JP2010051264A - Method for producing packed chilled food product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a packed chilled food product, by which a high sterilizing effect is obtained without performing a high temperature thermal treatment exceeding 100°C, whereby the deterioration of the flavor and texture of the food product can be prevented to give the chilled food product having a long open date. <P>SOLUTION: A packed chilled food product is subjected to two or more steps of high pressure treatments changing the pressure at least once in a pressure range of 100 to 700 MPa in a state heated at a temperature little affecting the flavor of the food product at about 40 to 80°C for a total time of 4 to 30 min, thereby highly efficiently germinating spore bearing bacteria growing at low temperature of not more than 10°C, and then subjecting to a low temperature sterilizing treatment at 60 to 100°C for sterilizing the germinated spore bearing bacteria. Thus, since the germinated spore bearing bacteria can be sterilized by the high pressure treatment, the very high sterilizing effect is obtained without performing a high temperature thermal treatment exceeding 100°C, and the spore bearing bacteria growing at low temperature of not more than 10°C can especially efficiently be sterilized. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing chilled food in a container, in particular, improvement of sterilization ability in a non-high temperature heat sterilization treatment process, and production of chilled food in a container with a long shelf life by which deterioration of flavor and texture is suppressed. Regarding the method.

It is desired that a food in a container that has been cooked can be stored for a long period of time while maintaining good flavor and texture. For this reason, in each distribution food field, such as a retort food, a chilled food, and a frozen food, although the expiration date is prolonged by heat sterilization or frozen storage, for example, as shown in the following (1) to (3) Thus, it has been difficult to achieve both good flavor and texture and long-term storage stability.
(1) Although the food which carried out the retort sterilization process (pressurization heating-and-killing process) at the temperature exceeding 100 degreeC can be preserve | saved for a long time at normal temperature, its flavor and texture are bad.
(2) Food sterilized only by heating by hot water sterilization or cooking, while having a good taste, can be stored only for about 1 day at room temperature and only about 3 to 10 days even at chilled storage because of insufficient sterilization.
(3) Although it can be stored for a long time if it is stored frozen, there are ingredients such as potatoes and winter rice cakes that have a worse texture.

  On the other hand, a high-pressure treatment method is known as a non-heat sterilization method, and it has been confirmed that it exhibits a high sterilization effect against specific bacteria. However, the conventional high pressure treatment method has a problem that spore bacteria growing at a low temperature of 10 ° C. or less cannot be sufficiently sterilized. Regarding the improvement of such a high-pressure treatment method, for example, a method in which pressurization and depressurization are repeatedly treated (for example, see Patent Document 1) and a method in which a high-pressure treatment and a pasteurization treatment at 100 ° C. or lower are used in combination (for example, a patent However, in any of these methods, the bactericidal effect against spore bacteria growing at a low temperature of 10 ° C. or less is still insufficient, and among conventional chilled foods, contamination with spore bacteria. In the case of foods that may be used, it has been impossible to maintain good flavor and texture for a long period of time. For this reason, conventionally, development of the manufacturing method of the chilled foodstuff which can maintain favorable flavor and texture for a long period of time was desired.

JP-A-63-82667 JP-A-4-91770

  The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to obtain a high bactericidal effect without performing high-temperature heat treatment exceeding 100 ° C., thereby reducing the flavor and texture. It is an object of the present invention to provide a method for producing a chilled food in a container, which can suppress the chilled food with a long shelf life.

  As a result of intensive studies by the present inventors in view of the above-mentioned problems of the prior art, 100 to 700 MPa in a state where the chilled food in a container is heated to a temperature lower than the temperature that has little influence on the flavor of the food at about 40 to 80 ° C. By performing two or more stages of high-pressure treatment at a pressure of at least once in the pressure range of 4 to 30 minutes in total, spore bacteria that grow at a low temperature of 10 ° C. or less germinate very efficiently, In order to sterilize germinated spore bacteria, it is possible to sterilize spore bacteria germinated by high-pressure treatment by performing a pasteurization treatment at 60 to 100 ° C. The present inventors have found that a high bactericidal effect can be obtained, and that spore bacteria growing at a low temperature of 10 ° C. or less can be sterilized efficiently, thereby completing the present invention.

  That is, in the method for producing a chilled food containing a container according to the present invention, a cooked or half-prepared food sealed in a container is heated to 40 to 80 ° C. in a range of 100 to 700 MPa for a total of 4 to 30 minutes. A high-pressure treatment step for pressurization, which is held at a predetermined pressure for a predetermined time, and then held at a predetermined pressure for at least one predetermined pressure different from the predetermined pressure without reducing the pressure to atmospheric pressure. A multi-stage high-pressure treatment step, a pasteurization treatment step in which the pressure is reduced to atmospheric pressure after the high-pressure treatment step, and heat sterilization is performed at a temperature of 60 to 100 ° C., and cooling is immediately cooled to a chilled storage temperature after the pasteurization treatment step. And a process.

