JP2019135165A - Package for garden stuff including soybean, and freshness keeping method of garden stuff - Google Patents

Abstract

To provide a package capable of suppressing yellow discoloration of soybean for a long period especially at room temperature, which is a package formed by storing a garden stuff including soybean in a packaging container containing a polymeric film.SOLUTION: There is provided a package formed by storing a garden stuff including soybean in a packaging container containing a polymeric film. In the package, a vitamin C content of soybean after being held for 72 hours at room temperature after sealing the package is 35 mg/100 g or more.SELECTED DRAWING: None

Description

  The present invention relates to a package excellent in the freshness retention performance of fruits and vegetables containing green soybeans, more specifically, containing fruits and vegetables containing green beans in a packaging container having a polymer film, and a predetermined time has elapsed after sealing. It is related with the package body whose vitamin C content of the said green soybean later is below a specific value.

  Green soybeans continue to work after being harvested. For this reason, it is necessary to prevent quality degradation of green soybeans during storage and distribution after harvesting and before eating. Sealed packaging such as polypropylene film is used to maintain the freshness of green soybeans, but the sealed green soybeans are exposed to an anaerobic atmosphere and are forced to breathe anaerobically. When you open the bag, you will notice a strange odor in most packages. Therefore, in order to provide a green soybean package that does not cause a bad odor of green soybeans, does not deteriorate in taste and does not wither, and can maintain the freshness of green soybeans for a long period of time, a porous synthetic resin film is used. In the green soybean package containing green soybeans, there has been proposed a green soybean package that limits the open area ratio of the perforated synthetic resin film and the bag area per 100 g of green soybeans within a specific numerical range. (See Patent Document 1).

  However, even if these techniques are used, a so-called yellowing phenomenon may occur in which the pods of green soybeans turn yellow, and a technique that can sufficiently suppress yellowing has been desired.

JP 2006-204194 A

  In view of the limitations of the prior art described above, the present invention is a packaged body in which fruits and vegetables containing green soybeans are stored in a packaging container including a polymer film. It is an object to provide a package that can be effectively suppressed.

As a result of intensive studies, the present inventor has found that there is a close relationship between the vitamin C content of green soybeans and the yellowing of strawberries, etc. It was found that when the vitamin C content is less than a specific value, yellowing of edamame koji is effectively suppressed, and based on these findings, the present invention has been completed.
That is, the present invention
[1] A package body in which fruits and vegetables containing green soybeans are stored in a packaging container including a polymer film, and after the package body is sealed, the green soybeans are held at room temperature for 72 hours. It is the said package body whose vitamin C content is 35 mg / 100g or more.
The following [2] to [4] are each a preferred embodiment of the present invention.
[2] The package according to [1], wherein the polymer film has an oxygen permeability of 35,000 to 60000 (cc / m ² · day · atm).
[3] The package according to [1] or [2], wherein yellowing of the green soybeans is suppressed at room temperature for 72 hours or more after the package is sealed.
[4] The package according to any one of [1] to [3], wherein the internal carbon dioxide concentration is 1% by volume or less.

ADVANTAGE OF THE INVENTION According to this invention, yellowing of the green soybeans in the fruits and vegetables accommodated in the packaging container containing a polymer film can be suppressed effectively over a long period of time.
The

Hereinafter, modes for carrying out the present invention will be described.
The present invention contains vitamin C contained in green soybeans after storing the green fruits and vegetables containing green soybeans in a packaging container containing a polymer film, and after holding the package for 72 hours at room temperature. A package having an amount of 35 mg / 100 g or more. That is, the package of the present invention has at least a packaging container and fruits and vegetables stored therein.

<Packing container>
The packaging container constituting the package of the present invention comprises a polymer film. Here, “comprising a polymer film” means that when the entire packaging container is made of a polymer film and when a part of the packaging container such as a lid is made of a polymer film, It is intended to include both.
Therefore, the packaging container may be a flexible packaging container, or a so-called packaging bag, whose whole or main part is composed of a flexible polymer film, such as a flexible polymer film and coated paper. It 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 in the form of a combination of a molecular film and a rigid member such as a tray or 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. A packaging bag can be formed by, for example, fusing. The remaining one side can be sealed by arranging the contents such as fruits and vegetables in the packaging bag and then fusing it by heat sealing.
Such a packaging bag may have a circular shape, a triangular shape, a quadrangular shape, or a polygonal shape equal to or more than a quadrangular shape in a plan view, but is preferably rectangular from the viewpoint of processability and ease of handling. In addition, if the density of green soybeans in the bag is too high, the green beans are scratched by contact between the green beans and easily discolored.

