Method for preparing beef jerky through synergistic fermentation of mixed microbial fermentation agent and spices

Abstract

The invention provides a method for preparing beef jerky through synergistic fermentation of a mixed microbial fermentation agent and spices, and belongs to the technical field of microbial fermentation and beef food deep processing. The spices are used for pickling the beef, the flavor of the beef is improved, the mixed microbial leavening agent is added for fermentation, macromolecular substances such as protein and fat in the beef are decomposed in the growth and reproduction process of microorganisms, and substances such as micromolecular peptide, amino acid and fatty acid which are better absorbed are generated; the nutritional value, flavor and quality of the beef jerky can be remarkably improved, meanwhile, microbial fermentation acid production effectively inhibits growth of other microorganisms, and the safety of the beef jerky is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial fermentation and deep processing of beef food, and specifically relates to a method for preparing beef jerky by synergistic fermentation of a mixed microbial fermentation agent and spices. Background Art

[0002] Beef is deeply loved by consumers due to its high nutritional value, delicious taste and rich flavor, and beef products are also active in the vast consumer market. At present, the most representative of the common traditional beef products in my country is beef jerky, but traditional beef jerky has the disadvantages of single process, unstable quality, difficult digestion, brown-black color, stiff taste and poor chewiness in production. As a new meat product, fermented beef jerky innovatively combines probiotic fermentation technology with meat product production. Although it can solve some of the shortcomings of traditional beef jerky in production, it still has problems such as unstable nutritional value and flavor quality. At present, the production process of fermented beef jerky is still not perfect, and further research is needed. Therefore, providing a fermented beef jerky preparation method that can effectively improve the nutritional value and flavor quality of fermented beef jerky is still the key to research in this field. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a method for preparing beef jerky by synergistic fermentation of a mixed microbial starter and spices, wherein the prepared beef jerky has better nutritional value and flavor quality and is more safe.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: The present invention provides a method for preparing beef jerky by synergistic fermentation of a mixed microbial fermentation agent and spices, comprising the following steps: (1) Wash and cut the beef; (2) preparing spices to obtain pickling material; the spices include salt, white sugar, glucose, soy sauce, white wine, monosodium glutamate, sodium nitrite and yeast extract; (3) The marinade is mixed with the mixed microbial fermentation agent, and then mixed with the beef, and then sealed and marinated; the mixed microbial fermentation agent is composed of plant lactobacillus ( Lactobacilluc plantarum )IMAUJBP3 and Lactobacillus reuteri ( Limosilactobacillus reuteri )IMAUJBR3 mixed; (4) The marinated beef is baked using a two-stage baking method, and the baked beef is sterilized and cooled to obtain fermented beef jerky.

[0005] Preferably, in step (1), the beef is fresh beef or aged beef, and the beef does not contain surface tendons, fascia and fat.

[0006] Preferably, in step (1), the beef is cut into strips along the direction of muscle fiber extension.

[0007] Preferably, in step (2), the marinade comprises, by weight, 0.5-2.5 parts of salt, 0.5-2.5 parts of white sugar, 0.5-2.5 parts of glucose, 1.5-3.5 parts of soy sauce, 0.5-3.0 parts of liquor, 0.2-0.6 parts of monosodium glutamate, 0.005-0.015 parts of sodium nitrite and 0.2-0.4 parts of yeast extract.

[0008] Preferably, in step (2), the yeast extract is selected from one or more combinations of solid yeast extract, paste yeast extract or liquid yeast extract, and the alcohol content of the liquor is ≥50% vol.

[0009] Preferably, in step (3), the marinade, the mixed microbial fermentation agent and the beef are prepared in a mass ratio of (44.3-150.5): (0.05-0.08): (800-1200); the viable count of the mixed microbial fermentation agent is 1.8×10 8 ~5.6×10 9 CFU / g.

[0010] Preferably, in step (3), the temperature of the sealed pickling is 18-25° C., and the sealed pickling time is 18-24 hours; the sealed pickling is performed until the pH value of the meat is less than 5.1.

[0011] Preferably, in step (4), the two-stage baking method comprises the following steps: drying the beef at 50-65°C for 0.5-1h, cooling at room temperature for 0.5-0.6h, and then cooking at 80-90°C for 1.5-2h.

[0012] Preferably, in step (4), the sterilization conditions are: sterilization at 110-120°C for 8-12 minutes.

[0013] The invention also provides fermented beef jerky prepared by the method.

[0014] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: The present invention uses spices to marinate beef to improve the flavor of beef, and ferments by adding a mixed microbial fermentation agent. During the growth and reproduction of microorganisms, macromolecular substances such as protein and fat in the beef are decomposed to produce small molecule peptides, amino acids, fatty acids and other substances that are better absorbed, thereby significantly improving the nutritional value and flavor quality of the beef jerky. At the same time, the acid produced by microbial fermentation effectively inhibits the growth of other microorganisms, thereby improving the safety of the beef jerky.

