JPH0994082A - Preservation of food or beverage and container used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent change in quality such as change in taste, fragrance, etc., phase separation, etc., caused by freezing and thawing when preserving a food or beverage in a frozen state. SOLUTION: In this method for preserving a food or beverage in a frozen state, the food, etc., are stored in a metal container. Or an assembly of metal wire or plates is put in the food, etc., and a low-temperature liquid is brought into contact with the outside of the container or the exposed part of the metal assembly. The food, etc., is rapidly frozen and quickly thawed before use after the preservation.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for preserving foods and the like and a container therefor, in particular, foods or beverages are frozen and preserved,
The present invention relates to a method for storing foods or beverages that are thawed before use and a container therefor.

[0002]

2. Description of the Related Art Animal foods such as meat, poultry, fish, eggs, ham and sausages, vegetable foods such as beans, potatoes, fruits and tofu, and beverages such as milk, fruit juice and alcohol are stored for a long time. Therefore, it is widely practiced to freeze and store them. Cryopreserved foods or beverages must be thawed and returned to the same state as before storage before they are edible or used for reference.

[0003]

The foods that have been thawed often have different tastes, aromas, softnesses, etc., as compared to fresh foods. In the case of beverages, the taste, aroma, texture and the like change. In extreme cases, it may be separated into two or more phases, or apparently altered.

The object of the present invention is to preserve foods or beverages, which prevent changes in taste, fragrance, softness, texture, etc. due to freezing and thawing, or alterations such as phase separation when freeze-preserving foods or beverages. To provide a method.

[0005]

According to the present invention, in order to solve the above-mentioned problems, a food or a beverage is contained in a container made of a good heat conductor, and the outer surface of the container is rapidly brought into contact with a low temperature liquid or a solid, thereby rapidly. Cool to freeze the food or beverage (referred to as the first method). Alternatively, a continuous or discontinuous assembly of filaments, plates, or foils of good heat conductor is incorporated in food or beverage, and a portion of this assembly is placed so as to substantially contact the outside world, and this portion is rapidly To freeze the food or beverage by cooling (referred to as the second method). In either case, it is desirable to rapidly thaw by heating the outer surface of the container or the portion in contact with the outside of the good thermal conductor before the food or beverage is put into service.

A metal is usually used as a good heat conductor, but a carbon powder combination, carbon fiber, etc. can also be used. Since the wall of the container has good heat conduction to accelerate freezing, it is preferable that the wall is as thin as possible in terms of strength. For example, 350 or 500
Use iron or aluminum plates 0.1 to 0.4 millimeters thick in milliliter containers. It is necessary to select the material and thickness of the container in consideration of the internal pressure due to the expansion when the contents are frozen, so that the container has strength enough not to burst. Instead of being housed in a container having a good thermal conductor, the food may be wrapped in a water-impermeable polymer film having a thickness not exceeding 30 microns and frozen. Since it comes into contact with foods or beverages, it is desirable that both the good thermal conductor and the water-impermeable polymer are materials that are neither toxic nor corrosive at least on the surface.

For the purpose of the present invention, it is preferable that the depth (height) or width or diameter of the container is 2 cm or less, particularly 1 cm or less. Alternatively, it is preferable to provide partition walls made of a good thermal conductor connected to the outer wall of the container at intervals of 2 cm or less. It is more preferable that the partition walls have an interval of 1 cm or less. It is desirable that the food to be contained is in contact with the partition wall in an area as wide as possible.

As the low temperature liquid, liquid nitrogen, liquid air, liquid helium, liquid argon, acetone or methanol solution of solid carbon dioxide (dry ice) can be used. −
Concentrated aqueous salt solution, alcohol, cooled to 20 ° C or lower
You may use antifreeze liquids, such as acetone, ethylene glycol, glycerin, and dimethyl sulfoxide. The antifreeze is preferably allowed to flow around the container. It is also possible to utilize vapors produced from cryogenic liquids, for example cryogenic nitrogen gas produced from liquid nitrogen, for freezing purposes.

