A method for accurately regulating protease activity in a koji-making process of soybean pellets

Abstract

The application discloses a kind of accurate regulation and control methods of protease activity in soybean paste starter preparation process, it is related to soybean paste starter preparation technical field, the stirring mechanism includes semicircle frame, the inner chamber of the semicircle frame is equipped with inner frame, the left and right sides of the semicircle frame are equipped with support plate, the first through-hole is formed in the support plate, the left and right sides of the semicircle frame are equipped with second through-hole, after inoculation, the starter material is placed in the inner frame in semicircle frame, the starter material is prepared by fan, humidifier, heater and temperature sensor on cover plate, the equipment is accurately regulated and controlled by control panel, and then the protease activity is regulated and controlled, motor drives agitator plate to turn the starter material as needed, after preparation is completed, the first threaded rod is connected with transmission rod and cross plate, the motor will drive semicircle frame and inner frame to rotate, the starter material in inner frame will be discharged, the setting of scraper and pressing plate can clean the starter material attached to the inner wall of inner frame.

Description

Technical Field

[0001] This invention relates to the field of fermented soybean curd making technology, specifically a method for precisely controlling the activity of protease during the fermentation process of fermented soybean curd. Background Technology

[0002] Currently, there are some problems in the process of making fermented soybean paste. Existing fermented soybean paste does not make it easy to regulate the activity of protease during the fermentation process, which will reduce the fermentation effect. At the same time, the existing technology often combines stirring and regulation into a whole device, which makes it difficult to clean the inside of the device, and difficult to repair or disassemble the regulation equipment, thus reducing the working efficiency of the device. During the fermentation process, it is also difficult to discharge the fermented soybean paste. Summary of the Invention

[0003] To achieve the above objectives, the present invention provides the following technical solution: a method for precise regulation of protease activity during the fermentation of fermented soybean paste, comprising the following steps: S1 Loading and Turning Settings: The inoculated koji material is placed into the inner frame cavity of the mixing mechanism. The mixing mechanism uses a stirring component that can rotate in both directions to turn the koji material as needed according to the real-time status of koji making, breaking up the material layer caking and maintaining the permeability of the material layer. S2 Staged Environmental Regulation and Enzyme Activity Control: A regulation mechanism is installed on top of the stirring mechanism. Through the integrated heating, humidification, ventilation, and temperature sensing units, the environmental parameters of the koji material are dynamically regulated in four stages along the koji-making process, thereby precisely controlling the protease activity level. (1) Spore germination stage, corresponding to the beginning of koji making 0~6 hours: control the temperature of koji material to be constant at 30~31℃, adjust the relative humidity of the environment to 80%~85%RH, and carry out weak ventilation with a ventilation volume of 0.3~0.5vvm to supplement only the basic oxygen demand; (2) During the mycelial growth stage, the corresponding time for koji making is 6 to 24 hours: control the temperature of the koji material to be no higher than 35℃ and the maximum temperature must not exceed 37℃ to avoid protease inactivation. Adjust the relative humidity of the environment to 78% to 82%RH and carry out ventilation with a ventilation volume of 0.8 to 1.0 vvm to achieve heat dissipation and oxygen supply simultaneously. When the temperature of the koji material rises to 34℃ or the material layer shows signs of compaction, start the first turning of the koji material. Then, turn the koji material every 4 to 6 hours thereafter. (3) Peak enzyme production stage, corresponding to 24-36 hours of koji making: control the temperature of the koji material to be kept stable at 30-32℃, which is the optimal enzyme production temperature range for protease, adjust the relative humidity of the environment to 75%-80%RH, and carry out strong ventilation with a ventilation volume of 1.2-1.5vvm to ensure sufficient oxygen supply to promote enzyme secretion; during this stage, turn the koji as needed and monitor the changes in protease activity in real time. (4) Post-ripening stabilization stage, corresponding to 36~48 hours of koji making: control the temperature of the koji material to slowly drop to 28~30℃, reduce the ventilation to 0.5~0.8vvm, and maintain the relative humidity of the environment at 75%RH; when the protease activity in the koji material reaches more than 2000U / g, and the surface of the koji material turns yellow-green and the spores are mature, immediately terminate the cultivation. S3 Flip-type Discharge: After the cultivation is terminated, the transmission structure of the stirring mechanism is locked to the inner and outer frames. By driving the transmission structure to rotate, the inner and outer frames are flipped synchronously, and the finished koji material in the inner frame is poured out.

