A production process of fermented sufu by microorganism
By using microbial fermentation technology and specific strains of bacteria and flavorings, the flavor of fermented bean curd is enriched, solving the problems of excessive flavor and high production costs. This improves product quality and consumer acceptance, and achieves diversified and low-cost production of fermented bean curd.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HE SHAN SHI DONG GU DIAO WEI PIN YOU XIAN GONG SI
- Filing Date
- 2025-06-19
- Publication Date
- 2026-06-23
AI Technical Summary
Existing fermented bean curd products have an overly strong flavor, resulting in low consumer acceptance. They also suffer from low levels of automation in production, high production costs, limited product variety, and restricted consumption scenarios. Furthermore, flavor compounds are easily lost during storage and transportation, leading to a decline in quality.
Microbial fermentation technology is employed, utilizing strains such as Stenotrophomonas maltophilia, Bacillus subtilis, Aspergillus oryzae, and Bacillus cereus, combined with Maillard flavorings fermented with amino acids and glutamic acid, and seafood seasoning sauce. Through the use of compound seasonings and antibacterial compounds, multi-stage fermentation is carried out to generate a variety of flavor substances, thereby improving the flavor and shelf life of fermented bean curd.
It enriches the flavor of fermented bean curd, improves its taste and nutritional value, shortens the fermentation cycle, reduces production costs, increases product diversity and consumer acceptance, and extends shelf life.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of microbial fermentation technology, and more specifically, to a process for producing fermented bean curd using microbial fermentation. Background Technology
[0002] Fermented bean curd, also known as tofu, is a traditional Chinese fermented soybean food. It contains various nutrients such as free amino acids, peptides, calcium, phosphorus, riboflavin, and B vitamins. It also contains functional components such as antioxidant peptides, ACE inhibitory peptides, and soy isoflavones, exhibiting physiological activities including antioxidant, anti-aging, blood pressure lowering, and anti-tumor effects.
[0003] The main problems with fermented bean curd and its products are as follows: (1) The fermented bean curd and fermented bean curd juice on the market are still too strong due to natural fermentation or simple juicing processes, and some consumers cannot accept them, thus limiting the consumer base. (2) As a traditional fermented food, fermented bean curd is not currently produced with a high degree of automation, and there are many process problems. There are many defective products (broken pieces, dissolved soup, amino acid crystals, etc.) or scraps produced during production. If they are not further processed, the production cost will increase significantly, which puts a lot of pressure on enterprises. (3) The processing methods are simple, the product types are few, and the consumption scenarios are limited.
[0004] Flavor compounds are one of the important indicators for evaluating the quality of fermented bean curd. The content and proportion of different types of flavor compounds in fermented bean curd directly affect its overall flavor and texture. For example, the content and types of esters are closely related to the intensity of the aroma of fermented bean curd, while the content of amino acids and small molecule peptides directly affects its umami and flavor. In addition, the stability of flavor compounds is also an important factor affecting the quality of fermented bean curd. During the storage and transportation of fermented bean curd, some flavor compounds may be lost due to oxidation, decomposition, or volatilization, leading to a deterioration in the flavor. Summary of the Invention
[0005] This invention provides a process for producing fermented bean curd using microbial fermentation. The resulting fermented bean curd utilizes the combined action of microorganisms during fermentation to produce a variety of flavor substances, such as acetic acid, esters, and 2-phenylethanol, which further enriches the flavor of the fermented bean curd and achieves low salt content. Microbial fermentation can effectively extend the shelf life of fermented bean curd and maintain its quality.
[0006] In a first aspect, the present invention provides a process for producing fermented bean curd using microbial fermentation, comprising the following steps:
[0007] S1: Select high-quality soybeans or red beans, wash them and soak them until the beans swell, drain the water, and mix them with an appropriate amount of salt to form bean curd.
[0008] S2: After adding compound seasoning to the soybean curd, soak for 12-24 hours. After soaking, place the soybean curd in a ventilated place and let it ferment naturally for 3-5 days to produce a slightly sour taste and obtain the preliminary fermented product.
