JPH11266844A - Amino acid-containing aqueous solution and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an amino acid containing aqueous solution with high preservability and quality, useful as a nutritive drink or the like, by adding amino acid crystallization-suppressive compound(s) to an aqueous solution supersaturatedly containing amino acid(s) so as not to crystallize the amino acid(s) during storage, distribution or use of the solution. SOLUTION: This aqueous solution supersaturatedly containing amino acid(s) is obtained by adding amino acid crystallization-suppressive compound(s), e.g. one or more kinds of compounds selected from among polysaccharides such as agar-agar and peptides such as soybean peptides to a solution which is prepared by dissolving amino acid(s) such as tyrosine in an aqueous solution supersaturatedly containing the amino acid(s) under a condition enough to dissolve the amino acid(s); wherein the concentration of the amino acid crystallization-suppressive compound(s) in the solution is pref. 0.1-1 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous solution of an amino acid which contains an amino acid in a high content and which does not crystallize even when stored for a long period of time, a method for preventing the crystallization of the amino acid aqueous solution and the production of the aqueous solution containing the amino acid. About the method.

[0002]

BACKGROUND ART The elucidation of the nutritional physiology of amino acids has been advanced.
Attention has been paid to amino acid supplementation not only to patients who need supplementation due to abnormal amino acid metabolism and the like, but also to athletes and healthy persons. Therefore, aqueous solutions containing amino acids have been developed as nutritional drinks or sports drinks as well as amino acid infusions used in the medical field. For such amino acid supplementation, it is important to balance the nutritional function and energy metabolism function of interest.
There is a need to prepare an aqueous solution containing a highly soluble specific amino acid at a high concentration.

However, a product containing such an amino acid at a high concentration has a problem that the amino acid is crystallized in the product during storage or distribution. In particular, it is not preferable to mix an amino acid that is hardly soluble in water such as tyrosine with an aqueous solution of a beverage or the like because recrystallization occurs. For this reason, the amount of these amino acids is limited, and it is difficult to obtain a product that can satisfactorily exert the nutritional function of the amino acids.

[0004]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide an aqueous amino acid solution which contains an amino acid at a high content and which does not crystallize even when stored for a long period of time, a method for preventing the amino acid aqueous solution from crystallizing the amino acid and the amino acid. It is an object of the present invention to provide a method for producing an aqueous solution.

[0005]

According to the present invention, there is provided an aqueous solution containing an amino acid containing an amino acid crystallization inhibiting compound and a supersaturated amino acid in a supersaturated state, and an aqueous solution containing an amino acid crystallization inhibiting compound in an amino acid containing a supersaturated amino acid. A method for preventing crystallization of an amino acid in an aqueous solution containing an amino acid in supersaturation, and an aqueous solution containing an amino acid in supersaturation is dissolved under conditions sufficient to dissolve the amino acid, and the amino acid crystallization inhibitory compound is added to the solution. And a method for producing an aqueous solution containing an amino acid in supersaturation.

[0006]

The use of the aqueous solution containing an amino acid in supersaturation of the present invention is not particularly limited, but an aqueous solution for beverages is preferable, and examples thereof include aqueous solutions for drinks such as nutritional drinks, sports drinks, and soft drinks. In the present invention, an aqueous solution containing an amino acid in supersaturation is an aqueous solution containing an amino acid in an amount exceeding the saturated solubility of the amino acid in pure water having the same weight as the aqueous solution at the temperature during storage, distribution or use, Supersaturated amino acids refer to amino acids contained in the aqueous solution.

In the present invention, the amount of saturated amino acid differs depending on the kind of the amino acid and the storage, distribution or use temperature. When the storage, distribution or use temperature is, for example, 25 ° C., the amount of L-amino acid per 100 g of the aqueous amino acid solution is determined. And specifically, alanine (16.5 g), arginine (15 g),
Asparagine (3 g), aspartic acid (0.50
g), cysteine (0.001 g), glutamic acid (0.84 g), glutamine (4 g), glycine (2
5.0 g), histidine (4.3 g), hydroxyproline (36.1 g), isoleucine (4.1 g), leucine (2.2 g), lysine hydrochloride (40 g), methionine (3.3 g), phenylalanine (3 2.0 g), proline (162.3 g), serine (5.0 g), threonine (40 g), tryptophan (1.1 g), tyrosine (0.045 g), and valine (8.8 g). It is the amount of amino acid saturation dissolution at 25 ° C. in 100 g of pure water [Amino Acid Collection I (revised 1985), page 4, Japan Essential Amino Acid Association].

