Non-freezing solution

Abstract

To provide a nonfreezing solution that allows for a lowered supercooling release temperature.SOLUTION: A nonfreezing solution does not have an ice crystal growth inhibitor including a polysaccharide, added thereto. The nonfreezing solution contains water, a supercooling promoter including an organic compound extracted from coffee grounds, and an alcohol.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an antifreeze solution, and more particularly to an antifreeze solution containing a supercooling promoter. [Background technology]

[0002] Conventionally, antifreeze solutions containing supercooling promoters have been known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses an antifreeze solution containing water, an ice crystal growth inhibitor containing a polysaccharide, a supercooling promoter, and an antifreeze agent. In the above-mentioned Patent Document 1, the ice crystal growth inhibitor binds to ice crystals, thereby preventing the ice crystals from growing large. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-31635 Summary of the Invention [Problem to be solved by the invention]

[0005] Here, since antifreeze solutions are used in sub-zero environments, it is desirable to further lower the limit temperature (supercooling release temperature) at which the freezing point can be lowered below 0°C and the supercooled state can be maintained.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide an antifreeze solution that can lower the supercooling release temperature. [Means for solving the problem]

[0007] In order to achieve the above object, the inventors of the present application conducted extensive research and discovered that it is possible to further lower the supercooling release temperature by not adding an ice crystal growth inhibitor containing a polysaccharide, but by containing water, a supercooling promoter containing an organic compound extracted from coffee grounds, and alcohol.

[0008] That is, the antifreeze solution according to the first aspect of the present invention does not contain an ice crystal growth inhibitor containing a polysaccharide, and contains water, a supercooling promoter containing an organic compound extracted from coffee grounds, and alcohol. The antifreeze solution contains an alcohol at a concentration of 0.1 vol% or more and 10 vol% or less, the supercooling accelerator contains a polyphenol as an organic compound, the polyphenol concentration in the antifreeze solution is 0.2 μg / ml or more and 40 μg / ml or less, and the alcohol has a carbon number of 3 or less. .

[0009] As described above, the antifreeze solution according to the first aspect of the present invention does not contain an ice crystal growth inhibitor. The inventors further discovered that ice crystal growth inhibitors bind to water molecules to form ice nuclei. Therefore, the absence of an ice crystal growth inhibitor can prevent the ice crystal growth inhibitor from forming ice nuclei and freezing. Furthermore, the antifreeze solution contains a supercooling promoter containing an organic compound extracted from coffee grounds. This supercooling promoter adsorbs impurities that form ice nuclei and inhibits the formation of ice nuclei, thereby preventing the formation of ice nuclei and the release of the supercooled state. Furthermore, the antifreeze solution contains alcohol, which binds to water molecules, disrupting their arrangement, preventing the water molecules from becoming more easily frozen. These results allow the supercooling release temperature, which is the limit temperature at which the supercooled state can be maintained, to be lowered. Furthermore, the inventors have found through experiments described below that when the alcohol concentration in the antifreeze solution is between 0.1 vol% and 10 vol%, the supercooling state release temperature is lower than when the alcohol and supercooling accelerator are added to the antifreeze solution separately. Polyphenols are compounds that have a supercooling acceleration effect. Therefore, a polyphenol concentration of 0.2 μg / ml or higher in the antifreeze solution can provide sufficient supercooling acceleration. For example, adding polyphenols at 200 μg / ml or higher does not affect the supercooling acceleration effect or safety. However, the higher the polyphenol concentration, the darker the color of the antifreeze solution becomes. Therefore, a polyphenol concentration of 40 μg / ml or lower can prevent excessive coloration of the antifreeze solution due to the presence of a large amount of polyphenol. Furthermore, by using alcohols with a carbon number of 3 or less, which are easily soluble in water, freezing point depression can be reliably achieved.

[0014] The antifreeze solution according to the first aspect is preferably used as a humidification source for a humidifier. With this configuration, the antifreeze solution does not freeze even at sub-zero temperatures, and therefore can easily humidify, for example, a refrigerated warehouse where the room temperature is sub-zero.