[0009] S3: Inoculate the preliminary fermentation product with microbial inoculum and ferment it again to obtain the secondary fermentation product;
[0010] S4: Pickle the secondary fermented material to obtain the pickled tofu fermented material;
[0011] S5: Put the fermented tofu that has been pickled into a fermentation tank, add an antibacterial compound, and carry out the later fermentation to finally obtain fermented tofu.
[0012] The compound flavoring agent includes amino acids, Maillard flavorings fermented with glutamic acid, and seafood seasoning sauce.
[0013] Preferably, the mass ratio of the amino acid, the Maillard flavoring fermented with glutamic acid, and the seafood seasoning sauce is 1-5:1-2:3-8.
[0014] Preferably, the process for producing the Maillard flavoring product from glutamic acid fermentation includes the following steps:
[0015] (1) Glucose, sucrose, manganese sulfate, dipotassium hydrogen phosphate, sodium hydroxide, sodium chloride, sodium citrate, hydrochloric acid and L-glutamate were mixed and cultured at pH 7 to prepare a culture medium.
[0016] (2) Inoculate Corynebacterium glutamicum into the culture medium, shake and culture at 30-38℃ for 9-36 hours to obtain fermentation broth;
[0017] (3) Adjust the pH of the fermentation broth to 7.5, centrifuge, carry out Maillard reaction in an oil bath, cool after the reaction is completed, and obtain Maillard flavor product of glutamic acid fermentation.
[0018] Preferably, the seafood seasoning sauce is made from scallops using an enzymatic hydrolysis coupled with microbial fermentation method.
[0019] Preferably, the enzymatically coupled microorganism is one or more of trypsin, alkaline protease, neutral protease, papain, flavor protease, or pepsin.
[0020] Preferably, the bacterial species include Stenotrophomonas maltophilia, Bacillus subtilis, Aspergillus oryzae, and Bacillus cereus.
[0021] Preferably, the ratio of Stenotrophomonas maltophilia, Bacillus subtilis, Aspergillus oryzae, and Bacillus cereus is (1 × 10⁻⁶). 5 ~1×10 6 )∶(1×10 5 ~1×10 6 )∶(1×10 5 ~1×10 6 )∶(1×10 6 ~1×10 7 ).
[0022] Preferably, the antibacterial complex is one or more of curcumin, sorbitol, tamarind, pectinase, cellulase and papain.
[0023] Secondly, the present invention provides a fermented bean curd prepared by the aforementioned microbial fermentation process.
[0024] In summary, the present invention has the following beneficial effects:
[0025] 1. In this invention, the proteases produced by microorganisms can break down the proteins in tofu into smaller peptides and amino acids, while lipases can hydrolyze fats into glycerol and fatty acids. These decomposition products not only increase the variety of nutrients in tofu but also make it easier to digest and absorb, thus giving fermented tofu a unique flavor and texture. Amino acids are important flavor compounds in fermented foods. Amino acids combine with alcohols to form esters and react with sugars to produce carbonylamine reactions, generating special aromas and colors, thereby enhancing the flavor of the food. During fermentation, amino acids not only serve as a nitrogen source for microorganisms but also participate in metabolic processes.
[0026] 2. This invention incorporates Maillard flavor compounds derived from glutamic acid fermentation. The formation mechanism of glutamic acid during fermentation is closely related to the role of the Maillard reaction in flavor compound formation. Glutamic acid and reducing sugars produced by microbial protein decomposition provide precursors for the Maillard reaction. Ethanol and reducing sugars in the later fermentation stage promote the parallel esterification and Maillard reactions. During fermentation, microorganisms decompose proteins in tofu into amino acids and small peptides through enzymatic hydrolysis. Glutamic acid, as one of the main umami amino acids, provides the basic umami flavor for fermented tofu. Furthermore, glutamic acid undergoes a Maillard reaction with sugars in the later stages of fermentation, generating flavor compounds with appealing roasted and nutty aromas. The Maillard reaction not only involves the reaction of reducing sugars with amino acids but also brings about the synergistic effect of other sulfur-containing amino acids such as cysteine and sugars, resulting in a richer flavor profile.
