WO2022030493A1

WO2022030493A1 - Zinc protoporphyrin ix-forming agent containing lactic acid bacteria, and color tone-improving method and manufacturing method for processed food using same

Info

Publication number: WO2022030493A1
Application number: PCT/JP2021/028777
Authority: WO
Inventors: 純一若松; カウサーウルアラムムド; 徹早川; 朗人玖村
Original assignee: 国立大学法人北海道大学
Priority date: 2020-08-03
Filing date: 2021-08-03
Publication date: 2022-02-10
Also published as: JP7190750B2; JP2022028150A

Abstract

The present invention provides: an agent and a method for forming zinc protoporphyrin IX under an aerobic condition using lactic acid bacteria belonging to the genus Lactococcus; an agent and a method for improving the color tone of a meat product; and a method for manufacturing a meat product. According to the present invention, ZnPP can be formed, in particular, not only in the center of a meat product manufactured under an aerobic condition, but also on the surface or the surface layer part thereof, where ZnPP was hardly formed in the prior art due to being susceptible to oxygen.

Description

Zinc protoporphyrin IX forming agent containing lactic acid bacteria, and a method for improving the color tone and manufacturing method of processed foods using the same.

The present invention comprises an agent and method for forming zinc protoporphyrin IX under aerobic conditions using Lactococcus lactic acid bacteria, an agent and method for improving the color tone of a meat product, and a meat product. Regarding the method.

The color tone of meat is affected by the state of myoglobin, which is the main pigment protein in meat. Myoglobin has one heme, which is an iron complex of protoporphyrin IX, in its molecule, and its color tone changes greatly depending on the type of molecule coordinate-bonded to the sixth ligand of this heme iron and the charge state of iron. do.

The color tone of bright red meat seen in fresh meat is due to a derivative called oxymyoglobin in which an oxygen molecule is bound to the 6th ligand and the charge of heme iron is divalent. On the other hand, in old and deteriorated meat, the color tone becomes brown and it looks bad, but this is because the heme iron in myoglobin is oxidized to trivalent, and the oxygen of the 6th ligand is removed and replaced with water molecules. This is because the absorption spectrum of light changes by changing to a derivative called. In addition, when the meat is heated, it turns grayish brown because the protein portion (globin) of myoglobin in the meat is denatured by heating to become denatured globin hemicromium. All heme iron in the modified globin hemichrome is trivalent in the oxidized state.

On the other hand, many meat products use color-developing agents such as nitrates and nitrites, and nitric oxide produced by the decomposition of these color-developing agents during salting coordinates with heme iron in myoglobin. A stable bright red derivative called nitrosylmyoglobin is formed. When salted meat is heated, it becomes pinkish red, which is peculiar to meat products, because the heating denatures globin, which is the protein part of myoglobin, and changes it to a myoglobin derivative called modified globin nitrosylhemochrome. .. Not only is the bond between heme iron and nitric oxide strong, but because it stabilizes iron, the heme of modified globin nitrosylhemochrome binds nitric oxide even after heating, and the charge of heme iron remains divalent. Is. When heme iron becomes trivalent, it is unstable and the coordinated iron ion (III) is easily released. Since iron ions (III) in an oxidized state have an oxidation catalytic action on other substances, unpleasant odors such as warmed overflavors occur when a coloring agent is not used. Furthermore, since the coloring agent inhibits the growth of Clostridium botulinum, it also has an important function of preventing botulinum toxin, which has a high mortality rate, and has been used as an important additive for a long time.

However, nitrite derived from a color former produces a carcinogenic N-nitroso compound when it reacts with amines and amides under acidic conditions. In addition, in the carcinogenic risk of the International Agency for Research on Cancer, processed meat products are classified into Group 1 which is said to have high grounds for carcinogenicity to humans. .. However, the amount added is extremely small, and in many countries including Japan, the acceptable daily intake (ADI) is scientifically calculated and the usage standard is set, but there are consumers who are concerned about the danger. However, there are calls for unsalted meat products that are inferior in preservability and flavor as well as color tone.