[0015] Biological Deposit Description Lactobacillus reuteri ( Limosilactobacillus reuteri)IMAUJBR3, taxonomic name Lactobacillus reuteri ( Limosilactobacillus reuteri ), depository: China General Microbiology Center of Microbiological Culture Collection (CGMCC for short), depository address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, deposit number: CGMCC NO.29998, deposit date March 11, 2024. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 : Clustering heat map of flavor substances in fermented beef jerky. DETAILED DESCRIPTION

[0017] The present invention provides a method for preparing beef jerky by synergistic fermentation of a mixed microbial fermentation agent and spices, comprising the following steps: (1) Wash and cut the beef; (2) preparing spices to obtain pickling material; the spices include salt, white sugar, glucose, soy sauce, white wine, monosodium glutamate, sodium nitrite and yeast extract; (3) The marinade is mixed with the mixed microbial fermentation agent, and then mixed with the beef, and then sealed and marinated; the mixed microbial fermentation agent is composed of plant lactobacillus ( Lactobacilluc plantarum )IMAUJBP3 and Lactobacillus reuteri ( Limosilactobacillus reuteri )IMAUJBR3 mixed; (4) The marinated beef is baked using a two-stage baking method, and the baked beef is sterilized and cooled to obtain fermented beef jerky.

[0018] The beef raw material of the present invention is fresh beef or slow-aged beef, and the surface tendons, fascia and fat of the beef raw material are removed for use. The beef raw material is washed with water, and blood stains are washed away before segmentation. The beef segmentation method is: cutting into meat strips along the extension direction of muscle fibers, and the meat strips are preferably 10cm×1.5cm×1.5cm meat strips. The beef raw material of the present invention is preferably beef hind leg meat, and more preferably Simmental beef hind leg meat.

[0019] The present invention adopts spices to prepare the pickling material, and the pickling material comprises, by weight, 0.5-2.5 parts of salt, 0.5-2.5 parts of white sugar, 0.5-2.5 parts of glucose, 1.5-3.5 parts of soy sauce, 0.5-3.0 parts of white wine, 0.2-0.6 parts of monosodium glutamate, 0.005-0.015 parts of sodium nitrite and 0.2-0.4 parts of yeast extract. The pickling material is preferably 1.0-2.0 parts of salt, 0.5-1.5 parts of white sugar, 1.0-2.0 parts of glucose, 2.5-3.5 parts of soy sauce, 1.0-1.5 parts of white wine, 0.2-0.4 parts of monosodium glutamate, 0.01 parts of sodium nitrite and 0.2 parts of yeast extract; further preferably, 1.0 parts of salt, 1.5 parts of white sugar, 1.5 parts of glucose, 2.5-3.5 parts of soy sauce, 1.0 parts of white wine, 0.4 parts of monosodium glutamate, 0.01 parts of sodium nitrite and 0.2 parts of yeast extract; more preferably, 1.0 parts of salt, 1.5 parts of white sugar, 1.5 parts of glucose, 2.5 parts of soy sauce, 1.0 parts of white wine, 0.4 parts of monosodium glutamate, 0.01 parts of sodium nitrite and 0.2 parts of yeast extract.

[0020] In the spices of the present invention, the main function of glucose is to shorten the lag period in the microbial fermentation process and provide the substrate required for the growth of microorganisms. The main function of yeast extract is to shorten the lag period of microorganisms and improve the flavor of the product. The main function of salt is to increase the flavor. The main function of sodium glutamate is to increase the umami taste of the product. The main function of sodium nitrite is to inhibit the growth, color development and anti-oxidation of pathogenic bacteria. The main function of liquor is to inhibit the growth of harmful microorganisms and provide the prerequisite substances for flavor. The addition amount of sodium nitrite and liquor in the present invention will not affect the activity of Lactobacillus plantarum IMAUJBP3 and Lactobacillus reuteri IMAUJBR3. The main function of soy sauce is to increase the flavor and improve the color of the product. The yeast extract of the present invention is selected from solid yeast extract, paste yeast extract or liquid yeast extract, and the alcohol content of the liquor is ≥50%vol. The spices of the present invention are all conventional commercial products.

[0021] The present invention mixes the marinade prepared by spices with the mixed microbial fermentation agent, and then mixes with beef for sealing and marinating. The mass ratio of the marinade, the mixed microbial fermentation agent and the beef is (44.3-150.5): (0.05-0.08): (800-1200), preferably (80-120): (0.06-0.07): (900-1100). As an optional embodiment, the present invention uses purified pure water to fully dissolve the mixed microbial fermentation agent before use.

