JPWO2016181478A1 - System and method for removing potassium from food - Google Patents

Abstract

A system and method for removing potassium from food in a short time while keeping the texture and flavor of the food intact. SOLUTION: A food is sandwiched between opposed electrodes and placed in a water tank, and a DC current is passed from one opposed electrode to the other through a food while removing the eluted ions from the water by deionizing means. By doing so, potassium can be removed from food in a short time. [Selection] Figure 1

Description

  The present invention relates to a system for removing potassium without impairing the flavor and texture of food and a method for removing potassium using the system. In particular, the present invention relates to a system and method for performing potassium removal treatment in a short time.

  According to a survey by the Japanese Society for Dialysis Therapy, the number of chronic dialysis patients in Japan exceeded 300,000 in 2012, increasing by about 5,000 every year.

  The kidneys regulate the excretion of waste products, water and electrolytes, and maintain a constant body environment. When the kidney function falls and the homeostasis in the body cannot be maintained, various symptoms called uremia appear in the whole body.

  Patients who have lost renal function are treated with maintenance dialysis on a daily basis to remove waste and excess water from the body. Dialysis includes peritoneal dialysis and hemodialysis. In Japan, hemodialysis that circulates blood outside the body is the mainstream, and about 270,000 people are treated by hemodialysis. In the case of hemodialysis, currently, dialysis is generally performed 4 hours at a time, 3 times a week, but the function of dialysis is not as far as the living kidney. Therefore, patients are not allowed to eat an unlimited number of meals, and it is important to manage their diet through self-management.

  Dialysis patients need to pay attention to various components in their diet, and in particular, the amount of potassium that causes hyperkalemia needs to be limited to a certain level. Hyperkalemia can cause fatal arrhythmias and cardiac arrest. Therefore, it is necessary to continue dietary guidance for potassium restriction from the beginning of the introduction of dialysis treatment. The amount of potassium that can be taken per day varies depending on the stage of disease, but it is necessary to limit it to 1500 to 2000 mg or less.

  Vegetables and fruits are high in potassium among foods, and patients who are restricted by potassium are often restricted from taking vegetables and fruits that are high in potassium. In addition, depending on the cooking method, it is recommended to perform certain cooking because the amount of potassium can be reduced. Therefore, the dietary life of patients who are subject to potassium restriction is often limited. Patients may feel stress in their restricted diet, which can be a problem in terms of quality of life (QOL).

  When potassium restriction is performed, potassium easily flows out into water. Therefore, it is common to remove potassium by cooking the vegetables by cutting them into small pieces and exposing them to water, or spilling them with rice cake.

  In addition to the above general cooking methods, methods for cultivating with a culture solution such as hydroponics are known as methods for removing potassium from food (Patent Documents 1 and 2). Patent Document 1 discloses a technique for cultivating low potassium spinach by hydroponics. Patent Document 2 discloses a method of cultivating a low potassium crop by a method of cultivating a crop by hydroponic or pearlite plowing. It has been shown that over 40% of potassium can be removed from melon or the like using either hydroponics or perlite cultivation.

  Moreover, the technique which removes potassium when processing a foodstuff and manufactures a low potassium processed foodstuff is disclosed (patent documents 3 and 4). Patent Document 3 discloses a method of removing 90% or more of potassium content by treating vegetable juice or fruit juice with a cation exchange resin. Patent Document 4 discloses a method and a process for producing a processed food in which fruit and freeze are melted or heated to remove sugars and potassium, and then a gelling solution is injected to reproduce the elasticity and texture to the raw state. Food is listed.

  Moreover, the method and apparatus which removes salts, such as potassium, from a foodstuff by supplying with electricity are also disclosed (patent documents 5 and 6). Patent Document 5 discloses a method of removing metal ions such as potassium from food by immersing food contained in a metal ion permeable membrane between opposing electrodes in an electrolytic solution and energizing between the electrodes. Yes. Patent Document 6 describes a device for desalting while sandwiching an object to be desalted containing salts between electrodes arranged opposite to each other and energizing it while allowing the surrounding solvent to flow in and out.

