Soy sauce and method for producing the same
Patent Information
- Application Number
- CN202610220978.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-24
- Publication Date
- 2026-06-09
AI Technical Summary
In current soy sauce production, high turbidity leads to poor product appearance and storage stability. Furthermore, traditional clarification methods are time-consuming, have limited effectiveness, or introduce food safety risks.
The microbial fermentation broth, which uses high-enzyme-producing Aspergillus oryzae and highly active nutritionally metabolizing brewing yeast, is precisely sprayed during the koji-making process. Through the triple effects of molecularly targeted antibacterial action, microenvironmental regulation, and synergistic nutritional enzyme production promotion, it inhibits the growth of miscellaneous bacteria, promotes the growth of Aspergillus oryzae and enzyme activity, and reduces the turbidity of soy sauce.
It significantly reduces the turbidity of finished soy sauce, improves clarity and quality, has a simple and low-cost process, maintains the traditional flavor of soy sauce, and enhances product stability and safety.
Smart Images
Figure CN122162919A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of condiment production technology, and relates to soy sauce and its preparation method. Background Technology
[0002] Soy sauce, as a traditional fermented condiment, plays an important role in the diet. Its flavor, color, and clarity are key indicators affecting consumer acceptance and product market competitiveness. Among these, the turbidity (i.e., transparency) of soy sauce not only directly affects the product's appearance but is also closely related to storage stability, flavor purity, and sensory experience.
[0003] High turbidity in soy sauce often gives consumers the impression of poor quality, reducing their desire to buy it. At the same time, turbid substances may trap flavor components, affecting the release of the soy sauce's aroma and the purity of its taste. On an industrial level, soy sauce with higher turbidity is more prone to sedimentation and stratification during storage and transportation, affecting product shelf stability and commercial value.
[0004] Currently, the clarity of soy sauce is mainly improved through natural sedimentation, centrifugation, membrane filtration, and the addition of clarifying agents (such as diatomaceous earth and gelatin). However, these methods have certain limitations: natural sedimentation is time-consuming and difficult to adapt to the needs of large-scale production; centrifugation and filtration technologies have limited effectiveness in removing micron- or submicron-sized colloidal particles and may cause loss of flavor substances; the use of chemical clarifying agents may introduce foreign substances, affecting the natural properties of soy sauce and increasing food safety risks.
[0005] Therefore, developing a method for preparing soy sauce that can inhibit the formation of substances that affect the clarity of soy sauce from the source has become a key issue that urgently needs to be addressed in the soy sauce production industry. Summary of the Invention
[0006] Therefore, it is necessary to provide a low-turbidity soy sauce and its preparation method.
[0007] In some embodiments, a method for preparing soy sauce is provided, comprising the following steps:
[0008] Protein raw materials are mixed with starch raw materials and Aspergillus oryzae to prepare koji-making raw materials;
[0009] The raw materials for koji making are subjected to aeration and incubation to prepare koji material;
[0010] The koji material is mixed with a salt solution for fermentation, followed by solid-liquid separation to prepare soy sauce.
[0011] The time point at which ventilation incubation begins is recorded as 0h. Microbial fermentation broth is added to the raw materials for making koji from 18h to 24h after the start of ventilation incubation. The microorganisms used to prepare the microbial fermentation broth include one or two of Aspergillus oryzae and Saccharomyces cerevisiae.
[0012] In some embodiments, the method for preparing soy sauce includes the following steps:
[0013] The microorganisms were mixed with a composite culture medium and allowed to stand for 20-30 hours, then shaken for 10-20 hours. The solid and liquid were separated, and the clear liquid was collected to prepare the microbial fermentation broth.
[0014] In some embodiments, the method for preparing the microbial fermentation broth satisfies one or more of the following conditions:
[0015] (1) Static culture and shaking culture were carried out independently at 28℃~35℃;
[0016] (2) The inoculation amount of the microorganism is 2% (v / v) to 10% (v / v);
[0017] (3) Each 100 mL of the compound culture medium contains 8 g to 10 g of soybean powder, 5 g to 10 g of malt extract and 0.5 g to 3 g of glucose.
[0018] In some embodiments, in the method for preparing the microbial fermentation broth, under the condition that the microorganisms include Aspergillus oryzae and Saccharomyces cerevisiae, the mass ratio of Aspergillus oryzae to Saccharomyces cerevisiae is 1:(2~4) based on the amount of feed.