[0004] Preferably, in step one, the stirring mechanism includes a semi-circular frame, an inner frame within the semi-circular frame cavity, support plates on both the left and right sides of the semi-circular frame, each support plate having a first through hole, each semi-circular frame having a second through hole, and each inner frame having a third through hole on both the left and right sides. A motor is located on the left side of the support plate, and a transmission rod is fixedly connected to the motor's power output shaft. The right end of the transmission rod passes through the first through hole on the support plate, the second through hole on the semi-circular frame, and the third through hole on the inner frame. Two fixing rings are fixedly connected to the outer edge of the transmission rod near both the left and right sides, with adjacent fixing rings located on the left and right sides of the support plate, respectively. Three connecting rods are fixedly connected to the outer edge of the transmission rod near both the front and rear sides, and a stirring plate is fixedly connected to the end of each connecting rod away from the transmission rod. Two adjusting plates are fixedly connected to each stirring plate, and several adjusting plates are located within the inner frame cavity.

[0005] Preferably, in step two, the control mechanism includes a cover plate located at the top of the semi-circular frame and fitting snugly thereto. The top of the cover plate has grooves near both the front and rear sides, and the bottom of each groove has a slot. A heater is installed within each groove, and a swing plate is installed on the top of each heater. A hinge is located on the left side of each swing plate, and the swing plate is movably connected to the top of the cover plate via the hinge. Temperature sensors are installed through the top of the cover plate near each of the four corners. Two through slots are opened on both the front and rear sides of the cover plate, and humidifiers are fixedly connected to each through slot. A control panel is fixedly connected to the center of the front side of the cover plate. Several connecting slots are opened at the center of the top of the cover plate, and fans are fixedly connected to each connecting slot.

[0006] Preferably, L-shaped rods are fixedly connected to the outer edges of the semicircular frame near the four corners, and limit plates are fixedly connected to the outer edges of the cover plate near the four corners. Each limit plate has a vertical hole. The end of the L-shaped rod away from the semicircular frame passes through the adjacent vertical hole. Two second fixing plates are fixedly connected to the front and rear sides of the semicircular frame near the top, and two first fixing plates are fixedly connected to the front and rear sides of the cover plate near the bottom. Each of the first and second fixing plates has a first threaded hole, and a first bolt is threaded into two adjacent first threaded holes.

[0007] Preferably, the bottom of the cover plate is provided with a limiting groove near the front and rear sides, and a vertical plate is provided in each limiting groove. The bottom of the vertical plate is fixedly connected to the top of the semi-circular frame. A second threaded hole is provided on each vertical plate. A third threaded hole is provided on each of the front and rear sides of the inner frame. A third bolt is threaded into each of the second threaded holes, and one end of the third bolt is threaded into an adjacent third threaded hole.

[0008] Preferably, a vertical groove is formed at the center of the top of the transmission rod, and a scraper is inserted through the vertical groove. A baffle is fixedly connected to the top of the scraper, and the baffle is located at the top of the transmission rod. Two springs are fixedly connected to the bottom of the baffle near the left and right sides, and the bottom ends of the springs are fixedly connected to the top of the transmission rod. The bottom of the scraper is attached to the bottom of the inner frame cavity. Sliding grooves are formed on the left and right sides of the inner frame cavity near the top, and sliders are movably connected in the sliding grooves. A pressure plate is fixedly connected to one side of each slider, and the bottom of the pressure plate is attached to the top of the baffle. A fourth threaded hole is formed on each slider. A connecting hole is formed on the top of the inner frame near the left and right sides, and a second threaded rod is inserted through the connecting hole. The bottom end of the second threaded rod is threaded through the adjacent fourth threaded hole and inserted into the bottom of the sliding groove.

