A method for fermenting ham using a composite microecological fermentation agent

Abstract

The present invention relates to a method for fermenting ham using a composite microecological fermentation agent, and belongs to the technical field of fermented food processing. The present invention uses plant lactobacillus, acidophilus lactobacillus, and utilis candida as a composite microecological preparation to prepare bacterial liquid, adds hawthorn juice and microecology to jointly obtain a composite fermentation agent, and ferments and processes ham, which can improve the color and elasticity of meat muscle fibers, and shorten the fermentation and maturation period of ham to the maximum extent, and has good industrial application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of fermented food manufacturing, and in particular relates to a method for fermenting ham by using a composite microecological fermentation agent. Background Art

[0002] Ham is a traditional Chinese delicacy and is also well-known around the world. Ham is made from the hind legs of pigs and is a fermented meat product with a special flavor obtained through pickling, natural fermentation, drying and post-ripening. Depending on the different meat ingredients, beef ham, mutton ham, etc. are also derived. In China, the most famous hams are from Jinhua, Zhejiang, Xuanwei, Yunnan and Rugao, Jiangsu; looking around the world, Spanish Iberian ham, Italian Parma ham, French Bayonne ham, etc. are not inferior.

[0003] The meat is as soft as coral, and the fat is as bright as amber. The taste comes from the lightness, and the fragrance comes from the smoke. This is the praise people give to the shape, color and taste of ham. After cutting, high-quality ham is bright red or rose red, with clear texture, even distribution of fat and muscle fibers, and usually has beautiful snowflake patterns; it has a specific aroma, without unpleasant odors such as corruption or mold.

[0004] During the fermentation and maturation process of fermented ham, the maturation time is too long, and green mold often forms on the storage surface. Some scholars believe that they can play a positive role in the maturation and fermentation process of ham, such as promoting the degradation of macromolecular substances in meat and increasing the flavor of ham; but some people believe that this is a sign of ham deterioration. For example, citrinin and yellow-green penicillin also show green mold, but they produce toxins that are harmful to the human body and cannot be distinguished by the naked eye. Their safety cannot be ignored and poses a risk to human health. In addition, when the fermentation and maturation time is too long, it is easy to cause oxidation to darken or inconsistent the color of the ham surface, yellow fat, and inconsistent color, affecting the overall sensory quality of the product. The reasons for the long fermentation time include fermentation process, storage conditions, etc., and the fermentation process is the main factor in shortening the fermentation time and improving the color.

[0005] Traditional fermented hams mostly rely on natural conditions or traditional fermentation processes, which are inefficient and unstable in quality during the production process. Microecological fermentation agents play an important role in the ham fermentation process. However, there are few studies on the selection and matching of microecological fermentation agents, especially on shortening the fermentation time to improve the poor color and texture caused by long fermentation. This is a common problem faced by existing technologies.

[0006] Based on the above technical problems, the inventors proposed a method for fermenting ham using a composite microecological fermentation agent through research on the composite microecological fermentation agent, in order to effectively shorten the fermentation time and improve the color and texture of the fermented ham. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a method for fermenting ham using a composite microecological system, wherein a specific composite microecological starter is compounded to promote the rapid formation of flavor substances in fermented ham, and hawthorn juice is further compounded in the composite fermentation liquid to work together with the microecology to improve the color while improving the elasticity of the muscle fibers of the ham meat, thereby shortening the fermentation and maturation period of the ham to the maximum extent and enhancing the flavor, and the method has good prospects for industrial application.

[0008] On the one hand, the present invention provides a method for fermenting ham using a composite microecological fermentation agent, which is characterized by spraying the composite microecological agent and hawthorn juice to form a composite fermentation liquid after the ham is pickled for fermentation treatment;

[0009] The preparation method of the composite fermentation liquid is as follows: accurately weigh the following weight portions of composite microecological bacterial powder: 2-4 parts of Lactobacillus plantarum, 1-2 parts of Lactobacillus acidophilus, and 3-6 parts of Candida utilis; compound the above microecological bacterial powder, add 400-700 parts of pure water to prepare a composite microecological bacterial liquid, add 10-20 parts of hawthorn juice to the above bacterial liquid and stir well to prepare the composite fermentation liquid; wherein the mass ratio of the sum of Lactobacillus plantarum and Lactobacillus acidophilus to Candida utilis is 1:1;

[0010] The preparation method of the hawthorn juice comprises: selecting hawthorn raw materials, washing and removing seeds, squeezing juice in a ratio of hawthorn to water of 1:5, and obtaining hawthorn juice after clarification and filtration;

[0011] After pickling, spray the composite fermentation liquid, use vacuum tumbling and kneading to disperse, control the temperature at 0-10°C, the vacuum degree at -0.08 to -0.095MPa, and the time at 2-12h to allow it to be fully absorbed.

