JPH0799993B2 - Fresh fruits and vegetables preservation method and preservation container - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preserving fresh fruits and vegetables using a container having a tray having a certain shape and a packaging material having special performance for maintaining the freshness of fruits and vegetables, and a storage container used in this method. .

[0002]

2. Description of the Related Art Various attempts have heretofore been made to maintain the freshness of fruits and vegetables. For example, it is packed with a non-moisture permeable packing material to prevent moisture from escaping, the storage temperature is lowered, an oxygen scavenger is used to suppress breathing, ethylene gas is adsorbed to prevent additional ripening, etc. Various methods have been proposed.

For example, Japanese Examined Patent Publication No. 38-2757 describes that high-pressure polyethylene film is used to package fruits and store them in a refrigerator to prevent water from evaporating and ripening and storing them. Further, JP 61-216640 Patent permeability ratio of carbon dioxide and oxygen in Japanese _{(CO 2} / _O 2) is 3 to 4
It is described that the fruits and vegetables are packaged by using the synthetic resin film described above to control and store the respiration. However, even if the film is used as described above, a sufficient freshness preservation effect of fruits and vegetables cannot be obtained.

Further, it is considered that the appearance and normal appearance of fruits and vegetables are one of the factors for determining the quality of products, and therefore it is necessary to prevent damage such as deformation during storage. Conventionally, fruits and vegetables have been placed in a container such as a tray having a fixed shape and packaged in a film or the like. Deformation of fruits and vegetables can be prevented to some extent by using such a tray, but since neither the tray nor the packaging film can control the respiration of the fruits and vegetables, it cannot be preserved fresh.

[0005]

The problem with the prior art is that the basic problem of the loss of freshness of fruits and vegetables has not been fully elucidated, so the problem of preservation of freshness could not be solved to a satisfactory degree. . According to the research conducted by the present inventors, fruits and vegetables show a life reaction during storage, and when they breathe, plant hormones and enzymes also act. Therefore, for example, if ethylene gas is present in the storage atmosphere, aging hormone is actively secreted and aging is promoted. In addition, the composition of the storage atmosphere changes due to the respiration of fruits and vegetables, and when the oxygen content becomes too low and carbon dioxide gas increases, ateless breathing occurs and alcohol fermentation progresses, producing aldehydes and ammonia, and the freshness decreases. However, on the other hand, when there is a lot of oxygen, breathing is performed vigorously and maturation proceeds. In this way, the composition of the preservation atmosphere plays an important role in maintaining the freshness of fruits and vegetables,
Not only the carbon dioxide gas but also the amount of oxygen must be controlled to an appropriate value.

Most fruits and vegetables are 80 to 95 in most crops.
%, The water content is high, and when these are left under low humidity, water evaporates more violently than tissues such as pericarp and leaves, and this water loss immediately causes wilting and the freshness decreases.
Loss of 5% or more of water usually causes some change in appearance.

The present inventors have paid attention to the physiology of such plants and studied to adjust the composition of gas in the preservation atmosphere to put fruits and vegetables into a dormant state. As a result, in order to maintain the freshness of fruits and vegetables, the evaporation of water is suppressed, the amount of oxygen present in the storage atmosphere is adjusted to be in the range of 1 to 16%, preferably 2 to 12%. It has been clarified that it is necessary to minimize the existing amount of carbon dioxide gas in the range of 0 to 20%, preferably 2 to 15%.

The inventor of the present invention uses a carbon dioxide gas permeability coefficient P at 27 ° C. as a packaging material for forming the above-mentioned storage atmosphere.
co ₂ is 15 × 10 ⁻¹⁰ cm ³ (STP) cm /
(Cm ² · S · cmHg) or more, the ratio of the carbon dioxide gas permeability coefficient Pco ₂ to the oxygen permeability coefficient Po ₂ is 4.2 or more, and the water vapor permeability coefficient PH ₂ O is 80 × 10 ⁻⁹ cm.
The invention of a freshness-maintaining packaging material for fruits and vegetables, which is made of a synthetic resin film having ³ (STP) cm / (cm ² · S · cmHg) or less, has been completed. This is the invention of Japanese Patent Application No. 2-103131.

The present inventor conducted further research, succeeded in developing a film having further improved performance, and conducted research to give paper, which is the most widely used packaging material, the ability to form the above-mentioned storage atmosphere. It was succeeded in improving so that the fruits and vegetables could be preserved fresh. The present inventor carried out various studies by packaging fruits and vegetables with the above packaging materials. However, it has been found that the freshness of fruits and vegetables may be lost even in such packaging in which the storage atmosphere is adjusted. Then, I found out that the freshness is often lost in the transportation test. As a result of research on the cause, it was found that the major cause of such a decrease in freshness was injured fruits and vegetables.

Generally, fruits and vegetables change their physiological actions when stress such as wounds and bruises are applied, physiological metabolism is activated, respiration is significantly increased, and the production of hormones typified by ethylene is increased to improve freshness. It causes the occurrence of reduced rot. Therefore, it is not enough to simply package the fruits and vegetables in a bag that has a permeable and adjustable environment gas atmosphere. It is important to prevent the fruits and vegetables from being scratched or bruised due to vibration or shock during transportation. . The conventional packaging with only bags is very effective in improving the average level of the quality of fruits and vegetables by adjusting the atmosphere of the packaging material, but the packaging material itself does not have a certain shape and also has the function of maintaining the posture of the fruits and vegetables. Since it does not have it, it is not possible to prevent injuries of fruits and vegetables due to vibrations and shocks during transportation. In such a package where the posture of fruits and vegetables cannot be maintained, it is not possible to sufficiently preserve fresh fruits due to the occurrence of putrefaction due to scratches and bruises during handling during transportation, etc. is there.

