JPS6010701B2 - How to heat sealed starchy foods - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention heats a starchy food sealed in a heat-resistant container at a temperature of 100°C or less under pressure higher than atmospheric pressure, thereby preventing quality deterioration and producing a sealed starchy food with long shelf life. Concerning methods for producing starchy foods.

So-called retort food is heat sterilized at temperatures above 100 ℃ and under pressures above atmospheric pressure. According to this method, it is possible to produce foods with long shelf life, but the quality of starch-based foods deteriorates significantly, making it undesirable to apply retort sterilization. After all, it is clear that the reason for this is that the starch micelle structure in the starchy food is destroyed too much. Therefore, in the heat sterilization of noodles, etc., additives exhibiting sterilizing or antibacterial activity, such as hydrogen peroxide, are added in advance, and the food is heated at a temperature of 100 qo or less.

The present inventors researched a heat sterilization method that minimizes quality deterioration without using these additives, and found that even if the heating temperature is below 100°C, by adjusting the pressure to above atmospheric pressure. It was found that the bactericidal effect was significantly improved.

In other words, the food is sealed in a packaging container with an appropriate amount of air remaining, and then placed in a pressure-resistant oven or pressure-resistant container.
By heating at a heating temperature of 100°C or less and at atmospheric pressure or higher, preferably at least 1.2 times atmospheric pressure, most microorganisms, including heat-resistant spores, that remain in food can be killed. discovered. It is desirable that the air content in the sealed container is about 10% or more of the effective volume of the container; if it is less than this, the internal pressure of the sealed container may be overcome by the external pressure and the food may stick together in a lump.

The effects of the present invention can be further improved by replacing part or all of the air in the sealed container with carbon dioxide gas, nitrogen gas, or a mixed gas thereof.

The effects of the present invention can also be further improved by allowing ethyl alcohol to coexist in the sealed container or by adding one or more selected from ethyl alcohol, hydrogen peroxide, and propylene glycol to the starchy food in advance. I can do it.

In particular, it has been found that the sterilizing effect is synergistically improved when carbon dioxide gas or ethyl alcohol is allowed to coexist in a sealed container and heated sterilization is performed according to the method of the present invention.

The reason for this is thought to be that the carbon dioxide gas or ethyl alcohol that was dispersed in the space inside the sealed container dissolved into the water in the food in proportion to the pressure applied according to Raoult's law, which improved the sterilizing effect. . As a secondary effect of the present invention, since the sealed food is heated while being pressurized, the internal pressure and external pressure of the packaging container are kept in balance, thereby preventing damage and deformation of the packaging container.

Examples are shown below.

(The number of samples used in each example was 10 for both the control and test areas.) Example 1 110 minutes of washed rice and 120 hours of water were packed into a polypropylene nylon laminated film, and the emptying rate was approximately 30%. After sealing it, put it in a pressure-resistant pot whose temperature and pressure can be adjusted (this pressure-proof pot was also used in the following examples), and bring it to a temperature of 9.
8qo, pressure (absolute pressure, same below) 20 at 2.5 atm
Heated for minutes.

The control group was heated at a temperature of 98° C. and a pressure of 1 atm for 20 minutes.
After heating, each was quenched with running water and stored in a flan vessel at 30°C. As a result, in the control plot, 8'10 samples rotted by 8 days, but in the test plot (method of the present invention, the same applies hereinafter), 2.
Everything was normal even after day 0. (Decomposition was determined by appearance, properties, or odor. The same applies hereinafter.) Example 2 Washed rice was steam-heated at 10,000 for 18 minutes, and then immersed in a 1% glycine solution adjusted to 97°C for 4 minutes to determine the water content. 63.8% semi-fertilized rice was obtained.

This was divided into 200 pieces in polypropylene bags and sealed.
At this time, the void rate was set to approximately 30%. This packaged semi-rotted rice was heated to 90 pm, 2 atm (test area), or 90°C.
Each sample was heated at 1 atm (control) for 18 minutes, then rapidly cooled and stored in a 3 pi flan container. As a result, all of the seeds in the control plot had rotted by 9 days, but all of the plants in the test plot remained normal even after 20 days.

Example 3 Tray pack of 4 pieces of commercially available inarizushi (OPS), and at this time the air was replaced with nitrogen gas.

Also, the vacancy rate at this time was approximately 60%. This was heated to 85℃. After heating for 20 minutes at 2 atm (test area) or 860 and 1 atm (control area), the mixture was rapidly cooled.

As a result of storing these in a flan vessel at 30℃, the control group
It rotted after ~4 days, while rot in the test plots occurred after 7-11 days. Example 4 The same procedure as in Example 3 was carried out by packing three commercially available sweet and spicy dumplings into tray packs.

(However, the replacement gas used was a mixed gas of 20% carbon dioxide and 80% carbon dioxide, and the vacancy rate was approximately 70%.) As a result, the control plot rotted after 5 to 75 days, but the test plot rotted after 11 to 1
It was four days later.

Example 5 Boiled udon noodles (using a #12 cutting blade) prepared in a conventional manner from all-purpose wheat flour were treated with hydrogen peroxide, and the absorption amount was adjusted to be about 3 degrees.

This treated boiled udon was divided into 200 pieces and sealed in polypropylene bags (opening rate of about 20%), and then heated for 20 minutes at 90 qo and 2 atm (test group) or 90°C and 1 atm (control group). . Store this at room temperature (20-25qo
), everything in the test area remained normal even after one month, but in the control area, 9 items rotted after 4 to 10 days.
It accounted for 0%. Example 6 7K9 of water and 750K of polypropylene glycol were added to a mixed powder of 17.5K9 of strong wheat flour and 7.5K9 of whole grain buckwheat flour and mixed. Fresh Japanese soba was produced using 20 cutting blades.

This raw soba was sealed in a polypropylene bag for 130 minutes (
Heating was performed under the conditions of 70 qo and 1.7 atm (test area), and 70° C. and 1 atm (control area). As a result of quenching these and storing them in a flan container at 25°C, they were all normal in the test plots even after 12 days, but in the control plots they rotted after 3 to 7 days. Example 7 Boiled commercially available dried spaghetti to make boiled spaghetti 200
A mixture of Yu and Meat Sauce 802 was sealed in a polypropylene bag with 10 bottles of sake, and the emptying rate was approximately 30%.
), 80 o'clock, 2.3 atm (test area), or 8 and 0, 1
Each was heated under the conditions of atmospheric pressure (control area).

When these were stored at 10° C., everything remained normal in the test plot even after one month, but rot or mold developed in the control plot after 12 to 20 days. Example 8 Sekihan was produced by a conventional method, and 200 pieces of the rice were packed in a nylon-polypropylene laminated film and sealed at a void ratio of about 30%.

Claims (1)

[Claims] 1. A method for heating a starchy food sealed in a heat-resistant container, characterized by heating the starchy food under a pressure higher than atmospheric pressure and at a temperature lower than 100°C. 2. Heating the sealed starchy food according to claim 1, characterized in that part or all of the air in the heat-resistant container is replaced with carbon dioxide gas, nitrogen gas, or a mixed gas thereof. Method. 3. The method for heating a sealed starchy food according to claim 1 or 2, characterized in that ethyl alcohol is allowed to coexist in the heat-resistant container. 4. Claims 1 or 2, characterized in that one or more selected from ethyl alcohol, hydrogen peroxide, and propylene glycol is added in advance to the starchy food sealed in the heat-resistant container. A method of heating a sealed starchy food according to paragraph 3.