The packaging container used in the present invention comprises the above-described polymer film, and its oxygen permeability is not particularly limited. For example, the range is 35000 to 60000 (cc / m ² · day · atm). Of these, preferred is one. The carbon dioxide (carbon dioxide) permeability is not particularly limited, but is preferably within the range of, for example, 45,000 to 60000 (cc / m ² · day · atm).
In the polymer film constituting the packaging container used in the present invention, an appropriate oxygen permeability and / or carbonic acid according to the amount and type of fruits and vegetables to be stored and various gas concentrations such as a desired internal oxygen concentration and carbon dioxide concentration. Gas permeability can be selected.

<Vegetables>
The package of this invention accommodates the fruits and vegetables containing green soybeans in the said packaging container. Here, the phrase “including fruits and vegetables” means that both the case where all the fruits and vegetables are made of green soybeans and the case where some of the fruits and vegetables are made of green beans are included. Therefore, normally, all the fruits and vegetables are made of green soybeans, but if necessary, vegetables and fruits other than green beans can also be included as fruits and vegetables stored in the packaging container. In the present invention, fruits and vegetables other than “green soybeans” that can be stored together with “green soybeans” in the packaging container are not particularly limited, and unheated or heated fruits and vegetables can be appropriately stored.
Moreover, as long as it contains green soybeans, it may contain components other than fruits and vegetables, for example, foods other than fruits and vegetables, seasonings, food additives and the like.

The “green soybean” constituting the package of the present invention (specifically, stored in a packaging container) refers to a product of harvested soybeans that are immature and blue. There is no restriction | limiting in particular in the form of "edamame". It may be attached with a branch or it may be removed from the branch and made into a basket. Moreover, the thing with a basket may be sufficient and the thing without a basket (namely, the thing of the state of the bean taken out from the basket) may be sufficient. However, edamame with koji is preferred from the viewpoints of storage stability, flavor during eating, simplicity in production, and the like.
Further, the origin, production area, type and variety of “green soybeans” mentioned here are not particularly limited. The types of edamame are roughly classified into ordinary varieties, tea beans, and black beans, depending on the seed coat, and any of them can be used. Examples of common edamame include Osode Mai, Sapporo Midori, taste green, hot-daughter, Sayamusume. Examples of green beans of tea beans include Hakusan, Fukunari, and Chino Chataro. Examples of black soybeans include Tamba black, purple hood, and black hood. These green soybeans may be used alone or in combination of two or more. A product suitable for a product is suitably used by combining the maturity, color tone, hardness of the beans, strength of the pod, appearance, suitability for heating, and the like.

  As for “green soybeans”, the harvested ones may be used as they are, or in order to increase the commercial value as food from the viewpoints of hygiene, freshness, etc., washing treatment or sterilization treatment with water washing may be appropriately performed. .

  In the present invention, there is no particular limitation on the form of fruits and vegetables including “green soybeans” stored in the package and kept fresh. In addition, the fruits and vegetables may be those that have been subjected to any or all of the treatments such as washing, cooling, and dehydration, and may be those that do not perform any of these treatments.

<Vitamin C content in green soybeans>
In the present invention, vitamin C content of “green soybeans” stored in a package and kept fresh can be measured by a method conventionally known in the art. Ascorbic acid (reduced vitamin C) content can be measured by a simple analysis using a reflection photometer “RQ Flex” and a dedicated test paper “Reflect Quant”.
Specifically, the vitamin C content of the green soybeans after being sealed for 72 hours at room temperature after sealing the package is a value of 35 mg / 100 g or more (that is, 35 mg or more per 100 g of green soybeans). The vitamin C content is preferably a value of 35.2 mg / 100 g or more, particularly preferably a value of 35.5 mg / 100 g or more. Moreover, it is preferable that the vitamin C content of the green soybeans satisfies the above conditions for as long as possible over 72 hours at room temperature. Here, “room temperature” means 23 ° C. or more and 25 ° C. or less.

<Packaging body>
The carbon dioxide concentration of the package of the present invention is not particularly limited, but from the viewpoint of suppressing yellowing of green soybeans, the green beans are stored in the package at room temperature and the package is sealed, and then the packaging at room temperature. The body's internal carbon dioxide concentration is preferably 1% by volume or less. Moreover, it is preferable that the internal carbon dioxide density | concentration of the said package after 72 hours progress at room temperature after the said sealing is 1 volume% or less, and it is 0.3 volume% or more and 0.6 volume% or less. More preferably, it is 0.3 volume% or more and 0.5 volume% or less. After the sealing, the internal carbon dioxide concentration of the package after being held at room temperature for 168 hours is more preferably 0.3 volume% or more and 0.6 volume% or less, and 0.3 volume% or more and 0.5 volume% or less. It is particularly preferable that the volume is not more than% by volume.
Further, the internal oxygen concentration of the package of the present invention is not particularly limited, but from the same viewpoint, the green beans are stored in the package at room temperature and the package is sealed, and the package after 72 hours at room temperature has passed. The internal oxygen concentration of the package is preferably 17% by volume or more and 21% by volume or less, and after the sealing, the internal oxygen concentration of the package after 168 hours at room temperature is 20% by volume or more and 21% by volume or less. Is more preferable.

