Green production method, process and equipment of lactic acid for food

Abstract

The invention provides a green production method, process and equipment of lactic acid for food, and relates to the field of lactic acid fermentation. The green production method of the lactic acid for the food comprises the following steps: S1, mixing a mixed solution of glucose with the sugar content of 20-25% and corn starch with the sugar content of 40-45% according to the volume ratio of 100: 15, introducing the mixture into fermentation equipment, and heating at 100 DEG C for 10 minutes to eliminate infectious microbes; step S2, cooling the sterilized fermentation raw materials to 50 DEG C or below, then inoculating lactic acid bacteria into the fermentation raw materials, introducing sterile gas into the fermentation equipment, discharging the sterile gas, and then performing fermentation at 30-45 DEG C for 15-20 hours; and S3, cooling the fermented raw materials, separating and purifying, filling and refrigerating to obtain a finished product. The device is good in stirring effect, accurate in temperature control, free of air leakage in sampling acid-base neutralization, high in lactic acid yield and excellent in lactic acid quality.

Description

Technical Field

[0001] The present invention relates to the technical field of lactic acid processing, and in particular to a green production method, process and equipment for lactic acid for food. Background Art

[0002] Lactic acid is widely used as a food additive. With the development of science and technology, the large-scale fermentation production technology of lactic acid has become more mature.

[0003] Lactic acid is a product of anaerobic fermentation. During the fermentation process, the fermentation tank usually needs to be sealed, and the fermentation tank needs to be sealed during the fermentation process to facilitate the formation of lactic acid.

[0004] In the current lactic acid production process, the pH of the mixture in the fermentation tank needs to be tested. During this test, the sealing of the fermentation tank is damaged. If the pH in the fermentation tank exceeds the optimal fermentation value, the fermentation tank needs to be opened and a regulator needs to be introduced, which will cause the fermentation tank to lose its seal and may cause the fermentation product to be contaminated. In the existing lactic acid production process, the raw materials in the fermentation tank need to be slowly mixed and stirred. If the stirring is too fast, the growth and fermentation of the bacteria will be affected. If the stirring is too slow, the internal raw materials will accumulate heat, causing local temperature rise, which will destroy the optimal conditions for the growth and conversion of lactic acid by the bacteria. The existing stirring equipment rotates horizontally in the fermentation tank. The material at the bottom of the fermentation tank rotates quickly, while the material at the top of the fermentation tank rotates slowly, resulting in poor mixing effect and affecting fermentation. In the existing lactic acid production process, due to the relatively mild temperature of lactic acid fermentation, the equipment is usually heated by using a heat exchanger to provide heat outside the fermentation tank. Usually, only one set of temperature adjustment is set. Since the heating equipment will dissipate heat, the heat inside the fermentation tank will also be lost, so the temperature of the heating equipment will be slightly higher to compensate for the temperature. However, this method causes the temperature inside the fermentation tank to be heated unevenly, making it difficult to accurately adjust and improve. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention provides a green production method, process and equipment for lactic acid for food, which solves the problems of inaccurate temperature control, poor material mixing effect and easy leakage of fermentation tanks during sampling and acid-base adjustment in existing lactic acid production.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a green production method of lactic acid for food, comprising the following steps: Step S1, mixing a mixture of 20% to 25% glucose and 40% to 45% corn starch in a volume ratio of 100:15, introducing the mixture into a fermentation device, and heating the mixture at 100 degrees Celsius for 10 minutes to eliminate bacteria; Step S2, cooling the sterilized fermentation raw materials to below 50 degrees Celsius, inoculating lactic acid bacteria therein, introducing sterile gas into the fermentation equipment and exhausting it, and then fermenting at 30-45 degrees Celsius for 15-20 hours. During the fermentation process, sampling and testing the pH value of the fermentation liquid several times. If the pH value is lower than 5.5, 0.15-0.2 mol / L calcium hydroxide solution is added therein to adjust the pH to between 5.5-6.0. During the fermentation process, stirring is continuously performed to fully mix the materials; Step S3: Cooling the fermented raw materials, separating and purifying them, and then filling and refrigerating them to obtain the finished products.

