Preparation method of pleurotus ostreatus soy sauce

Abstract

The application discloses a preparation method of a seafood mushroom soy sauce, and steps of the method comprise the following steps of S1, fresh seafood mushrooms are selected as raw materials, and after being washed, water is added according to a material-liquid ratio of 1:4, the seafood mushrooms are subjected to extraction in a negative pressure extraction tank at a temperature interval of 70-80 DEG C, and residual debris and impurities of the seafood mushrooms are filtered out to obtain a seafood mushroom extract; and S2, the seafood mushroom extract is diluted in water with a water volume of 20-30% at a temperature interval of 50-55 DEG C. The application replaces soybean meal, a soybean allergen, with seafood mushroom powder, and solves the problem that soy products allergic groups will cause allergic reactions when eating soy sauce. The seafood mushrooms are dried through a gradient variable-temperature method, and the flavor of the seafood mushrooms is improved through drying. In combination with a variable-temperature fermentation process of high temperature first and then medium temperature, the flavor of a low-salt solid-state soy sauce product is significantly improved, the aroma and nutritional value of the product are improved, the product is convenient for the soy product allergic groups to eat, and the product provides a flavor soy sauce for selection for other non-allergic groups.

Description

Technical Field

[0001] This invention relates to a method for preparing seafood mushroom soy sauce, belonging to the field of seafood mushroom processing technology. Background Technology

[0002] Soy sauce is a commonly used condiment, widely used in various dishes and food processing. The traditional soy sauce production process mainly uses soybeans as raw materials for fermentation, and adds microorganisms such as koji to carry out the fermentation reaction, ultimately forming soy sauce with a unique flavor and aroma.

[0003] The main raw materials used in the preparation of soy sauce are soybeans, wheat, and salt. First, soybeans and wheat are mixed and soaked in water to fully absorb water and swell. Then, the soaked soybeans and wheat are ground to obtain a fine soybean cake. Next, the soybean cake is mixed with salt and placed in a fermentation chamber for fermentation. The fermentation time generally ranges from several months to several years. During this process, microorganisms such as yeast and lactic acid bacteria are produced, causing the mixture to ferment into soy sauce.

[0004] People with soy allergies cannot consume soy products or soy sauce made from soy, which causes inconvenience in their lives. Therefore, finding an alternative soy sauce production process to meet the needs of people with soy allergies has become an important issue. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for preparing seafood mushroom soy sauce, so as to solve the problem that people with soy product allergies cannot eat soy products or soy sauce made from soy products, which brings inconvenience to their lives.

[0006] To achieve the above objectives, the present invention provides a method for preparing seafood mushroom soy sauce.

[0007] A method for preparing seafood mushroom soy sauce, comprising the following steps:

[0008] S1. Select fresh seafood mushrooms as raw materials, wash them, add water at a ratio of 1:4, place them in a negative pressure extraction tank and extract them at a temperature range of 70-80℃, and filter out the residual debris and impurities of the seafood mushrooms to obtain seafood mushroom extract.

[0009] S2, dilute the seafood mushroom extract in water at a temperature range of 50-55℃ at a volume ratio of 20-30%, and add salt to increase the salt concentration of the diluted solution to 8-10% to form the base solution;

[0010] S3, prepared into a broth;

[0011] S31, weigh and mix the seafood mushroom powder, bran powder, and flour in a weight ratio of 1.5:2.5:6 to form a mixture.

[0012] S32, add 60-70% water by weight of the material to the mixture, stir evenly, and obtain a moistened material;

[0013] S33, the wetted material is pressure-cooked and sterilized, then air-cooled to 35-40℃, and then AS3.042 Aspergillus oryzae is mixed in at a weight ratio of 0.03-0.05% of the material, stirred evenly, to obtain the inoculation material;

[0014] S34, inoculate the material for 32 hours to obtain the finished product;

[0015] S4. Place the koji in a fermentation tank and add base liquid at 1 to 1.2 times the weight of the koji for fermentation. The fermentation temperature range for the first 15 days is 40 to 45°C for hydrolysis fermentation. The temperature is controlled at 35 to 40°C for the next 15 days. During this period, seafood mushroom extract is poured on the mash every 5 days for aroma fermentation to form mature soy sauce mash.

[0016] S5. Add 1.5 to 2 times the weight of the starter culture to the fermentation tank and soak the fermented mash at 90℃-100℃ for 10-12 hours.

