Freshness-preserving packaging for fruits and vegetables

Abstract

To provide a packaging body capable of obtaining a high freshness-preserving effect for green soybeans without lowering a productivity of a work of packing individual green soybean packages in an outer box.SOLUTION: There is provided a freshness-preserving package in which an individual package 13 containing green soybeans 2 in a film bag 11 made of an air permeable synthetic resin film is packed in an air permeable outer box 15, and a gas exchange rate E of the film bag 11 is 1.0×105 cc / m2.day.atm or more and 2.0×105 cc / m2.day.atm or less, and the green soybeans 2 occupy a spatial volume ratio of 40% or more and 80% or less in the outer box 15.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a freshness-preserving package for preserving the freshness of fruits and vegetables. [Background technology]

[0002] Synthetic resin film bags are commonly used as packaging for storing and transporting fruits and vegetables. Attempts have been made to maintain the freshness of fruits and vegetables for a long period of time by providing the bags with a certain level of breathability and adjusting the amount of water vapor, oxygen concentration, and carbon dioxide concentration inside the bags. If water vapor accumulates inside the bags and condenses, the fruits and vegetables contained therein may be damaged when they come into contact with the condensed water, so it has been proposed to punch holes in the bags to prevent water vapor from accumulating inside. However, in the case of holes as large as punch holes, the oxygen permeability is too high, and even if condensation does not occur inside the bag, the oxygen concentration becomes the same as in the atmosphere, so the freshness of the fruits and vegetables cannot be maintained. For this reason, it has been considered to ensure appropriate breathability by opening smaller holes.

[0003] For example, Patent Document 1 proposes a film for freshness-keeping bags for fruits and vegetables that ensures breathability by perforating the film with a needle that does not use heat, thereby creating perforations in a synthetic resin film without reducing the processing speed.

[0004] However, if too many holes are made in the bag, it becomes difficult to protect the fruit and vegetables contained therein from external pressure. In response to this, Patent Document 2 proposes a freshness-preserving packaging bag for fruit and vegetables in which the ratio of peak pressure (burst strength) and moisture permeability is adjusted to fall within a specified range in order to ensure the protective performance of the contents.

[0005] On the other hand, if the holes become blocked, the expected breathability cannot be ensured. Possible causes of the holes becoming blocked are deformation of the film due to the weight of the fruits and vegetables, contact with the side of the box when packed, or contact between bags when stacked.

[0006] Patent Document 3 proposes a freshness-preserving packaging bag in which the shape of the through hole is oval and the direction of the through hole is adjusted to prevent the shape of the through hole from changing.

[0007] Patent document 4 proposes a packing method in which, when packing fruit and vegetable packages into a packaging box, the angle between the bottom of the packaging box and the film material of the fruit and vegetable packages is vertical or inclined, thereby preventing the pores of the fruit and vegetable packages from becoming blocked by each other.

[0008] Patent Document 5 proposes a packing method for packing fruit and vegetable packages flat in a box, in which the number of stacks is adjusted to prevent the pores from becoming clogged and maintain the freshness-retaining effect. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2020-029261 A [Patent Document 2] JP 2018-100112 A [Patent Document 3] Patent No. 6168228 [Patent Document 4] JP 2020-37422 A [Patent Document 5] JP 2020-70079 A Summary of the Invention [Problem to be solved by the invention]

[0010] However, these proposed forms may cause inconveniences depending on the situation in which they are used. When individual packages, such as edamame, in which many pods are packed together in one bag, are packed in multiple boxes for shipping, it has been confirmed that several problems arise during the process.

[0011] The bag using the film described in Patent Document 1 has two-way slits processed with unheated needles, but when pressure is applied from the outside, the slits may become deformed around the slits and close. When packing individual packages containing edamame into an outer box, the individual packages are manually pressed to remove the air and reduce the volume of each package in order to increase the number that can be accommodated in the outer box. However, when the bag described in Patent Document 1 is used for edamame, the slits become blocked during this air removal process, making it difficult to remove the air, which can result in a long packing process and reduced productivity, or in some cases, the individual packages may burst.

[0012] The packaging bag described in Patent Document 2 also emphasizes cushioning to protect the contents, making it difficult for air to escape, and like Patent Document 1, there is a risk of the bag bursting or reducing productivity in the boxing process.

[0013] When edamame are packed in bags with punched holes, it is easy to remove the air and the productivity of the boxing process is high, but the oxygen concentration inside is almost the same as that in the atmosphere, so as mentioned above, the freshness of the edamame cannot be maintained.

