Ice nucleus activator

Abstract

There has been a demand for ice nucleus activating substances that have higher safety for living bodies and can be used in various fields. However, there are not yet enough reports of such ice nucleus activating substances.　According to the present invention, an ice nucleus activator containing an effective amount of a plant pulverization product and / or an extraction residue thereof is prepared.

Description

Ice nucleating agent

[0001] The present invention relates to an ice nucleating agent.

[0002] Freezing technology has improved in recent years, making it possible to use quick freezing methods and more appropriate control of freezing temperatures.

[0003] The freezing phenomenon of water can be divided into two stages: the ice crystal formation stage and the ice crystal growth stage. In pure water, the temperature at which tiny ice crystals form is between -40°C and -70°C, and the subsequent growth temperature is around 0°C to -20°C, and freezing requires supercooling and time. Therefore, by adding an ice nucleating agent that can catalyze this ice crystal formation stage, water will freeze at a higher negative temperature.

[0004] Known examples of such ice nucleation active substances include Pseudomonas bacteria and silver iodide. Silver iodide can raise the ice crystal formation temperature to approximately -2°C to -4°C, enabling efficient freezing.

[0005] However, existing ice nucleation active materials are limited in their application fields due to safety concerns for living organisms, and are not fully utilized in products that are applied to living organisms, such as food and pharmaceutical products.

[0006] Patent Document 1 proposes an ice nucleating agent containing calcium oxalate as an active ingredient, and reports that the ice nucleating activity increases depending on the hydration state. However, calcium oxalate is a needle-like crystal that irritates and damages the living body, so its application fields may be limited.

[0007] JP 2014-55273 A

[0008] There is a need for ice nucleating agents that are safer for living organisms and can be used in various fields, but there have not yet been sufficient reports on them.

[0009] In view of the above-mentioned problems, the inventors conducted extensive research and discovered that crushed plant material and / or its extraction residue can be used as an ice nucleation active substance, and by incorporating an effective amount of this substance, they have completed an ice nucleation active agent.

[0010] That is, the present invention provides the ice nucleating activator described below.

[0011] Item 1. An ice nucleating agent containing an effective amount of crushed plant material and / or its extraction residue.

[0012] Item 2. The ice nucleating activator according to Item 1, wherein the plant is tea plant (Camellia sinensis L.), rice (Oryza sativa), coconut palm (Cocos nucifera), oil palm (Elaeis guineensis), or oil palm (Elaeis oleifera).

[0013] Item 3. The ice nucleation activator according to Item 1, wherein the extraction residue is an extraction residue of green tea, brown rice tea, black tea, rice straw (rice husk), or palm fruit or leaves.

[0014] Item 4. The ice nucleating activator according to Item 1, which is used so that the ice nucleation temperature is -2°C to 0°C.

[0015] By using plant materials that are widely consumed and incorporating effective amounts of crushed plant material and / or its extract residue, it is possible to provide an ice nucleating agent that can be used in a variety of fields.

[0016] [Ice Nucleating Activator] The ice nucleating activator of the present invention contains an effective amount of crushed plant material and / or its extraction residue.

[0017] In this specification, the term "crushed plant material" refers to a plant body that has been subjected to physical treatment such as cutting or crushing to make it into small pieces (crushed).

[0018] The crushed material can be obtained by finely crushing the plant body using, for example, a sawdust maker, a cutting device, a crusher, a crusher, a mill, a blender, a millstone, or the like.

[0019] The crushed plant material can be sieved as needed to adjust the particle size appropriately.

[0020] The plant may be dried before or after crushing. The moisture content of the crushed plant material is not particularly limited and can be set appropriately.

[0021] The drying treatment is not particularly limited, but examples include a treatment in which the plant body is dried to a moisture content of 10% or less, preferably 5% or less. The drying treatment can be carried out by any method known to those skilled in the art, such as hot air drying, high-pressure steam drying, electromagnetic wave drying, or freeze drying. Drying by heating can be carried out at a temperature and for a time such that the plant body does not discolor due to heating, for example, at 40°C to 140°C, preferably 80°C to 130°C.

