Soy sauce and preparation method thereof

Abstract

This invention provides a method for preparing soy sauce, comprising the following steps: A) Pre-treating soybean meal and then moistening it with water to obtain moistened soybean meal; pre-treating wheat to obtain pre-treated wheat; B) Steaming and cooling the moistened soybean meal to obtain cooled soybean meal; C) Mixing the cooled soybean meal and pre-treated wheat, adding Aspergillus oryzae and Monascus purpureus to make koji (fermentation starter); D) Mixing the koji with brine for fermentation, adding a first antibacterial fermentation liquid after preliminary fermentation, and then performing a full fermentation to obtain a fermentation liquid; E) Pressing and filtering the fermentation liquid to obtain raw soy sauce; F) Sterilizing the raw soy sauce to obtain a semi-finished soy sauce product; mixing the semi-finished soy sauce product with the second antibacterial fermentation liquid, and bottling to obtain soy sauce. The soy sauce prepared by the above steps of this invention possesses natural preservative properties, eliminating the need to add preservatives in subsequent refining processes, making the soy sauce safer and achieving a good flavor, while also simplifying the process.

Description

Technical Field

[0001] This invention relates to the field of food technology, and in particular to a soy sauce and its preparation method. Background Technology

[0002] Soy sauce is a traditional Chinese liquid condiment. It is made from soybeans, defatted soybeans, black beans, wheat or wheat bran, with the addition of water and salt. It has a reddish-brown color, a unique soy aroma, and a delicious flavor that stimulates the appetite. The production process of soy sauce generally involves the raw materials being decomposed by microorganisms and fermented with brine to obtain crude soy sauce. This crude soy sauce then undergoes sterilization and blending processes to produce the marketable soy sauce. To ensure the soy sauce does not spoil within its shelf life, various additives, such as preservatives, are usually added during the blending process of the semi-finished soy sauce.

[0003] In recent years, people have paid more and more attention to the safety and low toxicity of preservatives. Soy sauce preservation technology is developing towards natural, safe, nutritious and functional directions, and people are becoming more selective about additive-free soy sauce.

[0004] In existing technologies, to achieve preservative-free soy sauce production, high salt content, the addition of edible alcohol, or adjustment of acidity are typically used to ensure its preservative properties. Furthermore, higher salt concentrations generally result in better preservative effects, leading manufacturers to employ long fermentation cycles, sometimes even double fermentation. However, this can cause the crude soy sauce to develop a sour or astringent flavor. High salt content during soy sauce production can result in a sour or astringent flavor, or an alcoholic taste, making the flavor less appealing than soy sauces with added preservatives. Long fermentation cycles, and sometimes double fermentation, also significantly increase production costs for manufacturers.

[0005] Therefore, it is essential to provide a method for preparing soy sauce that achieves both good preservation and flavor without the need for preservatives. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a method for preparing soy sauce, wherein the soy sauce provided by the present invention does not require the addition of preservatives, has good preservative effect, and has a good flavor.

[0007] This invention provides a method for preparing soy sauce, comprising the following steps:

[0008] A) After pre-treating the soybean meal, it is moistened with water to obtain moistened soybean meal;

[0009] Wheat is pretreated to obtain pretreated wheat;

[0010] B) Steam the moistened soybean meal, and then cool it to obtain cooled soybean meal.

[0011] C) Mix the cooled soybean meal and pretreated wheat, add Aspergillus oryzae and Monascus purpureus to make koji, and obtain koji material;

[0012] D) Mix the starter and brine for fermentation. After initial fermentation, add the first antibacterial fermentation liquid and then carry out full fermentation to obtain the fermentation liquid.

[0013] E) The fermentation liquid is pressed and filtered to obtain raw soy sauce;

[0014] F) After sterilizing the raw soy sauce, a semi-finished soy sauce product is obtained; the semi-finished soy sauce product is mixed with the second antibacterial fermentation liquid and bottled to obtain soy sauce.

[0015] Preferably, step A)

[0016] The soybean meal pretreatment specifically involves spraying the surface of the soybean meal with a 20% salt solution and soaking it for 10-20 minutes.

[0017] The wheat pretreatment specifically involves: puffing and pulverizing wheat at 300-350℃ using a wheat roasting machine to obtain wheat flour;

[0018] The specific parameters of the wetting water are: a wetting water ratio of 100-120% and a wetting water temperature of 80-85℃.

[0019] Preferably, the cooking in step B) is performed using an FM continuous cooking device, and the cooking time is 3.5 to 5 minutes at a temperature of 128 to 133°C and a pressure of 0.17 to 0.20 MPa.

[0020] The cooling process specifically refers to cooling to 40°C.

[0021] Preferably, the mass ratio of the cooled soybean meal to the pretreated wheat in step C) is (6-8):(2-4);

[0022] The amount of Aspergillus oryzae added is 2-3 wt%; the amount of Monascus purpureus added is 1-2 wt%.

[0023] Preferably, the koji-making process in step C) is a disc koji-making process, and the koji-making time is 32-42 hours;

[0024] The music production process includes a first stage of music production, a second stage of music production, and a third stage of music production.

[0025] Preferably, the first stage of music production specifically includes:

[0026] Temperature control: The temperature of the koji material is raised to 30-32℃ for the first 30 minutes and maintained for 3 hours, and then raised to 30-34℃; the temperature is raised to 36℃ before the first turning of the koji material; the temperature difference between the upper and lower koji materials is <6℃; the disc blows internal circulating air for 3 hours, and then mixed air.