By the way, the traditional Italian prosciutto ham, Parma Ham, is prohibited from using a coloring agent, but its color tone is bright red. This is due to the heme in which the meat pigment myoglobin is coordinated with iron to protoporphyrin IX, whereas a large amount of zinc protoporphyrin IX (ZnPP) in which zinc is coordinated with protoporphyrin IX is accumulated. (Non-Patent Document 1). ZnPP is more stable to heat and light than heme due to the difference in the coordinated metal. Therefore, elucidation of the formation mechanism and applied technology have been studied, and a patent application has been filed as a color tone improvement technology using ZnPP (Patent Document 1 and Patent Document 2). ZnPP is thought to be formed by the intrinsic components of meat, but the formation mechanism has not been completely elucidated until now. On the other hand, promotion of ZnPP formation by a specific type of microorganism has also been reported as an extrinsic factor of meat (Non-Patent Document 2 and Non-Patent Document 3).

ZnPP is gradually formed during manufacturing and accumulated in the final product, so it is considered to be particularly suitable for improving the color tone of long-term aged meat products. Long-term aged prosciutto ham and dry sausages such as salami, which are examples of such long-term aged meat products, have established a solid position as high-class foodstuffs and continue to be widely produced even today. There is.

It has been clarified that the formation of ZnPP is inhibited by oxygen at the test tube level using meat (Non-Patent Document 4). This has been reported in both the system using only the intrinsic factor of meat excluding the influence of microorganisms and the experimental system considering external factors such as microorganisms. In large bone-in hams made of thigh meat such as palma ham that does not use a coloring agent, most of them are covered with skin and subcutaneous fat, and the red meat inside is not exposed to oxygen, so ZnPP is used. It is formed and exhibits a vivid color tone. On the other hand, since the excised part near the hip joint is significantly dried from the surface layer and has an effect of oxidation, the surface is generally excised and the inside is sliced and eaten.

On the other hand, most dry sausages such as salami are smaller than prosciutto, although it depends on the product. In the product using the coloring agent, the whole is bright red, but when the coloring agent is not used, ZnPP is formed inside the product and it is bright red, but ZnPP is not formed in the part where oxygen comes in contact. It turns brown. Specifically, the surface and the surface layer a few millimeters from the surface are significantly discolored, and unlike prosciutto, the surface is not cut off, so the unfavorable color tone of the appearance is unsightly and suppresses consumer behavior. However, even in the cross section, discoloration of the surroundings may be regarded as quality deterioration and eating behavior may be suppressed.

Since oxygen inhibits ZnPP formation, it is possible to block oxygen by vacuum packaging or the like. However, in long-term aged molded meat products, drying during production is an important storage means, so blocking oxygen suppresses drying, and the original purpose of processing and storage cannot be achieved.

Japanese Patent No. 3949588 Japanese Unexamined Patent Publication No. 2006-254818

An object of the present invention is to provide a new means capable of forming ZnPP in a meat product whose influence of oxygen cannot be eliminated because it is produced under aerobic conditions.

The present inventors have found that lactic acid bacteria belonging to the genus Lactococcus have the ability to form ZnPP even under aerobic conditions in which oxygen, which is a ZnPP formation inhibitor, is present. Was completed.

(1) An agent for forming zinc protoporphyrin IX under aerobic conditions in a meat-containing material containing Lactococcus lactic acid bacteria.
(2) The agent according to (1), wherein the lactic acid bacterium is a bacterium belonging to Lactococcus lactis.
(3) The agent according to (1) or (2), wherein the lactic acid bacterium is a bacterium belonging to the Lactococcus lactis subsp. Cremoris.
(4) A method for forming zinc protoporphyrin IX in a meat-containing material under aerobic conditions, which comprises adding Lactococcus lactic acid bacteria to the meat-containing material.
(5) The method according to (4), wherein the lactic acid bacterium is a bacterium belonging to Lactococcus lactis.
(6) The method according to (4) or (5), wherein the lactic acid bacterium is a bacterium belonging to the Lactococcus lactis subspecies Cremoris.
(7) An agent for improving the color tone of all meat products produced under aerobic conditions, which contains Lactococcus lactic acid bacteria.
(8) The agent according to (7), wherein the lactic acid bacterium is a bacterium belonging to Lactococcus lactis.
(9) The agent according to (7) or (8), wherein the lactic acid bacterium is a bacterium belonging to the Lactococcus lactis subspecies Cremoris.
(10) A method for improving the color tone of a whole meat product produced under aerobic conditions, which comprises adding Lactococcus lactic acid bacteria to a meat product raw material.
(11) The method according to (10), wherein the lactic acid bacterium is a bacterium belonging to Lactococcus lactis.
(12) The method according to (10) or (11), wherein the lactic acid bacterium is a bacterium belonging to the Lactococcus lactis subspecies Cremoris.
(13) A meat product having an improved color tone as a whole, including the addition of Lactococcus lactic acid bacteria to the raw material of the meat product and the production of the meat product from the raw material of the meat product after the addition of the lactic acid bacteria under aerobic conditions. How to manufacture.
(14) The method according to (13), wherein the lactic acid bacterium is a bacterium belonging to Lactococcus lactis.
(15) The method according to (13) or (14), wherein the lactic acid bacterium is a bacterium belonging to the Lactococcus lactis subspecies Cremoris.
(16) Lactococcus lactis subspecies Cremoris GB (A) -1 strain deposited under accession number NITE BP-03229.