However, in order to put fruits and vegetables on the market, handling at the distribution stage such as transportation is indispensable. Therefore, it is difficult to maintain the quality of freshness at a practical level in a package that cannot maintain the packaging attitude of fruits and vegetables. However, the present invention completed on the basis of such new knowledge prevents the generation of scratches and bruises of fruits and vegetables due to transportation and the like, dramatically improves the quality of preserved fruits and vegetables, and ensures the freshness of a practical level. It has become possible.

To this end, (A) a tray having a fixed shape is used, in particular, a tray that maintains the packaging posture of fruits and vegetables is effective, (B) a packaging material for packaging the tray is (a) synthetic. When a resin film is used, it is necessary to use a resin film having a low density of 0.914 g / cm ³ or less and containing a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms. Gas permeability coefficient Pco ₂ is 15 × 10 ⁻¹⁰ c
If the m ³ (STP) cm / (cm ² · S · cmHg) or more, the storage atmosphere cannot be satisfied no matter how the other conditions are changed. Next, the carbon dioxide gas permeability coefficient Pco ₂ and the oxygen permeability coefficient Po
_It is necessary that the ratio of ₂ be 3.5 or more, and if it is 3.5 or less, the concentration of carbon dioxide and oxygen cannot be sufficiently controlled, and fruits and vegetables cannot be kept in a dormant state. The coefficient PH ₂ O is 80 × 10 ⁻⁹ c
If it is not less than m ³ (STP) cm / (cm ² · S · cmHg), the amount of moisture released to the outside of the packaging material will increase, and the moisture of the fruits and vegetables in the packaging will evaporate vigorously, causing withering and keeping the fruits and vegetables fresh. Things impossible.

(B) When using resin-coated paper,
(A) It is necessary to coat a low-density copolymer having a density of 0.914 g / cm ³ or less with ethylene and an α-olefin having 3 to 12 carbon atoms, and (b) the resin layer coating the paper, The carbon dioxide gas permeability coefficient Pco ₂ is 15 × 10 ⁻¹⁰ c as in the film.
m ³ (STP) cm / (cm ² · S · cmHg) If the above conditions are not satisfied, the storage atmosphere cannot be satisfied no matter how the other conditions are changed. Next, the carbon dioxide gas permeability coefficient Pco ₂ and the oxygen permeability coefficient Po
_It is necessary that the ratio of ₂ be 3.5 or more, and if it is 3.5 or less, the concentration of carbon dioxide and oxygen cannot be sufficiently controlled, and fruits and vegetables cannot be kept in a dormant state. The coefficient PH ₂ O is 80 × 10 ⁻⁹ c
If it is not less than m ³ (STP) cm / (cm ² · S · cmHg), the amount of water released to the outside of the packaging material will increase, and the water loss of the fruits and vegetables in the packaging will become vigorous and cause the fruits to wither, thus keeping the fruits and vegetables fresh. By clarifying that it is not possible, we have completed the invention of a tray packaging container with excellent preservation of freshness. Therefore, in the present invention, all of the above conditions are combined with each other to exert a synergistic effect of fresh preservation of fruits and vegetables.

The present invention relates to

1. (A) a tray having a constant shape;
(B) The tray is sealed and packaged (a) Density of ethylene and α-olefin having 3 to 12 carbon atoms is 0.914 g / cm 3.
^It contains a copolymer of ³ or less and has a carbon dioxide gas permeability coefficient of 15 × 10 ⁻¹⁰ cm ³ (STP) cm / (cm ² at 27 ° C.
・ S · cmHg) or more, the transmission coefficient ratio Pco ₂ / Po ₂
Is 3.5 or more and the water vapor transmission coefficient is 80 × 10 ⁻⁹ c
m ³ (STP) cm / (cm ² · S · cmHg) or less resin film, (b) ethylene and 3 to 12 carbon atoms
Containing a copolymer having a density of 0.914 g / cm ³ or less with an α-olefin and having a carbon dioxide gas permeability coefficient at 27 ° C. of 15
× 10 ⁻¹⁰ cm ³ (STP) cm / (cm ² · S · c
mHg) or more, the transmission coefficient ratio Pco ₂ / Po ₂ is 3.5.
And above, the water vapor transmission coefficient is 80 × 10 ⁻⁹ cm ³ (S
TP) cm / (cm ² · S · cmHg) or less, at least one side of which is covered with a packaging material selected from wrapping paper with a resin layer coated on at least one side thereof. A fresh preservation method for fruits and vegetables, characterized in that the atmosphere gas is adjusted by breathing to reduce the pressure inside the container, and the packaging material is brought into close contact with the tray and the fruits and vegetables are fixed to the tray for packaging.

2. The method for preserving fruits and vegetables according to claim 1, wherein the gas in the container is degassed and then sealed, and then the residual gas is adjusted by breathing the fruits and vegetables.

3. The posture maintaining tray according to claim 1, characterized in that an unevenness tray for arranging at least a part of the stored items is fixed at the bottom. How to save fresh fruits and vegetables.

4. A tray having a fixed shape, and a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms and having a density of 0.914 g / cm ³ or less, which is hermetically packaged in the tray, at 27 ° C. Carbon dioxide permeability coefficient of 15 × 10 ⁻¹⁰ c
m ³ (STP) cm / (cm ² · S · cmHg) or more, the permeability coefficient ratio Pco ₂ / Po ₂ is 3.5 or more, and the water vapor permeability coefficient is 80 × 10 ⁻⁹ cm ³ (STP) cm /
A fresh preservation container for fruits and vegetables, which is composed of a resin film of (cm ² · S · cmHg) or less.

