JP4102883B2 - Simple and quick drying method for new water-containing samples - Google Patents

Description

  The present invention relates to a method for drying water-containing samples such as plants, animals and microorganisms. Specifically, the present invention relates to a method for drying a cell and tissue of a water-containing sample in a natural state and useful components contained in the sample without destroying them. More specifically, the present invention relates to a method for quickly, efficiently and inexpensively drying a hydrated plant sample while maintaining its natural color and / or fragrance or alive microbial cells.

Conventionally, there have been various methods for drying plants and their parts. For example, there is a pressed flower manufacturing method in which a water-absorbing material is placed either on the top or bottom of the plant to be dried or on one of the top and bottom, and the plant is dried while absorbing moisture in the plant. As a method of pressing flowers, there has been a weight processing method that forcibly discharges moisture in plants by applying pressure with a weight. Further, a method of sandwiching a plant with a water-absorbing material and a ceramic plate, irradiating with microwaves and accelerating moisture evaporation (Japanese Patent Laid-Open No. 4-49202), a pressure plate having a water-absorbing material and a large number of small holes In the method of compressing scissors and irradiating microwaves to accelerate moisture evaporation (US Pat. No. 5,948,311), the method of compressing plants with water absorbent materials and pressurizing wooden plates and irradiating microwaves to accelerate moisture evaporation ( Japanese Patent Laid-Open No. 2001-302401). Further, there has been a method (US Pat. No. 3,861,053) in which a plant to be dried is placed in a hygroscopic material such as silica gel and dried. However, the method of compressing the plant body is to destroy the plant tissues and cells by the compression and forcibly drain the water inside, and to shorten the drying time. At this time, the pigment and the aromatic component are also removed from the plant body. Completely or partly lost, the color and aroma possessed by the native plant could not be maintained. It was also impossible to maintain the three-dimensional shape of the plant for compression. Furthermore, even when the plant is placed in a hygroscopic material such as silica gel, the plant is deformed due to the weight of the hygroscopic material, and the three-dimensional shape cannot be maintained, and it takes time to absorb moisture, during which the plant itself is altered. However, it was impossible to maintain the color and fragrance of plants in their natural state.
In addition, methods for preserving microorganisms include freezing and freeze-drying. However, cryopreservation requires freezing equipment for keeping microorganisms in a frozen state. In addition, the freeze-drying method is not necessarily a method of storing microorganisms while they are alive, and the survival rate is not high when the cultured microorganisms are stored after being frozen and stored. Further, in microorganisms that produce and retain useful pigment components and nutritional components, the components are denatured by freeze-drying, and the components of the microorganisms in the natural state cannot be retained.
In order to solve such problems, the present inventors first covered the outer surface of the water-containing sample with a hygroscopic porous flexible sheet, and can absorb all the moisture contained in the water-containing sample on the outer periphery of the sheet. A water-containing sample characterized in that it is surrounded by an amount of hygroscopic granules, the outer surface of the water-containing sample, the hygroscopic porous flexible sheet and the hygroscopic granules are brought into close contact, irradiated with microwaves, and allowed to cool. A rapid drying method was developed (Japanese Patent Laid-Open No. 2001-071695).
In this method, it is not necessary to compress the plant, and the tissue and cells of the plant are maintained as they are, so that it is possible to maintain the three-dimensional shape, color and aroma in the natural state. In addition, the moisture evaporated by the microwave irradiation was once absorbed by the hygroscopic porous flexible sheet, and then the moisture was absorbed by the hygroscopic granular material such as silica gel, so that quick drying was possible.
This method has made it possible to produce a dry product that retains the color and aroma of a natural water-containing sample.
JP-A-4-49202 US Pat. No. 5,948,311 JP 2001-302401 A U.S. Pat. No. 3,861,053 JP 2001-071695 A

