WO2014013795A1 - Method for improving color tone of meat - Google Patents

Abstract

The present invention addresses the problem of providing a novel means that is effective for improving the color tone of meat or a processed meat product. A method that comprises treating meat or a processed meat product with an imidazole ring-containing compound and metmyoglobin reductase.

Description

How to improve the color of meat

The present invention relates to a color tone improving method. Specifically, the present invention relates to a method for improving the color tone of meat and processed meat products and a color tone improving agent. This application claims priority based on Japanese Patent Application No. 2012-159732 filed on July 18, 2012, the entire contents of which are incorporated by reference.

Meat color is an important factor when consumers evaluate meat quality. Meat color has a great influence on consumers' willingness to purchase and evaluation of meat. For example, if it is bright red, it is judged as good quality meat, and if it is brown it is considered old.

In order to prevent browning of meat, nitrate and nitrite colorants are generally used in processed meat products such as ham and sausage. However, since nitrates and nitrites have acute toxicity that causes methemoglobinemia in humans, the amount used is limited to 70 ppm or less as residual nitrite. It has also been pointed out that nitrous acid may react with secondary amines to form nitrosamines, which are carcinogenic substances. For this reason, from the viewpoint of safety, a search has been made for a substance having a coloring effect and a coloring method instead of nitrate and nitrite coloring agents. For example, a method for preventing browning by adding raffinose (see Patent Document 1), a method for preventing browning by adding an enokitake extract (see Patent Document 2), and using ingredients contained in vegetables And a method of developing the color (see Patent Document 3) has been found. However, the method of Patent Document 1 and the method of Patent Document 2 have problems that the coloring effect is not sufficient and the coloring effect is lost by heating, and the method of Patent Document 3 uses nitrate contained in vegetables. There is a problem with safety.

On the other hand, a method for coloring meat using imidazole or a related compound (for example, histidine) has been proposed (see Patent Documents 4 and 5). However, the effect of the method is limited and is not particularly effective for improving the color tone of meat that has been browned.

In addition, in the previous patent application, the present applicant proposed a method using an enzyme derived from a Bacillus microorganism as an effective method for improving the color tone of meat or processed meat (Patent Document 6).

JP 2003-18976 A JP 2008-228702 A JP 2009-165445 A British Patent 1,173,446 JP 58-23766 International Publication No. 2011/142300 A1 Pamphlet

The present invention has been made in view of the above-mentioned problems included in the prior art, and an object thereof is to provide a new means effective for improving the color tone of meat and processed meat products.

The present inventors paid attention to the point that the coloring effect of meat by imidazole and histidine is presumed to be due to the coordination of nitrogen of the imidazole ring to heme iron (Fe ²⁺ ) of myoglobin. Then, he established a strategy to increase the coloring effect by supplying heme iron as an acceptor with an enzyme (methmyoglobin reductase), and verified its effectiveness. As a result, an excellent effect exceeding the expectation was recognized, and it was clarified that the combined use of imidazole or its related compound and metmyoglobin reductase is extremely effective for improving the color tone. According to this new means, it is possible to compensate for the insufficient color development effect of imidazole or its related compound alone, and a high color development effect can be obtained. Further, since the amount of metmyoglobin that causes browning can be reduced by the action of metmyoglobin reductase, an improvement in color tone can be expected even when browning occurs. Furthermore, unlike the case where metmyoglobin reductase is allowed to act alone, the coloring effect can be maintained after the heat treatment.

As a result of investigations aimed at further improving the color development effect, in addition to imidazole or related compounds and metmyoglobin reductase, ferrochelatase, a substance that shows the action of replacing iron in the heme group of myoglobin with zinc, is used in combination. It was revealed that a higher coloring effect was obtained and that the coloring effect lasted for a long time.

