is provided in at least a part of the heat-sealed part of a bag made of a non-porous film, and the fruits and vegetables in the bag are allowed to breathe through the minute voids created in the unbonded part. There is.

Japanese Patent Application Publication No. 6-46749 Japanese Patent Application Publication No. 2000-59

However, in the conventional packaging bags described in Patent Documents 1 and 2, there is room for improvement in maintaining the freshness of fruits and vegetables at a high level.

Normally, the amount of gas and water vapor passing through the packaging bag tends to vary depending on the size of the holes provided in the packaging bag, the total opening area, etc., and the freshness of fruits and vegetables may be affected by this. In order to stably maintain the freshness of fruits and vegetables, the inventors of the present invention focused on the back part of the packaging bag, and when providing a communication path in the back part that allows gas and water vapor to pass through, the inventor discovered that the communication path It has been found that it is effective to configure the device so as to satisfy a predetermined index.

That is, according to the present invention, the following freshness preservation bag, package, and freshness preservation method are provided.

[1] A freshness-preserving bag comprising a bag body for accommodating fruits and vegetables obtained by pasting both ends of a synthetic resin film together to form a cylinder and closing one side, and a back patch,
The back sticking part has a communication area that communicates the outside and the inside of the bag main body,
A freshness preservation bag that satisfies the following condition a.
(Condition a) A dyeing solution containing an organic solvent and mineral oil is brought into contact with the outer end of the bag body in the communication region, and the dyeing solution is caused by capillary action to spread to the outer end of the bag body in the communication region. When measuring the time (t seconds) required to reach the inner end of the bag body in the communication area from the end, t is 0.6 to 3.
[2] In the freshness preservation bag described in [1],
A freshness-preserving bag, wherein the width of the spine is 5 to 700 mm.
[3] In the freshness preservation bag described in [1] or [2],
The freshness-preserving bag, wherein the number of communication areas is 10 to 250 per 10 cm ² of area of the spine part in plan view.
[4] In the freshness preservation bag described in any one of [1] to [3],
The freshness-preserving bag, wherein the distance between the adjacent communication areas at the end of the back pasted portion on the bag body side is 1 to 100 mm.
[5] In the freshness preservation bag described in any one of [1] to [4],
A freshness-preserving bag, wherein the communication region has a width of 0.2 to 7 mm in plan view.
[6] In the freshness preservation bag described in any one of [1] to [5],
A freshness-preserving bag, wherein the communication area has a path length of 10 to 50 mm.
[7] In the freshness preservation bag described in any one of [1] to [6],
The freshness-preserving bag has a geometric pattern formed by alternately and repeatedly arranging the communicating areas and the joining areas in the length direction of the back sticking part.
[8] In the freshness preservation bag described in [7],
The freshness preserving bag, wherein the pattern constituent unit of the geometric pattern includes one or more selected from a straight line, a rectangle, a circle, and a curved line.
[9] In the freshness preservation bag described in any one of [1] to [8],
The bag is a freshness-preserving bag, wherein the spine part has a band-shaped non-sealed part extending from the upper end to the lower end of the back part on the side opposite to the bag main body.
[10] In the freshness preservation bag described in [9],
A freshness-preserving bag, wherein the band-shaped non-sealed portion has a width of 1 to 40 mm.
[11] In the freshness preservation bag according to any one of [1] to [10],
The freshness preserving bag, wherein the synthetic resin film has a thickness of 20 to 200 μm.
[12] In the freshness preservation bag according to any one of [1] to [11],
The synthetic resin film is a film containing one or more selected from polyethylene, ethylene copolymer, polypropylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, and polyamide resin, or the film contains the film. A freshness preservation bag made of multilayer film.
[13] A package containing fruits and vegetables in the bag body of the freshness-preserving bag according to any one of [1] to [12].
[14] A method for preserving freshness, comprising storing fruits and vegetables in the bag body of the freshness-preserving bag according to any one of [1] to [12], and preserving the fruits and vegetables.