5. A tray having a constant shape and a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms and having a density of 0.914 g / cm ³ or less, which is hermetically sealed and packaged, are contained at 27 ° C. Carbon dioxide permeability coefficient of 15 × 10 ⁻¹⁰ c
m ³ (STP) cm / (cm ² · S · cmHg) or more, the permeability coefficient ratio Pco ₂ / Po ₂ is 3.5 or more, and the water vapor permeability coefficient is 80 × 10 ⁻⁹ cm ³ (STP) cm /
A fresh preservation container for fruits and vegetables, which comprises a wrapping paper having at least one surface coated with a resin layer having a size of (cm ² · S · cmHg) or less.

6. The fresh preservation of fruits and vegetables according to claim 4 or 5, wherein the tray having a fixed shape is a posture-maintaining tray in which a concave and convex portion for receiving and fixing at least a part of a stored item is arranged at the bottom. container. Regarding

Next, the tray, the resin film for packaging, and the resin layer of the packaging paper used in the present invention will be described. As the posture-maintaining tray of the present invention, a thermoplastic resin such as polyethylene, polystyrene, polyvinyl chloride, or polyester, or a foam sheet made of these foam sheets by vacuum molding, pressure molding, in-mold foam molding, or the like, or paperboard A more bonded or molded product is used. From the viewpoint of matching the peculiar shape of fruits and vegetables, a pulp mold or a mixed paper containing thermoplastic resin fibers which is thermocompression molded is preferable. In this case, it is preferable from the viewpoint of environmental protection such as easy incineration as compared with the conventional tray made of only resin. Further, as the tray, it is necessary to use a tray having a certain degree of rigidity, since it is necessary to fix the position of fruits and vegetables with a film or resin-coated paper. Among the above-mentioned various materials, a material made of a paper pulp material is preferable because rigidity is easily obtained even if the thickness is relatively thin and the weight is light. As the tray shape, a conventional boat-shaped or dish-shaped tray can be naturally used depending on the shape of the fruits and vegetables, and a shape that maintains the packed posture of the fruits and vegetables has a good effect. In the case of spherical or irregular shaped fruits and vegetables, it is more effective to form a convex portion or a concave portion for receiving and fixing at least a part of the fruits and vegetables in order to improve the position fixing state. When doing so, it is also effective to partition and store individual fruits and vegetables so that they may not come into contact with each other and rub against each other. Further, the combined use of a buffer material such as a foam or an air cap with these trays also contributes to further improvement of the effect.

The resin film and the resin layer satisfying the requirements of the gas permeation property of the present invention can be formed of a single synthetic resin, but a plurality of them are required to satisfy the requirements different from each other independently. It is desirable to use a synthetic resin. Typical examples of such synthetic resins include ethylene and α-olefin copolymers having 3 to 12 carbon atoms, such as ethylene-butene-1 copolymer and ethylene-hexene-polymer.
1 copolymer, ethylene-4-methylpentene-1 copolymer, ethylene-octene-1 copolymer and the like can be mentioned, and it is preferable to use as a blend of at least two kinds selected from these resins. . A blend of ethylene, an α-olefin copolymer having 3 to 12 carbon atoms and low density polyethylene can also be used. To obtain a particularly high carbon dioxide permeability coefficient, a low-density ethylene-α-olefin copolymer having a relatively high α-olefin copolymerization ratio or a so-called ultra-low density (LLDPE) having a high α-olefin copolymerization ratio Ethylene-α-
It is preferable to use an olefin copolymer as a main component, and in order to obtain a high selective permeation ratio, at least two kinds of resins composed of different monomers from the above resin group, for example, low density polyethylene and ethylene- It is preferable to select and use a combination of a hexene-1 copolymer, an ethylene-butene-1 copolymer and an ethylene-hexene-1 copolymer, and the like.

As another method for obtaining a resin film and a resin layer satisfying the requirements of the transmission characteristics of the present invention, the above-mentioned resin alone or a blend of a plurality of resins is used as a base polymer, while ethylene-acetic acid is used. Vinyl copolymer (EVA), ethylene-acrylic acid copolymer,
Ethylene copolymer such as ethylene-methyl methacrylate copolymer, ethylene or α-olefin-propylene-non-conjugated diene terpolymer, styrene / butadiene block copolymer, hydrogenated product of styrene / isoprene block copolymer, etc. It is also possible to blend and use the above resins.

When these resins are used as a single resin as shown in the following examples, it is difficult to satisfy all the requirements of the permeability of the present invention, and therefore the ratio of 90:10 to the above base polymer is used. It is necessary to use a blend ratio of 50:50. Although the detailed reason why the selective permeation ratio of carbon dioxide gas and oxygen is increased by blending resins having different repeating units is not clear, the present inventor has found that the molecular chains having different molecular motility have different concentrations. It is considered that this is because there is a region that exists in the above region, and the permeability of both gases in that region changes depending on the molecular chain concentration.

These resin films and resin layers include
In accordance with a formulation known per se, phenolic, organic sulfur, organic nitrogen, organic phosphorus, and other antioxidants or heat stabilizers, lubricants such as fatty acid derivatives such as metal soap and other fatty acid esters, and anti-fogging Agents, antistatic agents, calcium carbonate, white carbon, titanium white, magnesium carbonate, magnesium silicate, carbon black, various clays, inorganic fillers such as natural or synthetic zeolite, and other colorants and other compounding agents. It can be compounded in a compounding ratio known per se.