JP 2011-36226 A JP 2011-135797 A JP 2001-103945 A JP 2007-105000 A JP-A-10-165113 JP-A-6-90685 JP 2003-204768 A

Mori Okura et al., Toyo Foods Institute, Toyo Food Research Institute Research Report (2000), 23, 47-56 Tomoko Makigami, Journal of the Japan Society of Cookery Science (2007), Vol. 1, p. 1-9

  In order to prevent hyperkalemia, it is necessary to limit the amount of potassium taken from the diet according to the symptoms. However, in order to realize a low potassium food, there are various methods as described above, but each has the following problems.

  When cooking ingredients with a high potassium content, it was necessary to boil them for a long time and then spill them or chop them finely and expose them to water. This is because vegetables other than leafy vegetables, for example, root vegetables such as carrots and pumpkins, have very little decrease in potassium due to boiling. In addition, since it is boiled for a long time or exposed to water, not only potassium but also umami components of food are eluted. Therefore, various problems have occurred such as limited food ingredients and cooking methods.

  In the low potassium vegetable cultivated by hydroponics, at least 40% or more of potassium can be reduced as described above (Patent Documents 1 and 2). However, since it is limited to crops that can be cultivated by hydroponics, the types of crops that can be provided as low potassium crops are limited. For example, leafy vegetables such as leaf lettuce and komatsuna are mainly used, and root vegetables such as carrots and burdocks, and leafy vegetables such as cabbage and ball lettuce (heading lettuce) are time and cost to harvest. It is not cultivated because it costs.

  The method described in the cited document 3 is limited to vegetable juice and fruit juice, and the method described in the cited document 4 is limited to processed fruit foods. Therefore, the method described in Citation 3 is limited to some vegetables and fruits suitable for vegetable juice. Moreover, it was applicable only in the form of juice as the form during processing.

  In the method described in the cited document 4, the amount of potassium that can be removed is determined by the drip that comes out of the fruit cell by freezing and thawing or heating, so that the amount cannot be adjusted. In addition to the sugar and potassium, both the flavor and scent components of the fruit are removed. Although the texture such as touch can be reproduced to some extent by adding a thickener, a gelling agent, etc., it has been difficult to restore the taste and aroma.

  The method of removing salts by energizing has the advantage that the type of food is not limited. However, the conventional method does not control the amount of potassium to be removed, and how much potassium has been removed can only be measured after the treatment. Patent Document 5 does not consider the amount of salt removed from food, and it is necessary to individually define energization conditions in order to produce food for patients with kidney disease who are subject to potassium restriction. It was not practical. In addition, since the electrode is not in contact with food, when current is passed, the current flows through the electrolyte solution with low resistance, and the food is hardly energized. For this reason, the removal efficiency of metal ions is poor, and potassium removal cannot be performed in a short time.

  The device of Patent Document 6 is for desalinating seafood and salted products by exchanging a solvent such as water, and energization is only for shortening the desalting operation. That is, desalting is not intended only by energization. In addition, as disclosed in the examples, it is an apparatus for removing sodium chloride contained at a concentration as high as several percent, and sodium ions that have a moderate salty taste remain in the desalted product. ing. Therefore, the amount of remaining potassium is not so low as to be suitable for the purpose of reducing potassium intake in patients with renal disease.

  Although various low potassium food production methods have been disclosed as described above, no technology that can provide various low potassium foods has been developed so far. The present invention removes potassium quickly without damaging the texture and flavor of food, as much as possible, while maintaining the advantages of the energization method that can remove potassium in any food. It is an object of the present invention to provide a system and method capable of performing the above. In particular, in order to provide a low-potassium food that is safe to provide to patients with kidney disease, it is an object to provide an apparatus and a method for producing with good productivity while monitoring how much potassium has been removed. And