  Moreover, in the manufacturing method of the chilled food containing a container according to the present invention, the multi-stage high-pressure treatment step is performed at 100 to 300 MPa in a state where the cooked or half-prepared food sealed in the container is heated to 40 to 80 ° C. After a total pressure holding of at least one or more predetermined pressures in the range is performed for a total of 2 to 15 minutes, the pressure holding by at least one or more predetermined pressures in the range of 300 to 700 MPa is subsequently performed without reducing the pressure to atmospheric pressure. It is preferable that it is a multistage high-pressure treatment process for 15 minutes.

  Moreover, in the manufacturing method of the said chilled food containing a container, the said multistage high-pressure treatment process is the state of the range of 100-300 MPa in the state which heated the cooked food in the container sealed or in the middle of cooking to 40 to 80 degreeC. Two-stage high-pressure treatment in which pressure is maintained for 2 to 15 minutes at one predetermined pressure, and then pressure is maintained for 2 to 15 minutes at one predetermined pressure in the range of 300 to 700 MPa without reducing the pressure. It is preferable that it is a process.

  In the method for producing chilled food in a container, the multi-stage high-pressure treatment step may be performed at a temperature in a range of 100 to 300 MPa in a state where a cooked or half-prepared food sealed in a container is heated to 40 to 80 ° C. The pressure is held for 2 to 15 minutes at a predetermined pressure of 2 to 15 minutes, and then the pressure is held for 2 to 15 minutes at a predetermined pressure in the range of 300 to 500 MPa without reducing the pressure. It is preferable that it is a three-stage high-pressure treatment process in which the pressure is maintained for 2 to 15 minutes at a predetermined pressure in the range of 500 to 700 MPa without reducing the pressure.

  Moreover, in the manufacturing method of the said chilled foodstuff containing a container, the said multistage high-pressure process process is the state which heated at 40-80 degreeC in the state which heated the cooked food in the container or in the middle of cooking at least in the range of 300-700 MPa. After holding the pressure at one or more predetermined pressures for a total of 2 to 15 minutes, the pressure holding at least one or more predetermined pressures in the range of 100 to 300 MPa is then performed for a total of 2 to 15 minutes without reducing the pressure to atmospheric pressure. It is preferable that it is a multistage high-pressure treatment process.

  Moreover, in the manufacturing method of the said chilled food containing a container, the said multistage high-pressure process process is the predetermined pressure of the range of 300-700 MPa in the state which heated the cooked food sealed by the container at 40 to 80 degreeC. Is a two-stage high-pressure treatment step in which the pressure is held for 2 to 15 minutes and then the pressure is adjusted to a reduced pressure, and the pressure is held for 2 to 15 minutes at a predetermined pressure in the range of 100 to 300 MPa. Is preferred.

  Moreover, in the manufacturing method of the said chilled food containing a container, the said multi-stage high-pressure treatment process is the state of 500-700 MPa in the state which heated the food which has been cooked or in the middle of cooking sealed to the container at 40 to 80 degreeC. After maintaining the pressure for 2 to 15 minutes with one predetermined pressure, the pressure is subsequently adjusted to reduce the pressure, and the pressure is maintained for 2 to 15 minutes with one predetermined pressure in the range of 300 to 500 MPa. It is preferable that it is a three-stage high pressure treatment step in which the pressure is adjusted to a reduced pressure and the pressure is maintained for 2 to 15 minutes at a predetermined pressure in the range of 100 to 300 MPa.

  According to the method of the present invention, a very high bactericidal effect can be obtained without performing high-temperature heat treatment exceeding 100 ° C., and it is particularly possible to efficiently sterilize spore bacteria growing at a low temperature of 10 ° C. or less. As a result, it is possible to obtain a chilled food product that suppresses deterioration of flavor and texture and has a long shelf life.