[0012] The composite fermentation liquid prepared from composite microecology and hawthorn juice is used for fermentation treatment, and the vacuum tumbling and dispersing operation facilitates the fermentation liquid to fully penetrate and absorb into the meat, which can effectively improve the fermentation effect.

[0013] Preferably, the preparation method of the composite fermentation liquid is: accurately weigh the following weight portions of composite microecological bacterial powder: 3 parts of Lactobacillus plantarum, 1.5 parts of Lactobacillus acidophilus, and 4.5 parts of Candida utilis; compound the above microecological bacterial powder, add 550 parts of pure water to prepare a composite microecological bacterial liquid, add 15 parts of hawthorn juice to the above bacterial liquid and stir well to prepare the composite fermentation liquid; wherein the mass ratio of the sum of Lactobacillus plantarum and Lactobacillus acidophilus to Candida utilis is 1:1;

[0014] The composite fermentation liquid is sprayed after pickling, and vacuum rolling and kneading are used for dispersion, and the temperature is controlled at 5° C., the vacuum degree is -0.09 MPa, and the time is 7 hours to allow it to be fully absorbed.

[0015] Further preferably, the composite fermentation liquid is added so that each square centimeter of the meat sample contains 105-109 CFU / g of the fermentation agent.

[0016] More preferably, the Lactobacillus plantarum is Lactobacillus plantarum with a deposit number of ATCC NO.8014, the Lactobacillus acidophilus is Lactobacillus acidophilus with a deposit number of ATCC NO.4356, and the Candida albicans is Candida albicans with a deposit number of CICC NO.1268.

[0017] The above-mentioned strains used in the present invention are all from commercially available strains, the raw materials are easily available, the quality is stable, the prepared starter has reliable effect, and is convenient for industrial production and application.

[0018] Preferably, the hawthorn juice is filtered through coarse filtration and fine filtration steps in sequence.

[0019] Through coarse filtration and fine filtration, particulate matter can be filtered and removed to the maximum extent, and can be sprayed evenly during the spraying and fermentation process, reducing the impact of particulate matter in hawthorn on the spray.

[0020] Further preferably, the method specifically comprises:

[0021] S1. Raw material selection: Select high-quality fresh pig hind legs with thin skin, thin legs, plump thighs, and clean blood and hair, and trim to remove the fat on both sides; the trimmed pig legs are required to weigh 5-8 kg;

[0022] S2. Low humidity acid removal: hang the selected pig hind legs in an acid removal room at 4-10℃ and humidity of 50%-60% for 6-12 hours to make the moisture content of the pork reach 60%-65%;

[0023] S3, smearing and marinating: smear salt evenly on the surface of the pork leg, add salt and rub it in batches, control the amount of salt to 5-8%, and marinate it at a temperature of 2-10°C for 10-20 days;

[0024] S4, low temperature fermentation: spray the cured ham with the composite fermentation liquid, and use vacuum rolling and kneading to disperse it, control the temperature to 0-10°C, the vacuum degree to -0.08 to -0.095MPa, and the time to 2-12h to allow it to be fully absorbed; then hang the ham in a fermentation room for low temperature storage, fermentation and maturation, control the relative humidity of the fermentation room to about 70%, the temperature to 10-20°C, and the maturation time to 90-120 days;

[0025] S5. Dry leg shaping: correct the excess fat on both sides of the ham into an arc shape, remove the fat, lean meat protrusions and uneven surface parts;

[0026] S6. Stacking packaging.

[0027] Another aspect of the present invention also provides a fermented ham prepared by a method of fermenting ham using a composite microecological fermentation agent.