The thickness of the resin film and the resin layer depends on the type of resin used and its physical strength, the relationship of the properties of the paper used, and in some cases, the type of fruits and vegetables to be packaged, the storage temperature, etc. It is necessary to set it appropriately, but generally about 5 to 100 μm, preferably 30 to 8
0 μm is suitable. The melt index (MI) of the resin used in the present invention is not particularly limited, but for example, the MI value is 0.1 to 10 g / 10 minutes (JISK676.
It is preferable to use those having a degree of 0).

The resin layer of the packaging paper used in the tray packaging container of the present invention can be formed by extrusion or lamination of resin film, sheet or the like. As the wrapping paper used in the present invention, besides paper made of cellulose pulp, paper made by mixing synthetic resin fibers such as polyethylene can be used, and these papers usually have high gas permeability. The packaging material of the present invention may be packaged by sealing a tray on which fruits and vegetables are placed like a usual wrapping paper or a packaging film by sealing and sealing the mating portion of the packaging material, or as a bag or a tube-shaped container. It is also possible to store the tray on which is mounted and seal the opening by sealing. When sealed in this manner, the atmosphere inside becomes appropriate due to the physiological action of the fruits and vegetables, and the freshness of the fruits and vegetables is maintained.

The tray packaging container of the present invention may be combined with a known means effective for keeping the freshness of fruits and vegetables. For example, when a gas adsorbent against ethylene, aldehyde, etc. generated from fruits and vegetables, a moisturizer or a hygroscopic agent to control the moisture content of the bag, or an oxygen scavenger or a carbon dioxide gas remover is more effective in maintaining freshness. There is. These auxiliary agents are usually used in the form of another bag inside the tray package of the present invention, but in some cases, the packaging material of the present invention is impregnated with a coat or blended in a resin layer, mixed as paper, etc. This method is also effective.

[0023]

In the sealed packaging, a packaging method known per se can be used. For example, a film formed in advance with a wide width can be cut into a predetermined size, and then a three-way seal can be performed while filling the contents with a horizontal pillow or vertical pillow packaging machine. Since a tray is used, filling and sealing can be performed at high speed even if the vegetables and fruits are spherical and have a poor sitting quality. Further, it is also possible to prepare a narrow tube-shaped film which is preliminarily adapted to the size of the tray and to fill it with the tray. Further, the film cut into a square or a rectangle may be used as a handkerchief to wrap it so that the tray is wrapped, and the ends can be sealed with a tape, a rubber band, or heat sealing. The hot plate seal,
Well-known means such as impulse seal and high-frequency seal can be used, and means such as tape, rubber band and string can also be used supplementarily. At the time of packaging, in addition to deaeration and removal of residual air in the packaging, a method of substituting with a gas having an appropriate composition is also effective in extending the freshness retention period of fruits and vegetables.

The movement of the gas generated between the atmosphere in the tray package and the outside air during storage of fruits and vegetables will be briefly described. Carbon dioxide gas CO ₂ generated by respiration of fruits and vegetables permeates the packaging film or the resin-coated paper and diffuses to the outside air.
On the other hand, oxygen O ₂ consumed by respiration of fruits and vegetables permeates the packaging film or the resin-coated paper from the outside air and enters the packaging body. Here, in order to form an atmosphere that keeps fruits and vegetables in a dormant state, the carbon dioxide gas in the package is diffused to the outside air as much as possible to reduce the existing amount, and the invading oxygen is controlled to control the existing amount. It is important to control the amount so that the minimum necessary breathing is performed.

Further, as another effect of using the packaging material of the present invention, since the packaging material of the present invention has high gas permeability and ethylene gas generated by fruits and vegetables is released to the outside very efficiently, gas permeability is improved. Even if a non-functional tray is used, the increase in the ethylene gas concentration inside the package is suppressed, and the effect of preventing the aging of fruits and vegetables is obtained.

The detailed operation and effects will be shown together with a comparative test in the section of Examples. By adjusting the atmosphere of the present invention, an extension of the fresh preservation days of 150% or more was recognized as compared with the conventional package. The packaging container of the present invention has a carbon dioxide permeability coefficient Pco ₂
Then, the ratio between the carbon dioxide gas permeation coefficient Pco ₂ and the oxygen permeation coefficient Po ₂ and the water vapor permeation coefficient PH ₂ O must all be in the numerical values within the specific range. This is explained in detail in the Examples section below.

The packaging material of the present invention is 0.914 g / cm.
^Since it contains a copolymer of ethylene and α-olefin having a relatively low density of ³ or less, it is excellent in bending workability, and even if bending work is performed during packaging of the tray, gas permeability and water vapor permeability are adversely affected. Does not occur. In addition, it has excellent pinhole resistance and stress cracking resistance, and even if it is packed closely on fruits and vegetables or trays, it will not stick to the edges of fruits and vegetables, cuts, sepals or flower axes, and corners and flange ends of trays. It can prevent pinholes and cracks from occurring. Further, as will be described later, when the inside of the package is decompressed, wrinkles are generated in the package, but pinholes and cracks can be prevented from occurring at that portion. The excellent action of the present invention is synergistically achieved by the posture-maintaining tray and the packaging material having the above characteristics.

