Method for improving utilization rate of soy sauce raw materials

Abstract

The invention relates to the technical field of food fermentation and brewing, and particularly discloses a method for increasing the utilization rate of soy sauce raw materials. The ultrasonic technology and the negative pressure cooking technology are combined, low-temperature cooking of the soybeans and moderate denaturation of protein are achieved, a porous structure is formed, effective utilization of the soybean raw materials by aspergillus oryzae is promoted, the cooking time is effectively shortened, and starter propagation quality and the utilization rate of the raw materials are improved. Soybean raw materials are subjected to ultrasonic treatment, so that the structure of the soybean raw materials is destroyed, favorable conditions are created for subsequent negative-pressure cooking, and the cooking time is shortened; through a low-temperature negative-pressure cooking technology, the protein is moderately denatured to form a loose and porous structure, the utilization of the mold starter on the protein is improved, the nutrient loss caused by excessive denaturation of the protein and Maillard reaction is effectively avoided, and the utilization rate of the raw materials is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of food fermentation and brewing, and particularly relates to a method for improving utilization rate of soy sauce raw materials. BACKGROUND

[0002] Soy sauce is a traditional Chinese liquid seasoning, which is mainly made from raw materials such as soybeans, wheat or bran, etc. through processes such as steaming, inoculation, koji making and fermentation. The color of soy sauce is reddish brown, and it has a unique sauce fragrance and delicious taste, which can significantly stimulate appetite.

[0003] Koji making is a key link in soy sauce production, and its core lies in the degradation and transformation of raw materials by microorganisms and their secreted enzyme systems. The quality of koji directly affects the quality of soy sauce, and is related to the fermentation efficiency and yield in the later period, and determines the utilization rate of raw materials. Improving the utilization rate of soy sauce raw materials means that more soy sauce can be produced with the same amount of raw materials, directly reducing the raw material cost per unit product, so the research on improving the utilization rate of soy sauce raw materials is of great significance.

[0004] In the preparation of soy sauce, soybean steaming is one of the most critical pretreatment links that determine the final quality, flavor and yield of soy sauce. After steaming, the protein is denatured, and more peptide bonds are exposed, so that proteases can act on specific sites and cut them into amino acids and small peptides. If the protein denaturation is not enough, enzyme hydrolysis will be difficult; if the steaming is too much, the protein will be over-entangled and hardened, which is also difficult to be hydrolyzed. Therefore, the moderate denaturation of protein is the core of the steaming process, which directly affects the total nitrogen utilization rate and the generation of amino acids of soy sauce. The high temperature and pressure of traditional high-pressure steaming technology will make the protein molecules overstretch and entangle with each other, forming a dense and hard network structure, affecting the effective decomposition of proteases secreted by Aspergillus oryzae, and in addition, high temperature will also destroy the natural enzyme system and flavor precursors of soybeans.

[0005] The negative pressure steaming technology reduces the internal gas pressure by vacuumizing, so that the boiling point of water is reduced. Then steam is introduced to steam the soybeans at low temperature. The core advantage lies in the fact that the protein is moderately denatured at low temperature, forming a loose and porous structure, and the proteases secreted by Aspergillus oryzae can more efficiently decompose it into amino acids, thereby effectively improving the utilization rate of raw materials. In addition, negative pressure steaming reduces the use of steam and energy consumption, which meets the current trend of green production, but the negative pressure steaming technology has the problems of relatively long steaming time and the need for precise control of vacuum degree (which determines the boiling point), temperature and time, etc., which limits the application of negative pressure steaming technology. Therefore, the research and application of negative pressure steaming technology in soybean steaming for soy sauce has great significance. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of the prior art and provide a method for improving the utilization rate of soy sauce raw materials.