The present invention was made by paying attention to the sterilization of spore bacteria that could not be sufficiently sterilized only by the conventional high-pressure treatment method, particularly the germination and inactivation of spore bacteria that grow at a low temperature of 10 ° C. or less. .
And according to the manufacturing method of the chilled food with a container concerning this invention, in the state which heated the chilled food with a container to about 40-80 degreeC, the pressure was changed at least once in the pressure range of 100-700 MPa. In order to sterilize the germinated spore bacteria, the spore bacteria that grow at a low temperature of 10 ° C. or less are germinated very efficiently by performing the multi-stage high-pressure treatment of the step or more for a total of 4 to 30 minutes. Since the spore germs germinated by the high-pressure treatment can be sterilized by performing the low temperature pasteurization treatment, the spore germs can be efficiently sterilized without performing a high temperature heat treatment exceeding 100 ° C.
In addition, it is known that germination of spore bacteria is suppressed by high-pressure treatment, and that germinated spore bacteria can be sterilized by low-temperature heat sterilization of about 60 to 100 ° C. (Y. Aoyama) , Et al., Food.Sci.Technol.Res., 11 (1), 101-105, 2005).

  In the present invention, the chilled food in a container is usually a food stored in a chilled temperature range of about 10 to -5 ° C, and the present invention is not particularly limited as long as it is such a food. be able to. As chilled foods, for example, curry, meat potato, potov, bouillabaisse, oden, soup, stewed beef curd, mochi stew, etc. or roux, soup, broth, sauce, etc. What combined the liquid and solid ingredients, such as meat, fish, and vegetables, is mentioned.

  The container for containing the chilled food is not particularly limited, but usually has heat resistance that can withstand pasteurization, and can be changed in volume by pressure, such as a metal container such as a can, or a soft cup such as a plastic cup or pouch. A packaging container is used. In order to enable long-term storage, a container having a barrier property against gas and light is preferable, and a metal container is particularly preferable.

  Hereinafter, a preferred embodiment of the present invention will be described using an example of a method for producing a chilled food containing a container according to the present invention. In FIG. 1, the flowchart of the manufacturing method of the chilled foodstuff with a container concerning an example of this invention is shown.

  In the method for producing a chilled food in a container according to an example of the present invention, first, food is prepared in the first cooking step, and this is filled in a metal or flexible packaging container in a filling and sealing step, and then double-rolled or heated. Seal with a seal. Further, cooking at 100 ° C. or lower is performed in the second cooking step, and the temperature is adjusted to a temperature suitable for high-pressure processing in the subsequent preheating step. Thereafter, multistage high-pressure treatment in which the pressure is changed at least once is performed to germinate spore bacteria that grow at a low temperature of 10 ° C. or less in the food. Thereafter, the pressure is reduced to atmospheric pressure, a low-temperature heat sterilization step of 100 ° C. or lower is performed, the germinated spore bacteria are sterilized, and immediately cooled to 10 ° C. or lower and stored.

Hereafter, it demonstrates for every said process.
<First cooking process>
Peel the vegetables, cut the ingredients to a size that is easy to eat, prepare with a lower bowl, prepare lye, etc., and prepare a seasoning liquid.
<Filling and sealing process>
The ingredients prepared in the first cooking step and the seasoning liquid are mixed and sealed in a metal container or flexible packaging container by double winding or heat sealing. If there is a head space when filling and sealing, the head space is compressed during high-pressure processing, the volume of the container is reduced, and the container is deformed. Also, since the power for compressing the head space is wasted, it is desirable to reduce the head space as much as possible. It is desirable that filling is performed at about 70 to 90 ° C., and if possible, vacuum deaeration and sealing is performed.

<Second cooking process>
Cooking is performed at about 60 to 98 ° C. from a temperature at which the protein is not denatured to a temperature suitable for cooking that does not impair the flavor of the food. The protein begins to coagulate from about 63 ° C and begins to separate water from about 68 ° C.
Since the food is heated in the low temperature heat sterilization process after the high pressure treatment, the cooking time of the second cooking process is adjusted so that the best finish is obtained when all the processes are completed.

<Preheating process>
In order to operate an expensive high-pressure treatment apparatus most efficiently, the object to be treated is heated or cooled to a high-pressure treatment temperature of about ± 5 ° C. before being put into the pressurizing chamber. The temperature of the high-pressure treatment is heated or cooled to about ± 5 ° C. and then charged into the pressurizing chamber. Therefore, high-pressure processing can be performed quickly.

<Multi-stage high pressure treatment process>
In the method for producing a chilled food product in a container according to the present invention, it is necessary to start pressurization from atmospheric pressure and change the pressure held at 100 to 700 MPa at least once. When the pressure is changed once, the relationship between time and pressure has a two-step shape. Similarly, when the pressure is changed twice, the relationship between time and pressure has a three-step shape. That is, in the production method of the present invention, a spore bacterium that grows at a low temperature of 10 ° C. or less by performing a multi-stage high-pressure treatment in which the relationship between the elapsed time during the high-pressure treatment and the high-pressure treatment pressure becomes a multi-step shape. The process of germinating efficiently is included.
The retention time of high-pressure treatment in one stage is 2 minutes or more, and there is a remarkable germination effect of spore bacteria. The longer the high-pressure treatment time, the greater the germination effect of spore bacteria. 2-15 minutes per hit is good. For this reason, as for the processing time in the whole multistage high-pressure processing process, 4 to 30 minutes are desirable.

