JP2014140386A - Packaging bag for retaining freshness of vegetable and fruit, package containing vegetable and fruit using the same, and method for retaining freshness of vegetable and fruit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress stably deterioration or decay of vegetables and fruits.SOLUTION: In a packaging bag for retaining freshness of vegetables and fruits constituted of a perforated synthetic resin film, open holes are provided in the perforated synthetic resin film. In the packaging bag for retaining freshness of vegetables and fruits, when the hole area on the outer surface of the packaging bag for retaining freshness of vegetables and fruits is expressed as Sout and the hole area on the inner surface of the packaging bag for retaining freshness of vegetables and fruits is expressed as Sin, concerning the open holes, the following inequality is satisfied: Sout/Sin>1.

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.

  Vegetables and fruits and other fruits and vegetables continue to have a respiration after harvesting. Because of the energy consumed by this respiration, the freshness of the fruits and vegetables deteriorates during storage, distribution or preservation after harvest.

  In order to suppress the deterioration of fruits and vegetables, in recent years, when selling fruits and vegetables, film packaging is often performed on the fruits and vegetables. When packaging fruits and vegetables, not only wrapping but also hermetically packaging, the fruits and vegetables freshness-keeping material having a MA (Modified Atomsphere) effect is used as the film. Such a packaging method for fruits and vegetables is called MA packaging (Patent Documents 1-4). Here, the MA packaging means that fruits and vegetables are packaged in a bag with controlled gas permeation amount, and the package body has a low oxygen concentration and high carbon dioxide concentration state according to the balance between the respiration rate of the packaged fruits and vegetables and the gas permeation amount of the packaging bag. By doing so, the freshness is maintained by suppressing the respiration of fruits and vegetables.

As a method for supplying oxygen to fruits and vegetables and maintaining freshness, a method using a perforated film has been proposed (Patent Document 5). In the technique described in Patent Document 5, the area of the hole per 100 g of the contents is 1.0 × 10 ⁻⁸ to 1.0 mm ² .

JP-A-4-53445 JP-A-7-170907 JP 63-44837 A JP 61-259982 A JP 2003-199490 A

  However, even when fruits and vegetables are packaged using the film described in Patent Document 5, the freshness or decay of fruits and vegetables may be accelerated as a certain amount of time elapses after the contents are packaged. all right.

  This invention is made | formed in view of the said situation, and provides the technique which suppresses deterioration or decay of fruit and vegetables stably.

  The present inventors diligently studied that the freshness and decay of fruits and vegetables are accelerated as time passes after the fruits and vegetables are packaged. As a result, it was found that the scale of the ratio of the hole area between the outer surface and the inner surface of the fruit and vegetable freshness-keeping packaging bag is effective as a design guideline for stably suppressing deterioration or rot of the fruits and vegetables. Specifically, the freshness of fruits and vegetables decreases with the passage of time by adopting a configuration in which the hole area on the outer surface is larger than the inner surface of the packaging bag for the through-holes provided in the fruit and vegetable freshness-holding packaging bag. As a result, the present inventors have found that it is possible to stably suppress premature decay and rot.

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,
With regard to the through-hole, when the hole area on the outer surface of the fruit and vegetable freshness holding packaging bag is Sout and the hole area on the inner surface of the fruit and vegetable freshness holding packaging bag is Sin, the fruit and vegetable freshness holding packaging bag satisfying Sout / Sin> 1 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.

  ADVANTAGE OF THE INVENTION According to this invention, deterioration or rot of fruit and vegetables can be suppressed stably.

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.
And about each through-hole provided in the fruit and vegetable freshness maintenance packaging bag, the structure where the hole area Sout in the outer surface of a packaging bag is larger than the hole area Sin in the inner surface of a packaging bag, ie, Sout / Sin is 1 It has a larger configuration. According to the fruit and vegetable freshness-keeping packaging bag in the present embodiment, the hole area on the outer surface and the inner surface of the packaging bag in each of all the through holes is larger on the outer surface, so that time has passed since the fruits and vegetables were packaged. However, an increase in the hole area can be suppressed. Therefore, it is possible to suppress the progress of deterioration or decay of fruits and vegetables, and to stably obtain an excellent freshness maintaining effect.

In the conventional fruit and vegetable freshness-maintaining packaging bag, it is considered that the phenomenon detailed below occurs.
That is, when fruits and vegetables are packaged using a conventional fruit and vegetable freshness-keeping packaging bag, the film surface is stressed by the weight of the contents (fruits and vegetables). Due to this stress, it is considered that the hole area is increasing with the passage of time since the fruits and vegetables were wrapped in the through holes provided in the film. Moreover, it is thought that the gas permeation performance is changing with the increase in the hole area as a cause of the decrease in freshness and decay of fruits and vegetables. As described in the background art section, the MA packaging is a technique in which the package body is brought into a low oxygen concentration and high carbon dioxide concentration state by a balance between the respiration rate of the packaged fruits and vegetables and the gas permeation amount of the packaging bag. Therefore, in the conventional fruit and vegetable freshness-keeping packaging bags using this method, the increase in the hole area breaks the balance between the respiration rate of the packaged fruits and vegetables and the gas permeation rate of the packaging bag. It is thought that it was premature.