[0007] To achieve the above objectives, the technical solution adopted in this application is as follows: This application provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: S1. After removing impurities from the soybeans, add water and soak them. Then, ultrasonically treat the soaked soybeans and steam them under negative pressure to obtain cooked soybeans. Cool them down. S2. Take wheat, roast it, cool it and then grind it to obtain roasted wheat. Mix the roasted wheat into cooled cooked beans, inoculate it with Aspergillus oryzae to make koji and obtain koji material. S3. Mix the starter culture with brine for high-salt dilute fermentation, then press and filter to obtain soy sauce.

[0008] This application is the first to use negative pressure cooking technology in the pretreatment of raw materials for soy sauce koji making. In the raw material processing stage, soybeans are treated with ultrasound. The ultrasound mainly uses microscopic physical damage to the soybeans to promote the faster penetration of water and heat into the soybeans. This effectively reduces the cooking time of the low-temperature negative pressure cooking technology, improves the problems of excessive cooking time and insufficient protein denaturation in negative pressure cooking technology, and thus improves the utilization rate of raw materials.

[0009] In this application, the technical solution primarily utilizes a combination of ultrasonic treatment and negative pressure cooking to achieve moderate denaturation of soybean protein, forming a porous structure. This promotes the effective utilization of soybean raw materials by Aspergillus oryzae, thereby improving the quality of koji production and the utilization rate of raw materials. The soybeans are first ultrasonically treated to achieve "pre-destruction" and "penetration enhancement," creating highly favorable conditions for subsequent negative pressure cooking. After ultrasonic treatment, moisture and heat can penetrate the soybean raw material more quickly and deeply through these microporous channels, thus shortening the cooking time and improving cooking uniformity. Subsequent negative pressure cooking gently denatures the protein and gelatinizes the starch, maximizing the preservation of flavor and nutrients. The combination of these two technologies results in a more porous and uniform physical structure of the soybean raw material, allowing the mycelium to penetrate the raw material particles more deeply, leading to more vigorous and uniform growth. This results in koji with a richer enzyme system and more stable quality, improving the utilization rate of soy sauce raw materials. This application combines ultrasonic technology with negative pressure cooking technology to improve problems such as long negative pressure cooking time and insufficient degree of denaturation, thereby achieving low-temperature cooking of soybean raw materials.

[0010] In a preferred embodiment of the method for improving the utilization rate of soy sauce raw materials described in this application, in step S1, the weight ratio of soybeans to water is 1:(1.5~1.7), preferably, the weight ratio of soybeans to water is 1.6; And / or, the soaking time is 5 to 6 hours.

[0011] As a preferred embodiment of the method for improving the utilization rate of soy sauce raw materials described in this application, the ultrasonic treatment conditions are: ultrasonic temperature of 30℃~50℃, ultrasonic frequency of 20kHz~40kHz, and ultrasonic time of 10 min~30 min.

[0012] This application primarily utilizes a combination of ultrasonic and negative pressure cooking technologies to achieve low-temperature cooking and moderate protein denaturation of soybeans, creating a porous structure. This promotes the effective utilization of soybean raw materials by Aspergillus oryzae and significantly shortens cooking time, thereby improving koji quality and raw material utilization. Ultrasonic treatment of soybean raw materials disrupts their structure, creating favorable conditions for subsequent negative pressure cooking and shortening cooking time. Negative pressure cooking technology moderately denatures proteins, forming a loose, porous structure, enhancing koji's utilization of protein and effectively preventing nutrient loss caused by excessive protein denaturation and Maillard reactions, thus improving raw material utilization.

[0013] Before steaming the soybeans, the soaked soybeans are subjected to ultrasonic treatment within the above parameter range to "pre-destroy" them, effectively breaking down the cell walls of the plant cells and forming micropores. Water and heat can penetrate into the raw material more quickly and deeply through these micropores, greatly improving mass and heat transfer efficiency, creating favorable conditions for subsequent negative pressure steaming, and shortening the steaming time.

[0014] In a preferred embodiment of the method for improving the utilization rate of soy sauce raw materials described in this application, the negative pressure condition in step S1 is as follows: The temperature is 60℃~80℃, and the pressure is -0.081 MPa~-0.054 MPa.

