JP2011058670A - Refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an improved structure of a refrigerator storing food in a freezing temperature zone, which has been difficult in the conventional structure, for the optimal refrigeration storage of food including meat and fish. <P>SOLUTION: The refrigerator includes a storage chamber and a refrigeration cycle inside its body and is formed with a cold air passage for guiding cold air from the refrigeration cycle to the storage chamber. The refrigerator is equipped with a chamber provided at a part of the storage chamber and having a space with its inside sealed from the outside, and uses, so-called, a low pressure chamber which is indirectly cooled by the refrigeration cycle to allow storage in the optimal freezing temperature zone for refrigeration storage of food. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a refrigerator, and more particularly to a refrigerator having a structure capable of suppressing deterioration of nutrient components and cells in accordance with a freezing temperature of food.

  Foods are oxidized by reacting with oxygen in the air during storage. In particular, unsaturated fatty acids such as DHA and EPA that are often contained in fish, some amino acids contained in meat, vitamin C contained in vegetables, and the like are lost by contact with oxygen in the air. Therefore, many techniques for preventing the oxidation of nutrient components by reducing the oxygen concentration by utilizing a vacuum pack, an antioxidant, or the like are routinely incorporated.

  As an example thereof, conventionally, for example, as known from Patent Document 1 below, the air in a sealed container in a refrigerator is sucked using a vacuum pump, thereby reducing the amount of oxygen in the container, There is a refrigerator that suppresses deterioration due to oxidation. That is, the refrigerator described in Patent Document 1 uses a room temperature as a refrigerated temperature zone from the viewpoint of preventing freezing of food, and improves the function of maintaining the freshness of food such as fish meat, dairy products, vegetables, and fruits. .

JP 2009-8292 A

  However, in the refrigerator according to the prior art described above, the temperature zone of the low-pressure chamber is set to a so-called refrigeration temperature zone, so that it can store fruits, vegetables, dairy products and the like whose freezing temperature is around 0 ° C. However, since meat and fish have less moisture than vegetables and the like, it has not always been an appropriate temperature setting for these.

  In general, as for the temperature range at the time of food storage, as long as the food is not frozen, the lower the temperature, the more the activity of the enzyme in the food is suppressed, so that the preservation is improved. If the activity of enzymes in food is suppressed, the degradation by the enzymes does not occur and there are few biological reactions, so it is possible to suppress the reduction of nutrient components.

  According to various studies by the inventors of the present invention, the following has been found. Nucleotides (ATP, ADP, etc.) contained in fresh fish and shellfish are degraded during storage, and in particular, fish mainly become IMP. If the decomposition further proceeds, it becomes inosine or hypoxanthine, which causes taste. Phospholipids are more easily decomposed during refrigeration than neutral lipids, produce free fatty acids, and cause food oxidation and protein denaturation. Therefore, the enzyme reaction is suppressed by storing at a lower temperature and at a temperature of 0 ° C. to −1 ° C. (hereinafter referred to as “ice temperature temperature zone”) in which meat and fish are not frozen. It becomes possible to improve the preservation.

  On the other hand, the temperature of each storage room of the refrigerator rises with the opening and closing of the door, defrosting, etc., or is uneven due to local cooling by cold air outlets installed at several places and on / off of the compressor It is difficult to adjust the temperature to an appropriate temperature. In particular, when trying to store the above-mentioned ice temperature, it is a problem that it is actually difficult to control the temperature of a predetermined region inside the refrigerator at a constant temperature (that is, an ice temperature temperature range). It was. In particular, the ice temperature temperature range of 0 ° C. to −5 ° C. is also the maximum ice crystal formation zone where ice crystals in foods are most likely to grow. Will be destroyed and damage is likely to occur. That is, if the temperature fluctuation is large in this ice temperature temperature zone, the food is repeatedly frozen and thawed, and small ice crystals present in the cells move out of the cells and bind to each other to form large crystals. Because of this property, the point that ice crystals grow greatly has been a problem.