[0015] The antifreeze solution according to the first aspect is preferably used to produce ice slurry by releasing supercooled water used as a humidification source in a humidifier. Here, the lower the supercooling release temperature, the smaller the particle size of the ice crystals. Therefore, by releasing the supercooled water of the present invention to produce ice slurry, the supercooling release temperature can be lowered, and therefore ice slurry with smaller particle size of ice crystals can be produced.

[0016] The antifreeze solution according to the first aspect is preferably used in a food thawing device for thawing food using running water or ice slurry. Here, the temperature of the liquid used for thawing food is preferably 0°C or lower to prevent deterioration of food quality. Therefore, by releasing the supercooled water of the present invention to produce an ice slurry, the supercooling release temperature can be lowered, allowing thawing to be performed using supercooled water or ice slurry at a low temperature. [Effects of the Invention]

[0017] According to the present invention, it is possible to further lower the supercooling release temperature. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a graph showing the relationship between the supercooling release temperature and the concentration of the added substance in Example 1. [Figure 2] 10 is a graph showing the relationship between the supercooling release temperature and the concentration of the added substance in Example 2. [Figure 3] 1 is a graph showing the relationship between the supercooling release temperature and the concentration of the added substance in Comparative Example 1. [Figure 4] 10 is a graph showing the relationship between the supercooling release temperature and the concentration of the added substance in Comparative Example 2. [Figure 5] 10 is a graph showing the relationship between the supercooling release temperature and the concentration of the added substance in Comparative Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0019] The composition of the antifreeze solution of the present invention will be described.

[0020] (Composition of antifreeze solution) The antifreeze solution is produced by dissolving a supercooling promoter and alcohol in water. The antifreeze solution does not contain any ice crystal growth inhibitors, including polysaccharides. The antifreeze solution of the present invention can reduce the size of ice crystals when the supercooling state is released, even without adding a crystal growth inhibitor, by lowering the supercooling elimination temperature. The lower the supercooling elimination temperature, the more ice nuclei are formed in a short time when the supercooling state is released. However, the formation of a large number of ice nuclei in a short time limits the space available, inhibiting the growth of the ice nuclei and resulting in a smaller particle size of the ice crystals.

[0021] (Supercooling promoter) The supercooling promoter adsorbs impurities with ice nucleation activity. By adsorbing the impurities, the supercooling promoter inhibits the impurities from combining with water to form ice nuclei. The impurities include dust and dirt in the air.

[0022] The supercooling accelerator includes an organic compound derived from coffee grounds. The supercooling accelerator also includes polyphenols, which are organic compounds having an aromatic hydrocarbon structure and a hydroxyl group. The organic compound derived from coffee grounds is, for example, an organic compound having the composition formula C 15 H 26 N2O7 is a compound with a molecular weight of 346. Coffee grounds are the residue remaining after coffee is extracted from coffee beans. Organic compounds derived from coffee grounds can be purified, for example, through a chromatographic fractionation process, an organic solvent extraction process, and a purification process.

[0023] The supercooling accelerator is used either as a solid coffee grounds extract or as a solution in water. The concentration of the supercooling accelerator solution is adjusted to, for example, 1 mg / ml.

[0024] The supercooling accelerator is added so that its concentration in the antifreeze solution is 0.1 vol% or more and 20 vol% or less. The concentration of the supercooling accelerator in the antifreeze solution is preferably 10 vol% or less. The concentration of the supercooling accelerator in the antifreeze solution is preferably 5 vol% or more.

[0025] The supercooling accelerator is added so that the Brix concentration of the supercooling accelerator in the antifreeze solution is 0.01 mg / ml or more and 0.2 mg / ml or less. The Brix concentration indicates the amount of soluble solid components contained in the liquid. The supercooling accelerator is added so that the polyphenol concentration in the antifreeze solution is 0.2 μg / ml or more and 40 μg / ml or less.

