A soy sauce production process capable of reducing secondary precipitation of soy sauce and the soy sauce

Abstract

The present application relates to the technical field of soy sauce production, and in particular to a production process capable of reducing secondary precipitation of soy sauce and the soy sauce. The present application fully inhibits the growth of miscellaneous bacteria during koji making through a low-temperature koji making process, which can not only achieve the original fermentation requirement of koji material, but also control the decrease of spore level of koji by 2 orders of magnitude. On this basis, the oxygen-heating process is used to further precipitate macromolecular substances such as protein, polyphenol, soybean polysaccharide and soybean protease hydrolysate in the raw oil, accelerate the flocculation and precipitation of potential secondary precipitation in the soy sauce, and effectively remove the secondary precipitation by combining with the filtration process to obtain the raw oil clear liquid. Compared with the prior art, no additional clarifying agent, enzyme preparation or lactic acid bacteria and the like are needed, and only by controlling the parameter conditions in the production, the amount of secondary precipitation after 180 days is reduced by about 40% compared with the control soy sauce of the normal process.

Description

Technical Field

[0001] This invention relates to the technical field of soy sauce production, specifically to a production process and soy sauce that can reduce secondary sedimentation. Background Technology

[0002] Soy sauce is an essential condiment in people's daily lives, but currently, domestically produced high-salt, thin-state soy sauce products on the market generally suffer from significant sedimentation, seriously affecting the quality and appearance of the soy sauce. Therefore, solving the problem of secondary sedimentation in brewed soy sauce is particularly important. In recent years, many domestic soy sauce companies and related research institutions have been continuously researching how to reduce secondary sedimentation in high-salt, thin-state soy sauce, and have successively developed a variety of safe, economical, and practical clarification methods.

[0003] Interception from the perspective of filter aids: Clarifying agent method (papain, egg white liquid, gelatin): Although this method is safe and non-toxic and has a certain effect on reducing secondary sedimentation of soy sauce, it may affect the flavor of soy sauce due to the addition of foreign substances that are not original components of soy sauce. In addition, it is costly and complicated to operate.

[0004] Controlling the process from the perspective of microbial fermentation: for example, adding lactic acid bacteria, halophilic Pediococcus, and halophilic tetracoccus. This approach can reduce secondary precipitation in soy sauce to a certain extent, but it is difficult to control the fermentation in large-scale fermentation tanks for high-salt dilute soy sauce, and all of them have the ability to produce acid, which will affect the quality of soy sauce. At present, the mechanism of reducing secondary precipitation is still unclear, so large-scale application and production is still a long way off.

[0005] Controlling the fermentation process, such as the selection of raw materials and the steaming method, can reduce secondary sedimentation in soy sauce to some extent, but the effect is not significant.

[0006] Controlling the process from the perspective of fermentation equipment intervention: Currently, many soy sauce companies use sedimentation tanks specifically designed to reduce or prevent secondary sedimentation in soy sauce. Most of these tanks allow for natural sedimentation, and the supernatant is then taken for filtration and bottling. This natural sedimentation method cannot intervene to accelerate the sedimentation process, thus severely impacting soy sauce production efficiency.

[0007] In summary, while high-salt dilute soy sauce fermentation technology is now widespread, most enterprises and research institutions have not been able to completely solve the problem of secondary sedimentation in finished soy sauce products. Existing technologies all have certain drawbacks, and apart from the commonly used soy sauce settling tank, most other methods are not very practical and are still in the research stage. Therefore, it is of great significance to develop a production method that reduces secondary sedimentation in finished soy sauce products based on the current production status of soy sauce enterprises in my country. Summary of the Invention

[0008] This invention addresses the shortcomings of existing technologies by providing a low-temperature koji-making and fermentation process, combined with oxygenation and heating technology. This eliminates the need for additional enzyme preparations, microbial strains, and filter aids, thus not affecting the traditional flavor requirements of Cantonese soy sauce and improving the secondary sedimentation during the shelf life of soy sauce.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] This invention provides a production process that reduces secondary sedimentation in soy sauce, comprising the following steps:

[0011] (1) Mix the starter culture and soy sauce starter culture ingredients evenly to obtain mixed starter culture;

[0012] (2) The mixed koji material obtained in step (1) is fermented at a low temperature to obtain normal koji; the low temperature is 24-32℃ and the fermentation time is 30-40h;

[0013] (3) Ferment the Daqu obtained in step (2), and perform oil drizzling or turning operations to obtain crude soy sauce;

[0014] (4) After heating and purging the crude soy sauce obtained in step (3) with oxygen, filter it once to remove the precipitate;

[0015] (5) The product obtained after the first filtration in step (4) is mixed, sterilized, blended, filtered a second time, sterilized a second time, filled, inspected and packaged to obtain the finished soy sauce.

