Method for producing meat product

Abstract

To provide a method for producing a meat product, capable of producing the meat product having a good color tone without using a color developer.SOLUTION: A method for producing a meat product comprises a first step of mixing raw meat with lactic acid bacteria to obtain a mixed raw material, and a second step of immersing the mixed raw material in a fermentation liquid and fermenting it to obtain the meat product.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to methods for producing meat products. [Background technology]

[0002] Conventionally, many meat products such as sausages and hams use nitrates or nitrites as color formers. The nitrite derived from the color formers may generate carcinogenic substances in the body. For this reason, there has been an increasing demand in recent years for meat products that use reduced amounts of color formers or meat products that do not use color formers. Summary of the Invention [Problem to be solved by the invention]

[0003] If a color former is not used in a meat product, the color tone of the meat product is likely to deteriorate. Therefore, the object of the present invention is to provide a method for producing a meat product that can produce a meat product having a good color tone without using a color former. [Means for solving the problem]

[0004] The method for producing a meat product of the present invention comprises the steps of: A first step of mixing raw meat and lactic acid bacteria to obtain a mixed raw material; A second step of fermenting the mixed material while immersed in a fermentation liquid to obtain a meat product. Effect of the Invention

[0005] According to the present invention, meat products having good color tone can be produced without using color formers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] [Description of the embodiment of the present invention] First, the embodiments of the present invention will be listed and described. (1) The method for producing a meat product of the present invention comprises the steps of: A first step of mixing raw meat and lactic acid bacteria to obtain a mixed raw material; and a second step of fermenting the mixed material while immersing it in a fermentation liquid to obtain a meat product.

[0007] According to the present invention, meat products having good color tone can be produced without using color formers.

[0008] (2) In the second step, it is preferable that the production of zinc protoporphyrin IX in the mixed raw material is promoted, which makes it easier to maintain a good color tone of the meat product.

[0009] (3) The fermentation liquid preferably contains 5% by mass or less of salt and 1% by mass or more and 10% by mass or less of sugar, which promotes the production of zinc protoporphyrin IX in the meat product.

[0010] (4) In the second step, it is preferable to immerse the mixed material in the fermentation liquid after forming the mixed material, so that the meat product can have a desired shape.

[0011] (5) It is preferable to include a third step of drying the meat product after the second step, which promotes the production of zinc protoporphyrin IX in the meat product.

[0012] [Details of the embodiment of the present invention] In order to deepen understanding of the present invention, the circumstances by which the present inventors arrived at the present invention will be described. Parma ham, a long-aged Italian raw ham, has a good color tone even though it does not use a coloring agent. It is known that zinc protoporphyrin IX (hereinafter also referred to as "ZnPP") contributes to this good color tone. Specifically, the higher the amount of ZnPP in a meat product, the better the color tone of the meat product. (Reference 1: Wakamatsu, J., Nishimura, T., & Hattori, (2004). A Zn-porphyrin complex contributes to bright red color in Parma ham. Meat Science, 67(1), 95-100.)

[0013] In addition, research is being conducted on microorganisms that promote the formation of ZnPP in meat products (Reference 2: Md. Kauser-Ul-Alam, Toru Hayakawa, Haruto Kumura, Jun-ichi Wakamatsu, (2021). High ZnPP-forming food-grade lactic acid bacteria as a potential substitute for nitrite / nitrate to improve the color of meat products. Meat Science, 176, 108467-108467.).

[0014] As a result of extensive research into the microorganisms described in Reference 2, the present inventors have newly discovered that meat products with good color tone can be produced without using color formers by using lactic acid bacteria and fermenting a mixed raw material while immersing it in a fermentation liquid. The method for producing meat products according to the present invention will be described below.

[0015] A method for producing a meat product according to one embodiment of the present invention (hereinafter also referred to as "the present embodiment") comprises the steps of: A first step of mixing raw meat and lactic acid bacteria to obtain a mixed raw material; and a second step of fermenting the mixed raw material while immersing it in a fermentation liquid to obtain a meat product.

[0016] In the present embodiment, the meat product may be a non-heated meat product or a dried meat product. For example, sausages such as semi-dry sausage and dry sausage, and hams such as lax ham and prosciutto. In particular, the meat product is preferably a semi-dry sausage or a dry sausage.

