JPH10295785A - Sterilizing method for bacteria spores - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve safety and to sterilize bacterial spores in a short time, by adding edible acid to dimer type quaternary ammonium salt solution expressed by the formula and heating the same and bringing in contact with a matter to be sterilized. SOLUTION: Edible acid, for instance citric acid, is added to dimer type bis-quaternary ammonium salt expressed by the formula. R1 -A<+> -R2 -R3 -R2 -A<+> -R1 2 X<-> In the formula, R1 represents an alkyl group with a carbon number of 6-8 combined with ammonium nitrogen, R2 a sulfur atom, carboxyl group, oxycarboxyl group, R3 methylene group with a carbon number of 3-18, A<+> pyridinium group, and X any anion of chlorine, bromine, or iodine. The solution of the dimer type bis-quaternary ammonium salt is heated up to about 50-100 deg.C, preferably about 70-80 deg.C, and brought in contact with a matter to be sterilized. In that case, an ultrasonic wave is irradiated to the matter to be sterilized. Microorganism contamination can be prevented by this method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for rapidly killing harmful microorganisms, particularly bacterial spores, using a solution containing a dimer-type bisquaternary ammonium salt.

[0002]

2. Description of the Related Art At present, hydrogen peroxide, peracetic acid, quaternary ammonium salts, amphoteric surfactants, and the like are used for sterilization of container packaging materials for food and the like and food production machines such as food filling and packaging machines with chemical agents. Chlorine and hypochlorite are used.

[0003] Among the quaternary ammonium salts, dimer type bis (II) ^- (I) represented by the general formula (I) R ₁ -A ⁺ -R ₂ -R ₃ -R ₂ -A ⁺ -R ₁₂ X-(I) A quaternary ammonium salt is an excellent bactericide that is not easily inhibited by proteins, exhibits strong bactericidal activity and a broad bactericidal spectrum that does not decrease even in a low pH region (acid side), is highly safe, and decomposes after use. (Japanese Patent Application Laid-Open No. 8-3017)
03 publication).

On the other hand, aseptic filling and packaging machine shown in FIG. 1 is known as an aseptic filling and packaging machine for sterilizing and using a packaging material web for a rectangular parallelepiped packaging container filled with juice, milk, etc. 1-23683). The outline of the entire aseptic filling and packaging machine is as follows: a rewinder 2 supporting the packaging material web 1 in a roll form; a sterilizing device 3 for sterilizing the packaging material web sequentially wound from the rewinder 2; Is formed into a tubular shape, and a longitudinal sealing device 4 for sealing both longitudinal ends of the tubular packaging material web, and a liquid supply pipe 5 for filling the tubular shaped web with a fluid content. While the tube filled with the contents is fed downward by a length substantially corresponding to one container, and sealed in a direction perpendicular to the longitudinal direction of the tubular packaging material web, and at the same time, a pillow-shaped container 6 having a rectangular cross-section. And a container forming device 8 that bends the end of the pillow-shaped container 6 to form a rectangular parallelepiped container that is the final form. The sterilizing apparatus 3 includes a sterilizing liquid tank 9 of a hydrogen peroxide solution, in which the packaging material web 1 is sunk to sterilize the packaging material web 1, and the sterilized packaging material web 1 is placed on the upper part of the sterilizing apparatus 3. Is introduced into the aseptic chamber 10 provided in the above, and is formed into a rectangular parallelepiped shape as described above.

[0005]

However, when hydrogen peroxide is used as a bactericide, a high-concentration drug of 30% by weight or more must be used in order to surely sterilize container packaging materials and food filling and packaging machines.
It is necessary to use at a high temperature of 0 ° C. or higher. At this time, the above-mentioned chemicals may irritate by contacting the skin, eyes or mucous membranes of workers, causing burns.For this reason, safety equipment must be worn to avoid contact with the human body. It was inconvenient. In addition, it is necessary to adequately ventilate the work environment in consideration of the impact on worker health.
There are disadvantages such as an increase in capital investment for utilities such as a treatment for purifying hydrogen peroxide contained in exhaust air.

Further, quaternary ammonium salt compounds which are widely used as bactericidal and bacteriostatic agents for food machines and the like have a bactericidal activity antagonized by carbohydrates, proteins, lipids and the like, and have a long sterilizing time. Problems have been pointed out, such as inefficiency on cell spores, which are the most problematic in production and most difficult to sterilize.

