Acid resistant powder, food product, and method for producing acid resistant powder

Abstract

To provide an acid resistant powder excellent in processing stability, storage stability, pressure resistance, and acid resistance.SOLUTION: An acid-resistant powder contains primary coated particles, which are coated with a primary coating material (B) as a continuous phase including powder particles of a core material (A) as multiple nuclei and secondary coated particles having a structure where the primary coated particles are coated with a secondary coating material (C) as a single nucleus. The core material (A) is powder that includes viable bacteria, and the primary coating material (B) contains lipids with a melting point of 40°C to 70°C, the secondary coating material (C) contains lipids with a melting point of 40°C to 100°C and unburned calcium, an average particle diameter of the primary coated particles is between 50 μm and 500 μm, and the average particle diameter of the secondary coated particles relative to the average particle size of the primary coated particles is 1.05 to 2.0 times.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an acid-resistant powder comprising coated particles that contain a powder containing live bacteria as a core substance, a food product, and a method for producing the acid-resistant powder. [Background technology]

[0002] Live bacteria such as bifidobacteria and lactic acid bacteria have beneficial effects on the host by suppressing the proliferation of bad bacteria in the intestines and improving the intestinal flora. The live bacteria also have an intestinal regulating effect, such as improving constipation and diarrhea. These live bacteria have been known as probiotics in recent years and are food materials used in foods for specified health uses. However, these live bacteria cannot fully exert their effects unless they can withstand gastric acid, bile acid, etc. after oral ingestion and reach the intestinal tract. Therefore, acid-resistant and enteric coatings have been invented to deliver bifidobacteria and lactic acid bacteria alive to the intestinal tract and exert their effects.

[0003] For example, Japanese Patent Application Laid-Open No. 5-186335 (Patent Document 1) and Japanese Patent Application Laid-Open No. 5-186336 (Patent Document 2) propose a method for producing an enteric granulated product using lactic acid bacteria and an excipient. In these methods, dry lactic acid bacteria powder, an excipient, and zein are mixed, and oil melted at 40°C is added to the mixture, stirred, extrusion granulated, and then a zein solution or palm oil melted at 40°C is sprayed to obtain an enteric granulated product. Specifically, this method obtains granulated products with a length of 1.5 to 2 mm using an extrusion granulator equipped with a screen with a hole size of 0.8 mm, and the obtained enteric granulated products have a cylindrical shape with a diameter of about 0.8 mm and a length of 1.5 to 2 mm. The methods for producing enteric coated granules described in Patent Documents 1 and 2 can impart acid resistance, but the bacteria are killed rapidly during the process of adding molten oil and fat and extrusion granulation, and the number of remaining bacteria after production tends to be low. Therefore, the number of bacteria in the preparation is low, and there is a risk that the value of the enteric coated preparation will be halved. In addition, the particles produced by the extrusion granulation method are large, making them unsuitable for use as powders for tableting such as pellets and tablets. In addition, large particles make it difficult to add them to soft capsules, and there is a problem that the powder is not versatile enough to be used as an acid-resistant powder.

[0004] In addition, live bacteria such as lactic acid bacteria and bifidobacteria are often used in tablet or chewable health foods and tablet confectioneries. However, these live bacteria are weak against the impact during tableting, and there is a problem that the survival rate of live bacteria is low when the tablet is made. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 5-186335 [Patent Document 2] Japanese Patent Application Publication No. 5-186336 Summary of the Invention [Problem to be solved by the invention]

[0006] In light of this background, first, it is required to reduce the death of live bacteria when powdered raw materials containing live bacteria such as lactic acid bacteria and bifidobacteria are processed into acid-resistant powders (processing stability). Next, it is required to suppress the death of live bacteria during storage of this acid-resistant powder (storage stability). When the acid-resistant powder is compressed into tablets, it is required to suppress the death of live bacteria due to the pressure during tableting (pressure resistance). It is also required to suppress the death of live bacteria when they come into contact with gastric acid (acid resistance) so that they can be delivered alive to the intestines after ingestion. In particular, the pH in the stomach is neutralized by the food ingested after a meal to about pH 3.0, but when fasting, it is about pH 1 to 2, the same as gastric acid, so acid resistance in the strong acid range of about pH 1 to 2 is also required to suppress the death of live bacteria even when a small amount of food containing live bacteria is ingested on an empty stomach.

[0007] An object of the present invention is to provide an acid-resistant powder having excellent processing stability, storage stability, pressure resistance, and acid resistance. [Means for solving the problem]

[0008] As a result of intensive research into solving the above problems, the present inventors have found that the above problems can be solved by primary coated particles having a specific average particle size, which contain a powder containing live bacteria as a core substance as multiple nuclei and are coated with a primary coating material containing a lipid having a specific melting point, and secondary coated particles having a specific average particle size, which are coated with a secondary coating material containing a lipid having a specific melting point and uncalcined calcium, and thus have completed the present invention. That is, the present invention is as follows: [1] to [6].