[0019] In some embodiments, the provided method for preparing soy sauce includes the following ventilated culture conditions: a wind frequency of 15 Hz to 50 Hz, and / or a culture temperature of 28 ℃ to 40 ℃, and / or a ventilated culture time of 30 h to 60 h.
[0020] In some embodiments, the provided method for preparing soy sauce satisfies one or both of the following conditions:
[0021] (1) The microbial fermentation broth is added by spraying;
[0022] (2) The ratio of the microbial fermentation liquid to the raw material for making koji is (10mL~30mL):1kg.
[0023] In some embodiments, the provided method for preparing soy sauce satisfies one or more of the following conditions:
[0024] (1) The protein raw material includes cooked soybeans, and the starch raw material includes wheat flour;
[0025] (2) In the raw materials for koji making, the inoculation amount of the first Aspergillus oryzae is 0.07% to 0.09% of the total mass of the protein raw materials and the starch raw materials;
[0026] (3) In the raw materials for making koji, the mass ratio of the protein raw material to the starch raw material is (1~4):1;
[0027] (4) The first Aspergillus oryzae and the second Aspergillus oryzae are the same.
[0028] In some embodiments, the provided method for preparing soy sauce satisfies one or more of the following conditions:
[0029] (1) The salt solution has a salt concentration of 18% to 22% by mass.
[0030] (2) The mass ratio of the koji material to the salt solution is (0.5~1):1;
[0031] (3) The fermentation temperature is 30℃~38℃ and the fermentation time is 50d~120d.
[0032] In some embodiments, a soy sauce is provided, which is prepared using the aforementioned preparation method.
[0033] In some embodiments, the turbidity of the soy sauce is 25 NTU to 55 NTU.
[0034] The aforementioned method for preparing soy sauce utilizes Aspergillus oryzae with high enzyme production function and / or highly active nutritional and metabolic brewing yeast to ferment and prepare a fermentation base containing complex antibacterial substances, free amino acids, and other complex components. During the stable growth period of Aspergillus oryzae in soy sauce koji making, the base is sprayed onto the koji material. By utilizing the triple effect of "molecular targeted antibacterial + microenvironment regulation + nutrient synergistic enzyme production promotion", the method achieves efficient inhibition of Bacillus and other miscellaneous bacteria, while promoting the growth and enzyme production of Aspergillus oryzae used in production. This inhibits the generation of substances that affect the clarity of soy sauce from the source, thereby reducing the turbidity of soy sauce and improving its quality.
[0035] The provided method for preparing soy sauce is simple, low-cost, and highly effective in controlling miscellaneous bacteria in soy sauce koji production. It effectively reduces the turbidity of the finished soy sauce by precisely spraying functional fermentation liquid once. Attached Figure Description
[0036] To more clearly illustrate the technical solutions in the embodiments and examples of this application, and to more completely understand this application and its beneficial effects, the accompanying drawings used in the description of the embodiments or examples will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of this application. Those skilled in the art can obtain other drawings based on these drawings without any creative effort.
[0037] Figure 1 This is a schematic diagram of the soy sauce preparation process in some embodiments;
[0038] Figure 2 This is a schematic diagram of the soy sauce preparation process in Example 1. Detailed Implementation
[0039] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.
[0040] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.
[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0042] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:
[0043] The terms "and / or," "or / and," and "and / or" as used in this application encompass any one of two or more related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected using at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes solutions connected by "logical AND," and also undoubtedly includes solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and "a combination of A and B."
[0044] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.
[0045] The terms “combinations thereof,” “any combination thereof,” and “any combination thereof” as used in this application include all suitable combinations of any two or more of the listed items.
[0046] In this application, the term "suitable" as used in "suitable combination", "suitable method", "any suitable method", etc., refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.
[0047] In this application, terms such as "preferred," "better," "more suitable," and "ideal" are merely used to describe implementation methods or embodiments that achieve better results, and should be understood not to limit the scope of protection of this application.
[0048] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.
[0049] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.
[0050] In this invention, the terms "first aspect," "second aspect," "third aspect," and "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," and "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.
[0051] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.
[0052] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.
[0053] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.
[0054] In this application, % (w / w) and wt% both represent weight percentage, % (v / v) refers to volume percentage, and % (w / v) refers to mass-volume percentage.
[0055] In this application, "room temperature" generally refers to 5℃~30℃, and more preferably 25±5℃.
