Method for preparing amino acid granules from fermented liquid

Abstract

To provide a method for preparing amino acid granules from fermented liquid.SOLUTION: The present disclosure relates to a method for preparing amino acid granules from fermented liquid, and amino acid granules prepared by the method. The inventors have accomplished the present application, after conducting intensive research in order to find out a method for efficiently granulating hardly soluble amino acid, and then, having confirmed that adding calcium source to fermented liquid containing amino acid before concentration make it possible to: enhance solubility of amino acid; improve the efficiency of steps; and eventually provide stabilized amino acid granules with a moisture absorption property being reduced.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present application relates to a method for producing amino acid granules from a fermentation broth, and the amino acid granules produced thereby. [Background technology]

[0002] One method for producing amino acid additives for feed is a fermentation method using microorganisms (Patent Document 1), and the amino acid additive can be produced by directly drying and solidifying the fermentation liquid. However, when the fermentation liquid is directly solidified in this way, the amount of impurities that cause coagulation increases, and the product becomes more hygroscopic, which makes it more likely to form lumps and makes it difficult to handle. Therefore, in order to overcome these drawbacks, it is necessary to find a method for producing granules from a fermentation liquid containing amino acids that are less hygroscopic and easier to handle.

[0003] Usually, the process of producing granules from a fermentation broth containing amino acids includes a step of concentrating the fermentation broth and a step of granulation. In this process, if as much water as possible is removed in the concentration step, the granulation step can be performed with a small amount of water vapor. However, if amino acid crystals are generated during the concentration step, problems occur in equipment operation, and when concentrating amino acids with low solubility (e.g., valine, tryptophan, threonine, isoleucine, leucine, methionine, etc.), there is a problem that the concentration step must be completed before crystal nuclei are generated. Therefore, there is a demand for a method of producing amino acid granules with improved process efficiency and reduced hygroscopicity by improving the solubility of amino acids in the fermentation broth and the concentration during the concentration step. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Pat. No. 5,431,933 [Patent Document 2] U.S. Patent No. 8,465,962 [Patent Document 3] U.S. Patent No. 9,885,093 [Patent Document 4] U.S. Pat. No. 1,035,1859 [Patent Document 5] U.S. Patent No. 7,863,435 [Patent Document 6] U.S. Pat. No. 1,078,7692 [Patent Document 7] U.S. Patent No. 9,029,105 [Patent Document 8] US Patent Application Publication No. 2021 / 0094903 [Patent Document 9] U.S. Patent No. 9,587,261 Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors conducted extensive research to find a method for efficiently granulating poorly soluble amino acids, and as a result discovered that by adding a calcium source to a fermentation liquid containing amino acids before concentration, the solubility of the amino acids can be increased, the efficiency of the process can be improved, and ultimately, stable amino acid granules with reduced hygroscopicity can be provided, which led to the completion of the present application. [Means for solving the problem]

[0006] The present application aims to provide a method for producing amino acid granules, which includes a first step (calcium source addition step) of adding a calcium source to a fermentation liquid containing an amino acid, the calcium source having a molar ratio of 0.02 to 2.0 relative to the amino acid, and a second step (granulation step) of granulating the result obtained in the previous step.

[0007] Another object of the present application is to provide an amino acid granule containing an amino acid and calcium ions in a molar ratio of 0.02 to 2.0 relative to the amino acid.

[0008] A further object of the present application is to provide a feed composition containing the amino acid granule. Effect of the Invention

[0009] The manufacturing method of the present application further includes a step of treating the fermentation liquid containing amino acids with a predetermined molar ratio of a calcium source prior to granulation, thereby enabling efficient utilization of conventional equipment to produce low-solubility amino acid granules. [Brief description of the drawings]

[0010] [Figure 1] This figure shows the particle size distribution before (top row) and after (bottom row) concentrated fermentation broth was ground in a homogenizer prior to granulation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] These will be described in detail below. Note that each description and embodiment disclosed in this application also applies to other descriptions and embodiments. In other words, all combinations of various elements disclosed in this application are included in this application. In addition, this application is not limited to the following specific description.

[0012] Furthermore, many papers and patent documents are referred to throughout this specification, and citations are provided thereto, the disclosures of which are incorporated herein by reference in their entirety in order to more clearly describe the state of the art to which the present invention pertains and the contents of the present invention.

[0013] In order to achieve the above-mentioned object, one aspect of the present application provides a method for producing amino acid granules, comprising a first step (calcium source addition step) of adding a calcium source to a fermentation liquid containing an amino acid, the calcium source having a molar ratio relative to the amino acid of 0.02 to 2.0, and a second step (granulation step) of granulating the resultant product obtained in the previous step.

[0014] The production method of the present application, when producing amino acid granules from a fermentation concentrate containing amino acids, can improve the efficiency of the concentration step by adding a calcium source to the fermentation liquid containing amino acids before granulation to increase the solubility in the fermentation liquid. This is based on the discovery that the amino acid granules containing calcium produced by the production method of the present application have improved content stability in the granule formulation compared to granules produced by further adding a binder such as PVP.

[0015] In this application, the term "calcium source" refers to calcium ions (Ca 2+ The calcium source refers to a material capable of supplying calcium hydroxide (Ca(OH)2), calcium oxide (CaO), calcium carbonate (CaCO3), calcium sulfate (CaSO4) or calcium chloride (CaCl2), but is not limited thereto. The calcium source is added in the form of, but not limited to, a powder, an aqueous solution, or a slurry.

[0016] In the first step of the present application, a calcium source is added to a fermentation liquid containing amino acids to increase the solubility of low-solubility amino acids, so that when the solution containing them is concentrated, a relatively highly concentrated concentrate is obtained.

[0017] "Calcium" in this application is an essential mineral for vertebrates, since it has the function of strengthening bones and smoothing blood circulation. More than 99% (w / w) of calcium is present in bones and teeth, and the remainder is present in blood, muscles, etc. A sufficient amount of calcium maintains bone health and prevents osteoporosis. It also plays a role in muscle contraction, preventing muscle cramps, lowering cholesterol levels, and reducing the incidence of cardiovascular disease. However, a lack of calcium leads to abnormal bone formation, muscle and nerve abnormalities, and even minor trauma can easily cause injuries such as fractures, increasing the risk of osteoporosis. Such calcium prevents diarrhea and dysentery, so it may be supplied to animals in the form of a feed additive to aid digestion and absorption, especially in piglets.

[0018] Therefore, since the amino acid granules produced by the production method of the present application contain calcium, they can simultaneously supply calcium, which is an inorganic substance necessary for the living body, together with amino acids, such as essential amino acids.

[0019] In the first step, calcium ions are added as a calcium source in a molar ratio to the amino acids in the fermentation liquid containing amino acids of 0.02 to 2.0, 0.05 to 2.0, 0.07 to 1.5, 0.1 to 1.0, or 0.2 to 0.6, but the molar ratio is not limited thereto.

