Salt-enhancing substances, how they are produced, and how salt is added.

Abstract

The purpose of this patent application is to provide a novel salty flavor enhancer. And how those substances are produced, and how salty flavors are added to food and drinks as a way to do so. Having achieved that objective, it provided a salty flavor enhancer, which included a compound that can be represented by the following names. By the following general formula (1) or salts of those substances [in the formula, R is as specified in the description]. (chemical formula) (1);

Description

[0001] [Cross-reference of related applications] This application claims priority under Japanese Patent Application No. 2012-230673, filed on 18 October 2012 (the entire disclosure thereof is incorporated herein by reference).

[0002] The present invention primarily relates to novel salt flavor enhancers and methods for producing the same, as well as methods for enhancing the salt flavor of food and beverages. The present invention also relates to food additives, seasonings, and food and beverages.

[0003] As a source of sodium, an essential mineral for living organisms, table salt (sodium chloride) is an extremely important substance. Sodium ions contribute to maintaining extracellular fluid volume, regulating osmotic pressure and acid-base balance, and forming membrane potentials involved in neurotransmission and active intermembrane transport of substances, and are indispensable for maintaining life.

[0004] However, in order to improve the palatability of food, salt tends to be consumed in excess. For example, the target intake of salt recommended by the Japanese Ministry of Health, Labour and Welfare is less than 9.0g per day for adult men and less than 7.5g per day for adult women ("Dietary Reference Intakes for Japanese 2010 Edition" (Ministry of Health, Labour and Welfare)). Also, the target intake of salt recommended by the World Health Organization (WHO) is less than 6.0g per day ("Dietary Reference Intakes for Japanese 2010 Edition" (Ministry of Health, Labour and Welfare)). In contrast, the actual salt intake of Japanese people is 11.6g per day for adult men and 9.9g per day for adult women, showing a large gap between actual intake and target values ​​("National Nutrition and Health Survey 2009" (Ministry of Health, Labour and Welfare)).

[0005] It has been pointed out that such excessive salt intake can be a contributing factor to elevated blood pressure and is a cause of concern as it may lead to stroke and heart disease. In this situation, as one means of reducing salt intake, there is a strong demand for salt substitutes and salt flavor enhancers that can impart a salty taste to food in the same way as salt.

[0006] A salt substitute refers to a material that exhibits a salty taste and can be used in place of salt. Potassium chloride is known as a salt substitute (Patent Document 1). However, potassium chloride exhibits a bitter taste in addition to a salty taste, which reduces the palatability of the food. Furthermore, excessive intake of potassium is physiologically undesirable.

[0007] As saltiness enhancers, there are components that do not have a salty taste themselves, but when used in combination with table salt (sodium chloride), they make the salty taste of table salt feel stronger. Various saltiness enhancers have been proposed to date. However, there is currently a need for further improvement in terms of the strength of the saltiness enhancing effect.

[0008] Japanese Unexamined Patent Publication No. 63-287460

[0009] The main objective of the present invention is to provide a novel saltiness enhancer and a method for enhancing the saltiness of food and beverages.

[0010] The inventors of the present invention conducted diligent studies to solve the above problems and found that a compound represented by the following general formula (1) or a salt thereof can be suitably used as a saltiness enhancer. The present invention was completed by further studies based on this finding.

[0011] That is, the present invention encompasses the inventions in the following embodiments.

[0012] Item 1, a saltiness enhancer comprising a compound represented by the following general formula (1) or a salt thereof.

[0013] [In the formula, R is (i) A linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may be interrupted by heteroatoms, A hydrocarbon group which may have at least one group selected from the group consisting of carboxyl groups and hydroxyl groups, (ii) Indicates a hydrogen atom.

[0014] Item 2, a saltiness enhancer according to Item 1, comprising a compound represented by any of the following general formulas (2) to (6) or a salt thereof.

[0015] [In the formula, Q represents a heteroatom. q is either 0 or 1.] m and n represent integers from 1 to 4, respectively, and m + n is an integer from 3 to 5. m' and n' each represent an integer from 1 to 3, and m' + n' is an integer from 2 to 4. k represents an integer from 0 to 3. ]

[0016] Item 3. The salt taste enhancer according to Item 1, comprising a compound represented by the following general formula (7) or a salt thereof.

[0017] [In the formula, p represents an integer from 3 to 5. ]

[0018] Item 4. A primary amine compound represented by the following general formula (X), and

[0019] [In the formula, R is (i) a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may be interrupted by a heteroatom, and a hydrocarbon group which may have at least one group selected from the group consisting of a carboxyl group and a hydroxyl group, or (ii) a hydrogen atom is shown. ] S-methylisothiourea or a salt thereof and reacting, comprising a process of A method for producing a salt taste enhancer comprising a compound represented by the following general formula (1) or a salt thereof.

[0020] [In the formula, R is as defined above. ]

[0021] Item 5. An amino alcohol compound represented by the following general formula (X2) or (X4), an aminocarboxylic acid compound represented by the general formula (X3) or (X5), or an alkylamine compound represented by the general formula (X6), and

[0022] [In the formula, Q represents a heteroatom. q is 0 or 1. m and n each represent an integer from 1 to 4, and m + n is an integer from 3 to 5. m' and n' each represent an integer from 1 to 3, and m' + n' is an integer from 2 to 4. k represents an integer from 0 to 3. ] S-methylisothiourea or a salt thereof and reacting, comprising a process of A method for producing a salt taste enhancer comprising a compound represented by any one of the following general formulas (2) to (6) or a salt thereof.

[0023] [In the formula, Q, q, m, n, m', n' and k are as defined above. ]

[0024] Item 6. An amino alcohol compound represented by the following general formula (X7), and

[0025] [In the formula, p represents an integer of 3 to 5.] S-methylisothiourea or a salt thereof and reacting them, A method for producing a saltiness enhancer comprising a compound represented by the following general formula (7) or a salt thereof.

[0026] [In the formula, p is as defined above.]

[0027] Item 7. A food additive comprising the compound according to any one of Items 1 to 3 or a salt thereof.