[0009] [1] An acid-resistant powder comprising primary coated particles in which powder particles of a core substance (A) are encapsulated as multiple nuclei and coated with a primary coating material (B) as a continuous phase, and secondary coated particles having a structure in which the primary coated particles are coated with a secondary coating material (C) as a single nucleus, The core material (A) is a powder containing live bacteria, The primary coating material (B) contains a lipid having a melting point of 40°C to 70°C, The secondary coating material (C) contains a lipid having a melting point of 40°C to 100°C and uncalcined calcium, The average particle size of the primary coated particles is 50 μm to 500 μm, An acid-resistant powder, characterized in that the ratio of the average particle size of the secondary coated particles to the average particle size of the primary coated particles (average particle size of secondary coated particles / average particle size of primary coated particles) is 1.05 to 2.00. [2] a mass ratio of the core material (A) to a total mass of the core material (A) and the primary coating material (B) is 0.65 to 0.90; The acid-resistant powder according to [1], characterized in that a mass ratio of the primary coated particles (B) to a total mass of the primary coated particles and the secondary coating material (C) is preferably 0.60 to 0.85. [3] The acid-resistant powder according to [1] or [2], which preferably has an average particle size of 50 μm to 500 μm and a viable cell survival rate after an acid resistance test of 32% or more. [4] The acid-resistant powder according to any one of [1] to [3], which is preferably for tableting. [5] A food product comprising the acid-resistant powder according to any one of [1] to [4]. [6] A method for producing an acid-resistant powder according to any one of [1] to [4], A step of mixing the core material (A) and the primary coating material (B) to obtain the primary coated particles; A method for producing an acid-resistant powder, comprising: a step of mixing the primary coated particles with a powdery secondary coating material (C) to obtain the secondary coated particles. Effect of the Invention

[0010] According to the present invention, it is possible to provide an acid-resistant powder in which the death of live bacteria is reduced when a powdered raw material containing live bacteria is processed into an acid-resistant powder (processing stability), the death of live bacteria is suppressed during storage of this acid-resistant powder (storage stability), when the acid-resistant powder is compressed into tablets, the death of live bacteria due to the pressure during tableting is suppressed (pressure resistance), and the death of live bacteria is suppressed when the live bacteria come into contact with gastric acid after ingesting the live bacteria so that they are delivered to the intestines alive (acid resistance). [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a schematic explanatory diagram showing the structure of a primary coated particle constituting the acid-resistant powder of the present invention. [Diagram 2] FIG. 2 is a schematic explanatory diagram showing the structure of a secondary coated particle constituting the acid-resistant powder of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In this specification, when a preferred numerical range (e.g., mass %) is described stepwise, each lower limit and upper limit can be independently combined. For example, in the description "preferably 10 or more, more preferably 20 or more, and preferably 100 or less, more preferably 90 or less," "preferably lower limit: 10" and "more preferably upper limit: 90" can be combined to "10 or more and 90 or less."

[0013] [Acid-resistant powder] The acid-resistant powder of the present invention is an acid-resistant powder comprising primary coated particles which encapsulate powder particles of a core substance (A) as multiple nuclei and are coated with a primary coating material (B) as a continuous phase, and secondary coated particles which have a structure in which the primary coated particles serve as single nuclei and are coated with a secondary coating material (C), characterized in that the core substance (A) is a powder containing live bacteria, the primary coating material (B) comprises a lipid having a melting point of 40°C to 70°C, the secondary coating material (C) comprises a lipid having a melting point of 40°C to 100°C and uncalcined calcium, the average particle diameter of the primary coated particles is 50 μm to 500 μm, and the average particle diameter of the secondary coated particles relative to the average particle diameter of the primary coated particles (average particle diameter of secondary coated particles / average particle diameter of primary coated particles) is 1.05 to 2.0.

[0014] FIG. 1 shows a schematic diagram of the structure of a primary coated particle constituting the acid-resistant powder of the present invention, and FIG. 2 shows a schematic diagram of the structure of a secondary coated particle contained in the acid-resistant powder of the present invention. As shown in FIG. 1, the primary coated particle 10 is a coated granule in which a core substance (A) is encapsulated as multiple nuclei inside a primary coating material (B) which is a continuous phase. 2, the secondary coated particle 20 has a structure in which the primary coated particle 10 serves as a single core and is coated with a secondary coating material (C) containing particulate lipid and uncalcined calcium. By using the particulate secondary coating material (C), it is possible to produce the secondary coated particle 20 having the primary coated particle 10 as a single core. The presence of a single primary coated particle 10 within the secondary coated particle 20 makes the secondary coated particle 20 less likely to crumble under the pressure during compression molding, and pressure resistance is more effectively exhibited.

[0015] The average particle diameter of the primary coated particles 10 is 50 μm to 500 μm. The lower limit is preferably 100 μm or more. The upper limit is preferably 400 μm or less, more preferably 300 μm or less. When the average particle diameter is less than 50 μm, the surface area of ​​the primary coated particles becomes large and sufficient coating with the secondary coating material cannot be obtained, so that acid resistance cannot be obtained. When the average particle diameter exceeds 500 μm, the secondary coating material is easily peeled off, and the coating state of the secondary coated particles becomes poor, so that acid resistance and processing stability cannot be obtained. In addition, when the primary coated particles are formed, the particles are grown large in a dissolved state of the primary coating material, so that the stability of the useful components during processing is reduced.