According to the present invention, a technique that can effectively maintain the freshness of fruits and vegetables can be provided.

FIG. 1 is a perspective view schematically showing a freshness-preserving packaging bag of the present embodiment. FIG. 3 is a perspective view schematically showing a modification of the freshness-preserving packaging bag of the present embodiment. It is a schematic diagram which expanded the spine part of the freshness preservation packaging bag of this embodiment. FIG. 2 is a perspective view schematically showing the manufacturing procedure of the freshness-preserving packaging bag of the present embodiment.

In the present specification, the notation "a to b" in the explanation of numerical ranges represents a range from a to b, unless otherwise specified. For example, "1 to 5% by mass" means "1 to 5% by mass". Further, the lower limit value and upper limit value of the numerical range can be arbitrarily combined with the lower limit value and upper limit value of other numerical ranges, respectively.
Each component and material illustrated in this specification may be used alone or in combination of two or more, unless otherwise specified.

In this specification, when the length direction of the back of the freshness preserving bag is parallel to the direction of gravity, "upper" means the direction where the opening of the freshness preserving bag is, and "lower" means the direction in which the freshness preserving bag has an opening. Intended to be on the opposite side from the opening of the bag, that is, the direction where the bottom of the freshness preservation bag is.
In addition, in this specification, the freshness preserving bag is also referred to as a packaging bag.

Embodiments of the present invention will be described below.

<Freshness preservation bag>
FIG. 1 is a schematic perspective view showing one aspect of a freshness preserving bag 100 of this embodiment.
As shown in FIG. 1, the freshness retaining bag 100 consists of a bag body 10 that stores fruits and vegetables obtained by pasting both ends of a synthetic resin film together to form a cylinder and closing one opening, and a back pasting part 20. , and has an opening at the top for putting in and taking out fruits and vegetables. The bag body 10 is provided with a seal portion 11 at the lower end, thereby forming the bottom of the bag. The back pasting part 20 is formed by pasting together both ends of a synthetic resin film, and has an end part 21 that joins to the bag body 10 and an end part 22 that is opposite to the bag body 10, and has a seal part at the lower end. 25.

In this embodiment, the back sticking part 20 has a communication area 30 that communicates the outside and the inside of the bag body 10, and is configured to satisfy the following condition a.
(Condition a) A dyeing solution containing an organic solvent and mineral oil is brought into contact with the outer end of the bag body 10 in the communication region 30, and the dyeing solution is applied to the outer end of the bag body 10 in the communication region 30 due to capillary action. When measuring the time (t seconds) required to reach the inner end of the bag body 10 in the communication region 30 from the end, t is 0.6 to 3.

Thereby, the amount of oxygen, carbon dioxide gas, and water vapor flowing in and out of the freshness preservation bag 100 are highly controlled, and a freshness preservation effect can be stably obtained.
In addition, since the freshness preservation bag 100 has the communication region 30 in the spine part 20, even if fruits and vegetables move within the bag body 10 or external stress is applied to the bag body 10, the spine part 20 Since the flow of gas and water vapor in the communication channel 30 is suppressed, the amount of oxygen and carbon dioxide gases and the amount of water vapor in the bag body 10 can be controlled more stably.

In condition a, the dyeing solution is preferably one that easily wets the synthetic resin film and easily causes capillary action. The dyeing solution contains an organic solvent and mineral oil, and the organic solvent can be selected as appropriate depending on the purpose. For example, high boiling esters, glycol ethers, methanol, ethanol, 1-propanol, 2-propanol, etc. , acetone, tetrahydrofuran, ethyl acetate and the like. Examples of the mineral oil include insulating oil, heavy oil, light oil, kerosene, gasoline, naphtha, machine oil, and cutting oil.
Specifically, the dyeing solution preferably contains 25 to 35% by mass of high-boiling ester, 5 to 10% by mass of glycol ethers, and 30 to 40% by mass of mineral oil.
Further, in order to make it easier to visually see how the dyeing liquid moves through the communication region 30, the dyeing liquid is preferably colored with a dye/pigment, and more preferably contains an azo oil-soluble dye. The content of the azo oil-soluble dye is preferably 1 to 5% by mass.
As the staining solution, commercially available products may be used, such as "Ageless Seal Check (Aerosol)" (manufactured by Taseto Co., Ltd.).