On the other hand, the aseptic filling and packaging machine for juice, milk and the like is capable of producing at least 8,000 packs per hour, which is capable of producing at least 8000 packs per hour, from the viewpoint of shortening working hours and improving working efficiency and operating efficiency in recent years. Filling and packaging machines have been required and for high speed operation of 8000 packs or more per hour, the speed of movement of the packaging material web is approximately 36 cm /
Seconds or more, in order to ensure the sterilization of the packaging material web, in order to ensure sufficient immersion time in the sterilizing solution tank, to increase the vertical length of the sterilizing solution tank, or in a short time In developing a sterilization method that can surely sterilize bacterial spores or in developing such a high-speed aseptic filling and packaging machine, the choice has been pressing. If the sterilizing liquid tank is made vertically long, it is inevitable that the apparatus becomes large, and eventually, the present inventors have been required to develop a sterilizing method capable of surely sterilizing bacterial spores in a short time. That is, an object of the present invention is to provide a sterilization method which has high safety, is the most problematic in food production, and can surely sterilize cell spores which are most difficult to sterilize in a short time.

[0008]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors thoroughly washed existing germicides and examined various germicidal conditions and completed the present invention. That is, the present invention provides a bacterium characterized in that a solution of a dimer-type bisquaternary ammonium salt represented by the general formula (I) to which an edible acid has been added is heated and brought into contact with an object to be sterilized. The present invention relates to a method for sterilizing spores. ^{_{R 1 -A + -R 2 -R 3}} -R 2 -A + -R 1 2X - (I) ( In the formula, R ₁ 6 carbon atoms that binds to ammonium nitrogen
An alkyl group of 18, R ₂ represents any one of a sulfur atom, a carboxyl group and an oxycarboxyl group, R ₃ represents a methylene group having ₃ to 18 carbon atoms, A ⁺ represents a pyridinium group, X
^- chlorine, bromine, one of the anions of iodine, respectively. )

The present invention also provides a method for disinfecting bacterial spores, which comprises heating a solution of the dimer-type bisquaternary ammonium salt to which an edible acid has been added while irradiating an ultrasonic wave, and bringing the solution into contact with an object to be sterilized. The present invention also relates to a method for sterilizing bacterial spores in which a solution of the dimer-type bisquaternary ammonium salt is heated while being irradiated with ultrasonic waves and brought into contact with an object to be sterilized.

Further, the present invention relates to a method for sterilizing bacterial spores by contacting another sterilizing / antibacterial agent with the material to be sterilized before applying the above-mentioned sterilizing method to the material to be sterilized such as a packaging material web.

[0011]

Used DETAILED DESCRIPTION OF THE INVENTION In the present invention, the following general formula ^{_{(I) R 1 -A + -R}} 2 -R 3 -R 2 -A + -R 1 2X - (I) ( wherein, R ₁ is from 6 to carbon atoms bonded to ammonium nitrogen
An alkyl group of 18, R ₂ represents any one of a sulfur atom, a carboxyl group and an oxycarboxyl group, R ₃ represents a methylene group having ₃ to 18 carbon atoms, A ⁺ represents a pyridinium group, X
^- chlorine, bromine, one of the anions of iodine, respectively. The dimer-type bisquaternary ammonium salt represented by the formula (1) can be produced, for example, by the method described in JP-A-8-301703.

Specific examples of the dimer-type bisquaternary ammonium salt represented by the general formula (I) include those shown in Table 1 below.

[0013]

[Table 1]

The dimer-type bisquaternary ammonium salt is used in an amount of usually 50 to 10000 ppm, preferably 1000 ppm.
It is used in a concentration range of up to 3000 ppm.

In the present invention, the edible acid to be added to the solution of the dimer-type bisquaternary ammonium salt includes:
Examples thereof include citric acid, lactic acid, phosphoric acid, and acetic acid, among which citric acid is preferred. In addition, a non-edible inorganic acid or the like can be used instead of the edible acid, but it is preferable to use an edible acid from the viewpoint of bactericidal spore effect and safety. The amount of these edible acids added is
Depending on the type of edible acid used, 1 to 20% by weight based on the solution of the dimer-type bisquaternary ammonium salt,
It is desirable to add so that it may become preferably 6 to 10% by weight.

In the present invention, examples of the form in which the solution of the dimer-type bisquaternary ammonium salt to which the edible acid is added is brought into contact with the object to be sterilized include immersion, spraying, and application. it can.