[0022] In the present invention, the mixed microbial fermentation agent is obtained by mixing Lactobacillus plantarum IMAUJBP3 and Lactobacillus reuteri IMAUJBR3, the viable bacterial count ratio of Lactobacillus plantarum IMAUJBP3 and Lactobacillus reuteri IMAUJBR3 is (1-2): (1-2), preferably 1:1, and the viable bacterial count of the mixed microbial fermentation agent is 1.8×10 8 ~5.6×10 9 CFU / g. The plant lactobacillus IMAUJBP3 of the present invention ( Lactobacillus plantarum IMAUJBP3) was isolated from homemade smoked horse sausage made by herders in Ili Kazakh Autonomous Prefecture, Xinjiang Uygur Autonomous Region in July 2019. It has the functional characteristics of low-temperature fermentation (20°C), rapid acid production, high organic acid production, color development, and antioxidant. The strain has been disclosed in patent CN115176975A and is deposited in the General Microbiology Center of China Microbiological Culture Collection Administration (CGMCC for short). The deposit address is No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, deposit number: CGMCC NO.24175, deposit date December 21, 2021. Lactobacillus plantarum ( Lactobacillus plantarum IMAUJBP3 has been renamed Lactobacillus plantarum ( Lactiplantibacillus plantarum ), the present invention still uses the strain name disclosed previously. The Lactobacillus mucilaginosus IMAUJBR3 ( Limosilactobacillus reuteri IMAUJBR3 was isolated from air-dried mutton made by herders in Albas Sumu, Ordos City, Inner Mongolia Autonomous Region in July 2020. It has functional characteristics such as lipase production, protease production, and antioxidant properties. The strain has been published in the literature (Han Jun, Wang Yi, Zhang Kaiping, et al. Analysis of biological characteristics of Lactobacillus reuteri JBR3 and the effect of protective agents on its vitality [J / OL]. Food Industry Science and Technology, 1-18 [2025-01-21]. https: / / doi.org / 10.13386 / j.issn1002-0306.2024030355.) and is deposited in the General Microbiology Center of China Microbiological Culture Collection Administration (CGMCC for short). The address of the deposit unit is No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, Deposit number: CGMCC NO.29998, and the deposit date is March 11, 2024.

[0023] The present invention uses a mixed microbial fermentation agent, and after fermentation, the fermentation agent strain can rapidly grow and multiply to become the dominant strain in beef jerky, shortening the fermentation cycle; at the same time, the strain has a strong acid production ability during the fermentation process, and can rapidly reduce the pH value of the product to inhibit the growth of harmful microorganisms; low-temperature fermentation (20°C) not only does not affect the vitality of lactic acid bacteria in the fermentation agent, but also can inhibit the growth of some harmful bacteria, which is beneficial to improve product safety and extend the shelf life. The mixed microbial fermentation agent used in the present invention produces protease and lipase during the fermentation process, decomposes some indigestible macromolecular substances in beef, and produces small molecules such as small peptides, amino acids, fatty acids, etc., making it easier for the human body to absorb and utilize, and at the same time, functional substances such as antioxidant peptides are produced during the fermentation process, further improving the functional characteristics of the product. In the mixed microbial fermentation agent used in the present invention, during the fermentation process, microorganisms participate in the metabolism of protein, fat and carbohydrates and produce a series of free amino acids, fatty acids and volatile flavor substances, which improves the texture of fermented beef jerky and makes the fermented beef have a better taste and flavor.

[0024] The sealed pickling of the present invention is preferably sealed with a plastic wrap and placed in a constant temperature and humidity incubator. The sealed pickling temperature of the present invention is 18-25°C, preferably 19-21°C, more preferably 20°C; the sealed pickling time is 18-24h, preferably 20-22h; the sealed pickling is performed until the pH value of the meat is less than 5.1.

[0025] The two-stage roasting method of the present invention comprises the following steps: the beef is dried at 50-65°C for 0.5-1h, then cooled at room temperature for 0.5-0.6h, and then cooked at 80-90°C for 1.5-2h.

[0026] The present invention sterilizes and cools the roasted beef to obtain fermented beef jerky; the sterilization conditions are: sterilization at 110-120°C for 8-12 minutes; the cooling is room temperature cooling. As an optional embodiment, the present invention packs the obtained roasted meat strips in a plastic bag specially used for beef jerky, seals the bag, and then sterilizes in a high pressure sterilizer (sterilization at 115°C for 10 minutes), and cools the bag to obtain the fermented meat jerky.

[0027] The present invention also provides fermented beef jerky prepared by the above method. The raw beef will form a large amount of aromatic substances such as alcohol, acid, heterocyclic compounds and nucleotides during the fermentation process, which improves the flavor quality of the fermented beef jerky. At the same time, the microorganisms in the meat ferment with beef and auxiliary materials as substrates during the fermentation process, producing organic acids, bacteriocins and other substances, which reduce the pH of the fermented beef jerky and form competitive inhibition on pathogenic bacteria and spoilage bacteria. The fermented beef jerky obtained by regulating the fermentation is both safe and has a longer product shelf life, and has better development prospects than traditional beef jerky.

[0028] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The yeast extract used in the present invention is: powdered yeast extract sold by Guangdong Kangda Biotechnology Co., Ltd. under the trade name of yeast extract; paste yeast extract sold by Angel Yeast Co., Ltd. under the trade name of Angel Yeast Extract LB18; liquid yeast extract sold by Guangdong Yipinxian Biotechnology Co., Ltd. under the trade name of Yipinxian Yeast Extract Y201; the liquor used in the present invention is a liquor with an alcohol content of 60%vol, which is sold by Niulanshan Distillery of Beijing Shunxin Agriculture Co., Ltd. under the trade name of Niulanshan Erguotou; the light soy sauce used in the present invention is a light soy sauce produced by Qianhe Flavor Food Co., Ltd. under the trade name of Qianhe Zero Additive Soy Sauce 180 Days; the glucose, sodium glutamate, sodium nitrite, sodium ascorbate and other components used in the present invention are all products currently sold on the market. The beef used in the present invention is Simmental cattle hind leg meat in Tongliao, China. The plant lactobacillus IMAUJBP3 and the mucolytic Lactobacillus reuteri IMAUJBR3 used in the present invention are in dry powder state.