  The mechanism by which yellowing is suppressed when the vitamin C content of green soybeans after holding for a predetermined time at room temperature after sealing the package is within the above range is not clear, but yellowing of green soybeans is related to oxidation. As a phenomenon, it is estimated that there is some optimum value or lower limit value for the concentration of vitamin C having antioxidant activity at a specific time when yellowing starts to become noticeable in normal cases.

The oxygen concentration and carbon dioxide concentration inside the package of the present invention can be determined by, for example, using a gas inside the package as an O ₂ & O ₂ / CO ₂ meter for food gas replacement packaging (CheckPoint II, CheckPoint3 or CheckMate3, MOCON Europe) The oxygen concentration and carbon dioxide concentration inside the packaging body of the present invention that can be specified by measuring with a gas chromatograph or gas detector tube (manufactured by Gastec) are, for example, the gas inside the packaging body, the food It can be specified by measuring with an O ₂ & O ₂ / CO ₂ meter for gas replacement packaging (CheckPoint II, CheckPoint3 or CheckMate3, Mocon Europe), a gas chromatograph, and a gas detector tube (manufactured by Gastec).
Here, “after sealing” means an elapsed time after sealing the package, specifically, a process after sealing the packaging container after storing the fruits and vegetables containing green soybeans in the packaging container. Say time. Therefore, for example, “24 hours at room temperature after sealing” specifically means that after storing fruits and vegetables containing green soybeans in a packaging container at room temperature, the packaging container is sealed and then 24 hours at room temperature. The state after the elapse.

  The storage temperature and storage temperature in the package of the present invention are not particularly limited, and can be stored and stored at room temperature. Storage and storage at room temperature is preferable in that a low-temperature facility or a heating facility is unnecessary, and a storage location is not selected. On the other hand, from the viewpoint of maintaining quality such as taste and appearance at a higher level, refrigeration, that is, storage at a temperature of 3 to 5 ° C. is also preferable.

<Polymer film>
Moreover, in order to implement | achieve the vitamin-C content mentioned above, it is desirable to comprise a packaging container using the polymer film whose oxygen permeability is in the range of a predetermined value.
That is, the oxygen permeability of the polymer film used in the present invention is preferably 35,000 to 60000 (cc / m ² · day · atm) at 20 ° C. and 90% RH. In the package in the present invention, the oxygen permeability of the polymer film constituting the packaging container is within the above range, so that the above-mentioned preferable internal oxygen concentration can be more easily realized.
The carbon dioxide (carbon dioxide) permeability of the polymer film used in the present invention is preferably in the range of, for example, 45,000 to 60000 (cc / m ² · day · atm) at 20 ° C. and 90% RH. . In the package in the present invention, the carbon dioxide gas permeability of the polymer film constituting the packaging container is within the above range, so that it becomes easier to realize the above-mentioned preferable internal carbon dioxide concentration.
In the package in the present invention, the polymer film constituting the packaging container has the oxygen permeability and / or carbon dioxide 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 suppress the yellowing of green soybeans over a long period of at least 72 hours after sealing, and more easily at room temperature.
The oxygen permeability of the polymer film used in the present invention is more preferably 40000 to 55000 (cc / m ² · day · atm) at 20 ° C. and 90% RH.
Further, the carbon dioxide gas permeability of the polymer film used in the present invention is more preferably 48000 to 58000 (cc / m ² · day · atm) at 20 ° C. and 90% RH.

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 size a (cm) × b (cm) is formed by the following method.
One film is folded almost equally into two, approximately 5 mm wide, and heat sealing is performed with an impulse sealer (manufactured by Fuji Impulse Co., product number Fi-200-10WK) with the heating condition scale set to 3, and the heat sealing is performed. Heat seal the whole of one side that is almost perpendicular to the heat seal side so that the side is almost in the middle, except the end of about 2 cm that is one communicating part of the other side, and the inner dimension a ( cm) × b (cm).
Next, nitrogen gas is injected from the communication portion, and when the inside of the bag becomes saturated, almost all the gas in the bag is discharged from the communication portion. After repeating this operation five 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 in a room at 22 ° C. and 40% relative humidity in air (1 atm, oxygen concentration: 21%, carbon dioxide concentration: 0.03%) for 6 hours.
Next, the oxygen concentration in the bag is measured using an O ₂ & O ₂ / CO ₂ meter for food gas replacement packaging (CheckPoint II, MOCON Europe). Furthermore, the volume of the gas in the bag is measured, and the oxygen permeability and carbon dioxide 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 (0.21 atm)
(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 Carbon partial pressure (0.0003 atm)

  By appropriately selecting the material, thickness, processing method and the like of the polymer film, the oxygen permeability of the polymer film can be adjusted as appropriate. For example, in the case of a biaxially oriented polypropylene (OPP) film, the thickness is 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 easier to make the oxygen permeability and carbon dioxide gas permeability at 90% RH within the above preferred ranges. Considering mechanical strength, workability and the like together, the thickness of the polymer film is preferably 5 to 60 μm, more preferably 10 to 55 μm, and further preferably 12 to 50 μm. It is still more preferable that it is 15-45 micrometers, and it is especially preferable that it is 18-30 micrometers.