In the present invention, the temperature of the solution of the dimer-type bisquaternary ammonium salt is usually 50 to 100 ° C., preferably 70 to 80 ° C.

In the present invention, the ultrasonic irradiation is usually performed on the object to be sterilized immersed in a solution of the dimer-type bisquaternary ammonium salt to which an edible acid has been added. It can also be performed on the sterilized material immediately after spraying. In addition, conditions such as a frequency in ultrasonic irradiation may be appropriately selected from conditions usually used.

In the present invention, other germicidal and antibacterial agents used prior to contacting the solution of the dimer-type bisquaternary ammonium salt to which the edible acid has been added with the object to be sterilized include alcohols such as ethanol. A mixture of an alcohol and an organic acid, hydrogen peroxide, peracetic acid, other quaternary ammonium salts, amphoteric surfactants, chlorine, hypochlorite, etc. An edible material such as a mixture with an organic acid is preferred.

In the present invention, examples of the materials to be sterilized include container packaging materials such as food containers and packaging webs used for food filling and packaging, food production machines such as food filling and packaging machines, and medical equipment and utensils. .

[0021]

EXAMPLES Hereinafter, the method for killing bacterial spores according to the present invention will be described with reference to examples and the like, but the present invention is not limited to these examples. (Reference Example 1) Bacillus subtilis (Ba
MIC (Minimum Inhibitory Concentration) was measured by agar plate dilution method using Cillus subtilis), Pseudomonas aeruginosa and Micrococcus luteus. First, the test bacteria were pre-cultured and adjusted to 10 ⁶ cfu / ml (cfu: colony forming unit). Next, 4DOCBP-6,8, which are dimer-type bisquaternary ammonium salts shown in Table 1, and 4DOC
BP-6,10 and 4DTBP-6,8 (I type
e) and a normal agar medium to which 4DTBP-6,8 (Cl type) was added to a predetermined concentration was prepared.
The above-mentioned test bacteria were inoculated thereon and incubated at 32 ° C. for 48 hours. After the culture, the presence or absence of proliferation was visually confirmed, and the minimum drug concentration at which no proliferation was observed was defined as the MIC. Table 2 shows the results
Shown in

[0022]

[Table 2]

(Reference Example 2) As a result of the MIC test of Reference Example 1, Bacillus subtilis (Baci) exhibiting a high MIC value for four dimer-type bisquaternary ammonium salts.
llus subtilis) ATCC 9372 for further experiments. Bacillus subtilis ATCC 9372 was cultured on a sporulation medium for 5 days to form bacterial spores. This test bacterial spore was diluted with sterile distilled water to a concentration of 10 ⁸ cfu / ml to obtain a bacterial spore suspension. 10 μl of the bacterial spore suspension was taken and inoculated in a packaging material, and the number of bacterial spores to be used for the test was adjusted to 10 ⁶ .
Next, 4DOCBP-6, 8 and 4DOCBP-, which are dimer-type bisquaternary ammonium salts shown in Table 1,
6,10 and 4DTBP-6,8 (I type)
And a 1000 ppm aqueous solution of each compound of 4DTBP-6,8 (Cl type) was heated to 75 ° C., and the bacterial spores inoculated in the packaging material were immersed therein for a predetermined time. afterwards,
After removing the effects of these bactericides, the packaging material was collected in a liquid medium and subjected to static culturing at 32 ° C. for 5 days, and the presence or absence of growth of the test bacterial spores was determined based on the change in color and turbidity of the medium. . Table 3 shows the results. In Table 3, "+" indicates that the growth of bacteria was observed, and "-" indicates that no growth was observed. As can be seen from Table 3, 10
The test bacterial spores died within minutes, but some did not die within 5 minutes, and satisfactory results could not be obtained only by heating the dimer-type bisquaternary ammonium salt solution. That is, this method is strictly said juice,
A test run using a high-speed aseptic filling and packaging machine to sterilize packaging material webs that require sterile products such as milk revealed that several out of 10,000 products were microbially contaminated and did not pass the inspection standards. It has been found.