  Thus, according to the storage in the ice temperature range described above, on the one hand, the growth of the bacteria is suppressed, but on the other hand, if the temperature fluctuation is large, the food is recrystallized during storage. The cells are damaged by the effect of such as. For this reason, there is a problem that the so-called drip flows out and the umami component is reduced, or the texture is lowered (for example, rustling) because moisture is removed from the food.

  In addition, especially in the case of directly cooled storage rooms, dry air hits the food surface, promoting drying and causing discoloration of the food surface. As a result of air becoming more likely to enter cells that have become dry and have a large surface area, there is a possibility of causing a change in freshness such as promotion of lipid oxidation.

  Therefore, the present invention has been made in view of the above-mentioned problems in the prior art, and more specifically, by adopting the above-mentioned ice temperature temperature range, it is possible to optimize foods including meat and fish. It is an object of the present invention to provide a refrigerator having an improved structure for enabling refrigerated storage.

  In order to achieve the above object, according to the present invention, first, a cold air passage having a plurality of storage chambers and a refrigeration cycle in the main body and guiding cold air from the refrigeration cycle to the plurality of storage chambers. In the refrigerator formed, at least a part of the plurality of storage chambers is provided with a chamber having a space sealed inside with respect to the outside, and the room temperature of the low-pressure chamber is set to ice by the refrigeration cycle. The refrigerator which comprised the said cold air | gas channel | path so that setting to a temperature zone is possible is provided.

  In the present invention, in the refrigerator described above, it is preferable that the cold air passage is configured to indirectly cool the chamber having a sealed space inside, and further, the cold air passage has an internal pressure thereof. It is preferable that the low-pressure chamber is lower than the external pressure, and includes a decompression unit that decompresses the low-pressure chamber.

  Furthermore, according to the present invention, in the refrigerator described above, the low-pressure chamber can be configured to selectively set the room temperature between the ice temperature temperature zone and the chilled temperature zone. Further, it is preferable that the low-pressure chamber controls the pressure after depressurization to 0.7 to 0.9 atm. Furthermore, it is preferable to control the humidity in the low-pressure chamber to 70% to 99%, and it is preferable to further have a decompression means for reducing the oxygen concentration in the low-pressure chamber.

  In addition, according to the present invention, in the refrigerator described above, the low-pressure chamber controls the operation of a damper device provided in a part of the cold air passage to thereby control the ice temperature temperature range and the chilled temperature. Preferably, the low-pressure chamber includes a heater, a temperature sensor that detects the temperature in the low-pressure chamber, and a temperature adjustment unit that adjusts the temperature in the low-pressure chamber. And a control device that controls the operation of the heater and the damper device based on the temperature detected by the temperature sensor and the temperature adjusted by the temperature adjusting unit. . Moreover, it is preferable that the said control apparatus controls the temperature in the said low voltage | pressure chamber so that it may be in the temperature fluctuation width of +/- 1 degreeC of the said setting temperature.

  According to the refrigerator according to the present invention described above, it is possible to adopt an ice temperature temperature range that has been difficult with the conventional structure, and thus to improve the optimal refrigeration storage of food including meat and fish It becomes possible to provide the refrigerator provided with the structured. Furthermore, according to the present invention, the low-pressure chamber can be switched between the chilled temperature zone and the ice temperature temperature zone by the stored food. In addition, temperature fluctuations that have been a problem when storing food in the ice temperature range can be reduced by reducing the convection of the cold air by reducing the pressure in the low-pressure chamber, and by suppressing the temperature fluctuation by indirectly cooling the low-pressure chamber. It is possible to suppress the influence on the food cells due to the growth of ice crystals. Moreover, since indirect cooling is performed with a hermetically sealed structure, it is possible to store while keeping the humidity constantly high, and it is possible to dry / discolor food, inhibit lipid oxidation, and the like.

It is a center longitudinal cross-sectional view of the refrigerator which becomes one embodiment of this invention. It is a cross-sectional perspective view of the lowermost space part of the refrigerator compartment shown in the said FIG. It is a front view of the back panel of the refrigerator compartment shown in the said FIG. It is a control block diagram which shows the content of the control in the refrigerator which becomes the said this Embodiment. It is a figure which shows the measurement result of the vitamin C of broccoli which changes with the difference in storage temperature and cooling structure. It is a figure which shows the result of having calculated | required the porosity by observing the beef cell after storing for 3 days by SEM based on the difference in cooling structure (temperature fluctuation width), image-processing, extracting ice particle | grains.