[0014] Although the packaging bag described in Patent Document 3 has been used for edamame, it was not designed to be used for packing edamame in a box, and the oxygen permeability is set on the assumption that the edamame will be stored in the individual bags. For this reason, when packing the edamame in an outer box, the through holes are likely to be blocked by contact between adjacent packaging bags, and it is considered that the expected freshness-preserving effect cannot be adequately achieved.

[0015] The fruit and vegetable package described in Patent Document 4 assumes that the package containing the fruit and vegetable is packed into a packing box, but focuses only on whether moisture is absorbed from the bottom. The productivity of the work of packing individual packages containing many pods of edamame into a packing box, which is not assumed in the document, was not taken into consideration.

[0016] If edamame are packed in the packaging described in Patent Document 5, there is a limit to the number of bags that can be stacked in order to ensure adequate oxygen permeability, and the number of packages that can be packed into one outer box is also limited, resulting in a reduced number of packages that can be stored per box, which in turn reduces transportation efficiency.

[0017] Therefore, an object of the present invention is to provide a freshness-preserving package that can fully preserve freshness without reducing the productivity of the work of packing individual packages of edamame into boxes. [Means for solving the problem]

[0018] This invention is a packaging body in which edamame is stored in a film bag made of a breathable synthetic resin film, and the packaging body is packed in a breathable outer box, The gas exchange rate E of the film bag in a 23°C, 60% RH environment is 1.0×10 5 cc / m 2 ·day · atm or more 2.0×10 5 cc / m 2 ·day·atm or less, The above problem was solved by providing a freshness-preserving package in which the edamame occupy a space volume ratio of 40% or more and 80% or less in the outer box.

[0019] By packing the edamame so that the space volume ratio of the edamame in the breathable exterior box is within an appropriate range, and by setting the gas exchange rate E of the film bag itself that stores the edamame within an appropriate range, the breathability with the outside air can be ensured and the freshness of the edamame can be maintained. Furthermore, by packing the edamame in the box within the above-mentioned space volume ratio range, the efficiency of transportation and storage can be improved, and the freshness-preserving effect can be prevented from being reduced due to the loss of breathability of the individual package caused by overpacking.

[0020] The individual packaging constituting the freshness-preserving package of the present invention can adopt an embodiment in which the volume of air that escapes when a load of 1 kgf is applied for 1 minute after 1000 cc of air is injected into the film bag and sealed, is 250 cc or more and 980 cc or less. In applications in which edamame in an amount to be retailed to consumers is stored and boxed, and then transported and stored, if air escape properties within this range can be ensured, it becomes a suitable individual packaging that makes it easy to remove excess air during boxing without reducing productivity, and also easily exerts a freshness-preserving effect without excessive air escape.

[0021] The exterior box constituting the freshness-preserving package according to the present invention may employ an embodiment in which the opening area ratio R is 0.001% or more and 60% or less. The gas exchange rate E of the film bag in an environment of 23°C and 60% RH is 1.0 x 10 5 cc / m 2 ·day · atm or more 2.0×10 5 cc / m 2 By combining this with the condition of 1.5-day-atm or less, both the individual packaging containing edamame stored in the film bag and the outer box can exhibit appropriate breathability, thereby ensuring sufficient breathability for the entire freshness-preserving packaging of the present invention.

[0022] The material for the freshness-preserving package of the present invention can be the synthetic resin film having a thickness of 15 μm to 60 μm, which is perforated using heat. By perforating the synthetic resin film itself to make it breathable, it is possible to achieve stable performance with less unevenness in breathability, and by perforating using heat, it is difficult for film residue to be generated, and it is possible to prevent the film residue from being mixed into the edamame.

[0023] In particular, it is preferable to adopt an embodiment in which the ratio a / b of the major axis a to the minor axis b of the micropores formed by the perforation is 1.0 to 3.5. With such a shape, even if pressure is applied to remove air from the bag when storing and packing edamame, the micropores are not easily deformed, so the micropores are not easily blocked, and the gas exchange rate E is not easily reduced as long as the bag is packed in an outer box within the above-mentioned space volume ratio range.