[0028] Item 8. A seasoning containing the compound according to any one of Items 1 to 3 or a salt thereof.

[0029] Item 9. The seasoning according to Item 5, further comprising sodium chloride.

[0030] Item 10. A food or drink containing the compound according to any one of Items 1 to 3 or a salt thereof.

[0031] Item 11. A food or drink containing 10 ppm or more of the compound according to any one of Items 1 to 3 or a salt thereof.

[0032] Item 12. The food or drink according to Item 10 or 11, wherein the compound according to any one of Items 1 to 3 or a salt thereof is added.

[0033] Item 13. The food or drink according to any one of Items 10 to 12, further comprising sodium chloride.

[0034] Item 14. A method for enhancing the saltiness of a food or drink, comprising adding the compound according to any one of Items 1 to 3 or a salt thereof to the food or drink.

[0035] According to the present invention, a novel saltiness enhancer is provided. The saltiness enhancer of the present invention has a high saltiness enhancing effect and does not have a salty taste or off-flavors / odors other than salty taste by itself. Therefore, by adding the saltiness enhancer of the present invention to salt as, for example, a food additive, a seasoning, etc., it is possible to provide a food having a highly palatable salty taste while reducing the salt content.

[0036] 1. Saltiness enhancer This invention relates to a saltiness enhancer. Here, a saltiness enhancer refers to a substance that does not substantially possess a salty taste itself, but when used in combination with table salt (sodium chloride), makes the salty taste of table salt feel stronger. Specifically, this includes, for example, substances that, when present with salty substances below a certain threshold, make a previously undetectable salty taste perceptible, and substances that, when added, induce a strong salty taste.

[0037] The saltiness enhancer of the present invention consists of a compound represented by the following general formula (1) or a salt thereof.

[0038] [In the formula, R is (i) A linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may be interrupted by heteroatoms, A hydrocarbon group which may have at least one group selected from the group consisting of carboxyl groups and hydroxyl groups, (ii) Hydrogen atom [This indicates...]

[0039] The compound represented by the above general formula (1) is a compound having a guanidino group or guanidine.

[0040] The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.

[0041] Examples of linear or branched hydrocarbon groups having 1 to 5 carbon atoms include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl(3-methylbutyl) group, neo-pentyl(2,2-dimethylpropyl) group, 1-methylbutyl group, 2-methylbutyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, and 1,2-dimethylpropyl group, when not interrupted by a heteroatom.

[0042] When the hydrocarbon group is interrupted by a heteroatom, examples include a hydrocarbon group having 2 to 5 carbon atoms that is interrupted by one or more, preferably one, heteroatoms in the carbon skeleton of the alkyl group.

[0043] Specific examples of heteroatoms include oxygen atoms and sulfur atoms. The heteroatom is preferably an oxygen atom.

[0044] The hydrocarbon group may have at least one group selected from the group consisting of carboxyl groups and hydroxyl groups. If there are two or more groups, they may be the same or different. Specifically, examples include having one carboxyl group, having one hydroxyl group, having a total of two groups including one carboxyl group and one hydroxyl group, having two carboxyl groups, having two hydroxyl groups, etc., but are not limited thereto. An embodiment having one or two hydroxyl groups is cited as one of the preferred embodiments from the viewpoint of having a particularly high saltiness-enhancing effect.

[0045] When the compound represented by the above general formula (1) has an asymmetric carbon, it may contain the R-isomer, the S-isomer, or a mixture of these in any proportion, and may be a racemic mixture. When it contains two or more asymmetric carbons, the compound of the present invention may be any isomer or a mixture thereof.

[0046] The salt of the above compound is not particularly limited as long as it does not affect the saltiness-enhancing effect. Furthermore, it is preferable that the salt does not impart off-flavors or off-odors. Examples of such salts include salts of organic acids and salts of inorganic acids. Among these, inorganic acids are preferred, and hydrochloride salts are particularly preferred.

[0047] As one preferred embodiment of the saltiness enhancer of the present invention, a saltiness enhancer comprising a compound represented by any of the following general formulas (2) to (6) or a salt thereof is exemplified. A saltiness enhancer comprising a compound represented by any of the following general formulas (2) to (6) or a salt thereof is particularly preferred from the viewpoint of having a high saltiness enhancing effect and having very little or no off-flavor and off-odor.

[0048] [In the formula, Q represents a heteroatom. q is either 0 or 1.] m and n represent integers from 1 to 4, respectively, and m + n is an integer from 3 to 5. m' and n' represent integers from 1 to 3, respectively, and m' + n' is an integer from 2 to 4. k represents an integer between 0 and 3.

[0049] In general formulas (2) and (3), m and n represent integers from 1 to 4, respectively, and m + n is an integer from 3 to 5. In general formulas (4) and (5), m' and n' represent integers from 1 to 3, respectively, and m' + n' is an integer from 2 to 4. In general formula (6), k represents an integer from 0 to 3.

[0050] In general formulas (2) to (6), -C , , , , H ２ｍ -, -C n H ２n -, -C ｍ’ H ２ｍ’ -, -C n’ H ２n’ - and -C ｋ H ２ｋ - each represents an alkylene group having m, n, m', n', or k carbon atoms. Preferred embodiments of the alkylene group include a linear alkylene group or a branched alkylene group having a methyl group as the branch within the range where m and n, m' and n', or k satisfy the above conditions.

[0051]

[0052] As one particularly preferred embodiment, the following linear alkylene group can be mentioned.

[0053]

[0054] Specific examples of the compound represented by the above general formula (2) are given below. ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

[0073] Specific examples of compounds represented by the above general formula (5) are listed below.

[0074]

[0075] Specific examples of compounds represented by the above general formula (6) are listed below.

[0076]

[0077] As one of the more preferred embodiments of the saltiness enhancer of the present invention, a saltiness enhancer comprising a compound represented by any of the following general formulas (2)' to (6)' or a salt thereof is exemplified.

[0078] [In the formula, Q, q, m, n, m', and n'k are the same as above.]