[0020] In the present application, the fermentation liquid containing the amino acid may be the fermentation liquid itself obtained by a known microbial fermentation method (Patent Documents 2, 3, 4, 5, 6, 7, 8) or a concentrate obtained by concentrating the fermentation liquid, but is not limited thereto. For example, a concentration step may be further performed before or after the first step, but is not limited thereto.

[0021] In the present application, the term "fermentation liquid" refers to a culture obtained by culturing a microorganism. The fermentation liquid contains the cultured microorganism.

[0022] In this application, the term "fermentation broth containing amino acids" is used interchangeably with "amino acid-containing fermentation broth" or "amino acid fermentation broth".

[0023] Specifically, the fermentation liquid containing the amino acid of the present application is obtained by culturing or fermenting a microorganism that produces the amino acid, and a person skilled in the art can select and use the microorganism and the culturing or fermenting method thereof from known types and methods. For example, the microorganism includes all wild-type microorganisms and microorganisms that have been genetically modified naturally or artificially, and is a microorganism in which a specific mechanism has been weakened or enhanced by inserting an exogenous gene or by enhancing or inactivating the activity of an endogenous gene, and is a microorganism that has undergone a genetic mutation or enhanced activity for the production of the target L-amino acid (Patent Documents 5, 9, etc.). Specifically, the microorganism is not particularly limited in type as long as it produces a desired amino acid, and is a microorganism belonging to the genera Enterobacter, Escherichia, Erwinia, Serratia, Providencia, Corynebacterium, and Brevibacterium. More specifically, it is a microorganism belonging to the genus Corynebacterium or Escherichia. The genus Corynebacterium includes Corynebacterium glutamicum, Corynebacterium ammoniagenes, and Corynebacterium thermoaminogenes. , Corynebacterium efficiens, Corynebacterium Corynebacterium stationis, Corynebacterium phocae, Corynebacterium flavescens, Corynebacterium humireducens, Corynebacterium halotolerans, Corynebacterium Corynebacterium pollutisoli, Corynebacterium ma Examples of the Escherichia microorganism include, but are not limited to, Corynebacterium marinum, Corynebacterium freiburgense, Corynebacterium cystitidis, Corynebacterium durum, Corynebacterium pilosum, and Corynebacterium testudinoris. The Escherichia microorganism includes, but is not limited to, Escherichia coli.

[0024] Specifically, the concentration may be performed at a concentration level of more than 0% (w / w) and not more than 75% (w / w). If the concentration level exceeds the above level, the concentrated liquid will gel and the fluidity will be significantly reduced, making it difficult to proceed to the next step. For example, the above concentration level is a value set to prevent the process from being hindered by early crystal nucleation when the liquid is put into a granulator in the granulation step, and the allowable concentration level varies depending on the type of equipment used and / or the driving method, etc., so the conditions of the present application are not limited to these. For example, the concentration level is 5% (w / w) or more and 75% (w / w) or less, 10% (w / w) or more and 70% (w / w) or less, or 20% (w / w) or more and 65% (w / w) or less, but is not limited to these.

[0025] The concentration step is a step of increasing the solid content by partially removing the liquid components in the fermentation broth, and can be carried out by, but is not limited to, a vacuum, heating and / or drying process.

[0026] For example, amino acids to which the manufacturing method of the present application can be applied are low-solubility amino acids having a solubility in water at 25°C of more than 0 g / 100 g and not more than 20 g / 100 g, but are not limited thereto. As described above, by applying the method to low-solubility amino acids, significant effects can be expected compared to conventional processes.

[0027] Specifically, the amino acid is, but is not limited to, valine, tryptophan, threonine, isoleucine, leucine, methionine, histidine, or phenylalanine.

[0028] In the present application, the second step of granulating the concentrated liquid is carried out to form granules of particles having a predetermined size from a powder or fine solid material, and any granulation method known in the art may be used. For example, a mixed granulation method in which seeds are injected into a mixed granulator from a feeder at a constant speed and the concentrated liquid is supplied by a constant-feed pump to obtain granules, or a fluidized bed granulation method in which a predetermined amount of seeds is fed into a fluidized bed granulator and a predetermined amount of concentrated liquid is injected into the fluidized bed granulator at a constant speed to form granules may be applied. Here, a step of drying the obtained granules may be further included, but is not limited thereto.

[0029] In this application, "granules" refers to macroscopic particles that are relatively large permanent aggregates formed by the aggregation of smaller particles such as powder, and have an average particle diameter of 50 μm to 5 mm, 75 μm to 4 mm, or 100 μm to 3 mm.

[0030] Specifically, the manufacturing method of the present application may further include a step of adjusting the discharged moisture content to 10 to 50% (w / w) before the granulation step. In the present application, the "discharged moisture content" is also called the "mixed moisture content" and means the proportion of moisture in the entire mixture, and is calculated by subtracting the total solid content (% (w / w)) from 100% (w / w) of the entire mixture. In the present application, it is considered that a higher discharged moisture content reduces the reuse rate when the concentrated liquid is mixed with seeds and fed into a mixer for subsequent granulation, resulting in an effect of increasing the productivity. For example, the discharged moisture percentage is adjusted to, but is not limited to, 10 to 40% (w / w), 10 to 30% (w / w), or 15 to 30% (w / w). However, if the discharged moisture percentage is below the above range, the slurry becomes difficult to transport due to the high viscosity of the unit, and if it exceeds the above range, problems of overloading the downstream process and excessive use of steam occur during granulation. The range of the discharged moisture percentage varies somewhat depending on the type of amino acid contained in the concentrate.

[0031] The water content of the discharged water is determined according to the feeding speed of the concentrated fermentation liquid slurry as described above. Specifically, the water content of the granular particles increases as the feeding speed of the slurry increases, and the water content of the granular particles decreases as the feeding speed of the slurry decreases. The feeding speed is determined according to the scale of the fermentation liquid slurry, and therefore, a person skilled in the art can appropriately determine the feeding speed. You can choose and decide.

[0032] Furthermore, the second step is carried out by adding seeds at a weight of 50-75% (w / w) based on the solid content of the concentrated liquid slurry. Alternatively, the second step is carried out by adding seeds at a weight of 55-75% (w / w), 58-75% (w / w), or 58-67% (w / w), but is not limited thereto. For example, in the case of a concentrated liquid prepared without adding a calcium source to the fermentation liquid, seeds at a weight of 80% (w / w) or more are used, whereas in the case of granulating the concentrated liquid prepared according to the present application, there is an advantage that the second step can be carried out using a much smaller amount of seeds. Specifically, the second step can produce granules at a yield equal to or higher than that in the case of granulating the concentrated liquid prepared without adding a calcium source to the fermentation liquid, even with only seeds at a level of 70-85% (w / w), 73-85% (w / w), 70-83% (w / w), or 73-83% (w / w).