[0056] In this application, "xh after the start of ventilation culture" in the context refers to the time when the start of ventilation culture is recorded as hh.
[0057] Soy sauce koji making is the core step in soy sauce brewing, essentially a process of pure culture of Aspergillus oryzae on a mixture of cooked protein and starch raw materials. The quality of koji making directly determines the yield, flavor, and quality of soy sauce. During koji making, a high moisture content (usually >45%) is crucial for ensuring vigorous growth of Aspergillus oryzae and the secretion of abundant enzymes. However, the high temperature and humidity environment of koji making is also highly conducive to the rapid reproduction of other microorganisms, especially Bacillus. These other microorganisms compete with Aspergillus oryzae for nutrients, produce off-flavors, and secrete metabolic products (such as polysaccharides and colloidal substances) that cause bacterial turbidity in the later stages of fermentation and the finished product, severely affecting the transparency and sensory quality of the soy sauce. Therefore, the key to inhibiting bacteria during koji making lies in creating a koji-making environment that is unfavorable to the growth of other microorganisms but favorable to the growth of Aspergillus oryzae.
[0058] In some embodiments, a method for preparing soy sauce is provided, comprising the following steps:
[0059] Protein raw materials are mixed with starch raw materials and Aspergillus oryzae to prepare koji-making raw materials;
[0060] The raw materials for koji making are ventilated and cultured to prepare koji material;
[0061] The koji material is mixed with a salt solution for fermentation, and the solid and liquid components are separated to produce soy sauce.
[0062] In this method, the start time of aeration cultivation is designated as hour 0. From hour 18 to 24 of aeration cultivation, microbial fermentation broth is added to the raw materials for koji making. The microorganisms used to prepare the fermentation broth include one or both of *Aspergillus oryzae* and *Saccharomyces cerevisiae*. In some embodiments, a schematic diagram of the soy sauce preparation method is provided as follows: Figure 1 As shown.
[0063] The provided method for preparing soy sauce involves adding one or two microbial fermentation broths, including Aspergillus oryzae and Saccharomyces cerevisiae, to the koji-making raw materials. This not only inhibits other microorganisms through various metabolites but also contains growth factors that stimulate the metabolic activity of Aspergillus oryzae, creating a complementary "microorganism inhibition-enzyme production promotion" function. While inhibiting other microorganisms, it creates a purer growth environment for Aspergillus oryzae, indirectly promoting its enzyme production activity and stability, improving raw material utilization, and seamlessly integrating with subsequent fermentation processes without affecting the traditional flavor characteristics of soy sauce.
[0064] The fermentation broth containing one or two of the microorganisms, including Aspergillus oryzae and Saccharomyces cerevisiae, can achieve targeted inhibition of contaminating bacteria in two ways: first, molecular targeted inhibition, where the complex antibacterial substances produced by the metabolism of the strains can interfere with the cell wall synthesis or membrane integrity of contaminating bacteria; second, microenvironment regulation, where the organic acids and ethanol in the substrate synergistically regulate the pH of the fermentation material to an unsuitable range for contaminating bacteria, thereby inhibiting the proliferation of contaminating bacteria and spore germination.
[0065] Enzyme production can be synergistically promoted by fermentation broths containing one or two of the microorganisms, namely Aspergillus oryzae and Saccharomyces cerevisiae: First, direct nutrient supply, with free amino acids and B vitamins produced by Saccharomyces cerevisiae metabolism providing raw materials for enzyme production by Aspergillus oryzae and activating key enzyme systems; Second, metabolic burden reduction, with enzymes secreted by Aspergillus oryzae homologous strains decomposing macromolecules of raw materials in advance, reducing the primary metabolic consumption of Aspergillus oryzae and allowing it to focus more on enzyme production.
[0066] By significantly reducing the total number of viable bacteria during the middle stage of koji making, the production of these turbid bacteria and their metabolites is fundamentally eliminated. Because Aspergillus oryzae grows better, its secreted enzyme systems, such as proteases, can more thoroughly decompose large protein molecules in the raw materials, reducing turbidity caused by incomplete protein depolymerization, ultimately achieving a reduction in the turbidity of the soy sauce product.