[0017] <1st process> In the first step, raw meat and lactic acid bacteria are mixed to obtain a mixed raw material.

[0018] In the present embodiment, the raw material meat may be any known raw material that is normally used for meat products, either singly or in combination. Examples of the raw material meat include mammalian or avian meat that is bright red, pink-red, or reddish in color. More specifically, examples of the raw material meat include, but are not limited to, pork, beef, mutton, goat, horse, venison, chicken, rabbit, and whale meat.

[0019] The raw meat is preferably cut into thin strips and then minced after removing bones, blood vessels, impurities, etc. When mincing the raw meat, fat can be added to the raw meat.

[0020] In this embodiment, the lactic acid bacteria may be lactococci or lactobacilli, and these may be used alone or in combination.

[0021] Examples of lactic acid bacteria include lactic acid bacteria of the genus Lactococcus, Streptococcus, and Leuconostoc. Examples of the genus Lactococcus include Lactococcus lactis, Lactococcus cremoris, and Lactococcus diacetylactis. Examples of the genus Streptococcus include Streptococcus thermophilus. Examples of the genus Leuconostoc include Leuconostoc cremoris. Among these, it is preferable to use Lactococcus lactis, and it is more preferable to use Lactococcus lactis subsp. cremoris.

[0022] Examples of lactobacilli include lactobacilli of the genus Lactobacillus. Examples of lactobacilli include Lactobacillus bulgaricus.

[0023] The lactic acid bacteria used in the present embodiment can be cultured under commonly used culture conditions, for example, using a yeast extract liquid medium at a temperature of 5 to 20° C. for 48 to 96 hours under aerobic or anaerobic conditions.

[0024] The lactic acid bacteria used in this embodiment can produce ZnPP under aerobic conditions by mixing with raw meat. Here, under aerobic conditions means that the mixed material obtained by mixing the raw meat and the lactic acid bacteria is placed in air or in a gas containing oxygen at a concentration similar to that in air.

[0025] The lactic acid bacteria used in this embodiment can produce ZnPP even under anaerobic conditions by mixing with raw meat. Here, anaerobic conditions means that the mixed material is placed in a gas with almost no oxygen, for example, an oxygen concentration of less than 0.1 vol%, as generally used for culturing anaerobic bacteria.

[0026] The form of the lactic acid bacteria when mixed with the raw meat is not particularly limited. For example, the lactic acid bacteria can be collected from the culture medium, washed with distilled water, suspended in distilled water, and mixed with the raw meat. Alternatively, concentrated frozen cells or dried frozen cells of the collected cells can be mixed with the raw meat.

[0027] The amount of lactic acid bacteria in raw meat is 1 x 10 per 1 g of raw meat. 0 CFU or more is preferable, 1×10 6 CFU or higher is more preferable.

[0028] In the first step, a mixed raw material can be obtained by mixing the raw material meat with lactic acid bacteria, water, seasonings, culture medium, etc., to the extent that the growth of the lactic acid bacteria is not inhibited. Examples of seasonings include salt, glucose, molasses, brown sugar, sodium citrate, spices, etc., and culture medium refers to the medium components in which microorganisms are grown, such as a yeast extract solution.

[0029] Examples of spices that can be used in the seasoning include cinnamon, marjoram, garlic, coriander, rosemary, dill weed, chives, nutmeg, sage, thyme, cloves, fennel, caraway, oregano, cardamom, ginger, cayenne pepper, cumin, mustard, black pepper, laurel, allspice, mace, and onion. The form of these spices is not particularly limited. Spices can be used in any conventional form, such as raw, dried, or pasty.

[0030] <Second process> In the second step, the mixed raw material obtained in the first step is fermented while being immersed in a fermentation liquid to obtain a meat product. The meat product obtained in the second step can have a good color tone without using a color former.