[0027] 3. The addition of seafood seasoning sauce in this invention significantly shortens the fermentation cycle of fermented bean curd, increases the content of free amino acids in the bean curd, and thus enhances its umami flavor. Simultaneously, the types and amounts of flavor compounds such as esters, aldehydes, and alcohols produced during fermentation also change, and these substances collectively constitute the unique flavor of fermented bean curd. The flavor nucleotides in the seafood sauce combine with the hydrolyzed amino acids glutamic acid and aspartic acid in the fermented bean curd to create a umami-enhancing effect. The lactic acid in the seafood sauce combines with the alcohols in the fermented bean curd to form fruity esters, imparting a complex aroma.
[0028] 4. This invention incorporates Stenotrophomonas maltophilia, which can utilize various sugars and produce a variety of metabolites, such as fatty acids and enzymes, under specific culture conditions. It primarily affects the flavor and texture of fermented bean curd through metabolic activity. This bacterium is an aerobic putrefactive bacterium with strong protein hydrolysis activity and the ability to generate volatile organic compounds, significantly altering the flavor characteristics of fermented bean curd. Furthermore, during fermentation, Stenotrophomonas maltophilia decomposes proteins and fats, producing flavor compounds such as alcohols, esters, and pyrazines, thereby enriching the aroma of the fermented bean curd.
[0029] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the scope of protection of the present invention. Detailed Implementation
[0030] The present invention will be further described in detail below with reference to the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments can be obtained from commercially available sources.
[0031] The Stenotrophomonas maltophilia CCM 1640, Bacillus subtilis CGMCC No. 29091, Aspergillus oryzae CGMCC No. 18109, and Bacillus cereus CGMCC No. 16672 used in this invention are deposited at the China General Microbiological Culture Collection Center, located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences.
[0032] Example
[0033] Example 1
[0034] A process for producing fermented bean curd using microbial fermentation includes the following steps:
[0035] S1: Select high-quality soybeans or red beans, wash them and soak them until the beans swell, drain the water, and mix them with an appropriate amount of salt to form bean curd.
[0036] S2: After adding compound seasoning to the soybean curd, soak for 12 hours. After soaking, place the soybean curd in a ventilated place and let it ferment naturally for 3 days to produce a slightly sour taste and obtain the preliminary fermented product.
[0037] S3: Inoculate the preliminary fermentation product with microbial inoculum and ferment it again to obtain the secondary fermentation product;
[0038] S4: Pickle the secondary fermented material to obtain the pickled tofu fermented material;
[0039] S5: Put the fermented tofu that has been pickled into a fermentation tank, add an antibacterial compound, and carry out the later fermentation to finally obtain fermented tofu.
[0040] The compound flavoring agents include amino acids, Maillard flavorings fermented with glutamic acid, and seafood sauce.
[0041] The mass ratio of Maillard flavorings fermented with amino acids and glutamic acid to seafood seasoning sauce is 1:1:3.
[0042] The process for producing Maillard flavored products by glutamic acid fermentation includes the following steps:
[0043] (1) Glucose, sucrose, manganese sulfate, dipotassium hydrogen phosphate, sodium hydroxide, sodium chloride, sodium citrate, hydrochloric acid and L-glutamate were mixed and cultured at pH 7 to prepare a culture medium.
[0044] (2) Inoculate Corynebacterium glutamicum into the culture medium, shake and culture at 30°C for 9 hours to obtain fermentation broth;
[0045] (3) Adjust the pH of the fermentation broth to 7.5, centrifuge, carry out Maillard reaction in an oil bath, cool after the reaction is completed, and obtain Maillard flavor product of glutamic acid fermentation.
[0046] The seafood seasoning sauce is made from scallops using an enzymatic hydrolysis coupled with microbial fermentation. The enzymatic hydrolysis coupled with microorganisms is trypsin.
[0047] The bacterial species included Stenotrophomonas maltophilia, Bacillus subtilis, Aspergillus oryzae, and Bacillus cereus, with a ratio of 1 × 10⁻⁶. 5 ∶1×10 5 ∶1×10 5 ∶1×10 6 .
