JP2024071176A - Package containing fruits and vegetables, method for manufacturing package containing fruits and vegetables, and method for preserving freshness of fruits and vegetables - Google Patents

Abstract

[Problem] To provide a package and a packaging method that can improve the freshness-retaining effect of fruits and vegetables. [Solution] The package of the present invention is a package containing fruits and vegetables, in which the fruits and vegetables are sealed in a packaging bag made of a synthetic resin film, and is configured to satisfy the following conditions: (Condition) When the oxygen transmission rate of the packaging bag at 23°C and 60% RH is p (ml/m2·day·atm), the weight of the fruits and vegetables is w (g), and the dead space of the package is v (cm3), (i) when p×w/1000≧3000, v/w is 0.070 or more and 1.4 or less, and (ii) when p×w/1000<3000, v/w is 0.60 or more and 2.6 or less. [Selected Figure] None

Description

The present invention relates to a package containing fresh produce, a method for manufacturing a package containing fresh produce, and a method for preserving the freshness of fresh produce.

Conventionally, a method for preserving the freshness of harvested fruits and vegetables is known that involves moderately suppressing the respiration of the fruits and vegetables to maintain their freshness. Packaging materials used to preserve the freshness of such fruits and vegetables are known as modified atmosphere (MA) packaging.

For example, Patent Document 1 discloses a method for preserving freshness by controlling the odor intensity (S) of a packaging bag containing fruits and vegetables including shredded cabbage to 600 or less, as measured by an odor monitor, in terms of _NH3 . According to Patent Document 1, odor suppression is possible by controlling the odor intensity (S) of an odor monitor in terms of _NH3 , which corresponds to the concentration of methyl sulfide, the cause of the odor, to a certain value or less. Patent Document 2 discloses that a freshness preservation effect is obtained for a package containing fruits and vegetables in a bag made of a propylene-based film, by filling the bag with an inert gas containing carbon dioxide and sealing it while controlling the oxygen permeability and carbon dioxide permeability of the bag.

JP 2018-199510 A JP 2018-118744 A

However, the techniques disclosed in Patent Documents 1 and 2 still leave room for improvement in terms of their effectiveness in preserving the freshness of fruits and vegetables.

Usually, packages of fruits and vegetables have a gap between the fruits and vegetables and the packaging bag. Such a gap is inevitably generated during packaging due to differences in the shapes and sizes of the fruits and vegetables and the packaging bag, and in some cases, a space is intentionally provided within the package for reasons such as providing cushioning to protect the fruits and vegetables or improving the appearance.
On the other hand, since the fruits and vegetables continue to breathe inside the package in which they are packaged, it is important to moderately control this breathing in order to maintain freshness. The inventors have found that in addition to the oxygen permeability of the packaging bag, the amount of oxygen present in the space (dead space) inside the package also contributes to the freshness-maintaining effect. As a result of further investigations focusing on the weight of the fruits and vegetables inside the package, they have devised new indicators for controlling the oxygen permeability, dead space, and weight of the fruits and vegetables in order to achieve a more stable freshness-maintaining effect, and have completed the present invention.

The present invention provides the following technologies related to packaging for fruits and vegetables:

