JP2018167895A - Package with excellent freshness retaining capacity for fruit and vegetables including radish, and method for retaining freshness of vegetables and fruit - Google Patents

Abstract

To provide a package which is comprised of a packaging container storing fruit and vegetables including radish, and which can inhibit generation of malodor and browning and suppress an increase in a number of viable cells, for a long time from packaging time of the radish, by controlling a moisture content of the radish to be a specific amount from a viewpoint of affecting freshness of the radish by the moisture content, and thus has an excellent freshness retaining function for the fruit and vegetables.SOLUTION: A package is comprised of a packaging container provided with polymeric film and storing fruit and vegetables including radish, and a moisture content of the radish is 20% to 40% when stored.SELECTED DRAWING: None

Description

  The present invention relates to a package that has excellent freshness retention performance of fruits and vegetables including radish, and more specifically, the fruits and vegetables including radish are stored in a packaging container including a polymer film. The present invention relates to a package having a specific amount of moisture.

A gas permeable film that allows a gas (gas) permeation portion to be provided on a polymer film base material and allows gas such as oxygen, carbon dioxide, and water vapor to permeate from the gas permeation portion. It is suitably used as a packaging material for fresh vegetables. When such vegetables, fruits, etc. are packaged using such a gas permeable film, the oxygen concentration (for example, about 1 to 4% oxygen concentration) suitable for maintaining the freshness of vegetables and fruits as contents is maintained. It is known that contents can be stored while maintaining freshness over a relatively long period of time.
For example, in Patent Document 1, in a package containing fruits and vegetables made of a polymer film in which fruits and vegetables are sealed, the package is composed of (A) a porous polymer film and (B) a non-porous polymer film, The water vapor transmission rate measured under the conditions where the film characteristics of at least one of (A) and (B) are 25 ° C. and the relative humidity is 75% is 50 to 800 gm ⁻² d ^{−1 based} on the effective surface area of the package. There is described a packaged product with fruits and vegetables characterized in that the open area ratio of (A) is 3 × 10 ^{−6 to} 7 × 10 ⁻⁴ % with respect to the effective surface area of the package. Specifically, (A) a porous polymer film made of stretched polypropylene having a thickness of 35 μm, having 95 holes with an average pore diameter of 30 μm, 9 holes with an average pore diameter of 60 μm, etc. It is used.

Among fruits and vegetables, radish is one of the widely distributed vegetables, and the packaging and storage methods described above can be applied.
However, radish is one of the vegetables that tend to generate off-flavors and is said to have a strong odor. In particular, when processing such as cutting and grated is performed, a strange odor is easily generated, and discoloration (also referred to as “browning”) and an increase in the number of viable bacteria are likely to occur.
The occurrence of such a bad odor gives the consumer and consumer the impression that the product quality is bad, and the product value is significantly reduced to lower the economic value. However, it could not be sufficiently suppressed, and an improvement was desired.

  Against this background, there is a strong demand for technology that can suppress the occurrence of off-flavors and browning of radish and the increase in the number of viable bacteria over a long period of time, exceeding the level of conventional technology, for maintaining the freshness of fruits and vegetables containing radish. It was.

  Moreover, the manufacturing process of cut vegetables consists of 1 cut, 2 washing | cleaning-water washing, and 3 dehydration, and is performed according to a "mass cooking facility hygiene management manual" (Ministry of Health and Welfare). However, the manual only mentions the degree of caution regarding the dehydration of 3 so that it will not be damaged during dehydration, and the degree of dehydration and dryness is not clarified, and the moisture content of the cut vegetables There was a fact that the effect on the freshness of the food is still unclear.

JP-A-5-168400

In view of the limitations of the above-mentioned background art, the present invention is a package in which fruits and vegetables containing radish are stored in a packaging container from the viewpoint of the influence of the amount of water on the freshness of cut vegetables (specifically, cut radish). It is an object of the present invention to provide a packaging body excellent in the function of maintaining the freshness of fruits and vegetables that can suppress the occurrence of off-flavors and browning and the increase in the number of viable bacteria for a long time after packaging of the radish. .
In the present invention, in particular, in view of the actual situation of commerce, regarding a packaging body in which fruits and vegetables containing radish are stored in a packaging container, after radish packaging, the commercial value is affected for a long time at about 10 ° C. Another object of the present invention is to provide a package that can both suppress the generation of an unpleasant odor and browning, and is excellent in suppressing the increase in the number of viable bacteria.