The present invention provides a method for drying cells and tissues of a natural water-containing sample and useful components contained in the sample without destroying them, for example, while maintaining the color and / or aroma of the natural water-containing sample. An object of the present invention is to provide a method for drying a water-containing sample quickly, efficiently and at low cost. Furthermore, the present invention provides a dry body in which cells and tissues of a water-containing sample and useful components contained therein are retained without being destroyed, for example, a dry body that retains the color and / or aroma of a water-containing sample in a natural state. Objective.
The present inventors have intensively studied to improve the rapid drying method of the water-containing sample developed earlier and to develop a drying method that can be performed easily and quickly at a lower cost. In the process, as a result of examining the drying mechanism of the rapid drying method of the moisture sample developed earlier, hygroscopic particles such as silica gel not only absorb the moisture evaporated from the moisture sample by microwave irradiation, It has been found that the evaporated water has a “chimney effect” in which it passes through the gap between the hygroscopic granules surrounding the water-containing sample and is released to the outside of the hygroscopic granules. Since the water molecules evaporated and released to the outside lose their motility and become difficult to be absorbed by the water-containing sample again during the cooling process after heating, rapid and complete drying of the water-containing sample can be achieved. However, in terms of exhibiting this “chimney effect”, hygroscopic granules such as silica gel may not release the water once evaporated completely, but may hold the vapor in the gap. There was a possibility that the water in the gap returned to the water-containing sample again during cooling. Therefore, the present inventors use a material that releases moisture evaporated from the water-containing sample to the outside in place of the hygroscopic granules and prevents the released water from being absorbed again into the water-containing sample. Therefore, it was considered that quick drying of a water-containing sample could be achieved more easily, and intensive studies were conducted on materials and drying methods. As a result, if the material has a certain moisture permeability, water molecules evaporated from the water-containing sample can be permeated and released without staying around the water-containing sample. If the material has a certain moisture-absorbing property, it is once permeated and released. It has been found that when a water molecule loses mobility, the water-containing sample that has been trapped in the water and dried can be prevented from reabsorbing moisture, and the present invention has been completed.
That is, the present invention
(1) A method for quickly drying a water-containing sample, comprising surrounding the outer surface of the water-containing sample with a porous material having moisture permeability, hygroscopicity, and heat resistance, placing the sample in a microwave generator, and irradiating the microwave.
(2) The outer surface of the water-containing sample is surrounded by a hygroscopic porous flexible sheet, and the periphery of the sheet is surrounded by a porous material having moisture permeability, hygroscopicity, and heat resistance, and is placed in a microwave generator and irradiated with microwaves. Quick drying method for water-containing samples, including
(3) The moisture-absorbing porous flexible sheet and the porous material having moisture permeability, hygroscopicity, and heat resistance are preliminarily heated by microwave irradiation in advance (1) or (2) the rapid drying method of the water-containing sample ,
(4) The rapid drying method of the water-containing sample according to any one of (1) to (3), wherein the water-containing sample is dried by irradiating the microwave in the microwave generator and then dried.
(5) The rapid drying method of a water-containing sample according to (4), wherein preheat drying is performed in a microwave generator,
(6) The rapid drying method for the water-containing sample according to any one of (1) to (3), wherein the porous material having moisture permeability and hygroscopicity is corrugated cardboard.
(7) The rapid drying method of the water-containing sample of (6), wherein the corrugated cardboard contains hygroscopic granules,
(8) The rapid drying method of the water-containing sample according to (1) to (3), wherein the ambient temperature of the water-containing sample immediately after microwave irradiation is less than 60 ° C.
(9) The rapid drying method of a water-containing sample according to (8), wherein the porous material having moisture permeability and hygroscopicity is felt or fleece,
(10) The rapid drying method of the water-containing sample according to any one of (1) to (9), wherein the microwave irradiation is performed until the water reduction rate in the water-containing sample reaches 95% or more.
(11) The rapid drying method of the water-containing sample according to (10), wherein the water-containing sample is a raw sample,
(12) The rapid drying method of the water-containing sample according to (11), wherein the raw sample is a plant body or a part thereof,
(13) The rapid drying method of a water-containing sample according to (11), wherein the raw sample is a microorganism and the dried microorganism is alive.
(14) Surround one petal of a plant with a candidate porous material, irradiate it with microwaves, measure the moisture reduction rate of the water-containing sample and the temperature in the vicinity of the water-containing sample at regular intervals, and reduce the water in 60 to 240 seconds Moisture permeability, hygroscopicity, and heat resistance suitable for the rapid drying method of a water-containing sample of (1), wherein a material whose rate is 100% and the temperature does not rise above 60 ° C. is selected as a material suitable for use in drying. A method for selecting a porous material having
(15) A rapid drying kit for a water-containing sample including a porous material having moisture permeability, hygroscopicity and heat resistance selected by the method of (14), and a porous flexible sheet,
(16) The rapid drying kit for a water-containing sample according to (14), wherein the porous material having moisture permeability and hygroscopicity is felt or fleece.
(17) A dried body of a water-containing sample in which cells and tissues produced by the method of (13) are not destroyed,
(18) A dried product of a water-containing sample, which retains the natural color and / or fragrance produced by the method of (13), and
(19) The dried body of the water-containing sample according to (17) or (18), wherein the dried body of the water-containing sample is a microorganism that can grow when cultured.
Hereinafter, the present invention will be described in detail.
The present invention is a rapid drying method for a water-containing sample comprising enclosing the outer surface of the water-containing sample with a porous material having moisture permeability and hygroscopicity and irradiating with microwaves.
The water-containing sample that can be dried in the present invention includes the whole plant and parts of plants such as flowers, leaves, stems, fruits and roots, arthropods such as insects and crustaceans, and arthropods such as insects and crustaceans. Live samples containing eggs, fish eggs, animal bodies such as animal flesh, skin and parts thereof, and microorganisms such as nematodes, protozoa, bacteria such as Escherichia coli and Bacillus subtilis, yeasts, algae, insect cells and animal cells , Hydrous mineral samples such as rocks, mud and sand. The use of the sample to be dried is not limited, and edible plants, edible animals, ornamental plants, plants / microorganisms for collecting useful components, microorganisms for research, cells and tissues, and contained useful components should be retained without being destroyed. It can be applied to any use as long as the sample is desirable. Of these, plants and their parts and microorganisms are particularly preferred. Further, the dried product dried by the method of the present invention retains not only the color in the natural state but also the aroma, so it is suitable for drying tea leaves, herbs and the like. Further, since the drying method of the present invention does not need to forcefully release moisture in the water-containing sample by compressing unlike the pressed flower method, it can be dried while maintaining the three-dimensional structure of the natural water-containing sample. . Therefore, a plant body having a complicated shape and a fragile plant body can be dried while maintaining the three-dimensional shape. In this respect, the method of the present invention is also suitable for the production of dried flowers. Moreover, the animal body dried by the method of the present invention and its cells and tissues are retained without being destroyed, and useful components contained in the sample before drying are also retained without being destroyed. Therefore, the animal body and the dried body thereof retain the color and flavor before drying. Furthermore, the microorganisms dried by the method of the present invention are retained without destroying the tissue, and useful components contained in the sample before drying are also retained without being destroyed. Therefore, the microorganism retains its biological activity, can be dried while alive, and can be grown by culture or the like after storage.
The present invention is a method of drying a water-containing sample by surrounding the water-containing sample with a porous material having moisture permeability, hygroscopicity, and heat resistance and irradiating with microwaves.
Here, surrounding the water-containing sample means that the entire periphery or almost the entire periphery of the water-containing sample is covered with a porous material having moisture permeability, hygroscopicity, and heat resistance. Preferably it is necessary for the majority to be in contact with the porous material. This is because water molecules evaporated from the water-containing sample are immediately absorbed into the porous material by contacting the water-containing sample with a porous material having moisture permeability, hygroscopicity, and heat resistance. Further, as described later, a porous flexible sheet may exist between the water-containing sample and the porous material. In order to surround the water-containing sample with the porous material, the water-containing sample may be wrapped when the porous material is rich in flexibility, and the water-containing sample may be inserted when the porous material lacks flexibility. When enclosing a hydrous sample, pressure may be applied to keep the petals and leaves of the plant flat, but the present invention aims to produce a dry body in which the pigment and / or aroma of the natural hydrous sample is retained. Therefore, the pressure of the strength that destroys the tissues and cells of the water-containing sample should not be applied. The pressure to keep the petals and leaves of the plant flat can be applied by pressing it with a weight. The moisture permeability of a material refers to a property that allows the water molecules evaporated from the material to permeate, and is also referred to as moisture permeability. The hygroscopic property of a material refers to the property that the material can retain water molecules that have lost mobility, and is also referred to as water absorption. If it has moisture permeability, moisture evaporated from the water-containing sample by microwave irradiation is easily transmitted, released from the moisture-permeable material surrounding the water-containing sample, and separated from the water-containing sample. Moreover, when water molecules that have evaporated and have heat are separated, heat hardly accumulates in the vicinity of the water-containing sample, and an increase in temperature in the vicinity of the water-containing sample can be suppressed. The moisture permeability (moisture permeability) can be measured by measuring the amount of water vapor (g) that permeates the moisture permeable material having a certain area under a certain condition for a certain time. The moisture permeability can be measured, for example, according to any of the A-1 method, the A-2 method, the A-3 method, or the A-4 method of the moisture permeability test method (JIS L 1099-1993) of JIS textiles. For example, in the A-1 method, a moisture-absorbing agent such as calcium chloride is put in a moisture permeable cup, the opening of the cup is covered with a material under test of a certain area, placed under a high humidity condition for a certain time, and the weight of the non-test material is The measurement is carried out by measuring the weight of the material to be tested again after a certain period of time. In the test method, moisture permeability (P _A1 ) Is the expression {10 × (a ₂ -A ₁ )} / S _A1 It is represented by Where a ₂ -A ₁ Indicates the amount of change (mg / h) in mass per hour of the material under test, S _A1 Is the moisture permeable area (cm ² ). P _A1 The unit of g / m ² . h. The moisture permeability of the material that can be used in the present invention is substantially the same as that of wool felt (for example, Nippon Felt Kogyo Co., Ltd., product number 227). It means ± 30%, preferably ± 20%, more preferably ± 10%, particularly preferably ± 5% with respect to the felt made. Furthermore, if it has hygroscopicity (water absorption), it absorbs and retains some of the water molecules that have evaporated and passed through the pores and water molecules that have lost their mobility during the cooling process after microwave irradiation. And water molecules can be prevented from being absorbed again into the water-containing sample. Water absorption can be performed, for example, according to a water absorption test method (JIS L 1907-1994) for JIS textiles. The test method includes a dropping method for measuring the water absorption rate, a bilek method, a sedimentation method, a method for measuring the water absorption rate, a method for measuring the maximum water absorption rate and the water absorption amount at the time of the maximum water absorption rate, You can test by the method. For example, the water absorption speed is determined by attaching a material to be tested of a certain size to the test piece holding frame, dropping water or sugar water from the burette onto the test material, and when the water droplet reaches the surface of the material, This is done by measuring the time until no more reflection occurs. The water absorption of the material that can be used in the present invention is substantially equivalent to wool felt (for example, Nippon Felt Kogyo Co., Ltd., product number 227), and is substantially equivalent to the value of moisture permeability in the above test method, It means ± 30%, preferably ± 20%, more preferably ± 10%, particularly preferably ± 5% based on wool felt. The heat resistance refers to a characteristic that is not easily affected by heat. In the present invention, it refers to a characteristic that does not melt, burn, or burn even when irradiated with microwaves. That is, having heat resistance in the present invention means resistance to microwave irradiation. For example, when it is directly irradiated with microwaves, it has heat resistance if it does not melt, burn or burn for 2 minutes, preferably 3 minutes, more preferably 5 minutes, more preferably 10 minutes. Further, when the water-containing sample is actually dried by the method of the present invention, water in the water-containing sample is evaporated by microwaves and generates heat. The material used in the present invention only needs to have heat resistance that does not cause alteration due to heat generation even when irradiated with microwaves for the time of microwave irradiation for drying by the method of the present invention. For example, when it is dried by the method of the present invention, it is a material that does not deteriorate even when irradiated with microwaves for the time required for drying the water-containing sample.For example, when microwaves are irradiated to dry the water-containing sample, It is said to have heat resistance if it does not melt, burn, or burn for 2 minutes, preferably 3 minutes, more preferably 5 minutes, more preferably 10 minutes. The porous material refers to a material having a large number of holes communicating from the front side to the back side of the material, and has moisture permeability, hygroscopicity, and heat resistance due to the presence of the holes. The size of the pore is not limited, but it is at least a size that allows water molecules to easily pass therethrough. FIG. 1 shows a schematic representation of the method of the present invention.
Furthermore, it is preferable that the material has flexibility and a small weight per unit volume or unit area so as not to break or deform the water-containing sample.
For example, as a porous material having moisture permeability, hygroscopicity, and heat resistance surrounding the water-containing sample of the present invention, a fibrous porous material can be mentioned. The fibrous porous material includes cloth and paper, and fibers themselves that are not molded as cloth may be used. Specifically, natural fibers such as wool (wool and cashmere, Angola, mohair, alpaca, camel, etc.), silk, cotton, hemp, etc., polyester, polystyrene, polyethylene terephthalate (PET), cupra, polypropylene , Nylon, rayon, acetate, vinylon, polyvinyl chloride, vinylden, acrylic, aramid, polyethylene, polyurethane, promix, polyclar, polyimide, alginate fiber, carbon fiber, ceramic fiber, etc. or any of these Examples thereof include cloth made of fibers and the like and these fibers themselves. Furthermore, felt, fleece, flannel (flannel), velour, woven felt such as a blanket with a felt surface made of felt, billiard cloth, nonwoven fabric or woven fabric such as a quilt core or domit core, and the like can be mentioned. Here, the felt is a fabric made by entwining fibers, a traditional felt made of wool, a synthetic felt such as a felt made of short fibers crimped to any kind of material, or a polyester. There is a felt made of fiber. A fleece is a cloth in which fibers are woven and densified, and its material is wool, polyester, or the like. Nell refers to a woven fabric using thick count yarn and raised on both sides or one side of a plain weave or twill weave, and velor refers to a fabric in which the fabric surface is fluffed and fluffed. Glass wool or quartz wool made of glass or quartz fiber is also used, and these materials are also hygroscopic because they can permeate water vapor and retain moisture in the pores, and are included in the fibrous porous material of the present invention. . Paper is required to have a certain thickness from the viewpoint of hygroscopicity, and in the case of thin paper, it may be used repeatedly. Although the total thickness is not limited, it is several mm to several cm, preferably 1 to 2 cm. Examples of paper include cardboard, crepe paper, filter paper, and the like. Here, the crepe paper refers to paper with wrinkle-like wrinkles, and may be either a wet crepe that wrinkles wet paper in the paper making process or a dry crepe that processes dry paper. Examples of crepe paper include paper towels and paper napkins. Corrugated cardboard also needs a certain thickness from the viewpoint of hygroscopicity. Although the required thickness varies depending on the type of corrugated cardboard, it is several mm to several cm, preferably 1 to 2 cm. In the case of thin corrugated cardboard, several sheets may be used in the same manner as paper. The cloth may be woven, non-woven or knit, and may be a natural cloth or a synthetic cloth. Moreover, a certain amount of thickness is required from the viewpoint of hygroscopicity, and the thickness is several mm to several cm, preferably 5 mm to 2 cm, and more preferably 5 mm to 1 cm. In the case of a thin cloth, it may be used in layers. When the cardboard is used, the cardboard may contain a hygroscopic granular material such as silica gel. Corrugated cardboard is obtained by pasting a liner on one or both sides of a corrugated medium core, and a hygroscopic granular material can be included between the central core and the liner.
Note that a porous material having moisture permeability, hygroscopicity, and heat resistance suitable for enclosing the water-containing sample when the present method is carried out can be selected as follows. That is, a water sample such as a flower or petal of a plant, for example, a petal of a pansy with a raw weight of 0.03 to 0.05 or a delphinium flower with a raw weight of 0.3 to 0.5 g is surrounded by a candidate material, When a microwave is irradiated using a microwave oven (for example, one having an output of 500 W to 600 W), the moisture reduction rate is 100% in 60 seconds to 240 seconds, and the moisture reduction rate is 95%. Is a material that does not show discoloration in water-containing samples. Here, the moisture reduction rate after microwave irradiation for a certain time is (weight of sample before drying−weight of sample when microwave irradiation is performed for a certain time) / (weight of sample before drying−weight of complete drying) (Weight of sample) × 100 (%).
It is possible to dry the water-containing sample by surrounding the water-containing sample to be dried using such a porous material having moisture permeability, hygroscopicity, and heat resistance and irradiating it with microwaves. At this time, it is desirable that a porous flexible sheet is interposed between the porous material having moisture permeability, hygroscopicity and heat resistance and the water-containing sample. Here, examples of the porous flexible sheet include thin and flexible papers such as crepe paper, Japanese paper, tissue paper, newspaper, and filter paper. The porous flexible sheet is also a porous material having moisture permeability, moisture absorption and heat resistance, but does not include cloth or cardboard, and is used in this specification to distinguish it from a porous material having moisture permeability, moisture absorption and heat resistance. In the book, the term porous flexible sheet is used. Depending on the embodiment of the present invention, a plurality of crepe papers may be used as a porous material having moisture permeability, moisture absorption, and heat resistance. In this case, the crepe paper has moisture permeability, moisture absorption, and heat resistance. It is also a porous material having a porous flexible sheet. One porous flexible sheet may be used, or a plurality of porous flexible sheets may be used. The water-containing sample to be dried is surrounded by a porous flexible sheet, and further surrounded by the porous material having moisture permeability, hygroscopicity and heat resistance, and irradiated with microwaves. At this time, the porous flexible sheet is partially brought into contact with the water-containing sample, preferably most of the water-containing sample. Here, contacting the majority means bringing 50% or more of the surface area of the water-containing sample into contact with the porous flexible sheet. Furthermore, the porous material having moisture permeability, hygroscopicity, and heat resistance located outside the porous flexible sheet is brought into contact with the porous flexible sheet partially, preferably most. Here, contacting the majority means contacting 50% or more of the surface area of the porous flexible sheet with the porous material. Since the porous flexible sheet is in contact with the water-containing sample and the porous material having moisture permeability, hygroscopicity and heat resistance is further in contact with the porous flexible sheet, the water-containing sample, the porous flexible sheet and the moisture-permeable, hygroscopic property And a passage of water molecules through the porous material having heat resistance is formed. Moisture evaporated from the water-containing sample is immediately absorbed by the porous flexible sheet, and then the moisture moves into the porous material having moisture permeability, hygroscopicity and heat resistance, and is released outside through the pores of the material. The Since the porous flexible sheet has sufficient flexibility, even a water-containing sample having a somewhat complicated shape can be easily brought into contact with the sample. However, in the case of a water-containing sample having a highly complex shape such as a plant flower itself or a plant body itself, it is not easy to bring the porous flexible sheet into contact with a part having a complicated shape of the water-containing sample. In this case, the porous flexible sheet may be cut into an appropriate size, and the fragments may be sandwiched, inserted, or tied into contact with the complicated shape portion of the water-containing sample. The size and shape of the fragment are not limited, and may be appropriately determined depending on the size and shape of the water-containing sample to be dried. For example, when petals overlap like rose flowers and dandelion flowers, cut a porous flexible sheet to make a fragment larger than the petal (for example, strip shape), and place the fragment between the petal and petal Just plug it in. The surroundings are further surrounded by a porous flexible sheet, and further surrounded by a porous material having moisture permeability, hygroscopicity and heat resistance, so that between the water-containing sample and the porous flexible sheet and between the porous flexible sheet and the moisture permeability, Good contact can be achieved with a porous material having hygroscopicity and heat resistance. When trying to dry a plant having a more complicated shape, etc., the porous flexible sheet is cut into threads or cut into small pieces, and they are used so as to surround the plant. Enclose with a quality flexible sheet. In the present specification, even when a piece of a porous flexible sheet is inserted or pinched in this manner and brought into contact with the water-containing sample, the water-containing sample is referred to as being surrounded by the porous flexible sheet.