[0009] Preferably, a horizontal plate is fixedly connected to both the left and right sides of the semicircular frame, a fifth threaded hole is opened near the left and right sides of the inner cavity of the transmission rod, a sixth threaded hole is opened at the top of the horizontal plate, a first threaded rod is threadedly connected to each of the fifth threaded holes, and the bottom end of the first threaded rod is threadedly connected to the adjacent sixth threaded hole.

[0010] Preferably, a seventh threaded hole is provided on the top of the swing plate near the right side, and two eighth threaded holes are provided on the top of the cover plate near the right side. A second bolt is threaded into the seventh threaded hole, and the bottom end of the second bolt is threaded into the eighth threaded hole. A handle is fixedly connected to the center of the top of the swing plate.

[0011] Compared with the prior art, the beneficial effects of the present invention are: This invention utilizes the interplay of a semi-circular frame, a cover plate, a motor, and a fan to allow the inoculated koji material to be placed into the inner frame within the semi-circular frame. The koji material is prepared using a fan, humidifier, heater, and temperature sensor on the cover plate. The equipment is precisely controlled via a control panel, thereby regulating the protease activity. A motor-driven stirring plate tumbles the koji material as needed. After preparation, the motor rotates the semi-circular frame and inner frame via a connection between the first threaded rod, the transmission rod, and the horizontal plate, discharging the koji material from the inner frame. A scraper combined with a pressure plate cleans the koji material adhering to the inner wall of the inner frame. Attached Figure Description

[0012] Figure 1 This is a perspective view of the present invention; Figure 2 This is a right-side perspective view of the present invention; Figure 3 This is an exploded view of the present invention; Figure 4 This is a schematic diagram of the cover plate structure of the component of the present invention; Figure 5 This is a bottom view of the cover plate structure of the component of the present invention; Figure 6 This is a schematic diagram of the L-shaped rod structure of the component of the present invention; Figure 7 This is a schematic diagram of the motor structure of the component of the present invention; Figure 8 This is a schematic diagram of the inner frame structure of the component of the present invention; Figure 9 This is a schematic diagram of the pressure plate structure of the component of the present invention; Figure 10 This is a schematic diagram of the semi-circular frame structure of the component of the present invention; Figure 11 for Figure 7 Enlarged view of point A in the middle.

[0013] The following are the labels in the diagram: 1. Semicircular frame; 2. Support plate; 3. Cover plate; 4. Motor; 5. Transmission rod; 6. Inner frame; 7. Limiting plate; 8. First fixing plate; 9. First bolt; 10. Control panel; 11. Humidifier; 12. Temperature sensor; 13. Heater; 14. Swing plate; 15. Handle; 16. Second bolt; 17. Fan; 18. Second fixing plate; 19. Vertical plate; 20. Third bolt; 21. L-shaped rod; 22. Scraper; 23. Baffle; 24. Connecting rod; 25. Stirring plate; 26. Adjusting plate; 27. Fixing ring; 28. First threaded rod; 29. ​​Horizontal plate; 30. Pressure plate; 31. Slider; 32. Second threaded rod; 33. Spring. Detailed Implementation

