JPH06125754A - Sterilization of food - Google Patents

Abstract

PURPOSE:To safely and easily sterilize a food at a low cost without using a particular apparatus and to provide a consumer with a food which is safe and sanitary from the viewpoint of public health. CONSTITUTION:A food is made to contact with a solution having pH of >=10 and then with a solution having pH of <=4. More than 99% of bacteria in the food can be sterilized and food poisoning bacteria are also surely exterminated without using a particular apparatus. Since the process is inexpensive and easily operable, it is expected to widely prevail in food manufacturers to provide consumers with safe foods.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sterilization method for foods, which comprises contacting a food with a solution having a pH of 10 or more and then with a solution having a pH of 4 or less.

[0002]

2. Description of the Related Art In recent years, the elements required for food have diversified, and the elements that are strongly required are that food is hygienic and that pathogenic bacteria are not contained. Specifically, microbial standards are being set for each food.

The conventional methods for sterilizing foods are roughly classified into a method using a food additive containing a food additive that does not rely on chemical synthesis and a method not using a food additive. The features, drawbacks and the like of the sterilization method using food additives including food additives not based on chemical synthesis will be described in detail below.

The sterilization of foods by the method of dipping the food in the aqueous solution of hypochlorite or spraying the aqueous solution of hypochlorite on the food has been frequently used, but the chlorine odor tends to adhere to the food. However, the effect of hypochlorite is remarkably reduced unless the solution is acidified, and in this case, especially in foods containing a large amount of protein, acid denaturation is caused and the value of foods is lowered. In addition, the presence of organic substances such as proteins diminishes the bactericidal effect, and the reality is that they are evaluated as impractical.

Hydrogen peroxide is used for the sterilization of foods by the same method as hypochlorite, but it is known that it has carcinogenicity, and it is specified that it should not remain in foods, and it is practically used. Is prohibited.

Alcohols are also used in foods in the same manner as hypochlorite and hydrogen peroxide, but when bacteria are sterilized in foods with alcohols, the concentration is about 20 to 3.
0% by volume or more is required, and at this concentration, in foods containing a large amount of protein, denaturation of the protein by alcohol is caused, and the value of the food is reduced. Further, depending on the amount used, the food may have an alcohol odor and may be regarded as a bad food.

Ozone is permitted to be used as a food additive that does not rely on chemical synthesis. It is exposed to ozone gas, soaked in ozone solution, or sprayed with ozone solution. Although sterilization of food can be exemplified as a conventional technique, ozone itself has a possibility of poisoning gas to harm human health, corrodes equipment due to its strong oxidizing power, and ozone solution lacks sustainability. There are drawbacks such as.

[0008] Next, the sterilization method of the food containing the food additive which does not depend on the chemical synthesis does not include a method of heating the food, a method of exposing the food to ultrahigh pressure, and a method of irradiating with ultraviolet rays. A method of applying a direct current can be exemplified.
The drawbacks and the like will be described in detail below.

The method of heating food has a drawback that it cannot be used for non-heated food such as fresh food.

The method of exposing food to ultra-high pressure has the drawbacks that the physical properties of the food are changed and the application is limited, and the equipment is expensive and special equipment maintenance is required.

The method of irradiating with ultraviolet rays can be applied to liquid foods but cannot be applied to solid foods, and its use is extremely limited.

In the method of applying a direct current, it is necessary to contact the electrodes, and it is pointed out that the sterilization requires a relatively long time, the equipment is expensive, and special skill is required to maintain the equipment. .

Although there is a strong demand from food manufacturers and consumers to supply such safe foods, an inexpensive, easy and reliable food sterilization method is currently available.
I can't find it.

[0014]

In view of the above situation, the problem to be solved by the present invention is to provide food manufacturers with an inexpensive, easy, and reliable food sterilization method for consumers. The purpose is to provide food that is hygienic and safe.

