WO2025225690A1 - Production method for bacteria powder and composition to be spray-dryed - Google Patents

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

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

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 they are, but may also be dispersed in a solvent or solution, in which case good dispersibility is required (Patent Document 2). Furthermore, good yield is required in the production of bacterial powders.
That is, in the production of bacterial powder, it is important 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.

Japanese Patent Application Laid-Open No. 2005-052100 JP 2016-044173 A

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, whereas 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 is difficult to spray-dry and tends to result in a low yield.
The present invention aims to provide a technology that not only ensures good dispersibility when the bacterial powder obtained by the spray drying process is dispersed in a solvent or solution, and has a good yield, but also ensures that the proportion of bacterial count in the obtained bacterial powder is equivalent to that of conventional products.

As a result of extensive research into solving the above problems, the inventors discovered that the above problems could be solved by spray-drying a mixed liquid containing bacteria and starch hydrolysates and having a predetermined viscosity, and thus completed the present invention.

The present invention can provide a method for producing a bacterial powder, which includes 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 bacterium is a bacterium 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 bacterium is a Lactobacillus bacterium, and the DE value of the starch hydrolysate is higher than 18.
In a preferred embodiment of the production method, the bacterium is a Bifidobacterium bacterium, 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 DE value of the starch hydrolysate is 20 or less.
In a preferred embodiment of the production method, the bacterium is Bifidobacterium breve, and the DE value of the starch hydrolysate is 15 to 20.
In a preferred embodiment of the production method, the bacterium is Bifidobacterium longum subsp. longum, and the DE value of the starch hydrolysate is 12 or more.

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

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

In this specification, expressions such as "XX or greater and YY or less," "XX to YY," "XX to," and "to YY" refer to numerical ranges that include the endpoints unless otherwise specified.

The present invention will be described in detail below.
One aspect of the present invention is
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;
The method for producing a bacterial powder includes a spray drying step of spray-drying the mixed liquid to obtain a bacterial powder.

Incidentally, since the mixture contains the bacteria, it may be in the form of a suspended cell (i.e., in the form of a "suspension"), but in this specification it will be referred to as a "mixture" or "solution," etc.

The preparation step in the manufacturing 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.

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, and examples thereof include lactic acid bacteria and Bifidobacterium bacteria.
The bacteria used in this step may be one type of bacteria, or two or more types of bacteria.

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.

Specific examples include bacteria of the class Bacilli, order Lactobacillales, and bacteria of the class Bacilli, order Bacillales.

Examples of bacteria in the Bacilli order of the Lactobacillales include bacteria from the Aerococcaceae family, Carnobacteriaceae family, Enterococcaceae family, Streptococcaceae family, Lactobacillaceae family, and Leuconostocaceae family.

Examples of Enterococcaceae bacteria include bacteria of the genus Enterococcus and Tetragenococcus.

Examples of Enterococcus bacteria include Enterococcus faecalis and Enterococcus faecium.

Examples of bacteria in the family Streptococcaceae include bacteria in the genus Lactococcus and Streptococcus.

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

Specific examples of Lactococcus lactis subsp. lactis include MCC1723 (NITE BP-1204).

Examples of Streptococcus bacteria include Streptococcus thermophilus.

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

Examples of Lacticaseibacillus bacteria include Lacticaseibacillus paracasei (formerly known as Lactobacillus paracasei), such as Lacticaseibacillus paracasei subsp. paracasei and Lacticaseibacillus paracasei subsp. tolerans. Also included are Lacticaseibacillus casei (formerly known as Lactobacillus casei).

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) and the like.
Specific examples of Lacticaseibacillus paracasei subsp. tolerans include JCM 1171 (ATCC 25599, DSM 20258).

Examples of bacteria of the genus Lactobacillus 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, and Lactobacillus delbrueckii subsp. lactis. Other examples include Lactobacillus plantarum.

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

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

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

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

Examples of bacteria in the Leuconostocaceae family include bacteria of the genus Leuconostoc, Fructobacillus, Oenococcus, and Weissella.

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.

The genus Bifidobacterium is a group of bacteria that belong to the phylum Actinobacteria, class Actinobacteria, order Bifidobacteriales in the bacterial domain.

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 may be simply referred to as Bifidobacterium longum, and Bifidobacterium longum subsp. infantis may be simply referred to as Bifidobacterium infantis.

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

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

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

Specific examples of Bifidobacterium animalis subsp. lactis include DSM 10140.

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.

Specific examples of Bifidobacterium adolescentis include ATCC 15703.

Specific examples of Bifidobacterium dentium include DSM 20436.

Specific examples of Bifidobacterium pseudolongum subsp. globosum include JCM 5820.

Specific examples of Bifidobacterium pseudolongum subsp. pseudolongum include ATCC 25526.

Specific examples of Bifidobacterium thermophilum include ATCC 25525.

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.

Lacticaseibacillus paracasei MCC1849 (NITE BP-01633) (this strain was previously known as Lactobacillus paracasei MCC1849 (NITE BP-01633)) was deposited on June 6, 2013, with the Patent Microorganisms Depositary Center, 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 was assigned the accession number NITE BP-01633.

Lacticaseibacillus paracasei MCC1375 (FERM BP-11313) (this strain was previously known as Lactobacillus paracasei MCC1375 (FERM BP-11313)) was internationally deposited on November 5, 2010, 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-11313.

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.

Lactobacillus acidophilus MCC1847 (NITE BP-01695) was internationally deposited on August 23, 2013, with 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.

