WO2014041590A1

WO2014041590A1 - Refrigerator and refrigeration method

Info

Publication number: WO2014041590A1
Application number: PCT/JP2012/007572
Authority: WO
Inventors: 岳志加納
Original assignee: ダイワ・インターナショナル株式会社
Priority date: 2012-09-11
Filing date: 2012-11-26
Publication date: 2014-03-20
Also published as: JP2014055690A; TW201425844A

Abstract

Provided is a refrigerator in which it is possible to increase the effect of maintaining freshness in a refrigerated item such as a food item or a food ingredient, and to mature, at the same time as refrigerate, the refrigerated item in a simple and reliable manner. A refrigerator (1) for refrigerating a refrigerated item (6) placed in the refrigeration space (S). The refrigerator (1) has: a refrigerator wall (2) forming the refrigeration space (S) and having electrical insulating properties; a refrigeration device (7) for putting the refrigerated item (6) in an ice-temperature state; a fan (9) for forming an airflow (B) in the refrigeration space (S); electric field applying devices (5, 14) for applying an alternating electric field on the refrigerated item (6) placed in the refrigeration space (S); and a filter (15) disposed in the airflow (B) formed by the fan (9). The filter (15) has an action of subjecting bacteria contained in the airflow formed by the fan (9) to bacteriostatis.

Description

Refrigerator and refrigeration method

The present invention relates to a refrigerator and a refrigeration method for refrigerated storage of food, foodstuffs, beverages and other objects to be cooled.

The present invention relates to a refrigerator and a refrigeration method for refrigeration of food and the like. In the present specification, “refrigeration” refers to cooling a substance in a state where moisture in the substance does not freeze. Specifically, “refrigeration” is a temperature state within a range from the freezing point of a substance to room temperature. For a substance with a freezing point of minus 3 ° C., “refrigeration” is a temperature state in the range from minus 3 ° C. to room temperature. Room temperature is a natural temperature that does not heat or cool the material.

“Ice temperature” is a temperature in the range from around 0 ° C., the temperature at which water freezes, to the freezing point of the substance. For a material having an icing point of minus 3 ° C., the “ice temperature” is a temperature state in the range from minus 3 ° C. to around 0 ° C. That is, the “ice temperature” is a temperature range below about 0 ° C. in the “refrigeration”.

“Frozen” is to cool a substance in a state where moisture in the substance is frozen. Specifically, “freezing” is a temperature state below the freezing point of a substance. If the material has a freezing point of minus 3 ° C., “freezing” is in a temperature state below minus 3 ° C.

In the present specification, among substances to be cooled, a substance that is intended to be frozen may be referred to as an object to be frozen. In addition, a substance intended to be refrigerated among substances to be cooled may be referred to as a refrigerated object. Furthermore, the object to be frozen and the object to be refrigerated are sometimes collectively referred to as an object to be cooled.

Conventionally, there is known a freezer in which an alternating electric field is applied to an object to be frozen, that is, an AC voltage is applied (see, for example, Patent Document 1). In this freezer, the action of an alternating electric field suppresses the nucleation of ice crystals, prevents the destruction of cells of the object to be frozen, and maintains freshness.

Further, conventionally, in a thawing and refrigerator whose internal temperature is set to about minus 5 ° C. to plus 8 ° C., a technique for forming an alternating electric field while electrically insulating a storage object is known (for example, Patent Document 2).

Furthermore, conventionally, in a refrigeration and refrigerator whose internal temperature is set to 0 ° C. or less, a technique of forming an alternating electric field in the cabinet by applying an AC voltage having a frequency of 500 Hz or more to suppress the ice crystal from becoming coarse. Is known (see, for example, Patent Document 3).

By the way, the process of “aging” foods and the like has been conventionally performed in the industry using refrigerators, for example, restaurants, restaurants, and the like. “Aging” means to activate the action of an enzyme to soften meat as a food, increase the taste of meat, or adjust the fruit as a food to a seasonal taste.

Conventionally, in the industry where refrigerators are used, in order to perform aging, the objects to be cooled that have been cooled in the refrigerator or freezer are taken out of the refrigerator and the like, and the predetermined additives are added to mature the objects to be cooled. Had gone. Conventionally, according to Patent Document 4, in a refrigerator, a refrigeration apparatus in which refrigeration is performed at the same time while maintaining freshness by placing the object to be refrigerated in a negative high potential and high humidity environment. Proposed.

