JPS5966865A - Retort processing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides pressure and heat sterilization for the contents sealed in a packaging container having a relatively thin wall, especially the contents sealed with a space left inside, without deforming the container. Regarding how to.

The method of sterilizing the contents sealed in packaging containers by applying pressure and heating has traditionally been widely used for canned and bottled foods. Containers such as Lamicon Cups (registered trademark of Toyo Seikan Co., Ltd.) and Hyhooks (registered trademark of Toyo Seikan Co., Ltd.) have gradually come to be used for foods packaged in such containers, as well as pharmaceuticals packed in plastic bottles. It's here. however,
Packaging containers with walls that are relatively easily deformed such as paper-based retortable containers with excellent oxygen barrier properties, lamicon cups, and hyflex, and packaging containers that easily deform when heated such as plastic bottles, Due to the problem of destruction or deformation of the container during pressure and heat sterilization, there were many restrictions on its use.

The cause of deformation or destruction of packaging containers during pressurized heat sterilization is due to the difference between the internal pressure of the packaging container and the internal pressure of the retort. This is particularly likely to occur in sealed packages (hereinafter referred to as air-containing packages). In order to solve this problem, retort foods and the like have traditionally been packaged in a deaerated state, but for some products it is actually difficult to deaerate the packaging. There were many.

As a method for pressurizing and heating sterilization of air-containing packages that are difficult to deaerate, the following proposals have been made. According to Japanese Patent Publication No. 54-38190, a method is proposed in which pressure and heat sterilization is performed by maintaining an appropriate balance between the pressure inside the retort and the pressure inside the container during pressurization and cooling. The disadvantage is that pressure and heat sterilization takes too much time and is not suitable for mass production. Also, special public service in 1982-
According to No. 12100, a method is provided in which the internal pressure of a packaging container is detected during heating, sterilization, and cooling, and pressure and heat sterilization is performed while maintaining the retort pressure higher than the packaging container internal pressure by a certain pressure difference. Special Publication 1986-1983 as a method for detecting the internal pressure of containers
No. 52 and Japanese Patent Publication No. 556853 are disclosed.

However, although the above-mentioned method of detecting the internal pressure of the packaging container and controlling the internal pressure of the retort is an excellent idea, in practice, deformation of the packaging still occurs frequently, and it is difficult to say that it has sufficiently solved the problem. It was something. One of the reasons for this is that the internal pressure of the air-containing packaging container is detected using a model packaging container that is built into a rigid metal body with a relatively large heat capacity (see Japanese Patent Publication No. 55-6852). It is presumed that this is because the pressure detected in this case does not necessarily match the pressure inside many other packaging containers that are sterilized.

According to the present invention, there is provided a pressure and heat sterilization method that does not cause deformation of the packaging container as seen in the above-mentioned conventional methods and is extremely simple in processing operations.

The present invention detects the internal temperature of the packaging container in a pressure and heat sterilization method for packaging contents, which controls the internal pressure of the retort to approximately maintain equilibrium with the internal pressure of the packaging container. This invention relates to a method for heat sterilization of package contents by controlling the internal pressure of the package.

In this specification, "maintaining the internal pressure of the retort approximately in equilibrium" with the internal pressure of the packaging container means that the internal pressure of the retort is +10 kg/cm2 to -3 kg/cm of the internal pressure of the packaging container.
Within the range of 2, preferably +5kg/cm2 to -2kg/cm2
cm2, most preferably +0.2 kg/cm2
It is used to maintain the weight within the range of ~-02 kg/cm2. The internal pressure of the retort is + the internal pressure of the packaging container.
Too high, exceeding 10kg/cm2, or -3kg/cm2
If it is too low, less than cm2, the packaging container will be permanently deformed, which is not preferable.

The method of detecting the internal temperature of a packaging container in the present invention includes a thermocouple, a resistance thermometer, a magnetic thermometer, a capacitance thermometer, a transistor IC thermometer, an elastic thermometer, a radiation thermometer, a thermometer using thermal noise, and a firefly thermometer. A method using a light thermometer or the like is used, but a method using a thermocouple is particularly preferred.