[0024]

[Table 3]

Example 1 Based on the results of the experiment described in Reference Example 2 above, among the dimer-type bisquaternary ammonium salts shown in Table 1, 4DOCBP-6,8 and 4D
The following experiment was conducted with two compounds, TBP-6,8 (Cl type). 1000 of these compounds
The aqueous solution of ppm was heated to 75 ° C., and the bacterial spores inoculated in the packaging material were immersed for a predetermined time while irradiating ultrasonic waves (output: 100 W; frequency: 39 kHz). The collection, culture, and determination of the packaging material were performed in the same manner as in Reference Example 2, and the presence or absence of growth of the test bacterial spores was determined. In addition, the thing which did not irradiate an ultrasonic wave was made into the comparative example. Table 4 shows the results. As shown in Table 4, when the aqueous solution of the compound placed in the immersion tank was heated and further irradiated with ultrasonic waves, compared with the non-irradiated comparative example, the time required for sterilization of the bacterial spores was longer. 1/1
It turned out to be about 0.

[0026]

[Table 4]

Reference Example 3 Next, the effect of using an edible acid in combination was examined. Among the dimer-type bisquaternary ammonium salts shown in Table 1, 4DTBP-6,8 (Cl t
ype) with three different aqueous solutions, ie 10
Citric acid as an edible acid was added to each of the aqueous solutions of 00 ppm, 3000 ppm, and 5000 ppm so that the concentration became 10% by weight. These three solutions were used as they were at room temperature without heating. In these aqueous solutions,
The test bacterial spores inoculated in the packaging material were immersed for a predetermined time. The collection, culturing, and determination of the packaging material are performed in the same manner as in Reference Example 2,
The presence or absence of growth of the test bacterial spore was determined. Table 5 shows the results. As can be seen from Table 5, simply adding an edible acid to the dimer-type bisquaternary ammonium salt aqueous solution results in
Even when the concentration of the dimer-type bisquaternary ammonium salt is 3 to 5 times, the bactericidal effect of the test bacterial spores is lower than that of Reference Example 2 in which edible acid is not added and the mixture is simply heated. Was.

[0028]

[Table 5]

(Example 2) Next, as in Example 1, Table 1
Among the dimer bis quaternary ammonium salts shown in
4DOCBP-6,8 and 4DTBP-6,8 (Cl
Citric acid, lactic acid, phosphoric acid and acetic acid as edible acids were added to a 1000 ppm aqueous solution of the two compounds of type (10% by weight, respectively). The four types of solutions were heated to 75 ° C., and the test bacterial spores inoculated in the packaging material were immersed therein for a predetermined time. The collection, culture, and determination of the packaging material were performed in the same manner as in Reference Example 2, and the presence or absence of growth of the test bacterial spores was determined. In addition, what heated to 75 degreeC without adding edible acid was made into the comparative example. Table 6 shows the results. Table 6
As can be seen, when the edible acid was added to the dimer-type bisquaternary ammonium salt aqueous solution, the test bacterial spores died in 1/5 to 1/10 the time in Reference Example 2. .

[0030]

[Table 6]

(Example 3) Further, in order to shorten the sterilization time, the aqueous solution to which 10% by weight of citric acid prepared in Example 2 was added and heated was irradiated with ultrasonic waves (output: 100).
(W: frequency 39 kHz), the test bacterial spores inoculated in the packaging material were immersed for a predetermined time. The collection, culture, and determination of the packaging material were performed in the same manner as in Reference Example 2, and the presence or absence of growth of the test bacterial spores was determined. Also, 4DTBP-6,8 (Cl
An aqueous solution heated by adding 10% by weight of citric acid to type) and not subjected to ultrasonic irradiation was used as a comparative example. Table 7 shows the results. As can be seen from Table 7, when combined use of citric acid and ultrasonic irradiation, 4DOCBP-6,
8 for 10 seconds, 4DTBP-6,8 (Cl ty
In the case of pe), the surprising result that the test bacterial spores were killed in 5 seconds was obtained.

[0032]

[Table 7]

Example 4 A packaging material inoculated with a test bacterial spore was immersed in a 70% ethanol solution containing 10% by weight of citric acid for 5 seconds or 10 seconds, and then 10% by weight of citric acid 4DOCBP-6, 8 and 4 with the addition of
10 of each compound of DTBP-6,8 (Cl type)
A 00 ppm aqueous solution was immersed in a solution heated to 75 ° C. for a predetermined time. The collection, culture, and determination of the packaging material were performed in the same manner as in Reference Example 2, and the presence or absence of growth of the test bacterial spores was determined. Table 8 shows the results. As shown in Table 8, after contacting with a mixture of ethanol and citric acid for 5 seconds, 4DOCBP
-6,8 aqueous solution for 10 seconds, 4DTBP-6,8
It was found that the test bacterial spores had been killed by contacting with an aqueous solution of (Cl type) for 5 seconds.

