JPH119186A - Preservation of perishable food - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily preserve a perishable food for a long period while retaining its freshness, flavor and surface color, by maintaining the dissolved oxygen content of the immersion water in a preservative container at a given level. SOLUTION: In a method of preserving a perishable food comprising the immersion of the food in the water reserved in a preservative container, the dissolved oxygen content of the water is maintained at 3-12 ppm by feeding the water with oxygen through injecting an oxygen-contg. gas into the water, or by replenishing the water with oxygen-dissolved water; wherein, the temperature of the water is pref. <=5 deg.C, and further, the water may contain a preservative and/or a flavoring agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of preserving fresh food, and more particularly to a method of preserving fresh oxygen by maintaining a constant amount of dissolved oxygen in water stored in a storage container in which fresh food is immersed. A method for storing food.

[0002]

2. Description of the Related Art After harvesting, fresh foods go from a mature state to a mature state to an aged state, and eventually rot. It is known that this phenomenon is caused by the respiratory action and the action of producing ethylene during fresh food.

Conventionally, in order to prevent such spoilage, methods of preserving fresh food include (1) a cold storage method of subjecting fresh food to a low temperature to reduce the respiratory action of the fresh food, and (2)
Packaging fresh food with water-impermeable ethylene adsorption film,
A film packaging method that absorbs generated ethylene and prevents water from evaporating from fresh food, (3) CA storage method that stores fresh food under high carbon dioxide and low oxygen conditions,
(4) Fresh foods are stored under reduced pressure, and reduced oxygen partial pressure is used to suppress respiration of fresh foods and reduce the concentration of ethylene under reduced pressure.

However, in the cold storage method (1), the period during which fresh food can be stored is at most one month, and this method is not suitable for long-term storage. Therefore, it is considered that fresh food is stored for a long time by freezing, but in this case, the quality of the fresh food is maintained, but when the fresh food is thawed, its tissue softens, freshness, There is a disadvantage that the flavor and the like are significantly reduced.

In the film packaging method of (2), when the amount of ethylene adsorbed on the film reaches a saturation level, not only does the perishable food easily become spoiled, but also if the film for packaging the perishable food breaks. Fresh food will quickly rot. Further, since it is necessary to package the film according to the shape of the fresh food, there is a disadvantage that it takes time and effort.

[0006] In the CA storage method of (3), it is difficult to adjust the environment for storing fresh foods to a high carbon dioxide and low oxygen state. It has the disadvantage that it requires equipment and can be costly.

In the reduced pressure storage method (4), it is difficult to lower the oxygen partial pressure and the ethylene concentration similarly to the CA storage method (3). This has the drawback that a large-scale device may be required in order to do so.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to easily maintain freshness, flavor, surface color and the like of fresh foods. The purpose is to preserve fresh food for a long time.

[0009]

[Means for Solving the Problems]

(Claim 1) In order to solve the above-mentioned problems, a method for preserving fresh food according to the present invention includes a method for preserving fresh food by immersing the fresh food in water stored in a storage container. The amount of dissolved oxygen of is maintained at 3 ppm or more and 12 ppm or less.

If the amount of dissolved oxygen in the water stored in the storage container is less than 3 ppm, the oxygen required to maintain the tissue of the fresh food is insufficient, and the tissue of the fresh food is necrotic. In addition, the quality of perishable foods is degraded and spoiled.
On the other hand, the dissolved oxygen content of water stored in the storage container is 12 ppm
If the amount exceeds the oxygen amount, the amount of oxygen becomes excessive, so that the speed of perishing of the fresh food from the mature state to the aged state through the ripe state and finally decay becomes faster, resulting in deterioration of the quality of the fresh food, decay, etc. .

The amount of dissolved oxygen in the water stored in the storage container may be 3 ppm or more and 12 ppm or less.
It is preferable that it is 5 ppm or more and less than 8 ppm.

