Method for producing aged meat, method for aging meat, meat modifying agent, and method for producing meat modifying agent

Abstract

This method for producing aged meat comprises bringing meat into contact with a lactic acid bacteria-fermented liquid and wet-aging the meat brought into contact with the fermented liquid. The fermented liquid preferably contains table salt.

Description

Method for producing aged meat, method for aging meat, meat modifier, and method for producing meat modifier

[0001] This invention relates to a method for producing aged meat using lactic acid bacteria and a method for aging meat. Furthermore, this invention relates to a meat modifier containing lactic acid bacteria and a method for producing the same.

[0002] Beef, pork, and other meats are often aged to enhance their flavor and umami, and to make them more tender. There are various aging methods, but they can be broadly divided into dry aging and wet aging.

[0003] Of these aging methods, dry aging is a more costly method than wet aging because it requires time for aging and necessitates the removal of dried surface areas and areas where microorganisms such as mold have proliferated. In contrast, wet aging is more hygienic because contact with air is blocked during aging, thus suppressing drying and microbial contamination. Therefore, wet aging tends to be the preferred method of aging.

[0004] Patent Document 1 discloses a method for aging pork, in which vacuum-packed pork is stored at 4°C for 10 to 30 days.

[0005] Japanese Patent Application Publication No. 08-098644

[0006] However, conventional methods for aging meat required long periods of aging (for example, 10 days or more) to improve the texture and flavor of the meat. Therefore, there was room for improvement in the productivity of aged meat production.

[0007] Therefore, the first object of the present invention is to provide a method for producing aged meat, a method for aging meat, and a meat modifier that can produce aged meat with enhanced umami flavor and a soft texture that is highly palatable in a short period of time.

[0008] Furthermore, a second object of the present invention is to provide a method for producing a meat modifier with excellent storage stability.

[0009] The present invention provides the following:

[0010] <1> A method for producing aged meat, comprising contacting meat with a fermentation liquid of lactic acid bacteria and wet aging the meat that has been contacted with the fermentation liquid. <2> The method for producing aged meat according to <1>, wherein the fermentation liquid contains salt. <3> The method for producing aged meat according to <2>, wherein the salt contains sodium chloride, and the fermentation liquid has a sodium chloride content of 0.7 to 2% by mass. <4> The method for producing aged meat according to any one of <1> to <3>, wherein the fermentation liquid is a milk fermentation liquid. <5> The method for producing aged meat according to any one of <1> to <4>, wherein the lactic acid bacteria include lactic acid bacteria that satisfy the following condition 1: Condition 1: When the target lactic acid bacteria are cultured at the optimal temperature using a culture medium containing milk raw materials, the time required to lower the pH to 4.5 is 4 hours or more. <6> The method for producing aged meat according to any one of <1> to <5>, wherein the lactic acid bacteria include Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus). <7> A method for producing aged meat according to any one of <1> to <6>, wherein the above fermentation liquid is brought into contact with the above meat in an amount of 5 to 30% by mass relative to the weight of the meat. <8> A method for producing aged meat according to any one of <1> to <7>, wherein the meat that has been brought into contact with the above fermentation liquid is wet-aged by vacuum packaging or gas-purged packaging together with the above fermentation liquid. <9> A method for producing aged meat according to any one of <1> to <8>, wherein the wet aging is carried out at a temperature of 10°C or lower for 3 days or more. <10> A method for aging meat, wherein the meat is brought into contact with a fermentation liquid of lactic acid bacteria, and the meat that has been brought into contact with the above fermentation liquid is wet-aged. <11> A method for aging meat according to <10>, wherein the lactic acid bacteria include Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus). <12> A meat modifier containing salt and lactic acid bacteria. <13> A meat modifier according to <12>, which is in liquid form. <14> A meat modifier according to <12> or <13>, which is a milk fermentation liquid. <15> A meat modifier according to any one of <12> to <14>, wherein the salt contains sodium chloride, and the meat modifier has a sodium chloride content of 0.7 to 2% by mass.<16> A meat modifier according to any one of <12> to <15>, comprising two or more types of lactic acid bacteria. <17> A meat modifier according to any one of <12> to <16>, wherein the lactic acid bacteria include lactic acid bacteria that satisfy the following condition 1: Condition 1: When the target lactic acid bacteria are cultured at the optimal temperature using a culture medium containing milk raw materials, the time required to lower the pH to 4.5 is 4 hours or more. <18> A meat modifier according to any one of <12> to <17>, wherein the lactic acid bacteria include Lactobacillus lactic acid bacteria. <19> A meat modifier according to <18>, wherein the lactic acid bacteria further include Streptococcus thermophilus. <20> A meat modifier according to <19>, wherein the Streptococcus thermophilus has the prtS(+) gene. <21> The meat modifier according to any one of <18> to <20>, wherein the Lactobacillus lactic acid bacteria include Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus). <22> The meat modifier according to any one of <18> to <21>, wherein the Lactobacillus lactic acid bacteria is Lactobacillus delbrueckii classified into one of clusters I, II, III, and V in the MLSA classification based on seven housekeeping genes consisting of the fusA gene, gyrB gene, hsp60 gene, ileS gene, pyrG gene, recA gene, and recG gene. <23> A method for producing a meat modifier, comprising fermenting a fermentation base containing salt using lactic acid bacteria. <24> The salt includes sodium chloride, and the salt is added in an amount of 0.7 to 2% by mass relative to the fermentation base material, as described in <23>. <25> The lactic acid bacteria include lactic acid bacteria that satisfy the following condition 1, as described in <23> or <24>; Condition 1: When the target lactic acid bacteria are cultured at the optimal temperature using a culture medium containing milk raw materials, the time required to lower the pH to 4.5 is 4 hours or more.<26> The above lactic acid bacteria include lactic acid bacteria that satisfy the relationship in formula (1), a method for producing the meat modifier described in any one of <23> to <25>; D30 - D1 ≤ 0.25 ... (1) In formula (1), D1 is the acidity (unit: %) of the fermented product when the target lactic acid bacteria are added to a milk preparation solution containing raw milk, the milk preparation solution is fermented at 43°C until its pH becomes 4.65, the fermented product is allowed to stand and cooled to 5°C, left to stand at 5°C for 1 day, and then stored at 10°C for 1 day; D30 is the acidity (unit: %) of the fermented product when the target lactic acid bacteria are added to a milk preparation solution containing raw milk, the milk preparation solution is fermented at 43°C until its pH becomes 4.65, the fermented product is allowed to stand and cooled to 5°C, left to stand at 5°C for 1 day, and then stored at 10°C for 30 days. <27> A method for producing a meat modifier according to any one of <23> to <26>, wherein the lactic acid bacteria include Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus).

[0011] According to the present invention, it is possible to provide a method for producing aged meat, a method for aging meat, and a meat modifier that can produce aged meat with enhanced umami flavor and a tender texture in a short period of time, making it highly palatable.

[0012] Furthermore, the method for producing the meat modifier of the present invention makes it possible to produce a meat modifier with excellent storage stability.

[0013] This is a schematic diagram of a food property evaluation device. This figure shows the total impulse after 90 compressions using the food property evaluation device shown in Figure 1. This figure shows the change in impulse (moving average of impulse every 5 seconds) when compressed 90 times using the food property evaluation device shown in Figure 1. This figure shows the ratio of the area of ​​the compressed sample to the area of ​​the sample before compression, with the area of ​​the sample before compression being set to 1, when compressed using the food property evaluation device shown in Figure 1. This figure shows the sample before compression and the sample after 10 or 30 compressions using the food property evaluation device shown in Figure 1, placed on a 16M mesh. This figure shows the total impulse after 90 compressions for untreated, and aged samples of 1 day, 3 days, and 5 days, measured using the food property evaluation device shown in Figure 1. This figure shows the impulse at the time of the first compression measured using the food property evaluation device shown in Figure 1. This figure shows the total impulse after 90 compressions measured using the food property evaluation device shown in Figure 1. This figure shows the change in impulse (moving average of impulse every 4 seconds) when compressed 90 times using the food property evaluation device shown in Figure 1, when using the meat modifier obtained in Production Example 3. This figure shows the change in impulse (moving average of impulse every 4 seconds) when the meat modifier obtained in Production Example 4 is compressed 90 times using the food property evaluation device shown in Figure 1. This figure shows the change in impulse (moving average of impulse every 4 seconds) when the meat modifier obtained in Production Example 5 is compressed 90 times using the food property evaluation device shown in Figure 1. This figure shows the change in impulse (moving average of impulse every 4 seconds) when the meat modifier obtained in Production Example 6 is compressed 90 times using the food property evaluation device shown in Figure 1. This figure shows the change in impulse (moving average of impulse every 4 seconds) when the meat modifier obtained in Production Example 7 is compressed 90 times using the food property evaluation device shown in Figure 1. This figure shows the change in impulse (moving average of impulse every 4 seconds) when the meat modifier obtained in Production Example 8 is compressed 90 times using the food property evaluation device shown in Figure 1.

[0014] <Method for producing aged meat, method for aging meat> The present invention provides a method for producing aged meat, characterized by contacting meat with a fermentation solution containing lactic acid bacteria, and then wet aging the meat that has been contacted with the fermentation solution.

[0015] Furthermore, the present invention's method for aging meat is characterized by contacting meat with a fermentation solution containing lactic acid bacteria, and then wet aging the meat that has been contacted with the fermentation solution.

[0016] According to the present invention, by wet aging meat that has been in contact with the fermented liquid of the above-mentioned lactic acid bacteria, it is possible to obtain aged meat with enhanced umami and a tender texture, which is highly palatable, in a short period of time (for example, 1 to 7 days). Although the detailed reasons for obtaining such effects are unknown, it is presumed that by wet aging the meat while it is in contact with the fermented liquid of the lactic acid bacteria, the proteolytic effect of the lactic acid bacteria breaks down the meat proteins and produces flavor-enhancing amino acids (especially glutamic acid), thereby enhancing the umami. Furthermore, regarding the tenderizing effect of the meat, it is presumed that in addition to the proteolytic effect of the lactic acid bacteria, the marinating effect of organic acids such as lactic acid produced by the lactic acid bacteria also contributes.