[0016] Preferably, the koji-making steps in step (2) are as follows: the mixed koji material obtained in step (1) is sent into the koji tank and spread out loosely. The temperature is adjusted to 24-30℃. When the temperature of the mixed koji material rises by 1-3℃, ventilation and cultivation are started. After turning the koji twice, the temperature of the mixed koji material is controlled to 24-32℃. After 30-40 hours of cultivation from when the mixed koji material enters the koji tank, the koji can be discharged to obtain the normal koji.

[0017] Preferably, the total number of colonies and spores of the normal Daqu obtained in step (2) is ≤1×10⁻⁶. 4 CFU / g, and without any burnt, discolored, or acidic koji.

[0018] Preferably, the heating temperature in step (4) is 70-90°C, the volume fraction of oxygen introduced is 15-25%, and the treatment time is 30-60 min.

[0019] Preferably, the starter culture in step (1) is prepared by the following method: wheat bran and water are mixed in a mass ratio of 1:1-1.5, and after steaming, cooling, inoculation with fermentation bacteria, and cultivation, wheat bran starter culture is obtained; wherein, the steaming conditions are steaming at 121±10℃ for 10±5min; the cooling temperature is 40±5℃; the fermentation bacteria is Aspergillus oryzae; and the inoculation amount is 1-10×10 5 1 spore / g; the culture conditions are to culture at 28±2℃ until the surface is yellow-green, and then turn the spores twice when the temperature rises to 35℃.

[0020] Preferably, the raw materials for the soy sauce koji in step (1) include soybeans and wheat flour; the soybeans need to undergo pretreatment by soaking, steaming, and cooling; wherein, during the soaking process, the mass ratio of soybeans to water is 1:1.5-2.5, and the soaking time is 12±2h; the steaming conditions are 121±10℃ for 30±5min; the cooling temperature is ≤38℃; the wheat is selected from hard white wheat varieties with hard cores, and is roasted at 90±5℃ for 15±5min to obtain roasted and crushed wheat flour into 2-3 pieces; the pretreated soybeans and wheat flour are mixed at a mass ratio of 1:0.3-0.4, steamed, and cooled to obtain the raw materials for the soy sauce koji; the koji is added at a mass of 5±2% of the soybeans.

[0021] Preferably, in step (3), the fermentation step specifically involves: adding brine to the Daqu obtained in step (2) and carrying out fermentation under normal temperature sun and dew or heat preservation; the mass concentration of the brine is 8-22%; the mass ratio of Daqu to brine is 1:1-3; the fermentation temperature is 20-30℃, and the fermentation time is 3-6 months.

[0022] Preferably, in step (5), the mixing step is as follows: adding flavoring agents, yeast extract, and preservatives to the crude soy sauce after primary filtration; the flavoring agents include one or more of edible salt, white sugar, and sucralose; the preservatives include potassium sorbate and / or sodium benzoate; the blending step is as follows:

[0023] Add spices, yeast extract and other excipients.

[0024] Preferably, in step (5), the sterilization step is: ultra-high temperature instantaneous sterilization at 121℃ for 30 minutes; the secondary sterilization step is: first heat the soy sauce to 80±5℃ for 1-2 hours, and then cool it down to 60±5℃; the secondary filtration step is: add 0.1% of diatomaceous earth by weight of the soy sauce to filter the soy sauce.

[0025] The present invention also provides a high-salt dilute soy sauce produced by the above-described production process.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] The total bacterial count and total spore count obtained by the present invention using a low-temperature koji-making process are both ≤1×10⁻⁶. 4 Normal koji material with CFU / g and no signs of burning, spoilage, or sourness is used. Low temperatures effectively inhibit the growth of unwanted microorganisms during koji making, achieving both the original fermentation requirements and controlling the spore level in the koji to decrease by two orders of magnitude. Based on this, normal sun-drying fermentation is completed. An oxygen-heating process further precipitates large molecules such as proteins, polyphenols, soybean polysaccharides, and soybean protein hydrolysates from the crude oil, accelerating the flocculation and precipitation of potential "secondary precipitation" in the soy sauce. Combined with filtration, this effectively removes these substances, resulting in a clear crude oil solution. Compared to existing technologies, this method requires no additional additions of clarifying agents, enzymes, or lactic acid bacteria. By controlling parameters during production, free, invisible molecules can effectively condense and form at the beginning of the manufacturing process, and are then removed through filtration. This effectively reduces secondary precipitation during the shelf life of the soy sauce. Soy sauce produced by this method, after 180 days of storage, shows approximately 40% less secondary precipitation than the control soy sauce produced using normal processes, and is comparable to Japanese soy sauce (stored for 180 days) in terms of secondary precipitation formation, without affecting other physicochemical, sensory, or other factors of the soy sauce. Attached Figure Description

[0028] Figure 1 This chart compares the shelf life of the case study product, the control product, and products circulating in the market. Detailed Implementation

[0029] The specific embodiments of the present invention will be further described below with reference to examples, but the implementation and protection scope of the present invention are not limited thereto.