[0033] The mixing ratio of the seeds to the solids content of the slurry is commonly referred to as the "seed input ratio."

[0034] The term "seed" in this application is also referred to as seed crystal or seed crystal, and refers to a substance used as a catalyst for crystallization or granulation of a liquid. Specifically, the seed in this application is an amino acid crystal, for example, but not limited to, a crystal of the same type of amino acid as that contained in the fermentation concentrate to be granulated. When the seed comes into contact with the fermentation liquid, the solid components present in the fermentation liquid bind to the seed to form aggregates, thereby forming granules.

[0035] For example, the seeds used here may have an average particle size of 150 to 300 μm. Specifically, seeds having an average particle size of 150 to 250 μm, 200 to 300 μm, or 200 to 250 μm can be used, but are not limited thereto. As described above, the particle size of the seeds used ultimately affects the productivity in the manufacturing process of the granules according to the present application, and therefore can be appropriately selected by a person skilled in the art in consideration of the desired moisture content, etc.

[0036] Specifically, the manufacturing method of the present application may further include a step of pulverizing the resultant obtained in the previous step before the granulation step. This can be performed using a conventional homogenizer, but is not limited thereto. The pulverization step can reduce the average particle size of the crystals in the concentrated liquid, and can prevent nozzle clogging that may occur when using, for example, a fluidized bed granulator.

[0037] The production method of the present application may further include at least one step selected from the group consisting of a step of preparing a fermentation liquid, a step of adjusting pH, a step of concentrating, a step of drying, and a step of screening. Any method known in the art (e.g., Patent Document 8) may be used for each of the above steps. Furthermore, specific conditions may be appropriately changed to optimize the process, but are not limited thereto.

[0038] Another aspect of the present application provides an amino acid granule comprising an amino acid and calcium ions in a molar ratio of 0.02 to 2.0 relative to the amino acid.

[0039] For example, the amino acid granules have a moisture absorption rate of 7% (w / w) or less when left to stand for 1 to 48 hours from the time of granulation under conditions of a humidity of 60% (w / w) and a temperature of 40°C, but this is not limited thereto.

[0040] Specifically, the amino acid granules of the present application are produced by the above-mentioned method. Furthermore, the amino acid granules of the present application are used as a feed additive, but the use thereof is not limited thereto.

[0041] As defined above, granules are porous particles formed by the aggregation of powder or small particles, and therefore absorb moisture from the surroundings over time. The degree of moisture absorption can be calculated from the difference between the mass measured after a certain period of time and the mass in a dry state. On the other hand, when granule particles absorb excessive moisture, the wet granules clump together to form undesirable large lumps. Therefore, in order to accommodate long-term storage, it is preferable to adjust the hygroscopicity of the granules themselves to be low.

[0042] In a specific embodiment of the present application, when preparing amino acid granules from a fermentation liquid containing amino acids, the amino acid granules prepared by simply concentrating and granulating the granules increased in weight by about 10% (w / w) due to moisture absorption when left for 24 hours under conditions of 60% (w / w) humidity and 40°C temperature, and the weight increased by another about 1% (w / w) when stored for 48 hours. In contrast, it was confirmed that the amino acid granules prepared by the method of the present application increased in weight by only about 3.3% (w / w) due to moisture absorption when left for 24 hours under conditions of 60% (w / w) humidity and 40°C temperature, and no further weight increase occurred even when the period was extended to 48 hours. This indicates that the amino acid granules of the present application have significantly improved low hygroscopicity compared to amino acid granules prepared by conventional processes, and maintain the granular state without aggregation and / or coagulation due to moisture absorption during storage, which is advantageous for storage.

[0043] Yet another aspect of the present application provides a feed composition comprising the amino acid granules of the present application.

[0044] The amino acid granules of the present application are suitable for use in the manufacture of animal feed as a feed additive. For example, the amino acid granules as a feed additive can be part of an animal feed premix or a precursor of an animal feed and can be mixed with the feed material as such. The feed composition comprising the amino acid granules can be administered to the animal alone or in combination with other feed additives in an edible carrier. The feed composition can also be administered to the animal as a top dressing or by mixing them directly with the animal feed or in an oral dosage form separate from the feed. EXAMPLES

[0045] The present application will be described in more detail below with reference to examples. However, these examples are merely illustrative of the present application and are not intended to limit the present application. Example 1

[0046] Comparison of amino acid enrichment at various molar ratios of calcium added to fermentation broth Example 1-1: Preparation of a valine-containing concentrated solution by adding calcium to the fermentation solution at a molar ratio of 0.4 60 L of the valine fermentation liquid having the composition shown in Table 1 was placed in a 110 L plastic container and stirred at 25°C and 100 rpm using a stirrer (model name PL-SS-500D, Punlim). 1.3 kg of calcium hydroxide and 1.6 kg of water were added to the above solution so that the calcium / valine molar ratio was 0.4, and the mixture was further stirred for 1 hour. Here, the pH was 9.5, the volume of the above mixture was 62.2 L, the valine concentration was 77.2 g / L, the purity was 71.4% (w / w), and the total solid amount was 19.5% (w / w). The above mixture was placed in a 20 L concentration tube (model name N-21NS, EYELA) and concentrated. The mixture was concentrated under conditions of a pressure of 0.1 atmosphere and a water tank temperature of 70°C until the total concentration reached 40% (w / w). The concentrate obtained by the above concentration level had a concentration of 322.1 g / L, a purity of 71.4% (w / w), a total solid content of 40% (w / w), and a volume of 14.9 L. Next, the concentrate was granulated using a mixer granulator (Ploughshare mixer granulator, Lodige). The following was produced. To produce these granules, seeds with a purity of 78.5% (w / w), total solid content of 99% (w / w), and average particle size of 200-250 μm were used. A total of 35.4 kg of the seeds were fed into the screw feeder of the mixing type granulator at a rate of 20 kg per hour. The concentrated liquid was fed at a rate of 9.5 kg per hour using a constant-volume liquid delivery pump (model name RP-2100, EYELA). A total of 16.8 kg was added. 52.2 kg of granules with a solid content of 80% (w / w) were recovered. These were dried in a fluidized bed dryer (FBG-3, S-Won Korea Co., Ltd.). Since fine powder was generated, 41.7 kg was recovered, which is a recovery rate of 99% (w / w). The purity was 77.3% (w / w), and the total solid content was 99% (w / w).

