A method for microbial color fixation on the surface of dried meat

Abstract

This invention discloses a method for microbial color fixation on the surface of dried meat, belonging to the application of biotechnology in the field of deep processing of meat products. Using semi-finished dried meat made from bloody meat as raw material, before drying, the semi-finished meat is soaked in a compound bacterial solution fermented with a mixture of Oceanobacillus sp. and Bacillus cereus for 15-30 minutes. After draining the surface moisture, it is placed in a constant humidity environment at 30-40℃ for 30-50 hours. Once the color of the semi-finished meat surface has stabilized, it is then dried. This method avoids the drawbacks of using color-protecting agents to maintain the color of dried meat. Instead, it uses microbial fermentation to stabilize the surface color of dried meat made from red meat, preventing browning due to oxidation of surface hemoglobin during later storage, thus achieving a long-term maintenance of good color for dried meat made from red meat.

Description

Technical Field

[0001] This invention discloses a method for fixing the color of dried meat with microorganisms, which belongs to the application of biotechnology in the field of meat processing, and in particular, a method for protecting the color of dried meat by using microbial fermentation technology. Background Technology

[0002] Dried meat products are widely loved by consumers both domestically and internationally for their convenience, appealing color, and delicious flavor. Among dried meat products, hand-shredded yak meat and air-dried meat are particularly popular. However, a technical challenge exists in the production of dried meat products: the surface color deteriorates over time. Newly made dried meat products, after vacuum packaging, have a pleasant brown color, but with increased storage time, the ferrous ions in the hemoglobin on the surface oxidize, causing browning. Simultaneously, fat stratification results in a milky white secretion on the surface. This phenomenon not only severely degrades the appearance of the dried meat products but also misleads consumers into believing they are spoiled. Therefore, technologies to address the issues of blackening of the surface color and the appearance of milky white secretions in dried meat products are urgently needed by dried meat processing enterprises.

[0003] Traditional jerky products typically include nitrites in their formula. Nitrites react with myoglobin in the meat to produce an appealing brownish-red color, and they also have antibacterial properties. However, due to their carcinogenic effects, current jerky production methods often omit nitrites and instead use coloring agents to maintain the brownish-red color of the jerky. However, the color from these coloring agents differs from the natural reddish-brown of the jerky itself, and consumers have a lower psychological acceptance of dyed foods. Furthermore, coloring agents are prone to fading during storage due to light and temperature, eventually causing the product to lose its reddish-brown color and turn purplish-black.

[0004] Based on this, a color-fixing method that breaks through the previous approach of protecting blood cells from browning to achieve color preservation, and also consumes the surface fat of the dried meat, can make the dried meat products present a better flavor while fixing the color, is urgently needed in the industry. Summary of the Invention

[0005] Based on the above analysis, this invention provides a method for microbial color fixation on the surface of dried meat. This method can maintain the stable color of dried meat made from meat containing blood, avoiding the use of nitrite-based colorants while also improving the flavor of the dried meat. The technical solution adopted in this invention patent is as follows:

[0006] A method for microbial color fixation on the surface of dried meat, comprising:

[0007] (1) Preparation of semi-finished dried meat: Cut the meat into strips according to the bloody meat, marinate and season it with a marinating agent, and then take it out and let it dry the surface moisture;

[0008] (2) Preparation of compound bacterial culture: Oceanobacillus sp. and Bacillus cereus were inoculated into the fermentation broth and cultured at 30~35℃ to make their OD600 value between 0.7 and 1.2;

[0009] (3) Infecting semi-finished dried meat with bacteria: Immerse the marinated and dried semi-finished dried meat completely in the compound bacterial solution for 15-30 minutes, then take it out and drain the bacterial solution from the surface.

[0010] (4) Fermentation and color protection: After wrapping the semi-finished meat jerky in plastic wrap, place it in a constant humidity environment with a temperature of 30~40℃ and a humidity of 85%~95% for 30~50 hours;

[0011] (5) Processing: After the color of the semi-finished meat is stable, remove the plastic wrap and then dry or process it.