[0030] In the following embodiments, unless otherwise specified, all of them are conventional methods.

[0031] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0032] Example 1 The mixed microbial fermentation medium (2.0×10 9 CFU / g), and synergistically fermented with spices to prepare fermented beef jerky, the steps are as follows: (1) Raw meat pretreatment: Choose fresh beef hind leg meat, remove the surface fascia and fat, and cut the beef into 10cm×1.5cm×1.5cm strips along the direction of muscle fibers and set aside.

[0033] (2) Preparation of marinade: Prepare according to the following formula for every 100g of beef: 1.0g of salt, 0.4g of MSG, 1.5g of glucose, 1.5g of white sugar, 1.0g of white wine, 2.5g of soy sauce, 0.2g of yeast extract (powdered), and 0.01g of sodium nitrite, and mix well.

[0034] (3) Mixing, pickling and fermentation 0.05 g of the microbial fermentation agent was fully dissolved in 10 mL of purified water, and the dissolved fermentation agent was evenly mixed with the marinade obtained in (2). Then, 1000 g of the meat strips obtained in step (1) were added, mixed well, wrapped and sealed with plastic wrap, placed in a constant temperature and humidity incubator, and marinated at a temperature of 20° C. for 20 h until the pH value of the meat strips dropped below 5.1.

[0035] (4) Baking and cooking A two-stage baking process is adopted: first, the fermented beef jerky is baked in an oven at 55°C for 0.5h. After the baking, the beef jerky is taken out and allowed to rest at room temperature for 0.5h. After resting, the beef jerky is placed in an oven at 85°C and continued to be baked for 2h.

[0036] (5) Packaging and sterilization The baked beef strips obtained in (4) are packaged and sealed in a plastic bag specially used for beef jerky, and then sterilized in a high pressure sterilizer (115° C. for 10 min), and cooled to obtain the fermented beef jerky.

[0037] Example 2 Lactobacillus plantarum IMAUJBP3 and Lactobacillus reuteri IMAUJBR3 were mixed in a ratio of 1:2 to obtain a mixed microbial fermentation culture (1.0×10 9 CFU / g), and synergistically fermented with spices to prepare fermented beef jerky, the steps are as follows: (1) Pretreatment of raw meat: Select fresh beef hind leg meat, remove the surface fascia and fat, and cut the beef into 10cm×1.5cm×1.5cm strips along the direction of the muscle fibers for later use.

[0038] (2) Preparation of marinade: Prepare according to the following formula for every 100g of beef: 1.0g of salt, 0.4g of MSG, 1.5g of glucose, 1.5g of white sugar, 1.0g of white wine, 2.5g of soy sauce, 0.2g of yeast extract (powdered), and 0.01g of sodium nitrite, and mix well.

[0039] (3) Mixing, pickling and fermentation Dissolve 0.05 g of the microbial fermentation agent in 10 mL of purified water, mix the dissolved fermentation agent with the marinade obtained in (2), then add 1000 g of the meat strips obtained in step (1), mix well, wrap and seal with plastic wrap, place in a constant temperature and humidity incubator, and marinate at a temperature of 20°C for 20 hours until the pH value of the meat strips drops below 5.1.

[0040] (4) Baking and cooking A two-stage baking process was adopted. First, the fermented beef jerky was baked in an oven at 55°C for 0.5h. After that, the beef jerky was taken out and allowed to rest at room temperature for 0.5h. After resting, the beef jerky was put into the oven at 85°C and continued to be baked for 2h.

[0041] (5) Packaging and sterilization The baked beef strips obtained in (4) are packaged and sealed in a plastic bag specially used for beef jerky, and then sterilized in a high pressure sterilizer (115° C. for 10 min), and cooled to obtain the fermented beef jerky.

[0042] Example 3 Lactobacillus plantarum IMAUJBP3 and Lactobacillus reuteri IMAUJBR3 were mixed in a ratio of 2:1 to obtain a mixed microbial fermentation culture (8.0×10 8 CFU / g), and synergistically fermented with spices to prepare fermented beef jerky, the steps are as follows: (1) Raw meat pretreatment: Choose fresh beef hind leg meat, remove the surface fascia and fat, and cut the beef into 10cm×1.5cm×1.5cm strips along the direction of muscle fibers and set aside.

[0043] (2) Preparation of marinade: Prepare according to the following formula for every 100g of beef: 1.0g of salt, 0.4g of MSG, 1.5g of glucose, 1.5g of white sugar, 1.0g of white wine, 2.5g of soy sauce, 0.2g of yeast extract (powdered), and 0.01g of sodium nitrite, and mix well.