The following invention is based on the above results and knowledge.
[1] A method for improving color tone, comprising a step of treating meat or processed meat with an imidazole ring-containing compound and metmyoglobin reductase.
[2] A method for improving color tone, comprising a step of treating meat or a processed meat product with an imidazole ring-containing compound, metmyoglobin reductase, and a substance having an action of replacing iron in the heme group of myoglobin with zinc.
[3] The color tone improving method according to [2], wherein the substance is ferrochelatase.
[4] The color tone improving method according to any one of [1] to [3], wherein the imidazole ring-containing compound is histidine or an imidazole peptide.
[5] The color tone improving method according to [4], wherein the imidazole peptide is an imidazole dipeptide.
[6] The metmyoglobin reductase according to any one of [1] to [5], wherein the metmyoglobin reductase is a metmyoglobin reductase derived from Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus natto, Bacillus thuringiensis, or Bacillus mycoides. To improve color tone.
[7] A color tone improving agent comprising a combination of an imidazole ring-containing compound and metmyoglobin reductase.
[8] The color tone improving agent according to [7], further comprising a substance having an action of substituting iron in the heme group of myoglobin with zinc.
[9] A meat or processed meat product having a color tone improved by the color tone improving method according to any one of [1] to [6] or by using the color tone improving agent according to [7] or [8].

Appearance (upper stage) and cross-sectional state (lower stage) of each sample (sausage sample) after heat treatment. Sample 1 (not added), sample 2 (added 0.05% sodium nitrite (0.05%)), sample 3 (added 20 mg L-histidine), sample 4 (20 mg L-histidine and purified Meth from Bacillus subtilis) Myoglobin reductase (with 5 mg of purified YodCbr (Mbr)), sample 5 (with 50 mg of L-histidine), sample 6 (with 50 mg of L-histidine and 5 mg of purified YodC (Mbr)), sample 7 (L-histidine) 100 mg added), sample 8 (100 mg L-histidine and 5 mg purified YodC® (Mbr) ® added). The state of the cross section of each sample (sausage sample) after heat processing. Sample 1 (not added), sample 2 (added 0.05% sodium nitrite (5 mg)), sample 3 (added 50 mg L-histidine), sample 4 (added carnosine 50 mg), sample 5 (carnosine 50 mg) And purified YodC (Mbr) 5 mg), sample 6 (Imida 40 (Nippon Ham Co., Ltd.) 50 mg added). The degree of color development on the day of heat treatment and the amount of ZnMb (myoglobin in which iron in the heme group is replaced with zinc).

The first aspect of the present invention provides a method for improving the color tone of meat and processed meat products in which color change (typically browning) becomes a problem during processing or distribution. The color tone improving method of the present invention improves the color tone of the object to be processed by a color development action, a color development promotion action and / or a fading prevention action. That is, the color tone improving method of the present invention is used for coloring, maintaining color tone or preventing fading of meat or processed meat products. “Meat coloring” means that a red color characteristic of meat or processed meat is developed.

The present invention is applicable to all meat or processed meat products containing myoglobin. Specifically, livestock such as pork, beef, and chicken, or processed products thereof, other meat (such as salmon and whale meat) or processed products thereof, or fish or processed products such as tuna, bonito and salmon are processed. Can be. However, it can be said that meat having a red color is a preferable processing target. The processed meat product, which is one of the treatment targets, is not particularly limited as long as it is a food produced using meat as a raw material. Examples of processed meat products include raw ham, bacon, sausage, loin ham, and salami. Examples of processed fish products include fish sausages, fish hamburgers, and negitoro. There is no particular limitation on the shape of the processed meat or processed meat food. Block meat, minced meat, etc. can be selected as appropriate according to the application.

In the color tone improving method of the present invention, a process of treating a treatment target with an imidazole ring-containing compound and metmyoglobin reductase is performed. Without being bound by theory, when the color tone improving method of the present invention is applied, a coloring effect is brought about by coordination of the nitrogen atom of the imidazole ring of the imidazole ring-containing compound with heme iron (Fe ²⁺ ) of myoglobin. . On the other hand, by the action of metmyoglobin reductase, heme iron (Fe ²⁺ ) serving as an acceptor is supplied, and the coloring effect of the imidazole ring-containing compound is enhanced. Further, metmyoglobin is reduced by the action of metmyoglobin reductase to produce reduced myoglobin. Reduced myoglobin is converted to oxymyoglobin which exhibits a bright red color tone by oxygenation. Therefore, when the color tone improving method of the present invention is applied, the amount of metmyoglobin in the meat or processed meat product is reduced, and as a result, oxymyoglobin is generated, resulting in an improvement in color tone. Moreover, the oxidation of reduced myoglobin or oxymyoglobin is prevented, and as a result, the effect of preventing fading of meat can be expected. Thus, not only color development but also color tone maintenance, that is, fading prevention effect can be exhibited.