[0026] (alcohol) Alcohols are alcohols with three or fewer carbon atoms. Specifically, they are primary or secondary alcohols with three or fewer carbon atoms. For example, alcohols are monohydric alcohols such as methanol, ethanol, and isopropanol. When antifreeze solutions are used for food, ethanol or isopropanol is used.

[0027] Alcohols contain hydroxyl groups, which form hydrogen bonds with water molecules. When the hydroxyl groups of the alcohol form hydrogen bonds with the water molecules, the arrangement of the water molecules becomes disordered, making it difficult to freeze.

[0028] The alcohol concentration in the antifreeze solution is added so that it is 0.1 vol% or more and 20 vol% or less, preferably 10 vol% or less. The higher the alcohol concentration added, the lower the freezing point and the more suppressed the variation in the temperature at which the supercooled state is released.

[0029] (water) The water is added with a supercooling promoting substance and alcohol, and it is preferable that the water does not contain impurities that can form ice nuclei.

[0030] (Antifreeze solution production) This example explains the process of producing 20 mg of antifreeze solution with an ethanol concentration of 10 vol% and a supercooling accelerator Brix concentration of 0.1 mg / ml. In this case, the Brix concentration refers to the amount of organic compounds contained in the supercooling accelerator. In this case, 2 ml of ethanol (20 ml x 10 vol%), 2 mg of supercooling accelerator (20 ml x 0.1 mg / ml), and 18 ml of pure water are prepared and mixed.

[0031] (Example of using antifreeze solution) The antifreeze solution is used in a humidifier or a food thawing device. The humidifier is used, for example, in a refrigerated warehouse. The humidifier includes a humidifying tank, an air inlet, and an air supply. A humidification source is stored in the humidifying tank. The air inlet introduces air into the humidifying tank and humidifies it, and then the air supply supplies the humidified air into the room. The room temperature is set to 0°C or below.

[0032] The humidification source is either supercooled water or ice slurry made from the antifreeze solution of the present invention.

[0033] Ice slurry is produced by removing the supercooled state of an antifreeze solution. Ice slurry is a fluid liquid that is a mixture of ice and liquid. For example, ice slurry can be produced by applying ultrasonic vibrations to an antifreeze solution to remove the supercooled state. Note that fluidity means that the ice particles contained in the liquid are small. Specifically, the ice particles are about several hundred micrometers in size.

[0034] Another example of use of the antifreeze solution of this embodiment is in a food thawing device. The food thawing device includes a thawing tank for thawing food and a supply unit for supplying a thawing solution consisting of supercooled water or ice slurry to the thawing tank. When using supercooled water, the food thawing device thaws the food by placing the food in the thawing tank and supplying the antifreeze solution from the supply unit in a flowing state. When using ice slurry, the food is placed in the thawing tank, the antifreeze solution is supplied, and then the supercooled state is released.

[0035] (Effects of the embodiment) In this embodiment, the following effects can be obtained.

[0036] In this embodiment, the antifreeze solution does not contain an ice crystal growth inhibitor containing a polysaccharide, but instead contains water, a supercooling promoter containing an organic compound extracted from coffee grounds, and alcohol. The inventors further discovered that the ice crystal growth inhibitor forms ice nuclei by binding with water molecules. Therefore, the absence of an ice crystal growth inhibitor prevents the ice crystal growth inhibitor from forming ice nuclei and freezing. Furthermore, the antifreeze solution contains a supercooling promoter containing an organic compound extracted from coffee grounds. This allows the supercooling promoter to adsorb impurities that form ice nuclei and inhibit the formation of ice nuclei, thereby preventing the formation of ice nuclei and the release of the supercooled state. Furthermore, the antifreeze solution contains alcohol, which binds with water molecules, disrupting their arrangement, preventing the water molecules from becoming more easily frozen. These results allow the supercooling release temperature, which is the limit temperature at which the supercooled state can be maintained, to be lowered.

