JP6674408B2 - A package excellent in freshness maintaining performance of fruits and vegetables including cabbage, and a method of maintaining freshness of fruits and vegetables including cabbage - Google Patents

Description

  The present invention relates to a package excellent in freshness holding performance of fruits and vegetables including cabbage, and more specifically, a product in which fruits and vegetables including cabbage are stored in a packaging container having a polymer film. The present invention relates to a package capable of effectively suppressing browning and off-flavor generation.

By providing a gas permeable portion in the polymer film base material, a gas permeable film that allows gas such as oxygen, carbon dioxide, and water vapor to pass therethrough from the gas permeable portion is used in the food field to produce fruits and vegetables, particularly fresh vegetables such as cut vegetables. It is suitably used as a packaging material. When vegetables, fruits, and the like are packaged using such a gas-permeable film, for example, an oxygen concentration suitable for maintaining the freshness of the contents of vegetables and fruits, for example, an oxygen concentration of about 1 to 4% can be maintained. It is known that contents can be stored while maintaining freshness for a relatively long period of time.
For example, in Patent Document 1, in a package of fruits and vegetables comprising a polymer film in which fruits and vegetables are sealed, the package is composed of (A) a perforated polymer film and (B) a non-porous polymer film; (A), at least one of the film properties (B), the water vapor permeability measured at 25 ° C. and a relative humidity of 75% is 50 to 800 gm ⁻² d ^{−1 based} on the effective surface area of the package. There is described a package containing fruits and vegetables characterized in that the open area ratio of (A) is 3 × 10 ^{−6 to} 7 × 10 ⁻⁴ % with respect to the effective surface area of the package. Specifically, (A) a perforated polymer film made of stretched polypropylene having a thickness of 35 μm and having 95 holes with an average pore diameter of 95 μm, and having nine holes with an average pore diameter of 60 μm, etc. in use.

  Cabbage is one of the most widely distributed vegetables among fruits and vegetables, and the above-described package and storage method can be suitably applied. In particular, cut cabbage, which has been cut from cabbage, has been increasing in demand in recent years because it can be easily served for meals, and because cabbage is one of the most common vegetables for salads, etc., it has high economical efficiency. Have value. For this reason, packages and storage methods that are particularly suitable for maintaining the freshness of cut cabbage are being actively studied, and the oxygen transmission rate, carbon dioxide transmission rate, and water vapor transmission rate of the package, and the oxygen concentration in the package And setting the carbon dioxide concentration to specific values (for example, see Patent Document 2). However, even with the above technique, it has not always been easy to achieve both suppression of browning of cut cabbage and prevention of odor over a long period of time. For example, it was known that if the oxygen permeation amount and the oxygen filling amount were lower and the inside of the bag had a low oxygen concentration environment, browning would be suppressed, but in that case, an unpleasant odor accompanying anoxic respiration would occur Inevitably, the prior art has not always achieved both the suppression of browning and the prevention of off-flavor.

JP-A-5-168400 JP-A-2004-242504

The present invention, in view of the above-described limitations of the background art, is a package body containing vegetables and fruits including cabbage in a packaging container, even in an environment with a low oxygen concentration where browning of the fruits and vegetables including the cabbage is suppressed. Another object of the present invention is to provide a package excellent in a freshness maintaining function of the fruits and vegetables, for example, capable of effectively preventing an unpleasant odor.
The present inventor has conducted intensive studies, and as a result, by introducing a predetermined concentration of carbon dioxide, an unpleasant odor from fruits and vegetables including cabbage is prevented even in an environment with a low oxygen concentration, and by using this, the limitations of the conventional technology are reduced. The present inventors have found that it is possible to achieve both the suppression of browning and prevention of off-flavor of fruits and vegetables including cabbage at an exceedingly high level, and have completed the present invention.

That is, the present invention
[1]
A package in which fruits and vegetables including cabbage are stored in a packaging container containing a polymer film, wherein the internal carbon dioxide concentration after holding the package for 72 hours at 10 ° C. after sealing is 35. The above package, which is not less than% by volume.

Hereinafter, each of [2] to [13] is one aspect or one of preferred embodiments of the present invention.
[2]
The package according to [1], wherein the packaging container has an oxygen permeability of 3000 cc / m ² / atm / day or less at 20 ° C. and 90% RH.
[3]
The package according to [1] or [2], wherein browning and off-odor of fruits and vegetables including the cabbage are suppressed for 96 hours at 10 ° C. after sealing of the package.
[4]
The package according to any one of [1] to [3], wherein the internal carbon dioxide concentration immediately after sealing of the package is 50% by volume or more.
[5]
The package according to any one of [1] to [4], wherein the internal oxygen concentration immediately after sealing of the package is 20% by volume or less.
[6]
The package according to any one of [1] to [5], wherein the packaging container does not have a through hole that can be confirmed with an ink leak checker.
[7]
The package according to any one of [1] to [6], wherein the polymer film is a stretched polypropylene film, a polyethylene-based film, or a laminate of a stretched film and a polyethylene-based film.
[8]
The package according to any one of [1] to [7], wherein the polymer film contains at least one antibacterial agent, or has at least one antibacterial agent applied thereto.
[9]
The package according to any one of [1] to [8], wherein the cabbage is a cut cabbage.
[10]
The package according to any one of [1] to [9], further containing a hygroscopic agent and / or an antibacterial agent.
[11]
A step of storing fruits and vegetables including cabbage in a packaging container comprising a polymer film and having an oxygen permeability of not more than 3000 cc / m ² / atm / day at 20 ° C. and 90% RH, and inside the packaging container And a step of sealing the packaging container.
[12]
The method for maintaining freshness of fruits and vegetables according to [11], wherein browning and off-flavors of the fruits and vegetables including the cabbage are suppressed for 96 hours or more from the step of sealing the packaging container.
[13]
The method for maintaining freshness of fruits and vegetables according to [11] or [12], wherein in the step of setting the carbon dioxide concentration in the packaging container to 50% by volume or more, the oxygen concentration is set to 20% by volume or less.

  According to the present invention, by introducing a predetermined concentration of carbon dioxide into the inside of the package, the suppression of browning of cabbage and the prevention of off-flavor both at a high level beyond the limits of the prior art, freshness of fruits and vegetables including cabbage And a package having a practically high value and a method for maintaining the freshness of fruits and vegetables, which can effectively suppress the production of fresh fruits and vegetables.