Particularly, when a film is used as a packaging material, it has flexibility and flexibility. Therefore, when fruits and vegetables are placed in a tray and sealed and packed, carbon dioxide gas in the atmosphere is discharged to the outside due to the daily activities of the fruits and vegetables in the package. Then, a controlled amount of oxygen is supplied to the inside, the inside of the package is depressurized, the film adheres to the tray, and the self-fixing effect of fixing fruits and vegetables is exhibited. Although the detailed mechanism of decompression is unknown, carbon dioxide gas,
It is considered that the effect becomes more prominent because the amount of permeation of oxygen or nitrogen is different, especially because the present packaging material has a large permeation coefficient ratio. If the resin-coated paper is also a flexible paper, the same effect can be obtained. In this way, the fruits and vegetables are self-fixed and are not displaced or damaged in the package during handling such as transportation, and the packaging appearance is not spoiled by being biased to one side of the tray. In the case of normal packaging, it takes time for the reduced pressure and the fixed state to occur, and the time also varies depending on the kind and amount of the contents or the capacity of the package. Therefore, in order to more positively obtain the predetermined fixed state, degassing packaging may be performed. Since the packaging material used here has a high carbon dioxide permeability coefficient and a relatively high permeability coefficient ratio necessary for appropriate oxygen permeation, even when degassed and packed, the gas emission and decompression due to the daily activities of fruits and vegetables are performed, Self-fixation proceeds. Since excess oxygen, ethylene, etc. in the package can be removed by degassing, a better storage environment can be achieved than immediately after packaging, and the storage period can be further extended. In addition, although the detailed physiological characteristics are unknown, the rapid decrease in oxygen partial pressure and the increase in carbon dioxide partial pressure have the effect of further promoting the dormancy of fruits and vegetables. Further, the posture maintaining property of the tray also prevents the package from being deformed and the fruits and vegetables from being deformed.

[Example 1] First, the evaluation of the permeation characteristics of gas and water vapor at 27 ° C of the resin-coated paper used in the following examples will be described. (1) For gas permeability measurement, a mixed gas permeability measuring device (LYSSY GPM-20) using commercially available gas chromatography as a detector.
0) was used. Carbon dioxide gas and air were flowed to the inflow side of the film at normal pressure at a volume ratio of 1: 4, and helium gas was used as the carrier gas on the exhaust side, and the gas composition on the exhaust side was measured moment by moment. Correct the gas count of the gas with a calibration curve created in advance, calculate the permeation amount at each time, calculate the slope by the least squares method from those points, and consider the thickness of the film used and the effective area of the permeation cell. Permeability coefficient Pco ₂ , Po ₂ (cm ³ (STP) cm
⁻² cm ⁻¹ s ⁻¹ cmHg ⁻¹ ) was calculated. Also,
The transmission coefficient ratio Pco ₂ / Po ₂ was obtained from these two values. Both measurements were performed at 27 ° C in the transmission cell and chamber.
Was kept constant. (2) Water vapor permeability The commercially available water vapor permeability tester (LYSSY L
80-4000 type) and 25 as a standard sample
A biaxially stretched polyethylene terephthalate film having a thickness of μm was used by measuring the moisture permeability in advance by the cup method. According to this method, the water vapor permeability is g / (m ² · da
It is calculated in units of y). Therefore, here, from this measured value, the film thickness and the water vapor pressure at 27 ° C. (2.67
cm Hg), cm ³ (STP) cm / (cm ²
・ S · cmHg) converted into a unit and used as an index of water vapor permeability of the film or coated paper. For example, the thickness is 20μ
In the case of a film or coated paper having a transmittance of 50 g / (m ² · day) at m, it is 54 × 10 ⁻⁹ cm ³ (S
TP) cm / (cm ² · S · cmHg). The width, length, and height dimensions are each about 5 cm,
Pulp and polyethylene pulp mixed paper with 20 cm and 1.5 cm, which has spherical dents suitable for fixing the positions of three spherical fruits and vegetables (on a thermoforming tray using a basis weight of 450 g / m ² , a caps immediately after harvest) 3 for each (75 to 90
g) Ultra low density LLDPE (density 0.905 g / c) aligned and then composed of ethylene and butene-1 copolymer
c) and an ethylene-hexene-1 copolymer LLD
The film having a thickness of 50 μm and made of a 70:30 blend of PE (0.917 g / cc) was hermetically packaged using a horizontal pillow automatic packaging machine. In the present invention 1, the film is stretched at the time of center sealing in order to fix the position of the cabos on the tray during packaging (method A). In the invention 2, in addition to the method A, some degassing is applied to the film. Somehow closely fixed to the product (method B)
2 types were created. Further, for comparison, Comparative Example 1 was prepared by using only horizontal pillow packaging without using a tray. The effective surface area of these sealed film packaging bags is estimated to be 575 cm ² (width 2
3 cm × 25 cm in length). The carbon dioxide permeation coefficient Pco ₂ at 27 ° C. of this film is 30 × 10.
^-10 cm ³ (STP) cm / (cm ² · S · cmH
g), the transmission coefficient ratio Pco ₂ / Po ₂ is 5.2, and the water vapor transmission coefficient is 25 × 10 ⁻⁹ cm ³ (STP) cm / (cm
² · S · cmHg). Under each condition, 100 packaging bags were made, and each 25 bags were packed in an ordinary cardboard box and transported by truck for about 1000 km by mixed loading, and then stored at room temperature for 1 month to maintain the quality of Cabos. evaluated. The appearance characteristics of kabos are yellowing at 300 pcs each,
The number of occurrences of browning and rotting, the number of bags that were in a degassed state, and those that were not degassed were inspected for defects under reduced pressure in water, and the number of pinholes, etc. was confirmed. The results are shown in Table 1.