As the low temperature solid, dry ice, frozen salt aqueous solution or the like is used. It is preferable that the aqueous salt solution has a high concentration, particularly a solution close to saturation. Since the low-temperature solid maximizes the contact area with the outer surface of the container, it is preferably made into a small piece or powder. Dry ice powder generated from liquefied carbon dioxide (commonly called liquefied carbonic acid) can also be used.

When freezing the contents, it is desirable to immerse all or most of the container in a cold liquid or to fill it with a cold solid powder. The container may be closed or open,
It is rather chosen by the nature of the food or beverage it contains. When a closed container is used, it is necessary to select the shape of the container, the strength of the material, etc. so that the food or the like expands due to freezing, so that the container does not burst.

In the second method of the present invention, the assembly of filaments, plates or foils of a good thermal conductor to be incorporated in food or beverage can have various shapes. The filament may be linear or curved.

The linear filaments may or may not be parallel to each other. However, when the food before freezing and after thawing is relatively hard, it is convenient that the linear filaments are arranged in parallel because they can be easily inserted into and removed from the food. For example, an assembly of metal needles arranged in parallel is easy to handle. The parallel metal needle assembly preferably has a pedestal of a good thermal conductor, and by exposing this pedestal to the outside world,
The effect of the present invention can be further enhanced.

The aggregate of filaments may be one in which long and continuous curvilinear filaments are intertwined in a complicated shape, and are aggregated in, for example, a thread-like shape. A plurality of curved filaments that are not continuous with each other may be complicatedly intertwined. For example, it is possible to use a wire scissors-like wire made of entangled stainless steel wires.

In the case of beverages or foods having high fluidity at room temperature, the aggregate of filaments, plates or foils can be easily removed. In the case of a solid or viscous liquid food at room temperature, it cannot be separated from the food after thawing unless it is a parallel straight line or flat plate.

A metal container provided with a plurality of (for example, 25) metal needles parallel to each other is a container particularly suitable for the purpose of the present invention. The metal needle is preferably arranged parallel to the wall of the container and perpendicular to the bottom, but it may be perpendicular to the wall or parallel to the bottom.

As mentioned above, before the food or beverage is put into service,
It is desirable to thaw rapidly by warming the outer surface of the container or the part in contact with the outside of a good thermal conductor, but avoiding that part of the food or beverage exceeds 25 ° C, especially higher than 35 ° C. Should be. for that purpose,
Calculate the latent heat of melting of water from the water content of food or beverage, and calculate the amount of heat to reach the desired temperature above the freezing point from the heat capacity, and then heat the medium (for example, water) at an appropriate temperature and amount, or The exposed portion of the good thermal conductor (for example, the pedestal of the metal needle assembly) is brought into contact. For example, about 2.
Five times the weight of water at a temperature of 40 ° C. is used. The heat medium, for example water, is preferably fluidized by stirring or the like. Temperature 2
Running water at 5 ° C or lower is suitable for thawing.

The present invention can be applied to the cryopreservation of various foods. For example, it can be applied to root vegetables such as radish, fruits such as pears, tofu, chicken eggs, fish meat, sausage, cheese, butter and the like.

The present invention can be applied to the cryopreservation of various beverages. For example, sake, sake such as beer, vegetable juice, fruit juice,
It can be applied to milk etc.

[0019]

The present invention will be described more specifically with reference to the following examples. [Example 1] One piece of silk strained tofu having a thickness of about 2 cm was placed in a metal tray, and liquid nitrogen was poured around the metal tray in a Styrofoam box to be rapidly frozen. Take out the tofu in a metal tray and store it in a home freezer for 3 days (-20
C.) and then taken out of the freezer, and running water having a temperature of about 22 ° C. was flown around the metal tray to rapidly thaw. The entire tofu was thawed in less than 15 minutes.