  Hereinafter, a refrigerator according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  First, the structure of the refrigerator according to the present invention will be described with reference to FIGS. FIG. 1 is a central longitudinal sectional view of the refrigerator of the present embodiment, and FIG. 2 is a sectional perspective view of a lowermost space portion of the refrigerator compartment shown in FIG.

  As is clear from these drawings, the refrigerator includes a refrigerator body 1 and a plurality of doors 6 to 9 provided on the front surface thereof. The refrigerator body 1 is composed of a steel plate outer box 11, a resin inner box 12, a urethane foam heat insulating material 13 and / or a vacuum heat insulating material (not shown) filled therebetween, From the top of the figure, a plurality of storage rooms are formed in the order of the refrigerator compartment 2, the freezer compartments 3 and 4, and the vegetable compartment 5. In other words, the refrigerator compartment 2 is arranged at the top and the vegetable compartment 5 is divided and arranged at the bottom, and both the compartments are provided between the refrigerator compartment 2 and the vegetable compartment 5. Freezer compartments 3 and 4 that are thermally partitioned from each other are disposed. The refrigerator compartment 2 and the vegetable compartment 5 are storage compartments in a refrigeration temperature zone, and the freezer compartments 3 and 4 are storage compartments in a freezing temperature zone of 0 ° C. or lower (for example, a temperature zone of about −20 ° C. to −18 ° C.). It is. These storage chambers 2 to 5 are partitioned by partition walls 33, 34, and 35.

  As described above, doors 6 to 9 are provided on the front surface of the refrigerator body 1 in order to close the front opening portions of the plurality of storage chambers 2 to 5, respectively. The refrigerator compartment door 6 closes the front opening of the refrigerator compartment 2, the freezer compartment door 7 closes the front opening of the freezer compartment 3, and the freezer compartment door 8 closes the front opening of the freezer compartment 4. The vegetable compartment door 9 is a door that closes the front opening of the vegetable compartment 5. Moreover, the refrigerator compartment door 6 is comprised of a double door with double doors, and the freezer compartment door 7, the freezer compartment door 8, and the vegetable compartment door 9 are comprised of drawer type doors. The structure is drawn out.

  The refrigerator body 1 having the above-described structure is provided with a refrigeration cycle. This refrigeration cycle includes a compressor 14, a condenser (not shown), a capillary tube (not shown) and an evaporator 15, and again a compressor 14 connected in that order. The compressor 14 and the condenser are installed in a machine room provided at the lower back of the refrigerator body 1. The evaporator 15 is installed in a cooler room provided behind the freezing rooms 3 and 4, and a blower fan 16 is installed above the evaporator 15 in the cooler room.

  The cold air cooled by the evaporator 15 is sent to each storage room such as the refrigerator compartment 2, the freezer compartments 3, 4 and the vegetable compartment 5 by a blower fan 16 through a cold air passage (not shown). Specifically, a part of the cold air sent by the blower fan 16 is sent to a storage room in the refrigeration temperature zone of the refrigeration room 2 and the vegetable room 5 via a damper that can be opened and closed. The part is sent to the freezer compartment 3 and the storage compartment of the freezing temperature zone.

  The cool air sent to the storage rooms of the refrigerator compartment 2, the freezer compartments 3 and 4 and the vegetable compartment 5 by the blower fan 16 is returned to the cooler compartment through the cool air return passage after cooling each storage compartment. . Thus, the refrigerator which becomes this Embodiment has the circulation structure of cold air, and maintains each store room 2-5 at a suitable temperature.

  Moreover, in the refrigerator compartment 2, the multistage shelf 17-20 comprised with a transparent resin board is installed so that removal is possible. The lowermost shelf 20 is installed so as to be in contact with the back surface and both side surfaces of the inner box 12 and divides a so-called lowermost space 21, which is a lower space, from the upper space. Further, a plurality of door pockets 25 to 27 are installed inside each refrigerator compartment door 6, and these door pockets 25 to 27 protrude into the refrigerator compartment 2 with the refrigerator compartment door 6 being closed. It is provided as follows. A back panel 30 that forms a passage through which the cool air supplied from the blower fan 16 passes is provided on the back of the refrigerator compartment 2.