On the other hand, according to the fruit and vegetable freshness-keeping packaging bag of the present embodiment, the ratio Sout / Sin of the hole area between the outer surface and the inner surface of the packaging bag in each through hole satisfies a specific condition, so An increase in area can be suppressed. The reason for this is not necessarily clear, but the freshness-keeping packaging for fruits and vegetables generated when packaging fruits and vegetables by setting the ratio Sout / Sin of the hole area between the outer surface and the inner surface of the packaging bag in each through-hole to a specific range. It is considered that the force to pull the bag can be reduced. For this reason, the increase in the hole area is suppressed, and even when a certain amount of time has passed since the packaging of the fruits and vegetables, it becomes possible to maintain the balance between the respiration rate of the packaged fruits and vegetables and the gas permeation rate of the packaging bag. Deterioration or rot of can be suppressed.
Moreover, according to the fruit and vegetable freshness holding packaging bag of this embodiment, it is possible to suppress the deterioration of the freshness of the fruit and vegetables for a longer period. 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 Sout / Sin of the hole area between the outer surface and the inner surface of the packaging bag in each through hole satisfies a specific condition, the type and weight of the fruit and vegetable However, the freshness of the fruits and vegetables can be stably maintained for a longer period of time because the deterioration or decay of the fruits and vegetables can be stably suppressed. This point will be described in detail in an embodiment described later.

  In this embodiment, the ratio Sout / Sin of the hole area between the outer surface and the inner surface of the packaging bag in each through-hole provided in the fruit and vegetable freshness-keeping packaging bag is larger than 1.1, preferably 1.15 or more. . By carrying out like this, from the viewpoint that the flow path of oxygen and water vapor | steam is ensured and a density | concentration is stabilized, deterioration or decay of fruit and vegetables can be suppressed still more stably.

About the through-hole provided in the fruit and vegetables freshness holding packaging bag of this embodiment, the hole area Sout in the outer surface of a packaging bag is suitably selected according to the kind of fruit and vegetables. The hole area Sout on the outer surface of the packaging bag is, for example, 5500 μm ² or more and 1200000 μm ² or less, and preferably 7000 μm ² or more and 100,000 μm ² or less.

Moreover, about the through-hole provided in the fruit and vegetables freshness holding packaging bag, the hole area Sin in the inner surface of a packaging bag is also suitably selected according to the kind of fruit and vegetables. Open area Sin on the inner surface of the packaging bag, for example 5000μm ² or more 1,000,000 ² or less, preferably 6000 .mu.m ^more 500000Myuemu ² or less.

  According to this embodiment, the side wall of the through-hole provided in the fruit and vegetable freshness holding packaging bag is formed in a taper shape so as to gradually expand from the inner surface to the outer surface of the fruit and vegetable freshness holding packaging bag. The cross-sectional shape of the side wall of the through hole provided in the fruit and vegetable freshness holding packaging bag is formed in a shape that widens from the inside to the outside of the fruit and vegetable freshness holding packaging bag with respect to the thickness direction of the perforated synthetic resin film. . Specifically, the shape spreading from the inside to the outside of the perforated synthetic resin film may be a taper shape, a step shape, or a wavy shape. Among these, it is more preferable that the side wall of the through-hole has a tapered shape whose diameter increases outward with respect to the thickness direction. By carrying out like this, deterioration or decay of fruit and vegetables can be suppressed much more stably.

  Further, in the through hole provided in the fruit and vegetable freshness maintaining packaging bag, it is preferable that the hole diameter of the inner surface of the packaging bag is the smallest, but the portion where the hole diameter is the smallest is in a region between the outer surface and the inner surface. There may be.

  According to this embodiment, the average hole diameter of the through holes in the inner surface of the fruit and vegetable freshness-keeping packaging bag is preferably 80 μm or more and 1100 μm or less, and more preferably 84 μm or more and 950 μm or less. When the average hole diameter of the through holes on the inner surface of the fruit and vegetable freshness holding packaging bag is within the above range, the deterioration or decay of the fruit and vegetables can be more stably suppressed.