[0012] Furthermore, the raw meat used in the production of dried meat in step (1) can be pork, beef, mutton, or chicken or fish with blood on it; the marinating liquid used for marinating can be formulated in different ways according to the seasoning needs.

[0013] Furthermore, the selection of nutrients such as carbon and nitrogen in the fermentation broth described in step (2) is based on the principle of facilitating the suitable growth of the two types of bacteria.

[0014] Furthermore, the immersion time of the semi-finished dried meat product mentioned in step (3) depends on the number of blood cells on the surface of the semi-finished dried meat product. If there are more blood cells, the immersion time should be longer; otherwise, the immersion time should be shorter.

[0015] Furthermore, the static environment for the semi-finished dried meat products described in step (4) should be designed to prevent interference from miscellaneous bacteria and spoilage.

[0016] Furthermore, the color stability mentioned in step (5) is mainly determined by the change in the red value of the semi-finished dried meat.

[0017] Furthermore, the methods for isolating, purifying, and identifying the three strains include the following:

[0018] (1) Select a flower bone fish weighing about 100g as the fermentation raw material;

[0019] (2) Prepare fish sauce according to the factory's production process. Mix the raw fish and salt directly at a mass ratio of 3:1. Then place the fish sauce sample in a constant temperature incubator at 35℃ for constant temperature fermentation for 12 months. During the fermentation process, take a sample every 5 days to measure the salt content. Then add the evaporated water with sterile water to maintain a constant salinity (25%, w / w). After 12 months of fermentation, take a sample with a sterile 100 mL centrifuge tube (when taking the sample, mix the fish sauce fermentation liquid well) for later use.

[0020] (3) Under aseptic conditions, after the laboratory-brewed fish sauce was stirred evenly, 1 mL was added to 100 mL of sterilized MSA broth, PDA liquid medium, and YPD liquid medium, respectively, and cultured at 35°C for 24 h. The supernatant was serially diluted 10 times, and bacterial solutions with appropriate dilutions were selected. Strains with significant differences in morphology and size were selected and streaked multiple times until pure strains were obtained. The obtained strains were preserved on slant and morphological observation and description were performed.

[0021] (4) 16S rDNA identification and physiological and biochemical identification of the strains: Three pure strains were obtained by isolation and screening of fermented fish sauce. Genomic DNA was extracted from each strain and PCR amplification and 16S rDNA identification were performed. The three strains were identified as Bacillus cereus (B. cereus). Bacillus cereus ),staphylococcus( Staphylococcus sp. ) and marine bacteria ( Oceanobacillus sp. ).

[0022] The beneficial effects of this invention are as follows:

[0023] 1. The method of the present invention achieves the purpose of fixing the color on the surface of dried meat through compound microbial liquid fermentation, which replaces the method of using food additives such as colorants to protect the color of dried meat, thus improving the food safety of dried meat.

[0024] 2. The method of the present invention uses a compound bacterial solution to fix the color of the semi-finished meat jerky, while also utilizing the fermentation of Oceanobacillus sp. and Bacillus cereus and the cleaning effect of the fermentation liquid to remove the fat on the surface of the semi-finished meat jerky and to add flavor substances to the meat jerky product.

[0025] 3. The method for fixing the color of dried meat proposed in this invention has been identified in terms of operation procedures. It achieves color fixing without damaging the internal muscle structure of the semi-finished dried meat, thus preserving the original muscle fiber structure of the dried meat to the greatest extent. The texture of the dried meat after color fixing is similar to that of the raw meat. Attached Figure Description

[0026] Figure 1The changes in a* value of fish jerky, pork jerky, and beef jerky produced by compound microbial fermentation and nitrite coloring during 120 days of storage are shown from top to bottom: colored beef jerky, colored pork jerky, colored fish jerky, fermented beef jerky, fermented pork jerky, and fermented fish slices.