As long as the above effects can be exhibited, the imidazole ring-containing compound is not particularly limited, and for example, imidazole or a derivative thereof, histidine, or imidazole peptide can be used. Examples of imidazole peptides include imidazole dipeptides (carnosine (β-alanyl-1-dehydro-3-methyl-L-histindine), valenine (β-alanyl-1-methyl-L- histidine)). Two or more kinds of imidazole ring-containing compounds may be used in combination. As an example of combined use, combined use of histidine and imidazole dipeptide can be mentioned.

As used herein, “metmyoglobin reductase” refers to a protein that exhibits an activity of reducing metmyoglobin, which is a myoglobin derivative. The strength (degree) of the activity is not particularly limited. Therefore, even if the other enzyme activity is more dominant, it corresponds to “metmyoglobin reductase” in the present specification as long as it shows a reducing activity against metmyoglobin. As metmyoglobin reductase, nitroreductase (eg, Bacillus subtilis-derived yodC gene product), dehydrolipoyl dehydrogenase (eg, Bacillus subtilis-derived pdhD gene product), NADH-cytochrome b5 reductase (eg, Saccharomyces cerevisiae-derived CBR1, MCR1 gene product), NADPH-flavin reductase (for example, nfrA1 gene product derived from Bacillus subtilis) can be used. As an example of a preferred metmyoglobin reductase, heme reductase produced by the genus Bacillus described in Patent Document 6 described above can be given. The enzyme is produced by Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus natto, Bacillus thuringiensis or Bacillus mycoides. These microorganisms can be obtained from, for example, public preservation institutions (NBRC (National Institute for Product Evaluation and Technology, Biological Genetic Resources Division), JCM (RIKEN BioResource Center), ATCC (American Type Culture Collection), etc.) . Bacillus natto is commercially available and can be easily obtained. It can also be obtained from the Miyagino Natto fungus factory. In addition, as in the case of the imidazole ring-containing compound, two or more types of metmyoglobin reductase may be used in combination.

In the present invention, the imidazole ring-containing compound and metmyoglobin reductase are allowed to act on the treatment target simultaneously or separately. Preferably, the imidazole ring-containing compound and metmyoglobin reductase are allowed to act simultaneously from the viewpoint of ease of operation and instability to oxidation of myoglobin. The order in which the imidazole ring-containing compound and metmyoglobin reductase are allowed to act separately is arbitrary, but it is preferable that the imidazole ring-containing compound is allowed to act after the metmyoglobin reductase is acted from the viewpoint of the mechanism of action. In principle, the treatment conditions in the present invention may be such that the imidazole ring-containing compound and metmyoglobin reductase act well (preferably the optimum conditions). Preferred treatment conditions can be easily specified or set by a preliminary experiment using processed meat or processed meat. Hereinafter, a specific example of the processing method will be shown. First, an imidazole ring-containing compound and an enzyme solution (purified enzyme solution, microbial cell disruption solution of a microorganism that produces metmyoglobin reductase, etc.) are prepared. These are brought into contact with meat or processed meat products. The amount of the imidazole ring-containing compound used is not limited to this, but is, for example, 0.1 mg to 100 mg, preferably 1 mg to 50 mg per 1 g of the object to be treated. Further, the amount of metmyoglobin reductase used is not limited to this, but is, for example, 1 to 100 U, preferably 10 U to 50 U per 1 g of the object to be treated. The activity of metmyoglobin reductase is measured as follows. First, an enzyme solution is prepared (in the case of a dry enzyme, for example, dissolved in water to 10 mg / mL). Subsequently, 100 μL of 0.1% (w / v) myoglobin and 150 μL of enzyme solution are added to 200 μL of 0.1 M phosphate buffer (pH 5.5), and preincubated at 30 ° C. for 5 minutes. Then, 50 mM of 1 mM NADH is added, and the change in absorbance at a wavelength of 406 nm is measured for 5 minutes. Activity is indicated in units (U). The amount of enzyme that reduces metmyoglobin equivalent to 1 μM per minute under these conditions is 1 U.

