JP2014210616A - Packaging bag for preserving freshness of garden stuff, garden stuff-containing package using the same, and method for preserving freshness of garden stuff - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that suppresses variations in degree of garden stuff deterioration caused by a change in preservation condition.SOLUTION: A packaging bag for preserving freshness of garden stuff is made of a perforated synthetic resin film. A hole 14 is provided in the synthetic resin film 2. When Tmax represents the maximum thickness of the perforated synthetic resin film in an area within a distance of 10 mm from an outer periphery of the hole 14 and Tmin represents the minimum thickness thereof, the ratio Tmax/Tmin between the maximum thickness and the minimum thickness is in the range of 1.05-8.00, on the outer surface of the packaging bag for preserving the freshness of the garden stuff.

Description

  The present invention relates to a fruit and vegetable freshness-keeping packaging bag, a fruit and vegetable package using the same, and a fruit and vegetable freshness keeping method.

Fruits and vegetables continue to breathe even after harvesting, and the more they breathe, the more likely they are to deteriorate. The respiration of fruits and vegetables is suppressed in a low oxygen and high carbon dioxide environment that is moderate to the atmosphere. When fruits and vegetables are stored under such conditions, deterioration and ripening of the fruits and vegetables are suppressed.
In recent years, methods for maintaining the freshness of fruits and vegetables have been used as packaging methods for fruits and vegetables. This is a technology called MA (Modified Atmosphere) packaging, which is more suitable for the preservation of fruits and vegetables by adjusting the balance between the breathing rate of the fruits and vegetables packed by the packaging material and the gas permeation rate of the packaging materials. It achieves moderate low oxygen and high carbon dioxide conditions (Patent Documents 1-4). However, when packaging fruits and vegetables using a film made of a material such as polypropylene or polyethylene in MA packaging, the amount of gas permeation may be insufficient. In such a case, due to insufficient oxygen in the package, it is necessary to take measures against the problem that fruits and vegetables breathe abnormally and promote deterioration (Patent Documents 5-7).

  In order to solve such problems, Patent Documents 5 to 7 use a perforated film in which a plurality of fine through or non-through holes or cuts are formed in the film as a method for controlling the respiration rate by fruits and vegetables and maintaining freshness. A method has been proposed.

  That is, Patent Document 5 discloses a perforated film in which holes having an average diameter of 100 μm or less are provided and 1000 or less holes are provided per square meter. By doing so, it is described that the respiration rate of plant materials (fruits and vegetables) can be reduced.

  Furthermore, Patent Document 6 discloses that by forming an infinite number of fine or non-penetrating holes having a pore diameter of several μm to several tens of μm in a multilayer film in which at least the innermost layer is a heat-fusible resin layer. A technique for controlling the oxygen permeability of a multilayer film is disclosed. By doing so, it is described that an oxygen permeability of 5 to 10 times higher than that of a normal perforated film can be realized.

  In the technique described in Patent Document 7, a technique is disclosed in which there is one or more cuts in the packaging bag, and the total length of cuts per 100 g of fruits and vegetables is controlled to be 0.08 mm or more and 20 mm or less. By doing so, it is described that it is possible to realize a packaging bag having an MA effect that is easy to process, has an oxygen permeation rate that matches the respiration rate and other characteristics of fruits and vegetables, and does not deteriorate the appearance of the film.

JP-A-4-53445 JP-A-7-170907 JP 63-44837 A JP 61-259982 A JP-A-2-85181 JP-A-9-252718 JP 2007-186248 A

  However, the degree of deterioration of fruits and vegetables may still vary by changing the storage conditions in terms of accelerating the deterioration of fruits and vegetables due to abnormal breathing of fruits and vegetables by the technique described in References 5-7.

  Therefore, the present invention provides a technique for suppressing variations in the degree of deterioration of fruits and vegetables caused by changes in storage conditions.

  The present inventors examined the cause of variation in the degree of deterioration of fruits and vegetables due to changes in storage conditions. As a result, it was found that changes in the respiration rate of fruits and vegetables due to changes in storage conditions had an effect on the degree of deterioration of fruits and vegetables.

  Then, the present inventors diligently studied to provide a fruit and vegetables freshness-keeping packaging bag that can cope with changes in the preservation conditions of fruit and vegetables. As a result, in order to suppress variations in the degree of deterioration of fruits and vegetables caused by changes in storage conditions, it is effective to optimize the thickness of the perforated synthetic resin film in the peripheral area of the through holes on the outer surface of the fruit and vegetable freshness preservation packaging bag The knowledge that it is.

  The inventors further examined the thickness of the perforated synthetic resin film around the hole of the through hole provided in the perforated synthetic resin film, and the ratio of the maximum thickness and the minimum thickness of the perforated synthetic resin film around the hole. Has been found to be effective as a design guideline for suppressing variations in the degree of deterioration of fruits and vegetables caused by changes in storage conditions, leading to the present invention.

According to the present invention,
A fruit and vegetable freshness-keeping packaging bag composed of a perforated synthetic resin film,
The perforated synthetic resin film is provided with a through hole,
On the outer surface of the fruit and vegetable freshness holding packaging bag, the ratio Tmax between the maximum thickness and the minimum thickness, where Tmax is the maximum thickness of the perforated synthetic resin film in the region within 10 mm from the outer periphery of the through hole, and Tmin is the minimum thickness. A fruit and vegetables freshness-keeping packaging bag having / Tmin of 1.05 or more and 8.00 or less is provided.

  Moreover, according to this invention, the packaging body containing fruits and vegetables formed by sealing fruits and vegetables with the fruit and vegetables freshness maintenance packaging bag in the said invention is provided.

  Moreover, according to this invention, the fruit and vegetables freshness maintenance method which packages fruits and vegetables using the fruit and vegetables freshness maintenance packaging bag in the said invention is provided.

  According to the present invention, variations in the degree of deterioration of fruits and vegetables caused by changes in storage conditions can be suppressed.