[0067] Microbial fermentation broth was added 18-24 hours after the start of aeration cultivation. Through precise timing control, intervention was carried out during the stable growth period of Aspergillus oryzae and the most vulnerable proliferation period of miscellaneous bacteria. At this time, the resistance of Aspergillus oryzae was enhanced and miscellaneous bacteria were about to enter the outbreak period. This cleared the ecological niche for Aspergillus oryzae, allowing it to make fuller use of the nutrients and moisture in the koji material. By introducing the complex metabolites of beneficial microorganisms, the koji-making micro-ecosystem was directly and precisely regulated.
[0068] The provided soy sauce preparation method significantly reduces the total number of bacteria and heat-resistant spores in the koji-forming process, cuts off turbidity production at the source, significantly increases the activity of neutral protease, allows Aspergillus oryzae to reach its enzyme production peak under no competitive pressure, significantly reduces crude oil turbidity, and improves the clarity of soy sauce products.
[0069] Understandably, microbial fermentation liquid can be added to the koji-making raw materials at 18-24 hours after the start of aeration cultivation. Alternatively, it can be added at 18, 19, 20, 21, 22, 23, or 24 hours after the start of aeration cultivation. The timing of adding microbial fermentation liquid to the koji-making raw materials can also be within any range of the two aforementioned values.
[0070] In some embodiments, in the provided method for preparing soy sauce, the first Aspergillus and the second Aspergillus each independently include Aspergillus strains that produce high levels of protease and / or have high antibacterial activity.
[0071] In some embodiments, the provided method for preparing soy sauce uses brewing yeast including brewing yeast strains with high fermentation activity and / or high production of flavor substances.
[0072] In some embodiments, the method for preparing soy sauce and the method for preparing microbial fermentation broth include the following steps:
[0073] Microorganisms are mixed with a composite culture medium and incubated statically for 20-30 hours, followed by shaking incubation for 10-20 hours. Solid-liquid separation is then performed, and the clarified liquid is collected to prepare the microbial fermentation broth. For example, the static incubation time can be 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours, or any range of two of the aforementioned values. The shaking incubation time can be 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, or any range of two of the aforementioned values.
[0074] In some embodiments, in the preparation method of microbial fermentation broth, static culture and shaking culture are each carried out independently at a temperature of 28°C to 35°C. For example, static culture and shaking culture are each carried out independently at a temperature of 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, etc., or can be a range composed of any two of the aforementioned values.
[0075] In some embodiments, the inoculation amount of microorganisms in the preparation method of microbial fermentation broth is 2% (v / v) to 10% (v / v). For example, the inoculation amount of microorganisms can be 2% (v / v), 3% (v / v), 4% (v / v), 5% (v / v), 6% (v / v), 7% (v / v), 8% (v / v), 9% (v / v), 10% (v / v), etc., or it can be a range composed of any two of the aforementioned values.
[0076] In some embodiments, the preparation method of microbial fermentation broth contains 8g~10g of soybean flour, 5g~10g of malt extract and 0.5g~3g of glucose per 100mL of composite culture medium.
[0077] In some embodiments, the microbial fermentation broth can be Aspergillus oryzae fermentation broth, Saccharomyces cerevisiae fermentation broth, or a mixed fermentation broth of Aspergillus oryzae and Saccharomyces cerevisiae.
[0078] In some embodiments, when the microorganisms include Aspergillus oryzae and Saccharomyces cerevisiae, in the method for preparing the microbial fermentation broth, the mass ratio of Aspergillus oryzae to Saccharomyces cerevisiae is 1:(2~4) based on the amount of feed. For example, the mass ratio of Aspergillus oryzae to Saccharomyces cerevisiae can be 1:2, 1:3, 1:4, etc., or it can be any range of the two ratios mentioned above.
[0079] The first Aspergillus oryzae strain, the second Aspergillus oryzae strain, and the Saccharomyces cerevisiae strain can each be independently wild-type, mutagenesis-selected, or genetically engineered functionally enhanced strains.
[0080] In some embodiments, the provided method for preparing soy sauce includes the following ventilated culture conditions: a wind frequency of 15 Hz to 50 Hz, and / or a culture temperature of 28 ℃ to 40 ℃, and / or a ventilated culture time of 30 h to 60 h.
[0081] In some embodiments, the soy sauce preparation method provides a method of adding microbial fermentation liquid by spraying.
[0082] In some embodiments, in the provided method for preparing soy sauce, the ratio of microbial fermentation liquid to koji-making raw materials is (10mL~30mL):1kg. For example, the ratio of microbial fermentation liquid to koji-making raw materials can be 10mL:1kg, 20mL:1kg, 30mL:1kg, etc., or it can be any range of the two ratios mentioned above.