[0047] Example 1-2: Preparation of a valine-containing concentrated solution by adding calcium to the fermentation solution at a molar ratio of 0.2 60L of the valine fermentation liquid was put into a 110L plastic container and stirred at 25°C and 100 rpm using a stirrer. 0.6kg of calcium hydroxide and 0.8kg of water were added to the above solution so that the molar ratio of calcium / valine was 0.2, and the mixture was further stirred for 1 hour. Here, the pH was 8.8, the volume of the above mixture was 61.1L, the valine concentration was 78.6g / L, the purity was 74.6% (w / w), and the total solid amount was 10.3% (w / w). The above mixture was put into a 20L concentration tube and concentrated. The mixture was concentrated under conditions of a pressure of 0.1 atmosphere and a water bath temperature of 70°C until the total concentration reached 35% (w / w). The concentrated solution that had been concentrated to the above concentration had a concentration of 285.0g / L, a purity of 74.6% (w / w), a total solid amount of 35% (w / w), and a volume of 16.8L. Next, granules were produced using a mixing type granulator. As in Example 1-1, seeds were fed into the screw feeder of the mixing type granulator at a rate of 20 kg per hour up to a total of 65.7 kg. Concentrate was fed at a rate of 5.6 kg per hour up to a total of 18.4 kg. 84.1 kg of granules with a solid content of 85% (w / w) were collected. These were dried in a fluidized bed dryer. Since fine powder was generated, 71.5 kg was collected, which was a recovery rate of 99% (w / w). The purity was 78.1% (w / w), and the total solid content was 99% (w / w).

[0048] Example 1-3: Preparation of a valine-containing concentrated solution by adding calcium to the fermentation solution at a molar ratio of 0.6 60 L of the valine fermentation solution recovered from the fermentation tank was placed in a 110 L plastic container and stirred at 25 ° C. and 100 rpm using a stirrer. 1.9 kg of calcium hydroxide and 2.4 kg of water were added to the above solution so that the molar ratio of calcium / valine was 0.6, and the mixture was further stirred for 1 hour. Here, the pH was 10.2, the volume of the above mixture was 63.3 L, the valine concentration was 75.9 g / L, the purity was 67.1% (w / w), and the total solid amount was 10.9% (w / w). The above mixture was placed in a 20 L concentration tube and concentrated. The mixture was concentrated under conditions of a pressure of 0.1 atmosphere and a water tank temperature of 70 ° C. until the total concentration reached 33% (w / w). The concentrated solution after concentration at the above concentration level had a concentration of 246.9 g / L, a purity of 67.1% (w / w), a total solid amount of 33% (w / w), and a volume of 19.4 L. Next, granules were produced using a mixing granulator. As in Example 1-1, seeds were fed into the screw feeder in the mixing granulator at a rate of 20 kg per hour up to a total of 43.4 kg. A total of 21.7 kg of concentrated liquid was fed at a rate of 10.0 kg per hour. 65.1 kg of granules with a solid content of 87% (w / w) were collected. These were dried in a fluidized bed dryer. Since fine powder and the like were generated, 50.1 kg was collected, which was a recovery rate of 99% (w / w). The purity was 76.9% (w / w), and the total solid content was 99% (w / w).

[0049] Comparative Example 1: Preparation of a valine-containing concentrated solution without adding calcium to the fermentation solution 60 L of the valine fermentation liquid was put into a 20 L concentration tube and concentrated. It was concentrated under conditions of a pressure of 0.1 atmosphere and a water tank temperature of 70°C until the total concentration reached 25% (w / w). The concentrated liquid after concentration at the above concentration had a concentration of 210.5 g / L, a purity of 80.0% (w / w), a total solid amount of 25% (w / w), and a volume of 22.8 L. Next, granules were produced using a mixing type granulator. As in Example 1-1, seeds were put into the screw feeder in the mixing type granulator at a rate of 20 kg per hour up to a total of 137.5 kg. A total of 24 kg of the concentrated liquid was put in at a rate of 3.5 kg per hour. 161.5 kg of granules with a solid amount of 88% (w / w) were collected. This was dried in a fluidized bed dryer. Since fine powder and the like were generated, 142.1 kg was collected, which is a recovery rate of 99% (w / w). The purity was 78.6% (w / w) and the total solids was 99% (w / w).

[0050] [Table 1]

[0051] Overall, the addition of calcium at a molar ratio of 0.4 relative to the valine concentration in the fermentation broth resulted in the highest enrichment and produced granules with the highest purity with the smallest amount of seed added.

[0052] Examples 1-4 to 1-5 and Comparative Example 2: Preparation of tryptophan-containing concentrated liquid with or without calcium added to fermentation liquid In Examples 1-4 and 1-5, calcium hydroxide slurry was added at a molar ratio of 0.1 and 0.2, respectively, to prepare concentrated solutions in the same manner as in Examples 1-1 to 1-3, except that a tryptophan-containing fermentation broth having the composition shown in Table 2 was used. The pH was 8.8 and 9.0, respectively. The sample of Comparative Example 2 was prepared by concentrating the tryptophan-containing fermentation broth without adding calcium hydroxide. The fermentation broth used, the concentration and purity of the concentrated solution produced, etc. are shown in Table 2. The purity was somewhat reduced by adding the slurry. The fermentation broth to which the slurry was added was concentrated to a concentration of 30% (w / w) in Example 1-4 and 35% (w / w) in Example 1-5. It was confirmed that if the fermentation broth was concentrated further, it gelled and lost fluidity. Here, in the fermentation broth to which the slurry was not added, only a concentration of about 25.5% (w / w) was achieved.

[0053] Specifically, in Examples 1-4, the concentrated liquid and seeds were mixed in a mixing granulator, and the total solid amount discharged was adjusted to 80% (w / w) and discharged. 53.7 kg of seeds (purity 65.0% (w / w), total solid amount 99% (w / w)) were charged and mixed in the mixing granulator. The mixed granules were 76.4 kg (purity 65.0% (w / w), total solid amount 80% (w / w)). The mixture was dried in a fluidized bed dryer / cooler. With a solid loss of 1% (w / w), 61.1 kg was obtained (purity 65.0% (w / w), total solid amount 99% (w / w)).

[0054] In Examples 1-5, the concentrate and seeds were mixed in a mixing granulator, and the total solid amount discharged was adjusted to 80% (w / w) and discharged. 54.9 kg of seeds (purity 65.0% (w / w), total solid amount 99% (w / w)) were charged and mixed in the mixing granulator. The mixed granules were 78.1 kg (purity 64.8% (w / w), total solid amount 80% (w / w)). The mixture was dried in a fluidized bed dryer / cooler. With a solid loss of 1% (w / w), 62.5 kg was obtained (purity 64.8% (w / w), total solid amount 99% (w / w)).

[0055] Furthermore, a similar experiment was performed with the addition of calcium at a molar ratio of 0.4, and the increase in pH caused tryptophan to be decomposed into tryptamine, indole-acetate, and anthranilic acid.