It is sectional drawing of the manufacturing apparatus for demonstrating the manufacturing method of the fruit and vegetables freshness holding packaging bag which concerns on this embodiment. It is a principal part expanded sectional view of the manufacturing apparatus for demonstrating the manufacturing method of the fruit and vegetables freshness holding packaging bag which concerns on this embodiment. It is a principal part perspective view of the manufacturing apparatus for demonstrating the manufacturing method of the fruit and vegetables freshness holding packaging bag which concerns on this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

The fruit and vegetable freshness-keeping packaging bag in the present embodiment is composed of a perforated synthetic resin film provided with one or a plurality of through holes.
In this perforated synthetic resin film, the maximum thickness of the perforated synthetic resin film in the range within 10 mm from the outer periphery of the through hole on the outer surface of the fruit and vegetable freshness-keeping packaging bag (hereinafter also referred to as “hole peripheral region”) is Tmax. The minimum thickness is Tmin, and the ratio Tmax / Tmin between the maximum thickness and the minimum thickness is 1.05 or more and 8.00 or less. The ratio Tmax / Tmin between the maximum thickness and the minimum thickness of the perforated synthetic resin film in the peripheral area of the hole on the outer surface of the fruit and vegetable freshness-holding packaging bag corresponds to the change in the storage conditions of the fruit and vegetables. Therefore, variation in the degree of deterioration of fruits and vegetables can be suppressed, and an excellent freshness maintaining effect can be stably obtained. Here, the region (hole peripheral region) within 10 mm from the outer periphery of the through hole on the outer surface of the fruit and vegetable freshness holding packaging bag is drawn from the center point of the through hole so as to pass through the peripheral portion (outer periphery) of the through hole. On the straight line, it refers to the range from the intersection of the straight line and the peripheral edge of the through hole to a location 10 mm away from the center point of the through hole.

As described above in the section of the problem to be solved by the invention, the respiration rate of fruits and vegetables changes as the storage conditions change.
In the case of a conventional storage bag made of a perforated film, the amount of oxygen supplied to the packaging bag is always constant regardless of the storage conditions of fruits and vegetables. For this reason, in the conventional storage bag, it cannot respond to the change of the respiration rate of fruits and vegetables accompanying the change of storage conditions. That is, it cannot cope with the change accompanying the change in the storage condition of the oxygen amount required by the fruits and vegetables, and the degree of deterioration of the fruits and vegetables varies.

On the other hand, according to the fruit and vegetable freshness-keeping packaging bag of this embodiment, the ratio Tmax / Tmin of the maximum thickness and the minimum thickness of the perforated synthetic resin film in the hole peripheral region satisfies the above-mentioned specific condition, so that it is supplied to the packaging bag. The amount of oxygen produced can be made to correspond to a change in the respiration rate of fruits and vegetables accompanying a change in storage conditions. The reason for this is not necessarily clear, but it is considered that the adaptability to changes in use conditions is high, and the supply amount of oxygen changes as the use conditions change.
Moreover, according to the fruit and vegetable freshness holding packaging bag which concerns on this embodiment, even when a use condition changes, deterioration of the freshness of fruit and vegetables for a longer period can be suppressed. In addition, for example, it is possible to display fruits and vegetables in a marketable manner.

  Moreover, according to the fruit and vegetable freshness-keeping packaging bag according to the present embodiment, when the ratio Tmax / Tmin of the maximum thickness and the minimum thickness of the perforated synthetic resin film in the hole peripheral region satisfies the specific condition, Since the variation in the degree of deterioration of fruits and vegetables caused by changes in storage conditions can be suppressed without being limited to weight, the freshness of fruits and vegetables can be stably maintained for a longer period. This point will be described in detail in an embodiment described later.

  In the present embodiment, the ratio Tmax / Tmin between the maximum thickness and the minimum thickness of the perforated synthetic resin film in the hole peripheral region on the outer surface of the fruit and vegetable freshness holding packaging bag is 1.05 or more, preferably 1.50 or more. is there. By doing so, even when the use conditions change, the variation in the degree of deterioration of the fruits and vegetables can be more stably suppressed from the viewpoint of the stability of the hole size. The ratio Tmax / Tmin between the maximum thickness and the minimum thickness of the perforated synthetic resin film in the peripheral region of the hole on the outer surface of the fruit and vegetable freshness holding packaging bag is 8.00 or less, and preferably 6.00 or less. By doing so, even when the use conditions change, the variation in the degree of deterioration of the fruits and vegetables can be more stably suppressed from the viewpoint of the stability of the hole size.

  In the present embodiment, the maximum thickness Tmax of the perforated synthetic resin film in the region around the hole on the outer surface of the fruit and vegetable freshness holding packaging bag is appropriately selected according to the type of fruit and vegetable. The maximum thickness Tmax of the perforated synthetic resin film is, for example, 16 μm or more and 400 μm or less, and preferably 20 μm or more and 300 μm or less.

  Further, the minimum thickness Tmin of the perforated synthetic resin film in the region around the hole on the outer surface of the fruit and vegetable freshness holding packaging bag is appropriately selected according to the type of fruit and vegetable. The minimum thickness Tmin of the perforated synthetic resin film is, for example, 15 μm or more and 60 μm or less, and preferably 20 μm or more and 50 μm or less.

Next, the through-hole provided in the perforated synthetic resin film will be described.
The planar shape of the through hole on the outer surface of the fruit and vegetable freshness holding packaging bag and the planar shape of the through hole on the inner surface of the fruit and vegetable freshness holding packaging bag are not particularly limited, but are, for example, circular, polygonal, and slit shapes There is. Moreover, the notch provided in the film may be sufficient as the through-hole which concerns on this embodiment. Here, the “circular shape” is not limited to a true circle, and may be substantially circular. In addition to the circular shape, an elliptical shape, a semicircular shape, and a crescent shape may be used. The “polygon” may be a shape surrounded by three or more line segments such as a triangle, a quadrangle, and a pentagon. The plane shape of the through-hole on the outer surface of the fruit and vegetable freshness-holding packaging bag and the plane shape of the through-hole on the inner surface of the fruit and vegetable freshness-holding packaging bag should be substantially the same from the viewpoint of opening work, etc. desirable.

  Moreover, when it is set as a slit-shaped through-hole, it is necessary to be able to adjust the balance between the respiration rate of fruits and vegetables and the gas transmission rate of the packaging material.

  The average hole diameter (diameter) of the through holes in the outer surface and inner surface of the fruit and vegetable freshness holding packaging bag is desirably as small as possible, preferably 20 μm or more and 2000 μm or less, and more preferably 30 μm or more and 800 μm or less. . When the average hole diameter of the through holes is within the above range, even when the environmental conditions for using the freshness-keeping packaging bag for the fruits and vegetables are changed, the freshness of the fruits and vegetables is maintained and mold is generated in the fruits and vegetables. It can suppress more stably. In addition, when the average hole diameter of a through-hole is 20 micrometers or more, the outstanding fruit and vegetables freshness holding packaging bag can be obtained from a viewpoint of productivity of a perforated synthetic resin film. When the average hole diameter of the through holes is 2000 μm or less, the number of holes necessary for obtaining an appropriate hole area ratio can be maintained, so that an excellent fruit and vegetable freshness holding packaging bag can be obtained from the viewpoint of quality accuracy of freshness holding. Can do.

  Further, when the through hole has a slit shape, there is no problem if the diameter in the major axis direction is, for example, 2000 μm or less. In addition, when the shape of the through hole is an irregular shape, for example, the opening area of the through hole is calculated by dividing the shape into several shapes that are easy to calculate the shape, and then calculating the total of each area. It can ask for.

