Production method for bacteria powder and composition to be spray-dryed

Abstract

The present disclosure addresses the problem of providing technology which achieves good dispersibility, in a solvent or solution, of a bacteria powder that is obtained via a spray-drying step, which achieves good yield, and in which the ratio of the number of bacteria in a resultant bacteria powder is equivalent to that of conventional products. This problem is solved by a production method for a bacteria powder comprising: a preparation step for preparing a liquid mixture which contains bacteria and an amylolysis product and which has a viscosity of not less than 75 mPa･s at 10°C; and a spray-drying step for spray-drying the liquid mixture to obtain a bacteria powder.

Description

Method for producing bacterial powder and composition subjected to spray drying

[0001] The present invention relates to a method for producing a bacterial powder and a composition to be subjected to spray drying.

[0002] The spray drying method has long been used to produce useful bacterial cell powders (microbial powders) (Patent Document 1). The produced bacterial powders may be used as is, but may also be dispersed in a solvent or solution, in which case good dispersibility is required (Patent Document 2). Furthermore, a good yield is required in the production of bacterial powders. That is, it is important in the production of bacterial powders to achieve both good dispersibility when the bacterial powder obtained by the spray drying process is dispersed in a solvent or solution, and good yield.

[0003] JP 2005-052100 A JP 2016-044173 A

[0004] Bacterial powder obtained by subjecting a low-viscosity bacterial suspension to a spray-drying process tends to have poor dispersibility when dispersed in a solvent or solution. On the other hand, bacterial powder obtained by subjecting a high-viscosity bacterial suspension to a spray-drying process has good dispersibility when dispersed in a solvent or solution, but spray drying is difficult and the yield tends to be low. The objective of the present invention is to provide a technology that not only provides good dispersibility and good yield when dispersed in a solvent or solution, but also ensures that the proportion of bacteria in the obtained bacterial powder is equivalent to that of conventional products.

[0005] As a result of intensive research into solving the above-mentioned problems, the inventors discovered that the above-mentioned problems can be solved by spray-drying a mixed liquid containing bacteria and a starch hydrolysate and having a predetermined viscosity, and thus completed the present invention.

[0006] The present invention can provide a method for producing a bacterial powder, comprising: a preparation step of preparing a mixed liquid containing bacteria and a starch hydrolysate, the mixed liquid having a viscosity of 75 mPa·s or more at 10°C; and a spray-drying step of spray-drying the mixed liquid to obtain a bacterial powder. In a preferred embodiment of the production method, the bacteria are bacteria of the genus Bifidobacterium, Lacticaseibacillus, Lactobacillus, or Lactococcus. In a preferred embodiment of the production method, the bacteria are bacteria of the genus Lacticaseibacillus, and the DE value of the starch hydrolysate is 15 to 18. In a preferred embodiment of the production method, the bacteria are bacteria of the genus Lactobacillus, and the DE value of the starch hydrolysate is higher than 18. In a preferred embodiment of the production method, the bacteria are bacteria of the genus Bifidobacterium, and the DE value of the starch hydrolysate is 15 to 20. In a preferred embodiment of the production method, the bacterium is a Lactococcus bacterium, and the starch hydrolysate has a DE value of not more than 20. In a preferred embodiment of the production method, the bacterium is Bifidobacterium breve, and the starch hydrolysate has a DE value of 15 to 20. In a preferred embodiment of the production method, the bacterium is Bifidobacterium longum subsp. longum, and the starch hydrolysate has a DE value of 12 or more.

[0007] The present invention can also provide a composition comprising bacteria and a starch hydrolysate, having a viscosity of 75 mPa·s or more at 10°C, and suitable for spray drying. In a preferred embodiment of the composition, the bacteria are bacteria of the genus Bifidobacterium, Lacticaseibacillus, Lactobacillus, or Lactococcus. In a preferred embodiment of the composition, the bacteria are bacteria of the genus Lacticaseibacillus, and the starch hydrolysate has a DE value of 15 to 18. In a preferred embodiment of the composition, the bacteria are bacteria of the genus Lactobacillus, and the starch hydrolysate has a DE value of higher than 18. In a preferred embodiment of the composition, the bacteria are bacteria of the genus Bifidobacterium, and the starch hydrolysate has a DE value of 15 to 20. In a preferred embodiment of the composition, the bacteria are bacteria of the genus Lactococcus, and the starch hydrolysate has a DE value of 20 or less. In a preferred embodiment of the composition, the bacterium is Bifidobacterium breve, and the starch hydrolysate has a DE value of 15 to 20. In a preferred embodiment of the composition, the bacterium is Bifidobacterium longum subsp. longum, and the starch hydrolysate has a DE value of 12 or more.

[0008] According to the present invention, it is possible to provide a technology that provides good dispersibility when the bacterial powder obtained by the spray drying process is dispersed in a solvent or solution, good yield, and the proportion of bacterial count in the obtained bacterial powder is equivalent to that of conventional products. Good dispersibility has the advantage that, for example, the bacterial powder is easily dispersed when blended into a beverage, making it easier for those who consume the beverage to ingest the bacterial powder.

[0009] In this specification, the expressions "XX or more and YY or less", "XX to YY", "XX to", and "to YY" mean a range of values ​​including the endpoints, unless otherwise specified.

[0010] One aspect of the present invention is a method for producing a bacterial powder, comprising: a preparation step of preparing a mixed liquid containing bacteria and a starch hydrolysate, the mixed liquid having a viscosity of 75 mPa·s or more at 10°C; and a spray-drying step of spray-drying the mixed liquid to obtain a bacterial powder.

[0011] Since the mixture contains the bacteria, the cells may be in a suspended form (i.e., in the form of a "suspension"), but in this specification it will be referred to as a "mixture" or "solution", etc.

[0012] The preparation step in the production method according to this embodiment is a step of preparing a mixed liquid containing bacteria and a starch hydrolysate, the mixed liquid having a viscosity of 75 mPa·s or more at 10°C.

[0013] The bacteria used in this step are not particularly limited as long as they can be generally made into a bacterial powder by spray drying. Examples include lactic acid bacteria, Bifidobacterium bacteria, etc. The bacteria used in this step may be one type of bacteria, or two or more types of bacteria.

[0014] Lactic acid bacteria is a general term for bacteria that belong to the phylum Firmicutes in the bacterial domain and produce lactic acid through metabolism.

[0015] Specific examples include bacteria of the class Bacilli, order Lactobacillales, bacteria of the class Bacilli, order Bacillales, and the like.

[0016] Examples of Bacilli Lactobacillales bacteria include Aerococcaceae bacteria, Carnobacteriaceae bacteria, Enterococcaceae bacteria, Streptococcaceae bacteria, Lactobacillaceae bacteria, and Leuconostocaceae bacteria.

[0017] Examples of Enterococcaceae bacteria include bacteria of the genus Enterococcus and bacteria of the genus Tetragenococcus.

[0018] Examples of Enterococcus bacteria include Enterococcus faecalis and Enterococcus faecium.

[0019] Examples of bacteria of the family Streptococcaceae include bacteria of the genus Lactococcus and bacteria of the genus Streptococcus.

[0020] Examples of Lactococcus bacteria include Lactococcus lactis, such as Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris.

[0021] Specific examples of Lactococcus lactis subsp. lactis include MCC1723 (NITE BP-1204) and the like.

[0022] Examples of Streptococcus bacteria include Streptococcus thermophilus.

[0023] Examples of Lactobacillaceae bacteria include bacteria of the genus Lacticaseibacillus, bacteria of the genus Lactobacillus, and bacteria of the genus Pediococcus.

[0024] Examples of Lacticaseibacillus bacteria include Lacticaseibacillus paracasei (formerly known as Lactobacillus paracasei), such as Lacticaseibacillus paracasei subsp. paracasei and Lacticaseibacillus paracasei subsp. tolerans. Other examples include Lacticaseibacillus casei (formerly known as Lactobacillus casei).

[0025] Specific examples of Lacticaseibacillus paracasei include MCC1849 (NITE BP-01633) and MCC1375 (FERM BP-11313). Specific examples of Lacticaseibacillus paracasei subsp. paracasei include JCM 8130 (ATCC 25302, DSM 5622). Specific examples of Lacticaseibacillus paracasei subsp. tolerans include JCM 1171 (ATCC 25599, DSM 20258).

[0026] Examples of Lactobacillus bacteria include Lactobacillus gasseri, Lactobacillus acidophilus, Lactobacillus helveticus, and Lactobacillus rhamunosus. Other examples include Lactobacillus delbrueckii, such as Lactobacillus delbrueckii subsp. delbrueckii, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis, etc. Other examples include Lactobacillus plantarum, etc.

[0027] Specific examples of Lactobacillus gasseri include MCC1846 (NITE BP-01669) and ATCC 33323.

[0028] Specific examples of Lactobacillus acidophilus include MCC1847 (NITE BP-01695) and ATCC 4356.

[0029] Specific examples of Lactobacillus helveticus include MCC2430 (NITE BP-03882), MCC1848 (NITE BP-01671), MCC1844 (NITE BP-02185), and ATCC 15009.

[0030] Examples of Pediococcus bacteria include Pediococcus acidilactici, Pediococcus cellicola, Pediococcus claussenii, Pediococcus damnosus, Pediococcus ethanolidurans, Pediococcus inopinatus, Pediococcus parvulus, Pediococcus pentosaceus, and Pediococcus stilesii.

[0031] Examples of bacteria of the family Leuconostocaceae include bacteria of the genus Leuconostoc, bacteria of the genus Fructobacillus, bacteria of the genus Oenococcus, and bacteria of the genus Weissella.

[0032] Examples of Leuconostoc bacteria include Leuconostoc mesenteroides, such as Leuconostoc mesenteroides subsp. cremoris, Leuconostoc mesenteroides subsp. dextranicum, and Leuconostoc mesenteroides subsp. mesenteroides. Other examples include Leuconostoc lactis and Leuconostoc paramesenteroides.

[0033] Bifidobacterium bacteria are a group of bacteria that belong to the order Bifidobacteriales, class Actinobacteria, phylum Actinobacteria, domain Actinobacteria.