  As is apparent from FIG. 2, the lowermost space 21 is, in order from the left, an ice-making water tank 22 for supplying ice-making water to the ice-making tray in the freezer compartment 3, and a storage case for storing food such as desserts. 23, low-pressure chambers 24 are provided for maintaining the freshness of food and storing it for a long period of time by reducing the pressure inside the chamber. The low-pressure chamber 24 has a width that is narrower than the width of the refrigerator compartment 2, and is disposed adjacent to the side surface of the refrigerator compartment 2. As is clear from the drawing, the low-pressure chamber 24 is surrounded by walls and doors so as to be airtight, so that the internal atmospheric pressure can be lowered from the outside.

  The ice making water tank 22 and the storage case 23 are arranged behind the refrigerator compartment door 6 (FIG. 1) on the left side of FIG. Thereby, the ice making water tank 22 and the storage case 23 can be pulled out only by opening the left refrigerator compartment door 6. Further, the low pressure chamber 24 is disposed behind the refrigerator compartment door 6 on the right side of the drawing. Thereby, the food tray 60 of the low pressure chamber 24 can be pulled out only by opening the right refrigerator compartment door 6. In FIG. 1, the ice making water tank 22 and the storage case 23 are located behind the lowermost door pocket 27 of the refrigerator compartment door 6, and the low pressure chamber 24 is also provided in the refrigerator compartment door. It will be located behind the door pocket 27 of the 6th lowest stage.

  Next, details of the back panel 30 shown in FIG. 1 will be described with reference to FIG. The rear panel 30 includes a cold air discharge port (first cold air discharge port) 31 for supplying cold air to the refrigerating chamber 2 and a low pressure chamber cooling for supplying cold air to the lowermost space 21 of the refrigerating chamber 2. A cold air discharge port (second cold air discharge port) 32 and a cold air return port 33 are provided. The cold air return port 33 is provided on the back side of the low pressure chamber 24 on the side close to the side surface of the refrigerator compartment 2.

  The cool air discharge port 32 is provided toward the gap between the upper surface of the low-pressure chamber 24 and the lower surface of the shelf 20. The cold air discharged from the cold air discharge port 32 flows through the gap between the upper surface of the low-pressure chamber 24 and the lower surface of the shelf 20, and cools the low-pressure chamber 24 from the upper surface. Accordingly, the inside of the low pressure chamber 24 is indirectly cooled.

  Further, a damper device 41 for controlling the flow of cold air into the low pressure chamber 24 is provided upstream of the cold air discharge port 32. The opening and closing of the damper device 41 is controlled by a control device (not shown), and thereby the amount of cold air supplied to the low pressure chamber 24 is controlled.

  Further, as shown in FIG. 1, for example, a heater 43 is provided to raise the temperature in the low pressure chamber 24. The heater 43 is provided on the lower projection surface in the low-pressure chamber 24. In this example, the heater 43 has a substantially same area as the bottom surface in the low-pressure chamber 24.

  Here, the low pressure chamber 24 is disposed close to the right side surface of the refrigeration chamber 2 to eliminate the gap on the right side of the low pressure chamber 24, and a shelf (partition wall) (not shown) is provided at the left end of the upper surface of the low pressure chamber 24. Since the gap on the left side of the low pressure chamber 24 is eliminated, the cold air discharged from the cold air discharge port 32 flows on the upper surface of the low pressure chamber 24 without being diverted to the left and right sides of the low pressure chamber 24. Thus, the inside of the low pressure chamber 24 can be cooled quickly by increasing the amount of cool air that cools the upper surface of the low pressure chamber 24. The cool air that has cooled the upper surface of the low pressure chamber 24 is sucked into the cool air return port 33 from the front of the low pressure chamber 24 through the left side surface of the low pressure chamber 24, and returned to the cooler chamber through the cool air return passage. Since the cold air return port 33 is provided on the rear side of the low pressure chamber 24 and on the side close to the side surface of the refrigerator compartment 2, the cold air comes into contact with the rear surface and the left side surface of the low pressure chamber 24 to cool it.