[0007] Preferably, a green production equipment for lactic acid for food, which is the fermentation equipment for green production of lactic acid for food mentioned above, comprises: A fermentation tank, wherein a feeding port is provided on the top of the fermentation tank, a sealing cover is provided on the top of the feeding port, and an air supply mechanism and a sampling mechanism are provided in the middle of the fermentation tank; A temperature control mechanism, comprising a water tank and temperature control pipes. The water tank is cylindrical and sleeved outside the fermentation tank. A gap is formed between the water tank and the fermentation tank for passing hot water. Multiple groups of temperature control pipes are arranged in the gap from top to bottom. The driving mechanism includes a motor, a flexible shaft, a driving gear, an arc tube and a rotating shaft. There are two arc tubes in total. The two arc tubes are detachably mounted on the upper and lower parts of the fermentation tank through fixing rods. The motor is mounted on the top of the sealing cover. The driving end of the motor is fixed to the flexible shaft through a coupling. There are multiple driving gears and they are all arranged on the flexible shaft. Multiple rotating shafts are arranged on the arc tube. An internal gear ring is arranged on the inner side of the rotating shaft in the upper arc tube, and the internal gear ring and the driving gear cooperate with each other. The stirring mechanism includes a synchronous belt and a stirring plate. The upper and lower corresponding rotating shafts of the two arc tubes are connected by a synchronous wheel and a synchronous belt. Each synchronous belt is provided with multiple sets of stirring plates.

[0008] Preferably, a water inlet and a water outlet are installed on the water tank, and each of the temperature control tubes is provided with a water outlet pipe and a water inlet pipe.

[0009] Preferably, the air supply mechanism comprises a central pipe, an air inlet pipe, an air inlet, a connecting pipe, an air supply pipe and a Venturi tube, the central pipe is arranged in the middle of the fermentation tank and the top end of the central pipe penetrates the top of the fermentation tank, the air supply pipe is circular, the Venturi tube has a plurality of tubes arranged on the air supply pipe, the air supply pipe is detachably arranged in the lower part of the fermentation tank, the air supply pipe is connected with the connecting pipe, the connecting pipe is connected with the air inlet pipe, the air inlet pipe is arranged on one side of the central pipe, the top of the air inlet pipe is connected with the air inlet, the air inlet is connected with a sterile air supply device, the bottom of the air inlet pipe is provided with a remotely controlled electromagnetic valve, and the outside of the electromagnetic valve is provided with a waterproof cover.

[0010] Preferably, the sampling mechanism comprises a driving pipe, an electromagnet, a mounting seat, a sliding seat, an electromagnetic valve extension pipe, a fluid pump, a sampling pipe, a threaded rod and a motor, the driving pipe is arranged on the side of the central pipe away from the air inlet pipe, the threaded rod is rotatably connected in the driving pipe, the motor is arranged on the top of the driving pipe, the upper end of the threaded rod is connected with the driving end of the motor through a shaft coupling, the sliding seat is slidably connected in the driving pipe, the sliding seat is threadedly connected with the threaded rod, the sliding seat is made of iron, the sliding seat is slidably sleeved with the electromagnet on the outer side of the central pipe, one side of the electromagnet is fixedly connected with the mounting seat, the lower end of the extension pipe penetrates the mounting seat, the upper end of the extension pipe is connected with the water inlet end of the fluid pump, the fluid pump is arranged on the top of the fermentation tank, the output end of the fluid pump is connected with the sampling pipe, and the lower end of the extension pipe is connected with a remotely controlled electromagnetic valve.

[0011] Preferably, the top of the fermentation tank is provided with a pressure relief valve and an exhaust valve, and the bottom of the fermentation tank is provided with a discharge port.