In the present invention, the internal pressure of the packaging container at the internal temperature of the packaging container measured by a thermocouple or the like is determined from a temperature-pressure conversion curve prepared in advance, and the internal pressure of the retort is maintained at this value. be. Such conversion curves vary depending on the type of packaging container, the type of packaging contents, and the filling rate of the contents (% of the volume occupied by the contents in the packaging container). Set for each body.

The conversion curve may be set by any method as long as the internal pressure of the retort is approximately balanced with the internal pressure of the packaging container. For example, a model package in which a part of the packaging container (for example, a lid, etc., hereinafter referred to as the deformable part) is made of a reversibly deformable material is placed in a retort where the inside can be observed with the naked eye, and the package is heated to 5°C from 20°C. Measure the retort pressure at which the deformation part does not deform at each temperature, calculate the average value of the upper and lower limit pressures, and calculate the internal pressure of the packaging container at that temperature (approximate value). shall be. In this way, a temperature-pressure conversion curve is obtained every 5°C from 20°C to 160°C.

In a preferred embodiment of the present invention, the conversion curve does not necessarily need to be determined experimentally as described above, and the following conversion curve is preferably used. That is, here, T: Temperature detected by the pressure control wholesale thermocouple (°K) P: Pressure inside the retort pot (kg/cm2) at temperature T ρ293; Density of water at 293°K ρT; Density of water Aw at temperature T ; Water activity PWT of the filled contents; Saturated water vapor pressure (atm) H at temperature T; Ratio of the head space to the capacity of the packaging container (assumed to be 1).

The internal pressure P of the retort corresponding to the internal temperature P of the packaging container can be easily determined from the curve represented by .

In a further preferred embodiment, the conversion curve is a temperature-vapor pressure curve of water, in which the vapor pressure value is multiplied by n, where n is determined by the type of packaging container, the type of package contents, the filling rate of the contents, etc. Since the number is different, the optimum number is selected for each air-containing package to be sterilized, but the range of n is generally 0.5 to 3.
0 preferably 0.7 to 2.7, most preferably 0.75
~2.5. The optimum value of n can be easily selected by determining the internal pressure of the retort at one or more appropriate temperatures using the method of experimentally determining the conversion curve described above, and by correlating this with the water temperature-vapor pressure curve. can be calculated.

In the present invention, the internal temperature of the packaging container may be measured by measuring the temperature of the packaged contents (solid or liquid) or by measuring the temperature of the head space within the container, but preferably by measuring the temperature of the head space within the container. By measurement. This is because deformation of the packaging container is more effectively prevented by controlling the internal pressure of the retort using a conversion curve based on the temperature measured by the gas in the head space.

Next, an example of the operation of the pressure heat sterilization method of the present invention will be specifically explained using FIGS. 1 and 2.

After putting the package 19 with the contents sealed in the packaging container into the retort main body 1 and sealing the retort, the steam valve 3 is opened to introduce pressurized steam from the steam introduction pipe 2 into the retort main body 1, and the sterilization shelf is filled. Heating of the package 19 to be sterilized placed at 18 is started. When the temperature of the model package 22 to be sterilized with the thermocouple 20 attached to the headspace begins to rise, the voltage generated at the detection end of the thermocouple is converted into a conversion curve (internal temperature of the packaging container - internal pressure of the retort) by the converter 21. The internal pressure of the retort main body 1 based on the conversion curve (conversion curve) is converted into an indicated voltage. In the temperature raising process, if the retort internal pressure becomes too high than a predetermined internal pressure, the pressure reducing valve 7 is automatically operated to exhaust air from the pressure reducing pipe 6. On the other hand, if the retort internal pressure is too low than the predetermined internal pressure, the pressurizing valve 5 is automatically activated. The compressed air is supplied from the air pressurizing pipe 4 to increase the internal pressure of the retort. By automatically repeating such operations, the internal pressure of the retort during the temperature raising process and the sterilization process is automatically controlled so as to approximately balance with the internal pressure of the packaging container. Note that a steam stirring fan 8 is installed in order to improve the uniformity of temperature within the retort, and is suitably used in the temperature raising process and the sterilization process.