Lactobacillus helveticus MCC2430 (NITE BP-03882) was internationally deposited on April 13, 2023, 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) pursuant to the Budapest Treaty, and has been assigned the accession number NITE BP-03882.

Lactobacillus helveticus MCC1848 (NITE BP-01671) was internationally deposited on July 29, 2013, with 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-01671.

Lactobacillus helveticus MCC1844 (NITE BP-02185) was internationally deposited on December 25, 2015, with 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-02185.

Bifidobacterium longum subsp. infantis M-63 (NITE BP-02623) was internationally deposited on January 26, 2018, with 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 deposit number NITE BP-02623.

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.

Bifidobacterium longum BB536 (NITE BP-02621) 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-02621.

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.

Bifidobacterium longum MCC10345 (NITE BP-03751) was internationally deposited on September 14, 2022, 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) pursuant to the Budapest Treaty, and has been assigned the accession number NITE BP-03751.

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.

Bifidobacterium breve M-16V (NITE BP-02622) was internationally deposited on January 26, 2018, with 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.

Bifidobacterium breve MCC1095 (NITE BP-02460) was internationally deposited on April 24, 2017, with 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.

Bifidobacterium bifidum MCC1092 (NITE BP-02429) was internationally deposited on February 21, 2017, 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) in accordance with the Budapest Treaty, and has been assigned the accession number NITE BP-02429.

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.

Bifidobacterium bifidum MCC1868 (NITE BP-02432) was internationally deposited on February 21, 2017, 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) in accordance with the Budapest Treaty, and has been assigned the accession number NITE BP-02432.

Bifidobacterium bifidum MCC1870 (NITE BP-02433) was internationally deposited on February 21, 2017, 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) in accordance with the Budapest Treaty, and has been assigned the accession number NITE BP-02433.

Bifidobacterium bifidum MCC2030 (NITE BP-03058) was internationally deposited on November 8, 2019, 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) in accordance with the Budapest Treaty, and has been assigned the accession number NITE BP-03058.

Bacteria assigned 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 have been deposited.
Bacteria assigned 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 have been deposited.
Bacteria assigned JCM numbers can be obtained from the Japan Collection of Microorganisms (JCM, Postal Code: 305-0074, Address: Microbial Materials Development Division, RIKEN BioResource Research Center, 3-1-1 Takanodai, Tsukuba, Ibaraki, Japan) or from the depository institutions where the respective strains have been deposited.

The strains identified by the strain names exemplified above are not limited to the strains themselves deposited or registered with designated institutions under those strain names (hereinafter, for convenience of explanation, also referred to as "deposited strains"), but also include strains that are 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 itself deposited with the above depository institution under the deposit number NITE BP-01633, but also includes strains that are 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. 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.

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 the conditions are such that lactic acid bacteria and Bifidobacterium bacteria can grow.
For example, the culture medium is not particularly limited as long as it can grow Lacticase Bacillus paracasei MCC1849 (NITE BP-01633). For example, a method commonly used for culturing Lacticase Bacillus 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. 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 Lacticase Bacillus paracasei MCC1849 (NITE BP-01633) grows to the desired extent.

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 Lacticase Bacillus paracasei MCC1849 (NITE BP-01633), media typically used for culturing Lacticase Bacillus bacteria can be used as is or with appropriate modifications. Specifically, sugars such as galactose, glucose, fructose, mannose, cellobiose, maltose, lactose, sucrose, trehalose, starch, starch hydrolysates, and blackstrap molasses can be used as carbon sources depending on the assimilation potential. Nitrogen sources include ammonium salts such as ammonia, ammonium sulfate, ammonium chloride, and ammonium nitrate, as well as nitrates. Inorganic salts include sodium chloride, potassium chloride, potassium phosphate, magnesium sulfate, calcium chloride, calcium nitrate, manganese chloride, and ferrous sulfate. Organic components such as peptone, soybean flour, defatted soybean meal, meat extract, and yeast extract can also be used. Specific examples of media commonly used for culturing bacteria of the genus Lacticaseibacillus include BCP-supplemented plate count agar medium, reinforced clostridial medium, de Man, Rogosa, and Sharpe medium (MRS medium), and modified MRS medium (mMRS medium).

Furthermore, in the case of Bifidobacterium longum BB536 (NITE BP-02621), for example, methods commonly used for culturing bacteria of the genus Bifidobacterium (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, and preferably 35 to 42°C. Cultivation is preferably carried out under anaerobic conditions, for example, while aerating with anaerobic gas such as carbon dioxide. Cultivation can also be carried out under microaerobic conditions, such as liquid static culture. Cultivation can be carried out, for example, until Bifidobacterium longum BB536 (NITE BP-02621) grows to the desired extent.

The medium used for culturing 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).

The bacteria used in this step can be bacterial cells or a fraction containing the bacteria, without any particular limitations. For example, the culture obtained by culturing can be used as is, or the culture can be diluted or concentrated and used, or bacterial cells recovered from the culture can be used. Furthermore, various additional procedures such as heating and drying can 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 can be diluted, concentrated, heat-treated, or dried, etc.

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.
Examples of killed bacteria include killed bacteria sterilized by heating or the like (i.e., heat-sterilized bacteria, etc.). Heat-sterilized bacteria 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 bacteria can also be obtained by obtaining live bacterial 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 it may also be carried out after preparing the mixed solution. Heat-sterilization conditions can be appropriately adjusted to a temperature condition that kills the bacteria, and can be set, for example, within the 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, and chemical sterilization (alcohol sterilization, formalin fixation, electrolyzed water treatment).
The killed cells are not limited to those that maintain the morphology of the cells, but may be those that remain as part of the cells that have been crushed.