[0037] In this embodiment, the concentration of the supercooling accelerator in the antifreeze solution is 0.1 vol% or more and 20 vol% or less, and the concentration of alcohol in the antifreeze solution is 0.1 vol% or more and 10 vol% or less. The inventors of the present application have found through experiments described below that this results in a lower supercooled state release temperature than when the alcohol and the supercooling accelerator are added to the antifreeze solution separately.

[0038] In this embodiment, the Brix concentration of the supercooling accelerator in the antifreeze solution is 0.01 mg / ml or more and 0.2 mg / ml or less. Here, Brix concentration refers to the amount of soluble solid components contained in a liquid. Therefore, by making the Brix concentration of the supercooling accelerator 0.01 mg / ml or more, the supercooling accelerator is sufficiently dissolved in the antifreeze solution, thereby ensuring that the supercooling accelerator's ice nucleation inhibition effect is fully exerted. Furthermore, for example, even if the Brix concentration is 1 mg / ml or more, this does not affect the ice nucleation inhibition effect of the supercooling accelerator. However, making the Brix concentration of the supercooling accelerator 0.2 mg / ml or less is preferable because it prevents a large amount of supercooling accelerator that does not adsorb impurities from being present in the antifreeze solution.

[0039] In this embodiment, the supercooling accelerator contains a polyphenol as an organic compound, and the polyphenol concentration in the antifreeze solution is 0.2 μg / ml or more and 40 μg / ml or less. Here, polyphenol is a compound that has a supercooling accelerator effect. Therefore, a polyphenol concentration of 0.2 μg / ml or more in the antifreeze solution can sufficiently exhibit a supercooling accelerator effect. For example, adding polyphenol at a concentration of 200 μg / ml or more does not affect the supercooling accelerator effect or safety. However, the higher the polyphenol concentration, the darker the color of the antifreeze solution becomes. Therefore, by keeping the polyphenol concentration at 40 μg / ml or less, excessive coloring of the antifreeze solution due to the presence of a large amount of polyphenol can be prevented.

[0040] In this embodiment, the alcohol has a carbon number of 3 or less. By using an alcohol having a carbon number of 3 or less that is easily soluble in water, the freezing point depression can be reliably achieved.

[0041] In this embodiment, the antifreeze solution is used as a humidification source for a humidifier. As a result, the antifreeze solution does not freeze even at temperatures below freezing, making it easy to humidify, for example, a refrigerated warehouse where the room temperature is below freezing.

[0042] In this embodiment, the present invention is used to produce ice slurry by releasing supercooled water used as a humidification source in a humidifier. Here, the lower the supercooling release temperature, the smaller the particle size of the ice crystals. Therefore, by releasing the supercooled water of the present invention to produce ice slurry, the supercooling release temperature can be lowered, allowing for the production of ice slurry with smaller ice crystal particle size.

[0043] In this embodiment, the food thawing device uses running water or ice slurry to thaw food. Here, the temperature of the liquid used for thawing food is preferably 0°C or lower to prevent deterioration of food quality. Therefore, by releasing the supercooled water of the present invention to produce ice slurry, the supercooling release temperature can be lowered, allowing thawing to be performed using supercooled water or ice slurry at a low temperature.

[0044] [Example] Freezing point measurements were performed using comparative examples in which only one of a supercooling promoter or alcohol was added to pure water, and examples in which both a supercooling promoter and alcohol were added. In the examples, the total volume was adjusted to 20 ml after adding both the supercooling promoter and alcohol. In the comparative examples, the total volume was adjusted to 20 ml after adding either alcohol or the supercooling promoter. In both the examples and comparative examples, 0.5 mg (10 mg total) of silver iodide was added as an ice nucleating agent per 1 ml of solution. The supercooling promoter used was a coffee grounds extract dissolved in water with a Brix concentration adjusted to 1 mg / ml. The polyphenol content of the supercooling promoter in this case was 200 μg / ml.