[0079] As one particularly preferred embodiment of the saltiness enhancer of the present invention, a saltiness enhancer comprising a compound represented by the following general formula (7) or a salt thereof is exemplified. A saltiness enhancer comprising a compound represented by the following general formula (7) or a salt thereof is particularly preferred from the viewpoint of having a particularly high saltiness enhancing effect and having an undetectable level of off-flavor and off-odor.

[0080] [In the formula, p represents an integer between 3 and 5.] Specific examples of compounds represented by the above general formula (7) are listed below.

[0081]

[0082] Synthesis method The compound represented by the general formula (1) of the present invention or a salt thereof can be synthesized, for example, by reacting a primary amine compound (X) with guanidinylation reagents according to the Reaction Scheme-1 below.

[0083] [In the formula, R is as defined above.]

[0084] The primary amine compound (X) can be synthesized by known methods. Of course, commercially available compounds (X) may also be used.

[0085] As the guanidylation reagent, known guanidylation reagents can be used. Suitable guanidylation reagents include, but are not limited to, 1,3-Bis(tert-butoxycarbonyl)-2-(trifluoromethanesulfonyl)guanidine (Goodman reagent), 1-Amidinopyrazole Hydrochloride, N,N'-Bis(tert-butoxycarbonyl)-1H-pyrazole-1-carboxamidine, and N,N'-Bis(carbobenzoxy)-1H-pyrazole-1-carboxamidine. Generally, the guanidylation reagent is used in amounts ranging from about 0.1 moles to an excess amount, preferably about 0.8 moles to 2.0 moles, per mole of compound (X).

[0086] The reaction shown in Reaction Scheme-1 is preferably carried out in the presence of a base. Examples of bases that can be used include, but are not limited to, tertiary amines such as triethylamine, diisopropylethylamine, N,N-dimethylaniline, N,N-dimethylpiperazine, N-methylpiperazine, and pyridine. Generally, the amount of base used is 0.8 moles to an excess amount, preferably about 1.0 mole to 2.0 moles, per mole of compound (X).

[0087] The reaction shown in Reaction Scheme-1 can be carried out in a solvent. The solvent is not particularly limited as long as it does not hinder the progress of the reaction. Specific examples of such solvents include, but are not limited to, dichloromethane, chloroform, dimethylformamide, and tetrahydrofuran. The solvent can be used alone or as a mixture of two or more. Alternatively, if the base is a liquid, the base may be used as the solvent.

[0088] The reaction temperature for the reaction shown in reaction formula 1 is usually 0°C to 150°C, preferably 15°C to 50°C. The reaction time for the reaction shown in reaction formula 1 is usually 0.1 to 24 hours.

[0089] When using a guanidylation reagent to which a protecting group such as 1,3-bis(tert-butoxycarbonyl)-2-(trifluoromethylsulfonyl)guanidine is attached, the protecting group is deprotected. The deprotection reaction can be carried out, for example, under acidic conditions. Specific examples of acidic conditions include, but are not limited to, the presence of acids such as hydrochloric acid, sulfuric acid, and trifluoroacetic acid.

[0090] The compound represented by the general formula (1) of the present invention or a salt thereof can also be synthesized by reacting a primary amine compound (X) with S-methylisothiourea or a salt thereof, according to the Reaction Scheme-2 (reaction formula-2) below. Since the guanidylation reagent used in the synthesis method of Reaction Scheme-1 is expensive, the synthesis method according to Reaction Scheme-2 is more preferable from the viewpoint of cost.

[0091] [In the formula, R is as defined above.]

[0092] The salt of S-methylisothiourea is not particularly limited, as long as it does not inhibit the synthesis of the compound represented by general formula (1). Examples include salts of organic acids and salts of inorganic acids. Specifically, examples include hydrochloride salts, sulfate salts, nitrate salts, acetate salts, trichloroacetate salts, and formate salts. From the viewpoint of easy availability, sulfate salts are preferred.

[0093] S-methylisothiourea or its salt is generally used in an amount of about 0.1 to 10 moles, preferably about 0.5 to 3.0 moles, per mole of compound (X).

[0094] The reactions shown in Reaction Scheme-2 can be carried out without a solvent or in a solvent. The solvent is not particularly limited as long as it does not hinder the progress of the reaction. Water is a specific example of a solvent, but is not limited to it.

[0095] The reaction temperature for the reaction shown in Reaction Scheme-2 is usually 0 to 200°C, preferably 50 to 150°C. The reaction time for the reaction shown in Reaction Scheme-2 is usually 10 minutes to 24 hours.

[0096] When a salt of S-methylisothiourea is used in the reaction shown in Reaction Scheme-2, the product is usually a salt of the compound represented by general formula (1). For example, when S-methylisothiourea sulfate is used, the product is a sulfate of the compound represented by general formula (1). In this case, the salt of the compound represented by general formula (1) obtained can be used as is, or it can be converted to other salts as needed.

[0097] The method for performing the conversion is not particularly limited. For example, when converting sulfate to hydrochloride, the sulfate is dissolved in silica gel, and approximately 0.1 to 100 moles, preferably 1 to 10 moles, of sodium chloride (NaCl) or calcium chloride (CaCl) per mole of sulfate is added. ２ By adding ( ), it is converted into a mixture of hydrochloride and sulfate, and from the resulting mixture, the difference in physical properties between sulfate and hydrochloride (e.g., solubility in solvents) can be used to isolate and purify only the hydrochloride. In a different embodiment, in chromatography (e.g., using silica gel as a support), it can be converted to the corresponding organic acid by eluting with a solution containing an organic acid (e.g., acetic acid, formic acid, etc.) as the mobile phase, and the resulting organic acid can be converted to hydrochloride by azeotropic action with an excess amount of hydrochloric acid.

[0098] The products obtained by the reactions shown in reaction formula 1 and reaction formula 2 can be isolated and purified by commonly used means. Examples of such means include, but are not limited to, recrystallization, distillation, and chromatography.

[0099] Thus, a compound represented by general formula (1) or a salt thereof is produced. The synthesis of the above compound is, for example １ H-NMR measurement, １３This can be confirmed by known means such as C-NMR measurement and mass spectrometry (e.g., MS-ESI (electrospray ionization mass spectrometry)).