  In this way, the low pressure chamber 24 is indirectly cooled by the cold air passing through the outside thereof. Therefore, by reducing the convection of the cold air by reducing the pressure, and by indirect cooling in the closed container, against the effects of compressor on / off, temperature rise such as opening and closing of the refrigerator door and defrosting However, it is possible to suppress the adverse effect on the internal temperature and maintain a constant temperature and high humidity. The cold air that has cooled the entire refrigerator compartment 2 is also sucked into the cold air return port 33.

  An ice making water pump 28 is installed behind the ice making water tank 22. A negative pressure pump 29, which is an example of a decompression device for decompressing the low pressure chamber 24, is disposed behind the storage case 23 and in a space behind the low pressure chamber 24. The negative pressure pump 29 is in contact with a pump connection portion provided on the side surface of the low pressure chamber 24 via a conduit.

  Further, as shown in FIG. 2, the low-pressure chamber 24 described above includes a box-shaped low-pressure chamber body 40 having an opening for taking in and out food (opening-out opening for food), and the food in and out of the low-pressure chamber main body 40. The low-pressure chamber door 50 that opens and closes the opening for food use, and the food tray 60 that accommodates food in the interior and passes the low-pressure chamber door 50 into and out of the low-pressure chamber are configured. That is, in the low-pressure chamber main body 40, the space surrounded by the low-pressure chamber main body 40 and the low-pressure chamber door 50 is formed as a low-pressure space that is depressurized by closing the food loading / unloading opening of the low-pressure chamber door 50. The food tray 60 is attached to the back side of the low pressure chamber door 50 and can be moved back and forth as the low pressure chamber door 50 moves.

  In addition, an antioxidant component release cassette 80 containing an antioxidant 81 (not shown) is installed inside the low pressure chamber 24. In other words, in the low-pressure chamber 24 for storing fresh foods such as vegetables, meat, and fish, an antioxidant component release cassette 80 containing an antioxidant 81 for preventing oxidation loss due to oxygen in the air inside is stored. is set up. As shown in FIG. 2, the antioxidant component release cassette 80 is detachably attached to the back wall portion of the food tray 60. As the anti-oxidant 81, an anti-oxidant that does not release the anti-oxidant component under the atmospheric pressure group and releases the anti-oxidant component under the pressure state lower than the atmospheric pressure is used. That is, the antioxidant 81 contained in the antioxidant component release cassette 80 depressurizes the inside of the low pressure chamber 24, thereby reducing the pressure inside the antioxidant component release cassette 80 and the pressure outside the antioxidant component release cassette 80. The antioxidant component is released due to the pressure difference.

  The low pressure chamber 24 is placed in a closed state by placing food on the food tray 60 and closing the low pressure chamber door 50. Further, the door switch is turned on and the negative pressure pump 29 is driven, and the low pressure chamber 29 is driven. 24 is depressurized to a state lower than atmospheric pressure. Thereby, the oxygen concentration in the store room 13 can fall and deterioration of the nutrient component in a foodstuff can be prevented.

  Moreover, after the low pressure chamber 24 is sealed and decompressed, the release of the antioxidant component from the antioxidant 81 is started, so that the antioxidant is contained in the low pressure chamber 24 of the limited volume. It is possible to prevent the binding of nutritional components in the food and oxygen due to the components. As a result, the antioxidant component release cassette 80 can be downsized, the negative pressure pump 29 can be downsized, the strength of the casing of the low pressure chamber 24 can be reduced, and the food storage space can be increased and the cost can be reduced. Oxidative deterioration of nutritional components in the food stored in the chamber 24 can be prevented over a long period of time.

  Then, by pulling the low-pressure chamber door 50 forward, first, the pressure release valve provided in a part of the low-pressure chamber door 50 is operated to release the low-pressure chamber 24 from the reduced pressure state. The low pressure chamber door 50 can be opened due to the atmospheric pressure. As a result, the low pressure chamber door 50 can be easily opened and food can be taken in and out.