According to the present invention, in meat products manufactured under aerobic conditions, not only in the central portion thereof, but also on the surface where it is conventionally difficult to form ZnPP due to the influence of oxygen. ZnPP can also be formed on the surface layer portion.

A bright-field observation image (upper row) of salted ground meat to which various bacteria were added and incubated under anaerobic conditions, and a fluorescence image (lower row) at an excitation wavelength of 420 nm and a fluorescence wavelength of 590 nm. It is a graph which quantified the color tone of the salted minced meat which was incubated under anaerobic conditions to which various bacteria were added. A bright-field observation image of a cross section of a dry sausage produced by adding various bacteria (left column) and a fluorescence image at an excitation wavelength of 420 nm and a fluorescence wavelength of 590 nm (right column). It is a graph which quantified the color tone of the cross section of the dry sausage produced by adding various bacteria. It is a bright-field observation image of the surface of a dry sausage produced by adding various bacteria. It is a graph which quantified the color tone of the surface of the dry sausage produced by adding various bacteria. It is a graph which shows the fluorescence intensity at the excitation wavelength of 420 nm and the fluorescence wavelength of 590 nm of the pork homogenate which was incubated under aerobic or anaerobic conditions to which various bacteria were added. A heated or unheated pork homogenate supplemented with Lactococcus lactis subspecies Cremoris GB (A) -1 strain and incubated under aerobic or anaerobic conditions at an excitation wavelength of 420 nm and a fluorescence wavelength of 590 nm. It is a graph which shows the fluorescence intensity. It is a graph which shows the fluorescence intensity at the excitation wavelength of 420 nm and the fluorescence wavelength of 590 nm of the pork homogenate which was added with Lactococcus lactic acid bacteria and incubated under aerobic conditions.

ZnPP Forming Agent and ZnPP Forming Method The present invention provides an agent for forming ZnPP under aerobic conditions in a meat-containing material containing Lactococcus lactic acid bacteria. The present invention also provides a method for forming zinc protoporphyrin IX in a meat-containing material under aerobic conditions, which comprises adding Lactococcus lactic acid bacteria to the meat-containing material.

ZnPP is Dihydrogen [3,8,13,17-tetramethyl-7,12-divinyl-21H, 23H-porphine-2,18-dipropionato (4-)-N21, N22, N23, N24] zincate (4-) Also represented (CAS No. 15442-64-5), zinc (Zn) is added to porphyrin (protoporphyrin IX), which has a structure in which four methyl groups, two vinyl groups, and two propionic acid groups are bonded to the porphyrin ring. It is a coordinated complex compound.

The lactic acid bacterium used in the present invention is a bacterium belonging to the genus Lactococcus, for example, Lactococcus allomyrinae, Lactococcus chungangensis, Lactococcus formosensis, Lactococcus fujiensis, Lactococcus garvieae, Lactococcus hircilactis, Lactococcus kimchi, Lactococcus kimchi, Lactococcus lactis Lactococcus laudensis, Lactococcus nasutitermitis, Lactococcus petauri, Lactococcus piscium, Lactococcus piscium, Lactococcus planta It can be a bacterium belonging to (Lactococcus raffinolactis), Lactococcus reticulitermitis, Lactococcus taiwanensis or Lactococcus termiticola.

