JP2644063B2 - Manufacturing method of retort food - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a retort food.

(Prior Art) JP-A-61-63271 discloses that a food is filled and sealed in a heat-resistant container while leaving air therein, and the food is sealed under pressure.
After heating while rotating or inverting in hot water of at least ℃, by cooling in cold water in a pressurized state, sterilization of food can be sufficiently performed, and a method for producing a retort food without discoloration of food is disclosed. Have been.

In this method, since air is left in the container,
There is an advantage that the food is stirred by the movement of the air in the container during the sterilization, whereby heat transfer to the food is promoted and the sterilization efficiency is improved. And, in order to obtain this advantage, it is usually necessary that the container contains 5% or more of air. However, if air remains in the container in such a state, the discoloration of the food due to the presence of the air during sterilization, the deterioration of the food during storage is promoted, and the container is easily damaged during transportation etc. There is.

(Problems to be Solved by the Invention) Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a method for producing a retort food with high sterilization efficiency.

(Means for Solving the Problems) The present invention provides a sterilization method in which the internal pressure of a retort pot is slightly lower than the internal pressure of a container, and a rotary pressurized heat sterilization treatment is performed while maintaining a constant pressure difference between the two. The food is agitated by the vaporized water in the food in the middle container, the heat transfer to the food is promoted, and the sterilization efficiency is improved.

In other words, the present invention provides a flexible heat-resistant container in which a liquid or paste food having a high water content less than the maximum volume of the container is hermetically contained at an air content of 2% or less, and the container is heated under pressure. In the sterilization process, the internal pressure of the sterilizer is slightly lower than the internal pressure of the container, while maintaining a constant pressure difference between the two, and the container is rotated and / or inverted, and the food in the food is vaporized by the vaporized water in the food. A method for producing a retort food, which is performed by stirring.

As the container, a flexible heat-resistant container is used. By flexible container is meant a flexible container capable of hermetically containing less than the container's maximum volume of food with reduced aeration. Examples of such a container include a bag-shaped container such as a retort pouch and a cup-shaped container made of a flexible material such as a synthetic resin. In particular, in the conventional sterilization treatment, the capacity is
When a container of 500 cc or more is used, heating is required for a long time, and deterioration of food quality has been a problem. However, in the present invention,
Since the sterilization efficiency is improved by the following sterilization treatment, even if such a large-capacity container is used, the above problem does not appear. Therefore, the large-capacity container can be suitably used.

As the food, a liquid or paste-like food is used, and a food having a high moisture content is preferable. In particular, food has a viscosity of 1000
0 cp or less, preferably 6000 cp or less is used. This is because when the viscosity exceeds 10,000 cp, even if the sterilization treatment is performed by the method of the present invention described below, the food cannot be sufficiently stirred by the vaporized vapor from the food being sterilized, and the desired sterilization efficiency is obtained. This is because there may be no case. Therefore, sufficient sterilization efficiency can be obtained depending on the viscosity of the food. In the present invention, the viscosity is a value obtained by measuring the viscosity of a food at 60 ° C. with a B-type viscometer.
Examples of food types include soups, stews, curries, and foods containing these ingredients.

The above-mentioned food is housed and sealed in a container with an air content of 2% or less, preferably 0.8% or less to full filling. If the air content exceeds 2%, the above-mentioned problems due to air content are likely to become apparent. In the differential pressure sterilization treatment unique to the present invention, a sufficient sterilization efficiency can be obtained at an air content in the above range, and therefore, the problem caused by the air impairment hardly occurs.

 Next, the sterilization treatment method of the present invention will be described.

The container containing the food is subjected to pressure and heat sterilization while keeping the internal pressure of the sterilizer slightly lower than the internal pressure of the container and maintaining a constant pressure difference between the two. That is, when the sterilization treatment is performed in this manner, the food is stirred by the vaporized water in the food in the container during the sterilization, and the heat transfer to the food is promoted, so that the sterilization efficiency is improved.

The above sterilization treatment is performed at a temperature of 110 to 135 ° C. for 2 to 60 minutes by using the internal pressure of the sterilization apparatus, and the differential pressure between the internal pressure of the sterilizer and the internal pressure of the sterilizer (hereinafter simply referred to as differential pressure) is 1.0 kg / cm ² (gauge pressure, in the present invention). (All pressures indicate gauge pressures). In this case, the internal pressure of the sterilizer is preferably 0 to 2.0 kg / cm ² . More preferably, at a temperature of 110 to 125 ° C. for 10 to 60 minutes,
It is recommended to maintain the pressure difference between 0.1 kg / cm ² and 0.5 kg / cm ² . In this case, the internal pressure of the sterilizer is preferably 0.1 to 1.2 kg / cm ² . If there is no differential pressure, it is not possible to obtain the stirring effect of the vapor vaporized in the container during sterilization and the sterilization efficiency due to this. On the other hand, if the differential pressure exceeds the numerical range under each of the above conditions, problems such as breakage of the container during sterilization are likely to occur. Therefore, with the pressure difference in the above numerical range, good sterilization efficiency can be obtained without any problem such as breakage of the container under each condition.

