Method for producing an aqueous solution containing chlorite used as a disinfectant.

Abstract

The objective is to provide a method for producing an aqueous solution containing chlorous acid that is safe for human use, easy to handle, and generates little chlorine dioxide, for use as a disinfectant in pre-treatment for food processing. [Solution] A method for producing an aqueous solution containing chlorous acid, which is safe for the human body, easy to handle, and generates little chlorine dioxide, for use as a pre-treatment disinfectant for food processing. Chloric acid is generated by adding sulfuric acid or an aqueous solution thereof in an amount and concentration that can maintain the pH value of the aqueous solution between 2.3 and 3.4 to an aqueous sodium chlorate solution and reacting the two, and then adding an amount of hydrogen peroxide equal to or greater than the amount required for the reduction reaction to the chloric acid to produce chlorous acid.

Description

[Technical Field]

[0001] The present invention relates to a method for producing an aqueous solution containing chlorite for use in sterilizing and disinfecting food and related equipment in the pre-treatment stage of food processing. [Background technology]

[0002] Traditionally, chlorine oxides (chlorine, hypochlorous acid, chlorite, chlorine dioxide, etc.) have been primarily used for sterilization and disinfection of food products in the pre-processing stage of food processing, such as fresh foods like vegetables and fruits, and related facilities used in the processing and manufacturing of these foods, such as containers, processing and cooking machinery, and factory equipment. Of these, chlorine and hypochlorous acid have been pointed out to produce trihalomethanes, which are carcinogenic substances, when they react with organic compounds. For this reason, coupled with the recent health consciousness, acidified chlorite (AC), developed in the United States, which has fewer harmful effects from trihalomethanes and also has high sterilization efficacy, is attracting attention.

[0003] To obtain the above-mentioned acidified chlorite (AC), it is necessary to add a GRAS (Generally Recognized As Safe) acid to an aqueous sodium chlorite solution and adjust the pH value to 2.3-3.2.

[0004] However, chlorous acid, the main component of the above-mentioned acidified chlorite (AC), lacks stability and decomposes quickly after preparation, significantly reducing its bactericidal power. Therefore, when using the above-mentioned acidified chlorite (AC), preparation is required immediately before use.

[0005] Therefore, it is time-consuming, and chlorine dioxide gas may be generated during the adjustment process. Inhaling this gas poses a high risk of adverse effects on the human body, and it also has the drawback of corroding food processing and cooking equipment. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] United States Patent No. 6,524,624 [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention has been made in view of the above-mentioned drawbacks, and its purpose is to provide a pre-treatment disinfectant for food processing that is safe for the human body and has excellent bactericidal power, by stabilizing an aqueous solution containing chlorite for a long period of time, thereby facilitating handling, suppressing the generation of chlorine dioxide, and providing a disinfectant. [Means for solving the problem]

[0008] To achieve the above objective, the first feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that chloric acid is generated by reacting an aqueous solution of sodium chlorate with sulfuric acid or an aqueous solution thereof in an amount and concentration that can maintain the pH value of the aqueous solution within 2.3 to 3.4, and then chlorous acid is produced by adding an amount of hydrogen peroxide equal to or greater than the amount required for the reduction reaction of the chloric acid.

[0009] Furthermore, a second feature of the method for producing an aqueous solution containing chlorite for use as a disinfectant according to the present invention is that chlorite is produced by reacting an aqueous solution of sodium chlorate with sulfuric acid or an aqueous solution thereof in an amount and concentration that can maintain the pH value of the aqueous solution within 2.3 to 3.4. The process involves generating a solution of chlorous acid by adding an amount of hydrogen peroxide equivalent to or greater than the amount required for the reduction reaction of the chloric acid, and then adding an inorganic acid or inorganic salt, or two or more of them individually or in combination, to adjust the pH value to a range of 3.2 to 7.0.

[0010] Furthermore, a third feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is to react an aqueous solution of sodium chlorate with sulfuric acid or an aqueous solution thereof in an amount and concentration that can maintain the pH value of the aqueous solution within 2.3 to 3.4 to generate chloric acid, and then add an amount of hydrogen peroxide equal to or greater than the amount required for the reduction reaction of the chloric acid to the aqueous solution to produce chlorous acid, and then add one or more inorganic acids or inorganic acid salts, or organic acids or organic acid salts, one or more of them, or a combination thereof, to adjust the pH value to within the range of 3.2 to 7.0.