[0027] Figure 2 To determine the crude fat content of three types of meat products that have undergone fermentation and color development treatments;

[0028] Figure 3 To evaluate the fermentation flavor of three types of meat products that have undergone fermentation and color development treatments;

[0029] Figure 4 The image shows the surface fat seepage of beef jerky. The sample on the left is beef jerky obtained by traditional nitrite coloring, while the sample on the right is beef jerky obtained by compound bacteria fermentation for color protection.

[0030] Figure 5 The images show the microstructure of fish meat, specifically the muscle fiber microstructure of cooked and raw fish meat.

[0031] Figure 6 The images show the microstructure of pork, specifically the muscle fiber microstructure of cooked and raw pork.

[0032] Figure 7 The images show the microstructure of beef, specifically the muscle fiber microstructure of cooked and raw beef. Detailed Implementation

[0033] The following examples of different meat raw materials and their products further explain and illustrate the specific application of the color protection method provided by the present invention, but the scope of protection of the present invention is not limited to the examples provided.

[0034] Prior to this, the present invention obtained the three key strains of the present invention through the following means:

[0035] (1) Select a flower bone fish weighing about 100g as the fermentation raw material;

[0036] (2) Prepare fish sauce according to the factory's production process. Mix the raw fish and salt directly at a mass ratio of 3:1. Then place the fish sauce sample in a constant temperature incubator at 35℃ for constant temperature fermentation for 12 months. During the fermentation process, take a sample every 5 days to measure the salt content. Then add the evaporated water with sterile water to maintain a constant salinity (25%, w / w). After 12 months of fermentation, take a sample with a sterile 100 mL centrifuge tube (when taking the sample, mix the fish sauce fermentation liquid well) for later use.

[0037] (3) Under aseptic conditions, after the laboratory-brewed fish sauce was stirred evenly, 1 mL was added to 100 mL of sterilized MSA broth, PDA liquid medium, and YPD liquid medium, respectively, and cultured at 35°C for 24 h. The supernatant was serially diluted 10 times, and bacterial solutions with appropriate dilutions were selected. Strains with significant differences in morphology and size were selected and streaked multiple times until pure strains were obtained. The obtained strains were preserved on slant and morphological observation and description were performed.

[0038] (4) 16S rDNA identification and physiological and biochemical identification of the strains: Three pure strains were obtained by isolation and screening of fermented fish sauce. Genomic DNA was extracted from each strain and PCR amplification and 16S rDNA identification were performed. The three strains were identified as Bacillus cereus (B. cereus). Bacillus cereus ),staphylococcus( Staphylococcus sp. ) and marine bacteria ( Oceanobacillus sp. ).

[0039] Example 1

[0040] A method for microbial color fixation on the surface of dried meat, using beef as an example.

[0041] (1) Preparation of semi-finished dried meat: Cut the bloody beef into strips, marinate and season with a marinating agent, and take it out to dry the surface moisture;

[0042] (2) Preparation of compound bacterial culture: Oceanobacillus sp. and Bacillus cereus were inoculated into the fermentation broth and cultured at 35°C to allow their OD to reach the desired concentration. 600 The value reaches 1;

[0043] (3) Contamination of semi-finished dried meat: Immerse the dried semi-finished meat completely in the compound bacterial solution for 28 minutes, and then take it out and drain the bacterial solution from the surface.

[0044] (4) Fermentation and color protection: After wrapping the semi-finished meat jerky in plastic wrap, place it in a constant humidity environment of 32℃ and 90% for 40 hours;

[0045] (5) Processing: After the color of the semi-finished meat jerky has stabilized, remove the plastic wrap and then bake or dry it.

[0046] Example 2

[0047] A method for microbial color fixation on the surface of dried meat, taking pork raw meat as an example.