The present invention relates to a system for removing potassium from foods described below, a removal method, and a low potassium food using the method.
(1) A system for removing potassium from food by energization,
A power supply for applying a direct current;
A tank,
At least a pair of electrodes disposed in the aquarium and facing each other via food,
A potassium removal system comprising a deionization means for adsorbing eluted ions.
(2) The potassium removal system according to (1),
The potassium removal system, wherein the deionization means is an ion exchange resin.
(3) The potassium removal system according to (1) or (2),
A potassium removing system, wherein the water tank is provided with a circulating means for circulating water.
(4) The potassium removal system according to (3),
The circulation means is a circulation channel;
A circulation pump for circulating water in the circulation channel;
A potassium removal system comprising an ion exchange resin tower filled with the ion exchange resin.
(5) The potassium removal system according to (4),
A potassium removal system, wherein an electrical conductivity meter or a potassium ion meter is provided upstream of the ion exchange resin tower in the circulation channel.
(6) The potassium removal system according to (5),
A potassium removal system further comprising an electric conductivity meter or a potassium ion meter on the downstream side of the ion exchange resin tower in the circulation channel.
(7) The potassium removal system according to any one of (1) to (6),
The potassium removal system, wherein the power source is a constant current DC power source.
(8) The potassium removal system according to any one of (1) to (7),
A potassium removal system comprising a cooling system that cools water in which food is immersed to 0 to 15 ° C.
(9) A method for removing potassium from food,
Place it in the water tank so that the food is sandwiched between the opposing electrodes,
While removing the eluted ions from the water by deionization means,
A method for removing potassium from food, wherein the potassium is removed by passing a direct current from the opposite electrode to the other electrode through the food.
(10) A method for removing potassium from the food according to (9),
A method for removing potassium from food, wherein the water in the water tank is removed while monitoring the amount of potassium ions eluted by an electric conductivity meter or a potassium ion meter.
(11) A method for removing potassium from a food according to (9) or (10),
A method for removing potassium from food, wherein the temperature of the food is maintained at 0 to 15 ° C.
(12) A method for removing potassium from a food according to any one of (9) to (11),
A method for removing potassium from food, characterized by energizing at a constant current.
(13) A method for removing potassium from a food according to any one of (9) to (12),
A method for removing potassium from food, characterized by treating the current density at 1 to 16 mA / cm ² .
(14) By the method according to any one of (9) to (13),
Food from which potassium has been removed.

  By disposing deionization means in the potassium removal system, leakage of current outside the sample can be prevented, and potassium can be removed from food in a short time. Moreover, in the system of this invention, since potassium removal processing is performed while monitoring the eluted ions, the amount of potassium eluted from food can be grasped. Therefore, the potassium removal process can be completed at an appropriate time.

  In addition, when industrially producing low potassium foods, a large amount of cooling water is required, but ions are removed by deionization means and the electrical conductivity is kept low, so the water in the aquarium is replaced. Can be reduced. As a result, cost can be reduced.

FIG. 1A shows an overview of a system for removing potassium from food according to the first embodiment. FIG. 1B shows an overview of a system for removing potassium from food according to the second embodiment. The figure which shows the system which removes potassium from the foodstuff of 2nd Embodiment. The potassium elution rate according to the energization time is shown. FIG. 3A shows a diagram using pumpkin as a specimen. FIG. 3B shows a diagram using sweet potato as a specimen. The figure which shows the potassium movement distance with respect to electricity density and time.

  In the present invention, food includes agricultural products such as vegetables, meat, fish, etc., and there is no limitation on the type. However, since the method for removing potassium according to the present invention needs to energize the food, it is preferably a food having a thickness and hardness that do not allow the electrodes to come into contact with each other when sandwiched between the electrodes. For example, it is not suitable for removing potassium from small grains such as rice and liquid foods such as juice.

  Further, the food may be used as it is, or may be subjected to heat treatment as a pre-process or post-process of the energization process. The heat treatment may be a light heat treatment of about 70 to 80% in the case of normal cooking. By performing the heat treatment before energization, the efficiency of removing potassium ions can be expected for some vegetables. Moreover, the neutralization efficiency mentioned later can be expected to be improved by performing the heat treatment after energization.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1A shows an outline of a system 1 for removing potassium from food according to the first embodiment of the present invention. As shown in FIG. 1A, the food 4 is sandwiched between the opposing electrodes 2 and 3 and disposed in the water tank 5. The electrodes 2 and 3 are connected to a DC power source 6. Alternating current periodically changes polarity, so potassium hardly elutes from food.

  The present inventors have found that it is necessary to energize while adjusting the energization density in order to maintain the texture and flavor in the same manner as the original food. For this reason, the DC power source 6 is preferably a power source that can be controlled to a constant current. For example, it may be energized with a constant current from the beginning to the end, or depending on the food, the resistance value is high at the beginning of energization, so the voltage is set high, and after a certain period of time it may be controlled to a slightly lower voltage . Moreover, as long as it is an electrode which opposes, either side is good also as an anode and a cathode.

  The water in the water tank 5 functions as a reservoir of eluted ions and has a role of supplying moisture. That is, since cations such as potassium ions and sodium ions are eluted from the cathode side by energization, they function as a reservoir for these cations. On the anode side, moisture is supplied from the sample surface.