[0030] The sensory evaluation method for soy sauce involved in this invention refers to the corresponding part of the national food safety standard GB2717-2018 for soy sauce. The method for collecting and determining the content of secondary sedimentation refers to the method of Zeng Xin'an et al. (Zeng Xin'an, Li Guoji, Yu Shujuan. Study on sedimentation components of soy sauce [J]. Food Science, 2002, 23(11): 32-34.). The secondary sedimentation collected in this invention is the secondary sedimentation after soy sauce has been stored for 180 days.

[0031] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0032] Example 1

[0033] (1) Aspergillus oryzae was used as the fermentation strain. Wheat bran was moistened (wheat bran:water mass ratio = 1:1.2), steamed (121℃ / 10min), cooled (40℃), and inoculated (5×10). 5 After culturing the bran starter (spores / g) at 28℃ in a fermentation room until the surface turns yellow-green (turn the starter twice when the temperature rises to 35℃), the prepared bran starter is ready for use.

[0034] (2) Roasted wheat: Wheat flour is made from hard white wheat from the core. It is roasted at 90℃ for 15 minutes to obtain roasted wheat that is crushed into 2-3 pieces.

[0035] (3) Soaking and steaming soybeans: Add tap water to soybeans at a ratio of 1:2 and let them soak for 12 hours to allow them to expand. After soaking, steam the soybeans (121℃ / 30min) and cool them to ≤38℃. Then, mix them thoroughly with roasted and crushed wheat flour (2-3 pieces) at a ratio of 1:0.36 with the bran starter obtained in step (1) (the bran starter is added at 5% of the soybean mass) to obtain the mixed starter.

[0036] (4) Low-temperature koji making: The koji making time is 35 hours. The mixed koji material obtained in step (3) is sent into the koji tank and spread out loosely. The temperature is adjusted to 24℃. The spore germination period is 4-6 hours after the koji material enters the tank. When the temperature rises to 27℃, ventilation is started. After the first and second turning of the koji, the temperature is maintained at 27℃. After 4-6 hours, the koji material loses water and cracks. The koji should be removed in time. The enzyme activity reaches its peak 35 hours after the koji material enters the tank. At this time, the koji can be removed and the total number of colonies and the total number of spores are ≤1×10. 4 Large-grain koji with CFU / g that exhibits no burning, bleaching, or acidification.

[0037] (5) Sun-drying of sauce mash: After the Daqu obtained in step (4) is put into the tank or pool, salt water is added for fermentation under normal temperature sun and night dew or heat preservation fermentation (20℃). The salt water concentration is 18wt%, and the mass ratio of Daqu to salt water is 1:1.5. During the fermentation period, oil is sprayed or the mash is turned as needed. The tank is closed and naturally sun-dried for 6 months to obtain crude oil.

[0038] (6) Oxygen heating: Heat the dried crude oil to 70°C and simultaneously introduce 20% oxygen by volume for 30 minutes.

[0039] (7) Filtration: The turbid crude oil is coated and filtered once to remove precipitated and free substances such as protein macromolecules.

[0040] (8) Preparation: Prepare the crude oil after primary filtration by adding edible salt, white sugar, yeast extract, sucralose, potassium sorbate or sodium benzoate as needed to meet the requirements of product quality, flavor and shelf life.

[0041] (9) Sterilization: The mixed oil is subjected to ultra-high temperature instantaneous sterilization at 121℃ for 30min to kill microorganisms such as colonies and spores in the mixed oil.

[0042] (10) Filtration: After heating and clarifying, the soy sauce is filtered through diatomaceous earth (0.1% of the mass of soy sauce). The filtered soy sauce is then filtered a second time to remove microbial precipitates.

[0043] (11) Blending: After the second filtration is completed, spices, yeast extract and other auxiliary materials are added to the mixed oil to obtain the finished soy sauce;

[0044] (12) Heating and cooling: The finished soy sauce is heated to 80°C for sterilization again, then kept warm for 1 hour and then cooled to 60°C before filling.

[0045] (13) Filling, inspection and packaging: After filling, the soy sauce is tested for routine indicators. If it passes the test, it is packaged as a finished product.

