JP2020055549A - Package for vegetables and fruits including broccoli and method for keeping freshness of the vegetables and fruits - Google Patents

Abstract

To provide a package that stores fruits and vegetables including broccoli in a packaging container and can effectively suppress deterioration in taste of broccoli.SOLUTION: A package stores fruits and vegetables including broccoli in a packaging container comprising a polymer film. When a value of total chlorophyll content in 100 g of flower buds of the broccoli at the time of sealing of the package is represented by CLand the value after the package is kept at 5°C for 72 hours after sealing is represented by CL, a ratio CL/CLis 0.87 to 1.20.SELECTED DRAWING: None

Description

  The present invention relates to a package excellent in freshness preserving performance of fruits and vegetables including broccoli, and more specifically, comprises storing fruits and vegetables including broccoli in a packaging container having a polymer film, and containing the total chlorophyll content of the broccoli. It relates to a package, the quantity of which satisfies certain conditions.

Broccoli rapidly declines in freshness after harvest, and at room temperature, yellowing rapidly progresses within a few days after harvest, and its commercial value is reduced. For this reason, especially in the case of transporting to a remote place, a device for suppressing yellowing is required in order to maintain commercial value, and various methods for maintaining freshness have been conventionally attempted.
For example, in Patent Document 1, broccoli is hermetically packaged with a film having micropores and an appropriate water vapor permeability, so that the oxygen concentration in the pouch is 3 to 15% and the carbon dioxide concentration is 6 to 18%. It has been proposed to maintain the freshness of broccoli, more specifically, to suppress yellowing, off-flavor, and withering by maintaining the broccoli.
However, even when such a technique is used, the taste of broccoli may decrease, and a technique capable of sufficiently suppressing the decrease in taste while suppressing yellowing and the like has been demanded.

JP-A-5-316942

  The present invention has been made in view of the above-described limitations of the prior art, and provides a package in which vegetables and fruits including broccoli are stored in a packaging container, which can effectively suppress a decrease in the taste of broccoli. The task is to

As a result of intensive studies, the present inventors have found that there is a close relationship between the total chlorophyll content of broccoli and its taste. It has been found that when the change satisfies specific conditions, the taste of broccoli can be maintained in a good state, and based on these findings, the present invention has been completed.
That is, the present invention
[1]
A package containing vegetables and fruits containing broccoli in a packaging container containing a polymer film,
The value of the total chlorophyll content in 100 g of the flower bud of the broccoli at the time of sealing the package was defined as CL _0, and the value after being held at 5 ° C. for 72 hours after sealing the package was defined as CL ₇₂ . The above-mentioned package, wherein the ratio CL ₇₂ / CL ₀ is 0.87 or more and 1.20 or less;
It is.
The following [2] to [6] are each one of preferred embodiments of the present invention.
[2]
The package according to [1], wherein the total chlorophyll content CL _{72 in} 100 g of the broccoli florets after being kept at 5 ° C. for 72 hours after sealing of the package is 13.0 mg / 100 g or more.
[3]
The package according to [1] or [2], wherein the polymer film has an oxygen permeability of 20,000 (cc / m ² · day · atm) or more and 55000 (cc / m ² · day · atm) or less. .
[4]
The package according to any one of [1] to [3], wherein the carbon dioxide concentration is 21% by volume or less.
[5]
A step of storing a fruit and vegetable containing broccoli in a packaging container comprising a polymer film to form a package and sealing it, and a step of holding the package, comprising:
The value of the total chlorophyll content in 100 g of the flower bud of the broccoli at the time of sealing the package was defined as CL _0, and the value after being held at 5 ° C. for 72 hours after sealing the package was defined as CL ₇₂ . The ratio CL ₇₂ / CL ₀ is 0.87 or more and 1.20 or less.
[6]
The method for retaining freshness of fruits and vegetables according to [5], wherein the step of retaining the package is performed at a temperature within a range of 3 to 5 ° C.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of the taste of broccoli in the fruits and vegetables stored in a packaging container can be suppressed effectively over a long period of time.