[1] A package containing fresh produce comprising fresh produce sealed in a packaging bag made of a synthetic resin film, the package being configured to satisfy the following conditions:
(Conditions) When the oxygen transmission rate of the packaging bag at 23°C and 60% RH is p (ml/ ^m2 ·day·atm), the weight of the fruit or vegetable is w (g), and the dead space of the package is v ( ^cm3 ),
(i) when p×w/1000≧3000, v/w is 0.070 or more and 1.4 or less;
(ii) When p×w/1000<3000, v/w is 0.60 or more and 2.6 or less.
[2] The fruit and vegetable package according to [1],
The package containing fruits or vegetables, wherein s/w is 2 or more and 10 or less, when the inner area of the packaging bag is s (cm ² ).
[3] The fruit and vegetable package according to [1] or [2],
The packaging bag has an oxygen permeability p (ml/ ^m2 ·day·atm) at 23°C and 60% RH, and the p is 500 or more and 30,000 or less.
[4] In the package containing fruits and vegetables according to any one of [1] to [3],
The thickness (μm) of the packaging bag is 5 to 300 μm.
[5] In the package containing fruits and vegetables according to any one of [1] to [4],
The opening of the packaging bag is sealed by heat sealing, thereby forming a package containing fruits and vegetables.
[6] In the package containing fruits and vegetables according to any one of [1] to [5],
The opening of the packaging bag is sealed with a back seal, thereby forming a package containing fruits and vegetables.
[7] In the package containing fruits and vegetables according to any one of [1] to [6],
The packaging bag does not have a through hole, and is a package containing fruits and vegetables.
[8] In the package containing fruits and vegetables according to any one of [1] to [7],
The synthetic resin film is a film containing one or more resins selected from polyethylene, ethylene copolymer, polypropylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, and polyamide resin, or a multilayer film containing such a film.
[9] In the package containing fruits and vegetables according to any one of [1] to [8],
The package containing fruits and vegetables, wherein the fruits and vegetables are head vegetables.
[10] In the package containing fruits and vegetables according to any one of [1] to [9],
The fruit and vegetable package contains head vegetables divided into 1/8 to 1/2 portions.
[11] A step of placing fruits and vegetables inside a packaging bag made of a synthetic resin film through an opening of the packaging bag;
A step of closing and sealing the opening of the packaging bag while discharging air from inside the packaging bag so as to satisfy the following conditions;
The method for producing a package containing fruits and vegetables includes the steps of:
(Conditions) When the oxygen transmission rate (ml/ ^m2 ·day·atm) of the packaging bag at 23°C and 60% RH is p, the weight of the fruit or vegetable is w (g), and the dead space of the packaging body is v ( ^cm3 ),
(i) when p×w/1000≧3000, v/w is 0.070 or more and 1.4 or less;
(ii) When p×w/1000<3000, v/w is 0.60 or more and 2.6 or less.
[12] A method for preserving the freshness of fruits and vegetables, comprising a step of storing the fruits and vegetables in a package containing the fruits and vegetables described in any one of [1] to [10].
[13] The method for preserving freshness of fruits and vegetables according to [13],
The method for preserving the freshness of fruits and vegetables comprises storing the package containing the fruits and vegetables at a temperature of 2 to 20°C.

The present invention provides technology related to packaging that can improve the freshness retention effect of fruits and vegetables.

The following describes in detail an embodiment of the present invention.

In this specification, the term "approximately" means that a range taking into consideration manufacturing tolerances, assembly variations, and the like, is included, unless otherwise specified explicitly.
In this specification, unless otherwise specified, the expression "X to Y" in the description of a numerical range means from X to Y. For example, "1 to 5% by mass" means "1% by mass to 5% by mass."

<Packaging>
The package containing fruits and vegetables (hereinafter also referred to as the "package") of this embodiment is made by sealing the fruits and vegetables in a packaging bag made of a synthetic resin film and is configured to satisfy the following conditions, thereby improving the freshness-preserving effect of the fruits and vegetables.
(Conditions) When the oxygen transmission rate of the packaging bag at 23°C and 60% RH is p (ml/ ^m2 ·day·atm), the weight of the fruit or vegetable is w (g), and the dead space of the package is v ( ^cm3 ),
(i) when p×w/1000≧3000, v/w is 0.070 or more and 1.4 or less;
(ii) When p×w/1000<3000, v/w is 0.60 or more and 2.6 or less.

Conventionally, packages containing fruits and vegetables have been designed to maintain the freshness of the fruits and vegetables by reducing the oxygen permeability of the packaging bag to suppress the respiration of the fruits and vegetables. However, if the oxygen permeability of the packaging bag is made too low, there will be a shortage of oxygen inside the package, and the respiration of the fruits and vegetables will switch to anaerobic respiration, causing the fruits and vegetables to emit unpleasant odors, and the freshness of the fruits and vegetables will tend to decrease. Furthermore, if the dead space inside the package is made too small, problems such as crushing the fruits and vegetables will occur.
Here, in the package of this embodiment, in addition to specifying the oxygen transmission rate of the packaging bag and the dead space of the packaging bag to specify the amount of oxygen in the package to a higher degree, attention is also paid to the balance with the weight of the fruit or vegetable. Specifically, the above (i) is intended for a case where at least one of the weight of the fruit or vegetable or the oxygen transmission rate when contained in the packaging bag is relatively high, and the dead space is intended to be small relative to the weight of the fruit or vegetable. The above (ii) is intended for a case where at least one of the weight of the fruit or vegetable or the oxygen transmission rate when contained in the packaging bag is relatively low, and the dead space is intended to be high relative to the weight of the fruit or vegetable.

