Sauced dried bean curd and preparation method thereof

Abstract

The invention relates to the technical field of food processing, and discloses sauced dried bean curds and a preparation method thereof.The preparation method comprises the following steps that soybean protein, pea protein and wheat protein are mixed with water, protein slurry is obtained, the protein slurry is subjected to forming treatment, and a composite vegetable protein gel blank is obtained; inoculating the composite vegetable protein gel blank with fermentation microorganisms, and carrying out first-step solid-state fermentation to obtain a primary fermentation blank; immersing the primary fermentation blank into seasoning sauce, and carrying out second-step immersion fermentation to obtain a fermentation product; and performing post-treatment on the fermentation product to obtain the sauced dried bean curd. Through a composite vegetable protein base material and a gradient fermentation process, comprehensive breakthrough in texture, flavor and health attributes of the sauced dried bean curd is realized, and the technical problems that tasty and shape preservation of a traditional product are difficult to consider, the flavor is single, and the salt content is high are fundamentally solved.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and more specifically, to a soy-sauce-flavored dried bean curd and its preparation method. Background Technology

[0002] Dried tofu is a popular traditional plant-based protein food. Its savory, umami flavor enjoys widespread market demand due to its unique richness and lingering aftertaste. Currently, commercially available savory dried tofu mainly uses a process of first preparing the raw tofu, then braising and seasoning it. This process has the following significant drawbacks: First, to achieve proper flavor absorption, prolonged cooking or soaking is often required, which can easily lead to the tofu becoming soft and mushy, losing its proper elasticity and chewiness. Conversely, shortening the flavor absorption time to maintain texture results in a bland taste throughout the product, with the flavor remaining only on the surface and uneven in flavor. Second, current processes rely heavily on added seasonings, making it difficult for flavor substances to penetrate the product and undergo complex flavor transformations. The resulting soy sauce aroma is mostly a direct salty and savory taste, lacking the layered, rich soy sauce aroma produced by microbial fermentation. Third, the product mainly uses soybeans as raw material, which limits its amino acid profile, textural adjustment potential, and functional expansion. The single raw material restricts its nutritional and functional benefits. Furthermore, existing technologies focus primarily on adjusting seasoning formulas, lacking fundamental innovation in raw materials and production processes, leading to homogenization of taste and flavor in market products.

[0003] Therefore, there is an urgent need for a new technological solution that can fundamentally solve the above problems and develop a plant protein product that has excellent texture, rich flavor, and is healthier and more differentiated. Summary of the Invention

[0004] In view of this, the present invention proposes a soy sauce-flavored dried bean curd and its preparation method, aiming to solve the technical problems of existing dried bean curd products, such as difficulty in balancing flavor and texture, lack of rich and natural soy sauce aroma, single raw material and nutritional function, high salt and high additive content, and serious product homogenization.

[0005] This invention proposes a method for preparing soy sauce-flavored dried tofu, characterized by comprising the following steps: (1) Mix soybean protein, pea protein and wheat protein with water to obtain a protein slurry, and then perform molding treatment on the protein slurry to obtain a composite plant protein gel blank. (2) Inoculate the composite plant protein gel blank obtained in step (1) with fermentation microorganisms to carry out the first step of solid-state fermentation to obtain the primary fermentation blank; (3) Immerse the primary fermented blank obtained in step (2) in the seasoning sauce for the second step of immersion fermentation to obtain the fermentation product; (4) The fermentation product obtained in step (3) is post-processed to obtain the soy sauce-flavored dried bean curd.

[0006] More preferably, in step (1), the dry basis mass ratio of the soybean protein, pea protein and wheat protein is (5-9):(1-4):(0.5-3).

[0007] More preferably, in step (1), before the molding process, the protein slurry is modified to obtain a modified protein slurry; the modification process is an enzymatic modification process or a physical modification process.

[0008] More preferably, the enzyme used in the enzymatic modification treatment is a protease or transglutaminase; the physical modification treatment is a wet heat treatment or an ultrasonic treatment.

[0009] More preferably, in step (1), the molding process includes heating and solidifying the modified protein slurry at a temperature of 75-95°C for 15-60 minutes.

[0010] More preferably, in step (2), the fermenting microorganism includes at least one selected from Aspergillus oryzae, Aspergillus soysarum, and Bacillus.

