JP3053529B2 - Sterilization and cooking of aerated foods - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sterilizing and heating an aerated food.

[0002]

2. Description of the Related Art Conventionally, in the sterilization treatment of aerated foods,
Store the cooked food or semi-cooked ingredients cooked to a predetermined stage in a bag (retort pouch) made of a laminated sheet with excellent gas barrier properties or a rust-proof can, etc.
Replace the air in these bags or cans with inert gas,
The bag mouth is sealed by heat sealing, or the can is sealed with a sealing machine. In this state, the bag is stored in a sterilization tank, and hot water or heated steam is sent to the sterilization tank to sterilize food in the bag or the can. The way has been taken. In order to enhance the effect of the sterilization treatment, and to maintain the taste and shape of the food and maintain the quality of the food, high-temperature and short-time treatment is desirable. In general, 120 ° C. for 4 minutes at the center of the food (F value 4) Heat sterilization is standard. In the conventional sterilization method, hot water is filled in a sterilization tank, and the aerated food is immersed in the hot water, or hot water or heated steam is injected into the aerated food in a state where the sterilization tank is pressurized and heated. However, in order to ensure the sterilizing effect, the heating time is long. For example, depending on the food, 100 to 12
Sterilization treatment is performed at a temperature near 0 ° C. for about 10 to 60 minutes. If the heating time of the sterilization process is long, the unique smell of cans and retort pouches impairs the taste and smell of the food, and even if you try to ship the food in a partially cooked state, the cooking stage will progress due to long heating. There is a problem that the food is deformed and the appearance is impaired. Conversely, if the heating time is shortened, it will not be possible to achieve a sufficient bactericidal effect on bacteria that cause food poisoning. Therefore, a bactericide or preservative such as 3% hydrogen peroxide or sorbic acid is used together, or vacuum packaging is performed. By taking such measures, there is a problem that the sterilizing effect must be compensated.

[0003]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention reduces the heating time of the sterilization process by reliably performing the sterilization process at a high temperature in a short time, thereby reducing the appearance and the food quality of the food. It is an object of the present invention to provide a method for sterilizing and heating an air-containing food without impairing the taste and smell of the food.

[0004]

In order to achieve the above object, according to the present invention, a heat-resistant container is filled with uncooked food, the inside of the container is replaced with an inert gas, and the sealed aerated food is stored in a sterilization tank. A method of sterilizing and heating an aerated food, wherein the center temperature of the food is changed in multiple stages in the order of the following steps (1) to (5). (1) Set the center temperature of the food to 80 to 1 in 5 to 15 minutes.
A primary temperature raising step of rapidly raising the temperature to 00 ° C., (2) the central temperature of the food to 80 to 100 ° C.,
A cooking constant temperature step of maintaining for a predetermined time based on the type and amount of the aerated food; (3) setting the central temperature of the food to a food sterilization temperature of 110 to 12;
A secondary temperature raising step of raising the temperature to 0 ° C., (4) a sterilizing step of maintaining the center temperature of the food to 110 to 120 ° C. for 2 to 10 minutes, (5) a plurality of cooling water tanks, The cooling water in the inside was cooled, the cooling water in any one of the cooling water tanks was poured into the sterilization tank, and the central temperature of the food was rapidly lowered to room temperature in 4 to 15 minutes, and then used for cooling. A cooling process in which cooling water is collected in a cooling water tank and cooled, and for the next cooling, cooling water in another cooling water tank is used.

Further, the center temperature of the food is varied in multiple stages in the order of the following steps (1) to (6). (1) Set the center temperature of the food to 80 to 1 in 5 to 15 minutes.
A primary temperature raising step of rapidly raising the temperature to 00 ° C., (2) the central temperature of the food to 80 to 100 ° C.,
A cooking constant temperature step of maintaining for a predetermined time based on the type and amount of the aerated food; (3) setting the central temperature of the food to a food sterilization temperature of 110 to 12;
(4) a sterilization process in which the center temperature of the food up to 110 to 120 ° C. is maintained for 2 to 10 minutes; and (5) a center temperature of the food in addition to 122. ~ 124
(C) A plurality of cooling water tanks are provided, the cooling water in the cooling water tank is cooled, and the cooling water in one of the cooling water tanks is sterilized. After pouring water into the tank and rapidly lowering the central temperature of the food at 122 to 124 ° C. to normal temperature in 4 to 15 minutes, the cooling water used for cooling is collected in a cooling water tank and cooled, and the next cooling is performed. Sometimes a cooling process that uses cooling water in a different cooling water tank from the previous one.