[0044] (3) Mixing, pickling and fermentation Dissolve 0.05 g of the microbial fermentation agent in 10 mL of purified water, mix the dissolved fermentation agent with the marinade obtained in (2), then add 1000 g of the meat strips obtained in step (1), mix well, wrap and seal with plastic wrap, place in a constant temperature and humidity incubator, and marinate for 21 hours at a temperature of 20°C until the pH value of the meat strips drops below 5.1.

[0045] (4) Baking and cooking A two-stage baking process was adopted. First, the fermented beef jerky was baked in an oven at 55°C for 0.5h. After that, the beef jerky was taken out and allowed to rest at room temperature for 0.5h. After resting, the beef jerky was put into the oven at 85°C and continued to be baked for 2h.

[0046] (5) Packaging and sterilization The baked beef strips obtained in (4) are packaged and sealed in a plastic bag specially used for beef jerky, and then sterilized in a high pressure sterilizer (115° C. for 10 min), and cooled to obtain the fermented beef jerky.

[0047] Example 4 Lactobacillus plantarum IMAUJBP3 and Lactobacillus reuteri IMAUJBR3 were mixed in a ratio of 1:1 to obtain a mixed microbial fermentation culture (9.0×10 8 CFU / g), and synergistically fermented with spices to prepare fermented beef jerky, the steps are as follows: (1) Raw meat pretreatment: Choose fresh beef hind leg meat, remove the surface fascia and fat, and cut the beef into 10cm×1.5cm×1.5cm strips along the direction of muscle fibers and set aside.

[0048] (2) Preparation of marinade: Prepare according to the following formula for every 100g of beef: 1.0g of salt, 0.1g of MSG, 1.5g of glucose, 1.0g of white sugar, 1.0g of white wine, 2.5g of soy sauce, 0.3g of yeast extract (powdered), and 0.015g of sodium nitrite, and mix well.

[0049] (3) Mixing, pickling and fermentation Dissolve 0.05 g of the microbial fermentation agent in 10 mL of purified water, mix the dissolved fermentation agent with the marinade obtained in (2), then add 1200 g of the meat strips obtained in step (1), mix well, wrap and seal with plastic wrap, place in a constant temperature and humidity incubator, and marinate for 20 hours at a temperature of 25°C until the pH value of the meat strips drops below 5.1.

[0050] (4) Baking and cooking A two-stage baking process was adopted. First, the fermented beef jerky was baked in an oven at 60°C for 0.6h. After that, the beef jerky was taken out and allowed to rest at room temperature for 0.5h. After resting, the beef jerky was put into the oven at 85°C and continued to be baked for 2h.

[0051] (5) Packaging and sterilization The baked beef strips obtained in (4) are packaged and sealed in a plastic bag specially used for beef jerky, and then sterilized in a high pressure sterilizer (115° C. for 10 min), and cooled to obtain the fermented beef jerky.

[0052] Example 5 The mixed microbial fermentation medium (1.0×10 9 CFU / g), and synergistically fermented with spices to prepare fermented beef jerky, the steps are as follows: (1) Raw meat pretreatment: Choose fresh beef hind leg meat, remove the surface fascia and fat, and cut the beef into 10cm×1.5cm×1.5cm strips along the direction of muscle fibers and set aside.

[0053] (2) Preparation of marinade: Prepare according to the following formula for every 100g of beef: 1.2g of salt, 0.2g of MSG, 2.0g of glucose, 1.0g of white sugar, 1.0g of white wine, 3.0g of soy sauce, 0.3g of yeast extract (paste), and 0.01g of sodium nitrite, and mix well.

[0054] (3) Mixing, pickling and fermentation 0.07 g of the microbial fermentation agent was fully dissolved in 10 mL of purified water, and the dissolved fermentation agent was evenly mixed with the marinade obtained in (2). Then, 1100 g of the meat strips obtained in step (1) were added, mixed well, wrapped and sealed with plastic wrap, placed in a constant temperature and humidity incubator, and marinated at a temperature of 21° C. for 22 h until the pH value of the meat strips dropped below 5.1.

[0055] (4) Baking and cooking A two-stage baking process is adopted: first, the fermented beef jerky is baked in an oven at 60°C for 0.5h, then the beef jerky is taken out and allowed to rest at room temperature for 0.5h, and then put into the oven at 80°C for another 1.5h.

[0056] (5) Packaging and sterilization The baked beef strips obtained in (4) are packaged and sealed in a plastic bag specially used for beef jerky, and then sterilized in a high pressure sterilizer (115° C. for 10 min), and cooled to obtain the fermented beef jerky.

[0057] Example 6 The mixed microbial fermentation medium (6.0×10 8 CFU / g), and synergistically fermented with spices to prepare fermented beef jerky, the steps are as follows: (1) Raw meat pretreatment: Choose fresh beef hind leg meat, remove the surface fascia and fat, and cut the beef into 10cm×1.5cm×1.5cm strips along the direction of muscle fibers and set aside.

[0058] (2) Preparation of marinade: Prepare according to the following formula for every 100g of beef: 2.0g of salt, 0.4g of MSG, 2.5g of glucose, 1.0g of white sugar, 2.0g of white wine, 2.0g of soy sauce, 0.4g of yeast extract (liquid), and 0.008g of sodium nitrite, and stir well.