  As a result of the examination of the conditions by the present inventors, it has been clarified that the texture is remarkably impaired, for example, dehydration occurs when food is supplied without supplying water, and the food becomes soft. Therefore, the electrodes 2 and 3 are installed in the water tank 5.

  Moreover, the water in the water tank 5 is maintained at a low temperature of 0 to 15 ° C. by a cooling device (not shown). According to the results of the study by the present inventors, when food is energized at room temperature of about 25 ° C., dehydration occurs significantly from the food even if it is immersed in water in a water tank and subjected to energization treatment. Adversely affect. Accordingly, the temperature of the food needs to be maintained at 0 to 15 ° C., more preferably 0 to 10 ° C. with a cooling device. Here, 0 ° C. means a temperature at which food or water in the aquarium does not freeze, that is, a freezing point.

  Any cooling device may be used. For example, when the water in the water tank is circulated, a cooling device is provided in a part of the circulation flow path, and the circulating water can be cooled to maintain the temperature low. Further, a potassium removal system may be installed in a low temperature environment such as a low temperature chamber to keep the entire system at a low temperature.

  Furthermore, a deionization means is disposed in the water tank in order to remove ions such as potassium that have been eluted by energization. Any deionization means may be used as long as ions can be removed, and ion exchange resin, RO membrane (semipermeable membrane), electrodialysis, or the like may be used. Furthermore, a water treatment device combining ion exchange resin, RO membrane (semipermeable membrane), and electrodialysis can be used.

  As the deionization means, it is convenient and preferable to use an ion exchange resin. Any ion-exchange resin may be used as long as it can remove the eluted ions, but H-type strongly acidic cation exchange resin capable of removing cations and anions, OH-type strongly basic anions It is preferable to mix exchange resins or use as a two-bed type apparatus. Examples of such a resin include Diaion UBK10, Diaion UBA120 (manufactured by Mitsubishi Chemical Corporation), and the like. In addition, mixed bed resin (manufactured by Airi System Co., Ltd., MB-120) marketed as ion exchange resin for pure water production is H type strongly acidic cation exchange resin, OH type strongly basic anion exchange resin. It is a premixed resin and can be used as it is.

  The deionization means may be arranged in any way as long as it can adsorb ions eluted in the water in the water tank. For example, the ion exchange resin may be placed in a water tank, water may be stirred with a stirring blade, a stirrer, or the like, and contacted with the ion exchange resin to remove ions. FIG. 1A shows a configuration in which a circulation channel 7 is provided, an ion exchange resin tower 8 filled with an ion exchange resin is arranged in the channel, and water is circulated by a pump 9.

  An elution ion measuring instrument 10 such as an electric conductivity meter or a potassium ion meter is disposed upstream of the ion exchange resin tower 8 into which water flows from the water tank 5. If a potassium ion meter is used, the amount of potassium ions eluted from food can be calculated. If an electric conductivity meter is arranged, the amount of metal ions such as potassium and sodium eluted from food can be calculated based on the electric conductivity reflecting the increase in ions. By continuously monitoring the eluted potassium ions and metal ions and taking into account the speed of the water circulated by the pump 9, the amount of elution of potassium ions and the like can be integrated.

  The potassium content of food is usually not constant. In particular, the amount of potassium contained in vegetables varies depending on the production area and season. In order to accurately determine the amount of potassium remaining in the food, it is preferable to measure the amount of potassium contained in the food for each lot before removing potassium. The amount of potassium removed from the food can be accurately determined by monitoring the eluted potassium ions using a potassium ion meter and an electrical conductivity meter while performing the potassium removal treatment.

  Alternatively, the amount of potassium remaining in the food is based on the standard that describes the ingredients of standard foods, such as the 5th amended Japanese food standard ingredient table (hereinafter sometimes simply referred to as the food standard ingredient table). It may be calculated. The ingredients of the food listed in the food standard ingredient table are standard values to the last, but the proportion of potassium eluted from the food can be calculated based on this.

  Conventionally, the amount of residual potassium has been determined by measuring the amount of potassium in the food after elution. On the other hand, in the present invention, energization can be performed while monitoring the amount of ions eluted by the eluted ion measuring instrument 10. Therefore, the amount of removed potassium can be monitored and the removal of potassium can be performed until the target amount of removed potassium is reached.