[0034] Examples of Bifidobacterium bacteria include Bifidobacterium longum, such as Bifidobacterium longum subsp. infantis, Bifidobacterium longum subsp. longum, and Bifidobacterium longum subsp. suis. Another example is Bifidobacterium breve. Further examples include Bifidobacterium animalis, such as Bifidobacterium animalis subsp. lactis and Bifidobacterium animalis subsp. animalis. Further examples include Bifidobacterium bifidum, Bifidobacterium adolescentis, Bifidobacterium angulatum, Bifidobacterium dentium, and Bifidobacterium pseudocatenulatum.Other examples include Bifidobacterium pseudolongum, such as Bifidobacterium pseudolongum subsp. globosum and Bifidobacterium pseudolongum subsp. pseudolongm. Other examples include Bifidobacterium thermophilum. Bifidobacterium longum subsp. longum is sometimes simply referred to as Bifidobacterium longum. Bifidobacterium longum subsp. infantis is sometimes simply referred to as Bifidobacterium infantis.

[0035] Specific examples of Bifidobacterium longum subsp. infantis include M-63 (NITE BP-02623), MCC2042 (NITE BP-03068), ATCC 15697, ATCC 25962, and ATCC 15702.

[0036] Specific examples of Bifidobacterium longum subsp. longum include BB536 (NITE BP-02621), MCC1110 (NITE BP-02430), MCC10345 (NITE BP-03751), and ATCC 15707.

[0037] Specific examples of Bifidobacterium breve include MCC1274 (FERM BP-11175), M-16V (NITE BP-02622), MCC1095 (NITE BP-02460), ATCC 15700, and ATCC 15698.

[0038] Specific examples of Bifidobacterium animalis subsp. lactis include DSM 10140.

[0039] Specific examples of Bifidobacterium bifidum include MCC1092 (NITE BP-02429), MCC1319 (NITE BP-02431), MCC1868 (NITE BP-02432), MCC1870 (NITE BP-02433), MCC2030 (NITE BP-03058), and ATCC 29521.

[0040] Specific examples of Bifidobacterium adolescentis include ATCC 15703.

[0041] Specific examples of Bifidobacterium dentium include DSM 20436 and the like.

[0042] Specific examples of Bifidobacterium pseudolongum subsp. globosum include JCM 5820 and the like.

[0043] Specific examples of Bifidobacterium pseudolongum subsp. pseudolongum include ATCC 25526 and the like.

[0044] Specific examples of Bifidobacterium thermophilum include ATCC 25525 and the like.

[0045] Lactococcus lactis subsp. lactis MCC1723 (NITE BP-1204) was internationally deposited on January 17, 2012, in accordance with the Budapest Treaty with the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number NITE BP-1204.

[0046] Lacticaseibacillus paracasei MCC1849 (NITE BP-01633) (this strain was previously called Lactobacillus paracasei MCC1849 (NITE BP-01633)) was deposited on June 6, 2013, with the Patent Microorganisms Depositary of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan) under the accession number NITE P-01633, and was transferred to international deposit under the Budapest Treaty on January 31, 2014, and has been assigned the accession number NITE BP-01633.

[0047] Lacticaseibacillus paracasei MCC1375 (FERM BP-11313) (this strain was previously called Lactobacillus paracasei MCC1375 (FERM BP-11313)) was internationally deposited on November 5, 2010, in accordance with the Budapest Treaty with the International Patent Organism Depositary of the National Institute of Advanced Industrial Science and Technology (currently the International Patent Organism Depositary (IPOD) of the National Institute of Technology and Evaluation, Japan; postal code: 292-0818; address: Room 120, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number FERM BP-11313.

[0048] Lactobacillus gasseri MCC1846 (NITE BP-01669) was internationally deposited on July 29, 2013, in accordance with the Budapest Treaty with the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number NITE BP-01669.

[0049] Lactobacillus acidophilus MCC1847 (NITE BP-01695) was internationally deposited on August 23, 2013, at the Patent Microorganisms Depositary Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan) in accordance with the Budapest Treaty, and has been assigned the accession number NITE BP-01695.

[0050] Lactobacillus helveticus MCC2430 (NITE BP-03882) was internationally deposited on April 13, 2023, at the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan) in accordance with the Budapest Treaty, and has been assigned the accession number NITE BP-03882.

[0051] Lactobacillus helveticus MCC1848 (NITE BP-01671) was internationally deposited on July 29, 2013, in accordance with the Budapest Treaty with the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number NITE BP-01671.

[0052] Lactobacillus helveticus MCC1844 (NITE BP-02185) was internationally deposited on December 25, 2015, at the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan) in accordance with the Budapest Treaty, and has been assigned the accession number NITE BP-02185.

[0053] Bifidobacterium longum subsp. infantis M-63 (NITE BP-02623) was internationally deposited on January 26, 2018, in accordance with the Budapest Treaty with the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number NITE BP-02623.

[0054] Bifidobacterium longum subsp. infantis MCC2042 (NITE BP-03068) was internationally deposited on November 20, 2019, in accordance with the Budapest Treaty with the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number NITE BP-03068.

[0055] Bifidobacterium longum BB536 (NITE BP-02621) was internationally deposited on January 26, 2018, in accordance with the Budapest Treaty with the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number NITE BP-02621.

[0056] Bifidobacterium longum MCC1110 (NITE BP-02430) was internationally deposited on February 21, 2017, in accordance with the Budapest Treaty with the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number NITE BP-02430.

[0057] Bifidobacterium longum MCC10345 (NITE BP-03751) was internationally deposited on September 14, 2022, in accordance with the Budapest Treaty with the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number NITE BP-03751.

[0058] Bifidobacterium breve MCC1274 (FERM BP-11175) was internationally deposited on August 25, 2009, in accordance with the Budapest Treaty with the National Institute of Advanced Industrial Science and Technology (currently the National Institute of Technology and Evaluation (IPOD) Patent Organism Depositary, Room 120, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan; postal code: 292-0818), and has been assigned the accession number FERM BP-11175.

[0059] Bifidobacterium breve M-16V (NITE BP-02622) was internationally deposited on January 26, 2018, at the Patent Microorganisms Depositary Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan) in accordance with the Budapest Treaty, and has been assigned the accession number NITE BP-02622.

[0060] Bifidobacterium breve MCC1095 (NITE BP-02460) was internationally deposited on April 24, 2017, at the Patent Microorganisms Depositary Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan) in accordance with the Budapest Treaty, and has been assigned the accession number NITE BP-02460.

[0061] Bifidobacterium bifidum MCC1092 (NITE BP-02429) was internationally deposited on February 21, 2017, at the Patent Microorganisms Depositary Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan) in accordance with the Budapest Treaty, and has been assigned the accession number NITE BP-02429.

[0062] Bifidobacterium bifidum MCC1319 (NITE BP-02431) was internationally deposited on February 21, 2017, in accordance with the Budapest Treaty with the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number NITE BP-02431.

[0063] Bifidobacterium bifidum MCC1868 (NITE BP-02432) was internationally deposited on February 21, 2017, in accordance with the Budapest Treaty with the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number NITE BP-02432.

[0064] Bifidobacterium bifidum MCC1870 (NITE BP-02433) was internationally deposited on February 21, 2017, at the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan) in accordance with the Budapest Treaty, and has been assigned the accession number NITE BP-02433.

[0065] Bifidobacterium bifidum MCC2030 (NITE BP-03058) was internationally deposited on November 8, 2019, in accordance with the Budapest Treaty with the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Postal Code: 292-0818, Address: Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan), and has been assigned the accession number NITE BP-03058.

[0066] Bacteria with ATCC numbers can be obtained from the American Type Culture Collection (ATCC, Address: 10801 University Boulevard, Manassas, VA 20110, United States of America) or from the depository institution where the respective strains were deposited. Bacteria with DSM numbers can be obtained from the German Collection of Microorganisms and Cell Cultures (DSMZ, Address: Inhoffenstr. 7B, D38124 Braunschweig, Germany) or from the depository institution where the respective strains were deposited. Bacteria with JCM numbers can be obtained from the Japan Collection of Microorganisms (JCM, Postal Code: 305-0074, Address: Microbial Materials Development Laboratory, RIKEN BioResource Research Center, 3-1-1 Takanodai, Tsukuba, Ibaraki Prefecture, Japan) or from the depository institution where the respective strains were deposited.

[0067] The strains specified by the above-mentioned exemplified strain names are not limited to the strains deposited or registered with a designated institution under those strain names (hereinafter, for convenience of explanation, also referred to as "deposited strains"), but also include strains substantially equivalent to those deposited strains (hereinafter, also referred to as "derived strains"). That is, for example, "Lacticasei Bacillus paracasei MCC1849 (NITE BP-01633)" is not limited to the strain deposited with the above-mentioned depository institution under the deposit number NITE BP-01633, but also includes strains substantially equivalent to those deposited strains. A "strain substantially equivalent to the deposited strain" refers to a strain that belongs to the same species as the deposited strain, that exhibits good dispersibility and yield when the bacterial powder produced according to this embodiment is dispersed in a solvent or solution, that has a bacterial count equivalent to that of a conventional product, that has a 16S rRNA gene nucleotide sequence that is preferably 99.86% or more, more preferably 99.93% or more, and even more preferably 100% identical to the 16S rRNA gene nucleotide sequence of the deposited strain, and that preferably has the same biological properties as the deposited strain. A strain substantially equivalent to the deposited strain may be, for example, a derivative strain obtained using the deposited strain as a parent strain. Examples of derivative strains include strains bred from the deposited strain and strains that naturally arise from the deposited strain. Breeding methods include modification by genetic engineering techniques and modification by mutation treatment. Examples of mutation treatments include X-ray irradiation, ultraviolet irradiation, and treatment with mutagens (N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), ethyl methanesulfonate (EMS), methyl methanesulfonate (MMS), etc.). Strains naturally derived from the deposited strain include strains naturally derived during use of the deposited strain. Use of the deposited strain includes culturing (e.g., subculturing) the deposited strain. Derivative strains may be constructed by one type of modification, or by two or more types of modifications.