[0083] In some embodiments, the soy sauce preparation method provided includes cooked soybeans as the protein raw material and wheat flour as the starch raw material.
[0084] In some embodiments, in the provided method for preparing soy sauce, the inoculation amount of the first Aspergillus oryzae in the koji-making raw materials is 0.07% to 0.09% of the total mass of the protein raw materials and starch raw materials. For example, the inoculation amount of the first Aspergillus oryzae can be 0.07%, 0.08%, 0.09% of the total mass of the protein raw materials and starch raw materials, or it can be a range composed of any two of the aforementioned ratios.
[0085] In some embodiments, in the provided method for preparing soy sauce, the mass ratio of protein raw material to starch raw material in the koji-making raw material is (1~4):1. For example, the mass ratio of protein raw material to starch raw material can be 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, etc., or it can be any range of the two aforementioned ratios.
[0086] In some embodiments, the first Aspergillus oryzae and the second Aspergillus oryzae are the same in the provided method for preparing soy sauce.
[0087] In some embodiments, in the provided method for preparing soy sauce, the mass concentration of salt in the salt aqueous solution is 18% to 22%. For example, the mass concentration of salt can be 18%, 19%, 20%, 21%, 22%, etc., or it can be a range composed of any two of the aforementioned values.
[0088] In some embodiments, the mass ratio of koji to salt solution in the soy sauce preparation method is (0.5~1):1. For example, the mass ratio of koji to salt solution is 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, etc., or it can be any range of the two aforementioned ratios.
[0089] In some embodiments, the fermentation temperature in the provided soy sauce preparation method is 30℃~38℃, and the fermentation time is 50d~120d. For example, the fermentation temperature is 30℃, 31℃, 32℃, 33℃, 34℃, 35℃, 36℃, 37℃, 38℃, etc., or it can be any range of the aforementioned two values; the fermentation time is 50d, 60d, 70d, 80d, 90d, 100d, 110d, 120d, etc., or it can be any range of the aforementioned two values.
[0090] In some embodiments, a soy sauce is provided, which is prepared by a preparation method.
[0091] In some embodiments, the turbidity of the soy sauce is 25 NTU to 55 NTU. For example, the turbidity of the soy sauce is 25 NTU, 26 NTU, 27 NTU, 28 NTU, 29 NTU, 30 NTU, 31 NTU, 32 NTU, 33 NTU, 34 NTU, 35 NTU, 36 NTU, 37 NTU, 38 NTU, 39 NTU, 40 NTU, 41 NTU, 42 NTU, 43 NTU, 44 NTU, 45 NTU, 46 NTU, 47 NTU, 48 NTU, 49 NTU, 50 NTU, 51 NTU, 52 NTU, 53 NTU, 54 NTU, 55 NTU, etc., or it can be a range composed of any two of the aforementioned values.
[0092] The following are specific embodiments. They are intended to provide a more detailed description of this application to help those skilled in the art and researchers better understand it. The technical conditions described do not constitute any limitation on this application. Any modifications made within the scope of the claims of this application are protected by the claims.
[0093] Unless otherwise stated, all raw materials and reagents used in the following examples are commercially available or can be prepared by known methods. Experimental methods not specifying particular conditions in the examples were performed under conventional conditions, such as those described in literature, books, or methods recommended by the manufacturer.
[0094] Example 1
[0095] This embodiment provides a low-turbidity soy sauce, and the preparation method is as follows:
[0096] 1. Preparation of fermentation broth
[0097] Preparation of mixed-culture fermentation broth: Aspergillus oryzae and Saccharomyces cerevisiae were inoculated into a compound culture medium (8wt% soybean flour + 6wt% malt extract + 1wt% glucose) at a mass ratio of 1:2 and an inoculation amount of 5% (v / v). The medium was first statically cultured at 32℃ for 24 h, then transferred to a shaker at 32℃ for 12 h. After fermentation, the clarified liquid was collected by centrifugation at 6000 rpm for 20 min, which is the mixed-culture fermentation broth.
[0098] 2. Raw material processing: The soybeans are destoned and dusted.
[0099] 3. Steaming: Soak the soybeans in water, and then steam them at a high temperature of 115-125℃ and a high pressure of 0.1-0.2Mpa for 6 minutes.