[0027] Spraying begins 4 hours after koji making. The first stage of koji making takes 10-15 hours, followed by the first koji roll.

[0028] The second stage of music production specifically involves:

[0029] Temperature control: 32~36℃, temperature difference of koji material <6℃; air circulation is mixed air; the second stage of koji making time is 8h, and the second koji is turned 5~7h after the first koji turning. 0.08~0.2wt% of lactic acid bacteria agent is added before turning.

[0030] The third stage of music production specifically involves:

[0031] Temperature control: The temperature of the koji material is 29-36℃, and the temperature difference of the koji material is <5℃.

[0032] Preferably, the preparation method of the lactic acid bacteria inoculant is as follows:

[0033] Adjust the pH of the culture medium to 7.0–7.3, sterilize at 100–120℃ for 30–60 min, cool to 35℃, inoculate with soy sauce lactic acid bacteria, and culture at 30–35℃ for 4–5 days until the cell count reaches 102. 9 The above process involves centrifugation to obtain a precipitate; the culture medium raw materials include 10-20 wt% crude soy sauce, 10-30 wt% glucose, and 10-15 wt% salt.

[0034] The precipitate is dried at 30-40℃ and then mixed with flour at a mass ratio of 1:10; this yields the final product.

[0035] Preferably, in step D), the mass ratio of the koji material to the brine is 1:(1.9-2.3); and the concentration of the brine is 15%-23%.

[0036] The fermentation temperature is 20–30°C, and the fermentation time is 120–150 days;

[0037] The amount of the first antibacterial fermentation broth added is 5wt% to 10wt%.

[0038] After adding the first antibacterial fermentation broth for 30 days, mature fermentation is carried out; the mature fermentation time is 150-180 days.

[0039] The mass ratio of the semi-finished soy sauce to the second antibacterial fermentation liquid is 8:2 to 9:1.

[0040] Preferably, the preparation method of the first antibacterial fermentation liquid is as follows: after pretreatment, wheat is liquefied and saccharified, then mixed with raw soy sauce, and brewing yeast and lactococcus lactis are added for fermentation to obtain the product; the ammonia nitrogen of the raw soy sauce is >0.8g / 100mL.

[0041] The preparation method of the second antibacterial fermentation broth is as follows: Pretreated wheat is liquefied and saccharified, then mixed with raw soy sauce, and fermented with brewer's yeast to obtain the broth. The ammonia nitrogen content of the raw soy sauce is >0.8g / 100mL.

[0042] This invention provides a soy sauce, characterized in that it is prepared by any one of the preparation methods described in the above technical solutions.

[0043] Compared with existing technologies, this invention provides a method for preparing soy sauce, comprising the following steps: A) Pre-treating soybean meal and then moistening it with water to obtain moistened soybean meal; pre-treating wheat to obtain pre-treated wheat; B) Steaming and cooling the moistened soybean meal to obtain cooled soybean meal; C) Mixing the cooled soybean meal and pre-treated wheat, adding Aspergillus oryzae and Monascus purpureus to make koji, obtaining koji material; D) Mixing the koji material and brine for fermentation, adding a first antibacterial fermentation liquid after preliminary fermentation, and then performing mature fermentation to obtain fermentation liquid; E) Pressing and filtering the fermentation liquid to obtain raw soy sauce; F) Sterilizing the raw soy sauce to obtain a semi-finished soy sauce product; mixing the semi-finished soy sauce product with the second antibacterial fermentation liquid, and bottling to obtain soy sauce. The soy sauce prepared by the above steps of this invention possesses natural preservative properties, eliminating the need to add preservatives in subsequent refining processes, making the soy sauce safer and achieving a good flavor, while also being a simpler and more economical process. Detailed Implementation

[0044] This invention provides a soy sauce and its preparation method. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and fall within the scope of protection of this invention. The method and application of this invention have been described through preferred embodiments. Those skilled in the art can clearly modify or appropriately change and combine the method and application described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0045] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0046] This invention provides a method for preparing soy sauce, comprising the following steps:

[0047] A) After pre-treating the soybean meal, it is moistened with water to obtain moistened soybean meal;

[0048] Wheat is pretreated to obtain pretreated wheat;

[0049] B) Steam the moistened soybean meal, and then cool it to obtain cooled soybean meal.

[0050] C) Mix the cooled soybean meal and pretreated wheat, add Aspergillus oryzae and Monascus purpureus to make koji, and obtain koji material;

[0051] D) Mix the starter and brine for fermentation. After initial fermentation, add the first antibacterial fermentation liquid and then carry out full fermentation to obtain the fermentation liquid.

[0052] E) The fermentation liquid is pressed and filtered to obtain raw soy sauce;

[0053] F) After sterilizing the raw soy sauce, a semi-finished soy sauce product is obtained; the semi-finished soy sauce product is mixed with the second antibacterial fermentation liquid and bottled to obtain soy sauce.

[0054] The method for preparing soy sauce provided by the present invention first involves pretreatment of soybean meal and wheat.

[0055] According to the present invention, the soybean meal pretreatment specifically involves spraying the surface of the soybean meal with a 20% salt solution and soaking it for 10 to 20 minutes.