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, etc. of the polymer film. It is not necessary to provide an opening in the polymer film for adjusting the carbon dioxide gas permeability.
When the opening is not provided in the polymer film, the manufacturing process becomes simpler and less expensive, and it is not necessary to precisely control the size, shape, etc. of the opening.
The absence of openings in the polymer film (that is, “no holes”) means that, for example, the polymer film constituting the packaging container does not have through holes that can be confirmed by an ink leak checker. Can be confirmed.

On the other hand, in one embodiment of the present invention, when it is necessary to use a thick polymer film or a polymer material having a low oxygen permeability, a desired oxygen permeability for maintaining respiration of fruits and vegetables, In order to achieve carbon dioxide gas permeability, an opening provided in the polymer film may be used in combination. Since green soybeans have a relatively large respiration rate among fruits and vegetables, it is often preferable to use an opening together in the present invention for maintaining the freshness of green soybeans.
The shape of the opening is not particularly limited, and may be circular, substantially circular, or may be slit. A circular or substantially circular opening is preferable because it is easy to process, and a slit-shaped opening is preferable because it can effectively prevent foreign substances 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 carbon dioxide permeability of the polymer film are appropriate. For example, when the opening is circular, a diameter of about 20 to 100 μm, more preferably about 50 μm is preferable for adjusting the transmittance.
Although there is no restriction | limiting in particular in the number of openings, For example, it is preferable from a viewpoint of adjusting oxygen permeability and carbon dioxide permeability to have 1 to 300 openings per packaging container.
The distance between the openings is not particularly limited because it depends on the number of openings required, but is preferably about 1 to 100 mm from the viewpoint of manufacturing efficiency 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 and carbon dioxide permeability of the entire packaging container are appropriate. The number of openings in the effective area is a guideline. For example, when an opening having a diameter of about 50 μm (opening area of about 2000 μm ² ) is provided, there is an effect of increasing oxygen permeability by about 2000 cc / m ² / day / atm for each 200 mm × 200 mm packaging container. It is preferable to determine the number of slit openings from the oxygen permeability of the entire packaging container required based on such knowledge. In this case, the number of openings per packaging container is preferably 5 to 50, and particularly preferably 10 to 40.

  The thickness of the polymer film used in the present invention is not particularly limited, and suitable openings for oxygen permeability, carbon dioxide gas permeability, flexibility when forming a packaging container, strength, transparency, economy, etc. In the case of providing, an appropriate thickness may be selected as appropriate in relation to the material forming the polymer film from the viewpoint of accuracy and ease in forming the opening. Typically, the thickness of the polymer film in the case of providing the opening is preferably 5 to 60 μm, more preferably 10 to 55 μm, still more preferably 12 to 50 μm, and 15 to 45 μm. It is even more preferable that the thickness is 18 to 30 μm.

  Although there is no restriction | limiting in particular in the material of the said polymer film, The polymer used for the film for conventional fruit and vegetables packaging can be used suitably. Examples thereof include polyethylene, polypropylene, polyethylene terephthalate, polystyrene, nylon (polyamide), ethylene vinyl acetate copolymer (EVA), polybutylene succinate, polybutylene succinate adipate, and polylactic acid. Further, for example, natural polymers 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 ease of processing and cost, the polymer film is preferably made of 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 method low density polyethylene, linear low density polyethylene (LLDPE), high density polyethylene, propylene homopolymer, propylene / α-olefin random copolymer, propylene block copolymer. And propylene-based polymers such as poly 1-butene and poly 4-methyl / 1-pentene. The thermoplastic resin includes polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamides such as nylon-6, nylon-66, polymetaxylene adipamide, polyvinyl chloride, polyimide, ethylene / acetic acid. Examples thereof include a vinyl copolymer or a saponified product thereof, polyvinyl alcohol, polyacrylonitrile, polycarbonate, polystyrene, ionomer, polylactic acid, polybutylene succinate and the like, or a mixture thereof. These thermoplastic resins may be used alone or in combination of two or more. Among these, as the thermoplastic resin, polyolefin, polyester, polyamide and the like are preferable because of excellent rigidity and transparency. Further, as the thermoplastic resin, an ethylene polymer and a propylene polymer are more preferable because they are lightweight and excellent in film processability, and a propylene polymer is more preferable from the viewpoint of flexibility and transparency.