The sterilization process is carried out at a predetermined temperature for a predetermined time, for example at 120°C for 15
It takes place for a minute. When the sterilization process is finished, the steam valve 8 is closed, the primary water supply valve 10 is opened, and cooling water is supplied from the primary water supply pipe 9 to the side wall cooling pipe 11, and the cooling water mainly cools only the side wall of the retort body in a shower-like manner. do. When the water level of the cooling water accumulated at the bottom of the retort body reaches the water level sensor 12,
The primary water supply valve 10 automatically closes and the secondary water supply valve 14 automatically opens, allowing cooling water to flow from the secondary water supply pipe 18 to the shower cooling pipe 1.
5, the cooling water falls like a shower and uniformly cools the package 19 to be sterilized. At this time, the drain valve 17 automatically repeats opening and closing so that the cooling water level accumulated at the bottom of the retort is maintained at the position of the water level sensor 12 by the water level sensor.

Also in this cooling step, the voltage generated at the detection end of the thermocouple 20 is converted by the converter 21 into a voltage indicating the internal pressure of the retort body 1 based on the conversion curve (conversion curve of packaging container internal temperature - retort internal pressure). be done. If the retort internal pressure is too low than a predetermined internal pressure, the pressurizing solenoid valve 5 will automatically operate and compressed air will be sent from the air pressurizing pipe 4. If the retort internal pressure is too high than the predetermined internal pressure, the pressure reducing solenoid valve 7 will automatically operate. When activated, exhaust is exhausted from the pressure reducing pipe 6 and the pressure is reduced. By repeating such operations, the internal pressure of the retort body 1 is kept approximately in equilibrium with the internal pressure of the packaging container 1 during the cooling process.

The converter 21 is based on the following principle.

A temperature signal (electromotive force, DC mV) from a thermocouple temperature measurement sensor (copper-constantan) is converted into a DC voltage signal and transmitted by an electromotive force transmitter. This DC voltage signal is used to linearize the non-linear characteristics between the input and output signals using a characteristic converter. That is, temperature-pressure conversion is performed. When using this output signal by multiplying the temperature-pressure conversion curve by m, amplify it by m times using an amplifier with pressure-sensitive adjustment, and/or when adding or subtracting the differential pressure, add or subtract using a calculator. . The signal obtained here becomes a set pressure signal, and the operating amount is electro-pneumatically converted through a normal electronic PID pressure control device to operate the pneumatic operating valve.

The operation of the pressurized heat sterilization method of the present invention is described in Japanese Patent Publication No. 1983-
The retort shown in FIG. 1, page 4 of No. 88190 may also be used to effectively carry out the process.

Packaging containers to which the pressure and heat sterilization method of the present invention is suitably applied include plastic cup-shaped containers, paper-based molded containers, plastic trays, laminate trays, plastic bottles, plastic tubes, thin-walled metal cans, and aluminum lids. These are metal cans, etc., and the contents include luxury items such as oshiruko, coffee, jelly, and pudding; soups such as soup and miso soup; cooked rice such as fried rice, chicken rice, and sekihan; fried noodles, macaroni, Japanese soba, etc. Noodles; For side dishes such as vegetable umami, Yamato simmered fish, Chawanmushi, and spring rolls; Processed fish meat products such as kabayaki, young chicken momoyaki, meatballs, and hamburgers; Processed fruits such as mandarin oranges and peaches, and shellfish. In addition to the above-mentioned foods, there are also sugar solutions such as Ringer's solution, glucose, and gluctose, and pharmaceutical solutions such as amino acid solutions and Textran solutions.

Example 1. A truncated conical thin-walled container (manufactured by Toyo Seikan Co., Ltd., trade name: Lamicon Cup) made of a laminate of polypropylene and ethylene-vinyl alcohol copolymer, with an internal volume of 250 ml and a height of 85 mm, was filled with 200 ml of corn potage soup, and polyester-aluminum A foil-polypropylene laminate molded drop lid (manufactured by Toyo Seikan Co., Ltd.) was heat-pressed and sealed. 120 such packages were prepared, and 40 of them were subjected to retort treatment using the temperature-pressure conversion pressure control system according to the present invention. (The remaining 40 pieces were subjected to pressurized heat sterilization treatment in which the package was housed in a rigid container and the pressure was controlled by detecting this pressure outside the retort pot, as in the example described in Japanese Patent Publication No. 56-12100 [Comparative Example 1 ], and the remaining 40 pieces were subjected to conventional constant pressure retort treatment [Comparative Example 2].) First, the temperature-pressure conversion pressure controlled retort of the present invention was performed. One of the packages to be sterilized was equipped with a packing gland for fixing a thermocouple (manufactured by Elab, trade name, TCG31-1.2) used for temperature measurement to perform temperature-pressure conversion pressure control.
) is attached so that the temperature measurement part of the thermocouple is in the head space, and the other is a packing gland for fixing the thermocouple to obtain the temperature history curve necessary for heat sterilization. It was attached to become the food section.