[0017] S6. Press and filter the fermented soybean paste to obtain seafood mushroom soy sauce. After standing and clarifying, take the supernatant for sterilization, stir thoroughly and bottle it.

[0018] As a further improvement, in step S1, the negative pressure range in the negative pressure extraction tank is -0.06 to -0.04 MPa, the extraction time range is 30-60 min, and the seafood mushroom extract is filtered using 4 layers of gauze.

[0019] As a further improvement, in step S4, the koji is placed in a fermentation tank, and base liquid is added at 1 to 1.2 times the mass of the koji for fermentation. For the first 15 days, the fermentation temperature is 40 to 45°C for hydrolysis fermentation. For the next 15 days, the temperature is controlled at 35 to 40°C. Specifically, the koji is irrigated with seafood mushroom extract every 5 days.

[0020] The fermentation tank is sealed, and the base liquid is thoroughly poured into the fermentation tank every 5 days by stirring for 3-5 minutes.

[0021] As a further improvement, in step S31, the seafood mushroom powder, bran powder, and flour are weighed and mixed in a weight ratio of 1.5:2.5:6 to form a mixture, specifically as follows:

[0022] The preparation of the seafood mushroom powder involves selecting fresh seafood mushrooms, cleaning them, and then drying them with hot air. For the first 6-8 hours of drying, the temperature is controlled within the range of 45-48°C. Then, the temperature is increased to the range of 55-58°C and dried for 12 hours. After that, the temperature is gradually reduced to 50°C and maintained for 6-8 hours until the moisture content of the seafood mushrooms is 11-13%.

[0023] As a further improvement, in step S32, the addition of water at 60-70% of the material weight to the mixture and stirring until homogeneous to obtain a moistened material further includes:

[0024] The water temperature range is 50-70℃, and the wetting time range is 20-30 minutes.

[0025] As a further improvement, in step S33, after pressurizing and sterilizing the wetted material, and then air-cooling it to 35-40°C, AS3.042 Aspergillus oryzae is mixed in at a weight ratio of 0.03-0.05% of the material and stirred evenly to obtain the inoculated material, the method further includes: the thickness of the inoculated material is 3-5 cm.

[0026] As a further improvement, in step S34, the inoculation material is cultured for 32 hours to obtain the finished product, specifically as follows:

[0027] The temperature range of the inoculated material is controlled at 32-34℃. The koji is cultured for 10 hours, and the temperature gradually rises to about 37℃. The koji is then turned over for the first time after ventilation, and then turned over again after another 6 hours. The fermentation is carried out for 32 hours to obtain the koji.

[0028] The beneficial effects of this invention are:

[0029] This invention replaces soybean meal, a soy allergen, with seafood mushroom powder, solving the problem of allergic reactions to soy sauce in people with soy product allergies. A gradient temperature drying method for seafood mushrooms improves drying efficiency, reduces nutrient loss, and enhances the mushroom's flavor. Combined with a high-temperature followed by medium-temperature fermentation process, the flavor of the low-salt solid soy sauce is significantly improved, enhancing its aroma and nutritional value. This makes it convenient for people with soy product allergies to consume, and also provides a flavorful soy sauce option for those without allergies. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0031] Figure 1This is a flowchart illustrating the steps of a method for preparing seafood mushroom soy sauce according to the present invention.

[0032] Figure 2 This is a comparison chart of enzyme activity with different raw material ratios according to the present invention.

[0033] Figure 3 This is a comparison chart of enzyme activity at different koji-making temperatures according to the present invention.

[0034] Figure 4 This is a comparison chart of enzyme activity at different fermentation times according to the present invention.

[0035] Figure 5 This is a comparison chart of enzyme activity with different amounts of hydration according to the present invention.

[0036] Figure 6 This is a response surface methodology diagram of neutral protease activity according to the present invention.

[0037] Figure 7 This is a graph showing the effect of saline concentration on amino acid nitrogen content according to the present invention.

[0038] Figure 8 This is a graph showing the effect of the amount of brine added on the amino acid nitrogen content according to the present invention.

[0039] Figure 9 This is a graph showing the effect of fermentation temperature on amino acid nitrogen content according to the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] In recent years, allergic symptoms, particularly skin conditions, especially in infants and young children, have been increasing annually, and food allergies caused by food ingredients have become a social problem. Soybeans, eggs, and milk are the three most common allergens, often referred to as the "three major allergies." Soy sauce, a condiment fermented from soybeans, is a daily necessity, and restricting its consumption is difficult for allergy sufferers. Therefore, this paper considers replacing the raw materials used in soy sauce fermentation to address allergic reactions caused by consuming soy sauce products.