Further, the center temperature of the food is changed in multiple stages in the order of the following steps (1) to (7). (1) Set the center temperature of the food to 80 to 1 in 5 to 15 minutes.
A primary temperature raising step of rapidly raising the temperature to 00 ° C., (2) the central temperature of the food to 80 to 100 ° C.,
(3) keeping the center temperature of the food at about 110 in 3 to 4 minutes, wherein the cooking temperature is maintained for a predetermined time based on the type and amount of the aerated food;
Additional cooking step of rapidly raising the temperature to 0 ° C., (4) secondary temperature raising step of raising the central temperature of the food to the food sterilization temperature of 120 ° C., (5) maintaining the central temperature of the food for 3 to 4 minutes (6) The central temperature of the food is further increased by 122 to 124.
° C, and a high-temperature sterilization treatment step of rapidly raising the temperature to about 1 minute, and (7) providing a plurality of cooling water tanks, cooling the cooling water in the cooling water tank, and dissolving the cooling water in any one of the cooling water tanks After the water is poured into the chiller and the center temperature of the food is rapidly lowered to room temperature in 4 to 15 minutes, the cooling water used for cooling is collected in a cooling water tank and cooled, and the next cooling is different from the previous cooling. Cooling process using cooling water in the water tank.

[0007]

[Action] As described above, the temperature is raised in multiple stages (the central temperature of the food
To the cooking temperature and then to the sterilization temperature)
So the time to reach the sterilization temperature is short and the food
Deterioration of food due to exposure to sterilization temperature can be prevented.
Moreover, the cooling water sufficiently cooled in the cooling water tank is transferred to the sterilization tank.
With water injection, food can be rapidly cooled to room temperature,
Prevents the taste and smell of food from being reduced by exposure to sterilization temperatures
I can. In addition, the cooling water used for cooling alternates the cooling water tank.
By using it, collect and cool it sufficiently in the cooling water tank.
Can be reused.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing a configuration of a sterilization and cooking system for aerated foods that realizes the present invention. A sterilization tank 6 for accommodating and sealing sterilized and cooked air-containing foods replaced with an active gas, a superheated steam generator 2 for further heating the supplied steam, and a heat exchanger for exchanging heat with hot water sent to the sterilization tank 6. 3, a circulation pump 5, an air pressure adjusting unit for adjusting the air pressure in the sterilizing tank, a cooling unit for cooling down to a temperature at which the cooked and sterilized food can be taken out,
It is composed of various control valves for controlling them and a control panel 24.

Hereinafter, the operation control of the sterilization and cooking system will be described in detail. Heated steam is supplied from a boiler (not shown) for supplying heated steam to the primary side of the heat exchanger 3 via a steam regulating analog valve 1 and a superheated steam generator 2,
The heat is exchanged with the hot water circulating on the secondary side of the heat exchanger 3, and the hot water is disinfected by the circulating pump 5 through the two-way switching valve 4a.
The hot water that has been injected into the sterilized tank 6 and poured into the sterilized tank 6 and heat-exchanged accumulates at the bottom of the sterilized tank 6, passes through the drain valve 7, and is returned to the secondary side of the heat exchanger 3 by the return line 21. It returns, is heated again, and is repeatedly circulated by the circulation pump 5.