[0048] (1) Preparation of semi-finished dried meat: Cut the pork into strips according to the bloody pork, marinate and season it with a marinating agent, and then take it out and let it dry the surface moisture;

[0049] (2) Preparation of compound bacterial culture: Oceanobacillus sp. and Bacillus cereus were inoculated into the fermentation broth and cultured at 32°C to allow their OD to reach the desired concentration. 600 The value reached 0.8;

[0050] (3) Contamination of semi-finished dried meat: The semi-finished dried pork after marinating and drying is completely immersed in the compound bacterial solution for 20 minutes, and then taken out and drained of the bacterial solution on the surface.

[0051] (4) Fermentation and color protection: After wrapping the semi-finished meat jerky in plastic wrap, place it in a constant humidity environment of 30℃ and 85% for 34 hours;

[0052] (5) Processing: After the color of the pork jerky semi-finished product has stabilized, remove the plastic wrap and then bake or air dry it.

[0053] Example 3

[0054] A method for microbial color fixation on the surface of dried meat, using fish as an example.

[0055] (1) Preparation of semi-finished dried meat: After killing the live fish, remove the head, tail, internal organs and skin, marinate and season with a marinating agent, and then take it out to dry the surface moisture.

[0056] (2) Preparation of compound bacterial culture: Oceanobacillus sp. and Bacillus cereus were inoculated into the fermentation broth and cultured at an appropriate temperature of 30°C to allow their OD to reach the desired concentration. 600 The value reached 0.7;

[0057] (3) Contamination of semi-finished dried meat: The semi-finished dried fish meat that has been marinated and dried is completely immersed in the compound bacterial solution for 15 minutes, and then taken out and drained of the bacterial solution on the surface.

[0058] (4) Fermentation and color protection: After wrapping the semi-finished dried fish meat in plastic wrap, place it in a constant humidity environment of 30℃ and 85% for 30 hours;

[0059] (5) Processing: After the color of the dried fish meat semi-finished product has stabilized, remove the plastic wrap and then bake or air dry.

[0060] Experimental Example 1

[0061] The method of this invention achieves the purpose of fixing the color on the surface of dried meat through fermentation of compound microbial liquid, which replaces the method of using food additives such as colorants to protect the color of dried meat and improves the food safety of dried meat.

[0062] The changes in a* value of fish jerky, pork jerky, and beef jerky fermented with compound microorganisms and colored by nitrite were measured during 120 days of storage using a colorimeter. The results are as follows: Figure 1 As stated. Figure 1 Data shows that at day 0, the a* values ​​of the three meat products in the fermentation group were lower than those in the color development group. Moreover, as the storage time increased, the a* values ​​of the three meat products in the fermentation group showed an increasing trend, while those in the color development group showed a decreasing trend, especially the color development beef jerky, which showed the most significant decrease in a* value.

[0063] The color development of meat products is achieved through the binding of nitrite groups with hemoglobin. During storage, the outward migration of internal substances and the oxidation of surface fat lead to the accumulation and further oxidation of hemoglobin on the surface of the meat products. This may be a possible reason for the decrease in a* values ​​of the three meat products in the color development group during storage. In contrast, the fermentation group of three meat products, due to microbial fermentation and the removal of surface fat, experienced an outward migration of internal hemoglobin, resulting in an increase in their a* values.

[0064] Experimental Example 2

[0065] The method of this invention uses a compound bacterial solution to fix the color of semi-finished dried meat, while also utilizing the fermentation of Oceanobacillus sp. and Bacillus cereus and the cleaning effect of the fermentation liquid to remove the fat on the surface of the semi-finished dried meat and to impart flavor substances to the dried meat products.

[0066] The crude fat content of three types of meat products that underwent fermentation and color-development treatments was determined, and the results are shown in the table below. Figure 2 .according to Figure 2 Data showed that the crude fat content of the three meat products in the fermentation group was lower than that in the color-developed group, especially the dried pork products. Fifteen trained sensory evaluators were invited to evaluate the fermentation flavor of the three meat products treated with fermentation and color development. The results are shown in [Figure 1]. Figure 3 .according to Figure 3 Data shows that all three meat products in the fermentation group had a distinct fermented meat flavor, while the color-developed group had no fermented meat flavor.