(Claims 2 and 3) As a means for maintaining the dissolved oxygen amount of the water stored in the storage container at 3 ppm or more and 12 ppm or less, an oxygen-containing gas is passed through the water and the water stored in the storage container is charged with oxygen. And a means for replenishing the storage container with water in which oxygen is dissolved. The means for supplying oxygen to the water stored in the storage container through oxygen-containing gas is preferable, and the means for passing the oxygen-containing gas to the water stored in the storage container includes bubbling the water with the oxygen-containing gas. Is preferred. When bubbling the water stored in the storage container with the oxygen-containing gas, the fresh food is immersed in order to prevent the bubbles generated by the bubbling from contacting the fresh food and preventing the fresh food from being oxidized by oxygen in the bubbles. It is preferably carried out in a container different from the storage container in which the water is exchanged in connection with the storage container.

When the storage container is provided with a means for replenishing water in which oxygen is dissolved, the replenishment of water in which oxygen is dissolved may be continuous or intermittent. When replenishing water, the water in the storage container may be drained immediately before replenishment.

The oxygen-containing gas is not particularly restricted but includes, for example, air.

(Claim 4) The water used in the present invention is not particularly limited, and examples thereof include tap water and deionized water. Further, ultra-low temperature water that maintains a liquid state even at 0 ° C. or lower may be used. The temperature of the water stored in the storage container may be any temperature as long as it does not adversely affect the amount of dissolved oxygen in the water to be maintained at 3 ppm or more and 12 ppm or less. 3ppm dissolved oxygen
The temperature is preferably 5 ° C. or lower from the viewpoint that it can be easily maintained at 12 ppm or lower and the respiratory rate of the fruit can be further suppressed.

The amount of water stored in the storage container is not particularly limited, but when the weight of the water used in the present invention is less than the weight of the fruit, the water stored in the storage container by respiration of the fruit. When the dissolved oxygen is consumed, the amount of dissolved oxygen in the water stored in the storage container tends to be less than 3 ppm.

(Claim 5) The water stored in the storage container may optionally contain a preservative. Such preservatives are not particularly limited, for example, benzoic acid,
Examples include sodium benzoate, sorbic acid, sodium sorbate, dehydroacetic acid, sodium dehydroacetate and the like.

(Claim 6) The water stored in the storage container contains, if necessary, additives such as a flavoring agent, a seasoning, an ethylene production inhibitor, a respiratory inhibitor, a pH adjuster, and a softening inhibitor. obtain. As the flavoring agent, the same component as the scent component of the preserved fresh food is preferable. More preferably, a saturated amount of flavoring is used. As such a flavoring agent, an extract, a concentrate or the like of a scent component can be used, and in the case of fruits, an essence and a concentrated essence can also be used.

Examples of the ethylene production inhibitor and the respiratory inhibitor include hinokitiol, allyl isothiocyanate and the like. Examples of the pH adjusting agent and the softening inhibitor include calcium hydroxide, calcium glutamate and the like.

(Continued from the claims) The storage container is not particularly limited, but the storage container is formed from the viewpoint that the dissolved oxygen amount of water stored in the storage container is not adversely affected to be maintained at 3 ppm or more and 12 ppm or less. The material used is preferably oxygen impermeable. Such materials include plastic, glass, and metal.

The storage container is preferably a light-shielding container in order to prevent a chemical reaction of fresh food due to light.

The fresh food is not particularly limited,
From the viewpoint that freshness needs to be maintained when provided to consumers, fresh foods to be subjected to the preservation method of the present invention include vegetables, fruits, seafood, and the like. Of these, fruits are preferred, and citrus is more preferred. From the viewpoint that water does not easily penetrate inside the fruit,
Citrus that are difficult to separate from the skin and pulp (for example,
Hassaku, Kabos, Sudachi, etc.) are even more preferred.

[0023]

Embodiments of the present invention will be described below in detail. The method of storing fresh food according to the present invention comprises storing tap water in a plastic brown storage container installed in a refrigerator, putting sudachi in the storage container, and further storing the water stored in the storage container. After adding dehydroacetic acid and sudati essence as a flavor, the water stored in the storage container is bubbled with air to maintain the dissolved oxygen content of the water at 3 ppm or more and 12 ppm or less.