As the contact method, there are generally methods such as injecting and tumbling a suspension in a block meat or immersing in a dipping solution, or mixing a suspension in a minced meat. By performing a suitable contact method, the suspension penetrates the whole meat. The temperature condition at the time of contact is, for example, 4 ° C. to 40 ° C., preferably 4 ° C. to 30 ° C., more preferably 4 ° C. to 25 ° C., and most preferably 4 ° C. to 20 ° C. The contact time is, for example, 1 hour to 3 days, preferably 3 hours to 2 days, and more preferably 6 hours to 2 days. However, if the contact state is maintained even during the subsequent processing step, the operation may proceed to the next processing step immediately after an operation such as injection or mixing. After the contact operation, necessary processing such as casing, heat treatment, smoking and molding is performed.

By the way, when only metmyoglobin reductase is used, color development generally decreases with heating. On the other hand, according to the present invention in which the imidazole ring-containing compound and metmyoglobin reductase are used in combination, the decrease in color due to the heat treatment is small, and the color development can be maintained after the heat treatment. Therefore, the color tone improving method of the present invention is particularly effective for improving the color tone of products that are heat-treated during the manufacturing process.

Here, as shown in the examples described later, although the effect when metmyoglobin reductase was used in combination, an imidazole ring-containing compound (in the examples, histidine, carnosine, chicken-derived imidapeptide was used) alone was used. In some cases, a relatively high color tone improving effect was recognized. Based on this result, a color tone improving method including a step of treating meat or a processed meat product with an imidazole ring-containing compound is provided as one of modifications of the present invention. Preferably, imidazole dipeptide is used.

In one embodiment of the present invention, in addition to an imidazole ring-containing compound and metmyoglobin reductase, a substance that has an action of substituting iron in the heme group of myoglobin with zinc (hereinafter referred to as “iron / zinc substitute substance”) is used. To do. That is, in the color tone improving method of this aspect, a treatment target is treated with an imidazole ring-containing compound, metmyoglobin reductase, and an iron / zinc substitute substance. According to this embodiment, the color tone is further improved by the combined effect of the combined use of the iron / zinc substitute substance in addition to the above-described effect of the imidazole ring-containing compound and metmyoglobin reductase. In particular, the effect of maintaining good color tone and preventing fading can be expected. For example, ferrochelatase can be used as the iron / zinc substitute substance (see JP-A-2006-61016 for details). Ferrochelatase is present in animal tissues (particularly built-in), plant tissues (mushrooms, bean sprouts, peas, etc.), yeasts (bakers yeast, beer yeast, sake yeast, wine yeast, shochu yeast, etc.), bacteria and the like. Ferrochelatase extracted from these natural products can be used. In addition, since the mitochondrial fraction contains a large amount of ferrochelatase, it is particularly preferable to use the mitochondrial fraction. Saccharomyces genus yeast (beer yeast, baker's yeast, sake yeast, shochu yeast, etc.) can also be used as the iron / zinc substitute substance (see JP-A-2005-87058 for details).