<Propylene polymer>
Examples of the propylene polymer include a propylene homopolymer (also referred to as homo PP) manufactured and sold under the name of polypropylene, and a propylene / α-olefin random copolymer (also referred to as random PP). And crystalline polymers mainly composed of propylene such as a mixture of propylene homopolymer and low crystalline or amorphous propylene / ethylene random copolymer (also called block PP). . Further, the propylene-based polymer may be a mixture of propylene homopolymers having different molecular weights, and is composed of 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.

  Specific examples of the propylene polymer include polypropylene, propylene / ethylene copolymer, propylene / ethylene / 1-butene copolymer, propylene / 1-butene copolymer, and propylene / 1-pentene copolymer. Copolymer of propylene such as propylene / 1-hexene copolymer and propylene / 1-octene copolymer as a main monomer and at least one selected from ethylene and α-olefin having 4 to 10 carbon atoms Coalescence is mentioned. These may use 1 type and may use 2 or more types together.

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

<Ethylene polymer>
Examples of the ethylene polymer include a homopolymer of ethylene, a copolymer of ethylene as a main monomer and at least one α-olefin having 3 to 8 carbon atoms, an ethylene / vinyl acetate copolymer, Saponifications and ionomers are mentioned. Specifically, polyethylene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 1-pentene copolymer, ethylene / 1-hexene copolymer, ethylene / 4-methyl-1-pentene Examples thereof include copolymers of ethylene as a main monomer, such as a copolymer and an ethylene / 1-octene copolymer, and at least one kind of an α-olefin having 3 to 8 carbon atoms. The proportion of α-olefin in these copolymers is preferably 1 to 15 mol%.

  Examples of the ethylene polymer include ethylene polymers manufactured and sold under the name of polyethylene. Specifically, high pressure method low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE) are preferable, and LLDPE is more preferable. 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. The ethylene polymer may be an ethylene homopolymer 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. Moreover, 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 and / or laminate of any of the above polymers, and any of the above polymers and a material other than the polymer. Blends and / or laminates. That is, the polymer film is 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, an antifogging agent In addition to pigments and dyes, various fillers such as talc, silica, and diatomaceous earth may be included, or a laminate of a polymer film and metal foil, paper, nonwoven fabric, or the like may be used.

In the present invention, the polymer film constituting the packaging container may be an unstretched film or 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.
Further, the film using the ethylene polymer (polyethylene film) may be either a non-stretched film or a stretched film, but a non-stretched film is particularly preferably used from the viewpoint of heat sealability and the like. be able to.
Examples of the polymer film that is particularly suitable as the polymer film constituting the packaging container in the present invention include a stretched polypropylene film, a polyethylene film, and a laminate of the stretched film and the polyethylene 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. Moreover, when obtaining a biaxially stretched film as a stretched polypropylene film, it can also be easily manufactured by, for example, sequential or simultaneous biaxial stretching. 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 stretched 8 to 10 times in the transverse direction using a tenter mechanism, and the film thickness is finally adjusted. Or 20 to 40 μm, or by stretching 5 to 10 times (25 to 100 times in terms of surface magnification) in the vertical and horizontal directions, respectively.
<Polyethylene film>
The polyethylene film preferably used in the present invention is a film containing the ethylene polymer. Various known molding methods can be used for the polyethylene film, but cast molding by extrusion using an extruder is preferred 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 Films, polystyrene films, polyolefins such as polypropylene, and poly-L lactic acid, poly-D lactic acid, or uniaxial or biaxially stretched films composed of stereocomplex crystal polylactic acid in which poly-L lactic acid and poly-D lactic acid are coordinated precisely.

<Laminated body of stretched film and polyethylene film>
A laminate of a stretched film and a polyethylene film preferably used in the present invention is obtained by laminating the polyethylene film layer and the stretched film layer. The polyethylene film may be stretched in one or two directions, but is preferably an unstretched film from the viewpoint of the stability of the mechanical strength of the packaging bag.
Dry lamination is performed by adhering a stretched film and a polyethylene film prepared in advance with an adhesive. From the viewpoint of adhesion stability, the surface of the stretched film to which the adhesive is applied should be corona treated. preferable. Specifically, the surface tension of the film surface after the corona treatment is preferably 35 mN / m or more, more preferably 40 mN / m or more, from the viewpoint of adhesion stability.

These polymer films may be stretched, antifogged or printed, and include inorganic antibacterial agents such as silver and copper, and organic antibacterial agents such as chitin, chitosan, and allylisothiocyanate. The agent may be applied, or these may be kneaded in the film.
From the viewpoint of maintaining the freshness of contents such as fruits and vegetables, the polymer film preferably contains at least one antibacterial agent.
Further, a specific amount of a specific surfactant is present on the surface of the polymer film, or the polymer film may have a specific amount of a specific surfactant to have an antibacterial function. For example, it is preferable that at least one compound selected from the group consisting of palmityl diethanolamine, stearyl diethanolamine, glycerol monolaurate and diglycerol monolaurate is present on at least one surface of the polymer film, it is particularly preferred that one compound 0.002~0.5g / ^{m 2} is present. Alternatively, the polymer film preferably contains at least one compound selected from the group consisting of palmityl diethanolamine, stearyl diethanolamine, glycerol monolaurate, and glycerol monocaprate, 0.001 to 3 parts by mass It is particularly preferable to contain.
When a specific amount of a specific surfactant is present on the surface of the polymer film, or the polymer film contains a specific amount of a specific surfactant, dew condensation on the surface of the polymer film is suppressed, Suppression of the growth of bacteria suppresses the growth of germs in the dew (drip) and exhibits an antibacterial function.