[0044] Therefore, in order to solve the above-mentioned technical problems, the present invention discloses the following technical solution:

[0045] Reference Figure 1-9 As shown, a method for preparing seafood mushroom soy sauce includes the following steps:

[0046] S1. Select fresh seafood mushrooms as raw materials, wash them, add water at a ratio of 1:4, place them in a negative pressure extraction tank and extract them at a temperature range of 70-80℃, and filter out the residual debris and impurities of the seafood mushrooms to obtain seafood mushroom extract.

[0047] S2, dilute the seafood mushroom extract in water at a temperature range of 50-55℃ at a volume ratio of 20-30%, and add salt to increase the salt concentration of the diluted solution to 8-10% to form the base solution;

[0048] S3, prepared into a broth;

[0049] S31, weigh and mix the seafood mushroom powder, bran powder, and flour in a weight ratio of 1.5:2.5:6 to form a mixture.

[0050] S32, add 60-70% water by weight of the material to the mixture, stir evenly, and obtain a moistened material;

[0051] S33, the wetted material is pressure-cooked and sterilized, then air-cooled to 35-40℃, and then AS3.042 Aspergillus oryzae is mixed in at a weight ratio of 0.03-0.05% of the material, stirred evenly, to obtain the inoculation material;

[0052] S34, inoculate the material for 32 hours to obtain the finished product;

[0053] S4. Place the koji in a fermentation tank and add base liquid at 1 to 1.2 times the weight of the koji for fermentation. The fermentation temperature range for the first 15 days is 40 to 45°C for hydrolysis fermentation. The temperature is controlled at 35 to 40°C for the next 15 days. During this period, seafood mushroom extract is poured on the mash every 5 days for aroma fermentation to form mature soy sauce mash.

[0054] S5. Add 1.5 to 2 times the weight of the starter culture to the fermentation tank and soak the fermented mash at 90℃-100℃ for 10-12 hours.

[0055] S6. Press and filter the fermented soybean paste to obtain seafood mushroom soy sauce. After standing and clarifying, take the supernatant for sterilization, stir thoroughly and bottle it.

[0056] In step S1, the negative pressure range in the negative pressure extraction tank is -0.06 to -0.04 MPa, the extraction time range is 30-60 min, and the seafood mushroom extract is filtered using 4 layers of gauze.

[0057] The negative pressure range in the extraction tank is -0.06 to -0.04 MPa: extraction under negative pressure effectively reduces the oxygen concentration during the extraction process, minimizing oxidation reactions. This helps protect the active ingredients in the seafood mushroom, preventing their loss or degradation during extraction.

[0058] The extraction time range is 30-60 minutes: The extraction time is set based on a comprehensive consideration of the extraction effect and stability of the active ingredients in seafood mushrooms. An appropriate extraction time can fully extract the target components while avoiding unnecessary reactions or component loss due to excessively long extraction times.

[0059] The seafood mushroom extract was filtered using four layers of gauze: Filtering with multiple layers of gauze effectively removes solid particles, impurities, and suspended matter from the extract. This contributes to the clarification and improved purity of the extract, resulting in a clearer and more usable final product.

[0060] In step S2, the seafood mushroom extract is diluted in water at a temperature range of 50-55°C at a volume ratio of 20-30%, and salt is added to increase the salt concentration of the diluted solution to 8-10% to form a base solution.

[0061] The water in the temperature range of 50 to 55°C is sterile water.

[0062] In this preparation, the ratio of seafood mushroom extract to sterile water in the base solution is 2:8 or 3:7, both of which meet the preparation requirements. The difference lies in that increasing the amount of seafood mushroom extract further enhances the flavor of the soy sauce, while reducing the amount can control costs. In this embodiment, to further enhance the flavor of the soy sauce, a ratio of seafood mushroom extract to sterile water of 3:7 is preferred. Additionally, controlling the temperature of the sterile water at 50–55°C allows the salt to dissolve quickly during mixing.

[0063] To maximize the activity of neutral protease and saccharifying enzyme during the koji-making process, the optimal flour / bran ratio was first determined based on the enzyme activity levels. Then, the content of added seafood mushroom powder was investigated, and the optimal raw material ratio for seafood mushroom soy sauce was determined to be flour:bran:seafood mushroom powder. Based on this, experiments were designed with factors such as water content, koji-making time, and koji-making temperature.