  As a result of diligent study, the present inventor, in a packaging body containing fruits and vegetables containing radish in a packaging container comprising a polymer film, by controlling the amount of water of the radish at a specific amount, The present inventors have found that the above problems can be solved and have completed the present invention.

That is, the present invention
[1]
A package comprising fruits and vegetables containing radish in a packaging container comprising a polymer film, wherein the water content when the radish is stored is 20% or more and 40% or less.
[2]
The package according to claim 1, wherein the oxygen concentration after 96 hours have passed under conditions of 10 ° C after radish packaging in the packaging container is 1.10% by volume or more and 2.0% by volume or less.
[3]
The package according to [1] or [2], wherein the inside of the packaging container is sealed with nitrogen.
[4]
The package according to any one of [1] to [3], wherein after the packaging, the radish odor and browning can be suppressed for 144 hours or longer under conditions of 10 ° C.
[5]
Any of [1] to [4], wherein the viable count of the radish can be suppressed after packaging for 168 hours or more under the condition of 10 ° C. than when the amount of water when the radish is stored exceeds 40%. The package described in 1.
[6]
The oxygen permeability of the polymer film is 500 cc / m ² / day / atm or more and 7000 cc / m ² / day / atm or less at 20 ° C. and 90% RH, according to any one of [1] to [5] The package described.
[7]
The packaging body according to any one of [1] to [6], wherein the packaging container does not have a through hole that can be confirmed by an ink leakage checker.
[8]
The package according to any one of [1] to [7], wherein the polymer film has a thickness of 15 μm or more and 45 μm or less.
[9]
The package according to any one of [1] to [8], wherein the polymer film is a stretched polypropylene film, a polyethylene film, or a laminate of a stretched film and a polyethylene film.
[10]
The package according to any one of [1] to [9], wherein the polymer film contains at least one antibacterial agent or is coated with at least one antibacterial agent.
[11]
The package for maintaining freshness of fruits and vegetables according to any one of [1] to [10], further containing a hygroscopic agent and / or an antibacterial agent.
[12]
A method for maintaining freshness of fruits and vegetables under a condition of 2 ° C or higher and 15 ° C or lower, comprising a step of storing fruits and vegetables containing radish having a water content of 20% or higher and 40% or lower in a packaging container comprising a polymer film.
[13]
The method for maintaining freshness of fruits and vegetables according to [12], further comprising a step of enclosing nitrogen in the packaging container.

According to the present invention, in a package that contains fruits and vegetables containing radish in a packaging container, the moisture content of the radish to be stored is controlled to a specific amount, for a long time from the time of encapsulation, its off-flavor, browning, And viable count can be suppressed effectively. Therefore, the fruit and vegetable packaging body and the freshness maintaining method including the radish according to the present invention can achieve an effect of being excellent in the freshness maintaining function of the fruit and vegetables.
According to the present invention, in particular, with respect to a package that contains fruits and vegetables containing radish in a packaging container, after the radish is packaged, an unpleasant odor that affects the commercial value for a long time at about 10 ° C. And the browning can be suppressed at the same time, and a package excellent in suppressing the increase in the number of viable bacteria can be provided, and an effect of having a high commercial value in commercial transactions can be achieved.

Hereinafter, modes for carrying out the present invention will be described.
This invention is a package body which accommodates the fruits and vegetables containing Japanese radish in the packaging container containing a polymer film, and the moisture content at the time of accommodation of the Japanese radish is 20 to 40%. Thus, the package of this invention has a packaging container and the fruit and vegetables accommodated there at least.
The numerical range in the present application includes a lower limit value and an upper limit value unless otherwise specified. Therefore, for example, the expression “20 to 40%” means 20% or more and 40% or less unless otherwise specified.

Packaging container The packaging container which comprises the package of this 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.

  The packaging container used in the present invention comprises the polymer film described above, and its oxygen permeability is not particularly limited. The amount and type of fruits and vegetables to be stored and after a predetermined time has elapsed after packaging. An appropriate oxygen permeability can be selected in accordance with a desired internal oxygen concentration. Usually, what is in the range of 500-7000 cc / day / atm in 20 degreeC and 90% RH can be used preferably.