  Moreover, the state of the water flowing into the water tank 5 can be monitored by disposing the eluted ion measuring device 11 on the downstream side of the ion exchange resin tower 8. Thereby, the exchange time of the ion exchange resin with which the ion exchange resin tower 8 is filled can be grasped | ascertained.

  Water in the water tank 5 is circulated by a pump 9 disposed in the circulation channel 7. Any pump such as a peristaltic pump, a tube pump, or a diaphragm pump may be used. In order to calculate the amount of potassium eluted, it is preferable that the flow rate of the pump is clear.

  The food 4 and the electrodes 2 and 3 in the water tank 5 will be further described. In FIG. 1B, the food 4 is cut into a substantially rectangular parallelepiped shape and sandwiched between the electrodes 2 and 3 and energized. However, the food 4 may have any shape as long as the food 4 is in close contact with the electrodes 2 and 3.

  By using a flexible material for the electrodes 2 and 3 and making the surface of the food 4 in contact with the electrodes 2 and 3 flat to some extent, the food 4 can be brought into close contact with each other and can be energized over a wide area. Since the electrodes 2 and 3 of the present invention directly contact the food 4 and conduct electricity, it is necessary to consider the safety. Specifically, iron, aluminum, platinum, and titanium specified in “Standards for Foods, Additives, etc.” may be used. In particular, the anode electrode 2 needs to be a corrosion-resistant electrode such as a platinum electrode in order to prevent elution of metal ions. Further, the electrodes 2 and 3 can be efficiently energized by using mesh surface electrodes.

  Moreover, by arranging the buffer material 12 on the outer side of the electrode on one side, the electrodes 2 and 3 are in close contact with the food 4 and can be energized efficiently. Any material may be used as the cushioning material 12 as long as it is flexible and can diffuse ions eluted from food. For example, porous materials such as sponge, fabrics made of cotton, chemical fibers, mountain-shaped cushioning materials, etc., which do not adhere to the electrodes 2 and 3 and are capable of diffusing eluted ions into the surrounding water Any type may be used. Although not shown here, if the electrodes 2 and 3 are fixed so as to be in close contact with the food 4 using a fixing member such as a weight or a band, the current is passed through the food 4 only, so that the efficiency is high.

  A mounting table 13 is disposed below the cushioning material 12. Cations such as potassium that have moved to the cathode side when energized are finally eluted out of the food. A hole 14 is provided in the mounting table 13 disposed below the cushioning material 12. The eluted ions do not stay near the mounting table 13 but are adsorbed by the ion exchange resin.

  FIG. 2 schematically shows a second embodiment of the present invention. When many foods are processed at a time, a large number of units with the foods 4 sandwiched between the opposing electrodes 2 and 3 shown in the first embodiment may be arranged adjacent to each other with the cushioning material 12 interposed therebetween. By adopting such a configuration, even a large number of foods can be energized and processed at a time.

  The unit is placed in the water tank 5. Since water in the circulation channel 7 circulates, water in the water tank 5 circulates, so there is no need to stir. Further, if the buffer material 12 is a continuous mountain-shaped material, such as a material that promotes the adhesion between the electrodes 2 and 3 and the food 4 while making contact with the electrodes in a small area, It is possible to promote the diffusion of ions into water.

  By keeping the thickness of the food 4 (distance between the electrodes 2 and 3) substantially the same, the amount of ions eluted by the energization process is substantially the same even when a plurality of foods are processed simultaneously. Therefore, a large amount of food can be subjected to the same degree of depotassium treatment at a time.

  When potassium is removed from food by energization, it is important that the taste and texture are not impaired. Examples of the deterioration of the taste and texture due to the energization treatment include softening due to dehydration and acidity due to a decrease in pH. The present inventors examined and clarified that there are presence / absence of water supply, energization condition, and temperature condition as conditions relating to these.

In the system of the present invention, food is placed in a water tank and energization processing is performed, so that water is always supplied from the surroundings. Therefore, no problem arises in terms of water supply, and food softening is unlikely to occur. With respect to the energization conditions, the taste and texture are maintained by performing the treatment at an energization density of 1 to 16 mA / cm ² and the temperature conditions at a low temperature of 0 to 15 ° C. However, even if the potassium removal treatment is performed under optimum energization conditions and temperature conditions, some foods may soften and deteriorate the taste. For foods that tend to soften and foods with a sour taste, the following treatment is preferably performed.