In condition a, the time (t) starts when the staining liquid contacts the outer end of the bag body 10 in the communication area 30 and at least a part of it is sucked up, and starts when the staining solution contacts the outer end of the bag body 10 in the communication area 30. The time required for the staining solution to reach the side end (in other words, the end 21 of the back pasted part 20 on the bag main body 10 side) earliest is measured.
For example, measurements can be made at multiple locations and the average value can be taken as the time (t).

In this embodiment, in order to utilize the capillary phenomenon of the staining solution, the ends of the communication regions 30 are brought into contact perpendicularly to the staining solution surface. It is desirable that the communication region 30 not be submerged in water.
In addition, when the back sticking part 20 is provided with the below-mentioned non-sealing area 35 (FIG. 2), it is preferable to cut the non-sealing area 35 and expose the end of the communication channel 30 to the cut surface.

Hereinafter, other configurations of the freshness preserving bag 100 of this embodiment will be explained.

[Synthetic resin film]
The freshness preservation bag 100 of this embodiment is made of a synthetic resin film. Thereby, it is possible to obtain an MA effect while obtaining appropriate respiration of fruits and vegetables. In addition, it suppresses odor and makes it easier to maintain a good appearance of fruits and vegetables.

The synthetic resin film is preferably transparent or translucent, and more preferably transparent, from the viewpoint of allowing fruits and vegetables to be viewed from the outside. Further, it may be printed for the purpose of identifying fruits and vegetables.

The resin constituting the synthetic resin film is not particularly limited as long as it can be used for packaging fruits and vegetables, and any known resin can be used.
For example, synthetic resin films are made of polyethylene, ethylene copolymers such as ethylene/vinyl alcohol copolymers, polyester resins such as polypropylene, polyvinyl chloride, polystyrene, (meth)acrylic resins, and polylactic acid, and polyamides such as nylon. It is preferable that the resin is one or more selected from the group consisting of resins.
Among these, polyethylene, ethylene/vinyl alcohol copolymer, polypropylene, polylactic acid, and nylon are preferred from the viewpoint of appropriately controlling water vapor permeability and oxygen permeability, which will be described later.

The method of forming the synthetic resin film is not particularly limited, but methods such as extrusion, inflation, and calendering are used. When molding a resin film, additives such as an antifogging agent may be kneaded as needed, or one or more types of resin may be blended.
Further, the synthetic resin film may be subjected to stretching treatment, annealing, etc., and may also be provided with a sealant layer to impart heat sealability.

The thickness of the synthetic resin film is preferably 20 to 200 μm, more preferably 20 to 100 μm, even more preferably 20 to 50 μm.

The synthetic resin film may be used as a single layer or as a multilayer structure of two or more layers.

[Back pasting part 20]
In this embodiment, the back bonding portion 20 is a sealing area obtained by bonding both ends of the synthetic resin film described above. The back sticking part 20 is formed to protrude from the bag main body 10 across both adhered ends. That is, the back sticking part 20 protrudes from the upper end to the lower end of the freshness preserving bag 100. The protruding spine part 20 may be used in such a manner that it falls down along the bag body 10 and covers the bag body 10.

The width of the spine part 20 is adjusted appropriately depending on the size of the freshness-keeping bag 100, but is preferably 5 to 700 mm, more preferably 20 to 650 mm, and even more preferably 100 to 600 mm. A particularly preferred range is 200 to 600 mm. By setting the width of the spine part 20 to be equal to or greater than the above lower limit, the sealing strength for maintaining the shape of the freshness preservation bag 100 can be improved while providing the communication region 30. By setting the width of the spine part 20 to be equal to or less than the above upper limit value, it becomes easier to maintain the freshness retaining effect.