Hereinafter, embodiments for implementing the present invention will be described.
The present invention is a package containing vegetables and fruits containing broccoli in a packaging container containing a polymer film,
The value of the total chlorophyll content in 100 g of the flower bud of the broccoli at the time of sealing the package was defined as CL _0, and the value after being held at 5 ° C. for 72 hours after sealing the package was defined as CL ₇₂ . In the above package, the ratio CL ₇₂ / CL ₀ is from 0.87 to 1.20. 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.
In addition, such a packaging bag may have a circular shape, a triangular shape, a quadrangular shape, or a polygonal shape of a quadrangle or more in a plan view, but it is preferable to form a quadrangular shape, particularly a rectangular shape, from the viewpoint of workability and ease of handling. If the density of the broccoli in the bag is too high, the broccoli may be damaged due to contact between the broccoli and the color may be easily discolored.

The packaging container used in the present invention comprises the above-described polymer film, and its oxygen permeability is not particularly limited. However, from the viewpoint of maintaining the total chlorophyll content, for example, 15,000 or more, 60,000 (cc / cc). m ² · day · atm) or less is appropriate, preferably 20,000 or more and 55000 (cc / m ² · day · atm) or less, more preferably 20,000 or more and 50000 (cc / m ² · day · atm) or less. The carbon dioxide (carbon dioxide) permeability is not particularly limited, either. For example, from 15,000 to 60,000 (cc / m ² · day · atm) or less, from the viewpoint of maintaining the total chlorophyll content, from 20,000 to 55,000. (Cc / m ² · day · atm) or less, preferably 20,000 or more and 45,000 (cc / m ² · day・ Atm) The following is more preferable. In the polymer film constituting the packaging container used in the present invention, the amount and type of the fruits and vegetables to be stored, and the appropriate internal oxygen concentration and various gas concentrations such as carbon dioxide concentration are appropriately adjusted. Oxygen permeability and / or carbon dioxide permeability can be selected.

<Fruits>
The package of the present invention is obtained by storing fruits and vegetables including broccoli in the packaging container. Here, the phrase "the fruit or vegetable includes broccoli" is intended to include both the case where the whole fruit and vegetable is composed of broccoli and the case where a part of the fruit and vegetable is composed of broccoli. Therefore, usually, all of the fruits and vegetables are made of broccoli, but if necessary, vegetables, fruits, and the like other than broccoli can also be included as fruits and vegetables stored in the packaging container. In the present invention, there is no particular limitation on fruits and vegetables other than "broccoli" that can be stored together with "broccoli" in the packaging container, and non-heated or heated fruits and vegetables can be appropriately stored.
In addition, as long as broccoli is contained, ingredients other than fruits and vegetables, for example, foods other than fruits and vegetables, seasonings, food additives, and the like may be contained.

"Broccoli" that constitutes the package of the present invention (specifically, contained in a packaging container) is a green-yellow vegetable classified in the Brassicaceae / Brassica genus, and its flower buds and stems are mainly edible. I do. In the package of the present invention, broccoli having flower buds may be used, and one or a combination of two or more can be accommodated in a packaging container.
In addition, “broccoli” referred to here is not particularly limited in its origin, production place, type and variety. Representative varieties of broccoli include "Pixel", "Endeavor", "Green Veil", "Shurster", "Para Green", "Marshall", "Challenger", "Ridge", "Thundering", "Green Flame" , "Green Emperor", "Green flute", "Green ridge", and the like, but are not limited thereto. In addition, its variant cauliflower is also included in the term "broccoli". In addition, broccoli, such as "Romanesque", "Hanakkori", "Stick Senor", "Aletta", or "Asskko", is also included in the term "broccoli". .
These broccoli may be used alone or in combination of two or more. The broccoli ripeness, taste, color tone, appearance, etc. are comprehensively used, and a suitable product is suitably used.

  "Broccoli" may be used as it is, or may be subjected to washing treatment or sterilization treatment by washing with water, as appropriate, in order to enhance the commercial value of food from the viewpoint of hygiene and freshness. .

  In the present invention, there is no particular limitation on the form of fruits and vegetables including "broccoli" stored in a package and kept fresh. 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.