[0056] [Table 2]

[0057] In Examples 1-5, in which calcium was added at a molar ratio of 0.2 relative to the tryptophan concentration in the fermentation liquid, the concentration was significantly increased compared to Comparative Example 2, in which calcium was not added, resulting in a concentrated liquid with a concentration increased by approximately 33% (w / w).

[0058] Examples 1-6 to 1-8 and Comparative Example 3: Preparation of isoleucine-containing concentrated solution with or without calcium added to fermentation liquid Except for using the isoleucine-containing fermentation broth having the composition shown in Table 3, calcium hydroxide slurry was added at a molar ratio of 0.4, 0.2, and 0.6 in the same manner as in Examples 1-1 to 1-3 to prepare concentrated solutions. The pH of each was 9.5, 8.8, and 10.2 (Examples 1-6 to 1-8, respectively). The sample of Comparative Example 3 was prepared by concentrating the isoleucine-containing fermentation broth without adding calcium hydroxide. The fermentation broth used, the concentration and purity of the concentrated solution produced, etc. are shown in Table 3. The purity was somewhat reduced by adding the slurry. The fermentation broth to which the slurry was added was concentrated to a concentration of 42, 35, and 32% (w / w), respectively. It was confirmed that if the fermentation broth was concentrated further, it gelled and lost fluidity. Here, in the fermentation broth to which the slurry was not added, only a concentration of about 30% (w / w) was achieved.

[0059] For example, in the case where calcium was added at a molar ratio of 0.4, the concentrate and seeds were mixed in a mixing granulator, and the total solid amount discharged was adjusted to 77% (w / w) and discharged. 19.3 kg of seeds (purity 57.0% (w / w), total solid amount 99% (w / w)) were charged and mixed in the mixing granulator. The mixed granules were 31.5 kg (purity 56.3% (w / w), total solid amount 77% (w / w)). The mixture was dried in a fluidized bed dryer / cooler. With a solid loss of 1% (w / w), 24.3 kg was obtained (purity 56.3% (w / w), total solid amount 99% (w / w)).

[0060] For example, in the case where calcium was added at a molar ratio of 0.2, the concentrate and seeds were mixed in a mixing granulator, and the total solid amount discharged was adjusted to 80% (w / w) and discharged. 33.3 kg of seeds (purity 57.0% (w / w), total solid amount 99% (w / w)) were charged and mixed in the mixing granulator. The mixed granules were 47.4 kg (purity 56.8% (w / w), total solid amount 80% (w / w)). The mixture was dried in a fluidized bed dryer / cooler. With a solid loss of 1% (w / w), 37.9 kg was obtained (purity 56.8% (w / w), total solid amount 99% (w / w)).

[0061] For example, in the case where calcium was added at a molar ratio of 0.6, the concentrate and seeds were mixed in a mixing granulator, and the total solid amount discharged was adjusted to 80% (w / w) and discharged. 41.8 kg of seeds (purity 57.0% (w / w), total solid amount 99% (w / w)) were charged and mixed in the mixing granulator. The mixed granules were 53.8 kg (purity 56.4% (w / w), total solid amount 80% (w / w)). The mixture was dried in a fluidized bed dryer / cooler. With a solid loss of 1% (w / w), 46.6 kg was obtained (purity 56.4% (w / w), total solid amount 99% (w / w)).

[0062] [Table 3]

[0063] Overall, the addition of calcium at a molar ratio of 0.4 relative to the isoleucine concentration in the fermentation broth resulted in the highest enrichment and produced granules with the highest purity with the smallest amount of seed added.

[0064] Examples 1-9 to 1-11 and Comparative Example 4: Preparation of leucine-containing concentrated solution with or without calcium added to fermentation liquid Except for using the leucine-containing fermentation broth having the composition shown in Table 4, calcium hydroxide slurry was added at a molar ratio of 0.4, 0.2, and 0.6 in the same manner as in Examples 1-1 to 1-3 to prepare concentrated solutions. The pH of each was 9.3, 8.9, and 10.0 (Examples 1-9 to 1-11, respectively). The sample of Comparative Example 4 was prepared by concentrating the leucine-containing fermentation broth without adding calcium hydroxide. The fermentation broth used, the concentration and purity of the concentrated solution produced, etc. are shown in Table 4. The purity was somewhat reduced by adding the slurry. The fermentation broth to which the slurry was added was concentrated to a concentration of 32, 27, and 28% (w / w) before crystal nuclei were generated. It was confirmed that further concentration caused gelation and loss of fluidity. Here, in the fermentation broth to which the slurry was not added, only a concentration of about 25% (w / w) was achieved.

[0065] For example, in the case where calcium was added at a molar ratio of 0.4, the concentrate and seeds were mixed in a mixing granulator, and the total solid amount discharged was adjusted to 80% (w / w) and discharged. 23.0 kg of seeds (purity 60.0% (w / w), total solid amount 99% (w / w)) were charged and mixed in the mixing granulator. The mixed granules were 32.1 kg (purity 59.7% (w / w), total solid amount 80% (w / w)). The mixture was dried in a fluidized bed dryer / cooler. With a solid loss of 1% (w / w), 25.7 kg was obtained (purity 59.7% (w / w), total solid amount 99% (w / w)).

[0066] For example, in the case where calcium was added at a molar ratio of 0.2, the concentrate and seeds were mixed in a mixing granulator, and the total solid amount discharged was adjusted to 83.0% (w / w) and discharged. 36.5 kg of seeds (purity 60.0% (w / w), total solid amount 99% (w / w)) were charged and mixed in the mixing granulator. The mixed granules were 46.9 kg (purity 60.0% (w / w), total solid amount 83.0% (w / w)). The mixture was dried in a fluidized bed dryer / cooler. With a solid loss of 1% (w / w), 38.9 kg was obtained (purity 60.0% (w / w), total solid amount 99% (w / w)).

[0067] For example, in the case where calcium was added at a molar ratio of 0.6, the concentrate and seeds were mixed in a mixing granulator, and the total solid amount discharged was adjusted to 82.0% (w / w) and discharged. 34.2 kg of seeds (purity 60.0% (w / w), total solid amount 99% (w / w)) were charged and mixed in the mixing granulator. The mixed granules were 45.0 kg (purity 56.9% (w / w), total solid amount 82.0% (w / w)). The mixture was dried in a fluidized bed dryer / cooler. With a solid loss of 1% (w / w), 36.9 kg was obtained (purity 56.9% (w / w), total solid amount 99% (w / w)).

[0068] [Table 4]

[0069] Overall, the addition of calcium hydroxide at a molar ratio of 0.4 relative to the leucine concentration in the fermentation broth resulted in the highest enrichment and produced granules with the highest purity with the smallest amount of seed added.