[0015] This application replaces traditional high-temperature and high-pressure cooking with low-temperature negative pressure cooking. By employing this low-temperature negative pressure cooking technology, appropriate denaturation of proteins can be achieved, forming a loose and porous structure, thereby effectively improving raw material utilization. This application achieves this by controlling the low-temperature negative pressure cooking method and reducing the cooking time.

[0016] This application employs a low-temperature negative pressure cooking method, supplemented by an ultrasonic method. The ultrasonic method effectively disrupts the structure of soybeans, reducing the problems of excessively long negative pressure cooking time or insufficient denaturation of soybean protein.

[0017] In a preferred embodiment of the method for improving the utilization rate of soy sauce raw materials described in this application, the steaming time in step S1 is 25 min to 50 min.

[0018] Soybean raw materials are steamed at relatively low temperatures (60℃~80℃), causing moderate protein denaturation and forming a loose, porous structure. This allows mycelia to penetrate the raw material particles more deeply, resulting in more vigorous and uniform growth and improved protein utilization by the inoculum. Combined with ultrasonic technology, this effectively enhances the uniformity of steaming and the efficiency of raw material pretreatment.

[0019] In a preferred embodiment of the method for improving the utilization rate of soy sauce raw materials described in this application, in step S2, the mass ratio of soybeans to wheat is (5.5~7.5):(2.5~4.5), preferably, the mass ratio of soybeans to wheat is 6:4.

[0020] In a preferred embodiment of the method for improving the utilization rate of soy sauce raw materials described in this application, in step S2, the inoculation amount of Aspergillus oryzae is 0.1% to 0.4%, preferably, the inoculation amount of Aspergillus oryzae is 0.3%.

[0021] Using the above-mentioned inoculum amount of Aspergillus oryzae, the protease secreted by Aspergillus oryzae can effectively decompose the raw materials and improve the utilization rate of the raw materials.

[0022] As a preferred embodiment of the method for improving the utilization rate of soy sauce raw materials described in this application, in step S2, the conditions for koji making are: initial relative humidity of 90%~95%, koji making time of 35 h~46 h, preferably, koji making time of 38 h.

[0023] In a preferred embodiment of the method for improving the utilization rate of soy sauce raw materials described in this application, in step S3, the salt concentration of the brine is 18%~23%, preferably 20%; And / or, the volume ratio of koji to brine is 1:(1.4~2.3), preferably, the volume ratio of koji to brine is 1.8.

[0024] In a preferred embodiment of the method for improving the utilization rate of soy sauce raw materials described in this application, in step S3, the fermentation temperature is 31℃~38℃ and the fermentation time is 45 days~70 days. Preferably, the fermentation temperature is 35℃ and the fermentation time is 60 days.

[0025] In a preferred embodiment of the method for improving the utilization rate of soy sauce raw materials described in this application, in step S3, the filtrate of the pressed and filtered soy mash is collected and heated at 65°C for 5 hours to obtain soy sauce.

[0026] The method provided in this application has the following advantages: 1) Moderate protein denaturation improves raw material utilization: The method provided in this application avoids the excessive denaturation of proteins caused by traditional high pressure and high temperature, which forms a dense and hard network structure; moderate protein denaturation allows the protease secreted by Aspergillus oryzae to effectively decompose raw materials and improve the utilization rate of raw materials.

[0027] 2) Retaining more flavor precursors and nutrients: The method provided in this application avoids the burnt taste and unpleasant odor produced by high temperature, while better preserving the natural sugars and amino acids in soybeans, providing richer substrates for the Maillard reaction in subsequent fermentation.

[0028] 3) Improve the uniformity of steaming and avoid the phenomenon of "overcooked on the outside and undercooked on the inside": The method provided in this application avoids the problem of uneven steaming of soybeans caused by local high temperature due to traditional high temperature and high pressure steaming.

[0029] 4) Shorten cooking time and effectively improve cooking efficiency: The combination of ultrasonic technology and low-temperature cooking effectively destroys the cell walls of plant cells, forming micropores and greatly improving mass and heat transfer efficiency. This also shortens the cooking time of negative pressure cooking technology.