[0048] The antibacterial complex is a mixture of curcumin and sorbitol in a 1:1 mass ratio.
[0049] Example 2
[0050] A process for producing fermented bean curd using microbial fermentation includes the following steps:
[0051] S1: Select high-quality soybeans or red beans, wash them and soak them until the beans swell, drain the water, and mix them with an appropriate amount of salt to form bean curd.
[0052] S2: After adding compound seasoning to the soybean curd, soak for 12 hours. After soaking, place the soybean curd in a ventilated place and let it ferment naturally for 3 days to produce a slightly sour taste and obtain the preliminary fermented product.
[0053] S3: Inoculate the preliminary fermentation product with microbial inoculum and ferment it again to obtain the secondary fermentation product;
[0054] S4: Pickle the secondary fermented material to obtain the pickled tofu fermented material;
[0055] S5: Put the fermented tofu that has been pickled into a fermentation tank, add an antibacterial compound, and carry out the later fermentation to finally obtain fermented tofu.
[0056] The compound flavoring agents include amino acids, Maillard flavorings fermented with glutamic acid, and seafood sauce.
[0057] The mass ratio of Maillard flavorings fermented with amino acids and glutamic acid to seafood seasoning sauce is 2:1:3.
[0058] The process for producing Maillard flavored products by glutamic acid fermentation includes the following steps:
[0059] (1) Glucose, sucrose, manganese sulfate, dipotassium hydrogen phosphate, sodium hydroxide, sodium chloride, sodium citrate, hydrochloric acid and L-glutamate were mixed and cultured at pH 7 to prepare a culture medium.
[0060] (2) Inoculate Corynebacterium glutamicum into the culture medium, shake culture, culture temperature is 32℃, time is 12h, and fermentation broth is obtained;
[0061] (3) Adjust the pH of the fermentation broth to 7.5, centrifuge, carry out Maillard reaction in an oil bath, cool after the reaction is completed, and obtain Maillard flavor product of glutamic acid fermentation.
[0062] The seafood seasoning sauce is made from scallops using an enzymatic hydrolysis coupled with microbial fermentation. The enzymatic hydrolysis coupled with microorganisms is trypsin.
[0063] The bacterial species included Stenotrophomonas maltophilia, Bacillus subtilis, Aspergillus oryzae, and Bacillus cereus, with a ratio of 1 × 10⁻⁶. 5 ∶1×10 6 ∶1×10 5 ∶1×10 6 .
[0064] The antibacterial complex is a mixture of curcumin and sorbitol in a 1:1 mass ratio.
[0065] Example 3
[0066] A process for producing fermented bean curd using microbial fermentation includes the following steps:
[0067] S1: Select high-quality soybeans or red beans, wash them and soak them until the beans swell, drain the water, and mix them with an appropriate amount of salt to form bean curd.
[0068] S2: After adding compound seasoning to the soybean curd, soak for 12 hours. After soaking, place the soybean curd in a ventilated place and let it ferment naturally for 3 days to produce a slightly sour taste and obtain the preliminary fermented product.
[0069] S3: Inoculate the preliminary fermentation product with microbial inoculum and ferment it again to obtain the secondary fermentation product;
[0070] S4: Pickle the secondary fermented material to obtain the pickled tofu fermented material;
[0071] S5: Put the fermented tofu that has been pickled into a fermentation tank, add an antibacterial compound, and carry out the later fermentation to finally obtain fermented tofu.
[0072] The compound flavoring agents include amino acids, Maillard flavorings fermented with glutamic acid, and seafood sauce.
[0073] The mass ratio of Maillard flavorings fermented with amino acids and glutamic acid to seafood seasoning sauce is 3:1:3.
[0074] The process for producing Maillard flavored products by glutamic acid fermentation includes the following steps:
[0075] (1) Glucose, sucrose, manganese sulfate, dipotassium hydrogen phosphate, sodium hydroxide, sodium chloride, sodium citrate, hydrochloric acid and L-glutamate were mixed and cultured at pH 7 to prepare a culture medium.