<Total chlorophyll content of broccoli>
In the present invention, the total chlorophyll content of the flower buds of `` broccoli '' stored and kept fresh in a package can be measured by a method conventionally known in the art. After taking out, chlorophyll is extracted from the flower buds into acetone or the like, and the total chlorophyll content contained in the flower buds can be measured by a spectrophotometric method (visible). Can be measured.
In the present invention, the total chlorophyll content refers to the total content of chlorophyll a and chlorophyll b.
The total chlorophyll content was measured for the broccoli flower bud before storing the package, and the broccoli flower bud after being stored and sealed in the package for 72 hours at 5 ° C., and the total chlorophyll content in 100 g of the flower bud CL ₀ and CL ₇₂ are obtained, and the ratio of CL ₇₂ / CL ₀ is calculated.
In the present invention, the ratio CL ₇₂ / CL ₀ is from 0.87 to 1.20, preferably from 0.93 to 1.15, more preferably from 0.95 to 1.10.
The total chlorophyll content CL _{72 in} 100 g of the broccoli florets after being kept at 5 ° C. for 72 hours after sealing of the package is preferably 13.0 mg / 100 g or more in terms of the weight ratio of total chlorophyll / florets. , And more preferably 14.0 mg / 100 g or more. The upper limit is preferably 18.0 mg / 100 g or less.
Furthermore, it is particularly preferable that the total chlorophyll content CL ₁₆₈ , CL _{336 of the} broccoli flower bud after being kept at 5 ° C. for 168 hours, further 336 hours after the sealing is within the above range.
Means for maintaining the total chlorophyll content of broccoli florets above a certain value include maintaining broccoli in a cold and normal environment before storing in a packaging container, and keeping the oxygen concentration at a level not excessively low. And keeping the carbon dioxide concentration at a level not excessively high, and the like, but are not limited thereto.

<Package>
The internal oxygen concentration of the package of the present invention is not particularly limited, but is preferably, for example, 1.5% by volume or more.
Since the internal oxygen concentration can fluctuate with the passage of time after sealing, if the elapsed time after sealing is specified, for example, the internal oxygen concentration after holding the package at 5 ° C. for 72 hours after sealing is 1. Particularly preferred is 5% by volume. Further, the oxygen concentration immediately after the sealing of the package is preferably 6% by volume or more.
When the internal oxygen concentration of the package satisfies any of the conditions in the above range, it becomes easy to control the total chlorophyll content of broccoli in the fruits and vegetables contained in the packaging container so as to satisfy the above conditions, and the broccoli The taste can be kept more effectively. In this preferred embodiment, the good taste of the broccoli in the fruits and vegetables can be maintained for a long time after sealing of the package, preferably for more than 72 hours at 5 ° C.

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 adjust appropriately by adjusting the oxygen in the gas filled in the packaging container.
Also, the internal oxygen concentration of the package can be adjusted to a predetermined concentration by adjusting the amount of oxygen flowing out of the package and / or the amount of oxygen consumed by breathing of fruits and vegetables including broccoli in the package. It is possible. More specifically, by adjusting the gas permeability of the packaging container, the amount of oxygen flowing out of the package can be adjusted, and the amount of fruits and vegetables stored in the packaging container and / or the amount filled in the packaging container can be adjusted. By adjusting the amount of oxygen produced, it is possible to adjust the amount of oxygen after consumption by the respiration of the fruits and vegetables.
The oxygen concentration inside the package can be specified, for example, by sampling the gas inside the package with a sampling needle tube and measuring the oxygen concentration with a zirconia oximeter for food packaging.
Here, "after the package is sealed" refers to an elapsed time when a packaged fruit or vegetable containing broccoli is stored at a predetermined temperature after the packaging container is sealed, and "After holding for 72 hours at 5 ° C. after sealing,” refers to a state immediately after storing the fruits and vegetables including broccoli in the packaging container, sealing the packaging container, and then holding at 5 ° C. for 72 hours.

The internal carbon dioxide concentration of the package of the present invention is not particularly limited, but is preferably, for example, 21% by volume or less.
Since the internal carbon dioxide concentration can fluctuate over time after sealing, if the elapsed time after sealing is specified, for example, the internal carbon dioxide concentration after holding the package at 5 ° C. for 72 hours after sealing is It is preferably at most 21.0% by volume. Further, the carbon dioxide concentration immediately after the sealing of the package is preferably 8% by volume or more.
When the internal carbon dioxide concentration of the package satisfies any of the conditions in the above range, it becomes easy to control the total chlorophyll content of broccoli in the fruits and vegetables contained in the packaging container, and the taste of broccoli can be further effectively improved. Can hold. In this preferred embodiment, the good taste of the broccoli in the fruits and vegetables can be maintained for a long time after sealing of the package, preferably for more than 72 hours at 5 ° C.
The internal carbon dioxide concentration of the package can be adjusted to a desired range by adjusting the carbon dioxide concentration immediately after packaging. 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. 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 broccoli in the package. It is possible. More specifically, by adjusting the gas permeability of the packaging container, the amount of carbon dioxide flowing out of the packaging body can be adjusted, and the amount of fruits and vegetables stored in the packaging container and / or the amount of By adjusting the amount of oxygen to be filled, it is possible to adjust the amount of carbon dioxide generated by respiration of fruits and vegetables.