JP 2003-088347 A JP 2011-182697 A JP 2011-182700 A Japanese Patent Laid-Open No. 2003-325101

As described above, conventionally, a refrigeration method for maintaining the freshness of an object to be cooled by applying an alternating electric field has been known. However, a sufficient freshness maintaining effect is often not obtained only by applying an alternating electric field.

In addition, when aging a refrigerated product that has been refrigerated, conventionally, it has been common to perform a process of releasing the refrigeration and adding the necessary additives. However, this aging process is time consuming and troublesome.

In addition, as in Patent Document 4, there is an idea of realizing aging at the same time while maintaining freshness by refrigeration, but the method disclosed in this document has complicated condition setting and is difficult to realize. There was a problem that there was.

The present invention has been made in view of the above-described problems, and can enhance the effect of maintaining freshness for food to be refrigerated, such as foods and foodstuffs, and further ripen at the same time as refrigerated food is refrigerated. It is an object of the present invention to provide a refrigerator and a refrigeration method capable of simply and reliably performing.

The refrigerator according to the present invention is a refrigerator that refrigerates an object to be refrigerated placed in a refrigeration space. The refrigerator wall that forms the refrigeration space and has electrical insulation, and the object to be refrigerated Refrigeration means for bringing into an ice temperature state, airflow formation means for forming an airflow in the refrigeration space, electric field application means for applying an alternating electric field to an object to be refrigerated placed in the refrigeration space, and the airflow formation It has a filter which is arranged in the air current formed by the means and which bacterioculates the bacteria contained in the air current.

In the above configuration, “bacteriostasis” is not to kill and reduce bacteria, but to reduce the bacteria by suppressing the growth of bacteria.

In the refrigerator, there may be bacteria that adversely affect the object to be refrigerated, such as food poisoning bacteria (for example, O-157, Vibrio parahaemolyticus, Salmonella, Norovirus, etc.), and the object to be refrigerated is aged. In some cases, suitable bacteria (for example, bifidobacteria or lactic acid bacteria) may be present. The bacteriostatic filter of the present invention appropriately suppresses the presence of food poisoning bacteria and the like, and leaves suitable bacteria for aging.

According to the present invention, in addition to applying an alternating electric field to the object to be cooled, a cold air bacterized by a filter is applied to the object to be cooled, so that the freshness is maintained only by the alternating electric field. Compared to a refrigerator, the effect of maintaining the freshness of the object to be cooled can be further enhanced.

In addition, according to the present invention, by using a bacteriostatic filter, bacteria suitable for aging are imparted to the refrigerated product being refrigerated, so that the enzymes contained in the refrigerated product and the bacteria suitable for aging are This synergistic effect makes it possible to reliably ripen the items to be refrigerated without adding any additives. Aging means to activate the enzyme to soften the meat that is food, increase the taste of the meat, or adjust the fruit that is food to the seasonal taste.

In the refrigerator according to the present invention, the filter is a porous substance that is a substance having a large number of fine pores therein, and the material forming the pores is copper or copper on the surface. It can be a material formed by coating. If it carries out like this, the filter which carries out bacteriostasis of the microbe contained in an airflow can be provided reliably.

In addition, the metal given to the surface of the porous material is not limited to copper, but a metal capable of bacteriostatic effect (that is, it does not kill and reduce bacteria, but suppresses bacterial growth and reduces bacteria). Any substance can be applied as long as it is a substance. For example, silver can be used instead of copper.

In the refrigerator according to the present invention, the filter is a sponge-like foam having a large number of holes therein, and the copper is fibrous copper or the surface thereof is coated with copper. The material can be a fibrous material. If it carries out like this, the function of the bacteriostatic of the filter which suppresses the proliferation of bacteria and reduces bacteria, not killing and reducing bacteria, can be realized with high ability.

In the refrigerator according to the present invention, the airflow forming means may be a fan that rotates by being driven by an electric motor. If it carries out like this, an airflow formation means can be provided in a refrigerator simply and cheaply.

The refrigerator which concerns on this invention WHEREIN: The said electric field provision means can form an alternating electric field by the application of the alternating voltage in the range of 600 volts to 2000 volts, and has the said electrical insulation at the time of this voltage application. The value of current flowing through the storage wall by the wall can be 1 mA or less. With this configuration, it is possible to apply a suitable alternating electric field to the object to be refrigerated. As a result, a high freshness maintaining effect can be realized in combination with the selectivity of bacteria by the filter.

