JPH07274921A - Microbicidal process for food, etc., and apparatus for producing strongly acidic water for the process - Google Patents

Abstract

PURPOSE:To improve the stability of long storage of a food by effectively performing microbicidal treatment on the food by immersing it into a specific strongly acidic water. CONSTITUTION:A microbicidal treatment is performed by immersing a food into a strongly acidic water of 1.5-3.3 in pH produced by removing impurities such as Ca, Mg and Fe from original water with a filter and subjecting the treated water to electrolysis after adding salt and preferably heating at >=40 deg.C after sealing. Further, the strongly acidic water is produced by using an apparatus for producing a strongly acidic water composed of a filtering apparatus for removing impurities from original water, a salt-water tank 5 for adding the filtered water with a salt water, an electrolysis tank 10 for subjecting the salt mixed water to electrolysis and output ports for taking out the obtained strongly acidic water and basic water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sterilizing foods and the like and a strongly acidic water producing apparatus used for the method.

[0002]

2. Description of the Related Art As a sterilizing method for foods, there is a conventional method using sodium hypochlorite.
JP-A-4-131052 discloses a method in which water, seasoning liquid, acidic ingredients and the like are added and organic acid salt and alkali are added to adjust the pH of the container to pH 4.3 to 5.4, followed by sealing and heat sterilization. It is disclosed in the official gazette. Further, in Japanese Patent Application Laid-Open No. 4-144461, the refined rice is immersed in acidic water (pH 4.0 or less), sealed and packaged, heated and pressed, and then the immersed water is removed and vacuum or deaeration packaging is performed and heated. By pressure treatment,
A method for producing a wash-free rice package that can be stored for a long time is disclosed.

[0003]

However, since chlorine is stable when sodium hypochlorite is used,
The bactericidal effect is small, so when the amount used is large, the amount of residual chlorine after sterilization is large (40 ppm or more), which becomes a problem. pH 3.5
When the above-mentioned acidic water is used, ordinary tap water or ground water is used, so there are impurities and no salt water is added, so active oxygen and active chlorine are small, and the bactericidal effect is weak. The acidic water disclosed in JP-A-4-131052 uses an organic acid and has a pH of 4.3 to 5.4. Since it has no active oxygen and active chlorine, it cannot be completely sterilized. The acidic water disclosed in JP-A-4-144461 has a pH of 4.
Although it is set to 0 or less, organic acids such as acetic acid and citric acid, hydrochloric acid, and sulfuric acid are used, and they are sour in the Example of pH 2.5 that they are not edible.

In any of the above cases, strong acidic water having a pH of 1.5 to 3.3 is not used, and neither active oxygen nor active chlorine produced by electrolysis exhibits a bactericidal action. Therefore, there is a problem that acidic water having a pH of 3.5 or more using an organic acid as described above has a small amount of active oxygen and active chlorine, poor thermal conductivity, and a small bactericidal effect. The object of the present invention is to solve the above problems and to achieve pH 1.5 by electrolysis.
By continuously supplying strongly acidic water of ~ 3.3 and immersing vegetables, rice, beef, fish and other foods in this strongly acidic water, active oxygen and active chlorine act to increase the redox potential and heat. Since the conductivity is good, it is possible to sterilize the microbial bacteria on the surface of the food promptly and hygienically.For foods such as meat and fish where the microbial bacteria propagate to the inside, soak it in strong acid water and heat it. By doing so, complete sterilization is achieved to the inside,
An object of the present invention is to provide a sterilization method for foods and the like that can enhance long-term storage stability, and a strongly acidic water producing apparatus used for this sterilization method.

[0005]

In order to solve the above-mentioned problems, in the first invention, salt is added to water from which impurities have been removed and electrolyzed to obtain strongly acidic water having a pH of 1.5 to 3.3. Was soaked and sterilized. In the second invention, the pH obtained by electrolyzing salt with water after removing impurities
After immersing the food in 1.5 to 3.3 strongly acidic water and sealing,
In the third invention, salt (NaCl 95% or more) was added to water obtained by removing impurities such as Ca, Mg, and Fe from raw water with a filter after heating at ℃ or higher.
Was added and electrolyzed to obtain strongly acidic water having a pH of 1.5 to 3.3. In the fourth invention, the reverse osmosis membrane is used as the filtration membrane used in the filter. In the fifth invention, a filter device for removing impurities from raw water, a salt water tank for adding salt water to the filtered water, an electrolytic tank for electrolyzing this salt mixed water, and a generated strong acidic water and alkaline water A strong acid water producing apparatus used for a method of sterilizing foods, etc., which comprises an extraction section, and a filtration apparatus for removing impurities such as Ca, Mg, Fe from raw water in the sixth invention,
A water pressure gauge for adjusting the pressure of the filtered production water, a valve for controlling the amount of water, a salt water tank for adding salt to this water, a cushion tank for salt water mixing, and a salt water mixture from this cushion tank are electrically operated. Multiple electrolyzers connected in series so as to decompose, an automatic control unit equipped with a pH meter, redox potential meter, dissolved oxygen meter, chlorine meter, etc., and strongly acidic water generated by electrolysis A strongly acidic water producing apparatus was provided, which was composed of a switching valve for separately taking out alkaline water.