[0030] 5) Energy saving and consumption reduction, in line with the trend of green production: negative pressure cooking technology reduces cooking time, and the combined use of ultrasonic technology shortens the cooking time, significantly reducing energy consumption.

[0031] Compared with the prior art, this application has the following beneficial effects: This application provides a method for improving the utilization rate of soy sauce raw materials. This method primarily utilizes a combination of ultrasonic technology and negative pressure cooking technology to achieve low-temperature cooking of soybeans and moderate protein denaturation, forming a porous structure. This promotes the effective utilization of soybean raw materials by Aspergillus oryzae and effectively shortens the cooking time, thereby improving the quality of koji production and the utilization rate of raw materials. Ultrasonic treatment of soybean raw materials disrupts their structure, creating favorable conditions for subsequent negative pressure cooking and shortening the cooking time. Low-temperature negative pressure cooking technology moderately denatures the protein, forming a loose and porous structure, improving the utilization of protein by the koji and effectively avoiding excessive protein denaturation and nutrient loss caused by Maillard reactions, thus improving the utilization rate of raw materials. The method of this application results in improved koji quality, with the neutral protease activity of the koji increasing from 2750~3100 U / g to 3110~3690 U / g, and the pH value of the koji increasing from 6.23~6.30 to 6.30~6.58. The sensory quality is good, and the koji aroma is rich. Furthermore, the utilization rate of soy sauce raw materials obtained in this application is improved, and the total nitrogen content of crude oil at the end of fermentation increases from 1.67~1.73g / 100mL to 1.78~1.87g / 100mL. The raw material utilization rate increases from 76%~80% to 82%~86%. Detailed Implementation

[0032] To better illustrate the purpose, technical solution, and advantages of this application, the following will provide further explanation of this application in conjunction with specific embodiments.

[0033] In the following examples and comparative examples, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available unless otherwise specified. Furthermore, the raw materials used in each parallel experiment are the same.

[0034] Example 1, A method for improving the utilization of soy sauce raw materials This embodiment provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: Take a certain amount of soybeans, remove impurities and put them into a soaking tank. Add water with a weight of 1.6 times that of the soybeans and soak for 6 hours. Then, treat the soaked soybeans with ultrasound at 20 kHz for 30 minutes at 35℃. Then, cook the ultrasonically treated soybeans at 60℃ for 50 minutes under a negative pressure of -0.081 MPa and keep them under pressure for 10 minutes. Cool the cooked soybeans to 33±1℃. Take wheat, bake it, cool it and grind it to obtain roasted wheat.

[0035] (2) Making koji: Stir-fried wheat is mixed into cooled cooked soybeans. Soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added and the mixture is loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0036] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0037] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0038] Example 2, A method for improving the utilization of soy sauce raw materials This embodiment provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: After removing impurities, take a certain amount of soybeans and put them into a soaking tank. Add water with a weight of 1.6 times that of the soybeans and soak for 6 hours. Then, treat the soaked soybeans with ultrasound at 40 kHz for 10 minutes at 35℃. After that, cook the ultrasonically treated soybeans at 60℃ for 50 minutes under a negative pressure of -0.081 MPa and hold the pressure for 10 minutes. Cool the cooked soybeans to 33±1℃. Take wheat, roast it, cool it and grind it to obtain roasted wheat.

[0039] (2) Making koji: Stir-fried wheat is mixed into cooled cooked soybeans. Soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added and the mixture is loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0040] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0041] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0042] Example 3, A method for improving the utilization of soy sauce raw materials This embodiment provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: After removing impurities, take a certain amount of soybeans and put them into a soaking tank. Add water with a weight of 1.6 times that of the soybeans and soak for 6 hours. Then, treat the soaked soybeans with ultrasound at 20 kHz for 30 minutes at 35℃. After that, cook the ultrasonically treated soybeans at 80℃ for 25 minutes under a negative pressure of -0.054 MPa and hold the pressure for 10 minutes. Cool the cooked soybeans to 33±1℃. Take wheat, roast it, cool it and grind it to obtain roasted wheat.