From the viewpoints of transparency, flexibility, cost, etc., it is particularly preferable to use a stretched polypropylene film or a laminate of a stretched polypropylene film and a polyethylene film that has been widely used in the art 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 the stretched propylene film is used alone, the thickness is preferably 10 to 100 μm, and when the laminate of the stretched polypropylene film and the polyethylene film is used, the former thickness is 10 to 50 μm. The latter thickness is preferably 10 to 120 μm.

  When a polymer film that is not necessarily suitable for heat sealing is used, it may be formed by laminating or coating a sealant layer on all or part of the polymer film. Examples thereof include a cellophane film coated with an acrylic resin and a film obtained by laminating polyethylene terephthalate (PET) with linear low density polyethylene (LLDPE) polystyrene and EVA, and these can be used as suitable polymer films.

<Manufacturing method of package and method for maintaining freshness>
The package of the present invention can be produced by storing vegetables and fruits containing green soybeans in the packaging container of the present invention and optimally adjusting the vitamin C content of the green beans, and is an embodiment of the present invention. The yellowing suppression of the said fruit and vegetables can be implemented.
Hereinafter, the manufacturing method of the package of the present invention will be described by taking as an example a package for maintaining freshness of green soybeans.

  First, in the pretreatment step, the branches are removed from the harvested edamame to give a pod with pods, which are washed with water with a washing machine to remove dirt and germs such as mud and dehydrated with a centrifugal dehydrator or the like. The dehydrated green soybeans are weighed and packed at room temperature into a packaging container (not sealed on one side) containing the polymer film used in this embodiment, after which the packaging container is sealed, A package for maintaining the freshness of green soybeans is produced.

If a lot of germs are attached to the green soybeans packed in the packaging container from the beginning, it is more difficult to maintain the freshness and it is unsanitary. It is preferable to reduce. Washing is particularly effective for maintaining freshness because it not only reduces the adhesion of germs but also has the effect of removing cell fluids that contain highly active enzymes and the like and can cause discoloration.
In addition, it is also effective for maintaining the freshness to sufficiently remove the water adhering to the surface of the green soybean koji after the washing and before filling the packaging container.

  In addition, the packaging body for fruit and vegetable freshness preservation | save of this embodiment may perform nitrogen enclosure and / or deaeration at the time of storage of the fruits and vegetables containing the said green soybeans, and sealing of a packaging container. Moreover, you may deaerate after sealing a packaging container from a viewpoint of the efficiency improvement in the process of distribution, space saving, exclusion of specific gas, etc.

  After carrying out the step of storing the green soybeans in the packaging container comprising the polymer film according to the method as described above, the vitamin C content of the green soybeans in the packaging container is 35 mg / 100 g or more (35 mg per 100 g green soybeans) By carrying out the step having the above value, yellowing of green soybeans (specifically, green soybeans) can be effectively suppressed.

The packaging body of the present invention may contain only fruits and vegetables containing green soybeans in the packaging container, or may contain other members.
For example, in addition to fruits and vegetables, a hygroscopic agent and / or an antibacterial agent may be stored in the packaging container.
There is no limitation in particular in a moisture absorbent, The well-known or commercially available material which has a moisture absorption effect or a humidity control effect can be used. Suitable examples of the hygroscopic agent include 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. For example, but not limited to.
Among these, it is particularly preferable to use activated carbon which has relatively little concern about the influence on fruits and vegetables and the use of fruits and vegetables near foods. The activated carbon can be either powdered or granular, and the raw material can be anything from coconut husk, sawdust, charcoal, bamboo charcoal, lignite, peat, diamond, and petroleum pitch. The activated carbon is preferably wrapped in non-woven fabric, cellophane, paper, etc. for each unit used, but the activated carbon itself may be in the form of a fiber. The activated carbon packaging material is preferably a heat-sealable material such as a non-woven fabric made of a synthetic resin. However, any material such as paper or natural fiber can 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, but there is relatively little concern about the effect on fruits and vegetables including shredded cabbage and use in the vicinity of fruits and vegetables that are foods. Antibacterial agents can be preferably used. More specifically, natural antibacterial agents such as chitosan, allyl isothiocyanate, hinokitiol, and limonene can be stored in the packaging container.

  Hereinafter, the present invention will be specifically described with reference to Examples / Reference Examples. It should be noted that the present invention is not limited in any way by the following examples.