[0100] If a compound represented by general formula (1) or a salt thereof is available commercially, a commercially available product may be used.

[0101] The saltiness enhancer of the present invention exhibits a saltiness-enhancing effect that makes the saltiness of table salt feel stronger. The saltiness-enhancing effect can be evaluated by a sensory test. An example of a sensory test is to compare the saltiness intensity of a saline solution of a predetermined concentration (for example, 0.7% by weight) (control) with a saline solution of the same concentration containing the test component (sample A). If the test component has a saltiness-enhancing effect, sample A will feel saltier than the control.

[0102] In addition, in evaluating the saltiness-enhancing effect, the saltiness-enhancing effect can be quantified by comparing the saltiness intensity of a saline solution containing the test component (Sample B) with a group of saline solutions with a higher concentration than Sample B (Control Group), and searching for a salt concentration that produces a similar level of saltiness as Sample B.

[0103] For the saltiness enhancer of the present invention to be effective, it is necessary to use it in combination with salt. However, since most food and beverage products such as seasonings and soups that require reduced salt content already contain salt, it is possible to exert a saltiness-enhancing effect by coexisting with the salt contained in the food and beverage product. Moreover, the saltiness enhancer of the present invention is hardly associated with off-flavors and off-odors, which were problems with conventional technology. In other words, by having the saltiness enhancer of the present invention and salt coexist in food and beverage products, it is possible to achieve both a reduction in salt content and improved palatability of the food.

[0104] Food and beverages are not particularly limited, but include seasonings such as soy sauce, miso, sauces, and ketchup; seasonings mainly composed of hydrolyzed animal and plant proteins (HAP, HVP), yeast extract, amino acids, peptides, etc.; seasonings used to flavor foods such as dashi stock, noodle soup, sauces, roux, and dressings; processed grain products such as noodles, bread, and snack foods; processed meat and fish products such as ham, sausage, and fish paste products; soups, pickles, and prepared foods. Food and beverages also include instant foods that can be cooked by adding hot water or water (for example, powdered and liquid instant noodle soups, instant consommé soup, potage soup, Chinese soup, miso soup, clear soup, and instant noodle soups).

[0105] The amount of salt flavor enhancer of the present invention added to food and beverages is not particularly limited. Food and beverages that require reduced salt content usually contain about 0.2 to 2.0% by weight of salt, and particularly about 0.5 to 1.5% by weight, at the time of consumption. The salt flavor enhancer of the present invention can exert its salt flavor-enhancing effect by adding, for example, 1 ppm or more, preferably 10 ppm or more, and particularly preferably 15 ppm or more, to the amount of salt contained in food at such a concentration. The upper limit is not particularly limited, but from the viewpoint of solubility and taste, it can be 20% or less, preferably 5% or less.

[0106] The saltiness enhancer of the present invention may be provided in the form of the above compound alone, or in the form of a solid composition or a liquid composition. If provided as a composition, it may optionally contain additives that can be used in the manufacture of food and beverages, such as excipients, colorants, and flavorings, to the extent that they do not interfere with the saltiness enhancing effect.

[0107] The saltiness enhancer of the present invention may be provided as a food additive comprising, for example, the above compound or a salt thereof.

[0108] 2. Seasonings, food and drinks The present invention also provides a seasoning containing the above compound or a salt thereof (the saltiness enhancer of the present invention).

[0109] The above compound or its salt refers to the saltiness enhancer of the present invention as described in section "1." above.

[0110] The seasoning of the present invention contains the above compound or a salt thereof, and is not particularly limited as long as it is a seasoning that can be used to flavor food. Specific examples include soy sauce, miso, sauces, ketchup, etc., or seasonings mainly composed of hydrolyzed animal and plant proteins (HAP, HVP), yeast extract, amino acids, peptides, etc., as well as dashi stock, noodle soup, sauces, roux, dressings, etc., but is not limited to these.

[0111] From the viewpoint that the above compound or its salt exhibits a saltiness-enhancing effect when it is in the presence of sodium chloride (table salt), one preferred embodiment of the seasoning of the present invention is an embodiment that includes sodium chloride. Such embodiments include a seasoning consisting of the above compound or its salt (saltiness-enhancing agent of the present invention) and sodium chloride, or a seasoning that contains, as necessary, excipients, colorants, flavorings, and other additives that can be used in the manufacture of food and beverages.

[0112] The seasoning of the present invention may contain the above compound or a salt thereof in an amount of 1 ppm or more, preferably 10 ppm or more, and particularly preferably 15 ppm or more, when consumed. If the seasoning of the present invention contains sodium chloride, it may contain sodium chloride in an amount of about 0.1 to 2.0% by weight, particularly about 0.3 to 1.5% by weight, when consumed.

[0113] The present invention also provides food and beverages containing the above compound or a salt thereof (the saltiness enhancer of the present invention). One preferred embodiment is a food or beverage to which the above compound or a salt thereof has been added. Here, "added" means that the above compound or a salt thereof is not derived from the raw materials of the food or beverage but has been added separately.

[0114] The specific form of food and beverages is not particularly limited. Specific examples of food and beverages include processed grain products such as noodles, bread, and snack foods, processed meat and fish products such as ham, sausages, and fish paste products, soups, pickles, and prepared foods. Food and beverages also include instant foods that can be prepared by adding hot water or water (for example, powdered and liquid instant noodle soups, instant consommé soup, potage soup, Chinese soup, miso soup, clear soup, and instant noodle soups).

[0115] One preferred embodiment of the food and beverage of the present invention is an embodiment that contains sodium chloride.

[0116] The food and beverage of the present invention may contain the above compound or a salt thereof in an amount of 1.0 ppm or more, preferably 10.0 ppm or more, and particularly preferably 15 ppm or more, at the time of consumption. If the food and beverage of the present invention contains sodium chloride, it may contain sodium chloride in an amount of approximately 0.1 to 2.0% by weight, particularly approximately 0.3 to 1.5% by weight, at the time of consumption.