  Next, the temperature switching control means in the refrigerator according to the present invention will be described with reference to FIG. In addition, this FIG. 4 is a control block diagram which shows schematic structure of the control means of the refrigerator which becomes a present Example.

  In the figure, for example, a temperature control device 45 constituted by a microcomputer or the like is between a temperature detected by a temperature sensor 42 that detects the internal temperature of the low-pressure chamber 24, and between an ice temperature temperature range and a chilled temperature range. The temperature set by the switchable temperature adjusting unit 44 is input, that is, a control signal is output to the damper device 41 and the heater 43 based on those temperatures.

  More specifically, when the temperature detected by the temperature sensor 42 is low, the amount of cold air is controlled (suppressed) by decreasing the opening degree of the damper device 41 or by closing it completely. When the temperature becomes too low, the heater 43 is energized to increase the temperature. When the temperature detected by the temperature sensor 42 is too high, the opening degree of the damper device 41 is increased, so that cool air is supplied to the cool air circulation space in the low pressure chamber 24 to lower the temperature in the low pressure chamber 24.

  Furthermore, in order to improve the usability of the low-pressure chamber, by disposing a temperature switching operation panel on the refrigerator door 6, the user can easily open the door via the temperature adjustment unit 44 without opening the door. Temperature switching is possible. At the time of operation, it is also possible to notify the user of the temperature zone by switching the position of the light that is lit at each temperature.

  Furthermore, the relationship between the freezing temperature of food and nutrient components will be described with reference to FIG. In addition, the foodstuff put into a chilled temperature range here has many water | moisture contents and is therefore easy to freeze, for example, vegetables, dairy products, processed foods, etc. are mentioned. Generally, vegetables have a water content of about 90%, and the freezing point is 0 ° C to -1 ° C. In addition, it is considered effective to maintain quality when the temperature during storage is as close as possible to the freezing temperature.

  FIG. 5 shows the relationship between the storage temperature of vegetables and vitamin C. As an example of vegetables, broccoli, which contains a lot of vitamin C, has a high respiration rate, and is suitable for cold storage, was used. The initial moisture content of this broccoli is 91%. The freezing point is -0.6 ° C. As conditions at the time of storage, the air temperature of the storage room is set every 1 ° C. from −2 ° C. to 1 ° C., stored for 4 days under reduced pressure and atmospheric pressure, and then the residual rate of vitamin C in the vegetables % Comparison. In each case, the initial residual rate was calculated as 100%.

  In the bar graph of the figure, reference numeral 51 denotes a residual ratio of vitamin C when stored at a temperature of −2 ° C. and under reduced pressure, and 52 denotes a vitamin when stored at a temperature of −1 ° C. and under reduced pressure. The residual ratio of C, 53 is the residual ratio of vitamin C when stored at a temperature of 0 ° C. and under reduced pressure, and 54 is the residual ratio of vitamin C when stored at a temperature of 1 ° C. and under reduced pressure , 55 is a temperature at −2 ° C., but the residual rate of vitamin C when stored at atmospheric pressure, 56 is a temperature at a temperature of −1 ° C., but when stored at atmospheric pressure, the residual rate of vitamin C , 57 is a temperature at 0 ° C., but the residual ratio of vitamin C when stored at atmospheric pressure, and 58 is a temperature at 0 ° C. and the residual ratio of vitamin C when stored at atmospheric pressure, respectively. Show.

  In addition, when the effect of freezing was confirmed after storage, freezing was partially observed under conditions of a temperature of −1 ° C. or lower. Moreover, according to FIG. 5, since vitamin C of vegetables has the largest remaining amount at 0 ° C. both under reduced pressure and atmospheric pressure, the decrease in vitamin C is suppressed if stored at low temperature unless it is frozen. It was confirmed that the effect of This is presumably because storage at a low temperature reduces the respiratory action of the vegetables, thereby reducing the consumption of the components in the vegetables and thus suppressing the deterioration of vitamin C. Moreover, it can be said that the storage under reduced pressure has the effect of suppressing the deterioration of vitamin C compared to the storage under atmospheric pressure.