[0045] In Examples 1 and 2, an antifreeze solution was first prepared by adding coffee grounds extract, adjusted to 1 mg / ml in water, as a supercooling accelerator to achieve a Brix concentration of 0.1 mg / ml. Then, in Example 1, ethanol was added to the prepared antifreeze solution to achieve 0.1 vol%, 1 vol%, and 10 vol%, respectively. In Example 2, isopropanol was added to the prepared antifreeze solution to achieve 0.1 vol%, 1 vol%, and 10 vol%, respectively.

[0046] In Comparative Example 1, antifreeze solutions were prepared by adding a supercooling accelerator to give Brix concentrations of 0.001 mg / ml, 0.01 mg / ml, 0.10 mg / ml, and 0.2 mg / ml. In Comparative Example 2, antifreeze solutions were prepared by adding ethanol to concentrations of 0.1 vol%, 1 vol%, and 10 vol% without adding a supercooling accelerator. In Comparative Example 3, antifreeze solutions were prepared by adding isopropanol to concentrations of 0.1 vol%, 1 vol%, and 10 vol% without adding a supercooling accelerator.

[0047] The supercooling release temperature was measured by placing test tubes containing the antifreeze solutions of the Examples and Comparative Examples in a thermostatic bath and lowering the temperature inside the thermostatic bath. The initial temperature was 1.0°C, and the temperature was lowered at a cooling rate of -3°C / hour. The supercooling release temperature was calculated from the temperature at which a color change was visually observed and the cooling temperature at which the cooling temperature changed to the equilibrium temperature. For each of Comparative Examples 1 to 3 and Examples 1 and 2, multiple samples were prepared, and the average supercooling release temperature for each addition concentration was calculated.

[0048] The results of Comparative Example 1 are shown in Figure 3. In Figure 3, the solid line indicates the supercooling release temperature of a solution containing only pure water and silver iodide. The open circles indicate the average supercooling release temperature calculated for each antifreeze solution to which a supercooling promoter was added so that the Brix concentration was 0.001 mg / ml, 0.01 mg / ml, 0.10 mg / ml, and 0.2 mg / ml. The whiskers on the open circles represent the variation in the supercooling release temperature. As shown in Figure 3, when no supercooling promoter was added, the supercooled state was released at -4°C. When a supercooling promoter was added so that the Brix concentration was 0.001 mg / ml or 0.01 mg / ml, the supercooled state was released at -5°C. When a cooling promoter was added so that the Brix concentration was 0.1 mg / ml, the supercooled state was released at -6°C. Furthermore, when a cooling promoter was added so that the Brix concentration was 0.2 mg / ml, the supercooled state was released at -9°C.

[0049] The results of Comparative Example 2 are shown in Figure 4. In Figure 4, the solid line indicates the supercooling release temperature of a solution containing only pure water and silver iodide. The dashed line indicates the predicted supercooling release temperature calculated by calculating the freezing point depression due to the addition of ethanol based on the supercooling release temperature of the pure water and silver iodide mixture. The open circles indicate the average supercooling release temperature calculated for antifreeze solutions containing ethanol at concentrations of 0.1 vol%, 1 vol%, and 10 vol% without the addition of a supercooling promoter. The whiskers on the open circles represent the variation in the supercooling release temperature. As shown in Figure 4, when ethanol was added to a concentration of 0.1 vol%, the supercooled state was released at -3°C. When ethanol was added to a concentration of 1 vol%, the supercooled state was released at -4°C. When ethanol was added to a concentration of 10 vol%, the supercooled state was released at -8°C.