Considering productivity, equipment cost, and running cost, it is preferable that the high pressure processing pressure is low, and it is desirable that the upper limit of the high pressure processing pressure is 700 MPa or less. On the other hand, spore bacteria cannot germinate in a short time at a pressure of less than 100 MPa.
The difference in high-pressure treatment pressure between the previous stage and the next stage is preferably 100 MPa or more. When the difference in high-pressure treatment pressure between the previous stage and the next stage is less than 100 MPa, the germination effect of spore bacteria is remarkable compared to the case of high-pressure treatment using only the pressure of the previous stage or the case of high-pressure treatment using only the pressure of the next stage. There is no difference.

In addition, the spore bacteria in which germination is induced by high-pressure treatment includes a strain that germinates best at 100 to 300 MPa and a strain that germinates best at a pressure of 300 MPa or more. For this reason, in order to germinate both strains efficiently, it is desirable to hold the pressure in each pressure range at least once. The multi-stage high-pressure treatment of the present invention performs pressure holding for 2 to 15 minutes at least once in the range of 100 to 300 MPa, and then holds pressure for 2 to 15 minutes in the range of 300 to 700 MPa without reducing the pressure to atmospheric pressure. One time or more (100 to 300 MPa → 300 to 700 MPa), or 300 to 700 MPa, pressure holding for 2 to 15 minutes or more and then 100 to 300 MPa without reducing pressure to atmospheric pressure. It is preferable to hold the pressure for 2 to 15 minutes at least once (300 to 700 MPa → 100 to 300 MPa).
However, since the pressure holding time of 2 to 15 minutes is required in each stage, if the number of pressure changes is increased, the pressure holding time of each stage is added, and the high-pressure treatment process time for all stages is increased, resulting in production. The nature will decline. In order to perform sterilization efficiently in a short time, the number of pressure changes is preferably 2 times or less (3 stages or less).

  The temperature during the high-pressure treatment is preferably low so as not to deteriorate the flavor of the food, and is preferably high so as to promote germination of the spore bacteria. Considering the burden on the equipment, the energy required for heating, and the safety of work, the temperature during high-pressure processing should be low. Considering these balances, the temperature during the high-pressure treatment is preferably 40 to 80 ° C. Spores are hard to germinate at temperatures below 40 ° C. On the other hand, when temperatures exceed 80 ° C, food is greatly damaged by heat, and the flavor and texture are deteriorated. In addition, the packing of the device is damaged and energy loss increases. .

<Decompression process>
After the multistage high pressure treatment is completed, the pressure is reduced to atmospheric pressure.
<Low temperature heat sterilization process>
Next, the spore germs induced to germinate by high-pressure treatment are sterilized at a temperature and time sufficient to sterilize the germinated spore germs. In order to reliably sterilize germinated spore bacteria, the temperature during low temperature heat sterilization should be high and the time should be long, but considering the flavor and texture deterioration due to the heat of food, the temperature is low, Shorter time is better. Considering these balances, it is desirable to perform the low temperature heat sterilization at 60 to 100 ° C. for about 1 to 120 minutes. For example, it is desirable to heat sterilize at 60 ° C for about 60 to 120 minutes, 75 ° C for about 10 to 30 minutes, 90 ° C for about 1 to 5 minutes, and 100 ° C for about 1 to 3 minutes. If the temperature is less than 60 ° C., the germinated spores cannot be sufficiently sterilized. If the temperature exceeds 100 ° C., the flavor and texture of the food are significantly deteriorated.

<Cooling process>
Immediately after low temperature heat sterilization, cool to chilled storage temperature (10 ° C or lower). In addition, although the temperature of the chilled foodstuff after cooling should just be 10 degrees C or less, it is desirable that it is about 10-5 degreeC more specifically. Also, the cooling rate is not particularly limited, but it is desirable to perform it as quickly as possible, for example, it is desirable to cool at about 0.5 to 20 ° C./min.