[0100] 4. Cooling and mixing: Quickly cool the steamed and cooked crushed soybeans to below 38°C to obtain cooked material that is not undercooked, has a uniform color, and a distinct soybean aroma. Then mix it with wheat flour and Aspergillus oryzae. The mass ratio of soybeans to wheat flour is 2.5:1, and the amount of Aspergillus oryzae added is 0.09 wt% of the mixture of soybeans and wheat flour.
[0101] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50 Hz and a temperature of 28-35℃. 20 hours after the start of ventilation and incubation, the mixed fermentation liquid is sprayed evenly onto the koji material at a rate of 20 mL / kg of koji material. The koji making time is 45 hours.
[0102] 6. Fermentation: Mix the starter culture with a 22% salt solution, wherein the mass ratio of starter culture to salt solution is 0.8:1, and ferment for 80 days.
[0103] 7. Pressing: The fermented soy sauce mash is pressed to obtain the soy sauce. A schematic diagram of the soy sauce preparation process is shown below. Figure 2 As shown.
[0104] Example 2
[0105] This embodiment provides a low-turbidity soy sauce, and the preparation method is similar to that of Embodiment 1, except that steps 1 and 5 in this embodiment are as follows:
[0106] 1. Preparation of fermentation broth
[0107] Preparation of Aspergillus oryzae fermentation broth: Aspergillus oryzae was inoculated at an inoculum rate of 5% (v / v) into a compound culture medium (8% soybean meal + 6% malt extract + 1% glucose). The medium was first incubated statically at 32℃ for 24 hours, then transferred to a shaker at 32℃ for 12 hours. After fermentation, the clarified liquid was collected by centrifugation at 6000 rpm for 20 minutes; this was the Aspergillus oryzae fermentation broth.
[0108] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50 Hz and a temperature of 28-35℃. On the 20th hour after the start of ventilation and incubation, Aspergillus oryzae fermentation liquid is evenly sprayed onto the koji material at a rate of 20 mL / kg of koji material. The koji making time is 45 hours.
[0109] Example 3
[0110] This embodiment provides a low-turbidity soy sauce, and the preparation method is similar to that of Embodiment 1, except that steps 1 and 5 in this embodiment are as follows:
[0111] 1. Preparation of fermentation broth
[0112] Preparation of brewing yeast fermentation broth: Brewing yeast was inoculated at 5% (v / v) into a compound culture medium (8 wt% soybean flour + 6 wt% malt extract + 1 wt% glucose). The mixture was first statically cultured at 32℃ for 24 h, then transferred to a shaker at 32℃ for 12 h. After fermentation, the clarified liquid was collected by centrifugation at 6000 rpm for 20 min, which is the brewing yeast fermentation broth.
[0113] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50Hz and a temperature of 28-35℃. 20 hours after the start of ventilation and incubation, the brewing yeast fermentation liquid is evenly sprayed onto the koji material at a rate of 20mL / kg of koji material. The koji making time is 45 hours.
[0114] Example 4
[0115] This embodiment provides a low-turbidity soy sauce, and the preparation method is similar to that of Embodiment 1, except that step 5 in this embodiment is as follows:
[0116] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50 Hz and a temperature of 28-35℃. 18 hours after the start of ventilation and incubation, the mixed fermentation liquid is sprayed evenly onto the koji material at a rate of 20 mL / kg of koji material. The koji making time is 45 hours.
[0117] Example 5
[0118] This embodiment provides a low-turbidity soy sauce, and the preparation method is similar to that of Embodiment 1, except that step 5 in this embodiment is as follows:
[0119] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50 Hz and a temperature of 28-35℃. 24 hours after the start of ventilation and incubation, the mixed fermentation liquid is sprayed evenly onto the koji material at a rate of 20 mL / kg of koji material. The koji making time is 45 hours.
[0120] Example 6
[0121] This embodiment provides a low-turbidity soy sauce, and the preparation method is similar to that of Embodiment 1, except that step 5 in this embodiment is as follows:
[0122] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50Hz and a temperature of 28-35℃. 20 hours after the start of ventilation and incubation, the mixed fermentation liquid is sprayed evenly onto the koji material at a rate of 10mL / kg. The koji making time is 45 hours.
[0123] Example 7
[0124] This embodiment provides a low-turbidity soy sauce, and the preparation method is similar to that of Embodiment 1, except that step 5 in this embodiment is as follows:
[0125] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50Hz and a temperature of 28-35℃. 20 hours after the start of ventilation and incubation, the mixed fermentation liquid is sprayed evenly onto the koji material at a rate of 30mL / kg. The koji making time is 45 hours.
