Method for producing dried lactic acid bacteria

Abstract

To provide a technology capable of producing dried lactic acid bacteria with a higher viable cell count using simpler production equipment.SOLUTION: A method for producing dried lactic acid bacteria includes: a pure culture step for lactobacillus fermentum; a mixing step of adding, to the purely cultured liquid of lactobacillus fermentum, trehalose, tapioca starch, roasted soybean flour, oligosaccharide, glucose, enzyme, peptone, dextrin, and sodium chloride (NaCL), so as to make an auxiliary material therefrom; a stirring step of stirring a mixture made from the auxiliary material added with purified water, so as to bring it into a paste state; a proliferation step of causing the lactobacillus fermentum to proliferate by keeping, at a predetermined first temperature for a predetermined first period, the mixture stirred in the stirring step; a drying step of drying the mixture after the proliferation of the lactobacillus fermentum, by keeping it in a dryer at a predetermined second temperature for a predetermined second period; and a powdering step of pulverizing the mixture dried in the drying step into powder.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing a dried lactic acid bacteria product containing a higher number of lactic acid bacteria more reliably. [Background technology]

[0002] Conventionally, there have been known dried powders containing high-purity lactic acid bacteria (dried lactic acid bacteria), which are used in, for example, health foods and livestock feed. Regarding a method for producing such dried lactic acid bacteria, for example, 1.5% of a pure culture solution of Lactobacillus fermentum, 4% of skim milk, 0.5% to 1.5% of natural salt, 1% of molasses, 0.5% of monosodium glutamate, 2% to 6% of potato starch, and 3% to 9% of defatted soybean flour are mixed with 100% purified water by stirring, and after a predetermined time of growth process, the mixture is spray-dried in a spray dryer set at an inlet temperature of 150°C to 180°C and an outlet temperature of 75°C to 87°C, resulting in a viable cell count of Lactobacillus fermentum of 1.1 × 10 9 cfu / g ~ 1.2 × 10 10 A method for producing dried lactic acid bacteria has been proposed, which produces powdery dried lactic acid bacteria having a mean particle size of 1 μm to 9 μm and a high cfu / g (see, for example, Patent Document 1).

[0003] In the above-mentioned method for producing dried lactic acid bacteria, the additives to the pure culture solution of Lactobacillus fermentum are not optimized, and there is a problem that uneven drying is easily caused during spray drying.As a result, the number of dead bacteria is relatively large when powdered, and the number of live bacteria is not optimized.In addition, since it is assumed that a spray dryer is used, the equipment may be expensive. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4067474 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a technology that enables the production of dried lactic acid bacteria with a higher viable cell count using simpler production equipment. [Means for solving the problem]

[0006] To solve the above problems, the present invention provides a pure culture process of Lactobacillus fermentum, A mixing step of adding trehalose, tapioca, soybean flour, oligosaccharides, glucose, enzymes, peptone, dextrin, and NaCl to the pure culture solution of Lactobacillus fermentum to obtain auxiliary materials; A stirring step of stirring a mixture of the auxiliary material and purified water to form a paste; A growth step of growing the Lactobacillus fermentum by incubating the mixture stirred in the stirring step at a predetermined first temperature for a predetermined first time; A drying step of drying the mixture after the Lactobacillus fermentum has been grown by keeping it at a predetermined second temperature for a predetermined second time in a dryer; a powdering step of grinding the mixture dried in the drying step into powder; The present invention relates to a method for producing a dried lactic acid bacteria product, characterized in that:

[0007] Here, in the method for producing the dried lactic acid bacteria, skim milk, natural salt, molasses, sodium glutamate, potato starch, and defatted soybean flour are added to a pure culture solution of Lactobacillus fermentum. When used as a secondary material, there are still many dead bacteria, making it difficult to efficiently cultivate live bacteria. However, through intensive research by the inventors, it has been found that by adding trehalose, tapioca, soybean flour, oligosaccharides, glucose, enzymes, peptone, dextrin, and NaCl to a pure culture solution of Lactobacillus fermentum as a secondary material, it is possible to reduce the number of dead bacteria and more reliably grow live bacteria. Therefore, by using the above secondary material, it is possible to obtain a dried lactic acid bacteria product containing a larger number of live bacteria.