For example, pumpkins tend to weigh more heavily when placed in a packaging bag than other fruits and vegetables. Therefore, the oxygen permeability of the packaging bag can be set high, so a package containing pumpkin may correspond to (i). In this case, as in (i), it is preferable that the v/w tends to be lower than in the case of (ii). Also, for example, Chinese cabbage tends to weigh less than pumpkins when placed in a packaging bag, so a package containing Chinese cabbage may correspond to (ii). In this case, as in (ii), it is preferable that the v/w tends to be higher than in the case of (i).

(i) When p×w/1000≧3000, v/w is 0.070 or more and 1.4 or less, preferably 0.080 or more, more preferably 0.10 or more, and even more preferably 0.15 or more, while preferably 1.2 or less, more preferably 0.9 or less, and even more preferably 0.6 or less.

(ii) When p×w/1000<3000, v/w is 0.60 or more and 2.6 or less, preferably 0.65 or more, while preferably 2.0 or less, more preferably 1.5 or less.

In this embodiment, the dead space refers to the air volume (cm ³ ) excluding the volume (cm ³ ) of the fruit or vegetable inside the package, that is, the space volume (cm ³ ).
The dead space was measured as follows: First, a package in which fruit or vegetables were placed in a packaging bag and sealed was pushed into a water tank filled with water, and the volume of the package was calculated from the weight of the overflowing water, assuming the density of water to be 1 g/cm ^3. On the other hand, the weight of the fruit or vegetables was measured, and the volume was calculated assuming the specific gravity of the fruit or vegetables to be 1. The dead space (cm ³ ) of the package was then calculated by subtracting the volume of the fruit or vegetables from the volume of the package calculated above.

The packaging of this embodiment can further improve the freshness-retaining effect more stably by satisfying the following conditions:

When the inner surface area of the packaging bag is s (cm ² ) and the weight of the fruit or vegetable is w (g), s/w is preferably 2-10, and more preferably 3-9.
This makes it possible to more effectively reduce mold and odor in fruits and vegetables.

(Oxygen permeability)
When the oxygen transmission rate of the packaging bag at 23°C and 60% RH is p (ml/ ^m2 ·day·atm), p is preferably 500 to 30,000, more preferably 800 to 20,000, and even more preferably 1,000 to 10,000. From the viewpoint of placing importance on the selectivity of fruits and vegetables in the package, p is preferably 3,000 to 5,000, and more preferably 3,500 to 4,500.

The oxygen permeability can be calculated, for example, by measuring the oxygen concentration inside the packaging bag immediately after filling it with nitrogen and after it has been left to stand for a certain period of time after filling it with nitrogen, and then calculating it from the oxygen concentration gradient.

(Water vapor permeability)
The water vapor transmission rate of the packaging bag at 40° C. is preferably 1 g/(m ² ·day) or more, and more preferably 3 g/(m ² ·day) or more, from the viewpoint of releasing water vapor due to respiration of fruits and vegetables.
On the other hand, from the viewpoint of suppressing respiration of fruits and vegetables, the water vapor permeability of the packaging bag at 40°C is preferably 300 g/( ^m2 ·day) or less, more preferably 100 g/( ^m2 ·day) or less, even more preferably 50 g/( ^m2 ·day) or less, and particularly preferably 10 g/( ^m2 ·day) or less.

Water vapor permeability can be measured using a method conforming to JIS Z 0208 (cup method).

In addition, in the present invention, the oxygen permeability and water vapor permeability (moisture permeability) of the packaging bag can be adjusted by controlling the selection of the synthetic resin film material, the film manufacturing method, the layer structure of the film, the presence or absence of through holes and their average diameter, the presence or absence of non-through grooves, etc.

The package of this embodiment is obtained by placing fruits and vegetables in a packaging bag made of a synthetic resin film and then sealing and packaging the same.
The method of sealing and packaging is not particularly limited as long as the packaged fruit or vegetable does not fall out of the packaging bag and the oxygen concentration can be kept constant, and examples of the method include a sealing method such as heat sealing, a bag seal, a crimping method such as a rubber band, an adhesive tape, and a clip. A zipper may also be attached to the opening. The sealing method may be a combination of two or more of these methods.
In particular, in terms of making it easier to maintain the deaerated packaging state, it is preferable that the opening of the packaging bag be sealed by heat sealing, and in terms of making it easier to package the fruits and vegetables in accordance with their outer shapes, it is preferable that the opening of the packaging bag be sealed by back sealing.