[0056] The preferred amount of salt sprayed is 3-5 wt%.

[0057] The wheat pretreatment described in this invention specifically involves: puffing and pulverizing wheat using a roasting machine at 300–350°C to obtain wheat flour. The puffing temperature is preferably 310–350°C; more preferably 320–350°C.

[0058] After pretreatment, the soybean meal is moistened with water to obtain moistened soybean meal.

[0059] The specific parameters of the wetting water described in this invention are: a wetting water ratio of 100% to 120% and a wetting water temperature of 80 to 85°C.

[0060] In some embodiments, the parameters of the wetting water are specifically: the wetting water ratio is 110% to 120%, and the wetting water temperature is 80 to 85°C.

[0061] The moistened soybean meal is steamed; the steaming is carried out using an FM continuous steaming device at a temperature of 128-133℃ and a pressure of 0.17-0.20 MPa for 3.5-5 minutes.

[0062] In some embodiments, the cooking is performed using an FM continuous cooking device, at a temperature of 130–133°C and a pressure of 0.18–0.20 MPa for 3.5–4.5 minutes.

[0063] In one embodiment, the cooking is performed using an FM continuous cooking device, at a temperature of 133°C and a pressure of 0.20 MPa for 3.5 minutes.

[0064] The cooked soybean meal is rapidly depressurized and cooled to 40°C using a steel belt cooling device.

[0065] The mass ratio of cooled soybean meal to pretreated wheat described in this invention is (6-8):(2-4);

[0066] In some embodiments, the mass ratio of the cooled soybean meal to the pretreated wheat is 8:2, 6:4, or 6:2.

[0067] After mixing, Aspergillus oryzae and Monascus purpureus are added to make koji, thus obtaining koji material.

[0068] The inventors have innovatively combined Aspergillus oryzae and Monascus purpureus in the koji-making process, resulting in better performance.

[0069] Specifically, the amount of Aspergillus oryzae added is 2-3 wt%; the amount of Monascus purpureus added is 1-2 wt%.

[0070] The koji-making method described in this invention is disc koji-making. The inventors do not limit this method; any method known to those skilled in the art is acceptable.

[0071] The koji-making time for this invention is 32–42 hours.

[0072] According to the present invention, the music production includes a first stage of music production, a second stage of music production, and a third stage of music production.

[0073] Specifically, the first stage of music production is as follows:

[0074] Temperature control: The temperature of the koji material is raised to 30-32℃ for the first 30 minutes and maintained for 3 hours, and then raised to 30-34℃; the temperature is raised to 36℃ before the first turning of the koji material; the temperature difference between the upper and lower koji materials is <6℃; the disc blows internal circulating air for 3 hours, and then mixed air.

[0075] Spraying begins 4 hours after koji making. The first stage of koji making takes 10-15 hours, followed by the first koji roll.

[0076] In some embodiments, the first stage of koji-making temperature control is as follows: Rapid temperature equalization is performed for the first 30 minutes, controlling the koji material temperature at 30-32℃. The air and product temperatures are maintained at 30-32℃ for 3 hours. The fan is gradually increased, with the overall temperature controlled at 30-34℃. Before the first turning of the koji, the temperature will rise to 36℃. The temperature difference between the upper and lower koji materials is <6℃. Internal circulating air is blown from the disc for 3 hours, followed by mixed air. Spraying begins 4 hours after koji-making, with the spray volume proportional to the fan frequency; the spray volume is maximized when the fan is at maximum. The first stage of koji-making takes 10-15 hours. Before turning the koji, the disc is manually rotated to check the koji temperature at different locations, and then the first turning is performed.

[0077] The second stage of music production in this invention specifically includes:

[0078] Temperature control: 32~36℃, temperature difference of koji material <6℃; air circulation is mixed air; the second stage of koji making time is 8h, and the second koji is turned 5~7h after the first koji turning. 0.08~0.2wt% of lactic acid bacteria agent is added before turning.

[0079] In some embodiments, the second-stage koji-making temperature is controlled at 32-36℃, not exceeding 38℃, with a koji material temperature difference of <6℃. The fan frequency and spray volume are maintained, and the air circulation is mixed air. The second-stage koji-making time is 8 hours (based on the sensory condition of the koji material). The second turning is performed approximately 5-7 hours after the first turning. Before turning, the disc is manually rotated, and 0.08%-0.2% lactic acid bacteria inoculant is added.

[0080] According to the present invention, the preparation method of the lactic acid bacteria inoculant is as follows:

[0081] Adjust the pH of the culture medium to 7.0–7.3, sterilize at 100–120℃ for 30–60 min, cool to 35℃, inoculate with soy sauce lactic acid bacteria, and culture at 30–35℃ for 4–5 days until the cell count reaches 102. 9 The above steps involve centrifugation to obtain a precipitate.

[0082] The precipitate is dried at 30-40℃ and then mixed with flour at a mass ratio of 1:10; this yields the final product.

[0083] Specifically, the culture medium raw materials include 10-20 wt% crude soy sauce, 10%-30 wt% glucose, and 10-15 wt% salt;

[0084] Preferably, the culture medium raw materials include 13-20 wt% soy sauce crude oil, 15%-30 wt% glucose, and 10-14 wt% salt.

[0085] More preferably, the culture medium raw materials include 15-20 wt% soy sauce crude oil, 20-30 wt% glucose, and 10-13 wt% salt.