[0043] (2) Making koji: Stir-fried wheat is mixed into cooled cooked soybeans. Soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added and the mixture is loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0044] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0045] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0046] Example 4, A method for improving the utilization of soy sauce raw materials This embodiment provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: After removing impurities, take a certain amount of soybeans and put them into a soaking tank. Add water with a weight of 1.6 times that of the soybeans and soak for 6 hours. Then, treat the soaked soybeans with ultrasound at 40 kHz for 10 minutes at 35℃. After that, cook the ultrasonically treated soybeans at 80℃ for 25 minutes under a negative pressure of -0.054 MPa and hold the pressure for 10 minutes. Cool the cooked soybeans to 33±1℃. Take wheat, roast it, cool it and grind it to obtain roasted wheat.

[0047] (2) Making koji: Stir-fried wheat is mixed into cooled cooked soybeans. Soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added and the mixture is loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0048] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0049] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0050] Example 5, A method for improving the utilization of soy sauce raw materials This embodiment provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: After removing impurities, take a certain amount of soybeans and put them into a soaking tank. Add water with a weight of 1.6 times that of the soybeans and soak for 6 hours. Then, treat the soaked soybeans with ultrasound at 20 kHz for 30 minutes at 35℃. After that, cook the ultrasonically treated soybeans at 75℃ for 30 minutes under a negative pressure of -0.063 MPa and maintain the pressure for 10 minutes. Cool the cooked soybeans to 33±1℃. Take wheat, roast it, cool it and grind it to obtain roasted wheat.

[0051] (2) Making koji: Stir-fried wheat is mixed into cooled cooked soybeans. Soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added and the mixture is loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0052] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0053] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0054] Example 6, A method for improving the utilization of soy sauce raw materials This embodiment provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: After removing impurities, take a certain amount of soybeans and put them into a soaking tank. Add water with a weight of 1.6 times that of the soybeans and soak for 6 hours. Then, treat the soaked soybeans with ultrasound at 40 kHz for 10 minutes at 35℃. After that, cook the ultrasonically treated soybeans at 75℃ for 30 minutes under a negative pressure of -0.063 MPa and hold the pressure for 10 minutes. Cool the cooked soybeans to 33±1℃. Take wheat, roast it, cool it and grind it to obtain roasted wheat.

[0055] (2) Making koji: Stir-fried wheat is mixed into cooled cooked soybeans. Soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added and the mixture is loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0056] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0057] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0058] Comparative Example 1 This comparative example provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: Take a certain amount of soybeans, remove impurities and put them into a soaking tank. Add water with a weight of 1.6 times that of the soybeans and soak for 6 hours. Then, steam the soybeans at 0.10 MPa and 120℃ for 15 minutes. Then, cool the cooked soybeans to 33±1℃. Take wheat, bake it, cool it and grind it to obtain roasted wheat.

[0059] (2) Making koji: Stir-fried wheat is mixed into cooled cooked soybeans. Soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added. The mixture is then loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0060] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0061] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0062] Comparative Example 2 This comparative example provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: Take a certain amount of soybeans, remove impurities and put them into a soaking tank. Add water with a weight of 1.6 times the weight of the soybeans and soak for 6 hours. Then, steam the soaked soybeans at 75°C for 30 minutes under a negative pressure of -0.063 MPa and hold the pressure for 10 minutes. Cool the cooked soybeans to 33±1°C. Take wheat, roast it, cool it and grind it to obtain roasted wheat.

[0063] (2) Making koji: Stir-fried wheat is mixed into cooled cooked soybeans. Soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added and the mixture is loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0064] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0065] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0066] Comparative Example 3 This comparative example provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: After removing impurities, take a certain amount of soybeans and put them into a soaking tank. Add water with a weight of 1.6 times that of the soybeans and soak for 6 hours. Then, treat the soaked soybeans with ultrasound at 45 kHz for 10 minutes at 35 ℃. After that, cook the ultrasound-treated soybeans at 75 ℃ for 30 minutes under a negative pressure of -0.063 MPa and hold the pressure for 10 minutes. Cool the cooked soybeans to 33±1 ℃. Take wheat, roast it, cool it and grind it to obtain roasted wheat.