In a preferred embodiment, the lactic acid bacterium is a bacterium belonging to Lactococcus lactis or Lactococcus rafinolactis. Bacteria belonging to Lactococcus lactis are, for example, Lactococcus lactis subsp. Tructae, Lactococcus lactis subsp. Lacttis, and Lactococcus lactis subsp. Lactococcus. It can be a bacterium belonging to lactis subsp. Cremoris) or Lactococcus lactis subsp. Hordniae.

In a more preferred embodiment, the lactic acid bacterium is a bacterium belonging to Lactococcus lactis subspecies Turkutae, Lactococcus lactis subspecies Lactis or Lactococcus lactis subspecies Cremoris. Particularly preferably, the lactic acid bacterium is a bacterium belonging to the Lactococcus lactis subspecies Cremoris.

In the present invention, Lactococcus lactic acid bacteria stored or commercially available in various microbial strain storage institutions can be used. Examples of such lactic acid bacteria are, for example, Lactococcus lactis subspecies Lactis NBRC12007 strain, Lactococcus lactis subspecies Lactis NBRC100933 strain, and lacto deposited at the Bioresource Center (NBRC), Incorporated Administrative Agency. Coccus lactis subspecies Cremoris NBRC100676 strain, Lactococcus lactis subspecies Holdoniae NBRC100931 strain, Lactococcus lactis subspecies Turkutae NBRC110453 strain; Examples thereof include Lactococcus lactis subspecies Cremoris AHU1983 strain and Lactococcus lactis subspecies Cremoris AHU1987 strain conserved in.

In addition, Lactococcus lactis subspecies Cremoris GB (A) -1 strain, Lactococcus raffinolactis OM (A) -1 strain and Lactococcus lactis CH-1 strain, which are newly isolated lactic acid bacteria by the present inventors. Can also be used in the present invention. GB (A) -1 strain was issued to the Patent Microorganisms Depositary Center, National Institute of Technology and Evaluation, 2-5-8 Kazusakamatari, Kisarazu City, Chiba Prefecture, Japan, on June 10, 2020. It has been deposited internationally as 03229 (Indication of identification: GB (A) -1).

Table 1 below shows the mycological properties of the GB (A) -1 strain.

In a preferred embodiment of the invention, the lactic acid bacteria are Lactococcus lactis subspecies Cremoris GB (A) -1, Lactococcus lactis subspecies Lactis NBRC12007 strain, Lactococcus lactis subspecies Lactis NBRC100933 strain, Lactococcus lactis. Subspecies Turkutae NBRC110453 strain or Lactococcus lactis CH-1 strain. Particularly preferred is the Lactococcus lactis subspecies Cremoris GB (A) -1 strain.

Lactococcus lactic acid bacteria are prepared by culturing under commonly used culture conditions, for example, using MRS medium at a temperature of 25 to 37 ° C. for 8 to 48 hours under aerobic or anaerobic conditions. can do.

Lactococcus lactic acid bacteria can produce ZnPP under aerobic conditions in a material containing meat. Here, the aerobic condition means that the meat-containing material is placed in the air or in a gas containing oxygen having a concentration similar to that in the air. Lactococcus lactic acid bacteria can produce ZnPP by coexisting with a meat-containing material and leaving it under aerobic conditions, for example, at a temperature of 4 to 37 ° C. for several days to several weeks.

Lactococcus lactic acid bacteria can produce ZnPP even under anaerobic conditions in a material containing meat. Here, the anaerobic condition means that the gas is placed in a gas having almost no oxygen, for example, an oxygen concentration of less than 0.1 vol%, which is generally used for culturing anaerobic bacteria.

The meat-containing material is not limited as long as it contains meat, and is a test sample for an experiment, for example, pork homogenate or minced pork described in J. Wakamatsu et al., Meat Science, 2020, 165, 107989. It may be a raw material for meat products. Examples of meat include beef, pork, mutton, goat meat, horse meat, deer meat, chicken meat, rabbit meat, whale meat and other meats of mammals having a bright red, pinkish red or reddish color. , Not limited to these. When a meat product raw material is used as a material containing meat, the meat product raw material may contain, in addition to the meat, ingredients necessary for the production of the meat product, such as salt and optionally spices.

As described in Examples described later, it has been confirmed that the amount of ZnPP produced by the Lactococcus lactis subspecies Cremoris GB (A) -1 strain is reduced by heating the coexisting meat-containing material. Therefore, when GB (A) -1 strain is used as Lactococcus lactic acid bacteria, it is preferable to use unheated meat-containing material, and even when heating is required, the amount of ZnPP produced is not excessively reduced. It is preferable to keep it in a mild heat treatment.