The bacteria used in this process 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 include the aforementioned lactic acid bacteria and Bifidobacterium bacteria.

The mixed liquid used in this process contains bacteria and starch hydrolysates and has a viscosity of 75 mPa·s or higher at 10°C.

Examples of the mixed solution used in this step include a mixed solution prepared so that the culture solution after bacterial culture contains a starch hydrolysate, as described below; a mixed solution 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 mixed solution 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 mixed solution 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 bacteria, etc.).

The viscosity of the mixed liquid at 10°C in this step is the viscosity measured as follows.
Measuring equipment: 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℃

The rotation speed was set as shown in Table 1 according to the viscosity of the sample being measured. In other words, the rotation speed was set so that the viscosity, when measured at the specified rotation speed, did not deviate from the corresponding range shown in Table 1.

The viscosity of the mixture 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. Having this viscosity value results in less fine powder, which improves dispersibility when the resulting bacterial powder is dispersed in a solvent or solution after being subjected to the subsequent spray drying process.

The viscosity of the mixed solution at 10°C depends on the volume per individual bacterial cell, the number of bacterial cells relative to the total volume of the mixed solution, the type and amount of polysaccharides produced by the bacteria, and, if the mixed solution contains other components that are neither bacteria nor starch hydrolysates (described below), the type and amount of the components.
Therefore, when the mixed liquid does not contain a starch hydrolysate described below, the viscosity at 10°C may be less than 75 mPa·s. In this embodiment, in such a case, 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 an embodiment in which the viscosity at 10°C is less than 75 mPa·s when the mixed liquid does not contain a starch hydrolysate described below, and in such a case, 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 contain a starch hydrolysate, since starch hydrolysates are components that are typically contained in compositions to be subjected to spray drying. 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 preferably, the method involves selecting the type of starch hydrolysate described below, appropriately setting the amount of the hydrolysate, and mixing it with the mixed liquid.

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. Having this viscosity value results in good drying efficiency in the subsequent spray drying process and reduced adhesion to the dryer walls, resulting in a good yield.

The viscosity of the mixed liquid at 10°C may be any combination of the upper and lower limits listed 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, 200-450 mPa·s, 300-400 mPa·s, 350-400 mPa·s, 450-1500 mPa·s, 480-1500 mPa·s, 700-1500 mPa·s, 75-200 mPa·s, 75-180 mPa·s, 75-150 mPa·s, 75-130 mPa·s, 75-100 mPa·s, etc.

To reduce the viscosity of the mixed liquid at 10°C, a solvent or solution that does not interfere with spray drying can be selected, its amount appropriately set, and mixed with the mixed liquid. Examples of such solvents or solutions include culture media, buffer solutions commonly used in bacterial treatment, and water.

Furthermore, 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, pH adjusters, etc. On the other hand, the mixture may not contain such components, i.e., it may consist of the bacteria and the starch hydrolysate described below.

The solids content of the mixed liquid is the content excluding water. That is, the proportion of solids in the mixed liquid depends on the solids content of the bacteria (including bacterial-derived components) and the solids content of the starch hydrolysate described below, as well as the solids content of other components if any, but is not particularly limited as long as it is a proportion commonly 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 also 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.

That is, the solid content in the mixed liquid is, for example, 30-60% by mass, 30-55% by mass, 30-50% by mass, 30-48% by mass, 35-60% by mass, 35-55% by mass, 35-50% 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.

The starch hydrolysate used in this step is a component that is usually contained in a composition to be subjected to spray drying.
Starch hydrolysates are a general term for starch hydrolyzed to an appropriate molecular weight using enzymes and/or acids. 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. They may be decolorized or purified, for example, by deionization, as needed. They may be in liquid form or may be powdered by spray drying, drum drying, or the like. Reduced starch hydrolysates obtained by hydrogenating these may also be used. Specific examples include dextrin and maltodextrin. The starch hydrolysates used in this step may be linear, branched, or cyclic.

Starch hydrolysates are graded according to the degree of degradation (saccharification rate, degree of hydrolysis) and distinguished by their dextrose equivalent (dextrin value, 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 it is to 0, the more similar its properties are to starch, and the closer it is to 100, the more hydrolyzed the starch is and the more similar its properties are to glucose.

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 and mix, 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. Calculate the dextrose equivalent (DE) value 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: Weighed amount of sample (g)
B: Moisture content of sample (%)

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 (indicating higher than 18), 21 or more, 25 or more, 28 or more, etc., while it is, 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 acceptable, such as 12 to 15, 15 to 18, 15 to 20, more than 18 to 36, more than 18 to 40, 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.).

Examples of the combination of bacteria and starch hydrolysates contained in the mixed solution include:
a combination of bacteria belonging to the genus Lacticase Bacillus and a starch hydrolysate having a DE value of 15 to 18;
A combination of Bifidobacterium bacteria and a starch hydrolysate having a DE value of 15 to 20 (other lower limits include, for example, 18 or more, more than 18, etc., as described above, and other upper limits include, for example, 18 or less, as described above),
A combination of Lactobacillus bacteria and 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),
A combination of Lactococcus bacteria and 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, 18 or less as described above),
Commercially available starch hydrolysates may be appropriately selected from those listed above.