[0064] Table 1-1 Effect of different flours: bran ratio on koji-forming enzyme activity

[0065]

[0066]

[0067] Note: Different letters in the same row indicate significant differences (p<0.05). (The same applies below)

[0068] As shown in Table 1-1, the moisture content of the koji produced by different flour / bran ratios ranged from 35% to 40%, remaining within the normal range. However, there were some differences between the koji produced by different ratios, which is due to moisture loss and microbial growth during the koji-making process. During koji-making, too low a moisture content results in low Aspergillus activity, while too high a moisture content makes the koji material prone to spoilage. The quality of the koji is somewhat correlated with the number of spores in the koji material, but this is not the primary determining factor; enzyme activity is the key element determining the success of koji production.

[0069] Therefore, during koji making, Aspergillus grows and reproduces, secreting a large number of extracellular enzymes to decompose the koji material, including neutral proteases, saccharifying enzymes, amylases, and cellulases. These enzymes can break down the raw materials into smaller molecules, providing a reserve of substances for subsequent fermentation.

[0070] When the flour / bran ratio is 6:4, the activities of neutral protease, alkaline protease, and cellulase are highest, while the activities of saccharifying enzyme and amylase are highest at a ratio of 5:5. This shows that the activities of saccharifying enzyme and amylase are related to the type and proportion of starch raw materials in the koji (fermentation starter). Overall, the activities of various enzymes secreted by Aspergillus are higher when the flour / bran ratio is 6:4 than at the other four ratios. In conclusion, a flour / bran ratio of 6:4 is the optimal ratio for common koji-making raw materials.

[0071] Table 1-2 Analysis of main components in different raw material ratios

[0072]

[0073]

[0074] As can be seen from Table 1-2, the optimal raw material ratio for seafood mushroom soy sauce was selected based on the different proportions of raw materials used in the above-mentioned koji-making process, with the activity of neutral protease and saccharifying enzyme as indicators.

[0075] Previous studies have shown that high-quality soy sauce has a carbon-to-nitrogen ratio of around 5:1. The carbon-to-nitrogen ratio of all five ingredients in this recipe is close to 5:1, with ingredient number 2 having the closest ratio. Figure 2 It can be seen that the activities of neutral protease and saccharifying enzyme vary among different raw material ratios. Neutral protease activity analysis showed that ratio 2 had higher neutral protease activity than the control group and ratios 1, 3, and 4. This is because the total protein content in ratio 2 is slightly higher than the other ratios. Saccharifying enzyme activity analysis showed that ratio 2 also had higher saccharifying enzyme activity than the control group and ratios 1, 3, and 4, because microorganisms exhibit selective utilization of raw materials. In conclusion, ratio 2 is superior to the control group and the other ratios in both neutral protease and saccharifying enzyme activities. Therefore, ratio 2 (flour: bran: seafood mushroom = 6:2.5:1.5) was selected as the optimal raw material ratio for subsequent single-factor experiments.

[0076] In step S31, the seafood mushroom powder, bran powder, and flour are weighed and mixed in a weight ratio of 1.5:2.5:6 to form a mixture, specifically as follows:

[0077] The preparation of the seafood mushroom powder involves selecting fresh seafood mushrooms, cleaning them, and then drying them with hot air. For the first 6-8 hours of drying, the temperature is controlled within the range of 45-48°C. Then, the temperature is increased to the range of 55-58°C and dried for 12 hours. After that, the temperature is gradually reduced to 50°C and maintained for 6-8 hours until the moisture content of the seafood mushrooms is 11-13%.

[0078] Among them, seafood mushroom powder and wheat bran powder need to be sieved through a 40-mesh sieve once, and then through a 60-mesh sieve once.

[0079] In this embodiment, the seafood mushrooms are dried by slow drying at a low temperature followed by heating and then baking at a lower temperature. This stepped temperature method allows for precise control of the moisture content of the seafood mushrooms, keeping it between 11-13%, which maximizes the flavor of the seafood mushrooms.