[0031] The fermentation liquid preferably contains water and sugar. In this case, the fermentation liquid preferably contains water and sugar, and the fermentation liquid preferably contains sugar in an amount of 1% by mass or more and 10% by mass or less. When the fermentation liquid contains sugar within the above range, the production of ZnPP is easily promoted in the mixed raw material. The fermentation liquid preferably contains water and sugar, and the fermentation liquid more preferably contains sugar in an amount of 2% by mass or more and 9% by mass or less, and even more preferably contains sugar in an amount of 4% by mass or more and 6% by mass or less. The amount of water is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more.

[0032] The sugar contained in the fermentation liquid may be any known sugar such as glucose, molasses, brown sugar, etc. Among them, glucose is preferred from the viewpoint of improving the flavor of meat products.

[0033] The fermentation liquid preferably contains salt in addition to water and sugar. The fermentation liquid preferably contains water, salt, and sugar, and the fermentation liquid preferably contains 5% by mass or less of salt and 1% by mass or more and 10% by mass or less of sugar. When the fermentation liquid contains salt and sugar within the above ranges, the production of ZnPP is easily promoted in the mixed raw material. The fermentation liquid more preferably contains 1% by mass or more and 5% by mass or less of salt and 2% by mass or more and 9% by mass or less of sugar, and further preferably contains 2% by mass or more and 4% by mass or less of salt and 4% by mass or more and 6% by mass or less of sugar.

[0034] The fermentation liquid may contain a solution containing an extract of spices. The solution can be prepared, for example, by adding spices to water, boiling the water, cooling the water, and removing the spices. Even if the fermentation liquid contains the solution, the mixed raw material can be immersed in the fermentation liquid to obtain the effects of improving the moldability of the final product and early formation of ZnPP. As the spices, those listed as the spices used in the first step above can be used. The spices used in the first step and the spices used to prepare the solution may be the same or different.

[0035] The method for immersing the mixed raw material in the fermentation liquid is not particularly limited as long as the mixed raw material can be entirely immersed in the fermentation liquid. For example, the mixed raw material and the fermentation liquid may be enclosed in a sealed bag.

[0036] The time for soaking the mixed raw material in the fermentation liquid is preferably from 48 hours to 96 hours, more preferably from 48 hours to 72 hours, which allows the production of meat products with good color tone and excellent moldability.

[0037] The temperature of the fermentation liquid when the mixed raw material is immersed in the fermentation liquid for fermentation is preferably from 10° C. to 25° C., more preferably from 15° C. to 20° C., and even more preferably from 15° C. to 19° C. This makes it possible to produce meat products that exhibit good color tone and excellent moldability.

[0038] In the second step, it is preferable to immerse the mixed raw material in a fermentation liquid after forming the mixed raw material. The mixed raw material can be formed, for example, by filling the mixed raw material into a casing. The material of the casing can be a known material having air permeability that is usually used for meat products. Examples of the casing include pig intestines, sheep intestines, artificial casing, cellophane, etc.

[0039] In the second step, it is preferable that the production of zinc protoporphyrin IX in the meat product is promoted. The meat product produced using the production method including the above-mentioned first and second steps has a good color tone even though no color former is used. Furthermore, since no color former is used, there is no risk of producing carcinogenic substances, and the product is highly safe.

[0040] <Other processes> The method for producing a meat product of the present invention includes the above-mentioned first and second steps, and may include other general production steps as long as a color former is not used. For example, after the second step, the method may include a third step of drying the meat product. By carrying out the third step, the production of ZnPP in the meat product is further promoted.

[0041] The third step is preferably carried out at a relative humidity of 50% to 65%, at a temperature of 15° C. to 20° C., and for 14 days to 60 days. From the viewpoint of promoting the production of ZnPP, the temperature of the third step is more preferably 18° C. to 20° C. EXAMPLES

[0042] The present embodiment will be described in more detail with reference to examples, but the present embodiment is not limited to these examples.

[0043] [Study 1: Relationship between immersion in fermentation liquid, ZnPP production rate, and color of meat products] <Production of meat products> A plurality of meat products were prepared for each sample by the following procedure. For Studies 2 to 7 described below, a plurality of meat products were also prepared for each sample. <Sample 1-1: Immersed in fermentation liquid> The raw materials were prepared as follows: The raw meat used was commercially available domestic crossbred pig arm meat, which was ground using a meat grinder (MADO MEW713).