[0017] In this specification, "aged meat" refers to meat obtained through the aging process. "Aging" refers to the process that occurs in meat of livestock and poultry immediately after rigor mortis, resulting in changes in meat quality that improve palatability. Changes that occur during the aging process include a series of changes that improve palatability, such as a decrease in pH due to lactic acid production in the muscle, softening of the meat due to weakening of tissues such as Z-lines and connective tissue that make up myofibrils, improved water retention, and improved umami and aroma due to the accumulation of peptides and amino acids. These changes are due to enzymatic reactions of endogenous proteases such as calpain and cathepsin, and exo-proteases such as aminopeptidases, which are endogenous to the meat. In this specification, "method for aging meat" refers to a method for storing meat that yields the above-mentioned aging effects. Furthermore, in this specification, "aged meat" is a concept that includes fermented meat. "Fermented meat" refers to meat whose meat quality has been altered by microorganisms or their products.

[0018] In this specification, "wet aging" refers to a method of maturing meat by packaging it under reduced pressure or gas displacement and storing it at low temperatures.

[0019] In this specification, "meat" refers to meat intended for consumption, and mainly refers to meat derived from livestock, poultry, and other wild animals that is used for food. Examples of livestock include pigs, cattle, sheep, goats, horses, camels, rabbits, and alpacas; examples of poultry include chickens, pigeons, ducks, geese, and quail; and examples of wild animals include deer, wild boars, and bears. The meat used in this invention is preferably beef or pork. The shape of the meat is not particularly limited. Examples include bone-in cuts, cuts of meat, and sliced ​​meat.

[0020] In the present invention's method for producing aged meat and for aging meat, the meat may be pre-treated by washing, drying, cutting, or compressing before being brought into contact with the fermentation solution of lactic acid bacteria.

[0021] In the present invention's method for producing aged meat and for aging meat, it is preferable to contact the meat with a fermentation solution of lactic acid bacteria at an amount of 5 to 30% by mass relative to the meat's weight (wet weight). According to this embodiment, when the resulting aged meat is grilled, the generation of drip and other issues can be suppressed, and grilled meat with a beautiful char can be obtained. The upper limit of the amount of the fermentation solution is preferably 29% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, relative to the meat's weight (wet weight). The lower limit of the amount of the fermentation solution is preferably 5% by mass or more, more preferably 7% by mass or more, and even more preferably 9% by mass or more, relative to the meat's weight (wet weight). Details of the fermentation solution will be described later.

[0022] In the present invention's method for producing aged meat and for aging meat, it is preferable to wet age meat that has been in contact with a fermentation solution of lactic acid bacteria by vacuum packaging or gas displacement packaging together with the fermentation solution of lactic acid bacteria, and it is more preferable to wet age meat that has been in contact with a fermentation solution of lactic acid bacteria by vacuum packaging together with the fermentation solution of lactic acid bacteria.

[0023] The above-mentioned "vacuum packaging or gas-filled packaging" preferably involves placing meat that has been in contact with a fermentation liquid containing lactic acid bacteria into a gas-impermeable packaging container, removing the air inside the container (vacuum packaging) or replacing it with nitrogen gas (gas-filled packaging), and then sealing it. The gas-impermeable packaging container may be made of a single-layer material or a multi-layer material. In the case of a multi-layer structure, it is sufficient that at least one layer is made of a gas-impermeable material. Examples of multi-layer packaging containers include laminates made of a metal layer and a resin layer, and laminates including at least one gas-impermeable resin layer.

[0024] The pressure (vacuum level) inside the container during the above-mentioned vacuum packaging is 10 ５ It is preferable that it be Pa or less, 10 ２ It is more preferable that the pressure be less than or equal to Pa.

[0025] The above wet aging is preferably carried out at a temperature of 10°C or less for one day or more, and more preferably for three days or more. The lower limit of the wet aging temperature is preferably -1°C or higher, more preferably 0°C or higher, even more preferably 0.5°C or higher, and even more preferably 1°C or higher. The upper limit of the wet aging temperature is preferably 5°C or lower, more preferably 3°C or lower, and even more preferably 2°C or lower. The upper limit of the wet aging period is preferably 10 days or less, more preferably 8 days or less, even more preferably 7 days or less, and even more preferably 5 days or less.

[0026] Next, the fermentation liquid of lactic acid bacteria used in the method for producing aged meat and the method for aging meat of the present invention will be described.

[0027] The above fermentation liquid contains lactic acid bacteria. Lactic acid bacteria are a general term for microorganisms that utilize glucose to produce lactic acid with a sugar yield of 50% or more. Physiologically, they are Gram-positive cocci or bacilli, non-motile, non-spore-forming, and catalase-negative. Examples of lactic acid bacteria include those of the Lactococcus genus (e.g., Lactococcus lacticis subsp.). Examples include those classified into the genera Lactobacillus, Leuconostoc, Pediococcus, Streptococcus, Wissella, Tetragenococcus, Oenococcus, Enterococcus, Vagococcus, Carnobacterium, and Bifidobacterium. All of these lactic acid bacteria can be used in the fermentation liquid described above.

[0028] The above fermentation broth preferably contains lactic acid bacteria of the genus Lactobacillus. Examples of lactic acid bacteria of the genus Lactobacillus include Lactobacillus gasseri, Lactobacillus paragasseri, Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacillus acidophilus, Lactobacillus crispatus, Amycolactobacillus amylovorus, Lactobacillus kefiranofaciens (including Lactobacillus kefiranofaciens subsp. kefiranofaciens), Lactobacillus delbrueckii, etc., and it is preferably Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus). Further, in one embodiment of the present invention, at least one selected from the group consisting of Lactobacillus gasseri and Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus) can be used.

[0029] The above fermentation broth preferably contains two or more types of lactic acid bacteria. At least one of the two or more types of lactic acid bacteria is preferably a lactic acid bacterium of the genus Lactobacillus, more preferably Lactobacillus gasseri or Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus), and still more preferably Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus).

[0030] Lactobacillus delbrueckii (hereinafter, sometimes referred to as "L. delbrueckii") is a bacterium classified into the Delbrueckii species of the genus Lactobacillus, and subspecies such as Lactobacillus delbrueckii subsp. delbrueckii, Lactobacillus delbrueckii subsp. lactis, Lactobacillus delbrueckii subsp. indicus, Lactobacillus delbrueckii subsp. sunkii, and Lactobacillus delbrueckii subsp. jakobsenii are known. Among these, an embodiment using one or more of Lactobacillus delbrueckii subsp. indicus, Lactobacillus delbrueckii subsp. lactis, Lactobacillus delbrueckii subsp. jakobsenii, and Lactobacillus delbrueckii subsp. delbrueckii is also one of the preferred embodiments of the present invention.

[0031] L. delbrueckii includes L. delbrueckii that can decompose lactose (lactose) into glucose and galactose and use it as an energy source, that is, L. delbrueckii with lactose-assimilating ability (hereinafter, sometimes referred to as "L. delbrueckii Lac(+)"), and L. delbrueckii that cannot use lactose as an energy source, that is, L. delbrueckii without lactose-assimilating ability (hereinafter, sometimes referred to as "L. delbrueckii Lac(-)").

[0032] The method for confirming whether L. delbrueckii has lactose-assimilating ability is not particularly limited. For example, in a medium containing lactose as a single sugar source, even if cultured at an appropriate temperature and appropriate pH for 48 hours, it can be confirmed by the fact that lactose in the medium cannot be decomposed into glucose and galactose or the pH of the medium does not change due to lactic acid.

[0033] Lactobacillus delbrookii is not particularly limited and may be selected from the known subspecies mentioned above, but it is preferable that it be Lactobacillus delbrookii classified in one of clusters I, II, III, and V in the MLSA classification based on seven housekeeping genes consisting of the fusA gene, gyrB gene, hsp60 gene, ileS gene, pyrG gene, recA gene, and recG gene, for the reason that it can suppress the decrease in pH and increase in acidity during the aging of meat and produce aged meat with enhanced umami, and the following conditions (i) to (vii): (i) Possesses a fusA gene with allele number 2 or 14, (ii) Possesses a gyrB gene with allele number one selected from 3, 17, 18, and 25, (iii) Possesses an hsp60 gene with allele number one selected from 4, 18, 26, and 27 It is more preferable that the L. delbrookii is selected from the group consisting of L. delbrookii that satisfies all of the following conditions: (iv) possessing an ileS gene with allele number selected from 16, 20, 21, 30, and 33; (v) possessing a pyrG gene with allele number 22 or 23; (vi) possessing a recA gene with allele number selected from 2, 7, 24, and 28; and (vii) possessing a recG gene with allele number 3, as well as at least one L. delbrookii that is classified in the same cluster as L. delbrookii that satisfies all of the above conditions (i) to (vii) in the MLSA classification based on seven housekeeping genes consisting of the fusA gene, gyrB gene, hsp60 gene, ileS gene, pyrG gene, recA gene, and recG gene.

[0034] In this specification, "fusA gene" refers to the gene encoding the elongation factor EF-2 (protein elongation factor ES-2), "gyrB gene" refers to the gene encoding DNA gyrase subunit B, "hsp60 gene" refers to the gene encoding heat shock protein 60, "ileS gene" refers to the gene encoding isoleucyl-tRNA synthase, "pyrG gene" refers to the gene encoding CTP synthase, and "recA gene" refers to the gene encoding recombinase A. A) shows the gene encoding the function, and "recG gene" refers to the gene encoding ATP-dependent DNA helicase. All seven of these genes are essential housekeeping genes for the maintenance and proliferation of L. delbruckii.

[0035] MLSA classification based on these seven housekeeping genes is a classification method using multilocus sequence analysis (MLSA). For each bacterial strain, a sequence (concatenated sequence) is obtained by concatenating the base sequences of each of the above-mentioned housekeeping genes. A phylogenetic tree is then constructed using the obtained concatenated sequence, and the bacterial strains are classified into clusters based on the resulting phylogenetic tree.