[0070] Examples 1-12 to 1-14 and Comparative Example 5: Preparation of threonine-containing concentrated solution with or without calcium added to fermentation liquid Except for using the threonine-containing fermentation broth of the composition shown in Table 5, calcium hydroxide slurry was added at a molar ratio of 0.4, 0.2, and 0.6 in the same manner as in Examples 1-1 to 1-3 to prepare concentrated solutions. The pH of each was 9.5, 8.8, and 10.2 (Examples 1-12 to 1-14, respectively). The sample of Comparative Example 5 was prepared by concentrating the threonine-containing fermentation broth without adding calcium hydroxide. The fermentation broth used, the concentration and purity of the concentrated solution produced, etc. are shown in Table 5. The purity was somewhat reduced by adding the slurry. The fermentation broth to which the slurry was added was concentrated to a concentration of 35, 25, and 26% (w / w) before crystal nuclei were generated. In the case of threonine, since the crystal particles were generated in a needle shape and had an excellent shape, it was confirmed that all of them were at the same level when concentrated to the maximum concentration. Here, in the fermentation broth to which the slurry was not added, it was confirmed that crystal nuclei were generated at a concentration of about 18% (w / w).

[0071] [Table 5]

[0072] Overall, the highest enrichment was achieved when calcium hydroxide was added at a molar ratio of 0.4 relative to the threonine concentration in the fermentation broth. Example 2

[0073] Comparison of amino acid granule production at various discharge moisture contents of granules Examples 2-1 to 2-3 and Comparative Examples 6 and 7: Granulation of valine-containing concentrate with added calcium by mixed granulation method 300L of the valine-containing fermentation liquid used in Example 1-1 was put into a 500L stainless steel tank, and the fermentation liquid was stirred using a stirrer. 6.4kg of calcium hydroxide and 8.0kg of water were added to the solution so that the calcium / valine molar ratio was 0.4, and the mixture was further stirred for 1 hour. Here, the pH was 9.5, the volume of the mixture was 310.9L, the valine concentration was 77.2g / L, the purity was 71.4% (w / w), and the total solid amount was 10.5% (w / w). The mixture was put into a forced circulation type concentration tube (Manmin machine) and concentrated. Under conditions of a pressure of 0.1 atmosphere and a pressure of 3 atmospheres of steam put into the heat exchanger, the mixture was concentrated until the total solid amount was 40% (w / w). The concentrated liquid after concentration at the above concentration level had a concentration of 322.1g / L, a purity of 71.4% (w / w), a total solid amount of 40.0% (w / w), and a volume of 74.5L. Next, granules were produced using a mixing type granulator. As in Example 1-1, seeds were added at a rate of 20 kg per hour, and a concentrated liquid was added according to the total solid amount of the discharged granules. The produced granules were dried in a fluidized bed dryer. Since fine powder was generated, the recovery rate was at the level of 99% (w / w). The experimental results are shown in Table 6.

[0074] Further, granules were produced in the same manner as above, and the discharged moisture percentage of the granules was adjusted to 15.0% (w / w) to 27.5% (w / w), respectively, to prepare samples of Examples 2-1 to 2-3 and Comparative Examples 6 and 7. In the sample of Comparative Example 1, the discharged moisture percentage was only 12% (w / w), and a large amount of seeds was required, but in the samples of Examples 1-1 and 2-1 to 2-3, the discharged moisture percentage could be increased to 17.5% (w / w) to 25.0% (w / w). However, in the samples of Comparative Examples 6 and 7, which had discharged moisture percentages of 15.0% (w / w) and 27.5% (w / w), respectively, they were not suitable for granule formation. For example, in the case of the granules with a discharged moisture percentage of 17.5% (w / w), it was not possible to granulate uniformly to the same or approximately the same size as the seeds, and in the case of the granules with a discharged moisture percentage of 27.5% (w / w), a phenomenon occurred in which the granules aggregated with each other. The properties of the samples of the above examples and comparative examples are summarized in Table 6.

[0075] [Table 6]

[0076] Examples 2-4 and 2-5 and Comparative Examples 8 and 9: Granulation of tryptophan-containing concentrate with added calcium by mixed granulation method The concentrated liquid prepared in Example 1-4 was granulated by adjusting the discharged moisture rate to 20.0% (w / w) to 25.0% (w / w). In the sample of Comparative Example 2, the discharged moisture rate was only 12% (w / w), and a large amount of seeds was required, but in the samples of Examples 1-5, 2-4, and 2-5, the discharged moisture rate could be increased to 20.0% (w / w) to 25.0% (w / w). However, in the samples of Comparative Examples 8 and 9, which had discharged moisture rates of 17.5% (w / w) and 27.5% (w / w), respectively, granules could not be formed. The properties of the samples of the above examples and comparative examples are summarized in Table 7.

[0077] [Table 7]

[0078] Examples 2-6 and 2-7 and Comparative Examples 10 and 11: Granulation of calcium-added isoleucine-containing concentrate by mixed granulation method In Examples 1-6, the concentrated solution prepared by reacting with calcium hydroxide at a molar ratio of 0.4 was adjusted to have a discharged moisture content of 20.0% (w / w) to 25.0% (w / w) and granulated. In the sample of Comparative Example 3, the discharged moisture content was only 15% (w / w) and a large amount of seeds was required, but in the samples of Examples 1-6, 2-6 and 2-7, the discharged moisture content could be increased to 20.0% (w / w) to 25.0% (w / w). However, in the samples of Comparative Examples 10 and 11, which had discharged moisture contents of 17.5% (w / w) and 27.5% (w / w), respectively, granules could not be formed. The properties of the samples of the above Examples and Comparative Examples are summarized in Table 8.

[0079] [Table 8]

[0080] Examples 2-8 and 2-9 and Comparative Examples 12 and 13: Granulation of leucine-containing concentrate with added calcium by mixed granulation method In Examples 1-9, the concentrated solution prepared by reacting with calcium hydroxide at a molar ratio of 0.4 was adjusted to have a discharged moisture content of 18.0% (w / w) to 23.0% (w / w) and granulated. In the sample of Comparative Example 4, the discharged moisture content was only 15% (w / w) and a large amount of seeds was required, but in the samples of Examples 1-9, 2-8 and 2-9, the discharged moisture content could be increased to 18.0% (w / w) to 23.0% (w / w). However, in the samples of Comparative Examples 12 and 13, which had discharged moisture contents of 15% (w / w) and 27% (w / w), respectively, granules could not be formed. The properties of the samples of the above Examples and Comparative Examples are summarized in Table 9.