[0086] The third stage of music production in this invention specifically includes:

[0087] Temperature control: The temperature of the koji material is 29-36℃, and the temperature difference of the koji material is <5℃.

[0088] In some embodiments, the third stage of koji making specifically involves: the temperature of the koji material gradually decreasing, with the temperature ranging from approximately 29 to 36°C, and the temperature moving towards the lower limit over time; the temperature difference of the koji material is less than 5°C.

[0089] Mix the starter culture with brine and ferment.

[0090] According to the present invention, the mass ratio of the koji material to the brine is 1:(1.9-2.3); the concentration of the brine is 15%-23%; the fermentation temperature is 20-30°C; and the fermentation time is 120-150 days.

[0091] In some embodiments, the mass ratio of the koji material to the brine is 1:(2-2.2); the concentration of the brine is 17%-22%; the fermentation temperature is 20-30°C; and the fermentation time is 120-140 days.

[0092] In some embodiments, the mass ratio of the koji and brine is 1:2; the concentration of the brine is 18%; the fermentation temperature is 20-30°C; and the fermentation time is 120-130 days.

[0093] After initial fermentation, a first antibacterial fermentation liquid is added and then mature fermentation is carried out; preferably, mature fermentation is carried out 30 days after adding the first antibacterial fermentation liquid; the mature fermentation time is 150-180 days.

[0094] In some preferred embodiments, the fermentation time is 150–170 days;

[0095] In some preferred embodiments, the fermentation time is 150–160 days;

[0096] In some preferred embodiments, the amount of the first antibacterial fermentation broth added is 5wt% to 10wt%.

[0097] Specifically, 5wt%, 8wt%, or 10wt% of the first antibacterial fermentation broth can be added.

[0098] The preparation method of the first antibacterial fermentation broth of the present invention is as follows: Pretreated wheat is liquefied and saccharified, then mixed with raw soy sauce, and brewer's yeast and lactococcus lactis are added for fermentation to obtain the broth; wherein the mass ratio of the pretreated wheat to the soy sauce is 1:1. The present invention does not limit the type of raw soy sauce; any raw soy sauce with an ammonia nitrogen content >0.8 g / 100 mL, as is well known to those skilled in the art, is acceptable.

[0099] The present invention does not limit the specific parameters of the above-mentioned liquefaction and saccharification, which are known to those skilled in the art.

[0100] After fermentation, the raw soy sauce is obtained by pressing and filtering.

[0101] The present invention does not limit the specific parameters of the pressing and filtering, which are known to those skilled in the art.

[0102] The raw soy sauce is sterilized to obtain a semi-finished soy sauce product. The sterilization is specifically UHT sterilization, with a sterilization temperature of 120-125℃ and a sterilization time of 15-30 seconds.

[0103] The soy sauce semi-finished product is mixed with the second antibacterial fermentation liquid and then bottled to obtain soy sauce.

[0104] According to the present invention, the mass ratio of the soy sauce semi-finished product to the second antibacterial fermentation liquid is 8:2 to 9:1.

[0105] In some embodiments, the mass ratio of the soy sauce semi-finished product to the second antibacterial fermentation liquid is 8:2;

[0106] In some embodiments, the mass ratio of the soy sauce semi-finished product to the second antibacterial fermentation liquid is 9:1.

[0107] The preparation method of the second antibacterial fermentation liquid of the present invention is as follows: after pretreatment, wheat is liquefied and saccharified, then mixed with soy sauce, and brewing yeast is added for fermentation to obtain the product.

[0108] This invention provides a soy sauce prepared by any one of the preparation methods described in the above technical solutions.

[0109] The preparation method described above has been clearly described in this invention, and will not be repeated here.

[0110] This invention improves the natural preservative properties of soy sauce through the following measures, achieving the goal of eliminating the need to add preservatives during the later refining process, resulting in soy sauce with good flavor and high raw material utilization:

[0111] 1. During raw material pretreatment, the surface of the raw materials is soaked in brine to inhibit the growth and reproduction of salt-tolerant microorganisms, creating favorable conditions for the growth and reproduction of Aspergillus. In the first and second stages of koji making, Aspergillus fully utilizes the nutrients in the koji material to produce abundant enzymes, ensuring that the protein is fully utilized. Simultaneously, lactic acid bacteria are added in advance during the later stages of koji making to inhibit the growth and reproduction of other salt-tolerant microorganisms, improve the quality of the koji, reduce contaminants, and ensure that as much of the soybeans initially added as possible are converted into components soluble in raw soy sauce, increasing the concentration of substances in the raw soy sauce. Compared to traditional processes, the water activity is lower, thus improving preservative properties. Soy sauce brewed using this process already possesses high preservative properties.

[0112] 2. Adding antibacterial fermentation liquid in the later stages of fermentation compensates for the decrease in preservative properties caused by external microorganisms during fermentation, while also enriching the flavor of the soy sauce.

[0113] 3. This invention uses a compound of Aspergillus oryzae and Monascus purpureus for koji making, providing abundant amylase, saccharifying enzymes, esterifying enzymes, etc. This results in high raw material utilization, bright product color, rich texture, mellow taste, and fragrant aroma.

[0114] To further illustrate the present invention, the following describes in detail a soy sauce and its preparation method provided by the present invention with reference to embodiments.