[0076] (2) Inoculate Corynebacterium glutamicum into the culture medium, shake culture, culture temperature is 35℃, time is 16h, and fermentation broth is obtained.
[0077] (3) Adjust the pH of the fermentation broth to 7.5, centrifuge, carry out Maillard reaction in an oil bath, cool after the reaction is completed, and obtain Maillard flavor product of glutamic acid fermentation.
[0078] The seafood seasoning sauce is made from scallops using an enzymatic hydrolysis coupled with microbial fermentation. The enzymatic hydrolysis coupled with microorganisms is trypsin.
[0079] The bacterial species included Stenotrophomonas maltophilia, Bacillus subtilis, Aspergillus oryzae, and Bacillus cereus, with a ratio of 1 × 10⁻⁶. 5 ∶1×10 5 ∶1×10 6 ∶1×10 6 .
[0080] The antibacterial complex is a mixture of curcumin and sorbitol in a 1:1 mass ratio.
[0081] Example 4
[0082] A process for producing fermented bean curd using microbial fermentation includes the following steps:
[0083] S1: Select high-quality soybeans or red beans, wash them and soak them until the beans swell, drain the water, and mix them with an appropriate amount of salt to form bean curd.
[0084] S2: After adding compound seasoning to the soybean curd, soak for 12 hours. After soaking, place the soybean curd in a ventilated place and let it ferment naturally for 3 days to produce a slightly sour taste and obtain the preliminary fermented product.
[0085] S3: Inoculate the preliminary fermentation product with microbial inoculum and ferment it again to obtain the secondary fermentation product;
[0086] S4: Pickle the secondary fermented material to obtain the pickled tofu fermented material;
[0087] S5: Put the fermented tofu that has been pickled into a fermentation tank, add an antibacterial compound, and carry out the later fermentation to finally obtain fermented tofu.
[0088] The compound flavoring agents include amino acids, Maillard flavorings fermented with glutamic acid, and seafood sauce.
[0089] The mass ratio of Maillard flavorings fermented with amino acids and glutamic acid to seafood seasoning sauce is 5:2:3.
[0090] The process for producing Maillard flavored products by glutamic acid fermentation includes the following steps:
[0091] (1) Glucose, sucrose, manganese sulfate, dipotassium hydrogen phosphate, sodium hydroxide, sodium chloride, sodium citrate, hydrochloric acid and L-glutamate were mixed and cultured at pH 7 to prepare a culture medium.
[0092] (2) Inoculate Corynebacterium glutamicum into the culture medium, shake and culture at 38°C for 24 hours to obtain fermentation broth;
[0093] (3) Adjust the pH of the fermentation broth to 7.5, centrifuge, carry out Maillard reaction in an oil bath, cool after the reaction is completed, and obtain Maillard flavor product of glutamic acid fermentation.
[0094] The seafood seasoning sauce is made from scallops using an enzymatic hydrolysis coupled with microbial fermentation. The enzymatic hydrolysis coupled with microorganisms is trypsin.
[0095] The bacterial species included Stenotrophomonas maltophilia, Bacillus subtilis, Aspergillus oryzae, and Bacillus cereus, with a ratio of 1 × 10⁻⁶. 6 ∶1×10 5 ∶1×10 5 ∶1×10 6 .
[0096] The antibacterial complex is a mixture of curcumin and sorbitol in a 1:1 mass ratio.
[0097] Example 5
[0098] A process for producing fermented red bean curd using microbial fermentation includes the following steps:
[0099] S1: Select high-quality soybeans or red beans, wash them and soak them until the beans swell, drain the water, and mix them with an appropriate amount of salt to form bean curd.
[0100] S2: After adding compound seasoning to the soybean curd, soak for 24 hours. After soaking, place the soybean curd in a ventilated place and let it ferment naturally for 5 days to produce a slightly sour taste and obtain the preliminary fermented product.