Next, in the refrigeration method according to the present invention, the object to be refrigerated is placed in a refrigeration space surrounded by a wall having electrical insulation, the inside of the refrigeration space is set to a refrigeration temperature, and the refrigeration object An air field passing through the object to be refrigerated is formed in the refrigeration space, and a filter capable of performing bacteriostatic action is disposed in the flow path of the air current, and the object to be refrigerated It is characterized by aging while refrigerated.

According to this refrigeration method, in addition to applying an alternating electric field to the object to be cooled, the cold air bacterized by the filter is applied to the object to be cooled, so that the freshness is maintained only by the alternating electric field. Compared to a refrigerator, the effect of maintaining the freshness of the object to be cooled can be further enhanced.

In addition, according to this refrigeration method, since bacteria suitable for ripening are imparted to the refrigerated product under refrigeration by using a bacteriostatic filter, the bacteria contained in the refrigerated product and suitable for aging As a result, it became possible to reliably ripen the refrigerated product during refrigeration without adding additives. For example, if the object to be refrigerated is meat, the meat can be softened and the umami can be increased. Moreover, if a to-be-refrigerated thing is a fruit, a fruit can be adjusted to a season taste.

According to the refrigerator and the refrigeration method according to the present invention, since the cold air sterilized by the filter is applied to the object to be cooled in addition to applying the alternating electric field to the object to be cooled, the freshness is obtained only by the alternating electric field. The effect of maintaining the freshness with respect to the object to be cooled can be further enhanced as compared with the refrigerator in which holding is performed.

It is a front view of one embodiment of the refrigerator concerning the present invention. It is a top view of the refrigerator. FIG. 2 is a cross-sectional view taken along line AA in FIG. It is a perspective view which shows the state which looked at one Embodiment of the bacteriostatic filter which is main components of said refrigerator from the diagonal direction. It is a perspective view which shows the state which looked at the filter for bacteriostatic from another diagonal direction. It is a photograph which shows the result of the experiment conducted using the conventional refrigeration method by making a strawberry into a test substance. It is a photograph which shows the result of the experiment conducted using the refrigeration method of this invention using the strawberry as a specimen. It is the photograph which compares and shows the result of the 5th day of the conventional refrigeration method which used lettuce as a sample, and the refrigeration method of this invention. It is the photograph which expands and shows the sample cooled with Daiwa fresh (refrigerator of this invention) in FIG. It is the photograph which expands and shows the sample cooled with the conventional refrigerator in FIG. It is the photograph which compares and shows the result of the 7th day of each conventional refrigeration method of this invention shown in FIG. It is a photograph which shows the result of the other experiment conducted using the conventional refrigeration method by making a strawberry into a test substance. It is a photograph which shows the result of the other experiment conducted using the refrigeration method of this invention by making a strawberry into a test substance. It is a photograph which shows the result of the experiment conducted using the leeks as a specimen and using the conventional refrigeration method. It is a photograph which shows the result of the experiment conducted by using the refrigeration method of the present invention using a green onion as a specimen.

1. Refrigerator, 2. Warehouse wall, 3a, 3b. Door, 4a, 4b. Handle, 5. Shelf, 6. Refrigerated items, 7. Refrigeration equipment (refrigeration means), 8. Radiator, 9. Fan (airflow forming means), 12. Vinyl chloride board, 13. Control box, 14. Power supply, 15. Filter, B. Airflow, S. Refrigerated space

Hereinafter, a refrigerator and a refrigeration method according to the present invention will be described based on embodiments. Of course, the present invention is not limited to this embodiment. In addition, in the drawings attached to the present specification, components may be shown in different ratios from actual ones in order to show characteristic parts in an easy-to-understand manner.

(One embodiment of refrigerator)
FIG. 1 shows a front view of a refrigerator according to the present invention. FIG. 2 shows a plan view of the refrigerator. FIG. 3 shows a cross-sectional view of the refrigerator according to the arrow AA in FIG. In these drawings, the refrigerator 1 of the present embodiment has a warehouse wall 2 that forms a refrigerator compartment inside. The warehouse wall 2 is a rectangular parallelepiped box which seals the inside, and the front surface (the front surface in FIG. 1 and the left surface in FIG. 3) is an open surface.

On the open surface of the warehouse wall 2,

doors

3 a and 3 b are provided over two upper and lower levels.

Handles

4a and 4b are provided on the

doors

3a and 3b. The

doors

3a and 3b are rotatably attached to the storage wall 2 on the side opposite to the side where the

handles

4a and 4b are provided. The user can open and close the

doors

3a and 3b by grasping and pulling or pushing the

handle

4a or 4b.