The following combinations are also examples:
A combination of Bacillus paracasei and 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 upper limits include, 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 (the lower limit can be, for example, 18 or more, or more than 18, as described above, and the upper limit can be, 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);
a combination of Bifidobacterium breve with a starch hydrolysate having a DE value of 15 to 20 (other lower limits include, for example, 18 or more, more than 18, etc., as described above, and other upper limits include, for example, 18 or less, as described above) (for example, a combination with a starch hydrolysate 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 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);
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);
Examples include:
Commercially available starch hydrolysates may be appropriately selected from those listed above.

The ratio (mass % ratio) of the amount of bacteria to the amount of starch hydrolysate contained in the mixed liquid is, when the amount of bacteria is taken as 1, 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.

The amount of bacteria contained in the mixed solution is, for example, 5.0×10 ¹⁰ cells/g or more, 5.5×10 ¹⁰ cells/g or more, 6.0×10 ¹⁰ cells/g or more, 6.5×10 ¹⁰ cells/g or more, 7.0×10 ¹⁰ cells/g or more, 7.5×10 ¹⁰ cells/g or more, 8.0×10 ¹⁰ cells/g or more, 1.0×10 ¹¹ cells/g or more, 2.0×10 ¹¹ cells/g or more, 3.0×10 ¹¹ cells/g or more, 3.2×10 ¹¹ cells/g or more, 4.0×10 ¹¹ cells/g or more, 5.0×10 ¹¹ cells/g or more, 6.0×10 ¹¹ cells/g or more, 6.1×10 ¹¹ cells/g or more, 6.2×10 On the other hand, for example, ^1.5 ×10 ^{12 cells/g or less, 1.0×10 12 cells} /g or less, 6.5×10 ¹¹ cells/g or less, 6.1×10 ¹¹ cells/g or less, 6.0×10 ¹¹ cells/g or less, 5.0×10 ¹¹ cells/g or less, 4.0×10 ¹¹ cells/g or less, 3.0×10 ¹¹ cells/g or less, 2.0×10 ¹¹ cells/g or less, 8.5×10 ¹⁰ cells/g or less, 8.0×10 ¹⁰ cells/g or less, 7.5×10 ¹⁰ cells/g or less, 7.0× ^{10 10 cells} /g or less, 6.5×10 ¹⁰ cells/g or less, 6.0×10 ¹⁰ cells/g or less, 5.5× ¹⁰ cells/g or less, etc.
For example, 5.0×10 ¹⁰ to 1.0×10 ¹² cells/g, 5.5× ^{10 10} to 6.5×10 ¹¹ cells/g, 6.0× ^{10 10} to 6.1×10 ¹¹ cells/g, 6.5×10 ¹⁰ to 6.0×10 11 cells/g, 7.0× ^{10 10} to 3.0×10 ¹¹ cells/g, 7.5× ^{10 10} to 2.0×10 ¹¹ cells/g, 8.0×10 ¹⁰ to 8.5× ^{10 10 cells} /g, ^1.0 ×10 11 to 1.0×10 ¹² cells/g, 2.0×10 ¹¹ to 1.0×10 ¹² cells/g, 3.0×10 ¹¹ to 1.0×10 ¹² cells/g, 3.2×10 ¹¹ to 4.0×10 ¹¹ cells/g, 3.2×10 ¹¹ to 5.0×10 ¹¹ cells/g, 4.0×10 ¹¹ to 1.0×10 ¹² cells/g, 5.0 ^{×10 11} to 1.0×10 ¹² cells/g, 6.0× ^{10 11} ～1.0×10 ¹² cells/g, 6.1×10 ¹¹ ～1.0×10 ¹² cells/g, 6.2×10 ¹¹ ～1.0×10 ¹² cells/g, 1.0×10 ¹² ～1.5×10 ¹² cells, 5.0×10 ¹⁰ ～8.0×10 ¹⁰ cells/g, 5.0× ^{10 10} ～7.5×10 ¹⁰ cells/g, 5.0×10 ¹⁰ to 7.0×10 ¹⁰ cells/g, 5.0× ^{10 10 to} 6.5×10 ¹⁰ cells/g, 5.0×10 10 to 6.0×10 ¹⁰ cells/g, 5.0× ^{10 10} to 5.5×10 ¹⁰ cells/g, etc.

As mentioned above, the bacteria used in this process 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.

The amount of starch hydrolysate contained in the mixed liquid (corresponding to the "starch hydrolysate blending ratio (%)" 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 also being, 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 consistent 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.

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 the "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 it is also, 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 of these are also acceptable, such as 16-19% by mass, 19-21% by mass, 21-25% by mass, 25-30% by mass, etc.

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 also, 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 of these are also acceptable. For example, 70-83% by mass, 75-81% by mass, 80-83% by mass, 81-83% by mass, 70-78% by mass, 70-75% by mass, etc.

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

The spray drying method used in this step is not limited, as long as it is a conventional spray drying method for obtaining bacterial powder. For example, it may be a spray drying method suitable for producing food and beverage products.

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 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 this value, the pressure during spraying can be maintained appropriately, resulting in good dispersibility and yield of the resulting bacterial powder.

On the other hand, the temperature of the mixed solution in this step is not particularly limited as long as it is a temperature that is typically used in spray drying to obtain bacterial powder, and is, for example, 100°C or less, 90°C or less, 80°C or less, etc. By setting the temperature to this value, the droplet size during spraying can be maintained appropriately, resulting in a good yield of the resulting bacterial powder.

The temperature of the mixed solution in this step may be any compatible combination of these. For example, 20 to 100°C, 40 to 90°C, 70 to 80°C, etc.

The temperature of the mixed liquid can be adjusted using the usual temperature control methods used in conventional spray drying.