  Moreover, according to this embodiment, the average hole diameter of the through holes on the outer surface of the fruit and vegetable freshness-keeping packaging bag is preferably 85 μm or more and 1200 μm or less, and more preferably 90 μm or more and 1150 μm or less. When the average hole diameter of the through holes on the outside of the fruit and vegetables freshness holding packaging bag is in the above range, deterioration or decay of the fruits and vegetables can be more stably suppressed.

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. By carrying out like this, deterioration or decay of fruit and vegetables can be suppressed much more stably.

  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.

  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.
In this embodiment, the aperture area ratio of the perforated synthetic resin film is 1.0 × 10 ⁻⁶ % or more and 5.0 × 10 ⁻² % or less from the viewpoint of suppressing the deterioration of freshness of fruits and vegetables. When the aperture area ratio of the perforated synthetic resin film is in the above range, variation in the degree of deterioration of fruits and vegetables can be further suppressed even when the use conditions are changed. More preferably, they are 1.0 * 10 < ^-5 >% or more and 5.0 * 10 < ^-3 >% or less. When the aperture area ratio of the perforated synthetic resin film is 1.0 × 10 ⁻⁶ % or more, it is possible to obtain an excellent fruit and vegetable freshness-keeping packaging bag from the viewpoint of suppressing the off-flavor generated during storage of fruit and vegetables. it can. When the aperture area ratio of the perforated synthetic resin film is 5.0 × 10 ⁻² % or less, the browning phenomenon of fruits and vegetables can be suppressed, so that excellent freshness of fruits and vegetables is maintained from the viewpoint of suppressing abnormal breathing of fruits and vegetables. A packaging bag can be obtained.

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, from the viewpoint of cost and physical properties, it is preferable to use an antifogging stretched polypropylene film, a low-density polyethylene film, a linear low-density polyethylene film, or a metallocene-catalyzed polyethylene that can be heat-sealed as the porous synthetic resin film.

  In addition, when the fruits and vegetables packed in the freshness-keeping packaging bag for fruits and vegetables are heavy, synthetic resin films such as non-stretched polypropylene, stretched polypropylene, unstretched nylon, stretched nylon, stretched polyester, etc. are dry-laminated and extruded. Alternatively, a multilayer film formed by coextrusion may be used.

  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, in each through-hole provided in the packaging bag according to the present embodiment, the fruit and vegetables freshness-maintaining packaging bag satisfying the above-mentioned specific condition, the ratio Sout / Sin of the outer and inner hole areas of the packaging bag, It is difficult to obtain by the conventional method for producing a perforated film described in the above section. Specifically, the fruit and vegetable freshness-keeping packaging bag according to the present embodiment is a highly controlled combination of factors such as the film tension in the perforated portion, the temperature of the hot needle, the shape of the hot needle, the speed of sticking the hot needle, etc. It can be manufactured for the first time. Thus, in order to obtain the fruit and vegetable freshness-keeping packaging bag that stably suppresses the deterioration or decay of the fruits and vegetables according to the present embodiment, it is particularly important to highly control the above factors.

  However, the manufacturing method of the fruit and vegetables freshness-keeping packaging bag of the present embodiment is not limited to the processing method using the hot needle, and may be punching processing or laser processing, for example. However, even when these processing methods are adopted, various factors such as laser energy and laser irradiation distance need to be highly controlled and combined.

  In some cases, the inner and outer hole areas of the fruit and vegetable freshness-keeping packaging bags manufactured using conventional methods are larger or the same on the inner side. 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 fruits and vegetables can be obtained. Such a fruit and vegetable freshness-keeping packaging bag has a ratio Sout / Sin between the outer and inner hole areas of the packaging bag in each through-hole provided in the packaging bag that satisfies a specific condition. That is, according to the manufacturing method according to the present embodiment, it is possible to obtain a packaging bag that has a higher MA effect than a conventional packaging bag and can maintain the MA effect for a long time. 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. Specifically, by controlling each factor when the hole is provided in the film, it is possible to provide a hole having no variation in the outer peripheral shape of the opening portion. Thereby, since the peripheral reinforcement effect can be exhibited on the outer periphery of the opening portion, it is considered that a packaging bag having high resistance to gravity due to the weight of the fruits and vegetables can be obtained.

  By carrying out like this, the fruit and vegetables freshness holding packaging bag which Sout / Sin based on this embodiment satisfy | fills specific conditions can be obtained for the first time. The selection of the film material and the selection of the hot needle 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 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 opening 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 mm to 1 mm ² per 100 g of fruits and vegetables 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, and storage using the fruit and vegetable freshness-keeping packaging bag in this embodiment is suitable. 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 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-keeping packaging bag 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 not more than 10,000 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% by weight.

  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
An anti-fogging biaxially oriented 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) Nine holes having a diameter of 180 μm (average diameter) and an opening area of 0.026 mm ² at 40 ° C. were provided. In addition, the total open area at 40 ° C. was 0.24 mm ² . In this way, a packaging bag for maintaining freshness of fruits and vegetables was obtained.