  Moreover, the through-hole provided in the perforated synthetic resin film is good also as a structure which can ooze a liquid. At this time, even if the hole is apparently blocked, it is sufficient that a liquid such as water oozes out. Further, for example, the pore diameter may be controlled so that water hardly oozes out at normal pressure and oozes out and released only during vacuum precooling.

  When the through-hole provided in the perforated synthetic resin film is a cut, the shape of the cut provided in the film is not particularly limited. The notch may be a single straight line or may be a combination of a plurality of straight lines, or a shape in which a straight crack has developed from the end of the hole, such as an ellipse or a circle. Shapes with curved parts such as letter shape, U shape, semi-circle, wave shape, V shape, L shape, H shape, T shape, W shape, U shape, x mark, etc. A shape having corners may be used. The shape of the notch is not limited to that shown here. A plurality of types of cut shapes may be used in combination.

The cut into the film may be cut with a sharp blade such as a cutter, or may be punched with a mold that can cut into a desired shape. Processing with a laser is also possible.
The cutting time is not particularly limited. You may carry out at the time of manufacture of a film, the time of bag making, or after bag making. When processing in the state of a roll, it can also process in parallel with printing, a slit, etc., and can also process when packaging fruits and vegetables with automatic packaging machines, such as a horizontal pillow machine and a vertical pillow machine. Further, the cutting process can be performed manually, and can be easily manufactured even with a single bag.

Next, the hole area ratio of the holes will be described.
On the outer surface and inner surface of the fruit and vegetable freshness-keeping packaging bag according to the present embodiment, the aperture area ratio R1 of the porous synthetic resin film at 40 ° C. is appropriately selected according to the type of the fruit and vegetable. The aperture area ratio R1 is, for example, 1.0 × 10 ⁻⁶ % or more and 5.0 × 10 ⁻² % or less, preferably 1.0 × 10 ⁻⁵ % or more and 5.0 × 10 ⁻³ % or less. is there. By being in the said range, even when a use condition changes, the variation in the deterioration degree of fruit and vegetables can be suppressed further.

In addition, on the outer surface and inner surface of the fruit and vegetable freshness-keeping packaging bag according to this embodiment, the aperture area ratio R2 at 5 ° C. of the perforated synthetic resin film is also appropriately selected according to the type of fruit and vegetables. The aperture area ratio R2 is, for example, 5.0 × 10 ⁻⁷ % or more and 2.5 × 10 ⁻² % or less, preferably 5.0 × 10 ⁻⁶ % or more and 2.5 × 10 ⁻³ % or less. is there. By being in the said range, even when a use condition changes, the variation in the deterioration degree of fruit and vegetables can be suppressed further.

  Moreover, the hole opening change rate calculated by the following formula (1) from the hole area ratios R1 and R2 on the outer surface or inner surface of the fruit and vegetable freshness holding packaging bag according to the present embodiment is, for example, 5 or more and 50 Or less, preferably 8 or more and 30 or less. By doing so, it is possible to further suppress variations in the degree of deterioration of fruits and vegetables caused by changes in storage conditions.

Formula: Rate of hole change = {(R1-R2) / R2} × 100 (1)

Next, the water vapor permeability of the holes will be described.
The water vapor transmission rate at 40 ° C. and 90% RH of the porous synthetic resin film is, for example, 4 g / m ² · day or more, for example, 20 g / m ² · It is preferably day or more. Moreover, there is no restriction | limiting in particular in the upper limit of the water-vapor-permeation rate in 40 degreeC and 90% RH, but it is 400 g / m < ² > * day or less, for example from a viewpoint of preventing withering.

Next, the material of the perforated synthetic resin film will be described.
The synthetic resin constituting the perforated synthetic resin film is not particularly limited as long as it can be used for packaging fruits and vegetables, but various polyethylene and ethylene copolymers, polypropylene, polyvinyl chloride, polystyrene, acrylic resins, Examples thereof include polyester resins such as polyethylene terephthalate and polylactic acid, and polyamide resins such as 6 nylon. These may be homopolymers, may be two or more types of copolymers, and may be a blend containing two or more types of these homopolymers and copolymers.
More specifically, the various polyethylenes and ethylene copolymers include high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, metallocene-linear low density polyethylene, ethylene-vinyl acetate copolymer, Copolymers such as ethylene-acrylic acid copolymer, ethylene-propylene copolymer, and ethylene-α-olefin copolymer, ionomers, and the like may be mentioned, or a blend of two or more of these with other resins may be used.

  Furthermore, a film obtained by molding the synthetic resin exemplified above may be used as a single layer film, or may be used in the form of a multilayer film having two or more layers.

  The method for forming the film is not particularly limited, and methods such as extrusion, inflation, and calendering are used. When the film is formed, additives such as an antifogging agent may be kneaded as necessary, or two or more kinds of resins may be blended. Further, the film may be stretched or annealed. These films may be provided with a sealant layer, or may be a film coated to give some function. Further, these films may be transparent, opaque, or printed.

  In particular, it is preferable to use an anti-fogging stretched polypropylene film, a low-density polyethylene film, a linear low-density polyethylene film, or a metallocene-catalyzed polyethylene as a synthetic resin film from the viewpoints of cost and physical properties.

  In addition, when the contents packed in the freshness-keeping packaging bag for fruits and vegetables are heavy, polyethylene is dry-laminated and extruded as a synthetic resin film into films such as unstretched polypropylene, stretched polypropylene, unstretched nylon, stretched nylon and stretched polyester. You may use what was made into the multilayer film by lamination and coextrusion.

  Although the thickness of the film used for the fruit and vegetables freshness holding packaging bag in this embodiment is not specifically limited, For example, what is necessary is just to be 15 micrometers or more and 400 micrometers or less. If the film is too thin, the strength may be insufficient. On the other hand, if the film is too thick, the production cost increases, so the practicality decreases. Furthermore, these films may be transparent or opaque, and there is no problem even if the surface is printed.

Next, the manufacturing method of the fruit and vegetables freshness maintenance packaging bag in this embodiment is demonstrated.
In order to obtain the fruit and vegetable freshness-keeping packaging bag according to the present embodiment, it is necessary to provide holes at predetermined positions of the film or the film processed into a bag shape. However, the fruit and vegetables freshness-keeping packaging bag in which the ratio Tmax / Tmin of the maximum thickness and the minimum thickness of the perforated synthetic resin film satisfies the above-described specific conditions in the hole peripheral region on the outer surface of the packaging bag according to the present embodiment, It is difficult to obtain by the conventional method for producing a perforated film described in the technical section. Specifically, the fruit and vegetable freshness-keeping packaging bag according to the present embodiment is a combination of highly controlled factors such as the shape of the support base on which the film to be perforated is mounted, laser energy, laser irradiation distance, etc. It can be manufactured for the first time. Thus, in order to obtain a fruit and vegetable freshness-maintaining packaging bag that can suppress variations in the degree of deterioration of fruits and vegetables caused by changes in storage conditions according to the present embodiment, it is particularly important to highly control each of the above factors. It becomes.

