JPH0662817A - Method for freezing food and apparatus for freezing food - Google Patents

Abstract

PURPOSE:To prevent the quality of a food from being impaired due to the accumulation of an internal pressure in the food in freezing thereof by housing the food in a freezing chamber, then proving the interior of the freezing chamber with an atmosphere at a prescribed temperature or below, alternately changing the atmosphere in a windless state and a state of a prescribed wind velocity and freezing the food. CONSTITUTION:A food is housed in a freezing chamber of a box 1 and the interior of the box 1 is provided with an atmosphere at <=-40 deg.C with a cooler 6 composed of a liquefied gaseous carbon dioxide cylinder 7, branch passages 8, a gas feed passage 9, solenoid valves 10, etc. The atmosphere is then alternately changed into a windless state and a state of a prescribed wind velocity at a prescribed interval with a stirrer 11. The stirrer 11 is composed of stirring blades 12, a stirring motor 13, an inverter 14, a timer 15, a temperature sensor 16 and a temperature controller 17. As a result, the internal pressure can be accumulated in the food in freezing to prevent the quality of the food from being impaired in both freezing and thawing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the production of frozen foods.
The present invention relates to a food freezing method and a food freezing device.

[0002]

2. Description of the Related Art Conventionally, when freezing food, it is -0.5 ° C.
There are slow freezing, which slowly passes through the ice crystal formation zone around -2 ° C, and quick freezing, which allows rapid passing in a short time. It is said that quick frozen is better than slow freezing, and frozen foods can be produced. ing. To freeze conventional food rapidly, lower the temperature of the atmosphere where the food is placed as low as possible,
It is carried out by keeping the temperature constant and letting air in the atmosphere in contact with the food flow as quickly as possible to increase the heat exchange rate between the atmosphere and the food.

[0003]

According to the conventional rapid freezing method for foods, since the foods are frozen from the outer surface toward the inside during the quick freezing, the water content inside the foods is frozen, as shown in FIG. As described above, the volume is expanded and pressure is accumulated inside the food. For this reason, the conventional thawing has a drawback that the quality of the food is impaired by destroying the cell membrane of the food due to a change in internal pressure as shown in FIG. 3 during thawing.

In view of the above-mentioned conventional drawbacks, the present invention has been made.
To provide a food freezing method and a food freezing device that can be frozen without rapidly accumulating pressure inside the food even when rapidly frozen, and can be thawed without impairing the quality of the food in normal thawing work. It is an object.

In order to achieve the above object, the present invention provides a food storing step of storing food in a freezing chamber of a box or a tunnel, and -40 ° C. in the freezing chamber after the food storing step.
A freezing method of food is constituted by the following atmosphere, and the freezing step in which the atmosphere is alternately kept at a constant interval in a no-air state and at a predetermined wind speed to freeze.

[0006]

The freezing method of the food configured as described above is -4
Since the product is frozen in an atmosphere of 0 ° C. or less at regular intervals in a windless state and in a predetermined wind speed state, the food is frozen without accumulating pressure inside.

The present invention will be described in detail below with reference to the embodiments shown in the drawings.

In the first embodiment of the present invention shown in FIGS. 1 to 3, reference numeral 1 denotes a freezing box having an opening / closing door 2 for storing food to be frozen, and casters 3, 3 are provided on the bottom surface of the freezing box 1. 3, 3 and 3 are attached, an exhaust port 4 is formed in a portion near the upper portion, and a cover chamber 5 is formed in an inner bottom portion.

A cooling device 6 cools the inside of the freezing box 1 to -40 ° C. or lower, preferably -60 ° C. or lower. The cooling device 6 is a liquefied carbon dioxide gas cylinder 7 and liquefied carbon dioxide gas from the liquefied carbon dioxide gas cylinder 7. The freezing box 1
A gas supply passage 9 which is supplied into the interior through the branch passages 8 and 8,
The gas supply passage 9 is composed of branch passages 8 and solenoid valves 10 and 10 interposed in the passages 8.

Reference numeral 11 designates a fixed interval in the freezing box 1,
For example, a stirrer for alternately maintaining no wind and a predetermined wind speed, for example, about 0.5 m / sec at intervals of 1 minute to 10 minutes. The stirrer 11 is a freezer provided in the cover chamber 5 of the freezer box 1. A stirring motor 13 for rotating the stirring blade 12 for stirring the inside of the box 1, an inverter 14 for controlling the air volume of the stirring motor 13, and the stirring motor.
Timer-15 that drives the target 13 alternately at regular intervals
And a temperature sensor 16 for detecting the temperature in the freezer box 1, and a temperature controller 17 for receiving a signal from the temperature sensor 16 and outputting a signal to the timer 15 and the solenoid valves 10 and 10. ing.

The food freezing device 18 having the above-described structure is provided with an opening / closing door 2.
Open to store food to be frozen in the freezer box 1,
After the food storage step of closing the opening / closing door 2, the cooling device 6 is operated in the freezing box 1 to supply liquefied carbon dioxide into the freezing box 1 to cool it to -40 ° C or lower.

When the inside of the freezing box 1 is cooled to -40 ° C. or lower, the stirring device 11 is activated to alternately rotate and stop the stirring blades 12 at regular intervals. That is, a freezing process is performed in which the food is frozen in a windless state where the wind speed in the freezing box 1 is around 0.5 m / sec and no wind is repeated.