  This is considered to be because the oxygen concentration is reduced by reducing the pressure, the oxidation of vitamin C is suppressed, and further, the respiration rate is also reduced, thereby suppressing the deterioration of vitamin C. In addition, after freezing, the tendency for vitamin C to decrease due to damage to cells was confirmed, and as a result, non-uniformity (variation) in the value of vitamin C occurred depending on the presence or absence of freezing. As mentioned above, since vegetables may freeze in the temperature range of 0 degreeC--1 degreeC, it is desirable to preserve | save above this chilled temperature.

  Next, as an example, beef was preserved, and the effect of the temperature / cooling structure on the cells was confirmed. As described above, it is important that the ice temperature is stored in a very narrow temperature range. If the temperature fluctuation is large, the food is repeatedly frozen and thawed, and rather the quality is deteriorated. Therefore, the preservation of the meat in the ice temperature region was confirmed at the cell level. In addition, as the method, the inside of beef was observed with SEM (low vacuum electron microscope), and the deterioration of the meat quality by the production | generation of an ice crystal was compared.

  SEM observations were conducted in three cases: (1) initial stage, (2) under reduced pressure (however, temperature = −1 ° C., temperature fluctuation ± 0.5 ° C.), (3) under atmospheric pressure (however, temperature = −1 ° C.) Comparison was made at a temperature variation of ± 2.0 ° C.). As an observation method, the SEM observation image was subjected to image processing, and the porosity of muscle cells was obtained. The result of image processing based on the SEM image thus obtained and the calculation result of the obtained cell porosity are shown in FIG.

  From FIG. 6, the cell porosity was 34.7% on average at the initial stage (before storage), 39.2% under reduced pressure, and 56% at atmospheric pressure. That is, the porosity after storage is larger than the initial value, and the deterioration is progressing. However, comparing the two after storage, the vacuum clearly showed the effect of reducing the generation of voids (number and size of pores, gaps between cells, etc.).

  When the temperature under reduced pressure = −1 ° C., the temperature fluctuation is in the range of ± 0.5 ° C., and the influence on the cell tissue is small. However, when the temperature under atmospheric pressure = 1 ° C., the temperature fluctuation is ± 2 ° C. Since the temperature is as high as 0.0 ° C., it is considered that the ice crystals grew greatly as a result of repeated freezing and thawing of water, and the tissue was greatly damaged. From the size of the vacancies in the image in the figure, it is considered that the intracellular freezing is apparently caused under atmospheric pressure because the vacancies in the cells are large.

  In addition, the number and size of vacancies that cause crispy texture and umami degradation when eating beef is more suppressed when stored under reduced pressure. In particular, it is considered that by performing the indirect cooling structure to suppress the adverse effect due to the temperature and storing at high humidity, it is possible to perform the storage that suppresses the cell destruction due to the growth of ice crystals on the food cells. In addition, by suppressing cell destruction, it is possible to suppress the drip of the savory component that flows out during thawing, and it is also possible to thaw deliciously.

  According to the above, even in a temperature range called the ice temperature range where the temperature control is difficult, the low-pressure chamber described above is hermetically sealed by closing the low-pressure chamber door. The internal temperature does not fluctuate easily by opening and closing, and by reducing the internal pressure, so-called indirect cooling that suppresses convection of cold air inside the internal air can be suppressed. Therefore, it is possible to suppress the cell influence due to the growth of ice crystals of food and to keep its freshness and quality good.

  In addition, in the case of so-called partial freezing, which lowers the temperature after switching from the ice temperature temperature zone, some of the water in the food freezes, causing concentration of components inside and outside the cell, and microorganisms It becomes difficult to breed. That is, the storage period becomes longer, but since the generation and growth of ice crystals are repeated during storage, the cells are damaged with the passage of time, and the taste when eaten slightly decreases. Therefore, when cooking in 2 or 3 days, store at the above-mentioned ice temperature temperature range, or when storing for about a week without eating immediately, store at the above-mentioned partial freezing temperature range. Thus, it is preferable to properly use them appropriately.