[0044] The lactic acid bacteria used was Lactococcus lactis subsp. cremoris GB(A)-1, which was deposited internationally on June 10, 2020 at the National Institute of Technology and Evaluation, Patent Microorganisms Deposit Center, Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, Japan, under the accession number NITE BP-03229 (identification: GB(A)-1).

[0045] Table 1 below shows the mycological properties of Lactococcus lactis subsp. cremoris GB(A)-1 strain.

[0046] [Table 1]

[0047] The lactic acid bacteria was added to a yeast extract medium at a concentration of 1 × 10 8 CFU was added and cultured in an incubator (CRB-14A, Hitachi Appliances, Inc.) at 9° C. for 3 days to obtain a lactic acid bacteria culture liquid. The yeast extract medium was sterilized in an autoclave and then brought to room temperature for use.

[0048] The fermentation liquid was prepared by thoroughly mixing water, salt, and glucose until they were completely dissolved. The water content of the fermentation liquid was 92.6% by mass, the salt content was 2.8% by mass, and the glucose content was 4.6% by mass.

[0049] The shoulder meat was ground and used to produce a meat product by carrying out the following first, second and third steps.

[0050] (1st step) The mixed raw material was prepared by mixing 88.9 g of pork shoulder meat with 1.5 g of salt, 3.0 g of glucose, 4.0 g of water, 0.1 g of sodium citrate, 1.5 g of sauteed onion, and 1.0 g of lactic acid bacteria culture liquid. The mixed raw material was packed into a cellophane casing (Shikoku Tocello Co., Ltd. #340 SP-S) with a folded diameter of 6 cm.

[0051] (2nd process) The mixed raw material packed in a cellophane casing was immersed in the fermentation liquid and left to stand for 3 days (72 hours) at 19°C. In the second step, the temperature of the fermentation liquid was about 19°C.

[0052] (3rd step) The mixed raw materials packed in the cellophane casing were then removed from the fermentation liquid and dried while hanging in a temperature-controlled drying device (Taiyo Seisakusho CRD-10 model) to obtain the meat product sample 1-1. Drying was carried out at a relative humidity of 50% and a temperature of 20°C for 14 days.

[0053] <Sample 1-2: Not immersed in fermentation liquid> For sample 1-2, a meat product was obtained under the same conditions as sample 1-1, except that in the second step of sample 1-1, the sample was not immersed in the fermentation liquid but was left to stand at 19°C under aerobic conditions for 3 days (72 hours).

[0054] <Evaluation> <Color tone of bright-field image> After the second step (immediately after removal from the fermentation liquid) and after the third step (14 days after drying), each sample was cut so that the cross section was circular, allowing the inside of the meat product to be visually observed. The cross section of each sample was photographed with a digital camera Nikon D5600 (Nikon Corporation), and the color tone of the meat product in the bright field image was evaluated according to the following criteria. ++ is the most preferable. ++ Meat products are reddish throughout + Part of the meat product is reddish ± The meat product as a whole has the same color as the mixed ingredients, but fermentation has begun. - The meat product as a whole is the same color as the mixed ingredients or has a whitish color. The results are shown in Table 2.

[0055] <Color tone of fluorescent images> After the second and third steps, each sample was cut so that the cross section was circular, allowing the inside of the meat product to be viewed. The cross section of each sample was excited with ZnPP at a wavelength of 420 nm using a Select 100 LED Stand Light (420 nm) purple LED light (Optocode Corporation LED420-100STEND), and the red fluorescence (590 nm) of ZnPP was photographed using a digital camera equipped with a monochrome contrast YA3-PROFESSIONAL (55 mm) (Kenko Corporation) photographing filter that transmits around 600 nm, and the color tone of the meat product in the fluorescent image was evaluated. Red fluorescence in the fluorescent image indicates the presence of ZnPP. ++ indicates that ZnPP is in sufficient amount. ++ Strong red fluorescence visible throughout the meat product + Red fluorescence visible in parts of meat products or weak red fluorescence visible throughout meat products ± No red fluorescence is observed in meat products, but fermentation has started and only a small amount of ZnPP is produced. - No red fluorescence is observed in meat products The results are shown in Table 2.