[0008] Since the saturated solubility of the amino acid varies depending on the storage, distribution or use temperature, the above-mentioned saturated solubility is corrected by the saturated solubility of various amino acids in 100 g of pure water at the storage, distribution or use temperature. The storage, distribution or use temperature is often not constant, so in such cases the saturated solubility of the amino acid at the lowest temperature should be applied. For example, since the solubility of tyrosine in 100 g of pure water at 25 ° C. is 0.045 g, an aqueous solution containing tyrosine in supersaturation is 45 g / 100 g of the aqueous solution.
It means an aqueous solution containing at least mg of tyrosine. If the minimum temperature during storage, distribution or use is 0 ° C,
Since the saturated solubility of tyrosine in 100 g of pure water at 0 ° C. is 0.020 g, the aqueous solution containing tyrosine in supersaturation means an aqueous solution containing 20 mg or more of tyrosine in 100 g of the aqueous solution.

The amino acid in the aqueous solution containing the amino acid of the present invention in supersaturation may be any amino acid, but is preferably an amino acid that is hardly soluble in water. Histidine, isoleucine, leucine, methionine, phenylalanine, serine, tryptophan,
Examples include valine, aspartic acid, tyrosine, and glutamic acid, with aspartic acid, tyrosine, and glutamic acid being preferred, and tyrosine being particularly preferred. As amino acids,
D-form, L-form or a mixture thereof may be used.

The method of preparing the aqueous solution containing amino acids in supersaturation is not particularly limited, but preferably, the temperature and pH are sufficient to dissolve the supersaturated amount of amino acids.
After completely dissolving under the conditions, other necessary components may be added and prepared. The temperature condition is higher than the storage, distribution or use temperature, preferably 40 ° C or higher, more preferably 70 ° C or higher. The pH condition is acidic or alkaline. The pH is adjusted by a pH adjuster.
H can be adjusted. The pH is preferably set to a value at which the target amino acid is dissolved in a high concentration. For example, to prepare an amino acid aqueous solution containing tyrosine at a high concentration, an aqueous solution whose pH is made acidic or alkaline is used. The pH of the aqueous solution is preferably pH 1 to 5,
pH 2-3 is more preferred. Upon dissolving the amino acid, a compound other than the pH adjuster may be contained in the aqueous solution.However, when a protein, a compound having a buffering action with an amino acid other than the amino acid to be dissolved at a high concentration, etc. It is not preferable because it is necessary to add a pH adjuster at a concentration higher than necessary for pH adjustment. Therefore, in the present invention, it is preferable to dissolve an aqueous solution to which only a target amino acid is added with a pH adjuster under the above-mentioned temperature conditions, and then add an additive if necessary.

The aqueous solution of a supersaturated amino acid produced by the above-described method is subjected to one or more amino acid crystallization inhibiting compounds selected from peptides and polysaccharides under the temperature conditions at the time of preparation, preferably at a higher temperature condition. Is added and dissolved by stirring. Under such temperature conditions or after cooling to an appropriate temperature, other additives may be added as necessary to produce an aqueous solution containing amino acids in supersaturation.

The amino acid crystallization inhibitory compound may be any compound as long as it suppresses the crystallization of amino acids, and examples thereof include peptides and polysaccharides. The amino acid crystallization inhibitory compounds can be used alone or in any combination. The concentration in the solution is 0.01 to
It is 10% by weight, preferably 0.05 to 5% by weight, particularly preferably 0.1 to 1% by weight.

The peptide can be used without any particular limitation, and examples thereof include peptides having an average molecular weight of 5,000 or less. In particular, a peptide having an average molecular weight of 5,000 or less and a maximum molecular weight of 10,000 or less is preferable. The average molecular weight and the maximum molecular weight can be measured by gel filtration, high performance liquid chromatography, SDS electrophoresis, or the like, and the target peptide can be prepared by the method or the like.