[0101] S3: Inoculate the preliminary fermentation product with microbial inoculum and ferment it again to obtain the secondary fermentation product;
[0102] S4: Mix red yeast rice, wheat koji, yellow rice wine, etc. and ferment to make red yeast brine;
[0103] S5: The secondary fermented product is dyed in red yeast rice brine, then placed in a jar, sealed and fermented to obtain the tertiary fermented product;
[0104] S6: Pickle the three-stage fermented product to obtain the pickled tofu fermented product;
[0105] S7: Put the fermented tofu that has been pickled into a fermentation tank, add an antibacterial compound, and carry out the later fermentation to finally obtain fermented tofu that has been fermented.
[0106] The compound flavoring agents include amino acids, Maillard flavorings fermented with glutamic acid, and seafood sauce.
[0107] The mass ratio of Maillard flavorings fermented with amino acids and glutamic acid to seafood seasoning sauce is 5:2:8.
[0108] The process for producing Maillard flavored products by glutamic acid fermentation includes the following steps:
[0109] (1) Glucose, sucrose, manganese sulfate, dipotassium hydrogen phosphate, sodium hydroxide, sodium chloride, sodium citrate, hydrochloric acid and L-glutamate were mixed and cultured at pH 7 to prepare a culture medium.
[0110] (2) Inoculate Corynebacterium glutamicum into the culture medium, shake and culture at 38℃ for 36 hours to obtain fermentation broth;
[0111] (3) Adjust the pH of the fermentation broth to 7.5, centrifuge, carry out Maillard reaction in an oil bath, cool after the reaction is completed, and obtain Maillard flavor product of glutamic acid fermentation.
[0112] The seafood seasoning sauce is made from scallops using an enzymatic hydrolysis coupled with microbial fermentation. The enzymatic hydrolysis coupled with microorganisms is trypsin.
[0113] The bacterial species included Stenotrophomonas maltophilia, Bacillus subtilis, Aspergillus oryzae, and Bacillus cereus, with a ratio of 1 × 10⁻⁶. 6 ∶1×10 6 ∶1×10 6 ∶1×10 7 .
[0114] The antibacterial complex is a mixture of curcumin and sorbitol in a 1:1 mass ratio.
[0115] Comparative Example 1
[0116] The difference from Example 1 is that Stenotrophomonas maltophilia was not added to the bacterial strain.
[0117] Comparative Example 2
[0118] The difference from Example 1 is that no seafood sauce was added.
[0119] Comparative Example 3
[0120] The difference from Example 1 is that Maillard flavor compounds from glutamic acid fermentation were not added. The examples and comparative examples underwent strain screening, flavor compound determination, and amino acid nitrogen determination.
[0121] Table 1 Results of secondary screening of Aspergillus oryzae strains
[0122]
[0123] Table 2. Colony diameters (mm) of Aspergillus oryzae strains on plates with different NaCl concentrations.
[0124]
[0125] Table 3. Changes in enzyme activity under high salt content (u / g dry basis)
[0126] Storage time (d) A2 K9 N11 control strain 0 1118 2253 1211 981 1 771 1782 754 644 2 727 1837 673 653 3 514 1021 528 477 4 217 569 184 221 5 109 162 90 96 6 66 243 92 117 7 39 116 60 47
[0127] Table 4. Results of flavor compound determination in Example 1
[0128] Fermented bean curd prepared in Example 1 content(%) ethanol 0.76 propanol 0.76 3-Methylbutanol 1.13 Death alcohol 0.87 Octyl alcohol = polymer 1.41 benzyl alcohol 5.41 Phenylacetyl alcohol 0.95 Terpenols 0.84 Ethyl octanoate 1.09 Ethyl benzoate 0.83 Ethyl palmitate 4.27 Ethyl octanoate 2.11 Ethyl linoleate 6.76 Anethole (p-propenyl anethole) 19.66
[0129] Table 5. Results of flavor compound determination in Example 5
[0130] Fermented bean curd prepared in Example 5 content(%) 2-Methylpropanol 2.52 3-Methylbutanol 9.19 furfuryl alcohol 0.85 Phenylacetyl alcohol 9.68 Ethyl butyrate 0.9 2-Methylbutyrate 0.8 Ethyl ester 0.98 Ethyl octanoate 2.85 Ethyl nonanoate 0.91 Ethyl benzoate 3.68 Ethyl succinate 2.57 Ethyl phenylacetate 0.74 Ethyl dodecanoate 0.85 Ethyl tetradecenoate 0.74 Ethyl palmitate 9.92 Ethyl octanoate 3.23 Ethyl linoleate 8.98 2-Methylpropionic acid 1 butyric acid 4.5 benzoic acid 15.61 phenol 1.13
[0131] Table 6. Detection results of Examples 1-5 and Comparative Examples 1-3
[0132]
[0133]
[0134] As shown in Tables 1-6, the fermented bean curd prepared in the examples has a good taste and flavor. The proteases produced by the microorganisms can break down the proteins in the tofu into small peptides and amino acids, while the lipases can hydrolyze the fats into glycerol and fatty acids. These decomposition products not only increase the variety of nutrients in the tofu, but also make it easier to digest and absorb, thus giving the fermented bean curd a unique flavor and taste.