The back sticking part 20 has a bonding area 31 and a communication area 31 consisting of a non-bonding area. In this embodiment, the bonding region 31 is provided from the end portion 21 to the end portion 22 of the back sticking portion 20 .

However, the bonding area 31 is not limited to being provided from the end 21 to the end 22 of the back sticking part 20.
For example, as shown in FIG. 2, the back sticking part 20 may have a band-shaped non-sealing part 35 extending from the upper end to the lower end of the freshness preservation bag 100 at the end 22 on the opposite side from the bag main body 10. .
The band-shaped non-sealed portion 35 corresponds to the end portion of the synthetic resin film that was not bonded when the ends of the synthetic resin film were bonded together to form a cylinder. Further, the lower end of the non-sealed portion 35 may be bonded together to form the sealed portion 25.
The width of the band-shaped non-sealed portion 35 is preferably 1 to 20 mm, more preferably 3 to 10 mm.
In the freshness preservation bag 101 as well, the freshness preservation effect can be obtained by satisfying condition a. In this case, it is preferable to cut the non-sealed area 35 in advance to expose the end of the communication area 30.

[Communication area 30]
The communication area 30 of this embodiment is provided in the back pasting part 20, and is an area that allows communication between the bag body 10 and the outside. Thereby, the amount of oxygen gas, carbon dioxide gas, and water vapor flowing in and out of the bag body 10 is controlled, making it easier to maintain the freshness of fruits and vegetables. The communication region 30 can be formed by providing a non-bonding region when bonding the back bonding portion 20 together.
Specifically, the communication area 30 includes the following examples.

In this embodiment, the communication region 30 is provided from the end portion 21 to the end portion 22 of the back sticking portion 20, and forms a single flow path.
When the communication region 30 is a single channel, the path length thereof is preferably 10 to 50 mm, more preferably 15 to 45 mm, and even more preferably 20 to 40 mm.
Note that the path length is the average length when tracing the center of the communication area 30.

However, the communication region 30 is not limited to being connected through a single channel, and may be a branched channel.
When the communication region 30 is a branched flow path, the length of the path is preferably 10 to 50 mm, more preferably 15 to 45 mm, and 20 to 40 mm, with the intention of the shortest path. is even more preferable.

Further, as shown in FIGS. 1 and 3(a), the communication region 30 of this embodiment is a non-linear, S-shaped channel, and is formed from the end 21 to the end 22. It is set so that the width spreads over the whole area.
In other words, the communication region 30 of this embodiment is a flow path having a non-uniform width from one end 21 of the backing part 20 to the other end 22 in a plan view.
The average width of the communication region 30 is preferably 0.2 to 7 mm, more preferably 0.3 to 6 mm.

However, the communication channel 20 is not limited to being non-linear, and may be linear, non-linear, or a combination thereof.
For example, as shown in FIG. 3(b), the communication region 31 may be a single straight channel, and may be provided so that the width increases from the end portion 21 to the end portion 22.
Further, for example, the width of the communication region 30 may be a channel of equal width, a parallel straight line, or a non-linear channel.

Further, as shown in FIGS. 1 and 3(a) and 3(b), two communication areas 30 of this embodiment are provided in the back sticking part 20. Further, it is preferable that the communication areas 30 are provided at equal intervals, and the intervals (pitch p1, p2) are determined at the joint side of the back sticking part 20 with the bag body 10 (the end 21 of the back sticking part 20). , preferably 1 to 100 mm, more preferably 2 to 50 mm, and even more preferably 3 to 30 mm.

However, the number of communication areas 30 is not limited to this. The number of communicating regions 30 is preferably plural, and may be 3 to 200, or 50 to 100 in the back sticking portion 20.
In this case, the number of the plurality of communication regions 30 is preferably 10 to 250, more preferably 15 to 200, and more preferably 20 to 150 per 10 cm ² of area of the back sticking part 20 in plan view. It is more preferable that

As shown in FIG. 1 and FIGS. 3(a) and 3(b), in the communication region 30 of this embodiment, channels having the same shape, same size, and length are repeatedly arranged.