[0080] like Figure 3The figure shows the effect of different koji-making temperatures on the enzyme activity of koji. As can be seen from the figure, with increasing koji-making temperature, the activities of both neutral protease and saccharifying enzyme show a trend of first increasing and then decreasing. The optimal temperature range for koji-making is 30–35℃. Too low or too high a temperature will severely affect the germination rate of Aspergillus spores, which is detrimental to the preparation of koji. The figure also shows that the activities of both neutral protease and saccharifying enzyme reach their highest levels at a koji-making temperature of 32℃, indicating that 32℃ is the optimal temperature for koji-making.

[0081] like Figure 4 The figure shows the effect of different fermentation times on the enzyme activities in the fermented koji. As can be seen from the figure, with the continuous increase of fermentation time, the activities of neutral protease and saccharifying enzyme both show a trend of first increasing and then decreasing. During the fermentation time of 24–32 hours, *Aspergillus oryzae* is in a rapid growth and reproduction stage, and the enzyme activities continuously increase, with the activities of neutral protease and saccharifying enzyme rising rapidly. At a fermentation time of 32 hours, the activities of neutral protease and saccharifying enzyme reach their peak. Subsequently, with the extension of fermentation time, the activities of both enzymes gradually decrease. This is because in the later stages of *Aspergillus* growth and development, the growth and maturation stages are basically completed, and the enzyme activities decrease accordingly.

[0082] like Figure 5 The figure shows the effect of different wetting amounts on the enzyme activity of koji. As can be seen from the figure, with the increase of wetting amount, the activities of neutral protease and saccharifying enzyme show a trend of first increasing and then decreasing. Among these, the wetting amount is crucial to the quality of koji. When the wetting amount is low, the koji material is loose, nutrients are not easily dissolved, Aspergillus is difficult to utilize, the growth and reproduction rate decreases, and enzyme activity also decreases accordingly. When the wetting amount is high, the koji material is prone to clumping, ventilation is reduced, the growth and reproduction of Aspergillus is inhibited, the corresponding enzyme activity decreases, and the reproduction rate of other miscellaneous bacteria accelerates, greatly affecting the quality of the koji. Therefore, from... Figure 5 As shown, the activity of both enzymes is highest when the water content is 60%.

[0083] In addition, to further optimize the koji-making process of seafood mushroom soy sauce based on the results of single-factor experiments, a response surface methodology experiment was conducted, with koji-making temperature, koji-making time, and water content as independent variables and neutral protease activity as the response value.

[0084] Table 1-3 Response Surface Design Schemes

[0085]

[0086] The response surface design test conditions are shown in Table 1-3. The response surface tests shown in Table 1-4 are conducted.

[0087] Table 1-4 Results of Response Surface Experiment

[0088]

[0089] As shown in Table 1-4, the neutral protease activity is strongest when the water content is 60%, the fermentation time is 32 hours, and the fermentation temperature is 32°C.

[0090] By performing multiple regression analyses on Tables 1-4, the quadratic polynomial regression equation of the fitted model was obtained: Neutral protease activity = 1500.00 - 89.41 × A - 29.38 × B - 85.58 × C - 30.65 × A × B + 25.55 × A × C + 79.19 × B × C - 273.59 × A² - 112.66 × B² - 250.60 × C². Based on this equation, the following calculations were performed... Figure 6 The 3D response surface analysis shown in the figure reveals the interaction between neutral protease activity and the three factors.

[0091] Table 1-5 Results of regression analysis of neutral proteases

[0092]

[0093] As shown in Tables 1-5, regression analysis was performed on the neutral protease activity.

[0094] Regression analysis was performed on the neutral protease activity (Table 1-5). The table shows that the F-value for the lack-of-fit term was 0.11, and the p-value was 0.9516 > 0.05, indicating that the model fits the data well and the experimental results are reliable. The p-values ​​show that the linear terms of water content and koji-making temperature have a highly significant impact on the results; the quadratic terms of water content, koji-making time, and koji-making temperature also have a highly significant impact; and the interaction term BC has a significant impact. Retaining the significant terms of the equation, the final regression equation is: Neutral protease activity = 1500.00 - 89.41 × A - 85.58 × C + 79.19 × B × C - 273.59 × A² - 112.66 × B² - 250.60 × C².

[0095] Based on this mathematical model, parameter optimization analysis was performed, and the optimal process conditions for neutral protease activity were obtained as follows: water content = 56.73%, koji-making time = 31.28 hours, and koji-making temperature = 31.58℃. Under these conditions, the neutral protease activity obtained was 1518.84 U / g, and the influence of each factor on enzyme activity was as follows: water content > koji-making temperature > koji-making time.