This manufacturing method is as described above, and has the following effects. By maintaining the dissolved oxygen content of the water stored in the storage container at 3 ppm or more and 12 ppm or less, it becomes possible to store the Sudachi without lowering its freshness and flavor. Furthermore, Sudachi has the advantage that the pericarp is difficult to separate from the pericarp and the pericarp, and the pericarp is low in water permeability, so that the pericarp is not swollen even after immersion.

By bubbling the water stored in the storage container with air and lowering the temperature of the water to 5 ° C. or lower, it is possible to maintain the dissolved oxygen amount of the water stored in the storage container at 3 ppm or higher and 12 ppm or lower. It will be easier.

By using a plastic container as the storage container, oxygen does not permeate from the storage container, and it is ensured that the dissolved oxygen amount of water stored in the storage container is maintained at 3 ppm or more and 12 ppm or less. Further, since the storage container is colored brown, the light is blocked, and the fresh food in the storage container is prevented from being discolored or spoiled by the light.

By adding dehydroacetic acid to the water stored in the storage container, the propagation of microorganisms in the water stored in the storage container is prevented, and mold or the like is generated in the fresh food in the storage container. Is more effectively prevented.

By adding Sudachi essence as a flavor to the water stored in the storage container to a saturated amount, the fragrance component of Sudachi is prevented from being extracted into the water stored in the storage container. In this way, this fragrance is emitted even when processing and cooking the sudachi after storage.
It becomes easy to maintain this flavor.

[0029]

The following examples are given, but the following examples are used for illustrative purposes only and should not be used for limiting purposes. Example 1 2 kg of tap water was placed in a brown plastic storage container placed in a refrigerator maintained at a temperature of 5 ° C. in a refrigerator, and then 2 kg of Sudachi was placed in the storage container. The dissolved oxygen amount of this water is measured using a dissolved oxygen meter (manufactured by Iijima Electronics Co., Ltd.)
Was 5.8 ppm. Then
The other end of the flexible tubing with an air supply pump at one end was placed in a plastic storage container containing water and water bubbling was started at 30 liters / hour. Table 1 shows the dissolved oxygen concentrations one month, two months, three months, and four months after the start of bubbling together with the results of Examples 2 to 5. Table 2 shows the atrophy of the skin surface of Sudachi and the occurrence of mold, and the freshness, flavor, and surface color of the fruit of Sudachi before, 1 month, 2 months, 3 months, and 4 months after the start of bubbling. 6 is shown.

Example 2 Before the start of bubbling, 1 g of sodium dehydroacetate (manufactured by Wako Pure Chemical Industries, Ltd.) was used as a preservative.
Except having added, it carried out similarly to Example 1. Tables 1 to 6 show the dissolved oxygen concentration and the state of Sudachi, respectively, as in Example 1.

Example 3 The same operation as in Example 1 was carried out except that 2 g of Sudachi essence was added as a Sudachi flavor before the start of bubbling. The dissolved oxygen concentration and the state of Sudachi are shown in Tables 1 to 6 in the same manner as in Example 1.
Shown in

Example 4 Before starting bubbling, 1 g of sodium dehydroacetate (manufactured by Wako Pure Chemical Industries, Ltd.) was used as a preservative.
Example 2 was carried out in the same manner as in Example 1 except that 2 g of Sudachi essence was added as a flavoring agent for Sudachi. Tables 1 to 6 show the dissolved oxygen concentration and the state of Sudachi, respectively, as in Example 1.