In the following examples / reference examples, each property was evaluated by the following method.
(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 film is folded almost equally into two, approximately 5 mm wide, and heat sealing is performed with an impulse sealer (manufactured by Fuji Impulse Co., product number Fi-200-10WK) with the heating condition scale set to 3, and the heat sealing is performed. Heat seal the whole of one side that is almost perpendicular to the heat seal side so that the side is almost in the middle, except for the end of about 2 cm that becomes one communicating part of the other side. A 190 mm bag was formed. At that time, one pinch cock for gas measurement was provided in the heat seal part.
Next, nitrogen gas was injected from the communication portion, and after the bag was saturated, almost all 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 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 and carbon dioxide concentration in the bag were measured using an O ₂ & O ₂ / CO ₂ meter for food gas replacement packaging (CheckPoint II, MOCON Europe). Furthermore, the volume of the gas in the bag was measured, and the oxygen permeability and carbon dioxide permeability were calculated from the following equations.
(Expression) Oxygen permeability = change in internal oxygen concentration (%) / 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 permeability = change in internal carbon dioxide concentration (%) / 100 × volume (cm ³ ) × 24 × 60 / hour (360 minutes) × 10000 cm ² / area (665 cm ² ) / partial pressure of carbon dioxide ( 0.0003 atm)
(Oxygen concentration and carbon dioxide concentration)
The gas in the package was collected from the pinch cock for gas measurement, and the oxygen concentration and carbon dioxide concentration in the bag were measured using CheckPoint II.
(Weight of green soybeans)
The weight of green soybeans was determined by continuously measuring the weight of green beans packed with straw using a pan balance.
(Vitamin C content of green soybeans)
Grind the seeds removed from the edamame pods to be measured, crush and mix (mixer) in 10% metaphosphoric acid (final concentration 2%) using a mixer, and then pass through a membrane filter (0.45 μm). Liquid. The sample solution was measured using RQ Flex Plus, manufactured by Merck Milpore, and the vitamin C content of green soybeans was determined.
(Yellow degree)
The color tone of the amber is measured for the L ^* value (brightness), a ^* value (+ redness to -greenness), and b ^* value (+ yellowness to -blueness) according to the color system (CIE1976). A color difference meter (CR400, manufactured by Konica Minolta) was used to calculate L ^* × b ^* / | a ^* × 100 | as the degree of yellowing. Nine peas with pods were used for measurement (n = 9), and the bulge portion closer to the branch was evaluated for the pods with 3 grains and the cocoons with 2 grains. As the degree of yellowing increases, the green color disappears and yellowing progresses.
(With or without opening)
The presence or absence of an opening provided in the polymer film was confirmed by an ink leakage checker. Specifically, after injecting a red penetrant (Mitsubishi Gas Chemical Co., Ltd., trade name: Ageless Seal Check Spray) into the packaging container, set the scale of heating conditions to 3 with an impulse sealer, and heat at about 5 mm width. Sealing was performed, and paper (Kokuyo PPC paper, common paper A4) was pressed to confirm whether or not ink was transferred to the paper.

Example 1
A film in which an opening having a diameter of about 50 μm was provided by laser processing on a biaxially stretched polypropylene film having a thickness of 30 μm was prepared.
A bag having an inner size of 175 mm × 190 mm was heat sealed using the above film. The number of openings was 28. A pinch cock was attached to the bag.
The oxygen permeability and carbon dioxide gas permeability of this bag were measured and found to be 48344 (cc / m ² · day · atm) and 51051 (cc / m ² · day · atm), respectively.
After preparing 200 g of green soybeans with rice cake (variety: Sayamusume (produced in Saitama Prefecture)) prepared in advance in a bag at room temperature and in air, the upper part of about 1 cm was sealed with a heat seal to obtain a package. A total of three bags of this package were made.
These packages are stored at room temperature, and the oxygen concentration and carbon dioxide concentration inside the package and the green soybeans are passed daily (specifically, after the sealing, 0 hours, 24 hours, 72 hours, 168 hours). The amount of vitamin C contained in the seeds removed from the rice cake and the degree of yellowing were measured, and the yellowing of the edamame with rice cake was evaluated. Here, the amount of vitamin C and the degree of yellowing for 24 hours after sealing were as follows. One bag of the package was opened 24 hours after sealing, and 9 green soybeans were taken out. The vitamin C amount and yellowing degree actually contained are evaluated by measuring as described above, and after sealing, the vitamin C amount and yellowing degree after 72 hours are as follows: After sealing, it was opened 72 hours later, and 9 green soybeans were taken out, and the amount of vitamin C and yellowing degree contained in the grains removed from the pods were evaluated as described above. After sealing, 168 hours The degree of yellowing after that, after sealing the remaining one bag of the above package, after opening 168 hours, take out nine green soybeans, and the degree of yellowing contained in the fruit removed from the basket as described above Evaluation was made by measuring. In addition, the oxygen concentration and carbon dioxide concentration at 0 hours after sealing are the oxygen concentration and carbon dioxide concentration inside the package immediately after sealing, and the amount of vitamin C and yellow at 0 hours after sealing. The degree of conversion was evaluated by taking 9 green soybeans immediately before encapsulation and measuring the amount of vitamin C and the degree of yellowing contained in the grains removed from the basket as described above.
The results are shown in Table 1.
According to the package of this example, the vitamin C content of green soybeans after 0 hours after sealing is 31.7 mg / 100 g, and vitamin C of green soybeans after 24 hours and 72 hours after sealing. The contents were 41.0 mg / 100 g and 35.8 mg / 100 g, respectively. And according to this package, the yellowing degree of green soybeans is 1.34 after 0 hours after sealing, 1.26 after 24 hours after sealing, and 1 after 72 hours after sealing. .26, and after 168 hours after sealing, the degree of yellowing is 1.30, which is similar to the degree of yellowing for 0 hours after sealing. It was confirmed that it was possible.