  The softening of food is a major factor that deteriorates the taste. For softening, pretreatment for preventing alteration of pectin, which is a skeleton-forming component of plants, can be performed to prevent softening. For example, there is a method of pre-treating food using a calcium salt solution, binding pectin and calcium salt, utilizing the fact that the cell wall is strengthened and the tissue is hardened, and the food is softened (Patent Document 7, Non-patent documents 1, 2).

  The present inventors have also examined whether or not excessive softening of vegetables due to energization can be prevented using this reaction, and have obtained a result that there is a significant effect on softening prevention. Specifically, about 120 g of a pumpkin specimen cut into 2.5 cm in length, 2.5 cm in width and 2.5 cm in thickness is immersed in 3 L of a 0.7 wt% calcium chloride solution, and at room temperature for 16 hours every 2 hours. The sample was pretreated with gentle stirring. After pre-treatment, electricity was applied to remove potassium, and the hardness of the food was analyzed. As a result, softening was clearly prevented in the case where the calcium chloride solution treatment was performed, compared to the case where the calcium chloride solution treatment was not performed.

  The above result that the softening can be prevented by the pretreatment with the calcium chloride solution indicates that the softening of the food by the energization treatment can be prevented by the other pretreatment that prevents the deterioration of pectin. For example, softening can be prevented by adopting various methods for preventing alteration of other pectin, such as preheating treatment at 50 to 65 ° C. using an enzymatic reaction of pectin methylesterase.

  Moreover, by removing cations such as potassium, the acidity may be strongly felt. When the taste of food is impaired by being sour, it is necessary to perform alkali treatment to restore the original taste.

  When the present inventors examined separately, supplemented with sodium and / or calcium having an equivalent ratio of 0.15 to 1.1 with respect to the removed potassium, the sourness was neutralized and the flavor of the food was restored. be able to.

  Even when the texture and flavor are impaired by the potassium removal treatment, the pectin alteration prevention treatment and alkali treatment can be performed before and after the energization so that the texture can be recovered to the extent that it cannot be distinguished from the original food.

  Next, the present invention will be described with further specific examples, but the present invention is not limited to such examples.

1. Examination of energization condition and temperature condition << Example 1 >>
The effect of the current density per energized area of food and the temperature during energization on the hardness of the food was investigated. It has been confirmed in advance that there is a correlation between the taste of food such as sweetness and aroma and the texture such as hardness and texture. That is to say, those having good hardness have good taste.

A pumpkin (Japanese pumpkin) was cut to have a length of 2.5 cm, a width of 2.5 cm, and a thickness of 2.5 cm, and used as a specimen. The temperature was kept at 0 ° C. and the current density was changed from 0 to 16 mA / cm ² for processing, and the sweetness, fragrance, hardness and touch were examined. In addition, a sample immersed in water at room temperature (23 ° C.) without conducting an energization treatment was similarly examined for sweetness and the like. The analysis was performed by energizing for 6 hours with an apparatus having no deionization means.

  As compared with the untreated specimen, the hardness is good, the hardness is reduced and the elasticity is soft, and the softness is lost and the clay-like plasticity is extremely soft.

  The amount of potassium remaining in the pumpkin was measured according to the analysis method used in the Japanese food standard ingredient table. That is, the specimen was pretreated by a wet ashing method using nitric acid and perchloric acid, and then the amount of potassium was measured by an atomic absorption method. Potassium has been removed from all the specimens (samples 1 to 5) that have been energized with a direct current.

  On the other hand, the alternating current (sample 6) was 12%, or the samples that were not energized (samples 7 and 8) were 1% and 3%, respectively, and almost no potassium was removed regardless of temperature conditions.

Since the amount of potassium varies depending on the cultivar of the vegetable used as the specimen, the place of production, the storage period and conditions after harvesting, in Table 1, the potassium removal rate varies widely based on the results of several experiments. Is shown. For the samples derived from the same pumpkin, which were performed on the same day under the experimental conditions shown in Table 1, the samples treated with 4 mA / cm ² (sample 1) were 39%, the samples treated with 8 mA / cm ² and 16 mA / cm ^2. As for (Samples 2 to 5), 82%, 95%, 91%, and 98% are respectively removed from potassium by 80% or more.

