JP2016086720A - Sterilized cut cabbage production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sterilized cut cabbage production method capable of achieving both sufficient sterilization and offensive odor suppression, and excellent appearance.SOLUTION: A sterilized cut cabbage production method includes: a sterilization step S3 for sterilizing a cut cabbage by causing the cut cabbage to contact ozone water; and a warm water treatment step S4 for performing warm water treatment by causing the cut cabbage sterilized in the sterilization step S3 to contact warm water of 30-50°C.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for producing a sterilized cut cabbage.

  Demand for cut vegetables that can be cooked and eaten as they are without cutting them is increasing against the backdrop of becoming a nuclear family and increasing working together. Cut vegetables are produced by cutting vegetables harvested from the field, and the harvested vegetables are contaminated with dirt such as mud and dust and viable bacteria. Therefore, the vegetables harvested from the field are often washed and sterilized and then cut to obtain cut vegetables. And the obtained cut vegetables are packaged (bagging etc.) and shipped as a product.

  As a method for sterilizing cut vegetables, there is a method using a sodium hypochlorite aqueous solution described in a mass cooking facility hygiene management manual. Specifically, the vegetables are sterilized by being immersed in a sodium hypochlorite aqueous solution for a predetermined time. However, when a chlorine-based disinfectant such as sodium hypochlorite is used, a chlorine odor may remain in vegetables. In addition, organochlorine by-products may be generated, which may require the vegetables to be rinsed with a large amount of water to remove the by-products.

  Therefore, ozone water having a strong sterilizing power has been attracting attention in recent years. Ozone has an advantage that it is quickly decomposed by a catalyst or the like and hardly remains. Therefore, a sterilization method using ozone water in which ozone gas is dissolved in water is known. Specifically, for example, Patent Document 1 describes that leaf vegetables after washing are sterilized using ozone water.

Japanese Patent No. 4381349

  Ozone has a strong sterilizing power. Therefore, when vegetables are sterilized using water in which ozone is dissolved, that is, ozone water, damage to the vegetables is too great and browning may occur in the sterilized vegetables. In addition, although most viable bacteria attached to the vegetables are killed by the sterilization treatment with ozone water, some viable bacteria often remain in the vegetables without being killed. Thereby, the preservability (namely, length of shelf life) of cut vegetables may fall.

  Then, when the present inventors examined about suppression of browning and improvement of preservability, what is necessary is just to perform the heat shock process using the hot water of about 40 to 60 degreeC with respect to the vegetables sterilized by ozone water, for example. Was found. In particular, it has been found that by such heat shock treatment, viable bacteria remaining without being killed by sterilization treatment with ozone water can be actively washed away with warm water that is contacted during the heat shock treatment.

  However, in the case of cut cabbage among cut vegetables, the present inventors have examined, and it has been found that when the above-mentioned sterilization and heat shock treatment is performed on the cut cabbage, off-flavors may be generated in the cut cabbage. In addition, in the case of cut cabbage, compared to other cut vegetables, the above-mentioned sterilization and heat shock treatment result in loss of “freshness” on the appearance (also referred to as “no tension”, “shrinking”, etc.) I also found that there was a tendency.

  The present invention has been made in view of the above problems, and the problem to be solved by the present invention is to provide a method for producing a sterilized cut cabbage capable of achieving both sufficient sterilization, suppression of the generation of off-flavors and good appearance. It is to be.

  As a result of intensive studies to solve the above problems, the present inventors have found the following findings. That is, the present invention is a sterilization step of sterilizing the cut cabbage by bringing the cut cabbage into contact with ozone water, and the cut cabbage sterilized in the sterilization step in contact with hot water of 30 ° C. to 50 ° C. And a hot water treatment process for performing a sterilized cut cabbage.

  ADVANTAGE OF THE INVENTION According to this invention, the production method of the sterilization cut cabbage which can make sufficient sterilization, generation | occurrence | production suppression of a strange odor, and a favorable external appearance can be provided.

It is a systematic diagram of the sterilization system of a 1st embodiment. It is a flowchart explaining the production method of the sterilization cut cabbage performed in the sterilization system of 1st Embodiment. It is a systematic diagram of the sterilization system of 2nd Embodiment. It is a systematic diagram of the sterilization system of 3rd Embodiment. It is a systematic diagram of the sterilization system of 4th Embodiment. It is a systematic diagram of the sterilization system of 5th Embodiment. It is a systematic diagram of the sterilization system of 6th Embodiment. It is a systematic diagram of the sterilization system of 7th Embodiment. It is a systematic diagram of the sterilization system of 8th Embodiment. It is a systematic diagram of the sterilization system of 9th Embodiment.

  Hereinafter, a form for carrying out the present invention (this embodiment) will be described with reference to the drawings as appropriate.

[1. First Embodiment]
FIG. 1 is a system diagram of a sterilization system 100 according to this embodiment. The sterilization system 100 includes a prewash tank 1, a sterilization tank 2, a warm water tank 3, and a rinse tank 4. Cut cabbage is processed in each tank in this order to obtain a sterilized cut cabbage. In addition, the sterilization system 100 includes a cooling device 5 and an ozone water preparation tank 6 for preparing ozone water supplied to the sterilization tank 2, a recovered ozone gas tank 7 for storing the recovered ozone gas, and a hot water circulation line. Are provided with a heating device 8 and a mixing device 9 for preparing the hot water circulated and a cooling device 10 for preparing the cold water supplied to the rinsing tank 4.

  As the water supply source, tap water is used and, for example, well water subjected to sterilization treatment is supplied to the sterilization system 100. The water supplied to the sterilization system 100 is supplied to the prewash tank 1 as it is, and after being cooled by the cooling device 5 and the cooling device 10, is supplied to the ozone water preparation tank 6 and the rinsing tank 4. In addition, although not shown, a part of the supplied water is also supplied to the heating device 8, and after being heated, is supplied to the hot water tank 3 and flows through the hot water circulation line.