[0011] More preferably, in step (2), the fermenting microorganisms also include lactic acid bacteria.

[0012] More preferably, in step (2), the temperature during the first solid-state fermentation is 25-37℃, the relative humidity is 70-90%, and the fermentation time is 12-72 hours.

[0013] More preferably, in step (3), the temperature during the second step of soaking and fermentation is 10-30℃, and the fermentation time is 1-10 days.

[0014] On the other hand, this application also provides a savory bean curd, characterized in that the savory bean curd is prepared by the aforementioned method for preparing savory bean curd.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention pre-determines the product's textural basis by designing a gel network on a composite protein substrate. A two-step fermentation process precisely constructs flavor on this optimized structure. The first fermentation creates pores within the substrate and generates aroma precursors, while the second fermentation efficiently fills and locks in flavor substances. This results in an ideal gradient texture that is firm and flavorful on the outside, and tender and juicy on the inside, breaking the limitations of traditional processes.

[0016] This invention is not simply about external flavoring, but rather guides a complete flavor evolution path from the generation of endogenous precursor substances to the penetration and integration of external flavor substances through a two-step fermentation process using microorganisms on a specific substrate. The resulting soy sauce aroma is a complex fragrance produced by a combination of various flavor substances, such as amino acids, peptides, organic acids, esters, and pyrazines, exhibiting strong layers, a mellow and natural flavor, and a long-lasting aftertaste. The amino acid pattern of the complex plant protein is more balanced, resulting in higher nutritional value. Through the fermentation process, beneficial components are naturally enriched, producing a richly flavored product without the need for excessive chemical additives, aligning with the trends of clean labels and healthy foods.

[0017] This invention innovates from two fundamental levels: raw materials and process. The resulting product is fundamentally different from existing commercially available soy sauce-flavored dried tofu in terms of taste, flavor, and nutritional components. Moreover, the process steps are clear and the key parameters are controllable, which is conducive to achieving large-scale and standardized production and ensuring stable product quality. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a flowchart of a method for preparing savory soybeans according to an embodiment of the present invention. Detailed Implementation

[0019] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] See Figure 1 The invention proposes a method for preparing soy sauce-flavored dried tofu, characterized by the following steps: (1) Mix soybean protein, pea protein and wheat protein with water to obtain a protein slurry, and then perform molding treatment on the protein slurry to obtain a composite plant protein gel blank. (2) Inoculate the composite plant protein gel blank obtained in step (1) with fermentation microorganisms to carry out the first step of solid-state fermentation to obtain the primary fermentation blank; (3) Immerse the primary fermented blank obtained in step (2) in the seasoning sauce for the second step of immersion fermentation to obtain the fermentation product; (4) The fermentation product obtained in step (3) is post-processed to obtain the soy sauce-flavored dried bean curd.

[0021] Step (1) Mix soybean protein, pea protein and wheat protein with water to obtain a protein slurry. Then, perform a molding process on the protein slurry to obtain a composite plant protein gel preform. Specifically, the present invention first mixes soybean protein, pea protein, and wheat protein with water, wherein the dry basis mass ratio of soybean protein, pea protein, and wheat protein is preferably (5-9):(1-4):(0.5-3) to obtain a protein slurry. Preferably, the protein slurry is modified to obtain a modified protein slurry. The modification treatment is preferably enzymatic modification or physical modification. The enzyme used in the enzymatic modification treatment is preferably protease or transglutaminase; the physical modification treatment is preferably wet heat treatment or ultrasonic treatment. After modification, the modified protein slurry is subjected to molding treatment, which preferably includes heating and coagulating the modified protein slurry at a temperature of 75-95°C for a time of 15-60 minutes, resulting in a composite plant protein gel preform.