[0115] Example 1

[0116] Step 1: Pretreatment: The soybean meal and wheat raw materials are evenly sprayed with 3% (by weight) of a 20% salt solution and soaked for 20 minutes. The wheat raw materials are then puffed and pulverized at 350℃ using a wheat roasting machine to obtain wheat flour.

[0117] Step 2: Moistening: Moisten the soybean meal raw material again with a water ratio of 120% and a watering temperature of 85℃. After moistening, preheat the steam to 95℃.

[0118] Step 3: Steaming: Steam the moistened soybean meal raw material to cook it. Use an FM continuous steaming device to steam for 3.5 minutes at a temperature of 133℃ and a pressure of 0.20Mpa.

[0119] Step 4: Cooling and inoculation: After rapidly depressurizing and cooling to 40°C using a steel belt cooling device, mix soybean meal and wheat flour in a mass ratio of 8:2, then add 3% Aspergillus oryzae and 1% Monascus purpureus by mass for ventilation and koji making;

[0120] Step 5: Koji Making: The koji material is koji-made using a disc koji-making process. The total koji-making time is 42 hours (based on the sensory condition of the koji material).

[0121] First stage of koji-making temperature control: Rapid temperature equalization is performed for the first 30 minutes, controlling the koji material temperature at 30-32℃. The air and product temperatures are maintained at 30-32℃ for 3 hours. The fan is gradually increased, maintaining the overall temperature at 30-34℃. The temperature will rise to 36℃ before the first turning of the koji. The temperature difference between the upper and lower koji materials should be less than 6℃. Internal circulating air is blown from the disc for 3 hours, followed by mixed air.

[0122] Spraying begins 4 hours after koji preparation. The spray volume is directly proportional to the fan frequency; when the fan is at its maximum, the spray volume is also at its maximum. The first stage of koji preparation lasts 0-15 hours (based on the sensory condition of the koji material). Before turning the koji, manually rotate the disc to check the koji temperature at different locations, and then perform the first turning.

[0123] The second stage of koji making temperature control: 32-36℃, not exceeding 38℃, with a koji material temperature difference of <6℃. Maintain the fan frequency and spray volume, with mixed air circulation. The second stage of koji making time is 15-23 hours (based on the sensory condition of the koji material). The second turning is carried out approximately 8 hours after the first turning. Before turning, manually rotate the disc and add 0.08% lactic acid bacteria inoculant.

[0124] Preparation method of lactic acid bacteria inoculum: Prepare a culture medium using 20% ​​soy sauce crude oil, 20% glucose, and 10% salt, and adjust the pH to 7.3. Sterilize at 120℃ for 30 min, cool to 35℃, inoculate with soy sauce lactic acid bacteria, and culture at 35℃ for 5 days until the cell count reaches 10 to the power of 9 or higher. Centrifuge to obtain the precipitate. Dry at 40℃ and mix with flour at a ratio of 1:10.

[0125] The third stage of koji-making temperature control: the temperature of the koji material gradually decreases, with the temperature ranging from approximately 29-36℃, and the temperature moves towards the lower limit over time; the temperature difference between the koji material and the temperature difference is less than 5℃.

[0126] Step 6: Fermentation: Add 2.0 times the weight of the koji material to salt water for fermentation. The mass concentration of the salt water is 18%. The fermentation temperature is controlled at 25℃. After 120 days of fermentation, add 5% antibacterial fermentation liquid. After 30 days, carry out mature fermentation. The fermentation cycle ends after 150 days.

[0127] Preparation method of antibacterial fermentation liquid 1: Step 1: Wheat flour is liquefied and saccharified and then mixed with soy sauce at a ratio of 1:1. Brewing yeast and lactococcus lactis at a ratio of 1:1 are added to ferment the liquid.

[0128] Step 7: Oil Extraction: After fermentation, the raw soy sauce is obtained by pressing and filtering.

[0129] Step 8: After sterilization, the semi-finished soy sauce is added at a ratio of 9:1 with antibacterial fermentation liquid 2, and then bottled to obtain the finished soy sauce. No preservatives are required.

[0130] Preparation method of antibacterial fermentation liquid 2: Step 1: Wheat flour is liquefied and saccharified and then mixed with soy sauce at a ratio of 1:1. Brewing yeast is added to ferment the liquid.

[0131] Example 2

[0132] Step 1: Pretreatment: The soybean meal and wheat raw materials are evenly sprayed with 5% of their respective weight of a 20% salt solution and soaked for 15 minutes. The wheat raw materials are then puffed and pulverized at 350℃ using a wheat roasting machine to obtain wheat flour.

[0133] Step 2: Moistening: Moisten the soybean meal raw material again with a water ratio of 110% and a watering temperature of 80℃. After moistening, preheat the steam to 90℃.

[0134] Step 3: Steaming: Steam the moistened soybean meal raw material to cook it. Use an FM continuous steaming device to steam for 3.5 minutes at a temperature of 133℃ and a pressure of 0.20Mpa.

[0135] Step 4: Cooling and inoculation: After rapidly depressurizing and cooling to 40°C using a steel belt cooling device, mix soybean meal and wheat flour in a mass ratio of 8:2, then add 2% Aspergillus oryzae and 2% Monascus purpureus by mass for ventilation and koji making;

[0136] Step 5: Koji Making: The koji material is koji-made using a disc koji-making process. The total koji-making time is 42 hours (based on the sensory condition of the koji material).