[0014] Please see Figure 1-11This invention provides a technical solution: a method for precisely controlling the activity of protease during the fermentation of fermented soybean paste, comprising the following steps: S1 Loading and Turning Settings: The inoculated koji material is placed into the inner frame cavity of the mixing mechanism. The mixing mechanism uses a stirring component that can rotate in both directions to turn the koji material as needed according to the real-time status of koji making, breaking up the material layer caking and maintaining the permeability of the material layer. S2 Staged Environmental Regulation and Enzyme Activity Control: A regulation mechanism is installed on top of the stirring mechanism. Through the integrated heating, humidification, ventilation, and temperature sensing units, the environmental parameters of the koji material are dynamically regulated in four stages along the koji-making process, thereby precisely controlling the protease activity level. (1) Spore germination stage, corresponding to the beginning of koji making 0~6 hours: control the temperature of koji material to be constant at 30~31℃, adjust the relative humidity of the environment to 80%~85%RH, and carry out weak ventilation with a ventilation volume of 0.3~0.5vvm to supplement only the basic oxygen demand; (2) During the mycelial growth stage, the corresponding time for koji making is 6 to 24 hours: control the temperature of the koji material to be no higher than 35℃ and the maximum temperature must not exceed 37℃ to avoid protease inactivation. Adjust the relative humidity of the environment to 78% to 82%RH and carry out ventilation with a ventilation volume of 0.8 to 1.0 vvm to achieve heat dissipation and oxygen supply simultaneously. When the temperature of the koji material rises to 34℃ or the material layer shows signs of compaction, start the first turning of the koji material. Then, turn the koji material every 4 to 6 hours thereafter. (3) Peak enzyme production stage, corresponding to 24-36 hours of koji making: control the temperature of the koji material to be kept stable at 30-32℃, which is the optimal enzyme production temperature range for protease, adjust the relative humidity of the environment to 75%-80%RH, and carry out strong ventilation with a ventilation volume of 1.2-1.5vvm to ensure sufficient oxygen supply to promote enzyme secretion; during this stage, turn the koji as needed and monitor the changes in protease activity in real time. (4) Post-ripening stabilization stage, corresponding to 36~48 hours of koji making: control the temperature of the koji material to slowly drop to 28~30℃, reduce the ventilation to 0.5~0.8vvm, and maintain the relative humidity of the environment at 75%RH; when the protease activity in the koji material reaches more than 2000U / g, and the surface of the koji material turns yellow-green and the spores are mature, immediately terminate the cultivation. S3 Flip-type Discharge: After the cultivation is terminated, the transmission structure of the stirring mechanism is locked to the inner and outer frames. By driving the transmission structure to rotate, the inner and outer frames are flipped synchronously, and the finished koji material in the inner frame is poured out.