Fruits and vegetables The package of this invention accommodates the fruits and vegetables containing Japanese radish in the said packaging container. Here, the phrase “including fruits and vegetables” means that both the case where all of the fruits and vegetables are made of radish and the case where some of the fruits and vegetables are made of radish are included. Therefore, the fruits and vegetables stored in the packaging container may or may not contain other vegetables and fruits. Furthermore, as long as radish is included, it may contain components other than fruits and vegetables, for example, foods other than fruits and vegetables, seasonings, food additives and the like.

In addition, “radish” constituting the package of the present invention (contained in a packaging container) is a concept that includes vegetables in general belonging to the Brassicaceae radish genus, and for vegetables distributed under the name “radish” itself. It is not limited.
That is, "radish" here is generally known varieties, such as blue neck radish, white neck radish, pungent radish, etc., but is not particularly limited to varieties, etc. In addition, radish, Variants such as radish, black radish, and radish may also be used.
The site of “radish” is generally a root, but is not particularly limited to this, and may be a leaf or a stem, or a combination of these, for example, a radish with leaves. It may be something like this. Further, the “radish” is not limited to the peeled skin, and may include a part or all of the skin.

The radish (contained in the packaging container) constituting the package of the present invention has a water content of 20 to 40% when stored. The moisture content is preferably 25 to 40%, and more preferably 28 to 38%. The amount of water is excellent in that it can suppress the occurrence of off-flavors and browning of radish over a long period of time, and can achieve both of them, and can also suppress the number of viable bacteria.
The moisture content in the present application refers to zero (starting point) of a sample that has been dried under reduced pressure for 5 hours at 70 ° C. based on “Analysis method for nutrition labeling according to nutrition labeling standards” (Consumer Agency). Say that from the weight. For example, when 100 g of cut radish becomes 90 g by drying under reduced pressure at 70 ° C. for 5 hours, the water content is 10 g / 100 g = 10%.

  Control of the water content of the radish at the time of storage is performed by a drying process by draining water, but is not limited to this process as long as the object can be achieved. Examples of the dehydration or drying treatment by draining include, for example, a method by centrifugation, shaking, wind, absorption by a hygroscopic agent (drying agent), or a method by a combination of two or more thereof. However, the present invention is not limited to these methods.

There is no restriction | limiting in particular in the form of the radish (it accommodates in a packaging container) which comprises the package of this invention. It may be as-harvested, so-called pre-treated after removing the outer leaves or the like, or a cut form called cut radish.
The form of the radish may be processed like grated, sliced, etc. in addition to cut, and is not limited to these processing methods as long as the object of the present invention can be achieved.
In addition, the radish constituting the package of the present invention (stored in the packaging container) may be any one or all of the treatments such as washing, cooling, and dehydration within the scope of the present invention. In addition, none of these processes may be performed.

In the present invention, when the radish is stored in the packaging container, there is no particular limitation on the other fruits and vegetables that can be stored together, and unheated or heated fruits and vegetables that can be used together with radish can be appropriately stored. Specific examples of such fruits and vegetables include bananas, mangoes, ume, apples, strawberries, mandarin oranges, grapes, Japanese pears, fruit like Western pears, carrots, Chinese yam, root vegetables like burdock, tomatoes, cucumbers, Fruit vegetables such as eggplant, bell pepper, green beans, okra, sprouts such as mung bean sprout, soybean sprout, cypress, fungi such as shiitake mushroom, shimeji mushroom, eringi, maitake, matsutake, broccoli, spinach , Leaf stem vegetables such as Komatsuna, Chingen rhinoceros, cabbage, lettuce, asparagus, florets or seedlings.
In the case of storing radish, the form in which the oxygen concentration is controlled and held, which is one form of this embodiment, is particularly effective for maintaining the freshness of fruits and vegetables that are substantially breathing.

  In this invention, there is no restriction | limiting in particular also in the form of the other fruit and vegetables which can be accommodated with a Japanese radish in a packaging container. Therefore, it may be harvested as it is, it may be a so-called pre-treated one from which outer leaves or the like have been removed, or a cut vegetable called a cut vegetable. In addition, the fruits and vegetables may be those that have undergone any or all of the treatments such as washing, cooling, and dehydration, and may be those that do not perform any of these treatments.