[0008] In addition, in the drying process of the present invention, the mixture after Lactobacillus fermentum is grown is kept at a predetermined second temperature for a predetermined second time in a dryer to be dried.Therefore, the mixture after Lactobacillus fermentum is grown can be dried evenly, and it is possible to obtain the lactic acid bacteria dried product that contains more live bacteria.In addition, compared with spray dryers, the dryer that simply has a heat-retaining function is generally cheaper, so it is possible to reduce equipment costs.

[0009] In addition, in the present invention, in the growth process, the pH of the mixture after the Lactobacillus fermentum is grown can be 3.0 or more and 3.4 or less.Here, because lactic acid bacteria produce lactic acid, if the number of viable bacteria in the mixture is large, the value of pH tends to be small.Therefore, in the present invention, in the growth process, by controlling the relationship between the passage of time and the value of pH, and making the pH of the mixture be 3.0 or more and 3.4 or less, the number of viable bacteria in the mixture after the Lactobacillus fermentum is grown can be made to be sufficient value more reliably.

[0010] More preferably, in the present invention, the relationship between the passage of time and the pH value may be controlled in the growth process, and the pH of the mixture after the growth of Lactobacillus fermentum may be set to 3.2. This makes it possible to obtain the maximum stable value for the number of viable bacteria. In conventional methods, the pH after the growth of lactic acid is set to 3.9 to 4.2, and since it is not a strong acid, many dead bacteria are generated in the decay environment, which impairs the activity of viable bacteria. According to the present invention, it is possible to grow viable bacteria more reliably.

[0011] In the present invention, in the mixing step, the secondary material is a pure culture of Lactobacillus fermentum (lactic acid bacteria count 1.2 × 10 8 (c) The solution may be 100% to which 60% trehalose, 15% tapioca, 10% soybean flour, 4% oligosaccharides, 5% glucose, 1% enzymes, 2% peptone, 2% dextrin, and 1% NaCl have been added. The inventors' extensive research has revealed that the above ratios of each component in the auxiliary materials enable the maximum proliferation of viable bacteria. The present invention makes it possible to more reliably increase the viable bacteria count.

[0012] In the present invention, in the mixing step, the ratio of the aforementioned secondary materials is 20% and purified water is 80%, and purified water is added to the secondary materials to make 100%, and the mixture is mixed to form a paste. In the proliferation step, the first temperature is set to a temperature of 35°C or higher and 40°C or lower, and the first time period is set to 45 hours or higher and 50 hours or lower; The second temperature in the drying step may be set to a temperature of 35° C. or more and 40° C. or less, and the second time period may be set to 70 hours or more and 75 hours or less.

[0013] According to this, in the growth process, Lactobacillus fermentum can be more reliably grown, and the number of live bacteria can be maintained by drying evenly and sufficiently.More preferably, the first temperature is 37°C, the first time is 48 hours, the second temperature is 37°C, and the second time is 72 hours.This can further reliably increase the number of live bacteria after the drying process.

[0014] In the present invention, the dried mixture may be ground into powder using a mill with a mesh size of 4 μm in the powdering step, which makes it possible to obtain powder with a particle size of 4 μm or less more stably than when a spray dryer is used, and to make the particle size of the final product uniform. [Effects of the Invention]

[0015] According to the present invention, a technique can be provided that enables the production of dried lactic acid bacteria having a higher viable cell count using simpler production equipment. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a flowchart showing the method for producing dried lactic acid bacteria in this example. BEST MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The method for producing a dried lactic acid bacteria product shown below is merely an example, and it is not intended that the production conditions and specifications be limited to those described.

[0018] Fig. 1 is a flowchart showing a method for producing a dried lactic acid bacteria product according to an embodiment of the present invention, which illustrates an example of producing a dry powder of lactic acid bacteria from a Lactobacillus fermentum strain.

[0019] Step S101 corresponds to the pure culture process of Lactobacillus fermentum strain. In step S101, for example, 1 liter of purified water (purified water) is placed in a hard heat-resistant container, mixed with 5 g of glucose, 5 g of yeast, and 5 g of piptone, sterilized by autoclave (for example, at 120 ° C for 20 minutes), cooled to 40 ° C or below, added with 50 ml of Lactobacillus fermentum, and cultured in an incubator at 40 ° C for 48 hours. This produces a pure culture solution of Lactobacillus fermentum.