In FIG. 3, the space surrounded by the storage wall 2 is a refrigeration space S. When the

doors

3a and 3b are closed, the refrigeration space S becomes a sealed space. A plurality of (in this embodiment, three shelves 5 are provided in the refrigeration space S. A vinyl chloride board that is a member for electrical insulation on the entire inner surface of the storage wall 2 and the inner surfaces of the

doors

3a and 3b. The surface of the inner wall 2 is electrically insulated by the action of the vinyl chloride board 12.

Refrigerated objects 6 such as food and ingredients are placed on the shelf 5. In the upper part of the warehouse wall 2, a refrigeration device 7, a radiator (that is, a radiator) 8, a control box 13, and a power source 14 are provided. The control device stored in the control box 13 controls the operation of various electric devices installed with respect to the refrigerator 1. Further, the power source 14 supplies power to various electric devices installed with respect to the refrigerator 1. The refrigeration apparatus 7 as the refrigeration means includes, for example, a condenser (that is, a compressor) and an evaporator (that is, a vaporizer). A fan 9 is provided at the lower part of the refrigeration apparatus 7 as airflow forming means.

The fan 9 blows the cold air formed by the refrigeration device 7 as shown by an arrow B, and forms a cold airflow circulating in the refrigeration space S. Due to the formation of cold air by the refrigeration device 7 and the formation of airflow by the fan 9, the inside of the refrigeration space S is set to a temperature suitable for refrigeration of the article 6 to be refrigerated, for example, a temperature suitable for achieving an ice temperature. The ice temperature is a temperature ranging from around 0 ° C. (temperature at which water freezes) to the freezing point of the object to be refrigerated. A temperature suitable for bringing the object 6 to be cooled to an ice temperature is, for example, minus 5 ° C. to 2 ° C., more preferably minus 3 ° C. to 2 ° C.

The control device in the control box 13 applies an AC voltage to each shelf 5 using the output voltage of the power supply 14. For example, an appropriate voltage appropriately selected from the range of 600V to 2000V is applied. By applying this AC voltage, an alternating electric field is applied to the object 6 to be refrigerated placed in the refrigeration space S. That is, in the present embodiment, the electric field applying means is configured by a combination of the control device in the control box 13, the power supply 14 and the shelf 5.

In addition, the method of applying a voltage for forming an alternating electric field in the refrigeration space S is not limited to a specific method, and an appropriate method is selected as necessary. In the refrigerator 1 of the present embodiment, since the vinyl chloride board 12 is attached to the inner surface of the warehouse wall 2, even if an alternating electric field is generated in the refrigeration space S, current does not flow outside the warehouse, Or it is 1 mA or less by electric current control.

3, a filter 15 is provided at a position below the refrigeration apparatus 7. The filter 15 is provided in the air flow path formed by the fan 9. The filter 15 may be arranged at an arbitrary position in the refrigeration space S as long as it is in the flow path of the airflow.

The filter 15 is a filter functionally capable of bacteriostatic bacteria contained in the airflow. Bacteriostasis is not to kill and reduce bacteria, but to reduce the bacteria by suppressing the growth of bacteria. Bacteria that adversely affect the refrigerated product 6 such as food poisoning bacteria (for example, O-157, Vibrio parahaemolyticus, Salmonella, Norovirus, etc.) may be present in the refrigerator, which is suitable for aging the refrigerated product 6 May be present (for example, bifidobacteria or lactic acid bacteria). The filter 15 appropriately suppresses the presence of food poisoning bacteria and the like, and at the same time, exerts a function of leaving suitable bacteria for aging.

The filter 15 is a sponge-like filter as shown in FIGS. 4 and 5, for example. A sponge-like filter is a porous material in which a fibrous material is closely entangled, and a large number of pores are formed between the fibrous materials. The fibrous material itself is made of copper, or the fibrous material is made of an appropriate material and the surface thereof is covered with copper. Such a copper coating can be formed, for example, by immersing a sponge-like foam in a liquid copper solution.

The filter 15 is not limited to the sponge-like foam as described above, and has an arbitrary structure and an arbitrary shape having a large number of fine pores therein, that is, an arbitrary structure and an arbitrary porous shape. Any material can be used.

As is well known, copper has a bactericidal action, and is particularly effective if a filter formed by arranging copper on the surface of the fine structure of the porous member is placed in the airflow, as in this embodiment. It was found that fungal selectivity can be obtained.