In addition, what is necessary is just to bundle a fiber and to cover a porous flexible sheet, when using a fiber as a porous material which has moisture permeability, moisture absorption, and heat resistance. When a material other than corrugated cardboard is used as the porous material, the porous material may be further sandwiched by corrugated cardboard and dried. For example, a water-containing sample may be sandwiched between porous flexible sheets, further covered with a porous material having moisture permeability, hygroscopicity, and heat resistance, and then sandwiched between corrugated cardboard plates. The number of cardboards at this time is not limited, but the total thickness is about several mm to several cm, for example, about 2 mm to 15 mm.
The area of the porous material and porous flexible sheet having moisture permeability, hygroscopicity, and heat resistance used in the method of the present invention may be appropriately set depending on the size of the water-containing sample to be dried. Further, the area can be appropriately changed depending on whether the hydrated sample is used between the upper and lower sides or wrapped.
As the microwave generator used in the present invention, a commercially available household microwave oven may be used. A large-scale microwave generator can be used for industrially producing a large amount of a dried product. In this case, the dried sample of the hydrated sample is produced in a larger amount by moving the hydrated sample continuously into the microwave generator using a belt conveyor or the like and irradiating the microwave for a certain period of time. Can do. In the present invention, it is referred to as a microwave generator, which is also called a microwave heating furnace. In the present invention, when a water-containing sample is irradiated with microwaves, the microwaves are applied to dielectrically heat water molecules. (Microwave heating) Evaporation.
The microwave irradiation time varies depending on the volume of the water-containing sample to be dried, the water content, etc., and when the water-containing sample is a plant, it varies depending on the presence or absence of the surface cuticle layer, but may be about 10 to several hundred seconds. . For example, when a single Aoki leaf having a thick leaf and a cuticle layer is dried, the leaf can be sufficiently dried in about 60 seconds. In the case of microorganisms, for example, OD ₆₅₀ In the case where a microscopic suspension of several micron to several tens of microliter of about 3 is impregnated or sandwiched in a filter paper which is a porous flexible paper, it takes about 10 seconds to several hundred seconds, preferably 30 seconds. 60 seconds may be sufficient. If the microwave irradiation time is too long, the water-containing sample may be discolored, which is not desirable. By appropriately changing the irradiation time according to the output of the microwave generator, a good dry body can be obtained. The moisture-containing sample to be used can be dried in advance by changing the microwave irradiation time, the dry state and the degree of discoloration can be investigated, and an appropriate irradiation time can be set, or a microwave can be irradiated for a short time. It is also possible to achieve an optimal dry state by repeatedly checking the dry state and the degree of discoloration. In the examples in this specification, the weight loss due to water evaporation during drying is measured, and when the weight does not decrease, that is, when the moisture reduction rate from the water-containing sample reaches 100%, the complete drying is completed. It is said. However, depending on the moisture-permeable and hygroscopic material used, the water-containing sample may be discolored when completely dried. Desirably, the dried body of the water-containing sample prepared by the method of the present invention is stored in a dry state in the presence of a desiccant or under low-humidity conditions. Is done. Therefore, when discoloration is observed, the microwave irradiation is stopped before reaching the complete drying, and after that, it may be stored in the presence of a desiccant or under low humidity conditions. In addition, when the dried sample of the water-containing sample of the present invention is used for decoration, not for food, drinking or preservation of biological resources, it is not always necessary to maintain a highly dry state. Even if it contains water, it is not a problem. Therefore, in this case, drying is stopped at an irradiation time that does not cause discoloration, and even after being stored under atmospheric conditions as it is, the natural state is maintained for a very long period of at least several months to several years without any practical problem. The color and fragrance of can be preserved. When the weight loss of the water-containing sample in the process of microwave irradiation ceases to be 100%, the water decrease rate after microwave irradiation for a certain period of time is (weight of sample before drying-microwave for a certain period of time) The weight of the sample at the time of irradiation) / (weight of the sample before drying-weight of the sample when complete drying is completed) × 100 (%). The moisture reduction rate of the dried body of the water-containing sample produced by the method of the present invention is preferably 95%, more preferably 98%, and particularly preferably 99%.
In addition, it is possible to prevent the water-containing sample from being exposed to a high temperature by appropriately selecting a porous material having moisture permeability, hygroscopicity, and heat resistance surrounding the water-containing sample. For example, when felt or fleece is used as the porous material, the water-containing sample can be prevented from being exposed to an excessively high temperature. This is thought to be because molecular motion is activated by microwave irradiation and water molecules evaporated and immediately enter the porous material without passing around the water-containing sample, and further pass through the material. At this time, water molecules in the substance irradiated with microwaves are released from the substance at a very high speed. The water molecules moving at a high speed and the “chimney effect” of the porous material combine to separate the water molecules without increasing the temperature of the water-containing sample. Microwaves increase the kinetic energy of water molecules in a substance and heat the substance by friction between water molecules, so if water molecules with increased kinetic energy are immediately separated from the substance, the temperature rise of the substance is It can be suppressed. That is, the method of the present invention can achieve drying at a low temperature. When drying is performed under the optimum conditions for suppressing the temperature increase of the method of the present invention, the temperature to which the water-containing sample is exposed is less than 100 ° C, preferably less than 90 ° C, more preferably less than 80 ° C, particularly preferably less than 70 ° C, Most preferably, it is less than 60 ° C. The temperature around the water-containing sample can be measured by taking out the water-containing sample and a porous material having moisture permeability, hygroscopicity and heat resistance surrounding it immediately after the microwave irradiation, and placing a temperature sensor such as a thermometer or thermocouple near the water-containing sample. Can be measured. The temperature measured by this method is not the exact temperature to which the water-containing sample is exposed when actually radiating microwaves, but is a measure of the temperature to which the raw sample is actually exposed. The temperature in the vicinity of the water-containing sample measured by the temperature measurement method when drying is performed under the optimum conditions for suppressing the temperature rise of the method of the present invention is less than 100 ° C, preferably less than 90 ° C, more preferably less than 80 ° C, particularly Preferably it is less than 70 degreeC, Most preferably, it is less than 60 degreeC.
The temperature at which the water-containing sample is exposed to some extent during drying can be controlled by the type of porous material having moisture permeability, hygroscopicity, and heat resistance. Some water-containing samples originally have a high water content or have a layer that prevents water evaporation on the surface and are difficult to dry. When such a water-containing sample is dried, it may be better to perform it under some high temperature conditions. By appropriately selecting the type of the porous material, the temperature during drying can be changed. For example, when a fleece or felt is used as the porous material, drying at a relatively low temperature can be achieved, and when cardboard or crepe paper is used, the porous material can be dried at a relatively high temperature.
In addition, before drying a water-containing sample, it is desirable that the porous material having moisture permeability, hygroscopicity, and heat resistance used for drying and / or the porous flexible sheet is irradiated with microwaves in advance. By irradiating with microwaves in advance, the porous material having moisture permeability, hygroscopicity and heat resistance and / or the porous flexible sheet is heated to some extent, and subsequent drying is performed quickly and efficiently. This heating is referred to as preheating, and depending on the kind of the porous material having moisture permeability, hygroscopicity and heat resistance and the porous flexible sheet to be used, it is preferably 60 to 90 seconds.
Further, it is desirable that after the microwave irradiation to the water-containing sample is finished, the dried water-containing sample is not immediately taken out from the microwave generator, but left as it is for a certain period of time, and then allowed to cool or be preheated. By leaving the heated water-containing sample, the porous material having moisture permeability, hygroscopicity and heat resistance and / or the porous flexible sheet in a microwave generator, the water-containing sample is slightly changed by the retained heat. The water remaining in the water further evaporates, and a good dry product is obtained. The preheating drying time is 5 to 10 minutes.
FIG. 2 shows the presumed principle of the drying method of the present invention. In FIG. 2, a block with diagonal lines represents a porous material having moisture permeability, hygroscopicity, and heat resistance, a circle represents a water molecule, and an arrow represents the movement of the water molecule. The movement of water molecules in the water-containing sample is activated by microwave irradiation, and is released from the water-containing sample at a high speed. The released water molecules pass through the pores in the moisture-permeable porous material surrounding the water-containing sample one after another while maintaining the high speed, and the flow of water molecules newly passes the water molecules released from the water-containing sample into the pores of the porous material. Water molecules are led out one after another (chimney effect). Once the water molecules have gone out, the kinetic energy decreases after the microwave irradiation is completed, and the water molecules are absorbed by the hygroscopic porous material and remain there. Alternatively, some of the water molecules evaporated from the water-containing sample are absorbed by the porous material and remain there when passing through the pores of the porous material. Water molecules once absorbed and retained in the porous material are not absorbed again into the water-containing sample.
As described above, the present invention is a method for quickly drying a water-containing sample, comprising surrounding the outer surface of the water-containing sample with a porous material having moisture permeability, hygroscopicity, and heat resistance, and placing the sample in a microwave generator. In the present invention, the outer surface of the water-containing sample is surrounded by a hygroscopic porous flexible sheet, and the periphery of the sheet is surrounded by a porous material having moisture permeability, hygroscopicity, and heat resistance. This is a rapid drying method for water-containing samples including irradiation with microwaves. Further, in the present invention, the water-containing sample is sandwiched between one and several porous flexible sheets, and the upper and lower portions are sandwiched with one to several porous materials and placed in a microwave generator to irradiate microwaves. Is a rapid drying method for water-containing samples containing
The present invention further includes a dried body of the water-containing sample obtained by the above drying method. Since the tissues and cells of the water-containing sample are not destroyed in the dried body, nutrient components, pigments and fragrance substances remain inside the dried body, and the color and / or fragrance in the natural state is retained for a long time. For example, anthocyan, which is a red to blue color pigment in plants, is unstable, and it is difficult to maintain the color of plants containing anthocyanes by drying methods such as the pressed stone method that compresses and dry plants. It was. However, the method of the present invention can retain the color for a long time even in plants containing anthocyan. Moreover, it has been reported that the phenol pigment contained in the plant turns black when left untreated, and it is considered that the blackening is caused by excessive heating during drying. According to the drying method of the present invention, the plant can be dried without being exposed to an excessively high temperature, so that the blackening of the phenol pigment due to heat can be suppressed. Whether the tissue or cells of the dried body of the present invention remains unbroken can be observed with a microscope. For example, whether the pigment remains in the dried body or whether vacuoles in the cell remain. Can be evaluated. Moreover, it can also evaluate by extracting a nutrient component, a pigment | dye, and an enzyme from a dried body, and measuring whether the activity is hold | maintained. Examples of plant pigments include chlorophyll, carotenoid, phenol pigment, betalain and the like in addition to the aforementioned anthocyan. Examples of aromatic components of plants include terpenes, thymol, carvacrol, cymene, pinene, linalool, and 1,8-shioner (eucalyptol). Moreover, there are vitamins such as ascorbic acid as nutritional components. In the drying method of the present invention, the nutrient components, pigments and aroma components of the plants containing them are partially, preferably mostly retained. Confirmation that these nutrients, pigments and / or fragrance components are retained is visually the same as the natural state color, or the natural state fragrance remains by olfaction Can be performed. In addition, the pigment component and / or fragrance component is confirmed to be retained by measuring the pigment component and / or fragrance component by a known chemical method, physical method, or biochemical method. Is possible. When the nutritional component, pigment component and / or fragrance component of the dried product obtained by the method of the present invention is measured by a known method, the dried product obtained by the method of the present invention is the natural nutrient component, pigment component and / or Or at least 10%, preferably 25%, more preferably 50%, more preferably 75%, more preferably 90%, particularly preferably 95% or more of the fragrance component remains. Therefore, in the dried body obtained by the method of the present invention, the tissues and cells are not destroyed, the vacuoles in the cells remain, and the nutrients, pigments and / or fragrance components that existed in the natural state remain. It is a dry body of the raw sample that remains partially or mostly remains. Furthermore, the dried product obtained by the method of the present invention retains some or most of proteins and nucleic acids such as enzymes and the like that have been retained in the natural state while maintaining the structure and activity in the natural state. For this reason, when the dried body is a microorganism, not only the nutrient components, pigment components and / or fragrance components in the natural state are retained, but also substances such as enzymes having biological activity are retained. It can be stored as a dry body without being killed. In this case, it is not necessary that all of the dry microorganisms are alive, and when the dried microbial population is dried for a certain period and then placed in the culture medium for microbial culture, the number of microorganisms sufficient to start growth survive. It only has to be. For example, 0.01% or more of the number of dry microorganisms, preferably 0.1% or more, more preferably 1% or more, more preferably 10% or more, more preferably 20% or more, more preferably 30% or more, Preferably, 40% or more, more preferably 50% or more, more preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, more preferably 90% or more should be alive. The microorganism dried by the method of the present invention is 5 days or more at 4 ° C., preferably 10 days or more, more preferably 1 month or more, more preferably 3 months or more, more preferably 6 months or more, more preferably 1 year. More preferably, more than 2 years, more preferably more than 3 years, more preferably more than 5 years, more preferably more than 10 years, more preferably more than 20 years. Growth can begin when placed in conditioned medium.
Furthermore, when insects and the like are dried by the method of the present invention, the dried body can be used as an insect specimen having a natural color. Furthermore, the eggs of arthropods such as insects and crustaceans and fish eggs dried by the method of the present invention can be hatched by placing them in water or under high humidity conditions.
The dried product obtained by the method of the present invention may be stored in the air as it is, and even in this case, the nutrient components, colors and / or aromas in the natural state are retained for a long time. In addition, when it is necessary to maintain a high degree of dryness, such as when used in the field of food and beverages, it can be stored in a sealed state together with a desiccant and the humidity can be controlled. May be stored in a low humidity state in a clean container or room.
Since the dried body obtained by the method of the present invention retains the nutrient components, colors and / or aromas in the natural state, it can be used as a decorative product or a decorative product with aroma. It can also be used as a fragrance. Furthermore, if tea etc. are dried, it can be utilized as dry tea. Furthermore, it can also be used as a scientific specimen such as a plant specimen. In particular, by controlling the kind of porous material having moisture permeability, hygroscopicity and heat resistance used in the method of the present invention and the microwave irradiation time, the temperature at which the water-containing sample is exposed can be prevented from becoming excessively high. Some or most of the proteins such as can be retained without denaturation. Therefore, the dried product dried in the present invention can be used as a biological experimental material equivalent to a water-containing sample. For example, undenatured proteins, nucleic acids and the like can be extracted from the dried product of the present invention. The presence of dried protein and / or nucleic acid can be confirmed by a known chemical method, physical method or biochemical method. For example, the specific protein that the raw sample to be dried has in the natural state may be quantified, or the activity of the specific enzyme that the natural sample has in the natural state may be measured. The dry body obtained by the method of the present invention is at least 10%, preferably 25%, more preferably 50%, more preferably 75%, more preferably 90%, especially 90%, in particular, of any protein possessed in the natural state. Preferably 95% or more remains. In addition, the dried product obtained by the method of the present invention has at least 10%, preferably 25%, more preferably 50%, more preferably 75%, more preferably more than 10% of the enzyme activity of any enzyme possessed in the natural state. Remains 90%, particularly preferably 95% or more. Accordingly, the dried body obtained by the method of the present invention is a dried body in which the protein and / or nucleic acid in the natural state is partially left or most of them are left.
Moreover, since the microorganisms dried by the method of the present invention survive after storage for a certain period, the microorganisms can be easily dried and stored at low cost.
Furthermore, the present invention also includes a water-containing sample drying kit. The kit includes a porous material having at least moisture permeability, hygroscopicity, and heat resistance, and may further include a porous flexible sheet. Here, the definitions of the porous material having moisture permeability, hygroscopicity, and heat resistance and the porous flexible sheet are as described above. In particular, the water-containing sample drying kit of the present invention is intended to produce a pressed flower or dried flower that can easily retain a nutrient component, color and / or aroma in a natural state for a long period of time at home. As mentioned above, the temperature at which the water-containing sample is exposed depends on the type of porous material having moisture permeability, hygroscopicity, and heat resistance, so that the drying temperature can be changed depending on the type of water-containing sample. A plurality of different porous materials having moisture permeability, hygroscopicity, and heat resistance may be included. For example, felt or fleece can be used as the low-temperature drying porous material, and corrugated cardboard or crepe paper can be used as the high-temperature drying porous material. Therefore, if the kit of the present invention includes felt or fleece and cardboard or crepe paper, high-temperature drying can be performed. Can also be dried at low temperatures. That is, the kit of the present invention includes a kit that can appropriately select both low temperature drying and high temperature drying. In the case of a pressed flower production kit, the kit is a plate-like moisture-permeable, hygroscopic and heat-resistant porous material, a porous flexible sheet, and a means such as a weight applying a pressure that does not destroy the cells and tissues of the water-containing sample. including. As the weight, for example, cardboard can be used. The areas of the porous material and the porous flexible sheet vary depending on the size of the object to be dried, but for example, the porous material and the porous flexible sheet may contain several rectangular pieces each having a size of 5 to 30 cm × 5 to 30 cm. It is also possible to include a large one and fold or cut it as appropriate. Furthermore, the kit of the present invention may be made of a thick paper such as cardboard, a heat resistant material such as a heat resistant resin, and may include a container capable of transmitting microwaves. By including a container, you can easily carry a set of materials used for drying, and in general households use microwave ovens that are usually used for cooking as microwave generators. In some cases, it may not be desirable to adhere to the floor or wall of the microwave oven. In this case, it may be placed in a container and dried.
This specification includes the contents described in the specification and / or drawings of Japanese Patent Application No. 2001-306868, which is the basis of the priority of the present application.