[0022] Understandably, in this invention, a protein slurry obtained by mixing soy protein, pea protein, and wheat protein in a dry weight ratio of (5-9):(1-4):(0.5-3) is used as the raw material, aiming to actively design and construct an optimal gel network structure at the molecular level. Soy protein provides the main framework and hydrophilic substrate. When pea protein is co-gelled with soy protein, it can effectively insert into and modify the soy protein network, increasing the network's flexibility and extensibility. Simultaneously, it can neutralize the brittleness or powdery texture of pure soy gel, giving the product a better mouthfeel and a chewy texture. Furthermore, based on the different amino acid compositions of pea protein and soy protein, it can also generate richer flavor peptides and amino acids during subsequent fermentation, enhancing the complexity of the flavor. Wheat protein possesses unique viscoelasticity and extensibility, significantly enhancing the mechanical strength and toughness of the gel network. This prevents the product from easily disintegrating or crumbling during prolonged soaking and fermentation, solving the shape-preserving problem inherent in traditional preparation methods. Simultaneously, wheat protein imparts a chewy texture to dried bean curd products, distinguishing them from traditional products. Its viscoelasticity also contributes to the formation of a more uniform and better-encapsulating porous structure, facilitating microbial colonization and flavor substance penetration. This invention constructs a strong and stable gel network through the combination of soybean protein (shape-preserving framework) and wheat protein (toughness enhancement), sufficient to withstand the physical impact of subsequent fermentation and cooking. Furthermore, the formation of pea protein (softening and elasticizing) and controllable pores ensures that the strong network is not dense and solid, but rather possesses suitable permeation channels. By limiting the proportions of these three proteins, the gel is ensured to possess excellent water retention, elasticity, and toughness, while also providing a more balanced and efficient nitrogen and carbon source for subsequent microorganisms, promoting their growth and metabolism, and generating a more optimized flavor enzyme system.

[0023] In traditional tofu production, the formation of the protein network is a passive and random process of heating and coagulation, and its structure, such as pore size and connection strength, is difficult to control. This invention modifies the protein network before molding, aiming to pre-alter the conformation, charge state, and intermolecular forces of the protein molecules, guiding them to assemble in a predetermined structural direction. Specifically, moderate enzymatic hydrolysis can pre-create microscopic channels in the protein network, significantly reducing the resistance to flavor substance penetration; while transglutaminase cross-linking or physical modification can enhance the overall strength and elasticity of the network framework while creating pores, preventing collapse during subsequent long-term soaking. The regulated network has more suitable surface roughness, hydrophilicity, and internal pore connectivity. This provides a better colonization microenvironment for microorganisms in subsequent fermentation steps, promoting their uniform and rapid growth and metabolism, thereby more efficiently producing proteases, flavor precursors, etc., improving the soy sauce aroma quality from the source.

[0024] Step (2) Inoculate the composite plant protein gel blank obtained in step (1) with fermentation microorganisms to carry out the first step of solid-state fermentation to obtain the primary fermentation blank; Specifically, in this invention, the composite plant protein gel blank obtained in step (1) is inoculated with fermenting microorganisms, preferably at least one of Aspergillus oryzae, Aspergillus soysarum, and Bacillus, and also includes lactic acid bacteria. After inoculation, a first-step solid-state fermentation is carried out. The ambient temperature during the first-step solid-state fermentation is preferably 25-37℃, the relative humidity is preferably 70-90%, and the fermentation time is preferably 12-72 hours.

[0025] Understandably, during their growth, the inoculated microorganisms secrete abundant proteases, peptidases, and amylases into the gel blank. These enzymes act on the protein networks of soybeans, peas, and wheat, as well as any small amounts of carbohydrates present, partially hydrolyzing them into small peptides, free amino acids, and reducing sugars. These products form the core precursor pool for the subsequent development of the soy sauce aroma. The microorganisms utilize these precursors for their own metabolism, producing a series of volatile flavor compounds. In the specific microaerobic environment of solid-state fermentation, certain microorganisms can promote the accumulation and initial reaction of Maillard reaction precursors, generating typical soy sauce aroma substances such as pyrazines, forming a preliminary, endogenous base aroma. Traditional processes rely entirely on external soy sauce penetration for flavor, while this invention, through this step, industrially and in-situ produces flavor-enhancing amino acids, umami peptides, and reducing sugars within the tofu blank. This results in the final product's soy sauce aroma emanating from the inside out, with a rich, mellow, and long-lasting flavor, overcoming the shortcomings of an externally fragrant but internally weak aroma and a single flavor profile. Meanwhile, the growth and enzymatic hydrolysis of microorganisms, while maintaining the integrity of the overall gel skeleton, create a large number of interconnected pores and channels inside, providing a basis for the rapid, deep and uniform penetration of the external sauce during the second step of maceration and fermentation.

