JP2923404B2 - How to improve the quality of retort cooked rice - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for improving the quality of retort cooked rice. More specifically, the present invention relates to a retort sterilization method for suppressing a decrease in quality of cooked rice, which is caused when retort sterilizing cooked rice filled and sealed in a container.

[0002]

2. Description of the Related Art In recent years, so-called retort foods, in which cooked foods are hermetically packaged and retort-sterilized, have come into wide use because of their easy handling. Among them, cooked rice is filled in a tray-shaped container and sealed and retort-sterilized.Some are generally referred to as retort rice, which can be stored for a long time and can be cooked at any time simply by heating in a microwave oven. Because they can be eaten, they have come to be sold as a set together with retort-sterilized and hermetically sealed curry in response to the needs of consumers accompanying changes in their dietary habits.

[0003] Generally, in retort sterilization, cooked food is filled and sealed in a packaging container, placed in a pressure cooker, and brought into direct contact with steam or hot water to rapidly raise the temperature. Sterilization is performed by maintaining the temperature for a predetermined time for a predetermined time. The same has been done for cooked rice, but there is a time lag between the time when the temperature of the periphery of the cooked rice block is raised to the predetermined temperature and the time when the temperature of the center is raised to the predetermined temperature. Since the setting of the predetermined time is based on the temperature of the central portion of the cooked rice block, the peripheral portion is exposed to a high temperature for an unnecessarily long time, so that the texture, aroma, Deterioration of quality such as color was inevitable.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for improving the quality of retort cooked rice which suppresses the deterioration of cooked rice quality, which is a drawback of conventional retort sterilization, and brings the quality of cooked rice as close as possible to the quality of cooked rice immediately after cooking. For the purpose of providing.

[0005]

According to the present invention, in the retort sterilization of cooked rice in a sealed container, the temperature is gradually increased after the start of heating until the ambient temperature reaches 110 ° C.
It is based on the knowledge that the temperature can be rapidly increased and then sterilized at high temperature for a short time after the temperature has reached, so that the quality of the retort cooked rice can be exceeded.

That is, according to the present invention, in the retort sterilization treatment of cooked rice in a sealed container, after the start of heating, the atmospheric temperature is set to 11 hours.
When the temperature reaches 0 ° C, the temperature of the cooked rice is controlled to be 85 to 110 ° C.
It is a method for improving the quality of retort cooked rice characterized by heating and raising the temperature as described above.

In the present invention, cooked rice is prepared by washing washed rice by a conventional method such as steaming or cooking rice. However, there is no particular problem even if the water content is slightly lower than that of a normal rice.

The material of the container used in the present invention is not particularly limited as long as it has high heat resistance. Examples of the form of the container include various containers such as a tray-shaped container, a cup-shaped container, and a standing pouch, but a tray-shaped container is preferable from the viewpoint of convenience in eating.

When rice is filled in a container, it is preferable to make the container as thin as possible in order to improve the thermal efficiency.

In the present invention, the ambient temperature refers to the temperature in the pressure cooker, and the product temperature refers to the temperature of the slowest rising portion (center portion) of the rice chunks in the container, that is,
The temperature at the slowest heating point.

After the start of heating, the product temperature also rises in a form dragged by the rising ambient temperature. In the present invention, the product temperature is reduced to the ambient temperature as much as possible until the ambient temperature reaches 110 ° C. It is important to keep them close and it is necessary to keep them at least 85-110 ° C. When the ambient temperature exceeds 110 ° C, the product temperature becomes 85
If the temperature is lower than ° C, the sterilization time must be increased accordingly, so that the time required for the peripheral portion of the cooked rice block to be exposed to a high temperature is inevitably increased, and the quality is inevitably deteriorated as described above. That is, it is necessary to suppress the state where the temperature of the peripheral portion of the cooked rice block exceeds 110 ° C. in as short a time as possible.
In other words, in the present invention, it is an important factor to perform heating such that the rice rice block has a temperature distribution as uniform as possible before the ambient temperature reaches a temperature that adversely affects the quality such as browning.

In the present invention, as described above, it is important to keep the product temperature as close to the ambient temperature as possible before the ambient temperature reaches 110 ° C. As a specific method, (1) Or (2) increasing the ambient temperature as usual and stopping the temperature increase when the temperature reaches 110 ° C., and maintaining the temperature for the required time. To control,
And so on.

In the present invention, immediately after the above conditions are satisfied, the temperature is raised immediately so that the ambient temperature becomes 121 ° C. or higher, and then heat sterilized so that the F0 value becomes 4 or more. It is preferable from the viewpoint of suppressing the deterioration of the quality of cooked rice that heating is performed so as to be as rapid as possible and the sterilization treatment is completed in as short a time as possible, that is, to raise the ambient temperature as high as possible. .

[0014]

EXAMPLES Cooked rice in a sealed container used in Comparative Examples and Examples was prepared as follows. First, 1 kg of rice
Was washed with water, drained, and added with 1.37 liters of water, and cooked using a rice cooker to obtain cooked rice. The cooked rice thus obtained is heated to a heat-resistant 385 ml volume (outer diameter 14
Tray-shaped containers (4.0 mm × 39.6 mm in total height) were each filled with 200 g of each container so as to be flat, and further sealed with a heat-resistant lid.

The rice cooked in a sealed container obtained as described above was subjected to the retort sterilization treatment of Comparative Examples and Examples 1 to 3 under the heating conditions shown in Table 1 using a retort sterilizer. The changes in the ambient temperature and the product temperature at this time are shown in FIGS. In Table 1, the heating rate a refers to the heating rate from the start of heating to the change point of the ambient temperature, and the heating rate b refers to the heating rate from the change point to the temperature increase. Further, the comparative example is a conventional retort sterilization treatment, and the embodiment 2 stops the temperature rise when the ambient temperature reaches 110 ° C., holds the temperature for a certain period of time, and the product temperature becomes 110 ° C. After that, the ambient temperature is raised again.

Comparative Example and Examples 1 to 3
Table 1 shows the results of sensory evaluation of the cooked rice obtained in the above. As is clear from the results, the scent of Example 3 was almost the same as that of the comparative example, but all other items exceeded the comparative example. Therefore, in terms of overall quality, it can be said that the cooked rice obtained in Examples 1 to 3 all exceeds the cooked rice obtained in Comparative Example.

[0017]

[Table 1]

[0018]

According to the present invention, even if retort sterilization is applied to cooked rice in a sealed container, the quality of cooked rice can be prevented from deteriorating, so that the quality close to cooked rice can be maintained. become.

[Brief description of the drawings]

FIG. 1 is a diagram showing changes in an ambient temperature and a product temperature in a comparative example.

FIG. 2 is a diagram showing changes in an ambient temperature and a product temperature in Example 1.

FIG. 3 is a diagram showing changes in the ambient temperature and the product temperature in Example 2.

FIG. 4 is a diagram showing changes in the ambient temperature and the product temperature in Example 3.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-236753 (JP, A) JP-A-2-255051 (JP, A) JP-A-5-304911 (JP, A) JP-A-62- 51959 (JP, A) JP-A-58-179445 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A23L 1/10 A23L 3/00-3/30

Claims (1)

(57) [Claims] 1. In the retort sterilization treatment of cooked rice in a sealed container, after the start of heating, when the ambient temperature reaches 110 ° C., the temperature of the cooked rice is controlled to be 85 to 110 ° C., and immediately thereafter, the ambient temperature is controlled. A method for improving the quality of retorted cooked rice, wherein the temperature is increased to 121 ° C. or more.