[0020] Regarding pure culture, in order to detect lactic acid bacteria and measure the number of bacteria, a BCP plate count agar medium is formed by pouring molten agar containing the above-mentioned ingredients into a petri dish, and the Lactobacillus fermentum strain is applied to a 2 mm thick layer with a platinum rod. The petri dish with the Lactobacillus fermentum strain applied is then placed in an incubator and cultured at a constant temperature of 36°C for 24 hours to measure the number of viable bacteria in the pure culture of lactic acid bacteria. In the pure culture process, 1.2 x 10 8 Increase the number of live bacteria to about 100.

[0021] Next, in step S102, trehalose, tapioca, soybean flour, oligosaccharides, glucose, enzymes, peptone, dextrin, and NaCl are added to the pure culture solution of Lactobacillus fermentum obtained in step S101 to prepare a secondary material. Specifically, the pure culture solution of Lactobacillus fermentum (1.2 × 10 lactic acid bacteria count) is 8 To 100% of the liquid, 60% trehalose, 15% tapioca, 10% soybean flour, 4% oligosaccharides, 5% glucose, 1% enzyme, 2% peptone, 2% dextrin, and 1% NaCl are added to make the secondary materials. Note that in this example, all percentages (%) refer to weight %. In this example, the step S102 corresponds to the mixing step.

[0022] In the above example, in other words, a pure culture of Lactobacillus fermentum (1.2 x 10 lactic acid bacteria) 8 60% by weight of trehalose, 15% by weight of tapioca, 10% by weight of soybean flour, 4% by weight of oligosaccharides, 5% by weight of glucose, 1% by weight of enzymes, 2% by weight of peptone, 2% by weight of dextrin, and 1% by weight of NaCl are added to the liquid. The total weight of these additives is the weight of the pure culture liquid of Lactobacillus fermentum. is equivalent to (100%).

[0023] Then, in the step S103, purified water is added to the above-mentioned secondary materials to make a ratio of 20% secondary materials produced in the above mixing step and 80% purified water, and the mixture is stirred to form a paste. The step S103 corresponds to the stirring step in this embodiment.

[0024] Next, in step S104, for example, purified water is added to the auxiliary materials and stirred to form a paste, which is then placed in an incubator and kept at 37°C for 48 hours to grow the number of Lactobacillus fermentum bacteria to 1.0 x 10 12 The mixture is cultured and grown to cfu / g or more. Growth can be confirmed by the mixture becoming cloudy and a swirling state being observed when the container is tilted, and by measuring the pH, which indicates a pH value of 3.2 to 3.5. The mixture may then be further mixed in a mixer to form a slurry. Step S104 corresponds to the growth step in this embodiment. The temperature of 37°C in the growth step corresponds to the first temperature. If this temperature is in the range of 35°C to 40°C, results similar to those obtained when the temperature is 37°C can be obtained. The 48-hour incubation period corresponds to the first hour. If this incubation period is 45 to 50 hours, results similar to those obtained when the temperature is 48 hours can be obtained.

[0025] Next, in step S105, the mixture after growth culture is dried at low temperature using a low-temperature dryer. Specifically, the mixture is dried for 72 hours in a low-temperature dryer set at 37°C. Here, when drying is performed using a spray dryer, uneven viable cell counts occur in the dried mixture, making it difficult to achieve the target total cell count. In contrast, in this embodiment, by drying the mixture at low temperature for a long period of time in the dryer, the mixture is dried evenly, ensuring a more uniform and stable viable cell count and enabling an increase in the total viable cell count. Furthermore, using a low-temperature dryer can reduce equipment costs compared to using a spray dryer. Step S105 corresponds to the drying step in this invention. Note that the temperature of 37°C in the drying step corresponds to the second temperature. If this temperature is in the range of 35°C to 40°C, results similar to those obtained when the temperature is 37°C can be obtained. Furthermore, the 72-hour incubation period corresponds to the second hour. If this incubation period is 70 to 75 hours, results similar to those obtained when the temperature is 72 hours can be obtained.