[0022] The plant body used for plant crushing may be any part of the plant, such as leaves, branches, wood, petals, stems, roots, flesh, skin, and seeds, but from the perspective of repeatedly harvesting the plant while leaving the roots, it is preferable to use the above-ground parts that are exposed above ground.

[0023] The plant to be used may be any plant whose safety to the human body has been confirmed, and preferably a plant that has been used as food. The plant may be used alone or in combination of two or more kinds.

[0024] The type of plant is not particularly limited, but from the viewpoint of significantly achieving the effects of the present invention, examples include plants of the Theaceae, Poaceae, Palmaceae, Malvaceae, Fabaceae, Vitaceae, Apiaceae, Polygonaceae, etc., and plants of the genus Camellia, Oryza, Hordeum, Coconut, Oil palm, Cacao, Arachis, Vitis, Angelica, Buckwheat, etc. are preferred, and tea plant (Camellia sinensis L.), rice (Oryza sativa), barley (Hordeum vulgare), coconut palm (Cocos nucifera), oil palm (Elaeis guineensis), oil palm (Elaeis oleifera), cacao (Theobroma cacao L.), etc. are particularly preferred. cacao), peanut (Arachis hypogaea), grape (Vitis spp.), angelica tree (Angelica keiskei), or buckwheat (Fagopyrum esculentum) are more preferred, and tea leaves, used tea leaves, rice straw, rice husks, coconut shells, coconut leaves, cacao skin, peanut skin, grape skin, angelica tree leaves, buckwheat husks, and barley seeds are even more preferred.

[0025] As used herein, the term "plant extraction residue" refers to the residue that remains when a plant body is immersed in a solvent to extract desired components into the solvent (solid-liquid extraction), and then the solvent (extract) containing the components is separated by filtration or the like.

[0026] In the extraction of plants, it is also possible to obtain crushed material using a crusher or the like as described above and then subject the crushed material to extraction treatment. In addition, in the extraction treatment, heating or stirring, for example, may be performed as necessary.

[0027] Examples of the extraction solvent include water and / or organic solvents (ethyl alcohol, oil, etc.), and the solvent may be mixed with an extractant such as a chelating agent, acid, or alkali, if necessary.

[0028] The plant extraction residue is not particularly limited, but examples include used tea leaves obtained from tea leaves, coconut shells obtained from oil palm, coffee grounds obtained from coffee beans, potato waste, shochu dregs, grape skins, awamori dregs (moromi lees), etc. These extraction residues are waste products that are discharged in large quantities during the production processes of tea, coffee beverages, shochu, wine, awamori, etc., and reusing them is preferable from the viewpoint of reducing the environmental load.

[0029] Used tea leaves are obtained from tea leaves, and examples thereof include used tea leaves after hot water extraction in the production of sencha, genmaicha, black tea, roasted green tea, oolong tea, etc.

[0030] Coconut shells are the residues left after oil is extracted from the fruits of oil palms and the like (also called palm fruits).

[0031] Extraction residues of plants other than those mentioned above may also be used, such as residues obtained after hot water extraction of rice straw, cacao skin, peanut skin, grape skin, angelica tree leaves, buckwheat husks, barley seeds, etc.

[0032] The average particle size of the plant is not particularly limited, and examples thereof include 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more, 100 μm or more, 110 μm or more, 120 μm or more, 130 μm or more, 140 μm or more, 150 μm or more, 160 μm or more, 170 μm or more, 180 μm or more, 190 μm or more, 200 μm or more, 210 μm or more, 220 μm or more, etc. Furthermore, examples of the average particle size of the plant include 500 μm or less, 450 μm or less, less than 425 μm, 420 μm or less, 410 μm or less, 400 μm or less, etc. The average particle size of the plant may be, for example, 10 to less than 425 μm, 50 to less than 425 μm, 60 to less than 425 μm, 100 to less than 425 μm, 110 to less than 425 μm, 200 to less than 425 μm, 210 to less than 425 μm, 220 to less than 425 μm, 10 to 420 μm, 50 to 420 μm, 6 Examples include 0 to 420 μm, 100 to 420 μm, 110 to 420 μm, 200 to 420 μm, 210 to 420 μm, 220 to 420 μm, 10 to 210 μm, 50 to 210 μm, 60 to 210 μm, 100 to 210 μm, 110 to 210 μm, 10 to 110 μm, 50 to 210 μm, 60 to 210 μm, etc. Although not limited thereto, it is preferred that the formulation of the present invention contains crushed material having the above average particle size.