[0028] Compared with the prior art, the technical solution adopted by the present invention can at least achieve the following beneficial effects:

[0029] (1) The present invention selectively selects composite microecological fermented ham to replace natural bacteria, making the composite microecological fermentation agent the dominant bacteria in ham fermentation, competing with spoilage bacteria for oxygen, inhibiting the growth of spoilage bacteria, and the selected composite microecological fermentation agent reduces the abundance of microorganisms, making the uniformity of beneficial microorganisms higher, which can accelerate the formation of flavor substances and promote the maturation of ham.

[0030] (2) The inventors targetedly selected specific lactic acid bacteria and yeasts for compounding, and the compounding effect was good. The plant lactobacillus and acidophilus used in the present invention can utilize the protein and fat substances in the ham to decompose and produce polypeptides, amino acids and short-chain fatty acids, giving the fermented ham a sour and fresh taste. At the same time, the utilis compounded with the two lactic acid bacteria can utilize a variety of carbon sources and nitrogen sources, can decompose the nitrites that may be produced in the pickling process of the ham, and promote the production of flavor substances such as mellow flavor and ester flavor during the maturation of the ham. In addition, plant lactobacillus and acidophilus can make the muscle protein in the ham form a gelatinous tissue, improve the hardness and elasticity of the fermented ham; after the addition of utilis, the metabolic activity of the yeast helps to improve the texture of the ham, making it softer and easier to chew. The addition of facultative anaerobic yeast has a weak dependence on oxygen demand, which helps to improve the fermentation efficiency of the ham, thereby shortening the maturation cycle. Therefore, the compounding of the specific microecology of the present invention can promote the rapid formation of various flavors, improve the texture, and thus achieve the purpose of shortening the fermentation cycle as much as possible.

[0031] (3) The inventors found that the composite microecology of the present invention can effectively improve the color of fermented ham, and the effect is more prominent after adding hawthorn juice. Specifically, the mold species are abandoned in the compounding process of the present invention, and two lactic acid bacteria are added to the compound strains to inhibit the growth of harmful bacteria and reduce the moldy appearance color during the maturation process. The hawthorn juice added to the composite leavening agent is rich in organic acids, which can form an acidic protective layer on the surface of the ham to prevent external mold from entering the ham and producing undesirable color; at the same time, the hawthorn juice can also work with lactic acid bacteria and yeast to restore the elasticity of the hardened muscle fibers after pickling; work with the leavening agent to accelerate the rapid maturation of the fermented ham, shorten the production cycle, and at the same time, effectively improve the color and appearance texture of the fermented ham, inhibit fat oxidation and the formation of biogenic amines during the maturation of the ham, and improve the safety and quality of the ham.

[0032] (4) The present invention greatly shortens the maturation period of fermented ham and improves the color, texture and taste of ham by spraying composite microecology and hawthorn juice during the fermentation process of ham. Experimental studies have confirmed that the fermented ham of the embodiment group has stable hardness, good chewiness and elasticity in a short period of time; and better color and sensory evaluation indicators. Therefore, fermenting ham using the method of the present invention can help companies shorten the production cycle and reduce production costs. The resulting product has a good appearance and taste, good flavor quality, and can produce green and healthy fermented ham, which has a good market prospect. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all embodiments.

[0034] The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in 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.

[0035] The main raw material sources of the present invention are as follows:

[0036] Lactobacillus plantarum with a deposit number of ATCC NO.8014, Lactobacillus acidophilus with a deposit number of ATCC NO.4356, and Candida albicans with a deposit number of CICC NO.1268 are all commercially available strains.

[0037] Example 1

[0038] A method for fermenting ham using a composite microecological fermentation agent comprises the following steps:

[0039] S1. Raw material selection: Select high-quality fresh pig hind legs with thin skin, thin legs, plump thighs, and clean blood and hair, and trim to remove the fat on both sides; the trimmed pig legs are required to weigh 6 kg;

[0040] S2, low humidity acid removal: hang the selected pig hind legs in an acid removal room at 7°C and humidity of 50%-60% for 8 hours to make the moisture content of the pork reach 60%-65%;

[0041] S3, smearing and marinating: smear salt evenly on the surface of the pork leg, add salt and rub it in batches, control the amount of salt to 6.5%, and marinate at a temperature of 6°C for 15 days;