(One embodiment of refrigeration method)
Hereinafter, operation | movement of the refrigerator 1 of the said structure is demonstrated. In FIG. 3, when the user connects the power source 14 to a predetermined power supply source, for example, a commercial power source, a personal power source facility, etc., the refrigeration device 7, the radiator 8, and the fan 9 are activated, and the refrigeration space of the refrigerator 1 The inside of S is cooled, and airflow B is further formed. The refrigeration space S is set in a refrigerated state, particularly in an ice temperature state, for example, in a temperature range of minus 3 ° C. to 2 ° C. The user opens the

doors

3 a and 3 b and places the article 6 to be refrigerated on the shelf 5 in the refrigeration space S of the refrigerator 1. Thereafter, the user closes the

doors

3a and 3b.

In this state, the object to be refrigerated 6 is cooled to the same temperature as the temperature in the refrigeration space S. Specifically, the internal water is cooled to a refrigerated state where it does not freeze. Further, since the power source 14 applies an AC voltage to the shelf 5, an alternating electric field acts on the object 6 to be refrigerated. In this way, the refrigerated object 6 is refrigerated under application of an alternating electric field, whereby the freshness of the refrigerated object 6 is maintained. That is, the object 6 to be refrigerated is kept fresh without rot.

In this embodiment, the object 6 to be refrigerated is exposed to the airflow that has passed through the filter 15. The filter 15 has a property of suppressing the growth of bacteria (for example, food poisoning bacteria) that are contained in the circulating airflow and adversely affect the refrigerated product 6. Thus, in this embodiment, in addition to applying an alternating electric field to the object 6 to be refrigerated, the filter 15 prevents excessive bacteria from being applied to the object 6 to be refrigerated. Can be maintained at a high freshness for an even longer period. That is, this embodiment can achieve a high freshness maintaining effect with respect to the object to be refrigerated 6.

Furthermore, in this embodiment, by using the filter 15, it is possible to suppress the growth of bacteria that are contained in the airflow circulating in the refrigerator and adversely affect the object to be refrigerated 6. Since suitable bacteria (for example, bifidobacteria or lactic acid bacteria) for aging are not sterilized but are left in the air stream to be applied to the refrigerated object 6, the refrigerated object 6 is properly kept in the refrigerated state. Mature. For example, if the object 6 to be refrigerated is meat, the meat becomes soft and umami increases. Moreover, if the to-be-refrigerated thing 6 is a fruit, the fruit will be adjusted to a seasonal taste. That is, this embodiment can achieve an aging effect while refrigerated object 6 is refrigerated.

Ripening effect can also be grasped from the viewpoint as described below. That is, according to the refrigerator and the refrigeration method of the present embodiment, the object to be refrigerated is kept in an ice temperature state. In the ice temperature state, the cells of the object to be refrigerated store antifreeze. This antifreeze contains free amino acids and sugars. Since free amino acids and sugars are also umami components, they can form a seasonal taste with respect to the items to be refrigerated. Moreover, if the thing to be refrigerated is meat, it can be made soft. This is the effect of aging.

(Modification of refrigeration method)
A bag (that is, a packaging material) formed of a film obtained by mixing copper particles in polyethylene is prepared. Or the bag formed with the film formed by mixing a copper particle and a copper oxide particle in polyethylene is prepared. The object 6 to be refrigerated was put in one of these bags. And it put in the space S for refrigeration in the refrigerator 1 in the state which put the to-be-refrigerated thing 6 in the bag. As a result, the object to be refrigerated 6 was surely placed in a bacteriostatic environment, and as a result, the object to be refrigerated 6 was kept fresh and further aged appropriately. Thus, it was confirmed that a synergistic effect was obtained by the combined use of the bacteriostatic filter and the bacteriostatic packaging material. In addition, it can replace with a bag and a container can also be used as a packaging material.

(Other embodiments)
The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications can be made within the scope of the invention described in the claims.

For example, the shape of the refrigerator is not limited to the shape shown in FIGS. 1 to 3, and can be any other shape. Moreover, in FIG. 3, the method for electrically insulating the article 6 to be refrigerated is not limited to attaching the vinyl chloride board 12 to the inner surface of the warehouse wall 2, and any other insulating method can be adopted. Further, the position where the filter 15 is disposed is not limited to the position shown in FIG. 3, and may be any other position on the airflow B. In some cases, the filter 15 does not necessarily have to be on the airflow B as long as the filter 15 is in a position that can prevent bad bacteria from being imparted to the object 6 to be refrigerated.