However, the shape, size, length, etc. of the plurality of communication regions 30 may be different from each other, and as shown in FIG. 3(c), the plurality of communication regions 30 are combined to form one repeating unit. You may do so.
In this case, the number of at least one repeating unit is preferably 10 to 250, more preferably 15 to 200, and more preferably 20 to 150 per 10 cm ² of area of the backing part 20 in plan view. It is even more preferable.
Moreover, it is preferable that at least one repeating unit is provided at equal intervals, and the interval (pitch p3) is determined at the joining side of the back sticking part 20 with the bag body 10 (the end 21 of the back sticking part 20). , preferably 1 to 100 mm, more preferably 2 to 50 mm, and even more preferably 3 to 30 mm.

Further, the plurality of communication regions 30 may be arranged alternately and repeatedly with the joint region 31 to form a geometric pattern on the back sticking portion 20. That is, the bonding areas 31 and the communication areas 30 are regularly arranged in the longitudinal direction of the back sticking part 20.
The pattern constituent units of the geometric pattern include one or more selected from straight lines, rectangles, circles, and curves.

(Formation method)
For example, as shown in FIG. 4(a), the communication region 30 can be formed by overlapping both ends of the synthetic resin film so that the inner surfaces of the bag body 10 face each other, and then, as shown in FIG. As shown in b), the area except the communication area 30 is bonded. Examples of the adhesion method include known methods such as thermal fusion by heating and fusion by ultrasonic waves.

[Bag body 10]
In this embodiment, the bag main body 10 stores fruits and vegetables obtained by pasting both ends of the synthetic resin film together to form a cylinder, and forming a bottom part with a sealing part 11 made by pasting one side of the cylinder. This is the area of the freshness preservation bag 100 excluding the spine part 20.

The oxygen permeability of the synthetic resin film constituting the bag body 10 at 23° C. and 60% RH is preferably 200 cc/(m ² ·day · atm) or more from the viewpoint of preserving the respiration of fruits and vegetables and maintaining their freshness. More preferably, it is 500cc/( ^m2・day・atm) or more, still more preferably 800cc/( ^m2・day・atm) or more, and even more preferably 1000cc/( ^m2・day・atm). That's all.
On the other hand, the oxygen permeability of the synthetic resin film at 23° C. and 60% RH is preferably 10,000 cc/(m ² ·day · atm) or less, more preferably 7,000 cc/(m 2 ·day · atm) from the viewpoint of maintaining the quality and freshness of fruits and vegetables. (m ² ·day · atm) or less, more preferably 4000 cc/(m ² ·day · atm) or less, and even more preferably 3000 cc/(m ² ·day · atm) or less.

The water vapor permeability of the synthetic resin film constituting the bag body 10 at 40° C. is preferably 1 g/(m ² ·day) or more, more preferably 3 g/(m ² days) or more.
On the other hand, the water vapor permeability of the synthetic resin film at 40°C is preferably 300 g/(m ² ·day) or less, more preferably 100 g/(m ² ·day) or less, from the viewpoint of suppressing the respiration of fruits and vegetables. It is more preferably 50 g/(m ² ·day) or less, and even more preferably 10 g/(m ² ·day) or less.

Water vapor permeability can be measured by a method based on JIS Z 0208 (cup method).

Furthermore, in the present embodiment, the oxygen permeability and water vapor permeability of the synthetic resin film constituting the bag body 10 are intended to be the oxygen permeability and water vapor permeability of the bag body 10 that does not include the communication area 30 described above. In this case, adjustment can be made by controlling the selection of the material of the synthetic resin film, the method of manufacturing the synthetic resin film, the layer structure of the synthetic resin film, the presence or absence of through holes, and the average diameter and number of through holes.