[0068] All of the bacteria used in this step can be easily obtained by conventional culture. The culture method is not particularly limited as long as it allows the growth of lactic acid bacteria and Bifidobacterium bacteria. For example, in the case of Lacticaseibacillus paracasei MCC1849 (NITE BP-01633), there is no particular limitation as long as the strain can grow. For example, a method commonly used for culturing Lacticaseibacillus bacteria can be used directly or with appropriate modifications. The culture temperature may be, for example, 25 to 50°C, preferably 35 to 42°C. Culture is preferably carried out under anaerobic conditions, for example, while aerating with anaerobic gas such as carbon dioxide. Culture can also be carried out under microaerobic conditions, such as liquid static culture. Culture can be carried out, for example, until Lacticaseibacillus paracasei MCC1849 (NITE BP-01633) grows to the desired extent.

[0069] The medium used for the culture is not particularly limited as long as it allows the growth of lactic acid bacteria and Bifidobacterium bacteria. For example, in the case of Lacticaceae Bacillus paracasei MCC1849 (NITE BP-01633), a medium commonly used for culturing Lacticaceae Bacillus bacteria can be used as is or with appropriate modifications. That is, as the carbon source, for example, sugars such as galactose, glucose, fructose, mannose, cellobiose, maltose, lactose, sucrose, trehalose, starch, starch hydrolysate, and blackstrap molasses can be used depending on the assimilation ability. As the nitrogen source, for example, ammonium salts such as ammonia, ammonium sulfate, ammonium chloride, and ammonium nitrate, and nitrates can be used. In addition, as the inorganic salt, for example, sodium chloride, potassium chloride, potassium phosphate, magnesium sulfate, calcium chloride, calcium nitrate, manganese chloride, ferrous sulfate, etc. can be used. Alternatively, organic components such as peptone, soybean flour, defatted soybean meal, meat extract, yeast extract, etc. Specific examples of media commonly used for culturing Lacticaseibacillus bacteria include BCP-supplemented plate count agar medium, reinforced clostridial medium, de Man, Rogosa, and Sharpe medium (MRS medium), and modified MRS medium (mMRS medium).

[0070] Furthermore, for example, in the case of Bifidobacterium longum BB536 (NITE BP-02621), methods commonly used for culturing Bifidobacterium bacteria (bifidobacteria) can be used as is, or with appropriate modifications, as long as the strain can grow. The culture temperature may be, for example, 25 to 50°C, preferably 35 to 42°C. The culture is preferably carried out under anaerobic conditions, for example, while aerating with anaerobic gas such as carbon dioxide. The culture can also be carried out under microaerobic conditions, such as liquid static culture. The culture can be carried out, for example, until Bifidobacterium longum BB536 (NITE BP-02621) grows to the desired extent.

[0071] The medium used for the culture is not particularly limited as long as it allows Bifidobacterium longum BB536 (NITE BP-02621) to grow, and examples thereof include the medium used for culturing Lactobacillus paracasei MCC1849 (NITE BP-01633).

[0072] The bacteria used in this step may be bacterial cells or a fraction containing the bacteria, without any particular limitation. For example, the culture obtained by culturing may be used as is, or the culture may be diluted or concentrated before use, or bacterial cells recovered from the culture may be used. Furthermore, various additional procedures such as heating and drying may be performed after culturing, as long as they do not impair the effects of this embodiment. That is, specific examples of the bacteria used in this step include cultures, bacterial cells recovered from the cultures, processed products of the cultures, processed products of the bacterial cells, etc., and the processed products may be diluted, concentrated, heat-treated, or dried.

[0073] The bacteria used in this step may consist of live cells, killed cells, or a mixture of live and killed cells, but killed cells are preferred. Killed cells include, for example, killed cells sterilized by heating or the like (i.e., heat-sterilized cells, etc.). Heat-sterilized cells can be obtained, for example, by culturing the bacteria used in this step as described above, centrifuging the resulting culture solution, and then heat-sterilizing it. Heat-sterilized cells can also be obtained by obtaining live cell powder, suspending it in sterilized water, and heat-sterilizing it. Heat-sterilization is preferably carried out before preparing a mixed solution containing the bacteria used in this step and a starch hydrolysate, as described below, but may also be carried out after preparing the mixed solution. Heat-sterilization conditions can be appropriately adjusted to a temperature that kills the bacteria, and can be set, for example, within a range of 90 to 150°C for 5 seconds to 30 minutes. Other sterilization methods for obtaining killed bacterial cells include retort sterilization, UHT sterilization, pressure sterilization, high-pressure steam sterilization, dry heat sterilization, circulating steam disinfection, electromagnetic wave sterilization, electron beam sterilization, high frequency sterilization, radiation sterilization, ultraviolet sterilization, ethylene oxide gas sterilization, hydrogen peroxide gas plasma sterilization, chemical sterilization (alcohol sterilization, formalin fixation, electrolyzed water treatment), etc. Killed bacterial cells are not limited to those that maintain their cell morphology, and may also be those that remain as parts of cells produced by pulverizing cells.

[0074] The bacteria used in this step may be probiotic bacteria. Probiotic bacteria are bacteria that have a positive effect on the health of the host by improving the balance of intestinal flora. Examples of probiotic bacteria include the aforementioned lactic acid bacteria and Bifidobacterium bacteria.

[0075] The mixed solution in this step contains bacteria and a starch hydrolysate and has a viscosity of 75 mPa·s or more at 10°C.

[0076] Examples of the mixture in this step include a mixture prepared so that the culture solution after bacterial culture contains a starch hydrolysate, as described below; a mixture prepared so that the culture solution is replaced with a fresh one after bacterial culture and then contains a starch hydrolysate, as described below; a mixture prepared so that the culture solution is replaced with a buffer solution commonly used in spray drying after bacterial culture and then contains a starch hydrolysate, as described below; and a mixture prepared by mixing a fraction containing bacterial cells obtained by separation or the like from the culture solution after bacterial culture with a starch hydrolysate, as described below. In either case, the bacteria may, as described above, consist of live bacterial cells, killed bacterial cells, or a mixture of live and killed bacterial cells. Killed bacterial cells may be killed bacterial cells sterilized by heating or the like (i.e., heat-sterilized bacterial cells, etc.).

[0077] The viscosity of the mixed solution in this step at 10°C is the viscosity measured as follows: Measuring instrument: B-type viscometer (manufactured by Toki Sangyo Co., Ltd., model: TVB-10M, rotor used: TM1) Rotation speed: 1.5 to 60 rpm Stop time: 60 seconds Container: 200 mL tall beaker Capacity: 200 mL Measurement temperature: 10°C

[0078] The rotation speed was set according to the viscosity of the sample to be measured, as shown in Table 1. That is, the rotation speed was set so that the viscosity did not deviate from the corresponding range shown in Table 1 when measured at the predetermined rotation speed.

[0079]

[0080] The viscosity of the mixed liquid at 10°C is, for example, 75 mPa·s or more, 80 mPa·s or more, 100 mPa·s or more, 130 mPa·s or more, 140 mPa·s or more, 150 mPa·s or more, 180 mPa·s or more, 190 mPa·s or more, 200 mPa·s or more, 300 mPa·s or more, 350 mPa·s or more, 450 mPa·s or more, 480 mPa·s or more, 700 mPa·s or more, etc. When the viscosity is within this range, the amount of fine powder is reduced, and the dispersibility of the bacterial powder obtained by the subsequent spray drying step when dispersed in a solvent or solution is improved.

[0081] The viscosity of the mixed liquid at 10°C depends on the volume per individual bacterial cell, the number of bacterial cells relative to the total volume of the mixed liquid, the type and amount of polysaccharides produced by the bacteria, and, if the mixed liquid contains other components that are neither bacteria nor starch hydrolysates described below, the type and amount of those components. Therefore, the viscosity of the mixed liquid at 10°C may be less than 75 mPa·s when it does not contain a starch hydrolysate described below. In this embodiment, the viscosity can be increased to 75 mPa·s or more by adding a starch hydrolysate described below. That is, a preferred embodiment of this embodiment is one in which the viscosity of the mixed liquid at 10°C is less than 75 mPa·s when it does not contain a starch hydrolysate described below, and in which the viscosity can be increased to 75 mPa·s or more by adding a starch hydrolysate described below. On the other hand, even if the viscosity of the mixed liquid at 10°C is 75 mPa·s or more when it does not contain a starch hydrolysate described below, the mixed liquid may still contain a starch hydrolysate, since starch hydrolysates are components typically contained in compositions to be spray-dried. In this case, it is sufficient for the mixed liquid to have a viscosity of 75 mPa·s or more even when it contains a starch hydrolysate. There are no particular limitations on the method for increasing the viscosity at 10°C, but it is preferably possible to select the type of starch hydrolysate described below, appropriately set its amount, and mix it with the mixed liquid.

[0082] On the other hand, the viscosity of the mixed liquid at 10°C is, for example, 1600 mPa·s or less, 1570 mPa·s or less, 1500 mPa·s or less, 1000 mPa·s or less, 800 mPa·s or less, 500 mPa·s or less, 480 mPa·s or less, 450 mPa·s or less, 400 mPa·s or less, 200 mPa·s or less, 180 mPa·s or less, 150 mPa·s or less, 130 mPa·s or less, 100 mPa·s or less, 90 mPa·s or less, etc. When the viscosity is within this range, the drying efficiency is good in the subsequent spray drying step, and adhesion to the wall surfaces of the dryer is reduced, resulting in a good yield.

[0083] The viscosity of the mixed liquid at 10°C may be any combination of the upper and lower limits mentioned above that is not inconsistent. For example, 75 to 1600 mPa·s, 75 to 1570 mPa·s, 75 to 1500 mPa·s, 80 to 90 mPa·s, 100 to 1600 mPa·s, 100 to 1000 mPa·s, 130 to 1600 mPa·s, 130 to 800 mPa·s, 140 to 1600 mPa·s, 150 to 500 mPa·s, 180 to 480 mPa·s, 190 to 1 600 mPa·s, 200 to 450 mPa·s, 300 to 400 mPa·s, 350 to 400 mPa·s, 450 to 1500 mPa·s, 480 to 1500 mPa·s, 700 to 1500 mPa·s, 75 to 200 mPa·s, 75 to 180 mPa·s, 75 to 150 mPa·s, 75 to 130 mPa·s, 75 to 100 mPa·s, etc.

[0084] The viscosity of the mixed solution at 10° C. can be reduced by selecting a type of solvent or solution that does not interfere with spray drying, appropriately setting the amount of the solvent or solution, and mixing it with the mixed solution. Examples of such solvents or solutions include culture media, buffer solutions commonly used in bacterial treatment, and water.