The amount of fruit or vegetable contained in a packaging bag may vary depending on the size of the container, the type of fruit or vegetable, the purpose of the package, etc. For fruit or vegetable intended for general consumers, the amount is preferably 50 to 1,000 g, more preferably 100 to 800 g, from the viewpoints of ease of consumption immediately after opening and ease of carrying and handling.

[Fruits and vegetables]
In this embodiment, fruits and vegetables refer to unheated vegetables from which inedible parts of soil- or hydroponically-grown vegetables, such as roots, skins, cores, stems, seeds, and flowers, have been removed, and the edible parts of the vegetables have been left to be easy to eat and cook.

Fruits and vegetables include, but are not limited to, semi-heading and head vegetables such as cabbage, Chinese cabbage, lettuce (lettuce, leaf lettuce, cos lettuce, sunny lettuce, salad lettuce, lettuce, etc.), and Brussels sprouts; non-heading leaf vegetables such as spinach, komatsuna, mizuna, bok choy, turnip (kakina), non-heading lettuce (romaine lettuce, sunny lettuce, etc.), chrysanthemum, kukitachina, shinobu-na, santouna, rapeseed, chijirena, kousai-tai, urui, field wasabi, flower wasabi, watercress, arugula, shepherd's purse, petit vert, ice plant, and leaf radish; root vegetables such as sweet potato, potato, nagaimo, yamaimo, taro, jinenjo, yamatoimo, radish, carrot, burdock, turnip, and ginger; green onion, ta Examples of the vegetables include Allium vegetables such as onion and Chinese chive; Brassica flower buds such as broccoli and cauliflower; Cucurbitaceae fruit vegetables such as cucumber and pumpkin; Solanaceae fruit vegetables such as eggplant, tomato, cherry tomato, green pepper, and paprika; and okra, bitter melon, zucchini, bitter gourd, and sweet corn; immature beans such as edamame, snow peas, green beans, and broad beans; stem vegetables such as celery, asparagus, and wasabi; herbs such as myoga, osmanthus, Japanese parsley, mitsuba, and herbs (thyme, sage, parsley, Italian parsley, rosemary, oregano, lemon balm, chives, lavender, salad burnet, lamb's ear, rocket, dandelion, and nasturtium); and fungi and mushrooms. These may be packaged in a mixture of one or more types. Among them, semi-head and head vegetables are preferable. Semi-head and head vegetables tend to have multiple layers of leaves, making them bulky. In other words, when semi-head and head vegetables are cut into appropriate amounts for packaging, their weight inside the package tends to be low.

Fruits and vegetables may be cut appropriately taking into consideration purchase and consumption, or may be divided into approximately equal portions, such as 1/8 to 1/2.

[Packaging bag shape]
The size of the packaging bag of this embodiment can be about 100 mm×100 mm to 250 mm×350 mm for packaging fruits and vegetables for general consumers. The packaging bag may or may not have a gusset.
The manufacturing method of the packaging bag can be a known method. The bag may be made by melt-cutting or solid sealing. Melt-cutting provides a better appearance and stronger seal strength.

[Synthetic resin film]
(raw materials)
The synthetic resin film is preferably transparent or semi-transparent, more preferably transparent, from the viewpoint of allowing the fruit or vegetable to be visually recognized from the outside. In addition, the synthetic resin film may be printed with information for the purpose of identifying the fruit or vegetable.

The synthetic resin constituting the synthetic resin film is not particularly limited as long as it can be used for packaging fruits and vegetables, and any known synthetic resin can be used.
Examples include various polyethylenes and ethylene copolymers, polypropylene, polyamide resins, polyvinyl chloride, polystyrene, acrylic resins, polyethylene terephthalate, and polyester resins such as polylactic acid, etc. These may be homopolymers, copolymers of two or more kinds, or may contain two or more kinds of these homopolymers or copolymers.

Specific examples of the various polyethylenes and ethylene copolymers mentioned above include ethylene-vinyl alcohol copolymers, high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, metallocene-linear low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-propylene copolymer, ethylene-α-olefin copolymer, and other copolymers or ionomers. These may contain one or more types, or may be mixed with other resins.

The polyamide resin may be nylon. Nylon 6, nylon 11, nylon 12, nylon 66, nylon 6.10, nylon 6.12, nylon 6.T, nylon 6.I, nylon 9T, nylon M5T, polymetaxylylene adipamide (MXD nylon), etc. may be used alone or in combination of two or more. Among these, nylon 6, nylon 11, nylon 12, and nylon 66 alone or in combination of two or more are preferred, and nylon 6 and nylon 66 alone or in combination of two or more are more preferred.