[0026] Both *Aspergillus oryzae* and *Aspergillus soysarum* can efficiently hydrolyze proteins in complex protein gels into peptides and amino acids, and convert residual carbohydrates into reducing sugars. These products are the absolute foundation for the subsequent generation of umami, richness, and Maillard reactions, ensuring the authenticity and depth of the flavor. Certain Bacillus strains are known high-yield strains of typical soy sauce and roasted aroma compounds such as pyrazines and tetramethylpyrazine. These substances are the hallmark components of top-grade soy sauce flavor. They are active under the micro-aerobic conditions of solid-state fermentation and can synthesize the aforementioned characteristic aroma compounds using precursor substances, directly endowing the product with a rich and complex soy sauce aroma.

[0027] The organic acids produced by lactic acid bacteria metabolism naturally lower the pH of the fermentation system, creating a mellow and harmonious sour and aromatic base flavor. This slightly acidic environment enriches the layers of flavor, avoids the cloying taste of a single soy sauce aroma, and better highlights and complements the umami brought by amino acids and peptides, making the overall soy sauce aroma more full-bodied, rounded, and with a lingering aftertaste. Furthermore, when lactic acid bacteria coexist with major aroma-producing microorganisms (such as Aspergillus oryzae and Bacillus), they can form metabolic complementarity and synergy. Their metabolic activities can provide growth factors for other microorganisms, and the slightly acidic environment they create may be more conducive to the formation and stability of certain soy sauce aroma compounds, improving the overall fermentation efficiency and flavor complexity.

[0028] Step (3) Immerse the primary fermented blank obtained in step (2) in the seasoning sauce for the second step of immersion fermentation to obtain the fermentation product.

[0029] Specifically, in this invention, the primary fermented blank obtained in step (2) is immersed in a seasoning sauce for a second immersion fermentation. The ambient temperature during the second immersion fermentation is preferably 10-30℃, and the fermentation time is preferably 1-10 days.

[0030] It is understandable that step (3) builds on the results of the first solid-state fermentation in step (2) and utilizes the external sauce environment to achieve gradient penetration and uniform distribution of flavor. During the second step of maceration fermentation, the complex components of the external sauce meet the rich endogenous flavor precursors, residual active enzymes and microbial autolysates inside the body. During the maceration fermentation for several days, a series of slow and complex subsequent reactions occur, generating more pyrazines, furans and other soy sauce aroma compounds. Furthermore, the reaction of acids and alcohols forms esters, adding complex aroma layers such as fruit or wine aromas. This elevates the single external seasoning in the traditional production process to the synergistic aroma generation of internal and external substances, creating a complex soy sauce aroma that is rich in layers, mellow and natural, and has a long aftertaste.

[0031] Step (4) The fermentation product obtained in step (3) is post-processed to obtain the soy sauce-flavored dried tofu.

[0032] Understandably, post-processing mainly includes subsequent steps such as cleaning, drying, sterilization, and packaging, in order to stop fermentation, reduce water activity to stabilize the product, and ultimately form the final product of soy sauce-flavored dried tofu.

[0033] On the other hand, this application also proposes a savory-flavored dried bean curd, characterized in that the savory-flavored dried bean curd is prepared by the aforementioned method for preparing savory-flavored dried bean curd.

[0034] Understandably, this invention pre-defines the product's textural foundation by designing a gel network on a composite protein substrate. The two-step fermentation process precisely constructs flavor on this optimized structure. The first fermentation creates pores within the substrate and generates aroma precursors, while the second fermentation efficiently fills and locks in flavor substances, achieving an ideal gradient texture that is firm and flavorful on the outside, and tender and juicy on the inside, breaking the limitations of traditional processes. This invention is not simply external flavoring, but rather guides a complete flavor evolution path from the generation of endogenous precursor substances to the penetration and fusion of external flavor substances through a two-step fermentation of microorganisms on a specific substrate. The resulting soy sauce aroma is a complex aroma produced by the combination of various flavor substances, such as amino acids, peptides, organic acids, esters, and pyrazines, with strong layers, a mellow and natural flavor, and a long-lasting aftertaste. The amino acid pattern of the composite plant protein is more balanced, resulting in higher nutritional value. Through the fermentation process, beneficial components are naturally enriched, producing a richly flavored product without excessive chemical additives, aligning with the trends of clean labels and healthy foods.