[0046] Example 2

[0047] (1) Aspergillus oryzae was used as the fermentation strain. Wheat bran was moistened (wheat bran:water mass ratio = 1:1.2), steamed (121℃ / 10min), cooled (40℃), and inoculated (5×10). 5 After culturing the bran starter (spores / g) at 28℃ in a fermentation room until the surface turns yellow-green (turn the starter twice when the temperature rises to 35℃), the prepared bran starter is ready for use.

[0048] (2) Roasted wheat: Wheat flour raw material is made from hard white wheat from the core. It is roasted at 90℃ for 15 minutes to obtain roasted wheat that is crushed into 2-3 pieces.

[0049] (3) Soaking and steaming soybeans: Add tap water to soybeans at a ratio of 1:2 and let them soak for 12 hours to allow them to expand. After soaking, steam the soybeans (121℃ / 30min) and cool them to ≤38℃. Then, mix them thoroughly with roasted and crushed wheat flour (in 2-3 pieces) at a ratio of 1:0.36 with the bran starter obtained in step (1) (the bran starter is added at 5% of the soybean mass) to obtain the mixed starter.

[0050] (4) Low-temperature koji making: The koji making time is 35 hours. The mixed koji material obtained in step (3) is sent into the koji tank and spread out loosely. The temperature is adjusted to 26℃. The spore germination period is 4-6 hours after the koji material enters the tank. When the temperature rises to 28℃, ventilation is started. After the first and second turning of the koji, the temperature is maintained at 30℃. After 4-6 hours, the koji material loses water and cracks. The koji should be removed in time. The enzyme activity reaches its peak 35 hours after the koji material enters the tank. At this time, the koji can be removed and the total number of colonies and spores is ≤1×10. 4 Large-grain starter with CFU / g that exhibits no burning, bleaching, or acidic phenomena.

[0051] (5) Sun-drying of fermented mash: After the Daqu obtained in step (4) is put into the tank or pool, salt water is added for fermentation under normal temperature sun and night dew or heat preservation fermentation (26℃). The salt water concentration is 18wt%, and the mass ratio of Daqu to salt water is 1:1.5. During the fermentation period, oil is sprayed or the mash is turned as needed. The tank is closed and naturally sun-dried for 180 days to obtain crude oil.

[0052] (6) Oxygen heating: Heat the dried crude oil to 70°C and simultaneously introduce 20% oxygen by volume for 60 minutes.

[0053] (7) Filtration: The turbid crude oil is coated and filtered once to remove precipitated and free substances such as protein macromolecules.

[0054] (8) Preparation: Prepare the crude oil after primary filtration by adding edible salt, white sugar, yeast extract, sucralose, potassium sorbate or sodium benzoate as needed to meet the requirements of product quality, flavor and shelf life.

[0055] (9) Sterilization: The mixed oil is subjected to ultra-high temperature instantaneous sterilization at 121℃ for 30 minutes to kill microorganisms such as total number of colonies and total number of spores in the mixed oil.

[0056] (10) Filtration: Filter the soy sauce through diatomaceous earth (0.1% of the mass of soy sauce). After filtration, the soy sauce is filtered a second time to remove microbial precipitates.

[0057] (11) Blending: After the second filtration is completed, spices, yeast extract and other auxiliary materials are added to the mixed oil to obtain the finished soy sauce;

[0058] (12) Heating and cooling: The finished soy sauce is heated to 80°C for sterilization again, then kept warm for 1 hour and then cooled to 60°C before filling.

[0059] (13) Filling, inspection and packaging: After filling, the soy sauce is tested for routine indicators. If it passes the test, it is packaged as a finished product.

[0060] Example 3

[0061] (1) Aspergillus oryzae was used as the fermentation strain. The wheat bran was moistened with water (wheat bran:water mass ratio = 1:1.2), steamed (121℃ / 10min), cooled (40℃), and inoculated (5×105 spores / g). It was then cultured in a fermentation room at 28℃ until the surface turned yellow-green (the fermentation was turned twice when the temperature rose to 35℃). The prepared wheat bran starter was ready for use.

[0062] (2) Soaking and steaming soybeans: Add tap water to soybeans at a mass ratio of 1:2 and let them soak for 12 hours to allow them to expand. After soaking, steam the soybeans (121℃ / 30min) and cool them to ≤34℃. Then, mix them thoroughly with ordinary wheat flour at a mass ratio of 1:0.36 and with the bran starter obtained in step (1) (the bran starter accounts for 5% of the mass of the soybeans) to obtain the mixed starter.