Example 5 2 kg of tap water was placed in a brown plastic storage container placed in a refrigerator maintained at a temperature of 5 ° C., and then 2 kg of Sudachi was placed in the storage container. When the amount of dissolved oxygen in this water was measured by a dissolved oxygen meter, it was 5.8 ppm. Every week from the start of the experiment, the water in the storage container is drained, and the dissolved oxygen content of the water is 5 ppm.
Water (2 kg) having a concentration of 8 ppm or less was supplied to the storage container. Table 1 shows the dissolved oxygen concentrations one month, two months, three months, and four months after the start of the experiment. Immediately before the start of the experiment, start the experiment 1
Table 2 to Table 6 show atrophy and mold development on the skin surface of Sudachi, and freshness, flavor, and surface color of the fruit after months, February, March, and April, respectively.

(Comparative Example 1) 2 kg of tap water was placed in a brown plastic storage container installed in a refrigerator kept at a temperature of 5 ° C., and then 2 kg of Sudachi was placed in the storage container. When the amount of dissolved oxygen in this water was measured by a dissolved oxygen meter, it was 5.8 ppm. Table 1 shows the dissolved oxygen concentrations one month, two months, three months, and four months after the start of the experiment. Similarly, just before the start of the experiment, one month after the start of the experiment, two months after the start of the experiment,
The atrophy and mold development on the pericarp surface of Sudachi after months and April and the freshness, flavor and surface color of the fruits are shown in Tables 2 to 6, respectively.

Comparative Example 2 2 kg of Sudachi was placed in a brown plastic storage container placed in a refrigerator maintained at a refrigerator temperature of 5 ° C., and allowed to stand. Immediately before the start of the experiment, one month, two months, three months, and four months after the start of the experiment, the atrophy and the occurrence of mold on the skin surface of Sudachi, and the freshness, flavor, and surface color of the fruit are shown in Table 2 respectively. To Table 6 below.

(Comparative Example 3) 2 kg of Sudachi was placed in a polyethylene bag having a thickness of about 0.03 mm and placed in a refrigerator maintained at a refrigerator temperature of 5 ° C, and the opening of the polyethylene bag was covered with a rubber band. Tied and left. Immediately before the start of the experiment, one month, two months, three months, and four months after the start of the experiment, atrophy and mold development on the skin surface of Sudachi, and freshness of the fruit,
The flavor and surface color are shown in Tables 2 to 6, respectively.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

[Table 4]

[0041]

[Table 5]

[0042]

[Table 6] From Tables 1-6, by maintaining the dissolved oxygen content of water from 3 ppm to 12 ppm, fresh food can be easily stored for a long time,
It is understood that the freshness is maintained. Also, from the results of Example 5, by maintaining the dissolved oxygen content of water from 5 ppm to 8 ppm, fresh food can be preserved for at least 4 months without preservatives and flavors, and its freshness can be maintained. Is understood.

[0043]

According to the present invention, there is provided a method for preserving fresh food for a long period of time (at least two months or more) and maintaining its freshness by maintaining the amount of dissolved oxygen at a constant level. ADVANTAGE OF THE INVENTION According to this invention, when fresh food is needed, it becomes easy to provide fresh food which maintained freshness, flavor, surface color, etc. as needed.

Claims (6)

[Claims] 1. A method for preserving fresh food by immersing the fresh food in water stored in a storage container, wherein the dissolved oxygen content of the water is maintained at 3 ppm or more and 12 ppm or less. How to store fresh food. 2. The freshness according to claim 1, wherein the amount of dissolved oxygen in the water is maintained at 3 ppm or more and 12 ppm or less by supplying oxygen to the water stored in the storage container through an oxygen-containing gas. How to store food. 3. The oxygen stored in the storage container is supplemented with oxygen-dissolved water to maintain the dissolved oxygen content of the water stored in the storage container at 3 ppm or more and 12 ppm or less.
Or the method for storing fresh food according to any of 2. 4. The temperature of water stored in a storage container is 5 ° C.
The method for preserving fresh food according to any one of claims 1 to 3, characterized in that: 5. The method for storing fresh food according to claim 1, wherein the water stored in the storage container contains a preservative. 6. The method for storing fresh food according to claim 1, wherein the water stored in the storage container contains a flavoring agent.