The package was placed in a retort equipped with a temperature-pressure conversion pressure control device. The package equipped with the packing gland for fixing the thermocouple contains a thermocouple for pressure control (copper-constantan, manufactured by Elab, trade name: DCK33-1.2) and a thermocouple for temperature measurement (copper-constantan, manufactured by Elab). (trade name, DCK33-1.2) was inserted and fixed. The thermocouple was connected to the outside of the retort using a lead wire covered with silicone rubber, and a pressure control device and temperature recorder (manufactured by Elab, trade name, Z
4FD).

After the retort was sealed, pressurized steam was introduced into the retort body, a steam stirring fan was rotated, and pressurized heat sterilization was started. The sterilization process was performed at 120°C for 40 minutes. The temperature-pressure conversion curve used for pressure control at this time was a curve (curve α in FIG. 3) obtained by multiplying the water vapor curve by 1.3 times (n=1.3). After the sterilization process was completed, the introduction of pressurized steam and the rotation of the steam stirring fan were stopped, and the cooling process began. Cooling first
In the subsequent cooling, only the inner wall of the retort body was cooled in order to prevent a sudden pressure drop caused by steam condensation outside the pressure control system caused by the introduction of cooling water into the retort body.

Next, as secondary cooling, water was supplied in a shower form from the water supply pipe at the top of the retort to uniformly cool the packages to be sterilized.

During this retort processing, the temperature inside the retort pot (curve 1 in Figure 4) and the temperature inside the package (curve 2 in Figure 4) are as shown in Figure 4, and the pressure inside the retort is as shown in Figure 5. It showed pressure change.

When the retort pressure became 0 kg/cm2 and the temperature inside the package was sufficiently cooled, cooling was terminated, and the entire retort treatment process was completed through a drainage process. The 40 packages taken out from the retort pot were in exactly the same state as before they were processed (0.5
There was no deformation of more than mm).

Comparative example 1. The retort treatment described in Japanese Patent Publication No. 56-12100 was carried out.

The retort is equipped with a hot water storage tank similar to the example in the upper part, and is connected to the retort main body through a hot water supply pipe and a hot water ring pipe, and the main body has a pressurized steam pipe, a water supply pipe, a drain pipe, a pressurizing pipe, and a pressure reducing pipe. The package was housed in a rigid container made of brass, and the package was housed in a retort equipped with a pressure detection device for detecting this pressure outside the retort pot.

After the retort was sealed, hot water preheated to 100°C was supplied from the hot water storage tank to the retort body. After the hot water supply was completed, the temperature of the hot water in the retort was 85°C. After that, pressurized steam was introduced from the pressurized steam pipe to raise the temperature to the set temperature. Pressure control is 0.5kg/c based on the pressure detected by the pressure detection device.
m2 was added.

Incidentally, when the temperature of the packaged food was 100°C, the pressure inside the retort pot was 2.1 kg/cm2.

After completing the sterilization process at 120° C. for 30 minutes, the hot water in the retort pot was partially filled into the hot water storage tank through the hot water pipe, and cooling water was sent into the retort pot through the water supply pipe.

At this time, the temperature inside the pot rapidly decreased, and the temperature inside the package also decreased accordingly. However, the pressure detected by the pressure sensing device did not show a significant decrease.

Even though cooling was continued and the temperature inside the package became 30° C. or lower, the pressure in the pot did not drop to 0.5 kg/cm 2 . The cooling water was drained, the entire retort process was completed, and the package was taken out from the retort pot and inspected. Figure 7 shows the deformation of the packaging container. X indicates the bulge (mm) of the lid, and y indicates the dent (mm) of the extended wall. The test results were as shown in the table below.