[0011] Furthermore, a fourth feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is to react an aqueous solution of sodium chlorate with sulfuric acid or an aqueous solution thereof in an amount and concentration that can maintain the pH value of the aqueous solution within 2.3 to 3.4 to generate chloric acid, and then add an amount of hydrogen peroxide equal to or greater than the amount required for the reduction reaction of the chloric acid to the aqueous solution to generate chlorous acid, and then add an inorganic acid or inorganic salt, or two or more of them individually or in combination, to the aqueous solution, and then adjust the pH value to within the range of 3.2 to 7.0.

[0012] Furthermore, a fifth feature of the method for producing an aqueous solution containing chlorous acid used as a disinfectant according to the present invention is that the inorganic acid in the method for producing an aqueous solution containing chlorous acid in any one of the second to fourth features is carbonic acid, phosphoric acid, boric acid, or sulfuric acid.

[0013] Furthermore, a sixth feature of the method for producing an aqueous solution containing chlorous acid used as a disinfectant according to the present invention is that the inorganic salt in the method for producing an aqueous solution containing chlorous acid in any one of the second to fifth features is a carbonate, hydroxide, phosphate, or borate.

[0014] Furthermore, a seventh feature of the method for producing an aqueous solution containing chlorous acid used as a disinfectant according to the present invention is that the carbonate in the method for producing an aqueous solution containing chlorous acid in the sixth feature is sodium carbonate, potassium carbonate, sodium bicarbonate, or potassium bicarbonate.

[0015] Furthermore, an eighth feature of the method for producing an aqueous solution containing chlorous acid used as a disinfectant according to the present invention is that the hydroxide in the method for producing an aqueous solution containing chlorous acid in the sixth or seventh feature is sodium hydroxide or potassium hydroxide.

[0016] Furthermore, a ninth feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that the phosphate in the method for producing an aqueous solution containing chlorous acid according to any one of the sixth to eighth features is disodium hydrogen phosphate, sodium dihydrogen phosphate, trisodium phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, or potassium dihydrogen phosphate.

[0017] Furthermore, a tenth feature of the method for producing an aqueous solution containing chlorous acid used as a disinfectant according to the present invention is that the borate in the method for producing an aqueous solution containing chlorous acid in any one of the features from the sixth to the ninth is sodium borate or potassium borate.

[0018] Furthermore, the 11th method for producing an aqueous solution containing chlorite to be used as a disinfectant according to the present invention The characteristic of this method is that the organic acid in the method for producing an aqueous solution containing chlorous acid according to any one of the third to ten characteristics above is succinic acid, citric acid, malic acid, acetic acid, or lactic acid.

[0019] Furthermore, the twelfth feature of the method for producing an aqueous solution containing chlorous acid used as a bactericide according to the present invention is that the organic acid salt in the method for producing an aqueous solution containing chlorous acid in any one of the third to eleventh features is sodium succinate, potassium succinate, sodium citrate, potassium citrate, sodium malate, potassium malate, sodium acetate, potassium acetate, sodium lactate, potassium lactate or calcium lactate.

Advantages of the Invention

[0020] According to the present invention, since chlorous acid having high bactericidal power is maintained for a long time, it is not necessary to perform adjustment operations immediately before use, and it can also be stored. In addition, it is possible to suppress the generation of chlorine dioxide, and it is safe for the human body and can be used with confidence.

[0021] In addition, since it is possible to maintain chlorous acid for a long period of time, it is also fully possible to distribute an aqueous solution containing chlorous acid produced in advance under an acidic region as a product.