[0035] This invention innovates from two fundamental levels: raw materials and process. The resulting product is fundamentally different from existing commercially available soy sauce-flavored dried tofu in terms of taste, flavor, and nutritional components. Moreover, the process steps are clear and the key parameters are controllable, which is conducive to achieving large-scale and standardized production and ensuring stable product quality.

[0036] Example 1 (1) Substrate preparation and modification: Weigh out 70g of soy protein isolate, 20g of pea protein powder, and 10g of wheat gluten (dry basis mass ratio 7:2:1), mix them, add 400mL of purified water, and stir well to form a protein slurry. Add 0.1g of neutral protease (based on total protein mass) to the slurry, and perform enzymatic modification treatment at 50℃ for 60 minutes. Then, raise the temperature to 85℃ and maintain it for 10 minutes to inactivate the enzyme, obtaining the modified protein slurry.

[0037] (2) Molding: The modified protein slurry was poured into a square mold and heated in an 85°C water bath for 30 minutes to solidify. After cooling, it was demolded to obtain a composite plant protein gel preform (white preform), which was then cut into 5cm×5cm×1cm blocks.

[0038] (3) First step solid-state fermentation: Aspergillus oryzae CGMCC3.384 spores were eluted with sterile water to prepare a concentration of 5 × 10⁻⁶. 7A spore suspension of spores / mL was prepared. The spore suspension was evenly sprayed onto the surface of the gel blank using a spray method, with an inoculation amount of 1.5 mL per 100 g of gel blank. The inoculated gel blank was placed in a constant temperature and humidity incubator and fermented for 48 hours at 30℃ and 85% relative humidity, turning it once every 24 hours, to obtain a primary fermented blank with a surface covered with white mycelium and emitting a strong fermented aroma.

[0039] (4) Second step: soaking and fermentation: Prepare the seasoning sauce (ingredients: brewed soy sauce, white sugar, spice extract, water, salt content 8% w / w). Completely immerse the primary fermented cake in the seasoning sauce and place it in a constant temperature environment of 15℃. Use a reduced-pressure-atmospheric-pressure circulation method: every 12 hours, first apply vacuum to -0.08 MPa and maintain for 30 minutes, then restore atmospheric pressure for 30 minutes. The total immersion fermentation time is 5 days.

[0040] (5) Post-processing: The fermented tofu blocks were removed and lightly rinsed with purified water. They were then dried in a 55℃ hot air drying oven until the moisture content reached 45% (w / w). Finally, they were vacuum-packed and pasteurized at 85℃ for 30 minutes to obtain the finished soy sauce-flavored tofu (labeled as sample S1).

[0041] Example 2 (1) Substrate preparation and modification: Weigh out 60g of soy protein isolate, 25g of pea protein powder, and 15g of wheat gluten (dry basis mass ratio 6:2.5:1.5), mix them, add 400mL of purified water, and stir until a protein slurry is formed. Physically modify the slurry by treating it with ultrasound at a frequency of 28kHz and a power density of 300W / L for 20 minutes to obtain a modified protein slurry.

[0042] (2) Molding: The modified protein slurry was injected into a mold and heated in a 90°C steam environment for 40 minutes to solidify. After cooling and demolding, it was cut into gel blanks of the same size.

[0043] (3) First step solid-state fermentation: Bacillus licheniformis CGMCC1.813 and Lactobacillus plantarum CGMCC1.557 were mixed at a viable count ratio of 1:1 to prepare a mixed bacterial solution (total viable count approximately 1 × 10⁻⁶). 8 (CFU / mL). The gel compact was immersed in the bacterial solution for 5 seconds, then removed and placed in a fermentation dish. Fermentation was carried out at 33°C and 80% relative humidity for 36 hours to obtain the primary fermentation compact.

[0044] (4) Second step: soaking and fermentation: Prepare a low-sodium seasoning sauce (5% w / w salt content, flavor enhanced by yeast extract). Immerse the primary fermented material in the sauce and allow it to ferment under normal pressure in a constant temperature workshop at 25°C for 3 days.