[0059] (3) Mixing, pickling and fermentation 0.06 g of microbial fermentation agent was fully dissolved in 10 mL of purified water, and the dissolved fermentation agent was evenly mixed with the marinade obtained in (2). Then, 1000 g of the meat strips obtained in step (1) were added, mixed well, wrapped and sealed with plastic wrap, placed in a constant temperature and humidity incubator, and marinated at a temperature of 24° C. for 22 h until the pH value of the meat strips dropped below 5.1.

[0060] (4) Baking and cooking A two-stage baking process is adopted: first, the fermented beef jerky is baked in an oven at 50°C for 1 hour. After the baking, the beef jerky is taken out and allowed to rest at room temperature for 0.5 hour. After resting, the beef jerky is placed in an oven at 90°C and continued to be baked for 1.5 hours.

[0061] (5) Packaging and sterilization The baked beef strips obtained in (4) are packaged and sealed in a plastic bag specially used for beef jerky, and then sterilized in a high pressure sterilizer (115° C. for 10 min), and cooled to obtain the fermented beef jerky.

[0062] Comparative Example 1 Use Lactobacillus plantarum IMAUJBP3 single lactic acid bacteria starter to synergistically ferment with spices to prepare fermented beef jerky, the steps are as follows: (1) Raw meat pretreatment: Choose fresh beef hind leg meat, remove the surface fascia and fat, and cut the beef into 10cm×1.5cm×1.5cm strips along the direction of muscle fibers and set aside.

[0063] (2) Preparation of marinade: Prepare according to the following formula for every 100g of beef: 1.0g of salt, 0.4g of MSG, 1.5g of glucose, 1.5g of white sugar, 1.0g of white wine, 2.5g of soy sauce, 0.2g of yeast extract, and 0.01g of sodium nitrite, and mix well.

[0064] (3) Mixing, pickling and fermentation 0.05 g of microbial fermentation agent (Lactobacillus plantarum IMAUJBP3, 2.0 × 10 9 CFU / g) is fully dissolved in 10 mL of purified water, the dissolved starter culture is evenly mixed with the marinade obtained in (2), and then 1000 g of the meat strips obtained in step (1) are added, mixed well, wrapped and sealed with plastic wrap, placed in a constant temperature and humidity incubator, and marinated for 20 h at a temperature of 20°C until the pH value of the meat strips drops below 5.1.

[0065] (4) Baking and cooking A two-stage baking process was adopted. First, the fermented beef jerky was baked in an oven at 55°C for 0.5h. After that, the beef jerky was taken out and allowed to rest at room temperature for 0.5h. After resting, the beef jerky was put into the oven at 85°C and continued to be baked for 2h.

[0066] (5) Packaging and sterilization The baked beef strips obtained in (4) are packaged and sealed in a plastic bag specially used for beef jerky, and then sterilized in a high pressure sterilizer (115° C. for 10 min), and cooled to obtain the fermented beef jerky.

[0067] Comparative Example 2 The fermented beef jerky is prepared by using Lactobacillus reuteri IMAUJBR3 single fermentation culture and synergistic fermentation with spices, and the steps are as follows: (1) Raw meat pretreatment: Choose fresh beef hind leg meat, remove the surface fascia and fat, and cut the beef into 10cm×1.5cm×1.5cm strips along the direction of muscle fibers and set aside.

[0068] (2) Preparation of marinade: Prepare according to the following formula for every 100g of beef: 1.0g of salt, 0.4g of MSG, 1.5g of glucose, 1.5g of white sugar, 1.0g of white wine, 2.5g of soy sauce, 0.2g of yeast extract, and 0.01g of sodium nitrite, and mix well.

[0069] (3) Mixing, pickling and fermentation 0.05 g of microbial fermentation agent (Lactobacillus reuteri IMAUJBR3, 2.0 × 10 9 CFU / g) is fully dissolved in 10 mL of purified water, the dissolved starter culture is evenly mixed with the marinade obtained in (2), and then 1000 g of the meat strips obtained in step (1) are added, mixed well, wrapped and sealed with plastic wrap, placed in a constant temperature and humidity incubator, and marinated for 20 h at a temperature of 20°C until the pH value of the meat strips drops below 5.1.

[0070] (4) Baking and cooking A two-stage baking process was adopted. First, the fermented beef jerky was baked in an oven at 55°C for 0.5h. After that, the beef jerky was taken out and allowed to rest at room temperature for 0.5h. After resting, the beef jerky was put into the oven at 85°C and continued to be baked for 2h.

[0071] (5) Packaging and sterilization The baked beef strips obtained in (4) are packaged and sealed in a plastic bag specially used for beef jerky, and then sterilized in a high pressure sterilizer (115° C. for 10 min), and cooled to obtain the fermented beef jerky.

[0072] According to the fermented beef product specifications listed in Table 1 below, an evaluation team consisting of 10 evaluation experts (5 males, 5 females) was organized to evaluate the fermented beef jerky prepared in Examples 1 to 4 and Comparative Examples 1 to 2. The evaluation results are shown in Table 2.