Brief Description of the Drawings

[0022] [Figure 1] It shows the measurement result of Specimen A by a spectrophotometer on the specimen preparation date. [Figure 2] It shows the measurement result of Specimen A by a spectrophotometer on the 10th day from the specimen preparation date. [Figure 3] It shows the measurement result of Specimen A by a spectrophotometer on the 20th day from the specimen preparation date. [Figure 4] It shows the measurement result of Specimen A by a spectrophotometer on the 30th day from the specimen preparation date. [Figure 5] It shows the measurement result of Specimen B by a spectrophotometer on the specimen preparation date. [Figure 6] It shows the measurement result of Specimen B by a spectrophotometer on the 10th day from the specimen preparation date. [Figure 7] It shows the measurement result of Specimen B by a spectrophotometer on the 20th day from the specimen preparation date. [Figure 8] This shows the spectrophotometer measurement results for sample B 30 days after the sample preparation date. [Figure 9] This shows the spectrophotometer measurement results for sample C on the day the sample was prepared. [Figure 10] This shows the spectrophotometer measurement results for sample C one hour after sample preparation. [Figure 11] This shows the spectrophotometric measurement results for sample C one day after sample preparation. [Figure 12] This shows the spectrophotometer measurement results for sample C on the 5th day after sample preparation. [Figure 13] This shows the spectrophotometer measurement results for sample D on the day the sample was prepared. [Figure 14] This shows the spectrophotometric measurement results for sample D 10 days after the sample preparation date. [Figure 15] This shows the spectrophotometer measurement results for sample D 20 days after the sample preparation date. [Figure 16] This shows the spectrophotometer measurement results for sample D 30 days after the sample preparation date. [Figure 17] This figure compares the pH change over time between aqueous solutions containing chlorous acid according to Examples 2, 3, and 4 and the conventional ASC. [Modes for carrying out the invention]

[0023] The best embodiment of the present invention will be described below with reference to the figures and tables. [Examples]

[0024] Example 1 of the present invention is a method for producing an aqueous solution containing chlorous acid (HClO2) for use as a disinfectant. In this production method, chloric acid (HClO3) obtained by adding sulfuric acid (H2SO4) or an aqueous solution thereof to an aqueous solution of sodium chlorate (NaClO3) to create acidic conditions is reacted with an excess amount of hydrogen peroxide necessary to convert it to chlorous acid through a reduction reaction, thereby producing chlorous acid (HClO2). The basic chemical reactions of this production method are represented by equations A and B below.

[0025] [ka]

[0026] In formula A, the pH value of the sodium chlorate (NaClO3) aqueous solution is maintained within 2.3 to 3.4. This indicates that by adding sulfuric acid (H2SO4) or an aqueous solution thereof in the amount and concentration that can be produced, chloric acid is obtained while simultaneously removing sodium ions.

[0027] Next, in equation B, chloric acid (HClO3) is reduced by hydrogen peroxide (H2O2), This indicates that chloric acid (HClO2) is produced. At this time, the amount of hydrogen peroxide (water) added must be equal to or greater than the amount required for the reduction reaction. Using less than this amount will only produce chlorine dioxide.

[0028] [ka]

[0029] Furthermore, if chlorine dioxide is generated, chlorous acid will be produced via the reaction described in equations C-F.

[0030] By the way, the generated chlorous acid (HClO2) undergoes decomposition reactions between multiple chlorous acid molecules, and also contains chloride ions (Cl -It has the property of quickly decomposing into chlorine dioxide gas or chlorine gas in the presence of chlorine dioxide, hypochlorous acid (HClO), and other reducing agents. Therefore, in order to make it useful as a disinfectant, it is necessary to prepare it in a way that maintains the state of chlorite acid (HClO2) for a long time.

[0031] Therefore, there is a need for a method of producing an aqueous solution that can stably maintain chlorous acid (HClO2) for a long period of time by creating a transition state and delaying the decomposition reaction by adding an inorganic acid, inorganic acid salt, organic acid, or organic acid salt, either individually or in combination with two or more of these, to an aqueous solution containing chlorous acid (HClO2) obtained by the method of Example 1 above. Examples 2, 3, and 4 demonstrate this method. [Examples]

[0032] In other words, Example 2 involves adding an inorganic acid or inorganic salt, specifically a carbonate or hydroxide, either individually or in combination, to an aqueous solution containing chlorous acid (HClO2) obtained by the method of Example 1. This refers to adding one or more substances of the same class, or using them in combination. [Examples]

[0033] Furthermore, Example 3 involves adding an inorganic acid, inorganic acid salt, organic acid, or organic acid salt, either individually or in combination with two or more other types, to the aqueous solution produced in Example 2. [Examples]

[0034] Furthermore, Example 4 involves adding an inorganic acid or inorganic acid salt, or an organic acid or organic acid salt, either individually or in combination with two or more other types, to the aqueous solution produced in Example 1.