[0016] The average particle diameter of the secondary coated particles 20 is not particularly limited, but is, for example, 50 μm to 500 μm. The lower limit is preferably 100 μm or more. The upper limit is preferably 400 μm or less, and more preferably 300 μm or less. When the average particle diameter is less than 50 μm, the particle diameter of the primary coated particles is also less than 50 μm, and as described above, sufficient coating with the secondary coating material cannot be achieved, and acid resistance cannot be obtained. When the average particle diameter exceeds 500 μm, the secondary coating material is easily peeled off, and the coating state of the secondary coated particles deteriorates, making it impossible to achieve acid resistance and processing stability.

[0017] The ratio of the average particle size of the secondary coated particles 20 to the average particle size of the primary coated particles 10 (average particle size of secondary coated particles / average particle size of primary coated particles) is 1.05 to 2.00. The upper limit is preferably 1.60 or less, and more preferably 1.40 or less. When this ratio exceeds 2.00, the amount of secondary coating material is too large, and acid resistance, processing stability, and pressure resistance cannot be obtained, and the content of useful components is reduced. When this ratio is less than 1.05, the secondary coating layer does not have a sufficient thickness or the primary coated particles are broken into small particles, so that processing stability, pressure resistance, and acid resistance cannot be obtained.

[0018] In the primary coated particles, the mass ratio of the core substance (A) to the primary coating material (B) is not particularly limited, but for example, the mass ratio of the core substance (A) to the total mass of the core substance (A) and the primary coating material (B) is 0.65 to 0.90. The lower limit is preferably 0.70 or more, and more preferably 0.75 or more. The upper limit is preferably 0.85 or less. When the mass ratio is 0.65 or more, the content of the core substance (A) can be increased. On the other hand, when the mass ratio is 0.90 or less, the content of the primary coating material (B) increases, and there is an effect of improving the coating performance.

[0019] In the secondary coated particles, the mass ratio of the primary coated particles to the secondary coating material (C) is not particularly limited, but for example, the mass ratio of the primary coated particles (B) to the total mass of the primary coated particles and the secondary coating material (C) is preferably 0.40 to 0.80. The lower limit is preferably 0.50 or more, more preferably 0.55 or more. The upper limit is preferably 0.70 or less. When the mass ratio is 0.45 or more, the content of the core substance (A) contained in the primary coated particles can be increased. Also, when the mass ratio is 0.80 or less, the content of the secondary coating material (C) increases, and there is an effect of improving the coating performance.

[0020] The processing stability of the acid-resistant powder of the present invention is, for example, such that the viable cell survival rate in the processing stability test of the present invention is 70% or more, preferably 80% or more, and more preferably 90% or more.

[0021] The acid resistance of the acid-resistant powder of the present invention is, for example, such that the viable cell survival rate in the acid resistance test of the present invention is 10% or more, preferably 20% or more, more preferably 30% or more, even more preferably 32% or more, and particularly preferably 35% or more.

[0022] The pressure resistance of the acid-resistant powder of the present invention is, for example, such that the viable cell survival rate in the pressure resistance test of the present invention is 75% or more, preferably 85% or more, and more preferably 95% or more.

[0023] The storage stability of the acid-resistant powder of the present invention is, for example, such that the viable cell survival rate in the storage stability test of the present invention is 50% or more, preferably 60% or more, and more preferably 70% or more.

[0024] The oil content of the acid-resistant powder of the present invention is not particularly limited, but is, for example, 20 to 60% by mass or more. The lower limit is preferably 25% by mass or more, more preferably 30% by mass or more. The upper limit is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. The oil content is measured according to the "ether extraction method". When the oil content is high, the water absorbency of the acid-resistant powder is low, and therefore, there is an effect of excellent storage stability. When the oil content is low, the content of live bacteria can be increased.

[0025] Each component of the present invention will be described in detail below. [Core substance (A)] The core substance (A) of the present invention is not particularly limited as long as it is a powder containing live bacteria, such as bifidobacteria and lactic acid bacteria.

[0026] Furthermore, the core substance (A) may contain, as an excipient that does not affect the action of the present invention, for example, powders of lactose, starch, white sugar, maltitol, sorbitol, dextrin, trehalose, crystalline cellulose, and the like.

[0027] The average particle size of the core material (A) is not particularly limited as long as it is within the range in which the effects of the present invention are exhibited, and is, for example, 10 to 200 μm. The upper limit is preferably 150 μm or less, more preferably 100 μm or less, and further preferably 80 μm or less. When the average particle size of the core material (A) is small, there is an advantage that the size of the primary coated particles can be easily adjusted.

[0028] [Primary covering material (B)] The primary coating material (B) of the present invention contains an edible lipid having a melting point of 40° C. to 70° C. The lower limit of the melting point of the lipid in the primary coating material (B) is preferably 50° C. or higher, more preferably 55° C. or higher. When the melting point of the lipid in the primary coating material (B) is 40° C. or higher, the coating performance is improved, and the pressure resistance and acid resistance are excellent. On the other hand, when the melting point of the lipid in the primary coating material (B) is 70° C. or lower, the primary coating material (B) can be softened without exposing the core substance (A) to high temperatures during the formation of the primary coated particles.