Linear low-density polyethylene (L-LDPE) is usually a copolymer of ethylene and a small amount of α-olefin. The type of α-olefin is not particularly limited. Typical α-olefins include α-olefins with 3 to 10 carbon atoms, such as 1-butene, 1-hexene, 4-methylpentene-1, and 1-octene.

For example, when the fruits or vegetables to be packaged are heavy, it is preferable to use a multilayer film made of polyethylene by dry lamination, extrusion lamination, or coextrusion in addition to a film such as unstretched polypropylene, oriented polypropylene, unstretched nylon, oriented nylon, or oriented polyester.
The synthetic resin film may be stretched or annealed, or may have a sealant layer. In particular, the synthetic resin film may be stretched to improve its rigidity, pinhole resistance, water vapor and oxygen barrier properties, and appearance. For example, stretched nylon, stretched polylactic acid, and stretched polystyrene are preferred.

The synthetic resin film may contain additives such as anti-fog agents, anti-blocking agents, heat stabilizers, lubricants, impact resistance improvers, processing aids, antistatic agents, UV absorbers, antioxidants, weather resistance inhibitors, fillers, and pigments, as necessary, to the extent that the performance of the synthetic resin film is not impaired.

Specific examples of the anti-fogging agent include glycerin laurate, diglycerin laurate, decaglycerin laurate, glycerin monostearate, sorbitan stearate, etc.

The antiblocking agent may be particulate inorganic compounds such as silica, alumina, alumina silicate, and diatomaceous earth; or particulate organic compounds such as polyethylene, cross-linked polyethylene, polymethyl methacrylate, and cross-linked polymethyl methacrylate. Among these, particulate inorganic compounds are preferred from the viewpoint of maintaining freshness-preserving effect, and silica is more preferred.

The method for obtaining a synthetic resin film is not particularly limited. Examples of methods for obtaining a synthetic resin film include known methods such as extrusion, inflation, and calendaring.

The synthetic resin film may be a single layer or a multi-layer film having two or more layers.

(Multilayer film)
By making the synthetic resin film multi-layered, the desired functionality can be enhanced. For example, by adding a function such as slipperiness to the surface layer of the synthetic resin film, the handling property and heat sealability of the synthetic resin film can be improved, and a packaging bag with an excellent balance between elongation and rigidity can be stably obtained. In addition, for example, by making the synthetic resin film into a two-layer or three-layer structure and making a layer containing an antiblocking agent into at least one of the surface layers, slipperiness can be obtained.
When the synthetic resin film is multi-layered, the base resins of the layers may be the same or different from each other. From the viewpoint of obtaining good adhesion between the layers, it is preferable that the layers use the same resin.

When the synthetic resin film is multi-layered, the thickness of each layer may be the same as or different from each other. For example, in the case of a three-layer structure, the thickness of the middle layer may be the thickest and the thickness of the surface layer may be the thinnest. The surface layer preferably accounts for 10 to 20% of the total thickness of the synthetic resin film, and more preferably for 12 to 17%.

To obtain a multilayer film, known methods such as dry lamination, extrusion lamination, coextrusion, and coating can be used as appropriate. Coextrusion is preferable from the viewpoint of improving adhesion between layers and controlling the layer thickness.

(Thickness)
The thickness of the synthetic resin film is preferably 5 to 300 μm, more preferably 10 to 200 μm, even more preferably 20 to 100 μm, and particularly preferably 20 to 70 μm.
By making the thickness of the synthetic resin film equal to or greater than the lower limit, the strength of the packaging bag is increased and deformation due to external stress is suppressed, while a freshness-preserving effect is stably obtained. By making the thickness of the synthetic resin film equal to or greater than the upper limit, the flexibility (pliability) of the packaging bag can be maintained, and the dead space can be varied according to the amount of gas in the package.

(Through hole)
The synthetic resin film may have through holes formed therein, which makes it possible to easily adjust the oxygen permeability of the package.

The planar shape of the through hole may be, for example, a circle, a polygon, or a slit. A circle is not limited to a perfect circle, but includes an approximate circle. In addition to a circle, the hole may be a semicircle or a crescent shape. A polygon may be any shape surrounded by three or more line segments, such as a triangle, a rectangle, or a pentagon. A slit is a cut or narrow gap that penetrates a synthetic resin film, and may be a straight line, a curve, an L-shape, an X mark, or the like, and its length is not particularly limited.