In addition, sterilization treatment is performed at a device internal pressure of 0 kg / cm ² and a temperature of 80 to 100.
2 to 10 minutes at a pressure of 0.5 kg / cm ² or less at an internal pressure of 0 to 0.6 kg / cm ^{2 at} a temperature of 100 to 115 ° C. for 2 to 1
0 minutes, the differential pressure is maintained at 0.5 kg / cm ² , the internal pressure of the apparatus is 0 to 2.0 kg / cm ² , the temperature is 115 to 135 ° C., and the differential pressure is 1 to 5 minutes.
It can be carried out continuously under the above conditions, while keeping it at 1.0 kg / cm ² or less. The meaning of the numerical limitation is the same as in the above case.

The above sterilization treatment may be performed using a retort pot or the like and using a heating medium such as superheated steam, hot air, or oil. The sterilization process is performed while rotating and / or inverting the heat-resistant container.
Thereby, the stirring effect by the steam in the container can be enhanced, and more favorable sterilization efficiency can be obtained. The above-mentioned rotation (reversal) type sterilization treatment may be performed, for example, by housing the container in a retainer rotatably installed around a horizontal rotation axis in a retort pot and driving the rotation axis. .
In this case, when the container is in the shape of a bag, the horizontal axis thereof is rotated, and when the container is in the shape of a cup, the vertical or horizontal axis is rotated by 3 to 45 degrees, preferably 5 to 20 degrees. It is desirable to perform the sterilization process while inverting. By doing so, the movement of steam in the container during sterilization is promoted, and the food is agitated, so that higher sterilization efficiency is obtained. In order to achieve the above method, for example, the inclination of the bottom wall of the portion of the retort pot that holds the container of the retainer may be set to an angle in the above range. Also, rotation or reversal is 5-50 rp during sterilization.
It is better to perform at a rotation speed of m.

In the present invention, after the above sterilization treatment, the food in the container can be cooled by an ordinary method. Note that the cooling process can be performed while maintaining the pressure difference in the same manner as in the above-described sterilization process, while the cooling process is performed in a pressurized state. In this case, the cooling efficiency of the food can be improved.

(Effect of the Invention) According to the method of the present invention, it is possible to obtain a stirring ability with the vaporized vapor in the container during sterilization, thereby obtaining sufficient sterilization efficiency. Only a minimum amount of air is required in the container. Do not discolor food during sterilization due to air,
An excellent effect is obtained that the food is not deteriorated by air during storage and the container is not damaged during transportation.

[Example 1] 900 g of a soup having a water content of 85% and a viscosity of about 1000 cp was used.
Fully filled into a 1000cc retort pouch and sealed. Using the above retort pouch in a retort pot, superheated steam is used to set the pressure inside the pot to 0 to 1.1 kg / cm ² and a temperature of 122 ° C. for 20 minutes, with a differential pressure of 0.
While maintaining the pressure at 5 kg / cm ² or less, a rotary pressurized heat sterilization treatment was performed. After the above sterilization treatment, cooling water was fed into the retort pot, and the pouch was cooled to room temperature to produce a retort food. During the sterilization treatment and the cooling treatment, the retainer in the retort pot was rotated in one direction at 15 rpm.

The obtained retort food could be stored at room temperature for about 2 years, and after eating for 6 months, the soup had no fading and had a good flavor.

[Example 2] 900 g of a soup having a water content of 83% and a viscosity of about 3000 cp was used.
Fully filled into a 1000cc retort pouch and sealed. The retort house was housed in a housing member (5 degrees of inclination of the bottom wall) of a retainer which was installed in the retort pot so as to be rotatable around a horizontal rotation axis. Using the above equipment, the pressure difference from the superheated steam was set at 0 kg / cm ^{2 in the} pot and at 100 ° C for 2 minutes.
While maintaining the pressure at 0.1 kg / cm ² or less,
kg / cm ^2, 5 min at a temperature 110 ° C., while maintaining the differential pressure 0.3 kg / cm ² or less, followed by the kettle pressure 0.3~0.8kg / cm ^2, temperature 120
The sterilization treatment was continuously performed at 10 ° C. for 10 minutes while maintaining the differential pressure at 0.2 to 0.5 kg / cm ² under the above conditions. And
After the above sterilization treatment, cooling water at 15 ° C. was fed into the kettle and subjected to a cooling treatment for 10 minutes to obtain a retort food. The retainer was rotated in one direction at 15 rpm during the sterilization and cooling treatments.

The obtained retort food could be stored at room temperature for about 2 years, and after eating for 6 months, the soup had no fading and had a good flavor.

Claims (3)

(57) [Claims] 1. A highly heat-resistant flexible container containing a liquid or paste food having a high water content less than the maximum volume of the container in an airtight condition at an air content of 2% or less, and pressurizing and heat sterilizing the container. In the treatment, the internal pressure of the sterilizer is slightly lower than the internal pressure of the container, and while maintaining a constant pressure difference between the two, the container is rotated and / or inverted, and the food is agitated by the vaporized water in the food. A method for producing a retort food. 2. The method according to claim 1, wherein the food is a liquid or paste having a viscosity of 10,000 cp or less. 3. A pressure and heat sterilization treatment at a temperature of 110 to 135 ° C.
60 min, The method of claim 1 or 2, wherein the differential pressure between the internal pressure of which the container internal pressure of the sterilizing apparatus performs while adjusting so that 1.0 kg / cm ² or less.