The oxygen concentration and carbon dioxide concentration inside the package of the present invention can be determined, for example, by measuring the gas inside the package using a food gas replacement packaging O ₂ & O ₂ / CO ₂ meter (CheckPoint II, CheckPoint3 or CheckMate3, MoconEurope) or It can be specified by measuring with a gas chromatograph or a gas detector tube (manufactured by Gastec).
Here, "after sealing" refers to the elapsed time since the packaging body was sealed, specifically, the time elapsed after storing the broccoli-containing fruits and vegetables in the packaging container and then sealing the packaging container. Say time. Therefore, for example, “after sealing, at 5 ° C. for 72 hours” specifically means that after storing vegetables and broccoli-containing fruits and vegetables at room temperature in a packaging container, and then sealing the packaging container at 5 ° C. The state after 72 hours has elapsed.

<Polymer film>
In addition, in order to realize the above-mentioned total chlorophyll content, it is desirable to configure the packaging container using a polymer film having an oxygen permeability within a predetermined value range.
That is, the oxygen permeability of the polymer film used in the present invention is preferably 40,000 (cc / m ² · day · atm) or less at 20 ° C. and 90% RH. In the package of the present invention, when the oxygen permeability of the polymer film constituting the packaging container is within the above range, it is much easier to realize the above preferable internal oxygen concentration.
Further, the carbon dioxide (carbon dioxide) permeability of the polymer film used in the present invention is preferably, for example, 40000 (cc / m ² · day · atm) or less at 20 ° C. and 90% RH. In the package according to the present invention, when the carbon dioxide gas permeability of the polymer film constituting the packaging container is within the above range, it is much easier to achieve the above-mentioned preferable internal carbon dioxide concentration.
In the package according to the present invention, the polymer film constituting the packaging container has the oxygen permeability and / or the carbon dioxide gas permeability at 20 ° C. and 90% RH within the above range, so that the fruits and vegetables stored in the packaging container It becomes easier to maintain the taste of the broccoli in it at 5 ° C. for a long period of time after sealing, for example for 72 hours.
The oxygen permeability of the polymer film used in the present invention at 20 ° C. and 90% RH is more preferably 10,000 (cc / m ² · day · atm) or less, and 5000 (cc / m ² · day · atm). ) Or less, and particularly preferably 1900 (cc / m ² · day · atm) or less.
The carbon dioxide permeability of the polymer film used in the present invention at 20 ° C. and 90% RH is more preferably 20,000 (cc / m ² · day · atm) or less, and 10,000 (cc / m ² · (day · atm) or less, more preferably 4000 (cc / m ² · day · atm) or less.
When a higher oxygen permeability and / or carbon dioxide permeability is suitable, the oxygen permeability and / or carbon dioxide permeability is appropriately adjusted by providing an opening in the polymer film as described later. be able to.

The oxygen permeability and carbon dioxide permeability of the polymer film used in the present invention 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 40% relative humidity in air (1 atm, oxygen concentration: 21%, carbon dioxide concentration: 0.03%).
Next, the oxygen concentration in the bag is measured using an O ₂ & O ₂ / CO ₂ meter (CheckPoint II, MOCONeurope) for food gas replacement packaging. Further, the volume of the gas in the bag is measured, and the oxygen permeability and the carbon dioxide gas permeability are calculated from the following equations.
(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)
(Formula) carbon dioxide gas permeability = internal carbon dioxide concentration change (%) / 100 × volume ^{(cm 3) × 24 × 60} / time (360 minutes) × 10000 cm ² / area ^{(2 × a × b cm 2} ) / dioxide Partial pressure of carbon (0.0003atm)
The water vapor permeability (moisture permeability) of the polymer film used in the present invention can be measured, for example, by the following method.
In order to evaluate the moisture permeability based on JIS Z0208 “Test method for moisture permeability of moisture-proof packaging material”, a test is performed using a moisture-permeable cup. The temperature and humidity conditions at that time are 40 ° C. and 90% RHM.
The measurement is performed by enclosing a moisture absorbent / calcium chloride (anhydrous) in a moisture-permeable cup and repeating the weighing operation at regular intervals (every 24 hours, every 48 hours, or every 96 hours). To be evaluated. Use a film-sealing agent that has no water absorption and moisture permeability, does not easily come off from the sample and the inner edge of the cup, and is easy to seal.