[0006]

According to the first aspect of the invention, salt is added to water (fresh water) from which impurities have been removed, whereby electrolysis is efficiently performed,
There is no reduction in redox potential and reduction in active oxygen or active chlorine due to the mediation of impurities contained in groundwater or tap water, and strong active oxygen and active chlorine can act.

Especially when using conventional organic acids, the oxidation-reduction potential may be 1000 mV or less, the amount of active oxygen is small, and the dissolved oxygen (DO) is considered to be 8.0 ppm or less, and the thermal conductivity is poor and the bactericidal effect is small. On the other hand, in the present invention, the redox potential is 1100 mV or more, the thermal conductivity is good, the dissolved oxygen (DO) is 12.0 ppm or more, prompt and hygienic in the surface microorganisms of food, germination bacteria. Of course, even the spore bacterium has come to be completely sterilized.

Impurities are other ions of bacteria, chlorine molecules, Ca, M
It is desirable to remove g, Fe and other molecules that affect electrolysis. Strongly acidic water with a pH of 1.5 or less cannot be obtained as a production machine because only a small amount can be obtained by electrolysis.
As mentioned above, in acidic water of 3.4 or higher, active oxygen and active chlorine are low, the thermal conductivity is poor, and the bactericidal effect is small, so
The pH was set in the range of 1.5 to 3.3. At pH 1.5, residual chlorine is
It is about 5ppm and no sourness remains.

In the second invention, the food sealed with the strongly acidic water in the first invention is heat-treated at 40 ° C. or higher to synergistically effect active oxygen, active chlorine, and heat, so that microbial cells can reach inside. Strong bactericidal action and complete sterilization are also obtained for meat, fish, etc., as foods that can grow. This is because the bactericidal action works when the oxidation-reduction potential (ORP) becomes worse during heating (when it decreases from 1100 mV to 700 mV) and when the dissolved oxygen (DO) of active oxygen becomes about 12.0 ppm to 6.0 ppm. Conceivable. At this time, the active oxygen becomes stable oxygen. Heating at a low temperature of 40 ° C or higher is sufficient.

After heat treatment with strongly acidic water, the hydrogen ion concentration becomes neutral at pH 6.0 to 7.5, and the oxidation-reduction potential becomes 600 to 700 mV, which is the same as ordinary water. Dissolved oxygen (DO)
It will be from 4.0ppm to 6.0ppm. In the third invention, a filter is used to remove impurities such as bacteria and Ca, from the raw water.
Use fresh water without Mg, Fe, etc. Salt in this fresh water (NaCl 95
(More than%), the electrolysis can be efficiently performed, and strong acidic water having a pH of 1.5 to 3.3 can be obtained.
Impurities to be removed are not limited to Ca, Mg and Fe, but a softening device or an ion exchange device is used so that bacteria and salt ions can be removed depending on the relationship with food and electrolysis.

In the fourth aspect of the invention, since the reverse osmosis membrane is used as the filtration membrane used in the filter, other ions such as bacteria are filtered, and fresh water is obtained as raw water from raw water. In the fifth aspect of the invention, raw water is filtered by a filtering device to obtain fresh water, and salt water is added to the fresh water and sent as salt mixed water to the electrolytic cell. Therefore, electrolysis is efficiently generated in the electrolytic cell to generate strongly acidic water and alkaline water.

In the sixth aspect of the present invention, Ca, Mg,
An appropriate amount of water is obtained by removing the impurities such as Fe and adjusting the pressure of the water that is continuously sent, and a valve that controls the amount of water, and salt is added to this water with a saline tank to make a salt mixed water, A cushion tank sends an appropriate amount to the electrolyzer one after another, and multiple electrolyzers connected in series
It became possible to continuously obtain strongly acidic water having a pH range of 1.5 to 3.3.

Since a plurality of electrolytic cells are connected in series and electrolyzed continuously, strong strongly acidic water of pH 1.5 or more can be stably obtained. If the series electrolytic cells are arranged in parallel, the amount of strong acidic water obtained can be increased. Adjustment of the hydrogen ion concentration (pH) during electrolysis is automatically controlled by a pH measuring instrument, other redox potential measuring instrument, dissolved oxygen measuring instrument, chlorine measuring instrument, etc.