[0067] (2) Making koji: Stir-fried wheat is mixed into cooled cooked soybeans. Soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added and the mixture is loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0068] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0069] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0070] Comparative Example 4 This comparative example provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: After removing impurities, take a certain amount of soybeans and put them into a soaking tank. Add water with a weight of 1.6 times that of the soybeans and soak for 6 hours. Then, treat the soaked soybeans with ultrasound at 15 kHz for 30 minutes at 35℃. After that, cook the ultrasonically treated soybeans at 75℃ for 30 minutes under a negative pressure of -0.063 MPa and maintain the pressure for 10 minutes. Cool the cooked soybeans to 33±1℃. Take wheat, roast it, cool it and grind it to obtain roasted wheat.

[0071] (2) Making koji: Stir-fried wheat is mixed into cooled cooked soybeans. Soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added and the mixture is loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0072] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0073] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0074] Comparative Example 5 This comparative example provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: After removing impurities, take a certain amount of soybeans and put them into a soaking tank. Add water with a weight of 1.6 times that of the soybeans and soak for 6 hours. Then, treat the soaked soybeans with ultrasound at 40 kHz for 10 minutes at 35℃. After that, cook the ultrasonically treated soybeans at 55℃ for 50 minutes under a negative pressure of -0.086 MPa and maintain the pressure for 10 minutes. Cool the cooked soybeans to 33±1℃. Take wheat, roast it, cool it and grind it to obtain roasted wheat.

[0075] (2) Making koji: Mix the roasted wheat mixture into the cooled cooked soybeans. The soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added. The mixture is then loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0076] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0077] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0078] Comparative Example 6 This comparative example provides a method for improving the utilization rate of soy sauce raw materials, including the following steps: (1) Raw material pretreatment: After removing impurities, take a certain amount of soybeans and put them into a soaking tank. Add water with a weight of 1.6 times that of the soybeans and soak for 6 hours. Then, treat the soaked soybeans with ultrasound at 40 kHz for 10 minutes at 35℃. After that, cook the ultrasonically treated soybeans at 85℃ for 25 minutes under a negative pressure of -0.043 MPa and hold the pressure for 10 minutes. Cool the cooked soybeans to 33±1℃. Take wheat, roast it, cool it and grind it to obtain roasted wheat.

[0079] (2) Making koji: Mix the roasted wheat mixture into the cooled cooked soybeans. The soybeans and wheat are mixed evenly at a mass ratio of 6:4. At the same time, 0.3% of Aspergillus oryzae koji is added. The mixture is then loosely spread into a disc. The initial relative humidity is controlled at 90%~95%. The koji material is obtained after 38 hours of koji making.

[0080] (3) Fermentation: Mix the koji material with 20% salt water evenly for high-salt dilute fermentation. The ratio is controlled at koji material: salt water = 1:1.8. The fermentation temperature is 35℃ and the fermentation cycle is 60 days. Then press and filter to obtain soy sauce mash filtrate.

[0081] (4) Collect the filtrate of the pressed and filtered soy sauce, keep it at 65°C and heat it for 5 hours to obtain soy sauce.

[0082] Data analysis was performed on the koji-making and matured crude oil of Examples 1-6 and Comparative Examples 1-6, and the results are shown in Table 1.

[0083] Table 1 As shown in Table 1, compared with Comparative Examples 1-6, the quality indicators of the starter culture of Examples 1-6 were significantly improved, the total nitrogen index of the fermented soy sauce was higher, and the raw material utilization rate was higher than that of the comparative examples.