The ratio Tmax / Tmin of the maximum thickness and the minimum thickness of the perforated synthetic resin film in the peripheral region of the hole on the outer surface of the fruit and vegetable freshness-keeping packaging bag manufactured using the conventional method is the same even when holes are provided under the same conditions. However, the value changed every time it was manufactured. That is, according to the conventional manufacturing method, the degree of strain at the periphery of the through hole is low in reproducibility.
On the other hand, according to the manufacturing method of the fruit and vegetable freshness-keeping packaging bag according to the present embodiment, a fruit and vegetable freshness-holding packaging bag capable of stably suppressing deterioration or decay of the fruit and vegetables is obtained. Moreover, according to the manufacturing method of the fruit and vegetable freshness holding packaging bag which concerns on this embodiment, a through-hole with high reproducibility and without a distortion can be obtained. Specifically, a packaging bag that satisfies the specific condition that the ratio Tmax / Tmin of the maximum thickness and the minimum thickness of the perforated synthetic resin film in the peripheral area of the hole on the outer surface is 1.05 or more and 8.00 or less was manufactured by the above method. In this case, the shape of the provided through hole appropriately changes according to the temperature change.
The reason for this is not necessarily clear, but it is considered that an opening portion having no strain can be obtained by highly controlling each factor when forming a hole in the film. That is, a hole without distortion can be provided by highly controlling each factor applied when providing a hole in the film. Thereby, since the peripheral reinforcement effect can be exerted on the outer periphery of the opening portion, it is considered that the shape of the through hole appropriately changes along with the expansion and contraction of air due to the temperature change.

  Hereinafter, an example of the manufacturing method of the fruit-and-fruit freshness maintenance packaging bag which concerns on this embodiment is shown. However, the manufacturing method of the fruit-and-fruit freshness holding packaging bag of this embodiment is not limited to the following examples.

  The manufacturing method of the fruit-and-fruit freshness holding packaging bag demonstrated below uses the laser processing technique using a grooved roller.

  More specifically, for example, holes are perforated in the film using the following method.

  First, FIG. 1 and FIG. 2 are sectional views of a manufacturing apparatus for explaining a method for manufacturing a fruit and vegetable freshness-keeping packaging bag according to this embodiment, and FIG. 3 is a perspective view of a main part. Hereinafter, an example is demonstrated using FIGS. 1-3 about the manufacturing method of the fruit and vegetables freshness holding packaging bag which concerns on this embodiment.

  According to the manufacturing apparatus of FIG. 1, when the synthetic resin film 2 unwound from the unwinding roll 1 passes between the laser irradiation device 3 and the rotation support roll 4, the laser irradiation device 3 synthesizes a pulsed laser beam. The resin film 2 can be irradiated. By carrying out like this, the hole equivalent to the shape of the irradiated beam can be provided in the synthetic resin film 2.

  The synthetic resin film 2 provided with holes by the above method is taken up by the take-up roll 5. Two guide rolls 6 are provided before and after the rotation support roll 4.

  Further, the upper end of the rotation support roll 4 is located above the line connecting the upper ends of the two guide rolls 6. For this reason, the synthetic resin film 2 can be pressed so that it may contact | adhere to the rotation support roll 4, a laser irradiation position can be positioned and generation | occurrence | production of a vertical wrinkle can be prevented.

  Further, in the manufacturing apparatus of FIG. 1, an unwinding roll 1 and a winding roll 5 are provided via a rotation support roll 4. In the manufacturing apparatus of FIG. 1, the guide roll 6 is provided between the rotation support roll 4 and the unwinding roll 1 and between the rotation support roll 4 and the take-up roll 5. Further, the floating roll 7 is provided between the unwinding roll 1 and the guide roll 6 and between the guide roll 6 and the winding roll 5. By doing so, an appropriate tension can be applied to the synthetic resin film 2 by the floating roll 7.

  Further, the laser irradiation device 3 is provided with a compressed gas introduction path 8, and during the laser irradiation, compressed gas is applied to the synthetic resin film 2 from the nozzle tip 9 (see FIG. 2) along the laser beam. Can be sprayed.

FIG. 2 is an enlarged cross-sectional view of a main part of the laser irradiation apparatus 3 in the manufacturing apparatus shown in FIG.
According to the manufacturing method of the fruit and vegetable freshness-keeping packaging bag according to this embodiment, the synthetic resin film 2 can be run under the nozzle tip 9 of the laser irradiation device 3 as shown in FIG.

  Further, since the pulse laser 10 passes through the light guide path 11 and is focused by the emission optical unit (lens) 12, the pulse laser 10 can be irradiated to the synthetic resin film 2 from the nozzle tip 9 as a conical beam 13. At this time, the inner diameter of the nozzle tip 9 is made larger than the beam diameter of the pulse laser 10 that passes therethrough. Further, the focal position of the pulse laser 10 focused by the emission optical section (lens) 12 is preferably set to a position slightly outside the film from the surface opposite to the laser incident surface of the synthetic resin film 2.

  As described above, by irradiating the conical beam 13, the beam irradiation portion in the synthetic resin film 2 is melted, decomposed, and volatilized, whereby the hole 14 is formed.

  The pitch of the holes 14 drilled in the synthetic resin film 2 can be adjusted by synchronizing the traveling speed of the synthetic resin film 2 and the pulse frequency of the pulse laser 10. Since one laser irradiation device can usually open 20 to 1,000 holes 14 per second, the traveling speed of the synthetic resin film 2 can be increased and high productivity can be achieved.

  The shape of the hole 14 drilled in the synthetic resin film 2 is substantially the same as the shape of the conical beam 13 passing through the synthetic resin film 2, and a hole having a constant shape can always be formed. The conical trapezoidal hole can be made closer to a cylindrical shape by increasing the focal length of the emission optical section (lens) 12.

  Further, as described above, the compressed gas introduction path 8 is provided in the vicinity of the nozzle tip 9 of the light guide path 11 in the laser irradiation device 3. By carrying out like this, compressed gas can be sprayed along a laser beam with respect to the synthetic resin film 2 during laser irradiation.

  The flow rate of the compressed gas is set to 2-10 m / s at the nozzle tip 9 so that decomposition products generated by perforation do not enter the nozzle tip 9 and contaminate the emission optical part (lens) 12. Is preferable, and it is more preferable to set to 3 to 6 m / s.