ZnPP can be extracted from the meat-containing material after coexisting with Lactococcus lactic acid bacteria using 75% acetone or the like, and can be detected or measured by HPLC or other methods. In addition, ZnPP is detected and measured by measuring the fluorescence intensity at 590 nm when irradiated with excitation fluorescence at 420 nm according to the method described in J. Wakamatsu et al., Meat Science, 2007, 77, 580-586. You can also do it.

Color tone improving agent for meat products, color tone improving method The present invention provides an agent for improving the color tone of all meat products produced under aerobic conditions, including Lactococcus lactic acid bacteria. The present invention also provides a method for improving the overall color tone of a meat product produced under aerobic conditions, which comprises adding Lactococcus lactic acid bacteria to the raw material of the meat product. Further, the present invention includes the addition of Lactococcus lactic acid bacteria to the raw material of the meat product and the production of the meat product from the raw material of the meat product after the addition of the lactic acid bacteria under aerobic conditions, and the color tone is improved as a whole. Provide a method for producing a meat product.

In the present invention, color tone improvement means to change the color tone of a meat product, which causes browning or fading under the influence of oxygen when manufactured and stored by a conventional method, to a preferable color tone, specifically, freshness. It means to change to a highly palatable color tone such as red, pink red or reddish color, or to maintain the color tone.

The color tone improvement is performed by measuring the lightness L *, the chromaticity a * and b * by a known method for evaluating the color tone of the meat product, for example, by visual observation or by using a color difference meter, and the saturation C * and the hue. It can be evaluated by a method of calculating the angle h or the like.

As mentioned above, Lactococcus lactic acid bacteria can produce ZnPP in meat-containing materials under aerobic conditions. Therefore, by adding Lactococcus lactic acid bacteria to the raw material of meat products and subjecting them to manufacturing processes such as aging under aerobic conditions, the surface that comes into contact with oxygen and the surface through which oxygen can permeate to a depth of about 5 mm. It is possible to produce a meat product in which ZnPP is formed in a portion (referred to as a surface layer portion). Furthermore, since Lactococcus lactic acid bacteria can produce ZnPP even under anaerobic conditions, the above-mentioned meat products produced using Lactococcus lactic acid bacteria can be produced in any of the central, surface and surface layers thereof. It is also possible that ZnPP is formed in.

The formation and accumulation of ZnPP, which is a bright red pigment, brings about an improvement in the color tone of meat products. Therefore, by using Lactococcus lactic acid bacteria to form a sufficient amount of ZnPP in the whole meat product for improving the color tone, it is possible to produce a meat product having an improved color tone as a whole. To form a sufficient amount of ZnPP to improve the color tone, adjust the addition amount according to the ZnPP forming ability of the Lactococcus lactic acid bacterium to be added, or lengthen the contact time between the Lactococcus lactic acid bacterium and the raw material of the meat product. Can be achieved by.

The meat products in the present invention include hams such as bone-in ham, boneless ham, loin ham, shoulder ham, berry ham, lux ham, and raw ham; pressed hams such as pressed ham and mixed pressed ham; Boronia sausage, Frankfurt sausage, and Wiener. Sausages such as sausages, liona sausages, lever sausages, semi-dry sausages, dry sausages, pressurized heated sausages, mixed sausages, pressurized heated mixed sausages; bacon, loin bacon, shoulder bacon, middle bacon, side bacon and other bacon However, it is not limited to these.

Meat products are required to have more remarkable color deterioration due to oxygen, that is, products that require long-term aging or drying under aerobic conditions in the manufacturing process, or long-term storage under aerobic conditions. Those are preferable.

In the case of meat products that are heat-treated during production, the heme derived from the meat becomes grayish brown modified globin hemichrome by heating, so more ZnPP formation may be required to obtain the effect of improving the color tone. When it is desired to avoid the influence of such heat denaturation of heme, the meat product is preferably a non-heated meat product or a dried meat product. Examples of such meat products include lux ham, prosciutto, semi-dry sausage, and dry sausage. In the present invention, a particularly preferable meat product is semi-dry sausage or dry sausage.