[0056] <Effects on moldability> After the second and third steps, each sample was cut so that the cross section was circular, allowing the inside of the meat product to be seen, and evaluated visually. From the viewpoint of appearance, + is preferable. +…Meat products retaining an approximately circular shape - The meat product is misshapen or has holes in it. The results are shown in Table 2.

[0057] [Table 2]

[0058] <Results and Discussion> In sample 1-1, which was immersed in the fermentation liquid in the second step, after the second step (immediately after being removed after being immersed in the fermentation liquid for 3 days), a sufficient amount of ZnPP was produced (color tone evaluation of the fluorescent image: "++"), and the color tone of the meat product was good (color tone evaluation of the bright field image: "++").

[0059] In sample 1-2, which was not immersed in the fermentation liquid in the second step, even after the second step (3 days at 19°C) under aerobic conditions, ZnPP was not produced (color tone evaluation of the fluorescent image was "-"), and the color tone of the meat product was poor (color tone evaluation of the bright field image was "-").

[0060] From the above results, it was confirmed that the method of immersing in a fermentation liquid in the second step can promote the production of ZnPP more than the method of not immersing. Furthermore, in the method of immersing in a fermentation liquid in the second step, the meat product obtained in the second step has a good color tone, and it was confirmed that the color tone of the meat product is improved in the second step even without performing the third step.

[0061] The shape of the meat product after the third step (after 14 days of drying) was better for sample 1-1 than for sample 1-2. This result confirmed that the method of immersing in the fermentation liquid in the second step has the effect of imparting shape stability and moldability to the meat product.

[0062] [Study 2: Relationship between the presence or absence of lactic acid bacteria, the rate of ZnPP production, and the color of meat products] <Sample 2-1: Lactic acid bacteria added> A meat product was produced in the same manner as Sample 1-1 to obtain a meat product of Sample 2-1.

[0063] <Sample 2-2: No lactic acid bacteria added> In the first step of sample 1-1, a lactic acid bacteria culture medium in which Lactococcus lactis subsp. cremoris GB(A)-1 was cultured was not added, but instead an equal amount of yeast extract medium was added to the lactic acid bacteria culture medium to prepare a mixed raw material. The second and third steps were carried out in the same manner as sample 1-1, and the meat product of sample 2-2 was obtained.

[0064] <Evaluation> The meat products of Sample 2-1 and Sample 2-2 were evaluated for their effects on the color tone of the bright field image, the color tone of the fluorescent image, and moldability using the same method as in Study 1. The results are shown in Table 3.

[0065] [Table 3]

[0066] <Results and Discussion> In sample 2-1, in which lactic acid bacteria culture liquid was added to the mixed raw material in the first step, after the second step (immediately after being removed from the fermentation liquid after immersion for 3 days), a sufficient amount of ZnPP was produced (color tone evaluation of the fluorescent image: "++"), and the color tone of the meat product was good (color tone evaluation of the bright field image: "++").

[0067] In sample 2-2, to which no lactic acid bacteria culture solution was added in the first step, ZnPP was not produced after the second step (color tone evaluation of the fluorescent image was "-"), and the color tone of the meat product was poor (color tone evaluation of the bright field image was "-"). From these results, it was confirmed that even if the method of immersion in fermentation solution is used in the second step, the addition of Lactococcus lactis subsp. cremoris GB(A)-1 to the raw meat is necessary to promote the production of ZnPP in the mixed raw material during immersion in the fermentation solution.

[0068] Regarding the adhesion of the meat when it was taken out of the fermentation liquid after the second step, sample 2-2 was soft and not stuck like raw meat, whereas sample 2-1 was well stuck.

[0069] After the third process, sample 2-1 was nicely bound and dried, turning a beautiful red color (bright-field image color tone evaluation "++"), but sample 2-2 had holes, looked bad, and was not as red as sample 2-1 (bright-field image color tone evaluation "-"). The holes in sample 2-1 were thought to be caused by gases emitted by bacteria. It was also thought that the lactic acid bacteria culture solution had the effect of optimizing drying.