[0085] As long as the viscosity of the mixture at 10°C is set to the above-mentioned viscosity, it may contain components that contribute to the viscosity in addition to the bacteria and the starch hydrolysate described below. Examples of such components include components contained in probiotic products. Specific examples include antioxidants, excipients, binders, disintegrants, lubricants, stabilizers, flavorings, diluents, and pH adjusters. Alternatively, the mixture may be free of such components, i.e., it may consist of the bacteria and the starch hydrolysate described below.

[0086] The solid content of the mixed liquid is the content excluding water. That is, the proportion of the solid content in the mixed liquid depends on the solid content of the bacteria (including bacteria-derived components) and the solid content of the starch hydrolysate described below, as well as the solid content of other components if any, but is not particularly limited as long as it is a proportion typically used in spray drying. For example, it is 30% by mass or more, 35% by mass or more, 37% by mass or more, 40% by mass or more, 42% by mass or more, 47% by mass or more, 49% by mass or more, etc., while it is, for example, 60% by mass or less, 55% by mass or less, 53% by mass or less, 50% by mass or less, 49% by mass or less, 48% by mass or less, 47% by mass or less, 42% by mass or less, etc.

[0087] That is, the solid content in the mixed liquid is, for example, 30 to 60% by mass, 30 to 55% by mass, 30 to 50% by mass, 30 to 48% by mass, 35 to 60% by mass, 35 to 55% by mass, 35 to 50% by mass, 3 5-48% by mass, 40-60% by mass, 40-55% by mass, 40-50% by mass, 40-48% by mass, 37-42% by mass, 42-47% by mass, 47-49% by mass, 49-53% by mass, etc.

[0088] The starch hydrolysate used in this step is a component typically contained in a composition subjected to spray drying. Starch hydrolysate is a general term for starch hydrolyzed to an appropriate molecular weight using an enzyme and / or an acid. Examples include dextrin obtained by dispersing starch in water, adding an enzyme (e.g., α-amylase) and / or an acid (e.g., hydrochloric acid, oxalic acid), and heating to gelatinize and hydrolyze it; and indigestible dextrin obtained by acid-roasting starch and then treating the dextrin with an enzyme such as α-amylase. If necessary, the starch hydrolysate may be decolorized or purified by deionization or other methods. It may be in a liquid form or may be powdered by spray drying, drum drying, or the like. It may also be a reduced starch hydrolysate obtained by hydrogenating the above. Specific examples include dextrin, maltodextrin, and the like. The starch hydrolysate used in this step may be linear, branched, or cyclic.

[0089] Starch hydrolysates are graded according to the degree of degradation (saccharification rate, degree of hydrolysis) and distinguished by their dextrose equivalent (DE value). The DE value indicates the relative reducing power when the reducing power of dextrose (glucose) is set at 100; the closer to 0 the DE value, the more similar the properties to starch, and the closer to 100 the starch is hydrolyzed, the more similar the properties to glucose.

[0090] The DE value can be measured, for example, by the following method. Accurately weigh 2.5 g of sample and dissolve in water to make 200 mL. Accurately measure 10 mL of this solution, add 10 mL of 0.04 mol / L iodine solution and 15 mL of 0.04 mol / L sodium hydroxide solution, and leave in the dark for 20 minutes. Next, add 5 mL of 2 mol / L hydrochloric acid, mix, and then titrate with 0.04 mol / L sodium thiosulfate solution. When the solution turns slightly yellow near the end of the titration, add two drops of starch indicator and continue titrating. The end point is when the solution's color disappears. A separate blank test is performed. The dextrose equivalent (DE) value is calculated using the following formula: DE value = (b - a) x f x 3.602 / (1 / 1000) / (200 / 10) / {A x (100 - B) / 100} x 100 a: Titration value (mL) b: Blank value (mL) f: Factor value of sodium thiosulfate solution A: Amount of sample taken (g) B: Moisture value of sample (%)

[0091] The DE value of the starch hydrolysate used in this step is, for example, 12 or more, 15 or more, 18 or more, more than 18 (meaning higher than 18), 21 or more, 25 or more, 28 or more, etc., and also, for example, 45 or less, 40 or less, 36 or less, 29 or less, 25 or less, 20 or less, 18 or less, 15 or less, etc. Consistent combinations thereof are also possible. For example, 12 to 15, 15 to 18, 15 to 20, more than 18 to 36 or less, more than 18 to 40 or less, 21 to 25, 25 to 29, 28 to 36, 28 to 40, 12 to 45, etc. When the starch hydrolysate is dextrin, the DE value is 10 or less, when it is maltodextrin, the DE value is about 10 to 20, and when it is powdered candy, the DE value is about 20 to 40. Specific examples of the starch hydrolysate used in this step include NSD500 (DE value: 12 to 15, manufactured by Sanei Sugar Chemical Co., Ltd.), Glister P (DE value: 14 to 16, manufactured by Matsutani Chemical Industry Co., Ltd.), no trade name (DE value: 15 to 18, manufactured by Matsutani Chemical Industry Co., Ltd.), TK-16 (DE value: 18, manufactured by Matsutani Chemical Industry Co., Ltd.), Pine Oligo 20 (DE value: 21 to 25, manufactured by Matsutani Chemical Industry Co., Ltd.), K-SPD-M (DE value: 25 to 29, manufactured by Showa Sangyo Co., Ltd.), no trade name (DE value: 28 to 36, manufactured by Matsutani Chemical Industry Co., Ltd.), MALTRIN (registered trademark) T400 (DE value: 36 to 42, manufactured by Sansho Corporation), and Pine Index 6 (DE value: 40, manufactured by Matsutani Chemical Industry Co., Ltd.).

[0092] Examples of combinations of bacteria and starch hydrolysates contained in the mixed solution include: a combination of Lacticaseibacillus bacteria with a starch hydrolysate having a DE value of 15 to 18; a combination of Bifidobacterium bacteria with a starch hydrolysate having a DE value of 15 to 20 (other lower limits include, for example, 18 or more, as described above, and other upper limits include, for example, 18 or less, as described above); a combination of Lactobacillus bacteria with a starch hydrolysate having a DE value of more than 18 (other lower limits include, for example, 21 or more, as described above, and other upper limits include, for example, 45 or less, as described above); and a combination of Lactococcus bacteria with a starch hydrolysate having a DE value of 20 or less (other lower limits include, for example, 12 or more, as described above, and other upper limits include, for example, 18 or less, as described above). Commercially available starch hydrolysates can be appropriately selected from the above.

[0093] Other examples of combinations include the following: a combination of Lacticase Bacillus paracasei with a starch hydrolysate having a DE value of 15 to 18, a combination of Lactobacillus helveticus with a starch hydrolysate having a DE value of more than 18 (other lower limits include, for example, 21 or more as described above, and an upper limit includes, for example, 45 or less as described above) (for example, a combination with a starch hydrolysate having a DE value of 28 to 36), a combination of Lactobacillus acidophilus with a starch hydrolysate having a DE value of 15 or more (other lower limits include, for example, 18 or more, or more than 18 as described above, and an upper limit includes, for example, 45 or less as described above) (for example, a combination with a starch hydrolysate having a DE value of 15 to 18 or a combination with a starch hydrolysate having a DE value of 21 to 25), combinations of Bifidobacterium breve with starch hydrolysates having a DE value of 15 to 20 (other lower limits include, for example, 18 or more, more than 18, as described above, and other upper limits include, for example, 18 or less, as described above) (for example, combinations with starch hydrolysates having a DE value of 15 to 18); combinations of Bifidobacterium longum subsp. longum with starch hydrolysates having a DE value of 12 or more (other lower limits include, for example, 15 or more, as described above, and other upper limits include, for example, 45 or less, 40 or less, 36 or less, as described above) (for example, combinations with starch hydrolysates having a DE value of 12 to 15, combinations with starch hydrolysates having a DE value of 15 to 18); Examples include a combination of Lactococcus lactis subsp. lactis with a starch hydrolysate having a DE value of 20 or less (the lower limit is, for example, 12 or more, as described above, and the upper limit is, for example, 45 or less, as described above) (for example, a combination with a starch hydrolysate having a DE value of 12 to 20, a combination with a starch hydrolysate having a DE value of 12 to 15, or a combination with a starch hydrolysate having a DE value of 15 to 18). Commercially available starch hydrolysates may be appropriately selected from those described above.

[0094] The ratio (mass % ratio) of the amount of bacteria to the amount of starch hydrolysate contained in the mixed solution, when the amount of bacteria is taken as 1, is, for example, 1.5 or more, 2.0 or more, 2.5 or more, 3.0 or more, 3.1 or more, 3.2 or more, 3.3 or more, 3.5 or more, 3.8 or more, 4.0 or more, 4.5 or more, 5.0 or more, 5.5 or more, etc., while 6.0 or less, 5.5 or less, 5.0 or less, 4.6 or less, 4.2 or less, 4.0 or less, 3.9 or less, 3.5 or less, 3.3 or less, 3.2 or less, 3.1 or less, 3.0 or less, 2.7 or less, etc. Any compatible combination thereof is also acceptable. For example, 1.5 to 6.0, 2.0 to 6.0, 2.5 to 5.5, 3.0 to 5.0, 3.1 to 4.6, 3.2 to 4.2, 3.3 to 4.0, 3.5 to 3.9, 3.8 to 6.0, 4.0 to 6.0, 4.5 to 6.0, 5.0 to 6.0, 5.5 to 6.0, 2.0 to 3.5, 2.0 to 3.3, 2.0 to 3.2, 2.0 to 3.1, 2.0 to 3.0, 2.0 to 2.7, etc.

