JP7356696B2 - How to thaw and refrigerate frozen foods - Google Patents

Description

The present invention relates to a thawing cabinet and a refrigerator that can thaw and refrigerate frozen foodstuffs.

BACKGROUND ART Various foodstuffs such as meat, fish, and fruits are stored frozen and thawed when needed for cooking.
However, during thawing, so-called umami components called drips are eluted, and there are variations in thawing between the outside and the inside of the food, resulting in the problem that the original taste of the food is not retained.

For example, when frozen foods are thawed naturally at room temperature, etc., not only do thawing variations occur, but also it is difficult to store them in a refrigerator afterwards.
Furthermore, when trying to thaw frozen foods in a refrigerator, the thawing time becomes long, sometimes even several tens of hours, and there is a problem that the food cannot be cooked in time.

Patent Document 1 discloses a technology in which a thawing chamber maintained at 0°C to -5°C is provided separately from the refrigerator, but at such a thawing temperature, foods frozen at -40°C to -60°C, etc. It takes a long time to thaw.

Japanese Patent Application Publication No. 2013-201941

An object of the present invention is to provide a thawing chamber and a refrigerator that can quickly thaw and refrigerate food while maintaining the quality of the food.

The thawing warehouse according to the present invention is characterized by comprising a thawing chamber and a means for supplying superheated steam to replace the air in the thawing chamber.
Moreover, the refrigerator according to the present invention is characterized in that it includes a refrigerating chamber and a means for supplying superheated steam to replace the air in the refrigerating chamber.
Moreover, it may have a means for switching between the thawing chamber and the refrigerating chamber.

Here, frozen food (food) includes not only frozen food stored in a household freezer (-18°C or lower), but also ultra-low temperature frozen food with a temperature of -30 to -80°C for commercial use. .
For example, fish such as tuna are stored at temperatures below -50°C, as their flesh may turn black if the temperature exceeds -40°C.

The present inventor conducted comparative research on thawing under various conditions using bread and tuna for sashimi that had been frozen and stored at -40 to -60°C.
As a result, it was found that by injecting a very small amount of dry superheated steam at 300 to 500 degrees Celsius, called dry steam, into the thawing chamber, food could be thawed without causing discoloration or dripping.
This is presumed to be because by supplying superheated steam to the thawing chamber, the air in the thawing chamber is expelled (replaced) and the inside of the thawing chamber becomes a reducing atmosphere with low oxygen conditions.

As a result, by controlling the temperature of the thawing chamber to an appropriate temperature of 10 to 15 degrees Celsius, food could be thawed in a short time of about 2 to 3 hours while maintaining its original freshness and flavor.

Even when the thawed food was stored in a refrigerator at temperatures below 10°C, for example 2 to 6°C, it could be stored for a long time without discoloration or dripping by simply injecting heated steam at 300 to 500°C into the refrigerator.

In the present invention, by injecting superheated steam into the thawing chamber or refrigerator chamber and replacing the air inside with the superheated steam, food products can be thawed and refrigerated while maintaining their quality.

An example of the structure of a thawing cabinet and a refrigerator according to the present invention is shown. An example of a superheated steam generator is shown, with (a) showing a front view and (b) showing a perspective view.

FIG. 1 shows an example of the structure of a thawing cabinet and a refrigerator according to the present invention.
This also includes devices that can be switched between a thawing chamber and a refrigerator.
The defrosting chamber or refrigerator 10 has a defrosting chamber or a refrigerating chamber in which food is stored, and has a plurality of partition shelves 12 therein as required.
The structure of the door may be a sliding type or a type that opens and closes in the front and rear directions, and there are no restrictions on the structure example.

The present invention is characterized in that it includes a superheated steam generator 20, and its generation conditions are integrally controlled with the thawing conditions and the refrigeration conditions by the operation panel 13.
The thawing chamber may be switched and controlled so that it becomes a refrigerating chamber as it is after thawing, or the thawing chamber and the refrigerating chamber may be provided separately.

If the superheated steam generator 20 generates dry superheated steam by boiling water to obtain water vapor and then heating this water vapor to a temperature exceeding 100°C, for example, 300 to 500°C, the structure of the superheated steam generator 20 is There are no restrictions.
In the present invention, the purpose of superheated steam is not to heat the food, but to expel the air in the thawing chamber or refrigerator chamber to the outside to create a low oxygen state.
Therefore, the amount generated may be very small.
For example, as shown in FIG. 2, heating heaters 21a and 21b are arranged in a boiling chamber 21 to heat and boil water injected into the boiling chamber 21 to generate water vapor, which is then passed through the connecting portion 23. and guide it to the upper pipe-shaped superheating chamber 22.
This superheating chamber 22 is provided with a superheating heater 22a for superheating water vapor to a high temperature of 300 to 500°C.
The superheated steam obtained in the superheating chamber 22 is supplied from a supply hole 14 provided in the thawing chamber (refrigeration chamber) 11.
The amount of superheated steam supplied depends on the airtightness of the thawing chamber, etc., but may be such that once the air inside is replaced with superheated steam, that state can be maintained.
For example, it is sufficient to supply an amount of superheated steam that is about the same as to about 10 times the indoor capacity of the thawing chamber per minute.

In this way, tuna for sashimi, frozen foodstuffs at -60°C, were temperature-controlled to an indoor temperature of about 15°C using a thawing chamber, and comparisons were made between those with and without superheated steam supplied.
As a result, the meat that was thawed while supplying superheated steam remained lean, but the meat that was not supplied with superheated steam turned black.

The above-mentioned tuna was thawed while supplying superheated steam, then the thawing chamber was changed to refrigeration conditions around 5°C, and the tuna was kept refrigerated for 25 hours, and the tuna was kept refrigerated for 25 hours with the supply of superheated steam stopped. compared.
For refrigerated storage, the tuna was placed in a Styrofoam container and wrapped in plastic wrap.
As a result, no change was observed in the containers to which superheated steam was supplied, but in the containers to which superheated steam was not supplied, not only did the containers turn black, but drips were eluted into the container.
This has revealed that by supplying superheated steam indoors, it is possible to thaw and refrigerate food while maintaining its quality.

10 Defrosting/refrigerator 11 Defrosting room (refrigerating room)
12 Partition shelf 13 Operation panel 14 Supply hole 20 Superheated steam generator 21 Boiling chamber 22 Superheating chamber 23 Connection section

Claims (1)

A thawing chamber is provided with a thawing chamber and a superheated steam generator for supplying superheated steam of 300 to 500° C. into the thawing chamber, and the superheated steam generator includes a boiling chamber in which a heating heater is arranged; It is connected to a pipe-shaped superheating chamber with a superheating heater installed above it at a connecting part.
The temperature of the thawing chamber is adjusted to 10 to 15°C, and a small amount of superheated steam of 1 to 10 times the capacity of the thawing chamber is supplied per minute to the thawing chamber to overheat the frozen food in a low oxygen state. Defrost without heating with steam, then switch the thawing chamber to a refrigerator whose temperature is controlled at 2 to 6°C, and heat the refrigerator with a slight overheating of 1 to 10 times the capacity of the refrigerator for 1 minute. A method for thawing and refrigeration of frozen foods, characterized by refrigeration in a low oxygen state by supplying steam .

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