The demand for cut vegetables has increased in recent years because it can be easily used for meals, and its commercial value is high, and thus has high economic value. Cut radish is representative of cut vegetables, and those that are mixed as they are can be used for meals as salads and the like, and thus have particularly high economic value. On the other hand, radish generally has a tendency that the respiratory action and metabolic reaction are rapidly activated by cutting and the quality is rapidly lowered. For this reason, cut radish tends to have a strange odor, browning, and an increase in the number of viable bacteria, which have a great influence on the commercial value as time passes. Among them, off-flavors are said to be particularly strong compared to other general vegetables, and have a great influence on the commercial value. However, this embodiment can also effectively suppress this off-flavor, so that it can be used effectively for maintaining the freshness of cut radish along with browning and suppression of the number of viable bacteria.
The viable cell count usually means the mesophilic aerobic viable cell count that grows under a certain condition, and is the most representative index indicating the degree of microbial contamination of food. Used for comprehensive evaluation and judgment of food safety, storage stability, hygienic handling, etc. In general, the number of colonies was calculated after culturing at 35 ° C. ± 1.0 ° C. for 48 hours ± 3 hours under aerobic conditions using a standard agar medium. Said.

  Within the scope of the present invention, within the scope of the present invention, the oxygen permeability and the mode of the polymer film that provides such oxygen permeability, depending on the type and form of the radish constituting the package of the present invention (contained in the packaging container) Can be selected as appropriate. By appropriately setting these, it is possible to maintain more effective freshness within the scope of the present invention for both the radish and the fruits and vegetables stored together when present.

Packaging Body The internal oxygen concentration of the packaging body of the present invention is not particularly limited as long as the object of the present invention can be achieved, but usually a low oxygen concentration of 0.2% to 5% by volume is maintained. It is desirable to do so. Here, about a lower limit, 0.5 volume% is more preferable, 0.8 volume% is still more preferable, 1.0 volume% is still more preferable, 1.1 volume% is especially preferable. Moreover, about an upper limit, 3 volume% is more preferable, 2.0 volume% is still more preferable, and 1.8% is especially preferable.
The temperature condition for placing the package of the present invention is not particularly limited as long as the object of the present invention can be achieved, but it is preferably 2 ° C. or higher and 15 ° C. or lower, more preferably 10 ° C. in view of the actual situation of commercial transactions. .
In order to more effectively maintain the freshness, it is preferable to appropriately adjust the oxygen concentration inside the package of the present invention according to the temperature condition where the package is placed. For example, when cut radish is stored in the package of the present invention, the package after 4 days (96 hours) have passed after the cut radish is packaged at 2 ° C. to 15 ° C., more preferably 10 ° C. The internal oxygen concentration is preferably in the range of 1.1% to 2.0% by volume.
The oxygen concentration and the carbon dioxide concentration inside the package can be specified by, for example, measuring using a Dansensor O ₂ / CO ₂ analyzer for food packaging, Check Mate 3.
Here, “after packaging” refers to the elapsed time since the packaging container was sealed after storing the fruits and vegetables containing radish in the packaging container. For example, “after 3 days after packaging” This refers to the state after 3 days have passed since the packaging container was sealed after storing the radish inside (that is, after 72 hours have elapsed).

From the viewpoint of realizing the above-mentioned desired internal oxygen concentration, it is preferable that nitrogen is enclosed in the packaging container. It is because the internal oxygen concentration immediately after packaging can be kept low by sealing nitrogen at the time of sealing the packaging container. Further, by further enclosing nitrogen, the pressure in the packaging container can be kept high, the inflow of outside air having a higher oxygen concentration can be prevented, and the internal oxygen concentration can be kept low for a long time after packaging.