The bacterial powder obtained in this embodiment has the following properties.
In short, 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.

The ratio (mass % ratio) of bacteria to starch hydrolysate contained in the bacterial powder (in the examples described below, this roughly corresponds to the "starch hydrolysate ratio (%)/bacteria ratio (%)" in the mixed liquid) is not particularly limited as long as it is a normal ratio for bacterial powder obtained by spray drying, but when the bacteria is taken as 1, the starch hydrolysate 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., while on the other hand, 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.

The amount of bacteria contained in the bacterial powder (in the examples described later, 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 a bacterial powder obtained by spray drying, and may be, for example, 1.0 x ¹⁰ cells/g or more, 3.0 x ¹⁰ cells/g or more, 5.0 x ¹⁰ cells/g or more, 5.5 x ¹⁰ cells/g or more, 6.0 x ¹⁰ cells/g or more, 6.5 x ¹⁰ cells/g or more, 7.0 x ¹⁰ cells/g or more, 7.5 x ¹⁰ cells/g or more, 8.0 x ¹⁰ cells/g or more, 1.0 x ¹⁰ cells/g or more, 2.0 x ¹⁰ cells/g or more, 3.0 x ¹⁰ cells/g or more, 3.2 x 10 ¹² cells/g or more, 4.0×10 ¹² cells/g or more, 5.0×10 ¹² cells/g or more, 6.0×10 ¹² cells/g or more, 6.1×10 ¹² cells/g or more, 6.2×10 ¹² cells/g or more, 1.0×10 ¹³ cells/g or more, and the like, on the other hand, for example, 1.5×10 ¹³ cells/g or less, 1.0×10 ¹³ cells/g or less, 6.5×10 ¹² cells/g or less, 6.1×10 ¹² cells/g or less, 6.0×10 ¹² cells/g or less, 5.0×10 ¹² cells/g or less, 4.0×10 ¹² cells/g or less, 3.0×10 ¹² cells/g or less, 2.0×10 ¹² cells/g or less, 8.5×10 ¹¹ cells/g or less, 8.0× ¹⁰ cells/g or less, 7.5× ¹⁰ cells/g or less, 7.0× ¹⁰ cells/g or less, 6.5× ¹⁰ cells/g or less, 6.0× ¹⁰ cells/g or less, 5.5× ¹⁰ cells/g or less, etc.
It may also be a consistent combination thereof. For example, 1.0×10 ¹¹ to 1.0×10 ¹³ cells/g, 3.0×10 ¹¹ to 1.0×10 ¹³ cells/g, 5.0× ^{10 11} to 1.0×10 ¹³ cells/g, 5.5×10 ¹¹ to 6.5×10 ¹² cells/g, 6.0× ^{10 11} to 6.1×10 ¹² cells/g, 6.5×10 ¹¹ to 6.0×10 ¹² cells/g, 7.0× ^{10 11} to 3.0×10 ¹² cells/g, 7.5×10 ¹¹ to 2.0×10 ¹² cells/g, 8.0×10 ¹¹ to 8.5×10 ¹¹ cells/g, 1.0×10 ¹² to 1.0×10 ¹³ cells/g, 2.0×10 ¹² to 1.0×10 ¹³ cells/g, 3.0×10 ¹² to 1.0×10 ¹³ cells/g, 3.2× ^{10 12} to 4.0×10 ¹² cells/g, 3.2× ^{10 12} to 5.0×10 ¹² cells/g, 4.0×10 ¹² ～1.0×10 ¹³ cells/g, 5.0×10 ¹² ～1.0×10 ¹³ cells/g, 6.0×10 ¹² ～1.0×10 ¹³ cells/g, 6.1×10 ¹² ～1.0×10 ¹³ cells/g, 6.2×10 ¹² ～1.0×10 ¹³ cells/g, 1.0×10 ¹³ ~1.5×10 ¹³ cells, 5.0×10 ¹¹ to 8.0×10 ¹¹ cells/g, ^5.0 ×10 ¹¹ to 7.5×10 ¹¹ cells/g, 5.0×10 11 to 7.0×10 ¹¹ cells/g, 5.0× ^{10 11} to 6.5×10 ¹¹ cells/g, 5.0× ^{10 11} to 6.0×10 ¹¹ cells/g, 5.0× ^{10 11} to 5.5×10 ¹¹ cells/g, etc.
The bacteria in the bacterial powder obtained by spray drying usually consist of dead cells, but may consist of viable cells or a mixture of viable and dead cells. For viable cells, cfu/g can be substituted for cell/g.

The amount of starch hydrolysate contained in the bacterial powder (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 examples described below, this roughly corresponds to the "starch hydrolysate ratio (%)" in the mixed liquid) is not particularly limited, as long as it is a typical amount in a bacterial powder obtained by spray drying, but 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 also including, 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 of these are also acceptable, such as 70-83% by mass, 75-81% by mass, 80-83% by mass, 81-83% by mass, 70-78% by mass, 70-75% by mass, etc.

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 below, this roughly corresponds to the "bacteria ratio (%)" in the mixed liquid) is not particularly limited, as long as it is a typical amount in a bacterial powder obtained by spray drying, but 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 also including, 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 of these are also acceptable, such as 16-19% by mass, 19-21% by mass, 21-25% by mass, 25-30% by mass, etc.