[0096] Based on single-factor analysis, the koji-making conditions were optimized using response surface methodology with neutral protease activity as the indicator. The optimal process conditions obtained were: 56.73% moisture content, 31.28 hours of koji-making time, and 31.58℃, with a neutral protease activity of 1518.84 U / g.

[0097] In step S32, the step of adding 60-70% water by weight of the material to the mixture and stirring evenly to obtain a moistened material further includes:

[0098] The water temperature range for wetting is 50-70℃, and the wetting time range is 20-30 minutes. Since an appropriate water temperature can help accelerate wetting, but an excessively high water temperature can easily accelerate the reaction of the material, in order to maximize efficiency, in this embodiment, the water temperature for wetting is preferably 50℃, and the wetting time is 20 minutes.

[0099] In this embodiment, the preferred conditions are: 60% water content, 32 hours of fermentation time, and 32°C of fermentation temperature. Under these conditions, the neutral protease activity reaches 1583.79 U / g, and the saccharifying enzyme activity is measured to be 1763.28 U / g.

[0100] In step S33, the process of pressurizing and sterilizing the wetted material, followed by air cooling to 35-40°C, and then mixing it with AS3.042 Aspergillus oryzae at a weight ratio of 0.03-0.05% to obtain the inoculated material, further includes: the thickness of the inoculated material being 3-5 cm. Since excessively thick material can increase the difficulty of recurving, in this embodiment, the preferred thickness of the inoculated material is 5 cm.

[0101] In step S34, the inoculation material is cultured for 32 hours to obtain the finished product, specifically as follows:

[0102] The temperature of the inoculum material is controlled within the range of 32-34℃. After 10 hours of cultivation, the temperature gradually rises to around 37℃. Aeration is then performed for the first turning of the koji, followed by a second turning after 6 hours. Fermentation continues for 32 hours to obtain the final koji. In this embodiment, the initial temperature of the inoculum material is preferably controlled at 32℃, rising to 37℃ in the later stages.

[0103] In step S4, the koji is placed in a fermentation tank, and base liquid is added at 1 to 1.2 times the mass of the koji for fermentation. For the first 15 days, the fermentation temperature is 40 to 45°C for hydrolysis fermentation. For the next 15 days, the temperature is controlled at 35 to 40°C. Specifically, the koji is irrigated with seafood mushroom extract every 5 days.

[0104] The fermentation tank is sealed, and the base liquid is stirred for 3-5 minutes every 5 days to ensure it is fully poured into the fermentation broth. The advantages of this method are:

[0105] Uniform mixing: Regular stirring ensures that the components in the seafood mushroom extract are evenly mixed, preventing precipitation or stratification. This helps maintain the stability and consistency of the extract, ensuring that each batch has a similar composition.

[0106] Promoting solute transport: The stirring process increases the contact area between the solute and solvent in the extract, promoting solute transport and diffusion. This helps improve extraction efficiency, allowing the target components to be released more quickly from the seafood mushroom into the extract.

[0107] Preventing microbial contamination: Stirring effectively prevents the growth and contamination of microorganisms in the seafood mushroom extract. Stirring evenly disperses microorganisms in the extract, reducing their chance of growth and thus maintaining the hygiene and quality of the extract.

[0108] Improving stability: Regular stirring helps maintain a uniform distribution of components in the extract, reducing differences between different parts. This contributes to improving the stability of the extract and reducing potential changes or stratification.

[0109] To ensure optimal koji-making conditions, a fermentation process was conducted to investigate the effects of brine concentration, brine addition amount, and fermentation temperature on the amino acid nitrogen content of seafood mushroom soy sauce.

[0110] like Figure 7 The figure shows the effect of different brine addition amounts on the amino acid nitrogen content of soy sauce. When the brine addition amount is 120% of the koji (fermentation starter), the amino acid nitrogen content reaches its highest value, 0.533 g / 100 mL. Further increasing the brine addition amount gradually decreases the amino acid nitrogen content of the finished soy sauce. When using the low-salt solid-state fermentation method for soy sauce, the moisture content of the fermented mash should be between 50% and 60%. If the brine addition amount is too low, microbial growth is limited, raw material decomposition is incomplete, and the amino acid nitrogen content of the finished soy sauce is low. If the brine addition amount is too high, miscellaneous bacteria can easily grow and multiply, and the slow heating of the mash also slows down its maturation, reducing the soy sauce yield.