- There were 6 dents in the side wall for each package.

Comparative example 2. Next, conventional constant pressure retort processing was performed. Forty of the packages were housed in a retort body, and after the retort was sealed, pressurized steam was introduced into the retort body. When the temperature inside the retort pot reached 90° C., the pressure reducing valve was closed and air pressurization was started from the pressure tube. Pressure condition is 1.5kg/cm
It is 2. The temperature-time conditions were 120°C and 80 minutes. After the sterilization process was completed, the pressurized steam valve was closed and the cooling process started. The cooling process requires 1 to improve cooling efficiency.
For the next cooling, water was supplied from the upper part of the retort in the form of a shower to completely condense the remaining steam. At this time, a sudden drop in retort pressure was observed, but it instantly returned to 1.5 kg/cm2.

Subsequently, secondary cooling was performed. Water was rapidly supplied from the lower part of the retort to cool it. After confirming that the temperature inside the package had cooled down sufficiently, drainage was started.

At this time, the retort pot pressure also rapidly decreased to 0 kg/cm.
It became 2. When the water was drained and the retort treatment was completed, the packages were removed from the retort, and significant permanent deformation was observed in all 40 packages. The test results are shown in the table below.

- There were 6 dents in the side wall for each package.

Example 2. A truncated conical thin-walled container (manufactured by Toyo Seikan Co., Ltd., trade name: Lamicon Cup) made of a laminate of polypropylene and ethylene-vinyl alcohol copolymer with an internal volume of 250 ml and a height of 85 mm contains 150 g of Ogura Zensai and 10 g of Shiratama mochi. )3
They were filled individually and sealed with thermocompression with polyester, aluminum foil, and polypropylene laminate molded drop lids (manufactured by Toyo Seikan Co., Ltd.). At this time, the filling rate of the package is 6
It was 0%. Forty of the above-mentioned packages were prepared, one of which had a backing gland for fixing the pressure control thermocouple (manufactured by Elab, trade name, TCG31-1.2), and the temperature measurement part of the thermocouple was in the head space. I installed it like this.

The package was subjected to the retort treatment using the temperature-pressure conversion pressure control method according to the present invention in Example 1. The temperature-pressure conversion curve used for pressure control at this time is a curve obtained by multiplying the water vapor pressure curve by 1.2 times (n = 1.2) (curve b in Figure 3).
). After all the retort processing steps were completed, the 40 packages taken out from the retort pot were completely the same as before the processing, and an extremely excellent retort food packaged in thin-walled containers was obtained.

Example 3. Ringer's solution 5 was placed in a bottle made of a laminate of polypropylene and ethylene-vinyl alcohol copolymer with a content of 710 ml.
It was filled with 30ml, sealed with a rubber cap, and sealed with aluminum. 40 such packages were prepared, one of which was for pressure control, and a thermocouple fixing packing gland (manufactured by Elab, trade name, TCG31- 1.2) was fixed.

Here, the temperature-pressure conversion curve of the package is T; temperature detected by the pressure control thermocouple (°K) P; pressure inside the retort pot at temperature T (kg/cm2) ρ293; 0.998 ρT; temperature T Density of water Aw at 1.0 PWT; Saturated water vapor pressure at temperature T (atm) H; 0
．． Pressure control is performed using the curve represented by 25 (Fig. 6), and 115
The temperature according to the invention of Example 1 was sterilized for 60 minutes at -
Processing was performed in the same manner as retort processing using the pressure conversion pressure control method. After completing all the retort processing steps, the 40 packages taken out from the retort pot were the same as before the processing.

Example 4. 45 g of bamboo shoots was placed in a thin-walled tray (manufactured by Toyo Seikan Co., Ltd.; product) made of a laminate of polypropylene and ethylene-vinyl alcohol copolymer with an internal volume of 100 ml and a height of 20 mm.
After filling, a laminate molded drop lid (manufactured by Toyo Seikan Co., Ltd.; product) of polyester, aluminum foil, and polypropylene was sealed by thermocompression.