[0081] [Table 9] Example 3

[0082] Production of calcium-added amino acid granules by fluidized bed granulation method Example 3-1 and Comparative Example 14: Production of valine-containing granules with added calcium by fluidized bed granulation 2 L of the valine fermentation solution having the composition shown in Table 10 was placed in a 3 L glass beaker and stirred at 25°C using a stirrer (model name HT-50AX, Tehan Scientific). 43 g of calcium hydroxide and 53 g of water were added so that the molar ratio of valine was 0.4, and the mixture was further stirred for 1 hour. Here, the pH was 9.5, the volume of the mixture was 2.1 L, the valine concentration was 77.2 g / L, the purity was 71.4% (w / w), and the total solid content was 10.5% (w / w). The mixture was poured into a 2 L concentration tube (model name N-1200B, EYELA) and concentrated. The mixture was concentrated under conditions of a pressure of 0.1 atm and a water bath temperature of 70°C until the total concentration reached 31% (w / w). In order to feed the fluidized bed granulator nozzle, the concentration was completed at a concentration of 31% (w / w) before crystallization. The concentrated liquid after this concentration had a concentration of 242.7 g / L, a purity of 71.4% (w / w), a total solid amount of 31% (w / w), and a volume of 0.7 L. Next, 361 g of seeds were added to a laboratory fluidized bed granulator / dryer (GR Engineering), and a total of 722.7 g of the concentrated liquid was added at a rate of 180.7 g per hour. The seeds were the same as those used in the above-mentioned examples. The recovered granules were 558.2 g, had a purity of 75.8% (w / w), and a total solid amount of 99% (w / w) (Example 3-1).

[0083] Separately, 2 L of valine fermentation liquid was placed in a 2 L concentration tube and concentrated. The pressure was 0.1 atm, and the water tank temperature was 70°C, and the concentration was increased to 15% (w / w). The concentrate that had been concentrated to the above concentration had a concentration of 123.7 g / L, a purity of 80.0% (w / w), a total solid content of 15% (w / w), and a volume of 1.3 L. Next, 667 g of seeds were placed in a laboratory fluidized bed granulator / dryer, and a total of 1,333 g of the concentrate was placed at a rate of 333 g per hour. The seeds were the same as those used in the above-mentioned examples. The recovered granules weighed 825 g, had a purity of 78.8% (w / w), and a total solid content of 99% (w / w) (Comparative Example 14).

[0084] Table 10 shows the fermentation liquid used in Example 3-1 and Comparative Example 14, and the concentration and purity of the produced concentrated liquid.

[0085] [Table 10]

[0086] Example 3-2 and Comparative Example 15: Preparation of tryptophan-containing granules with added calcium by fluidized bed granulation Furthermore, samples of Example 3-2 and Comparative Example 15 were prepared by concentration (concentration was completed at a concentration of 28% (w / w) and 15% (w / w), respectively) and granulation in the same manner as in Example 3-1 and Comparative Example 14, except that a tryptophan-containing fermentation broth having the composition shown in Table 11 was used instead of the valine-containing fermentation broth. The fermentation broth used, and the concentration and purity of the produced concentrated broth, etc. are shown in Table 11.

[0087] [Table 11]

[0088] Example 3-3 and Comparative Example 16: Production of calcium-added isoleucine-containing granules by fluidized bed granulation Furthermore, samples of Example 3-3 and Comparative Example 16 were prepared by concentration (concentration was completed at a concentration of 18% (w / w) and 10% (w / w), respectively) and granulation in the same manner as in Example 3-1 and Comparative Example 14, except that an isoleucine-containing fermentation broth having the composition shown in Table 12 was used instead of the valine-containing fermentation broth. The fermentation broth used, and the concentration and purity of the produced concentrated broth, etc. are shown in Table 12.

[0089] [Table 12]

[0090] Examples 3-4 and Comparative Example 17: Production of leucine-containing granules with added calcium by fluidized bed granulation Furthermore, samples of Examples 3-4 and Comparative Example 17 were prepared by concentration (concentration was completed at a concentration of 16% (w / w) and 10% (w / w), respectively) and granulation in the same manner as in Example 3-1 and Comparative Example 14, except that the valine-containing fermentation broth was replaced with a leucine-containing fermentation broth having the composition shown in Table 13. The fermentation broth used, and the concentration and purity of the resulting concentrated broth, etc. are shown in Table 13.

[0091] [Table 13]

[0092] Examples 3-5 and Comparative Example 18: Preparation of Threonine-Containing Granules with Added Calcium by Fluidized Bed Granulation Furthermore, samples of Example 3-5 and Comparative Example 18 were prepared by concentration (concentration was completed at a concentration of 35% (w / w) and 18% (w / w), respectively) and granulation in the same manner as in Example 3-1 and Comparative Example 14, except that the valine-containing fermentation broth was replaced with a threonine-containing fermentation broth having the composition shown in Table 14. The fermentation broth used, and the concentration and purity of the resulting concentrated broth, etc. are shown in Table 14.

[0093] [Table 14] Example 4

[0094] Effect of homogenization on concentrated liquid before granulation In Example 3-2, before granulation using a fluidized bed granulator, the calcium- and tryptophan-containing concentrate was treated with a homogenizer, and the particle size before and after treatment was measured by focused beam reflectance measurement (FBRM). The results are shown in FIG. 1 and Table 15. As shown in FIG. 1 and Table 15, while there was almost no change due to other factors, the particle distribution at 100 μm or more after treatment decreased compared to before homogenizer treatment, and the average particle size also decreased significantly from 43 μm to 35 μm. This suggests that the use of a homogenizer before granulation can solve problems such as nozzle clogging in a fluidized bed granulator.

[0095] [Table 15]

[0096] Comparative Example 19: Effect of adding zinc hydroxide on concentration of fermentation broth 60 L of the valine fermentation liquid used in Example 1-1 was placed in a 110 L plastic container and stirred at 25 ° C. and 100 rpm using a stirrer. 1.7 kg of zinc hydroxide (content 98% (w / w), Daejeong Hwagum) and 2.5 kg of water were added to the above solution so that the zinc / valine molar ratio was 0.4, and the mixture was further stirred for 1 hour. Here, the pH was 9.3, the volume of the above mixture was 63.0 L, the valine concentration was 76.1 g / L, the purity was 67.6% (w / w), and the total solid amount was 10.9% (w / w). The above mixture was placed in a 20 L concentration tube and concentrated. It was concentrated under conditions of a pressure of 0.1 atmosphere and a water tank temperature of 70 ° C. until the total concentration reached 25% (w / w). The concentrated liquid after concentration at the above concentration level had a concentration of 183.9 g / L, a purity of 67.6% (w / w), a total solid content of 25% (w / w), and a volume of 26.1 L. Next, granules were produced using a mixing type granulator. As in Example 1-1, a total of 82.3 kg of seeds were fed into the screw feeder in the mixing type granulator at a rate of 20 kg per hour. A total of 28.4 kg of the concentrated liquid was fed at a rate of 6.9 kg per hour using a constant-volume liquid feed pump. 110.7 kg of granules with a solid content of 80% (w / w) were collected. This was dried in a fluidized bed dryer. Since fine powder and the like were generated, 88.6 kg was collected, which was a recovery rate of 99% (w / w). The purity was 77.6% (w / w), and the total solid content was 99% (w / w).