[0015] In step one, the stirring mechanism includes a semi-circular frame 1, an inner frame 6 inside the semi-circular frame 1, support plates 2 on both the left and right sides of the semi-circular frame 1, each support plate 2 having a first through hole, each semi-circular frame 1 having a second through hole, and each inner frame 6 having a third through hole. A motor 4 is located on the left side of the support plate 2, and a transmission rod 5 is fixedly connected to the power output shaft of the motor 4. The right end of the transmission rod 5 passes through the first through hole on the support plate 2, the second through hole on the semi-circular frame 1, and the third through hole on the inner frame 6. Two fixing rings 27 are fixedly connected to the outer edge of the transmission rod 5 near the left and right sides, and two adjacent fixing rings 27 are located on the left and right sides of the support plate 2, respectively. Three connecting rods 24 are fixedly connected to the outer edge of the transmission rod 5 near the front and rear sides, and a stirring plate 25 is fixedly connected to the end of the connecting rod 24 away from the transmission rod 5. Two adjusting plates 26 are fixedly connected to the stirring plate 25, and several adjusting plates 26 are located inside the inner frame 6. In step two, the control mechanism includes a cover plate 3, which is located on top of the semi-circular frame 1 and fits against it. The top of the cover plate 3 has grooves near the front and rear sides, and the bottom of each groove has a slot. Each groove contains a heater 13, and the top of each heater 13 has a swing plate 14. The left side of the swing plate 14 has a hinge, and the swing plate 14 is movably connected to the top of the cover plate 3 through the hinge. Temperature sensors 12 are installed through the top of the cover plate 3 near the four corners. Two through slots are opened on the front and rear sides of the cover plate 3, and humidifiers 11 are fixedly connected in each through slot. A control panel 10 is fixedly connected to the center of the front side of the cover plate 3. Several connecting slots are opened at the center of the top of the cover plate 3, and fans 17 are fixedly connected in each connecting slot. L-shaped rods 21 are fixedly connected to the outer edges of the semicircular frame 1 near the four corners. Limiting plates 7 are fixedly connected to the outer edges of the cover plate 3 near the four corners. Each limiting plate 7 has a vertical hole. The end of the L-shaped rod 21 away from the semicircular frame 1 passes through the adjacent vertical hole. Two second fixing plates 18 are fixedly connected to the front and rear sides of the semicircular frame 1 near the top. Two first fixing plates 8 are fixedly connected to the front and rear sides of the cover plate 3 near the bottom. Both the first fixing plates 8 and the second fixing plates 18 have first threaded holes. A first bolt 9 is threaded into two adjacent first threaded holes. The bottom of the cover plate 3 near the front and rear... Limiting grooves are provided on both sides, and vertical plates 19 are provided in each limiting groove. The bottom of the vertical plates 19 is fixedly connected to the top of the semi-circular frame 1. A second threaded hole is provided on each vertical plate 19. A third threaded hole is provided on both the front and rear sides of the inner frame 6. A third bolt 20 is threaded into each of the second threaded holes. One end of the third bolt 20 is threaded into the adjacent third threaded hole. A vertical groove is provided at the center of the top of the transmission rod 5. A scraper 22 is provided through the vertical groove. A baffle 23 is fixedly connected to the top of the scraper 22. The baffle 23 is located at the top of the transmission rod 5. Two springs 33 are fixedly connected to the bottom of the baffle 23 near the left and right sides. The bottom end of spring 33 is fixedly connected to the top of transmission rod 5. The bottom of scraper 22 is attached to the bottom of the inner cavity of inner frame 6. Slide grooves are provided on both the left and right sides of the inner cavity of inner frame 6 near the top. Slide sliders 31 are movably connected in the slide grooves. Pressure plates 30 are fixedly connected to one side of each slide slider 31. The bottom of pressure plates 30 is attached to the top of baffle 23. A fourth threaded hole is provided on each slide slider 31. Connection holes are provided on the top of inner frame 6 near the left and right sides. A second threaded rod 32 passes through the connection hole. The bottom end of the second threaded rod 32 passes through the adjacent fourth threaded hole and is inserted into the bottom of the slide groove. The left and right sides of semicircular frame 1 are fixedly connected to the slide groove. A horizontal plate 29 is fixedly connected. The inner cavity of the transmission rod 5 is provided with a fifth threaded hole near the left and right sides. The top of the horizontal plate 29 is provided with a sixth threaded hole. A first threaded rod 28 is threaded into each of the fifth threaded holes. The bottom end of the first threaded rod 28 is threaded into the adjacent sixth threaded hole. A seventh threaded hole is provided near the right side of the top of the swing plate 14. Two eighth threaded holes are provided near the right side of the top of the cover plate 3. A second bolt 16 is threaded into each of the seventh threaded holes. The bottom end of the second bolt 16 is threaded into the eighth threaded hole. A handle 15 is fixedly connected to the center of the top of the swing plate 14.