In addition, in order to realize the above-described desired internal oxygen concentration, it is desirable to configure the packaging container using a polymer film having an oxygen permeability of a predetermined value or more.
That is, the lower limit of the oxygen permeability of the polymer film used in the present invention, 20 ° C., in 90% ^RH, it is ^{preferably, 1000cc / m 2 / day /} atm is 800cc / m 2 / day / atm It is preferable. When the oxygen permeability at 20 ° C. and 90% RH is 500 cc / m ² / atm / day or more, oxygen from outside air is introduced, and a desired internal oxygen concentration of 0.2 vol% or more can be maintained. it can. The upper limit value of the oxygen permeability of the polymer film used in the present invention is not particularly limited, but at 20 ° C. and 90% RH, it is 7000 cc / m ² / day / atm or less, 5000 cc / m ² / day / atm or less. Is preferably 3000 cc / m ² / day / atm or less, and more preferably 2000 cc / m ² / day / atm or less.

The oxygen 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 of 220 mm × 240 mm 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 center, except the end of about 2 cm that is one communicating part of the other side, and the inner dimension is 220 mm × A 240 mm bag is formed.
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%, nitrogen concentration: 79%) for 6 hours.
The oxygen concentration inside the bag was measured using a Dansensor O ₂ / CO ₂ analyzer Chec Mate ₃ for food packaging. Furthermore, the volume of the gas in the bag is measured, and the oxygen permeability is calculated from the following formula.
(Expression) Oxygen permeability = change in internal oxygen concentration (%) / 100 × volume (cm ³ ) × 24 × 60 / hour (360 minutes) × 10000 cm ² / area (1232 cm ² ) /0.21 (partial pressure of oxygen )

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, the oxygen permeability of a 30 μm OPP (biaxially oriented polypropylene) bag is 1000 cc / m ² / atm / day, but if one 100φ hole is made, it becomes 2000 cc / m ² / atm / day. Considering the mechanical strength and the like, the thickness of the polymer film is more preferably 15 to 45 μm, and particularly preferably 20 to 40 μm.

As described above, the oxygen 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. In particular, the oxygen permeability of 1000 cc / m ² / atm / day or more at 20 ° C. and 90% RH in a preferred embodiment of the present invention can be realized without providing an opening in the polymer film.
Since it is not necessary to provide an opening in the polymer film, the manufacturing process is simpler and less expensive, and it is not necessary to precisely control the size, shape, etc. of the opening.
The absence of an opening in the polymer film can be confirmed, for example, by the fact that the polymer film constituting the packaging container does not have a through-hole that can be confirmed with an ink leak checker.

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, the polymer film is used to achieve a desired oxygen permeability. You may use together the opening provided in. 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 of the polymer film is appropriate. In that case, the openings occupying the effective area of the polymer film The number of For example, a slit-like opening having a length of 2 mm, and in the closed state, the width as a through-hole cannot be visually recognized with an optical microscope (Olympus, model SZH-131) at a magnification of 4 times. When a product is provided, there is an effect of increasing the oxygen permeability of about 1000 cc / m ² / day / atm for every 200 mm × 200 mm packaging container. Packaging required based on such knowledge It is preferable to determine the number of slit openings from the oxygen permeability of the entire container.

  There is no particular limitation on the thickness of the polymer film used in the present invention, and when an opening is provided such as suitable oxygen permeability, flexibility when forming a packaging container, strength, transparency, economy, etc. From the viewpoint of accuracy and ease in forming the part, a suitable thickness may be selected as appropriate in relation to the material forming the polymer film. Typically, the thickness of the polymer film is preferably 10 to 45 μm, more preferably 20 to 40 μm, still more preferably 15 to 35 μm, and particularly preferably 18 to 32 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 they are excellent in 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. Further, 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 longitudinal direction and the transverse direction, 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.

The present invention relates to a method for producing a package, and a method for maintaining freshness.The present invention includes storing fruits and vegetables containing radish in a packaging container comprising a polymer film, and appropriately adjusting the amount of water that the radish has when stored. Can be produced, and the method for maintaining the freshness of fruits and vegetables, which is an embodiment of the present invention, 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 keeping freshness made of cut radish.

  First, in the radish pretreatment process, the skin is well washed with water. This is supplied to the conveyor. The radish transported by the conveyor is cut with a slicer, washed with cooling in a washing tank filled with cold water, and sufficiently dehydrated as a drainer until the water content reaches 20 to 40% by volume with a centrifugal dehydrator or the like. .