[0063] (3) Low-temperature koji making: The koji making time is 35 hours. The mixed koji material obtained in step (2) is sent into the koji tank and spread out loosely. The temperature is adjusted to 29℃. The spore germination period is 4-6 hours after the koji material enters the tank. When the temperature rises to 30℃, ventilation is started. After the first and second turning of the koji, the temperature is maintained at 30℃. After 4-6 hours, the koji material loses water and cracks. The koji should be removed in time. The enzyme activity reaches its peak 35 hours after the koji material enters the tank. At this time, the koji can be removed and the total number of colonies and spores is ≤1×10. 4 Large-grain starter with CFU / g that exhibits no burning, bleaching, or acidic phenomena.

[0064] (4) Sun-drying of fermented mash: After the Daqu obtained in step (3) is put into the tank or pool, salt water is added for fermentation under normal temperature sun and night dew or heat preservation fermentation (26℃). The salt water concentration is 18wt%, and the mass ratio of Daqu to salt water is 1:1.5. During the fermentation period, oil is sprayed or the mash is turned as needed. The tank is closed and naturally sun-dried for 180 days to obtain crude oil.

[0065] (5) Oxygen heating: Heat the dried crude oil to 80°C and simultaneously introduce 20% oxygen by volume for 30 minutes.

[0066] (6) Filtration: The turbid crude oil is filtered once to remove precipitates and free substances such as protein macromolecules.

[0067] (7) Preparation: Prepare the crude oil after primary filtration by adding edible salt, white sugar, yeast extract, sucralose, potassium sorbate or sodium benzoate as needed to meet the requirements of product quality, flavor and shelf life.

[0068] (8) Sterilization: The mixed oil is subjected to ultra-high temperature instantaneous sterilization at 121℃ for 30 minutes to kill microorganisms such as total number of colonies and total number of spores in the mixed oil.

[0069] (9) Filtration: After heating and clarifying, the soy sauce is filtered through diatomaceous earth (0.1% of the mass of the soy sauce). The filtered soy sauce is then filtered a second time to remove microbial precipitates.

[0070] (10) Blending: After the second filtration is completed, add the appropriate proportions of spices, yeast extract and other auxiliary materials to the mixed oil to obtain the finished soy sauce;

[0071] (11) Heating and cooling: The finished soy sauce is heated to 80°C for sterilization again, then kept warm for 1 hour and then cooled to 60°C before filling.

[0072] (12) Filling, inspection and packaging: After filling, the soy sauce is tested for routine indicators. If it passes the test, it is packaged as a finished product.

[0073] Example 4

[0074] (1) Aspergillus oryzae was used as the fermentation strain. Wheat bran was moistened (wheat bran:water mass ratio = 1:1.2), steamed (121℃ / 10min), cooled (40℃), and inoculated (5×10). 5 After culturing the bran starter (spores / g) at 28℃ in a fermentation room until the surface turns yellow-green (turn the starter twice when the temperature rises to 35℃), the prepared bran starter is ready for use.

[0075] (2) Roasted wheat: Wheat flour is made from hard white wheat from the core. It is roasted at 90℃ for 15 minutes to obtain roasted wheat that is crushed into 2-3 pieces.

[0076] (3) Soaking and steaming soybeans: Add tap water to soybeans at a mass ratio of 1:2 and let them soak for 12 hours to allow them to expand. After soaking, steam the soybeans (121℃ / 30min) and cool them to ≤34℃. Then, mix them thoroughly with ordinary wheat flour at a mass ratio of 1:0.36 and with the bran starter obtained in step (1) (the bran starter accounts for 5% of the mass of the soybeans) to obtain the mixed starter.

[0077] (4) Low-temperature koji making: The koji making time is 35 hours. The mixed koji material obtained in step (3) is sent into the koji tank and spread out loosely. The temperature is adjusted to 30℃. The spore germination period is 4-6 hours after the koji material enters the tank. When the temperature rises to 31℃, ventilation is started. After the first and second turning of the koji, the temperature is maintained at 32℃. After 4-6 hours, the koji material loses water and cracks. The koji should be removed in time. The enzyme activity reaches its peak 35 hours after the koji material enters the tank. At this time, the koji can be removed and the total number of spores is ≤1×10. 4 Large-grain koji with CFU / g that exhibits no burning, bleaching, or acidification.

[0078] (5) Sun-drying of fermented mash: After the Daqu obtained in step (4) is put into the tank or pool, salt water is added for fermentation under normal temperature sun and night dew or heat preservation fermentation (26℃). The salt water concentration is 18wt%, and the mass ratio of Daqu to salt water is 1:1.5. During the fermentation period, oil is sprayed or the mash is turned as needed. The tank is closed and naturally sun-dried for 180 days to obtain crude oil.

[0079] (6) Oxygen heating: Heat the dried crude oil to 80°C and simultaneously introduce 20% oxygen by volume for 30 minutes.

[0080] (7) Filtration: The turbid crude oil is filtered once to remove precipitates and free substances such as protein macromolecules.