[0033] In one embodiment, the content of particles of the plant having an average particle size of less than 425 μm can be, for example, 30% by mass or more, 35% by mass or more, 40% by mass or more, or 45% by mass or more, relative to the total amount of the plant.

[0034] In another embodiment, the content of particles of the plant having an average particle size of 210 to less than 425 μm can be, for example, 25% by mass or more, 30% by mass or more, 35% by mass or more, or 36% by mass or more, relative to the total amount of the plant.

[0035] In the ice nucleating activator of the present invention, the content of crushed plant material and / or its extraction residue is appropriately adjusted depending on the form of the formulation, the type and content of other components, etc., and is not limited, and can be, for example, 0.000001% by mass or more, such as 0.000005% by mass or more, 0.00001% by mass or more, 0.00005% by mass or more, 0.0001% by mass or more, 0.0005% by mass or more, 0.001% by mass or more, etc. Furthermore, the content of crushed plant material and / or its extraction residue can be, for example, 99.999% by mass or less, such as 99.9% by mass or less, 99.5% by mass or less, 99% by mass or less, 98.5% by mass or less, 98% by mass or less, etc., based on the total amount of the formulation. In another embodiment, when prepared as a liquid formulation, the content of crushed plant material and / or its extraction residue can be, for example, but is not limited to, 80% by mass or less, relative to the total amount of the formulation, including 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 10% by mass or less, 5% by mass or less, 1% by mass or less, etc.

[0036] [Uses] The use of the present invention can suppress supercooling and promote ice nucleation, making it suitable for use as an ice nucleation activator. In this specification, ice nucleation activity refers to an index that indicates the ease of phase transition from liquid to solid. The higher the ice nucleation activity, the more likely it is that freezing will occur at temperatures closer to 0°C. In other words, the higher the ice nucleation activity, the more likely it is that supercooling will be suppressed during freezing, and the less energy is required to achieve freezing.

[0037] In one embodiment, the ice nucleating activator can be used for the following applications, but is not limited to these: (1) Freezing and cryopreservation of various substances (2) Freezing and freezing of foodstuffs and the like where safety is required (3) Energy and power saving applications in freezers, cold storage devices, refrigeration devices, etc. (4) Freezing and concentration of liquids (5) Separation methods using freeze and concentration (6) Freezing at temperatures higher than - (7) Manufacturing of ice slurry (sherbet, etc.) (8) Cold-hardening cultivation of vegetables, etc. (9) Freezing treatment applications in waste disposal and cleaning (10) Freezing detection (freeze indicator, etc.) (11) Freezing prevention applications (12) Applications such as artificial rainfall and artificial snowfall

[0038] The ice nucleation activity can be measured by a known method, and is not limited thereto. For example, it can be measured by the following method.

[0039] A predetermined amount of sample containing the test substance is placed in a test tube (17.5 x 130 mm), 10 ml of deionized water is added, and a temperature sensor (Temperature Sensor Jr. RTR-502, T&D Corporation) is attached to each tube. The tubes are immersed in a refrigerated thermostatic bath set at -20°C in groups of 10, and the temperature is gradually lowered, and the temperature at which each tube forms ice nuclei is recorded. This method is hereinafter referred to as the "test tube method" in this specification.

[0040] Typically, to measure the ice nucleation temperature, the microdroplet freezing method is used to measure one or two samples, and the temperature at which 50% of 30 10 μL water droplets freeze is taken as the ice nucleation temperature, and the same procedure is performed three times. However, while this method can measure the ice nucleation activity of each sample, it cannot measure other temperatures, such as the temperature at which ice crystals grow or the time it takes for all the water to freeze.