[0016] Working principle: When the device starts working, the inoculated material is placed into the inner frame 6 inside the semi-circular frame 1. Then, the second threaded rod 32 is rotated, which drives the slider 31 to move upward. The slider 31 drives the pressure plate 30 to move upward. The spring 33 at the baffle 23 will drive the baffle 23 and the scraper 22 to move upward. Then, the cover plate 3 is placed on the top of the semi-circular frame 1. The four limiting plates 7 on the surface of the cover plate 3 are aligned with the L-shaped rod 21 on the semi-circular frame 1. The L-shaped rod 21 passes through the limiting plates 7, thereby initially limiting the cover plate 3. The first fixing plate 8 and the second fixing plate 18 are in contact with each other. The first bolt 9 is threaded through the first fixing plate 8 and the second fixing plate 18, thereby further limiting the installation of the semi-circular frame 1 and the cover plate 3. The broth is adjusted in four stages, and controlled through the control panel 10. Phase 1: Spore germination period (0-6 hours) The temperature of heater 13 is controlled at 30-31℃ (constant temperature). Humidifier 11 maintains a humidity level of 80%-85%RH (high humidity). Five fans (17 units) are started simultaneously, providing weak ventilation (0.3-0.5 vvm) and supplementing only a small amount of oxygen. Second stage: Mycelial growth period (6-24 hours) The temperature of heater 13 should be controlled at ≤35℃ (it is strictly forbidden to exceed 37℃ to prevent enzyme inactivation). Humidifier 11 maintains a humidity level of 78%-82%RH. Five fans (17 units) start simultaneously, providing ventilation: medium ventilation (0.8-1.0 VVM), heat dissipation + oxygen supply. When the material temperature reaches 34℃ or the material layer becomes caking, the first turning is performed. Motor 4, a servo motor, is started. Motor 4 drives the transmission rod 5 to rotate forward and backward. The transmission rod 5 drives the connecting rod 24 to rotate forward and backward. The connecting rod 24 drives the stirring plate 25 and the adjusting plate 26 to rotate forward and backward. The stirring plate 25 turns the material every 4-6 hours to maintain the air permeability of the material layer. Phase 3: Peak enzyme production period (24-36 hours) The temperature of heater 13 is strictly maintained at 30-32℃ (the optimal temperature for protease production). Humidifier 11 maintains a humidity level of 75%-80%RH (slightly lowers humidity to promote enzyme secretion). Five fans (17 units) are started simultaneously to provide ventilation: strong ventilation (1.2-1.5 VVM) to ensure sufficient oxygen. Turn the koji as needed, monitor enzyme activity in real time. Phase 4: Post-ripening stabilization period (36-48 hours) The temperature of heater 13 slowly drops to 28-30℃ Ventilation reduced to 0.5-0.8 VVM Humidity maintained at 75% RH When the protease activity reaches 2000 U / g or higher and the surface of the substrate turns yellowish-green (spores are mature), immediately stop the culture. Then, rotate the first bolt 9 to remove it from the first fixing plate 8 and the second fixing plate 18. Use external equipment to move the cover plate 3 upwards, moving it away from the top of the semi-circular frame 1, exposing the semi-circular frame 1 and the inner frame 6. Remove the first threaded rod 28, whose threads pass through the transmission rod 5 and connect it to the threaded hole at the top of the horizontal plate 29, completing the connection between the transmission rod 5 and the semi-circular frame 1. Start the motor 4, which drives the transmission rod 5 to rotate. The transmission rod 5, through the first threaded rod 28 and the horizontal plate 29, drives the semi-circular frame 1 to rotate. The semi-circular frame 1, through the vertical plate 19 and the third bolt 20, drives the inner frame 6 to rotate, discharging the material inside the inner frame 6. If it is necessary to clean the material adhering to the inner wall of the inner frame 6, rotate the second threaded rod 32. The second threaded rod 32 drives the slider 31 to move downward. The slider 31 drives the pressure plate 30 to move downward. The pressure plate 30 drives the baffle 23 to move downward. The baffle 23 drives the scraper 22 to move downward. The baffle 23 drives the spring 33 to compress. The bottom of the scraper 22 is attached to the inner wall of the inner cavity of the inner frame 6. The motor 4 drives the scraper 22 to rotate. The scraper 22 cleans the inner wall of the inner frame 6. If it is necessary to disassemble the heater 13, rotate the second bolt 16. The second bolt 16 is removed from the cover plate 3 and the swing plate 14. Adjust the swing plate 14 to disassemble and remove the heater 13.