Hereinafter, embodiments for implementing the present invention will be described.
The present invention relates to a package in which fruits and vegetables including cabbage are stored in a packaging container containing a polymer film, wherein the internal carbon dioxide concentration is 72% by volume or more 72 hours after the package is sealed. And the package. That is, the package of the present invention has at least a packaging container and fruits and vegetables stored therein.

Packaging Container The packaging container constituting the package of the present invention contains a polymer film. Here, "comprising a polymer film" means that the entire packaging container is composed of a polymer film, and that a part of the packaging container such as a lid is composed of a polymer film. The purpose is to include both.
Therefore, the packaging container may be a flexible packaging container in which all or a main part is formed of a flexible polymer film, a so-called packaging bag, such as a flexible polymer film and coated paper. May be a flexible packaging container in which other flexible members are combined, or a packaging container in which a flexible polymer film and a rigid member are combined, for example, as a lid material. It may be a combination of a molecular film and a rigid member such as a tray or a cup.

In an embodiment in which the packaging container is a so-called packaging bag, for example, three or two sides are heat-sealed in a state where two polymer films are overlapped with each other or one polymer film is folded. To form a packaging bag. The remaining one side can be sealed by arranging the contents such as fruits and vegetables in the packaging bag and then similarly fusing by heat sealing.
The shape of such a packaging bag in a plan view may be a circle, a triangle, a rectangle, or a polygon having a rectangle or more, but it is preferable to form a rectangle from the viewpoint of workability and ease of handling.

The packaging container used in the present invention contains a polymer film as described above, and its oxygen permeability is not particularly limited, but the oxygen permeability is 3000 cc / at 20 ° C. and 90% RH. It is desirable to use a packaging container having a value of m ² / atm / day or less.
By using a packaging container having an oxygen permeability within the above range, fluctuations in the internal gas composition due to internal gas, especially carbon dioxide outflow, outside air, especially oxygen inflow, etc. are suppressed or reduced, and the freshness of fruits and vegetables including cabbage is reduced. It is easy to maintain an environment suitable for holding. The oxygen permeability of the packaging container is more preferably 2000 cc / m ² / atm / day or less, and particularly preferably 1500 cc / m ² / atm / day or less.
Although there is no particular lower limit to the oxygen permeability of the packaging container, from the viewpoint of allowing a certain amount of respiration of fruits and vegetables including cabbage and more effectively preventing the generation of offensive odor, 100 cc / m ² / atm / day or more. , And particularly preferably 300 cc / m ² / atm / day or more. In addition, in consideration of cost and the like, as long as a packaging container is formed with a relatively simple structure using a generally available polymer film, its oxygen permeability is 800 cc / m ² / atm / day or more. Is common.

The oxygen permeability of the packaging container can be measured, for example, by the following method.
First, a bag having an inner dimension a (cm) × b (cm) is formed by the following method.
One film is almost equally folded in half and is about 5 mm wide. The scale of the heating condition is set to 3 with an impulse sealer (manufactured by Fuji Impulse, part number Fi-200-10WK), and heat sealing is performed. One of the sides substantially perpendicular to the heat-sealed side is heat-sealed so that the side is substantially at the center, and the other side is heat-sealed except for an end of about 2 cm, which is one communicating part of the other side. (cm) x b (cm).
Next, nitrogen gas is injected from the communicating portion, and when the inside of the bag becomes saturated, almost all the gas in the bag is discharged from the communicating portion. After repeating this operation 5 times, nitrogen gas is injected to saturate the inside of the bag with nitrogen gas, and the communicating portion is heat-sealed with the impulse sealer under the same conditions. The bag saturated with nitrogen gas is left for 6 hours in a room at 22 ° C. and a relative humidity of 40% in the air (1 atm, oxygen concentration: 21%, nitrogen concentration: 79%).
Next, about 20 cc is sampled with a sampling needle tube, and the oxygen concentration in the bag is measured with a zirconia oxygen concentration meter for food packaging (model number LC-750F, manufactured by Toray Engineering Co., Ltd.). Further, the volume of the gas in the bag is measured, and the oxygen permeability is calculated from the following equation.
(Formula) oxygen permeability = internal oxygen concentration change (%) / 100 × volume ^{(cm 3) × 24 × 60} / time (360 minutes) × 10000 cm ² / area ^{(2 × a × b cm 2} ) / oxygen min Pressure (0.21atm)
The oxygen permeability of the packaging container can be adjusted to a desired range by appropriately selecting and adjusting the material, thickness, layer configuration, presence / absence of coating, type, applicable area, etc. of the polymer film constituting the packaging container. it can. Details of the polymer film will be described later.
Also, by providing (or not providing) an opening in the polymer film, the oxygen permeability of the packaging container can be appropriately adjusted. The oxygen permeability can be appropriately adjusted also by the size, shape, and number of the openings. The details of the opening will also be described later.

Fruits and Vegetables The package of the present invention contains fruits and vegetables including cabbage in the packaging container. Here, the phrase "the vegetable or vegetable""contains" cabbage means that both the case where the whole vegetable is composed of cabbage and the case where a part of the vegetable is composed of cabbage are included. . Therefore, the fruits and vegetables stored in the packaging container may or may not include vegetables and fruits other than cabbage. Furthermore, as long as cabbage is included, it may contain components other than fruits and vegetables, for example, foods other than fruits and vegetables, seasonings, food additives, and the like.

The “cabbage” that constitutes the package of the present invention (contained in a packaging container) is a concept that includes general head vegetables belonging to the Brassicaceae Brassica genus, and is limited to vegetables distributed under the name “cabbage” itself. Not done.
That is, the “cabbage” referred to here is, as a preferable example, a cold cabbage (winter) cabbage, a spring cabbage, a plateau cabbage, a red cabbage, a green ball (round ball), a savoy cabbage (crepe cabbage), a brussels sprouts, a petite veil, It is a concept that includes all of Misaki Kanai / Tongari Kyubetsu etc., but is not limited to these.

  In the present invention, there is no particular limitation on the fruits and vegetables other than the cabbage that can be stored together with the cabbage in the packaging container, and non-heated or heated fruits and vegetables that can be edible with the cabbage can be appropriately stored. Specific examples of such fruits and vegetables include fruits such as banana, mango, plum, apple, strawberry, orange, grape, Japanese pear, pear, root vegetables such as radish, carrot, yam, burdock, tomato, Fruits and vegetables such as cucumber, eggplant, pepper, edamame, okra, mushrooms such as mung bean sprouts, soy bean sprouts, syrup, shiitake mushrooms, shimeji mushrooms, fungi and mushrooms such as mushrooms, broccoli , Spinach, komatsuna, pak choi, lettuce, asparagus, leafy vegetables, flowers or seedlings, but are not limited thereto. The effect of the present embodiment of controlling and maintaining the oxygen concentration is particularly effective for maintaining the freshness of a fruit or vegetable in a substantially breathing mode.