  The compressed gas is not particularly limited, and for example, in addition to compressed air, an inert gas such as nitrogen gas or carbon dioxide gas can be used. Compressed air has no handling risk and is advantageous in terms of cost. The inert gas suppresses oxidation of the decomposition product of the plastic film, and can reduce wrinkles, scorching, blackened products, and the like.

  In the manufacturing method of the fruit and vegetable freshness-keeping packaging bag according to this embodiment, the surface opposite to the laser incident surface is brought into contact with the rotation support roll 4 and the synthetic resin film 2 is supported by the rotation support roll 4. Moreover, as shown in FIG. 3, for example, the groove 15 corresponding to the laser irradiation position is formed on the rotary support roll 4 so that the decomposition product of the synthetic resin film 2 can be volatilized also from the side opposite to the laser incident surface. It is better to have

  The rotation support roll 4 shown in FIG. 3 has five grooves 15. When five laser irradiation apparatuses are used together with such a rotation support roll 4, five rows of holes can be provided in the synthetic resin film 2.

  The laser according to the present embodiment is not particularly limited, and examples thereof include a ruby laser, a neodymium YAG laser, a neodymium glass laser, and a carbon dioxide gas laser. Among these, a carbon dioxide laser is particularly suitable because it has high energy efficiency, high output, and easy heat removal.

According to the manufacturing method of the fruit and vegetable freshness-keeping packaging bag according to this embodiment, holes can be provided in the synthetic resin film at high speed and with high productivity. Since the shape of the hole is determined by the shape of the pulse laser beam, a hole having a constant shape can always be formed.
Further, most of the material of the synthetic resin film perforated by the laser is decomposed and volatilized and blown off by the compressed gas. For this reason, the emission optical part (lens) of the laser irradiation apparatus is not contaminated by decomposition products.

  In addition, by selecting the number of the laser irradiation device and adjusting the pulse laser cycle and the running speed of the synthetic resin film, it has a hole with an arbitrary hole density ranging from sparse to dense holes. A synthetic resin film can be manufactured.

  By carrying out like this, it can be set as the perforated synthetic resin film by which the hole diameter and the position of the hole were controlled highly, and Tmax / Tmin which concerns on this embodiment obtains the fruit and vegetables freshness maintenance packaging bag which satisfy | fills specific conditions for the first time. Can do. The selection of the film material and the selection of the laser processing conditions when producing the fruit and vegetable freshness-keeping packaging bag according to this embodiment will be described in more detail in the examples described later in comparison with the conventional manufacturing method.

  In addition, the manufacturing method of the fruit and vegetables freshness maintenance packaging bag which concerns on this embodiment is not limited to the processing method using the said laser, For example, punching processing or hot needle processing may be sufficient. However, even when employing these processing methods, it is necessary to combine various factors such as the temperature and shape of the hot needle in a highly controlled manner.

  In the fruit and vegetable freshness-keeping packaging bag according to the present embodiment, the hole is not particularly limited, but it is preferably provided in a place where water is easily collected when the packaged fruit and vegetables are transported and displayed at the store. By doing so, it is possible to prevent deterioration of the quality of the fruits and vegetables due to the oozing of water, condensation inside the packaging bag, and accumulation of water inside. Therefore, it is possible to provide fruits and vegetables that look good when displayed on the market as viewed from the consumer.

Moreover, the total open area per bag of the fruit and vegetables freshness preservation packaging bag obtained by the manufacturing method in this embodiment is about 1 × 10 ^{−5 to 2} mm ² per 100 g of contents in the bag, for example. .

  In the fruit and vegetable freshness preservation packaging bag according to the present embodiment, fruits and vegetables are packaged, and more specifically, fruits and vegetables washed in the process from harvesting to packaging are packaged.

  Fruits and vegetables generally contain a lot of moisture, and they often condense in the package due to transpiration by respiration, which is suitable for storage using the fruit and vegetable freshness-keeping packaging bag in this embodiment. Specific examples of fruits and vegetables include: mackerel, spinach, komatsuna, mizuna, beech, asparagus, cucumber sinus, lettuce, thyme, parsley, italian parsley, rosemary, oregano, lemon balm, chives, lavender, salad barnet, ramsyear, rocket , Dandy lion, nastatum, basil, arugula, watercress, morroheiya, celery, kale, leek, cabbage, cabbage, sardine, saladna, sanchu, fuki, nabana, chinsai, honey bee, seri, me cabbage, broccoli, cauliflower, ginger, radish, Carrot, burdock, radish, turnip, sweet potato, potato, yam, yam, taro, ginenjo, yamatomo, bell pepper, paprika, shishito, cucumber, eggplant, tomato Door, mini tomatoes, pumpkin, bitter gourd, okra, sweet corn, green soybean, peas, green beans, broad beans, Kinkinokorui, and the like. It is also effective for fruits such as citrus, apples, pears, grapes, blueberries, strawberries, strawberries, and cut flowers. These are also effective in a cut state, so-called cut vegetables and cut fruits.

  In this embodiment, since the fruits and vegetables washed with water or the fruits and vegetables wet with rain or dew can be packaged without draining, workability is improved. It is also possible to quickly evaporate all or part of the moisture of the fruits or vegetables, for example, to keep the fruits or vegetables cool to keep them fresh, or to reduce the moisture to remove the effects of moisture on the fruits and vegetables as soon as possible. . In such a case, the fruit and vegetables may be sealed in a fruit and vegetables freshness-keeping packaging bag according to the present embodiment, and vacuum precooled.

  The freshness of fruits and vegetables is affected by, for example, temperature and humidity. In addition, although fruits and vegetables are not specifically limited, For example, it is preferable to preserve | save at the temperature of 0 degreeC or more and 50 degrees C or less, and humidity 10% or more and 98% or less.

The package in the present embodiment is formed by sealing fruits and vegetables with the fruit and vegetable freshness maintaining package in the present embodiment.
Moreover, the freshness maintenance method in this embodiment includes the process of packaging fruits and vegetables using the freshness-keeping packaging bag for fruits and vegetables in this embodiment. It is necessary to seal the fruit and vegetables after they are packaged in the fruit and vegetable freshness preservation packaging bag.
Although it does not specifically limit as a sealing method, The method of using a heat seal, an adhesive tape, a rubber band, a string etc., methods, such as paste pasting and a zipper, are mentioned.

The packaging body area of the fruit and vegetable freshness-keeping packaging bag can be set according to the shape, size, density, and the like of the fruit and vegetable to be packaged. Then, the packaging body area of vegetables and fruits fresh-keeping packaging bag per fresh produce 100g is, for example 100 cm ² or more 5000 cm ² or less, preferably 200 cm ² or more 3000 cm ² or less.

