JPS5929207B2 - How to sterilize food - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a sterilization method suitable for sterilizing foods, especially leafy vegetables such as Chinese cabbage, cabbage, and spinach.

Conventionally, food has been sterilized by washing it with dilute chlorine water.

However, this method required a long cleaning time of several tens of minutes, and the resulting sterilization rate was low at about 50 cm.

On the other hand, although sterilization using high heat can be carried out in a short time and has a high sterilization rate, it cannot be applied to foods that are easily denatured by heat, such as leafy vegetables.

The object of the present invention is to improve the above-mentioned drawbacks and obtain a high sterilization rate in a short period of time without causing food denaturation.

In order to achieve the above purpose, the present inventor has conducted extensive research, and as a result,
When sterilization is carried out by blowing oxygen gas or oxygen-containing gas into water, sterilization can be carried out extremely quickly even when heated at a low temperature that causes almost no heat denaturation, even for foods that are easily denatured by heat, such as leafy vegetables. I discovered this surprising fact.

The present invention will be explained in detail below.

The water used in the present invention may be untreated, but the PH
If adjusted to 4 or less, the sterilization efficiency will be significantly improved.

To adjust the pH to such an acidic level, it is desirable to use an acid that is harmless to the human body, such as hydrochloric acid, acetic acid, citric acid, or malic acid.

Furthermore, chlorine may be added to the water used in the present invention.

As a chlorine source, chlorine gas, liquid chlorine, or a compound that decomposes to generate chlorine, such as sodium hypochlorite, is used.

The amount of chlorine added is approximately 0.2 to 0.4 chlorine.

Although the water used in the present invention is heated, when oxygen gas or oxygen-containing gas is blown into the water, a sufficient sterilization effect can be obtained at a low temperature of 40° C. or higher.

The processing temperature should be 70°C or lower for foods that are easily denatured by heat.

However, it has been found that when the pH is set to 4 or less, a high sterilization rate can be obtained even without heating the water used in the present invention.

Other disinfectants, salt, surfactants, etc. may be added to the water used in the present invention.

For carrying out the sterilization method of the present invention, for example, the aeration tank shown in the figure is used.

In the figure, 1 is a tank body, 2 is an aeration pipe installed at the bottom of the tank body 1, and air is blown into the tank via an air pipe 4 by an air pump 3.

The above-mentioned aeration tank is filled with water, and if desired, after the above-mentioned treatment is performed, the objects to be treated are immersed directly or in a basket or the like.

The processing time may be a single time of about 2 to 3 minutes to 20 minutes.

In this way, a high sterilization rate can be obtained at low temperatures and in a short time.

The effects of the present invention are clarified in Table 1.

Test method: A predetermined number of cucumbers are placed as samples in an aeration tank as shown in Figure 1, and sterilized for 15 minutes.

The number of viable bacteria is determined before and after treatment according to the official test method notified by the Ministry of Health and Welfare dated March 23, 1971.

The above trial law is detailed below.

(1) After taking out 4 to 5 samples and performing calculations, they are ground using a homogenizer under sterile conditions.

(2) Take 10 g of the obtained triturating powder and add a certain amount of sterile water to dilute it.

(3) Add the obtained diluted triturant to a sterile standard agar medium, mix well, pour into a sterile container with a lid, and cover.

(4) Cultivate the above medium at 37°C for 48 hours, count the number of bacteria generated, and express this as the number of viable bacteria attached to the sample (Table 1 shows the number of viable bacteria per 1 g of sample). ).

■ Comparing the influence of air aeration between 1, 3, 5.7 and 2, 4, 6, 8, there is no air aeration; The sterilization rate is significantly lower than that of 2, 4, and 6.8.

2. Effect of processing temperature AI, A2, A9. A10 is 20°C, A3. A16°4, Al l and Al 2 were at 50°C, A5. Ya 6-1
6°13, A14 is 60°C, 115.7- JFy,
No. 8 is 70°C, and as the treatment temperature increases, the sterilization rate increases dramatically, especially when aeration is performed.

In particular, A8 has a sterilization rate of nearly 100% at 70°C without adding anything to the water.

3. Effect of pH A 10 , 129 times 14 and 9. Bian 11. Comparing with No. 13, if the pH is set to 4 or less, especially around 3, a high sterilization rate can be seen even if the treatment temperature is room temperature.

. As mentioned above, the present invention is particularly suitable for sterilizing foods that are easily denatured by heat because a high sterilization rate can be obtained at low temperatures and in a short period of time.

The present invention can also be applied to disinfecting objects other than food, such as tableware and medical instruments.

[Brief explanation of the drawing]

The drawings show an embodiment of the apparatus used in the method of the present invention, with FIG. 1 being a side view and FIG. 2 being a plan view. In the figure, 1... tank body, 2... aeration pipe.

Claims (1)

[Claims] A method for sterilizing food, which comprises blowing oxygen gas or oxygen-containing gas into water heated to 140° C. or higher and immersing the food in the water. 2. A food sterilization method according to Claim 1, characterized in that chlorine is dissolved in the water. A method for sterilizing food, which comprises adjusting water heated to 340°C or higher to a pH of 4 or lower, blowing oxygen gas or oxygen-containing gas into the water, and immersing the food. 4. A food sterilization method according to claim 3, characterized in that chlorine is dissolved in the water.