In the present invention, there is no particular limitation on the form of fruits and vegetables including cabbage stored in a packaging container and kept fresh.
Therefore, the fruits and vegetables including cabbage may be as-harvested, so-called pre-processed ones from which outer leaves and the like have been removed, or so-called cut vegetables (cut cabbage). It may be. The fruits and vegetables may have been subjected to any or all of the processing such as washing, cooling, and dehydration, or may be those without any of these processings.
In addition, in the case of the cabbage in which the stored and preserved freshness is cut, it is preferable that the cabbage is cut, washed, dehydrated, and / or dried to adjust the water content to an appropriate value. More specifically, for example, the cut cabbage is washed with hypochlorous acid at 80 to 120 ppm for 10 to 20 minutes based on the “Manual for Mass Cooking Facilities Hygiene Management” (Ministry of Health and Welfare), and then “analysis of nutrition labeling etc. based on nutrition labeling standards”. Method "(Consumer Affairs Agency), when the amount of water measured based on weight loss when dried under reduced pressure at 70 ° C. for 5 hours is in the range of 10 to 20%, it is possible to prevent odor generation and browning etc. It is particularly preferable from the viewpoint of the balance of prevention of appearance deterioration.

  In recent years, demand for cut vegetables has been increasing because they can be easily served for meals, and has high economic value. Cut cabbage is a typical example of cut vegetables and can be easily served as a salad or the like as it is, and therefore has a particularly high economic value. On the other hand, vegetables, especially cabbage, tend to sharply activate their respiratory action and metabolic reaction when cut, and their quality tends to decrease sharply. The present embodiment has a particularly high economic value because it can be effectively used for maintaining the freshness of such cut cabbage.

  Depending on the type and morphology of the cabbage (and the fruits and vegetables that are stored with the cabbage, if present), the preferred carbon dioxide concentration for preserving freshness will vary to some extent within the scope of the present invention, and accordingly the preferred carbon dioxide permeability will be indirectly adjusted. The specified oxygen permeability and the mode of the polymer film that provides such oxygen permeability are also different, but by appropriately setting these, the cabbage (and the fruits and vegetables stored together with the cabbage if present) can be obtained. In any case, the present invention can effectively maintain freshness.

Package The internal carbon dioxide concentration of the package of the present invention after being kept at 10 ° C. for 72 hours after sealing is 35% by volume or more. Since the internal carbon dioxide concentration after holding the package at 10 ° C for 72 hours after sealing was 35% by volume, it was housed in a packaging container in a low oxygen concentration environment suitable for suppressing browning. It is possible to effectively prevent the generation of off-flavors from cabbage in fruits and vegetables, and to achieve both suppression of browning and prevention of off-flavors of fruits and vegetables including cabbage at a high level beyond the limits of the conventional technology.
It has been conventionally known that by adjusting the oxygen concentration in a package within a predetermined range, deterioration of appearance such as browning of fruits and vegetables stored in the package can be suppressed. However, when the oxygen concentration is set to a predetermined value or less, there is a problem that an odor such as alcohol smell is generated due to anoxic respiration of fruits and vegetables. Cabbage is particularly prone to browning among fruits and vegetables, and low oxygen concentration is strongly required for its suppression.For maintaining freshness of fruits and vegetables including cabbage, it is necessary to achieve both suppression of browning and prevention of off-flavor. Conventionally, it has been particularly difficult.
In the present invention, in a package containing vegetables and fruits including cabbage, by introducing carbon dioxide and keeping the internal carbon dioxide concentration within a predetermined range, the suppression of browning and the prevention of off-flavors limit the conventional technology. The surprising effect of achieving a balance at a higher level is achieved.
In the present invention, the internal carbon dioxide concentration after a predetermined time has elapsed after the sealing of the package is equal to or higher than a predetermined value, thereby suppressing the browning of fruits and vegetables including cabbage contained in the packaging container and preventing the odor, The mechanism that can achieve compatibility at a high level beyond the limits of the conventional technology is not always clear, but by excessively increasing the amount of carbon dioxide, which is a product of normal respiration, it reduces the respiration of fruits and vegetables including cabbage and makes it dormant It is presumed that there is some relationship between the suppression of wear and the oxidation of the cut surface.

The internal carbon dioxide concentration after keeping the package at 10 ° C. for 72 hours after sealing is preferably 50.0% by volume or more, more preferably 65.0% by volume or more.
There is no particular upper limit on the internal carbon dioxide concentration after the package is sealed and maintained at 10 ° C. for 72 hours, but from the viewpoint of effectively preventing browning, it is 95.0% by volume. Or less, more preferably 85.0% by volume or less.
The internal carbon dioxide concentration of the package can be adjusted to a desired range by adjusting the carbon dioxide concentration immediately after the package is sealed. More specifically, when producing a package, it is possible to appropriately adjust the concentration of carbon dioxide in the gas filled in the packaging container. For example, when producing a package, it is preferable that the concentration of carbon dioxide in the gas filled in the package is 50% by volume or more.
Also, the internal carbon dioxide concentration of the package is adjusted to a predetermined concentration by adjusting the amount of carbon dioxide flowing out of the package and / or the amount of carbon dioxide generated by respiration of fruits and vegetables including cabbage in the package. It is possible. More specifically, by adjusting the gas permeability of the packaging container, it is possible to adjust the amount of carbon dioxide flowing out of the package, the amount of fruits and vegetables including cabbage stored in the packaging container and / or packaging By adjusting the amount of oxygen charged in the container, it is possible to adjust the amount of carbon dioxide generated by respiration of fruits and vegetables including cabbage.