FIG. 1 is a diagram showing an outline of the drying method of the present invention. In FIG. 1, the blocks with horizontal lines represent the porous material having moisture permeability, hygroscopicity and heat resistance according to the present invention. The white block represents a hygroscopic porous flexible sheet.
FIG. 2 is a diagram showing the principle of the drying method of the present invention.
FIG. 3 is a diagram illustrating the method performed in the first embodiment. FIG. 3A shows a method using felt, fleece or cardboard, FIG. 3B shows a method using crepe paper, and FIG. 3C shows a method using a towel. In FIG. 3, the blocks with horizontal lines indicate the porous material having moisture permeability, hygroscopicity and heat resistance according to the present invention. The towel, which is the porous material of FIG. 3C, is shown to be folded in four. A white block represents a hygroscopic porous flexible sheet (crepe paper).
FIG. 4 is a photograph of delphinium flowers dried by the method of the present invention and the OK001 method. 4A is the OK001 method, FIG. 4B is a method using felt, FIG. 4C is a method using fleece, FIG. 4D is a method using a towel, FIG. 4E is a method using crepe paper, and FIG. 4F is a cardboard. Delphinium dried by the method.

表１に示すように、対照乾燥法であるＯＫ００１法の乾燥完了が２８０秒であるのに対し、フェルトを用いた実施例１Ａで３２０秒、フリースを用いた実施例１Ｂで２００秒、段ボールを用いた実施例１Ｃで２４０秒、クレープ紙を用いた実施例１Ｄで１８０秒、タオルを用いた実施例１Ｅで１２０秒であった。各実施例における温度上昇は、ＯＫ００１法が最高１０２℃、フェルトを用いた実施例１Ａで最高５１℃、フリースを用いた実施例１Ｂで５６℃、段ボールを用いた実施例１Ｃで９１℃、クレープ紙を用いた実施例１Ｄで９６℃、タオルを用いた実施例１Ｅで９４℃であった。含水試料の乾燥体の外観は段ボール（実施例１Ｃ）およびクレープ紙（実施例１Ｄ）を用いた場合に１８０秒で変色が認められた。対象乾燥法および実施例１Ａ、１Ｂおよび１Ｅでは変色は認められなかった。
含水試料が天然状態の色彩および／または芳香を維持できるか否かは、含水試料が乾燥過程でどれ位の時間高温にさらされるかで決まり、タンパク質変性温度である約６０℃以上の温度に長時間さらされるのは、好ましくない。この点で、フェルトおよびフリースは対照乾燥法であるＯＫ００１法と比較して乾燥にかかる時間は大差ないが、温度上昇はタンパク質変性温度以下であり、またタオルおよびクレープ紙は６０℃以上の高温にさらされるが乾燥は迅速に終了する。また段ボールは比較的高温にさらされ乾燥完了までの時間も長いが、ＯＫ００１法に比較すると時間は若干短く、また温度も低い。従って、乾燥時の含水試料へ与えるダメージが少ないという点で実施例１Ａ〜１Ｅの方法は、いずれもＯＫ００１法より優れている。ＯＫ００１法により乾燥したものは、乾燥終了時に全体的に変色が認められる。段ボール、クレープ紙およびタオルを用いた場合は、乾燥完了時に、花弁の縁が茶色に変色しているのが観察された。図４に本方法で乾燥させ約３ヶ月間保存したデルフィニウムの花の写真を示す。ＯＫ００１法により乾燥したものは全体的に変色が認められる。また、段ボール、クレープ紙およびタオルを用いた方法により乾燥したものも、乾燥終了時と同様に花弁の縁の変色が認められる。
〔実施例２〕 予備加熱の乾燥に与える影響の検討
実施例１においては、予備過熱を行って含水試料の乾燥を行ったが、本実施例においては予備加熱の必要性を検討した。用いた含水試料は実施例１と同様にデルフィニウムの花弁であった。用いた透湿性吸湿性乾燥用材料は実施例１Ａおよび１Ｂと同様にフェルト（実施例２Ａ）およびフリース（実施例２Ｂ）であった。対照乾燥として、特開２００１−０７１６９５号公報に記載の方法（ＯＫ００１法）で乾燥を行った。ＯＫ００１法も含めて予備加熱を行った場合と行わない場合で含水試料の乾燥を行った。また、含水試料と多孔性材料の間に多孔質柔軟シートとして、クレープ紙を置いた。含水試料の乾燥は、実施例１と同様にマイクロ波の間歇照射により行い、経時的に重量及び温度を測定した。マイクロ波照射終了後は、実施例１と同様に余熱乾燥を行った。
結果を表２に示した。