  In addition, the manufacturing method of the chilled food containing a container concerning this invention can be applied not only to a flexible packaging container but to a metal container. For example, when producing curry, a large material of about 20 to 50 mm square can be cooked and sterilized without problems, but in a soft packaging container such as a pouch, the material may be crushed during transportation. On the other hand, when a metal container (can) is used, the ingredients are not crushed. Moreover, since it is excellent in the barrier property with respect to oxygen and light and can prevent deterioration by oxidation or light, the shelf life of food can be extended. However, metal containers (cans) usually do not have the flexibility to follow changes in the volume of their contents, and thus undergo plastic deformation when subjected to high pressure treatment. Therefore, for example, as shown in FIG. 2, by using an aluminum heat seal lid, it can withstand a high pressure treatment of about 600 MPa, and can cope with hot water heating in a cooking process or a hot water sterilization process. In addition, these metal containers can be retorted before or after the high-pressure treatment.

Hereinafter, although the Example of the manufacturing method of the chilled foodstuff with a container concerning this invention is given and demonstrated in more detail, this invention is not limited to these.
First, the test conditions and test methods used in this example will be described.

<Indicator bacteria>
Bacillus cereus (Bacillus pumilus), Paenibacillus polymyxa (Paenibacillus polymyxa) and other spore bacteria that grow at low temperatures, and other general living bacteria, molds, and yeasts.
As for the above indicator bacteria, Bacillus cereus (Bacillus cereus), Bacillus pumilus (Bacillus cereus), which survives after cooking, and is the most pressure-resistant among spore bacteria growing at a low temperature of 10 ° C. or less. Bacillus pumilus), Paenibacillus polymixa (Paenibacillus polymyxa) were selected. Bacillus cereus and Bacillus pumilus are known as bacteria causing food poisoning, and Paenibacillus polymixer is known as a causative agent for deterioration. Microorganisms such as bacteria, molds and yeasts that grow at low temperatures other than spore bacteria are sterilized by heating at a low temperature of 100 ° C. or lower in the pasteurization process.

<Sample preparation>
Bacteria Bacillus cereus (Bacillus cereus JCM2152T strain), Bacillus pumilus (Bacillus pumilus NBRC 12092T strain), Paenibacillus polymyxa (Paenibacillus polymyxa JCM7507 buffer buds) The liquid was inoculated to 106 CFU / mL, and 5 mL of the mixture was filled in a sterilized pouch, and the mouth was heat-sealed. In order to sterilize the vegetative cells in the inoculated spore bacteria solution, the mixture was heated in hot water at 70 ° C. for 20 minutes, and immediately cooled to 4 ° C. or less to prepare a sample.

<High pressure processing>
As the high-pressure treatment apparatus, ITP-70 manufactured by Ishikawajima-Harima Heavy Industries Co., Ltd. was used. Before the sample was put into the pressurizing chamber, it was heated to a temperature at which high pressure treatment was performed in hot water and then put into the pressurizing chamber. The pressurized chamber is filled with tap water, which is a pressurized medium, and hydrostatic pressure acts on the sample. The time required for pressure increase from atmospheric pressure to 600 MPa and pressure reduction from 600 MPa to atmospheric pressure is about 2 minutes, respectively. The temperature in the pressurizing chamber was adjusted by circulating hot water in the thermostatic water tank to the jacket outside the pressurizing chamber.

<Inspection method>
The treated sample was mixed with a standard agar medium (Nissui Pharmaceutical), and the number of bacteria was measured after culturing aerobically at 30 ° C. using a constant temperature incubator (ADVANTEC TVA460DA) for 2 days.

<Inactivation rate>
The number of surviving bacteria N (CFU / mL) immediately after the treatment was divided by the number of bacteria N ₀ (CFU / mL) before the treatment, and the inactivation rate was determined by the numerical value obtained by taking the common logarithm.
Inactivation rate = log (N / N ₀ )
CFU: Colony Forming Unit (colony forming unit)

Comparative test example 1 (high pressure treatment only)
After the sample was adjusted to a temperature suitable for high-pressure treatment in the preheating step, high-pressure treatment was performed in which various set pressures were maintained for 20 minutes and then reduced to atmospheric pressure. Preheating was performed by immersing in warm water set at a high pressure treatment temperature + 5 ° C. for 5 minutes. The test was performed at three holding pressures of 100 MPa, 300 MPa, and 600 MPa and a high pressure treatment temperature of 60 ° C. in the high pressure treatment.

  In Comparative Test Example 1, Bacillus cereus and Bacillus pumilus were most inactivated at 600 MPa. Bacillus cereus had a reduced 4 order bacterial count and Bacillus pumilus had a reduced 3 order bacterial count. The Paenibacillus polymixer was most inactivated at 300 MPa and the number of 3-order bacteria decreased, and at 500 MPa, the number of 2-order bacteria decreased. In Comparative Test Example 1, the number of bacteria in the order of 2 to 4 could be reduced. However, since these spore bacteria grow at a low temperature of 10 ° C. or lower, sterilization is insufficient for long-term storage at 10 ° C. or lower.