In this embodiment, from the viewpoint of appropriately controlling the respiration rate of fruits and vegetables according to the temperature environment, the following configuration may be used.
The oxygen permeability of the perforated synthetic resin film per fresh produce 100g ^{is, 50mL / 100g · m 2 ·} day · atm or more ^{50000mL / 100g · m 2 · day} · atm or less, preferably 60 mL / 100g · ^{m 2} It is not less than day · atm and 10000 mL / 100 g · m ² · day · atm.

  Further, from the viewpoint of more stably suppressing the progress of deterioration of fruits and vegetables, the oxygen concentration in the package containing fruits and vegetables is, for example, 0.1% or more and less than 19% in a state before opening the package, Is 1% or more and 17% or less.

  Further, from the viewpoint of maintaining the freshness of the fruits and vegetables more stably, the weight reduction rate of the whole package with fruits and vegetables is 0.05% by weight or more and less than 1% by weight, preferably 0.08% by weight. % To 0.9 weight or less.

  As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above are also employable.

  Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to these.

Example 1
At the bottom of a bag of an anti-fogging biaxially stretched polypropylene film (hereinafter also referred to as “anti-fogging OPP”) (manufactured by Gunze Co., Ltd., trade name: Sylphan MV2, thickness 40 μm, bag size 140 mm × 180 mm) at 25 ° C. Nine holes having a diameter of 180 μm (average hole diameter) and an opening area of 0.026 mm ² at 40 ° C. were provided. In addition, the total opening area at 40 ° C. was 0.24 mm ² . In this way, a packaging bag for maintaining freshness of fruits and vegetables was obtained. Moreover, the planar shape of the through-hole in the outer surface of the obtained fruit and vegetable freshness holding packaging bag and the planar shape of the through-hole in the inner surface of the fruit and vegetable freshness-holding packaging bag were both circular and substantially the same shape.

In this example, perforation was performed by the following method.
First, a rotating support roll having five rolls having a diameter of 318 mm and a width of 800 mm and a groove having a width of 5 mm and a depth of 5 mm at a distance of 100 mm from a position 150 mm from both ends so as to have the shape shown in FIG. On the other hand, a carbon dioxide laser with an output of 150 watts was prepared as a laser irradiation device. Each of the five laser irradiation devices was installed so that the laser irradiation position corresponded to the groove position of the rotation support roll. In addition, the laser irradiation apparatus was installed so that the distance with a film might be 10-15 mm.

Next, by using the apparatus shown in FIG. 1-2, the rotating support roll is rotated at a peripheral speed of 60 m / min, so that the film runs on the rotating support roll at a running speed of 60 m / min. Were irradiated with a pulse laser 10 times per second. At this time, a nitrogen gas pressure of 1.0 kg / cm ² (gauge pressure) was applied to the compressed gas introduction path, and nitrogen gas was blown along the laser beam from the nozzle tip during laser irradiation.

(Example 2)
At the bottom of the bag of anti-fogging OPP (Toyobo Co., Ltd., trade name: Pyrene film-FG: P5562, thickness 25 μm, bag size 160 mm × 190 mm), the diameter is 600 μm (average diameter) at 25 ° C. Four holes with an opening area of 0.287 mm ² at 40 ° C. were provided. In addition, the total opening area at 40 ° C. was 1.15 mm ² . In this way, a packaging bag for maintaining freshness of fruits and vegetables was obtained. The perforation was performed using the same method as in Example 1.

Example 3
At the bottom of the bag of anti-fogging OPP (Toyobo Co., Ltd., trade name: Pyrene film-FG: P5562, thickness 25 μm, bag size 160 mm × 190 mm), the diameter is 600 μm (average diameter) at 25 ° C. Four holes with an opening area of 0.224 mm ² at 40 ° C. were provided. In addition, the total opening area at 40 ° C. was 0.90 mm ² . In this way, a packaging bag for maintaining freshness of fruits and vegetables was obtained. The perforation was performed using the same method as in Example 1.

Example 4
At the bottom of the bag of anti-fogging OPP (Toyobo Co., Ltd., trade name: Pyrene film-FG: P5562, thickness 25 μm, bag size 160 mm × 190 mm), the diameter is 600 μm (average diameter) at 25 ° C. And 5 holes with an opening area of 0.129 mm ² at 40 ° C. were provided. In addition, the total opening area at 40 ° C. was 0.64 mm ² . In this way, a packaging bag for maintaining freshness of fruits and vegetables was obtained. The perforation was performed using the same method as in Example 1.

(Example 5)
At the bottom of the bag of anti-fogging OPP (Toyobo Co., Ltd., trade name: Pyrene film-FG: P5562, thickness 25 μm, bag size 160 mm × 190 mm), the diameter is 600 μm (average diameter) at 25 ° C. Ten holes with an opening area of 0.051 mm ² were formed at 40 ° C. In addition, the total opening area at 40 ° C. was 0.51 mm ² . In this way, a packaging bag for maintaining freshness of fruits and vegetables was obtained. The perforation was performed using the same method as in Example 1.

(Comparative Example 1)
At the bottom of the bag of anti-fogging OPP (Toyobo Co., Ltd., trade name: Pyrene film-FG: P5562, thickness 25 μm, bag size 160 mm × 190 mm), the diameter is 6000 μm (average diameter) at 25 ° C. Four holes with an opening area of 27.792 mm ² at 40 ° C. were provided. In addition, the total aperture area at 40 ° C. was 111.17 mm ² . For punching, punching was performed. In this way, a packaging bag for maintaining freshness of fruits and vegetables was obtained.

(Comparative Example 2)
A fruit and vegetables freshness-keeping packaging bag was obtained in the same manner as in Example 5 except that a laser irradiation device in which no groove was provided in the rotating support roll was used as the laser irradiation device.

In addition, for each measurement and evaluation, a package body in which green soybeans were packaged as described below was used.
An average of 180 g of green soybeans that had been washed with water was put into each of the fruit and vegetable freshness-keeping packaging bags of Examples 1 to 5 and Comparative Examples 1 and 2, and 20 packs of sealed packages sealed with a heat sealer were produced. The packed package was packed in a cardboard box so that the bottom of the bag faces downward. In addition, the packaged body area of the green soybean-containing package was as follows. The packaging body area per 100 g of green soybeans of Example 1 was 280 cm ² , and the packaging body area per 100 g of green soybeans of Examples 2 to 5 and Comparative Examples 1 and 2 was 337 cm ² .

  The package was stored at 5 ° C. for 5 days and then stored at 40 ° C. for 2 days, and quality changes such as the appearance, smell, and taste of green soybeans were followed.

(Example 6)
20 packs of broccoli containing 20 pieces of broccoli in a state of freshness and fruit freshness holding packaging bags of Example 1 were put in an average of 180 g each and sealed with a heat sealer. In addition, the packaging body area per 100 g of the broccoli was 280 cm ² . The broccoli-containing package was also stored for 5 days at 5 ° C. and then stored for 2 days at 40 ° C., and changes in quality such as the appearance and smell of broccoli were followed.