[0111] like Figure 8 The figure shows the effect of different fermentation temperatures on the amino acid nitrogen content of soy sauce. The highest amino acid nitrogen content (0.56 g / 100 mL) was observed when the fermentation temperature was 45℃ for the first 15 days and 40℃ for the next 15 days. Throughout the low-salt solid-state fermentation process, the biochemical reactions involving various enzyme systems are closely related to temperature, mainly divided into two stages: early raw material enzymatic hydrolysis and later flavor formation. In the early fermentation stage, the protein decomposition process directly affects the raw material utilization rate of soy sauce. Enzyme activity increases with temperature within a certain range, but excessively high temperatures cause protein denaturation and loss of enzyme activity. Conversely, excessively low temperatures decrease enzyme activity, slow protein decomposition, and prolong the fermentation cycle. In the later flavor formation stage, studies have shown that a fermentation temperature of 38–40℃ is ideal. Appropriately lowering the temperature in the later stages of fermentation facilitates the production of alcohols and enhances aroma by beneficial microorganisms, thereby improving the quality of the soy sauce.

[0112] Based on this, in order to further verify, an orthogonal experiment was designed to optimize the fermentation process, with brine concentration, brine addition amount, and fermentation temperature as independent variables, and soy sauce amino acid nitrogen content as the indicator.

[0113] Table 1-6 Factor Level Table for Orthogonal Experiment

[0114]

[0115] Table 1-7 Orthogonal Experiment Results of Seafood Mushroom Soy Sauce Fermentation Process

[0116]

[0117] Tables 1-6 and 1-7 show that the order of importance of factors affecting amino acid nitrogen is: B > A > C, i.e., brine addition amount > brine concentration > fermentation temperature. The trends of each factor and indicator are as follows: Figure 9 As shown in the figure, the optimal combination of factors is A1B2C1, which corresponds to a brine concentration of 8%, a brine addition amount of 120%, and fermentation temperatures of 45℃ in the early stage and 40℃ in the later stage. Analysis of variance (Table 1-8) of the orthogonal experiment revealed the influence of each individual factor on the amino acid nitrogen content of soy sauce. The results showed that the brine addition amount had a significant impact on the amino acid nitrogen content of soy sauce, while the brine concentration and fermentation temperature had no significant effects.

[0118] Based on the optimal fermentation conditions obtained from the orthogonal experiment, three parallel experiments were conducted. The results showed that the fermented seafood mushroom soy sauce exhibited high amino acid nitrogen content, with an average content of 0.62 g / 100 mL, which is very close to the theoretical calculation. Therefore, this further verifies that the optimal fermentation conditions determined by the orthogonal experiment are reasonable.

[0119] Table 1-8 Analysis of Variance in Orthogonal Experiments

[0120]

[0121]

[0122] In this embodiment, the optimal fermentation conditions for the seafood mushroom soy sauce were: brine concentration of 8%, brine addition of 120%, fermentation temperature of 45°C for the first 15 days, and fermentation temperature of 40°C for the next 15 days. Under these fermentation conditions, the amino acid nitrogen content of the seafood mushroom soy sauce was 0.62 g / 100 mL.

[0123] The amino acid nitrogen content reached its maximum at a brine concentration of 8%, a brine addition of 120%, and a fermentation temperature of 40℃. Based on this, an orthogonal experiment was designed to optimize the fermentation process. Using brine concentration, brine addition, and fermentation temperature as independent variables, and the amino acid nitrogen content of the soy sauce as the indicator, the optimal fermentation conditions for seafood mushroom soy sauce were determined to be: a brine concentration of 10%, a brine addition of 120%, a fermentation temperature of 45℃ for the first 15 days, and a fermentation temperature of 40℃ for the last 15 days. Under these fermentation conditions, the amino acid nitrogen content of the seafood mushroom soy sauce was 0.62 g / 100 mL.

[0124] In step S5, after fermentation, the mature fermented mash is leached from the original tank, 1.5 to 2 times the mass of the fermented mash is added to boiling water, soaked for 18 to 20 hours, filtered to obtain the first oil, then 1 volume of boiling water is added, soaked for 15 hours, filtered to obtain the second oil, then 1 volume of boiling water is added, soaked for 10 hours, filtered to obtain the third oil.

[0125] In step S6, the filtered first oil, second oil, and third oil are sterilized at 85-90℃ for 25 minutes, cooled to room temperature, and allowed to stand for clarification to obtain the seafood mushroom soy sauce product.