  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, the thickness is set to 100 μm or less, preferably 60 μm or less, more preferably 50 μm or less, still more preferably 45 μm or less, and most preferably 40 μm or less. It becomes even easier to set the oxygen permeability and carbon dioxide gas permeability at 90% RH within the above preferred ranges. If mechanical strength, workability and the like are also taken into consideration, the thickness of the polymer film is preferably 5 to 60 μm, more preferably 10 to 55 μm, and still more preferably 12 to 50 μm, It is still more preferably from 15 to 45 μm, particularly preferably from 18 to 30 μm.

As described above, the oxygen permeability and carbon dioxide gas permeability of the polymer film can be adjusted by appropriately selecting the material, thickness, processing method, and the like of the polymer film. It is not necessary to provide an opening in the polymer film for adjusting carbon dioxide permeability.
If no opening is provided in the polymer film, the manufacturing process becomes simpler and less costly, and it is not necessary to precisely control the size and shape of the opening.
The absence of an opening in the polymer film (that is, “no hole”) means that, for example, the polymer film constituting the packaging container does not have a through hole that can be confirmed by an ink leakage checker. , You can check.

On the other hand, in one embodiment of the present invention, when a thick polymer film or a polymer material having a low oxygen permeability needs to be used, a desired oxygen permeability for maintaining the respiration of fruits and vegetables or In order to realize carbon dioxide gas permeability, an opening provided in the polymer film may be used in combination. Since broccoli has a relatively large respiration rate among fruits and vegetables, it is often preferable to use an opening together in the present invention, which is one of the objects for maintaining freshness of broccoli.
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 and the carbon dioxide gas permeability of the polymer film are appropriate. For example, when the openings are circular, the diameter is preferably about 20 to 100 μm, and more preferably about 50 μm, in order to adjust the transmittance.
Although the number of openings is not particularly limited, for example, by having 1 to 300 openings per packaging container, it is also possible to adjust the oxygen permeability and the carbon dioxide permeability.
The interval between the openings is not particularly limited since it depends on the number of required openings, but is preferably about 1 to 100 mm from the viewpoint of the efficiency of the production and the strength of the film.
The size of each opening and the number of openings can be appropriately set and changed as long as the oxygen permeability or carbon dioxide permeability of the entire packaging container is appropriate. The guideline is the number of openings occupying the effective area. For example, in the case where an opening having a diameter of about 50 μm (opening area of about 2000 μm ² ) is provided, there is an effect of increasing the oxygen permeability by about 2000 cc / m ² / day / atm for every 200 mm × 200 mm packaging container. It is preferable to determine the number of slit openings from the required oxygen permeability of the entire packaging container based on such knowledge. In this case, the number of openings per packaging container is preferably 5 to 100, and particularly preferably 10 to 80.
In the embodiment in which the polymer film is provided with an opening, the oxygen permeability of the polymer film is preferably 15,000 or more and 60,000 (cc / m ² · day · atm) or less from the viewpoint of maintaining freshness and flavor of broccoli. And preferably from 20,000 to 55000 (cc / m ² · day · atm), and particularly preferably from 20,000 to 50,000 (cc / m ² · day · atm).
Similarly, in this embodiment, the carbon dioxide permeability of the polymer film is suitably from 15,000 to 60000 (cc / m ² · day · atm), and from 20,000 to 55000 (cc / m ² · day · atm). Or less, particularly preferably 20,000 or more and 45,000 (cc / m ² · day · atm) or less.

The water vapor permeability of the polymer film constituting the packaging container used in the present invention is not particularly limited, but is preferably 250 (g / m ² · day) or less from the viewpoint of maintaining good taste. , 100 (g / m ² · day) or less, more preferably 50 (g / m ² · day) or less.
If not packed, or if the water vapor permeability is high, the evaporation of water proceeds, which tends to cause yellowing and deterioration of taste.