[0024] Furthermore, in the case where the exterior box is made of a cardboard box, an embodiment in which the opening area ratio R is 0.001% or more and 30% or less can be suitably adopted. Effect of the Invention

[0025] The freshness-preserving package of the present invention makes it possible to produce a freshness-preserving package in which a large number of individual packages containing edamame are packed in a box while reducing the workload. The edamame packaged in this freshness-preserving package can be transported and stored while maintaining its freshness, and can be conveniently transported from the production site to the consumption site while still stored in the outer box. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a partially transparent perspective view of a freshness-preserving package according to the present invention; [Diagram 2] An example of individual packaging in which edamame are packed in a film bag before being packed into a freshness-preserving package [Diagram 3] FIG. 1 is a plan view showing an example of a freshness-preserving package according to the present invention, in which individual packages are packed vertically in an outer box. [Figure 4] Schematic diagram of perforations to be formed in the synthetic resin that constitutes the film bag [Diagram 5] Photographs showing the method for measuring air release in the examples DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments. The present invention relates to a freshness-preserving package for packaging edamame.

[0028] The freshness-preserving package 1 according to the present invention is an individual package 13, in which multiple pods of edamame 2 are stored in a film bag 11 made of a breathable synthetic resin film, packed in a breathable outer box 15. Fig. 1 shows a perspective view of an embodiment of the freshness-preserving package 1 using a cardboard box as the outer box 15, and Fig. 2 shows a perspective view of an example of each individual package 13. Fig. 3 shows a plan view of an example of the internal state of the individual packages 13 packed in the outer box 15.

[0029] The number of pods of edamame 2 stored in one film bag 11 is not particularly limited, but it is preferable that it is the amount that is retailed to general consumers in the market. The number of individual packages 13 packed in the outer box 15 is at least a plurality, and if the number of individual packages is too small, the advantage of packing in the outer box 15 in terms of transportation and storage cannot be fully obtained. Furthermore, it may be more time-consuming than transporting them as individually wrapped, which is a problem in terms of handling. On the other hand, if too much is packed, the outer box becomes large and heavy, making it difficult to handle the freshness-preserving package 1 by hand. In addition, if too many individual packages 13 are packed in without making the outer box large, the edamame 2 as the contents may be easily damaged.

[0030] The synthetic resin film constituting the film bag 11 is not particularly limited in material, but it is necessary that it has no adverse effect on the edamame 2 and is durable enough not to be easily torn during storage and transportation. As a synthetic resin that satisfies these requirements, for example, a polyolefin film such as polyethylene or polypropylene is preferably used. This is particularly desirable from the standpoint of safety and cost. Among them, a polyolefin film having anti-fogging properties is more preferable because it can suppress the adhesion of water droplets that cause the edamame 2 to spoil due to condensation of water vapor released from the edamame 2 during transportation and storage.

[0031] The thickness of the synthetic resin film is preferably 15 μm or more, more preferably 20 μm or more. If it is less than 15 μm, it may be easily torn, especially when it is made into a perforated film as described later, and it may be difficult to keep the size of the micropores formed inside the perforated portion within a suitable range. On the other hand, it is preferably 60 μm or less, more preferably 50 μm or less. If it exceeds 60 μm, it is difficult to form a perforated portion of a suitable shape.

[0032] The synthetic resin film is used to make a film bag 11. Examples of the shape of the film bag include a two-sided bag, a three-sided bag, a palm-shaped bag, and a gusset bag, but the shape is not particularly limited as long as the gas exchange rate E described below can be realized. Examples of the method of making the bag and the method of sealing the storage opening of the film bag include heat sealing, melt-cut sealing, pack sealing, and zipper, but the method is also not particularly limited as long as the gas exchange rate E described below can be realized.

[0033] The film bag 11 storing the edamame 2 has a gas exchange rate E of 1.0×10 5 cc / m 2 ·day·atm or more is preferable, and 1.2×10 5 cc / m 2 It is preferable that the temperature is 1.0×10 5 cc / m 2 If the temperature is less than 1.0×10·day·atm, the breathability will be insufficient, and there is a high possibility that the freshness of the edamame 2 stored in the film bag will not be sufficiently maintained. On the other hand, the gas exchange rate E of the film bag 11 is 2.0×10 5 cc / m 2 ·day·atm or less is preferable, and 1.8×10 5 cc / m 2 If the breathability is too high, even if the edamame 2 is stored in a film bag, it will be too close to being exposed to the air, and the freshness preservation effect will not be achieved.