[0117] 3. Method for enhancing the saltiness of food and beverages The present invention also provides a method for enhancing the saltiness of food and beverages. The method of the present invention includes the step of adding the above compound or a salt thereof to food and beverages.

[0118] Food and beverages are not particularly limited. Specific examples of food and beverages that can be used are those listed in section "2." above. Preferably, they contain sodium chloride (table salt).

[0119] The above compound or its salt refers to the saltiness enhancer of the present invention as described in section "1." above.

[0120] The specific method of adding the above compound or its salt to food and beverages is not particularly limited. It may be blended as one of the raw materials during the preparation of food and beverages, or it may be added to food and beverages immediately before consumption. The amount of the above compound or its salt added is not particularly limited, but it should be added so that its content in the food and beverage is 1 ppm or more, preferably 10 ppm or more, and particularly preferably 15 ppm or more at the time of consumption.

[0121] Thus, the saltiness of food and beverages is enhanced.

[0122] The present invention will be described in more detail below with reference to examples. The present invention is not limited to these examples.

[0123] The measurements were performed using the following apparatus. １ H-NMR and １３ C-NMR measurement: Varian Inova 500 MS-ESI measurement: JEOL Ltd. JMS-T100LC AccuTOF.

[0124] [Synthesis Example 1]: 4-Guanidino-1-Butanol Hydrochloride (a)

[0125] 4-amino-1-butanol (Xa) (1 g, 11.2 mmol) was dissolved in dichloromethane (25 ml), and triethylamine (1.14 g, 11.2 mmol, 1.0 equivalent) was added and the mixture was stirred at room temperature. 1,3-Bis(tert-butoxycarbonyl)-2-(trifluoromethanesulfonyl)guanidine (3.95 g, 10.1 mmol, 0.9 equivalent) dissolved in dichloromethane (25 ml) was added dropwise, and the mixture was stirred at room temperature for 1 hour. After adding water to stop the reaction, the mixture was extracted with ethyl acetate, the organic layer was washed with saturated sodium bicarbonate aqueous solution and saturated brine, and then dried over anhydrous sodium sulfate. After removing the solvent with an evaporator, the mixture was purified by silica gel chromatography (n-hexane:ethyl acetate = 10:1 → 2:1) to obtain 3.32 g (10.0 mmol, 89.3%) of (a') as a white powder.

[0126] (a') (2.85 g, 8.60 mmol) was dissolved in 10 ml of ethyl acetate, and concentrated hydrochloric acid (10 ml) was added dropwise. The mixture was stirred at room temperature for 2 hours. After azeotropic mixing with methanol, the residue was extracted with dilute hydrochloric acid, washed with dichloromethane, and the aqueous layer was azeotropically mixed with methanol to obtain a white powder. This white powder was washed with ethyl acetate to obtain 817 mg (4.87 mmol, 56.7%) of 4-guanidino-1-butanol hydrochloride (a) as a white powder.

[0127] 1 H-NMR(CD3OD, 500MHz):δ=1.55-1.70(m, 4H), 3.21(t, 2H, J=7.0Hz), 3.58(t, 2H, J=7.0Hz) 13 C-NMR(CD3OD, 125MHz):δ=26.5, 30.4, 42.3, 62.3, 158.5 MS-ESI(C5H 14 ON3Cl):2M+HCl+H : 299.21 (Calculated value: 299.20).

[0128] [Synthesis Example 2] 3-Guanidino-1-propanol hydrochloride (b) ​

[0129] Using 3-amino-1-propanol (xb) (150 mg, 2.00 mmol), 282.4 mg (1.84 mmol, 92.1%) of 3-guanidino-1-propanol hydrochloride (b) was obtained as a colorless oily substance in the same manner as in Synthesis Example 1, except that washing with ethyl acetate was not performed.

[0130] 1 H-NMR (CD3OD, 500MHz): δ=1.75(tt, 2H, J=6.0, 6.0Hz), 3.25(t, 2H, J=6.0Hz), 3.60(t, 2H, J=6.0Hz) 13 C-NMR(CD3OD, 125MHz): δ=32.4, 39.5, 59.7, 158.8 MS-ESI (C4H 12 ON3Cl):2M+HCl+H : 271.17 (Calculated value: 271.17).

[0131] [Synthesis Example 3] 5-Guanidino-1-pentanol hydrochloride (c)

[0132] Using 5-amino-1-pentanol (xc) (206 mg, 2.00 mmol), 250.0 mg (1.38 mmol, 68.9%) of 5-guanidino-1-pentanol hydrochloride (c) was obtained as a colorless oily substance in the same manner as in Synthesis Example 1, except that washing with ethyl acetate was not performed.

[0133] 1 H-NMR (CD3OD, 500MHz): δ=1.40-1.48(m, 2H), 1.57(tt, 2H, J=6.8, 6.8Hz), 1.62(tt, 2H, J=6.8, 6.8Hz), 3.18(t, 2H, J=6.8Hz), 3.57(t, 2H, J=6.8Hz) 13 C-NMR(CD3OD, 125MHz): δ=24.0, 29.6, 33.0, 42.4, 62.6, 158.6 MS-ESI(C6H 16 ON3Cl):2M+HCl+H : 327.24 (Calculated value: 327.23).

[0134] [Synthesis Example 4] 2-Guanidinoethanol hydrochloride (d) ​​

[0135] Using 2-aminoethanol (xd) (122 mg, 2.00 mmol), 247.5 mg (1.77 mmol, 88.8%) of 2-guanidinoethanol hydrochloride (d) was obtained as a colorless oily substance in the same manner as in Synthesis Example 1, except that washing with ethyl acetate was not performed.

[0136] 1 H-NMR(CD3OD, 500MHz): δ=3.33(t, 2H, J=5.1Hz), 3.69(t, 2H, J=5.1Hz) 13 C-NMR(CD3OD, 125MHz): δ=45.1, 61.4, 159.3 MS-ESI(C3H 10 ON3Cl):2M+HCl+H : 243.13 (Calculated value: 243.13).