[0012] Preferably, a food-grade lactic acid green production process uses the food-grade lactic acid green production device described above, and comprises the following process steps: Step one, fermentation process: through the feeding port, glucose with a sugar content of 20%-25% and corn starch mixed liquid with a content of 40%-45% are put into the fermentation tank, hot water at 100 degrees Celsius is introduced into the water tank, water vapor higher than 100 degrees Celsius is introduced into the temperature control pipe to keep the water temperature in the water tank boiling at all times, the raw material substrate in the fermentation tank is heated at 100 degrees Celsius for 10 minutes, then the temperature in the fermentation tank is reduced to below 50 degrees Celsius through the water tank, then lactic acid bacteria are inoculated into the fermentation tank, after inoculation, the electromagnetic valve on the air inlet pipe is opened, the sterile air supply assembly is used to introduce sterile anaerobic gas into the air inlet pipe through the air inlet, the gas is released in the fermentation tank through the connecting pipe, the air supply pipe and the Venturi tube in turn, after the oxygen in the fermentation tank is gradually squeezed out, the feeding port is sealed with a sealing cover, the water tank is supplied with 40 degrees Celsius water, and the fermentation tank is fermented at 30-45 degrees Celsius for 15-20 hours; Step two, stirring management process during fermentation: the motor drives the soft shaft to drive the gear and the inner tooth ring to rotate synchronously, the inner tooth ring drives the rotating shaft to rotate through the synchronous wheel, the stirring plate on the synchronous belt lifts the fermentation materials at the bottom of the fermentation tank upwards, the fermentation raw materials in the fermentation tank are fully mixed and the temperature is balanced, and the bacteria fully decompose the sugar to form lactic acid through slow mixing; Step three, acid-base adjustment process during fermentation: the motor drives the slide to slide up and down in the drive pipe, and when sliding, the slide drives the electromagnet to slide up and down outside the center pipe, the electromagnet drives the mounting seat to different depths in the fermentation tank, and the electromagnetic valve is opened at different depths, the fluid pump draws the fermentation liquid from the sampling pipe through the extension pipe, the acid-base value at different depths in the fermentation tank is measured, the pH value is lower than 5.5, the sampling pipe is connected to 0.15 moles per liter of calcium hydroxide solution, the fluid pump reverses to pass the calcium hydroxide solution into the fermentation tank through the extension pipe, and the pH value in the fermentation tank is increased to 5.5-6.0 through the stirring mechanism 34; Step four, temperature process during fermentation: the water tank changes the internal temperature of the fermentation tank, and the temperature of the water tank is fine-tuned through the temperature control pipe to compensate for the temperature loss caused by the fermentation tank and the water tank; Step five, after the fermentation is completed, the mixture in the fermentation tank is discharged through the discharge port for the next step processing.

[0013] The application provides a green lactic acid production method, process and equipment for food. The application drives the soft shaft to drive the gear and the inner tooth ring to rotate synchronously through the motor, the inner tooth ring drives the rotating shaft to rotate through the synchronous wheel, the stirring plate on the synchronous belt lifts the fermentation materials at the bottom of the fermentation tank upwards, the fermentation raw materials in the fermentation tank are fully mixed and the temperature is balanced, the bacteria fully decompose the sugar to form lactic acid through slow mixing, the materials deposited at the bottom of the fermentation tank are lifted up and fully mixed with the upper materials through the upward stirring, and the slow stirring is convenient for the bacteria to breed and produce lactic acid, the efficiency of the upward stirring of the materials is stable, the materials are not fermented unevenly due to the fast rotating speed of the lower materials and the slow rotating speed of the upper materials, and the temperature is balanced.

[0014] The present invention drives the threaded rod through a motor to make the slide slide up and down in the driving tube. During the sliding, the slide drives the electromagnet to slide up and down outside the central tube. The electromagnet drives the mounting seat to different depths in the fermentation tank. The solenoid valve is opened at different depths respectively. The fluid pump draws the fermentation liquid through the extension tube and outputs it from the sampling tube to measure the pH values ​​at different depths in the fermentation tank. When the acid and alkali adjustment is required, the sampling tube is connected to the calcium hydroxide solution, and the fluid pump reversely passes the calcium hydroxide solution through the extension tube into the fermentation tank. The pH value in the fermentation tank is increased to between 5.5 and 6.0 through the stirring mechanism. The sealed sampling and airtight acid-base neutralization settings make the production of lactic acid green and environmentally friendly. No air will flow into the fermentation tank, and the fermented material will not be contaminated, making the fermentation production of lactic acid more green and environmentally friendly. The multi-point contactless rapid sampling setting can accurately control the fermentation status in the fermentation tank and ensure that the lactic acid is fermented in the optimal process.