  Moreover, as waste water, the water after being used in the pre-washing tank 1, the water after being used in the sterilization tank 2 and the dissolved ozone gas being recovered, and the water after being used in the rinsing tank 4 are appropriately treated as wastewater. And discharged to the outside. Although not shown, the hot water flowing through the hot water circulation line is discharged to the outside according to the degree of contamination.

  In FIG. 1, main devices are illustrated, and various sensors such as a pump, a flow rate adjusting valve, a transport device, a flow meter and a thermometer used for feeding each liquid are illustrated for simplification of illustration. Not shown.

  The pre-washing tank 1 performs pre-cleaning (hereinafter referred to as pre-washing) of cut cabbage that is an object to be sterilized before sterilization. That is, cabbage (cut cabbage) cut by a cutting device (not shown) is supplied to the prewash tank 1. Pre-washing is performed using water. In the prewash tank 1, mud, dust, etc. adhering to the cut cabbage are washed. Then, a cut cabbage that is clean to some extent is supplied to the sterilization tank 2.

  The sterilization tank 2 performs sterilization processing on cut cabbage from which dirt such as mud has been removed. Specifically, the sterilization treatment is performed by immersing (contacting) cold water (ozone water) in which ozone gas is dissolved in a cut cabbage. The immersion time varies depending on the ozone content of ozone water, the mass of cut cabbage, and the like, but is, for example, about 0.2 to 15 minutes, and preferably about 0.2 to 5 minutes.

  The temperature of the ozone water is preferably about 4 ° C. to 20 ° C., for example, from the viewpoint of maintaining the freshness of the cut cabbage. However, the temperature of the ozone water may be, for example, about 20 ° C. to 40 ° C. close to normal temperature. Here, the amount of ozone gas dissolved in water increases as the temperature of water decreases. Therefore, by using ozone water in such a temperature range, the amount of ozone water dissolved can be increased, and a more powerful sterilization treatment can be performed.

  Moreover, the ozone gas content in the ozone water to be used is, for example, 1 mg / L to 30 mg / L. Therefore, in the ozone water preparation tank 6, ozone water is prepared so that the content of ozone gas falls within this range, for example. Here, when the cut cabbage is immersed in ozone water in the sterilization tank 2, ozone may be separated from the ozone water to generate ozone gas. Therefore, the ozone gas generated from the ozone water generated in the sterilization tank 2 is recovered in the recovery ozone gas tank 7.

  The hot water tank 3 performs hot water treatment on the cut cabbage sterilized in the sterilization tank 2. In the hot water tank 3, the cut cabbage is rinsed, and the ozone water attached in the sterilization tank 2 is removed. The cut cabbage is damaged by the sterilization treatment with ozone water in the sterilization tank 2. Therefore, in order to recover this damage and wash away the attached bacteria, hot water treatment is performed by immersing the cut cabbage in hot water and changing the temperature of the cut cabbage.

  Although immersion time changes also with the mass etc. of cut cabbage, it is about 0.1 to 15 minutes, for example. However, from the viewpoint of more surely suppressing the generation of off-flavors, about 0.1 to 12 minutes is preferable. On the other hand, from the viewpoint of further suppressing the increase in the number of general viable bacteria and achieving sufficient preservation, it is 0. About 2 to 15 minutes is preferable. Therefore, from the viewpoint of achieving a well-balanced effect of suppressing off-flavor generation and good storage stability and appearance, the immersion time is preferably about 0.2 to 10 minutes. Among these, the immersion time is particularly preferably about 0.5 to 5 minutes from the viewpoint of more surely suppressing the generation of a strange odor and ensuring storage stability and appearance.

  The temperature of the hot water is 30 ° C to 50 ° C, preferably 35 ° C to 45 ° C. By setting the temperature range of the hot water within this range, it is possible to suppress the generation of a strange odor from the cut cabbage and to improve the appearance of the cut cabbage after the hot water treatment. That is, the generation of off-flavor is suppressed and the appearance of the cut cabbage becomes fresh, which suppresses the growth of viable bacteria and improves the storage stability.

  Here, the advantage obtained by performing warm water treatment using warm water of 30 ° C. to 50 ° C. after sterilization with ozone water will be described. As described above, the temperature of the ozone water used in the sterilization tank 2 is, for example, about 4 ° C. to 20 ° C., and the temperature of the hot water used in the hot water tank 3 is 30 ° C. to 50 ° C. Therefore, from the viewpoint of energy saving, considering that the final cut cabbage product is stored at a low temperature, first, hot water treatment with warm hot water is performed, and then sterilization treatment with cold ozone water is performed in that order. It is preferable. This sterilization treatment also serves as a cooling treatment for lowering the temperature of the cut cabbage raised by the hot water treatment.

  However, in the present embodiment, as described above, first, sterilization treatment with ozone water is performed, and then hot water treatment is performed. Although details will be described later, the cut cabbage subjected to the hot water treatment is cooled, and the cut cabbage is shipped as a product after cooling. According to the study by the present inventors, the reason why an excellent effect can be obtained by performing the hot water treatment after the sterilization treatment with ozone water is considered as follows.

  By using ozone water, due to its strong sterilizing power, sufficient sterilization is possible even in a short time treatment or a low temperature treatment. In addition, since ozone becomes oxygen when it is decomposed, there is an advantage that there are few by-products and residues. However, since ozone has a strong oxidizing power, when the cut cabbage is brought into contact with ozone water, the surface and cut surface of the cut cabbage are damaged as described above. As a result, microscopically, the cut cabbage cells themselves are damaged.