When through holes are formed, the average diameter of the through holes is preferably 10 μm to 200 μm, more preferably 20 to 100 μm, even more preferably 40 to 80 μm, and even more preferably 50 to 70 μm. By making the diameter equal to or greater than the above lower limit, the oxygen permeability of the package is improved and the generation of unpleasant odors is easily suppressed. On the other hand, by making the diameter equal to or less than the above upper limit, the MA effect can be maintained while preventing the intrusion of foreign matter, making it easier to maintain the freshness of fruits and vegetables.
The average diameter of the through holes is calculated from the opening area of the through holes, assuming that the through holes are perfect circles.

When a synthetic resin film has multiple through holes, from the viewpoint of ease of manufacture, it is preferable that the diameters of all the through holes are within the above numerical range, but it is acceptable for the diameters of some of the through holes to be outside the range of 10 to 200 μm.

The hole density is set appropriately depending on the oxygen permeability and dead space of the package, but it may be preferably 1 to 20 holes, more preferably 1 to 10 holes, and even more preferably 1 to 5 holes per package.

The method for forming the through holes is not particularly limited, and any known method can be used. Examples of such known methods include laser processing, needle processing including hot needles, and methods using a mold such as a roll cutter.

<How to maintain freshness>
The freshness preservation method of the present embodiment includes a step of storing fruits and vegetables in the above-described package containing the fruits and vegetables.
Storage can be performed by a known method, but it is preferable to store the package at an environmental temperature of 2 to 20° C. The environmental temperature refers to, for example, the temperature setting of a refrigerator or a refrigerator in which the package is stored, or the temperature setting of a showcase in which the package is displayed in a storefront or the like. It is not intended to be a measured value obtained by strictly measuring the temperature around the package. In addition, it is sufficient that the average environmental temperature is 2 to 20° C., and it may temporarily become around 10° C. due to unavoidable circumstances such as the opening and closing of a door during transportation of the package.

<Manufacturing method of packaging body>
The method for producing a package containing fruit or vegetable in this embodiment includes the following steps.
placing fruit or vegetables in a packaging bag made of a synthetic resin film through an opening of the packaging bag;
A process of closing and sealing the opening of the packaging bag while exhausting the air inside the packaging bag so as to satisfy the following conditions.
(Conditions) When the oxygen transmission rate (ml/ ^m2 ·day·atm) of the packaging bag at 23°C and 60% RH is p, the weight of the fruit or vegetable is w (g), and the dead space of the packaging body is v ( ^cm3 ),
(i) when p×w/1000≧3000, v/w is 0.070 or more and 1.4 or less;
(ii) When p×w/1000<3000, v/w is 0.60 or more and 2.6 or less.
This provides a package that improves the freshness-preserving effect of fruits and vegetables.

The method of closing and sealing the opening of the packaging bag while discharging the air from inside the bag may be performed in a manner that adjusts the dead space, and any known method may be used. In the manufacturing method of the package of this embodiment, it is preferable not to use a completely degassed vacuum pack or to replace the air with a gas with a predetermined composition. This makes it possible to obtain a package that can maintain the freshness of fruits and vegetables in a simple manner.

The above describes the embodiments of the present invention, but these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of the present invention are included in the present invention.

The present invention will be described in detail below based on examples and comparative examples. It should be noted that the present invention is not limited to the examples.

<Measurement>
Measurement of dead space: Each fruit or vegetable was placed in a packaging bag and the package was then pushed into a water tank filled with water. The overflowing water was collected and weighed, and the volume of the package was calculated assuming the density of water to be 1 g/ ^cm3 . The weight of the fruit or vegetable was also measured, and the volume of the fruit or vegetable was calculated assuming the specific gravity of the fruit or vegetable to be 1.
The volume of the fruit or vegetable was subtracted from the volume of the package calculated above to determine the dead space (cm ³ ) of the package.