[0042] S4, low-temperature fermentation: spray the cured ham with the composite fermentation liquid to make the meat sample contain 105-109 CFU / g of the fermentation agent per square centimeter, and use vacuum rolling and kneading to disperse it, control the temperature to 5°C, the vacuum degree to -0.09MPa, and the time to 7h to make it fully absorbed; then hang the ham in a fermentation room for low-temperature storage, fermentation and maturation, control the relative humidity of the fermentation room to about 70%, the temperature to 15°C, and the maturation time to 110 days;

[0043] The preparation method of the composite fermentation liquid is as follows: accurately weigh the following weight portions of composite microecological bacterial powder: 3 parts of Lactobacillus plantarum, 1.5 parts of Lactobacillus acidophilus, and 4.5 parts of Candida utilis; compound the above microecological bacterial powder, add 550 parts of pure water to prepare a composite microecological bacterial liquid, add 15 parts of hawthorn juice to the above bacterial liquid, and stir well to prepare the composite fermentation liquid;

[0044] The preparation method of the hawthorn juice comprises: selecting hawthorn raw materials, washing and removing seeds, squeezing juice in a ratio of hawthorn to water of 1:5, clarifying, and filtering through coarse filtration and fine filtration steps in sequence to obtain the hawthorn juice;

[0045] S5. Dry leg shaping: correct the excess fat on both sides of the ham into an arc shape, remove the fat, lean meat protrusions and uneven surface parts;

[0046] S6. Stacking packaging.

[0047] Example 2

[0048] A method for fermenting ham using a composite microecological fermentation agent comprises the following steps:

[0049] S1. Raw material selection: Select high-quality fresh pig hind legs with thin skin, thin legs, plump thighs, and clean blood and hair, and trim to remove the fat on both sides; the trimmed pig legs are required to weigh 6 kg;

[0050] S2, low humidity acid removal: hang the selected pig hind legs in an acid removal room at 7°C and humidity of 50%-60% for 8 hours to make the moisture content of the pork reach 60%-65%;

[0051] S3, smearing and marinating: smear salt evenly on the surface of the pork leg, add salt and rub it in batches, control the amount of salt to 6.5%, and marinate at a temperature of 6°C for 15 days;

[0052] S4, low-temperature fermentation: spray the cured ham with the composite fermentation liquid to make the meat sample contain 105-109 CFU / g of the fermentation agent per square centimeter, and use vacuum rolling and kneading to disperse it, control the temperature to 5°C, the vacuum degree to -0.09MPa, and the time to 7h to make it fully absorbed; then hang the ham in a fermentation room for low-temperature storage, fermentation and maturation, control the relative humidity of the fermentation room to about 70%, the temperature to 15°C, and the maturation time to 110 days;

[0053] The preparation method of the composite fermentation liquid is as follows: accurately weigh the following weight portions of composite microecological bacterial powder: 2 parts of Lactobacillus plantarum, 1 part of Lactobacillus acidophilus, and 3 parts of Candida utilis; compound the above microecological bacterial powder, add 400 parts of pure water to prepare a composite microecological bacterial liquid, add 10 parts of hawthorn juice to the above bacterial liquid, and stir well to prepare the composite fermentation liquid;

[0054] The preparation method of the hawthorn juice comprises: selecting hawthorn raw materials, washing and removing seeds, squeezing juice in a ratio of hawthorn to water of 1:5, clarifying, and filtering through coarse filtration and fine filtration steps in sequence to obtain the hawthorn juice;

[0055] S5. Dry leg shaping: correct the excess fat on both sides of the ham into an arc shape, remove the fat, lean meat protrusions and uneven surface parts;

[0056] S6. Stacking packaging.

[0057] Comparative Example 1

[0058] Compared with Example 1, 6 parts of Lactobacillus plantarum and 3 parts of Lactobacillus acidophilus were added to the composite microecological bacterial powder, and Candida utilis was not added. The rest was exactly the same as in Example 1.

[0059] Comparative Example 2

[0060] Compared with Example 1, 9 parts of Candida utilis were added to the composite microecological bacterial powder, and Lactobacillus plantarum and Lactobacillus acidophilus were not added. The rest was exactly the same as in Example 1.

[0061] Comparative Example 3

[0062] Compared with Example 1, 4.5 parts of Lactobacillus plantarum, 3 parts of Lactobacillus acidophilus, and 1.5 parts of Candida utilis were added to the composite microecological bacterial powder, and the rest was exactly the same as in Example 1.