[0126] Comparative Example 1
[0127] This comparative example provides a soy sauce, prepared using a method similar to that of Example 1, except that step 5 in this comparative example is as follows:
[0128] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50Hz and a temperature of 28-35℃ for 45 hours. No microbial fermentation liquid is sprayed.
[0129] Comparative Example 2
[0130] This comparative example provides a soy sauce, prepared using a method similar to that of Example 1, except that step 5 in this comparative example is as follows:
[0131] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50Hz and a temperature of 28-35℃. At the beginning of the ventilation and incubation, the mixed fermentation liquid is evenly sprayed onto the koji material at a rate of 20mL / kg of koji material. The koji making time is 45 hours.
[0132] Comparative Example 3
[0133] This comparative example provides a soy sauce, prepared using a method similar to that of Example 1, except that step 5 in this comparative example is as follows:
[0134] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50 Hz and a temperature of 28-35℃. Ten hours after the start of ventilation and incubation, the mixed fermentation liquid is evenly sprayed onto the koji material at a rate of 20 mL / kg of koji material. The koji making time is 45 hours.
[0135] Comparative Example 4
[0136] This comparative example provides a soy sauce, prepared using a method similar to that of Example 1, except that step 5 in this comparative example is as follows:
[0137] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50Hz and a temperature of 28-35℃. 30 hours after the start of ventilation and incubation, the mixed fermentation liquid is sprayed evenly onto the koji material at a rate of 20mL / kg of koji material. The koji making time is 45 hours.
[0138] Comparative Example 5
[0139] This comparative example provides a soy sauce, prepared using a method similar to that of Example 1, except that steps 1 and 5 in this comparative example are as follows:
[0140] 1. Preparation of fermentation broth
[0141] Preparation of Bacillus subtilis fermentation broth: Bacillus subtilis was inoculated at an inoculum rate of 5% (v / v) into a compound culture medium (8 wt% soybean flour + 6 wt% malt extract + 1 wt% glucose). The medium was first incubated statically at 32℃ for 24 h, then transferred to a shaker at 32℃ for 12 h. After fermentation, the clarified liquid was collected by centrifugation at 6000 rpm for 20 min, which is the Bacillus subtilis fermentation broth.
[0142] 5. Koji making: The mixture is ventilated and incubated at a frequency of 20-50Hz and a temperature of 28-35℃. 20 hours after the start of ventilation and incubation, Bacillus subtilis fermentation liquid is sprayed evenly onto the koji material at a rate of 20mL / kg of koji material. The koji making time is 45 hours.
[0143] The neutral protease activity, total bacterial count, heat-resistant spore count, and crude soy sauce turbidity in the examples and comparative examples were detected using the following methods:
[0144] Neutral protease activity in finished product: SBT 10317-1999 Protease Activity Assay.
[0145] Total bacterial count in finished product: GB 4789.2-2016 Determination of total bacterial count.
[0146] The number of heat-resistant spores in the finished product: The number of colonies formed after heat treatment at 92±1℃ for 15 min and incubation at 36±1℃ for 48±2 h is counted as the number of heat-resistant spores.
[0147] Turbidity of crude soy sauce: measured directly using a turbidimeter.
[0148] The test results are shown in Tables 1 to 3 below.
[0149] Table 1 Comparison of the effects of different fermentation broth types
[0150]
[0151] Table 2 Comparison of the effects of different spraying times
[0152]
[0153] Table 3 Comparison of the effects of different spray volumes
[0154]
[0155] (1) As can be seen from Table 1, the Aspergillus oryzae-yeast symbiotic fermentation broth sprayed in Example 1 inhibited miscellaneous bacteria while exhibiting higher protease activity than other cases. This demonstrates the high efficiency and stability of the triple effect of "molecular targeted antibacterial action + microenvironment regulation + nutrient synergistic enzyme production promotion". The final soy sauce turbidity decreased from 100 NTU to 25 NTU, showing a very significant improvement. At the same time, single bacterial broths (Examples 2 and 3) also showed good results, indicating that the Aspergillus oryzae fermentation broth or Saccharomyces cerevisiae fermentation broth can also effectively control miscellaneous bacteria and enhance enzyme activity when used alone. The high neutral protease activity of the koji indicates that the enhanced protein hydrolysis is thorough, fundamentally reducing the colloidal turbidity and precipitate formation caused by macromolecular protein residues in the soy sauce, which helps to achieve high clarity, high stability and rich flavor in the soy sauce.