[0137] [Synthesis Example 5] 6-Guanidino-1-hexanol hydrochloride (e)

[0138] Using 6-amino-1-hexanol (xe) (234 mg, 2.00 mmol), 368.7 mg (1.88 mmol, 94.4%) of 6-guanidino-1-hexanol hydrochloride (e) was obtained as a colorless oily substance in the same manner as in Synthesis Example 1, except that washing with ethyl acetate was not performed.

[0139] 1 H-NMR (CD3OD, 500MHz): δ=1.37-1.46(m, 4H), 1.52-1.58(m, 2H), 1.58-1.64(m, 2H), 3.19(t, 2H, J=6.6Hz), 3.55(t, 2H, J=6.6Hz) 13 C-NMR (CD3OD, 125MHz): δ=26.5, 27.5, 29.8, 33.4, 42.4, 62.8, 158.6 MS-ESI(C7H 18 ON3Cl):2M+HCl+H : 355.26 (Calculated value: 355.26).

[0140] [Synthesis Example 6] (±)-1-Guanidino-2-propanol hydrochloride (f) ​​

[0141] Using (±)-1-amino-2-propanol (xf) (400 mg, 5.33 mmol), 435.2 mg (2.83 mmol, 53.2%) of (±)-1-guanidino-2-propanol hydrochloride (f) was obtained as a colorless oily substance in the same manner as in Synthesis Example 1, except that washing with ethyl acetate was not performed.

[0142] 1 H-NMR (CD3OD, 500MHz): δ=1.19(d, 3H, J=6.9Hz), 3.09(dd, 1H, J=8.6, 12.8Hz), 3.23-3.32(m, 1H), 3.88-3.93(m, 1H) 13 C-NMR (CD3OD, 125MHz): δ=20.7, 49.7, 67.1, 159.3.

[0143] [Synthesis Example 7] (S)-2-guanidino-1-propanol hydrochloride (g)

[0144] Using (S)-(+)-2-amino-1-propanol (xg) (400mg, 5.33 mmol), 432.9 mg (2.82 mmol, 52.9%) of (S)-2-guanidino-1-propanol hydrochloride (g) was obtained as a colorless oily substance in the same manner as in Synthesis Example 1, except that washing with ethyl acetate was not performed.

[0145] 1 H-NMR (CD3OD, 500MHz): δ=1.20(d, 3H, J=8.1Hz), 3.47(dd, 1H, J=8.1, 12.1Hz), 3.59-3.63(m, 1H), 3.64-3.70(m, 1H) 13 C-NMR (CD3OD, 125MHz): δ=17.1, 51.3, 66.3, 158.6.

[0146] [Synthesis Example 8] 3-Guanidino-2,2-dimethyl-1-propanol hydrochloride (h) ​​

[0147] Using 3-amino-2,2-dimethyl-1-propanol (xh) (100 mg, 0.97 mmol), 120.1 mg (0.66 mmol, 68.2%) of 3-guanidino-2,2-dimethyl-1-propanol hydrochloride (h) was obtained as a colorless oily substance in the same manner as in Synthesis Example 1, except that washing with ethyl acetate was not performed.

[0148] 1 H-NMR(CD3OD, 500MHz):δ=0.93(s, 6H), 3.08(s, 2H), 3.32(s,2H) 13 C-NMR (CD3OD, 125MHz): δ=22.6(×2), 37.4, 49.7, 68.8, 159.4 MS-ESI(C6H 16 ON3Cl):2M+HCl+H : 327.20 (Calculated value: 327.23).

[0149] [Synthesis Example 9] 2-(2-Guanidinoethoxy)ethanol hydrochloride (i)

[0150] Using 2-(2-aminoethoxy)ethanol (xi) (400 mg, 3.80 mmol), 577.8 mg (3.15 mmol, 82.7%) of 2-(2-guanidinoethoxy)ethanol hydrochloride (i) was obtained as a colorless oily substance in the same manner as in Synthesis Example 1, except that washing with ethyl acetate was not performed.

[0151] 1 H-NMR (CD3OD, 500MHz): δ=3.39(t, 2H, J=5.0Hz), 3.59(t, 2H, J=5.0Hz), 3.63(t, 2H, J=5.0Hz), 3.69(t, 2H, J=5.0Hz) 13 C-NMR (CD3OD, 125MHz): δ=43.0, 62.1, 70.5, 73.6, 159.2.

[0152] [Synthesis Example 10] 2-(2-guanidinoethylthio)ethanol hydrochloride (j) ​​

[0153] Using 2-(2-aminoethylthio)ethanol (xj) (400 mg, 3.30 mmol), 541.6 mg (2.71 mmol, 82.2%) of 2-(2-guanidinoethylthio)ethanol hydrochloride (j) was obtained as a colorless oily substance in the same manner as in Synthesis Example 1, except that washing with ethyl acetate was not performed.

[0154] 1 H-NMR (CD3OD, 500MHz): δ=2.72(t, 2H, J=6.1Hz), 2.78(t, 2H, J=6.8Hz), 3.42(t, 2H, J=6.8Hz), 3.72(t, 2H, J=6.1Hz) 13 C-NMR (CD3OD, 125MHz): δ=32.2, 35.3, 42.3, 62.7, 158.7.

[0155] [Synthesis Example 11] (R)-3-guanidino-1,2-propanediol hydrochloride (k)

[0156] (R)-3-amino-1,2-propanediol (xk) (400 mg, 4.39 mmol) was used in accordance with Synthesis Example 1 to obtain 628.5 mg (3.71 mmol, 84.4%) of (R)-3-guanidino-1,2-propanediol hydrochloride (k) as a white powder.

[0157] 1 H-NMR (CD3OD, 500MHz): δ=3.24(dd, 1H, J=6.7, 14.1Hz), 3.37(dd, 1H, J=4.0, 14.1Hz), 3.51(dd, 1H, J=6.0, 12.1Hz), 3.56(dd, 1H, J=6.0, 12.1Hz), 3.74-3.80(m, 1H) 13 C-NMR (CD3OD, 125MHz): δ=45.5, 64.4, 71.6, 159.5.