[0035] Examples of the inorganic acids mentioned above include carbonic acid, phosphoric acid, boric acid, or sulfuric acid. Examples of inorganic salts include carbonates, hydroxides, phosphates, or borates. More specifically, suitable carbonates include sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate; suitable hydroxides include sodium hydroxide and potassium hydroxide; suitable phosphates include disodium hydrogen phosphate, dihydrogen phosphate, trisodium phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, and dihydrogen phosphate; and suitable borates include sodium borate and potassium borate. Examples of the organic acids mentioned above include succinic acid, citric acid, malic acid, acetic acid, or lactic acid. Suitable organic salts include sodium succinate, potassium succinate, sodium citrate, potassium citrate, sodium malate, potassium malate, sodium acetate, potassium acetate, sodium lactate, potassium lactate, or calcium lactate.

[0036] In Examples 2, 3, and 4, Na was temporarily used. + +ClO2 - ⇔ Na-ClO2 and K + +ClO2 - ⇔ K-ClO2 and H + +ClO2 - This creates a transition state such as H-ClO2, which can slow down the conversion of chlorous acid (HClO2) to chlorine dioxide (ClO2). As a result, it is possible to produce an aqueous solution containing chlorous acid that maintains chlorous acid (HClO2) for a long time and generates less chlorine dioxide (ClO2).

[0037] Incidentally, it has been observed that the lower the pH value (the stronger the acidity) of chlorine oxides, the stronger their bactericidal power. The table below shows the relationship between pH value and bactericidal power obtained from experiments. Here, pathogenic Escherichia coli O157:H7 was used as the bacterial strain, sodium chlorite (80% manufactured by Wako Pure Chemical Industries, Ltd.) was used as the chlorine oxide tested, and citric acid (98% manufactured by Wako Pure Chemical Industries, Ltd.), lactic acid (85-92% manufactured by Wako Pure Chemical Industries, Ltd.), and acetic acid (99.7% manufactured by Wako Pure Chemical Industries, Ltd.) were used as activators. Then, citric acid, lactic acid, and acetic acid were added to 30 ml of sodium chlorite aqueous solution (0.5 g / l) (pH 9.8), and the pH was adjusted to 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, and 8.0 respectively. Using the carbolic coefficient measurement method, 10 ml of the appropriately diluted test solution was placed in a test tube and kept warm in a constant temperature water bath at 20 ± 1 °C for at least 5 minutes. After that, 1 ml of the bacterial solution, which had been kept warm in the same manner, was poured into the test tube, and after 2.5, 5, 10, and 15 minutes, the amount was removed using a platinum loop, inoculated into ordinary broth medium, and incubated at 37 °C for 48 hours. After that, bacterial growth was observed with the naked eye, and those showing growth were marked (+) and those not showing growth were marked (-).

[0038] [Table 1]

[0039] [Table 2]

[0040] [Table 3]

[0041] As can be seen from the table above, sodium chlorite solutions with a pH of 7.0 or higher failed to kill the E. coli test bacteria even after 15 minutes of exposure. However, by adjusting the pH to 4.0 or lower, sterilization was achieved in 2.5 minutes, in 10 minutes when adjusted to 5.0, and in 15 minutes when adjusted to 6.0. This indicates that the bactericidal efficacy of sodium chlorite solutions increases as the pH becomes more acidic. Furthermore, no significant difference in the bactericidal efficacy of sodium chlorite was observed due to differences in the activator.

[0042] Thus, while the bactericidal power of chlorite solutions increases with increasing acidity, highly acidic solutions with a pH of around 2 can cause adverse effects such as protein denaturation in target foods during sterilization, thus limiting their use in the food industry.

[0043] [ka]

[0044] Chemical formula 2 above represents the decomposition of chlorite in an acidic solution. The decomposition rate of an aqueous chlorite solution increases as the pH decreases, i.e., as the acidity increases. In other words, the absolute rates of reactions (a), (b), and (c) in the above formula increase. For example, the proportion of reaction (a) decreases as the pH decreases, but the total decomposition rate fluctuates greatly, i.e., becomes large, so the amount of ClO2 (chlorine dioxide) generated also increases as the pH decreases. For this reason, sterilization and bleaching are faster at lower pH values, but the irritating and harmful ClO2 gas makes work difficult and has adverse effects on human health. In addition, the reaction of chlorous acid to chlorine dioxide proceeds quickly, the chlorous acid becomes unstable, and the time during which it can maintain its bactericidal effect is extremely short.