[0126] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A method for preparing a Pleurotus ostreatus soy sauce, characterized by, The steps include: S1, fresh seafood mushroom is selected as raw material, after washing, water is added according to the ratio of 1:4, and the mixture is placed in a negative pressure extraction tank for extraction at a temperature interval of 70-80 DEG C, and the residual debris and impurities of seafood mushroom are filtered to obtain seafood mushroom extract; S2, the seafood mushroom extract is diluted in water with a volume of 20-30% at a temperature interval of 50-55 DEG C, and salt is added to increase the salt concentration of the diluted solution to 8-10%, forming a base solution; S3, koji is prepared; S31, seafood mushroom powder: bran powder: flour is weighed and mixed in a ratio of 1.5:2.5:6 to form a mixture; S32, water is added to the mixture in an amount of 60-70% of the weight of the mixture, and the mixture is stirred uniformly to obtain a moist mixture; S33, the moist mixture is pressure cooked and sterilized, and then cooled to 35-40 DEG C, and AS3.042 Aspergillus oryzae is mixed in an amount of 0.03-0.05% of the weight of the mixture, and the mixture is stirred uniformly to obtain inoculated material; S34, the inoculated material is cultured for 32h to obtain koji; Specifically, the temperature of the inoculated material is controlled in the range of 32-34 DEG C, the koji is cultured for 10h, the temperature is gradually increased to 37 DEG C, the koji is turned over for the first time, and then turned over for the second time after 6h, and the koji is fermented for 32h to obtain the koji; S4, the koji is placed in a fermentation tank, and the base solution is added according to 1-1.2 times the mass of the koji for fermentation, the fermentation temperature is 40-45 DEG C in the first 15 days for hydrolysis fermentation, and the temperature is controlled at 35-40 DEG C in the last 15 days for aroma production fermentation, wherein the seafood mushroom extract is poured once every 5 days to form mature mash; S5, water is added to the mature mash in the fermentation tank in an amount of 1.5-2 times the mass of the koji, and the water temperature is 90-100 DEG C to soak the mash for 10-12h; S6, the mash is pressed and filtered to obtain seafood mushroom soy sauce, and the upper clear liquid is taken after standing and clarification, and then sterilized, fully stirred and bottled.

2. The method for preparing seafood mushroom soy sauce according to claim 1, characterized in that, In step S1, the negative pressure interval in the negative pressure extraction tank is-0.06~-0.04MPa, and the extraction time interval is 30-60min, and the seafood mushroom extract is filtered by 4 layers of gauze.

3. The method according to claim 1, wherein the method is characterized by, In step S4, the koji is placed in a fermentation tank, and the base solution is added according to 1-1.2 times the mass of the koji for fermentation, the fermentation temperature is 40-45 DEG C in the first 15 days for hydrolysis fermentation, and the temperature is controlled at 35-40 DEG C in the last 15 days for aroma production fermentation, wherein the seafood mushroom extract is poured once every 5 days to form mature mash; The fermentation tank is in a sealed state, and the base solution is fully poured into the koji by stirring for 3-5min every 5 days.

4. The method according to claim 1, wherein the method is characterized by, In step S31, the seafood mushroom powder, bran powder and flour are weighed and mixed in a ratio of 1.5:2.5:6 to form a mixture, and the preparation of the seafood mushroom powder is as follows: The fresh seafood mushroom is washed, dried by hot air, and dried for 6-8h at a temperature control interval of 45-48 DEG C, then dried for 12h at a temperature interval of 55-58 DEG C, then gradually decreased to 50 DEG C, and maintained for 6-8h, and dried to a moisture content of 11-13%.

5. The method according to claim 4, wherein the method is characterized by, In step S32, the water is added in the mixture material, and the water weight is 60-70% of the mixture material, and the mixture material is stirred to obtain the watered mixture material, and the step further comprises: The water temperature is 50-70℃, and the watered mixture material stirring time is 20-30min.

6. The method according to claim 5, wherein the method is characterized by, In step S33, the watered mixture material is sterilized by pressure cooking, and then air-cooled to 35-40℃, and then AS3.042 Aspergillus oryzae is added in the watered mixture material according to the weight ratio of 0.03-0.05%, and the watered mixture material is stirred to obtain the inoculated mixture material, and the step further comprises: the thickness of the inoculated mixture material is 3-5cm.

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