The method of causing the imidazole ring-containing compound, metmyoglobin reductase, and the iron / zinc-substituted substance to act on the treatment target is in accordance with the embodiment using the imidazole ring-containing compound and metmyoglobin reductase. That is, these three substances are allowed to act on the treatment target simultaneously or separately. Preferably, these three substances are caused to act simultaneously from the viewpoint of easy operation, instability to oxidation of myoglobin, and synergistic effects. Preferred treatment conditions can be easily specified or set by a preliminary experiment using processed meat or processed meat. Hereinafter, a specific example of the processing method will be shown. First, an imidazole ring-containing compound, a metmyoglobin reductase solution, and an iron / zinc substitute substance solution (for example, a purified ferrochelatase solution, a mitochondrial fraction solution) are prepared. These are brought into contact with meat or processed meat products. The amount of the imidazole ring-containing compound and the amount of metmyoglobin reductase used are in accordance with the above embodiment. On the other hand, the amount of the iron / zinc-substituted substance used is, for example, 0.1 U to 100 U, preferably 1 U to 20 U per 1 g of the object to be treated, taking ferrochelatase as an example.

The second aspect of the present invention relates to a color tone improving agent used in the color tone improving method of the present invention. One of the characteristics of the color tone improving agent of the present invention is to use a combination of an imidazole ring-containing compound and metmyoglobin reductase. In the present specification, “using a combination of an imidazole ring-containing compound and metmyoglobin reductase” or “combining an imidazole ring-containing compound and metmyoglobin reductase” means that the imidazole ring-containing compound and metmyoglobin reductase are used in combination. That means. Typically, the color tone improving agent of the present invention will be provided as a compounding agent in which an imidazole ring-containing compound and metmyoglobin reductase are mixed. On the other hand, for example, the color tone of the present invention is improved in the form of a kit comprising a first agent (first component) containing an imidazole ring-containing compound and a second agent (second component) containing metmyoglobin reductase. Agents can also be provided. In this case, typically these two agents are used simultaneously. That is, as a part of the manufacturing process of meat or processed meat products, a processing step of using these two agents simultaneously is provided. Unlike this, a treatment process using the first agent and a treatment process using the second agent may be provided.

In one embodiment, an imidazole ring-containing compound, metmyoglobin reductase, and an iron / zinc substitute substance are used in combination. That is, an imidazole ring-containing compound, metmyoglobin reductase, and an iron / zinc substitute substance are used in combination. In this embodiment, typically, the color tone improving agent of the present invention is provided as a compounding agent in which an imidazole ring-containing compound, metmyoglobin reductase, and an iron / zinc substitute substance are mixed. On the other hand, for example, a first agent (first component) containing an imidazole ring-containing compound, a second agent (second component) containing metmyoglobin reductase, and a third agent containing an iron / zinc substitute substance. The color tone improving agent of the present invention can also be provided in the form of a kit comprising an agent (third component). In this case, typically these three agents are used simultaneously. That is, as a part of the manufacturing process of meat or processed meat products, a processing step for simultaneously using these three agents is provided. Unlike this, a treatment process using the first agent, a treatment process using the second agent, and a treatment process using the third agent may be provided. Two agents may act simultaneously, and then the remaining one may act. In this case, the combination of two agents that act simultaneously is not particularly limited.