As the peptide used in the present invention, for example, a peptide which does not precipitate at all when a 1% by weight aqueous solution of the peptide is mixed with an equal amount of a 20% by weight aqueous trichloroacetic acid solution is preferable. Examples of these peptides include those obtained by hydrolyzing a natural protein using an enzyme such as papain, acidic protease, neutral protease, or alkaline protease, or peptides synthesized by a method such as the blastin reaction. Can be used regardless of amino acid sequence. Particularly, in the present invention, peptides obtained by enzymatic degradation of plant proteins and animal proteins are preferably used. Peptides derived from plant proteins include, for example, soybean peptides and corn peptides, and peptides derived from animal proteins include, for example, casein peptides and collagen peptides. The hydrolyzate can be used, for example, by purifying a fraction having the above-mentioned molecular weight using a known method such as a gel filtration method or a membrane separation method.

The polysaccharide is not particularly restricted but includes, for example, agar, pectin, gum arabic and β-cyclodextrin, with pectin being preferred. The pectin used in the present invention is a water-soluble polygalacturonic acid. Particularly, pectin which is preferably used in the present invention is one in which the carboxyl group of a galacturonic acid residue is methylated, and high methoxy pectin in which 50% or more of the carboxyl residue is methylated is particularly preferred.

The aqueous solution containing a supersaturated amino acid of the present invention may be a mixed solution of amino acids, and may be any aqueous solution in which one or more of the amino acids is supersaturated. Amino acids other than amino acids may further contain one or more,
Vitamins, fruit juices, minerals, sweeteners,
Flavorings and the like may be contained.

Examples of the amino acid include alanine, arginine, asparagine, aspartic acid, cysteine,
Examples include glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine and the like. The concentration of the amino acid added to the present invention depends on the use of the aqueous solution containing the amino acid in supersaturation, for example, nutritional drinks,
In drinks such as sports drinks and soft drinks, for example, in the case of poorly soluble tyrosine, nutritionally, it is preferably 20 mg / dl or more, more preferably 50 mg / dl or more, and more preferably 1 mg / dl or more.
00 mg / dl or more is particularly preferred.

Examples of the vitamins such as vitamin A, provitamin A, vitamin D, provitamin D, vitamin E, vitamin K, vitamin B _1, vitamin B _2, niacin, vitamin B ₆ group, pantothenic acid, biotin, myo - inositol, choline, folic acid, vitamin B _12, vitamin C, ubiquinone, lipoic acid, essential fatty acids, orotic acid, carnitine, p- aminobenzoic acid, vitamin P, vitamin U and the like.

Examples of the mineral include ions of sodium, magnesium, potassium, calcium, iron, manganese, zinc, cobalt, nickel, copper and the like.
Examples of the sweetener include sugar, fructose, glucose, sugar alcohol, erythritol, stevia and the like. Examples of the pH adjuster include an alkali and an acid. Examples of the alkali include inorganic salts such as potassium hydroxide and sodium hydroxide. Examples of the acid include an inorganic acid and an organic acid, and an organic acid is preferable. Examples of the inorganic acid include hydrochloric acid, sulfuric acid and the like. Organic acids include citric acid, lactic acid, malic acid, tartaric acid, gluconic acid and the like.

The beverage may contain carbon dioxide. Hereinafter, the present invention will be described specifically with reference to examples.

[0021]

Example 1 100 mg of tyrosine was dispersed in 100 ml of pure water, 200 mg of citric acid was added to adjust the pH to 4, and the mixture was heated in boiling water for 10 minutes. Was added so as to have the concentrations shown in Table 1, and the pH was adjusted to 4 again. After heating in boiling water for 10 minutes, the amino acid aqueous solution was added to a 50 ml vial.
0 ml was injected, sealed, and refrigerated at 5 ° C. As a comparison, a tyrosine solution prepared in a similar manner without the addition of peptides and polysaccharides was similarly stored. The test was performed in three test sections.