[0026] Next, in step S106, the dried mixture is pulverized using a mill. The mill mesh, through which the pulverized mixture passes, is set to 4 μm, and a powdered lactic acid bacteria dried product (Lactobacillus fermentum dried product) with an average particle size of 4 μm or less can be obtained. This step corresponds to the pulverization step in this example.

[0027] In this example, it is possible to efficiently obtain powdered dried lactic acid bacteria (dried Lactobacillus fermentum) using common equipment. Table 1 shows the components of the auxiliary materials used in this example and the results of measuring the number of bacteria in the final dried product. As shown in Table 1, in this example, 1.2 × 10 10 A high viable cell count of cfu / g can be stably obtained.

[0028] [Table 1]

[0029] According to the measurement results of the conventional technology, the number of viable Lactobacillus fermentum bacteria in the dried lactic acid bacteria product is 1.2 × 10 on average. 9 cfu / g, and it can be said that, on average, a higher viable cell count was obtained in this example than in the prior art. The test method for the measurement results (viable cell count) in Table 1 may also be as follows: 0.1 g and 0.2 g of specimen are dispersed in 10 ml of physiological saline. These are used as stock solutions to prepare a 10-fold dilution series, and 1 ml of each is poured onto a standard agar medium. After culturing at 3°C for 16 to 24 hours, the number of colonies that appear can be counted to determine the viable cell count per 1 g of specimen.

[0030] Lactobacillus fermentum is generally said to be weak to heat and unsuitable for powdering. However, in the drying process of this example, the mixture after growth and culture was dried at low temperature in a low-temperature dryer. This resulted in a stable drying rate of 1.2 × 10 10 It is now possible to produce powdered lactic acid bacteria containing a single strain of bacteria with high purity and a high viable cell count (cfu / g). (This can also be applied to other bacteria with low heat tolerance.) Furthermore, because the product is in powder form, the activity of the bacteria can be stopped, allowing for long-term storage. Furthermore, the powder form makes it easy to add to health foods and supplements, which have been attracting attention recently. In particular, the bacteria are stabilized while maintaining a high viable cell count. [Explanation of symbols]

[0031] S101: Pure culture process S102: Mixing process S103: Mixing process S104: Proliferation process S105:Drying process S106: Powdering process

Claims

1. A pure culture process of Lactobacillus fermentum, A mixing step of adding trehalose, tapioca, soybean flour, oligosaccharides, glucose, enzymes, peptone, dextrin, and NaCl to the pure culture solution of Lactobacillus fermentum to obtain auxiliary materials; A stirring step of stirring a mixture of the auxiliary material and purified water to form a paste; A growth step of growing the Lactobacillus fermentum by keeping the mixture stirred in the stirring step at a predetermined first temperature for a predetermined first time; A drying step of drying the mixture after the Lactobacillus fermentum has been grown by keeping it at a predetermined second temperature for a predetermined second time in a dryer; a powdering step of grinding the mixture dried in the drying step into powder; A method for producing a dried lactic acid bacterium product, comprising:

2. 2. The method for producing a dried lactic acid bacterium product according to claim 1, wherein the pH of the mixture after the Lactobacillus fermentum has been grown in the growth step is 3.0 or more and 3.4 or less.

3. 2. The method for producing dried lactic acid bacteria according to claim 1, wherein the secondary materials used in the mixing step are 100% of the pure culture solution of Lactobacillus fermentum to which 60% trehalose, 15% tapioca, 10% soybean flour, 4% oligosaccharides, 5% glucose, 1% enzymes, 2% peptone, 2% dextrin, and 1% NaCl have been added.

4. In the stirring step, the ratio of the secondary material is 20% and the purified water is 80%, and the secondary material is mixed with purified water to make 100%, and the mixture is stirred to form a paste. In the proliferation step, the first temperature is set to a temperature of 35°C or higher and 40°C or lower, and the first time period is set to 45 hours or higher and 50 hours or lower; The method for producing dried lactic acid bacteria according to claim 3, characterized in that the second temperature in the drying step is set to a temperature of 35°C or higher and 40°C or lower, and the second time period is set to 70 hours or higher and 75 hours or lower.

5. 5. The method for producing dried lactic acid bacteria according to claim 4, wherein in the powdering step, the dried mixture is ground into powder using a mill with a mesh size of 4 μm.

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