The color tone improving agent of the present invention includes an active ingredient (imidazole ring-containing compound and metmyoglobin reductase, or imidazole ring-containing compound, metmyoglobin reductase, and iron / zinc substitute substance), excipient, buffer, suspension. Agents, stabilizers, pH adjusters, preservatives, preservatives, fragrances, thickeners, fats and oils, brighteners, binders, binder reinforcing agents, emulsion stabilizers, physiological saline, etc. . As the excipient, starch, dextrin, maltose, trehalose, lactose, D-glucose, sorbitol, D-mannitol, sucrose, glycerol and the like can be used. Phosphate, citrate, acetate, etc. can be used as the buffer. As the stabilizer, propylene glycol, ascorbic acid or the like can be used. pH adjusters include itaconic acid, succinic acid, tartaric acid, fumaric acid, citric acid, malic acid, adipic acid, gluconic acid, pyrophosphoric acid, acetic acid, lactic acid, α-ketoglutaric acid, phytic acid and other organic acids or organic acid salts Inorganic acids such as carbonic acid or inorganic acid salts; acidic amino acids such as aspartic acid and glutamic acid; basic amino acids such as arginine, lysine and histidine can be used. As preservatives, phenol, benzalkonium chloride, benzyl alcohol, chlorobutanol, methylparaben, and the like can be used. As preservatives, ethanol, benzalkonium chloride, paraoxybenzoic acid, chlorobutanol and the like can be used. Perfumes include animal perfumes such as musk, civet, castorium, ambergris; anise essential oil, angelica essential oil, ylang ylang essential oil, iris essential oil, fennel essential oil, orange essential oil, cananga essential oil, caraway essential oil, cardamom essential oil, guayakwood essential oil, cumin essential oil , Black letter essential oil, cinnamon essential oil, cinnamon essential oil, geranium essential oil, copaiba balsam essential oil, coriandel essential oil, perilla essential oil, cedarwood essential oil, citronella essential oil, jasmine essential oil, gingergrass essential oil, cedar essential oil, spearmint essential oil, western peppermint essential oil Essential Oil, Tuberose Essential Oil, Clove Essential Oil, Orange Flower Essential Oil, Winter Green Essential Oil, Truval Sam Essential Oil, Batule Essential Oil, Rose Essential Oil, Palmarosa Essential Oil, Crude Essential Oil, Hiba Essential Oil, Sandalwood Essential Oil, Petit Glen Essential Oil, Bay Essential Oil, Vetiva Essential Oil, Bergamot Essential Oil Perfume balsam essential oil, boad rose essential oil, melamine essential oil, mandarin essential oil, eucalyptus essential oil, lime essential oil, lavender essential oil, linaloe essential oil, lemongrass essential oil, lemon essential oil, rosemary essential oil, Japanese mint essential oil, etc .; Etc. can be used. As the thickener, natural polymers, starch-based or cellulose-based natural polymer derivatives, and the like can be used. Examples of the natural polymer include seaweed extracts such as fucoidan and carrageenan, seed exudates such as guar gum, resin-like adhesives such as gum arabic, and microorganism-generated adhesive substances such as xanthan gum. Examples of the starch-based or cellulose-based natural polymer derivative include starch-based starch-based starch-based or cellulose-based natural polymer derivatives such as methylcellulose. Examples of oils and fats include avocado oil, linseed oil, almond oil, fennel oil, sesame oil, olive oil, orange oil, orange rafa oil, cacao oil, chamomile oil, carrot oil, cucumber oil, coconut oil, sesame oil, rice oil, Safflower oil, shea fat, liquid shea fat, soybean oil, camellia oil, corn oil, rapeseed oil, persic oil, castor oil, sunflower oil, camellia seed oil, cottonseed oil, peanut oil, turtle oil, mink oil, egg yolk oil, Palm oil, palm kernel oil, owl, coconut oil, beef tallow, lard, etc. can be used. In addition, oils and fats modified by hydrogenation, fractionation, transesterification and the like can be used. As a brightener, waxes (whether plant or animal) such as beeswax, carnauba wax, whale wax, lanolin, liquid lanolin, reduced lanolin, hard lanolin, candelilla wax, montan wax, shellac wax, rice wax, squalene, squalane, pristane, etc. ); Mineral oils such as liquid paraffin, petrolatum, paraffin, ozokelide, ceresin, microcrystalline wax and the like can be used. As the binder, soybean protein, egg protein, milk protein, blood protein, casein, starch, transglutaminase and the like can be used. As the binder reinforcing agent, a polymerized phosphate or the like can be used. As the emulsion stabilizer, sodium caseinate or the like can be used. Other additives include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid, linolenic acid, docosahexaenoic acid, eicosapentaenoic acid, 1 2-hydroxystearic acid, undecylenic acid, tall oil, lanolin Natural fatty acids such as fatty acids; fatty acids such as synthetic fatty acids such as isononanoic acid, caproic acid, 2-ethylbutanoic acid, isopentanoic acid, 2-methylpentanoic acid, 2-ethylhexanoic acid, and isopentanoic acid.