The collagen peptide was manufactured by Kyowa Hakko Kogyo Co., Ltd., the soybean peptide was manufactured by Fuji Oil Co., Ltd., the casein peptide was manufactured by DMV Japan, the corn peptide was manufactured by Nippon Shokuhin Processing Co., Ltd. Methoxy pectin is manufactured by Snow Brand Foods, gum arabic is Saneigen FFI
The agar was manufactured by Ina Foods Co., Ltd., and the echo gum was manufactured by Dainippon Pharmaceuticals.

Table 1 shows the period of time until the first crystallization of amino acids in the solution in vial bin. In addition, the period until crystal precipitation was shown until the day when the crystallization of amino acid was first recognized in any of the three test plots, and was visually judged.

[0024]

[Table 1]

By adding an amino acid crystallization inhibitory compound to an aqueous solution containing an amino acid in supersaturation, the crystallization period of the amino acid can be extended or the crystallization of the amino acid can be prevented.

Example 2 After dissolving 250 mg of citric acid and 130 mg of tyrosine in 100 ml of hot water at 80 ° C. (pH 2.6 at this time), an amino acid recrystallization inhibiting compound shown in Table 2 was added at a concentration shown in Table 2. After dissolution, fructose 2 g, erythritol 4 g, flavor 0.2 ml, arginine 75 mg, isoleucine 100 mg, lysine hydrochloride 190 mg, methionine 10
mg, phenylalanine 80 mg, tryptophan 50
mg, aspartic acid 3 mg, serine 30 mg, glutamic acid 60 mg, alanine 70 mg, threonine 100
mg, and the mixture was sterilized by filling into a vial bottle to prepare a beverage having a pH of 3.8. As a comparison, one prepared similarly without adding the amino acid crystallization inhibitory compound was used. These prepared beverages were stored at 5 ° C. The same product as in Example 1 was used for the compound having the same name as in Example 1, and β-cyclodextrin was used from Saltwater Port Refining Co., Ltd.

Table 2 shows the period until amino acid crystallization was observed in the solution in the vial bin.

[0028]

[Table 2]

When the amino acid crystallization inhibiting compound is not added, the amino acid is crystallized in 5 days. However, by adding the amino acid crystallization inhibiting compound shown in the table, the amino acid does not crystallize even after storage for 2 years.

[0030]

Industrial Applicability According to the present invention, in a supersaturated amino acid-containing aqueous solution, an amino acid-rich aqueous solution in which the amino acid contained therein does not recrystallize during storage, distribution or use, a method for producing the aqueous solution, and recrystallization of the amino acid in the aqueous amino acid solution An outflow control method is provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C07C 227/44 C07C 229/00 229/00 A23L 2/00 F

Claims (9)

[Claims] 1. An aqueous solution containing an amino acid in supersaturation, comprising an amino acid crystallization inhibitory compound and a supersaturated amino acid. 2. An aqueous solution containing an amino acid in supersaturation,
An aqueous solution containing the amino acid according to claim 1 in supersaturation, which is an aqueous solution for beverages. 3. The aqueous solution containing an amino acid in supersaturation according to claim 1, wherein the amino acid crystallization inhibitory compound is one or more compounds selected from polysaccharides and peptides. 4. A method for preventing crystallization of an amino acid in an aqueous solution containing an amino acid in supersaturation, comprising adding the amino acid crystallization inhibitory compound to an aqueous solution containing an amino acid in supersaturation. 5. An aqueous solution containing an amino acid in supersaturation,
The method according to claim 4, which is an aqueous solution for a beverage. 6. The method according to claim 4, wherein the amino acid crystallization inhibitory compound is one or more compounds selected from polysaccharides and peptides. 7. An aqueous solution containing an amino acid in supersaturation,
A method for producing an aqueous solution containing an amino acid in supersaturation, comprising dissolving the amino acid under conditions sufficient to dissolve the amino acid, and adding an amino acid crystallization inhibitory compound to the solution. 8. An aqueous solution containing an amino acid in supersaturation,
The method according to claim 7, which is an aqueous solution for a beverage. 9. The method according to claim 7, wherein the amino acid crystallization inhibitory compound is one or more compounds selected from polysaccharides and peptides.