[0036] The linked sequence for each strain is obtained by linking the nucleotide sequences of the seven acquired genes in the following order: fusA gene, gyrB gene, hsp60 gene, ileS gene, pyrG gene, recA gene, and recG gene. A conventionally known method can be appropriately used to construct a phylogenetic tree using the above linked sequence. For example, the above phylogenetic tree can be constructed using software such as Genetyx v. 13 (manufactured by Genetyx Corporation), but the unweighted pair group method with arithmetic mean (UPGMA) is preferred.

[0037] L. delbruckie is classified as one of the clusters I, II, III, or V in the MLSA classification mentioned above. It is preferable that the L. is Delbruckii, and that it satisfies all of the following conditions (i) to (vii): (i) possesses a fusA gene with allele number 2 or 14, (ii) possesses a gyrB gene with allele number 3, 17, 18, and 25, (iii) possesses an hsp60 gene with allele number 4, 18, 26, and 27, (iv) possesses an ileS gene with allele number 16, 20, 21, 30, and 33, (v) possesses a pyrG gene with allele number 22 or 23, (vi) possesses a recA gene with allele number 2, 7, 24, and 28, (vii) possesses a recG gene with allele number 3. It is more preferable that the species is selected from the group consisting of L. delbruckii and L. delbruckii classified in the same cluster (cluster I in Figure 1) as L. delbruckii that satisfy all of the above conditions (i) to (vii) in the MLSA classification, and even more preferable that the species is selected from the group consisting of L. delbruckii that satisfy all of the above conditions (i) to (vii) and L. delbruckii classified in the same subcluster as L. delbruckii that satisfy all of the above conditions (i) to (vii).

[0038] "L. delbruckii classified into any of clusters I, II, III, and V (hereinafter referred to as "L. delbruckii (I, II, III, V)" as may be used)" refers to any L. delbruckii classified into clusters II, III, and V (excluding cluster IV) among the four clusters (clusters II to V) that are sequentially classified using the non-weighted combination method, where cluster I is the cluster to which L. delbruckii that satisfies all of the above conditions (i) to (vii) are classified, and any L. delbruckii classified into cluster I. Clusters I to V may be further divided into subclusters. Among these, L. delbruckii classified into cluster I is preferred.

[0039] A list of allele numbers, base sequences, and polymorphism sites for the seven housekeeping genes comprising the fusA gene, gyrB gene, hsp60 gene, ileS gene, pyrG gene, recA gene, and recG gene according to the present invention is described in Tables 1 to 3 and Figures 2A to 8E of Japanese Patent Application Publication No. 2020-137517, and these contents are incorporated herein by reference.

[0040] L satisfies all of the above conditions (i) to (vii). A preferred example of Delbrucky is when the allele numbers of the enucleating housekeeping genes it possesses are 2, 3, 4, 16, 22, 2, 3; 2, 3, 4, 21, 22, 7, 3; 2, 3, 4, 21, 23, 7, 3; 2, 3, 4, 21, 23, 7, 3; 2, 3, 18, 21, 22, 2, 3; 2, 3, 18, 21, 22, 7, 3; 2, 3, 18, 21, 23, 2, 3; 2, 3, 18, 30, 22, 7, 3; 2, 18, 4, 16, 22, 7, 3; 2, 18, 4, 16, 23, 7, 3; 2, 25, 18, 21, 22, 28, 3; Examples include L. Delbrucky, which is 14, 17, 18, 20, 22, 7, 3; 14, 17, 18, 21, 22, 7, 3; 14, 17, 18, 21, 22, 24, 3; 14, 17, 18, 33, 22, 7, 3; 14, 17, 26, 21, 22, 7, 3; or 2, 3, 27, 21, 22, 7, 3.

[0041] L. delbruckii is more preferably at least one species selected from the group consisting of L. delbruckii identified by accession number NITE BP-02874 (L. delbruckii NITE BP-02874: strain No. 46 listed in Table 2 of Japanese Patent Publication No. 2020-137517), and L. delbruckii classified in the same cluster (i.e., cluster I) as L. delbruckii identified by accession number NITE BP-02874 in the above MLSA classification, and L. delbruckii classified in the same subcluster as L. delbruckii identified by accession number NITE BP-02874 in the above MLSA classification. It is more preferable that it be at least one species selected from the group consisting of L. delbruckii, and particularly preferable that it be L. delbruckii as specified by accession number NITE BP-02874.

[0042] L. delbrüeckii, identified by accession number NITE BP-02874, is deposited with the above-mentioned depositary institution under the following conditions: (1) Depositary institution: National Institute of Technology and Evaluation Patent Microbial Depositary Center (NPMD) (2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture 292-0818, Room 122), (2) Date of receipt (original deposit date): February 5, 2019, (3) Accession number NITE BP-02874, (4) Identification mark: Lactobacillus delbrüeckii OLL204989. L. delbruckii can be a subculturing of the same strain, or an artificial mutant, a natural mutant, or a genetically modified strain of the same strain or its subculturing, within a range that does not inhibit the effects of the present invention (preferably within a range that satisfies the preferred conditions for L. delbruckii according to the present invention). L. delbruckii identified by accession number NITE BP-02874 is L. delbruckii Lac(+), L. delbruckii (I-B), and the allele numbers of the housekeeping genes it possesses are 2, 3, 18, 21, 22, 2, and 3 in the order of fusA, gyrB, hsp60, ileS, pyrG, recA, and recG.

[0043] The above fermentation liquid preferably contains Streptococcus thermophilus (hereinafter sometimes referred to as "S. thermophilus"), as this provides a stable symbiotic fermentation effect, stabilizes the fermentation, suppresses the decrease in pH and increase in acidity during meat maturation, and allows for the production of aged meat with enhanced umami and a tender texture in a shorter period of time. For this reason, it is even more preferable to include Lactobacillus lactic acid bacteria and S. thermophilus. The Lactobacillus lactic acid bacteria used in combination with S. thermophilus is preferably L. delbruckii.

[0044] When Lactobacillus lactic acid bacteria and S. thermophilus are used in combination, the ratio of Lactobacillus lactic acid bacteria to S. thermophilus is preferably Lactobacillus lactic acid bacteria:S. thermophilus = 1:0.1 to 1:100, and more preferably 1:1 to 1:10.

[0045] The S. thermophilus used in combination with Lactobacillus lactic acid bacteria is preferably S. thermophilus having the prtS(+) gene (hereinafter, sometimes referred to as "S. thermophilus prtS(+)"). In this specification, "prtS gene" refers to a gene that encodes a cell wall-bound serine protease that degrades casein.

[0046] S. Whether or not a Thermophilus possesses the prtS gene can be determined by amplifying a portion of the prtS gene using a primer made from a highly conserved sequence of the prtS gene and determining whether or not a desired PCR product can be obtained. Specifically, this can be determined by the method described in paragraph 0076 of International Publication No. 2022 / 039249.

[0047] Preferably, S. thermophilus prtS(+) is the S. thermophilus specified by accession number NITE BP-02875. The S. thermophilus specified by accession number NITE BP-02875 is S. thermophilus prtS(+) derived from raw milk in Japan. Other examples of S. thermophilus prtS(+) include the S. thermophilus specified by accession number NITE BP-03505.

[0048] The S. thermophilus identified by accession number NITE BP-02875 is deposited with the following details: (1) Depositary: National Institute of Technology and Evaluation Patent Microbial Depositary Center (NPMD) (2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture 292-0818, Room 122), (2) Date of receipt (original deposit date): February 5, 2019, (3) Accession number NITE BP-02875, (4) Identification mark: Streptococcus thermophilus OLS4496. The thermophilus may be a subcultivated strain of the same strain, or, within the limits of satisfying the conditions of the present invention, an artificial mutant, a natural mutant, or a genetically modified strain of the same strain or its subcultivated strain.

[0049] The above fermentation liquid preferably contains L. delbruckii and S. thermophilus, and more preferably contains L. delbruckii and S. thermophilus prtS(+), because it provides a stable symbiotic fermentation effect, stabilizes fermentation, suppresses the decrease in pH and increase in acidity during meat maturation, and allows for the production of aged meat with enhanced umami and a tender texture in a short period of time. Furthermore, the ratio of the bacterial counts of L. delbruckii to S. thermophilus is preferably L. delbruckii:S. thermophilus = 1:0.1 to 1:100, and more preferably 1:1 to 1:10. In another embodiment, the ratio of the bacterial counts of L. delbruckii to S. thermophilus can also be L. delbruckii:S. thermophilus = 1:0.1 to 1:1 million, 1:0.1 to 1:500,000, 1:0.1 to 1:100,000, etc.

[0050] The above fermentation liquid preferably contains lactic acid bacteria that produce little acid. Specifically, the above fermentation liquid preferably contains lactic acid bacteria that satisfy condition 1 below. Examples of such lactic acid bacteria include L. delbruckii, identified by accession number NITE BP-02874, and S. thermophilus, identified by accession number NITE BP-02875.

[0051] Condition 1: When the target lactic acid bacteria are cultured at the optimal temperature using a culture medium containing milk raw materials, the time required to lower the pH to 4.5 is 4 hours or more.

[0052] The optimal temperature during the above-mentioned culture varies depending on the type of lactic acid bacteria, but is preferably 36 to 48°C (preferably 39 to 45°C).

[0053] As the "medium containing milk raw material" used for culturing the above lactic acid bacteria, a skim milk medium can be mentioned. As a preferable embodiment of the skim milk medium, a 10% reduced skim milk medium (pH 6.5) can be mentioned. As the 10% reduced skim milk medium, a medium (reduced skim milk) containing 10% (W / W) of skim milk components, sterilized by appropriate means, for example, a medium sterilized by reaching the temperature of 95°C, can be mentioned. As an example of the composition of skim milk, one having 1% by mass of fat, 34% by mass of protein, 54% by mass of lactose, 8% by mass of ash, and 96% by mass of non-fat milk solids can be mentioned. As an example of the composition of the 10% reduced skim milk medium, one containing 5.4% by mass of lactose content and 9.6% by mass of non-fat milk solids can be mentioned. In addition, no additives such as fermentation promoters shall be added to the medium used when identifying lactic acid bacteria with little acid production (that is, the medium used under condition 1).