[0081] (8) Preparation: Prepare the crude oil after primary filtration by adding edible salt, white sugar, yeast extract, sucralose, potassium sorbate or sodium benzoate as needed to meet the requirements of product quality, flavor and shelf life.

[0082] (9) Sterilization: The mixed oil is subjected to ultra-high temperature instantaneous sterilization at 121℃ for 30 minutes to kill microorganisms such as total number of colonies and total number of spores in the mixed oil.

[0083] (10) Filtration: After heating and clarifying, the soy sauce is filtered through diatomaceous earth (0.1% of the mass of the soy sauce). The filtered soy sauce is then filtered a second time to remove microbial precipitates.

[0084] (11) Blending: After completing the second filtration, add the appropriate proportions of spices, yeast extract and other auxiliary materials to the mixed oil to obtain the finished soy sauce;

[0085] (12) Heating and cooling: The finished soy sauce is heated to 80°C for sterilization again, then kept warm for 1 hour and then cooled to 60°C before filling.

[0086] (13) Filling, inspection and packaging: After filling, the soy sauce is tested for routine indicators. If it passes the test, it is packaged as a finished product.

[0087] Control group 1

[0088] (1) Aspergillus oryzae was used as the fermentation strain. Wheat bran was moistened (wheat bran:water mass ratio = 1:1.2), steamed (121℃ / 10min), cooled (40℃), and inoculated (5×10). 5 After culturing the bran starter (spores / g) at 28℃ in a fermentation room until the surface turns yellow-green (turn the starter twice when the temperature rises to 35℃), the prepared bran starter is ready for use.

[0089] (2) Roasted wheat: Wheat flour is made from hard white wheat from the core. It is roasted at 90℃ for 15 minutes to obtain roasted wheat that is crushed into 2-3 pieces.

[0090] (3) Soaking and steaming soybeans: Add tap water to soybeans at a ratio of 1:2 and let them soak for 12 hours to allow them to expand. After soaking, steam the soybeans (121℃ / 30min) and cool them to ≤34℃. Then, mix them thoroughly with roasted and crushed wheat (2-3 pieces) at a ratio of 1:0.36 and with the bran starter obtained in step (1) (the bran starter is added at 5% of the soybean mass) to obtain the mixed starter.

[0091] (4) High-temperature koji making: The koji making time is 40 hours. The mixed koji material obtained in step (3) is loosely spread in the koji tank. The temperature is 35℃. The spore germination period is 4-6 hours after the koji material enters the tank. When the temperature rises to 38℃, ventilation is started. After the first and second turning of the koji, the temperature is maintained at 38℃. After 4-6 hours, the koji material loses water and cracks. The koji should be scraped in time. The enzyme activity reaches its peak 40 hours after the koji material enters the tank. At this time, the koji can be removed and the large koji can be obtained. At this time, the total number of spores is 3×10. 5 CFU / g.

[0092] (5) Sun-drying of soy sauce mash: After Daqu is put into the tank or pool, salt water is added for fermentation at room temperature under the sun and at night under the dew or for heat preservation fermentation (26℃). The salt water concentration is 18wt%, and the mass ratio of Daqu to salt water is 1:1.5. During the fermentation period, oil is sprayed or the mash is turned over as needed. The tank is closed and naturally sun-dried for 180 days to obtain crude oil.

[0093] (6) Preparation: The crude oil is prepared by adding edible salt, white sugar, etc. as needed to meet the requirements of product quality, flavor and shelf life.

[0094] (7) Sterilization and filtration: The mixed oil is subjected to ultra-high temperature instantaneous sterilization at 121℃ for 30 minutes to kill microorganisms such as total bacterial count and total spore count in the mixed oil. After heating, the soy sauce is allowed to cool naturally, then clarified at room temperature for 7 days, and then filtered through diatomaceous earth (0.1% of the soy sauce mass).

[0095] (8) Blending: After filtration, spices, yeast extract and other auxiliary materials are added to the mixed oil to obtain the finished soy sauce;

[0096] (9) Heating and cooling: The finished soy sauce is heated to 80°C for sterilization again, then kept warm for 1 hour and then cooled to 60°C before filling.

[0097] (10) Filling, inspection and packaging: After filling, the soy sauce is tested for routine indicators. If it passes the test, it is packaged as a finished product.

[0098] Control group 2

[0099] (1) Aspergillus oryzae was used as the fermentation strain. Wheat bran was moistened (wheat bran:water mass ratio = 1:1.2), steamed (121℃ / 10min), cooled (40℃), and inoculated (5×10). 5 After culturing the bran starter (spores / g) at 28℃ in a fermentation room until the surface turns yellow-green (turn the starter twice when the temperature rises to 35℃), the prepared bran starter is ready for use.