表２に示すように、対照乾燥法であるＯＫ００１法で、乾燥完了までの時間は予備加熱なしの場合は２４０秒、予備加熱ありの場合は２７０秒と予備加熱なしの場合の方が早く乾燥が完了した。フェルト（実施例２Ａ）では予備加熱なしの場合が３００秒、予備加熱ありの場合が１８０秒と予備加熱ありの場合の方が乾燥完了が早かった。フリース（実施例２Ｂ）では予備加熱なしの場合が２４０秒、予備加熱ありの場合が１８０秒と予備加熱ありの場合の方が若干乾燥完了が早かった。
ＯＫ００１法では、予備加熱なしの場合は１２０秒照射で、予備加熱ありの場合は１８０秒照射で、色彩の変化が認められ、乾燥完了時には花弁全体が青紫色から赤紫色に変色した。また、フリースを用いた実施例では、予備加熱なしの場合、ありの場合ともに１８０秒で含水試料がやや茶色に変色した。但し、乾燥させたものの装飾的効果を減じるほどの変色ではなかった。フェルトを用いた場合は、乾燥完了後も色彩の変化は認められなかった。
〔実施例３〕 パンジーの花弁の乾燥
乾燥させる含水試料としては、紫色のパンジーの花弁１枚を用いた。乾燥前の生重量は、０．０３６〜０．０４４ｇであった。含水試料を覆う多孔性材料として、フェルト（羊毛製、日本フェルト工業株式会社、品番２２７または２２９、厚さ約２ｍｍ）、クレープ紙、段ボールを用いた。また、含水試料と多孔性材料の間に多孔質柔軟シートを置く場合は、クレープ紙を用いた。実施例３Ａにおいては、パンジーの花弁１枚の上下をクレープ紙４枚ずつではさみ、さらにフェルト１枚ずつではさんだ。実施例３Ｂにおいては、パンジーの花弁１枚の上下をフェルト１枚ずつではさんだ。実施例３Ｃにおいては、パンジーの花弁１枚の上下をクレープ紙４枚ずつではさみ、さらにフェルト１枚ずつではさみ、さらにその上下を段ボール２枚ずつではさんだ。実施例３Ｄにおいては、パンジーの花弁１枚の上下をクレープ紙４枚ずつではさみ、さらにフェルト１枚ずつではさみ、さらにその上のみに段ボール２枚をのせた。実施例３Ｅにおいては、パンジーの花弁１枚の上下をクレープ紙４枚ずつではさみ、さらにフェルト２枚ずつではさんだ。実施例３Ｆにおいては、パンジーの花弁１枚の上下をクレープ紙４枚ずつではさみ、さらにフェルト２枚ずつではさみ、さらにその上下を段ボール２枚ずつではさんだ。実施例３Ｇにおいては、パンジーの花弁１枚の上下をクレープ紙４枚ずつではさみ、さらにフェルト３枚ずつではさんだ。実施例３Ｈにおいては、パンジーの花弁１枚の上下をクレープ紙４枚ずつではさみ、さらにフェルト４枚ずつではさんだ。対照として特開２００１−０７１６９５号公報に記載の方法（ＯＫ００１法とする）でも乾燥を行った。対照乾燥および実施例３Ａおよび３Ｂでは、予備加熱をした場合としない場合で乾燥を行い、実施例３Ｃから３Ｇはいずれも予備加熱を行った。予備加熱は実施例１と同様の方法で行った。含水試料の乾燥は、実施例１と同様にマイクロ波の間歇照射により行い、経時的に重量及び温度を測定した。マイクロ波照射終了後は、実施例１と同様に余熱乾燥を行った。
結果を表３に示した。

予備加熱を行った場合と行わなかった場合で、行った場合の方が完全乾燥が完了するまでの時間がやや短かった。含水試料をクレープ紙で囲んだ方が完全乾燥が完了するまでの時間が短かった（実施例３Ａおよび３Ｂ）。フェルトは１、２枚よりも３枚または４枚重ねた方が完全乾燥が完了するまでの時間が短かった（実施例３Ｆおよび３Ｇ）。乾燥時の温度は、対照乾燥法で８０〜９０℃以上に上昇したのに対して、実施例３Ａから３Ｆでは約５０℃以下であった。フェルトを上下４枚ずつ用いた実施例３Ｇではフェルトが３枚以下の場合に比べて、若干温度が高くなったが、６０℃以下であった。実施例３においては、含水試料の変色は認められなかった。
この結果より、含水試料を多孔性柔軟シートで囲い、さらにフェルトを３枚ずつ上下に重ねた場合、完全乾燥が完了するまでの時間および温度上昇の点で良好な乾燥が達成できることがわかった。
〔実施例４〕 アオキの葉の乾燥
乾燥させる含水試料としては、アオキの葉１枚を用いた。乾燥前の生重量は、０．５〜０．７ｇであった。含水試料を覆う多孔性材料として、フリース（ダイソー製、ポリエステル１００％、厚さ約３ｍｍ）、ポリプロピレン不織布（ダイソー製、厚さ約０．８ｍｍ）およびコルク板（ダイソー製、厚さ約２ｍｍを用いた。含水試料と多孔性材料の間に多孔質柔軟シートを置く場合は、ティッシュ（株式会社ネピア社製）、キムワイプ（株式会社クレシア社製）またはクレープ紙を用いた。ティッシュおよびキムワイプの上からみた場合の大きさは、それぞれ２０×２３ｃｍおよび１２×２２ｃｍであった。実施例４Ａは、含水試料の上下をティッシュ２枚ではさみ、さらにその上下をフリース４枚ずつではさんだ。実施例４Ｂは、含水試料の上下をクレープ紙２枚ではさみ、さらにその上下をフリース４枚ではさんだ。実施例４Ｃは、含水試料の上下をキムワイプ２枚ではさみ、さらにその上下をフリース４枚ではさんだ。実施例４Ｄは、含水試料の上下をキムワイプ２枚ではさみ、さらにその上下をポリプロピレン不織布１６枚ではさんだ。実施例４Ｅは、含水試料の上下をキムワイプ２枚ではさみ、さらにその上下をコルク板４枚ではさんだ。上から見た場合のコルク板、ポリプロピレン不織布の大きさはどちらも１３×１８ｃｍであった。対照として特開２００１−０７１６９５号公報に記載の方法（ＯＫ００１法）でも乾燥を行った。ＯＫ００１法、実施例４Ｃ、実施例４Ｄおよび実施例４Ｅは、予備加熱をした場合としない場合とで行った。実施例４Ａおよび４Ｂは予備加熱を行った。予備加熱は実施例１と同様の方法で行った。含水試料の乾燥は、実施例１と同様にマイクロ波の間歇照射により行い、経時的に重量及び温度を測定した。マイクロ波照射終了後は、実施例１と同様に余熱乾燥を行った。
結果を表４に示す。

完全乾燥が完了するまでの時間は、フリースを用い予備加熱を行った場合で３３０〜４２０秒、予備加熱を行わなかった場合で約６００秒であった、ポリプロピレン不織布を用いた場合およびコルク板を用いた場合の完全乾燥が完了するまでの時間は未測定であるが、ポリプロピレンがほぼフリースと同等で、コルク板がそれよりも早い。乾燥時の温度は、フリースを用いた場合は５０℃以下、ポリプロピレン不織布を用いた場合は６０℃以下、コルク板を用いた場合はＯＫ００１法と同等で約９０℃であった。
ＯＫ００１法では、乾燥完了時に葉全体が黒変していた。また、コルク板およびポリプロピレン不織布を用いた場合は、乾燥完了時に葉の縁が黒変していた。また、フリースを用いた場合、予備加熱をしないときおよび予備加熱をした場合で多孔質柔軟シートとしてティッシュを用いたとき乾燥完了時に葉の縁が黒変していた。フリースを用いた場合で多孔質柔軟シートとしてクレープ紙またはキムワイプを用いたときは葉の変色は認められなかった。
〔実施例５〕 ポリエステル製の繊維性多孔性材料を用いての乾燥
乾燥させる含水試料としては、パセリを用いた。乾燥前の生重量は、０．３〜０．７ｇであった。含水試料を覆う多孔性材料として、ポリエステル１００％のキルト芯（日本バイリーン株式会社、厚さ約１０ｍｍ）、ポリエステル１００％のドミット芯（日本バイリーン株式会社、厚さ約７ｍｍ）およびウール１００％のフェルト作製用繊維（クローバー株式会社）を用いた。また、含水試料と多孔性材料の間の多孔質柔軟シートとしては、クレープ紙を用いた。
パセリの上下をクレープ紙ではさみ、さらに上下を４枚のキルト芯、２から４枚のドミット芯ではさんだ。フェルト作製用ウール繊維は、パセリの上下をクレープ紙ではさんだものの上下に、束ねたウール繊維（束の厚さが約１０ｍｍ）をクレープ紙を覆うように置いた。
次いで、このようにして準備した多孔質柔軟シートおよび透湿性、吸湿性および耐熱性を有する多孔性材料で囲まれた含水試料を市販の電子レンジ（岩谷産業（株）製、型番ＩＭＯ６００、出力５００Ｗ）に入れ、マイクロ波を照射した。照射は、９０秒間行った。マイクロ波照射が終了した後、乾燥体は直ぐに電子レンジから取り出すか（余熱乾燥０分）、あるいは５分または１０分間放置し、余熱乾燥を行った。ウール繊維の場合は、１０分間放置し、余熱乾燥を行った。
表５、表６および表７に、それぞれキルト芯、ドミット芯およびウール繊維を用いた乾燥法の結果を示す。