  In addition, although the potassium removal apparatus performs the treatment by immersing the specimen in water in the water tank, the dehydration occurs remarkably when the treatment is performed at room temperature, which affects the taste (Sample 5). . On the other hand, specimens (samples 1 to 4) processed at a low temperature (0 to 10 ° C.) had a degree of dehydration in the range of minus (−) to plus (+) regardless of the current density.

The specimen treated at 0 ° C. and 4 mA / cm ² (Sample 1) or the specimen treated at 8 mA / cm ² (Sample 2) has the same hardness as the untreated specimen, and the dent due to dehydration is 8 mA / cm ² . Only a very small dent of about 1 mm was generated on the cathode side in the treated specimen (sample 2).

In addition, the specimen (sample 3) treated at 0 ° C. and 16 mA / cm ² had a strong dent on the cathode side. Therefore, even at a low temperature, at 16 mA / cm ² , dehydration proceeds, so the taste and texture are slightly lowered.

In addition, in the specimen (sample 4) treated at 10 ° C. and 8 mA / cm ² , depressions of about 5 mm due to dehydration were observed on all five surfaces other than the skin. Moreover, the hardness of the specimen was also soft.

The specimen (sample 5) treated at 23 ° C. and 8 mA / cm ² is heavily dehydrated, the specimen is clay-like, and the texture is remarkably poor. Therefore, not only the energization conditions but also the temperature conditions are very important for maintaining the taste and texture.

2. Effect of ion exchange resin << Example 2 >>
A pumpkin (Japanese pumpkin) was cut into a length of 2.5 cm, a width of 2.5 cm, and a thickness of 2.5 cm and used as a specimen. Using the system 1 shown in FIG. 1, the temperature was kept at 5 ° C., and the energization process was performed at 4 mA / cm ² and 8 mA / cm ² . Using ion-exchange resin for pure water production mixed with H-type strongly acidic cation-exchange resin and OH-type strongly basic anion-exchange resin as ion-exchange resin, electricity was applied while removing ions eluted from pumpkin. .

  The potassium removal rate (K elution%) depending on the energization time is calculated from the value measured by the ion measuring device 10 upstream of the ion exchange resin tower 8 shown in FIG. 1A. A rate at which water circulates through the circulation flow path 7 by the pump 9 and an integration of ions eluted by energization are obtained by calculation using an electric conductivity meter as the ion measuring device 10.

  Specifically, water is sucked from directly under the negative electrode at a rate of 1.2 L / min, and the eluted ions are removed through the ion exchange resin and then returned to the water tank. The amount of ions before flowing into the ion exchange resin tower is measured with an electric conductivity meter to calculate the amount of ions eluted by energization.

  As a comparative example, only water was circulated without using an ion exchange resin, and potassium was removed to obtain a potassium removal rate. About what removed potassium without using ion exchange resin, the sample was extract | collected for every fixed time, and the amount of potassium which remains in a pumpkin was measured based on the analysis method used for the Japanese food standard ingredient table | surface. The results are shown in FIG. 3A. In the figure, “+” indicates that the energization was performed while removing ions from the circulating water with the ion exchange resin, and “−” indicates that only the water was circulated and the water was not treated with the ion exchange resin. Indicates.

As shown in FIG. 3A, for removing 50% of potassium from the sample, in the case of using the system of the present invention, 4mA / cm ² at 128 minutes, it took 8 mA / cm ² in 66 minutes. On the other hand, in the case of the comparative example, it is estimated that it takes about 430 minutes at 4 mA / cm ² . Moreover, it took 180 minutes at 8 mA / cm ² . When a potassium removal treatment is performed while removing ions from the circulating water using an ion exchange resin, potassium can be removed in about 1/3 of the time when electricity is supplied without removing ions. .
Example 3
The effect of removing ions from the water in the water tank was analyzed using ion exchange resin in the same manner using sweet potato as a specimen. As in Example 2, sweet potato was cut to have a length of 2.5 cm, a width of 2.5 cm, and a thickness of 2.5 cm. Except for using sweet potato instead of pumpkin, the energization treatment was performed in the same manner as in Example 2 to obtain the potassium removal rate. Moreover, what removed potassium without using ion exchange resin was made into the comparative example. The results are shown in FIG. 3B.

As shown in FIG. 3B, for removing 50% of potassium from the sample, in the case of using the system of the present invention, 4mA / cm ² at 103 minutes, 8 mA / cm according ² in 45 minutes. On the other hand, in the case of not using the ion exchange resin, 4mA / cm ² at 297 minutes, it took 8 mA / cm ² in 212 minutes.