[0041] In the present invention, the test tube method measurement of a sample containing a test substance was carried out at least three times using 10 tubes, and the average value of the 30 measurement results was taken as the ice nucleation temperature of each sample.

[0042] The present invention can be used for, for example, a refrigeration device, a cold storage device, or a cold insulation device to suppress supercooling and reduce power consumption.

[0043] The present invention can also be used to promote snowfall or rainfall by spraying it into the sky, or to prevent disasters by spraying it against typhoons, cyclones, etc.

[0044] The present invention can also be used for weed control by, for example, spraying it on soil to promote frost.

[0045] The present invention can also be used for freeze concentration by acting on a supercooled liquid, for example, to promote ice nucleation of the solvent, and then removing the frozen solvent.

[0046] The present invention can also be used, for example, to suppress supercooling and freeze and preserve objects at an appropriate temperature. Examples of objects include various aqueous solutions, gases, cells and tissues of humans, animals, plants, insects, seafood, microorganisms, and other biological resources, such as cultures, liquids and alcoholic beverages in which volatile flavor components are important, vegetables, seafood such as fresh fish, and frozen foods. [Formulations] The compositions of the present invention can be formulated as solid formulations such as tablets, capsules, granules, and powders; or liquid formulations such as solutions, syrups, creams, lotions, pastes, emulsions, gels, and suspensions. Solid formulations can contain, for example, excipients, lubricants, binders, and disintegrants; and liquid formulations can contain, for example, solvents, solubilizers, emulsifiers, emulsion stabilizers, thickeners, suspending agents, isotonicity agents, and buffers.

[0047] Next, the present invention will be specifically explained with reference to examples and test examples, but the present invention is not limited to the following examples and test examples.

[0048] Test Example 1: Screening of plant resources for substances with ice nucleation activity The ice nucleation temperature was evaluated using various crushed plant materials and extraction residues. Each sample used in the test was prepared as follows.

[0049] (Preparation of various crushed plant materials 1) Commercially purchased green tea, brown rice tea, or black tea was dried for 10 hours using a dry food maker (Apix AFD-550-WH) with a cooking sheet placed on top to completely dry the tea. After drying, the tea was finely crushed using a Magic Bread Deluxe (compact mixer) to obtain crushed material. In the following, the crushing process using the compact mixer was carried out under the same conditions for each plant.

[0050] (Preparation of various crushed plant materials 2) Commercially purchased rice straw, coconut shells, or sawdust was directly crushed into fine powder using a Magic Bullet Deluxe (compact mixer) to prepare crushed materials.

[0051] (Preparation of Various Plant Extract Residues 1) The plant extract residues of Sencha, Genmaicha, or Black tea after hot water extraction were dried for 10 hours using a dry food maker (Apix Co., Ltd., AFD-550-WH) with a cooking sheet placed on top. After drying, the residues were finely pulverized using a Magic Bread Deluxe (compact mixer) to obtain crushed material.

[0052] (Preparation of Various Plant Extract Residues 2) To completely dry the hot water extracted rice straw, coconut shell, or sawdust, a cooking sheet was placed on top and the mixture was dried for 10 hours using a dry food maker (Apix Co., Ltd. AFD-550-WH). After drying, the mixture was finely pulverized using a Magic Bread Deluxe (compact mixer) to obtain a crushed product.

[0053] The specific test method was as follows: 5 mg of a predetermined amount of sample containing the dried test substance was placed in a test tube (17.5 x 130 m), 10 ml of deionized water was added, and each tube was immersed in a refrigerated thermostatic bath set at -20°C using a temperature sensor (Temperature Sensor Jr. RTR-502, T&D Co.) in groups of 10, and the temperature was gradually lowered, and the temperature at which ice nuclei formed in each tube was recorded. The results are shown in Table 1.