For comparison, the same tofu was placed in a metal tray, placed in a home freezer as it was, and frozen in the refrigerator.
Stored for days. After removing from the freezer, the temperature is about 26 ℃
It was left to stand in the room and slowly thawed (for comparison).

The tofu treated by the method of the present invention had a smooth surface, no pores inside, and taste and texture were almost the same as those of the original tofu. The tofu of the comparative product had fine pores on the surface and inside, had a watery taste and a rough texture, and the taste as silk strain tofu was impaired.

[Embodiment 2] Height of about 10 cm, diameter of about 5 c
Sake enclosed in a rust-proof steel can with a thickness of about 0.3 mm and a plate thickness of about 0.3 mm is poured into the can, and liquid nitrogen is poured to freeze it quickly.
Stored in home freezer for 3 days. It was taken out of the freezer and rapidly thawed in running water at a temperature of about 22 ° C. For comparison, the other one was placed in a freezer for home use, frozen in the freezer, stored in the freezer for 3 days, and then left in a room at a temperature of about 26 ° C to be naturally thawed (comparative product). . After thawing, the temperature was once set to about the same in the refrigerator, the bottle was opened, and the bottle was used for drinking. The taste and aroma were sensory evaluated by 5 people.

The raw liquor treated by the method of the present invention is not inferior to the original liquor (those stored at room temperature for the same period and kept at the same temperature during drinking). Was also obtained from 4 or more out of 5. The comparison product is
It was evaluated that 4 out of 5 people were inferior in both taste and aroma.

[Example 3] About 400 ml of glycerin was cooled to -20 ° C in advance. The flesh of pears (Housui seeds) cut to a thickness of about 2 cm was wrapped with a 10-micron-thick Saran wrap film (Asahi Kasei Co., Ltd.) and dipped in glycerin so that the liquid did not enter the package. This was taken out after about 24 hours, and thawed by immersing it in hot water having a temperature of 40 ° C. which was about twice the weight of the pulp.

For comparison, the same pear flesh was wrapped in Saran wrap film, placed in a freezer at -20 ° C to be frozen, taken out 24 hours later, and naturally thawed in a room at a temperature of about 22 ° C.

The taste and texture of the pear flesh treated by the method of the present invention did not differ from those stored in the refrigerator.
The comparative pear flesh was semitransparently enlarged and had a watery taste.

[Embodiment 4] A brass alloy wire (called a needle) having a diameter of 0.3 mm and a length of 5 cm is erected vertically and horizontally in 10 rows at a pitch of 3 mm on a tin alloy pedestal having a diameter of 4.8 cm and a height of 5 mm. And fixed, and the pedestal was plated with gold. Height about 8cm, diameter about 5c
A pedestal was placed on the bottom of a rust-proof steel can having a thickness of m and a plate thickness of about 0.3 mm so that the needle faces upward. Pour sake into the container until the needle sinks, cover with Saran wrap, seal, and pour dry ice-acetone solution around the can for rapid freezing, Example 2
It was frozen and stored in the same manner as in 1. and thawed. The same result as in Example 2 was obtained.

[0028]

EFFECTS OF THE INVENTION According to the present invention, the taste, aroma and softness due to freezing and thawing when a food or beverage is frozen and stored,
It is possible to avoid changes such as texture and deterioration such as phase separation. Therefore, because they cannot be frozen because they hate these alterations, foods or beverages that had to rely on refrigerated storage,
Cryopreservation enables long-term storage, and the storage period of foods or beverages can be greatly extended. This not only increases the degree of freedom in inventory of products, but also is advantageous for long-term storage of food in case of a disaster.