[0015]

[Means for Solving the Problems] As a result of various studies to achieve the above-mentioned object, by immersing a food in a solution having a pH of 10 or more, and then immersing it in a solution having a pH of 4 or less, Bacteria is significantly reduced without compromising the quality of
It was found that it was due to sterilization instead of sterilization. The present invention has been completed based on this finding.

The foods to which the method of the present invention is applicable are all solid foods except liquid foods, such as udon for vegetable foods and kamaboko, fresh seafood, meats for animal foods. .

Examples of the method of bringing the food of the present invention into contact with a solution having a pH of 10 or more and a solution having a pH of 4 or less include dipping and spraying.

The solution having a pH of 10 or more may be an aqueous solution of an arbitrary substance which is alkaline and has a pH of 10 or more, and specifically, preferably sodium hydroxide in food additives. An aqueous solution of any one or more compositions selected from carbonates including bicarbonates such as sodium hydrogen carbonate, sodium carbonate, potassium carbonate, and polymeric phosphates such as tetrasodium pyrophosphate can be used.

The solution having a pH of 4 or less may be an aqueous solution of an arbitrary substance whose pH is 4 or less. Specifically, phosphoric acid hydrochloride in food additives is preferable. An aqueous solution of one or more arbitrary compositions selected from mineral acids such as and organic acids such as acetic acid, lactic acid, citric acid, malic acid, and the like can be used.

A solution having a pH of 10 or more and a pH of 4
The effect of the present invention can be achieved at any concentration as long as the above-mentioned concentration of the substance used in the solution is 10 or more or pH of 4 or less, which is an element of the present invention.

A solution having a pH of 10 or more and a pH of 4
The contact time and temperature of the food with the solution below are not particularly defined, but the effects of the present invention can be achieved in about 10 minutes or less, and the contact time with the solution having a pH of 4 or less is the target food. It is recommended that the contact is allowed for a period of time for the pH to recover. The temperature is also not particularly limited, but a high temperature is desirable as long as the quality of the target food does not change.

A solution having a pH of 10 or more and a pH of 4
To the following solution, salt, seasoning and the like can be added for the purpose of seasoning, and if necessary, known antibacterial substances such as alcohol and bactericidal substances can be added.

A solution having a pH of 10 or more and a pH of 4
If the method of contacting the food with the solution is a dipping method as described below, even if the solution is homogenized by stirring using a known technique, the present invention The effect of can be achieved.

[0024]

It is generally known that when bacteria are exposed to a low pH range, they cause growth inhibition and die. However, when it is intended to sterilize bacteria existing in foods at a low pH, foods, particularly foods containing a large amount of protein, cause acid denaturation, and the value of foods is greatly impaired.

It is known that most solid foods, except for a part thereof, have uneven distribution of bacteria in the surface layer. Taking squid for sashimi as an example, the portion of 1 mm below the surface layer is the surface layer portion, and the inside is the inside, and when the number of general viable bacteria is measured,
The surface layer has about 1,000,000 cells per gram, and the inside has about 100 cells per gram. From this, it can be considered that solid foods can provide consumers with substantially hygienic foods by killing bacteria unevenly distributed in the surface layer.

In the method of the present invention, by contacting a food with a solution having a pH of 10 or more, the tissue of the food surface layer in which the bacteria are unevenly distributed is slightly weakened and the pH is moved to the alkaline range. Then, the food is brought into contact with a solution having a pH of 4 or less, a neutralization reaction is caused in the surface layer of the food, and acid denaturation, which is a disadvantage when the bacteria are exposed to the above low pH range for sterilization, It can be considered that bacteria are sterilized at low pH while preventing changes that reduce the value of food.

Further, it is considered that the fluctuation of the pH is greatly changed from 10 or more to 4 or less to cause fatal damage to the cell membrane of bacteria, but the details are unknown. Hereinafter, the present invention will be described in more detail with reference to Examples.

[0028]

Example 1 As a material, shredded Mongolian squid was inoculated with 100 cells of Staphylococcus aureus per gram, and in the first section, 100 g of the material was prepared in accordance with the method of the present invention, and 100 ml of the material had a pH of 12.4. Immersed in 0.04 mol aqueous solution of sodium hydroxide for 5 minutes, taken up, and immediately immersed in 1000 ml of 0.04 mol aqueous hydrochloric acid solution having a pH of 1.1 for 5 minutes, and then tap water Wash with water.