[0097] However, unlike Example 1-1 using calcium hydroxide, when zinc hydroxide (Comparative Example 19) was added, it was confirmed that the effect of improving the enrichment degree was not observed, and the experiment was terminated.

[0098] Experimental Example 1: Binder effect of calcium in calcium-containing amino acid granules The calcium-containing amino acid was prepared by granulating a fermentation liquid containing tryptophan to which calcium hydroxide was added at a molar ratio of 0.2. For comparison, a sample was prepared by granulating a fermentation liquid adjusted to pH 5.0 by adding sulfuric acid without adding calcium hydroxide or a separate binder, and the purity of the total solids and the purity of the granules to be manufactured were measured, and the purity value of the granules relative to the purity of the total solids, which is indicated by the difference between the two, was calculated. As a result, the calcium-containing tryptophan granules were produced from a basic fermentation liquid of pH 9.0, which is expected to reduce the amount of crystals due to the increased solubility caused by the use of calcium hydroxide, but the purity value of the granules relative to the purity of the total solids was almost unchanged at -0.6, which is low, whereas the purity of the granules produced from a fermentation liquid of pH 5.0 that did not contain calcium was significantly reduced by more than 4% (w / w). This suggests that calcium acts as a binder to strengthen the cohesive force between the tryptophan crystals and the liquid phase.

[0099] Therefore, in order to confirm whether such a difference in purity decrease was due to a difference in pH, the purity value of the granules was calculated relative to the purity of the total solid content of the granules prepared using a fermentation broth adjusted to the same pH of 9.0 as the calcium-containing fermentation broth prepared by adding calcium hydroxide instead of adding sulfuric acid to adjust the pH to 5.0, and compared with that of the fermentation broth prepared by adding calcium hydroxide at a molar ratio of 0.2, which showed a small purity decrease of -0.8% (w / w) or less than 1% (w / w), whereas the purity of the amino acid granules produced from the fermentation broth of the same pH to which sodium hydroxide was added showed a significant decrease of -6.6% (w / w).

[0100] Furthermore, the purity value of the granules was calculated relative to the purity of the total solid content of amino acid granules produced by adding 1 weight % (w / w) of PVP, known as a binder, instead of adding calcium, and the two were compared. As a result, the amino acid granules produced by adding calcium hydroxide at a molar ratio of 0.2 showed a purity decrease of -0.9, still less than 1% (w / w), whereas the amino acid granules produced by adding 1 weight % (w / w) of PVP as a binder showed a significant decrease of -3.5% (w / w).

[0101] Overall, these results are summarized in Table 16. This suggests that amino acid granules produced with added calcium ions ensure excellent content stability, regardless of pH adjustment or the inclusion of a binder.

[0102] [Table 16]

[0103] Specifically, as shown in Table 16, under the same fermentation liquid conditions, when calcium hydroxide was added at a molar ratio of 0.2, the difference in the purity of the total solids and the granule content showed a small deviation of less than 1% (w / w). On the other hand, when PVP, which has been widely used as a binder, was added at 1 wt% (w / w), the difference in the granule content was 3.5% (w / w), more than three times larger. Furthermore, when sodium hydroxide was added at the same molar ratio instead of calcium hydroxide, the difference in the granule content increased significantly to 6.6% (w / w). This suggests that metals other than calcium are not effective as binders.

[0104] Experimental Example 2: Improvement of granule moisture absorption by adding calcium The sample prepared in Example 1-1 and the sample prepared in Comparative Example 1 were left under conditions of humidity 60% (w / w) and temperature 40°C, and the weights of the samples immediately after production and after 24 hours and 48 hours were measured to confirm the hygroscopicity. The results are summarized in Table 17. As shown in Table 17, the sample of Example 1-1 showed a weight increase of about 3% (w / w) after 24 hours and did not show any further weight increase thereafter, whereas the sample of Comparative Example 1 showed a weight increase of about 10% (w / w) by 24 hours, and although the increase rate decreased significantly, it continued to show further weight increase thereafter. This shows that the amino acid granules produced by adding calcium show improved stability during storage because the moisture absorption rate decreases over time under high temperature and / or somewhat high humidity conditions.

[0105] [Table 17]

[0106] From the above description, a person skilled in the art to which the present application pertains will understand that the present application can be implemented in other specific forms without changing its technical ideas or essential features. It should be understood that the above examples are merely illustrative and not limiting. The present application should be interpreted as including all modifications and variations derived from the meaning and scope of the claims and their equivalent concepts, rather than the specification. For example, certain embodiments provide the following: (Item 1) A first step of adding a calcium source to a fermentation liquid containing an amino acid, the calcium source having a molar ratio of 0.02 to 2.0 relative to the amino acid; A second step of granulating the result of the previous step. A method for producing amino acid granules. (Item 2) Further comprising a step of concentrating before or after the first step; The manufacturing method according to item 1. (Item 3) The result of the concentration step is produced at a concentration of more than 0% (w / w) and not more than 70% (w / w). It was done. The manufacturing method according to item 2. (Item 4) The amino acid has a solubility in water at 25° C. of more than 0 g / 100 g and not more than 20 g / 100 g. The manufacturing method according to item 1. (Item 5) The amino acid is valine, tryptophan, threonine, isoleucine or leucine; The manufacturing method according to item 1. (Item 6) The method further includes a step of adjusting the moisture content of the result of the previous step to 10 to 50% (w / w) before the granulation step. The manufacturing method according to item 1. (Item 7) Prior to the granulation step, the step of grinding the result of the previous step may be further included. The manufacturing method according to item 1. (Item 8) An amino acid and a calcium ion having a molar ratio of 0.02 to 2.0 relative to the amino acid, Amino acid granules. (Item 9) The amino acid granules have a moisture absorption rate of 7% (w / w) or less when left to stand for 1 to 48 hours from the time of granulation under conditions of a humidity of 60% (w / w) and a temperature of 40°C. Item 9. Amino acid granules according to item 8. (Item 10) The amino acid granules are produced by the method according to any one of items 1 to 7. Item 9. Amino acid granules according to item 8. (Item 11) Item 9. The amino acid granules according to item 8 are included. Feed composition.

Claims

1. An amino acid granule comprising an amino acid and calcium ions having a molar ratio to the amino acid of 0.02 to 2.

0.

2. The amino acid granule described in claim 1, wherein the amino acid granule contains calcium ions in a molar ratio to the amino acid of 0.1 to 0.

6.

3. The amino acid granules described in claim 8, which have a moisture absorption rate of 7% (w / w) or less when left to stand for 1 to 48 hours from the time of granulation under conditions of a humidity of 60% (w / w) and a temperature of 40°C.

4. A feed composition comprising the amino acid granules described in claim 1.

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