[0050] The results of Comparative Example 3 are shown in Figure 5. In Figure 5, the solid line indicates the supercooling release temperature of a solution containing only pure water and silver iodide. The dashed line indicates the predicted supercooling release temperature calculated by calculating the freezing point depression due to the addition of isopropanol based on the supercooling release temperature of the pure water and silver iodide mixture. The open circles indicate the average supercooling release temperature calculated for antifreeze solutions containing no supercooling promoter and to which isopropanol was added at concentrations of 0.1 vol%, 1 vol%, and 10 vol%. The whiskers on the open circles represent the variation in the supercooling release temperature. As shown in Figure 5, when isopropanol was added to a concentration of 0.1 vol%, the supercooled state was released at -4°C. When isopropanol was added to a concentration of 1 vol%, the supercooled state was released at -6°C.

[0051] The results of Example 1 are shown in Figure 1. In Figure 1, the solid line indicates the supercooling release temperature of a solution containing only pure water and silver iodide. The dotted line indicates the supercooling release temperature when the supercooling promoter was added so that the Brix concentration was 0.1 mg / ml. The dashed-dotted line indicates a graph of the supercooling release temperature for each concentration predicted from Comparative Examples 1 and 2. The open circles indicate the average supercooling release temperature calculated for antifreeze solutions containing ethanol at concentrations of 0.1 vol%, 1 vol%, and 10 vol%. The whiskers on the open circles represent the variation in the supercooling release temperature. As shown in Figure 1, when ethanol was added to a concentration of 0.1 vol%, the supercooled state was released at -6°C. When ethanol was added to a concentration of 1 vol%, the supercooled state was released at -6°C. When ethanol was added to a concentration of 10 vol%, the supercooled state was released at -8°C. In all results, the supercooling release temperature was lower than expected, and it was found that the supercooling release temperature could be made significantly lower than expected, especially when the ethanol concentration was around 10 vol%.

[0052] The results of Example 2 are shown in Figure 2. In Figure 2, the solid line indicates the supercooling release temperature of a solution containing only pure water and silver iodide. The dashed line indicates the supercooling release temperature of an antifreeze solution to which a supercooling promoter was added so that the Brix concentration was 0.1 mg / ml. The dashed-dotted line indicates a graph of the supercooling release temperature for each concentration predicted from Comparative Examples 1 and 3. The open circles indicate the average supercooling release temperature calculated for antifreeze solutions to which isopropanol was added at concentrations of 0.1 vol%, 1 vol%, and 10 vol%. The whiskers on the open circles represent the variation in the supercooling release temperature. As shown in Figure 2, when isopropanol was added to a concentration of 0.1 vol%, the supercooled state was released at -6°C. When isopropanol was added to a concentration of 1 vol%, the supercooled state was released at -6°C. When isopropanol was added to a concentration of 10 vol%, the supercooled state was released at -8°C. In all results, the supercooling release temperature was lower than expected, and it was found that the supercooling release temperature could be made significantly lower than expected, especially when the isopropanol concentration was around 10 vol%.

[0053] (Variation in supercooling release temperature) The variation in the supercooling termination temperature for each concentration was calculated for Examples 1 and 2 and Comparative Examples 1 to 3. Tables 1 and 2 show the variation in the supercooling termination temperature. The variation was defined as the standard deviation σ [K].

[0054] [Table 1] TIFF0007747267000001.tif80168

[0055] [Table 2] TIFF0007747267000002.tif42168

[0056] As shown in Table 1, in Example 1, the variation was 0.7 when ethanol was added to a concentration of 0.1 vol%. The variation was 0.9 when ethanol was added to a concentration of 1 vol%. The variation was 0.8 when ethanol was added to a concentration of 10 vol%. The average variation in Example 1 was 0.8.

[0057] In Example 2, the variation was 0.9 when isopropanol was added to a concentration of 0.1 vol%. The variation was 0.8 when isopropanol was added to a concentration of 1 vol%. The variation was 0.9 when isopropanol was added to a concentration of 10 vol%. The average variation in Example 2 was 0.9.

[0058] As shown in Table 2, in Comparative Example 1, the variation was 1.2 when the supercooling accelerator was added so that the Brix concentration was 0.01 mg / ml. The variation was 1.1 when the cooling accelerator was added so that the Brix concentration was 0.1 mg / ml. The variation was 1.0 when the cooling accelerator was added so that the Brix concentration was 0.2 mg / ml. The average variation in Comparative Example 1 was 1.3.