  The cut radish dehydrated in the pretreatment step described above is weighed to a predetermined amount, and packed in a packaging container (not sealed on one side) containing the polymer film used in this embodiment, The packaging container is sealed, and a freshness-maintaining packaging body containing cut radish is produced.

From the viewpoint of maintaining the freshness of the cut radish, it is preferable to use a sharp blade and reduce the number of scratches on the cut surface.
In addition, as the cut width is narrower, the cutting area increases and it becomes more difficult to maintain freshness. From the viewpoint of maintaining freshness, it is preferable that the cut width is wider as long as it matches the form of demand.
Furthermore, if many germs are attached to the cut radish from the beginning, it is more difficult to maintain freshness. Therefore, it is preferable to reduce the adhesion of germs as much as possible by washing well. Washing is particularly effective for maintaining freshness because it not only reduces the adhesion of various bacteria, but also has the effect of removing cell fluids and the like that contain highly active enzymes and the like and can cause discoloration.
In addition, it is important to sufficiently remove the water adhering to the surface of the cut radish after washing, in order to maintain freshness. In cut radish, the amount of water needs to be reduced to 20 to 40%. Is particularly important. Even if the water is drained by standing after washing, a lot of water is still attached to the surface of the cut lettuce. Therefore, it is effective to sufficiently remove water using a centrifugal dehydrator or the like.

In addition, the packaging body for fruit and vegetable freshness maintenance of this embodiment may perform nitrogen enclosure and / or deaeration after storage of the fruits and vegetables containing cut radish and sealing of a packaging container. By performing nitrogen sealing and / or degassing, it becomes possible to quickly reach a desired oxygen concentration designed as an equilibrium state between the oxygen permeability of the packaging container and the respiration rate of fruits and vegetables, which is advantageous for maintaining freshness. .
In addition, deaeration may be performed after sealing the packaging container from the viewpoint of improving efficiency in the process of distribution, saving space, and eliminating a specific gas.

  According to the method as described above, for example, after carrying out the step of storing fruits and vegetables containing cut radish having a water content of 20 to 40% in a packaging container comprising a polymer film, the oxygen concentration in the packaging container is adjusted. Under the condition of 10 ° C., the freshness of the fruits and vegetables including cut radish can be effectively maintained by carrying out the process of maintaining the volume to 2% by volume or less for 6 days (144 hours) after packaging.

The packaging body of the present invention may contain only fruits and vegetables including radish 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 a natural antibacterial agent with relatively little concern about the effect on fruits and vegetables and use in the vicinity of fruits and vegetables as foods. It can be preferably used. More specifically, natural antibacterial agents such as chitosan, allyl isothiocyanate, hinokitiol, limonene and the like can be stored in the packaging container.

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

In the following examples / comparative examples, each characteristic was evaluated by the following method.
(With or without opening)
After injecting the red penetrant (Mitsubishi Gas Chemical Co., Ltd., trade name: Ageless Seal Check Spray) into the packaging container, set the scale of the heating condition to 3 with an impulse sealer, heat seal with a width of about 5 mm, and paper (Kokuyo PPC paper, common paper A4) was pressed and the presence or absence of an opening was confirmed by the presence or absence of the transfer of the ink to paper.
(amount of water)
As described above, the moisture content in the radish stored in the packaging container was dried under reduced pressure at 70 ° C. for 5 hours based on the “analysis method of nutrition labeling according to nutrition labeling standards” (Consumer Agency). The sample was defined as zero (starting point) and the weight from there. For example, when 100 g of cut radish becomes 90 g by drying under reduced pressure at 70 ° C. for 5 hours, the water content is 10 g / 100 g = 10%.
(Oxygen concentration and carbon dioxide concentration)
The measurement was performed using an O ₂ / CO ₂ analyzer, Check Mate 3, for food packaging manufactured by Dansensor.
(appearance)
The package was opened, the radish taken out were arranged, and the area of the entire browning portion was visually evaluated with n (number of samples) = 5 around the cut cross section.
The evaluation criteria are as follows.
A: No problem in fresh state B: Slightly browned but can be said to be fresh C: Browned but in the same state as commercially available D: Further browning is strong and consumers care E: Further browning is not possible for sale In addition, in this application, in the case of evaluation of D and E, it is evaluated that browning has occurred.
(odor)
When the package was opened, the face was brought close to it and the inner odor was smelled, and n (number of samples) was evaluated as 5 (sensory evaluation).
The evaluation criteria are as follows.
A: There is no problem in the fresh state B: There is a little smell but it can be said that it is fresh C: The state is strong but it is in the same state as the market and can be sold D: The state is more smelly and the consumer cares E: Further smell is strong and unsaleable In addition, in this application, in the case of evaluation of D and E, it evaluates that the smell generate | occur | produced.
(Viable count)
The number of viable bacteria was determined under aerobic conditions using standard agar medium for n (number of samples) = 5 on the 4th day (96 hours later) and 7th day (168 hours later) after packaging of cut radish. The number of colonies observed after culturing at 35 ° C. ± 1.0 ° C. for 48 hours ± 3 hours (unit: CFU / g) was calculated.