[0015] The present invention combines a water tank and a temperature control tube. The water tank quickly improves the temperature in the fermentation tank, so that it quickly reaches the ideal fermentation temperature range. The temperature control tube can compensate for the temperature lost by the water tank within the fermentation range and accurately adjust the temperature. Through coarse and fine temperature control, the fermentation tank is accurately heated and heated evenly. The fermentation temperature is accurately adjusted, so that the yield of fermented lactic acid is high and the quality is excellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a front cross-sectional view of the present invention; Figure 2 The structure of the present invention Figure 1 ; Figure 3 It is a front view of the stirring mechanism of the present invention; Figure 4 A top view of the driving mechanism of the present invention; Figure 5 For the present invention Figure 3 Enlarged view of point A in the middle; Figure 6 A three-dimensional diagram of the flexible shaft of the present invention; Figure 7 It is a front view of the gas supply mechanism and the sampling mechanism of the present invention; Figure 8 It is a three-dimensional schematic diagram of the sampling mechanism of the present invention.

[0017] Among them, 1. fermentation tank; 2. water tank; 3. central tube; 4. synchronous belt; 5. arc tube; 6. discharge port; 7. air supply pipe; 8. venturi tube; 9. connecting pipe; 10. stirring plate; 11. sampling mechanism; 12. flexible shaft; 13. feeding port; 14. motor; 15. fixed rod; 16. rotating shaft; 17. driving mechanism; 18. internal gear ring; 19. driving gear; 20. motor; 21. air inlet; 22. air inlet pipe; 23. sampling tube; 24. fluid pump; 25. extension tube; 26. driving tube; 27. threaded rod; 28. electromagnet; 29. ​​slide seat; 30. solenoid valve; 31. mounting seat; 32. temperature control mechanism; 33. air supply mechanism; 34. stirring mechanism; 35. temperature control tube. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] Example 1: Reference Figures 1-8 As shown, the embodiment of the present invention provides a green production method of lactic acid for food, comprising the following steps: Step S1, mixing a mixture of 20%-25% glucose and 40%-45% corn starch in a volume ratio of 100:15, then introducing the mixture into a fermentation device, and heating the mixture at 100 degrees Celsius for 10 minutes to eliminate bacteria; Step S2, cooling the sterilized fermentation raw materials to below 50 degrees Celsius, inoculating lactic acid bacteria therein, introducing sterile gas into the fermentation equipment and exhausting it, and then fermenting at 30-45 degrees Celsius for 15-20 hours, sampling the fermentation liquid several times during the fermentation process to detect the pH value, and adding 0.15-0.2 mol / L calcium hydroxide solution when the pH value is lower than 5.5 to adjust the pH to between 5.5-6.0, stirring continuously during the fermentation process to fully mix the materials, and the fermentation process is carried out without oxygen into the fermentation equipment. At the same time, the pH value is accurately adjusted, thereby achieving green and environmentally friendly fermentation of lactic acid and improving the quality of lactic acid fermentation; Step S3: Cooling the fermented raw materials, separating and purifying them, and then filling and refrigerating them to obtain the finished products.