  Here, an enzyme called myrosinase is localized in the cells of cut cabbage. However, this localization is lost due to damage to cells by ozone water. Then, sinigrin (glycoside) that is also present in the cell comes into contact with this myrosinase, and an enzyme reaction of sinigrin occurs. As a result, sinigrin, which is a component derived from sugar content, changes to allyl isothiocyanate (AITC), which is a pungent component. In addition, depending on the storage state of cut cabbage, the state at the time of processing, and the like, a sulfur compound having a strange odor (abundant odor or rot odor) such as dimethyl disulfide (DMDS) or dimethyl sulfide (DMS) is produced as a metabolite from AITC Sometimes.

  Therefore, in this embodiment, by subsequently performing warm water treatment using warm water having a relatively mild temperature, wax components (such as pectin) that may be present on the surface of the cut cabbage are melted by heat and damage is caused. It acts to cover the received part. Thereby, the damaged part of cut cabbage is recovered, and the localization of myrosinase can be recovered. Thereby, the production | generation of AITC is suppressed and generation | occurrence | production of a strange odor is prevented.

  In addition, by using warm water having a relatively mild temperature, it is possible to wash away sinigrine and AITC leaked from the cells of the cut cabbage while suppressing damage to the cells. Thereby, off-flavor generation is suppressed by metabolism from AITC. In the cut cabbage, in addition to the cut surface, leakage of nutrients that can cause the growth of viable bacteria is likely to occur at the portion rubbed against the inner wall of the apparatus during cleaning. Therefore, the effect of washing off is particularly great, and the generation of off-flavors is sufficiently suppressed.

  Furthermore, by using warm water having a temperature of 30 ° C. to 50 ° C., metabolism that is a biological reaction can be suppressed, and changes from AITC to DMDS or DMS can be suppressed. Thereby, the production | generation of the sulfur compound used as a causative substance of a strange odor can be suppressed. Furthermore, by using warm water at a temperature of 30 ° C. to 50 ° C., damage to the cells is reduced, new leakage of sinigrin due to cell destruction can be prevented, and the generation of off-flavors can also be suppressed in this respect. .

  Thus, after performing sterilization with ozone water, generation of off-flavor in cut cabbage can be suppressed by performing warm water treatment with warm water of 30 ° C. to 50 ° C. Therefore, even if sterilization is performed using ozone water having a stronger oxidizing power than that of the prior art, that is, ozone water having a high ozone content, generation of off-flavor can be suppressed because damage is recovered by the hot water treatment. Therefore, sterilization using ozone water can be performed more sufficiently than before, and the strong sterilization power of ozone can be fully utilized. And since it can sterilize more reliably than before, the preservability of cut cabbage can be improved, and the appearance, flavor, texture, etc. can be maintained well.

  Furthermore, it has been found by the study of the present inventors that even in a cut cabbage damaged by ozone water, the cut cabbage absorbs moisture and the cut cabbage is sharpened by the hot water treatment. For this reason, it is considered that the hot water treatment gives a firmness and improves the storage stability.

  Moreover, ozone water has the advantage that there are few residues as mentioned above, and the component which has bactericidal property does not remain in the cut cabbage after sterilization. On the other hand, if a component having bactericidal properties does not remain, the growth rate will be faster when viable bacteria start to grow after sterilizing the cut cabbage. However, it was found that when the sterilization was performed using ozone water with little residue and then the hot water treatment was performed as in this embodiment, the growth of viable bacteria in the cut cabbage after the hot water treatment was suppressed. The reason for this is not clear, but according to the study by the present inventors, it is considered as follows.

  The hot water treatment performed in the present embodiment is not usually performed under conditions that can sufficiently exhibit sterilizing power. Therefore, rather than the sterilizing effect by the hot water treatment, it is considered that the washing out effect of viable bacteria (including bacteria entangled with the waxy substance) by contacting with warm water is increased. Thereby, the number of viable bacteria remaining in the cut cabbage after the hot water treatment can be reduced, and it is considered that the time until the viable cell count reaches a predetermined reference value can be delayed after the cut cabbage is shipped. .

  In addition, by contacting with hot water, substances that become nutrients for viable bacteria (eg, cabbage cell fluid that leaks from the damaged surface of the cut surface or ozone water) can be removed from the surface of the cut cabbage. Conceivable. Therefore, it is thought that the nutrient for viable bacteria to grow decreases, thereby effectively inhibiting the proliferation of viable bacteria.

  In addition, the warm water after washing the cut cabbage contains bacteria. And this microbial cell does not die at the temperature and time normally used for warm water treatment as mentioned above. Therefore, in this embodiment, sterilization using ozone gas is performed on the hot water to be reused. In addition, it is conceivable that the used hot water is heated to, for example, 75 ° C. or more and treated for 1 minute or longer, or is removed using a filtration membrane having a pore size that bacteria cannot permeate (these points will be described later). And by using such sterilization and sterilization, it becomes possible to reuse the used hot water.

  As described above, the hot water tank 3 performs hot water treatment on the cut cabbage sterilized in the sterilization tank 2. And a warm water process is performed by immersing a cut cabbage in warm water. Here, the sterilization treatment using ozone water and the warm water treatment using warm water are usually performed continuously in a cut cabbage production factory or the like. In such a factory, in order to handle cut cabbage which is a fresh food, the factory is often managed at a low temperature. Therefore, there may be no heat source in the factory, and enormous energy may be required for preparation of hot water. Here, it is also possible to collect the heat of the hot water discharged using the heat exchanger and reuse the heat. However, it is impossible to completely recover the heat, and the cost and maintenance of the heat exchanger are required.

  Therefore, in the sterilization system 100, the hot water used for the hot water treatment in the hot water tank 3 is not drained after use but is used again. However, the hot water once used may contain viable bacteria that have not been completely killed in the sterilization tank 2. Therefore, the hot water discharged from the hot water tank 3 is sterilized by the mixing device 9 with ozone gas, and then reheated by the heating device 8 and supplied again to the hot water tank 3 as treated hot water. ing. The heating amount in the heating device 8 is preferably equal to the amount of heat that decreases when the cut cabbage is immersed in the hot water tank 3. Thus, in the sterilization system 100, the hot water tank 3, the mixing device 9, and the heating device 8 form a hot water circulation line.