The volume moment mean diameter (D[4.3]) of the bacterial powder is not particularly limited as long as it is a typical 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, such as 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 instrument: Laser diffraction particle size measuring device (Marvern, model: Mastersizer 3000)
Particle refractive index: 1.450
Particle absorption rate: 0.100
Venturi type: Standard venturi Tray type: General-purpose tray Hopper gap: 2-2.5mm

Regarding the composition of the fungal powder, the lipid content is not particularly limited as long as it is the usual lipid content of fungal powder obtained by spray drying, but may be, for example, 0% by mass or more, more than 0% by mass (meaning 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. Lipid content can be quantified using commonly used methods such as the Roese-Gottlieb method.

The protein content of the fungal powder is not particularly limited as long as it is the normal protein content of fungal powder obtained by spray drying, but 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 of these may also be used. 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 using commonly used measurement methods such as the Kjeldahl method or combustion methods including modified Dumas method.

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

The ash content of the fungal powder is not particularly limited, as long as it is a typical ash content for 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, etc., 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, etc. Consistent combinations thereof are also acceptable. For example, 1.4-2.5% by mass, 1.6-2.2% by mass, 1.8-2.0% by mass, 2.0-2.5% by mass, 2.2-2.5% by mass, 1.4-1.8% by mass, 1.4-1.6% by mass, etc. The ash content can be quantified by commonly used methods such as the direct ashing method.

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, 1.0 to 2.9 mass%, 1.2 to 3.0 mass%, 1.4 to 3.1 mass%, 1.5 to 3.2 mass%, 2.5 to 3.3 mass%, 3.0 to 3.4 mass%, 3.2 to 3.5 mass%, 3.3 to 4.0 mass%, 3.4 to 5.0 mass%, 1.0 to 7.0 mass%, 1.0 to 6.0 mass%, etc.
The moisture content of the fungal powder is the amount measured by a normal pressure heat drying method (drying temperature: 105°C).

The dry mass of bacteria in the bacterial powder is not particularly limited as long as it is a normal dry mass in a bacterial powder obtained by spray drying, but 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. A consistent combination thereof is also acceptable, such as 5 to 60% by mass, 10 to 50% by mass, 15 to 40% by mass, etc.
The dry mass of the bacteria is the total weight minus the water content and the amount of starch hydrolysate. The amount of starch hydrolysate can be quantified by a known method such as HPLC.

The bulk density (loose bulk density) of the fungal powder is not particularly limited as long as it is a normal bulk density of fungal powder obtained by spray drying, but is, for example, 0.2 g/cm ³ or more, 0.3 g/cm ³ or more, 0.4 g/cm ³ or more, etc., and on the other hand, for example, 1.0 g/cm ³ or less, 0.8 g/cm ³ or less, 0.7 g/cm ³ or less, etc. Consistent combinations of these are also acceptable, such as 0.2 to 1.0 g/cm ³ , 0.3 to 0.8 g/cm ³ , 0.4 to 0.7 g/cm ³ , etc.
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)).

The bacterial powder obtained in the above embodiment can be used by adding it to food and drink, for example.
Food and drink products include tablets, liquid foods, beverages, feed (including for pets), etc., regardless of whether they are in liquid, paste, solid, powder, etc., 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, compound seasonings, frozen foods, and confectioneries.

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 drinks, soy milk, soy milk drinks, coffee drinks, tea drinks, powdered drinks, concentrated drinks, sports drinks, nutritional drinks, alcoholic drinks, and beverages.
Examples of flour products include bread, macaroni, spaghetti, noodles, cake mix, fried chicken flour, breadcrumbs, etc.
Examples of instant foods include instant noodles, cup noodles, retort/prepared foods, canned foods, microwave foods, instant soups/stews, instant miso soup/cleaning liquids, canned soups, freeze-dried foods, and the like.
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 (fish stew).
Examples of processed livestock products include canned livestock products and pastes, livestock ham and sausages, etc.
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, vegetable oils, etc.
Examples of basic seasonings include soy sauce, miso, sauces, tomato-based seasonings, mirin, and vinegars.
Examples of complex seasonings include cooking mixes, curry bases, sauces, dressings, noodle soups, and spices.
Examples of frozen foods include raw frozen 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 snacks, bean snacks, and dessert sweets.
Examples of foods other than those mentioned above include baby food, furikake, and ochazuke nori seaweed.

The food and drink products can be produced by adding the bacterial powder obtained in the above-described manner to the raw materials of ordinary food and drink products, and can be produced in the same manner as ordinary food and drink products, except for the addition of the bacterial powder obtained in the above-described manner. The bacterial powder obtained in the above-described manner can be added at any stage in the production process of the food and drink products.

Another aspect of the present invention is
containing bacteria and starch hydrolysates,
The viscosity at 10°C is 75 mPa s or more and is subjected to spray drying.
It is a composition.

Here, "subjected to spray drying" means to be powdered using a spray dryer. Furthermore, in the present invention, a composition to be subjected to spray drying is a liquid composition that can be suitably powdered using a spray dryer, and can also be called a "composition for spray drying."

The explanations for the bacteria, starch hydrolysate, viscosity at 10°C, and spray drying in this embodiment are the same as those in the previous embodiment.

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, when spray-dried to produce a bacterial powder, the bacterial powder has good dispersibility when dispersed in a solvent or solution, has a good yield, and the bacterial count ratio in the resulting bacterial powder is equivalent to that of conventional products. For example, the form of a mixed liquid is exemplified. The explanation of the mixed liquid is as set forth in the previous embodiment.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples. Percentages are expressed by weight unless otherwise specified.

[Test Example 1]
<1. Bacteria powder production>
(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 culture solution. The culture solution was then sterilized. The obtained bacterial solution had a solid content of 15% by mass, contained 4.4 x ¹⁰ cells/g of bacteria, and had a viscosity of approximately 14 mPa s at 10°C.