[0030]

[Table 1]

The film used here has a large permeability coefficient ratio Pco ₂ / Po ₂ in addition to a relatively high carbon dioxide gas permeability, so that when the crops that carry out the respiratory action are hermetically packaged, the gas inside will naturally occur. It has the feature of being lost and shrinking. When the tray of Comparative Example 1 was not used, there were many bags that did not show a degassing state, and as a result of the inspection, the sharp cut edge etc. broke through the film due to the swaying of the cabos in the bag during transportation. Was the majority. Due to the defect of the film, the atmosphere in the bag was not sufficiently controlled, and many outer coats were yellowed after one month of storage. In addition, it was often observed that the peels were damaged by the vibration during transportation, and the peels were browned due to the bruises, and further putrefaction. On the other hand, by using the tray (inventions 1 and 2), the contents can be self-fixed sufficiently during transportation, so that the occurrence of bag defects can be suppressed to a low level, and damage to crops can be prevented. We were able to fully demonstrate the original packaging function. The method B, in which the bag was slightly deaerated, generally showed good preservability, probably because the crops were sufficiently fixed.

[Example 2] The present invention 3. Approximately 140 g of fresh shiitake mushrooms immediately after harvesting are placed in polyethylene trays with width, length, and height of 10 cm, 15 cm, and 2.5 cm, respectively.
(7-8 pieces) Umbrellas are lined up, and ultra-low density LLDPE (density 0.900 g) made of ethylene and butene 1 copolymer
/ Cc) and ethylene, hexene 1 copolymer of ultra low density LLDPE (density 0.910 g / cc) 60: 4
Horizontal pillow packaging was performed using a film having a thickness of 30 μm, which is a blend of No. 0. The surface area of this package excluding the seal part was 520 cm ² . On the other hand, Comparative Example 2 for comparison. Using the same tray, a polybutadiene-based stretch film having a thickness of 25 μm was used for packaging by an automatic stretch film packaging machine, and Comparative Example 3. Further thickness 30μ
m LLDPE-based shrink film (density 0.932
g / cc) was used for pillow type heat sealing, and then shrink packaging. Table 2 shows the transmission characteristics and test results of these films at 27 ° C.

[0033]

[Table 2]

* Pco ₂ × 10 ¹⁰ cm ³ (STP) cm / (cm ² · S · cmHg) ** PH ₂ O × 10 ⁹ cm ³ (STP) cm / (cm ² · S · cmHg) 90 pieces each The packaging was prepared, 30 pieces of each were packed in corrugated board, and transported by truck for about 1000 km by mixed flight. It took about 2 days for transportation, but at this point, there is a particular problem in any of the above packaging forms. There was no change in the contents. Next, these packages were stored at room temperature (18 to 25 ° C., 60 to 80% RH), and the umbrella was blackened, softened and decayed, and the weight loss rate (average) was evaluated as a storage state for 6 days after harvesting. In Comparative Example 2, since the film has high gas permeability and water vapor permeability and incomplete sealing, breathing similar to unpackaged is performed, blackening of the umbrella progresses, and many molds are observed. Due to the significant evaporation of water, the stalk was conspicuously dried and hardened, and the weight was greatly reduced, making it difficult to maintain the quality. Further, in Comparative Example 3, since the film has small oxygen permeability and insufficient carbon dioxide permeation, the inside of the bag is in an oxygen-deficient state, and the flesh is softened and a lot of spoilage occurs with atelectasis, Generation of offensive odor due to decomposed components was remarkable, and quality deterioration was noticeable. On the other hand, in the present invention 3, since the gas permeability that can suppress the respiration of the crop to some extent is secured, although a slight defect due to the original variation of the crop has occurred, a black discoloration that deteriorates the commercialability and No softening or decay,
The weight loss was suppressed to a low level, and the stem was not hardened, and the tensioned state could be sufficiently maintained.

[Embodiment 3] Width, length, and height are 11 cm, 22 cm, and 3.5 cm, respectively.
After placing 18 Oume (variety: Minamitakaume) pre-cooled for 8 hours in a pre-cooling box at 10 ° C after harvesting on a polyethylene vacuum forming tray with partitions divided into 6 = 18 pieces, this tray was placed. Layered in two, thickness 35 with different permeability
Horizontal pillow packaging was performed using a film of μm.
The type of film used for packaging and gas permeation characteristics are shown.
The present invention 4 uses a 70:30 blend film of ethylene / butene-1 copolymer (ρ = 0.905) and ethylene / vinyl acetate copolymer (VA 15%) as a film, and Pco ₂ = 56 × 10 ^-10 cm ³ (STP)
cm / (cm ² · S · cmHg) (hereinafter PCo ₂ is expressed in this unit), Pco ₂ / Po ₂ = 5.1, PH ₂ O
= 54 × 10 ⁻⁹ cm ³ (STP) cm / (cm ² · S
-CmHg) (hereinafter, PH ₂ O is expressed in this unit). Comparative Example 4 used the same film as Invention 4 but did not use a tray. In the present invention 5, an ethylene / hexene-1 copolymer (ρ = 0.912) and an ethylene-4-methylpentene-1 copolymer (ρ = 0.12) were used as films.
908) using a 60:40 blend film,
Pco ₂ = 25, Pc1 ₂ / Po ₂ = 4.6, PH ₂ O
= 23.0. Invention 6 uses a 60:40 blend film of ethylene / octene-1 copolymer (ρ = 0.914) and hydrogenated styrene / butadiene block copolymer (styrene content 60%) as the film, Pco ₂ = 18, Pco ₂ / Po ₂ = 4.3, PH
₂ O = 32. Comparative Example 5 uses a biaxially oriented polypropylene film, Pco ₂ = 8.5, Pco ₂ / P
o ₂ = 4.0 and PH ₂ O = 15.0. Comparative Example 6
Is an ethylene / butene-1 copolymer (ρ =
0.918), Pco ₂ = 14, Pco ₂ / P
o ₂ = 3.8 and PH ₂ O = 13. Comparative Example 7 uses a poly-4-methylpentene-1 polymer film and P
co ₂ = 85, Pco ₂ / Po ₂ = 3.3, PH ₂ O =
31. Comparative Example 8 uses an ethylene / butene-1 copolymer (ρ = 0.920) containing 50 PHR of aluminosilicate having an average particle size of 5 μm, and Pco ₂ = 148 and Pco ₂ = 148.
co ₂ / Po ₂ = 0.9 and PH ₂ O = 68. Comparative Example 9 is an ethylene / vinyl acetate copolymer (VA 15%)
Using a film, Pco ₂ = 42, Pco ₂ / Po ₂
= 4.7, PH ₂ O = 90. Table 3 shows the test results.