表には、余熱時間それぞれの多孔性材料の重ね合せ枚数、乾燥前重量、乾燥後重量および水分除去率を示した。
いずれの材料でもパセリは、同程度の水分除去率を示し、乾燥後の変色等も認められなかった。
〔実施例６〕 各種素材の繊維性多孔性材料を用いての乾燥
繊維性多孔性材料として以下のものを用いた。
（１） ウール製不織布（ウール１００％）
（２） 段ボール（厚さ８／３ｍｍのものを３枚重ねで使用）
（３） 綿製（綿１００％）コットンキルト綿（日本バイリーン株式会社製、型番ＫＭＷ−１Ｐ）
（４） ポリエステル製（ポリエステル１００％）パッチワークキルト綿 ドミット薄手タイプ（日本バイリーン株式会社製、型番ＱＢ−９５）
（５） ポリエステル製（ポリエステル１００％）パッチワークキルト綿 ドミット薄手タイプ（日本バイリーン株式会社製、型番ＴＫＳ−３５Ｐ）
（６） ポリエステル製（ポリエステル１００％）パッチワークキルト綿 ドミット厚手タイプ（日本バイリーン株式会社製、型番ＫＳＰ−１２０Ａ）
（７） コットン＆ポリエステルキルト芯（綿６０％、ポリエステル４０％）（ＫＩＮＫＡＭＥ社製、型番４８０５５７）
（８） パッチワークキルト綿（黒色）（ポリエステル６０％、レーヨン４０％）（日本バイリーン株式会社製、型番ＭＨ−１４−ＢＫＰ）
上記繊維性多孔性材料は、すべて２枚重ねで用いた。
材料は、約０．２ｇ〜０．６ｇのパセリを用いた。
乾燥方法は、実施例５とほぼ同様であるが、マイクロ波の照射を最初６０秒間行い、次いで、３０秒間の照射を間歇的に２から３回行うことにより乾燥した（トータルの乾燥時間は、１２０から１８０秒間）。間歇照射毎にパセリを取り出し、触覚により乾燥程度を判断すると共に、重量を測定した。
以下に、それぞれの材料についての乾燥結果を示す。表８から１５は、それぞれ上記の（１）から（８）の繊維性多孔性材料に対応している。表において、乾燥過程のマイクロ波間歇照射の後に取り出したパセリの乾燥状態および／または重量を記載した。

表８から表１５が示すように、いずれの繊維性多孔性材料を用いても良好に乾燥できた。
〔実施例７〕 繊維性多孔性材料の耐熱性（耐マイクロ波性）
各種繊維性多孔性材料の耐熱性（耐マイクロ波性）について検討を行った。
用いた繊維性多孔性材料は以下の通りであった。
（１） ウール製不織布（ウール１００％）
（２） 段ボール（厚さ８／３ｍｍのものを３枚重ねで使用）
（３） ポリエステル製（ポリエステル１００％）パッチワークキルト綿 ドミット薄手タイプ（日本バイリーン株式会社製、型番ＱＢ−９５）
（４） ポリエステル製（ポリエステル１００％）パッチワークキルト綿 ドミット薄手タイプ（日本バイリーン株式会社製、型番ＴＫＳ−３５Ｐ）
（５） ポリエステル製（ポリエステル１００％）パッチワークキルト綿 ドミット厚手タイプ（日本バイリーン株式会社製、型番ＫＳＰ−１２０Ａ）
（６） コットン＆ポリエステルキルト芯（綿６０％、ポリエステル４０％）（ＫＩＮＫＡＭＥ社製、型番４８０５５７）
（７） パッチワークキルト綿（黒色）（ポリエステル６０％、レーヨン４０％）（日本バイリーン株式会社製、型番ＭＨ−１４−ＢＫＰ）
上記繊維性多孔性材料の上下を段ボール（厚さ８／３ｍｍを３枚）で挟み込み、これを５００Ｗで６０秒間加熱した。加熱後、材料を速やかに取り出し、変化を確認した。まだ乾燥していない場合は速やかに（平均１５秒以内）電子レンジ内に戻し、更に５００Ｗで６０秒間加熱した。以後、材料に変化が現れるまで一分刻みで加熱した。材料から発煙もしくは異臭の発生があり次第、速やかに電子レンジを停止し、材料を取り出した。

また、段ボールで挟まずに、各材料を直接マイクロ波照射した。いずれの材料もマイクロ波を少なくとも１０分、照射しても変化は認められなかった。
実施例５より、いずれの材料も耐熱性（耐マイクロ波性）を有していることがわかった。
〔実施例８〕 乾燥体の色素、芳香成分の分析
実施例５の方法のうち、本発明の方法で乾燥させたパセリ、および同様の方法で乾燥させた月桂樹の葉を分析に用いた。乾燥前の試料と乾燥後の試料について水分含量を調べ、パセリについては乾燥前後のアスコルビン酸含量を測定し、月桂樹の葉については、乾燥前後の１，８−シネオール（ユーカリプトール）の含量を測定した。測定は、財団法人 日本食品分析センターに委託して行った。また、コントロールとして凍結乾燥法により乾燥したサンプルについても測定を行った。測定は１から２サンプルについて行った。
含水試料 アスコルビン酸含量
パセリ（乾燥前） ０．７８％
パセリ（乾燥後：本発明法） ０．７９％
含水試料 １，８−シオネール含量
月桂樹の葉（乾燥前） ０．７７％
月桂樹の葉（乾燥後：凍結乾燥） ０．８１％
月桂樹の葉（乾燥後：本発明法） ０．７９％
表中の値は、（）内の状態の試料をさらに７０℃で５時間乾燥した乾燥体重量ベースである。
表に示すように、本発明の方法で、パセリ中のアスコルビン酸および月桂樹の葉中の１，８−シネオールは分解されることなく保持されていた。
〔実施例９〕 微生物の乾燥
大腸菌の乾燥
大腸菌（Ｅｓｃｈｅｒｉｃｈｉａ ｃｏｌｉ ＩＡＭ１２６４株）を２７℃で２日間培養し、生理食塩水にＯＤ６５０＝３になるように懸濁し、その８μｌを薄手の直径６ｍｍのペーパーディスクにのせた。大腸菌をのせたペーパーディスクをクレープ紙、ウール製フェルト、ダンボールで挟んで、３０秒または６０秒、家庭用電子レンジ（５００Ｗ）を用いてマイクロ波を照射し、乾燥させた。マイクロ波照射後５分間余熱乾燥させ、ＰＹＳ−２培地（ポリペプトン８ｇ、酵母エキス３ｇ、ＮａＣｌ５ｇを蒸留水１０００ｍｌに溶解させたもの）に乾燥大腸菌を含むペーパーディスクを入れ、５日間２７℃で培養し、大腸菌が増殖するかを調べた。保護剤有り無しで実験を行い、保護剤有りのものは菌体懸濁液中に１０％スキムミルクおよび２％グルタミン酸ナトリウムを添加した。実験はＮ＝３で行った。
結果を以下に示す。
照射時間 保護剤有 保護剤無
３０秒 ３／３ ３／３
６０秒 ３／３ ０／３
上記表中、３／３は３試料のうち、３試料が乾燥後の再培養で増殖したことを示す（以下の実験においても同様である）。
酵母の乾燥
上記の実験を大腸菌の代わりに酵母（Ｓａｃｃｈａｒｏｍｙｃｅｓｃｅｒｅｖｉｃｉａｅ ＪＣＭ７２５５Ｔ）について行った。但し、培地は市販のポテトデキストロース培地を用いた。
結果を以下に示す。
照射時間 保護剤有 保護剤無
３０秒 ２／３ ０／３
６０秒 ０／３ ０／３
乾燥大腸菌の保存
照射時間３０秒で、保護剤有りで乾燥させた大腸菌を５日間４℃に保存した後に、培地に入れ増殖するかどうかを調べた。Ｎ＝３で調べたところ３回の実験すべてで乾燥保存した大腸菌を再培養したところ増殖が認められた。
本明細書で引用した全ての刊行物、特許および特許出願をそのまま参考として本明細書にとり入れるものとする。EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited by these Examples.
Example 1 Drying of Delphinium Flowers As a water-containing sample to be dried, one blue delphinium flower (5 petals) was used. The raw weight before drying was 0.3 to 0.5 g. As a material covering the water-containing sample, felt (manufactured by wool, Nippon Felt Kogyo Co., Ltd., product number 227 or 229 (product numbers 277 and 229 are substantially the same product in different colors), thickness of about 2 mm), fleece (manufactured by Daiso, Polyester 100%, thickness about 3 mm), cardboard (thickness about 3 mm), paper napkin (crepe paper) and towel (100% cotton, thickness about 1.25 mm) were used. Moreover, when placing the porous flexible sheet between the water-containing sample and the porous material, crepe paper was used. Examples using felt, fleece, corrugated cardboard, crepe paper and towel were designated as Examples 1A, 1B, 1C, 1D and 1E, respectively. When viewed from above, the felt was 15 × 19 cm, the fleece was 10 × 15 cm, the cardboard was 10 × 15 cm, the crepe paper was 19 × 30 cm, and the towel was folded in 28 × 19 cm.
As shown in FIG. 3A, felt, fleece, and corrugated cardboard were sandwiched between crepe paper and the upper and lower parts of Delphinium petals were sandwiched between four felts, fleece, or corrugated cardboard. As shown in FIG. 3B, the crepe paper was used by sandwiching four sheets of crepe paper above and below the petals of delphinium. As shown in FIG. 3C, the towel was sandwiched between crepe paper and a four-fold towel. Here, “upper and lower” refers to the upper and lower relationship when placed in a microwave oven.
Subsequently, a water-containing sample surrounded by the porous flexible sheet and the porous material having moisture permeability, hygroscopicity, and heat resistance prepared in this manner was placed in a commercially available microwave oven (manufactured by Iwatani Corporation, model number IMO600, output 600 W). ) And irradiated with microwaves. Irradiation is performed for 10 to 60 seconds, and after irradiation, the temperature of the portion where the moisture-containing sample of the laminate is present is measured using a thermometer, and the weight of the moisture-containing sample is balanced (manufactured by SHIMAZU CORPORATION, model number D417400157). This operation was repeated. The time when the weight of the water-containing sample was not reduced was defined as the completion of drying. At this time, changes in appearance such as color changes were observed. Prior to drying the water-containing sample, the crepe paper and the material sandwiching the water-containing sample were preheated by irradiation with microwaves for 60 seconds. As a control, drying was also performed by the method described in JP-A-2001-071695 (referred to as OK001 method). That is, the water-containing sample was covered with a tissue, placed in a heat-resistant container so as to be covered with silica gel, and irradiated with microwaves. In the control drying method, the microwave irradiation conditions of the water-containing sample were as described above, but the preheating of the drying material (soft sheet and silica gel) was not performed.
Moreover, after complete drying was completed and finally microwave irradiation was completed, the dried product was not immediately taken out from the microwave oven, but was left for 5 to 10 minutes to perform preheat drying.
Table 1 shows the weight and temperature change of the water-containing sample for each microwave irradiation time. After stopping microwave irradiation inside the microwave oven, remove the water-containing sample, porous material with moisture permeability, hygroscopicity and heat resistance, and porous flexible sheet, if present, from the microwave oven, moisture permeability, moisture absorption Open porous material and porous flexible sheet having heat resistance and heat resistance, and contact the measurement part of the alcohol thermometer near the sample and again, porous material and porous material having moisture permeability, hygroscopicity and heat resistance The flexible sheet was closed and lightly pressed from above to read the scale on the thermometer. Although the time from the stop of microwave irradiation to the temperature measurement is as short as possible (60 seconds to 180 seconds), it may be lower than the actual temperature of the water-containing sample during microwave irradiation.