(Example 1)
Meat was placed in a conventional refrigerator without applying an alternating electric field and without a filter for 3 days. A lot of drip oozes out immediately after placing the meat on the bat. Along with moisture, umami components also flowed out. On the other hand, meat was put in the refrigerator according to the present invention for 3 days. After 3 days, this meat clearly had a good surface color and almost no drip. From this experiment, it was found that freshness retention and aging were properly realized in the refrigerator of the present invention.

(Example 2)
Pork was placed in a conventional refrigerator without applying an alternating electric field and without using a filter for 3 days. On the other hand, pork was put in the refrigerator according to the present invention for 3 days. When both were compared, the appearance did not change much, but the softness and scent differed when eaten. What was put in the conventional refrigerator was a little worried about acidity and smell.

Furthermore, when both were fried in oil and cut into cutlets, the softness was dramatically different. What was refrigerated in the refrigerator of the present invention, that is, aged, was as soft as if it was chewing cotton. This softness represents the result of aging.

(Comparative Example 1)
The sliced loin was placed in Daiwa Fresh (alternating electric field applied, bacteriostatic filter not attached) and thawed. The results are shown in the following table.

In Table 1 above, it was observed that the number of general bacteria increased on the third and fourth days. This indicates that bacteriostasis is not performed normally. That is, it is shown that sufficient bacteriostasis cannot be obtained unless the bacteriostatic filter is attached only by applying an alternating electric field.

Example 3 FIGS. 6 and 7
Strawberries were stored for 20 days in a state where the door was not opened and closed in a conventional refrigerator without applying an alternating electric field and using no filter. On the other hand, the strawberry was stored in the refrigerator according to the present invention for 20 days with the door not opened or closed. When both were compared after the lapse of 20 days, all the strawberries placed in the conventional refrigerator were damaged (see FIG. 6). On the other hand, the strawberry put in the refrigerator according to the present invention had no change in color and a strong sweet scent (see FIG. 7). From this, it can be seen that according to the present invention, freshness retention and aging are achieved.

Example 4
Australian rib rolls and cochlear sirloin were stored for one week in a conventional refrigerator that applied no alternating electric field and no filters. On the other hand, Australian rib rolls and cochlear sirloin were stored in the refrigerator according to the present invention for one week. One week later, the number of viable bacteria, the number of coliforms, the amount of inosinic acid, and the amount of glutamic acid were measured for each meat. The results are shown in the following table.

In the above table and the following description, Daiwa Fresh is the trade name of the refrigerator according to the present invention.

As shown in Table 2, the amount of glutamic acid in the meat refrigerated in the refrigerator of the present invention was significantly high. This indicates that aging is progressing. In addition, although the amount of inosinic acid in meat refrigerated in the refrigerator of the present invention is slightly reduced, if glutamic acid is increased, it is considered that there is no problem with aging.

(Example 5)
1. Purpose of test For the sample "soy milk" (general storage and Daiwa fresh storage), the bacterial test (based on "Food Hygiene Inspection Guidelines") and sugar content (Brix equivalent value) were measured.
2. Exam overview

3. Outline of test method (1) Bacteria test [General bacteria]
1 ml of a soymilk sample was weighed and suspended in 90 ml of sterilized physiological saline (hereinafter referred to as a sample solution), 1 ml was mixed in a standard agar medium, cultured at 35 ° C. for 48 hours, and the appearance colonies were counted. .

[Coliform bacteria]
A sample of 1 ml of soymilk was poured on a desoxycholate agar medium, cultured at 35 ± 1 ° C. for 24 hours, and typical colonies among the appearing colonies were counted.

[Escherichia coli]
A sample of 1 ml of soymilk was poured on a desoxycholate agar medium and cultured at 44.5 ° C. ± 1 ° C. for 24 hours.

(2) Sugar content measurement Soymilk samples were directly measured with a sugar content meter (liquid concentration meter PAL-1; ATAGO). The measurement was performed three times, and the average was defined as sugar content (Brix%).

4). Test results The results shown in the following table were obtained.

As a result of the above, according to refrigeration using Daiwa Fresh (refrigerator of the present invention), the number of general bacteria was smaller than refrigeration using general storage (conventional refrigerator). In addition, Escherichia coli was sometimes detected in general storage, but Escherichia coli was not detected at all in Daiwa Fresh. From the above, it was found that bacteriostasis can be achieved according to the refrigerator and the refrigeration method according to the present invention.