[0070] From the above, it was confirmed that the addition of Lactococcus lactis subsp. cremoris GB(A)-1 to raw meat has the following effects. It promotes the production of ZnPP in the raw meat. It increases the adhesion of the meat and inhibits the growth of bacteria, allowing the meat to be dried in a neatly settled state, improving the formability of the meat product. It gives the final meat product a beautiful red color.

[0071] [Study 3: Relationship between the duration of immersion in fermentation liquid, the rate of ZnPP production, and the color of meat products] <Samples 3-1 to 3-4: Differences in immersion period in fermentation liquid> For sample 3-1, a meat product was obtained in the same manner as sample 1-1, except that in the second step of the production method for sample 1-1, the immersion time in the fermentation liquid was changed to one day (24 hours). For sample 3-2, a meat product was obtained in the same manner as sample 1-1, except that in the second step of the production method for sample 1-1, the immersion time in the fermentation liquid was changed to 2 days (48 hours). For sample 3-3, a meat product was obtained in the same manner as for sample 1-1. For sample 3-4, a meat product was obtained in the same manner as sample 1-1, except that in the second step of the production method for sample 1-1, the immersion time in the fermentation liquid was changed to 4 days (96 hours).

[0072] <Evaluation> For each sample meat product, the color tone of the bright field image, the color tone of the fluorescent image, and the effect on moldability were evaluated using the same method as in Study 1. The results are shown in Table 4.

[0073] [Table 4]

[0074] <Results and Discussion> In Samples 3-2 to 3-4, the amount of ZnPP produced was sufficient (color tone evaluation of the fluorescent image was "++") after the second step (immediately after removal from the fermentation liquid).

[0075] In sample 3-4, the color of the meat product after the second step (immediately after removal from the fermentation liquid) was slightly whiter than in samples 3-2 and 3-3. This is thought to be due to the acid derived from the lactic acid bacteria.

[0076] After the third step, the color tone of the meat products was particularly good for Samples 3-2 and 3-3 (color tone evaluation of bright field image "++"), the amount of ZnPP produced was equivalent for Samples 3-1 to 3-4 (color tone evaluation of fluorescent image "++"), and the moldability was good for Samples 3-3 and 3-4. From the above, it was confirmed that the period of immersion in the fermentation liquid is more preferably 2 days (Sample 3-2) or 3 days (Sample 3-3).

[0077] [Study 4: Relationship between the temperature of the second process (temperature when immersed in the fermentation liquid and left to stand) and the rate of ZnPP production and color of meat products] <Samples 4-1 to 4-4: Differences in temperature in the second step> Sample 4-1 was a meat product obtained in the same manner as Sample 1-1, except that in the second step of the manufacturing method for Sample 1-1, the temperature (temperature of the fermentation liquid) when immersed in the fermentation liquid and left to stand was 10°C. Sample 4-2 was a meat product obtained in the same manner as Sample 1-1, except that in the second step of the manufacturing method for Sample 1-1, the temperature (temperature of the fermentation liquid) when immersed in the fermentation liquid and left to stand was 15°C. For sample 4-3, a meat product was obtained in the same manner as for sample 1-1. Sample 4-4 was a meat product obtained in the same manner as Sample 1-1, except that in the second step of the manufacturing method for Sample 1-1, the temperature (temperature of the fermentation liquid) when immersed in the fermentation liquid and left to stand was 25°C.

[0078] <Evaluation> For each sample meat product, the color tone of the bright field image, the color tone of the fluorescent image, and the effect on moldability were evaluated using the same method as in Study 1. The results are shown in Table 5.

[0079] [Table 5]

[0080] <Results and Discussion> In the second step, samples 4-3 and 4-4, which were immersed in the fermentation broth at a temperature of 19°C or higher, produced sufficient amounts of ZnPP (immediately after removal from the fermentation broth) after the second step (fluorescent image color tone evaluation: "++"). Samples 4-2 and 4-3 showed particularly good bright-field image color tone (bright-field image color tone evaluation: "++").

[0081] In the second step, sample 4-4, which was immersed in the fermentation liquid and allowed to stand at a temperature of 25°C (temperature of the fermentation liquid), had a slightly whitish color tone of the meat product after the second step (immediately after being removed from the fermentation liquid) compared to samples 4-2 and 4-3. This is thought to be due to the acid derived from the lactic acid bacteria.