[0158] [Synthesis Example 12] 1-Guanidinopropane hydrochloride (l)

[0159] Using propylamine (xl) (300 mg, 5.08 mmol), 597.2 mg (4.34 mmol, 85.5%) of 1-guanidinopropane hydrochloride (l) was obtained as a colorless oily substance, following the procedure in Synthesis Example 1 except that washing with ethyl acetate was omitted.​

[0160] 1 H-NMR (CD3OD, 500MHz): δ=0.98(t, 3H, J=7.7Hz), 1.61(tq, 2H, J=7.7, 7.7Hz), 3.15(t, 2H, J=7.7Hz) 13 C-NMR(CD3OD, 125MHz):δ=11.5, 23.2, 44.0, 158.6 MS-ESI (C4H 12 N3Cl): 2M + HCl + H : 239.14 (Calculated value: 239.18).

[0161] [Synthesis Example 13]: Synthesis of 3-guanidino-1-propanol hydrochloride (b) using S-methylisothiourea sulfate

[0162] 3-amino-1-propanol (Xb) (150 mg, 2.0 mmol) was dissolved in water (0.4 ml), and S-methylisothiourea sulfate (278 mg, 1.0 mmol) was added and suspended. The mixture was then heated under reflux for 6 hours. Water and any remaining 3-amino-1-propanol were removed using an evaporator to obtain 344 mg of 3-guanidino-1-propanol sulfate (m) as an oily crude product.

[0163] 344 mg of crude product of 3-guanidino-1-propanol sulfate (m) was suspended in 1.04 ml of 3M NaCl aqueous solution. 10 ml of methanol was added to the resulting suspension, followed by 2.0 g of silica gel (Wako Gel C-200). The solvent was removed using an evaporator, and the sample was adsorbed onto the silica gel to form a sample gel. 14.1 g of separation gel (Wako Gel C-200) was suspended in acetone and packed into a glass column. The sample gel was then overlaid on this column, and 50 ml of acetone was passed through it. After that, 200 ml of ethanol was passed through it, and the eluted ethanol layer was dried using an evaporator to obtain 241 mg (1.57 mmol, 78.5%) of 3-guanidino-1-propanol hydrochloride (b) as a colorless oily substance.

[0164] The obtained colorless oily substance 1 H-NMR and 13 The 1C-NMR data were consistent with those obtained for 3-guanidino-1-propanol hydrochloride (b) in synthesis example 2.​

[0165] [Synthesis Example 14] 3-Guanidino-1-propanol sulfate (m) 344 mg of crude 3-guanidino-1-propanol sulfate (m) was mixed with 10 ml of methanol, followed by 2.0 g of silica gel (Wako Gel C-200). The solvent was then removed using an evaporator, and the sample was adsorbed onto the silica gel to form a sample gel. 14.1 g of separation gel (Wako Gel C-200) was suspended in acetone and placed on a glass column packed with the acetone. The sample gel was then layered onto the suspended gel column. 50 ml of acetone and 50 ml of ethanol were passed through the column, followed by 200 ml of methanol. The eluted methanol layer was dried using an evaporator to obtain 235 mg (1.41 mmol, 70.5%) of 3-guanidino-1-propanol sulfate (m) as a colorless oily substance.

[0166] 1 H-NMR (CD3OD, 500MHz) :δ=1.79(tt, 2H, J=6.0, 6.0Hz), 3.27(t, 2H, J=6.0Hz), 3.63(t, 2H, J=6.0Hz) 13 C-NMR (CD3OD, 125MHz):δ=32.5, 39.2, 59.6, 158.9

[0167] [Example 1] Sensory evaluation The compounds synthesized in Synthesis Examples 1-11 and Synthesis Example 14, as well as commercially available guanidine hydrochloride, β-guanidinopropanoic acid, γ-guanidinobutyric acid, and 6-guanidinocaproic acid, were used as evaluation samples to assess their saltiness-enhancing effects.

[0168] The evaluation sample and sodium chloride (table salt) were dissolved in distilled water to prepare aqueous solutions containing 0.150% by weight of the evaluation sample and 0.700% by weight of sodium chloride, which were used as evaluation solutions. Solutions containing 0.700%, 0.735%, 0.770%, 0.805%, and 0.840% by weight of sodium chloride were used as comparison solutions.

[0169] Sensory evaluation was performed on each of the evaluation samples based on the following criteria.

[0170] ++++: Exhibits a saltiness equivalent to or greater than 0.840 wt% saline solution (shows a saltiness enhancement effect of 20% or more); +++: Exhibits a saltiness equivalent to or greater than 0.805 wt% saline solution (shows a saltiness enhancement effect of 15% or more); ++: Exhibits a saltiness equivalent to or greater than 0.770 wt% saline solution (shows a saltiness enhancement effect of 10% or more); +: Exhibits a saltiness equivalent to or greater than 0.735 wt% saline solution (shows a saltiness enhancement effect of 5% or more); ±: Exhibits a saltiness less than that of 0.735% by weight saline solution (saltiness enhancement effect is less than 5%), or evaluation is impossible due to bitterness, etc.

[0171] The results are shown in Tables 1 and 2.

[0172]

[0173] The above results demonstrate that the saltiness enhancer of the present invention has a saltiness enhancing effect.

[0174] [Example 2] Sensory evaluation The relationship between the concentration of 3-guanidino-1-propanol hydrochloride obtained in Synthesis Example 2 and its saltiness-enhancing effect was evaluated.

[0175] 3-Guanidino-1-propanol hydrochloride and sodium chloride (table salt) were dissolved in distilled water to prepare aqueous solutions containing 1.5 ppm (0.00015 wt%), 15 ppm (0.0015 wt%), 150 ppm (0.015 wt%), or 1500 ppm (0.15 wt%) of 3-Guanidino-1-propanol hydrochloride and 0.700 wt% of sodium chloride, which were used as evaluation solutions. Solutions containing 0.700 wt%, 0.735 wt%, 0.770 wt%, 0.805 wt%, and 0.840 wt% of sodium chloride were used as comparison solutions.