(Evaluation item)
Maximum thickness Tmax and minimum thickness Tmin of film in hole peripheral region: The film thickness in the hole peripheral region was measured according to JIS K7130. Specifically, the thickness of the film at multiple points arbitrarily selected in the hole peripheral region was measured according to JIS K7130. And among the several measurement results regarding the thickness of the obtained film, the maximum value was set to Tmax and the minimum value was set to Tmin. The unit was μm. Here, the region (hole peripheral region) within 10 mm from the outer periphery of the through hole on the outer surface of the fruit and vegetable freshness holding packaging bag is drawn from the center point of the through hole so as to pass through the peripheral portion (outer periphery) of the through hole. On the straight line, it refers to the range from the intersection of the straight line and the peripheral edge of the through hole to a location 10 mm away from the center point of the through hole.

Perforated area ratio: First, the perforated area of the inner surface of the 40 ° C. and 5 ° C. fruit and vegetables freshness-holding packaging bags was measured using a microscope (VH-6300, manufactured by Keyence Corporation). The surface area of the fresh fruit and vegetables holding packaging bag was calculated as twice the bag size. Next, a value calculated by the following calculation formula (1) from the obtained aperture area and surface area values was defined as the aperture area ratio. The unit is%.
Perforation area ratio = (Aperture area / bag surface area) × 100 (1)
Rate of change in aperture: Calculated by the following formula (A) from the aperture area ratio R1 (%) at 40 ° C. calculated from the above formula (1) and the aperture area ratio R2 (%) at 5 ° C.
Rate of change in opening = {(R1-R2) / R2} × 100 (A)

Oxygen transmission amount: The oxygen transmission amount of the resin film was measured by the method described in the following (1) to (5). The unit was mL / 100 g · m ² · day · atm.
(1) Preparation of bag A packaging bag for maintaining freshness of fruits and vegetables was prepared using a film for measuring oxygen permeation. At this time, the bag was sealed by heat sealing so that oxygen would not leak out from other than the film. The size of the bag to be measured was such that the inner surface area of the bag was 0.06 m ² or more. All the following operations were performed in the atmosphere.
(2) Entrapment of nitrogen gas After sealing the bag with heat sealing or the like, the bag was deaerated using an aspirator or the like. Deaeration was performed until both sides of the bag were stuck. Next, this bag was filled with nitrogen gas (purity 99.9% or more) using a white hard syringe. The amount of gas injected was determined by using the scale of the syringe barrel as much as possible without depending on the bag size, but in the range where the film was not tensioned. In addition, deaeration and nitrogen gas injection were performed by inserting an injection needle into a bag. When piercing the needle, a double-sided tape was applied to the film, and an adhesive tape made of a polypropylene film (hereinafter referred to as “PP tape”) was applied thereon. Further, after removing the needle, the needle hole was immediately closed with PP tape. The tape affixed to the bag was made to fit within an area of 4.5 cm ² or less. In the case of a microporous film, care was taken not to block the micropores.
(3) Initial oxygen concentration measurement The initial oxygen concentration (C ₀ ) in the bag immediately after nitrogen gas filling (t = ₀ ) was measured. The gas in the bag was sampled, and the initial oxygen concentration (C ₀ ) in the bag was determined by gas chromatography (TCD). _C0 is 0.2% or less, and when it exceeds this, work is performed again. The sampling gas for measuring the oxygen concentration was 10 cc or less. When injecting into gas chromatography, about 1 cc of sampling gas was injected.
(4) Storage of bag The bag whose initial oxygen concentration was measured is stored at 23 ° C. and 60% RH (constant temperature and humidity chamber). At this time, it left still so that an object might not be put on a bag and the wind of the fan of a constant temperature and humidity chamber might hit directly.
(5) Measurement of oxygen concentration in the bag and calculation of oxygen permeation during storage The oxygen concentration in the bag is within the range of 1% or more and 7% or less immediately after filling with nitrogen gas and after 3 hours or more after filling. In total, three or more points were measured. Since it is necessary to establish a proportional relationship (correlation coefficient of 0.98 or more) between the elapsed time t (hr) and the oxygen concentration (C _t ) in the bag, a retest was performed when the correlation coefficient did not hold.
If the oxygen permeation amount of the film is too large and the oxygen concentration in the bag increases too quickly and this condition cannot be cleared, a part of the film is made of the same material that is known to be smaller than the film whose oxygen permeation amount is known. A bag was made by laminating with a film, and the same procedure was performed. At this time, the surface area of the bag was determined by subtracting the oxygen permeation amount of the known film portion from the obtained oxygen permeation amount, excluding the portion pasted with another known film. The oxygen permeation amount was calculated by the following calculation formula (2) using the value with the longer elapsed time.
F = 1.143 × (C _t −C ₀ ) × V / t / s (2)
However,
F: Oxygen permeation amount (mL / 100 g · m ² · day · atm)
C _t : oxygen concentration in bag (%) at time t after nitrogen gas filling
C ₀ : oxygen concentration in bag immediately after filling with nitrogen gas (%)
V: Amount of nitrogen gas charged (cc)
t: Elapsed time from gas filling (hr)
s: surface area of the bag (m ² )

Water vapor transmission rate: The water vapor transmission rate at 40 ° C. and 90% RH was measured according to JIS K7129: 2008. The unit was g / m ² · day.

Oxygen concentration: The oxygen concentration at 40 ° C. and 5 ° C. was measured using a gas chromatograph (GC323, GC323) after sampling the air in the package before opening the package. The unit is%.

Weight reduction rate: The weight reduction rate at 40 ° C. and 5 ° C. was measured by the following procedure. First, regarding the weight of the bag in which 100 g of fruits and vegetables were packaged, the weight on the first day of the test (W0) and the weight on the seventh day after the start of the test (W7) were measured with an electronic balance. Next, from the weight of the obtained bag, a value calculated by the following calculation formula (3) was defined as a weight reduction rate.
Weight reduction rate = (W0−W7) / W0 × 100 (3)

  The evaluation results regarding the above evaluation items are shown in Table 1 below.

  The fruit and vegetable freshness-keeping packaging bags of Examples 1 to 6 and Comparative Example 2 are all punched using a laser irradiation apparatus. In the fruit and vegetable freshness-keeping packaging bags of Examples 1 to 6, there was almost no variation in the diameter of the through holes. On the other hand, when the hole diameters of the through holes provided in the fruit and vegetable freshness-keeping packaging bag of Comparative Example 2 were compared, there was a variation (difference) of 25 μm between the maximum hole diameter and the minimum hole diameter. As described above, the cause of the variation in the diameter of each through-hole in the fruit and vegetable freshness-keeping packaging bag of Comparative Example 2 was that a laser was provided by using a normal laser irradiation device in which no groove was provided in the rotary support roll. Radiant heat is generated and heat is accumulated on the rotating support roll. As a result, it is considered that the thermal diffusion around the through-holes is delayed and the diameter of each through-hole cannot be controlled.