[0034] In addition, the individual packaging body 13 in which edamame is stored in the film bag 11 and the storage opening is sealed is not only breathable, but also has a property of allowing an appropriate amount of air to escape when a load is applied in order to facilitate the escape of the internal air during the boxing work and improve the productivity of the boxing work. Specifically, the air escape property is preferably 250cc or more, more preferably 300cc or more, when a load of 1kgf is applied for 1 minute after 1000cc of air is injected into the film bag and sealed. If it is 250cc or less, even if an attempt is made to reduce the volume of the individual packaging body 13 during the boxing work, the air will not escape easily, and there is a high possibility that the productivity of the boxing work will be reduced. On the other hand, it is preferably 980cc or less, more preferably 800cc or less. If it escapes to the extent that it exceeds 980cc, there is a risk that most of the internal air will escape during transportation and the protective performance and freshness-preserving effect of the edamame will not be exhibited.

[0035] In order to achieve the above gas exchange rate E and air escape property, it is desirable that the synthetic resin film itself is breathable. Examples of a structure that ensures breathability include a structure in which a film is perforated by applying heat using a hot needle or laser after production to form perforations of the required number and size.

[0036] In order to ensure breathability in the synthetic resin film, when a film perforated with a hot needle or laser is used, the resin melted around the micro-holes cools and solidifies due to the heat applied during perforation. This makes it difficult for film residue to remain, and prevents film residue from adhering to the stored edamame. An enlarged view of the perforated portion 21 is shown in FIG. 4. The peripheral portion 23, which was once melted and solidified by heat, becomes thick, and micro-holes 22 are formed inside it. The micro-holes 22 may be circular or elliptical.

[0037] The ratio a / b of the major axis a to the minor axis b of the micropores 22 in the perforated portion 21 is 1.0 or more and is preferably 3.5 or less, and more preferably 3.0 or less. If the major axis is so long as to exceed 3.5, the peripheral portion 23 is likely to block the micropores 22 when air is removed from the bag during boxing, increasing the risk of impairing breathability.

[0038] In addition, the minor diameter b is preferably 0.05 mm or more, and more preferably 0.10 mm or more. If it is less than 0.05 mm, it is too small and air exchange is difficult, and the number of holes required to ensure breathability throughout the bag increases, which may reduce production efficiency, or it may be difficult to ensure the above-mentioned gas exchange rate E and air escape rate in the first place. On the other hand, the minor diameter b is preferably 1.0 mm or less, and more preferably 0.6 mm or less. If the minor diameter b exceeds 1.0 mm, the air escape rate and gas exchange rate E become too high, and not only will the freshness-preserving effect not be exerted, but air will also escape during transportation, which may cause the cushioning properties to be lost and the protective performance to be impaired. Furthermore, since each hole is clearly visible, there is a risk of impairing the appearance of the printed parts such as brand indications.

[0039] The freshness-preserving package 1 according to the present invention is a box in which a plurality of individual packages 13 are packed in a breathable exterior box 15. The shape of the exterior box 15 is not particularly limited, and a cardboard box as shown in Figs. 1 and 3, a plastic perforated container (hereinafter referred to as a "plastic container"), a wooden box, or the like can be used. The sides of these exterior boxes may be formed with handle holes 16 and ventilation holes 17 for vacuum pre-cooling as shown in Fig. 1, or may have holes separated by lattices for ventilation. However, boxes that are outer frame-type cases with completely open sides, such as boxes that are only rectangular parallelepiped frame parts other than the bottom, are not preferred. Examples of materials for the exterior box 15 include plastic, wood, and cardboard.

[0040] Among the various types of exterior boxes 15, the above-mentioned plastic containers have the advantage of being highly durable and reusable, and can be used as returnable boxes. Even if multiple ventilation holes are provided, the containers are easy to maintain their shape and ensure their strength. On the other hand, they are somewhat heavy, and require labor and transportation costs to collect them for reuse. In most cases, they must be washed before reuse, and the labor and cost of washing cannot be ignored.

[0041] Among the forms of the outer box 15, the wooden box has the advantage of being environmentally friendly since it does not require materials derived from fossil fuels for its manufacture. Since the wooden boards support the sides, it is easy to maintain the shape and ensure strength even if ventilation holes are provided mainly on the sides. On the other hand, the weight of the outer box is very large compared to the contents, which tends to lead to a decrease in productivity of the boxing work and an increase in transportation costs. It is naturally conceivable to reduce the weight by making the boards that form the wooden box thinner or reducing the area of ​​the boards, but if the area of ​​the boards is made too small, the individual packaged items will easily protrude from the sides, making it impossible to box them or causing damage to the individual packaged items during transportation and storage.