[0095] The amount of bacteria contained in the mixture is, for example, 5.0 × 10 10 Individual cells / g or more, 5.5 x 10 10 Individual cells / g or more, 6.0 x 10 10 Individual cells / g or more, 6.5 x 10 10 Individual cells / g or more, 7.0 x 10 10 Individual cells / g or more, 7.5 x 10 10 Individual cells / g or more, 8.0 x 10 10 Individual cells / g or more, 1.0 x 10 11 Individual cells / g or more, 2.0 x 10 11 Individual cells / g or more, 3.0 x 10 11 Individual cells / g or more, 3.2 x 10 11 Individual cells / g or more, 4.0 x 10 11 Individual cells / g or more, 5.0 x 10 11 Individual cells / g or more, 6.0 x 10 11 individual cells / g or more, 6.1×10 11 Individual cells / g or more, 6.2 x 10 11 Individual cells / g or more, 1.0 x 10 12 cells / g or more, while, for example, 1.5 x 10 12 Individual cells / g or less, 1.0 x 1012 Individual cells / g or less, 6.5 x 10 11 Individual cells / g or less, 6.1 x 10 11 Individual cells / g or less, 6.0 x 10 11 Individual cells / g or less, 5.0 x 10 11 Individual cells / g or less, 4.0 x 10 11 Individual cells / g or less, 3.0 x 10 11 Individual cells / g or less, 2.0 x 10 11 Individual cells / g or less, 8.5 x 10 10 Individual cells / g or less, 8.0 x 10 10 Individual cells / g or less, 7.5 x 10 10 Individual cells / g or less, 7.0 x 10 10 Individual cells / g or less, 6.5 x 10 10 Individual cells / g or less, 6.0 x 10 10 Individual cells / g or less, 5.5 x 10 10 5.0 × 10 cells / g or less. A consistent combination thereof is also acceptable. For example, 5.0 × 10 10 ~1.0 x 10 12 Individual cells / g, 5.5 x 10 10 ~6.5 x 10 11 Individual cells / g, 6.0×10 10 ~6.1 x 10 11 Individual cells / g, 6.5 x 10 10 ~6.0 x 10 11 Individual cells / g, 7.0×10 10 ~3.0 x 10 11 Individual cells / g, 7.5×10 10 ~2.0 x 10 11 Individual cells / g, 8.0×10 10 ~8.5 x 10 10 Individual cells / g, 1.0×10 11 ~1.0 x 10 12 Individual cells / g, 2.0×10 11 ~1.0 x 10 12 Individual cells / g, 3.0×10 11 ~1.0 x 10 12 Individual cells / g, 3.2×10 11 ~4.0 x 10 11 Individual cells / g, 3.2×10 11 ~5.0 x 10 11 Individual cells / g, 4.0×10 11 ~1.0 x 1012 Individual cells / g, 5.0×10 11 ~1.0 x 10 12 Individual cells / g, 6.0×10 11 ~1.0 x 10 12 Individual cells / g, 6.1×10 11 ~1.0 x 10 12 Individual cells / g, 6.2×10 11 ~1.0 x 10 12 Individual cells / g, 1.0×10 12 ~1.5 x 10 12 Individual cells, 5.0 x 10 10 ~8.0 x 10 10 Individual cells / g, 5.0×10 10 ~7.5 x 10 10 Individual cells / g, 5.0×10 10 ~7.0 x 10 10 Individual cells / g, 5.0×10 10 ~6.5 x 10 10 Individual cells / g, 5.0×10 10 ~6.0 x 10 10 Individual cells / g, 5.0×10 10 ~5.5 x 10 10 cells / g, etc.

[0096] As mentioned above, the bacteria used in this step may consist of live cells, dead cells, or a mixture of live and dead cells, but dead cells are preferred. For live cells, cells / g can be replaced with cfu / g. "Cfu" stands for colony-forming unit.

[0097] The amount of starch hydrolysate contained in the mixed solution (corresponding to the "blending ratio (%) of starch hydrolysate" in the examples described below) is, for example, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 43% by mass or more, 45% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, etc., while, for example, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 45% by mass or less, 40% by mass or less, 38% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, etc. Any compatible combination thereof is also acceptable. For example, 10-80% by mass, 15-70% by mass, 20-60% by mass, 25-50% by mass, 30-45% by mass, 35-40% by mass, 40-80% by mass, 45-80% by mass, 50-80% by mass, 60-80% by mass, 70-80% by mass, 10-35% by mass, 10-30% by mass, 10-25% by mass, 43-45% by mass, 30-38% by mass, etc.

[0098] The ratio of the solid content (dry weight) derived from the bacterial liquid to the solid content (dry weight) of bacterial powder in the mixed liquid (corresponding to "bacteria ratio (%)" in the examples described below) is, for example, 16% by mass or more, 19% by mass or more, 21% by mass or more, 25% by mass or more, etc., while, for example, 30% by mass or less, 25% by mass or less, 21% by mass or less, 19% by mass or less, etc. Consistent combinations thereof are also acceptable. For example, 16 to 19% by mass, 19 to 21% by mass, 21 to 25% by mass, 25 to 30% by mass, etc.

[0099] The ratio of the solid content (dry weight) derived from the starch hydrolysate to the solid content (dry weight) of the bacterial powder in the mixed solution (corresponding to "starch hydrolysate ratio (%)" in the examples described below) is 70% by mass or more, 75% by mass or more, 80% by mass or more, 81% by mass or more, etc., while it is, for example, 83% by mass or less, 81% by mass or less, 78% by mass or less, 75% by mass or less, etc. Consistent combinations thereof are also acceptable. For example, 70 to 83% by mass, 75 to 81% by mass, 80 to 83% by mass, 81 to 83% by mass, 70 to 78% by mass, 70 to 75% by mass, etc.

[0100] The spray drying step in the production method according to this embodiment is a spray drying step in which the mixed liquid is spray-dried to obtain a bacterial powder.

[0101] The spray drying method in this step is not limited as long as it is a conventional spray drying method for obtaining a bacterial powder, and may be, for example, a spray drying method suitable for producing foods and beverages.

[0102] The temperature of the mixed solution in this step is not particularly limited as long as it is a temperature used in normal spray drying to obtain a bacterial powder during spray drying, and is, for example, 20° C. or higher, 40° C. or higher, 70° C. or higher, etc. By setting the temperature to such a value, the pressure during spraying can be appropriately maintained, and the dispersibility and yield of the obtained bacterial powder will be good.

[0103] On the other hand, the temperature of the mixed solution in this step is not particularly limited as long as it is a temperature used in normal spray drying to obtain a bacterial powder during spray drying, and is, for example, 100° C. or less, 90° C. or less, 80° C. or less, etc. By setting the temperature to such a value, the droplet size during spraying can be properly maintained, and the yield of the obtained bacterial powder can be improved.

[0104] The temperature of the mixture in this step may be any compatible combination thereof, for example, 20 to 100°C, 40 to 90°C, 70 to 80°C, etc.

[0105] The temperature of the mixed liquid can be controlled by a normal temperature control method used in normal spray drying.

[0106] The bacterial powder obtained in this embodiment has the following properties. Simply put, the bacterial powder contains bacteria and starch hydrolysates because it is obtained by spray-drying a mixed liquid containing bacteria and starch hydrolysates. Furthermore, if the mixed liquid contains the other components, the bacterial powder contains the other components in addition to the bacteria and starch hydrolysates.

[0107] The ratio (mass % ratio) of bacteria to starch hydrolysates contained in the bacterial powder (in the examples described below, this roughly corresponds to the "starch hydrolysate ratio (%) / bacteria ratio (%)" in the mixed solution) is not particularly limited as long as it is a normal ratio in bacterial powder obtained by spray drying, but when the bacteria is taken as 1, the starch hydrolysates may be, for example, 1.5 or more, 2.0 or more, 2.5 or more, 3.0 or more, 3.1 or more, 3.2 or more, 3.3 or more, 3.5 or more, 3.8 or more, 4.0 or more, 4.5 or more, 5.0 or more, 5.5 or more, etc., or 6.0 or less, 5.5 or less, 5.0 or less, 4.6 or less, 4.2 or less, 4.0 or less, 3.9 or less, 3.5 or less, 3.3 or less, 3.2 or less, 3.1 or less, 3.0 or less, 2.7 or less, etc. Any compatible combination thereof may also be used. For example, 1.5 to 6.0, 2.0 to 6.0, 2.5 to 5.5, 3.0 to 5.0, 3.1 to 4.6, 3.2 to 4.2, 3.3 to 4.0, 3.5 to 3.9, 3.8 to 6.0, 4.0 to 6.0, 4.5 to 6.0, 5.0 to 6.0, 5.5 to 6.0, 2.0 to 3.5, 2.0 to 3.3, 2.0 to 3.2, 2.0 to 3.1, 2.0 to 3.0, 2.0 to 2.7, etc.