Measurement of oxygen transmission rate (cc/ ^m2 ·day·atm) at 23°C and 60% RH (1) Inclusion of nitrogen gas A synthetic resin film made of the raw materials and thickness shown in Table 1 was used to prepare a bag for measurement. The bag was sealed by heat sealing or the like, and then the bag was degassed using an aspirator or the like. Degassing was performed until both sides of the bag were stuck together. Next, nitrogen gas (purity 99.9% or more) was filled into the bag using a white hard syringe. The amount of nitrogen gas injected was adjusted to the bag size, and was injected as much as possible within the range where the film constituting the bag was not tensioned by the injected nitrogen gas and was slightly loose, and was measured using the scale of the white hard syringe. The degassing and injection of nitrogen gas were performed, for example, by piercing the bag with a syringe needle. When piercing the syringe needle, a double-sided tape was attached to the film constituting the bag, and an adhesive tape made of polypropylene film (hereinafter referred to as "PP tape") was further attached on top of the tape. In addition, after the needle was removed, the needle hole was quickly blocked with PP tape. The tape applied to the bag was limited to an area of 4.5 cm2 or ^less .
Furthermore, when the film constituting the bag was a microporous film, the micropores were not blocked with tape.
(2) Initial oxygen concentration measurement The initial oxygen concentration (C0) in the bag immediately after filling with nitrogen gas (t=0) was measured. The gas in the bag was sampled, and the initial oxygen concentration (C0) in the bag was determined by gas chromatography (TCD). C0 was 0.2% or less, and if it exceeded this, the work was redone. The amount of sampling gas for oxygen concentration measurement was 10 cc or less. When injected into gas chromatography, a fixed amount of about 1 cc was injected. In addition, the same amount of gas was injected to measure standard gas (two or more points including about 1% and about 10% oxygen), and a calibration curve was created.
(3) Storage of the Bag The bag used to measure the initial oxygen concentration was stored at 23°C and 60% RH (in a temperature and humidity chamber). The bag was left stationary so that no objects were placed on it and the bag was not directly exposed to the wind from the temperature and humidity chamber fan.
(4) Measurement of oxygen concentration in the bag during storage and calculation of oxygen transmission rate The oxygen concentration in the bag is measured at 3 to 5 points in total, at least 2 points immediately after filling with nitrogen gas and after 3 hours or more have passed, within the range of oxygen concentration of 1% to 7%, and a proportional relationship (correlation coefficient of 0.98 or more) must be established between the elapsed time t (hr) and the oxygen concentration in the bag. If the correlation coefficient does not hold, the test was repeated. If the oxygen transmission rate of the film constituting the bag is too high and the oxygen concentration in the bag increases too quickly and this condition cannot be met, a bag can be created by laminating a part of the film with a smaller oxygen transmission rate than the film being measured and a known film of the same material, and the same procedure can be performed. In this case, the surface area of the bag is excluding the part that is laminated with another known film, and the oxygen transmission rate of the measured film is determined by subtracting the oxygen transmission rate of the known film part from the calculated oxygen transmission rate.
The oxygen transmission rate was calculated using the value for the longer elapsed time according to the following formula (i).
F = 1.143 × (Ct-C0) × V / t (i)
F: Oxygen transmission rate (cc/bag-day-atm)
Ct: Oxygen concentration in the bag t hours after filling with nitrogen gas (%)
C0: Oxygen concentration in the bag immediately after filling with nitrogen gas (%)
V: Amount of nitrogen gas filled (cc)
t: time elapsed from gas filling (hr)

Measurement of water vapor permeability (g/ ^m2 ·day) at 40°C Using synthetic resin films made of the raw materials and having the thicknesses shown in Table 1, measurements were made in accordance with JIS Z 0208 (cup method).

<Examples and Comparative Examples>
(1) Preparation of Package The following synthetic resin film was used, and two pieces were cut into rectangles of a given size, which were then stacked together and three of the four sides of the rectangle were heat sealed to prepare bag-shaped packaging bags of the sizes shown in Table 1. For heat sealing, P-300 manufactured by Fuji Impulse Co., Ltd. was used.
Fresh fruits and vegetables as shown in Table 1 were placed in the resulting packaging bag, which was then deaerated and the opening was heat-sealed to obtain a package containing the fruits and vegetables.
[Synthetic resin film]
LLDPE: Linear low density polyethylene "T.U.X HC-E" manufactured by Mitsui Chemicals Tocello Co., Ltd. OPP: Biaxially oriented polypropylene film "Silfan MV2" manufactured by Gunze Co., Ltd. CPP: Unoriented polypropylene film "Pylen (registered trademark) Film-CT P1062" manufactured by Toyobo Co., Ltd.