  Furthermore, in some vegetables and fruits, when stored at several to 10 ° C., abnormalities occur in the state of the biological membrane and the function of the cells is destroyed, so-called browning, tissue softening, pitting, etc. Some cause cold injury. Therefore, for such summer vegetables such as cucumbers and eggplants, by setting the temperature of chilled switching higher, it is possible to maintain the freshness without causing the above-mentioned low-temperature failure. .

  In addition, when storing meat and vegetables at the same time, it is desirable to switch to a chilled temperature range and store them in consideration of the effects of freezing. In addition, when storing food in the above-described low-pressure chamber that is stored in a sealed bag or the like and the bag expands under reduced pressure, the vacuum pump is operated by, for example, releasing the reduced-pressure mode. It is also possible to store without storage, and according to this, the storage bag can be safely and efficiently stored while suppressing the expansion and rupture of the storage bag and further adverse effects on other foods.

DESCRIPTION OF SYMBOLS 1 ... Refrigerator body, 2 ... Refrigeration room, 3 ... Freezing room, 3, 4 ... Freezing room, 5 ... Vegetable room, 6 ... Cold room door, 7, 8 ... Freezing room door, 9 ... Vegetable room door, 11 ... Outside Box, 12 ... Inner box, 13 ... Foam insulation, 14 ... Compressor, 15 ... Evaporator, 16 ... Blower, 17-20 ... Shelf, 21 ... Bottom space, 22 ... Ice making water tank, 23 ... Storage case 24 ... Low pressure chamber, 25-27 ... Door pocket, 28 ... Ice-making water pump, 29 ... Negative pressure pump, 30 ... Back panel, 31 ... First cold air outlet, 32 ... Second cold air outlet, 33 ... Cold air return port, 34 to 36 ... partition wall, 37 ... cold air return passage,
40 ... Low pressure chamber body, damper device ... 41, temperature sensor ... 42, heater ... 43, temperature control unit ... 44, control device ... 45, 50 ... low pressure chamber door, 60 ... food tray, 80 ... antioxidant component release cassette.

Claims (10)

In the main body, a refrigerator having a plurality of storage chambers and a refrigeration cycle, and forming a cold air passage for guiding cold air from the refrigeration cycle to the plurality of storage chambers,
At least a part of the plurality of storage chambers is provided with a chamber having a space hermetically sealed with respect to the outside, and
The refrigerator is characterized in that the cold air passage is configured so that the indoor temperature of the low pressure chamber can be set to an ice temperature temperature zone by the refrigeration cycle.   The refrigerator according to claim 1, wherein the cold air passage is configured to indirectly cool the chamber having a sealed space therein.   3. The refrigerator according to claim 2, wherein the cold air passage is a low pressure chamber whose internal pressure is lower than an external pressure, and a decompression means for decompressing the low pressure chamber. .   The refrigerator according to claim 3, wherein the low-pressure chamber is configured to be able to selectively set the room temperature between the cold temperature range and the chilled temperature range. Refrigerator.   5. The refrigerator according to claim 4, wherein the low-pressure chamber controls the pressure after depressurization to 0.7 to 0.9 atm.   The refrigerator according to claim 5, wherein the humidity in the low-pressure chamber is controlled to 70% to 99%.   The refrigerator according to claim 6, further comprising a decompression means for reducing an oxygen concentration in the low-pressure chamber in the low-pressure chamber.   4. The refrigerator according to claim 3, wherein the low pressure chamber is switched between the ice temperature temperature range and the chilled temperature range by controlling an operation of a damper device provided in a part of the cold air passage. A refrigerator characterized by that.   9. The refrigerator according to claim 8, wherein the low-pressure chamber includes a heater, a temperature sensor that detects a temperature in the low-pressure chamber, and a temperature adjustment unit that adjusts the temperature in the low-pressure chamber. And a control device for controlling the operation of the heater and the damper device based on the temperature detected by the temperature sensor and the temperature adjusted by the temperature adjusting unit. .   The refrigerator according to claim 9, wherein the control device controls the temperature in the low-pressure chamber to be within a temperature fluctuation range of ± 1 ° C of the set temperature.

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