Claims

1. A method for precisely controlling protease activity during the fermentation of fermented soybean paste, characterized in that, Includes the following steps: S1 Loading and Turning Settings: The inoculated koji material is placed into the inner frame cavity of the mixing mechanism. The mixing mechanism uses a stirring component that can rotate in both directions to turn the koji material as needed according to the real-time status of koji making, breaking up the material layer caking and maintaining the permeability of the material layer. S2 Staged Environmental Regulation and Enzyme Activity Control: A regulation mechanism is installed on top of the stirring mechanism. Through the integrated heating, humidification, ventilation, and temperature sensing units, the environmental parameters of the koji material are dynamically regulated in four stages along the koji-making process, thereby precisely controlling the protease activity level. (1) Spore germination stage, corresponding to the beginning of koji making 0~6 hours: control the temperature of koji material to be constant at 30~31℃, adjust the relative humidity of the environment to 80%~85%RH, and carry out weak ventilation with a ventilation volume of 0.3~0.5vvm to supplement only the basic oxygen demand; (2) During the mycelial growth stage, the corresponding time for koji making is 6 to 24 hours: control the temperature of the koji material to be no higher than 35℃ and the maximum temperature must not exceed 37℃ to avoid protease inactivation. Adjust the relative humidity of the environment to 78% to 82%RH and carry out ventilation with a ventilation volume of 0.8 to 1.0 vvm to achieve heat dissipation and oxygen supply simultaneously. When the temperature of the koji material rises to 34℃ or the material layer shows signs of compaction, start the first turning of the koji material. Then, turn the koji material every 4 to 6 hours thereafter. (3) Peak enzyme production stage, corresponding to 24-36 hours of koji making: control the temperature of the koji material to be kept stable at 30-32℃, which is the optimal enzyme production temperature range for protease, adjust the relative humidity of the environment to 75%-80%RH, and carry out strong ventilation with a ventilation volume of 1.2-1.5vvm to ensure sufficient oxygen supply to promote enzyme secretion; during this stage, turn the koji as needed and monitor the changes in protease activity in real time. (4) Post-ripening stabilization stage, corresponding to 36~48 hours of koji making: control the temperature of the koji material to slowly drop to 28~30℃, reduce the ventilation to 0.5~0.8vvm, and maintain the relative humidity of the environment at 75%RH; when the protease activity in the koji material reaches more than 2000U / g, and the surface of the koji material turns yellow-green and the spores are mature, immediately terminate the cultivation. S3 Flip-type Discharge: After the cultivation is terminated, the transmission structure of the stirring mechanism is locked to the inner and outer frames. By driving the transmission structure to rotate, the inner and outer frames are flipped synchronously, and the finished koji material in the inner frame is poured out.

2. The method for precisely controlling protease activity during the fermentation of fermented soybean paste according to claim 1, characterized in that: In step one, the stirring mechanism includes a semi-circular frame (1), an inner frame (6) is provided inside the semi-circular frame (1), and support plates (2) are provided on both the left and right sides of the semi-circular frame (1). A first through hole is provided on each support plate (2), a second through hole is provided on both the left and right sides of the semi-circular frame (1), and a third through hole is provided on both the left and right sides of the inner frame (6). A motor (4) is provided on the left side of the support plate (2), and a transmission rod (5) is fixedly connected to the power output shaft of the motor (4). The right end of the transmission rod (5) passes through the first through hole on the support plate (2) and the semi-circular frame (1). The second through hole and the third through hole on the inner frame (6), two fixed rings (27) are fixedly connected to the outer edge of the transmission rod (5) near the left and right sides, and two adjacent fixed rings (27) are located on the left and right sides of the support plate (2), respectively. Three connecting rods (24) are fixedly connected to the outer edge of the transmission rod (5) near the front and rear sides, and a stirring plate (25) is fixedly connected to the end of the connecting rod (24) away from the transmission rod (5). Two adjusting plates (26) are fixedly connected to the stirring plate (25), and several adjusting plates (26) are located in the inner cavity of the inner frame (6).

3. The method for precisely controlling protease activity during the fermentation of fermented soybean paste according to claim 1, characterized in that: In step two, the control mechanism includes a cover plate (3), which is located on the top of the semi-circular frame (1) and fits against it. The top of the cover plate (3) is provided with grooves near the front and rear sides. The bottom of each groove is slotted and a heater (13) is provided in each groove. The top of each heater (13) is provided with a swing plate (14). The left side of the swing plate (14) is provided with a hinge. The swing plate (14) is movably connected to the top of the cover plate (3) through the hinge. Temperature sensors (12) are provided through the top of the cover plate (3) near the four corners. Two through slots are provided on the front and rear sides of the cover plate (3). Humidifiers (11) are fixedly connected in each through slot. A control panel (10) is fixedly connected at the center of the front side of the cover plate (3). Several connecting slots are provided at the center of the top of the cover plate (3). Fans (17) are fixedly connected in each connecting slot.