The sterilization tank 6 has a housing having a pressure-resistant structure, and a sealing door (not shown) is formed on the front surface thereof for inserting and removing a cart 13 on which air-containing food is loaded in multiple stages. A water injection container 14 for jetting out hot water is provided, and a plurality of nozzles (not shown) protruding are provided on the inner surfaces of the left and right water injection containers 14, respectively. The hot water is poured into the aerated food on the trolley 13 as a belt-like flow. An air pressure pipe 15 for adjusting the air pressure in the tank is provided on the ceiling of the sterilizing tank 6, the air pressure is increased by a compressor 16 via a pressure adjusting analog valve 17, and the pressure in the tank is increased by a pressure sensor 18 disposed in the tank. The air pressure is detected and sent to the control panel 24, and the pressure adjusting analog valve 17
And the exhaust analog valve 19 are operated to maintain the air pressure in the tank at a predetermined air pressure corresponding to the hot water temperature.

The superheated steam generator 2 reheats the heated steam passing through the inside of the device by another heat source, for example, an electric heater equipped with a heat exchange mechanism or the like to produce high-temperature heated steam, and the primary side of the heat exchanger 3 Is supplied to the hot water, and heat is exchanged with hot water flowing on the secondary side to generate high-temperature hot water, which is sent into the sterilization tank by the circulation pump 5. In this device, a spiral or U-shaped pipe through which steam flows is penetrated into a housing filled with silicone oil or the like having good heat resistance, and a heat source such as an electric heater is buried in the housing. A device that reheats steam flowing through the heater and controls the electric heater to generate steam having a predetermined degree of superheat.

The superheated steam is sent to the heat exchanger 3 to raise the temperature of hot water circulating on the secondary side of the heat exchanger 3, and this hot water is injected into the sterilization tank 6 through the supply pipe 20 by the circulation pump 5. It is sent to the container 14, injected into the tank, and heated and aerated to perform cooking and sterilization. When the heat sterilization is completed after a predetermined time has elapsed, the two-way switching valve 4a is switched to stop the flow of hot water, and the hot water in the sterilization tank 6 is discharged to the two-way switching valve 4b and the on-off valve 8
The hot water is recovered in the hot water recovery tank 9 through a. Then, cooling water is injected from the first cooling water tank 10 through the cooling water pipe 11 and the two-way switching valve 4a to the aerated food from the water supply container 14 of the sterilization tank 6 by the circulation pump 5, and the injected cooling water is supplied to the sterilization tank 6
Collected at the bottom of the first cooling water tank 10 through the drain valve 7, the two-way switching valve 4b, and the on-off valve 8b.
Cooling water is sent from the cooling water tank 12. In this way, the first cooling water tank 10 and the second cooling water tank 12 are alternately switched and circulated, and the collected cooling water is cooled by a cooling tower or the like, and cooled to a temperature at which the aerated food can be taken out.

A hot water temperature sensor 22 for detecting hot water temperature is provided on the secondary side of the heat exchanger 3, and a tank temperature sensor 23 for detecting the tank temperature in the sterilizing tank. Detecting the temperature and sending this temperature information to the control panel 24, the operation of the superheated steam generator 2 and the operation of the superheated steam generator 2 are performed so that the hot water temperature and the tank temperature change along a temperature-time transition curve set in advance for each food. The opening degree of the steam control analog valve 1 is controlled.

If the temperature information from the hot water temperature sensor 22 and the temperature sensor 23 inside the tank is lower than the set temperature on the temperature-time transition curve, the degree of opening and closing of the steam control analog valve 1 is increased, and at the same time, the superheated steam generator The electric heater 2 is energized to increase the temperature of the heating steam sent to the heat exchanger 3 and increase the temperature of the hot water circulating on the secondary side of the heat exchanger 3. On the other hand,
If the information signal from the in-bath temperature sensor 27 is higher than the set temperature on the temperature-time transition curve, the steam regulating analog valve 1
And the flow rate of the heated steam is reduced, the electric heater of the superheated steam generator 2 is turned off, the temperature of the flowing steam is reduced, the temperature of the hot water circulating in the sterilizing tank is reduced, and the temperature in the tank is reduced. Thus, a predetermined cooking and sterilizing temperature is maintained.

As described above, the temperature of the steam flowing into the primary side of the heat exchanger 3 is reheated at the inlet thereof by the superheated steam generator 2, and the temperature of the steam entering the heat exchanger 3 is reduced for a short time. And circulates the secondary side of the heat exchanger 3 to increase the temperature of the hot water injected into the aerated food, thereby accelerating the rise of the temperature in the tank and the temperature of the food. Control that follows the temperature-time transition curve can be performed.