[0054] When identifying lactic acid bacteria with little acid production using a skim milk medium as the "medium containing milk raw material", 1.0×10 ４ ~10×10 １０ cfu / g of the bacterial solution is added to the skim milk medium so as to be 1% by mass, and it is preferable to culture at the optimum temperature (for example, 36 to 48°C, preferably 39 to 45°C) and evaluate the time required to lower the pH to 4.5. The addition amount of the lactic acid bacteria is preferably an amount of 5×10 <00000​​​​​​​​​​​​​​​​​​​​​It is more preferable that the amount be cfu / g. Examples of culture media for activated culture include skim milk medium or MRS medium for bacteria belonging to L. delbrüeckii.

[0056] The above fermentation liquid preferably contains lactic acid bacteria that satisfy the relationship in formula (1). Examples of such lactic acid bacteria include L. delbruckii, identified by accession number NITE BP-02874, and S. thermophilus, identified by accession number NITE BP-02875.

[0057] D30 - D1 ≤ 0.25 ... (1) In formula (1), D1 is the acidity (in %) of the fermented product when the target lactic acid bacteria are added to a formula containing raw milk, the formula is fermented at 43°C until the pH of the formula becomes 4.65, the fermented product is allowed to stand, cooled to 5°C, left to stand at 5°C for 1 day, and then stored at 10°C for 1 day. D30 is the acidity (in %) of the fermented product when the target lactic acid bacteria are added to a formula containing raw milk, the formula is fermented at 43°C until the pH of the formula becomes 4.65, the fermented product is allowed to stand, cooled to 5°C, left to stand at 5°C for 1 day, and then stored at 10°C for 30 days.

[0058] The raw milk used in the above-mentioned formula milk solution may include the raw milk described later. Specific examples of the above-mentioned formula milk solution include skim milk culture medium, skim milk culture medium, raw milk, pasteurized milk, whole milk powder dissolution, etc. One embodiment of the above-mentioned formula milk solution is a formula milk solution containing skim milk powder and raw water. An example of the composition of the above-mentioned skim milk powder is one in which the milk fat concentration is 0.1% by mass, the non-fat milk solids concentration is 9.55% by mass, and the solids concentration is 9.65% by mass.

[0059] The above-mentioned fermented liquid is preferably a milk fermented liquid. A milk fermented liquid refers to a fermented product obtained by culturing lactic acid bacteria in a fermentation base material containing raw milk.

[0060] Examples of raw milk products include raw milk, pasteurized milk, skim milk, whole milk powder, skim milk powder, whole milk concentrate, skim milk concentrate, buttermilk, butter, cream, cheese, milk protein concentrate (MPC), whey protein concentrate (WPC), whey protein isolate (WPI), α-lactalbumin (α-La), and β-lactoglobulin (β-Lg). One or more of these can be used.

[0061] The above fermentation base material may further contain materials other than raw milk. Examples include salt, vitamins, stabilizers, thickeners, gelling agents, flavorings, seasonings, enzymes, and colorings. Examples of salt include sodium chloride, monovalent metal ion salts such as potassium chloride, and various organic acid salts. The above fermentation base material preferably contains salt, and more preferably contains sodium chloride. Since salt can suppress the occurrence of coagulation of milk proteins, the fermentation liquid obtained using a fermentation base material containing salt has less syneresis, low viscosity, and excellent storage stability. Furthermore, curd formation is suppressed, and it is easy to handle when in contact with meat.

[0062] The above-mentioned fermentation substrate may be subjected to homogenization treatment, heat sterilization treatment, or the like.

[0063] For the homogenization process, known means and conditions can be employed, such as passing the fermentation substrate through narrow gaps while pressurizing it. The homogenization process is not limited to processes using known homogenizers, but may also be performed using stirring, homomixers, extruders, or other shearing methods.

[0064] The heat sterilization treatment of the fermentation substrate can be carried out using known methods and apparatus. The heat sterilization treatment may be performed by indirect heating or direct heating. The heat sterilization treatment can be carried out using, for example, a plate heat exchanger, a tube heat exchanger, a steam injection heating device, a steam infusion heating device, an electric heating device, or a batch sterilization device (emulsification kettle, kneader, cooker, etc.). The heat sterilization treatment conditions can be appropriately selected from known conditions. For example, the heating temperature can be 70 to 150°C. The heating time can be appropriately adjusted according to the heating temperature. For example, the heating time can be 1 to 300 seconds. Specific examples of heat sterilization treatments include ultra-high temperature (UHT) sterilization, which involves heating at 120-150°C for 2-3 seconds; high temperature short-time (HTST) sterilization, which involves continuous heating at 72-75°C for 15 seconds or more; high temperature long-time (HTLT) sterilization, which involves holding at 75°C or higher for 15 minutes or more; high temperature short-time (HTST) sterilization, which involves continuous heating at 72°C or higher for 15 seconds or more; and ultra-high temperature (LL) sterilization, which involves heating at 135-150°C for 1-4 seconds. Two or more of these methods may be combined. Heat sterilization is preferably performed using either the HTST or UHT method.

[0065] The above fermentation liquid preferably contains salt, and more preferably contains sodium chloride. Fermentation liquid containing salt has less syneresis, low viscosity, and excellent storage stability. In addition, curd formation is suppressed, and handling when in contact with meat is also excellent. The sodium chloride content of the above fermentation liquid is preferably 0.7 to 2% by mass. The lower limit is preferably 0.7% by mass or more, preferably 0.8% by mass or more, and more preferably 0.9% by mass or more. The upper limit is preferably 1.8% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1% by mass or less. If the sodium chloride content is within the above range, the above-mentioned effects can be obtained more significantly. Furthermore, it is possible to produce aged meat with enhanced umami and a soft texture that is highly palatable in a short period of time.

[0066] The number of viable lactic acid bacteria in the above fermentation liquid is 1 x 10⁻⁶. ５~3 x 10 ９ It is preferably cfu / g, 1 × 10 ８ ~2 x 10 ９ It is more preferable that the concentration is cfu / g.

[0067] The solid content concentration of the above fermentation liquid is preferably 6 to 12% by mass. The lower limit is more preferably 8% by mass or more, and more preferably 9% by mass or more. The upper limit is preferably 11% by mass or less, and more preferably 10% by mass or less.

[0068] The fat concentration of the above fermented liquid is preferably 0.05 to 10% by mass. The lower limit is more preferably 0.075% by mass or more, and more preferably 0.1% by mass or more. The upper limit is preferably 5% by mass or less, and more preferably 3% by mass or less.

[0069] The pH of the above fermentation liquid is preferably 4.2 to 5.0. The lower limit is preferably 4.3 or higher, more preferably 4.4 or higher, and even more preferably 4.5 or higher. The upper limit is preferably 4.95 or lower, and more preferably 4.9 or lower.

[0070] The acidity of the above fermentation liquid is preferably 0.4 to 1.0%. The upper limit is preferably 0.9% or less, and more preferably 0.85% or less. The lower limit is preferably 0.5% or more, and more preferably 0.6% or more.

[0071] The viscosity of the above fermentation liquid at 10°C is preferably 10 to 600 mPa·s. The lower limit is preferably 20 mPa·s or more, and more preferably 30 mPa·s or more. The upper limit is preferably 500 mPa·s or less, and more preferably 300 mPa·s or less. The viscosity of the fermentation liquid is the value measured by the method described in the examples below.

[0072] The median diameter of the particle size distribution of the above fermentation liquid is preferably 10 to 30 μm. The upper limit is preferably 25 μm or less. The lower limit is preferably 11 μm or more, and more preferably 12 μm or more. The median diameter is the particle size corresponding to 50% of the integrated distribution curve obtained from the volume-based particle size distribution of the measurement sample. The volume-based particle size distribution of the measurement sample can be determined by laser diffraction scattering. A particle size distribution measuring device using the laser diffraction scattering method is used as the particle size distribution measuring device. For example, the SALD-2200 manufactured by Shimadzu Corporation can be used.

[0073] In the present invention's method for producing aged meat and for aging meat, after wet aging, the meat may be frozen and stored at -20°C or below.

[0074] The aged meat obtained by the method for producing aged meat and the method for aging meat of the present invention can be used after being cooked by conventionally known methods. The cooking method can be appropriately selected according to the purpose and is not particularly limited. Examples include grilling, boiling, steaming, frying, and simmering. These methods may be used individually or in combination of two or more methods. Furthermore, there are no particular limitations on the equipment used for cooking, and known equipment can be appropriately selected. Examples include frying pans, griddles, pots, steamers, microwave ovens, hot plates, toaster ovens, and steam convection ovens. These cooking devices may be used individually or in combination of two or more types.

[0075] <Meat Modifier> Next, the meat modifier of the present invention will be described. The meat modifier of the present invention is characterized by containing salt and lactic acid bacteria.

[0076] The lactic acid bacteria used in meat modifiers include those described in the sections on the fermentation liquid used in the meat aging method and the meat aging method mentioned above, and the preferred range is also the same.

[0077] The meat modifier may contain one type of lactic acid bacteria, but it is preferable that it contains two or more types of lactic acid bacteria. Of the two or more types of lactic acid bacteria, at least one is preferably a Lactobacillus species, and more preferably Lactobacillus delbrueckii.

[0078] The meat modifier preferably contains Lactobacillus lactic acid bacteria and S. thermophilus, and more preferably contains L. delbruckii and S. thermophilus. The ratio of the number of bacteria between L. delbruckii and S. thermophilus is preferably L. delbruckii:S. thermophilus = 1:0.1 to 1:100, and more preferably 1:1 to 1:10. The above S. thermophilus is preferably S. thermophilus prtS(+). In another embodiment, the ratio of the number of bacteria between L. delbruckii and S. thermophilus can also be L. delbruckii:S. thermophilus = 1:0.1 to 1:1 million, 1:0.1 to 1:500,000, 1:0.1 to 1:100,000, etc.