[0100] (2) Roasted wheat: Wheat flour is made from hard white wheat from the core. It is roasted at 90℃ for 15 minutes to obtain roasted wheat that is crushed into 2-3 pieces.

[0101] (3) Soaking and steaming soybeans: Add tap water to soybeans at a ratio of 1:2 and let them soak for 12 hours to allow them to expand. After soaking, steam the soybeans (121℃ / 30min) and cool them to ≤34℃. Then, mix them thoroughly with roasted and crushed wheat (2-3 pieces) at a ratio of 1:0.36 and with the bran starter obtained in step (1) (the bran starter is added at 5% of the soybean mass) to obtain the mixed starter.

[0102] (4) High-temperature koji making: The koji making time is 40 hours. After inoculation, the koji material is placed loosely and evenly in the koji tank. The temperature is 33℃. The spore germination period is 4-6 hours after the koji material enters the tank. When the temperature rises to 40℃, ventilation is started. After the first and second turning of the koji, the temperature is maintained at 40℃. After 4-6 hours, the koji material loses water and cracks. It is necessary to remove the koji in time. The enzyme activity reaches its peak 40 hours after the koji material enters the tank. At this time, the koji can be removed and the large koji can be obtained.

[0103] (5) Sun-drying of sauce mash: After Daqu is put into the tank or pool, salt water is added for fermentation under normal temperature sun and night dew or heat preservation fermentation (40℃). The salt water concentration is 14wt%, and the mass ratio of Daqu to salt water is 1:2. During the fermentation period, oil is sprayed or mash is turned as needed. The tank is closed and naturally sun-dried for 180 days to obtain crude oil.

[0104] (6) Preparation: The crude oil is prepared by adding edible salt, white sugar, etc. as needed to meet the requirements of product quality, flavor and shelf life.

[0105] (7) Sterilization and filtration: The mixed oil is subjected to ultra-high temperature instantaneous sterilization at 121℃ for 30 minutes to kill microorganisms such as total bacterial count and total spore count in the mixed oil. After heating, the soy sauce is allowed to cool naturally, then clarified at room temperature for 7 days, and then filtered through diatomaceous earth (0.1% of the soy sauce weight).

[0106] (8) Blending: After filtration, spices, yeast extract and other auxiliary materials are added to the mixed oil to obtain the finished soy sauce;

[0107] (9) Heating and cooling: The finished soy sauce is heated to 80°C for sterilization again, then kept warm for 1 hour and then cooled to 60°C before filling.

[0108] (10) Filling, inspection and packaging: After filling, the soy sauce is tested for routine indicators. If it passes the test, it is packaged as a finished product.

[0109] Implementation effect comparison

[0110] The research team also tested the above four examples and three commercially available products (the top three sellers on Tmall, all of which are premium-grade, high-salt, thin-state soy sauces) under single-variable conditions using the same detection method, and conducted secondary precipitation observations during shelf life under the same sample retention environment.

[0111] 1. Zero additives

[0112] No additional enzymes or filter aids were added. The research focused solely on improving the process design by increasing oxygenation, heating, and adjusting the fermentation temperature. This had no impact on the original flavor and performance requirements of the product.

[0113] 2. Product flavor

[0114] The physicochemical, microbiological, and sensory indicators of the examples showed no significant differences compared with the control group.

[0115] 3. Product turbidity and sedimentation

[0116] The turbidity of all examples was <20, and no precipitation was found, which showed a significant advantage compared with the control group. In contrast, commercially available products 2 and 3 showed varying degrees of turbidity and precipitation.

[0117] Table 1. Testing results of products, control products, and products circulating in the market in the implementation case.

[0118]

[0119] Table 2. Testing Basis

[0120] 1 Total acid GB 12456-2021 2 amino acid nitrogen GB / T 18186-2000 3 Sodium chloride GB / T 5009.39-200 4 Sedimentation After rinsing a 10ml test tube with a soy sauce sample, fill the test tube completely, centrifuge, and then visually observe the precipitation inside the test tube. 5 Turbidity / 6 Total bacterial count GB 4789.2-2022 7 Sensory measurement GB / T 5492

[0121] The products from the implementation case were grouped into groups of 10, while the control group retained 10 products per group, and the commercially available products retained 5 products per group. All products were stored on a sample shelf, and the shelf life of the products was observed regularly. The sediment at the bottom of the soy sauce bottles was observed with a strong flashlight, the thickness of the sediment was measured, and photos were taken for record-keeping.

[0122] The samples were observed at room temperature for 360 days. On the 30th, 60th, 120th, 180th and 360th days, a fixed slope support was used to check the sedimentation at the bottom of each retained sample.