[0137] First stage of koji-making temperature control: Rapid temperature equalization is performed for the first 30 minutes, controlling the koji material temperature at 30-32℃. The air and product temperatures are maintained at 30-32℃ for 3 hours. The fan is gradually increased, maintaining the overall temperature at 30-34℃. The temperature will rise to 36℃ before the first turning of the koji. The temperature difference between the upper and lower koji materials should be less than 6℃. Internal circulating air is blown from the disc for 3 hours, followed by mixed air.

[0138] Spraying begins 4 hours after koji preparation. The spray volume is directly proportional to the fan frequency; when the fan is at its maximum, the spray volume is also at its maximum. The first stage of koji preparation lasts 0-13 hours (based on the sensory condition of the koji material). Before turning the koji, manually rotate the disc to check the koji temperature at different locations, and then perform the first turning.

[0139] The second stage of koji making temperature control: 32-36℃, not exceeding 38℃, with a koji material temperature difference of <6℃. Maintain the fan frequency and spray volume, with mixed air circulation. The second stage of koji making time is 13-21 hours (based on the sensory condition of the koji material). The second turning is carried out approximately 8 hours after the first turning. Before turning, manually rotate the disc and add 0.2% lactic acid bacteria inoculant.

[0140] Preparation method of lactic acid bacteria inoculum: Prepare a culture medium using 15% crude soy sauce, 20% glucose, and 10% salt, and adjust the pH to 7.0. Sterilize at 120℃ for 30 min, cool to 35℃, inoculate with soy sauce lactic acid bacteria, and culture at 35℃ for 4 days until the cell count reaches 10 to the power of 9 or higher. Centrifuge to obtain the precipitate. Dry at 35℃ and mix with flour at a ratio of 1:10.

[0141] The third stage of koji-making temperature control: the temperature of the koji material gradually decreases, with the temperature ranging from approximately 29-36℃, and the temperature moves towards the lower limit over time; the temperature difference between the koji material and the temperature difference is less than 5℃.

[0142] Step 6: Fermentation: Add 2.0 times the weight of the koji material to salt water for fermentation. The mass concentration of the salt water is 18%. The fermentation temperature is controlled at 28℃. After 120 days of fermentation, add 8% antibacterial fermentation liquid. After 30 days, carry out mature fermentation. The fermentation cycle ends after 150 days.

[0143] Preparation method of antibacterial fermentation liquid 1: Step 1: Wheat flour is liquefied and saccharified and then mixed with soy sauce at a ratio of 1:1. Brewing yeast and lactococcus lactis at a ratio of 1:1 are added to ferment the liquid.

[0144] Step 7: Oil Extraction: After fermentation, the raw soy sauce is obtained by pressing and filtering.

[0145] Step 8: After sterilization, the semi-finished soy sauce is added to the antibacterial fermentation liquid at a ratio of 8:2, and then bottled to obtain the finished soy sauce. No preservatives are required.

[0146] Preparation method of antibacterial fermentation liquid 2: Step 1: Wheat flour is liquefied and saccharified and then mixed with soy sauce at a ratio of 1:1. Brewing yeast is added to ferment the liquid.

[0147] Example 3

[0148] Step 1: Pretreatment: The soybean meal and wheat raw materials are evenly sprayed with 4% (by weight) of a 20% salt solution and soaked for 15 minutes. The wheat raw materials are then puffed and pulverized at 350℃ using a wheat roasting machine to obtain wheat flour.

[0149] Step 2: Moistening: Moisten the soybean meal raw material again with a water ratio of 115% and a watering temperature of 82℃. After moistening, preheat the steam to 92℃.

[0150] Step 3: Steaming: Steam the moistened soybean meal raw material to cook it. Use an FM continuous steaming device to steam for 3.5 minutes at a temperature of 133℃ and a pressure of 0.20Mpa.

[0151] Step 4: Cooling and inoculation: After rapidly depressurizing and cooling to 40°C using a steel belt cooling device, mix soybean meal and wheat flour in a mass ratio of 8:2, then add 3% Aspergillus oryzae and 2% Monascus purpureus by mass for ventilation and koji making;

[0152] Step 5: Koji Making: The koji material is koji-made using a disc koji-making process. The total koji-making time is 40 hours (based on the sensory condition of the koji material).

[0153] First stage of koji-making temperature control: Rapid temperature equalization is performed for the first 30 minutes, controlling the koji material temperature at 30-32℃. The air and product temperatures are maintained at 30-32℃ for 3 hours. The fan is gradually increased, maintaining the overall temperature at 30-34℃. The temperature will rise to 36℃ before the first turning of the koji. The temperature difference between the upper and lower koji materials should be less than 6℃. Internal circulating air is blown from the disc for 3 hours, followed by mixed air.

[0154] Spraying begins 4 hours after koji preparation. The spray volume is directly proportional to the fan frequency; when the fan is at its maximum, the spray volume is also at its maximum. The first stage of koji preparation lasts 0-13 hours (based on the sensory condition of the koji material). Before turning the koji, manually rotate the disc to check the koji temperature at different locations, and then perform the first turning.

[0155] The second stage of koji making temperature control: 32-36℃, not exceeding 38℃, with a koji material temperature difference of <6℃. Maintain the fan frequency and spray volume, with mixed air circulation. The second stage of koji making time is 13-19 hours (based on the sensory condition of the koji material). The second turning is carried out approximately 8 hours after the first turning. Before turning, manually rotate the disc and add 0.15% lactic acid bacteria inoculant.