[0063] Comparative Example 4

[0064] Compared with Example 1, the hawthorn juice was replaced with an equal amount of pure water, and the rest was exactly the same as Example 1.

[0065] Test case study

[0066] 1. Study on the ripening time and texture characteristics of different treatment groups

[0067] Experimental method: During the fermentation and maturation period of ham, samples were taken within a certain period of time, and the samples were cut into 10mm×10mm×10mm sizes in the direction parallel to the muscle fibers, and placed on the TA-XT2i texture analyzer for testing. Texture analyzer conditions were set as follows: measurement mode: TPA; probe model: P / 1000 probe, probe speed before test: 2.0mm / s, probe speed during test: 1mm / s, probe speed after test: 2mm / s, compression ratio 50%, and starting force 1N. Repeat five times and take the average value.

[0068] The experimental results are shown in Table 1 below:

[0069] Table 1 Results of maturity and texture determination of hams in different treatment groups

[0070]

[0071]

[0072] From the data analysis of the texture, it can be seen that as the fermentation progresses, the main moisture content decreases and the hardness of the ham increases to make it stable, and the hardness range is moderate, which to a certain extent represents the fermentation maturity of the ham. The hardness of Examples 1 and 2 is about 5000g to 6000g, which can be maintained in a better range and has a moderate hardness; it can reach maturity within 120 days, and the maturation time is shorter; the ham is elastic, cohesive and chewy. Comparative Example 1 only uses lactic acid bacteria and lacks yeast, and its maturity is relatively slow, and the hardness index is still increasing within 150 days. Comparative Example 2 only used yeast and no lactic acid bacteria. Its hardness index increased rapidly during the determination of the maturity time, and the hardness of the obtained product was too high; Comparative Example 3 changed the ratio of the strains, and its maturity period and hardness value also had the same trend as other comparative examples; and Comparative Example 4 did not use hawthorn juice, and its maturity period was not as good as Examples 1 and 2. The elasticity of the ham was not good, and the elasticity changed slowly. Within the first 60 days of the maturity period, the elasticity of the ham fermented in other groups was not much different, but as the maturity progressed, the elasticity of the ham group lacking hawthorn juice was obviously not as good as that of the embodiment group, indicating that the lack of hawthorn juice had a great influence on the elasticity of the ham. In summary, under the conditions of the embodiments of the present invention, the product quality tended to be stable in a short time, and all indicators were better.

[0073] 2. Study on the changes of ham color indexes in different treatment groups

[0074] Experimental methods:

[0075] During the fermentation process, samples were taken at 90, 120, 150, and 180 days, and the color value of the fermented ham was measured using a portable colorimeter. The colorimeter was calibrated with a standard white plate before use. The ham was cut into 1 cm thick cylinders, and the L*, a*, and b* modes were selected in the test to represent the results, and the changes in color values ​​during the fermentation process were recorded.

[0076] Experimental results:

[0077] Table 2: Comparison of chromaticity of ham in the ripening period Example 1

[0078]

[0079] The results in Table 2 show that in the chromaticity analysis of ham, the chromaticity of each group of hams initially differed little, but as the maturity of Example 1 and Example 2 progressed, the brightness and redness indexes increased and tended to stabilize, while the yellowness b* increased very little, indicating that the degree of oxidative browning or fat oxidation yellowing in Example 1 and Example 2 was low during the maturity period; while the brightness and redness of Comparative Example 1-4 groups also had the same trends as Examples 1 and 2, but the chromaticity difference with the Example group was quite obvious, especially the yellowing degree of the Comparative Example group was obvious, indicating the presence of fat oxidation or browning. The results confirmed that the fermented ham product obtained under the conditions of the embodiment of the present invention had a better color.

[0080] 3. Sensory test study of ham

[0081] Experimental method: 10 professional sensory assessors were selected to conduct sensory evaluation on meat blocks that had completed fermentation at the same maturity period. The sensory evaluation was scored based on appearance, color, texture, taste and flavor. The evaluation criteria are shown in Table 3.