Here, "after the package is sealed" refers to the elapsed time since the package containing the cabbage was stored in the package and then the package was sealed. In other words, “72 hours after the package is sealed” means a state 72 hours after the fruits and vegetables including cabbage are stored in the package and then the package is sealed, and “72 hours after the package is sealed”. "After holding for 72 hours under the condition of 10 ° C after stopping,” means that after storing the fruits and vegetables including cabbage in the packaging container, the packaging container was sealed, and then kept under the condition of 10 ° C for 72 hours. Immediately after.
In the package of the present invention, since the internal carbon dioxide concentration is usually higher than the atmospheric carbon dioxide concentration, the internal carbon dioxide concentration often decreases with time due to the outflow of carbon dioxide. Therefore, in the present embodiment in which the internal oxygen concentration at 72 hours after sealing is 35% by volume or more, there is a high possibility that the internal carbon dioxide concentration is 35% by volume or more from 0 to 72 hours after sealing. Such a history of the carbon dioxide concentration is particularly preferable in order to more effectively suppress the generation of browning and off-flavor of cabbage in fruits and vegetables.
The concentration of carbon dioxide and the concentration of oxygen in the packaging container can be measured, for example, by an O ₂ / CO ₂ analyzer for food packaging Check Mat 3 manufactured by Dansensor.
There is no particular upper limit to the internal oxygen concentration after the package is sealed and maintained at 10 ° C. for 72 hours. However, it is possible to more effectively suppress deterioration in appearance such as browning of fruits and vegetables including cabbage. From the viewpoint, it is preferably 20% by volume or less, more preferably 10% by volume or less, further preferably 5% by volume or less, and particularly preferably 3% by volume or less.
Although there is no lower limit in the internal oxygen concentration after holding the package at 10 ° C. for 72 hours after sealing, the minimum breathing of vegetables and fruits including cabbage is allowed, and the unpleasant odor due to oxygen-free breathing is eliminated. From the viewpoint of more effectively suppressing the like, the content is preferably 0.25% by volume or more, and more preferably 0.50% by volume or more.
The internal oxygen concentration of the package can be adjusted to a desired range by adjusting the oxygen concentration immediately after packaging. More specifically, when manufacturing a package, it is possible to appropriately adjust the oxygen concentration in the gas filled in the packaging container. For example, when producing a package, it is preferable that the oxygen concentration in the gas filled in the package is 50% by volume or less.
Also, the internal oxygen concentration of the package can be determined by adjusting the amount of oxygen flowing out of the package or flowing in from the outside of the package and / or the amount of oxygen consumed by breathing of fruits and vegetables including cabbage in the package. Can be adjusted. More specifically, by adjusting the oxygen permeability of the packaging container, it is possible to adjust the amount of oxygen that flows out of the package or flows in from the outside of the package. By adjusting the amount of oxygen filled in the packaging container, it is possible to adjust the amount of oxygen consumed by breathing of the fruits and vegetables.
The oxygen concentration in the packaging container can be measured, for example, by the following method.
About 20 cc of gas in the package is sampled with a sampling needle tube, and the oxygen concentration in the bag is measured with a zirconia oximeter for food packaging.

In the package of the present invention, it is preferable that browning of fruits and vegetables including cabbage and generation of off-flavor be suppressed for 96 hours or more at 10 ° C. after sealing of the package.
This preferred embodiment suppresses the browning of fruits and vegetables including cabbage and the generation of off-flavors over 96 hours or more under the condition of 10 ° C. after sealing of the package, so that it is considered to be sufficient for distribution over a long period of time. Since fruits and vegetables including cabbage can be maintained at a high level of freshness, they have high practical and economic value.
In this preferred embodiment, it is more preferable to suppress the browning of fruits and vegetables including cabbage and the generation of off-flavors for 120 hours or more after the sealing of the package, and it is preferable to suppress the occurrence of 144 g at 10 ° C. after the sealing of the package. More preferably, it is suppressed over a period of time.

  From the viewpoint of realizing the desired internal carbon dioxide concentration and internal oxygen concentration described above, another gas such as nitrogen may be further sealed in the packaging container. This is because the internal carbon dioxide concentration and the internal oxygen concentration can be independently adjusted by enclosing another gas such as nitrogen at the time of sealing the packaging container.

Polymer Film In order to realize the above-described preferable oxygen permeability in the packaging container used in the present invention, it is desirable to configure the packaging container using a polymer film having an oxygen permeability of a predetermined value or less.
That is, the oxygen permeability of the polymer film used in the present invention is preferably 3000 cc / m ² / atm / day or less at 20 ° C. and 90% RH. By using a polymer film whose oxygen permeability at 20 ° C. and 90% RH is equal to or less than the above value, a preferred embodiment is 3000 cc / m ² / atm / day at 20 ° C. and 90% RH. The following packaging container can be manufactured at a relatively low cost with a relatively simple configuration and manufacturing method.
The oxygen permeability of the polymer film used in the present invention at 20 ° C. and 90% RH is more preferably 2500 cc / m ² / atmday or less, and particularly preferably 2300 cc / m ² / atm / day or less. preferable.
Although there is no particular lower limit to the oxygen permeability of the polymer film, as long as a normal polymer film not subjected to gas barrier coating or the like is used, 500 cc / m ² / atm / day at 20 ° C. and 90% RH is used. Generally, this is the case.
In addition, from the viewpoint of more effectively preventing the generation of off-flavors from the stored fruits and vegetables, it is preferable that the polymer film has an oxygen permeability sufficient to allow the minimum respiration of the fruits and vegetables. From this viewpoint, the oxygen permeability of the polymer film at 20 ° C. and 90% RH is preferably 750 cc / m ² / atm / day or more, and more preferably 900 cc / m ² / atm / day or more. Particularly preferred.

  The method for measuring the oxygen permeability of the polymer film used in the present invention can be measured, for example, by the same method as described above for the method for measuring the oxygen permeability of a packaging container.

By appropriately selecting the material, thickness, processing method, and the like of the polymer film, the oxygen permeability of the polymer film can be appropriately adjusted. For example, in the case of a biaxially oriented polypropylene (OPP) film, by setting the thickness to 20 μm or more, the oxygen permeability at 20 ° C. and 90% RH can be 3000 cc / m ² / atm / day or less. It is preferred. In consideration of mechanical strength and the like, the thickness of the polymer film is more preferably 10 to 50 μm, and particularly preferably 15 to 45 μm.

As described above, the oxygen permeability of the polymer film can be adjusted by appropriately raining the material, thickness, processing method, and the like of the polymer film. It is not necessary to provide an opening in the polymer film. In particular, in the preferred embodiment of the present invention, the relatively low oxygen permeability of 3000 cc / m ² / day or less at 20 ° C. and 90% RH is realized without providing an opening in the polymer film. can do.
If it is not necessary to provide an opening in the polymer film, the manufacturing process becomes simpler and lower in cost, and the size and shape of the opening need not be precisely controlled.
The absence of an opening in the polymer film can be confirmed, for example, by the fact that the polymer film forming the packaging container does not have a through hole that can be confirmed by an ink leakage checker.