  The sterilization process for the hot water discharged from the hot water tank 3 is performed using excess ozone gas generated in the sterilization system 100. Specifically, excess ozone gas that did not dissolve in cold water in the ozone water preparation tank 6, ozone gas generated from the ozone water used when processing cut cabbage in the sterilization tank 2, and exhausted from the sterilization tank 2 Dissolved ozone gas in used ozone water is used. That is, first, these ozone gases are recovered in the recovered ozone gas tank 7. Here, for example, the dissolved ozone gas can be recovered by diffusing air to the used ozone water using an air diffuser. And the used warm water is sterilized by the collected ozone gas contacting (mixing) the used warm water from the warm water tank 3 by the mixing device 9.

  Conventionally, surplus ozone gas in the system and dissolved ozone gas in used ozone water have been decomposed using a catalyst or the like and then released into the atmosphere as oxygen gas. However, the production of ozone gas takes time and cost. In addition, some processing may be required for discharging to the outside, and labor and cost may be required. Therefore, it is preferable that the ozone gas produced with such labor and cost is consumed within the system as much as possible to reduce the emission amount as much as possible and avoid labor and cost. Therefore, in the sterilization system 100, sterilization of warm water discharged from the warm water tank 3 is performed using the collected ozone gas. Thereby, the manufactured ozone gas can be utilized without wasting it. In addition, heat loss and labor can be saved compared to using a heat exchanger for recovering heat from hot water as described above.

  Further, according to the study by the present inventors, it has been found that the bactericidal effect by ozone is larger than the bactericidal effect on the bacterial cells adhering to the solid, compared to the bacterial cells present in the liquid. It was done. Therefore, even when the amount of ozone gas recovered in the system is small, it is possible to sufficiently sterilize the used hot water by bringing the recovered ozone gas into contact with the used hot water (specifically, aeration, etc.). it can. Thereby, warm water can be circulated and used repeatedly.

Returning to FIG. 1, the configuration of the sterilization system 100 will be continuously described.
The rinsing tank 4 performs rinsing using cold water on the cut cabbage that has been subjected to the hot water treatment in the hot water tank 3. The rinsing tank 4 also cools the cut cabbage that has been subjected to the hot water treatment. Thereby, the temperature of a cut cabbage is lowered. Thereafter, the cut cabbage is handled under a low temperature (for example, 7 ° C. or lower) in order to proliferate viable bacteria and maintain the freshness of the cut cabbage. In addition, the rinse time in the rinse tank 4 is shortened by supplying the cut cabbage sterilized in the said sterilization tank 2 to the warm water tank 3 which also has a role as a rinse tank.

  The cut cabbage cooled in the rinsing tank 4 is then dehydrated by a centrifugal dehydrator (not shown). Then, the dehydrated cut cabbage is packed in a bag and stored as appropriate, and then shipped as a sterilized cut cabbage.

  FIG. 2 is a flowchart for explaining a method for producing a sterilized cut cabbage executed in the sterilization system 100 of the first embodiment. First, the uncut cabbage transported to the factory is cut by a cutting device (not shown) after removing dirt on the surface to become a cut cabbage (step S1). Then, the obtained cut cabbage is sterilized using the sterilization system 100 shown in FIG.

  First, the cut cabbage is prewashed in a prewash tank 1 (see FIG. 1, hereinafter the same in other apparatuses). This removes mud and dirt that could not be removed in the uncut state. Next, the pre-washed cut cabbage is sterilized with ozone water in the sterilization tank 2 (step S3, sterilization step). As a result, the bacteria attached to the surface of the cut cabbage are sterilized. In particular, in the present embodiment, since the hot water treatment using warm water is performed as described above, it is possible to sterilize using ozone water having a higher concentration than in the past, and more sufficient sterilization is possible.

  The sterilized cut cabbage is subjected to warm water treatment using warm water in the warm water tank 3 (step S4, warm water treatment step). Thereby, generation | occurrence | production of the strange odor etc. which can arise with the said ozone water sterilization can be suppressed. After the hot water treatment, the cut cabbage is rinsed and rinsed with rinse water in the rinse tank 4 (step S5, cooling step). After cooling, the cut cabbage is packed in a bag after centrifugal dehydration, stored as appropriate at a low temperature, and then shipped as a product (step S6).

  Although not shown in FIG. 2, in this embodiment, the used hot water used for the hot water treatment in the hot water tank 3 is sterilized using the ozone gas collected in the system 100 (hot water treatment). Process). And the warm water obtained through the warm water treatment process is supplied to the warm water tank 3 again.

  According to the sterilization system 100 described above, the cut cabbage damaged by the hot water treatment can be recovered, so that it can be sterilized using ozone water having a higher concentration than the conventional one. Therefore, it can sterilize more reliably than before, and the preservability of the sterilized cut cabbage is improved. Thereby, an external appearance, food texture, etc. improve. Moreover, since generation | occurrence | production of a strange odor can be suppressed, a flavor becomes favorable, for example.

[2. Second Embodiment]
Next, the sterilization system 200 of 2nd Embodiment is demonstrated, referring FIG. In the sterilization system 200, components similar to those of the sterilization system 100 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the sterilization system 100, the cooling device 5 for preparing the cold water supplied to the sterilization tank 2 and the cooling device 10 for preparing the cold water supplied to the rinse tank 4 were provided. Moreover, the heating apparatus 8 for maintaining the temperature of warm water was provided in the middle of the warm water circulation line. However, the sterilization system 200 is provided with the heat pump 11 in which the heat of the water supplied from the water supply source is supplied to the used hot water from the hot water tank 3 instead of being provided with these.