In this example, perforation was performed by the following method.
First, a needle having a conical tip shape was prepared. The maximum diameter of this needle is 800 μm, and the height of the conical part is 4500 μm. Next, this needle was attached to a perforation apparatus and heated to 180 ° C. The film was mounted on the perforating apparatus so as not to cause wrinkles.
Next, by inserting a heated needle into the film, the side wall of the through hole has a tapered shape spreading from the inside to the outside of the fruit and vegetables freshness holding packaging bag in the thickness direction of the perforated synthetic resin film, and A perforation was performed. By doing so, the side wall of the through hole provided in the fruit and vegetables freshness holding packaging bag was formed in a taper shape so as to gradually expand from the inner surface to the outer surface of the fruit and vegetable freshness holding packaging bag. In addition, the needle piercing speed with respect to the film was 0.5 m / s, and the drawing speed was 1.5 m / s. The planar shape on the outer surface of the through hole and the planar shape on the inner surface were both circular and substantially the same shape.

(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 400 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 27.79 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 an unheated needle was used.

  About the obtained fruit and vegetables freshness maintenance packaging bag, the measurement and evaluation shown below were performed.

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)
Film thickness: The film thickness was measured according to JIS K7130. The unit was μm.

Perforated area ratio: Using a microscope (VH-6300, manufactured by Keyence Corporation), the perforated area of the inner surface of the packaging bag for freshness of fruits and vegetables at 40 ° C. and 5 ° C. was measured. The bag 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)

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 with heat seal so that oxygen would not leak out from other than the through-holes of 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 (C0) 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 (Ct) 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 needle. 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 variation in the hole shape and film thickness in the peripheral area of each through hole. Thus, in the fruit and vegetable freshness-keeping packaging bag of Comparative Example 2, the cause of the variation in the hole shape, the film thickness, etc. in the hole peripheral region is due to the use of an unheated needle. it is conceivable that.

  In the fruit and vegetable freshness-holding packaging bag of Comparative Example 2, when the hole area on the outer surface of the fruit and vegetable freshness-holding packaging bag is Sout and the hole area on the inner surface of the fruit and vegetable freshness-holding packaging bag is Sin, Sout / Sin is 1. It was less than 1. When a plurality of fruit and vegetable freshness-keeping packaging bags were continuously produced by the same method as in Comparative Example 2, variations occurred in the hole shape and the film thickness in the peripheral area of each through hole. 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.

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,
About the said through-hole, when the hole area in the outer surface of the said fruit and vegetables freshness maintenance packaging bag is set to Sout and the hole area in the inner surface of the said fruit and vegetables freshness maintenance packaging bag is set to Sin, the fruit and vegetables freshness maintenance which is Sout / Sin> 1.1 Packaging bag.   The fruit and vegetables freshness-keeping packaging bag according to claim 1, wherein the side wall of the through hole has a shape spreading from the inside to the outside of the fruit and vegetable freshness-holding packaging bag with respect to the thickness direction of the perforated synthetic resin film.   The fruits and vegetables according to claim 1 or 2, 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. A freshness-keeping packaging bag.   The fruit and vegetable freshness-keeping packaging bag according to claim 3, wherein an average hole diameter of the through holes on the inner surface of the fruit and vegetable freshness-keeping packaging bag is 80 µm or more and 1100 µm or less.   The fruit and vegetables freshness-keeping packaging bag according to claim 3 or 4, wherein an average hole diameter of the through holes on the outer surface of the fruit and vegetable freshness-keeping packaging bag is 85 µm or more and 1200 µm or less. The fruit and vegetable freshness-keeping packaging bag according to any one of claims 1 to 5, wherein the hole area Sout of the through hole on the outer surface of the fruit and vegetable freshness-keeping packaging bag is 5500 µm ² or more and 1200000 µm ² or less. The pore area Sin of the through holes in the inner surface of the vegetables and fruits fresh-keeping packaging bags, vegetables and fruits fresh-keeping packaging bag according to any one of claims 1 to 6 is 5000 .mu.m ² or more 1,000,000 ² or less. The fruit and vegetable freshness-maintaining packaging according to any one of claims 1 to 7, wherein an aperture area ratio of the perforated synthetic resin film is 1.0 x 10 ^-6 % or more and 5.0 x 10 ^-2 % or less. bag. The fruit and vegetables freshness-keeping packaging bag according to any one of claims 1 to 8, wherein the perforated synthetic resin film has a water vapor permeability at 40 ° C of 4 g / m ² · day or more and 400 g / m ² · day or less. .   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. The oxygen transmission rate 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.