In addition, although the bag main body 10 of this embodiment may be formed with a through hole, it may not have a through hole. Depending on the presence or absence of through holes, water vapor permeability and oxygen permeability can be further adjusted.

The planar shape of the through hole may be, for example, circular, polygonal, or slit. A slit is a cut or slit that penetrates the synthetic resin sheet that constitutes the packaging material, and may be straight, curved, L-shaped, cross-shaped, etc., and its length is not particularly limited. .

The average diameter of the through holes is preferably 10 μm to 800 μm, more preferably 20 μm to 500 μm, even more preferably 50 μm to 200 μm. In this case, the average diameter of the through hole is calculated from the open area of the through hole, assuming that the through hole is a perfect circle.

The above-mentioned through holes can be provided at least either before or after the synthetic resin film is formed into a bag shape.

[Fruits and vegetables]
The freshness maintaining bag 100 of this embodiment preferably stores fruits and vegetables.
Fruits and vegetables include, but are not particularly limited to, plantain, spinach, komatsuna, mizuna, mibuna, asparagus, cilantro, lettuce, thyme, sage, parsley, Italian parsley, rosemary, oregano, lemon balm, chives, lavender, salad burnet. , lamb's ear, rocket, dandelion, nasturtium, basil, arugula, watercress, molokheiya, celery, kale, green onion, cabbage, Chinese cabbage, Chinese chrysanthemum, saladana, sanchu, butterbur, nabana, bok choy, honeysuckle, Japanese parsley, Brussels sprouts, broccoli, cauliflower, Japanese ginger, radish, carrot, burdock, radish, turnip, sweet potato, potato, nagaimo, yam, taro, jinenjo, yam, green pepper, paprika, shishito pepper, cucumber, eggplant, tomato, cherry tomato, pumpkin, bitter melon, okra, sweet corn, Examples include edamame, snow peas, green beans, fava beans, and mushrooms. Fruits such as citrus fruits, apples, pears, grapes, blueberries, persimmons, and strawberries, as well as cut flowers, are also effective. It is also effective for cut vegetables and cut fruits.
Note that cut vegetables are non-edible vegetables that have been harvested in the fields and have their inedible parts, such as roots, stems, or flowers, removed and are cut using known methods to make them easier to eat and have a better appearance. It means heated vegetables.

<Package>
The package of this embodiment stores fruits and vegetables in the freshness-preserving bag 100 described above. It is preferable that the package is one in which the opening of the freshness-preserving bag 100 is sealed.
Further, in this embodiment, the inner surface area of the package per 100 g of fruits and vegetables is preferably 100 to 5000 cm ² , more preferably 200 to 1000 cm ² , even more preferably 250 to 800 cm ² , and even more preferably 300 to 600 cm ² preferable.

<How to maintain freshness>
The freshness preservation method of this embodiment is a method of preserving the freshness of fruits and vegetables by storing and preserving the fruits and vegetables in the freshness preservation bag 100 described above. After storing fruits and vegetables, the opening of the freshness preserving bag 100 is preferably sealed.
The above-mentioned sealing may be performed, for example, by heat-sealing the opening of the bag, or by using a member such as a back sealing tape, a binding band, a rubber band, or caulking.

Further, in this embodiment, the package is preferably stored at an environmental temperature of 2 to 25°C. However, depending on the application, distribution conditions, etc., there may be temperature changes.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above may also be adopted.

Next, the present invention will be explained in detail with reference to examples, but the content of the present invention is not limited to the examples.

<Measurement>
- Measurement under condition a First, "Ageless Seal Check (Aerosol)" (manufactured by Taseto Co., Ltd.) was used as a staining solution.
Next, the dyeing solution is brought into contact with the end of the back patch on the side opposite to the bag body, and using capillarity, the dye solution is transferred from the end through the communication area to the end of the back patch on the bag body side. The time required to reach this point was measured. In addition, if there was a non-sealed area on the back sticking part, the non-sealed area was cut so that the end of the communication area was exposed on the cut surface.
Measurements were performed at three locations, and the average value was taken as the time (t seconds).