The food thus frozen was frozen in a state where the internal pressure hardly changed as shown in FIG. 2, and the internal pressure did not change even when it was thawed as shown in FIG.

[0014]

Different Embodiments of the Present Invention Next, different embodiments of the present invention shown in FIGS. 4 to 7 will be described. In the explanation of these different embodiments of the present invention, the first embodiment of the present invention will be described.
The same components as those of the embodiment are denoted by the same reference numerals, and overlapping description will be omitted.

The second embodiment of the present invention shown in FIG. 4 is mainly different from the first embodiment of the present invention in the cooling device 6A.
In this cooling device 6A, the liquefied nitrogen gas cylinder 19 is connected to the gas supply path 9 so that the liquefied nitrogen gas can be supplied into the freezer box 1 to cool the cooling device 6A. The same effect as that of the first embodiment of the present invention can be obtained by using the food freezing device 18A.

The third embodiment of the present invention shown in FIG. 5 is mainly different from the first embodiment of the present invention in the cooling device 6B.
The cooling device 6B uses a refrigerator using a refrigerant, and even if the food cooling device 18B is configured by using the cooling device 6B using such a refrigerator, the first embodiment of the present invention can be realized. The same effect as that of the embodiment can be obtained.

The fourth embodiment of the present invention shown in FIG. 6 is mainly different from the first embodiment of the present invention in that a belt conveyor for transferring food to be frozen into a tunnel 20 serving as a freezing chamber at a low speed. With the -21 installed, the food can be continuously frozen by using the food freezing device 18C configured as described above. Reference numerals 22 and 23 are covers installed at the entrance 20a and the exit 20b of the tunnel 20, respectively.
It is a sheet.

The fifth embodiment of the present invention shown in FIG. 7 is mainly different from the fourth embodiment of the present invention in the cooling device 6A.
In this cooling device 6A, the liquefied nitrogen gas cylinder 19 is connected to the gas supply path 9 so that the liquefied nitrogen gas can be supplied into the tunnel 20 for cooling, and thus the cooling device 6A thus configured is used. Even if the food freezing device 18D is used, the same effect as that of the fourth embodiment of the present invention can be obtained.

Similar effects can be obtained even if a refrigerator using a refrigerant is used as a cooling device in the tunnel.

[0020]

As is apparent from the above description, the following effects can be obtained in the present invention.

(1) A food storing step of storing food in a freezing compartment of a box or a tunnel, and an atmosphere of -40 ° C. or lower in the freezing compartment after the food storing step, and the atmosphere is alternately kept at a fixed interval in a no-air state and at a predetermined level. Since it comprises the freezing step of freezing the food in the wind speed state, the food to be frozen can be frozen without accumulating pressure inside. Therefore, the food can be frozen without destroying the cell membrane or the like, and the quality of the food is not impaired.

(2) According to the above (1), since the pressure does not change even when the food is thawed, the cell membrane of the food is not destroyed and the quality of the food is the same as that before the freezing.
Therefore, the quality of frozen food can be improved.

(3) According to the above (2), the same quality of food as that before freezing can be obtained by any thawing method, so that the thawing work can be performed easily.

(4) Since the freezing requires a little extra time compared to the conventional rapid freezing method,
Can be frozen efficiently.

(5) Claims 2 and 3 are also the above (1) to (4).
The same effect as can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the relationship between the core temperature and the internal pressure of food when frozen using the first embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a relationship with internal pressure when thawing frozen food using the first embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a second embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a third embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a fourth embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a fifth embodiment of the present invention.

FIG. 8 is an explanatory diagram showing the relationship between the core temperature and the internal pressure of a conventional frozen food.

[Explanation of symbols]

1: Freezer box, 2: Open / close door, 3:
Caster, 4: Exhaust port, 5: Cover chamber 6, 6A, 6B: Cooling device, 7: Liquefied carbon dioxide gas cylinder, 8: Branch passage, 9: Gas supply passage, 10: Solenoid valve, 11: Stirrer, 12 : Stirring blade, 13: Stirring motor, 14: Inverter, 15: Timer, 16: Temperature sensor, 17: Temperature controller, 18, 18A, 18
B, 18D: Refrigerator for food, 19: Liquefied nitrogen gas cylinder, 20: Tunnel, 21: Belt conveyor, 22, 23: Cover sheet.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Haruki Horiuchi, 3-23 Misaki-cho, Chiyoda-ku, Tokyo 3-23, Showa Carbonate Co., Ltd. (72) Takashi Ono 6-16-4, Togoshi, Shinagawa-ku, Tokyo

Claims (3)

[Claims] 1. A food storing step of storing food in a freezing compartment of a box or a tunnel, and an atmosphere of -40 ° C. or lower in the freezing compartment after the food storing step, and the atmosphere is alternately kept at a fixed interval in a no-air state, and a predetermined temperature is maintained. And a freezing step of freezing in a wind speed state. 2. A freezing box for storing food to be frozen, which has an opening / closing door, a cooling device for cooling the inside of the freezing box to −40 ° C. or lower, and a constant air condition in the freezing box at regular intervals. And a stirrer for controlling the wind speed of the food. 3. A tunnel serving as a freezing chamber, a belt conveyor installed in the tunnel for transferring frozen food at a low speed, a cooling device for cooling the inside of the tunnel to −40 ° C. or less, and the inside of the tunnel. A food refrigeration apparatus comprising: a stirrer for alternately setting a constant wind and a predetermined wind speed.