FIG. 2 is a temperature-time transition curve based on two-stage heating control showing details of the present invention, FIG. 3 is a temperature-time transition curve based on three-stage heating, and FIG. In the graph, the horizontal axis represents time T, and the vertical axis represents the tank temperature t ° C. Hereinafter, the operation of the sterilization and cooking system will be described along the temperature-time transition curve. In FIG. 2, control programs along these temperature-time transition curves are input to the control panel 24 in advance, and the detection values of the tank temperature sensor 23, the pressure sensor 18, and the hot water temperature sensor 22 are stored in the control panel 24. And sequentially incorporated in a control program to control the temperature in the bath along the temperature-time transition curve.

The sterilized tank 6 contains the aerated food, and the control panel 24
To start the sterilization and cooking system, open the steam control analog valve 1, heat steam from the boiler flows into the heat exchanger 3 through the superheated steam generator 2, and adjust the steam control analog valve 1 to control the flow rate of the heat steam. And the temperature of the heated steam is increased by the superheated steam generator 2 to increase the temperature of the heat exchanger 3.
The hot water flows to the next side, exchanges heat with the hot water flowing on the secondary side of the heat exchanger 3 by the circulation pump 5, raises the temperature of the hot water, and injects hot water from the water injection container 14 of the sterilization tank 6 to the aerated food. To raise the temperature of the sterilization tank 6 at the same time.

At this time, the inside temperature of the tank and the inside pressure of the tank are detected by the inside temperature sensor 23 and the inside pressure sensor 18 provided in the sterilization tank 6 and sent to the control panel 24, and the inside temperature of the tank is adjusted to a predetermined temperature (8
(0 to 100 ° C.), and rapidly heated (5 to 15 minutes) until the pressure in the sterilization tank 6 is maintained at a pressure corresponding to the temperature in the sterilization tank 6 by the compressor 16 (first temperature rise A section). When the temperature in the tank reaches a predetermined temperature, the hot water temperature is detected by the hot water temperature sensor 22, and the steam control analog valve 1 and the superheated steam generator 2 are adjusted so as to maintain the hot water temperature. Cooking of the aerated food for a predetermined time (cooking B
section). The temperature at the center of the food follows the change in the temperature in the tank with a delay, as indicated by the dotted line in the figure. When the cooking of the aerated food is completed after a predetermined time, the temperature of the hot water is increased by operating the steam control analog valve 1 and the superheated steam generator 2, and the temperature in the tank is reduced to a predetermined sterilization temperature (110 to 120 ° C). And sterilize while maintaining the state for a predetermined time (2 to 10 minutes) (sterilization C
Section), and then rapidly cooled to return the aerated food to normal temperature (Cooling E section). As described above, cooking is performed at a relatively low temperature by controlling the temperature in the bath along the temperature-time transition curve, and sterilization is performed at a high sterilization temperature in a short time, so that cooking proceeds excessively. And a reliable sterilization treatment can be performed.

In FIG. 3, the sterilizing tank 6 is heated rapidly (5 to 15 minutes) until the temperature in the sterilizing tank 6 reaches a predetermined temperature (80 to 100 ° C.). It is maintained at a pressure corresponding to the internal temperature (first temperature rise A section). When the temperature in the tank reaches a predetermined temperature, the hot water temperature is detected by the hot water temperature sensor 22 and the steam regulating analog valve 1 and the superheated steam generator 2 are maintained so as to maintain the hot water temperature.
Is adjusted, and the aerated food is cooked for a predetermined time determined by the food (cooking B1 section). Then, in order to promote the cooking, the temperature in the tank is further raised to a predetermined additional cooking and sterilization temperature (110 to 120 ° C.), and the cooking is completed while the predetermined time (2 to 10 minutes) is maintained, and the sterilization process is performed ( Secondary heating B2 section). When the aerated food is composed of a mixture of materials having different cooking times, reliable cooking and sterilization can be performed in a short time by this secondary heating.
When the cooking is completed, the temperature in the tank is set to a predetermined sterilization temperature (122 to
124 ° C.), hold the state for about 1 minute, and perform high-temperature sterilization (third temperature rising C section), and then rapidly cool the air-containing food to normal temperature (cooling E section).