The filling rate of the package was 30%. 1 of the above packages
28 pieces were adjusted, one of which was a packing gland for fixing the thermocouple for pressure control (manufactured by Elab; trade name, TCG3).
1-1.2) was attached so that the temperature measurement site of the thermocouple was in the head space.

Temperature determined experimentally using a model package in which the package is reversibly deformed in a retort whose interior can be observed with the naked eye.
The pressure was controlled using a pressure conversion curve, and sterilization treatment at 120° C. for 20 minutes was carried out in the same manner as the retort treatment using the temperature-pressure conversion pressure control method according to the present invention in Example 1. After all the retort steps were completed, the 8 packages taken out from the retort pot were in exactly the same condition as before they were all processed.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a steam retort used in the pressurized heat sterilization method of the present invention, and FIG. 2 is a schematic vertical cross-sectional view of the same retort. 1: Retort main body 2: Steam introduction pipe 4: Air pressurization pipe 9: Primary water supply pipe 11: Side wall cooling pipe 12: Water level sensor 13: Secondary water supply pipe 15: Shower cooling pipe 16: Drain pipe 19: Sterilized package 20 : Thermocouple 21: Converter Figure 3 shows n=1.3 used in Example 1 and Example 2, respectively.
and temperature-pressure conversion curves a and b for n=1.2. Curve c is a saturated vapor pressure curve. FIG. 4 shows the course of changes over time in the temperature inside the retort pot and the temperature inside the package in Example 1, and FIG. 5 shows the course of changes over time in the pressure inside the retort pot in Example 1. FIG. 6 shows the temperature-pressure conversion curve used in Example 3. FIG. 7 is a cross-sectional view of the packaging containers of Comparative Examples 2 and 3 after retort treatment, and dotted lines indicate deformation of the lid and side wall. Patent applicant Akira Kishimoto Agent Patent attorney Heikichi Odajima et al. Written amendment: (mouth)''. November 18, 1981 Tomi Wakasugi Oro, Director of the Patent Office 1, Indication of the incident HjJ4u57 qlE'humiliation, 7i'1lli; Mi
No. 173969 No. 2, Name of the invention Retort A S L → J Law 3, Relation to the Nagisa case to be amended Patent applicant 4 representative Attorney Person 〒107' Details of the invention of Ming 11M, 11) Explanation of Ming 7 11th issue 7, attached sheet of amendments))・Risui, fl, 1. ll, II:,,,,Akihito J,? i:
@: Su, lines 19-11 QC ("...iftsuku, 1st"
A Certain Thought □ ``High Flex'', 5 City Hall 1-1. 'Moaning 1: l1flflO4Q,, 1f in 1.1 line,'
r, A1 (I + 4.q J and a certain firefly, correct it as Ti (Heshina) □. (3) 102F, Q / :ni in the same No. 7 white line
J and ll)ru♀1" 0.2 Kp/ : rl Correct to J. (4) Same v, 16 〒 or 64-3 K ＝S” ・〕　　　　　　　　　　　　　　　　　　　　　　》 , ti+ 171 2nd t*; 130 in i'<s row
□, correct the text "minutes" to "140 minutes". (6) On page 23, line 4, there is a statement that contradicts “30 minutes.”
Revised 11:40 minutes. □ Hand, continuation amendment (voluntary) April 28, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi Indication of the case 1982 Patent Application No. 173969'□2
, Name of the invention, Retort processing method, , Relationship between the incident, , Special t7 U+lfi
□Person 01'T'J (26th address, 4439 Kamaritani-cho, Kanazawa-ku, Yokohama-shi, Kanagawa Prefecture Name Kishimoto-Aki (Mr. N゛,)1 4th generation Toshihito〒1tJ7 Detailed explanation column□″7.Additional□ Positive content y;+1m.
゛Attachment (1+) The statement in the claims column of the specification is corrected as follows: “[Claims] 1. Maintaining the internal pressure of the retort approximately in equilibrium with the internal pressure of the packaging container In the pressure and heat sterilization method of the packaged contents, the internal temperature of the packaging container is detected and the internal pressure of the retort is controlled based on the detected temperature.2. A conversion curve showing the relationship between the internal temperature of the packaging container and the internal pressure of the retort is set in advance prior to the pressure heat sterilization treatment of the package contents, and the internal pressure of the retort corresponding to the detected internal temperature of the packaging container is determined. is determined from the conversion curve, and the internal pressure of the container is maintained at the determined internal pressure of 1/tort, thereby keeping the internal pressure of the container approximately in equilibrium with the internal pressure of the packaging container. Pressure heat sterilization method. 3 Pressure heat sterilization method according to claim 2, wherein the conversion curve is obtained by multiplying the vapor pressure value by n in the temperature-vapor pressure curve of water. 4 The pressure heat sterilization method according to claim 2. Here, 7': Detected temperature of thermocouple for L force control (°K)
P: The retort is placed at a temperature of 1" and the pressure inside the pot is (kg 7-
) ρ203 ; 293'J (ρ7 to water density 1 in
・;Density of water at temperature 7'
A patent claim that is a curve expressed by li+Japanese power (ki 1'TE (, a, f nt) T Jl; the ratio of -\sodosbeth to the capacity of the 7 containers on the packaging (assumed to be 1) The pressure and heat sterilization method described in item 1). 5. The conversion curve is obtained by experimentally successively determining the retort internal pressure that does not cause deformation of the packaging container at a specific temperature using a model package that is easily deformable and a T-tort whose interior can be observed. The pressure and heat sterilization method described in Scope 2. . 6. The pressurized and heat sterilization method according to any one of claims 1 to 5, wherein the internal temperature is measured by temperature measurement using a henodesbeth of a packaging container. 7. In a pressurized heat sterilization retort having steam introduction means for heating, air introduction means for pressurization, exhaust means for depressurization, and water introduction means for cooling, detecting the internal temperature inside the container of the packaged object to be sterilized. A retort for pressure and heat sterilization 1, characterized in that the internal pressure of the retort is controlled based on the internal temperature by a converting means for converting the detected internal temperature into an internal pressure. , J (2) Specification ν) It is written in the 1st line of page 1O and the 6th line of 26th page. .