[0036]

[Table 3]

The effective surface area of these hermetically sealed film packaging bags is 1221 / cm ² (width 3
7 cm x 33 cm in length, and the content of Ome was about 1 kg. These packages were packed in 2 rows x 3 rows x 2 layers in a total of 12 packs in a corrugated cardboard box and shipped by truck in 2 days. I did. In addition, in order to see the effect of this transportation, 36 Ome hermetically packed in a flat bag having the same effective surface area was placed in a cardboard box and transported in the same manner. Each condition was subjected to a test of 48 packs, half of which was 24 packs (total 864
The individual pieces) were opened at the end of transportation, left standing in a 65% RH atmosphere at room temperature for 3 days, and then subjected to visual inspection. The remaining 2
4 packs (total of 864 pieces) were left at room temperature for 4 days (6 days after harvest), opened, and quality evaluated at this point, and then left at room temperature in 65% RH atmosphere for 3 days, and then visually inspected again. I did. The evaluation results are mainly bruise and scratches for damage during transportation, yellowing, browning, and pitting weight reduction rate for storage stability (only when opened).
Was expressed as a defective occurrence rate (%) with respect to the total number of Ome tests. When the tray of Comparative Example 4 was not used, a lot of bruise and scratches were observed due to the boxing work and transportation. Imperfections were not so clear immediately after transportation, but when peeled and left at room temperature for 3 days, the bruise of the peel was The scratches are noticeable. In some cases, the bruise softened and turned brown. This defect became more prominent when stored at room temperature for 4 days after transportation. On the other hand, the present invention 4 using a tray shows almost no defects due to transportation and the like, and is good even after 6 days have passed since harvesting, and yellowing progresses when left at room temperature for 3 days after opening. However, since there were few scratches and bruises on the skin, the whole skin was uniformly yellowed and a good appearance was maintained. The permeation characteristics of the film used for packaging had a significant effect on the storage stability of Ome such as yellowing, browning and pitting. In Comparative Examples 5 and 6 in which the carbon dioxide permeability coefficient is smaller than the claimed range of the present invention, browning and pitting often occur. Browning and pitting tended to become more apparent when left at room temperature after opening than immediately after opening, and the smaller the carbon dioxide permeation coefficient, the greater the effect of carbon dioxide damage and the more browning and pitting occurred. On the other hand, in Comparative Examples 7 and 8 in which the carbon dioxide permeability coefficient is large, but the permeability coefficient ratio is small, the supply of oxygen becomes excessive and the respiration control by the packaging is insufficient, so that the yellowness of the flesh is 6 days after harvesting. There were many changes. This tendency was more remarkable as in the case of the porous film of Comparative Example 8. Also, in the case of Ome, the weight loss due to the evaporation of water is not so remarkable when it is stored for a relatively short period of time, but as shown in Comparative Example 9, when the weight loss at the opening stage exceeds a certain level, it is opened. Since the patient was left to stand at room temperature afterwards, his breathing was rapidly recovered, and a large number of wilts tended to occur. Therefore, in the case of Ome, the carbon dioxide permeability coefficient must be above a certain level in order to prevent carbon dioxide damage, and in order to prevent yellowing, the permeability coefficient ratio should be kept to the minimum necessary. The water vapor permeability coefficient needs to be a certain value or more, and further, the water vapor permeability coefficient needs to be a certain value or less from the viewpoint of suppressing water evaporation and preventing wilting, and only when satisfying all of these characteristics, as in the present inventions 4 to 6, Good preservation became possible.

[Example 4] With respect to the packaging form of the method B in Example 1, long-term storage of kabos after harvesting was performed using hinokitiol and bromine-added activated carbon as the freshness preservability improving agent. Then, after molding, the mixed solution was applied and impregnated on the mixed paper tray so as to be 5 mg / sheet.
Then, a non-woven small bag was filled with 3 g / bag, and it was attached to the back surface of the tray. According to Example 1, 100 bags of each packaging form were evaluated for storage conditions at room temperature for 1.5 months and after 2 months. The results are shown in Table 4.