[0176] Sensory evaluation was performed on each of the evaluation samples based on the following criteria. ++++: Exhibits a saltiness equivalent to or greater than 0.840 wt% saline solution (shows a saltiness enhancement effect of 20% or more); +++: Exhibits a saltiness equivalent to or greater than 0.805 wt% saline solution (shows a saltiness enhancement effect of 15% or more); ++: Exhibits a saltiness equivalent to or greater than 0.770 wt% saline solution (shows a saltiness enhancement effect of 10% or more); +: Exhibits a saltiness equivalent to or greater than 0.735 wt% saline solution (shows a saltiness enhancement effect of 5% or more); ±: Exhibits a saltiness less than that of 0.735% by weight saline solution (saltiness enhancement effect is less than 5%).

[0177] The results are shown in Table 3.

[0178] From the above results, it was found that 3-guanidino-1-propanol hydrochloride exerts a saltiness-enhancing effect at an added concentration of 15 ppm or higher, and that this effect is concentration-dependent.

[0179] [Example 3] Evaluation of saltiness-enhancing effect in food and beverages The saltiness-enhancing effect of 3-guanidino-1-propanol hydrochloride obtained in Synthesis Example 2 was evaluated in food and beverages.

[0180] The raw materials were prepared according to Table 4 below (powdered soba soup). This was dissolved in 1000 ml of hot water to obtain control and reduced-sodium food products (instant noodle soba soup). The sodium (Na) concentration of the control and reduced-sodium soups was 1.02% and 0.76%, respectively. Therefore, the reduced-sodium soup had 25% less salt than the control soup.

[0181] 3-guanidino-1-propanol hydrochloride obtained in Synthesis Example 2 was added to the reduced-sodium soup at concentrations of 0.1% by weight, 0.15% by weight, and 0.20% by weight to prepare samples 1 to 3. A sensory evaluation was conducted on samples 1 to 3 by comparing them with the control soup and the reduced-sodium soup.

[0182] The results of the sensory evaluation are shown in Table 5.

[0183] As shown in Table 5, the saltiness-enhancing effect improved in a concentration-dependent manner with 3-guanidino-1-propanol hydrochloride, and it was found that adding 0.2% by weight resulted in a 25% saltiness-enhancing effect in instant noodle soup. Furthermore, no significant off-flavors or off-odors were observed when 0.2% by weight of 3-guanidino-1-propanol hydrochloride was added.

[0184] From the above results, it was found that 3-guanidino-1-propanol hydrochloride, at an added concentration of 0.2% by weight, exerts a saltiness-enhancing effect of at least 25% in food and beverages.

Claims

1. A salt enhancer, which consists of a compound that can be represented by the following general formulas (1) or a salt of those compounds (chemical formulas) (1) in which R represents: (i) a linear or branched hydrocarbon group of 1 to 5 carbon atoms which may be separated by heteroatoms, in which the hydrocarbon group may contain at least one selectable group of groups consisting of carbonyl and hydroxyl groups; or (i) a hydrogen atom.

2. A salt enhancer according to claim 1, which consists of a compound that can be represented by the following general formulas (1) The general formula (1) or salts of those substances consist of compounds which can be represented by one of the following general formulas (2) through (6): (chemical formula)(2), (chemical formula)(3), (chemical formula)(4), (chemical formula)(5), (chemical formula)(6), where: Q represents heteroatoms, and q represents 0 or 1; m and n each represent integers from 1 to 4, and m+n are integers from 3 to 5; m' and n' each represent integers from 1 to 3, and m'+n' are integers from 2 to 4; and k represents integers from 0 to 23.The sanitary compound under claim 1, in which a compound denoted by the general formula (1) or a salt of such compounds consists of the following compounds denoted by the general formula (7) or their salts: (chemical formula) (7), in which p represents an integer from 3 to 54. The method of producing the sanitary compound which consists of the following compounds denoted by the general formula (1) or their salts: (chemical formula) (1), in which R represents: (i) a linear or branched hydrocarbon group of 1 to 5 carbon atoms which may be separated by heteroatoms, in which the hydrocarbon group may contain at least one selectable group of groups consisting of carboxyl and hydroxyl groups; or (ii) a hydrogen atom, the method of production of which consists of a procedure of reacting S-methyl isothiourea or its salt with a primary amine compound denoted by the general formula (X) as follows: H2N(formula)R, in which R is as specified above5.The preparation method according to claim 4, in which the step of reacting S-methyl isothiourea or its salt with a primary amine compound denoted by the general formula (X) is combined with the step of reacting S-methyl isothiourea or its salt with an amino alcohol compound denoted by the general formula (X2) or (X4) as follows, and an aminocarboxylic acid compound denoted by the general formula (X4). The following general (X3) or (X5) compounds, or alkylamine compounds which can be represented by the following general formulas (X6): (chemical formula)(X2), (chemical formula)(X3), (chemical formula)(X4), (chemical formula)(X5), (chemical formula)(X6) where: Q represents heteroatoms, and q represents 0 or 1; m and n each represent integers from 1 to 4, and m+n are integers from 3 to 5; m' and n' each represent integers from 1 to 3, and m'+n' are integers from 2 to 4; and k represents integers from 0 to 36.Preparation under claim 4, in which the procedure of reacting S-methyl isothiourea or its salt with a primary amine compound denoted by the general formula (X) is included with the procedure of reacting S-methyl isothiourea or its salt with an aminoalcohol compound denoted by the general formula (X7) as follows: (chemical formula) (X7) where p represents an integer from 3 to 57. Food additives, which contain any one of the compounds or salts of them as described in claims 1 through 3.

8.

9. Seasonings under claim 5, which contain sodium chloride.

10. Food and beverages, which contain compounds or salts of those substances as described in any of claims 1 through 3.

11. Food and beverages, which contain 10 parts per million or more of the compounds or residues of those substances as described in any of claims 1 through 3. 12.

13. Foods and beverages under any of the claims 10 to 12, which are further incorporated with sodium chloride; 14. Methods of adding saltiness to food and beverages, which involve the addition of compounds or salts of any of the substances described in claims 1 to 3 to the food and beverages.