In the second section, 100 g of the same material was immersed in 1000 ml of tap water having a pH of 7.1 for 5 minutes, and immediately after being picked up, it was immersed in another 1000 ml of tap water for 5 minutes. Rinse gently with tap water.

Materials: The general viable cell counts of the shredded Mongo squid of the first and second sections were measured by the standard agar plate dilution method, and Staphylococcus aureus was measured by the egg yolk-added Mannit salt agar plate dilution method. 1st ward, 2nd ward shredded squid 1
The number of general viable bacteria per gram is 12,000,000,
The number of Staphylococcus aureus was 100, 0, 82 per 1 gram of the shredded Mongow squid of the material, the 1st section, and the 2nd section, respectively.

The shredded Mungou squid in the first section treated by the method of the present invention showed a sterilization rate of 99% or more with respect to the material, and it was shown that all of the inoculated Staphylococcus aureus were sterilized. The method is clearly an excellent sterilization method.

The salt produced by neutralization by the method of the present invention is salt in Example 1, and since it is a trace amount, it has no effect on the quality of food and can be said to be extremely safe.

[0033]

Example 2 Cut cabbage was inoculated with 100 cells of Escherichia coli per gram as a material, and in the first section, 100 g of the material was added in an amount of 0.05 ml of 1000 at a pH of 12.4 according to the method of the present invention. It is immersed in a molar sodium hydroxide aqueous solution for 5 minutes, and then lactic acid is added dropwise until the pH becomes 2.0, and the mixture is left for 5 minutes, followed by a mild water wash with tap water.

In the second section, 100 g of the same material is immersed in 1000 ml of tap water having a pH of 7.1 for 10 minutes, and then lightly rinsed with tap water.

The third section uses the same material 100 as a control method.
Grams are soaked in a 100 ppm aqueous solution of sodium hypochlorite for 10 minutes, and lightly washed with tap water.

Material, the viable cell counts of cut cabbage in the first, second and third sections were measured by the standard agar plate dilution method, and E. coli was measured by the desoxycholate agar plate dilution method. The number of general viable bacteria per 1 gram of cut cabbage in the 1st and 2nd wards is 1500000 and 800, respectively.
0, 1300000, 1200000, and the number of E. coli per 1 gram of cut cabbage in the material, the first ward, the second ward, and the third ward was 14,000, 0, 13,000, respectively.
It was 13000. The fact that E. coli was much larger than the number of inoculations in the materials other than the first section, the second section and the third section of the present invention indicates that the material itself was contaminated with a large number of E. coli.

From these results, it was shown that the cut cabbage in the first section treated by the method of the present invention had a sterilization rate of 99% or more with respect to the material, and all the inoculated E. coli were sterilized. Is clearly an excellent sterilization method. This example shows that sodium hypochlorite, which is a control method, has been approved as a food additive as a germicide, but its effect is very poor.

The salt produced by neutralization by the method of the present invention is sodium lactate which is a food additive in Example 2, and since it is a trace amount, it has no effect on the quality of food and is extremely safe. You can

[0039]

As described above in detail, the method of sterilizing the food of the present invention, that is, the food is present in the food by contacting it with a solution having a pH of 10 or more and then with a solution having a pH of 4 or less. It is an excellent sterilization method that can reduce the number of bacteria to 1/100 or less, and the salt produced by the method of the present invention is a trace amount and is a safe substance, so it does not deteriorate food quality. . In addition, the method of the present invention does not require special equipment and can easily sterilize bacteria in foods at low cost, so even small food manufacturers can provide consumers with sanitary and safe foods in terms of public safety.

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Claims (1)

[Claims] 1. A method for sterilizing a food, which comprises contacting the food with a solution having a pH of 10 or more and then with a solution having a pH of 4 or less.