[0108] The amount of bacteria contained in the bacterial powder (in the examples described below, this corresponds to about 10 times the "number of bacteria (cells / g)" in the mixed solution) is not particularly limited as long as it is a normal amount of bacteria in bacterial powder obtained by spray drying. For example, it may be 1.0 x 10 11 Individual cells / g or more, 3.0 x 10 11 Individual cells / g or more, 5.0 x 10 11 Individual cells / g or more, 5.5 x 10 11 Individual cells / g or more, 6.0 x 10 11 Individual cells / g or more, 6.5 x 10 11 Individual cells / g or more, 7.0 x 10 11 Individual cells / g or more, 7.5 x 10 11 Individual cells / g or more, 8.0 x 10 11 Individual cells / g or more, 1.0 x 10 12 Individual cells / g or more, 2.0 x 10 12 Individual cells / g or more, 3.0 x 10 12 Individual cells / g or more, 3.2 x 10 12 Individual cells / g or more, 4.0 x 10 12 Individual cells / g or more, 5.0 x 1012 Individual cells / g or more, 6.0 x 10 12 individual cells / g or more, 6.1×10 12 Individual cells / g or more, 6.2 x 10 12 Individual cells / g or more, 1.0 x 10 13 cells / g or more, while, for example, 1.5 x 10 13 Individual cells / g or less, 1.0 x 10 13 Individual cells / g or less, 6.5 x 10 12 Individual cells / g or less, 6.1 x 10 12 Individual cells / g or less, 6.0 x 10 12 Individual cells / g or less, 5.0 x 10 12 Individual cells / g or less, 4.0 x 10 12 Individual cells / g or less, 3.0 x 10 12 Individual cells / g or less, 2.0 x 10 12 Individual cells / g or less, 8.5 x 10 11 Individual cells / g or less, 8.0 x 10 11 Individual cells / g or less, 7.5 x 10 11 Individual cells / g or less, 7.0 x 10 11 Individual cells / g or less, 6.5 x 10 11 Individual cells / g or less, 6.0 x 10 11 Individual cells / g or less, 5.5 x 10 11 1.0 × 10 cells / g or less. A consistent combination thereof is also acceptable. For example, 1.0 × 10 11 ~1.0 x 10 13 Individual cells / g, 3.0×10 11 ~1.0 x 10 13 Individual cells / g, 5.0×10 11 ~1.0 x 10 13 Individual cells / g, 5.5 x 10 11 ~6.5 x 10 12 Individual cells / g, 6.0×10 11 ~6.1 x 10 12 Individual cells / g, 6.5 x 10 11 ~6.0 x 10 12 Individual cells / g, 7.0×10 11 ~3.0 x 10 12 Individual cells / g, 7.5×10 11 ~2.0 x 10 12 Individual cells / g, 8.0×10 11 ~8.5 x 10 11Individual cells / g, 1.0×10 12 ~1.0 x 10 13 Individual cells / g, 2.0×10 12 ~1.0 x 10 13 Individual cells / g, 3.0×10 12 ~1.0 x 10 13 Individual cells / g, 3.2×10 12 ~4.0 x 10 12 Individual cells / g, 3.2×10 12 ~5.0 x 10 12 Individual cells / g, 4.0×10 12 ~1.0 x 10 13 Individual cells / g, 5.0×10 12 ~1.0 x 10 13 Individual cells / g, 6.0×10 12 ~1.0 x 10 13 Individual cells / g, 6.1×10 12 ~1.0 x 10 13 Individual cells / g, 6.2×10 12 ~1.0 x 10 13 Individual cells / g, 1.0×10 13 ~1.5 x 10 13 Individual cells, 5.0 x 10 11 ~8.0 x 10 11 Individual cells / g, 5.0×10 11 ~7.5 x 10 11 Individual cells / g, 5.0×10 11 ~7.0 x 10 11 Individual cells / g, 5.0×10 11 ~6.5 x 10 11 Individual cells / g, 5.0×10 11 ~6.0 x 10 11 Individual cells / g, 5.0×10 11 ~5.5 x 10 11 The bacteria in the bacterial powder obtained by spray drying are usually dead cells, but may be viable cells or a mixture of viable and dead cells. For viable cells, cfu / g can be substituted for cfu / g.

[0109] The amount of starch hydrolysates contained in the bacterial powder (the ratio of the solid content (dry weight) derived from the starch hydrolysates to the solid content (dry weight) of the bacterial powder) (in the examples described later, this roughly corresponds to the "starch hydrolysate ratio (%)" in the mixed liquid) is not particularly limited as long as it is a normal amount in a bacterial powder obtained by spray drying, and is, for example, 70% by mass or more, 75% by mass or more, 80% by mass or more, 81% by mass or more, etc., while, for example, 83% by mass or less, 81% by mass or less, 78% by mass or less, 75% by mass or less, etc. Consistent combinations thereof are also acceptable. For example, 70 to 83% by mass, 75 to 81% by mass, 80 to 83% by mass, 81 to 83% by mass, 70 to 78% by mass, 70 to 75% by mass, etc.

[0110] The amount of bacterial cells contained in the bacterial powder (the ratio of the solid content (dry weight) derived from the bacterial liquid to the solid content (dry weight) of the bacterial powder) (in the examples described later, this roughly corresponds to the "bacteria ratio (%)" in the mixed solution) is not particularly limited as long as it is a normal amount in a bacterial powder obtained by spray drying, and is, for example, 16% by mass or more, 19% by mass or more, 21% by mass or more, 25% by mass or more, etc., while on the other hand, for example, 30% by mass or less, 25% by mass or less, 21% by mass or less, 19% by mass or less, etc. Consistent combinations thereof are also acceptable. For example, 16 to 19% by mass, 19 to 21% by mass, 21 to 25% by mass, 25 to 30% by mass, etc.

[0111] The volume moment mean diameter (D[4.3]) of the bacterial powder is not particularly limited as long as it is a normal volume moment mean diameter (D[4.3]) of bacterial powder obtained by spray drying, but is, for example, 10 μm or more, 20 μm or more, 30 μm or more, etc., and on the other hand, for example, 300 μm or less, 200 μm or less, 150 μm or less, etc. Consistent combinations thereof are also acceptable. For example, 10 to 300 μm, 20 to 200 μm, 30 to 150 μm, etc. The volume moment mean diameter (D[4.3]) of the bacterial powder is the diameter measured as follows. Measuring equipment: Laser diffraction particle size measuring device (Marvern, model: Mastersizer 3000) Particle refractive index: 1.450 Particle absorption coefficient: 0.100 Venturi type: Standard venturi Tray type: General-purpose tray Hopper gap: 2-2.5 mm

[0112] Regarding the composition of the fungal powder, the lipid content is not particularly limited as long as it is a normal lipid content of a fungal powder obtained by spray drying, but may be, for example, 0% by mass or more, more than 0% by mass (indicating greater than 0% by mass), 0.1% by mass or more, 0.2% by mass or more, 0.3% by mass or more, 0.4% by mass or more, 0.5% by mass or more, etc., or, for example, 5% by mass or less, 3% by mass or less, 1% by mass or less, 0.7% by mass or less, 0.5% by mass or less, 0.4% by mass or less, 0.3% by mass or less, 0.2% by mass or less, etc. Consistent combinations thereof are also acceptable. For example, 0 to 0.2% by mass, greater than 0% by mass and 0.2% by mass or less, 0.1 to 0.3% by mass, 0.2 to 0.4% by mass, 0.3 to 0.5% by mass, 0.4 to 0.7% by mass, 0.5 to 1% by mass, 0.1 to 5% by mass, 0.1 to 3% by mass, etc. The lipid content can be quantified by a commonly used method such as the Roese-Gottlieb method.

[0113] The protein content of the fungal powder is not particularly limited as long as it is a normal protein content of a fungal powder obtained by spray drying, and may be, for example, 10.0% by mass or more, 11.0% by mass or more, 12.0% by mass or more, 13.0% by mass or more, 14.0% by mass or more, 15.0% by mass or more, etc., or, for example, 16.0% by mass or less, 15.0% by mass or less, 14.0% by mass or less, 13.0% by mass or less, 12.0% by mass or less, 11.0% by mass or less, etc. Consistent combinations thereof are also acceptable. For example, 10.0 to 16.0 mass%, 11.0 to 15.0 mass%, 12.0 to 14.0 mass%, 13.0 to 16.0 mass%, 14.0 to 16.0 mass%, 15.0 to 16.0 mass%, 10.0 to 13.0 mass%, 10.0 to 12.0 mass%, 10.0 to 11.0 mass%, etc. Protein can be quantified by commonly used measurement methods such as the Kjeldahl method or combustion methods including modified Dumas method.

[0114] The carbohydrate content of the fungal powder is not particularly limited as long as it is a typical carbohydrate content of a fungal powder obtained by spray drying, and may be, for example, 75% by mass or more, 80% by mass or more, 82% by mass or more, or 84% by mass or more, or, for example, 90% by mass or less, 87% by mass or less, 86% by mass or less, 84% by mass or less, 82% by mass or less, or 80% by mass or less. Consistent combinations thereof are also acceptable. For example, 75 to 90% by mass, 80 to 87% by mass, 80 to 86% by mass, 82 to 84% by mass, 84 to 90% by mass, 75 to 82% by mass, or 75 to 80% by mass. The carbohydrate content can be quantified by the subtraction method (a method in which the total of the four components, fat, protein, ash, and moisture, is subtracted from the total of all components, i.e., 100%).

[0115] The ash content of the fungal powder is not particularly limited as long as it is a typical ash content of a fungal powder obtained by spray drying, but may be, for example, 1.4% by mass or more, 1.6% by mass or more, 1.8% by mass or more, 2.0% by mass or more, 2.2% by mass or more, or, for example, 2.5% by mass or less, 2.2% by mass or less, 2.0% by mass or less, 1.8% by mass or less, 1.6% by mass or less, or any combination thereof that does not contradict these. For example, 1.4 to 2.5% by mass, 1.6 to 2.2% by mass, 1.8 to 2.0% by mass, 2.0 to 2.5% by mass, 2.2 to 2.5% by mass, 1.4 to 1.8% by mass, 1.4 to 1.6% by mass, or the like. The ash content can be quantified by a commonly used method such as the direct ashing method.

[0116] The moisture content of the fungal powder is not particularly limited as long as it is a normal moisture content of a fungal powder obtained by spray drying, and is, for example, 1.0% by mass or more, 1.2% by mass or more, 1.4% by mass or more, 1.5% by mass or more, 2.5% by mass or more, 3.0% by mass or more, 3.2% by mass or more, 3.3% by mass or more, 3.4% by mass or more, etc., while, for example, 7.0% by mass or less, 6.0% by mass or less, 5.0% by mass or less, 4.0% by mass or less, 3.5% by mass or less, 3.4% by mass or less, 3.3% by mass or less, 3.2% by mass or less, 3.1% by mass or less, 3.0% by mass or less, 2.9% by mass or less, etc. Consistent combinations thereof are also possible. For example, it is 1.0 to 2.9% by mass, 1.2 to 3.0% by mass, 1.4 to 3.1% by mass, 1.5 to 3.2% by mass, 2.5 to 3.3% by mass, 3.0 to 3.4% by mass, 3.2 to 3.5% by mass, 3.3 to 4.0% by mass, 3.4 to 5.0% by mass, 1.0 to 7.0% by mass, 1.0 to 6.0% by mass, etc. The moisture content of the fungal powder is the amount measured by a normal pressure heat drying method (drying temperature: 105°C).

[0117] The dry mass of bacteria in the bacterial powder is not particularly limited as long as it is a typical dry mass of bacterial powder obtained by spray drying, but it is, for example, 5% by mass or more, 10% by mass or more, 15% by mass or more, or, for example, 60% by mass or less, 50% by mass or less, 40% by mass or less, relative to the dry mass of the bacterial powder. Consistent combinations thereof are also acceptable. For example, 5 to 60% by mass, 10 to 50% by mass, 15 to 40% by mass, etc. The dry mass of bacteria is the total weight minus the amount of water and starch hydrolysates. The amount of starch hydrolysates can be quantified by known methods such as HPLC.