[0067] When using microbial fermentation for color preservation, the meat raw materials are soaked in the bacterial solution. Because fat is less dense than water, some fat is removed from the meat raw materials due to the action of water molecules. The color-preserving group, however, uses a solid-state additive method for color preservation. This may explain why the crude fat content of the three meat products in the color-preserving group is lower than that in the fermentation group. Additionally, microbial fermentation for color preservation produces flavor metabolites. This may explain why the three meat products in the microbial fermentation group have a distinct fermented meat flavor.

[0068] Taking beef jerky as an example, the extent of fat seepage on its surface is shown in the following figure. Figure 4 . Figure 4 The sample on the left in the middle image is beef jerky produced using traditional nitrite coloring, while the sample on the right is beef jerky produced using compound microbial fermentation for color preservation. It can be seen that the beef jerky on the left has obvious fat exudation on its surface, while the beef jerky on the right does not exhibit any fat exudation.

[0069] Experimental Example 3

[0070] The method for fixing the color of dried meat proposed in this invention, through operational procedures, achieves color fixing without damaging the internal muscle structure of the semi-finished dried meat, thus preserving the original muscle fiber structure of the dried meat to the greatest extent. The texture of the dried meat after color fixing is similar to that of the raw meat.

[0071] To compare the changes in muscle fibers after color fixation in this experimental scheme, the microstructures of muscle fibers from cooked and color-fixed fish fillets, pork jerky, and beef jerky were compared. The results are as follows: Figure 5 , 6 As shown in Figure 7. According to Figure 5 , 6 The muscle fiber structures in samples 7 and 8 show that the muscle fiber structures of the three meat products after cooking and color fixing are similar to those of raw meat. This indicates that the experimental method used causes minimal damage to the natural structure of the muscle fibers.

[0072] Because this technical solution achieves uniform color and color stability in meat products through surface consumption of red blood cells, it causes less damage to the natural structure of muscle fibers. This may be a possible reason why the muscle fiber structure of the three cooked meat products shown in the image below is similar to that of raw meat.

[0073] In summary, only the method of this invention, through the fermentation process of compound microbial liquid, can achieve color fixation without damaging the internal muscle structure of the semi-finished meat jerky, thus preserving the original muscle fiber structure of the jerky to the greatest extent. The texture of the color-fixed jerky is similar to that of the raw meat. This achieves the goal of fixing the color on the surface of the jerky, not only replacing the method of using color-fixing agents and other food additives to protect the color of the jerky, but also improving the safety of the jerky for consumption. Furthermore, the applicant unexpectedly discovered that while using compound microbial liquid to fix the color of the semi-finished meat jerky, the fermentation of Oceanobacillus sp. and Bacillus cereus, along with the washing effect of the fermentation liquid, can remove fat from the surface of the semi-finished meat jerky and remove the flavor compounds associated with the jerky product.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for fixing the color of dried meat surface with microorganisms, comprising: Cut the bloody meat into strips, marinate and season it, then remove and air dry the surface moisture to obtain a semi-finished product of dried meat; Preparation of compound bacterial solution; Semi-finished dried meat products are contaminated with a compound bacterial solution; Fermentation and color preservation of contaminated meat products; and Post-processing of color-protecting dried meat; Among them, the OD of the compound bacterial solution 600 The value is 0.7~1.2, and it is prepared by inoculating the fermentation broth with Oceanobacillus sp. and Bacillus cereus and culturing at 30~35℃. The inoculation time is 15-30 minutes; The fermentation conditions for color protection are a temperature of 30~40℃, a humidity of 85%~95%, and a fermentation time of 30~50h.

2. The color-fixing method according to claim 1, wherein: The bloody meat is selected from any one of poultry, livestock, or fish.

3. A type of dried meat prepared by a microbial fixation method for the surface of dried meat according to any one of claims 1 or 2.

Images