(2) Preparation of Mixed Liquids A starch hydrolysate (manufactured by Matsutani Chemical Industry Co., Ltd., DE value 15 to 18) was 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 as Samples No. 1 to 6, respectively, as described below.
The blending ratio of the starch hydrolysates in each mixed solution (ratio of starch hydrolysates to the total mass of the bacterial solution and starch hydrolysates) and viscosity at 10°C are shown in Table 2.

(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.

2. Evaluation
The viscosity of the mixed liquid at 10° C. was measured using a Brookfield viscometer (TVB-10M, manufactured by Toki Sangyo Co., Ltd.) (rotor used: TM1).
The dispersibility of the resulting bacterial powder was evaluated by adding 100 ml of purified water at 20°C to a 200 ml beaker, adding 1 g of bacterial powder at once while stirring at 500 rpm using a stirrer (NISSIN SLOW STIRRER SW-500SD), continuing stirring for a certain period of time, and visually observing the formation of clumps at a certain time after the end of addition. A: The bacterial powder was dispersed and clumps disappeared within 1 minute after the addition (better), B: The bacterial powder was dispersed and clumps disappeared within 1 to 3 minutes after the addition (good), and C: The clumps did not disappear even after stirring for 3 minutes or more after the addition (unsuitable).
The yield was rated as A: 80% or more (better), B: more than 50% but less than 80% (good), and C: 50% or less (unsuitable).
The viscosity, rotation speed, dispersibility and yield at 10° C. were as shown in Table 2.
In addition, "Reference" in the table refers to the case where the bacterial solution obtained in (1) above was used.

Regarding dispersibility, Sample No. 1 was unsatisfactory, but Samples Nos. 2 to 6, which had higher viscosities, were good.
The yield of samples No. 1 to No. 4 was higher than 80%, which was better. On the other hand, samples No. 5 and No. 6 were inferior to samples No. 1 to No. 4, but sample No. 5 was acceptable and was judged to be good. Sample No. 6 had a yield of less than 50%, which meant that production efficiency was low and was considered unsuitable for long-term production.
The composition and number of bacteria in each bacterial powder are shown in Table 3.
Here, the bacterial ratio (%) and the starch hydrolysate ratio (%) refer to the ratio of the solid content (dry weight) derived from the bacterial liquid 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.

[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 so that the solid content was 15% by mass, and then sterilized.
Next, a starch hydrolysate ("NSD500" manufactured by Sanei Sugar Chemical Co., Ltd., DE value 12 to 15), a starch hydrolysate ("Matsutani Chemical Industry Co., Ltd., DE value 15 to 18), or a starch hydrolysate ("Pine Oligo 20" manufactured by Matsutani Chemical Industry Co., Ltd., DE value 21 to 25) was added to the bacterial solution, and three types of mixed solutions with different viscosities and solid contents of approximately 45% by mass were prepared (Samples No. 7 to 9).
The viscosity and other properties of each mixed liquid at 10°C are shown in Table 4.
In addition, "Reference" in the table refers to the case where the bacterial solution before the addition of the starch hydrolysate was used.

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, it was suggested that for Bifidobacterium breve FERM BP-11175, starch hydrolysates with a DE value of 15 to 20 are preferred, and for example, starch hydrolysates with a DE value of 15 to 18 are preferred.

[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. The bacterial culture solution was prepared so that the solid content was 15% by mass, and then sterilized.
Next, a starch hydrolysate (manufactured by Matsutani Chemical Industry Co., Ltd., DE value 28 to 36) or a starch hydrolysate (manufactured by Matsutani Chemical Industry Co., Ltd., DE value 15 to 18) was added to the bacterial solution, and two types of mixed solutions with different viscosities and solid contents of approximately 40% by mass were prepared (Samples No. 10 and 11).
The viscosity and other properties of each mixed liquid at 10°C are shown in Table 5.
In addition, "Reference" in the table refers to the case where the bacterial solution before the addition of the starch hydrolysate was used.

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 having a DE value higher than 18 (i.e., a DE value of more than 18) are preferred, for example, starch hydrolysates having a DE value of 28 to 36 are preferred.

[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. The bacterial cell culture solution was prepared so that the solid content was 15% by mass, and then sterilized.
Next, a starch hydrolysate ("NSD500" manufactured by Sanei Sugar Chemical Co., Ltd., DE value 12 to 15) or a starch hydrolysate (manufactured by Matsutani Chemical Industry Co., Ltd., DE value 15 to 18) was added to the bacterial solution, and two types of mixed solutions with different viscosities and solid contents of approximately 40% by mass were prepared (Samples No. 12 and 13).
The viscosity and other properties of each mixed liquid at 10°C are shown in Table 6.
In addition, "Reference" in the table refers to the case where the bacterial solution before the addition of the starch hydrolysate was used.

The viscosities of Samples No. 12 and 13 were 322 mPa·s and 775 mPa·s, respectively, suggesting that both may be suitable for spray drying.
Furthermore, it was suggested that for Bifidobacterium longum subsp. longum, starch hydrolysates having a DE value of 12 or more are preferred, for example, starch hydrolysates having a DE value of 12 to 15 or a DE value of 15 to 18 are preferred.