[0029] The lipid of the primary covering material (B) may be any lipid having a melting point of 40° C. to 70° C., and examples thereof include fatty acid esters, higher alcohols, and waxes, and one or more of these may be used. Examples of fatty acid esters include triglycerides, which are typical edible fats and oils, and have a structure in which three molecules of fatty acid are ester-bonded to glycerin, and originate from, for example, soybean oil, rapeseed oil, cottonseed oil, rice oil, corn oil, sesame oil, peanut oil, sunflower oil, safflower oil, camellia oil, olive oil, coconut oil, palm oil, palm kernel oil, cacao butter, perilla oil, perilla oil, lard, beef tallow, chicken oil, whale oil, and fish oil. The melting point is adjusted by transesterification, hydrogenation, or the like. Other fatty acid esters include so-called emulsifiers, such as glycerin fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, sucrose fatty acid esters, and lecithin. Examples of higher alcohols include linear or branched alcohols having 20 to 36 carbon atoms. Specific examples include eicosanol (20 carbon atoms), docosanol (26 carbon atoms), octacosanol (28 carbon atoms), triacontanol (=myricyl alcohol, 30 carbon atoms), and hexatriacontanol (36 carbon atoms). Examples of waxes include carnauba wax, candelilla wax, and rice wax. Of these, triglycerides are most preferred.

[0030] The lipid of the primary coating material (B) may be in powder form or in liquid form melted by heating. When using a lipid of the powdered primary coating material (B), primary coated particles can be formed quickly and easily by spraying the liquid primary coating material (B) onto the mixed core substance (A).

[0031] [Lipids in secondary coating material (C)] The secondary coating material (C) of the present invention contains edible lipids having a melting point of 40°C to 100°C and uncalcined calcium. The lower limit of the melting point of the lipid of the secondary coating material (C) is preferably 50°C or higher, more preferably 55°C or higher, and even more preferably 60°C or higher. On the other hand, the upper limit of the melting point of the lipid of the secondary coating material (C) is preferably 90°C or lower, more preferably 80°C or lower, and even more preferably 75°C or lower. When the melting point of the lipid of the secondary coating material (C) is high, the lipids of the secondary coating material (C) are less likely to adhere to each other when the primary coated particles and the secondary coating material (C) are mixed, and are more likely to be arranged on the surfaces of the primary coated particles. On the other hand, when the melting point of the lipid of the secondary coating material (C) is lowered, the primary coated particles collide with each other when the primary coated particles and the secondary coating material (C) are mixed, so that the secondary coating material (C) arranged on the surfaces of the primary coated particles spreads, and the coating performance is improved.

[0032] The lipid of the secondary coating material (C) may be any lipid having a melting point of 40° C. to 100° C., and examples thereof include fatty acid esters, higher alcohols, and waxes, and one or more of these may be used. Examples of fatty acid esters include triglycerides, which are typical edible fats and oils, and have a structure in which three molecules of fatty acid are ester-bonded to glycerin, and originate from, for example, soybean oil, rapeseed oil, cottonseed oil, rice oil, corn oil, sesame oil, peanut oil, sunflower oil, safflower oil, camellia oil, olive oil, coconut oil, palm oil, palm kernel oil, cacao butter, perilla oil, perilla oil, lard, beef tallow, chicken oil, whale oil, and fish oil. The melting point is adjusted by transesterification, hydrogenation, or the like. Other fatty acid esters include so-called emulsifiers, such as glycerin fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, sucrose fatty acid esters, and lecithin. Examples of higher alcohols include linear or branched alcohols having 20 to 36 carbon atoms. Specific examples include eicosanol (20 carbon atoms), docosanol (26 carbon atoms), octacosanol (28 carbon atoms), triacontanol (=myricyl alcohol, 30 carbon atoms), and hexatriacontanol (36 carbon atoms). Examples of waxes include carnauba wax, candelilla wax, and rice wax. Of these, triglycerides are most preferred.

[0033] The average particle size of the lipid in the secondary coating material (C) is not particularly limited, but is, for example, 5 to 100 μm. The upper limit is preferably 80 μm or less, more preferably 60 μm or less, and further preferably 40 μm or less. When the average particle size of the lipid in the secondary coating material (C) is small, the secondary coating material (C) is densely arranged on the surface of the primary coating particles, thereby improving the coating performance.

[0034] [Uncalcined calcium of secondary coating material (C)] The uncalcined calcium of the secondary coating material (C) is basic and therefore functions as an antacid against stomach acid. The uncalcined calcium of the present invention is a white powder mainly composed of calcium carbonate, which is made by drying and finely grinding seashells, corals, eggshells, and bones. The uncalcined calcium may be a substance classified as a food additive, but it is not limited to food additives and may be any edible substance made in a similar manufacturing process.

[0035] By arranging the uncalcined calcium inside the secondary coating in such a way that it is caught in the lipids of the secondary coating material (C), it is possible to neutralize the gastric juice that penetrates from the outside of the secondary coated particles toward the core material, and reduce the death of live bacteria due to the acid. If the uncalcined calcium is present on the outside of the secondary coated particles, that is, if the secondary coated particles and the uncalcined calcium are simply mixed, the uncalcined calcium will dissipate into the gastric juice and will not be effective enough as an antacid against live bacteria. Also, if the uncalcined calcium is placed inside the primary coated particles, that is, if the core material (A) is a mixture of a powder containing live bacteria and uncalcined calcium, the primary coating material (B) is a continuous phase, so the uncalcined calcium is completely covered by the primary coating material and will not be effective. At the same time, if live bacteria and uncalcined calcium are present in close proximity, the storage stability of live bacteria that are sensitive to alkaline substances will decrease. If the uncalcined calcium is not the core material (A) or the primary coated particles (B) but the secondary coating material (C), any manufacturing method may be used, but a step of mixing the primary coated particles with the powdered secondary coating material (C) to obtain the secondary coated particles is preferable after a step of mixing the core material (A) with the primary coating material (B) to obtain the primary coated particles. In addition, the step of mixing the primary coated particles with the powdered secondary coating material (C) to obtain the secondary coated particles is preferably performed by mixing at a temperature lower than the melting point of the lipid of the secondary coating material (C) and stirring at high speed to cause the primary coated particles, the lipid of the secondary coating material, and the powder particles of the uncalcined calcium to collide with each other, and the lipid of the secondary coating material and the uncalcined calcium are layered around the primary coated particles to form a coating.

