JP2001025358A - Storage of fresh vegetable food and storage container therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fresh vegetable foods from deteriorating, for example, dropping off fruit granules, drying back of fruit bunch, change to morbid states, overripe, and the like, occurring during the storage and maintain the value of commodity by containing vegetable fresh foods in a vessel of a specific structure in the presence of zeolite, and the like inside a refrigerator under specific conditions. SOLUTION: A container 1 that is surrounded with a thermally insulating material so as to cause no air flow between the inside and the outside of the vessel and is equipped with a window 2 in which air is tightly sealed in a space surrounded with 2 or more plates of high thermal conductivity or a container 1 that has a window made of a thermally conductive layer with the conductivity of 1×10-3 to 1.5×10-2 cal/deg/sec/cm2 is used for storage. Fresh vegetable foods, for example, grape, melon, or the like, are placed in the container 1 together with zeolite or a porous stone, for example, Oya-ishi (Pumice tuff) and the container is stored in a refrigerator kept at -2 deg.C <= the average temperature or the midpoint temperature <=4 deg.C. In a preferred embodiment, this container is equipped with a partition wall 3 so that the wall 3 may separate the above space in the window 2 into a space contacting with the outside plate and a space contacting with the inside plate of the window.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for storing fresh vegetable foods and a food storage container, and more particularly to a method for low-temperature storage of these foods with little deterioration such as withering, shedding and lesions, and a food storage container suitable for the method.

[0002]

2. Description of the Related Art Cold storage of fresh fruit can be stored for a considerably long time depending on the kind of fruit. For example, apples can be stored for 5-6 months, and pears (La France) for 2-3 months. However, the fruits that can be stored for such a long time are limited.

[0003] In addition to the above-mentioned fruits, low-temperature storage has been attempted. By refrigerated grapes at a low temperature of about 2 ℃,
Varieties with good storage properties, such as the "Stuben" variety, can be stored for up to about 4 months. By refrigeration at a lower temperature (about −2 ° C.), “Kyoho” varieties can be stored for about 6 weeks without spoilage.

[0004]

However, after such storage, the taste and appearance of the grape grains themselves are not significantly degraded, but the fall of the grains (dropping) increases, and the branches become brown. For varieties that wither and have a high sense of quality, their commercial value is significantly reduced in appearance.

[0005] Mask melons are scarce during peak demand.
Although it is expensive, refrigeration at 5 ° C. is limited to two weeks of storage, even if you try to make bulk purchases in preparation for peak demand. At around 0 ° C, storage for more than 2 weeks is possible,
If stored at room temperature for more than 3 days after refrigeration, depression disease will occur and the commercial value will be lost. In addition, ripening progresses considerably during storage.

It is an object of the present invention to realize a method for refrigerated storage of fresh vegetable foods in which quality deterioration due to storage such as falling off of grains, bunch of bunches, lesions, overripening and the like is prevented.

[0007] Another object of the present invention is to provide a food storage container suitable for refrigerated storage of fresh vegetable foods, which can prevent deterioration in quality such as dropping of grains, wiping of fruit clusters, lesion of fruits and overripening. It is to realize.

[0008]

According to the present invention, in order to achieve the above object, at least two thermal conductors are surrounded by a wall of a heat insulating material to the extent that there is no air flow to the outside and on the side or upper part. Vegetable fresh food is stored in the presence of zeolite or Otani stone in a container having a window consisting of a board and a space between them, and the container has an average temperature or a midpoint temperature of less than 4 ° C., −2 ° C. or more. Store in refrigerator.

For the same purpose, the wall of the heat insulating material is surrounded to such an extent that there is no air flow to the outside, and 1 cm
Per 1 × ^{10 -3} not per ² to 1.5 × ¹⁰ -2 ca
a container having a window made of a layer having a thermal conductivity of 1 / deg, containing a vegetable-based fresh food in the coexistence of zeolite or Otani stone, and having the container having an average temperature or a midpoint temperature of less than 4 ° C;
This is achieved by storing in a refrigerator at -2 ° C or higher.

A second object of the present invention is to provide a heat insulating material which is surrounded by a wall made of a heat insulating material to the extent that there is no air flow to the outside, and which has at least two heat conductive plates and a space between them on the side or upper part. This was achieved by a food storage container, characterized by having a window consisting of a zeolite or valley stone therein. 1 × 10 ⁻³ per second per cm ^{2 on} side or top
To having a window consisting of a layer having a thermal conductivity of 1.5 × 10 -2 ^{cal /} deg, even by the container surrounded by walls of thermal insulating material, the same purpose is achieved.

The heat insulating material of the container wall is, for example, expanded polystyrene, expanded polyethylene, expanded polyurethane, moisture-proof cardboard, plastic cardboard. Simply cardboard (paper) is not suitable for the following reasons.