[0118] The bulk density (loose bulk density) of the bacterial powder is not particularly limited as long as it is a normal bulk density of bacterial powder obtained by spray drying, but for example, it is 0.2 g / cm ３ Above, 0.3g / cm ３ Above, 0.4g / cm ３ or more, while, for example, 1.0 g / cm ３ Below, 0.8g / cm ３ Below, 0.7g / cm ３ The following may be used in combination without any contradiction. For example, 0.2 to 1.0 g / cm３ , 0.3-0.8g / cm ３ , 0.4-0.7g / cm ３ The bulk density of the bacterial powder can be measured using a known measuring device (for example, a powder tester (manufactured by Hosokawa Micron Corporation, model: PT-X)).

[0119] The bacterial powder obtained in the above-described embodiment can be used by adding it to foods and beverages, for example. Food and beverages include tablets, liquid foods, beverages, feed (including for pets), etc., regardless of the form, such as liquid, paste, solid, or powder, as well as flour products, instant foods, processed agricultural products, processed marine products, processed livestock products, milk and dairy products, oils and fats, basic seasonings, complex seasonings, frozen foods, and confectioneries.

[0120] Examples of beverages include carbonated drinks, natural fruit juice drinks, fruit juice drinks, soft drinks containing fruit juice, fruit pulp drinks, fruit drinks containing fruit particles, vegetable-based drinks, soy milk, soy milk drinks, coffee drinks, tea drinks, powdered drinks, concentrated drinks, sports drinks, nutritional drinks, alcoholic drinks, and beverages. Examples of wheat flour products include bread, macaroni, spaghetti, noodles, cake mixes, fried chicken flour, and breadcrumbs. Examples of instant foods include instant noodles, cup noodles, retort pouches and prepared foods, canned foods, microwaveable foods, instant soups and stews, instant miso soup and clear soups, canned soups, and freeze-dried foods. Examples of processed agricultural products include canned agricultural products, canned fruit, jams and marmalades, pickles, boiled beans, dried agricultural products, and cereals (processed grain products). Examples of processed seafood products include canned seafood, fish ham and sausage, fish paste products, seafood delicacies, and tsukudani (simmered foods). Examples of processed livestock products include canned livestock products and pastes, and livestock ham and sausage. Examples of milk and dairy products include fermented milk, milk drinks, lactic acid bacteria drinks, sweetened condensed milk, skim milk powder, sweetened milk powder, modified milk powder, yogurt, cream, cheese, butter, and ice cream. Examples of fats and oils include butter, margarines, and vegetable oils. Examples of basic seasonings include soy sauce, miso, sauces, tomato-processed seasonings, mirin, and vinegars. Examples of complex seasonings include cooking mixes, curry bases, sauces, dressings, noodle soups, and spices. Examples of frozen foods include frozen ingredient foods, semi-cooked frozen foods, and cooked frozen foods. Examples of confectioneries include caramel, candy, chewing gum, chocolate, cookies, biscuits, cakes, pies, snacks, crackers, Japanese sweets, rice confectioneries, bean confectioneries, dessert confectioneries, etc. Examples of foods other than those mentioned above include baby food, furikake rice seasoning, and ochazuke nori seaweed.

[0121] The food and drink can be produced by adding the bacterial powder obtained according to the above embodiment to the raw materials of a normal food and drink, and can be produced in the same manner as normal food and drink except for the addition of the bacterial powder obtained according to the above embodiment. The addition of the bacterial powder obtained according to the above embodiment may be carried out at any stage in the production process of the food and drink.

[0122] Another aspect of the present invention is a composition comprising a bacterium and a starch hydrolysate, having a viscosity of 75 mPa·s or more at 10°C, and being subjected to spray drying.

[0123] Here, "subjected to spray drying" means to be powdered by a spray dryer. In addition, in the present invention, the composition to be spray dried is a liquid composition that can be suitably powdered by a spray dryer, and can also be called a "composition for spray drying."

[0124] The explanations given in the previous embodiment regarding the bacteria, starch hydrolysate, viscosity at 10° C., and spray drying in this embodiment are incorporated by reference.

[0125] The form of the composition according to this embodiment is a normal form used for spray drying, and is not particularly limited as long as the powder obtained by spray drying has good dispersibility when dispersed in a solvent or solution, has a good yield, and has a bacterial count ratio equivalent to that of conventional products. For example, the form of a mixed liquid can be mentioned. The description of the mixed liquid is as described in the previous embodiment.

[0126] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Note that percentages are by mass unless otherwise specified.

[0127] Test Example 1 1. Production of bacterial powder (1) Cultivation of Lacticase Bacillus paracasei NITE BP-01633 Lacticase Bacillus paracasei NITE BP-01633 was inoculated into a medium containing protein, amino acids, and a sugar source, and cultured at 32 to 41°C for 5 to 24 hours to obtain a bacterial cell culture solution. The culture solution was then sterilized. The obtained bacterial solution had a solid content of 15% by mass and a cell density of 4.4 x 10 11The solution contained 100 cells / g of bacteria and had a viscosity of approximately 14 mPa·s at 10°C.

[0128] (2) Preparation of Mixed Liquids Starch hydrolysates (manufactured by Matsutani Chemical Industry Co., Ltd., DE value 15 to 18) were added to the bacterial suspension obtained in (1) above to prepare six types of mixed liquids with different viscosities and solid contents of approximately 35 mass%, approximately 40 mass%, approximately 45 mass%, approximately 48 mass%, approximately 50 mass%, and approximately 55 mass%. These were designated Samples No. 1 to 6, which will be described later. The blending ratio of the starch hydrolysates in each mixed liquid (the ratio of the starch hydrolysates to the total mass of the bacterial suspension and the starch hydrolysates) and the viscosity at 10°C were as shown in Table 2.

[0129] (3) Spray drying The six mixed solutions obtained in (2) above were spray dried using a spray dryer (SD-1000, manufactured by Tokyo Rika Kikai Co., Ltd.) to obtain powders (bacterial powders) containing the heat-sterilized bacteria. Each bacterial powder was designated as Sample No. 1 to 6, respectively.

[0130] <2. Evaluation> The viscosity of the mixture at 10°C was measured using a Brookfield viscometer (TVB-10M, manufactured by Toki Sangyo Co., Ltd.) (rotor used: TM1). To evaluate the dispersibility of the resulting bacterial powder, 100 ml of purified water at 20°C was added to a 200 ml beaker. While stirring at 500 rpm using a stirrer (SLOW STIRRER SW-500SD, manufactured by Nissin), 1 g of bacterial powder was added all at once and stirring was continued for a certain period of time. The formation of clumps was visually observed after a certain period of time had elapsed from the end of the addition. A: The bacterial powder was dispersed and clumps disappeared within 1 minute after the addition of the bacterial powder (better); B: The bacterial powder was dispersed and clumps disappeared within 1 to 3 minutes after the addition of the bacterial powder (good); and C: The clumps did not disappear even after stirring for 3 minutes or more after the addition of the bacterial powder (unsuitable). The yield was classified as A: 80% or more (better), B: more than 50% but less than 80% (good), and C: 50% or less (unacceptable). The viscosity, rotation speed, dispersibility, and yield at 10°C were as shown in Table 2. In the table, "Reference" refers to the case where the bacterial liquid obtained in (1) above was used.

[0131]

[0132] Regarding dispersibility, sample No. 1 was inadequate, but samples Nos. 2 to 6, which had higher viscosities, were good. Regarding yield, samples Nos. 1 to 4 were higher, at 80% or higher, and were better. On the other hand, samples Nos. 5 and 6 were inferior to samples Nos. 1 to 4, but sample No. 5 was acceptable and was judged to be good. Sample No. 6 had a yield of 50% or less, indicating low production efficiency and was considered unsuitable for long-term production. The composition and cell count of each bacterial powder are shown in Table 3. Here, the bacterial ratio (%) and starch hydrolysate ratio (%) refer to the ratio of the solid content (dry weight) derived from the bacterial solution to the solid content (dry weight) of the bacterial powder, and the ratio of the solid content (dry weight) derived from the starch hydrolysate to the solid content (dry weight) of the bacterial powder, respectively.

[0133]

[0134] Test Example 2 Bifidobacterium breve FERM BP-11175 was inoculated into a medium containing protein, amino acids, and a sugar source and cultured in the same manner as in Test Example 1. A bacterial cell culture solution was prepared to a solids content of 15% by mass and sterilized. Next, a starch hydrolysate ("NSD500" manufactured by Sanei Sugar Chemical Co., Ltd., DE value 12-15), a starch hydrolysate ("Matsutani Chemical Industry Co., Ltd., DE value 15-18"), or a starch hydrolysate ("Pine Oligo 20" manufactured by Matsutani Chemical Industry Co., Ltd., DE value 21-25) was added to the bacterial cell culture solution to prepare three mixed solutions with different viscosities and a solids content of approximately 45% by mass (Samples No. 7-9). The viscosity and other properties of each mixed solution at 10°C were as shown in Table 4. The "Reference" in the table refers to the bacterial cell culture before the addition of the starch hydrolysate.

[0135]

[0136] The viscosity of sample No. 8 was 339 mPa s, suggesting that it may be more suitable for spray drying than samples No. 7 and 9. Furthermore, for Bifidobacterium breve FERM BP-11175, it was suggested that a starch hydrolysate with a DE value of 15 to 20 is preferred, for example, a starch hydrolysate with a DE value of 15 to 18 is preferred.

[0137] Test Example 3: Lactobacillus helveticus NITE BP-03882 was inoculated into a medium containing protein, amino acids, and a sugar source, and cultured in the same manner as in Test Example 1. A bacterial cell culture solution was prepared to a solids content of 15% by mass, and then sterilized. Next, a starch hydrolysate (manufactured by Matsutani Chemical Industry Co., Ltd., DE value 28-36) or a starch hydrolysate (manufactured by Matsutani Chemical Industry Co., Ltd., DE value 15-18) was added to the bacterial solution, and two mixed solutions with different viscosities and a solids content of approximately 40% by mass were prepared (Samples No. 10 and 11). The viscosity and other properties of each mixed solution at 10°C were as shown in Table 5. The "Reference" in the table refers to the bacterial solution before the addition of the starch hydrolysate.