On the other hand, in one embodiment of the present invention, it is necessary to realize a relatively high oxygen permeability among the oxygen permeability of 3000 cc / m ² / day or less at 20 ° C. and 90% RH, When it is necessary to use a film or a polymer material having a low oxygen permeability, an opening provided in the polymer film may be used in combination to achieve a desired oxygen permeability. The shape of the opening is not particularly limited, and may be circular, substantially circular, or slit-like. A circular or substantially circular opening is preferable in that processing is easy, and the like, and a slit-shaped opening is preferable in that foreign substances can be effectively prevented from entering.
The size of each opening and the number of openings can be appropriately set and changed as long as the oxygen permeability of the polymer film is appropriate, and in that case, the opening occupying the effective area of the polymer film The number is a guide. For example, it is a slit-shaped opening having a length of 2 mm, and in a closed state, the width as a through hole cannot be visually recognized by an optical microscope (manufactured by Olympus, model SZH-131) at a magnification of 4 ×. In the case where a package is provided, there is an effect of increasing the oxygen permeability of about 1000 cc / m ² / day / atm every time one package is present in a 200 mm × 200 mm package. It is preferable to determine the number of slit openings from the oxygen permeability of the whole container.

  There is no particular limitation on the thickness of the polymer film used in the present embodiment, and a suitable oxygen permeability, flexibility, strength, transparency, economy, and the amount of oxygen permeated by the opening when the packaging container is formed. From the viewpoints of accuracy and easiness in forming the openings, a suitable thickness may be appropriately selected in relation to the material for forming the polymer film. Typically, the thickness of the polymer film is preferably from 10 to 50 μm, more preferably from 15 to 45 μm.

  There is no particular limitation on the material of the polymer film, but a polymer used in a conventional film for packaging fruits and vegetables can be appropriately used. For example, polyethylene, polypropylene, polyethylene terephthalate, polystyrene, nylon (polyamide), ethylene vinyl acetate copolymer (EVA), polybutylene succinate, polybutylene succinate adipate, polylactic acid and the like can be mentioned. Also, for example, a natural polymer such as cellophane can be used. Further, any one of these materials may be used alone, or a plurality of these materials may be blended and / or laminated.

  From the viewpoint of easiness of processing and cost, the material of the polymer film is preferably a thermoplastic resin. Examples of the thermoplastic resin include homopolymers or copolymers of α-olefins such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. Specifically, ethylene polymers such as high-pressure low-density polyethylene, linear low-density polyethylene (LLDPE), and high-density polyethylene, propylene homopolymer, propylene / α-olefin random copolymer, and propylene block copolymer And polyolefins such as poly 1-butene and poly 4-methyl / 1-pentene. Examples of the thermoplastic resin include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyamides such as nylon-6, nylon-66, and polymethaxylene adipamide, polyvinyl chloride, polyimide, and ethylene / acetic acid. Biodegradable resins such as vinyl copolymers or saponified products thereof, polyvinyl alcohol, polyacrylonitrile, polycarbonate, polystyrene, ionomer, polylactic acid, polybutylene succinate, and mixtures thereof. One of these thermoplastic resins may be used, or two or more of them may be used in combination. Among these, as the thermoplastic resin, polyolefin, polyester, polyamide and the like are preferable because of their excellent rigidity and transparency. Further, as the thermoplastic resin, an ethylene polymer or a propylene polymer is more preferable because of its light weight and excellent film processability, and a propylene polymer is more preferable from the viewpoint of flexibility and transparency.

<Propylene polymer>
As the propylene-based polymer, propylene homopolymer (also referred to as homo PP) manufactured and sold under the name of polypropylene, propylene / α-olefin random copolymer (also referred to as random PP) And a crystalline polymer containing propylene as a main component, such as a mixture of a propylene homopolymer and a low-crystalline or amorphous propylene-ethylene random copolymer (also called a block PP). . The propylene-based polymer may be a mixture of propylene homopolymers having different molecular weights, and a propylene homopolymer and a random copolymer of propylene and ethylene or an α-olefin having 4 to 10 carbon atoms. It may be a mixture.

  As the propylene-based polymer, specifically, polypropylene, propylene / ethylene copolymer, propylene / ethylene / 1-butene copolymer, propylene / 1-butene copolymer, propylene / 1-pentene copolymer Propylene as a main monomer, such as propylene / 1-hexene copolymer or propylene / 1-octene copolymer, and copolymerized with this and at least one or more selected from ethylene and α-olefins having 4 to 10 carbon atoms. Coalescence. These may be used alone or in combination of two or more.

The density of the propylene-based polymer is preferably 0.890 to 0.930 g / cm ³ , more preferably 0.900 to 0.920 g / cm ³ . The MFR (ASTM D1238, load 2160 g, temperature 230 ° C.) of the propylene polymer is preferably 0.5 to 60 g / 10 min, more preferably 0.5 to 10 g / 10 min, and 1 to 5 g / 10 min. Is more preferred.

<Ethylene polymer>
As the ethylene polymer, a homopolymer of ethylene, ethylene as a main monomer, a copolymer thereof with at least one kind of α-olefin having 3 to 8 carbon atoms, an ethylene / vinyl acetate copolymer, Saponified products and ionomers. Specifically, polyethylene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 1-pentene copolymer, ethylene / 1-hexene copolymer, ethylene / 4-methyl-1-pentene Copolymers and copolymers of ethylene as a main monomer and at least one or more α-olefins having 3 to 8 carbon atoms, such as an ethylene / 1-octene copolymer, may be mentioned. The proportion of α-olefin in these copolymers is preferably from 1 to 15 mol%.

  Examples of the ethylene-based polymer include ethylene polymers manufactured and sold under the name of polyethylene. Specifically, high-pressure low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE) are preferred, and LLDPE is more preferred. LLDPE is a copolymer of ethylene and a small amount of propylene, butene-1, heptene-1, hexene-1, octene-1, 4-methyl-pentene-1, and the like. Further, the ethylene polymer may be a homopolymer of ethylene or a polymer mainly composed of ethylene such as LLDPE.

Density of the ethylene polymer is preferably ^{0.910~0.940g / cm 3, 0.920~0.930g / cm} 3 is more preferable. When the density is 0.910 g / cm ³ or more, heat sealability is improved. When the density is 0.940 g / cm ³ or less, workability and transparency are improved.

  The blend and / or laminate may be a blend of any of the above polymers and / or a laminate, and may be any of the above polymers and a material other than the polymer. And / or a laminate. That is, the polymer film is made of a material other than a polymer, such as a heat stabilizer (antioxidant), a weather stabilizer, an ultraviolet absorber, a lubricant, a slip agent, a nucleating agent, an antiblocking agent, an antistatic agent and an antifogging agent And various fillers such as talc, silica, and diatomaceous earth, in addition to pigments and dyes, or a laminate of a polymer film and metal foil, paper, nonwoven fabric, or the like.