[0014]

【Example】

(Example 1) 100 g of potatoes were immersed in strongly acidic water having a pH of 1.5 and stored at room temperature as they were. After one week, mildew developed on the strongly acidic water, but there was no offensive odor. 5p residual chlorine
At about pm, the potatoes had no sourness and could be taken out and shipped as they were. As a comparative example, 100 g of potato was immersed in ordinary water and stored at room temperature, but an offensive odor was generated on the third day. The offensive odor was found to be due to bacteria. (Example 2) 100 g of potatoes obtained in the above (Example 1) was adjusted to pH 1.
When dipped in 5 of strongly acidic water and sealed in a pouch, no mildew developed even after 1 month. (Example 3) 100 g of potatoes were immersed in strongly acidic water having a pH of 2.8, put in a sealing pouch, sealed, and heated at 100 ° C for 10 minutes, and then stored at a high temperature of 35 ° C for 3 months. Did not occur. (Example 4) When beef was immersed in strongly acidic water (pH 2.5), put in a pouch, sealed, and heated under pressure at 105 ° C for 15 minutes,
After being stored at room temperature for 6 months, there was no discoloration or change in taste. In addition, there was no generation of microbial bacteria. (Example 5) 200 g of ginseng is cut into 1 cm pieces, immersed in strongly acidic water of pH 2.5 for 10 minutes, the strongly acidic water is discarded, put in a sealing pouch and evacuated, and then at 95 ° C for 5 minutes. Heated.
It was stored at 35 ° C for 1 month, but no microbial cells were generated. (Example 6) Lettuce was immersed in strongly acidic water of pH 2.5 for 30 minutes, then strongly acidic water was drained off, and the pouch was sealed. It was stored at room temperature for 2 weeks, but no odor or discoloration was observed. (Example 7) Tuna was cut into square pieces, sealed in a pouch together with strongly acidic water of pH 2.7, and then heated and pressurized at 105 ° C for 15 minutes. There was no change when stored at 28 ° C for 6 months.

It is easy to use strongly acidic water at a pH of about 2.30 to 2.80, and the redox potential (ORP) at that time is 1147 to.
1195, dissolved oxygen (DO) 10.9 ~ 14.5, water temperature 13.7 ~
It costs 16.0. In contrast, the pH of ordinary tap water is
It was 7.35, ORP682, DO5.6, and water temperature 8.8. The strongly acidic water producing apparatus will be described below with reference to the drawings shown as examples.

In FIG. 1, 1 is a solenoid valve for stopping the supply of filtered water, 2 is a pressure reducing valve, 3 is a water pressure gauge, 4 is a solenoid valve for controlling a flow rate, 5 is a 20% saline solution tank, and a pump 6 is a pipe 7 Is supplied to the cushion tank 8 via the. In the cushion tank 8, saline and water are mixed in appropriate amounts.
The amount of salt to be added as the salt mixed water makes electrolysis efficient and is not limited. Practically, when operating for 20 hours a day, about 100 (liter) of 20% saline may be replenished to the saline tank about every 3 to 4 days. When filtered water can be obtained in 15 (liter) per minute and 900 (liter) in 1 hour, 100 (liter) salt water is used for 54,000 (liter) water (however, chlorine 500-700p)
pm).

Reference numeral 9 is a conductivity sensor, and 10 is an electrolytic cell. In the illustrated example, two units are connected in series. In this way, by connecting about two units in series, it is possible to stably obtain strongly acidic water up to a pH of about 1.5. Reference numeral 11 is a solenoid valve for strongly acidic water, and 12 is a solenoid valve for alkaline water. An automatic control unit 13 is provided with a pH measuring instrument, a redox potential measuring instrument, a dissolved oxygen measuring instrument, a chlorine measuring instrument, etc., and automatically controls pH, ORP, DO, ppm and the like.

In FIG. 2, 14 is a water tank for raw water, 15 is a motor, and 16 is a hose for feeding raw water to the filtering device 17. The filtration device 17 uses, for example, a reverse osmosis membrane. When using a softening device as well as an ion exchange device, it is possible to obtain strong acidic water that is stable for a certain period of time. Filtration device 1
In Fig. 7, microorganisms and impurities such as Ca, Mg and Fe are removed by the reverse osmosis membrane, solute components are removed from the discharge pipe 18, and fresh water is stored in the product water tank 20 through the pipe 19. The product water tank 20 was sent to the strongly acidic water producing apparatus 21 and the strongly acidic water was obtained from the extraction pipe 22 by electrolysis. Example of strong acid water production equipment (manufactured by Nikko Co., Ltd.) Electrolysis main unit dimensions 760 (W) x 660 (D) x 1300 (H) (mm) Power supply voltage Single phase AC220V 50Hz 40A Maximum power consumption 3.5KW Strong acid water Generation capacity pH 2.7 or less Redox potential (ORP) +1100 mV or more 5 to 8 (l / min) Saline tank Capacity 10 (liter) Dimensions 450 x 800 (mm) Electrolyzer 4 units Power supply max 48V x 32A x 22 Water supply device Water pressure 3 to 4 (Kg / cm ² ) Water amount 14.8 k to 20 (l / min) (water flow type) Example of reverse osmosis membrane used in filtration device Hollow fiber (Toyobo) or spiral (Toray) is used.