Claims (25)

[Claims] 1. A method for storing a food or beverage in which the food or beverage is frozen and stored and thawed before being used, wherein the food or beverage is contained in a container made of a good thermal conductor, and the outer surface of the container is a low temperature liquid or A method for preserving a food or beverage, characterized by rapidly cooling the food or beverage by contacting it with a solid to freeze the food or beverage. 2. The cryogenic liquid is liquid nitrogen.
Method for preserving foods or beverages. 3. The method for preserving food or beverage according to claim 1, wherein the low temperature solid is solid carbon dioxide. 4. The method for preserving food or beverage according to claim 1, wherein the low temperature liquid is acetone or alcohol solution of dry ice. 5. The method for preserving foods or beverages according to claim 1, wherein the low temperature liquid is glycerin or a concentrated aqueous solution thereof. 6. The depth or width or diameter of the container is 2
The method for preserving foods or beverages according to claim 1, which is not more than cm. 7. The depth or width or diameter of the container is 1
The method for preserving foods or beverages according to claim 6, which is not more than cm. 8. The method for preserving foods or beverages according to claim 1, wherein the container has partition walls made of a good heat conductor at intervals of 2 cm or less. 9. The method for preserving foods or beverages according to claim 8, wherein the container has partition walls made of a good heat conductor at intervals of 1 cm or less. 10. The method for preserving food or beverage according to claim 1, wherein the food or beverage is frozen and stored, and then thawed rapidly before use. 11. The method for preserving foods or beverages according to claim 10, wherein the whole is thawed within 15 minutes before use. 12. The method for preserving foods or beverages according to claim 10, wherein the whole is thawed within 10 minutes before use. 13. The outer surface of the container has a temperature of 25.degree.
The method for preserving foods or beverages according to claim 10, wherein the foods or beverages are thawed by bringing them into contact with a liquid at a temperature of not higher than ° C. 14. The method for preserving a food or beverage according to claim 10, wherein the outer surface of the container is brought into contact with a liquid flow having a temperature of 25 ° C. or lower to thaw the food or beverage. 15. A method for preserving a food or beverage in which the food or beverage is frozen and stored and thawed before being used, wherein a continuous or discontinuous aggregate of filaments, plates or foils of a good thermal conductor is contained in the food or beverage. Is placed so that a part thereof is substantially in contact with the outside world, and the part of the aggregate is rapidly cooled to freeze the food or drink. 16. The method for preserving foods or beverages according to claim 15, wherein the rapid cooling is performed by contacting the portion of the assembly with a cryogenic liquid, a solid, or a vapor generated from them. 17. The method for preserving food or beverage according to claim 15, wherein the food or beverage is rapidly thawed by warming the portion of the assembly before service. 18. The method for preserving food or beverage according to claim 15, wherein the portion is brought into contact with a liquid having a temperature of 25 ° C. or higher and 40 ° C. or lower to thaw the food or beverage. 19. The food or beverage is thawed by contacting the portion with a liquid flow having a temperature of 25 ° C. or lower.
5. The method for storing food or beverage according to 5. 20. A method for preserving a food, which comprises freezing and preserving the food and thawing before use, wherein the food is wrapped with a water-impermeable polymer film having a thickness not exceeding 30 microns, and the temperature is -20 ° C. or lower. A method for preserving food, which comprises immersing in liquid and freezing rapidly. 21. The method of preserving food according to claim 20, wherein the thickness of the film does not exceed 15 microns. 22. The food wrapped in the film is heated to a temperature of 2.
The method for preserving food or beverage according to claim 20, wherein the food or beverage is thawed by contacting it with a liquid at 5 ° C or higher and 40 ° C or lower. 23. The food wrapped in the film is heated to a temperature of 2.
The method for preserving foods or beverages according to claim 20, wherein the foods or beverages are thawed by being brought into contact with a liquid flow at 5 ° C or lower. 24. A container for cryopreserving food or beverage, wherein a plurality of metal filaments arranged in parallel to each other are provided inside a metal can. 25. A cryopreservation container for foods or beverages, wherein a plurality of metal plates arranged in parallel with each other are provided inside a metal can.