In the present invention, the polymer film constituting the packaging container may be any of a non-stretched film and a stretched film.
From the viewpoint of mechanical strength and the like, stretched films of various polymers can be suitably used.
In particular, a stretched film (stretched polypropylene film) using a propylene-based polymer is excellent in mechanical strength, transparency, heat resistance and the like, and therefore can be particularly preferably used in the packaging container used in the present invention.
In addition, a film using an ethylene-based polymer (polyethylene-based film) may be either a non-stretched film or a stretched film, but from the viewpoint of heat sealing properties and the like, a non-stretched film is particularly preferably used. be able to.
Examples of particularly preferable polymer films constituting the packaging container in the present invention include a stretched polypropylene film, a polyethylene-based film, and a laminate of a stretched film and a polyethylene-based film.

<Stretched polypropylene film>
The stretched polypropylene film preferably used in the present invention may be composed of a film stretched in at least one direction, or the stretched polypropylene film itself may be stretched in at least one direction. When a biaxially stretched film is obtained as the stretched polypropylene film, it can be easily produced by, for example, sequentially or simultaneously biaxially stretching it. When a biaxially stretched film is obtained as a stretched polypropylene film, it is usually stretched 5 to 8 times in the machine direction, and then 8 to 10 times in the transverse direction by using a tenter mechanism, and the film thickness is finally adjusted. It can be manufactured by a method in which the thickness is 20 to 40 μm, or the film is stretched in the longitudinal and transverse directions by 5 to 10 times (25 to 100 times in area ratio), respectively.
<Polyethylene film>
The polyethylene-based film preferably used in the present invention is a film containing the ethylene-based polymer. Although various known molding methods can be used for the polyethylene-based film, cast molding by extrusion with an extruder is preferable from the viewpoint of production efficiency.

<Stretched film>
Polyamide film made of nylon 6, nylon 66, etc., film made of polyester represented by polyethylene terephthalate, polyethylene naphthalate, polycarbonate film, ethylene-vinyl alcohol copolymer film, polyvinyl alcohol film, polyvinyl chloride film, polyvinylidene chloride It is a uniaxially or biaxially stretched film made of a film, a polystyrene film, a polyolefin such as polypropylene, poly-L-lactic acid, poly-D-lactic acid, or a stereocomplex polylactic acid in which poly-L-lactic acid and poly-D-lactic acid are precisely coordinated.

<Laminated body of stretched film and polyethylene film>
The laminate of a stretched film and a polyethylene-based film preferably used in the present invention is obtained by laminating the above-mentioned polyethylene-based film layer and the stretched film layer. The polyethylene film may be stretched in one or two directions, but is preferably a non-stretched film from the viewpoint of the stability of the mechanical strength of the packaging bag.
Dry lamination is performed to attach a stretched film and a polyethylene-based film that have been prepared in advance using an adhesive, but it is necessary to perform a corona treatment on the stretched film surface where the adhesive is applied from the viewpoint of adhesion stability. preferable. Specifically, the surface tension of the film surface after corona treatment is preferably 35 mN / m or more, more preferably 40 mN / m or more, from the viewpoint of adhesion stability.

Further, these polymer films may be subjected to a stretching process, an anti-fogging process or printing, and may be an inorganic antibacterial agent such as silver or copper, or an organic antibacterial agent such as chitin, chitosan or allyl isothiocyanate. Agents may be applied, or they may be kneaded in a film.
From the viewpoint of maintaining the freshness of contents such as fruits and vegetables, it is preferable that the polymer film contains at least one antibacterial agent.
Further, a specific surfactant may be present on the surface of the polymer film in a specific amount, or the polymer film may have a specific amount of a specific surfactant to have an antibacterial function. For example, palmityl diethanolamine, stearyl diethanolamine, at least one compound selected from the group consisting of glycerin monolaurate and diglycerin monolaurate is preferably present on at least one surface of the polymer film, It is particularly preferred that one compound is present at 0.002 to 0.5 g / m ² . Alternatively, it is preferable that the polymer film contains at least one compound selected from the group consisting of palmityl diethanolamine, stearyl diethanolamine, glycerin monolaurate and glycerin monocaprate, and 0.001 to 3 parts by mass. It is particularly preferred that it be contained.
When a specific amount of a specific surfactant is present on the surface of the polymer film, or when the polymer film contains a specific amount of the specific surfactant, dew condensation on the surface of the polymer film is suppressed, and various bacteria Is suppressed, the growth of various bacteria in dew (drip) is suppressed, and an antibacterial function is exhibited.

From the viewpoint of transparency, flexibility, cost, and the like, it is particularly preferable to use a stretched polypropylene film, which has been widely used in the related art, or a laminate of a stretched polypropylene film and a polyethylene-based film as a polymer film. . Since these films are generally excellent in heat sealability, productivity is good in the production of packaging containers.
In this case, when using a stretched propylene film alone, the thickness is preferably 10 to 100 μm, and when using a laminate of a stretched polypropylene film and a polyethylene-based film, the thickness of the former is 10 to 50 μm. The thickness of the latter is preferably from 10 to 120 μm.

  When a polymer film that is not always suitable for heat sealing is used, it may be formed by laminating or coating a sealant layer on all or a part of the polymer film. For example, a cellophane film coated with an acrylic resin, a film in which linear low-density polyethylene (LLDPE) polystyrene and EVA are laminated on polyethylene terephthalate (PET), and the like, can be used as a suitable polymer film.

A method for manufacturing a package, and a method for maintaining freshness A fruit and vegetable including cabbage is housed in the packaging container of the present invention, and by appropriately adjusting the internal carbon dioxide concentration, the package of the present invention can be manufactured. The method for maintaining freshness of fruits and vegetables, which is one embodiment of the present invention, can be performed.
Hereinafter, the method for producing a package of the present invention will be described by taking, as an example, a case where a fruit or vegetable including a cabbage housed in a packaging container is a cut cabbage.

  First, in the pretreatment step, the cabbage is removed from the outer leaves by hand, divided into two to four parts, and the core is removed, and the cabbage is supplied to the conveyor. The cabbage conveyed by the conveyor is cut by a slicer, washed in a washing tank filled with cold water, also serving as cooling, and drained by a centrifugal dehydrator after draining. The dehydrated cut cabbage is packed in a packaging container (one side not sealed) containing the polymer film used in the present embodiment, and after weighing, the packaging container is sealed to maintain the freshness of the cut cabbage. A package is manufactured.