- Measurement of water vapor permeability (g/m ² ·day) at 40° C. Measurement was performed according to JIS Z 0208 (cup method) using a synthetic resin film having the raw materials and thickness shown in Table 1.

・Measurement of oxygen permeability (cc/ ^m2・day・atm) at 23°C and 60% RH (1) Filling with nitrogen gas A bag for measurement is made using a synthetic resin film with the raw materials and thickness shown in Table 1. After producing and sealing the bag with heat sealing or the like, the bag was degassed using an aspirator or the like. Deaeration was performed until both sides of the bag were stuck together. Next, this bag was filled with nitrogen gas (purity of 99.9% or more) using a white hard syringe. The amount of nitrogen gas injected is as large as possible according to the bag size, so that the film that makes up the bag is not under tension and is slightly loosened by the injected nitrogen gas, and using the scale of the white hard syringe. It was measured using Note that the nitrogen gas was degassed and injected by, for example, sticking a syringe needle into the bag. When inserting the injection needle, double-sided tape was applied to the film constituting the bag, and an adhesive tape made of polypropylene film (hereinafter referred to as "PP tape") was further applied on top of this. Furthermore, after the injection needle was removed, the needle hole was immediately covered with PP tape. The tape attached to the bag was designed to fit within an area of 4.5 cm ² or less.
Moreover, when the film constituting the bag was a microporous film, the tape was not used to block the micropores.
(2) Initial oxygen concentration measurement The initial oxygen concentration (C0) in the bag immediately after filling with nitrogen gas (t=0) was measured. The gas inside the bag was sampled, and the initial oxygen concentration (C0) inside the bag was determined by gas chromatography (TCD). C0 was 0.2% or less, and if it exceeded this, the work was redone. The sampling gas for oxygen concentration measurement was 10 cc or less. When injecting into gas chromatography, a fixed amount of about 1 cc was injected. Further, measurement of standard gas (two or more points containing about 1% and about 10% oxygen) was also performed by injecting the same amount of gas, and a calibration curve was created.
(3) Storage of bags The bags whose initial oxygen concentration was measured were stored at 23° C. and 60% RH (constant temperature and humidity chamber). At this time, the bags were left still to prevent objects from falling on them and the air from the fan in the constant temperature and humidity chamber not directly hitting the bags.
(4) Measuring the oxygen concentration inside the bag and calculating the oxygen permeation rate during storage The oxygen concentration inside the bag should be measured immediately after filling with nitrogen gas and after 3 hours or more, within the range of 1% to 7%. A total of 3 to 5 points must be measured, and a proportional relationship (correlation coefficient of 0.98 or more) must be established between the elapsed time t (hr) and the oxygen concentration in the bag. If the correlation coefficient did not hold, a retest was performed. If the oxygen permeation rate of the film constituting the bag is too high and the oxygen concentration inside the bag rises too quickly and this condition cannot be met, use a part of the film whose oxygen permeation rate is known to be lower than the film being measured. You can create a bag by laminating it with a film of the same material and do the same thing. At this time, the oxygen permeation rate of the measured film was obtained by subtracting the oxygen permeation rate of the known film part from the determined oxygen permeation rate, excluding the part where the bag was attached to another film whose surface area was known.
The oxygen permeation rate was calculated using the following formula (i) using the value with the longer elapsed time.
F=1.143×(Ct-C0)×V/t (i)
F: Oxygen permeation rate (cc/bag/day/atm)
Ct: Oxygen concentration in the bag t hours after filling with nitrogen gas (%)
C0: Oxygen concentration in the bag immediately after filling with nitrogen gas (%)
V: Amount of nitrogen gas filled (cc)
t: Elapsed time from gas filling (hr)

<Examples, comparative examples>
(1) Preparation of freshness-preserving bag A bag having a back affixed portion was prepared using a synthetic resin film by a known method to obtain the freshness-preserving bag shown in Table 1.
Note that PP indicates polypropylene resin.
(2) Evaluation of freshness retention effect The fruits and vegetables shown in Table 1 were placed in the prepared freshness retention bags, and the openings were closed by heat sealing to obtain packages containing fruits and vegetables. Two of the obtained packages were stacked with the back side facing down, and after being stored under the conditions shown in Table 1, the freshness retention effect was evaluated based on the fresh state (initial stage) before storage. , evaluated according to the following evaluation criteria.