[0082] In Samples 4-1 to 4-4, the amount of ZnPP produced after the third step was sufficient (fluorescent image color tone evaluation "++"). The color tone of the bright field image was particularly good for Samples 4-2 and 4-3 (bright field image color tone evaluation "++"). Samples 4-2 to 4-4 had good moldability. From the viewpoints of the color tone of the meat after the third step, the production of ZnPP, and moldability, it was confirmed that the temperatures at which the meat was immersed in the fermentation liquid and allowed to stand (fermentation liquid temperature) were particularly suitable at 15°C (Sample 4-2) and 19°C (Sample 4-3).

[0083] [Study 5: Relationship between the temperature in the third process (drying) and the rate of ZnPP production and the color of meat products] <Samples 5-1 to 5-2: Difference in temperature in the third step> For sample 5-1, a meat product was obtained in the same manner as for sample 1-1. For sample 5-2, a meat product was obtained in the same manner as sample 1-1, except that in the third step, the drying temperature was 25°C.

[0084] <Evaluation> For each sample meat product, the color tone of the bright field image, the color tone of the fluorescent image, and the effect on moldability were evaluated using the same method as in Study 1. The results are shown in Table 6.

[0085] [Table 6]

[0086] <Results and Discussion> After the second process, in both samples 5-1 and 5-2, the color of the meat products was good (color tone evaluation of bright field image "++"), and the amount of ZnPP produced was sufficient (color tone evaluation of fluorescent image "++").

[0087] After the third step, the amount of ZnPP produced was sufficient in both sample 5-1 and sample 5-2 (fluorescent image color tone evaluation "++"). The color tone of the meat product was redder and better in sample 5-1 than in sample 5-2 (bright field image color tone evaluation "++"). Therefore, it was confirmed that the drying temperature in the third step was 19°C (sample 5-1) rather than 25°C (sample 5-2).

[0088] [Study 6: Relationship between the fermentation of spice-containing mixed ingredients and the rate of ZnPP production and the color of meat products] <Sample 6-1: Immersed in fermentation liquid> Spices prepared were garlic, coriander, cloves, and black pepper. 87.0 g of pork shoulder meat was mixed with 1.5 g of salt, 3.0 g of glucose, 4.0 g of water, 0.1 g of sodium citrate, 1.5 g of sauteed onion, 0.5 g of garlic, 0.3 g of coriander, 0.3 g of cloves, 0.8 g of black pepper, and 1.0 g of lactic acid bacteria culture liquid in the following ratio to prepare a mixed raw material. The mixed raw material containing spices was packed into a cellophane casing (Shikoku Tocello Co., Ltd. #340 SP-S) with a folded diameter of 6 cm. Then, the second and third steps were performed in the same manner as in Sample 1-1, and the meat product of Sample 6-1 was obtained.

[0089] <Sample 6-2: Not immersed in fermentation liquid> The same spice-containing mixed raw material as sample 6-1 was stuffed into a 6 cm folded cellophane casing (Shikoku Tocello Co., Ltd. #340 SP-S). Without going through the second process, the mixed raw material stuffed into the cellophane casing was hung and dried in a temperature-controlled drying device to obtain the meat product sample 6-2. Drying was carried out at a relative humidity of 50% and a temperature of 20°C for 12 days.

[0090] <Evaluation> For each sample meat product, the color tone of the bright field image, the color tone of the fluorescent image, and the effect on formability were evaluated using the same method as in Study 1. For the meat product of sample 6-2, the color tone of the bright field image, the color tone of the fluorescent image, and the effect on formability were evaluated on the 1st day and the 12th day of drying. The results are shown in Table 7.

[0091] [Table 7]

[0092] <Results and Discussion> In sample 6-1, which was immersed in the fermentation liquid in the second step, the color of the meat product was good (color evaluation of bright field image: "++") and the amount of ZnPP produced was sufficient (color evaluation of fluorescent image: "++") after the second step (immediately after removal from the fermentation liquid) and the third step (after 14 days of drying). In the fluorescent image of sample 6-1, the production of ZnPP was confirmed over the entire cross section of the meat product, including the edges, after the third step.