  That is, in the sterilization system 200, the used hot water from the hot water tank 3 is supplied to the heat pump 11 provided in the middle of the hot water circulation line. And the hot water supplied to the heat pump 11 is heated using the heat | fever collect | recovered when cooling the water supplied from the water supply source to the temperature of cold water. The heated warm water is supplied again to the warm water tank 3 via a warm water circulation line (more specifically, a warm water supply line formed between the heat pump 11 and the warm water tank 3). As described above, by using the heat pump 11, cold water can be obtained without using the cooling devices 5 and 10, and hot water can be obtained without using the heating device 8. Thereby, further energy saving can be achieved. The water supply source may be used in the rinsing tank 4 to cool the heated cut cabbage brought from the hot water tank 3, and the cold water whose temperature has risen may be diverted to reuse the rinse water.

[3. Third Embodiment]
Next, a sterilization system 300 according to the third embodiment will be described with reference to FIG. In the sterilization system 300, components similar to those of the sterilization systems 100 and 200 are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, in FIG. 4, the modification with respect to the sterilization system 200 shown in FIG. 3 is shown.

  In the said sterilization system 100,200, the cold water after ozone removal of the ozone water discharged | emitted from the sterilization tank 2, and the cold water discharged | emitted from the rinse tank 4 were drained as it was outside. However, the sterilization system 300 does not drain the cold water as it is, but uses the cold heat of the cold water. Specifically, the sterilization system 300 is provided with a heat exchanger 12 for cooling water supplied from a water supply source by the cold heat of the cold water.

  That is, the cold water supplied to the rinse tank 4 after being cooled by the heat pump 11 and the ozone water prepared in the ozone water preparation tank 6 using the cold water are used in the sterilization tank 2 and the rinse tank 4. It is still sufficiently cold. Therefore, used ozone water and cold water are supplied to the heat exchanger 12 after the ozone contained therein is recovered as necessary. In the heat exchanger 12, the water supplied from the water supply source is cooled by the supplied cold water, and the cooled water is supplied to the heat pump 11 and the ozone water preparation tank 6.

  That is, in the sterilization system 300, ozone water is prepared in the ozone water preparation tank 6 using water cooled by the heat exchanger 12 and the heat pump 11. The prepared ozone water is supplied to the sterilization tank 2 via an ozone water supply line connecting the ozone water preparation tank 6 and the sterilization tank 2. By doing in this way, the heat energy in the sterilization system 300 can be utilized more wastefully, and energy consumption can be reduced further.

[4. Fourth Embodiment]
Next, a sterilization system 400 according to the fourth embodiment will be described with reference to FIG. In the sterilization system 400, components similar to those of the sterilization systems 100 to 300 are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, in FIG. 5, the modification with respect to the sterilization system 300 shown in FIG. 4 is shown.

  In the sterilization systems 100 to 300, the cut cabbage from the hot water tank 3 was rinsed with cold water in the rinse tank 4 and cooled. However, the sterilization system 400 includes an air cooling tank 13 that cools by air cooling rather than cooling by cold water.

  That is, in the sterilization system 400, the rinsing tank 4 is not provided. The cold water obtained by the heat pump 11 is supplied only to the ozone water preparation tank 6 and is used only in the sterilization tank 2. On the other hand, the cut cabbage that has been subjected to the hot water treatment in the hot water tank 3 is cooled in the air cooling tank 13 by air (cold air or the like). Therefore, when the sterilization system 400 is operated in a cool environment such as a plateau area or a winter period, the cut cabbage can be cooled by air having a relatively low temperature such as outside air without using cold water. Further, it is not necessary to supply cold water to the rinsing tank 4, and cold water may be supplied only to the sterilization tank 2. Therefore, a sufficient amount of cold water can be supplied to the sterilization tank 2 more reliably.

[5. Fifth Embodiment]
Next, the sterilization system 500 of the fifth embodiment will be described with reference to FIG. In the sterilization system 500, components similar to those of the sterilization systems 100 to 400 are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, in FIG. 6, the modification with respect to the sterilization system 100 shown in FIG. 1 is shown.

  In the said sterilization system 100, the ozone gas in a system was collect | recovered and the used warm water discharged | emitted from the warm water tank 3 was sterilized using the ozone gas. However, the sterilization system 500 shown in FIG. 6 includes a heat sterilizer 14 that heats and sterilizes used hot water. And the heat sterilizer 14 fully heats and sterilizes a part or all of used hot water, and the hot water after the sterilization is supplied to the hot water tank 3 again.

  The heating temperature in the heat sterilizer 14 is, for example, 60 ° C to 150 ° C. Moreover, although heating time changes also with heating temperature, it can be set as 1 second-30 minutes as residence time in the heat sterilizer 14, for example. Heating in the heat sterilizer 14 can be performed using a heat exchanger using steam or hot water as a heating source. Further, heating with an electric heater, microwave heating, and dielectric heating can also be applied.

  By providing the heat sterilizer 14, the warm water supplied to the heater 8 is at a sufficiently high temperature. Therefore, the amount of heat given by the heating device 8 can be reduced. In addition, when warm water having a sufficiently high temperature can be supplied to the hot water tank 3 without heating in the heating device 8, the installation of the heating device 8 can be omitted. Accordingly, the provision of the heat sterilization apparatus 14 enables sterilization of used hot water, and supplies hot water at an appropriate temperature to the hot water tank 3 without performing new heating (or reducing the amount of supplied heat). can do.

[6. Sixth Embodiment]
Next, the sterilization system 600 according to the sixth embodiment will be described with reference to FIG. In the sterilization system 600, components similar to those of the sterilization systems 100 to 500 are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, in FIG. 7, the modification with respect to the sterilization system 500 shown in FIG. 6 is shown.