Comparative Test Example 2 (Pressurized and Depressurized Repeated Treatment: Japanese Patent Laid-Open No. 63-82667)
After the sample was adjusted to a temperature suitable for high pressure treatment in the preheating step, the high pressure treatment was repeated twice. After pressurizing to a predetermined pressure and holding the pressure for 10 minutes, the pressure was reduced to atmospheric pressure, and after 30 seconds, the pressure was increased again to maintain the predetermined pressure for 10 minutes, and then the pressure was reduced to atmospheric pressure. Preheating was performed by immersing in warm water set at a high pressure treatment temperature + 5 ° C. for 5 minutes. The test was performed at two high pressure treatment pressures of 300 MPa and 600 MPa, and at a high pressure treatment temperature of 60 ° C.

  In Comparative Test Example 2, as in Comparative Test Example 1, Bacillus cereus and Bacillus pumilus are most inactivated when the pressure is 600 MPa, and Bacillus cereus has a 4-5 order bacterial count reduction. Reduced the number of 3-order bacteria. The Paenibacillus polymixer was most inactivated at 300 MPa, the number of 3-order bacteria decreased, and the number of 2-order bacteria decreased at 600 MPa, but there was no significant difference from the result of Comparative Test Example 1.

Comparative test example 3 (high pressure treatment + pasteurization treatment: JP-A-4-91770)
After preheating and high-pressure treatment in the same manner as in Comparative Test Example 1, low-temperature heat sterilization was performed in 95 ° C. oil for 20 minutes. The test was performed at two high pressure treatment pressures of 300 MPa and 600 MPa, and at a high pressure treatment temperature of 60 ° C.

  In Comparative Test Example 3, Bacillus cereus and Bacillus pumilus were most inactivated when the pressure was 600 MPa, and both B. cereus and B. pumilus were reduced in the number of 5-6 orders. The Paenibacillus polymixer was most inactivated at 300 MPa, the number of 5-order bacteria decreased, and the number of 4-order bacteria decreased at 600 MPa. In this method, spore bacteria germinated by high-pressure treatment were sterilized by low-temperature heating, and thus were inactivated more than Comparative Test Examples 1 and 2. However, under any pressure condition, all three types of spore bacteria could not be sufficiently inactivated, and it could not be said that sterilization for long-term storage at 10 ° C. or lower was sufficient.

Test example 1 (two-stage high-pressure treatment + pasteurization treatment)
The sample was preheated by immersing it in water or warm water set at a high pressure treatment temperature + 5 ° C. for 5 minutes. After the preheating was completed, a pouch was placed in the pressurizing chamber, and the pressure was increased from atmospheric pressure to 300 MPa and maintained for 10 minutes. After the pressurization and holding for a total of 20 minutes, the pressure was reduced to atmospheric pressure. Then, low temperature heat sterilization was performed in 95 ° C. hot water for 20 minutes. The test was performed at three high-pressure treatment temperatures of 20 ° C., 40 ° C., and 60 ° C. FIG. 3 shows the relationship between the treatment temperature and the treatment pressure at each step in Test Example 1 (when the high-pressure treatment temperature is 60 ° C.).

  When pressurization of the first stage of the high-pressure treatment process was started, the temperature in the pressurizing chamber increased to about 5 ° C. by being pressurized to 300 MPa in about 1 minute. And it was cooled by the hot water flowing in the hot water jacket outside the pressurizing chamber, and after about 3 minutes, it became the set temperature ± 1 ° C. When the second stage of pressurization was started, the temperature in the pressurization chamber increased by about 5 ° C. by being pressurized to 600 MPa in about 1 minute. And it was cooled by the hot water flowing in the hot water jacket outside the pressurizing chamber, and after about 3 minutes, it became the set temperature ± 1 ° C.

  In Test Example 1, when the high-pressure treatment temperature was 20 ° C., and the high-pressure treatment time for the first and second stages was 10 minutes, respectively, the number of test spore bacteria decreased only by about one order. When the high-pressure treatment temperature was 40 ° C., and the high-pressure treatment time for the first and second stages was 10 minutes, the number of spore bacteria tested decreased by about 4 to 5 orders. When the high-pressure treatment temperature was 40 ° C., and the high-pressure treatment time for the first and second stages was 5 minutes, the number of test spore bacteria decreased only about 3 to 4 orders. Moreover, when the high-pressure treatment temperature was 60 ° C. and the high-pressure treatment time for the first and second stages was 5 minutes, no bacteria were detected, and the number of bacteria decreased by 6 orders or more.