[0079] The meat modifier is preferably in liquid form, and more preferably in the form of a milk fermentation liquid. The milk fermentation liquid is the same as described in the section on fermentation liquids used in the above-mentioned method for producing aged meat and the method for aging meat.

[0080] Examples of salts used in meat modifiers include table salt, monovalent metal ion salts such as potassium chloride, and various organic acid salts, with table salt being preferred.

[0081] The meat modifier preferably contains 0.7 to 2% by mass of salt. The lower limit is preferably 0.7% by mass or more, more preferably 0.8% by mass or more, and even more preferably 0.9% by mass or more. The upper limit is preferably 1.8% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1% by mass or less.

[0082] The number of viable lactic acid bacteria contained in meat modifiers is 1 x 10⁻⁶ ５ ~3 x 10 ９ It is preferably cfu / g, 1 × 10 ８ ~2 x 10 ９It is more preferable that the concentration is cfu / g.

[0083] When the meat modifier is in liquid form, the solid content concentration of the meat modifier is preferably 6 to 12% by mass. The lower limit is more preferably 8% by mass or more, and more preferably 9% by mass or more. The upper limit is preferably 11% by mass or less, and more preferably 10% by mass or less.

[0084] The fat concentration of the meat modifier is preferably 0.05 to 10% by mass. The lower limit is more preferably 0.075% by mass or more, and more preferably 0.1% by mass or more. The upper limit is preferably 5% by mass or less, and more preferably 3% by mass or less.

[0085] The pH of the meat modifier is preferably 4.2 to 5.0. The lower limit is preferably 4.3 or higher, more preferably 4.4 or higher, and even more preferably 4.5 or higher. The upper limit is preferably 4.95 or lower, and more preferably 4.9 or lower.

[0086] The acidity of the meat modifier is preferably 0.4 to 1.0%. The upper limit is preferably 0.9% or less, and more preferably 0.85% or less. The lower limit is preferably 0.5% or more, and more preferably 0.6% or more.

[0087] When the meat modifier is in liquid form, its viscosity at 10°C is preferably 10 to 600 mPa·s. The lower limit is preferably 20 mPa·s or more, and more preferably 30 mPa·s or more. The upper limit is preferably 500 mPa·s or less, and more preferably 300 mPa·s or less. The viscosity of the meat modifier is the value measured by the method described in the examples below.

[0088] The median diameter of the particle size distribution of the meat modifier is preferably 10 to 30 μm. The upper limit is preferably 25 μm or less. The lower limit is preferably 11 μm or more, and more preferably 12 μm or more.

[0089] The meat modifier of the present invention can be used in the production of aged meat. More specifically, it can be used in the production of aged meat by contacting meat with the meat modifier of the present invention and then wet aging the meat that has been contacted with the meat modifier. Details of the aged meat production process are as described above. By using the meat modifier of the present invention, it is possible to obtain aged meat with enhanced umami and a tender texture that is highly palatable in a short period of time.

[0090] There are no particular limitations on the method of applying the meat modifier of the present invention to meat. The meat modifier can be applied to meat by methods such as immersion, injection, tumbling, massage, spraying, or coating.

[0091] <Method for Producing the Meat Modifier> Next, the method for producing the meat modifier of the present invention will be described. The method for producing the meat modifier of the present invention is characterized by fermenting a fermentation base material containing salt using lactic acid bacteria.

[0092] According to the present invention's method for producing a meat modifier, by fermenting a fermentation base containing salt with lactic acid bacteria, the formation of curd during fermentation is suppressed by the salt, resulting in a meat modifier with less syneresis, low viscosity, and excellent storage stability. Furthermore, because curd formation is suppressed, the meat modifier obtained in this way offers excellent handling when in contact with meat, for example, by simplifying or eliminating the process of crushing the curd. In the present invention's method for producing a meat modifier, salt may be added to the fermentation base before fermentation or during fermentation. That is, there are no particular limitations on the order in which lactic acid bacteria and salt are added; salt may be added to the fermentation base after the lactic acid bacteria are added, or salt may be added to the fermentation base before or simultaneously with the addition of lactic acid bacteria. When salt is added after the addition of lactic acid bacteria, it is necessary to add the salt during the fermentation of the fermentation base. It is preferable to add salt to the fermentation base before or simultaneously with the addition of lactic acid bacteria in order to produce a meat modifier with even better storage stability.

[0093] The lactic acid bacteria used in the method for producing meat modifiers are those described in the sections on the fermentation liquid used in the method for producing aged meat and the method for aging meat, and the preferred range is the same.

[0094] While one type of lactic acid bacteria may be used, it is preferable to use two or more types. Of the two or more types of lactic acid bacteria, at least one is preferably a Lactobacillus species, and more preferably Lactobacillus delbrueckii.

[0095] It is preferable to use Lactobacillus lactic acid bacteria and S. thermophilus, and more preferable to use L. delbruckii and S. thermophilus. The ratio of the number of bacteria between L. delbruckii and S. thermophilus is preferably L. delbruckii:S. thermophilus = 1:0.1 to 1:100, and more preferably 1:1 to 1:10. The above S. thermophilus is preferably S. thermophilus prtS(+). In another embodiment, the ratio of the number of bacteria between L. delbruckii and S. thermophilus can also be L. delbruckii:S. thermophilus = 1:0.1 to 1:1,000,000, 1:0.1 to 1:500,000, 1:0.1 to 1:100,000, etc.

[0096] Examples of salts include table salt, salts of monovalent metal ions such as potassium chloride, and salts of various organic acids, with table salt being preferred.

[0097] Any fermentation substrate capable of culturing lactic acid bacteria is acceptable, but it is preferable that it contains raw milk. In other words, the meat modifier obtained by the method for producing the meat modifier of the present invention is preferably a milk fermentation liquid.

[0098] Examples of the raw milk products mentioned above include raw milk, pasteurized milk, skim milk, whole milk powder, skim milk powder, whole milk concentrate, skim milk concentrate, buttermilk, butter, cream, cheese, milk protein concentrate (MPC), whey protein concentrate (WPC), whey protein isolate (WPI), α-lactalbumin (α-La), and β-lactoglobulin (β-Lg). One or more of these can be used.

[0099] The above fermentation base material may further contain ingredients other than raw milk and salt. Examples include water, vitamins, stabilizers, thickeners, gelling agents, flavorings, seasonings, enzymes, and colorings.

[0100] The above-mentioned fermentation substrate may be subjected to homogenization treatment, heat sterilization treatment, etc. The homogenization treatment and heat sterilization treatment of the fermentation substrate are the same as those described above.

[0101] The solid content concentration of the fermentation substrate is preferably 6 to 12% by mass. The lower limit is more preferably 8% by mass or more, and more preferably 9% by mass or more. The upper limit is preferably 11% by mass or less, and more preferably 10% by mass or less.

[0102] The fat concentration of the fermentation base material is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, and particularly preferably 1% by mass or less. The lower limit can be 0.05% by mass or more, 0.07% or more, or 0.1% or more.

[0103] In the method for producing the meat modifier of the present invention, salt may be added to the fermentation base before adding lactic acid bacteria, or it may be added to the fermentation base at the same time as the lactic acid bacteria.

[0104] When using a salt containing sodium chloride, it is preferable to add 0.7 to 2% by mass of sodium chloride relative to the fermentation base material. The lower limit is preferably 0.7% by mass or more, more preferably 0.8% by mass or more, and even more preferably 0.9% by mass or more. The upper limit is preferably 1.8% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1% by mass or less.

[0105] The fermentation temperature can be appropriately selected depending on the type of lactic acid bacteria. For example, it can be carried out within a temperature range of 25 to 50°C.

[0106] The fermentation time is preferably 4 to 10 hours, and more preferably 4.5 to 6 hours.

[0107] In one embodiment, fermentation is preferably carried out until the pH of the resulting fermented product is in the range of 4.2 to 5.0. The upper limit of the pH is preferably 4.95 or less. The lower limit of the pH is preferably 4.4 or higher, and more preferably 4.6 or higher.

[0108] The meat modifier obtained by the method for producing the meat modifier of the present invention preferably has a salt content of 0.7 to 2% by mass. The lower limit is preferably 0.7% by mass or more, more preferably 0.8% by mass or more, and even more preferably 0.9% by mass or more. The upper limit is preferably 1.8% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1% by mass or less.

[0109] The number of viable lactic acid bacteria in the meat modifier obtained by the method for producing the meat modifier of the present invention is 1 × 10⁶. ５ ~3 x 10 ９ It is preferably cfu / g, 1 × 10 ８ ~2 x 10 ９ It is more preferable that the concentration is cfu / g.

[0110] The solid content concentration of the meat modifier obtained by the method for producing the meat modifier of the present invention is preferably 6 to 12% by mass. The lower limit is more preferably 8% by mass or more, and more preferably 9% by mass or more. The upper limit is preferably 11% by mass or less, and more preferably 10% by mass or less.

[0111] The fat concentration of the meat modifier obtained by the method for producing the meat modifier of the present invention is preferably 0.05 to 10% by mass. The lower limit is more preferably 0.075% by mass or more, and more preferably 0.1% by mass or more. The upper limit is preferably 5% by mass or less, and more preferably 3% by mass or less.

[0112] The pH of the meat modifier obtained by the method for producing the meat modifier of the present invention is preferably 4.2 to 5.0. The lower limit is preferably 4.3 or higher, more preferably 4.4 or higher, and even more preferably 4.5 or higher. The upper limit is preferably 4.95 or lower, and more preferably 4.9 or lower.