(Reference Example 1)
Except for using a 45 μm-thick biaxially stretched polypropylene film without an opening, a packaging body containing edamame with straw was prepared and evaluated in the same manner as in Example 1. The absence of an opening (through hole) was confirmed by an ink leakage checker.
The oxygen permeability of the package was 1430 (cc / m ² · day · atm), and the carbon dioxide permeability was 6550 (cc / m ² · day · atm).
The results are shown in Table 1.
According to the package of this reference example, the vitamin C content of green soybeans after 0 hours after sealing is 31.7 mg / 100 g, and the green soybeans after 24 hours and 72 hours after sealing. The vitamin C content was 34.9 mg / 100 g and 33.9 mg / 100 g, respectively. And according to this package, the yellowing degree of green soybeans exceeds 1.35 after 72 hours after sealing and 1.30 after 168 hours of Example 1, and after sealing. 168 hours later, 1.74, which is significantly greater than the degree of yellowing 1.34 of 0 hours after sealing, unlike the above examples, it is not possible to suppress the yellowing of green soybeans over a long period of time Was confirmed.

(Reference Example 2)
Except having made the package which provided 42 opening parts, it carried out similarly to Example 1, produced the package which accommodates a soybean with a potato, and evaluated.
The oxygen permeability of the package was 67416 (cc / m ² · day · atm), and the carbon dioxide permeability was 65811 (cc / m ² · day · atm).
The evaluation results are shown in Table 1.
According to the package of this reference example, the vitamin C content of green soybeans 24 hours after sealing is 38.6 mg / 100 g, and the vitamin C content of green soybeans 72 hours after sealing. Was 30.3 mg / 100 g. And according to this package, the yellowing degree of green soybeans after 72 hours and 168 hours after sealing is as large as 1.4 or more, and the yellowing degree of 0 hours after sealing is 1.34. It was confirmed that it was difficult to suppress the yellowing of green soybeans over a long period of time, unlike the above example, because the degree of yellowing after 168 hours of Example 1 greatly exceeded 1.30.

(Reference Example 3)
Except having set it as the package which provided 66 opening parts, it carried out similarly to Example 1, produced the package which accommodates a soybean with a potato, and evaluated.
The oxygen permeability of the package was 121895 (cc / m ² · day · atm), and the carbon dioxide permeability was 124413 (cc / m ² · day · atm).
The evaluation results are shown in Table 1.
According to the package of this reference example, the vitamin C content of green soybeans 24 hours after sealing is 39.5 mg / 100 g, and the vitamin C content of green soybeans 72 hours after sealing. Was 29.8 mg / 100 g. And according to this package, the yellowing degree of green soybeans after 72 hours and 168 hours after sealing is 1.38 and 1.35, both of which are 0 hours after sealing. Since it exceeded 1.34 and greatly exceeded the degree of yellowing of 1.30 after 168 hours of Example 1, it was confirmed that it was difficult to suppress yellowing of green soybeans over a long period of time, unlike the above examples. It was.

  The packaging body of the present invention is a packaging body in which fruits and vegetables containing green soybeans are stored in a packaging container, and can effectively suppress yellowing of green soybeans in the packaging body. And has high applicability in various fields of industry such as food processing, distribution, and dining out.

Claims (4)

  A packaging body containing vegetables and fruits containing green soybeans in a packaging container comprising a polymer film, wherein the green soybean contains vitamin C after being sealed for 72 hours at room temperature after sealing the packaging body The said package whose quantity is 35 mg / 100g or more. The package of Claim 1 whose oxygen permeability of the said polymer film is 35000-60000 (cc / m < ² > * day * atm).   The package according to claim 1 or 2, wherein yellowing of the green soybeans is suppressed at room temperature for 72 hours or more after sealing of the package. The package according to any one of claims 1 to 3, wherein the internal carbon dioxide concentration is 1% by volume or less.