As shown in Table 1, the completion of drying in the OK001 method, which is a control drying method, is 280 seconds, whereas in Example 1A using felt, 320 seconds, in Example 1B using fleece, 200 seconds, the corrugated board is used. It was 240 seconds for Example 1C used, 180 seconds for Example 1D using crepe paper, and 120 seconds for Example 1E using towels. The temperature rise in each example was 102 ° C. maximum in the OK001 method, 51 ° C. maximum in Example 1A using felt, 56 ° C. in Example 1B using fleece, 91 ° C. in Example 1C using cardboard, and crepe It was 96 ° C. in Example 1D using paper and 94 ° C. in Example 1E using towel. When the corrugated cardboard (Example 1C) and the crepe paper (Example 1D) were used, the appearance of the dried sample of the water-containing sample was discolored in 180 seconds. No discoloration was observed in the subject drying method and Examples 1A, 1B and 1E.
Whether or not the hydrated sample can maintain its natural color and / or fragrance depends on how long the hydrated sample is exposed to the high temperature during the drying process, and is long at a protein denaturation temperature of about 60 ° C. or higher. Exposure to time is undesirable. In this respect, felt and fleece are not much different in drying time from the control drying method OK001, but the temperature rise is below the protein denaturation temperature, and towels and crepe paper are heated above 60 ° C. Although it is exposed, drying is completed quickly. Corrugated cardboard is exposed to a relatively high temperature and takes a long time to complete drying, but the time is slightly shorter and the temperature is lower than that of the OK001 method. Therefore, the methods of Examples 1A to 1E are all superior to the OK001 method in that damage to the water-containing sample during drying is small. As for what dried by OK001 method, discoloration is recognized by the whole at the time of completion | finish of drying. When cardboard, crepe paper and towels were used, it was observed that the edges of the petals turned brown upon completion of drying. FIG. 4 shows a photograph of a delphinium flower dried by this method and stored for about 3 months. Discoloration is recognized as a whole in the product dried by the OK001 method. Moreover, the thing dried by the method using a corrugated cardboard, a crepe paper, and a towel also recognizes discoloration of the edge of a petal similarly to the time of completion | finish of drying.
[Example 2] Examination of influence of preheating on drying In Example 1, the preheating was performed to dry the water-containing sample, but in this example, the necessity of the preheating was examined. The water-containing sample used was a delphinium petal as in Example 1. The moisture permeable hygroscopic drying materials used were felt (Example 2A) and fleece (Example 2B) as in Examples 1A and 1B. As control drying, it dried by the method (OK001 method) as described in Unexamined-Japanese-Patent No. 2001-071695. The water-containing sample was dried with or without preheating including the OK001 method. Further, a crepe paper was placed as a porous flexible sheet between the water-containing sample and the porous material. The water-containing sample was dried by intermittent microwave irradiation as in Example 1, and the weight and temperature were measured over time. After the microwave irradiation, preheat drying was performed in the same manner as in Example 1.
The results are shown in Table 2.

As shown in Table 2, with the OK001 method, which is a control drying method, the time to completion of drying is 240 seconds without preheating, 270 seconds with preheating, and drying faster without preheating. Completed. In the felt (Example 2A), the drying was completed earlier in 300 seconds without preheating and 180 seconds with preheating and with preheating. In the fleece (Example 2B), when the preheating was not performed, 240 seconds was obtained, and when the preheating was performed, 180 seconds was obtained.
In the OK001 method, a change in color was observed after 120 seconds of irradiation with no preheating and 180 seconds of irradiation with preheating, and the entire petal changed from blue-violet to red-purple when drying was completed. Moreover, in the Example using a fleece, in the case where there was no preheating, in both cases, the water-containing sample turned slightly brown in 180 seconds. However, it was not discolored so as to reduce the decorative effect of the dried product. When felt was used, no color change was observed even after drying was completed.
[Example 3] Drying of pansy petals As a water-containing sample to be dried, one purple pansy petal was used. The raw weight before drying was 0.036 to 0.044 g. Felt (manufactured by wool, Nippon Felt Kogyo Co., Ltd., product number 227 or 229, thickness of about 2 mm), crepe paper and cardboard were used as the porous material covering the water-containing sample. Moreover, when placing the porous flexible sheet between the water-containing sample and the porous material, crepe paper was used. In Example 3A, the top and bottom of one pansy petal were sandwiched between four crepe papers and one felt piece. In Example 3B, the top and bottom of one pansy petal were sandwiched one by one. In Example 3C, one pansy petal was sandwiched between four pieces of crepe paper, one felt piece, and two pieces of corrugated board. In Example 3D, one pansy petal was sandwiched between four crepe sheets, one felt piece, and two cardboard pieces only on the top. In Example 3E, one pansy petal was sandwiched between four crepe sheets and two felt pieces. In Example 3F, one pansy petal was sandwiched between 4 pieces of crepe paper, 2 pieces of felt, and 2 pieces of cardboard were sandwiched between the top and bottom. In Example 3G, the top and bottom of one pansy petal were sandwiched between four pieces of crepe paper, and further three felt pieces. In Example 3H, one pansy petal was sandwiched between four crepe papers and four felt pieces. As a control, drying was also performed by the method described in JP-A-2001-071695 (referred to as OK001 method). In control drying and Examples 3A and 3B, drying was performed with and without preheating, and Examples 3C to 3G were all preheated. Preheating was performed in the same manner as in Example 1. The water-containing sample was dried by intermittent microwave irradiation as in Example 1, and the weight and temperature were measured over time. After the microwave irradiation, preheat drying was performed in the same manner as in Example 1.
The results are shown in Table 3.

When preheating was performed and when it was not performed, the time required for complete drying was slightly shorter when it was performed. The time until complete drying was shorter when the hydrated sample was surrounded by crepe paper (Examples 3A and 3B). The time required for complete drying was shorter when 3 or 4 felts were stacked than when 1 or 2 felts (Examples 3F and 3G). The temperature during drying rose to 80-90 ° C. or higher in the control drying method, whereas in Examples 3A to 3F, it was about 50 ° C. or lower. In Example 3G using four upper and lower felts, the temperature was slightly higher than in the case of three or less felts, but it was 60 ° C. or less. In Example 3, no discoloration of the water-containing sample was observed.
From this result, it was found that when the water-containing sample was surrounded by a porous flexible sheet and three felt pieces were stacked one on top of the other, good drying could be achieved in terms of time until complete drying and temperature increase.
[Example 4] Drying of Aoki leaves As a water-containing sample to be dried, one Aoki leaf was used. The raw weight before drying was 0.5 to 0.7 g. As a porous material that covers the water-containing sample, fleece (made by Daiso, 100% polyester, thickness about 3 mm), polypropylene nonwoven fabric (made by Daiso, thickness about 0.8 mm), and cork board (made by Daiso, thickness about 2 mm) are used. When placing a porous flexible sheet between a water-containing sample and a porous material, tissue (manufactured by Napier Co., Ltd.), Kimwipe (manufactured by Crecia Co., Ltd.) or crepe paper was used from above the tissue and Kimwipe. In the case of Example 4A, the top and bottom of the water-containing sample were sandwiched between two tissues, and the top and bottom were sandwiched by four fleeces. The upper and lower sides of the water-containing sample were sandwiched between two sheets of crepe paper, and the upper and lower sides were sandwiched between four sheets of fleece. The bottom is sandwiched between 2 sheets of Kimwipe, and the top and bottom are sandwiched between 4 sheets of fleece, and Example 4D is sandwiched between the top and bottom of a wet sample with 2 sheets of Kimwipe, and the top and bottom is sandwiched with 16 sheets of polypropylene nonwoven fabric. The wet sample was sandwiched between two Kimwipes and the top and bottom were sandwiched by four cork plates, both of which were 13 x 18 cm in size when viewed from above. Drying was also performed by the method (OK001 method) described in JP 2001-071695 A. The OK001 method, Example 4C, Example 4D and Example 4E were performed with and without preheating. 4A and 4B were preheated in the same manner as in Example 1. The water-containing sample was dried in the same manner as in Example 1. Carried out by intermittent irradiation, over time the weight and temperature were measured. Microwave irradiation after completion performed a residual heat drying in the same manner as in Example 1.
The results are shown in Table 4.

The time until complete drying was completed was 330 to 420 seconds when preheating was performed using a fleece, and about 600 seconds when preheating was not performed. The time to complete drying when used is not measured, but polypropylene is almost equivalent to fleece and cork board is faster. The drying temperature was 50 ° C. or less when using a fleece, 60 ° C. or less when using a polypropylene non-woven fabric, and about 90 ° C. equivalent to the OK001 method when using a cork board.
In the OK001 method, the entire leaf turned black when drying was completed. Moreover, when the cork board and the polypropylene nonwoven fabric were used, the edge of the leaf was blackened when the drying was completed. In addition, when the fleece was used, when the preheating was not performed and when the tissue was used as the porous flexible sheet when preheating was performed, the edge of the leaf was blackened when the drying was completed. When crepe paper or Kimwipe was used as the porous flexible sheet when fleece was used, no discoloration of the leaves was observed.
[Example 5] Drying using a polyester fibrous porous material Parsley was used as a water-containing sample to be dried. The raw weight before drying was 0.3 to 0.7 g. As a porous material for covering a water-containing sample, a quilt core made of 100% polyester (Nippon Vilene Co., Ltd., about 10 mm thick), a domit core made of 100% polyester (Nippon Vilene Co., Ltd., about 7 mm thick), and a felt made of 100% wool Fabrication fiber (Clover Co., Ltd.) was used. Further, crepe paper was used as the porous flexible sheet between the water-containing sample and the porous material.
The top and bottom of the parsley are sandwiched with crepe paper, and the top and bottom are sandwiched with 4 quilt cores and 2 to 4 domitt cores. The wool fibers for producing felt were placed on the top and bottom of the crepe paper sandwiched between the top and bottom of the parsley so that the bundled wool fibers (the thickness of the bundle was about 10 mm) covered the crepe paper.
Subsequently, a water-containing sample surrounded by the porous flexible sheet thus prepared and a porous material having moisture permeability, hygroscopicity, and heat resistance was obtained from a commercially available microwave oven (Iwatani Corp., model number IMO600, output 500 W). ) And irradiated with microwaves. Irradiation was performed for 90 seconds. After the microwave irradiation was completed, the dried product was immediately taken out of the microwave oven (preheated drying 0 minutes) or left for 5 minutes or 10 minutes to perform preheated drying. In the case of wool fiber, it was allowed to stand for 10 minutes and dried by preheating.
Tables 5, 6 and 7 show the results of drying methods using quilt cores, domit cores and wool fibers, respectively.