Example 1
Two OPP (biaxially stretched polypropylene) films with a thickness of 30 μm are overlapped, three sides are sealed with heat sealing and cut, and one side is unsealed packaging bag (170 mm × 235 mm, inner dimension Area: 799 cm ² ).
When the presence or absence of an opening in the film was confirmed, it was confirmed that there was no opening.
Regarding the gas permeation of the film, the oxygen permeability was 1000 cc / m ² / day / atm at 20 ° C. and 90% RH.
The oxygen concentration was maintained at a low concentration of 2% by volume or less during the measurement period.
Cut radish consisted of 1 cut, 2 washings-water washing, 3 dehydration, and was produced according to the "Manufacturing Manual for Mass Cooking Facilities" (Ministry of Health and Welfare). Specifically, according to the “Mass Cooking Facility Sanitation Management Manual” (Ministry of Health and Welfare), after passing through the steps of 1 cut, 2 washing to washing, Based on the “Analysis method” (Consumer Affairs Agency), a sample that had been dried under reduced pressure at 70 ° C. for 5 hours was defined as zero (starting point). Then, a dried radish with a moisture content of 25% was produced by drying under reduced pressure at 70 ° C. for 180 minutes using a dryer.
About 50 g of cut radish with a moisture content of 25% was stored in the packaging container, and the container was completely filled with nitrogen and then heat-sealed to prepare a package. The package was stored at 10 ° C., and the internal oxygen concentration and carbon dioxide concentration were measured every day from the cut radish packaging for 6 days to evaluate the odor and appearance of the cut radish. The results are shown in Table 1.
Moreover, the viable cell count (unit: CFU / g) on the 4th and 7th days from the cut radish packaging was examined.

(Examples 2 to 4)
According to the "Manufacturing Sanitation Management Manual for Large-scale Cooking Facilities" (Ministry of Health and Welfare), after passing through the steps of 1 cut, 2 washing to water washing, the 3 dehydration process is performed as "analysis method for nutrition labeling according to nutrition labeling standards" (consumption A sample that had been dried under reduced pressure at 70 ° C. for 5 hours based on a government agency) was defined as zero (starting point). Further, using a dryer, drying at 70 ° C. under reduced pressure for 120 minutes, 60 minutes, and 30 minutes resulted in a moisture content of 30% (Example 2), 32% (Example 3), and 35% (Example 4). The package was prepared and evaluated in the same manner as in Example 1 except that each cut radish was prepared and used. The results are shown in Table 1.

(Comparative Example 1)
According to the "Manufacturing Sanitation Management Manual for Large-scale Cooking Facilities" (Ministry of Health and Welfare), after passing through the steps of 1 cut, 2 washing to water washing, the 3 dehydration process is performed as "analysis method for nutrition labeling according to nutrition labeling standards" The package was prepared in the same manner as in Example 1 except that a cut radish with a moisture content of 42% was prepared and used by drying under reduced pressure at 70 ° C. for 5 hours based on the Evaluation was performed. The results are shown in Table 1.