Example 6 Lettuce Freshness Retention Test Test contents Freshly harvested lettuce was stored in Daiwa Fresh and a normal refrigerator. We compared the overgrowth of the cells with respect to their lettuce after storage. In this comparison, freshness maintenance and bacteriostatic effect were examined. In this case, a test was performed on a freshly collected sample without using any chemicals.

2. Test start date: July 12, 2012 3. Test set temperature: 4 ° C
4). Daiwa Fresh Applied Voltage: 2000V
5. Bacteriostatic filter: mounted

6). Situation (1) Comparison after 3 days The leaves on the outside of the lettuce stored in a general refrigerator were picked up. After the first skin of the lettuce was peeled, the touch of the contents was the same as the original. In addition, lettuce with the first skin peeled off was visually fresh. What was stored in Daiwa Fresh had a different feel from the time of purchase, and was visually unchanged from the time of purchase.
(2) Comparison after 5 days (see FIGS. 8, 9, and 10)
The leaf tips outside the lettuce stored in a general refrigerator started to rot and turned brown. The general refrigerator lettuce was crushed as a whole. What was stored in Daiwa Fresh was not inferior to that at the time of purchase.
(3) Comparison after 7 days (see Fig. 11)
In the lettuce stored in a general refrigerator, the leaves melted, and some rot odors began to appear. Moreover, when the lettuce stored in a general refrigerator was touched by hand, the tension was lost. Daiwa Fresh specimens remained similar in color and texture when purchased.

7). Bacterial test results (1) Test purpose Bacteria test was performed on the sample “Letus” (general storage and Daiwa Fresh storage day 7) (general bacteria count and count of E. coli even number “Food hygiene inspection guidelines”).
(2) Outline of the test

(3) Outline of test method ・ Bacteria test [general bacteria]
10 g of a sample was weighed and 1 ml suspended in 90 ml of sterilized physiological saline (hereinafter sometimes referred to as sample solution) was mixed with a standard agar medium and cultured at 35 ° C. for 48 hours. Counted.
[Coliform bacteria]
1 ml of the sample solution was mixed with a desoxycholate agar medium, and after culturing at 35 ± 1 ° C. for 24 hours, typical colonies among the appearing colonies were counted.
(4) Test results The test results shown in the following table were obtained.

From the above experiment, the number of general bacteria and the number of coliforms were reduced in Daiwa Fresh samples, which indicates that bacteriostasis was performed. In addition, through comparative observation over time, it was found that freshness retention and aging were achieved with Daiwa Fresh samples.

Example 7 FIGS. 12 and 13
Strawberries were stored for 10 days under the condition that the door was opened and closed in a normal use state in a conventional refrigerator without applying an alternating electric field and without using a filter. On the other hand, strawberries were stored for 10 days on the condition that the door was opened and closed in a normal use state in the refrigerator according to the present invention (Daiwa Freshy = alternating electric field applied, bacteriostatic filter mounted). What was put into the conventional refrigerator generate | occur | produced the mold | fungi from the 5th day after the test start (refer FIG. 12). On the other hand, what was put in Daiwa Fresh had no change and the fragrance was firm (see FIG. 13).

Example 8 FIGS. 14 and 15
The leeks were stored for 15 days in a conventional refrigerator where no alternating electric field was applied and no filter was used. On the other hand, the leeks were stored for 15 days in the refrigerator (Daiwa Fresh = alternating electric field applied, bacteriostatic filter mounted) according to the present invention. When both were compared after the lapse of 15 days, the freshness of the green onions stored in the conventional refrigerator was lost (see FIG. 14). There was no change at all (see FIG. 15).

Example 9 Net Melon Freshness Maintenance Test Details of the test The Furano melon (King Ruby) harvested on July 3, 2012 is quickly picked up and stored at room temperature and Daiwa Fresh low / medium temperature for one month, and then a freshness comparison test is conducted.