A general manufacturing method for meat products, except that lactococcus lactic acid bacteria are added to the raw material of meat products at any time in the manufacturing process, and in the case of heated meat products, at any time in the manufacturing process before heating. It can be manufactured by, and the implementation of such manufacturing methods is within the normal practice capacity of those skilled in the art. For example, in the case of sausages, the addition of lactococcus lactic acid bacteria is performed in any of the steps of meat grinding, salting, seasoning, and filling in a casing, and in the case of hams, shaping, salting, and filling in a casing. In any of the steps, in the case of bacon, it can be carried out in either the shaping or salting step. In the production of meat products, oxygen blocking means such as vacuum packaging and oxygen scavengers do not need to be used in particular, but the use is not excluded. In addition, conventional color formers such as nitrite do not need to be used in particular, but rather nitric oxide produced by the color former inhibits the formation of ZnPP (J. Wakamatsu et al., Meat Science, 2010, 84 (J. Wakamatsu et al., Meat Science, 2010, 84). 1), 125-128), In the present invention, it is preferable not to use a color-developing agent in the production of meat products, or if it is used, to keep the amount so as not to inhibit the formation of ZnPP.

The meat product produced in this way has an excellent color tone not only in the central portion but also on the surface and the surface layer portion, even though the coloring agent and the oxygen removing means are not used. Therefore, it is possible to avoid product disposal due to deterioration of appearance, and it is expected that it will lead to saving of animal protein resources and reduction of food waste. Furthermore, by not using a color former, there is no risk of nitrosamine formation, and safety is high.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 ZnPP formation and color tone improvement by GB (A) -1 strain (ground meat model of salted pork, anaerobic conditions)
The bacteria listed in Table 2 below were anaerobically cultured in each medium at 37 ° C. overnight, and then the cells were collected by centrifugation and suspended in sterile physiological saline.

AHU: National University Corporation Hokkaido University Graduate School of Agriculture Applied Mycological Strain Preservation Room

After vacuum-packing the minced meat of the longissimus chest and waist obtained from commercially available domestically produced crossed pork loin, it was sterilized overnight under UV irradiation to obtain sterilized minced pork. After adding NaCl to 3% by mass to 9 g of sterilized minced pork and mixing, 1 mL of the above bacterial suspension (final concentration 2 × 10 ⁶ CFU / g) was added and mixed. The mixture was packed in a vacuum package (Hiryu N-1, Asahi Kasei Pax Corp.), vacuum packaged and incubated at 18 ° C for 14 days. A mixture (control group and nitrite group, respectively) containing sterile water or sodium nitrite (final concentration 200 ppm) instead of the bacterial suspension was prepared and incubated in the same manner as above.

The surface of each sample after incubation was photographed using a digital camera (upper part of Fig. 1), and the color tone was observed. In addition, using two purple LED irradiators equipped with a sheet-type bandpass filter (Fujifilm BPB42, Fuji Corporation) that transmits around 420 nm, ZnPP is excited by light with a wavelength of 420 nm, and the red fluorescence of ZnPP (590 nm). ) Was photographed in dark conditions using a digital camera equipped with a sheet-type bandpass filter (Fujifilm BPB60, Fuji Corporation) that transmits around 600 nm (lower part of Fig. 1). All of the bacterial inoculation plots showed a bright red color by macroscopic observation, though not as much as in the nitrite plot. In addition, almost no red fluorescence of ZnPP was observed in the control group and the nitrite group, but strong red fluorescence of ZnPP was confirmed in both the bacterial inoculation group.

The brightness L *, redness a * and yellowness b * of each sample are measured using a color difference meter (CM-700d, Konica Minolta), and the saturation C * and hue angle h are calculated from a * and b *. (Fig. 2). The redness of the bacterial inoculated group was higher than that of the control group and showed a value close to that of the nitrite group. In addition, the bacterial inoculation group had a lower yellowness but the same hue angle as the nitrite group. This means that the shade of the bacterial inoculation plot is roughly equal to that of the nitrite plot. In addition, since the lightness of the bacterial inoculation area is slightly higher than that of the nitrite area and the saturation is slightly lower, the color tone of the bacterial inoculation area is slightly inferior in brightness and vividness, but the color tone is similar to that of the nitrite area. Was confirmed.