  From the above results, when the high-pressure treatment temperature is 40 ° C., it can be said that the first and second high-pressure treatment times are preferably 10 minutes or more. When the high-pressure treatment temperature is 60 ° C., it can be said that the first and second high-pressure treatment times are preferably 5 minutes or longer. In addition, when it preserve | saves for a long time with a chilled, in order to obtain a higher disinfection effect, the high pressure processing temperature of 60 degreeC or more is desirable.

Test example 2 (3-stage high-pressure treatment + pasteurization treatment)
The sample was heated in 65 ° C. hot water for 5 minutes, then placed in a pressure chamber, pressurized from atmospheric pressure to 200 MPa and held for 10 minutes, then repressurized without reducing pressure and pressurized to 400 MPa. After maintaining the pressure for 5 minutes, the pressure was further repressurized without reducing the pressure, the pressure was increased to 600 MPa, and the pressure was maintained for 10 minutes. After completing the pressurization and holding for a total of 30 minutes, the pressure is reduced to atmospheric pressure. Then, low temperature heat sterilization was performed in 95 ° C. hot water for 20 minutes. The test was conducted at a high pressure treatment temperature of 60 ° C. In addition, what illustrated the relationship between the process temperature at the time of each process in the said test example 2, and a process pressure is shown in FIG.

  In Test Example 2 above, although the holding pressure was changed twice during the high-pressure treatment step, the sample was subjected to a bacterial test performed by the method of making the relationship between time and the high-pressure treatment pressure into a three-stage step, None of the bacteria could be detected, and the number of bacteria decreased by 6 orders or more.

The test conditions of the above Comparative Test Examples 1 to 3 and Test Examples 1 and 2 and details of the measurement results are shown in Table 1 below.

Example 1 (beef curry)
Subsequently, as an example of an actual chilled food, a beef curry was prepared using the processing method of Test Example 1 above.
(material)
Domestic beef shoulder meat, onion, carrot, potato, salad oil, salt, pepper, commercial bouillon (maggie bouillon), commercial curry roux (primary Java curry made from house food).
The meat was previously simmered in bouillon for 60 minutes and chilled and stored in bouillon for about 16 hours.

(procedure)
The prepared material was put in an aluminum pouch and vacuum packed. Thereafter, after low-temperature cooking for 30 minutes in 95 ° C. hot water, preheating for 5 minutes in 60 ° C. hot water is performed in the same manner as in Test Example 1, and two-stage high-pressure treatment is performed to increase the pressure. After reducing the pressure to atmospheric pressure, low temperature heat sterilization was performed in 95 ° C. hot water for 20 minutes. Immediately after completion of low-temperature heat sterilization, the mixture was cooled to 10 ° C. or lower and stored in a chilled state. The pressure of the second stage high pressure treatment was 300 MPa for the first stage and 600 MPa for the second stage, the high pressure treatment temperature was 60 ° C., and the high pressure treatment time for each stage was 5 minutes.

  As a result of storing the curry prepared in Example 1 for 6 months in a chilled product, it was confirmed that a good flavor was maintained. Bacterial tests were conducted after 6 months storage in chilled, but no general bacteria, sputum, or spores growing at low temperature were detected.

Example 2 (beef curry)
Moreover, as an example of an actual chilled food, a beef curry was prepared using the processing method of Test Example 2 above.
(material)
Domestic beef shank, onion, carrot, potato, salad oil, salt, pepper, commercial bouillon (maggie bouillon), commercial curry roux (primary Java curry made from house food).
The meat was previously simmered in bouillon for 90 minutes and chilled and stored for 16 hours in bouillon.

(procedure)
The prepared material was put in an aluminum pouch and vacuum packed. Thereafter, after low-temperature cooking for 30 minutes in 95 ° C. hot water, preheating for 5 minutes in 60 ° C. hot water is performed in the same manner as in Test Example 2 above, three-stage high pressure treatment is performed, and the pressure is increased. After reducing the pressure to atmospheric pressure, low temperature heat sterilization was performed in 95 ° C. hot water for 20 minutes. Immediately after completion of low-temperature heat sterilization, the mixture was cooled to 10 ° C. or lower and stored in a chilled state. The pressure of the three-stage high-pressure treatment was 200 MPa for the first stage, 400 MPa for the second stage, 600 MPa for the third stage, the high-pressure treatment temperature was 60 ° C., and the high-pressure treatment time for each stage was 5 minutes.

  As a result of storing the curry prepared in Example 2 for 6 months in a chilled product, it was confirmed that a good flavor was maintained. Bacterial tests were conducted after 6 months storage in chilled, but no general bacteria, sputum, or spores growing at low temperature were detected.