In the reverse osmosis membrane method, water permeates from raw water,
It uses a semipermeable membrane having a property of not allowing ions or molecules dissolved in water to permeate. By applying a pressure equal to or higher than the osmotic pressure of the original aqueous solution, only water is permeated and the solute component remains on the pressure side. It becomes ultrafine filtration of molecular size. Examples of Films Used in Sealing Pouches It is desirable that they be heat resistant and heat shrinkable. For example, a bag-shaped package having a hermeticity such as vinyl chloride, vinylidene chloride resin, polyethylene, polypropylene, and polyolefin resin is preferable, but a box-shaped package instead of a bag-shaped package is also possible, and is not limited thereto.

[0020]

According to the first aspect of the invention, fresh water is electrolyzed to adjust the pH.
Strongly acidic water in the range of 1.5 to 3.3 produces strong active oxygen and active chlorine, so the dissolved oxygen (DO) action completely kills germinated bacteria as well as spores of microorganisms on the surface of food. Came to be. No acidity remains after sterilization, so it can be used as it is.

In the second aspect of the invention, the food is hermetically sealed with strongly acidic water and heat-treated at 40 ° C. or above, whereby a quick and complete bactericidal effect can be obtained. Not only the surface of food, but also the interior is sterilized by low temperature. After heating, it becomes the same as ordinary water with a pH of 6.0 or higher. According to the third aspect of the invention,
It becomes fresh water excluding Ca, Mg, Fe, etc., and by adding salt (NaCl 95% or more), electrolysis can be efficiently performed and stable strong acidic water in the pH range of 1.5 to 3.3 can be supplied. Became.

According to the fourth aspect of the invention, the reverse osmosis membrane used in the filter allows filtration of not only bacteria but also molecular size, efficient electrolysis, and stable acidic water can be obtained. In the fifth aspect of the invention, an apparatus for producing strongly acidic water used for sterilizing food is provided. According to the sixth aspect of the invention, a filter device is provided as a device for producing strongly acidic water up to an electrolytic cell that electrolyzes, and in the electrolytic cell, a pH measuring device, other redox potential measuring device,
Efficiently strong acidic water can now be obtained by automatically controlling each with a dissolved oxygen meter, chlorine meter, etc.

[Brief description of drawings]

FIG. 1 Flow sheet of a strongly acidic water production device used for a sterilizer

FIG. 2 is an overall explanatory view of a strongly acidic water production device

[Explanation of symbols]

 2: Pressure reducing valve 3: Water pressure gauge 5: Salt solution tank 8: Cushion tank 10: Electrolytic tank 17: Filter machine 21: Strongly acidic water production device

Claims (6)

[Claims] 1. A sterilization method comprising adding salt to water from which impurities have been removed, and immersing the food in strong acidic water of pH 1.5 to 3.3 obtained by electrolysis to sterilize the food. 2. A method in which salt is added to water from which impurities have been removed, and the food is immersed in strong acidic water of pH 1.5 to 3.3 obtained by electrolysis to seal the food, and then heated at 40 ° C. or higher. How to sterilize foods, etc. 3. Water (Cl, Mg, Fe, etc.) removed from raw water by a filter is added with salt (NaCl 95% or more) and electrolyzed to obtain strongly acidic water of pH 1.5 to 3.3. The method for sterilizing food or the like according to claim 1 or 2. 4. The method for sterilizing foods according to claim 3, wherein the filtration membrane used in the filtration machine is a reverse osmosis membrane. 5. A filter device for removing impurities from raw water,
A salt water tank that adds salt water to the filtered water, an electrolytic cell that electrolyzes this salt mixed water, and a strong acidity used for the sterilization method of foods, etc. that consists of a take-out part of the generated strong acid water and alkaline water. Water production equipment. 6. A filtration device for removing impurities such as Ca, Mg and Fe from raw water, a water pressure gauge for adjusting the pressure of filtered production water, a valve for controlling the amount of water, and salt for adding salt to this water. A water tank, a cushion tank for mixing salt water, a plurality of electrolytic cells connected in series to electrolyze the salt mixed water from this cushion tank, a pH measuring instrument, a redox potential measuring instrument, a dissolved oxygen measuring instrument , A strong acid water used for a sterilization method of foods, characterized by comprising an automatic control unit equipped with a chlorine measuring device and the like, and a switching valve for separately taking out strongly acid water and alkaline water generated by electrolysis. Manufacturing equipment.