[0135] The above description is merely an exemplary embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A process for producing fermented bean curd using microbial fermentation, characterized in that, Includes the following steps: S1: Select high-quality soybeans or red beans, wash them and soak them until the beans swell, drain the water, and mix them with an appropriate amount of salt to form bean curd. S2: After adding compound seasoning to the soybean curd, soak for 12-24 hours. After soaking, place the soybean curd in a ventilated place and let it ferment naturally for 3-5 days to produce a slightly sour taste and obtain the preliminary fermented product. S3: Inoculate the preliminary fermentation product with microbial inoculum and ferment it again to obtain the secondary fermentation product; S4: Pickle the secondary fermented material to obtain the pickled tofu fermented material; S5: Put the fermented tofu that has been pickled into a fermentation tank, add an antibacterial compound, and carry out the later fermentation to finally obtain fermented tofu. The compound flavoring agent includes amino acids, Maillard flavorings fermented with glutamic acid, and seafood seasoning sauce; The mass ratio of the amino acid, the Maillard flavoring compound fermented with glutamic acid, and the seafood seasoning sauce is 1-5:1-2:3-8; The process for producing Maillard flavor compounds by glutamic acid fermentation includes the following steps: (1) Glucose, sucrose, manganese sulfate, dipotassium hydrogen phosphate, sodium hydroxide, sodium chloride, sodium citrate, hydrochloric acid and L-glutamate were mixed and the culture medium was prepared under the condition of pH 7. (2) Inoculate Corynebacterium glutamicum into the culture medium, shake and culture at 30-38℃ for 9-36h to obtain fermentation broth; (3) Adjust the pH of the fermentation broth to 7.5, centrifuge, carry out Maillard reaction in an oil bath, cool after the reaction is completed, and obtain Maillard flavor product of glutamic acid fermentation.
2. The process for producing fermented bean curd according to claim 1, characterized in that, The seafood seasoning sauce is made from scallops using an enzymatic hydrolysis coupled with microbial fermentation method.
3. The process for producing fermented bean curd according to claim 2, characterized in that, The enzymatically coupled microorganism is one or more of trypsin, alkaline protease, neutral protease, papain, flavor protease, or pepsin.
4. The process for producing fermented bean curd according to claim 1, characterized in that, The bacterial species include Stenotrophomonas maltophilia, Bacillus subtilis, Aspergillus oryzae, and Bacillus cereus.
5. The process for producing fermented bean curd according to claim 4, characterized in that, The ratio of Stenotrophomonas maltophilia, Bacillus subtilis, Aspergillus oryzae, and Bacillus cereus was (1×10⁻⁶). 5 ~1×10 6 )∶(1×10 5 ~1×10 6 )∶(1×10 5 ~1×10 6 )∶(1×10 6 ~1×10 7 ).
6. The process for producing fermented bean curd according to claim 1, characterized in that, The antibacterial complex is one or more of curcumin, sorbitol, tamarind, pectinase, cellulase, and papain.
7. A type of fermented bean curd, characterized in that, It is prepared by the manufacturing process described in any one of claims 1-6.