[0042] Among the forms of the exterior box 15, the cardboard box described above is one-way and can be used hygienically. In addition, since the material itself has good breathability, the opening area can be reduced, and the strength of the box can be easily maintained. The shape of the cardboard box is not particularly limited as long as it is both breathable and strong, and may be formed with a handle hole 16 for carrying and a ventilation hole 17 for increasing breathability, as shown in FIG. 1. Since it is lighter than wooden boxes and plastic containers, the productivity of the boxing work is good, and since it can be stored in a sheet form when not in use, it does not take up much space in warehouses. Although the box itself is one-way, a system for recycling the material has been established, and there is also the advantage that the overall environmental load is small. In addition, in the freshness-preserving package 1 according to the present invention, since the edamame 2 is packed in the state of an individual package 13 stored in a film bag 11, the strength reduction of the cardboard box due to the water vapor emitted from the edamame 2 can be suppressed.

[0043] The ratio R of the opening area to the outer area of ​​the outer box 15 is preferably 0.001% or more, and more preferably 0.01% or more. If it is less than 0.001%, even if the film bag 11 has breathability, the breathability of the material of the outer box 15 itself will not be enough to exchange gas with the outside air, and the freshness preservation effect will not be fully exhibited. Note that the outer area mentioned above is the total area of ​​the actual or imaginary surfaces formed by the outer frame part of the box, which can be considered as a rectangular parallelepiped. In the case of a cardboard that covers six sides, even if there is an opening such as a handle hole 16, it is the total area of ​​the six sides assuming that there is no opening. The overlapping part of the flap is not doubled. In the case of a perforated plastic container, etc., it is the total area of ​​each side assuming that there is no opening for each side that has an opening such as an air hole. On the other hand, R is preferably 60% or less, and more preferably 50% or less. If it exceeds 60%, individual packaging body 13 will protrude and come into direct contact with the outside air, and it will be unable to exert any freshness-preserving effect as freshness-preserving package 1. For reference, the cardboard box having handle hole 16 and ventilation hole 17 shown in Figure 1 has an R of about 0.5%.

[0044] When the exterior box 15 is a cardboard box, it is more preferable that the opening area ratio R is 0.001% or more and 30% or less. Since the compressive strength of the cardboard box is supported particularly by the side portions, if R is too high, there is a risk of problems in terms of strength. On the other hand, as mentioned above, since the material itself has high breathability, it is easy to ensure breathability even without many holes.

[0045] In the freshness preserving package 1 according to the present invention, the individual packages 13 are packed in the outer box 15 in a manner not particularly limited. For example, they may be packed vertically as shown in FIG. 3, or may be packed flat in a manner of stacking multiple layers vertically. However, the ratio of the volume of the edamame 2 itself to the volume of the outer box 15 in the freshness preserving package 1 (hereinafter referred to as the "space volume ratio") is preferably 40% or more, more preferably 45% or more. If the space volume ratio is less than 40%, the transportation efficiency is poor, and the edamame 2 may move too freely in the outer box 15, which may damage the edamame 2. On the other hand, the space volume ratio is preferably 80% or less, more preferably 75% or less. If it exceeds 80%, most of the air in the individual packages 13 must be removed and the edamame 2 must be packed so tightly that they directly press against each other, which increases the risk of damage to the edamame 2 itself. In addition, if the outer box 15 is a cardboard box, it may be difficult to seal it.

[0046] The freshness-preserving package 1 according to the present invention can be used for packaging, transporting, and storing edamame 2 to appropriately exchange gas inside and outside the package and to maintain freshness for a long time. In addition, because air is appropriately released from the individual packaging body 13, the time and effort required for producing the freshness-preserving package 1 can be significantly reduced, and the productivity of the boxing work can be improved. EXAMPLES

[0047] Next, the present invention will be described more specifically with reference to examples in which the present invention is actually put into practice.