[0082] Table 3 Sensory evaluation standards for ham

[0083]

[0084] After sensory testing, the sensory test results obtained are:

[0085] Table 4 Sensory scores of fermented hams obtained in different treatment groups

[0086]

[0087]

[0088] The sensory scoring results in Table 4 show that the flavor index of Comparative Example 1, which lacks the yeast group, is significantly lower than that of the embodiment group. The reason is that the flavor substances such as esters and alcohols produced by yeast are lacking, which affects its flavor; Comparative Example 2 lacks lactic acid bacteria, and some green mold is produced in its appearance, which affects the visual appearance; the ratio range of the strains in Comparative Example 3 is different from that in the embodiment group, and the color of its slices is not good, indicating that its maturity period is insufficient; Comparative Example 4 lacks hawthorn juice, and the texture indicators reflect the lack of elasticity.

[0089] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for fermenting ham using a composite microecological fermentation agent, characterized in that: After the ham is pickled, a composite fermentation liquid consisting of composite microecological bacteria powder and hawthorn juice is sprayed on the ham for fermentation treatment; The preparation method of the composite fermentation liquid is as follows: accurately weigh the following weight portions of composite microecological bacterial powder: 3 parts of Lactobacillus plantarum, 1.5 parts of Lactobacillus acidophilus, and 4.5 parts of Candida utilis; compound the above microecological bacterial powder, add 550 parts of pure water to prepare a composite microecological bacterial liquid, add 15 parts of hawthorn juice to the above bacterial liquid, and stir well to prepare the composite fermentation liquid; The plant lactobacillus is the plant lactobacillus with a deposit number of ATCC NO.8014, the acidophilus is the acidophilus with a deposit number of ATCC NO.4356, and the utilis candida is the utilis with a deposit number of CICC NO.1268; The preparation method of the hawthorn juice comprises: selecting hawthorn raw materials, washing and removing seeds, squeezing juice in a ratio of hawthorn to water of 1:5, and obtaining hawthorn juice after clarification and filtration; After pickling, spray the composite fermentation liquid, use vacuum tumbling and kneading to disperse it, control the temperature to 0-10℃, the vacuum degree to -0.08 to -0.095MPa, and the time to 2-12h to allow it to be fully absorbed; then hang the ham in a fermentation room for low-temperature storage, fermentation and maturation, control the relative humidity in the fermentation room to 70%, the temperature to 10-20℃, and the maturation time to 90-120 days.

2. A method for fermenting ham using a composite microecological fermentation agent as claimed in claim 1, characterized in that: The composite fermentation liquid is sprayed after pickling, and vacuum rolling and kneading are used for dispersion, and the temperature is controlled at 5° C., the vacuum degree is -0.09 MPa, and the time is 7 hours to allow it to be fully absorbed.

3. A method for fermenting ham using a composite microecological fermentation agent as claimed in claim 1, characterized in that: The hawthorn juice is filtered through coarse filtration and fine filtration steps in sequence.

4. A method for fermenting ham using a composite microecological fermentation agent as claimed in claim 1, characterized in that: The method specifically comprises: S1. Raw material selection: Select high-quality fresh pig hind legs with thin skin, thin legs, plump thighs, and clean blood and hair, and trim to remove the fat on both sides; the trimmed pig legs are required to weigh 5-8 kg; S2. Low humidity acid removal: Hang the selected pork hind legs in an acid removal room at 4-10℃ and humidity of 50%-60% for 6-12 hours to make the moisture content of the pork reach 60%-65%; S3, smearing and marinating: smear salt evenly on the surface of the pork leg, add salt and rub it in batches, control the amount of salt to 5-8%, and marinate it at a temperature of 2-10°C for 10-20 days; S4, low temperature fermentation: spray the cured ham with the composite fermentation liquid, and disperse it by vacuum rolling and kneading, control the temperature to 0-10°C, the vacuum degree to -0.08 to -0.095MPa, and the time to 2-12h, so that it can be fully absorbed; then hang the ham in a fermentation room for low temperature storage, fermentation and maturation, control the relative humidity of the fermentation room to 70%, the temperature to 10-20°C, and the maturation time to 90-120 days; S5. Dry leg shaping: correct the excess fat on both sides of the ham into an arc shape, remove the fat, lean meat protrusions and uneven surface parts; S6. Stacking packaging.

5. A fermented ham prepared by the method for fermenting ham using a composite microecological fermentation agent as described in any one of claims 1 to 4.

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