[0113] The acidity of the meat modifier obtained by the method for producing the meat modifier of the present invention is preferably 0.4 to 1.0%. The upper limit is preferably 0.9% or less, and more preferably 0.85% or less. The lower limit is preferably 0.5% or more, and more preferably 0.6% or more.

[0114] The viscosity of the meat modifier obtained by the method for producing the meat modifier of the present invention at 10°C is preferably 10 to 600 mPa·s. The lower limit is preferably 20 mPa·s or more, and more preferably 30 mPa·s or more. The upper limit is preferably 500 mPa·s or less, and more preferably 300 mPa·s or less. The viscosity of the meat modifier is the value measured by the method described in the examples below.

[0115] The median particle size of the meat modifier obtained by the method for producing the meat modifier of the present invention is preferably 10 to 30 μm. The upper limit is preferably 25 μm or less. The lower limit is preferably 11 μm or more, and more preferably 12 μm or more.

[0116] The present invention will be described in more detail below with reference to examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate, as long as they do not depart from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[0117] <Test Example 1> [Manufacturing of Meat Modifier] (Manufacturing Example 1) 485 g of skim milk powder (milk fat concentration 0.1% by mass, non-fat milk solids concentration 9.55% by mass, solids concentration 9.65% by mass), 48.5 g of salt, and a total of 194 g of lactic acid bacteria 1 and lactic acid bacteria 2 as shown below (Lactic acid bacteria 1: number of bacteria in the sample after addition 6 × 10) ６cfu / g, Lactobacillus 2: Number of bacteria in the sample after addition: 6 × 10 ７ A sample was prepared by mixing cfu / g with 4122.5g of raw water. This sample was fermented at 43°C for 4 to 5 hours to obtain a lactic acid bacteria fermentation liquid, and the meat modifier (containing 1% by mass of salt) of Production Example 1 was produced.

[0118] (Manufacturing Example 2) 485 g of skim milk powder (milk fat concentration 0.1% by mass, non-fat milk solids concentration 9.55% by mass, solids concentration 9.65% by mass) and a total of 194 g of lactic acid bacteria 1 and lactic acid bacteria 2 as shown below (Lactic acid bacteria 1: number of bacteria in the sample after addition 6 × 10) ６ cfu / g, Lactobacillus 2: Number of bacteria in the sample after addition: 6 × 10 ７ A sample was prepared by mixing cfu / g with 4122.5g of raw water. The sample was fermented at 43°C for 4 to 5 hours to obtain a lactic acid bacteria fermentation liquid, and then 48.5g of salt was added to produce the meat modifier of Production Example 2 (salt content 1% by mass).

[0119] Lactobacillus 1: L. delbruckii identified by accession number NITE BP-02874 ((1) Identification mark: Lactobacillus delbruckii OLL204989, (2) Accession number: NITE BP-02874, (3) Date of accession: February 5, 2019, (4) Depositary: National Institute of Technology and Evaluation Patent Microorganism Depositary Center (NPMD) (Postal code 292-0818, 2-5-8-122 Kazusa Kamatari, Kisarazu City, Chiba Prefecture), deposited with the aforementioned depositary. L. delbruckii identified by accession number NITE BP-02874 is L. delbruckii Lac(+), and L. This is L. delbruckii (I-B), and the allele numbers of the housekeeping genes it possesses are 2, 3, 18, 21, 22, 2, and 3 for the fusA, gyrB, hsp60, ileS, pyrG, recA, and recG genes, in that order.

[0120] Lactic acid bacteria 2: S. thermophilus identified by accession number NITE BP-02875 ((1) Identification mark: Streptococcus thermophilus OLS4496, (2) Accession number: NITE BP-02875, (3) Date of deposit: February 5, 2019, (4) Depositary: National Institute of Technology and Evaluation Patent Microorganism Depositary Center (NPMD) (2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture 292-0818, Room 122), deposited with the aforementioned depositary. The S. thermophilus identified by accession number NITE BP-02875 is an S. thermophilus that possesses the prtS gene. The presence or absence of the prtS gene was confirmed by the method described in paragraph 0076 of International Publication No. 2022 / 039249.

[0121] Lactic acid bacteria 1 and lactic acid bacteria 2 are 1.0 x 10 9 When a bacterial suspension of cfu / g was added to a 10% reduced skim milk medium to a concentration of 1% by mass, and cultured at the optimal temperature (43°C for Lactobacillus 1 and 43°C for Lactobacillus 2), the time required to lower the pH to 4.5 was 4 hours or more in both cases. The 10% reduced skim milk medium used was a medium (reduced skim milk) containing 10% (w / w) skim milk (1% fat, 34% protein, 54% lactose, 8% ash, 96% non-fat milk solids) and sterilized at 95°C. The composition of the 10% reduced skim milk medium was 5.4% lactose and 9.6% non-fat milk solids.

[0122] Furthermore, Lactobacillus 1 and Lactobacillus 2 satisfy the following relationship in formula (1): D30 - D1 ≤ 0.25 ... (1) In formula (1), D1 is the acidity (in %) of the fermented product when the target lactic acid bacteria are added to a formula containing raw milk, the formula is fermented at 43°C until the pH of the formula becomes 4.65, the fermented product is allowed to stand, cooled to 5°C, left to stand at 5°C for 1 day, and then stored at 10°C for 1 day. D30 is the acidity (in %) of the fermented product when the target lactic acid bacteria are added to a formula containing raw milk, the formula is fermented at 43°C until the pH of the formula becomes 4.65, the fermented product is allowed to stand, cooled to 5°C, left to stand at 5°C for 1 day, and then stored at 10°C for 30 days.

[0123] The milk preparation used for measurements D1 and D30 consisted of 485 g of skim milk powder (milk fat concentration 0.1% by mass, non-fat milk solids concentration 9.55% by mass, solids concentration 9.65% by mass) mixed with 4122.5 g of raw water.

[0124] [Evaluation of the meat modifier] The obtained meat modifier was filled into a plastic container at a rate of 100 g, stored at 1°C for 7 weeks, and the following evaluation was performed.

[0125] (Evaluation of syneresis) Syneresis was evaluated by visually observing the presence or absence of syneresis in the meat modifier and measuring the length of the synergistic phase. The meat modifier of Production Example 1 showed more suppressed syneresis than the meat modifier of Production Example 2, and had superior storage stability. Even when the storage temperature was changed to 5°C and the same evaluation was performed, Production Example 1 was able to suppress syneresis more effectively than Production Example 2.

[0126]

[0127] (Evaluation of the number of viable lactic acid bacteria) The number of viable lactic acid bacteria contained in each meat modifier was measured. The number of viable lactic acid bacteria 1 (Lactobacillus delbrueckii OLL204989) and 2 (Streptococcus thermophilus OLS4496) was measured using BCP-added plate count agar medium (Eiken Chemical Co., Ltd.), an official medium for measuring lactic acid bacteria counts. After aerobic incubation at 37°C for 72 hours, the formed colonies (rough-shaped spherical colonies identified visually) were counted. As shown below, neither the meat modifiers of Production Example 1 nor Production Example 2 showed a significant decrease in the number of lactic acid bacteria during storage. Even when the storage temperature was changed to 5°C and the same evaluation was performed, neither the meat modifiers of Production Example 1 nor Production Example 2 showed a significant decrease in the number of lactic acid bacteria during storage.

[0128]

[0129]

[0130] (Viscosity Evaluation) Using a rotary B-type viscometer (TVB25 viscometer, manufactured by Toki Sangyo Co., Ltd.), the viscosity of each meat modifier was measured at a measurement temperature of 10°C by inserting an M2 rotor or an M3 rotor into the sample and rotating it (30 rpm for 30 seconds when using the M2 rotor, and 60 rpm for 30 seconds when using the M3 rotor). For the rotor, the M2 rotor was used when the viscosity of the sample was 400 mPa·s or less, and the M3 rotor was used when the viscosity of the sample exceeded 400 mPa·s. As shown below, the viscosity of the meat modifier in Production Example 1 was significantly lower immediately after production than that of the meat modifier in Production Example 2. Furthermore, the viscosity remained low even after storage, and the increase in viscosity over time was suppressed, indicating that the meat modifier in Production Example 1 had superior storage stability compared to the meat modifier in Production Example 2. Even when the storage temperature was changed to 5°C and the same evaluation was performed, the meat modifier of Production Example 1 had significantly lower viscosity immediately after production than the meat modifier of Production Example 2. Furthermore, it maintained low viscosity even after storage, suppressing the increase in viscosity over time, and the meat modifier of Production Example 1 had superior storage stability compared to the meat modifier of Production Example 2.

[0131]

[0132] (Evaluation of particle size) Using a particle size distribution analyzer (Shimadzu Corporation SALD-2200), the volume-based particle size distribution of each meat modifier was measured by laser diffraction scattering, and the median diameter was determined. As shown below, the particle size of the meat modifier in Production Example 1 was smaller immediately after production than that of the meat modifier in Production Example 2. Furthermore, the increase in particle size of the meat modifier in Production Example 1 was suppressed more effectively after storage than that of the meat modifier in Production Example 2, demonstrating superior storage stability. Even when the storage temperature was changed to 5°C and the same evaluation was performed, the particle size of the meat modifier in Production Example 1 was smaller immediately after production than that of the meat modifier in Production Example 2. Furthermore, the increase in particle size of the meat modifier in Production Example 1 was suppressed more effectively after storage than that of the meat modifier in Production Example 2, demonstrating superior storage stability.

[0133]

[0134] (Odor Evaluation) Four trained panelists evaluated the odor of the meat modifiers in Production Example 1 and Production Example 2 immediately after production, after 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, and 7 weeks of storage, and compared them to the meat modifier in Production Example 1 immediately after production to check for any differences. There were no differences in odor for any of the meat modifiers, and no changes in odor were observed over time. Even when the storage temperature was changed to 5°C and the same evaluation was performed, there were no differences in odor for either the meat modifiers in Production Example 1 or Production Example 2, and no changes in odor were observed over time.