4. The method for precisely controlling protease activity during the fermentation of fermented soybean paste according to claim 1, characterized in that: L-shaped rods (21) are fixedly connected to the outer edges of the semicircular frame (1) near the four corners. Limiting plates (7) are fixedly connected to the outer edges of the cover plate (3) near the four corners. Vertical holes are provided on the limiting plates (7). The end of the L-shaped rod (21) away from the semicircular frame (1) passes through the adjacent vertical holes. Two second fixing plates (18) are fixedly connected to the front and rear sides of the semicircular frame (1) near the top. Two first fixing plates (8) are fixedly connected to the front and rear sides of the cover plate (3) near the bottom. First threaded holes are provided on the first fixing plates (8) and the second fixing plates (18). A first bolt (9) is threadedly connected to the two adjacent first threaded holes.

5. The method for precisely controlling protease activity during the fermentation of fermented soybean paste according to claim 1, characterized in that: The cover plate (3) has a limiting groove at the bottom near the front and rear sides. Each limiting groove has a vertical plate (19). The bottom of the vertical plate (19) is fixedly connected to the top of the semi-circular frame (1). Each vertical plate (19) has a second threaded hole. Each inner frame (6) has a third threaded hole at the front and rear sides. Each second threaded hole has a third bolt (20) threadedly connected to it. One end of the third bolt (20) is threadedly connected to the adjacent third threaded hole.

6. The method for precisely controlling protease activity during the fermentation of fermented soybean paste according to claim 1, characterized in that: A vertical groove is provided at the center of the top of the transmission rod (5), and a scraper (22) is provided through the groove. A baffle (23) is fixedly connected to the top of the scraper (22). The baffle (23) is located at the top of the transmission rod (5). Two springs (33) are fixedly connected to the bottom of the baffle (23) near the left and right sides. The bottom of the springs (33) is fixedly connected to the top of the transmission rod (5). The bottom of the scraper (22) is attached to the bottom of the inner cavity of the inner frame (6). The left and right sides of the inner cavity of the inner frame (6) are close to the bottom of the inner frame (6). Each of the top sections is provided with a sliding groove, and each sliding groove is movably connected with a slider (31). Each slider (31) is fixedly connected with a pressure plate (30) on one side. The bottom of the pressure plate (30) is attached to the top of the baffle (23). Each slider (31) is provided with a fourth threaded hole. The top of the inner frame (6) is provided with a connecting hole near the left and right sides. A second threaded rod (32) is passed through the connecting hole. The bottom end of the second threaded rod (32) is threaded through the adjacent fourth threaded hole and inserted into the bottom of the sliding groove.

7. The method for precisely controlling protease activity during the fermentation of fermented soybean paste according to claim 1, characterized in that: The semi-circular frame (1) is fixedly connected to the left and right sides with horizontal plates (29). The inner cavity of the transmission rod (5) is provided with fifth threaded holes near the left and right sides. The top of the horizontal plate (29) is provided with a sixth threaded hole. The fifth threaded hole is threaded with a first threaded rod (28). The bottom end of the first threaded rod (28) is threaded into the adjacent sixth threaded hole.

8. The method for precisely controlling protease activity during the fermentation of fermented soybean paste according to claim 1, characterized in that: The top of the swing plate (14) near the right side is provided with a seventh threaded hole, and the top of the cover plate (3) near the right side is provided with two eighth threaded holes. The seventh threaded holes are threaded with a second bolt (16), and the bottom end of the second bolt (16) is threaded into the eighth threaded hole. The top center of the swing plate (14) is fixedly connected with a handle (15).

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