[0048] The following synthetic resin films were prepared for use in the film bags. These were perforated by laser, non-heated needle, and punch processing so as to meet the specifications described in Table 1 below. However, the fine holes perforated using non-heated needles in Comparative Examples 1 and 2 were slit-shaped, and only in Comparative Examples 1 and 2, the long diameter a indicates the length of the slit, and the short diameter b indicates the width of the slit. In each of the Examples and Comparative Examples, the following air escape properties and gas exchange rate E were measured for the perforated synthetic resin film. In each of the Examples and Comparative Examples, edamame was stored in a bag made from the perforated synthetic resin film, the storage opening was sealed by heat sealing to form an individual package, and the bag was packed into each of the outer boxes shown in Table 1. The following films were used as the synthetic resin films before perforation. Anti-fog biaxially oriented polypropylene film ("Anti-fog OPP" in the table) Thickness: 30 μm, manufactured by Futamura Chemical Co., Ltd.: AF-642

[0049] [Table 1]

[0050] <Air release measurement> Each film was used to heat seal a 200mm x 180mm back-pasted bag, into which 1000cc of air was injected using a gas syringe. When the needle of the gas syringe was inserted into the bag, the needle was inserted into a part where three layers of cellophane tape (CT405AP 18, manufactured by Nichiban Co., Ltd.) were attached in layers to prevent the bag from tearing. After the injection of air was completed and the needle was removed, the needle hole was quickly blocked with cellophane tape, and a 26 x 30 cm stainless steel plate (1 kg) was placed on the bag so that it was parallel to the floor. An example of this state is shown in the photograph in Figure 5. The bag was left to stand for one minute in this state, and the air was removed from the bag by the weight of the stainless steel plate. After one minute had passed, the stainless steel plate was quickly removed from the bag, and the needle of the gas syringe was inserted into the bag to degas the air in the bag. The bag was repeatedly degassed with a syringe until all the air was removed, and the air release rate of the film bag was evaluated based on the total volume of the air released. The calculated volume of the air released is shown in Table 1 as the air release rate (cc).

[0051] <Gas exchange rate E measurement> Using each film, a bag of 150 mm x 180 mm was made by heat sealing the four sides, and a syringe nozzle for sampling was attached, avoiding the perforated part of the perforated film. Next, the bag was degassed with an aspirator using the nozzle, and then 750 cc of nitrogen gas (purity 99.99% or more) was filled into the bag using a gas syringe. Immediately after filling with nitrogen gas, 1 cc of gas in the bag was sampled, and the oxygen concentration was measured by gas chromatography (TCD detector) equipped with a packed column, and the value was taken as the initial oxygen concentration (C0). After that, the bag was left to stand in a thermostatic chamber set at 23 °C and 60% RH, and the oxygen concentration in the bag was measured by gas chromatography 30 minutes, 1 hour, and 1 hour and 30 minutes after the start of storage. All measurements were performed in the atmosphere. It was confirmed that a proportional relationship was established between the elapsed time and the oxygen concentration in the bag (correlation coefficient 0.98 or more) in the obtained measured values, and if this was not established, the test was performed again. The oxygen concentration in the air was assumed to be 21%, and the gas exchange rate E of the entire air in the bag was calculated using the measured oxygen concentration in the bag 1 hour and 30 minutes after the start of storage using the following formula. E=(C t -C0) / C O2 ×V / t / s / P……(1) Here, each symbol is as follows: E: Gas exchange rate (cc / m 2 ·day·atm) C t : Oxygen concentration in the bag t hours after filling with nitrogen gas (%) C0: Oxygen concentration in the bag immediately after filling with nitrogen gas (%) C O2 : Oxygen concentration in the air (21%) V: Amount of nitrogen gas filled (750cc) t: Time elapsed since gas was filled (1.5hr = 0.0625day) s: inner surface area of ​​the bag (0.054 m 2 ) P: Atmospheric pressure during measurement (1 atm)

[0052] <Space volume ratio of edamame> The edamame beans to be packed in the bags were placed into a 500cc graduated cylinder, one by one with the pods, until the top reached the 500cc mark, then removed and weighed, which was 250g. Therefore, the apparent volume per unit volume of the edamame used in this study was calculated as 500cc / 250g. The void volume ratio to the outer box was calculated using the following formula from the apparent volume per unit volume of the edamame, the total mass of the edamame packed in the outer box, and the volume of the outer box.

[0053] {Edamame's space volume ratio to the outer box (%)} = {Edamame's apparent volume per unit volume (500cc / 250g)} × {Total mass of edamame packed in the outer box (g)} ÷ {Outer box volume (cc)} × 100 (%) The results were evaluated as follows: ○: Space volume ratio is 40% or more and 80% or less; △: Space volume ratio is 30% or more and less than 40% or more than 80% and 90% or less; ×: Space volume ratio is less than 30% or more than 90%.