Although it differs depending on the type of vegetable, when an ion exchange resin is used, the energization time required to remove equivalent potassium ions is 1/3 to 1/5 compared to the case where no ion exchange resin is used. It can be shortened to the extent.
Example 4
Since the movement distance of potassium is proportional to the product of the conduction density and the conduction time, the effect of the ion exchange resin on the potassium movement distance was examined.

Pumpkin was used as a specimen, and the moving distance of potassium with respect to current density (mA / cm ² ) and time was calculated. A Japanese pumpkin cut into a length of 2.5 cm, a width of 2.5 cm, and a thickness of 2.5 cm was used as a specimen.

  In the same manner as in Example 2, energization was performed while constantly removing ions with an ion exchange resin, and the distance of potassium movement was determined. A comparative example was obtained by conducting an energization treatment without using an ion exchange resin and removing potassium. The results are shown in FIG.

  As shown in FIG. 4, when an ion exchange resin is used (indicated by “+” in FIG. 4), the movement distance of potassium is fast, and electricity is applied without using an ion exchange resin (in FIG. 4, “ It is approximately twice that of “-”. By constantly removing ions such as potassium ions eluted from the pumpkin from the surrounding water, the electrical conductivity of the surrounding water is kept low, and electricity is efficiently conducted through the food, so that potassium moves. It is done.

  A low potassium food can be rapidly produced. Moreover, since it supplies with electricity monitoring the ion removed, a low potassium food can be manufactured, estimating the potassium which remains in food. Therefore, it is possible to provide a low-potassium food that can be consumed with peace of mind even in patients with limited potassium, such as patients with kidney disease.

DESCRIPTION OF SYMBOLS 1 ... System which removes potassium, 2, 3 ... Electrode, 4 ... Food, 5 ... Water tank, 6 ... DC power supply, 7 ... Circulation flow path, 8 ... Ion Exchange resin tower, 9 ... pump, 10, 11 ... elution ion measuring device, 12 ... buffer material, 13 ... mounting table

Claims (14)

A system for removing potassium from food by energization,
A power supply for applying a direct current;
A tank,
At least a pair of electrodes disposed in the aquarium and facing each other via food,
A potassium removal system comprising a deionization means for adsorbing eluted ions. The potassium removal system according to claim 1,
The potassium removal system, wherein the deionization means is an ion exchange resin. The potassium removal system according to claim 1 or 2,
A potassium removing system, wherein the water tank is provided with a circulating means for circulating water. The potassium removal system according to claim 3,
The circulation means is a circulation channel;
A circulation pump for circulating water in the circulation channel;
A potassium removal system comprising an ion exchange resin tower filled with the ion exchange resin. The potassium removal system according to claim 4,
A potassium removal system, wherein an electrical conductivity meter or a potassium ion meter is provided upstream of the ion exchange resin tower in the circulation channel. The potassium removal system according to claim 5, wherein
A potassium removal system further comprising an electric conductivity meter or a potassium ion meter on the downstream side of the ion exchange resin tower in the circulation channel. It is a potassium removal system of any one of Claims 1-6,
The potassium removal system, wherein the power source is a constant current DC power source. It is a potassium removal system of any one of Claims 1-7,
A potassium removal system comprising a cooling system that cools water in which food is immersed to 0 to 15 ° C. A method for removing potassium from food,
Place it in the water tank so that the food is sandwiched between the opposing electrodes,
While removing the eluted ions from the water by deionization means,
A method for removing potassium from food, wherein the potassium is removed by passing a direct current from the opposite electrode to the other electrode through the food. A method for removing potassium from a food according to claim 9,
A method for removing potassium from food, wherein the water in the water tank is removed while monitoring the amount of potassium ions eluted by an electric conductivity meter or a potassium ion meter. A method for removing potassium from a food according to claim 9 or 10,
A method for removing potassium from food, wherein the temperature of the food is maintained at 0 to 15 ° C. A method for removing potassium from a food according to any one of claims 9-11,
A method for removing potassium from food, characterized by energizing at a constant current. A method for removing potassium from a food according to any one of claims 9-12,
A method for removing potassium from food, characterized by treating the current density at 1 to 16 mA / cm ² . A method according to any one of claims 9 to 13,
Food from which potassium has been removed.