[0036] The particle size of the uncalcined calcium in the secondary coating material (C) is preferably 1 μm to 100 μm, more preferably 5 μm to 50 μm, and most preferably 10 μm to 30 μm. If the particle size of the uncalcined calcium is 1 μm or more, it is easily incorporated into the coating layer together with lipids, and the calcined calcium is easily arranged in the secondary coating layer. If it is 100 μm or less, it is easily dispersed without being localized in the coating layer, and at the same time, the surface area is widened, so that the antacid effect is enhanced. The bulk density of the uncalcined calcium in the secondary coating material (C) is preferably 0.6 to 1.1, more preferably 0.7 to 1.0, and most preferably 0.8 to 0.9. If the bulk density of the uncalcined calcium is 0.6 or more and 1.1 or less, it is easily incorporated into the coating layer together with lipids, and the calcined calcium is easily arranged in the secondary coating layer. The most preferable raw material for the uncalcined calcium is eggshell.

[0037] A similar substance is calcium carbonate derived from limestone, which also contains calcium carbonate as the main component (ground limestone, or limestone that has been heated and then water added to make calcium hydroxide, and then carbon dioxide gas is added to make calcium carbonate), but this does not exhibit the effects of the present invention, presumably due to the difference in particle structure. In detail, the primary coated particles are covered by being laminated when the lipid and uncalcined calcium as secondary coating materials collide with each other, and when the uncalcined calcium collides with the lipid as the primary coating material, the uncalcined calcium is porous and shapeless, so it is easy to adhere to the lipid by utilizing the plasticity of the lipid, and also when the uncalcined calcium collides with the lipid of the secondary coating material (C) that has been previously attached, it is easy to adhere for the same reason, and when the lipid of the secondary coating material (C) collides with the uncalcined calcium that has been previously attached, the lipid of the secondary coating material (C) is also easy to adhere to.

[0038] The lipids of the secondary coating material (C) and the uncalcined calcium are both in powder form. By using the lipids of the powdered secondary coating material (C), the lipids of the secondary coating material (C) adhere to the surfaces of the primary coated particles so as to envelop the uncalcined calcium, and secondary coated particles can be formed with the primary coated particles as single nuclei. If a liquid lipid is used, the secondary coating material (C) becomes a coated granule containing the primary coated particles as multiple nuclei with the continuous phase being used, and the effect of the present invention cannot be obtained. In addition, the uncalcined calcium cannot be uniformly dispersed in the secondary coating layer.

[0039] The mass ratio of uncalcined calcium to the mass of lipid in the secondary coating material (C) is preferably 0.3 to 1.0, more preferably 0.5 to 0.8, and most preferably 0.6 to 0.7. When the mass ratio of uncalcined calcium to the mass of lipid is 1, acid resistance is easily obtained when the mass ratio is more than 0.3, and the coating performance of the secondary coating is improved when it is less than 1.0.

[0040] [Processing method (manufacturing method)] The method for producing an acid-resistant powder containing secondary coated particles of the present invention includes, for example, a step of mixing the core material (A) and the primary coating material (B) to obtain the primary coated particles, and a step of mixing the primary coated particles and a powdered secondary coating material (C) to obtain the secondary coated particles. More specifically, a powder containing live bacteria, which is the core material (A), is charged into a stirring layer, and the lipid of the primary coating material (B) is melted at a temperature higher than the melting point to prepare it as a liquid. Then, while stirring the core material (A), the liquid primary coating material (B) is sprayed into the stirring layer. At this time, the temperature of the primary coating material (B) drops below the melting point and solidifies, so that multiple core materials (A) are bound to the primary coating material (B) and granulated, and are primarily coated. Next, the primary coated particles are charged into the stirring layer, and the secondary coating material (C) containing lipid and uncalcined calcium is further added and charged, and the secondary coating is performed by high-speed stirring. At this time, the lipid powder and uncalcined calcium particles collide with the lipid primary coating material (B) on the surface of the primary coated particles, causing them to adhere to the surface, and then other lipid or uncalcined calcium particles collide with them and form layers, and by repeating this process, a secondary coating layer containing lipid and uncalcined calcium is formed, completing the secondary coated particles. The secondary coating is preferably performed at a temperature lower than the melting point of the lipid secondary coating material (C), and it is preferable to coat the primary coated particles by stirring the primary coated particles and secondary coating material at high speed, causing the powder particles to collide with each other, and thereby laminating the lipid and uncalcined calcium secondary coating material around the primary coated particles. EXAMPLES

[0041] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto.