[0045] (5) Post-processing: After being removed, the product is directly placed in a 60℃ hot air dryer until the moisture content is 40%, and then vacuum-packed with nitrogen to obtain the finished product, soy sauce-flavored dried bean curd (marked as sample S2).

[0046] Comparative Example The traditional commercially available process for preparing savory-flavored dried tofu involves using pure soybeans as raw material to create white tofu blocks. These blocks are then placed in a traditional brine with a 15% salt content, brought to a boil, and then simmered over low heat for 60 minutes. The heat is then turned off, and the tofu is soaked overnight (approximately 12 hours). After soaking, the tofu blocks are removed and dried at 65°C until the moisture content reaches approximately 45%, then packaged and sterilized. This sample is labeled D1.

[0047] The above samples were tested. Headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to detect the total amount of key soy sauce flavor compounds in each sample; an automated amino acid analyzer was used to determine the content of flavor-enhancing amino acids in each sample; silver nitrate titration was used to determine the final salt content of the products; and a texture analyzer was used to measure the hardness of each sample by simulating the initial downward pressure of chewing. A moderate value indicates a chewy and elastic texture, while a value that is too high indicates a hard texture. The texture analyzer was used to measure the product's elasticity, specifically the percentage of height recovered after compression. A higher value indicates better elasticity and chewiness.

[0048] Key indicators were tested on the samples obtained in Examples 1 and 2 and the comparative sample. The results are shown in Table 1.

[0049] Table 1. Results of the performance comparison test The above examples and comparative data show that the total amount of flavor substances in the soy-sauce-flavored dried tofu of Examples 1 and 2 prepared using the method of the present invention is more than twice that of the comparative example. Furthermore, the hardness of Examples 1 and 2 is less than that of the comparative example, their elasticity is superior, and their salt content is significantly lower. It is evident that the product prepared by the present invention, through a gradient fermentation process, generates and enriches flavor substances far exceeding those of traditional processes. While significantly reducing the final salt content of the product, it still achieves a rich flavor, and while maintaining suitable hardness and good shape, it also achieves excellent elasticity and uniform texture.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing soy sauce-flavored dried tofu, characterized in that, The method comprises the following steps: (1) mixing soybean protein, pea protein and wheat protein with water to obtain a protein slurry, and subjecting the protein slurry to a shaping treatment to obtain a composite vegetable protein gel blank; (2) inoculating the composite vegetable protein gel blank obtained in step (1) with a fermentation microorganism, and performing a first step solid-state fermentation to obtain a primary fermentation blank; (3) immersing the primary fermentation blank obtained in step (2) in a seasoning sauce, and performing a second step immersion fermentation to obtain a fermentation product; (4) subjecting the fermentation product obtained in step (3) to a post-treatment to obtain the soybean jerky with soy sauce flavor.

2. The production method according to claim 1, characterized by, In step (1), the dry basis mass ratio of the soybean protein, pea protein and wheat protein is (5-9):(1-4):(0.5-3).

3. The production method according to claim 1 or 2, characterized by, In step (1), before the shaping treatment, the protein slurry is subjected to a modification treatment to obtain a modified protein slurry; the modification treatment is an enzymatic modification treatment or a physical modification treatment.

4. The production method according to claim 3, characterized by, The enzyme used in the enzymatic modification treatment is a protease or a transglutaminase; the physical modification treatment is a heat-moisture treatment or an ultrasonic treatment.

5. The preparation method according to claim 4, characterized in that, In step (1), the shaping treatment comprises subjecting the modified protein slurry to heat coagulation, the temperature of the heat coagulation being 75-95℃, and the time being 15-60 minutes.

6. The method of claim 1, wherein, In step (2), the fermentation microorganism comprises at least one selected from Aspergillus oryzae, Aspergillus sojae and Bacillus.

7. The production method according to claim 6, wherein In step (2), the fermentation microorganism further comprises lactic acid bacteria.

8. The method of claim 1, wherein, In step (2), the temperature during the first step solid-state fermentation is 25-37℃, the relative humidity is 70-90%, and the fermentation time is 12-72 hours.

9. The method of claim 1, wherein, In step (3), the temperature during the second step immersion fermentation is 10-30℃, and the fermentation time is 1-10 days.

10. A soy jerky with a sauce flavor, characterized by, The soybean jerky with soy sauce flavor is prepared by the method according to any one of claims 1-9.

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