[0054] <Packing workability evaluation> The outer box was a cardboard box with a width of 36 cm, length of 33 cm, and height of 15 cm. Approximately 250 g of edamame was placed in a 200 mm x 180 mm film bag made by heat sealing three sides, and the opening was heat sealed to seal the individual packages, for the number of "individual packages" shown in the table. The time required for one person to vertically pack all the individual packages into the outer box was measured. The work was repeated three times, and in order to take into account variability due to individual differences, the same work was performed by different people, and the packing workability was evaluated as follows based on the average time required for the work. 〇: Less than 1.5 minutes, △: 1.5 to 3 minutes, ×: 3 minutes or more.

[0055] <Freshness preservation effect evaluation> Using the synthetic resin film of each Example and Comparative Example, about 250 g of edamame was placed in a film bag made by heat sealing three sides, and the opening was heat sealed to produce individual packages for each example. Each package was vertically packed in each outer box for the number of packages shown in the table, and stored for 7 days in a fluctuating environment of 12 to 27 ° C. The quality of the edamame was evaluated comprehensively as follows by checking for changes in appearance, the presence or absence of abnormal odor, and changes in mass. ◯: Good, △: Bad, ×: Extremely bad.

[0056] The following outer boxes were prepared: Cardboard box (1) Made by Rengo Co., Ltd., with handle holes and ventilation holes. Inner dimensions: 36 cm x 33 cm x 15 cm. Opening area ratio R = 1.8%. Cardboard box (2) Manufactured by Rengo Co., Ltd., no handle holes. Inner dimensions: 36 cm x 33 cm x 15 cm. Opening area ratio R = 0.005%. Cardboard box (3) Manufactured by Rengo Co., Ltd., no top. Inner dimensions: 36 cm x 33 cm x 15 cm. Opening area ratio R = 27%. · Plastic container · Sanko Co., Ltd., Suntainer B # 19-N. Inner dimensions: 44 cm x 27 cm x 15 cm. Opening area ratio R = 50%. ·Styrofoam··Kasahara Kogyo Co., Ltd., Styrofoam Box (L) TK-14H (Large), Inner dimensions: 40cm x 31cm x 18cm. Opening area ratio R=0% ·Wooden box··Made of pine wood, inner dimensions: 36cm x 33cm x 15cm, opening area ratio R=72%

[0057] <Overall rating> Based on the evaluation of the space volume ratio, packing workability, and freshness preservation effect, an overall evaluation was made as follows. Good: Space volume ratio, packing workability, and freshness retention effect are all good; △: Space volume ratio, packing workability, and freshness retention effect are all good; ×: Space volume ratio, packing workability, and freshness retention effect are all bad.

[0058] <Comparison of different perforation shapes> (Examples 1 to 4) A synthetic resin film was obtained by perforating an anti-fog biaxially stretched polypropylene film with a laser under different conditions so that the major and minor diameters of the perforated portion were the values ​​shown in Table 1. The synthetic resin film was evaluated for air release and gas exchange rate E, and the three sides of each synthetic resin film were heat-sealed to form a film bag, which was then filled with about 250 g of edamame, and the remaining side of the bag was heat-sealed to obtain an individual package. Twenty of these individual packages were vertically packed in a cardboard box (1) to evaluate the packing workability and freshness-retaining effect, and all of the packages in the range of Examples 1 to 4 showed good results.

[0059] <Comparison based on number of individual packages> (Examples 5 and 6) Using the synthetic resin film and film bags of Example 1, the number of individual packages packed into the same cardboard box (1) was changed to 16 packages (Example 5) and 26 packages (Example 6) to change the volumetric space ratio, and good results were obtained in all cases within this range.

[0060] <Evaluation based on differences in air release properties of film bags> (Comparative Examples 1 and 2) When individual packages were produced in the same manner as in Example 1 using the anti-fog biaxially oriented polypropylene film used in Example 1 and a film bag made by perforating the film with a non-heated needle (Comparative Examples 1 and 2), the air did not escape sufficiently, and the packing work took a significantly long time.

[0061] Comparative Example 3 Instead of forming the perforations so that the major diameter a of the perforations is longer than in Example 1, the number of perforations per unit area is set to 80 / m 2 When individual packages were similarly produced using a synthetic resin film with a reduced thickness of 100 mm, the air escape was insufficient, and the boxing process took a little longer. It was confirmed that the air escape was impaired when the major axis / minor axis ratio of the ellipse was too large.

[0062] Comparative Example 4 In Comparative Example 3, individual packages were produced in the same manner except that the number of holes was increased by 1.5 times to 120. As a result, the air could be released and the time required for packing could be shortened, but the gas exchange rate E increased and the freshness preservation effect of the edamame was insufficient.