In FIG. 4, the sterilizing tank 6 is heated rapidly (5 to 15 minutes) until the temperature in the sterilizing tank 6 reaches a predetermined temperature (80 to 100 ° C.). It is maintained at a pressure corresponding to the internal temperature (first temperature rise A section). When the temperature in the tank reaches a predetermined temperature, the hot water temperature is detected by the hot water temperature sensor 22 and the steam regulating analog valve 1 and the superheated steam generator 2 are maintained so as to maintain the hot water temperature.
Is adjusted, and the aerated food is cooked for a predetermined time determined by the food (cooking B1 section). Then, in order to promote cooking, the temperature in the tank is further raised to a predetermined additional cooking and sterilization temperature (100 to 110 ° C.), and maintained for a predetermined time (1 to 4 minutes) to complete cooking and perform a sterilization process ( Secondary heating B2 section). When the cooking is completed, the temperature in the tank is raised to a predetermined sterilization temperature (120 ° C.), and the temperature is raised for a predetermined time (1 to 1).
(4 minutes) and sterilization is performed (third temperature rise C section). Furthermore, the temperature in the tank is raised to a predetermined sterilization temperature (122 to 124 ° C.), and the state is maintained for approximately one minute to perform high-temperature sterilization (fourth heating D section). (Cooling E section).

As described above, cooking of the aerated food enclosed in a semi-cooked state is surely completed in the sterilizing tank, and the aerated food is exposed to the outside air by successively increasing the temperature in the tank and sterilizing. It can be cooked without being oxidized, can be heated from a cooking temperature to a high temperature, and can be sterilized in a relatively short time. In addition, by performing the sterilization treatment in a short time by increasing the sterilization temperature, the sterilization treatment that satisfies the sterilization condition of the F value of 4 can be performed in a short time. In addition, the time during which the aerated food is kept in a high temperature state for sterilization can be shortened, and the cooking of the aerated food can be prevented from proceeding too much, and the smell of bags or cans can be prevented from adhering.

[0022]

As described above, according to the present invention, uncooked food is filled in a heat-resistant container, stored in a sterilization tank, heated and cooked, and after cooking is completed, the food is heated and sterilized. By controlling the center temperature of the
Cooking and sterilization are performed continuously. It is possible to avoid problems such as impairing the taste and smell of food and excessive cooking without exposing the aerated food to high temperatures for a long period of time for sterilization. Further, by pouring cooling water sufficiently cooled in the cooling water tank into the sterilizing tank, the food can be rapidly cooled to room temperature, and the taste and smell of the food due to long-term exposure to the sterilizing temperature can be prevented. In addition, the cooling water used for cooling can be collected, cooled sufficiently in the cooling water tank, and reused by alternately using the cooling water tanks.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a system for sterilizing and cooking aerated food.

FIG. 2 is a temperature-time transition curve according to a two-stage temperature increase showing details of the present invention.

FIG. 3 is a temperature-time transition curve based on a three-step temperature rise showing details of the present invention.

FIG. 4 is a temperature-time transition curve by four-step temperature rise showing details of the present invention.

FIG. 5 is a temperature-time curve showing details of a conventional sterilization and cooking system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steam control analog valve 2 Superheated steam generator 3 Heat exchanger 4a 2-way switching valve 4b 2-way switching valve 5 Circulation pump 6 Sterilization tank 7 Drain valve 8a Open / close valve 8b Open / close valve 8c Open / close valve 9 Hot water recovery tank 10 First Cooling water tank 11 Cooling water pipe 12 Second cooling water tank 13 Truck 14 Water injection container 15 Air pressure pipe 16 Compressor 17 Pressure control analog valve 18 Pressure sensor 19 Exhaust analog valve 20 Supply pipe 21 Reflux pipe 22 Hot water temperature sensor 23 Inside tank Temperature sensor 24 Control panel