  In the said sterilization system 500, the heat sterilizer 14 which heat-sterilizes used hot water was provided. However, the sterilization system 600 shown in FIG. 7 includes a filtering device 15 that filters and removes bacterial cells (including both live and dead bacteria) and contaminants from used hot water. As a result, the used hot water is filtered to remove the bacterial cells and contaminants and becomes a filtrate. And after this filtrate is heated with the heating apparatus 8, it is supplied to the hot water tank 3 again. On the other hand, the water that has not been permeated by the filtration device 15 is drained to the outside via a pipe or the like (not shown).

  The filtration device 15 includes a filtration membrane or the like, for example. Specifically, although not shown, the filtration device 15 is configured to include a water tank for storing used hot water from the hot water tank 3, a filtration unit including a filtration membrane and a housing, and the like. Yes. In addition, you may make it provide several filtration membranes from which a hole diameter differs as needed. The filtration device 15 is also provided with a pipe connecting the water tank and the filtration unit, a water supply pump for sending used hot water to the filtration unit, a flow meter for measuring the amount of water supply, a pressure gauge for measuring the water supply pressure, etc. Configured.

  As the filtration membrane to be used, for example, a microfiltration membrane, an ultrafiltration membrane, or a reverse osmosis membrane can be applied. Further, the pore diameter of the filtration membrane is preferably 0.1 μm or less when, for example, a microfiltration membrane is used. Either a dead-end filtration method or a cross-flow filtration method may be selected as the filtration method. In the case of the cross-flow filtration method, a circulation line that connects a part of the supply liquid that has not been filtered by the filtration unit to the water tank. Is built.

  By providing the filtering device 15, it is possible to sterilize used hot water and remove impurities. Therefore, clearer warm water can be supplied to the warm water tank 3.

[7. Seventh Embodiment]
Next, the sterilization system 700 according to the seventh embodiment will be described with reference to FIG. In the sterilization system 700, components similar to those in the sterilization systems 100 to 600 are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, in FIG. 8, the modification with respect to the sterilization system 500 shown in FIG. 6 is shown.

  In the said sterilization system 500, the heat sterilizer 14 which heat-sterilizes used hot water was provided. However, the sterilization system 700 shown in FIG. 8 includes an ultraviolet sterilizer 16 that sterilizes using ultraviolet rays. Thereby, the used warm water from the warm water tank 3 is sterilized by irradiating with ultraviolet rays. The sterilized warm water is heated by the heating device 8 and then supplied to the warm water tank 3 again.

  In the ultraviolet irradiation device 16, for example, light having a wavelength of 253.7 nm is applied to the used hot water. By this ultraviolet light, the DNA of live bacteria in warm water is cut and sterilized.

  By providing the ultraviolet irradiation device 16, even when a large amount of used hot water to be processed is used, sterilization can be performed efficiently.

[8. Eighth Embodiment]
Next, the sterilization system 800 of the eighth embodiment will be described with reference to FIG. In the sterilization system 800, components similar to those of the sterilization systems 100 to 700 are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, in FIG. 9, the modification with respect to the sterilization system 500 shown in FIG. 6 is shown.

  In the said sterilization system 500, the heat sterilizer 14 which heat-sterilizes used hot water was provided. However, the sterilization system 800 shown in FIG. 9 includes a drug sterilizer 17 that sterilizes used hot water using a drug. A medicine tank 18 is connected to the medicine sterilization apparatus 17, and a medicine stored in the medicine tank 18 is added to the medicine sterilization tank 17. Thereby, the used warm water from the warm water tank 3 is sterilized, and the sterilized warm water is heated by the heating device 8 and then supplied to the warm water tank 3 again.

  Examples of the drug to be added include a hydrogen peroxide solution, ethanol, a peracetic acid solution, and the like. These may be appropriately mixed and used. Moreover, when using a peracetic acid solution as a chemical | medical agent, it is preferable that the warm water after the added peracetic acid solution is removed is supplied to the warm water tank 3, for example.

  By providing the chemical sterilization device 17, a more reliable sterilization process can be performed on a larger amount of used hot water.

  In addition, although not shown in figure, after sterilizing with the chemical | medical-agent sterilizer 17, ultraviolet rays can also be irradiated with respect to the hot water after sterilization. By doing in this way, the unreacted chemical | medical agent is activated by ultraviolet irradiation. Therefore, the bactericidal action on live bacteria is promoted, and more powerful sterilization can be performed.

  Moreover, although not shown in figure, after sterilizing with the chemical | medical-agent sterilizer 17, the hot water after sterilization can be heated. By doing in this way, like the said ultraviolet irradiation, a chemical | medical agent is activated by heating and more powerful disinfection can be performed. Furthermore, when the added chemical | medical agent is volatile, the unreacted chemical | medical agent in warm water can be vaporized by heating, and the residual chemical | medical agent of the warm water supplied to the warm water tank 3 can be reduced easily.

[9. Ninth Embodiment]
Next, a sterilization system 900 according to the ninth embodiment will be described with reference to FIG. In the sterilization system 900, the same code | symbol shall be attached | subjected about the thing similar to the said sterilization system 100-800, and the detailed description is abbreviate | omitted. In addition, in FIG. 10, the modification with respect to the sterilization system 100 shown in FIG. 1 is shown.

  In the said sterilization system 100, reuse of ozone gas and reuse (circulation) of warm water were performed. However, these are not performed in the sterilization system 100 shown in FIG. That is, surplus ozone gas or the like from the ozone water preparation tank 9 or the like is discharged after being decomposed using a catalyst or the like. Moreover, the hot water used in the hot water tank 3 is discharged as it is after being used several times.

  That is, in the sterilization system 100, the cut cabbage is sterilized with ozone water and then treated with warm water, and then the sterilized cut cabbage is packaged and shipped. Even with the cut cabbage sterilized in this manner, a sufficient sterilizing effect is obtained, and a cut cabbage in which the generation of off-flavor is sufficiently suppressed and the storage stability is sufficient is obtained.