[0034]

[Table 8]

Reference Example 4 A solution of benzalkonium chloride (1000-5000 ppm), a commercially available quaternary ammonium salt other than the dimer-type bisquaternary ammonium salt, added with 10% by weight of citric acid as an edible acid. 75 ° C
The test bacterial spores inoculated in the packaging material were immersed therein for a predetermined time. The collection, culture, and determination of the packaging material were performed in the same manner as in Reference Example 2, and the presence or absence of growth of the test bacteria was determined. Table 9 shows the results. As can be seen from Table 9, the tested bacterial spores did not die in a short time with benzalkonium chloride even when combined with an edible acid.

[0036]

[Table 9]

[0037]

Industrial Applicability According to the present invention using a dimer type bisquaternary ammonium salt, it is highly safe and cannot be achieved with other quaternary ammonium salt compounds, and it is the most problematic in producing harmful microorganisms, especially food, and sterilization. The most difficult cell spores can be reliably sterilized in a short time.

By applying the sterilization method of the present invention,
The microbiological problem of high speed operation of aseptic filling and packaging machines with a production capacity of 8000 packs per hour or more has been cleared. In addition, the dimer-type bisquaternary ammonium salt has no adsorptivity to the polyester constituting the surface of the packaging material web used in the aseptic filling and packaging machine, and does not invade SUS, which is a material thereof. Was confirmed.

[Brief description of the drawings]

FIG. 1 is a front view of a conventional aseptic filling and packaging machine.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 packaging material web 2 rewinder 3 sterilizer 4 vertical sealing device 5 liquid supply pipe 6 pillow container 7 horizontal sealing device 8 container forming device 9 sterilizing liquid tank 10 sterile chamber

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Tadao Akai Ten No. 10 Nishikawa, Taro Yasu, Kitajima-cho, Itano-gun, Tokushima Prefecture Inside Shikoku Kakoki Co., Ltd. (72) Inventor Michio Ueda Kitajima-cho, Itano-gun, Tokushima Prefecture Taro Yasushi character West No. 10 1 Shikoku Kakoki Co., Ltd.

Claims (5)

[Claims] 1. A bacterial spore characterized in that a solution of a dimer-type bisquaternary ammonium salt represented by the general formula (I) to which an edible acid is added is heated and brought into contact with an object to be sterilized. Sterilization method. ^{_{R 1 -A + -R 2 -R 3}} -R 2 -A + -R 1 2X - (I) ( In the formula, R ₁ 6 carbon atoms that binds to ammonium nitrogen
An alkyl group of 18, R ₂ represents any one of a sulfur atom, a carboxyl group and an oxycarboxyl group, R ₃ represents a methylene group having ₃ to 18 carbon atoms, A ⁺ represents a pyridinium group, X
^- chlorine, bromine, one of the anions of iodine, respectively. ) 2. The method for sterilizing bacterial spores according to claim 1, wherein the bacteria are brought into contact with an object to be sterilized while being irradiated with ultrasonic waves. 3. Disinfection of bacterial spores, wherein a solution of a dimer-type bisquaternary ammonium salt represented by the general formula (I) is heated and brought into contact with an object to be disinfected while irradiating with ultrasonic waves. Method. ^{_{R 1 -A + -R 2 -R 3}} -R 2 -A + -R 1 2X - (I) ( In the formula, R ₁ 6 carbon atoms that binds to ammonium nitrogen
An alkyl group of 18, R ₂ represents any one of a sulfur atom, a carboxyl group and an oxycarboxyl group, R ₃ represents a methylene group having ₃ to 18 carbon atoms, A ⁺ represents a pyridinium group, X
^- chlorine, bromine, one of the anions of iodine, respectively. ) 4. The method according to claim 1, wherein prior to bringing the solution containing the dimer-type bisquaternary ammonium salt into contact with the material to be sterilized, another sterilizing / antibacterial agent is brought into contact with the material to be sterilized. Item 4. The method for killing bacterial spores according to any one of Items 3. 5. The method for sterilizing bacterial spores according to claim 1, wherein the material to be sterilized is a packaging material web.