1. Coloring effect of meat by imidazole ring-containing compound It is estimated that the coloring effect of meat by imidazole and histidine is due to coordination of nitrogen of imidazole ring to heme iron (Fe ²⁺ ) of myoglobin. In order to enhance the coloring effect, histidine (Wako Pure Chemical Industries, Ltd.) was used as an imidazole ring-containing compound with the expectation that the coloring effect would be enhanced by supplying heme iron as an acceptor with metmyoglobin reductase. Using the purified enzyme YodC (9.94 U / mg, see the above-mentioned Patent Document 6) derived from Bacillus subtilis JCM1465 (= ATCC6051, IAM12118, IFO13719) as metmyoglobin reductase, the following experiment Went.

To 10 g of commercially available pork minced meat, 150 mg of sodium chloride, 10 mg of L-ascorbic acid, 180 μL of 0.5 M potassium phosphate buffer (pH 5.5), 180 μL of 40 mg / mL myoglobin solution were added and mixed. To the solution thus prepared, each additive was further added and mixed as shown in Table 1 below. The mixed pork minced meat samples 1 to 8 were left on ice.

Next, after casing each sample on natural sheep intestine, it was left at 37 ° C. for 2 days. After heat treatment at 75 ° C. for 40 minutes, the sample was rapidly cooled, and the redness of the cross section of each sample was subjected to image analysis. ImageJ software (open source) was used for image analysis.

The color tone of the cross section of the sample after the heat treatment is shown in FIG. The analysis results are shown in Table 2 below (L * a * b * values of the cross section after the heat treatment). Each numerical value is an average value of the cross section.

Paying attention to the a ^* value representing the degree of color development (redness), a higher degree of color development is obtained when histidine and metmyoglobin reductase are used in combination than histidine alone. Further, when the amount of histidine used was increased, the degree of color development increased, and the maximum amount of sample used in this test showed a color developing effect equivalent to or higher than that obtained when sodium nitrite (0.05%) was used.

As described above, it has been clarified that when histidine and metmyoglobin reductase are used in combination, an excellent coloring effect can be obtained. Moreover, it was confirmed that the coloring effect is maintained even after the heat treatment. In addition, although it was inferior in the effect at the time of using metmyoglobin reductase together, when using histidine alone, the comparatively high color tone improvement effect was recognized. In particular, the samples (20 mg, 50 mg) with a large amount of use show a much higher a * value than the case where histidine is not used (no addition), and a high coloring effect is obtained.

2. Color development effect of meat by imidazole dipeptide The color development effect of meat by imidazole dipeptide which is an imidazole ring-containing compound was examined. The experimental method was as follows except that the additive was changed. It was the same. The additives for each sample in this experiment are shown in Table 3 below. Imida 40 (Nippon Ham Co., Ltd.) contains chicken-derived imidazole dipeptides (anserine and carnosine).

The color tone of the cross section of the sample after the heat treatment is shown in FIG. The analysis results are shown in Table 4 below (L * a * b * values of the cross section after the heat treatment). Each numerical value is an average value of the cross section.

When paying attention to the a ^* value, a higher degree of color development is obtained in the combination of carnosine and metmyoglobin reductase (sample 5) than in carnosine alone (sample 4). This result shows that the combined use of metmyoglobin reductase is effective for increasing the coloring effect even when imidazole dipeptide is used. On the other hand, from the results of Samples 4 and 6, it was found that even if imidazole dipeptide was used alone, a color tone improving effect was obtained. Moreover, if the color development degree of sample 3 and the color development degree of sample 4 are compared, it can be evaluated that the color development effect of imidazole dipeptide is high. In addition, it is considered that the color development degree of the sample 6 is lower than that of the sample 5 because the content of the imidazole dipeptide in the imida 40 is small.

3. Effect of combined use of imidazole ring-containing compound, metmyoglobin reductase, and iron / zinc substitute substance In addition to histidine and metmyoglobin reductase, ferrochelatase, a substance that has the effect of replacing iron in the heme group of myoglobin with zinc, was used in combination. The coloring effect in each case was examined.