[0073] Table 1 Sensory evaluation and scoring details of fermented beef jerky

[0074] Table 2 Average evaluation results of fermented beef jerky prepared in each group

[0075] The results in Table 2 show that the fermented beef jerky prepared in Example 1 has the highest average total score of 97.4 in terms of color, taste, smell and acceptance. This may be due to the equal proportion of the two lactic acid bacteria, which makes them mutually advantageous and synergistic, making the color, smell and overall acceptance of the fermented beef jerky better than those of Comparative Examples 1 and 2; while the average total score of Example 2 is 96.1, and the average total score of the fermented meat jerky prepared in Example 3 is 95.7, both of which are slightly lower than Example 1. This may be due to the inconsistent proportions of Lactobacillus plantarum and Lactobacillus mucosa Reuteri in the initial process, resulting in a lactic acid bacterium with more mass in the fermentation process becoming the main dominant strain, and the two lactic acid bacteria have functional differences, so the sensory score of the fermented product is slightly lower than that of the lactic acid bacteria fermented in equal proportions. The average total score of the fermented beef jerky prepared in Comparative Example 1 is 94.7; the average total score of the fermented beef jerky prepared in Comparative Example 2 is 94.3, which is the lowest. This shows that compounding the two lactic acid bacteria and mixed fermentation can better highlight the color and smell of the product, and is more conducive to promoting consumers' preference for the product.

[0076] In order to better evaluate the flavor quality of fermented beef jerky under different cases, solid phase microextraction-gas chromatography was used to detect the flavor substances of the beef jerky prepared in Examples 1 to 4 and Comparative Examples 1 to 2. The test results are as follows Figure 1 As shown, Figure 1Among them, Case 1 represents the beef jerky of the comparative example 1 group, which has 14 kinds of flavor substances including hydrocarbons, 5 kinds of aldehydes, 2 kinds of ketones, 13 kinds of alcohols, and 2 kinds of esters. Case 6 represents the beef jerky of the example 4 group, which has 13 kinds of hydrocarbons, 6 kinds of aldehydes, 2 kinds of ketones, 11 kinds of alcohols, and 2 kinds of esters. Case 4 represents the beef jerky of the example 2 group, which has 10 kinds of hydrocarbons, 6 kinds of aldehydes, 2 kinds of ketones, 9 kinds of alcohols, and 2 kinds of esters. Case 3 represents the beef jerky of the example 1 group, which has 18 kinds of hydrocarbons, 9 kinds of aldehydes, 2 kinds of ketones, 14 kinds of alcohols, and 5 kinds of esters. Case 5 represents the beef jerky of the example 3 group, which has 15 kinds of hydrocarbons, 8 kinds of aldehydes, 2 kinds of ketones, 12 kinds of alcohols, and 3 kinds of esters. Case 2 represents the beef jerky of the comparative example 2 group, which has 17 kinds of hydrocarbons, 7 kinds of aldehydes, 2 kinds of ketones, and 11 kinds of alcohols. The results show that among all the cases of the two esters, case 3 has a higher proportion of esters, among which ethyl nonanoate and ethyl palmitate with lower thresholds can provide more fat aroma, enriching the aroma components of beef jerky. It shows that the aldehydes, esters and ketones in Example 1 are significantly higher than those in the other five groups, indicating that the fermented beef jerky in Example 1 can better produce fruity aromas, which is also consistent with the results of sensory evaluation. At the same time, compounds such as 5-methyltetradecane, heptaldehyde, geranyl acetone, 1-nonanol, 1-octen-3-ol, and ethyl nonanoate were found during the detection process. These compounds have been increased due to the degradation of protein and fat oxidation pathways involved in lactic acid bacteria microorganisms, greatly enriching the flavor of beef jerky. This also shows that adding equal proportions of mixed fermentation agents to ferment beef can well promote the oxidative decomposition of protein and fat in beef, promote the formation of flavor substances in fermented beef jerky, and improve consumers' preference for it. At the same time, microbial fermentation can promote the oxidative decomposition of protein and fat in meat products, form small peptides and fatty acids, promote the body's digestion and absorption, and improve the nutritional value of the product.

[0077] Beef is rich in protein, and its amino acid composition is more in line with human needs than pork. Therefore, when evaluating the nutritional value of fermented beef jerky, the amino acid composition and content in the product is an important indicator. This study tested the amino acid content of Comparative Example 1, Comparative Example 2, and Example 1, Example 2, Example 3, and Example 4, and the results are shown in Table 3. The test results show that the inoculation of lactic acid bacteria in beef can effectively promote protein hydrolysis, thereby producing active amino acids and flavor peptides. Among all groups, the essential amino acid content of Example 1 reached 28.68 mg / kg, the non-essential amino acid content was 55.3 mg / kg, and the total amino acid content was 83.98 mg / kg, all of which were the highest. This is because the two strains of lactic acid bacteria are compounded in equal proportions, resulting in complementary advantages and synergistic effects, thereby increasing the content of essential amino acids and total amino acids in fermented beef jerky.