From the viewpoint of maintaining the freshness of the cut cabbage, it is preferable to use a sharp blade and reduce the number of scratches on the cut surface.
In addition, as the cut width is smaller, the cut area increases, and it becomes more difficult to maintain freshness. Therefore, from the viewpoint of maintaining freshness, it is preferable that the cut width is wide as long as it conforms to the form of demand.
Furthermore, if a lot of germs adhere to the cut cabbage from the beginning, it becomes more difficult to maintain the freshness. Therefore, it is preferable to reduce the adhesion of germs as much as possible by thoroughly washing the cut cabbage. Washing is particularly effective for maintaining freshness, since it not only reduces the adhesion of various bacteria, but also has the effect of removing cell fluids and the like that contain highly active enzymes and the like and may cause discoloration.
In addition, it is important to sufficiently remove moisture adhering to the cut cabbage surface after washing in order to maintain freshness. Even if water is drained by standing after washing, much water still adheres to the cut cabbage surface in many cases. Therefore, it is effective to remove water using a centrifugal dehydrator or the like.
This is because by adjusting the water content appropriately, it is possible to suppress the growth of various bacteria in extra small water droplets. More specifically, for example, after washing with hypochlorous acid at 80 to 120 ppm for 10 to 20 minutes based on the "Manual for Mass Cooking Facilities Hygiene Management" (Ministry of Health and Welfare), "analysis method of nutrition labeling in nutrition labeling standards" (consumer From the viewpoint of suppressing odor and preventing deterioration of appearance such as browning, it is necessary that the water content measured based on the weight loss when dried under reduced pressure at 70 ° C. for 5 hours based on the Agency) is in the range of 10 to 20%. Particularly preferred.

In the production of the package for maintaining freshness of fruits and vegetables of the present embodiment, after storing fruits and vegetables including cabbage in a packaging container having an oxygen permeability of 3000 cc / m ² / atm / day or less, a gas having a predetermined composition is used. For example, sealing may be performed after introducing a gas having a carbon dioxide concentration of 50% by volume or more. By introducing a gas having a predetermined composition, it is possible to quickly reach a desired carbon dioxide concentration in the packaging container, which is advantageous for maintaining freshness.
The carbon dioxide concentration of the gas introduced in the above embodiment is more preferably 70% by volume or more, particularly preferably 90% by volume or more. Although the oxygen concentration of the gas having the predetermined composition is not particularly limited, it is preferably 10% by volume or less, and is preferably 7% by volume or less because it is advantageous for maintaining the appearance of fruits and vegetables including cabbage. Particularly preferred. The other components of the gas introduced in the above embodiment are not particularly limited, but it is preferable to use nitrogen from the viewpoint of easy availability and small influence on human bodies, fruits and vegetables, and the like.
In addition, from the viewpoint of improving efficiency in the distribution process, saving space, eliminating a specific gas, etc., degassing may be performed before or at the time of sealing the packaging container.

In the package of the present invention, only fruits and vegetables including cabbage may be stored in the packaging container, or other members may be stored.
For example, in addition to the fruits and vegetables, a moisture absorbent and / or an antibacterial agent may be contained in the packaging container.
There is no particular limitation on the hygroscopic agent, and known or commercially available materials having a hygroscopic effect or a humidity controlling effect can be used. Examples of those preferably used as a moisture absorbent include, for example, activated carbon, silica gel, alumina gel, silica alumina gel, anhydrous magnesium sulfate, zeolite, synthetic zeolite, calcium oxide, calcium chloride, and calcined alum, or a mixture thereof. But not limited thereto.
Among them, it is particularly preferable to use activated carbon which has relatively little effect on fruits and vegetables and concerns about use near foods such as fruits and vegetables. Activated carbon can be in any form of powder or granules, and the raw material can be coconut shell, sawdust, charcoal, bamboo charcoal, lignite, peat, stone, oil pitch, or anything else. The activated carbon is desirably packaged for each unit of use with a nonwoven fabric, cellophane, paper, or the like, but the activated carbon itself may be fibrous. The activated carbon packaging material is preferably a heat-sealing material such as a nonwoven fabric made of a synthetic resin, but any paper or natural fiber may be used as long as it has water vapor permeability and does not spill activated carbon. no problem.

  There is no particular limitation on the antibacterial agent, and a substance having an antibacterial effect can be used as appropriate.However, a natural antibacterial agent having relatively little concern about the effect on fruits and vegetables and the use near foods such as fruits and vegetables can be used. It can be preferably used. More specifically, chitosan, allyl isothiocyanate, hinokitiol, limonene, and the like, which are natural antibacterial agents, can be stored in a packaging container.

  Hereinafter, the present invention will be specifically described with reference to Examples / Comparative Examples. The present invention is not limited in any sense by the following examples.

In the following Examples / Comparative Examples, each characteristic was evaluated by the following methods.
(With or without opening)
After injecting a red penetration liquid (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name: Ageless Seal Check Spray) into the packaging container, set the heating condition scale to 3 with an impulse sealer, heat seal with a width of about 5 mm, (Kokuyo PPC paper, paper A4) was pressed, and the presence or absence of the opening was confirmed by the presence or absence of transfer of the ink to the paper.
(Oxygen permeability)
First, a bag having an inner size of 170 mm × 235 mm was formed by the following method.
One film is almost equally folded in half and is about 5 mm wide. The scale of the heating condition is set to 3 with an impulse sealer (manufactured by Fuji Impulse, part number Fi-200-10WK), and heat sealing is performed. One of the sides substantially perpendicular to the heat-sealed side is heat-sealed so that the side is almost at the center, and the other side is heat-sealed except the end of about 2 cm, which is one communicating part of the other side. A 235 mm bag was formed.
Next, nitrogen gas was injected from the communication portion, and after the inside of the bag became saturated, almost all of the gas in the bag was discharged from the communication portion. After repeating this operation five times, nitrogen gas was injected to saturate the inside of the bag with nitrogen gas, and the communicating portion was heat-sealed with the impulse sealer under the same conditions. The bag saturated with nitrogen gas was allowed to stand in a room at 22 ° C. and 40% relative humidity (1 atm, oxygen concentration: 21%, nitrogen concentration: 79%) for 6 hours.
Next, about 20 cc of gas in the bag was sampled, and the oxygen concentration in the bag was measured using a zirconia oxygen concentration meter for food packaging (manufactured by Toray Engineering Co., Ltd., model number LC-750F). Further, the volume of the gas in the bag was measured, and the oxygen permeability was calculated from the following equation.
(Formula) Oxygen permeability = internal oxygen concentration change (%) / 100 × volume (cm ³ ) × 24 × 60 / hour (360 minutes) × 10000 cm ² / area (799 cm ² ) /0.21 (partial pressure of oxygen )
(Oxygen concentration / carbon dioxide concentration)
Measured using a CheckMate 3 O ₂ / CO ₂ analyzer for food packaging manufactured by Dansensor (appearance)
The package was opened, the fruits and vegetables were taken out, and the area of the whole browned portion was visually evaluated with n = 3 centering on the cabbage section. In addition, the presence or absence of mold was observed.
The evaluation criteria are as follows.
A: There is no browning B: There is browning but not more than 10% of the entire cross section C: There is browning but not more than 30% of the entire cross section, and it can be sold on a supermarket shelf D: There is browning but the whole cross section Less than 50% of the average, which is the level at which people are willing to eat, and cannot be sold on supermarket shelves.
E: Large browning, no level of eating (offensive odor)
When the package was opened, the face was approached and the internal odor was smelled, and the sensory evaluation was performed at n = 3.
The evaluation criteria are as follows.
A: No smell. B: Slight smell but not unpleasant. C: Smell, but no problem, at a level that can be sold on supermarket shelves. D: Slightly smelling, just barely enough to eat.
E: A level that does not cause me to eat because it smells so much