・Evaluation criteria <smell>
◎: No difference from the initial stage 〇: A slight off-odor is felt, but the smell of fruits and vegetables is stronger △: The off-odor is stronger than the smell of fruits and vegetables ×: Strong off-odor <Appearance (fruits and vegetables)>
◎: No difference from the initial value 〇: Approximately 10% discolored compared to the initial value △: Approximately 30% discolored compared to the initial value ×: Discolored 50% or more than the initial value <Taste>
◎: No difference from the initial stage 〇: The taste has become slightly weaker, but the original taste of fruits and vegetables is still there △: The original taste of fruits and vegetables has clearly become weaker ×: Unpalatable

Claims (14)

A freshness-preserving bag comprising a bag body for accommodating fruits and vegetables obtained by pasting both ends of a synthetic resin film together to form a cylinder and closing one side, and a back pasting part,
The back sticking part has a communication area that communicates the outside and the inside of the bag main body,
A freshness preservation bag that satisfies the following condition a.
(Condition a) A dyeing solution containing an organic solvent and mineral oil is brought into contact with the outer end of the bag body in the communication region, and the dyeing solution is caused by capillary action to spread to the outer end of the bag body in the communication region. When measuring the time (t seconds) required to reach the inner end of the bag body in the communication area from the end, t is 0.6 to 3. The freshness preservation bag according to claim 1,
A freshness-preserving bag, wherein the width of the spine is 5 to 700 mm. The freshness preservation bag according to claim 1 or 2,
The freshness-preserving bag, wherein the number of communication areas is 10 to 250 per 10 cm ² of area of the spine part in plan view. The freshness preservation bag according to any one of claims 1 to 3,
The freshness-preserving bag, wherein the distance between the adjacent communication areas at the end of the back pasted portion on the bag body side is 1 to 100 mm. The freshness preservation bag according to any one of claims 1 to 4,
A freshness-preserving bag, wherein the communication region has a width of 0.2 to 7 mm in plan view. The freshness preservation bag according to any one of claims 1 to 5,
A freshness-preserving bag, wherein the communication area has a path length of 10 to 50 mm. The freshness preservation bag according to any one of claims 1 to 6,
The freshness-preserving bag has a geometric pattern formed by alternately and repeatedly arranging the communicating areas and the joining areas in the length direction of the back sticking part. The freshness preservation bag according to claim 7,
The freshness preserving bag, wherein the pattern constituent unit of the geometric pattern includes one or more selected from a straight line, a rectangle, a circle, and a curved line. The freshness preservation bag according to any one of claims 1 to 8,
The bag is a freshness-preserving bag, wherein the spine part has a band-shaped non-sealed part extending from the upper end to the lower end of the back part on the side opposite to the bag main body. The freshness preservation bag according to claim 9,
A freshness-preserving bag, wherein the band-shaped non-sealed portion has a width of 1 to 40 mm. The freshness preservation bag according to any one of claims 1 to 10,
The freshness preserving bag, wherein the synthetic resin film has a thickness of 20 to 200 μm. The freshness preservation bag according to any one of claims 1 to 11,
The synthetic resin film is a film containing one or more selected from polyethylene, ethylene copolymer, polypropylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, and polyamide resin, or the film contains the film. A freshness preservation bag made of multilayer film. A packaged product comprising a freshness preserving bag according to any one of claims 1 to 12, in which fruits and vegetables are accommodated in the bag body. A method for preserving freshness, comprising accommodating fruits and vegetables in the bag body of the freshness-preserving bag according to any one of claims 1 to 12, and preserving the fruits and vegetables.

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