[0078] Example 2 and Example 3 also use plant lactobacillus IMAUJBP3 and reuteri mucus lactobacillus IMAUJBR3 compound, but due to the difference in the initial ratio, during the fermentation process, the strain with a higher number of viable bacteria becomes the dominant flora, resulting in the mutual inhibition of the metabolites produced by them, hindering the hydrolysis of protein in beef and reducing the generation of amino acids. This also further explains why the beef jerky flavor of Example 1 is superior to other groups. Comparing Example 2 with Example 3, it is found that the total amino acid content and essential amino acid content of Example 2 are significantly higher than those of Example 3. This is because reuteri mucus lactobacillus IMAUJBR3 has a certain ability to produce protease. During the fermentation process of Example 2, the proportion of this strain is higher than that of plant lactobacillus IMAUJBP3, so the amino acid content is higher. The same situation also occurs in Comparative Example 1 and Comparative Example 2. Comparing Example 1 with Example 4, it is found that although the strain compounding ratio of the two groups of embodiments is the same, due to the difference of 1000 times in the initial number of viable bacteria, the total amino acid and essential amino acid content of Example 4 are lower than those of Example 1, Example 2 and Example 3, but significantly higher than Comparative Example 1 and Comparative Example 2.

[0079] Comprehensive analysis of the amino acid content detection data of each comparative example and embodiment shows that in the production process of fermented beef jerky, the use of lactic acid bacteria plays a key role in the nutritional value of the product. Among them, the compounding of plant lactobacillus IMAUJBP3 and reuteri mucin lactobacillus IMAUJBR3 has obvious synergistic effect. When the two are compounded in equal proportions, protein hydrolysis can be effectively promoted, the production of active amino acids and flavor peptides can be significantly increased, and then the essential amino acids and total amino acid content in fermented beef jerky can be improved, and the product flavor can be optimized. Once the compounding ratio or the initial viable count changes, the flora advantage will be changed, and protein hydrolysis and amino acid formation will be inhibited. Therefore, giving full play to the synergistic effect of plant lactobacillus IMAUJBP3 and reuteri mucin lactobacillus IMAUJBR3 compounding, accurately regulating the compounding ratio and initial viable count of the two, is a key measure to improve the nutritional value and flavor quality of fermented beef jerky, and is of great significance to promoting product upgrading and market expansion.

[0080] Table 3 Amino acid content of fermented beef jerky prepared in each group

[0081] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing beef jerky by synergistic fermentation of mixed microbial fermentation agents and spices, characterized in that: The following steps are involved: (1) Wash and cut the beef; (2) preparing spices to obtain pickling material; the spices include salt, white sugar, glucose, soy sauce, white wine, monosodium glutamate, sodium nitrite and yeast extract; (3) The marinade is mixed with a mixed microbial fermentation agent, and then mixed with the beef, and then sealed and marinated; the mixed microbial fermentation agent is composed of plant lactobacillus ( Lactobacilluc plantarum )IMAUJBP3 and Lactobacillus reuteri ( Limosilactobacillus reuteri )IMAUJBR3 mixed; (4) The marinated beef is baked by a two-stage baking method, and the baked beef is sterilized and cooled to obtain fermented beef jerky; In step (3), the marinade, the mixed microbial fermentation agent and the beef are mixed in a mass ratio of (44.3-150.5): (0.05-0.08): (800-1200); the viable count of the mixed microbial fermentation agent is 1.8×10 8 ~5.6×10 9 CFU / g; the ratio of the number of viable bacteria of Lactobacillus plantarum IMAUJBP3 and Lactobacillus reuteri IMAUJBR3 in the mixed microbial fermentation agent is (1-2): (1-2); In step (4), the two-stage baking method includes the following steps: drying the beef at 50-65°C for 0.5-1h, cooling at room temperature for 0.5-0.6h, and then cooking at 80-90°C for 1.5-2h.

2. The method according to claim 1, characterized in that In the step (1), the beef is fresh beef or slow-cooked beef, and the beef does not contain surface tendons, fascia and fat.

3. The method according to claim 1, characterized in that In the step (1), the beef is cut into strips along the direction of muscle fiber extension.

4. The method according to claim 1, characterized in that: In the step (2), the pickling ingredients include, by weight: 0.5-2.5 parts of salt, 0.5-2.5 parts of white sugar, 0.5-2.5 parts of glucose, 1.5-3.5 parts of soy sauce, 0.5-3.0 parts of white wine, 0.2-0.6 parts of monosodium glutamate, 0.005-0.015 parts of sodium nitrite and 0.2-0.4 parts of yeast extract.

5. The method according to claim 1, characterized in that In the step (2), the yeast extract is selected from one or more combinations of solid yeast extract, paste yeast extract or liquid yeast extract; and the alcohol content of the liquor is ≥50%vol.

6. The method according to claim 1, characterized in that In the step (3), the temperature of the sealed pickling is 18-25° C., and the sealed pickling time is 18-24 hours; the sealed pickling is performed until the pH value of the meat is less than 5.

1.

7. The method according to claim 1, characterized in that In step (4), the sterilization conditions are: sterilization at 110-120° C. for 8-12 minutes.

8. The fermented beef jerky prepared by the method according to any one of claims 1 to 7.

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