[0156] Preparation method of lactic acid bacteria inoculum: Prepare a culture medium using 15% crude soy sauce, 30% glucose, and 10% salt, and adjust the pH to 7.1. Sterilize at 120℃ for 30 minutes, cool to 35℃, inoculate with soy sauce lactic acid bacteria, and culture at 30℃ for 5 days until the cell count reaches 10 to the power of 9 or higher. Centrifuge to obtain the precipitate. Dry at 30℃ and mix with flour at a ratio of 1:10.

[0157] The third stage of koji-making temperature control: the temperature of the koji material gradually decreases, with the temperature ranging from approximately 29-36℃, and the temperature moves towards the lower limit over time; the temperature difference between the koji material and the temperature difference is less than 5℃.

[0158] Step 6: Fermentation: Add 2.0 times the weight of the koji material to salt water for fermentation. The mass concentration of the salt water is 18%. The fermentation temperature is controlled at 30℃. After 120 days of fermentation, add 10% antibacterial fermentation liquid. After 30 days, carry out mature fermentation. The fermentation cycle ends after 150 days.

[0159] Preparation method of antibacterial fermentation liquid 1: Step 1: Wheat flour is liquefied and saccharified and then mixed with soy sauce at a ratio of 1:1. Brewing yeast and lactococcus lactis at a ratio of 1:1 are added to ferment the liquid.

[0160] Step 7: Oil Extraction: After fermentation, the raw soy sauce is obtained by pressing and filtering.

[0161] Step 8: After sterilization, the semi-finished soy sauce is added at a ratio of 8.5:1.5 with antibacterial fermentation liquid 2, and then bottled to obtain the finished soy sauce. No preservatives are required.

[0162] Preparation method of antibacterial fermentation liquid 2: Step 1: Wheat flour is liquefied and saccharified and then mixed with soy sauce at a ratio of 1:1. Brewing yeast is added to ferment the liquid.

[0163] Compare with Example 1:

[0164] Step 1: Pre-treatment: Wheat raw materials are puffed and pulverized at 350℃ using a wheat roasting machine to obtain wheat flour.

[0165] Step 2: Moistening: Moisten the soybean meal raw material again with a water ratio of 115% at a watering temperature of 80-85℃. After moistening, preheat the steam to 90-95℃.

[0166] Step 3: Steaming: Steam the moistened soybean meal raw material to cook it. Use an FM continuous steaming device to steam for 3.5 minutes at a temperature of 133℃ and a pressure of 0.20Mpa.

[0167] Step 4: Cooling and inoculation: After rapidly depressurizing and cooling to 40°C using a steel belt cooling device, mix soybean meal and wheat flour in a mass ratio of 8:2, and then add 4% Aspergillus oryzae by mass for ventilation and koji making;

[0168] Step 5: Koji Making: The koji material is koji-made using a disc koji-making process. The total koji-making time is 40 hours (based on the sensory condition of the koji material).

[0169] First stage of koji-making temperature control: Rapid temperature equalization is performed for the first 30 minutes, controlling the koji material temperature at 30-32℃. The air and product temperatures are maintained at 30-32℃ for 3 hours. The fan is gradually increased, maintaining the overall temperature at 30-34℃. The temperature will rise to 36℃ before the first turning of the koji. The temperature difference between the upper and lower koji materials should be less than 6℃. Internal circulating air is blown from the disc for 3 hours, followed by mixed air.

[0170] Spraying begins 4 hours after koji preparation. The spray volume is directly proportional to the fan frequency; when the fan is at its maximum, the spray volume is also at its maximum. The first stage of koji preparation lasts 0-13 hours (based on the sensory condition of the koji material). Before turning the koji, manually rotate the disc to check the koji temperature at different locations, and then perform the first turning.

[0171] The second stage of koji making temperature control: 32-36℃, not exceeding 38℃, with a koji material temperature difference of <6℃. Maintain the fan frequency and spray volume, and use mixed air circulation. The second stage of koji making time is 13-19 hours (based on the sensory condition of the koji material). The second turning of the koji is carried out approximately 8 hours after the first turning.

[0172] The third stage of koji-making temperature control: the temperature of the koji material gradually decreases, with the temperature ranging from approximately 29-36℃, and the temperature moves towards the lower limit over time; the temperature difference between the koji material and the temperature difference is less than 5℃.

[0173] Step 5: Fermentation: Add 2.0 times the weight of the koji material to salt water for fermentation. The mass concentration of the salt water is 20%. The fermentation temperature is controlled at 20-30℃. The fermentation cycle is completed in 150 days.

[0174] Step 7: Oil Extraction: After fermentation, the raw soy sauce is obtained by pressing and filtering.

[0175] Step 8: Sterilize to obtain the semi-finished soy sauce product, with or without adding preservatives.

[0176] Comparative Example 2

[0177] Except for step 5, which does not involve adding lactic acid bacteria inoculants, the rest of the steps are the same as in Example 1.

[0178] Comparative Example 3

[0179] Except for step 6, which does not include the antibacterial fermentation broth 1, the rest of the steps are the same as in Example 1.