The table shows the number of superposed porous materials for each preheating time, the weight before drying, the weight after drying, and the moisture removal rate.
In any material, parsley showed a similar water removal rate, and no discoloration after drying was observed.
[Example 6] Drying using various kinds of fibrous porous materials The following were used as the fibrous porous materials.
(1) Wool nonwoven fabric (100% wool)
(2) Corrugated cardboard (Thickness of 8 / 3mm is used in 3 layers)
(3) Cotton (100% cotton) cotton quilt cotton (Nippon Vilene Co., Ltd., model number KMW-1P)
(4) Made of polyester (100% polyester) patchwork quilt cotton Domit thin type (Nippon Vilene Co., Ltd., model number QB-95)
(5) Made of polyester (100% polyester) patchwork quilt cotton Domit thin type (Nippon Vilene Co., Ltd., model number TKS-35P)
(6) Made of polyester (100% polyester) patchwork quilt cotton Domit thick type (Nippon Vilene Co., Ltd., model number KSP-120A)
(7) Cotton & polyester quilt core (60% cotton, 40% polyester) (KINKAME, model number 480557)
(8) Patchwork quilted cotton (black) (60% polyester, 40% rayon) (manufactured by Japan Vilene Co., Ltd., model number MH-14-BKP)
All the fibrous porous materials were used in a stack of two.
The material used was about 0.2-0.6 g of parsley.
The drying method is almost the same as that of Example 5, but the microwave irradiation was first performed for 60 seconds, and then 30 seconds of irradiation was intermittently performed 2 to 3 times (the total drying time is 120 to 180 seconds). The parsley was taken out for every intermittent irradiation, the degree of dryness was judged by touch, and the weight was measured.
Below, the drying result about each material is shown. Tables 8 to 15 correspond to the fibrous porous materials (1) to (8) described above, respectively. In the table, the dry state and / or weight of the parsley taken out after the microwave intermittent irradiation in the drying process is described.

As Tables 8 to 15 show, any fibrous porous material could be dried well.
[Example 7] Heat resistance (microwave resistance) of fibrous porous material
The heat resistance (microwave resistance) of various fibrous porous materials was examined.
The fibrous porous material used was as follows.
(1) Wool nonwoven fabric (100% wool)
(2) Corrugated cardboard (Thickness of 8 / 3mm is used in 3 layers)
(3) Made of polyester (100% polyester) patchwork quilt cotton Domit thin type (Nippon Vilene Co., Ltd., model number QB-95)
(4) Made of polyester (100% polyester) patchwork quilt cotton Domit thin type (Nippon Vilene Co., Ltd., model number TKS-35P)
(5) Made of polyester (100% polyester) patchwork quilt cotton Domit thick type (Nippon Vilene Co., Ltd., model number KSP-120A)
(6) Cotton & polyester quilt core (60% cotton, 40% polyester) (KINKAME, model number 480557)
(7) Patchwork quilted cotton (black) (60% polyester, 40% rayon) (manufactured by Japan Vilene Co., Ltd., model number MH-14-BKP)
The upper and lower sides of the fibrous porous material were sandwiched by corrugated cardboard (3 sheets of thickness 8/3 mm), and this was heated at 500 W for 60 seconds. After heating, the material was quickly removed and changes were confirmed. When it was not yet dried, it was quickly returned to the microwave oven (within 15 seconds on average) and further heated at 500 W for 60 seconds. Thereafter, heating was performed in 1 minute increments until the material appeared to change. As soon as smoke or a strange odor was generated from the material, the microwave oven was immediately stopped and the material was taken out.

Further, each material was directly irradiated with microwaves without being sandwiched between cardboards. None of the materials showed any change when irradiated with microwaves for at least 10 minutes.
From Example 5, it was found that any material had heat resistance (microwave resistance).
[Example 8] Analysis of pigment and aroma component of dried body Among the methods of Example 5, parsley dried by the method of the present invention and bay leaves dried by the same method were used for analysis. Examine the moisture content of the sample before and after drying, measure the ascorbic acid content before and after drying for parsley, and the content of 1,8-cineole (eucalyptol) before and after drying for bay leaves. It was measured. The measurement was commissioned to the Japan Food Analysis Center. As a control, measurement was also performed on a sample dried by a freeze-drying method. Measurements were made on 1 to 2 samples.
Water-containing sample Ascorbic acid content parsley (before drying) 0.78%
Parsley (after drying: method of the present invention) 0.79%
Water-containing sample 1,8-Shionel content bay leaves (before drying) 0.77%
Laurel leaves (after drying: freeze-dried) 0.81%
Laurel leaf (after drying: the method of the present invention) 0.79%
The values in the table are based on the weight of a dried product obtained by further drying the sample in the parentheses at 70 ° C. for 5 hours.
As shown in the table, in the method of the present invention, ascorbic acid in parsley and 1,8-cineole in bay leaves were retained without being decomposed.
[Example 9] Drying of microorganism E. coli Dry Escherichia coli ( Escherichia coli IAM1264 strain) was cultured at 27 ° C. for 2 days, suspended in physiological saline so that OD650 = 3, and 8 μl thereof was a thin 6 mm diameter paper. I put it on the disc. The paper disk on which E. coli was placed was sandwiched between crepe paper, wool felt and cardboard, and dried for 30 seconds or 60 seconds using a microwave oven (500 W) for microwave irradiation. After microwave irradiation, preheated for 5 minutes, put a paper disk containing dry Escherichia coli in PYS-2 medium (polypeptone 8g, yeast extract 3g, NaCl 5g dissolved in distilled water 1000ml) and incubate at 27 ° C for 5 days. It was examined whether Escherichia coli grew. Experiments were conducted with and without a protective agent. For those with a protective agent, 10% skim milk and 2% sodium glutamate were added to the cell suspension. The experiment was performed with N = 3.
The results are shown below.
Irradiation time With protective agent Without protective agent 30 seconds 3/3 3/3
60 seconds 3/3 0/3
In the above table, 3/3 indicates that 3 of the 3 samples grew by re-culture after drying (the same applies to the following experiments).
Drying of yeast The above experiment was carried out on yeast ( Saccharomyces cerevisiae JCM7255T) instead of E. coli. However, a commercially available potato dextrose medium was used as the medium.
The results are shown below.
Irradiation time With protective agent Without protective agent 30 seconds 2/3 0/3
60 seconds 0/3 0/3
Storage of dried E. coli E. coli dried with a protective agent at an irradiation time of 30 seconds was stored at 4 ° C. for 5 days, and then examined if it was put into a medium to grow. When N = 3 was examined, E. coli that had been dry-stored in all three experiments was re-cultured and growth was observed.
All publications, patents and patent applications cited herein are incorporated herein by reference in their entirety.

Industrial applicability

  According to the method of the present invention, it is possible to dry a water-containing sample without destroying its cells and tissues and useful components contained therein more quickly and without exposing the sample to a high temperature as compared with conventional drying methods. By the method of the present invention, a dried product having a nutrient component, color and / or aroma in a natural state of a water-containing sample can be obtained. Further, the method of the present invention allows the microorganisms to be dried while they are alive, and is useful as a method for preserving microorganisms.

Claims (15)

This is a rapid drying method for a water-containing sample, which includes enclosing the outer surface of a water-containing sample with a porous material having moisture permeability, hygroscopicity, and heat resistance, placing it in a microwave generator, and irradiating the microwave with it. A quick drying method for water-containing samples in which a quality flexible sheet and a porous material having moisture permeability, hygroscopicity, and heat resistance are preheated by microwave irradiation in advance. Surrounding the outer surface of the water-containing sample with a hygroscopic porous flexible sheet, and surrounding the sheet with a porous material having moisture permeability, hygroscopicity, and heat resistance, placing it in a microwave generator and irradiating it with microwaves A rapid drying method for a water-containing sample including a hygroscopic porous flexible sheet and a porous material having moisture permeability, hygroscopicity, and heat resistance preliminarily heated by microwave irradiation . The rapid drying method of a water-containing sample according to claim 1 or 2 , wherein the water-containing sample is dried by irradiating microwaves in a microwave generator and then dried by preheating. The rapid drying method of a water-containing sample according to claim 3 , wherein the preheat drying is performed in a microwave generator. The rapid drying method for a water-containing sample according to claim 1 or 2 , wherein the porous material having moisture permeability, hygroscopicity, and heat resistance is corrugated cardboard. The rapid drying method of a water-containing sample according to claim 5, wherein the corrugated board contains hygroscopic granules. The rapid drying method of a water-containing sample according to claim 1 or 2 , wherein the ambient temperature of the water-containing sample immediately after microwave irradiation is less than 60 ° C. The method for rapidly drying a water-containing sample according to claim 7 , wherein the porous material having moisture permeability and hygroscopicity is felt or fleece. The rapid drying method of a water-containing sample according to any one of claims 1 to 8 , wherein the microwave irradiation is performed until the water reduction rate in the water-containing sample becomes 95% or more. The rapid drying method of a water-containing sample according to claim 9 , wherein the water-containing sample is a raw sample. The method for quickly drying a water-containing sample according to claim 10 , wherein the raw sample is a plant or a part thereof. The method for quickly drying a water-containing sample according to claim 10 , wherein the raw sample is a microorganism and the dried microorganism is alive.   Surround one petal of a plant with a candidate porous material, irradiate it with microwaves, measure the moisture reduction rate of the water-containing sample and the temperature in the vicinity of the water-containing sample at regular intervals, and the water reduction rate is 100 from 60 seconds to 240 seconds. %, And a material whose temperature does not rise above 60 ° C. is selected as a material suitable for use in drying. The moisture permeability, hygroscopicity, and heat resistance suitable for the rapid drying method for water-containing samples according to claim 1 are selected. A method for selecting a porous material. A rapid drying kit for a water-containing sample, comprising a porous material having moisture permeability, hygroscopicity and heat resistance selected by the method according to claim 13 , and a porous flexible sheet. Breathable rapid drying kit hydrous sample according to claim 13, wherein the porous material is a felt or fleece hygroscopic.

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