[0084] The results of Examples 1-6 and Comparative Example 1 show that, under the conditions of this application, the combined use of ultrasound and low-temperature negative pressure cooking results in better koji quality compared to traditional high-temperature and high-pressure cooking conditions, and the total nitrogen content and ammonia nitrogen utilization rate of the fermented soy sauce are higher. This indicates that under the conditions of this invention, Aspergillus can more effectively utilize soybean protein raw materials.

[0085] The results of Examples 5-6 and Comparative Example 2 indicate that single negative pressure cooking, due to the low cooking temperature and short cooking time of soybeans, results in insufficient protein denaturation, leading to a low yield of soy sauce raw materials. The results of Example 6 and Comparative Example 3 indicate that excessively high ultrasonic frequency leads to greater damage to the internal structure of soybeans, more vigorous growth of microorganisms during the koji-making process, and higher product temperature, resulting in a lower yield of soy sauce raw materials. The results of Example 5 and Comparative Example 4 indicate that excessively low ultrasonic frequency results in insufficient pre-crushing of soybeans, weakened heat transfer during cooking, and a lower yield of soybean raw materials. The results of Example 2 and Comparative Example 5 indicate that excessively low negative pressure results in a lower cooking temperature, insufficient denaturation of soybean protein, and a lower raw material yield. The results of Example 4 and Comparative Example 6 indicate that increased negative pressure causes over-denaturation of soybean protein and a decrease in raw material yield.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit the scope of protection of this application. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the substance and scope of the technical solutions of this application.

Claims

1. A method for improving the utilization rate of soy sauce raw materials, characterized in that, Includes the following steps: S1. After removing impurities from the soybeans, add water and soak them. Then, ultrasonically treat the soaked soybeans and steam them under negative pressure to obtain cooked soybeans. Cool them down. S2. Take wheat, roast it, cool it and then grind it to obtain roasted wheat. Mix the roasted wheat into cooled cooked beans, inoculate it with Aspergillus oryzae to make koji and obtain koji material. S3. Mix the starter culture with brine for high-salt dilute fermentation, then press and filter to obtain soy sauce.

2. The method for improving the utilization rate of soy sauce raw materials as described in claim 1, characterized in that, In step S1, the weight ratio of soybeans to water is 1:(1.5~1.7). And / or, the soaking time is 5 h to 6 h.

3. The method for improving the utilization rate of soy sauce raw materials as described in claim 1, characterized in that, The conditions for ultrasonic treatment are: ultrasonic temperature of 30℃~50℃, ultrasonic frequency of 20kHz~40kHz, and ultrasonic time of 10 min~30 min.

4. The method for improving the utilization rate of soy sauce raw materials as described in claim 1, characterized in that, In step S1, the negative pressure condition is: The temperature ranges from 60℃ to 80℃, and the pressure ranges from -0.081 MPa to -0.054 MPa.

5. The method for improving the utilization rate of soy sauce raw materials as described in claim 1, characterized in that, In step S1, the steaming time is 25 min to 50 min.

6. The method for improving the utilization rate of soy sauce raw materials as described in claim 1, characterized in that, In step S2, the mass ratio of soybeans to wheat is (5.5~7.5):(2.5~4.5).

7. The method for improving the utilization rate of soy sauce raw materials as described in claim 1, characterized in that, In step S2, the inoculum amount of Aspergillus oryzae is 0.1%~0.4%.

8. The method for improving the utilization rate of soy sauce raw materials as described in claim 1, characterized in that, In step S2, the conditions for koji making are: initial relative humidity of 90%~95% and koji making time of 35h~46h.

9. The method for improving the utilization rate of soy sauce raw materials as described in claim 1, characterized in that, In step S3, the salt concentration of the saline solution is 18%~23%; And / or, the volume ratio of koji and brine is 1:(1.4~2.3).

10. The method for improving the utilization rate of soy sauce raw materials as described in claim 1, characterized in that, In step S3, the fermentation temperature is 31℃~38℃, and the fermentation time is 45 days~70 days; and / or In step S3, the pressed and filtered soy sauce mash filtrate is collected and heated at 65°C for 5 hours to obtain soy sauce.

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