[0059] As shown in Table 1, in Comparative Example 2, the variation was 0.9 when ethanol was added to a concentration of 0.1 vol%. The variation was 0.9 when ethanol was added to a concentration of 1 vol%. The variation was 0.8 when ethanol was added to a concentration of 10 vol%. The average variation in Comparative Example 2 was 1.2.

[0060] In Comparative Example 3, the variation was 0.6 when isopropanol was added to a concentration of 0.1 vol%. The variation was 1.0 when isopropanol was added to a concentration of 1 vol%. The variation was 1.5 when isopropanol was added to a concentration of 10 vol%. The average variation for Comparative Example 3 was 1.0.

[0061] In Examples 1 and 2, unlike Comparative Examples 1 to 3, the average variation was 1 or less. Furthermore, it was found that in Examples 1 and 2, the variation did not change much even when the concentration of alcohol added increased.

[0062] [Variations] The embodiments and examples disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims rather than the description of the above embodiments and examples, and further includes all modifications (variations) within the meaning and scope equivalent to the claims.

[0063] For example, in the above embodiment, an example was shown in which the supercooling accelerator contains an organic compound derived from coffee grounds, but the present invention is not limited to this. In the present invention, the supercooling accelerator may contain, in addition to the organic compound derived from coffee grounds, an organic compound extracted from, for example, bananas, sake, soy sauce, bean paste residue, etc. Furthermore, in addition to the organic compound derived from coffee grounds, the supercooling accelerator may also contain an artificially synthesized supercooling accelerator such as tyrosine trimer.

[0064] Furthermore, in the above embodiment, an example was shown in which the number of carbon atoms in the alcohol was 3 or less, but the present invention is not limited to this. In the present invention, the number of carbon atoms in the alcohol may be more than 3.

[0065] In the above embodiment, the antifreeze solution is used in the humidifier, but the present invention is not limited to this. In the present invention, the antifreeze solution may be used in a heat storage device.

[0066] In the above embodiment, an example was shown in which the antifreeze solution was used in the thawing device, but the present invention is not limited to this. In the present invention, the antifreeze solution may also be used to freeze food.

[0067] In the above embodiment, the supercooling accelerator is added so that the Brix concentration in the antifreeze solution is 0.01 mg / ml or more and 0.2 mg / ml or less, but the present invention is not limited to this. In the present invention, the supercooling accelerator may be added so that the Brix concentration in the antifreeze solution exceeds 0.2 mg / ml, or may be added so that the Brix concentration in the antifreeze solution is less than 0.01 mg / ml.

[0068] In the above embodiment, the polyphenol concentration in the antifreeze solution is 0.2 μg / ml or more and 40 μg / ml or less, but the present invention is not limited to this. In the present invention, the supercooling promoter may be added so that the polyphenol concentration in the antifreeze solution exceeds 40 μg / ml, or may be added so that the polyphenol concentration in the antifreeze solution is less than 0.2 μg / ml.

Claims

1. No ice crystal growth inhibitors, including polysaccharides, are added. Water and a supercooling accelerator containing an organic compound extracted from coffee grounds; alcohol, The concentration of the alcohol in the antifreeze solution is 0.1 vol% or more and 10 vol% or less, The supercooling promoter contains a polyphenol as the organic compound, The polyphenol concentration in the antifreeze solution is 0.2 μg / ml or more and 40 μg / ml or less, The alcohol has 3 or less carbon atoms.

2. The antifreeze solution of claim 1 used as a humidification source for a humidification device.

3. 2. The antifreeze solution according to claim 1, which is used to produce ice slurry by releasing supercooled water used as a humidification source in a humidifier.

4. 10. The antifreeze solution according to claim 1, which is used in running water or ice slurry for thawing food in a food thawing device.

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