[10. Modified example]
Although the present embodiment has been specifically described with nine embodiments, the present embodiment is not limited to the above example. That is, the present invention can be implemented by appropriately modifying the above-described embodiments and by appropriately combining the above-described embodiments.

  For example, although the temperature of the ozone water to be used is usually lower than the temperature of the warm water (30 ° C. to 50 ° C.) as described above, the temperature of the ozone water having the same temperature as the temperature of the warm water may be used. Good. Even at the same temperature, for example, the above-described washing-out effect can be expected by performing warm water treatment with warm water after sterilization with ozone water.

  Furthermore, regarding the apparatus configuration of the production systems 100 to 900, for example, in the ozone water preparation tank 6, ozone gas is prepared by supplying ozone gas to cold water, but the method of preparing ozone water is not limited thereto. Therefore, ozone water may be prepared, for example, by a so-called electrolytic ozone water system. The electrolytic ozone water system is a system in which ozone water is generated directly from water by causing an electrode to act on the water in the ozone water preparation tank 6. In this case, the surplus ozone gas from the generated ozone water is negligibly small, and the surplus gas that is the exhaust gas from the sterilization tank 2 and the ozone gas from the effluent may be recovered in the recovery ozone gas tank 7.

  As a method for sterilizing used hot water from the hot water tank 3, ozone gas is mixed by the mixing device 9 in the first to fourth embodiments. Furthermore, the heat sterilizer 14 is used in the fifth embodiment, the filter device 15 is used in the sixth embodiment, the ultraviolet sterilizer 16 is used in the seventh embodiment, and the drug sterilizer 17 is used in the eighth embodiment. Accordingly, each of these devices is a hot water treatment device that sterilizes or sterilizes used hot water. However, the hot water treatment apparatus is not limited to these, and is an apparatus that can obtain used hot water (ie, treated hot water) that has been sterilized by performing at least one of sterilization and sterilization on the used hot water. Anything is acceptable.

  Further, a part of the ozone water prepared in the ozone water preparation tank 6 may be supplied to the mixing device 9. In this case, it can be considered that a part of the ozone gas dissolved in the ozone water in the ozone water preparation tank 6 is in contact with the hot water circulating in the hot water circulation line in the mixing device 9. That is, ozone water (including dissolved ozone gas) used to sterilize cut cabbage in the sterilization tank 2 is sent to the mixing device 9 by a liquid feed pump (ozone gas recovery device) that sends (recovers) ozone water. As a result, the ozone gas in the ozone water comes into contact with the hot water.

  Moreover, in the sterilization tank 2, the usage form of the ozone water when sterilizing the cut cabbage using the ozone water is not limited to the immersion as described above. That is, for example, the cut cabbage may be sterilized by spraying ozone water onto the cut cabbage. Similarly, the hot water treatment in the hot water tank 3 is not limited to the form in which the cut cabbage is immersed in the hot water. For example, the hot water treatment may be performed on the cut cabbage by spraying the hot water on the cut cabbage. . Similarly, the form of sterilization of hot water in the mixing device 9 is not limited to the mixing as described above, and any form may be used as long as the recovered ozone gas can be sterilized by contacting with circulating hot water.

  The cooling method in the rinsing tank 4 is the same, and the form in which the cold water is brought into contact is not limited to the method of immersing in the cold water, and for example, a method of spraying the cold water and the like can be mentioned. Furthermore, ozone water supplied from the outside may be used instead of providing the ozone water preparation tank 6.

  Furthermore, in the said embodiment, although the collection | recovery ozone gas tank 7 is provided as an ozone gas collection | recovery apparatus, if it is an apparatus which can collect | recover ozone gas, it will not be restricted to the form of a tank. Further, an apparatus necessary for recovering ozone gas can be provided as appropriate.

  Further, for example, in the above-described embodiment, the pre-washing tank 1 and the rinsing tank 4 are provided, but these devices may not be provided. Furthermore, in the said embodiment, the cold water supplied to the ozone water preparation tank 6 and the cold water supplied to the rinse tank 4 are prepared with the separate cooling devices 5 and 10. FIG. However, these may be combined into one and the cold water adjusted by one cooling device may be branched and supplied to them. Moreover, in the said embodiment, the waste_water | drain from the prewash tank 1, the sterilization tank 2, and the rinse tank 4 is discharge | released outside, after recovering cold heat as needed. However, this water may be returned to the water supply source and reused.

  Hereinafter, the present invention will be described more specifically with reference to examples.

<Evaluation method>
[Example 1]
The cut cabbage cut into pieces (width 1.5 mm) was immersed in ozone water (ozone concentration 5 mg / L (5 ppm)) for 1 minute, and then immersed in warm water at 30 ° C. for 1 minute to perform hot water treatment. The cut cabbage after the hot water treatment was stored at 7 ° C. for 3 days. And the general viable count, smell, and external appearance were evaluated about the cut cabbage after a preservation | save.

Measurement of the number of general viable bacteria was carried out by the pour method using a sample obtained by appropriately diluting an extract of shredded cabbage extracted by the stomacher treatment with sterile physiological saline. The standard agar medium was used as the medium, and the culture conditions were set to 35 ° C. ± 1 ° C. and 48 hours ± 3 hours. As a result of the measurement, “◯” if the number of viable bacteria per 1 g of cut cabbage is 10 ⁵ (cfu / g) or less, “Δ” if it is 10 ⁵ to 10 ⁶ (cfu / g), 10 ⁶ (cfu). / G) It was evaluated as “×” if it was greater than or equal to.

  The odor was determined by the same sensory tester (3 persons). As a result of the determination, the evaluation was “◯” if there was no off-flavor, “Δ” if there was almost no off-flavor, and “x” if there was a clear off-flavor.