[0042] (Examples 1 to 22, Comparative Examples 1 to 13) Acid-resistant powders were prepared according to the following methods for preparing primary coated particles and secondary coated particles. The obtained acid-resistant powders were evaluated for "survival rate of viable bacteria after processing" (processing stability), "survival rate of viable bacteria after storage" (storage stability), "survival rate of viable bacteria after tableting" (pressure resistance), and "survival rate of viable bacteria after acid resistance test" (acid resistance), and the evaluation results are shown in Tables 1-1 to 3-1.

[0043] (About ingredients) The raw materials used in the examples are as follows. In the present invention, the average particle size is measured using a laser diffraction particle size distribution analyzer "SALD-2100" (manufactured by Shimadzu Corporation). The melting point in the present invention is measured in accordance with the Standard Methods for the Analysis of Fats, Oils and Related Materials, "2.2.4.2 Melting Point (Slip Melting Point)." The bulk density in the present invention is defined as the loose bulk density (g / cm 3 ) and is calculated by pouring an excess of sample into a 100 mL cylindrical container until it overflows, and then measuring the mass of the powder when the excess powder is scraped off from the top of the container.

[0044] <Core substance (A)> Bifidobacteria A: "Bifidobacteria Powder BB536" (Morinaga Milk Industry Co., Ltd.), average particle size 29.0 μm, bulk density 0.64 Bifidobacteria B: "Bifidobacteria Powder M63" (Morinaga Milk Industry Co., Ltd.), average particle size 26.0 μm, bulk density 0.62 Lactic acid bacteria A: average particle size 35.2 μm, bulk density 0.45

[0045] <Primary covering material (B)> Hardened rapeseed oil: (NOF Corp.), melting point 67°C Hardened palm oil: (NOF Corp.), melting point 57°C Hardened rapeseed oil 1: (NOF Corp.), melting point 50°C Hardened palm oil: (NOF Corp.), melting point 42°C Carnauba wax: (manufactured by Toa Kasei Co., Ltd.), melting point 86°C

[0046] <Lipids in the secondary coating material (C)> The lipids described below were powdered by spray cooling or pulverization, and then subjected to secondary pulverization until the average particle size became 50 μm or less, to prepare secondary coating materials. Hardened rapeseed oil: (NOF Corp.), melting point 67°C, average particle size 6.8μm Hardened palm oil: (NOF Corporation), melting point 57°C, average particle size 14.6μm Glycerol fatty acid ester: (manufactured by Danisco Japan Co., Ltd.), melting point 62°C, average particle size 18.2 μm Hardened palm oil: (NOF Corporation), melting point 42°C, average particle size 42.5μm Rice wax: (manufactured by Toa Kasei Co., Ltd.), melting point 78°C, average particle size 14.5 μm Hardened rapeseed oil 2: (NOF Corp.), melting point 36°C, average particle size 40.4μm

[0047] <Secondary coating material (C) uncalcined calcium> Eggshell calcium: "Calhope" (Kewpie Egg Co., Ltd.), average particle size 14.6 μm, bulk density 0.87 Uncalcined scallop calcium: "Scallop powder" (manufactured by NC Corporation), average particle size 9.2 μm, bulk density 0.57 Uncalcined coral calcium: "CCP-08" (Marine Bio Co., Ltd.), average particle size 3.3 μm, bulk density 0.59

[0048] <Other components of the secondary coating material (C) (basic substances)> Bone calcined calcium: "Fishcal" (manufactured by NC Corporation), average particle size 8.7 μm, bulk density 0.81 Sodium bicarbonate: (Asahi Glass Co., Ltd.), average particle size 160 μm, bulk density 1.01 Disodium hydrogen phosphate: (Taihei Chemical Industry Co., Ltd.) Average particle size 48.6 μm, bulk density 0.67 Limestone-derived calcium carbonate: "Colocalso-WB" (Shiraishi Calcium Co., Ltd.) Average particle size 9.4 μm, bulk density 0.66

[0049] (Regarding the production of acid-resistant powder) The primary coated particles and secondary coated particles constituting the acid-resistant powders of the Examples and Comparative Examples were prepared as follows.

[0050] [Preparation method of primary coated particles] In Example 1, 250 g of "Bifidobacterium BB536" as the core material (A) was put into a high-speed stirring mixer. While stirring the high-speed stirring mixer, the temperature of the rapeseed hardened oil as the primary coating material (B) was adjusted to melt at its melting point +10°C, and 65 g of this was sprayed into the inside of the high-speed stirring mixer to coat the core material (A) with the primary coating material (B). Next, the product was cooled to a product temperature of 20°C in the high-speed stirring mixer to obtain the primary coated particles of Example 1.

[0051] [Preparation method of secondary coated particles] The primary coated particles of Example 1 were charged with 110 g of rapeseed hardened oil and 75 g of "Calhope", which were the secondary coating materials (C), in a high-speed stirring mixer. The high-speed stirring mixer was stirred and mixed with the jacket temperature cooled, and the lipids of the secondary coating material were attached to the surfaces of the primary coated particles while still in powder form. By continuing to stir and mix further, the powder of the secondary coating material was evenly distributed on the surfaces of the primary coated particles, and the secondary coated particles of Example 1 were prepared.