[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. The bacterial cell culture solution was prepared so that the solid content was 12% by mass, and then sterilized.
Next, a starch hydrolysate ("NSD500" manufactured by Sanei Sugar Chemical Co., Ltd., DE value 12 to 15), a starch hydrolysate ("Matsutani Chemical Industry Co., Ltd., DE value 15 to 18), or a starch hydrolysate ("Pine Oligo 20" manufactured by Matsutani Chemical Industry Co., Ltd., DE value 21 to 25) was added to the bacterial solution, and three types of mixed solutions with different viscosities and solid contents of approximately 45% by mass were prepared (Samples No. 14 to 16).
The viscosity and other properties of each mixed liquid at 10°C are shown in Table 7.
In addition, "Reference" in the table refers to the case where the bacterial solution before the addition of the starch hydrolysate was used.

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, it was suggested that for Bifidobacterium breve NITE BP-02622, starch hydrolysates with a DE value of 12 to 20 are preferred, and for example, starch hydrolysates with a DE value of 12 to 15 or 15 to 18 are preferred.

[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 in the same manner as in Test Example 1. The bacterial cell culture solution was prepared so that the solid content was 11% by mass, and then sterilized.
Next, a starch hydrolysate ("NSD500" manufactured by Sanei Sugar Chemical Co., Ltd., DE value 12 to 15), a starch hydrolysate ("Matsutani Chemical Industry Co., Ltd., DE value 15 to 18), or a starch hydrolysate ("Pine Oligo 20" manufactured by Matsutani Chemical Industry Co., Ltd., DE value 21 to 25) was added to the bacterial solution, and two types of mixed solutions with different viscosities and solid contents of approximately 40% by mass were prepared (Samples No. 17 to 19).
The viscosity and other properties of each mixed liquid at 10°C are as shown in Table 8.
In addition, "Reference" in the table refers to the case where the bacterial solution before the addition of the starch hydrolysate was used.

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 having a DE value of 20 or less are preferred, and for example, starch hydrolysates having a DE value of 12 to 20, 12 to 15, or 15 to 18 are preferred.

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

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, it was suggested that for Lactobacillus acidophilus NITE BP-01695, 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 starch hydrolysates with a DE value of 21 to 25 are preferred.

[comprehensive evaluation]
For bacteria of the genus Lacticaceibacillus, the results of Test Example 1 suggest that starch hydrolysates with a DE value of 15 to 18 are preferable.
For Lactobacillus bacteria, the results of Test Example 3 and Test Example 7 suggest that starch hydrolysates with a DE value higher than 18 (i.e., a DE value greater than 18) are preferred, and for example, starch hydrolysates with a DE value of 21 to 25 or a DE value of 28 to 36 are preferred.
For Bifidobacterium bacteria, the results of Test Examples 2, 4, and 5 suggest that starch hydrolysates with a DE value of 15 to 20 are preferred, and 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, and for example, starch hydrolysates with a DE value of 12 to 20, 12 to 15, or 15 to 18 are preferred.
For Bifidobacterium breve, the results of Test Examples 2 and 5 suggest that a starch hydrolysate having a DE value of 15 to 20 is preferred, and for example, a starch hydrolysate having a DE value of 15 to 18 is preferred.
For Bifidobacterium longum subsp. longum, the results of Test Example 4 suggest that starch hydrolysates having a DE value of 12 or more are preferred, and for example, starch hydrolysates having a DE value of 12 to 15 or a DE value of 15 to 18 are preferred.
For Bifidobacterium breve FERM BP-11175, the results of Test Example 2 suggest that a starch hydrolysate having a DE value of 15 to 20 is preferred, for example, a starch hydrolysate having a DE value of 15 to 18 is preferred.
With regard to Bifidobacterium breve NITE BP-02622, the results of Test Example 5 suggest that starch hydrolysates having a DE value of 12 to 20 are preferred, and for example, starch hydrolysates having a DE value of 12 to 15 or a DE value of 15 to 18 are preferred.
For Lactobacillus helveticus, the results of Test Example 3 suggest that starch hydrolysates having a DE value higher than 18 (i.e., a DE value of more than 18) are preferred, and for example, starch hydrolysates having 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 (16)

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;
A method for producing a bacterial powder, comprising a spray drying step of spray-drying the mixed liquid to obtain a bacterial powder. The manufacturing method according to claim 1, wherein the bacteria are bacteria of the genus Bifidobacterium, Lacticaseibacillus, Lactobacillus, or Lactococcus. The manufacturing method described in claim 2, wherein the bacterium is a bacterium of the genus Lacticaseibacillus, and the DE value of the starch hydrolysate is 15 to 18. The manufacturing method described in claim 2, wherein the bacterium is a Lactobacillus bacterium and the DE value of the starch hydrolysate is higher than 18. The manufacturing method described in claim 2, wherein the bacteria are Bifidobacterium bacteria and the DE value of the starch hydrolysate is 15 to 20. The manufacturing method described in claim 2, wherein the bacterium is a Lactococcus bacterium and the DE value of the starch hydrolysate is 20 or less. The manufacturing method described in claim 2, wherein the bacterium is Bifidobacterium breve and the DE value of the starch hydrolysate is 15 to 20. The production method described in claim 2, wherein the bacterium is Bifidobacterium longum subsp. longum, and the DE value of the starch hydrolysate is 12 or higher. containing bacteria and starch hydrolysates,
The viscosity at 10°C is 75 mPa s or more and is subjected to spray drying.
composition. The composition according to claim 9, wherein the bacteria are bacteria of the genus Bifidobacterium, Lacticaseibacillus, Lactobacillus, or Lactococcus. 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. 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. 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. 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. The composition according to claim 10, wherein the bacterium is Bifidobacterium breve and the DE value of the starch hydrolysate is 15 to 20. 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.