[0039]

[Table 4]

As shown in Example 1, when the packaging form of the present invention was adopted, it was possible to maintain the almost complete appearance of the Cabos after storage for one month at room temperature after harvesting. When stored for a longer period of time, yellowing started to occur in the 1.5-month group, and some rotting fruit also occurred, and in the 2-month group, almost half became yellow and the rotting fruit increased. On the other hand, when hinokitiol was used, it did not show a remarkable effect in preventing yellowing, but it showed an effect in suppressing the occurrence of rotting fruit, while a bromine-added activated carbon, on the contrary, was effective in suppressing yellowing. showed that.
By adopting the packaging form of the present invention, the occurrence of defects at the time of distribution can be minimized, and long-term preservability can be improved by suppressing the gas atmosphere according to the respiration of fruits and vegetables,
Furthermore, the combined use of the agents shown in this example makes it possible to further suppress the influence of variations among individuals having individual organisms.

Example 5 As a packaging material, the basis weight is 50 g /
the light soy vellum of ^{m 2, LDPE (ρ = 0.919} ) and very low density LLDPE (C4, ρ = 0.905) of 50: 5
A blend of 0 was extruded and laminated so that the coating film thickness was 15 μm. The transparency of this coated paper is P
co ₂ : 15.6 × 10 ⁻¹⁰ cm ³ (STP) cm /
(Cm ² · S · cmHg), Pco ₂ / Po ₂ : 3.
7, PH20: 13.2 × 10 ⁻⁹ cm ³ (STP) c
It was m / (cm ² · S · cmHg). Adhere the three sides with this coated paper to make a bag with dimensions, length 280 mm and width 120 mm, place the cabos on a polystyrene foam tray and store it in the bag, and after degassing, wrap the bag mouth with adhesive tape. I sealed it. When these 500 packages were stored at 5 ° C. for 3 months, the non-defective product ratio was 98.6%, which was extremely good although there was a defective product due to a scratch on the peel at some harvesting.
Next, pack this package in cardboard boxes at a rate of 10 kg, and
After transporting by 000km truck mixed loading flight and storing at room temperature for 2 weeks assuming distribution conditions, there is no defect such as pinholes in the packaging and the green color of the kabos can be maintained sufficiently to maintain freshness. The effect was recognized.

[0042]

According to the present invention, fruits and vegetables can be kept in a dormant state and can be stored in a fresh state for a long time without being deformed or damaged by being self-fixed to a posture maintaining tray.

Claims (6)

[Claims] 1. (A) a tray having a constant shape;
(B) The tray is sealed and packaged (a) Density of ethylene and α-olefin having 3 to 12 carbon atoms is 0.914 g / cm 3.
^It contains a copolymer of ³ or less and has a carbon dioxide gas permeability coefficient of 15 × 10 ⁻¹⁰ cm ³ (STP) cm / (cm ² at 27 ° C.
・ S · cmHg) or more, the transmission coefficient ratio Pco ₂ / Po ₂
Is 3.5 or more and the water vapor transmission coefficient is 80 × 10 ⁻⁹ c
m ₃ (STP) cm / (cm ² · S · cmHg) or less resin film, (b) ethylene and 3 to 12 carbon atoms
Containing a copolymer having a density of 0.914 g / cm ³ or less with an α-olefin and having a carbon dioxide gas permeability coefficient at 27 ° C. of 15
× 10 ⁻¹⁰ cm ³ (STP) cm / (cm ² · S · c
mHg) or more, the transmission coefficient ratio Pco ₂ / Po ₂ is 3.5.
And above, the water vapor transmission coefficient is 80 × 10 ⁻⁹ cm ₃ (S
TP) cm / (cm ² · S · cmHg) or less, at least one side of which is covered with a packaging material selected from wrapping paper with a resin layer coated on at least one side thereof. A fresh preservation method for fruits and vegetables, characterized in that the atmosphere gas is adjusted by breathing to reduce the pressure inside the container, and the packaging material is brought into close contact with the tray and the fruits and vegetables are fixed to the tray for packaging. 2. The method for preserving fruits and vegetables according to claim 1, wherein the gas in the container is degassed and then sealed, and then the residual gas is adjusted by breathing the fruits and vegetables. 3. The posture maintaining tray according to claim 1, characterized in that an unevenness tray for arranging at least a part of the stored items is fixed at the bottom. How to save fresh fruits and vegetables. 4. A tray having a fixed shape, and a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms and having a density of 0.914 g / cm ³ or less, which is hermetically packaged in the tray, at 27 ° C. Carbon dioxide permeability coefficient of 15 × 10 ⁻¹⁰ c
m ³ (STP) cm / (cm ² · S · cmHg) or more, the transmission coefficient ratio Pco ₂ / Po ₂ is 3.5 or more, and the water vapor transmission coefficient is 80 × 10 ⁻⁹ cm ³ (STP) cm /
A fresh preservation container for fruits and vegetables, which is composed of a resin film of (cm ² · S · cmHg) or less. 5. A tray having a constant shape and a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms and having a density of 0.914 g / cm ³ or less, which is hermetically sealed and packaged, are contained at 27 ° C. Carbon dioxide permeability coefficient of 15 × 10 ⁻¹⁰ c
m ³ (STP) cm / (cm ² · S · cmHg) or more, the permeability coefficient ratio Pco ₂ / Po ₂ is 3.5 or more, and the water vapor permeability coefficient is 80 × 10 ⁻⁹ cm ³ (STP) cm /
A fresh preservation container for fruits and vegetables, which comprises a wrapping paper having at least one surface coated with a resin layer having a size of (cm ² · S · cmHg) or less. 6. The fresh preservation of fruits and vegetables according to claim 4 or 5, wherein the tray having a fixed shape is a posture-maintaining tray in which a concave and convex portion for receiving and fixing at least a part of a stored item is arranged at the bottom. container.