[0045] Therefore, when adding the above-mentioned inorganic acids, inorganic acid salts, organic acids, or organic acid salts to an aqueous solution containing chlorous acid (HClO2), the pH value should be adjusted within the range of 3.2 to 7.0 from the viewpoint of suppressing the generation of chlorine dioxide and balancing it with the bactericidal power. However, if there is no problem with the bactericidal power, it is desirable to set the pH value as high as possible within the above range. This makes it possible to slow down the progression to sodium chlorite (NaClO2), maintain chlorous acid (HClO2) for a long time, and produce an aqueous solution containing chlorous acid with less generation of chlorine dioxide (ClO2).

[0046] In order to verify the effects of the present invention, experiments were conducted using the following samples. First, 1 mol / l sodium carbonate was added to the chlorous acid obtained according to Example 1 to adjust the pH to 5.7 (corresponding to Example 2), and this was then added to a 0.05 mol / l sodium borate / succinic acid (pH 5.7) buffer solution to obtain a chlorous acid content of 3%. An aqueous solution containing the inorganic salt was added, followed by the addition of a buffer containing both the inorganic and organic salts (corresponding to Example 3), and this was designated as Sample A.

[0047] Next, 1 mol / l sodium carbonate was added to the chlorous acid obtained according to Example 1 to adjust the pH to 5.7, and then the chlorous acid content was adjusted to 3% with deionized water. In other words, an inorganic salt was added to an aqueous solution containing chlorous acid (corresponding to Example 2), and this was designated as Sample B.

[0048] Furthermore, an aqueous solution of sodium chlorite (80% product manufactured by Wako Pure Chemical Industries, Ltd.) (25.0%) A 1 mol / L citric acid solution (98% product manufactured by Wako Pure Chemical Industries, Ltd.) was added to the mixture to adjust the pH to 2.6, and the chlorite content was adjusted to 3% using deionized water. This is the same as the conventional technology described above for AC, and this was designated as sample C.

[0049] Furthermore, the chlorous acid obtained according to Example 1 was mixed with 0.05 mol / l sodium borate / sucrose. Add chlorite (pH 6.8) to a buffer solution to achieve a final pH of 5.7, and ensure a chlorite content of 3%. Specifically, a solution containing both inorganic and organic acid salts was added as a buffer to an aqueous solution containing chlorite (corresponding to Example 4), and this was designated as Sample D.

[0050] Furthermore, the stability of each chlorous acid (HClO2) was determined by its UV spectrum and content over time. The samples were compared by measuring them precisely. The chlorite (HClO2) content was set to 3% in all cases. Furthermore, the UV spectrum was measured by diluting the sample with deionized water as appropriate and adjusting the spectrophotometer so that the absorbance at the maximum absorption wavelength was approximately 1. It was measured by []. Further, the measurement method of the content was the measurement by the iodometric titration method shown below. That is, the sample was aerated in a gas washing container to wash and remove the chlorine dioxide gas of this product. Then, about 10 g of this product was precisely weighed, water was added to make it exactly 100 ml, and it was used as a sample solution. An amount of sample corresponding to about 0.06 g as chlorous acid (HClO₂) was precisely weighed, put into an iodine bottle, 12 ml of sulfuric acid (3→100) was added, water was added so that the liquid volume became about 55 ml, then 4 g of potassium iodide was added, immediately sealed, left in the dark for 15 minutes, titrated with 0.1 mol / l sodium thiosulfate, and the content of chlorous acid in the solution was determined using the formula (1 ml of 0.1 mol / l sodium thiosulfate solution = 0.001711 g·HClO₂) (indicator starch test solution). Separately, a blank test was conducted for correction. The test was carried out in a dark room for the storage test. Immediately after preparation, the chlorous acid content, UV measurement, and pH were measured at 1, 2, 3, 24, 48, 72, 96, 120, 240, 480, and 720 hours later.

[0051] As a result, for specimens A, B, C, and D, immediately after specimen preparation, by measurement with a spectrophotometer, between wavelengths 248 to 420 nm, there were two absorption parts that could be simultaneously confirmed, an absorption part containing acidic chlorite ions (H + + ClO₂ - ) showing a peak near 260 nm and an absorption part containing chlorine dioxide (ClO₂) showing a peak near 350 nm. Therefore, the presence of chlorous acid (HClO₂) could be confirmed (Figs. 1, 5, 9, 13). Because, as shown in Chemical Formula 4 below, with chlorous acid (HClO₂) as the main component, the cycle reactions of chlorine dioxide (ClO₂) and acidified chlorite ions (C lO₂ - ) were proceeding simultaneously.