  For the fruit and vegetable freshness holding packaging bag of Comparative Example 2, on the outer surface of the fruit and vegetable freshness holding packaging bag, the maximum thickness of the perforated synthetic resin film in the region within 10 mm from the outer periphery of the through hole was Tmax, and the minimum thickness was Tmin. At that time, the ratio Tmax / Tmin between the maximum thickness and the minimum thickness was more than 8.00. When a plurality of fruit and vegetable freshness-keeping packaging bags were continuously produced by the same method as in Comparative Example 2, the hole diameter of each through hole was varied in the obtained packaging bag due to the radiant heat of the laser. As a result, in the same method as in Comparative Example 2, a bag that could withstand commercial production could not be obtained.

  The fruit and vegetable preservation packaging bags of Examples 1 to 5 were stored for 5 days at 5 ° C. and then stored for 2 days at 40 ° C., and the quality changes such as the appearance, smell, and taste of the green beans were traced. As a result, a good condition was maintained for a total of 7 days. On the other hand, the green beans preserved by using the fruit and vegetable preservation packaging bags of Comparative Examples 1 and 2 were deflated and were not sweet.

  The package of Example 6 is obtained by packaging broccoli instead of green beans in the fruit and vegetable freshness preservation packaging bag of Example 1. The broccoli-containing package of Example 6 was also stored at 5 ° C for 5 days, then stored at 40 ° C for 2 days, and the quality changes such as the appearance and smell of broccoli were traced. In addition, a good condition was maintained for a total of 7 days.

DESCRIPTION OF SYMBOLS 1 Unwinding roll 2 Synthetic resin film 3 Laser irradiation apparatus 4 Rotating support roll 5 Winding roll 6 Guide roll 7 Floating roll 8 Compressed gas introduction path 9 Nozzle tip 10 Pulse laser 11 Light guide path 12 Output optical part (lens)
13 Conical beam 14 Hole 15 Groove

Claims (17)

A fruit and vegetable freshness-keeping packaging bag composed of a perforated synthetic resin film,
The perforated synthetic resin film is provided with a through hole,
When the maximum thickness of the perforated synthetic resin film in the region within 10 mm from the outer periphery of the through hole is Tmax and the minimum thickness is Tmin on the outer surface of the freshness-keeping packaging bag for fruits and vegetables, the maximum thickness and the minimum thickness A fruit and vegetable freshness-maintaining packaging bag having a ratio Tmax / Tmin of 1.05 to 8.00.   2. The fruit and vegetable freshness retention according to claim 1, wherein the planar shape of the through hole on the outer surface of the fruit and vegetable freshness holding packaging bag and the planar shape of the through hole on the inner surface of the fruit and vegetable freshness retaining packaging bag are substantially the same shape. Packaging bag.   The fruit and vegetables freshness-keeping packaging bag according to claim 2, wherein the average hole diameters of the through holes on the outer surface and the inner surface of the fruit and vegetable freshness-keeping packaging bag are 20 μm or more and 2000 μm or less, respectively.   The fruit and vegetables freshness-keeping packaging bag according to any one of claims 1 to 3, wherein the maximum thickness Tmax of the perforated synthetic resin film is 16 µm or more and 400 µm or less.   The fruit and vegetables freshness-keeping packaging bag according to any one of claims 1 to 4, wherein the minimum thickness Tmin of the porous synthetic resin film is 15 µm or more and 60 µm or less. On the outer and inner surfaces of the fruit and vegetable freshness-keeping packaging bag, the pore area ratio R1 (%) at 40 ° C. of the porous synthetic resin film is 1.0 × 10 ⁻⁶ % or more and 5.0 × 10 ^−2. The fruit and vegetables freshness-keeping packaging bag according to any one of claims 1 to 5, wherein the packaging bag is fresh. On the outer surface and the inner surface of the fruit and vegetable freshness-keeping packaging bag, the pore area ratio R2 (%) at 5 ° C. of the porous synthetic resin film is 5.0 × 10 ⁻⁷ % or more and 2.5 × 10 ^−2. % Freshness-keeping packaging bag according to any one of claims 1 to 6. The aperture area ratio R1 (%) of the perforated synthetic resin film at 40 ° C. and the aperture area ratio R2 of the perforated synthetic resin film at 5 ° C. on the outer surface or inner surface of the fruit and vegetable freshness holding packaging bag. The freshness-keeping packaging bag for fruits and vegetables according to claim 7, wherein the value of the rate of change in opening calculated by the following formula (1) from (%) is 5 or more and 50 or less.
Rate of change in opening = {(R1-R2) / R2} × 100 (1) The fruit and vegetables according to any one of claims 1 to 8, wherein the porous synthetic resin film has a water vapor transmission rate at 40 ° C and 90% RH of 4 g / m ² · day to 400 g / m ² · day. A freshness-keeping packaging bag.   The fruit-and-fruit freshness holding packaging bag as described in any one of Claims 1 thru | or 9 with which the said through-hole is provided in the said fruit and vegetable freshness-keeping packaging bag.   The fruit and vegetables freshness preservation packaging bag as described in any one of Claims 1 thru | or 10 in which the fruit and vegetables washed with water in the process from after harvest to packaging are packaged. Oxygen transmission amount of the perforated synthetic resin film per fresh produce 100g ^{is, 50mL / 100g · m 2 ·} day · atm or more and ^{50000mL / 100g · m 2 · day} · atm or less, any one of claims 1 to 11 The fruit and vegetable freshness-keeping packaging bag described in the item.   A package containing fruits and vegetables formed by sealing fruits and vegetables with the freshness-keeping packaging bag for fruits and vegetables according to any one of claims 1 to 12. Of the vegetables and fruits containing packaging material, the packaging body area of the vegetables and fruits fresh-keeping packaging bag per the fresh produce 100g is 100 cm ² or more 5000 cm ² or less, vegetables and fruits containing packaging material of claim 13.   The package containing fruits and vegetables according to claim 13 or 14, wherein the oxygen concentration in the package containing fruits and vegetables is 0.1% or more and less than 19% before the package containing fruits and vegetables is opened.   The package containing fruits and vegetables according to any one of claims 13 to 15, wherein the weight reduction rate of the entire package including fruits and vegetables is 0.05% by weight or more and less than 1% by weight per day.   A method for maintaining the freshness of fruits and vegetables, wherein the fruits and vegetables are packaged using the fruit and vegetable freshness-keeping packaging bag according to any one of claims 1 to 12.

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