  The appearance was determined by visual observation by the same sensory tester (3 persons). As a result of the determination, the evaluation was “◯” if there was no discoloration or water separation, “Δ” if there was almost no discoloration or water separation, and “x” if discoloration or water separation was clearly recognized.

[Example 2]
The general viable count, odor, and appearance were evaluated in the same manner as in Example 1 except that the temperature of the hot water was changed to 35 ° C.

Example 3
The general viable cell count, odor, and appearance were evaluated in the same manner as in Example 1 except that the temperature of warm water was 40 ° C. and the immersion time in warm water was changed to 0.1 minutes.

Example 4
The general viable count, odor, and appearance were evaluated in the same manner as in Example 3 except that the immersion time in warm water was changed to 0.2 minutes.

Example 5
The number of viable bacteria, odor, and appearance were evaluated in the same manner as in Example 3 except that the immersion time in warm water was changed to 0.5 minutes.

Example 6
The general viable count, odor, and appearance were evaluated in the same manner as in Example 3 except that the immersion time in warm water was changed to 3 minutes.

Example 7
The general viable count, odor, and appearance were evaluated in the same manner as in Example 3 except that the immersion time in warm water was changed to 5 minutes.

Example 8
The general viable count, odor, and appearance were evaluated in the same manner as in Example 3 except that the immersion time in warm water was changed to 10 minutes.

Example 9
The general viable count, odor, and appearance were evaluated in the same manner as in Example 3 except that the immersion time in warm water was changed to 15 minutes.

Example 10
The general viable count, odor, and appearance were evaluated in the same manner as in Example 1 except that the temperature of the hot water was changed to 45 ° C.

Example 11
The general viable count, odor, and appearance were evaluated in the same manner as in Example 1 except that the temperature of the hot water was changed to 50 ° C.

[Comparative Example 1]
The general viable count, odor, and appearance were evaluated in the same manner as in Example 1 except that the temperature of the hot water was changed to 25 ° C.

[Comparative Example 2]
General viable count, odor, and appearance were evaluated in the same manner as in Example 1 except that the temperature of the hot water was changed to 55 ° C.

<Evaluation results>
The results of the above evaluation are shown in Table 1 below.

  As shown in Examples 1 to 11, in the cut cabbage that was subjected to hot water treatment using hot water of 30 ° C. to 50 ° C., all of the “general viable count”, “odor”, and “appearance” had good results. Obtained. That is, in Examples 1 to 11 using hot water of 30 ° C. to 50 ° C., an evaluation of “◯” or “Δ” was obtained, and there was no significant increase in the number of general viable bacteria or generation of a distinct odor. Therefore, according to the method for producing a sterilized cut cabbage of the present invention, it was shown that a cut cabbage that can be sufficiently sterilized, has a good appearance, and suppresses the generation of a strange odor is obtained.

  On the other hand, in the case of using warm water of 25 ° C. (Comparative Example 1), the evaluation of “general viable count” was bad. The reason for this is considered to be that the temperature of the hot water was too low, so that the recovery of the cells of the cut cabbage damaged by the ozone water and the washing off effect of the attached bacteria were insufficient. That is, for example, due to insufficient recovery, excessive leakage of nutrients from the cut cabbage cells resulted in an abundance of nutrients and an environment in which the cells could easily grow, so the number of viable bacteria increased significantly. It is considered a thing.

  In addition, in the case where hot water of 55 ° C. was used (Comparative Example 2), the “odor” was poorly evaluated. The reason for this is thought to be that the use of hot water at a high temperature of 55 ° C. caused greater damage to the cells and new leakage of sinigrin and the like from the cut cabbage cells. That is, it is considered that signiglin or the like leaks and an enzymatic reaction proceeds on the surface of the cut cabbage, and as a result, AITC and a sulfur compound that cause a strange odor are generated.

  In Examples 1 to 11 in which good results were obtained, it was found that particularly good results could be obtained by using warm water at a temperature of 35 ° C. to 45 ° C. if the immersion times were similar. Specifically, Example 2 where the temperature is 35 ° C and the time is 1 minute, Example 5 where the temperature is 40 ° C and the time is 0.5 minutes, Example 6 where the temperature is 40 ° C and the time is 3 minutes, Temperature In Example 10 where the time was 1 minute at 45 ° C., all of the evaluation items were “◯”. On the other hand, the “general viable count” is “Δ” in Example 1 at a temperature of 30 ° C., and the “odor” and “appearance” are “Δ” in Example 11 at a temperature of 50 ° C. It is considered that the “general viable count”, “odor”, and “appearance” can be improved in a well-balanced manner by using warm water having a temperature of 35 ° C. to 45 ° C.

  Moreover, when temperature was the same (40 degreeC, Examples 3-9), when immersion time became short, "general viable count" and "appearance" became "(triangle | delta)" (Example 3). On the other hand, when the immersion time was increased, the “odor” and “appearance” became “Δ” (Example 9). Therefore, when the temperature of the hot water used for the hot water treatment is about the same, the “viable count”, “odor”, and “appearance” are particularly balanced by setting the immersion time to 0.2 to 10 minutes. It is thought that it can be made well. In particular, it is considered that by setting the immersion time to 0.5 to 5 minutes, these can be made better in a balanced manner and more reliably.

2 Sterilization tank 3 Warm water tank 6 Ozone water preparation tank 100-900 Sterilization system

Claims (2)

A sterilization step of sterilizing the cut cabbage by bringing the cut cabbage into contact with ozone water;
A method for producing a sterilized cut cabbage, comprising: a hot water treatment step in which the cut cabbage sterilized in the sterilization step is brought into contact with hot water at 30 ° C to 50 ° C to perform a hot water treatment.   The method for producing a sterilized cut cabbage according to claim 1, wherein, in the warm water treatment step, the cut cabbage sterilized in the sterilization step is contacted with the warm water for 0.2 minutes to 10 minutes.

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