Claims (7)

[Claims] 1. In the pressurized and heat sterilization method for packaging contents, which controls the internal pressure of the retort to approximately maintain equilibrium with the internal pressure of the packaging container, the internal temperature of the packaging container is detected, and the internal pressure of the retort is adjusted based on the detected temperature. Controlled pressure and heat sterilization method for packaged contents 2. A conversion curve showing the relationship between the internal temperature of the packaging container and the internal pressure of the retort is set in advance prior to the pressure heat sterilization treatment of the package contents, and the conversion curve of the retort corresponding to the detected internal temperature of the packaging container is set in advance. Pressurization according to claim 1, in which the internal pressure of the retort is kept approximately in equilibrium with the internal pressure of the packaging container by determining the internal pressure from the conversion curve and maintaining the internal pressure of the retort at the determined internal pressure. Heat sterilization method. 3. 3. The pressure heat sterilization method according to claim 2, wherein the conversion curve is obtained by multiplying the vapor pressure value by n in the temperature-vapor pressure curve of water. 4. The conversion curve is expressed by the following formula: T: Temperature detected by the pressure control thermocouple (°K) P: Pressure inside the retort pot at temperature T (kg/cm2) ρ293; Density of water at 293°K ρT; Temperature 7'
The density of water at Aw; water activity PWT of the filled contents; saturated water vapor pressure (atm) H at temperature T; The pressure and heat sterilization method described in Scope 2. 5. Claim 2, wherein the conversion curve is obtained by experimentally determining the internal pressure of the retort that does not cause deformation of the packaging container at a specific temperature using a model packaging body that is easily deformable and a retort whose interior can be observed. Pressure heat sterilization method. 6. 6. The pressure and heat sterilization method according to any one of claims 1 to 5, wherein the detection of the internal temperature involves temperature measurement in the head space of the packaging container. 7. In a pressurized heat sterilization retort having steam introduction means for heating, air introduction means for pressurization, exhaust means for decompression, and water introduction means for cooling, means for detecting the internal temperature inside the container of the package to be sterilized; A retort for pressure and heat sterilization, characterized in that the internal pressure of the retort is controlled based on the internal temperature by means of a conversion means that converts the detected internal temperature into the retort internal pressure.