[0052] In Examples 2 to 22 and Comparative Examples 1 to 13, the primary coated particles and secondary coated particles were prepared according to the formulations in Tables 1-1 to 3-1. Examples 2 to 11, 13 to 22 and Comparative Examples 1, 3-4, and 8 to 12 were prepared under the same production conditions as Example 1. In Example 12, the stirring speed was decreased and the spraying speed of the primary coating material (B) was increased so that the particle diameter of the primary coating particles would be large when preparing the primary coating particles. In Comparative Example 2, the core material (A) was not primarily coated, and only the secondary coating was performed in the same manner as in Example 1. In Comparative Example 5, the stirring speed was increased and the spraying speed of the primary coating material (B) was decreased so that the particle diameter of the primary coating particles would be small when preparing the primary coating particles. In Comparative Example 6, the stirring speed was decreased and the spraying speed of the primary coating material (B) was increased so that the particle diameter of the primary coating particles would be large when preparing the primary coating particles. In Comparative Example 7, the secondary coating material (C) was melted by heating at a melting point of +10°C and sprayed onto the primary coating particles to prepare the secondary coating particles. In Comparative Example 13, after the secondary coating was completed, uncalcined calcium was mixed in a plastic bag. The rest of the manufacturing conditions were the same as in Example 1. The secondary coated particles thus obtained were used as acid-resistant powder and were evaluated.

[0053] (Evaluation method for acid-resistant powder) <Method for measuring live bacteria> In the method for measuring the viable bacteria of the present invention, 100 mg of a specimen was added to 100 mL of physiological saline and homogenized to extract the viable bacteria. This solution was appropriately diluted, and 1 mL of the diluted solution was mixed with 20 mL of BL agar medium (manufactured by Nissui Pharmaceutical Co., Ltd.) and subjected to anaerobic culture (37°C, 72 hours). After the culture was completed, the number of viable bacteria per 1 g of specimen was calculated from the number of colonies that grew on the medium.

[0054] <Processing stability: survival rate of live bacteria after processing (survival rate after processing)> The survival rate of live bacteria after processing was calculated using the following formula and evaluated according to the following criteria. Viable bacteria count before processing: The viable bacteria count of the powder containing viable bacteria as the raw material is measured and multiplied by the blending ratio. Viable bacteria count after processing: Viable bacteria count of secondary coated particles produced by processing Processing survival rate (%) = Number of viable bacteria after processing / Number of viable bacteria before processing × 100 [Standards for processing survival rate] ◎: 90% or more, 〇: less than 90%, 80% or more, △: less than 80%, 70% or more, ×: less than 70%

[0055] <Storage stability: Viable bacteria survival rate after storage (storage survival rate)> (Storage stability test) The acid-resistant powder was sealed in an aluminum bag and subjected to a storage test for 6 months at 25° C. The survival rate of live bacteria after storage was calculated using the following formula and evaluated according to the following criteria. Preservation survival rate (%) = Number of viable bacteria after storage / Number of viable bacteria before storage × 100 [Criteria for survival rate] ◎: 70% or more, 〇: less than 70%, 60% or more, △: less than 60%, 50% or more, ×: less than 50%

[0056] <Pressure resistance: Viable bacteria survival rate after tableting (survival rate after tableting)> (Pressure resistance test) In the evaluation of pressure resistance of the present invention, tablets containing the acid-resistant powder of the Examples or Comparative Examples were prepared under the following blending composition and tableting conditions, and the viable cell count was measured before and after tableting. The viable cell count in the tablets was measured by crushing the tablets in a mortar to obtain a powder, which was used as a sample for the viable cell count measurement method. The lactose used was "Lactose" (manufactured by Leprino Foods), the starch used was "ST Starch P" (manufactured by Nippon Starch Chemical Co., Ltd.), the crystalline cellulose used was "Ceolas UF-702" (manufactured by Asahi Kasei Co., Ltd.), and the sucrose fatty acid ester used was "Lute-Sugar Ester S-370" (manufactured by Mitsubishi Chemical Co., Ltd.). The pressure resistance of the viable cell was evaluated by the following formula. Tablet survival rate (%) = Number of viable bacteria after tableting / Number of viable bacteria before tableting × 100 [Tablet survival rate criteria] ◎: 95% or more, 〇: less than 95%, 85% or more, △: less than 85%, 75% or more, ×: less than 75% [Tablet composition] Acid-resistant powder of the examples or comparative examples 10% by mass Lactose granules 68% by mass Starch 10% by mass Crystalline cellulose 10% by mass Sucrose fatty acid ester 2% by mass Total 100% by mass [Tableting conditions for tablet production] Model: Rotary tablet press Collect 12HU (manufactured by Kikusui Seisakusho Co., Ltd.) Tableting pressure: 15kN Pestle size: diameter 15mmφ Tablet weight: 1g

[0057] <Vitamin survival rate after acid resistance test (acid resistance survival rate)> (Acid resistance test) In the present invention, the acid resistance evaluation is carried out by placing 100 mL of a hydrochloric acid aqueous solution of pH 1.2 in a 200 mL capacity beaker and adjusting the temperature to 37°C. Next, 100 mg of secondary coated particles are added and stirred for 1 hour at 100 rpm with a magnetic stirrer. After stirring is completed, the mixture is neutralized with a sodium hydroxide aqueous solution of pH 13 and the viable cell count is measured. When calculating the viable cell count, the amount of the sodium hydroxide aqueous solution added is corrected. Acid resistance survival rate (%) = number of viable bacteria after acid resistance test / number of viable bacteria before acid resistance test × 100 [Acid resistance survival rate standard] ◎: 30% or more, 〇: less than 30%, 20% or more, △: less than 20%, 10% or more, ×: less than 10%