[0054]

[0055] As shown in Table 1, ice nucleation temperatures exceeding -2°C were confirmed for samples using crushed plant material derived from tea plants and rice, and extraction residues derived from tea plants, rice, and palm. There have been few reports of ice nucleation temperatures exceeding -2°C in conventional technology, and the observation of extremely high ice nucleation activity in plants that are particularly safe for living organisms was an unexpected result.

[0056] [Reference Test Example: Investigation of factors affecting ice nucleation activity] In the above Test Example 1, when the samples of Example 5 and Comparative Example 2 were compared, a large difference occurred in the ice nucleation temperature, even though both samples were derived from the same coconut shell. Since Patent Document 1 reports the influence of calcium oxalate, the oxalic acid content of the samples of Example 5 and Comparative Example 2 was measured.

[0057] The specific test method is as follows. The quantification of oxalic acid was carried out by high performance liquid chromatography (HPLC) under the following conditions. Oxalic acid (manufactured by Kanto Chemical Co., Ltd.) was used as the standard substance for quantification. Apparatus: LC-20AD (manufactured by Shimadzu Corporation) Column: Shodex RSpak KC-811x2 (8.0 mm ID x 300 mm, manufactured by Showa Denko K.K.) Eluent: 0.5 w / v % phosphoric acid Flow rate: 1.0 mL / min Column temperature: 30°C Detector: UV-visible absorptiometer SPD-20AV (manufactured by Showa Denko K.K.) The results are shown in Table 2.

[0058]

[0059] In Test Example 1, the influence of oxalic acid was assumed to be one of the factors that caused the extremely high ice nucleation temperature. However, as shown in the Reference Test Example, the oxalic acid content in both the samples of Example 5 and Comparative Example 2 was below the detection limit by high-performance liquid chromatography, confirming that oxalic acid was not the only factor.

[0060] The reason why the samples in each Example of Test Example 1 showed extremely high ice nucleation temperatures is still unclear, but the following is a suspected mechanism: Ice nucleation is related to factors such as hydrophobicity, charge balance, and the particle shape of the powder of the test substance, and it is suspected that the samples in each Example of Test Example 1 were influenced by the fact that they were made of a material with a high degree of hydrophobicity and a surface charge close to the isoelectric point of water.

[0061] Test Example 2: Examination of the effect of the average particle size of plant extraction residue on ice nucleation activity Among the above-mentioned speculated mechanisms, the effect of the average particle size on ice nucleation activity was confirmed. In the above-mentioned Test Example 1, the crushed material of each plant body and the extraction residue were crushed under the same conditions, so as an example, the average particle size of crushed brown rice tea and the ice nucleation temperature for each particle size distribution were measured. The ice nucleation temperature was measured in the same way as in Test Example 1. The specific method for measuring the average particle size is as follows. For the crushed material or extraction residue prepared in Test Example 1, a laser diffraction / scattering particle size distribution measuring device (LA-960, manufactured by Horiba, Ltd.) was used to measure the arithmetic mean diameter on a volume basis, and the measurement result was taken as the average particle size. The results are shown in Table 3.

[0062]

[0063] As shown in Table 3, the ice nucleation temperature differs depending on the particle size distribution, and it was found that when the average particle size is equal to or smaller than a certain value, the ice nucleation temperature increases and ice nucleation activity improves. Although this is one embodiment and is not intended to be limiting, the formulation of the present invention preferably contains crushed material having an average particle size of less than 425 μm, and more preferably contains crushed material having an average particle size of 210 to 425 μm.

Claims

1. An ice nucleation activator containing an effective amount of crushed plant material and / or its extraction residue.

2. The ice nucleation activator according to claim 1, wherein the plant is tea plant (Camellia sinensis L.), rice (Oryza sativa), coconut palm (Cocos nucifera), oil palm (Elaeis guineensis), or oil palm (Elaeis oleifera).

3. The ice nucleation activator according to claim 1, wherein the extraction residue is an extraction residue of sencha, genmaicha, black tea, rice straw, or palm fruit or leaves.

4. The ice nucleation activator according to claim 1, which is used so that the ice nucleation temperature is -2°C to 0°C.

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