  There is no particular limitation on the thickness of the polymer film used in the present invention, and suitable oxygen permeability, carbon dioxide gas permeability, flexibility when forming a packaging container, strength, transparency, economy, etc. When it is provided, a suitable thickness may be appropriately selected in relation to the material for forming the polymer film from the viewpoint of accuracy and easiness in forming the opening. Typically, the thickness of the polymer film in the case of providing an opening is preferably 5 to 60 μm, more preferably 10 to 55 μm, further preferably 12 to 50 μm, and more preferably 15 to 45 μm. Is still more preferable, and it is particularly preferable that it is 18 to 30 μm.

  The material of the polymer film is not particularly limited, but a polymer used for 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; 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 them, as the thermoplastic resin, polyolefin, polyester, polyamide and the like are preferable because of their excellent rigidity and transparency. 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 the polymer, for example, 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. To 20 to 40 μm, or by stretching in the longitudinal and transverse directions by 5 to 10 times (25 to 100 times in area magnification).
<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, the polymer film 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.

<Production method of package and method of maintaining freshness>
By storing the fruits and vegetables including broccoli in the packaging container of the present invention and appropriately maintaining the total chlorophyll content of the broccoli, the package of the present invention can be manufactured, which is an embodiment of the present invention. The taste of the fruits and vegetables can be maintained.
Hereinafter, the method for producing a package of the present invention will be described using a package for maintaining freshness of broccoli as an example.

  First, in the pre-treatment process, the harvested broccoli is trimmed to an appropriate size if necessary, washed with a washing machine or the like to remove dirt such as mud and other germs, and dehydrated with a centrifugal dehydrator if necessary. I do. The broccoli after dehydration is weighed and packed in a packaging container (one side not sealed) containing the polymer film used in the present embodiment at room temperature, and then the packaging container is sealed, and A package for maintaining freshness is manufactured.

If the broccoli contained in the packaging container has a large amount of germs attached from the beginning, it is more difficult to maintain freshness and it is unsanitary, so wash it well and remove any germs before packing it in the packaging container. It is preferable to reduce as much as possible. In addition, washing 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 and the like. Therefore, washing is particularly effective for maintaining freshness.
In addition, after washing, it is effective to sufficiently remove the moisture adhering to the surface of the broccoli before storing the broccoli in the packaging container, which is also effective for maintaining freshness.

  In addition, the package for maintaining freshness of fruits and vegetables of the present embodiment may be filled with nitrogen and / or deaerated when storing the fruits and vegetables including broccoli and sealing the packaging container. Further, from the viewpoints of efficiency improvement, space saving, elimination of a specific gas, and the like during the distribution process, degassing may be performed after sealing the packaging container.

After performing the step of storing the broccoli in a packaging container containing a polymer film according to the method described above, the total chlorophyll content in 100 g of the florets of the broccoli in the packaging container is stored and sealed in a package. the value of the after holding for 72 hours at 5 ° C. after stopping, the ratio between the value at the time of sealing of the _package, as _CL 72 / CL ₀ is 0.87 to 1.20, preferably more _{CL 72} Is maintained at 13.0 mg / 100 g or more, so that the taste of broccoli can be effectively maintained. In this case, the deterioration of the appearance is maintained at a level comparable to that of the prior art. The holding temperature at that time is preferably in the range of 3 to 5 ° C.
In addition, in this embodiment, it can be carried out within a holding temperature range of 3 to 5 ° C. However, when holding at a temperature lower than 5 ° C., the test is carried out by holding at 5 ° C. in the same packaging container and gas atmosphere. It is determined whether the measured value of CL ₇₂ / CL ₀ is within the range of the present invention.