[0138]

[0139] The viscosity of sample No. 10 was 341 mPa s, suggesting that it may be more suitable for spray drying than sample No. 11. Furthermore, it was suggested that for Lactobacillus helveticus, starch hydrolysates with a DE value higher than 18 (i.e., a DE value greater than 18) are preferred, for example, starch hydrolysates with a DE value of 28 to 36 are preferred.

[0140] Test Example 4 Bifidobacterium longum subsp. longum NITE BP-02621 was inoculated into a medium containing protein, amino acids, and a sugar source, and cultured in the same manner as in Test Example 1. A bacterial cell culture solution was prepared to a solids content of 15% by mass, and then sterilized. Next, a starch hydrolysate ("NSD500" manufactured by Sanei Sugar Chemical Co., Ltd., DE value 12-15) or a starch hydrolysate (manufactured by Matsutani Chemical Industry Co., Ltd., DE value 15-18) was added to the bacterial solution to prepare two mixed solutions with different viscosities and a solids content of approximately 40% by mass (Samples No. 12 and 13). The viscosity and other properties of each mixed solution at 10°C were as shown in Table 6. The "Reference" in the table refers to the bacterial solution before the addition of the starch hydrolysate.

[0141]

[0142] The viscosities of Samples No. 12 and 13 were 322 mPa s and 775 mPa s, respectively, suggesting that both samples may be suitable for spray drying. Furthermore, it was suggested that for Bifidobacterium longum subsp. longum, starch hydrolysates with a DE value of 12 or higher are preferred, such as starch hydrolysates with a DE value of 12 to 15 or 15 to 18.

[0143] Test Example 5 Bifidobacterium breve NITE BP-02622 was inoculated into a medium containing protein, amino acids, and a sugar source and cultured in the same manner as in Test Example 1. A bacterial cell culture solution was prepared to a solids content of 12% by mass and then sterilized. Next, a starch hydrolysate ("NSD500" manufactured by Sanei Sugar Chemical Co., Ltd., DE value 12-15), a starch hydrolysate ("Matsutani Chemical Industry Co., Ltd., DE value 15-18"), or a starch hydrolysate ("Pine Oligo 20" manufactured by Matsutani Chemical Industry Co., Ltd., DE value 21-25) was added to the bacterial solution to prepare three mixed solutions with different viscosities and a solids content of approximately 45% by mass (Samples No. 14-16). The viscosity and other properties of each mixed solution at 10°C were as shown in Table 7. The "Reference" in the table refers to the bacterial solution before the addition of the starch hydrolysate.

[0144]

[0145] The viscosities of Samples No. 15 and 16 were 143 mPa s and 382 mPa s, respectively, suggesting that both may be more suitable for spray drying than Sample No. 14. Furthermore, for Bifidobacterium breve NITE BP-02622, it was suggested that a starch hydrolysate having a DE value of 12 to 20 is preferred, and for example, a starch hydrolysate having a DE value of 12 to 15 or a starch hydrolysate having a DE value of 15 to 18 is preferred.

[0146] Test Example 6: Lactococcus lactis subsp. lactis NITE BP-1204 was inoculated into a medium containing protein, amino acids, and a sugar source and cultured as in Test Example 1. A bacterial cell culture solution was prepared to a solids content of 11% by mass and then sterilized. Next, a starch hydrolysate ("NSD500" manufactured by Sanei Sugar Chemical Co., Ltd., DE value 12-15), a starch hydrolysate ("Matsutani Chemical Industry Co., Ltd., DE value 15-18"), or a starch hydrolysate ("Pine Oligo 20" manufactured by Matsutani Chemical Industry Co., Ltd., DE value 21-25) was added to the bacterial cell culture solution to prepare two mixtures with different viscosities and a solids content of approximately 40% by mass (Samples No. 17-19). The viscosity and other properties of each mixture at 10°C were as shown in Table 8. The "Reference" in the table refers to the bacterial cell culture before the addition of the starch hydrolysate.

[0147]

[0148] The viscosities of Samples No. 18 and 19 were 86 mPa s and 190 mPa s, respectively, suggesting that both may be more suitable for spray drying than Sample No. 17. Furthermore, it was suggested that for Lactococcus lactis subsp. lactis NITE BP-1204, starch hydrolysates with a DE value of 20 or less are preferred, and for example, starch hydrolysates with a DE value of 12 to 20, 12 to 15, or 15 to 18 are preferred.

[0149] Test Example 7: Lactobacillus acidophilus NITE BP-01695 was inoculated into a medium containing protein, amino acids, and a sugar source and cultured as in Test Example 1. A bacterial cell culture solution was prepared to a solids content of 15% by mass and then sterilized. Next, a starch hydrolysate ("NSD500" manufactured by Sanei Sugar Chemical Co., Ltd., DE value 12-15), a starch hydrolysate ("Matsutani Chemical Industry Co., Ltd., DE value 15-18"), or a starch hydrolysate ("Pine Oligo 20" manufactured by Matsutani Chemical Industry Co., Ltd., DE value 21-25) was added to the bacterial cell culture solution to prepare three mixtures with different viscosities and a solids content of approximately 40% by mass (Samples No. 20-22). The viscosity and other properties of each mixture at 10°C were as shown in Table 9. The "Reference" in the table refers to the bacterial cell culture before the addition of the starch hydrolysate.

[0150]

[0151] The viscosities of Samples No. 20 and 21 were 170 mPa s and 765 mPa s, respectively, suggesting that both may be more suitable for spray drying than Sample No. 22. Furthermore, for Lactobacillus acidophilus NITE BP-01695, it was suggested that starch hydrolysates with a DE value of 15 or higher are preferred, for example, starch hydrolysates with a DE value of 15 to 18 or a DE value of 21 to 25 are preferred.

[0152] [Overall Evaluation] For bacteria of the genus Lacticaseibacillus, the results of Test Example 1 suggest that starch hydrolysates with a DE value of 15 to 18 are preferred. For bacteria of the genus Lactobacillus, the results of Test Examples 3 and 7 suggest that starch hydrolysates with a DE value higher than 18 (i.e., a DE value greater than 18) are preferred, for example, starch hydrolysates with a DE value of 21 to 25 or 28 to 36 are preferred. For bacteria of the genus Bifidobacterium, the results of Test Examples 2, 4, and 5 suggest that starch hydrolysates with a DE value of 15 to 20 are preferred, for example, starch hydrolysates with a DE value of 15 to 18 are preferred. For Lactococcus bacteria, the results of Test Example 6 suggest that starch hydrolysates with a DE value of 20 or less are preferred, for example, starch hydrolysates with a DE value of 12 to 20, 12 to 15, or 15 to 18. For Bifidobacterium breve, the results of Test Examples 2 and 5 suggest that starch hydrolysates with a DE value of 15 to 20 are preferred, for example, starch hydrolysates with a DE value of 15 to 18 are preferred. For Bifidobacterium longum subsp. longum, the results of Test Example 4 suggest that starch hydrolysates with a DE value of 12 or more are preferred, for example, starch hydrolysates with a DE value of 12 to 15 or 15 to 18 are preferred. For Bifidobacterium breve FERM BP-11175, the results of Test Example 2 suggest that starch hydrolysates with a DE value of 15 to 20 are preferred, for example, starch hydrolysates with a DE value of 15 to 18 are preferred. For Bifidobacterium breve NITE BP-02622, the results of Test Example 5 suggest that starch hydrolysates with a DE value of 12 to 20 are preferred, for example, starch hydrolysates with a DE value of 12 to 15 or 15 to 18 are preferred. For Lactobacillus helveticus, the results of Test Example 3 suggest that starch hydrolysates with a DE value higher than 18 (i.e., a DE value greater than 18) are preferred, for example, starch hydrolysates with a DE value of 28 to 36 are preferred.For Lactobacillus acidophilus, the results of Test Example 7 suggest that starch hydrolysates with a DE value of 15 or more are preferred, for example, starch hydrolysates with a DE value of 15 to 18 or a DE value of 21 to 25 are preferred.

Claims

1. A method for producing bacterial powder, comprising: a preparation step of preparing a mixed liquid containing bacteria and a starch hydrolysate, the mixed liquid having a viscosity of 75 mPa·s or more at 10°C; and a spray drying step of spray-drying the mixed liquid to obtain bacterial powder.

2. The production method according to claim 1, wherein the bacteria are Bifidobacterium, Lacticaseibacillus, Lactobacillus, or Lactococcus.

3. The method according to claim 2, wherein the bacterium is a bacterium of the genus Lacticaseibacillus, and the DE value of the starch hydrolysate is 15 to 18.

4. The method according to claim 2, wherein the bacterium is a Lactobacillus bacterium and the DE value of the starch hydrolysate is higher than 18.

5. The method according to claim 2, wherein the bacterium is a Bifidobacterium bacterium and the DE value of the starch hydrolysate is 15 to 20.

6. The method according to claim 2, wherein the bacterium is a Lactococcus bacterium and the DE value of the starch hydrolysate is 20 or less.

7. The method according to claim 2, wherein the bacterium is Bifidobacterium breve and the DE value of the starch hydrolysate is 15 to 20.

8. The method according to claim 2, wherein the bacterium is Bifidobacterium longum subsp. longum and the DE value of the starch hydrolysate is 12 or more.

9. A composition comprising a bacterium and a starch hydrolysate, having a viscosity of 75 mPa·s or more at 10°C, and capable of being subjected to spray drying.

10. The composition of claim 9, wherein the bacterium is a Bifidobacterium, a Lacticaseibacillus, a Lactobacillus, or a Lactococcus.

11. The composition according to claim 10, wherein the bacterium is a bacterium of the genus Lacticaseibacillus, and the DE value of the starch hydrolysate is 15 to 18.

12. The composition according to claim 10, wherein the bacterium is a Lactobacillus bacterium and the DE value of the starch hydrolysate is higher than 18.

13. The composition according to claim 10, wherein the bacterium is a Bifidobacterium bacterium and the DE value of the starch hydrolysate is 15 to 20.

14. The composition according to claim 10, wherein the bacterium is a Lactococcus bacterium and the DE value of the starch hydrolysate is 20 or less.

15. The composition according to claim 10, wherein the bacterium is Bifidobacterium breve and the DE value of the starch hydrolysate is 15 to 20.

16. The composition according to claim 10, wherein the bacterium is Bifidobacterium longum subsp. longum and the DE value of the starch hydrolysate is 12 or more.

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