Example 2 ZnPP formation and color tone improvement by GB (A) -1 strain (dry sausage)
After adding NaCl and glucose to 3% by mass and 1% by mass, respectively, to sterilized minced pork and mixing them, the final concentrations of the bacterial suspensions of EF, LnL, LbP, LbC and LLC prepared in Example 1 were adjusted. It was added and mixed to 1 × 10 ⁶ CFU / kg. The mixture was filled in a casing (folding diameter 6 cm). After holding at 1 ° C for 7 days while hanging, it was fermented at 23 ° C for 8 hours. Immediately after that, the temperature was lowered to 7 ° C, raised by 1 ° C in 2 days, dried to 14 ° C for 2 weeks, and then dried and aged at 14 ° C for 1 week to produce dry sausages. The relative humidity during the drying and aging period was 80-90%. In addition, sterile water or sodium nitrite (final concentration 200 ppm) was added in place of the bacterial suspension to produce dry sausages (control group and nitrite group, respectively) in the same manner as above.

In the same manner as in Example 1, the color tone of each dry sausage cross section was observed, and the red fluorescence of ZnPP was measured (FIG. 3). The dry sausage in the nitrite group showed a bright red color both inside and on the surface, but no red fluorescence derived from ZnPP was observed. In the LnL group, the color tone was not bright red, and red fluorescence derived from ZnPP was not strongly observed. In the EF group and the LbP group, red fluorescence derived from ZnPP was strongly observed inside the cross section, but not on the surface layer, and the color tone was not good.

In contrast, the LbC and LLC plots showed a bright red color and were as bright as the nitrite plot. In addition, strong red fluorescence derived from ZnPP was also observed. In particular, in the LLC section, strong red fluorescence was observed not only inside the cross section but also in the entire cross section including the surface layer portion, and the entire cross section including the surface layer portion had a preferable vivid color tone. On the other hand, in the LbC group, red fluorescence was not observed in the surface layer portion, and the colors in the surface layer portion and the inside were significantly different.

In the same manner as in Example 1, the color tone of the central part of the dry sausage was quantified by a color difference meter (Fig. 4). In the LLC plot, not only was the redness comparable to that in the nitrite plot, but the saturation was also the highest.

Figure 5 shows the color tone of the surface of the dry sausage. The color tone of the LLC plot was as bright red as that of the nitrite plot. The LnL and EF plots showed a red color compared to the control plot, LbC plot or LbP plot, but were less vivid than the LLC and nitrite plots.

FIG. 6 shows a graph in which the color tone of the surface of the dry sausage is quantified by a color difference meter. The LLC group showed the same degree of redness as the nitrite group, and the hue angle and saturation were also the same.

As described above, the Lactococcus lactis subspecies Cremoris GB (A) -1 strain forms ZnPP on the entire dry sausage including the surface and surface layer in the production of dry sausage under aerobic conditions, and is dried. It was confirmed that the sausage had an effect of improving the color tone of the whole sausage.

Example 3 ZnPP formation with GB (A) -1 strain (pork homogenate, aerobic and anaerobic conditions)
Sterile minced pork was added to physiological saline to a concentration of 30% by mass, and homogenized at 10,000 rpm for 90 seconds using a homogenizer (CELL MASTER CM-100, AZ ONE Co.). Bacterial suspensions of homogenate, NaCl and LnL, LnM, LbP, LbC and LLC prepared in Example 1 were added to a sterile test tube and mixed (final concentration of minced pork 20% by mass, final concentration of NaCl 3 mass). %, Final bacterial concentration 2.0 x 10 ⁶ CFU / mL). The test tubes were covered and placed in a gas-impermeable bag and incubated at 25 ° C. for 5 days under aerobic or anaerobic conditions. Anaerobic conditions were maintained with an oxygen absorber (A-500HS, I.S.O. Inc.). In addition, a mixture in which sterile water was added instead of the bacterial suspension (control group), or an antibiotic (penicillin G potassium final concentration 70 μg / mL, streptomycin sulfate final concentration 250 μg / mL, gentamicin) instead of the bacterial suspension. A mixture (antibiotic group) to which the final concentration of sulfate 50 μg / mL) was added was prepared in the same manner as above and incubated. An antibiotic group was set up to confirm that there was no contamination of microorganisms capable of forming ZnPP during the operation.