In the package of the present invention, only fruits and vegetables including broccoli 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 action can be used as appropriate.However, there is relatively little concern about the effect on fruits and vegetables including shredded cabbage and use near foods such as fruits and vegetables. An antibacterial agent 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.
(Moisture permeability)
The moisture permeability was measured by a cup method based on JIS Z0208, "Test Method for Permeation Moisture of Moisture-Proof Packaging Material". The water vapor permeability is determined by the water vapor permeability of the polymer film itself, which is the material of the bag, because it is difficult to measure the water vapor permeability as a bag.
(With or without film 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 concentration and carbon dioxide concentration)
The gas (O ₂ , CO ₂ ) concentration in the package was measured using a gas detector tube. Three samples of each condition were prepared and used for the measurement.
(Oxygen permeability and carbon dioxide permeability)
First, a bag having an inner size of 175 mm × 190 mm was formed by the following method.
One sheet of the same film as the one forming the package is folded almost evenly into two pieces, about 5 mm in width, and the scale of the heating condition is set to 3 with an impulse sealer (manufactured by Fuji Impulse, part number Fi-200-10WK) to heat. Sealing is performed, and the entirety of one of the sides substantially perpendicular to the heat sealing side is heat-sealed so that the heat sealing side is substantially at the center, and the entire side excluding the end of about 2 cm which is one communicating part of the other side. Thus, a bag having an inner size of 175 mm × 190 mm was formed. At that time, one pinch cock for gas measurement was provided in the heat seal portion.
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%, carbon dioxide concentration: 0.03%) for 6 hours.
Next, the oxygen concentration and carbon dioxide concentration in the bag were measured in the same manner as described above. Further, the volume of the gas in the bag was measured, and the oxygen permeability and the carbon dioxide gas permeability were calculated from the following equations.

(Formula) Oxygen permeability = internal oxygen concentration change (%) / 100 × volume (cm ³ ) × 24 × 60 / hour (360 minutes) × 10000 cm ² / area (665 cm ² ) / oxygen partial pressure (0.21 atm) )
(Formula) Carbon dioxide gas permeability = internal carbon dioxide concentration change (%) / 100 × volume (cm ³ ) × 24 × 60 / hour (360 minutes) × 10000 cm ² / area (665 cm ² ) / partial pressure of carbon dioxide ( 0.0003 atm)
(Total chlorophyll content of flower buds of broccoli)
The total chlorophyll content contained in the flower buds was measured by a spectrophotometric method (visible). Flower buds of three broccoli strains were used as samples.
The measurement was performed according to the Mackinney method. 0.2 to 1 g of a sample is placed in a 50 ml volumetric flask, 0.1 g of calcium carbonate is added, 80% acetone is added, and the volume is increased. Then, the solution is placed in an ultrasonic cleaner for 5 minutes, and then left in a dark place for 2 hours. To extract chlorophyll. This was filtered, and the absorbance of the filtrate was measured at 750 nm, 663 nm, and 645 nm,
The values of the chlorophyll a content and the chlorophyll b content were determined according to the following formulas. A663 and A645 in the calculation formula are values obtained by subtracting the absorbance at 750 nm from the absorbance at 663 nm and 645 nm, respectively.
Chlorophyll a content = 12.7 × A663−2.59 × A645
Chlorophyll b content = −4.6 × A663−22.9 × A645
From the above,
Total chlorophyll content = chlorophyll a content + chlorophyll b content was calculated.
(Eating)
The taste of broccoli flower buds was evaluated based on the following five levels using sweetness, umami, aroma, and texture as indices.
◎: good (sweet and umami, with a broccoli-like flavor)
：: Moderately good (sweetness, umami, and broccoli-like flavor remain moderately)
△: Normal (sweetness, umami, and aroma remain moderately, but flavor is modest and slightly bitter)
×: Poor (weak sweetness, slight umami taste, flavor like radish)
XX: Impossible to taste (smell is strong and difficult to eat)
(Appearance (color of flower bud))
The color tone L ^* , a ^* , b ^* (color system CIE1976) of the flower bud was measured by a colorimeter.
Three broccoli strains were used for the measurement, and three points per strain (one vertex of the flower bud, two points on the outer periphery) were evaluated. From the obtained L ^* , a ^* , and b ^* , yellowing was performed according to the following formula. The degree was calculated.
(Degree of yellowing) = L ^** b ^* / | a ^** 100 |

(Example 1)
A polyethylene film having a thickness of 30 μm (moisture permeability: 10 g / (m ² · day)) provided with 50 holes (substantially circular openings) having a diameter of about 50 μm in the entire bag (oxygen permeability: 22765 cc / (m ²⁾ · day · atm), the carbon dioxide ^{permeability: 23110cc / (m 2 · day} · atm)) to prepare a bag inside dimension 250 mm × 300 mm was heat sealed with.
Approximately 300 g of broccoli (produced in Saitama) prepared in advance was packed in a bag at room temperature in the air, and the upper portion was sealed by heat sealing about 1 cm to obtain a package. A total of three bags of this package were prepared.
These packages were stored refrigerated (5 ° C., humidity 78-86%) and the oxygen concentration inside the packages daily (specifically, 0 hours, 72 hours, and 168 hours after sealing). The carbon dioxide concentration and the total chlorophyll content and taste of the broccoli flower buds were measured to evaluate the color tone.
The sweetness, umami, and broccoli-like flavor remained moderately, and the taste was rather good.
Table 1 shows the results.