It is a flowchart of the manufacturing method of the chilled food containing a container concerning an example of this invention. The state of the deformation | transformation at the time of each process of the metal container with an aluminum heat seal lid used for this invention is illustrated. The relationship between the process temperature and process pressure at the time of each step in Test Example 1 (two-stage high-pressure process) of the present invention is illustrated. The relationship between the process temperature and process pressure at the time of each process in Test Example 2 (three-stage high-pressure process) of the present invention is illustrated.

Claims (7)

A high-pressure treatment step of pressurizing a cooked or half-prepared food sealed in a container to a pressure of 100 to 700 MPa for a total of 4 to 30 minutes while being heated to 40 to 80 ° C. A multi-stage high-pressure treatment step of maintaining the pressure for a predetermined time by at least one or more predetermined pressures different from the predetermined pressure without holding the pressure for a period of time and subsequently reducing the pressure to atmospheric pressure;
After the high-pressure treatment step, the pasteurization treatment step is performed to reduce the pressure to atmospheric pressure and sterilize by heating at a temperature of 60 to 100 ° C.
And a cooling step of immediately cooling to a chilled storage temperature after the pasteurization treatment step. In the manufacturing method of the chilled food containing a container according to claim 1, the multi-stage high-pressure treatment step includes:
After the cooked or sealed food sealed in the container is heated to 40 to 80 ° C., the pressure is maintained at a predetermined pressure in the range of 100 to 300 MPa for a total of 2 to 15 minutes, and then continued. A method for producing chilled foods in a container, which is a multistage high-pressure treatment step in which pressure is maintained at a predetermined pressure in the range of 300 to 700 MPa for a total of 2 to 15 minutes without reducing the pressure to atmospheric pressure. In the manufacturing method of the chilled food containing a container according to claim 2, the multi-stage high-pressure treatment step includes:
After the cooked food being sealed in the container or in the middle of cooking is heated to 40 ° C. to 80 ° C., the pressure is maintained for 2 to 15 minutes with one predetermined pressure in the range of 100 to 300 MPa, and then continued. A method for producing chilled food in a container, which is a two-stage high-pressure treatment step in which pressure is maintained for 2 to 15 minutes at a predetermined pressure in the range of 300 to 700 MPa without reducing the pressure. In the manufacturing method of the chilled food containing a container according to claim 2, the multi-stage high-pressure treatment step includes:
In a state where the cooked or half-prepared food sealed in the container is heated to 40 to 80 ° C., the pressure is maintained for 2 to 15 minutes with one predetermined pressure in the range of 100 to 300 MPa, and then the pressure is maintained. Without depressurizing, the pressure is maintained for 2 to 15 minutes at a predetermined pressure in the range of 300 to 500 MPa, and further, the pressure is reduced to 2 with a predetermined pressure in the range of 500 to 700 MPa without reducing the pressure. A method for producing chilled food in a container, characterized in that it is a three-stage high-pressure treatment step for holding pressure for 15 minutes. In the manufacturing method of the chilled food containing a container according to claim 1, the multi-stage high-pressure treatment step includes:
After the cooked or sealed food sealed in the container is heated to 40 to 80 ° C., the pressure is maintained at a predetermined pressure in the range of 300 to 700 MPa for a total of 2 to 15 minutes, and then continued. A method for producing chilled foods in a container, which is a multistage high-pressure treatment step in which pressure is maintained at a predetermined pressure in the range of 100 to 300 MPa for a total of 2 to 15 minutes without reducing the pressure to atmospheric pressure. In the manufacturing method of the chilled food containing a container according to claim 5, the multi-stage high-pressure treatment step includes
After the cooked food or the food being cooked sealed in the container is heated to 40 ° C. to 80 ° C. and held at a predetermined pressure in the range of 300 to 700 MPa for 2 to 15 minutes, then A method for producing chilled food in a container, characterized in that it is a two-stage high-pressure treatment step in which the pressure is adjusted under reduced pressure and the pressure is maintained for 2 to 15 minutes at a predetermined pressure in the range of 100 to 300 MPa. In the manufacturing method of the chilled food containing a container according to claim 5, the multi-stage high-pressure treatment step includes
After the cooked food or the food being cooked sealed in the container is heated to 40 ° C. to 80 ° C. and held at a predetermined pressure in the range of 500 to 700 MPa for 2 to 15 minutes, then The pressure is adjusted to a reduced pressure, the pressure is maintained for 2 to 15 minutes at a predetermined pressure in the range of 300 to 500 MPa, and then the pressure is reduced to a pressure of 2 to a predetermined pressure in the range of 100 to 300 MPa. A method for producing a chilled food in a container, which is a three-stage high-pressure treatment step for holding pressure for 15 minutes.

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