[0058] [Table 1-1] [Table 1-2]

[0059] [Table 2-1] [Table 2-2]

[0060] [Table 3-1] [Table 3-2]

[0061] In Examples 1 to 22, primary coated particles with an average particle size of 50 μm to 500 μm were formed using lipids with a melting point of 40° C. to 70° C. as the primary coating material (B), and the surfaces of the obtained primary coated particles were coated with lipids with a melting point of 40° C. to 100° C. and uncalcined calcium as the secondary coating material (C), and secondary coated particles were formed so that the average particle size of the secondary coated particles relative to the average particle size of the primary coated particles was 1.05 to 2.0, resulting in excellent results in all evaluations of processing stability, storage stability, pressure resistance, and acid resistance. In addition, the obtained acid-resistant powder had an average particle size of about 50 μm to 500 μm, making it suitable as a raw material for use in other dosage forms such as tablets and soft capsules.

[0062] On the other hand, in Comparative Example 1, the primary coated particles were not coated with the secondary coating material (C), so the effects of pressure resistance and acid resistance were not obtained. Also, since the amount of the primary coating material (B) was large during the primary coating process, the particles were exposed to heat for a long time during coating with the primary coating material, and a tendency for processing stability to decrease was observed. In Comparative Example 2, since the primary coating process using the primary coating material was not performed, the coating with the secondary coating material was insufficient, and the effects of pressure resistance and acid resistance were not obtained. In Comparative Example 3, a primary coating material with a high melting point was used, so that during coating with the primary coating material, live bacteria were killed by contact with the high-temperature primary coating material, and processing stability was poor. In Comparative Example 4, a lipid having a melting point of less than 40° C. was used as the secondary coating material, and therefore the effects of pressure resistance and acid resistance were not obtained. In Comparative Example 5, the average particle size of the primary coated particles was less than 50 μm, so that no effect of acid resistance was obtained. In Comparative Example 6, since the average particle size of the primary coated particles was more than 500 μm, no effect of acid resistance was obtained. In Comparative Example 7, the secondary coating material was melted and the secondary coated particles were formed using the melted secondary coating material, so that the heat killed the live bacteria and the processing stability was reduced. Also, the average particle size of the secondary coated particles relative to the average particle size of the primary coated particles exceeded 2.0, and a granulated product of the primary coated particles with the secondary coating material as the continuous phase was formed. In Comparative Examples 8 to 11, similar tests were carried out using a basic substance other than uncalcined calcium, but no effect of acid resistance was obtained. In Comparative Example 12, uncalcined calcium, which is present in the secondary coating layer as the secondary coating material in Example 1, is present in the core, adjacent to the bifidobacteria, as the core substance (A), and therefore acid resistance was not obtained. In Comparative Example 13, although the uncalcined calcium exists separately from the secondary coated particles, acid resistance was not obtained. [Industrial Applicability]

[0063] The acid-resistant powder of the present invention can impart extremely excellent acid resistance to powders containing live bacteria, with a low mortality rate of live bacteria during processing such as coating, and can therefore be used as a raw material for enteric preparations such as foods (including health foods, functional foods, and foods for specified health uses), pharmaceuticals, quasi-drugs, and feed. Furthermore, the acid-resistant powder of the present invention has excellent storage stability and pressure resistance, and can therefore be suitably used as a raw material for tablets.

Claims

1. An acid-resistant powder comprising primary coated particles which contain powder particles of a core substance (A) as a plurality of nuclei and are coated with a primary coating material (B) as a continuous phase, and secondary coated particles which have a structure in which the primary coated particles are coated with a secondary coating material (C) as a single nucleus, The core material (A) is a powder containing live bacteria, The primary coating material (B) contains a lipid having a melting point of 40° C. to 70° C., The secondary coating material (C) comprises a lipid having a melting point of 40° C. to 100° C. and uncalcined calcium, The average particle size of the primary coated particles is 50 μm to 500 μm, The ratio of the average particle size of the secondary coated particles to the average particle size of the primary coated particles (average particle size of the secondary coated particles / average particle size of the primary coated particles) is 1.05 to 2.

00.

2. a mass ratio of the core material (A) to a total mass of the core material (A) and the primary coating material (B) is 0.65 to 0.90; 2. The acid-resistant powder according to claim 1, wherein a mass ratio of the primary coated particles to a total mass of the primary coated particles and the secondary coating material (C) is 0.40 to 0.

80.

3. 3. The acid-resistant powder according to claim 1, wherein the average particle size is 50 μm to 500 μm, and the viable cell survival rate after an acid resistance test is 32% or more.

4. 3. The acid-resistant powder according to claim 1 or 2, which is for tableting.

5. A food product comprising the acid-resistant powder according to claim 1 or 2.

6. A method for producing the acid-resistant powder according to claim 1 or 2, A step of mixing the core material (A) and the primary coating material (B) to obtain the primary coated particles; A method for producing an acid-resistant powder, comprising: a step of mixing the primary coated particles with a powdery secondary coating material (C) to obtain the secondary coated particles.

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