[0012] The degree of no airflow to the outside means that the container does not necessarily have to be airtight, but the container is kept at room temperature after refrigeration.
When exposed to the atmosphere of high humidity (for example, 75% or more)
The food in the container must be able to be closed and moisture-proof so that condensation does not occur.

The container may be on the side or top, preferably on the top,
It has a window, which consists of at least two plates of a good conductor, such as metal, and a closed space between them. The space is surrounded (possibly indirectly) by the insulating walls of the container itself. Preferred thermal conductors are metals, for example,
Copper, copper alloy, aluminum, aluminum alloy and stainless steel. The space may be filled with air, or may be evacuated or evacuated.

[0014] In the space between the plates of the thermal conductor, it is preferable to provide a partition which divides this space into a section in contact with the plate facing the outside of the container and a section in contact with the plate facing the inside of the container. The partition may be made of a good heat conductor such as metal, but is preferably made of a material having low heat conductivity such as paper or wood. However, since the transfer of heat must not be significantly impeded, its thickness should be at most about 1 mm. Each compartment need not be the same volume or shape, and the partitions need not be parallel to the inner or outer plates. The partitions need not seal the compartments on both sides, it is sufficient to prevent convection of air between the compartments.

The coexistence of zeolite or Otani stone is effective not only during refrigeration but also particularly for maintaining freshness (prevention of lesions, etc.) during temperature rise after refrigeration, and zeolite is particularly effective. Zeolite or Oya stone is a gas permeable film,
It may be stored in a bag, box, or the like made of cloth, nonwoven fabric, paper, or the like.
The amount of zeolite or valley stone used in the container is such that a sufficient effect of maintaining freshness can be obtained (for example, 0.5 kg per kilogram of food).

The storage temperature includes not only a temperature range of 0 ° C. or more but less than 4 ° C., but also a temperature range of less than 0 ° C. and higher than a freezing temperature. In the latter temperature zone, the period of time that can be stored without deterioration such as grain shattering and branch dying becomes long. By using the storage container of the present invention, even in an electric refrigerator utilizing the vaporization of a compressed refrigerant, even if the average temperature is lower than 0 ° C., freezing due to temperature fluctuations caused by the intermittent operation of the refrigerator does not occur, and the plant-based fresh Food can be stored.

[0017] sides or top, 1 cm ² per second 1 ×
When using a container having a window made of a layer having a thermal conductivity of 10 ⁻³ to 1.5 × 10 ⁻² cal / deg, the thermal conductivity is 1.5 × 10 ⁻³ to 1 / cm ² per second.
It is preferably × 10 ⁻² cal / deg. Such thermal conductivity is obtained by a hard vinyl chloride resin layer having a thickness of 1 mm, for example.

[0018]

FIG. 1 shows an embodiment of the present invention. The container 1 is a container of styrofoam resin, a window 2 is provided in a lid 1 a of the container 1, and an aluminum foil 2 is provided outside the window 2.
a, an aluminum foil 2b is stretched on the inside, and a paper partition wall 3 is provided therebetween. At the bottom of the container 1 is placed a flat nonwoven bag 5 packed with granular zeolite. The fruit 4 is stored in the container 1. In the container 1, cups 6 and 7 are placed in addition to the bag 5, and the cups 6 and 7, respectively,
Moisturizing liquid 6a (15% by volume propylene glycol aqueous solution)
And a preservative 7a (ethanol). Container 1
With the contents in an electric refrigerator.

FIG. 2 shows another embodiment of the present invention. The container 11 is a container of styrofoam resin,
A window 12 is provided at 1a, and a hard vinyl chloride resin plate 12a having a thickness of 1 mm is stretched over the window 12. At the bottom of the container 11, a flat bag 5 of nonwoven fabric packed with granular zeolite is placed. The fruit 4 is stored in the container 11.
The container 11 is provided with a cup 6 in addition to the bag 5.
Contains a moisturizing solution 6a (15% by volume propylene glycol aqueous solution). The container 11 is stored in the electric refrigerator together with the contents.

[0020]

[Example 1] 2 cm thick container 1 shown in FIG.
The temperature sensor of the temperature recorder was inserted into the container 1 using the Styrofoam resin box. The midpoint temperature of the entire storage container is-
It was housed in an electric refrigerator at 0.5 ° C., and another temperature sensor of a temperature recorder was also inserted near the container in the electric refrigerator.

After the temperature in the electric refrigerator is stabilized, the container 1
The temperature inside and outside was continuously recorded for 3 hours. The results were as follows.

The temperature in the electric refrigerator fluctuates in a range close to 6 ° C., but the fluctuation in the temperature in the container 1 is about 3 ° C., which is half of the range. Even if the temperature outside the container can drop below -3 ° C,
The temperature inside the container remained around -1 ° C.