Claims (3)

(57) [Claims] A heat-resistant container is filled with uncooked food, and the inside of the container is replaced with an inert gas, and the sealed aerated food is stored in a sterilization tank. The center temperature of the food is determined by the following (1). A method of sterilizing and heating an aerated food, wherein the method varies in multiple stages in the order of steps (5) to (5). (1) Set the center temperature of the food to 80 to 1 in 5 to 15 minutes.
A primary temperature raising step of rapidly raising the temperature to 00 ° C., (2) the central temperature of the food to 80 to 100 ° C.,
A cooking constant temperature step of maintaining for a predetermined time based on the type and amount of the aerated food; (3) setting the central temperature of the food to a food sterilization temperature of 110 to 12;
A secondary temperature raising step of raising the temperature to 0 ° C., (4) a sterilizing step of maintaining the center temperature of the food to 110 to 120 ° C. for 2 to 10 minutes, (5) a plurality of cooling water tanks, The cooling water in the inside was cooled, the cooling water in any one of the cooling water tanks was poured into the sterilization tank, and the central temperature of the food was rapidly lowered to room temperature in 4 to 15 minutes, and then used for cooling. A cooling process in which cooling water is collected in a cooling water tank and cooled, and for the next cooling, cooling water in another cooling water tank is used. 2. A heat-resistant container is filled with uncooked food,
The air-containing food sealed by replacing the inside of the container with an inert gas is accommodated in a sterilization tank, and the center temperature of the food is set in the following (1) to (6).
And sterilizing and heating the aerated food, wherein the method varies in multiple stages in the order of the steps. (1) Set the center temperature of the food to 80 to 1 in 5 to 15 minutes.
A primary temperature raising step of rapidly raising the temperature to 00 ° C., (2) the central temperature of the food to 80 to 100 ° C.,
A cooking constant temperature step of maintaining for a predetermined time based on the type and amount of the aerated food; (3) setting the central temperature of the food to a food sterilization temperature of 110 to 12;
(4) a sterilization process in which the center temperature of the food up to 110 to 120 ° C. is maintained for 2 to 10 minutes; and (5) a center temperature of the food in addition to 122. ~ 124
(C) A plurality of cooling water tanks are provided, the cooling water in the cooling water tank is cooled, and the cooling water in one of the cooling water tanks is sterilized. After pouring water into the tank and rapidly lowering the central temperature of the food at 122 to 124 ° C. to normal temperature in 4 to 15 minutes, the cooling water used for cooling is collected in the cooling water tank and cooled, and the next cooling is performed. In this case, a cooling process using cooling water in a different cooling water tank from the previous time. 3. Filling the heat-resistant container with uncooked food,
The aerated food sealed by replacing the inside of the container with an inert gas is accommodated in a sterilization tank, and the center temperature of the food is determined by the following (1) to (7).
And sterilizing and heating the aerated food, wherein the method varies in multiple stages in the order of the steps. (1) Set the center temperature of the food to 80 to 1 in 5 to 15 minutes.
A primary temperature raising step of rapidly raising the temperature to 00 ° C., (2) the central temperature of the food to 80 to 100 ° C.,
(3) keeping the center temperature of the food at about 110 in 3 to 4 minutes, wherein the cooking temperature is maintained for a predetermined time based on the type and amount of the aerated food;
Additional cooking step of rapidly raising the temperature to 0 ° C., (4) secondary temperature raising step of raising the central temperature of the food to the food sterilization temperature of 120 ° C., (5) maintaining the central temperature of the food for 3 to 4 minutes (6) The central temperature of the food is further increased by 122 to 124.
° C, and a high-temperature sterilization treatment step of rapidly raising the temperature to about 1 minute, and (7) providing a plurality of cooling water tanks, cooling the cooling water in the cooling water tank, and dissolving the cooling water in any one of the cooling water tanks After the water is poured into the chiller and the center temperature of the food is rapidly lowered to room temperature in 4 to 15 minutes, the cooling water used for cooling is collected in a cooling water tank and cooled, and the next cooling is different from the previous cooling. Cooling process using cooling water in the water tank.