Add 150 mg of salt, 10 mg of L-ascorbic acid, 180 μL of 10 mM NADH, 50 μL of Zn gluconate, 180 μL of 0.5 M potassium phosphate buffer (pH 5.5), 180 μL of 40 mg / mL myoglobin solution to 10 g of commercially available pork minced meat, Mixed. Each additive was further added to the solution thus prepared and mixed as shown in Table 5 below. The mixed pork minced meat samples 1 to 6 were left on ice.

Next, after casing each sample on natural sheep intestine, it was left at 37 ° C. for 2 days. After heat treatment at 75 ° C. for 40 minutes, the sample was rapidly cooled, and the redness of the cross section of each sample was subjected to image analysis. Further, ZnMb in the filtrate obtained by the ethyl acetate / acetic acid treatment was quantified. The quantification method was calculated from the value Ex / Em = 420 nm / 590 nm using a fluorometer.

The analysis results of the degree of color development (a *) redness of each sample are shown in Table 6 below. Each numerical value is an average value of the cross section.

The color development on the day of heat treatment (day 0) is higher when using His (histidine) than the control. FeCH (ferrochelatase) alone, combined use of FeCH and His, or combined use of FeCH, His and Mbr (metmyoglobin reductase) has higher color development. In addition, His alone and His and Mbr combined showed higher color development than FeCH alone. However, on the second day, the degree of coloration of His alone was greatly reduced. On the 9th day, FeCH alone is higher than His alone (equivalent to nitrous acid). When FeCH and His were used in combination, the degree of color development further increased, and when FeCH, His and Mbr were used together, the highest degree of coloration was exhibited.

On the other hand, the amount of ZnMb produced increased in the order of nitrous acid, His alone, control, FeCH alone, combined use of FeCH and His, and combined use of FeCH, His and Mbr (FIG. 3). As expected, the amount of ZnMb produced by nitrous acid, His alone, and control is small, and the combination of FeCH, His, and Mbr produced more ZnMb than FeCH alone because Fe ²⁺ increased due to the action of Mbr. it is conceivable that.

As described above, it has been clarified that the combined use of FeCH, His and Mbr can provide a high coloring effect and a stable coloring effect. The measurement results of ZnMb production confirmed that the iron-zinc substitution action of ferrochelatase contributed to the coloring effect. Based on this result, it can be said that the same effect can be obtained with any substance other than ferrochelatase as long as it is a substance exhibiting an iron / zinc substitution action.

According to the color tone improving method of the present invention, meat can be colored without using a coloring agent such as nitrite, so that it is possible to provide meat with high commercial value and processed meat products. The color tone improving method of the present invention can be applied to various meat products in which a change in color tone such as fading or browning is a problem.

The present invention is not limited to the description of the embodiments and examples of the above invention. Various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the description of the scope of claims. The contents of papers, published patent gazettes, patent gazettes, and the like specified in this specification are incorporated by reference in their entirety.

Claims (9)

1. A method for improving color tone, comprising a step of treating meat or processed meat products with an imidazole ring-containing compound and metmyoglobin reductase.
2. A method for improving color tone, comprising a step of treating meat or a processed meat product with an imidazole ring-containing compound, metmyoglobin reductase, and a substance having an action of substituting iron in the heme group of myoglobin with zinc.
3. The color tone improving method according to claim 2, wherein the substance is ferrochelatase.
4. The color tone improving method according to any one of claims 1 to 3, wherein the imidazole ring-containing compound is histidine or an imidazole peptide.
5. The method for improving color tone according to claim 4, wherein the imidazole peptide is an imidazole dipeptide.
6. The color tone improving method according to any one of claims 1 to 5, wherein the metmyoglobin reductase is a metmyoglobin reductase derived from Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus natto, Bacillus thuringiensis or Bacillus mycoides.
7. Color tone improver comprising a combination of an imidazole ring-containing compound and metmyoglobin reductase.
8. The color tone improving agent according to claim 7, further comprising a combination of substances exhibiting an action of replacing iron in the heme group of myoglobin with zinc.
9. A meat or processed meat product whose color tone has been improved by the color tone improving method according to any one of claims 1 to 6 or by the use of the color tone improving agent according to claim 7 or 8.

Images