[0135] (Evaluation of Acidity and pH) The acidity (lactic acidity) and pH of each meat modifier were measured. Acidity was measured by taking 9.0 g of the sample, adding 500 μL of phenolphthalein indicator, and titrating with 0.1 N NaOH until the point at which the faint pink color did not disappear after 30 seconds was the limit. pH was measured using a pH meter HM-30R (Mettler Toledo Co., Ltd.) and the glass electrode method. As shown below, no significant changes in acidity or pH over time were observed for either the meat modifiers in Production Example 1 or Production Example 2. Even when the storage temperature was changed to 5°C and the same evaluation was performed, no significant changes in acidity or pH over time were observed for either the meat modifiers in Production Example 1 or Production Example 2.

[0136]

[0137]

[0138] <Test Example 2> [Production of Aged Meat] Approximately 150g of pork loin from Hokkaido was used as the meat. The meat modifier obtained in Production Example 1 was added at a rate of 10% relative to the weight (weight) of the meat, and then vacuum-packed (vacuum degree 10%). ５ After heating to below Pa, the food was aged at 1-2°C for 24 hours (1 day) to 7 days.

[0139] [Evaluation of Aged Meat] (Evaluation of maturity level (myofibrillar fragmentation index), peptide / amino acid concentration, water retention (heat syneresis rate), and pH) After the prescribed maturation period, the meat was stored frozen at -20°C or below. The meat was thawed at 4°C overnight starting the day before evaluation, and the maturity level (myofibrillar fragmentation index), peptide / amino acid concentration, water retention (heat syneresis rate), and pH were evaluated. Untreated pork loin was used as a comparison.

[0140] The degree of maturity (myofibrillar fragmentation index) was determined based on the report by "TAKAHASHI, K., FUKAZAWA, T., & YASUI, T. (1967). Formation of myofibrillar fragments and reversible contraction of sarcomeres in chicken pictorial muscle. Journal of food science, 32(4), 409-413." Specifically, a myofibrillar suspension was prepared, and more than 500 myofibrillars were counted under a phase-contrast microscope. The proportion of myofibrillars with 4 or fewer sarcomeres was measured as the myofibrillar fragmentation index.

[0141] Peptide and amino acid concentrations were determined based on the report by Church, F. C., Swaisgood, H. E., Porter, D. H., & Catignani, G. L. (1983). Spectrophotometric assembly using o-phosphated hydrate for determination of proteinosis in milk and isolated milk proteins. Journal of Daily Science, 66(6), 1219-1227. The o-Phythaldehyde (OPA) solution was prepared by dissolving 40 mg of OPA in 1 mL of methanol, and then diluting the solution with 50 mM boric acid, 1% sodium dodecyl sulfate, and 0.2% β-mercaptoethanol to make up 50 mL. The sample solution and the OPA solution were mixed, and the absorbance at 340 nm was measured using a spectrophotometer. The obtained absorbance was used to calculate the peptide amino acid concentration as a converted value for glycylleucine.

[0142] Water retention (heat-induced water separation rate) was calculated by placing the sample in a nylon bag and immersing it in a 75°C bath for 45 minutes, measuring the change in weight before and after heating. The formula used for calculation is as follows: Heat-induced water separation rate (%) = {(Weight before heating - Weight after heating) / (Weight before heating)} × 100

[0143] pH was measured at three locations by directly inserting a pH meter (testo-205, Testo Corporation) into the meat sample, and the average value was calculated.

[0144]

[0145] An increase in the myofibril fragmentation index suggests that the meat has matured and softened due to the weakening of the Z-lines of the myofibrils. As shown in the table above, the myofibril fragmentation index increased even after a maturation period of just one day compared to untreated meat, but the increase was significant after a maturation period of three days or more.

[0146] An increase in peptide and amino acid concentrations suggests that protein breakdown has progressed, resulting in increased umami flavor. As shown in the table above, even with a maturation period of just one day, the peptide and amino acid concentrations increased compared to the untreated product, but the increase was significantly greater after a maturation period of four days or more.

[0147] An increase in the heat-induced water loss rate suggests that the meat's water retention has improved, resulting in increased juiciness. As shown in the table above, even with a maturation period of just one day, the heat-induced water loss rate increased compared to untreated meat, but the increase was significantly greater after a maturation period of four days.

[0148] Regarding pH, there was no significant change compared to untreated meat, indicating that aging with the above-mentioned meat modifier did not alter the acidity of the meat.

[0149] (Simulated Chewing Evaluation) - Regarding Sample Preparation Method - After the prescribed maturation period, the meat was frozen and stored at -20°C or below. It was thawed overnight at 4°C starting the day before the evaluation. The thawed meat was placed in a water bath set to 80°C. After the water temperature reached 80°C, it was heated in a water bath for 20 minutes, then removed from the water bath, wrapped in aluminum foil, and stored at room temperature for 20 minutes. After cooling to room temperature, the sample was prepared by storing it in a constant temperature chamber at 25°C. Untreated pork loin was used as a comparison subject, and the sample was prepared in the same manner as above.

[0150] -Regarding the Food Property Evaluation Device- The food property evaluation device shown in Figure 1 was used to evaluate the physical properties of simulated saliva. This food property evaluation device 1 comprises an upper jig 10, a lower jig 20, a sensor 12, a drive unit 30, a measurement control unit 40, and a simulated saliva supply unit 50. The following describes these components in detail.

[0151] As shown in Figure 1, an upper occlusal portion 11 is formed at the lower end of the upper jig 10. The upper occlusal portion 11 has a hemispherical convex shape. This upper jig 10 is made of ABS (acrylonitrile-butadiene-styrene copolymer) resin.

[0152] A lower occlusal portion 21 is formed at the upper end of the lower jig 20. The lower occlusal portion 21 is a hemispherical recess having approximately the same diameter as the upper occlusal portion 11, and is positioned to face the upper occlusal portion 11 in the vertical direction, as shown in Figure 1. That is, this lower occlusal portion 21 occludes with the upper occlusal portion 11. The lower jig 20 is made of ABS (acrylonitrile-butadiene-styrene copolymer) resin, similar to the upper jig 10. Furthermore, a cylindrical protective portion 22 is provided on the outer circumference of the lower jig 20, as shown in Figure 1. The upper jig 10 and the lower jig 20 are designed so that they do not come into contact with each other even when the upper occlusal portion 11 and the lower occlusal portion 21 are closest together. In addition, the occlusion of the upper jig 10 and the lower jig 20 is designed so that a force exceeding a set compressive force is not applied.

[0153] Sensor 12 is a 6-axis sensor that is incorporated into the upper end of the upper jig 10 and measures physical quantities applied to the upper jig 10 (such as force and torque applied to the upper jig 10).

[0154] The drive unit 30 can drive the lower jig 20 along the vertical direction so that it performs reciprocating linear motion in the direction in which the lower jig 20 engages with the upper jig 10 and in the direction in which the lower jig 20 moves away from the upper jig 10. The drive unit 30 can also drive the upper jig 10 so that it performs reciprocating rotational motion with the direction of the reciprocating linear motion of the lower jig 20 as the axis of rotation.

[0155] The measurement control unit 40 controls the reciprocating linear motion of the lower jig 20 and the reciprocating rotational motion of the upper jig 10, which are controlled by the drive unit 30. The measurement control unit 40 also measures the physical quantities applied to the upper jig 10 from the output of the sensor 12. The measurement control unit 40 can obtain impulse data by integrating the force data measured by the sensor 12 over time.

[0156] The artificial saliva supply unit 50 supplies artificial saliva to the lower occlusal portion 21 at a constant flow rate. A supply tube 51 extends from the artificial saliva supply unit 50, and this supply tube 51 penetrates the protective portion 22 and extends to the upper end of the lower occlusal portion 21.

[0157] - Regarding the simulated chewing evaluation method using the food property evaluation device, 3.5 g (±0.5) g of each sample was placed on the lower occlusal portion 21 of the lower jig 20 of the food property evaluation device described above, and simulated chewing was performed under the conditions shown below.

[0158] • Simulated saliva: 0.025% xanthan gum aqueous solution. Note that this simulated saliva does not contain buffers, amylase, or other components. • Compression force: 400 N • Simulated saliva addition rate: 4 ml / min • Initial saliva addition amount: 1 mL • Simulated chewing speed (compression speed): 1 second / time • Simulated chewing count (compression count): 90 times

[0159] The total impulse after 90 compressions and the change in impulse (moving average of impulse every 5 seconds) were calculated. The total impulse after 90 compressions is shown in Figure 2, and the change in impulse (moving average of impulse every 5 seconds) is shown in Figure 3. After washing the samples after 10 and 30 compressions in a beaker containing 30 mL of distilled water, the broken fibers were spread out on a 16 M mesh so that they did not overlap, and the ratio of the area of ​​the compressed sample to the area of ​​the pre-compression sample (set as 1) was calculated. The results are shown in Figure 4. Figure 5 shows the state of each sample placed on the 16 M mesh.

[0160] As shown in Figure 2, the total impulse of meat aged for 1 day and 5 days (aged meat) was smaller than that of untreated meat. Also, as shown in Figure 3, the impulse of meat aged for 1 day and 5 days (aged meat) was smaller than that of untreated meat from the initial to the later stages of compression. Furthermore, as shown in Figure 4, the ratio of the area of ​​the sample after 10 compressions to the area of ​​the sample before compression (set as 1) was larger for meat aged for 1 day and 5 days (aged meat) compared to untreated meat, indicating that aged meat can be broken down into smaller pieces with fewer chews than untreated meat.

[0161] Furthermore, 3.5 g (±0.5 g) of each sample—untreated (Control, n=6), aged for 1 day (n=6), and aged for 3 days (n=3)—was placed on the lower occlusal portion 21 of the lower jig 20 of the food physical property evaluation device described above, and simulated chewing was performed under the same conditions as described above. The evaluation results are shown in Figure 6. From Figure 6, the total impulse of the meat aged for 1 day and 3 days (aged meat) was smaller than that of the untreated meat, and the total impulse was significantly reduced compared to the untreated meat. After confirming that all samples had equal variances by one-way ANOVA, multiple comparisons were performed using the Tukey-Kramer method. * indicates that the p-value in the multiple comparison was less than 0.05.