[0180] Comparative Example 4

[0181] Step 8: Sterilize to obtain semi-finished soy sauce, then bottle to obtain finished soy sauce. Everything else is the same as in Example 1.

[0182] Table 1. Summary of Comparison Results of Soy Sauce Prepared in Examples 1-3 and the Comparative Example

[0183]

[0184]

[0185] As shown in Table 1, the raw material utilization rate and amino nitrogen content of the soy sauces described in Examples 1-3 of this invention are higher than those of the comparative example. The prepared koji has high enzyme activity and low levels of miscellaneous bacteria, and the soy sauce has a high amino acid content, particularly high levels of free amino acids and glutamic acid. This improves the raw material utilization rate and enhances the flavor. The preservative properties of the soy sauce are significantly improved, extending its shelf life.

[0186] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing soy sauce, characterized in that, Includes the following steps: A) After pre-treating the soybean meal, it is moistened with water to obtain moistened soybean meal; the pre-treatment of soybean meal specifically involves spraying the surface of the soybean meal with a 20% salt solution and soaking it for 10-20 minutes. Wheat is pretreated to obtain pretreated wheat; B) Steam the moistened soybean meal, and then cool it to obtain cooled soybean meal. C) The cooled soybean meal and pretreated wheat are mixed, and Aspergillus oryzae and Monascus purpureus are added to make koji, thus obtaining koji material; the amount of Aspergillus oryzae added is 2-3 wt%; the amount of Monascus purpureus added is 1-2 wt%; the koji making is done by disc koji making, and the koji making time is 32-42 hours; the koji making includes a first stage koji making, a second stage koji making, and a third stage koji making. The first stage of music production specifically involves: Temperature control: The temperature of the koji material is raised to 30-32℃ for the first 30 minutes and maintained for 3 hours, and then raised to 30-34℃; the temperature is raised to 36℃ before the first turning of the koji material; the temperature difference between the upper and lower koji materials is <6℃; the disc blows internal circulating air for 3 hours, and then mixed air. Spraying begins 4 hours after koji making. The first stage of koji making takes 10-15 hours, followed by the first koji roll. The second stage of music production specifically involves: Temperature control: 32~36℃, temperature difference of koji material <6℃; air circulation is mixed air; the second stage of koji making time is 8h, and the second koji is turned 5~7h after the first koji turning. 0.08~0.2wt% of lactic acid bacteria agent is added before turning. The third stage of music production specifically involves: Temperature control: The temperature of the koji material is 29-36℃, and the temperature difference of the koji material is <5℃; D) Mix the starter culture and brine for fermentation. After preliminary fermentation, add the first antibacterial fermentation liquid and then carry out full fermentation to obtain the fermentation liquid. The fermentation temperature is 20-30℃ and the fermentation time is 120-150 days. The preparation method of the first antibacterial fermentation liquid is as follows: after pretreatment, wheat is liquefied and saccharified, then mixed with raw soy sauce, and brewing yeast and lactococcus lactis are added. Fermentation is then carried out to obtain the fermentation liquid. E) The fermentation liquid is pressed and filtered to obtain raw soy sauce; F) After sterilization of raw soy sauce, a semi-finished soy sauce product is obtained; the semi-finished soy sauce product is mixed with the second antibacterial fermentation liquid and bottled to obtain soy sauce; the preparation method of the second antibacterial fermentation liquid is as follows: after pretreatment, wheat is liquefied and saccharified and then mixed with raw soy sauce, and brewing yeast is added for fermentation to obtain soy sauce.

2. The preparation method according to claim 1, characterized in that, Step A) The wheat pretreatment specifically involves: puffing and pulverizing wheat at 300-350℃ using a wheat roasting machine to obtain wheat flour; The specific parameters of the wetting water are: a wetting water ratio of 100-120% and a wetting water temperature of 80-85℃.

3. The preparation method according to claim 1, characterized in that, Step B) refers to steaming using an FM continuous steaming device, at a temperature of 128–133°C and a pressure of 0.17–0.20 MPa for 3.5–5 minutes. The cooling process specifically refers to cooling to 40°C.

4. The preparation method according to claim 1, characterized in that, In step C), the mass ratio of cooled soybean meal to pretreated wheat is (6-8):(2-4).

5. The preparation method according to claim 1, characterized in that, The preparation method of the lactic acid bacteria inoculant: Adjust the pH of the culture medium to 7.0–7.3, sterilize at 100–120℃ for 30–60 min, cool to 35℃, inoculate with soy sauce lactic acid bacteria, and culture at 30–35℃ for 4–5 days until the cell count reaches 102. 9 The above process involves centrifugation to obtain a precipitate; the culture medium raw materials include 10-20 wt% soy sauce crude oil, 10%-30 wt% glucose, and 10-15 wt% salt. The precipitate is dried at 30-40℃ and then mixed with flour at a mass ratio of 1:10; this yields the final product.

6. The preparation method according to claim 1, characterized in that, In step D), the mass ratio of the koji and brine is 1:(1.9-2.3); the concentration of the brine is 15%-23%. The amount of the first antibacterial fermentation broth added is 5wt% to 10wt%. After adding the first antibacterial fermentation broth for 30 days, mature fermentation is carried out; the mature fermentation time is 150-180 days. The mass ratio of the semi-finished soy sauce to the second antibacterial fermentation liquid is 8:2 to 9:

1.

7. A soy sauce, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 6.

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