<Cut cabbage>
After the cabbage was soiled and the damaged portion was removed, the cabbage was cut into a width of about 2 mm, and was washed with hypochlorous acid at 100 ppm for 10 minutes based on the "Manual for Sanitation Management of Mass Cooking Facilities" (Ministry of Health and Welfare). Thereafter, the cut cabbage was obtained by properly dehydrating and drying.
The cut water content of cut cabbage was 17 based on the weight loss when dried under reduced pressure at 70 ° C. for 5 hours based on “Analysis Method of Nutrition Labeling in Nutrition Labeling Standards” (Consumer Affairs Agency). % (Comparative Example 1)
Two OPP (biaxially oriented polypropylene) films having a thickness of 40 μm are superimposed on each other, three sides are sealed by heat sealing, and then cut. One side is an unsealed packaging bag (170 mm × 235 mm, inner size: (Area: 799 cm ² ).
When the presence or absence of an opening in the film was observed, it was confirmed that there was no opening. The oxygen permeability of the packaging container was 1000 CC / m ² / atm / day.
150 g of cut cabbage was sealed in a packaging container, filled with nitrogen, and heat-sealed to prepare a package. The package was stored at 10 ° C., and the internal oxygen concentration and the internal carbon dioxide concentration were measured every day, an odor sensor was measured, and the off-flavor and appearance of the cut cabbage were evaluated.
Table 1 shows the results.

(Example 1)
A package was prepared and evaluated in the same manner as in Comparative Example 1, except that carbon dioxide was sealed in place of nitrogen.
Table 1 shows the results.

(Example 2)
A package was prepared and evaluated in the same manner as in Example 1, except that one hole having a diameter of 100 μm was provided in the package by laser processing.
The oxygen permeability of the packaging container was 2000 CC / m ² / atm / day.
Table 1 shows the results.

(Comparative Example 2)
A package was prepared and evaluated in the same manner as in Example 1, except that one hole having a diameter of 300 μm was provided in an OPP (biaxially oriented polypropylene) film having a thickness of 40 μm.
The oxygen permeability of the packaging container was 10,000 CC / m ² / atm / day.
Table 1 shows the results.

(Comparative Example 3)
A package was prepared and evaluated in the same manner as in Example 1, except that three holes having a diameter of 300 μm were provided in an OPP (biaxially oriented polypropylene) film having a thickness of 40 μm.
The oxygen permeability of the packaging container was 15000 CC / m ² / atm / day.
Table 1 shows the results.

(Comparative Example 4)
A package was prepared and evaluated in the same manner as in Example 1, except that 10 holes having a diameter of 300 μm were provided in an OPP (biaxially oriented polypropylene) film having a thickness of 40 μm.
The oxygen permeability of the packaging container was 30,000 CC / m ² / atm / day.
Table 1 shows the results.

In the package of each embodiment that satisfies the predetermined internal carbon dioxide concentration condition of the present invention, the browning of cut cabbage and the generation of off-flavor are effectively suppressed for at least 96 hours after sealing, and even after 144 hours. The edible level was maintained.
On the other hand, in Comparative Example 1, the off-flavor already occurred at the 48th hour, and after the elapse of 144 hours, the off-flavor worsened to a level at which it could not be used for food.
In Comparative Examples 2 to 4, the appearance deteriorated after 120 hours, and the commercial value of cut cabbage was partially impaired. Further, after 144 hours, in some of the comparative examples, the appearance was further deteriorated and mold was generated, and the commercial value of the cut cabbage was significantly impaired.

  The package of the present invention has a high practical value, such as suppressing the browning of fruits and vegetables including cabbage and preventing an offensive odor at a high level exceeding the limit of the conventional technology, and is particularly effective for maintaining freshness. It has high applicability in various industrial fields such as food processing, distribution, and restaurant.

Claims (5)

The oxygen permeability is 500 cc / m ² / atm / day or more and 3000 cc / m ² / atm / day or less at 20 ° C. and 90% RH, and the stretched polypropylene film, the polyethylene-based film, and the stretched film and the polyethylene-based film look containing a polymer film selected from the stack, of the polymer film two state superposed on each other or cut in the polymeric film a sheet of folded and fused formed by packaging container in the state, A package containing vegetables and fruits including cabbage, wherein the internal carbon dioxide concentration after holding the package at 10 ° C. for 72 hours after sealing is 50% by volume or more.   The package according to claim 1, wherein the packaging container does not have a through hole that can be confirmed by an ink leakage checker.   The package according to claim 1, wherein the polymer film contains at least one antibacterial agent, or has at least one antibacterial agent applied thereto.   The package according to any one of claims 1 to 3, further comprising a moisture absorbent and / or an antibacterial agent. Oriented polypropylene film, polyethylene film, and a laminate of a stretched film and the polyethylene film, seen including a polymeric film selected from, state superposed the polymer film into two each other or one above the polymer film, And cut into a packaging container having an oxygen permeability of 500 cc / m ² / atm / day or more and 3000 cc / m ² / atm / day or less at 20 ° C. and 90% RH. A method for maintaining freshness of fruits and vegetables, comprising a step of storing fruits and vegetables including cabbage, a step of sealing the packaging container, and a step of adjusting the internal carbon dioxide concentration to 50% by volume or more for 72 hours after the sealing of the packaging container.