A muskmelon as a fruit 4 was placed in a container 1 (a 2 cm thick styrofoam resin box). The container 1 was stored together with the contents in an electric refrigerator at a midpoint temperature of about -0.5 ° C and stored for 4 weeks.

After the completion of refrigeration, the container 1 was taken out of the electric refrigerator and left in the atmosphere for 48 hours. The melon was taken out of the container 1 and left in the atmosphere for 4 days. There were no abnormalities in the fruit and the ripeness was appropriate.

[Example 2] Oya stone powder was used in place of zeolite in Example 1. The ripeness was more advanced than in Example 1, but there were no other abnormalities.

Example 3 In Example 1, instead of muskmelon, grapevine was placed in a container 1 and stored in an electric refrigerator having a midpoint temperature of about -1.5 ° C. and stored for 40 days.

After the completion of refrigeration, the container 1 was taken out of the electric refrigerator and left in the atmosphere for 24 hours. After storage, the grapes are full of berries,
The taste was not degraded, and the branches of the cluster remained green.

[0028]

According to the present invention, there is provided a window which is surrounded by a wall of a heat insulating material to the extent that there is no air flow to the outside, and is formed of at least two heat conductive conductors and a closed space therebetween. By storing fresh vegetable foods such as fruits in a container having a window with thermal conductivity in the presence of zeolite (or Oyaishi) at a temperature not freezing below 4 ° C, the storage period can be kept without deterioration. Can be extended significantly. In particular, the use of the container of the present invention can prevent dew condensation after the completion of refrigeration even for large-sized ones such as melon, so that lesions related to dew condensation can be avoided.

In general, fruits have a short harvesting period and are quickly degraded, so that the sales duration of the same variety is short, but the sales duration can be extended by extending the storage period. The present invention grape, fruits such as cherries, fruits and vegetables such as melon,
The present invention can be generally applied to fresh vegetable foods such as fruit and vegetables such as watermelon and cannabis such as broccoli, celery and asparagus.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a storage method and a storage container of the present invention.

FIG. 2 is an explanatory view showing a storage method and a storage container of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 1a Lid 2 Window 2a, 2b Aluminum foil 3 Partition wall 4 Fruit 5 Bag 6 Cup 6a Moisturizing liquid 7 Cup 7a Antiseptic liquid 11 Container 11a Lid 12 Window 12a Hard vinyl chloride resin plate

Claims (12)

[Claims] 1. A window which is surrounded by a wall of a heat-insulating material to such an extent that there is no airflow to the outside and which is formed on a side surface or an upper portion thereof with at least two heat conductive plates and a closed space therebetween. In a container having, in the coexistence of zeolite or Otani stone, house the plant-based fresh food, the average temperature or the midpoint temperature is less than 4 ° C, characterized by storing in a refrigerator of -2 ° C or more, How to store fresh vegetable foods. 2. The method according to claim 2, wherein said space has a partition dividing said space into a space in contact with said plate outside said window and a space in contact with said plate inside said window. 3. The method according to claim 1, wherein the food is stored in the container in the presence of zeolite. 4. The method according to claim 1, wherein the fresh vegetable food is a fruit or a fruit vegetable. 5. The method for storing fresh vegetable food according to claim 4, wherein said fresh vegetable food is grape or melon. 6. After storing the container in the refrigerator,
The method for storing fresh vegetable foods according to claim 1, wherein the fresh foods are stored outside the refrigerator for at least one day. 7. A wall made of a heat-insulating material, which is surrounded to such an extent that there is no air flow to the outside, and on the side or upper side, 1 × 10 ⁻³ to 1.5 × 10 ⁻² cal / deg / cm ² per second.
In a container having a window made of a layer having thermal conductivity of, containing fresh perishable food in the presence of zeolite or Otani stone, the container is heated at an average temperature or a midpoint temperature of less than 4 ° C and not less than -2 ° C. A method for storing plant-based fresh food, wherein the method is stored in a refrigerator. 8. The thermal conductivity of the layer is 1.5 × 10 ⁻³ to 1 × 10 ⁻² cal / deg / cm ² per second.
The method for storing a plant-based fresh food according to claim 7, which is: 9. A wall of heat-insulating material which is surrounded to such an extent that there is no air flow to the outside, and has a window on the side or upper side comprising at least two metal plates and a closed space therebetween. A food storage container for storing food in a refrigerator. 10. The food storage container according to claim 9, wherein said space has a partition dividing said space into a space in contact with said plate outside said window and a space in contact with said plate inside said window. 11. The food storage container according to claim 9, wherein the window is provided on an upper portion. 12. Surrounded by a wall of a heat insulating material to such an extent that there is no air flow to the outside, and on the side surface or upper portion, 1 × 10 ⁻³ to 1.5 × 10 ⁻² cal / de / cm ² per second.
A food storage container for storing food in a refrigerator, characterized by having a window consisting of a layer having a thermal conductivity in the range of g.