3 times the amount of cold acetone was added to the mixture after incubation, mixed, and allowed to stand in a dark place at 4 ° C for 30 minutes to extract ZnPP. After filtering with filter paper, the fluorescence intensity at a wavelength of 590 nm when excited with excitation light with a wavelength of 420 nm was measured using a fluorescence spectrophotometer (RF-5300PC, Shimadzu Corporation) and used as the amount of ZnPP formed.

The amount of ZnPP formed is shown in FIG. In the LnL, LnM, LbP and LbC sections, ZnPP was formed under anaerobic conditions, but ZnPP formation was almost completely suppressed under aerobic conditions. On the other hand, in the LLC section, ZnPP was formed under aerobic conditions to the same extent as under anaerobic conditions.

Example 4 ZnPP formation with GB (A) -1 strain (heated or unheated pork homogenate, aerobic and anaerobic conditions)
Using unheated salted pork homogenate, short-time heating (100 ° C, 20 seconds) to inactivate the enzyme, and autoclaved pressure-heating (121 ° C, 15 minutes) salted pork homogenate. The ZnPP formation of the Lactococcus lactis subspecies Cremoris GB (A) -1 strain was evaluated in the same manner as in Example 3.

The amount of ZnPP formed is shown in FIG. The amount of ZnPP formed in the LLC group decreased due to the heat treatment of the homogenate, and in particular, the ZnPP formation was no longer observed when the pressure heat treatment was performed.

Example 5 ZnPP formation by Lactococcus lactic acid bacteria (pork homogenate, aerobic conditions)
Lactococcus lactic acid bacteria shown in Table 3 below were added to the salted pork homogenate in the same manner as in Example 3, and ZnPP formation was evaluated under aerobic conditions.

NBRC: National Institute of Technology and Evaluation Biological Resources Center

ZnPP formation was confirmed under aerobic conditions when any Lactococcus lactic acid bacterium was used, and in particular, Lactococcus lactis subspecies Cremoris GB (A) -1 strain, Lactococcus lactis subspecies Lactis NBRC12007 The strain and NBRC100933 strain, Lactococcus lactis subspecies Turkutae NBRC110453 strain, and Lactococcus lactis CH-1 strain showed high ZnPP forming ability (Fig. 9).

Claims

An agent for forming zinc protoporphyrin IX under aerobic conditions in a material containing meat, including Lactococcus lactic acid bacteria.
The agent according to claim 1, wherein the lactic acid bacterium is a bacterium belonging to Lactococcus lactis.
The agent according to claim 1 or 2, wherein the lactic acid bacterium is a bacterium belonging to the Lactococcus lactis subsp. Cremoris.
A method for forming zinc protoporphyrin IX in a meat-containing material under aerobic conditions, which comprises adding Lactococcus lactic acid bacteria to the meat-containing material.
The method according to claim 4, wherein the lactic acid bacterium is a bacterium belonging to Lactococcus lactis.
The method according to claim 4 or 5, wherein the lactic acid bacterium is a bacterium belonging to the Lactococcus lactis subspecies Cremoris.
An agent for improving the color tone of all meat products manufactured under aerobic conditions, including Lactococcus lactic acid bacteria.
The agent according to claim 7, wherein the lactic acid bacterium is a bacterium belonging to Lactococcus lactis.
The agent according to claim 7 or 8, wherein the lactic acid bacterium is a bacterium belonging to the Lactococcus lactis subspecies Cremoris.
A method for improving the overall color tone of meat products manufactured under aerobic conditions, including the addition of Lactococcus lactic acid bacteria to the raw material of meat products.
The method according to claim 10, wherein the lactic acid bacterium is a bacterium belonging to Lactococcus lactis.
The method according to claim 10 or 11, wherein the lactic acid bacterium is a bacterium belonging to the Lactococcus lactis subspecies Cremoris.
Producing meat products with improved color tone as a whole, including adding Lactococcus lactic acid bacteria to meat product raw materials and producing meat products from meat product raw materials after adding lactic acid bacteria under aerobic conditions. Method.
The method according to claim 13, wherein the lactic acid bacterium is a bacterium belonging to Lactococcus lactis.
The method according to claim 13 or 14, wherein the lactic acid bacterium is a bacterium belonging to the Lactococcus lactis subspecies Cremoris.
Lactococcus lactis subspecies Cremoris GB (A) -1 strain deposited under accession number NITE BP-03229.