[0093] In the fluorescent image of sample 6-2, which was not immersed in the fermentation liquid, ZnPP formation was confirmed only on the inside of the cross section of the meat product after 12 days of drying, and no ZnPP formation was confirmed on the edge, and a ring-shaped area with a different color tone was confirmed along the outer edge. This was thought to be because microorganisms derived from spices proliferated during drying in sample 6-2, suppressing the formation of ZnPP. In addition, the color tone of the meat product of sample 6-2 after 12 days of drying was inferior to the color tone of the meat product of sample 6-1 after the second and third processes.

[0094] From the above, it is considered that in sample 6-1, the proliferation of microorganisms derived from spices was inhibited by immersion in the fermentation liquid, and therefore ZnPP was produced by lactic acid bacteria throughout the entire meat product from the inside to the edges. It is considered that the method of immersion in the fermentation liquid in the second step inhibits the activity of other microorganisms and promotes the production of ZnPP throughout the entire meat product from the inside to the edges.

[0095] [Study 7: Relationship between the type of lactic acid bacteria added, the rate of ZnPP production, and the color of meat products]

[0096] <Samples 7-1 to 7-3: Differences due to the type of lactic acid bacteria added> For sample 7-1, meat products were obtained using the same method as for sample 1-1. In Table 8 below, the lactic acid bacterium Lactococcus lactis subsp. cremoris GB(A)-1 strain used in sample 7-1 is referred to as "Znb." For sample 7-2, a meat product was obtained in the same manner as sample 1-1, except that the lactic acid bacteria contained in the lactic acid bacteria culture solution was changed to R-704 (a mixture of Lactococcus lactis and Lactococcus cremoris, manufactured by Christian Hansen). For sample 7-3, a meat product was obtained in the same manner as sample 1-1, except that the lactic acid bacteria contained in the lactic acid bacteria culture solution was changed to YF-L811 (a mixture of Lactobacillus bulgaricus and Streptococcus thermophilus, manufactured by Christian Hansen). For sample 7-4, a meat product was obtained in the same manner as sample 1-1, except that the lactic acid bacteria contained in the lactic acid bacteria culture solution was changed to CHN-11 (Christian Hansen, a mixture of Lactococcus lactis, Lactococcus cremoris, Lactococcus diacetylactis, and Leuconostoc cremoris).

[0097] [Table 8]

[0098] <Results and Discussion> For all samples, the meat products had a good color tone (color tone score of "++" in bright field images) and sufficient ZnPP production (color tone score of "++" in fluorescent images) after the second process, 7 days after drying, and 14 days after drying. For all samples, ZnPP production was confirmed throughout the entire cross-section of the meat products, including the edges, in the fluorescent images after the second process, 7 days after drying, and 14 days after drying. In other words, it was confirmed that ZnPP was produced throughout the entire meat product, from the inside to the edges, even when lactic acid bacteria other than Lactococcus lactis subsp. cremoris GB(A)-1 were used as the lactic acid bacteria.

[0099] As described above, the embodiments and examples of the present disclosure have been described. However, it is also intended from the beginning that the configurations of the above-described embodiments and examples may be appropriately combined or modified in various ways.

[0100] The embodiments and examples disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is indicated by the claims rather than the above-described embodiments and examples, and is intended to include the meaning equivalent to the claims and all modifications within the scope.

Claims

1. A first step of mixing a raw material meat and lactic acid bacteria to obtain a mixed raw material; A second step of fermenting the mixed raw material while immersing it in a fermentation liquid to obtain a meat product.

2. 2. The method for producing a meat product according to claim 1, wherein in the second step, production of zinc protoporphyrin IX in the mixed raw material is promoted.

3. The method for producing a meat product according to claim 1 or 2, wherein the fermentation liquid contains 5% by mass or less of salt and 1% by mass or more and 10% by mass or less of sugar.

4. 3. The method for producing a meat product according to claim 1 or 2, wherein in the second step, after the mixed raw material is shaped, the mixed raw material is immersed in the fermentation liquid.

5. 3. A method for producing a meat product according to claim 1 or claim 2, further comprising, after the second step, a third step of drying the meat product.

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