[0052]

Chemical Formula

[0053] However, in sample C, two peaks were clearly visible up to 1 hour later (Figure 10), but after 24 hours, the two peaks were barely visible (Figure 11), and thereafter it became almost entirely a single peak at 350 nm (Figure 12). From this, This shows that chlorous acid has been converted into chlorine dioxide.

[0054] On the other hand, samples A, B, and D still exhibit two peaks, one around 260 nm and the other around 350 nm, even after 30 days (Figures 4, 8, and 16). Therefore, it can be said that the aqueous solution containing chlorous acid produced by the present invention is considerably more stable than that of conventional examples.

[0055] In sample B, as shown in Figures 5, 6, 7, and 8, which illustrate the changes in the UV curve over time, it can be observed that the two peaks change as the 10th, 20th, and 30th days progress. On the other hand, in samples A and D, even after 30 days, the two peaks from day 0 remain unchanged. It can be seen that the state has been maintained as is (Figures 1, 2, 3, 4, 13, 14, 15, 16). From this, it can be seen that in samples A and D, the components of chlorous acid and chlorous acid It was found that the ionic components, chlorine dioxide, and other chlorine oxide components remained almost unchanged, and that Example 3 (addition of inorganic acid + organic acid or organic acid) or Example 4 (addition of organic acid or organic acid) better preserved the state of the contents in the aqueous solution than Example 2 (addition of inorganic acid). This shows that...

[0056] Table 4 shows the changes in chlorous acid content. Here, in sample C (AC), the chlorous acid content was halved after 2 hours from preparation, and by the 4th day, almost all chlorous acid had disappeared. On the other hand, samples A, B, and D still contained a large amount of chlorous acid even after 30 days. Therefore, the aqueous solution containing chlorous acid produced by the present invention has the advantage of maintaining chlorous acid for a longer period of time compared to conventional examples.

[0057] Of these, samples A and D were able to maintain their chlorous acid content from day 0 for approximately 30 days. From this, it can be seen that the aqueous solutions containing chlorous acid produced by Examples 3 and 4 have the ability to stably retain chlorous acid for the longest period of time.

[0058] [Table 4]

[0059] Figure 17 shows the changes in pH values ​​of samples A, B, C, and D over time. Sample B was initially adjusted to pH 5.7, but its pH rose to around 6 before subsequently decreasing. There was a tendency for it to continue in that state. On the other hand, sample A remained at pH 5.8 on day 0 even after 30 days. It is clear that the state is maintained and that it is exhibiting buffering capacity. At the same time, sample D also maintains its pH of 5.7 on day 0 even after 30 days, indicating that it is exhibiting buffering capacity. This shows that the pH can be further stabilized by either adding a buffer directly or by first adjusting the pH with sodium carbonate and then adding another buffer.

[0060] From the above, it can be seen that an aqueous solution obtained by simply acidifying an aqueous solution of sodium chlorite with AC loses its state containing chlorous acid (HClO2) due to the rapid acceleration of the reaction to chlorine dioxide (ClO2), but the aqueous solution obtained by the present invention maintains the pH within a certain range, which prevents excess or deficiency due to the oxidation-reduction reaction of chlorine oxides. It regulates the amount of hydrogen ions, and as a result stabilizes the pH, thus stabilizing the transition state of the salt. Hydrogen acid (HClO2), that is, H + • Allow the ClO2⇔HClO2 state to exist for a long time, It was found that this method helps maintain the balance of molecules and ions in the chlorous acid solution, thereby also maintaining the chlorous acid content. Therefore, it can be said that the present invention is an extremely advantageous method compared to conventional methods for producing an aqueous solution containing chlorous acid (HClO2) that has high bactericidal power and remains stable for a long period of time.

[0061] According to the present invention, chlorous acid, which has high bactericidal power, can be stabilized for a long period of time. This makes it possible to include aqueous solutions containing chlorous acid, which were previously difficult to distribute commercially, in the distribution process, thereby making chlorous acid, which is useful as a disinfectant, available to society.

[0062] Although embodiments of the present invention have been described in detail above with reference to drawings and tables, the present invention is not limited thereto and can be implemented in various forms within the scope of the configuration described in the claims. [Industrial applicability]

[0063] The aqueous solution containing chlorite obtained by this invention can be used not only as a disinfectant but also as a bleaching agent, blood-removing agent, and for other purposes.

Claims

[Claim 1] The pretreatment for food processing according to this specification.

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