[0162] (Sensory Evaluation) After the prescribed aging period, the meat was stored frozen at -20°C or below. The meat was thawed at 4°C overnight starting the day before the evaluation, placed on a preheated griddle, and cooked to medium-rare to obtain steaks. Untreated pork loin was used as a comparison. Steaks made with aged meat were superior in aroma, tenderness, juiciness, and flavor compared to steaks made with untreated pork loin. In particular, steaks made with aged meat for 3 days or more were superior in aroma, tenderness, juiciness, and flavor compared to steaks made with aged meat for 1 or 2 days.

[0163] In Test Example 2, the same effect as described above can be obtained even if the meat modifier obtained in Production Example 2 is used instead of the meat modifier obtained in Production Example 1.

[0164] (Production Examples 3-8) Except for changing Lactobacillus 1 and Lactobacillus 2 in Production Example 1 as shown in the table below, the meat modifiers of Production Examples 3-8 were produced in the same manner as in Production Example 1.

[0165]

[0166] Details of the abbreviations in the table are as follows: 2038: Lactobacillus bulgaricus strain 2038, which can be isolated from "Meiji Bulgaria Yogurt (manufactured by Meiji Co., Ltd.)". JCM1124T: Lactobacillus casei, which can be obtained as JCM 1134T from RIKEN BRC-JCM. JCM1131T: Lactobacillus gasseri, which can be obtained as JCM1131T from RIKEN BRC-JCM. JCM1012T: Lactobacillus delbrueckii, which can be obtained as JCM 1012T from RIKEN BRC-JCM. TM96 Del: Lactobacillus delbrueckii subsp. lactis strain OLL204989, which is internationally deposited at the National Institute of Technology and Evaluation (NITE) Patent Organism Depositary Center (2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture) under accession number NITE BP-02874. 1131: Streptococcus thermophilus strain 1131 can be isolated from "Meiji Bulgaria Yogurt". 1131 is a S. thermophilus that does not possess the prtS gene. Confirmation of the presence or absence of the prtS gene was performed using the method described in paragraph 0076 of International Publication No. 2022 / 039249. TM96 Thermo: Streptococcus thermophilus strain OLS4496 is internationally deposited at the National Institute of Technology and Evaluation (NITE) Patent Organism Depositary Center (2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture) under accession number NITE BP-02875. JCM5805T: Lactococcus lactis can be obtained as strain JCM 5805T from RIKEN BRC-JCM. NITE BP-03505: Streptococcus thermophilus strain OLS4802 is internationally deposited at the National Institute of Technology and Evaluation (NITE) Patent Organism Depository Center (2-5-8 Kazusa-Kamatari, Kisarazu City, Chiba Prefecture) under accession number NITE BP-03505. NITE BP-03505 is a S. thermophilus that possesses the prtS gene.The presence or absence of the prtS gene was confirmed by the method described in paragraph 0076 of International Publication No. 2022 / 039249.

[0167] The same method as in Test Example 2 was used to produce aged meat and to perform simulated chewing evaluations, except that the meat modifiers obtained in Production Examples 3 to 8 were used instead of the meat modifier obtained in Production Example 1 described above. For untreated meat and meat (aged meat) with aging periods of 1 day and 5 days using the meat modifiers obtained in Production Examples 3 to 8, the impulse of the first compression and the total impulse after 90 compressions were calculated. The results of the calculation of the impulse of the first compression are shown in Figure 7, and the total impulse after 90 compressions are shown in Figure 8.

[0168] Furthermore, Figures 9 to 14 show the change in impulse (moving average of impulse every 4 seconds) for untreated meat and meat (aged meat) that was aged for 1 day and 5 days using the meat modifiers obtained in production examples 3 to 8.

[0169] The results from using the meat modifier according to Production Example 3 show that when Lactobacillus bulgaricus is used and S. thermophilus does not possess the prtS gene, the effect is weak and difficult to obtain. The results from using the meat modifiers according to Production Examples 4 to 6 show that the effects of the present invention can be obtained even when various bacteria of the Lactobacillus genus are used. The results from using the meat modifier according to Production Example 7 show that the effects of the present invention can be obtained even when bacteria of the Lactococcus genus are used. The results from using the meat modifier according to Production Example 8 show that if the prtS gene is possessed, the effect is more likely to be obtained when various S. thermophilus are used. Also, from Figure 14, it can be seen that for a maturation period of one day, the impulse is close to that of untreated meat in the early stages when the number of simulated chews is small, but as the number of simulated chews increases, the impulse becomes smaller than that of untreated meat in the later stages. It is believed that products aged for five days have a lower impulse from the initial stage compared to untreated products, resulting in a softer texture from the very first bite.

[0170] 1: Food physical property evaluation device 10: Upper jig 11: Upper occlusal part 12: Sensor 20: Lower jig 21: Lower occlusal part 22: Protective part 30: Drive unit 40: Measurement control unit 50: Simulated saliva supply unit 51: Supply tube

Claims

1. A method for producing aged meat, comprising contacting meat with a fermentation solution of lactic acid bacteria, and then wet aging the meat that has been contacted with the fermentation solution.

2. The method for producing aged meat according to claim 1, wherein the fermentation liquid contains salt.

3. The method for producing aged meat according to claim 2, wherein the salt includes sodium chloride, and the fermentation liquid has a sodium chloride content of 0.7 to 2% by mass.

4. The method for producing aged meat according to claim 1 or 2, wherein the fermentation liquid is a milk fermentation liquid.

5. The method for producing aged meat according to claim 1 or 2, wherein the lactic acid bacteria include lactic acid bacteria that satisfy condition 1 below; condition 1: When the target lactic acid bacteria are cultured at the optimal temperature using a culture medium containing milk raw materials, the time required to lower the pH to 4.5 is 4 hours or more.

6. The method for producing aged meat according to claim 1 or 2, wherein the lactic acid bacteria include Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus).

7. The method for producing aged meat according to claim 1 or 2, wherein the fermentation liquid is brought into contact with the meat at an amount of 5 to 30% by mass relative to the weight of the meat.

8. A method for producing aged meat according to claim 1 or 2, wherein the meat that has been in contact with the fermentation liquid is wet-aged by vacuum packaging or gas-purging packaging together with the fermentation liquid.

9. The method for producing aged meat according to claim 1 or 2, wherein the wet aging is carried out at a temperature of 10°C or lower for 3 days or more.

10. A method for maturing meat, comprising contacting meat with a fermentation solution of lactic acid bacteria, and then wet-aging the meat that has been contacted with the fermentation solution.

11. The method for aging meat according to claim 10, wherein the lactic acid bacteria include Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus).

12. A meat modifier containing salt and lactic acid bacteria.

13. The meat modifier according to claim 12, which is in liquid form.

14. The meat modifier according to claim 12 or 13, which is a milk fermentation liquid.

15. The meat modifier according to claim 12 or 13, wherein the salt includes sodium chloride, and the meat modifier has a sodium chloride content of 0.7 to 2% by mass.

16. The meat modifier according to claim 12 or 13, comprising two or more types of lactic acid bacteria.

17. The meat modifier according to claim 12 or 13, wherein the lactic acid bacteria include lactic acid bacteria that satisfy the following condition 1: When the target lactic acid bacteria are cultured at the optimal temperature using a culture medium containing milk raw materials, the time required to lower the pH to 4.5 is 4 hours or more.

18. The meat modifier according to claim 12 or 13, wherein the lactic acid bacteria include Lactobacillus lactic acid bacteria.

19. The meat modifier according to claim 18, wherein the lactic acid bacteria further comprises Streptococcus thermophilus.

20. The meat modifier according to claim 19, wherein Streptococcus thermophilus has the prtS(+) gene.

21. The meat modifier according to claim 18, wherein the Lactobacillus lactic acid bacteria include Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus).

22. The meat modifier according to claim 18, wherein the Lactobacillus lactic acid bacteria is Lactobacillus delbrueckii classified in one of clusters I, II, III, and V in the MLSA classification based on seven housekeeping genes consisting of the fusA gene, gyrB gene, hsp60 gene, ileS gene, pyrG gene, recA gene, and recG gene.

23. A method for producing a meat modifier, comprising fermenting a salt-containing fermentation base material using lactic acid bacteria.

24. The method for producing a meat modifier according to claim 23, wherein the salt includes sodium chloride, and the sodium chloride is added to the fermentation base material in an amount of 0.7 to 2% by mass.

25. A method for producing a meat modifier according to claim 23 or 24, wherein the lactic acid bacteria include lactic acid bacteria that satisfy the following condition 1: Condition 1: When the target lactic acid bacteria are cultured at the optimal temperature using a culture medium containing milk raw materials, the time required to lower the pH to 4.5 is 4 hours or more.

26. A method for producing a meat modifier according to claim 23 or 24, wherein the lactic acid bacteria include lactic acid bacteria that satisfy the relationship in formula (1); D30 - D1 ≤ 0.25 ... (1) In formula (1), D1 is the acidity (unit: %) of the fermented product when the target lactic acid bacteria are added to a milk preparation liquid containing raw milk, the fermented product is allowed to stand at 43°C until the pH of the milk preparation liquid becomes 4.65, the product is allowed to stand and cool to 5°C, the product is allowed to stand at 5°C for 1 day, and then stored at 10°C for 1 day; and D30 is the acidity (unit: %) of the fermented product when the target lactic acid bacteria are added to a milk preparation liquid containing raw milk, the fermented product is allowed to stand at 43°C until the pH of the milk preparation liquid becomes 4.65, the product is allowed to stand and cool to 5°C, the product is allowed to stand at 5°C for 1 day, and then stored at 10°C for 30 days.

27. The method for producing a meat modifier according to claim 23 or 24, wherein the lactic acid bacteria include Lactobacillus delbrueckii (excluding Lactobacillus delbrueckii subsp. bulgaricus).

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