[0156] (2) As shown in Table 2, the protease activity was highest when sprayed 20 hours after inoculation, and the number of miscellaneous bacteria was controlled at an extremely low level, ensuring the clarity of the soy sauce from the source. Spraying too early had a clear stress inhibition on the initial growth of Aspergillus oryzae, resulting in its enzyme activity not reaching the optimal level. Spraying too late, on the other hand, allowed miscellaneous bacteria to consume a large amount of nutrients and may produce inhibitory substances, leading to a decrease in enzyme activity and a weakened effect on turbidity improvement.
[0157] (3) As can be seen from Table 3, when the spraying amount is 10-30 mL / kg, the inhibition of miscellaneous bacteria and the improvement of enzyme activity are obvious, and the turbidity is significantly reduced. The technical features of the above embodiments can be combined in any way. In order to simplify the description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0158] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.
Claims
1. A method for preparing soy sauce, characterized in that, Includes the following steps: Protein raw materials are mixed with starch raw materials and Aspergillus oryzae to prepare koji-making raw materials; The raw materials for koji making are subjected to aeration and incubation to prepare koji material; The koji material is mixed with a salt solution for fermentation, followed by solid-liquid separation to prepare soy sauce. The time point at which ventilation incubation begins is recorded as 0h. Microbial fermentation broth is added to the raw materials for making koji from 18h to 24h after the start of ventilation incubation. The microorganisms used to prepare the microbial fermentation broth include one or two of Aspergillus oryzae and Saccharomyces cerevisiae.
2. The method for preparing soy sauce according to claim 1, characterized in that, The method for preparing the microbial fermentation broth includes the following steps: The microorganisms were mixed with a composite culture medium and allowed to stand for 20-30 hours, then shaken for 10-20 hours. The solid and liquid were separated, and the clear liquid was collected to prepare the microbial fermentation broth.
3. The method for preparing soy sauce according to claim 2, characterized in that, The method for preparing the microbial fermentation broth satisfies one or more of the following conditions: (1) Static culture and shaking culture were carried out independently at 28℃~35℃; (2) The inoculation amount of the microorganism is 2% (v / v) to 10% (v / v); (3) Each 100 mL of the compound culture medium contains 8 g to 10 g of soybean powder, 5 g to 10 g of malt extract and 0.5 g to 3 g of glucose.
4. The method for preparing soy sauce according to claim 2, characterized in that, Under the condition that the microorganisms include Aspergillus oryzae and Saccharomyces cerevisiae, in the method for preparing the microbial fermentation broth, the mass ratio of Aspergillus oryzae to Saccharomyces cerevisiae is 1:(2~4) based on the amount of feed.
5. The method for preparing soy sauce according to any one of claims 1 to 4, characterized in that, The conditions for aeration culture include: a wind frequency of 15 Hz to 50 Hz, and / or a culture temperature of 28 ℃ to 40 ℃, and / or a culture time of 30 h to 60 h.
6. The method for preparing soy sauce according to any one of claims 1 to 4, characterized in that, One or both of the following conditions must be met: (1) The microbial fermentation broth is added by spraying; (2) The ratio of the microbial fermentation liquid to the raw material for making koji is (10mL~30mL):1kg.
7. The method for preparing soy sauce according to any one of claims 1 to 4, characterized in that, One or more of the following conditions must be met: (1) The protein raw material includes cooked soybeans, and the starch raw material includes wheat flour; (2) In the raw materials for koji making, the inoculation amount of the first Aspergillus oryzae is 0.07% to 0.09% of the total mass of the protein raw materials and the starch raw materials; (3) In the raw materials for making koji, the mass ratio of the protein raw material to the starch raw material is (1~4):1; (4) The first Aspergillus oryzae and the second Aspergillus oryzae are the same.
8. The method for preparing soy sauce according to any one of claims 1 to 4, characterized in that, One or more of the following conditions must be met: (1) The salt solution has a salt concentration of 18% to 22% by mass. (2) The mass ratio of the koji material to the salt solution is (0.5~1):1; (3) The fermentation temperature is 30℃~38℃ and the fermentation time is 50d~120d.
9. A soy sauce, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 8.
10. The soy sauce according to claim 9, characterized in that, The turbidity of the soy sauce is 25 NTU to 55 NTU.