2. Test start date: July 4, 2012

3. Temperature A: Test set temperature (Daiwa Fresh): 12 ° C
B: Test set temperature (Daiwa Fresh α): 2 ° C
C: Test set temperature: normal temperature

4). Voltage A: Daiwa Fresh Applied Voltage: 2000V
B: Daiwa Fresh α applied voltage: 2000V
C: No applied voltage

5. Bacteriostatic filter A: No bacteriostatic filter installed B: Bacteriostatic filter installed C: Bacteriostatic filter not installed

6). Situation (1) Comparison after 10 days There is no significant change in both the A sample and the B sample, but the net color of the A sample seems to be slightly faded. The C specimen is completely faded, and the place where it was placed is slightly softened as a whole.
(2) Comparison after 21 days Sample A and sample B clearly differed. Specifically, the specimen A was soft overall, and the color of the net was faded at portions other than the circumference. Sample B was bluish and well touched. Sample C was completely rotted and the portion held by the hand was depressed, making it impossible to continue and the observation was stopped.
(3) Comparison after 34 days The surface of the specimen A was slightly discolored and the touch was soft. The sample B was partially discolored, but the greenness remained. The sample A had begun to melt the cotton part, but it felt no problem as aging. Specimen B was cotton and was in an optimal condition. Compared to Sample B, Sample A was slightly overripe and had a fiber texture, but both were eaten without problems.

(Example 10) Domestic pork loin freshness maintenance test Test Contents Domestic pork loin slaughtered on July 9, 2012 was stored in a refrigerator at 0 ° C. to 2 ° C. for 1 day. This domestic pork loin was sliced on July 10, 2012. The sliced pork loin was purchased as a specimen on July 12. This purchased specimen was stored in Daiwa Fresh (alternating electric field applied, bacteriostatic filter attached) and refrigerator for one week to examine the cells.

2. Test start date: July 12, 2012 3. Test set temperature (Daiwa Fresh): 2 ° C
4). Test set temperature (refrigerator): 2 ° C
5. Daiwa Fresh Applied Voltage: 2000V
6). Bacteriostatic filter: mounted

7). Situation (1) Comparison after 3 days Although there was no difference between the two specimens, the refrigerator was slightly discolored.
(2) Comparison after 5 days The discoloration of the sample in the refrigerator became clear and the surface was brilliant with oil and had a slightly oxidized odor. On the other hand, Daiwa Fresh specimens did not change visually or smell.
(3) Comparison after 7 days The specimen of the refrigerator had a sticky surface, changed to brown, and had an odor of oxidation. Daiwa Fresh specimens were almost unchanged.

8). Bacterial cell inspection (1) Test purpose Bacteria test (general bacteria count and E. coli even count "food hygiene inspection guidelines" compliant) was performed on the specimen "pork" (general storage and Daiwa fresh storage 7th day).
(2) Outline of the test

(3) Outline of test method / Bacteria test [General test]
10 g of sample is weighed, 1 ml of suspension in 90 ml of sterilized physiological saline (hereinafter sometimes referred to as “sample solution”) is mixed with standard agar medium, cultured at 35 ° C. for 48 hours, and colonies appearing are counted. did.
[Coliform bacteria]
1 ml of the sample solution was poured on a desoxycholate agar medium, cultured at 35 ± 1 ° C. for 24 hours, and typical colonies among the appearing colonies were counted.
(4) Test results The results shown in the following table were obtained.

Claims

In a refrigerator that refrigerates items to be refrigerated placed in a refrigeration space,
A warehouse wall forming the refrigeration space and having electrical insulation;
Refrigeration means for bringing the object to be refrigerated into an ice temperature state;
An airflow forming means for forming an airflow in the refrigeration space;
Electric field applying means for applying an alternating electric field to the object to be refrigerated placed in the refrigeration space;
A refrigerator having a filter disposed in the airflow formed by the airflow forming means and bacteriostatic for bacteria contained in the airflow.
The filter is a porous substance which is a substance having a large number of fine pores therein, and the material forming the pores is copper or a material formed by coating copper on the surface. The refrigerator according to claim 1.
The filter is a sponge-like foam having a large number of holes inside,
3. The refrigerator according to claim 2, wherein the copper is fibrous copper, or the material obtained by coating copper on the surface is a fibrous material.
The refrigerator according to any one of claims 1 to 3, wherein the airflow forming means is a fan that is driven and rotated by an electric motor.
The electric field applying means forms an alternating electric field by applying an alternating voltage within a range of 600 to 2000 volts,
The refrigerator according to any one of claims 1 to 4, wherein a current value flowing through the storage wall is 1 mA or less by the storage wall having the electrical insulation when the voltage is applied.
Place the item to be refrigerated in a refrigeration space surrounded by a wall with electrical insulation,
Set the inside of the refrigeration space at ice temperature,
Applying an alternating electric field to the object to be refrigerated;
Forming an airflow passing through the object to be refrigerated in the refrigeration space;
A filter capable of acting as a bacteriostatic is disposed in the flow path of the airflow,
A refrigeration method, wherein the object to be refrigerated is aged while being refrigerated.