[0123] As shown in Table 3, none of the 40 samples in Examples 1, 2, 3, and 4 showed any precipitation after being stored on the shelf for 360 days. In contrast, the control group and commercially available products 2 and 3, under the same storage conditions, showed varying degrees of precipitation after being stored on the shelf for 30 days.

[0124] Table 3 Comparison of shelf life of products in the implementation case, control products, and products circulating in the market.

[0125]

[0126] This invention can be summarized in other specific forms that do not depart from the spirit or main features of the invention. The above embodiments of the invention are merely illustrative and not restrictive. Therefore, any minor modifications, equivalent variations, and alterations made to the above embodiments based on the essential technology of this invention fall within the scope of the invention's technical solution.

Claims

1. A production process for reducing secondary sedimentation in soy sauce, characterized in that, Includes the following steps: (1) Mix the starter culture and soy sauce starter culture ingredients evenly to obtain mixed starter culture ingredients; (2) The mixed koji material obtained in step (1) is sent into the koji tank and spread out loosely. The temperature is adjusted to 24-30℃. When the temperature of the mixed koji material rises by 1-3℃, ventilation and cultivation are started. After turning the koji twice, the temperature of the mixed koji material is controlled to 27-32℃. After 30-35 hours of cultivation from when the mixed koji material enters the koji tank, the koji can be discharged and the large koji can be obtained. The total number of colonies and spores of the obtained normal Daqu (fermented starter culture) is ≤1×10⁻⁶. 4 CFU / g, and there are no signs of burnt koji, flower koji, or acidic koji; (3) Ferment the Daqu obtained in step (2), and perform oiling or turning operations to obtain crude soy sauce; (4) After heating and purging the crude soy sauce obtained in step (3), filter it once to remove the precipitate; the heating temperature is 70-90℃, the volume fraction of oxygen is 15-25%, and the treatment time is 30-60min. (5) The product obtained after the first filtration in step (4) is mixed, sterilized, blended, filtered a second time, sterilized a second time, filled, inspected and packaged to obtain the finished soy sauce.

2. The production process according to claim 1, characterized in that, The starter culture mentioned in step (1) is prepared by the following method: wheat bran and water are mixed in a mass ratio of 1:1-1.5, and after steaming, cooling, inoculation with fermentation bacteria, and cultivation, wheat bran starter culture is obtained; The cooking conditions are as follows: cooking at 121±10℃ for 10±5 min; cooling temperature is 40±5℃; the fermentation strain is Aspergillus oryzae; and the inoculation amount is 1-10×10⁻⁶. 5 1 spore / g; the culture conditions are to culture at 28±2℃ until the surface is yellow-green, and then turn the spores twice when the temperature rises to 35℃.

3. The production process according to claim 1, characterized in that, The raw materials for the soy sauce starter in step (1) include soybeans and wheat flour; The soybeans need to undergo pretreatment including soaking, steaming, and cooling; wherein, during the soaking process, the mass ratio of soybeans to water is 1:1.5-2.5, and the soaking time is 12±2 hours; the steaming conditions are 121±10℃ for 30±5 minutes; and the cooling temperature is ≤38℃. The wheat selected is a hard white wheat variety with a core portion. It is roasted at 90±5℃ for 15±5 minutes to obtain roasted and crushed wheat flour into 2-3 pieces. Pretreated soybeans and wheat flour are mixed in a mass ratio of 1:0.3-0.4, steamed and cooled to obtain the raw material for the soy sauce koji. The amount of koji added is 5 ± 2% of the weight of soybeans.

4. The production process according to claim 1, characterized in that, In step (3), the fermentation step specifically involves adding salt water to the Daqu obtained in step (2) and carrying out fermentation under normal temperature sun and dew or fermentation under heat. The mass concentration of the brine is 8-22%; The mass ratio of the Daqu (a type of starter culture) to the brine is 1:1-3; The fermentation temperature is 20-30℃, and the fermentation time is 3-6 months.

5. The production process according to claim 1, characterized in that, In step (5), the mixing step is as follows: adding flavoring agent, yeast extract and preservative to the crude soy sauce after one filtration; the flavoring agent includes one or more of edible salt, white sugar and sucralose; the preservative includes potassium sorbate and / or sodium benzoate. The preparation steps are as follows: adding excipients, including spices and yeast extract.

6. The production process according to claim 1, characterized in that, In step (5), the sterilization step is: performing ultra-high temperature instantaneous sterilization at 121°C for 30 minutes; The secondary sterilization step is as follows: first heat the soy sauce to 80±5℃ for 1-2 hours, then lower it to 60±5℃; The secondary filtration step is as follows: add 0.1% diatomaceous earth by weight of the soy sauce to filter the soy sauce.

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