(2) Evaluation of freshness-retaining effect The obtained package was immediately stored at an environmental temperature of 20° C. (constant temperature bath, set temperature 20° C.) After storage for 3 days, the freshness-retaining effect (discoloration, mold, odor, crushing) was evaluated according to the following evaluation criteria, with the fresh state before storage (initial state) as the standard.
Discoloration: The appearance of the fruits and vegetables was visually observed by a specialist technician, and the presence or absence of discoloration was evaluated according to the following criteria.
(standard)
◎ "No discoloration at all."
○ "Slight discoloration."
△ "Discoloration occurred."
× "Significant discoloration observed."

Mold: The appearance of the fruits and vegetables was visually inspected by a specialist technician and the presence or absence of mold was evaluated according to the following criteria.
(standard)
◎ "No mold growth whatsoever."
○ "There was slight mold growth."
△ "Mold growth present."
× "Significant mold growth observed."

Odor: A specialist technician directly smelled the inside of the package and evaluated the presence or absence of an unpleasant odor according to the following criteria.
(standard)
◎ I didn't notice any strange odor.
○ I noticed a faint strange odor.
△ I noticed a strange odor.
× A strong odor was detected.

Crushing: The appearance of the fruit or vegetable inside the package was evaluated according to the following criteria.
(standard)
◎ "There was absolutely no collapse."
○ "There was slight crushing."
△ "There is some crushing."
× "Significant crushing"

Claims (13)

The package containing fruits and vegetables is made by sealing fruits and vegetables in a packaging bag made of a synthetic resin film, and is configured to satisfy the following conditions.
(Conditions) When the oxygen transmission rate of the packaging bag at 23°C and 60% RH is p (ml/ ^m2 ·day·atm), the weight of the fruit or vegetable is w (g), and the dead space of the package is v ( ^cm3 ),
(i) when p×w/1000≧3000, v/w is 0.070 or more and 1.4 or less;
(ii) When p×w/1000<3000, v/w is 0.60 or more and 2.6 or less. The fruit and vegetable package according to claim 1,
The package containing fruits or vegetables, wherein s/w is 2 or more and 10 or less, when the inner area of the packaging bag is s (cm ² ). The fruit and vegetable package according to claim 1 or 2,
The packaging bag has an oxygen permeability p (ml/ ^m2 ·day·atm) at 23°C and 60% RH, and the p is 500 or more and 30,000 or less. The fruit and vegetable package according to claim 1 or 2,
The thickness (μm) of the packaging bag is 5 to 300 μm. The fruit and vegetable package according to claim 1 or 2,
The opening of the packaging bag is sealed by heat sealing, thereby forming a package containing fruits and vegetables. The fruit and vegetable package according to claim 1 or 2,
The opening of the packaging bag is sealed with a back seal, thereby forming a package containing fruits and vegetables. The fruit and vegetable package according to claim 1 or 2,
The packaging bag does not have a through hole, and is a package containing fruits and vegetables. The fruit and vegetable package according to claim 1 or 2,
The synthetic resin film is a film containing one or more types selected from polyethylene, ethylene copolymer, polypropylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, and polyamide resin, or a multilayer film containing such a film. The fruit and vegetable package according to claim 1 or 2,
The package containing fruits and vegetables, wherein the fruits and vegetables are head vegetables. The fruit and vegetable package according to claim 1 or 2,
The fruit and vegetable package contains head vegetables divided into 1/8 to 1/2 portions. placing fruit or vegetables in a packaging bag made of a synthetic resin film through an opening of the packaging bag;
A step of closing and sealing the opening of the packaging bag while discharging air from inside the packaging bag so as to satisfy the following conditions;
The method for producing a package containing fruits and vegetables includes the steps of:
(Conditions) When the oxygen transmission rate (ml/ ^m2 ·day·atm) of the packaging bag at 23°C and 60% RH is p, the weight of the fruit or vegetable is w (g), and the dead space of the packaging body is v ( ^cm3 ),
(i) when p×w/1000≧3000, v/w is 0.070 or more and 1.4 or less;
(ii) When p×w/1000<3000, v/w is 0.60 or more and 2.6 or less. A method for preserving the freshness of fruits and vegetables, comprising a step of storing the fruits and vegetables in a package containing the fruits and vegetables according to claim 1 or 2. The method for preserving the freshness of fruits and vegetables according to claim 12,
The method for preserving the freshness of fruits and vegetables comprises storing the package containing the fruits and vegetables at a temperature of 2 to 20°C.