(Example 2)
A polyethylene film having a thickness of 30 μm (moisture permeability: 10 g / (m ² · day)) provided with 120 holes (substantially circular openings) of about 50 μm in diameter (oxygen permeability: 46866 cc / (m ²⁾ · day · atm), the carbon dioxide ^{permeability: 42824cc / (m 2 · day} · atm)) , except that to prepare a bag with, the same procedure as in example 1, to create a package accommodating the broccoli, It was stored in a refrigerator (5 ° C., humidity: 78 to 86%) and evaluated daily.
The sweetness, umami, and broccoli-like flavor remained moderately, and the taste was rather good. Table 1 shows the results.

(Comparative Example 1)
25 μm thick biaxially oriented polypropylene film (without openings, (moisture permeability: 6 g / (m ² · day), oxygen permeability: 2000 cc / (m ² · day · atm), carbon dioxide permeability: 5000 cc / ( except of manufacturing a bag with a m ² · day · atm)), the same procedure as in example 1, to create a package housing the broccoli, and stored under refrigeration (5 ° C., humidity 78-86%) Was evaluated over time.
Although the sweetness, umami, and aroma remained moderately good, the taste was a moderate level, with a little modest flavor and slight bitterness.
Table 1 shows the results.

(Comparative Example 2)
Broccoli was stored in the same manner as in Example 1 except that the broccoli was stored in the open air without using a packaging bag, and evaluated over time.
Although the sweetness, umami, and aroma remained moderately good, the taste was a moderate level, with a little modest flavor and slight bitterness.
Table 1 shows the results.

According to the package of the present invention shown in Examples 1 and 2, the total chlorophyll content of the broccoli florets after being kept at 5 ° C. for 72 hours after sealing is the ratio CL to the value at the time of sealing. ₇₂ / CL ₀ was 1.07 and 1.00. At this time, good taste was maintained even 72 hours after sealing. Also, yellowing was suppressed, at least at a level comparable to that of the prior art.
On the other hand, in the case of the package of Comparative Example 1 and the non-package of Comparative Example 2, the total chlorophyll content of the flower buds of the broccoli after being kept at 5 ° C. for 72 hours after sealing is the same as the value at the time of sealing. Ratio CL ₇₂ / CL ₀ was less than 0.87. At this time, the taste at 72 hours after sealing was at a normal level, and good taste could not be maintained.

  The package of the present invention has a technical effect of high practical value, such as the ability to maintain the taste of broccoli in the package at a very high level in a package containing vegetables and fruits containing broccoli in a packaging container. It has high applicability in various industrial fields such as food processing, distribution, and restaurant.

Claims (6)

A package containing vegetables and fruits containing broccoli in a packaging container containing a polymer film,
The value of the total chlorophyll content in 100 g of the flower bud of the broccoli at the time of sealing the package was defined as CL _0, and the value after being held at 5 ° C. for 72 hours after sealing the package was defined as CL ₇₂ . The above package, wherein the ratio CL ₇₂ / CL ₀ is from 0.87 to 1.20. The package the total chlorophyll content _{CL 72} in broccoli florets 100g after being held for 72 hours at 5 ° C. After the sealing of is 13.0 mg / 100g or more, the packaging body according to claim 1. The package according to claim 1, wherein the polymer film has an oxygen permeability of 20,000 (cc / m ² · day · atm) or more and 55000 (cc / m ² · day · atm) or less.   The package according to any one of claims 1 to 3, wherein the carbon dioxide concentration is 21% by volume or less. A step of storing a fruit and vegetable containing broccoli in a packaging container comprising a polymer film to form a package and sealing it, and a step of holding the package, comprising:
The value of the total chlorophyll content in 100 g of the flower bud of the broccoli at the time of sealing the package was defined as CL _0, and the value after being held at 5 ° C. for 72 hours after sealing the package was defined as CL ₇₂ . The ratio CL ₇₂ / CL ₀ is 0.87 or more and 1.20 or less. The method for retaining freshness of fruits and vegetables according to claim 5, wherein the step of retaining the package is performed at a temperature within a range of 3 to 5C.