In Examples 1 to 4, where the moisture content of the cut radish when stored in the packaging container is in the range of 20% to 40%, the odor is A or B even on the fifth day (after 120 hours) from the packaging. In the evaluation, it can be said that the fresh state is maintained, and even on the 6th day (after 144 hours) from the packaging, it is confirmed that the bad odor that affects the commercial value can be effectively suppressed by the evaluation of C or more. It was.
In addition, regarding the appearance (browning), even on the 4th day (after 96 hours) from the packaging, it can be said that the fresh state is maintained in the evaluation of A or B, and even on the 6th day (after 144 hours) from the packaging. Moreover, it was also confirmed by evaluation more than C that the browning which affects a commercial value can be suppressed effectively.
On the other hand, in Comparative Example 1 where the moisture content of the cut radish when stored in the packaging container exceeds 40%, the consumer is concerned with the evaluation of D on the third day (after 72 hours) from the packaging. It was confirmed that it had a bad smell and lost commercial value.
Moreover, regarding the appearance (browning), on the 6th day (after 144 hours) from the packaging, an appearance (browning) that consumers are concerned about in the evaluation of D occurs, and the commercial value is lost. It was confirmed.
For this reason, when the moisture content of cut radish is 20% or more and 40% or less when stored in the packaging container, it is the sixth day (after 144 hours) from the packaging in terms of both odor and appearance. However, the commercial value is not lost, but when it exceeds 40%, it was confirmed that the commercial value was lost on the third day (72 hours after packaging) in terms of odor.

Furthermore, using Examples 1-4 and Comparative Example 1, the number of viable bacteria on the fourth day (after 96 hours) and the seventh day (after 168 hours) from the packaging of cut radish was examined. In this case as well, the packaging was stored at 10 ° C. until the seventh day (after 168 hours) for investigation. The results are also shown in Table 1.
From this result, in Comparative Example 1 where the moisture content of cut radish exceeds 40%, the moisture content is 20% or more and 40% on both the fourth day (96 hours later) and the seventh day (168 hours later). It was confirmed that the viable cell count was high even when compared with any of the examples within the following range. Therefore, the example in which the moisture content of cut radish is in the range of 20% or more and 40% or less is superior also in terms of suppression of the number of viable bacteria than Comparative Example 1 in which the moisture content exceeds 40%. I understood.

  According to the present invention, in a package that contains fruits and vegetables containing radish having a high economic value, by controlling the moisture concentration in the radish to be packaged to an appropriate value, the odor and browning of the fruits and vegetables, and Since the number of viable bacteria can be effectively suppressed, it has high practical value and high applicability in various fields of industry such as food processing, distribution, and eating out.

Claims (13)

  A package comprising fruits and vegetables containing radish in a packaging container comprising a polymer film, wherein the water content when the radish is stored is 20% or more and 40% or less.   The package according to claim 1, wherein the oxygen concentration after 96 hours have passed under conditions of 10 ° C after radish packaging in the packaging container is 1.10% by volume or more and 2.0% by volume or less.   The package according to claim 1 or 2, wherein the inside of the packaging container is sealed with nitrogen.   The package according to any one of claims 1 to 3, wherein the radish odor and browning can be suppressed for 144 hours or longer under conditions of 10 ° C after packaging.   The number of viable bacteria of the radish can be suppressed for more than 168 hours under the condition of 10 ° C. after packaging, compared to the case where the water content when storing the radish exceeds 40%. The package described. The oxygen permeability of the polymer film is 500 cc / m ² / day / atm or more and 7000 cc / m ² / day / atm or less at 20 ° C. and 90% RH, according to claim 1. The package described.   The package according to any one of claims 1 to 6, wherein the packaging container does not have a through-hole that can be confirmed by an ink leakage checker.   The package according to any one of claims 1 to 7, wherein the polymer film has a thickness of 15 µm or more and 45 µm or less.   The package according to any one of claims 1 to 8, wherein the polymer film is a stretched polypropylene film, a polyethylene film, or a laminate of a stretched film and a polyethylene film.   The package according to any one of claims 1 to 9, wherein the polymer film contains at least one antibacterial agent or is coated with at least one antibacterial agent.   The package for maintaining freshness of fruits and vegetables according to any one of claims 1 to 10, further comprising a hygroscopic agent and / or an antibacterial agent.   A method for maintaining freshness of fruits and vegetables under a condition of 2 ° C or higher and 15 ° C or lower, comprising a step of storing fruits and vegetables containing radish having a water content of 20% or higher and 40% or lower in a packaging container comprising a polymer film.   The method for maintaining freshness of fruits and vegetables according to claim 12, further comprising a step of enclosing nitrogen in the packaging container.