[0063] Comparative Example 5 When individual packages were produced in the same manner as in Example 1 using a film bag made of a film having a circular punch hole with a diameter of 6.0 mm formed as a perforated portion, the air escaped too easily, and the air inside was completely escaped in the air escape measurement. In addition, the gas exchange rate E could not be measured because the packed air escaped immediately. Although the productivity of the boxing work was good, the freshness preservation effect of edamame was not exhibited at all.

[0064] <Evaluation of differences in gas exchange rates> (Comparative Examples 6 and 7) In Example 1, when the number of holes was halved, the air escape was ensured, but the gas exchange rate E decreased, resulting in insufficient freshness preservation effect (Comparative Example 6). In this Comparative Example 6, when the number of individual packages packed in the outer box was reduced from 20 to 8 (Comparative Example 7), the freshness preservation effect was ensured due to the increased spacing between the individual packages. However, the spatial volume ratio of edamame was significantly reduced, making it impractical in terms of transportation efficiency, and it was confirmed that a practical problem would arise if the gas exchange rate E was reduced too much.

[0065] <Evaluation of floor area ratio> (Comparative Examples 8 and 9) In Example 1, the number of individual packages packed in an outer box was changed from 20 to 29 (Comparative Example 8) and 8 (Comparative Example 9). In Comparative Example 8, in order to pack that many individual packages, the air had to be sufficiently removed before packing, which took too much time, causing problems in productivity of the boxing work. In addition, there was almost no gap between the bags of the individual packages, and it was thought that the holes were blocked by adjacent bags, resulting in insufficient freshness preservation effect. On the other hand, in Comparative Example 9, in which the number of individual packages was reduced, there was almost no need to remove the air, and the packages were packed as they were, so the work productivity was good and the freshness preservation effect was secured in the same way as in Example 1, but the number of packages that could be packed in one outer box was too small, causing problems in efficiency of transportation and storage.

[0066] <Evaluation based on differences in outer packaging> (Examples 7 to 9, Comparative Examples 10 and 11) In Example 1, the outer box was changed to a cardboard box (2) (Example 7), a cardboard box (3) (Example 8), a plastic container (Example 9), polystyrene foam (Comparative Example 10), and a wooden box (Comparative Example 11), and the individual packages were packed in the same manner. Note that only in Comparative Example 10 of polystyrene foam, the number of individual packages packed in the box was increased by two because the internal volume was large. In all of Examples 7 to 9, the opening area ratio R of the outer box was different, but the breathability was ensured and no problem occurred in the freshness preservation effect. On the other hand, in Comparative Example 10, where the opening area ratio R of the outer box was 0% and there was no breathability, even if the air escape property and gas exchange rate E of the individual packages were ensured, the air that escaped from them was not exchanged with the outside air, so the freshness preservation effect was not exhibited at all. In addition, the wooden box was essentially a wooden frame and could not support the packed individual packages, and the form of collective packaging could not be maintained. [Explanation of symbols]

[0067] 1. Freshness-preserving packaging 2. Edamame 11 Film Bag 13 individual packages 15 Outer box 16 Handle hole 17 Ventilation hole 21 Perforation 22 Micropore 23 Periphery

Claims

1. The individual packaging body, in which edamame is stored in a film bag made of a synthetic resin film having breathability due to micropores formed by perforation, is packed in a breathable outer box, The gas exchange rate E of the film bag in an environment of 23° C. and 60% RH is 1.0×10 ５ cc / m ２ ・day・atm or more 2.0×10 ５ cc / m ２ ・Day・atm or less, The film bag has a volume of air that escapes when 1,000 cc of air is injected into the film bag and a load of 1 kgf is applied for 1 minute, the volume of air that escapes being 250 cc or more and 980 cc or less; The opening area ratio R to the outer area of ​​the outer box is 0.001% or more and 60% or less, The freshness-preserving package in which the edamame occupies a space volume ratio of 40% or more and 80% or less in the outer box.

2. The freshness-preserving package according to claim 1, wherein the synthetic resin film is a polyolefin film having a thickness of 15 μm or more and 60 μm or less.

3. 3. A freshness-preserving package according to claim 2, wherein the ratio a / b of the major axis a to the minor axis b of the micropores formed by the perforation is 1.0 or more and 3.5 or less.

4. 4. The freshness-preserving package according to claim 1, wherein the outer box is a cardboard box, and the opening area ratio R is 0.001% or more and 30% or less.

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