[0020] Example 2: Reference Figures 1-8 As shown, an embodiment of the present invention provides a green production device for lactic acid for food, comprising: The fermenter 1 is provided with a feeding port 13 at the top of the fermenter 1, and a sealing cover is provided on the top of the feeding port 13. The middle of the fermenter 1 is provided with a gas supply mechanism 33 and a sampling mechanism 11. The gas provided by the gas supply mechanism 33 is an oxygen-free and sterile gas. The sealing cover is provided with a sealable pipeline for feeding fermentation raw materials; The temperature control mechanism 32 includes a water tank 2 and a temperature control tube 35. The water tank 2 is cylindrical and is sleeved on the outside of the fermentation tank 1. A gap for passing hot water is formed between the water tank 2 and the fermentation tank 1. Multiple groups of temperature control tubes 35 are arranged in the gap from top to bottom. The water tank 2 is equipped with a water inlet and a water outlet. Each temperature control tube 35 is provided with a water outlet pipe and a water inlet pipe. The temperature control tube 35 can pass hot water of different temperatures according to the actual fermentation time. Combined with the water tank 2, the fermentation tank 1 is heated over a large area to achieve large-scale temperature control. Through the combination of the water tank 2 and the temperature control tube 35, the water tank 2 quickly improves the temperature in the fermentation tank 1, so that it quickly reaches the ideal fermentation temperature range. The temperature control tube 35 can compensate for the temperature lost by the water tank 2 within the fermentation range, and accurately adjust. Through coarse and fine temperature control, the fermentation tank 1 is accurately heated and evenly heated, and the fermentation temperature is accurately adjusted, so that the fermentation lactic acid yield is high and the quality is excellent; The stirring mechanism 34 includes a synchronous belt 4 and a stirring plate 10. The upper and lower corresponding rotating shafts 16 of the two arc tubes 5 are connected by a synchronous wheel and a synchronous belt 4. Each synchronous belt 4 is provided with multiple sets of stirring plates 10, a driving mechanism 17, and a driving mechanism 17 includes a motor 14, a flexible shaft 12, a driving gear 19, an arc tube 5 and a rotating shaft 16. There are two arc tubes 5 in total. The two arc tubes 5 are detachably mounted on the upper and lower parts of the fermentation tank 1 through a fixing rod 15. The motor 14 is mounted on the top of the sealing cover. The driving end of the motor 14 is fixed to each other through a coupling and a flexible shaft 12. There are multiple drive gears 19 and they are all arranged on the flexible shaft 12. Multiple rotating shafts 16 are arranged on the arc tube 5, and an inner gear ring is provided on the inner side of the rotating shaft 16 in the upper arc tube 5. 18 and the inner gear ring 18 and the driving gear 19 cooperate with each other, and the motor 14 drives the flexible shaft 12 to drive the driving gear 19 and the inner gear ring 18 to rotate synchronously. The inner gear ring 18 drives the rotating shaft 16 to rotate through the synchronous wheel driving the synchronous belt 4. The stirring plate 10 on the synchronous belt 4 lifts the fermentation material at the bottom of the fermentation tank 1 upward from bottom to top. The fermentation raw materials in the fermentation tank 1 are fully mixed and the temperature is balanced. The bacteria are slowly mixed to fully decompose the sugar to form lactic acid. The stirring from bottom to top lifts the material deposited at the bottom of the fermentation tank 1 and fully mixes it with the upper material. At the same time, the slow stirring facilitates the reproduction of the bacteria to produce lactic acid, so that the efficiency of stirring the material from bottom to top is stable, and the material will not be unevenly fermented due to the fast rotation speed of the lower material and the slow rotation speed of the upper material, and the temperature is also balanced.

[0021] The air supply mechanism 33 comprises a central pipe 3, an air inlet pipe 22, an air inlet 21, a connecting pipe 9, an air supply pipe 7 and a Venturi tube 8, the central pipe 3 is arranged in the middle of the fermentation tank 1 and the top end of the central pipe 3 penetrates the top of the fermentation tank 1, the air supply pipe 7 is circular, the Venturi tube 8 has a plurality of Venturi tubes arranged on the air supply pipe 7, the air supply pipe 7 is detachably arranged in the lower part of the fermentation tank 1, the air supply pipe 7 is connected with the connecting pipe 9, the connecting pipe 9 is connected with the air inlet pipe 22, the air inlet pipe 22 is arranged on one side of the central pipe 3, the top of the air inlet pipe 22 is connected with the air inlet 21, the air inlet 21 is connected with a sterile air supply device, the bottom of the air inlet pipe 22 is provided with a remotely controlled electromagnetic valve, and the outside of the electromagnetic valve is provided with a waterproof cover.

[0022] The sampling mechanism 11 comprises a driving pipe 26, an electromagnet 28, a mounting seat 31, a sliding seat 29, an electromagnetic valve 30, an extension pipe 25, a fluid pump 24, a sampling pipe 23, a threaded rod 27 and a motor 20, the fluid pump 24 is a bidirectional gear pump, which can facilitate sampling and inputting calcium hydroxide solution into the fermentation tank 1, the driving pipe 26 is arranged on the side away from the air inlet pipe 22 in the central pipe 3, the threaded rod 27 is rotatably connected in the driving pipe 26, the motor 20 is arranged on the top of the driving pipe 26, the upper end of the threaded rod 27 is connected with the driving end of the motor 20 through a shaft coupling, the sliding seat 29 is slidably connected in the driving pipe 26, the sliding seat 29 is threadedly connected with the threaded rod 27, the sliding seat 29 is made of iron, the sliding seat 29 is slidably sleeved with the electromagnet 28 on the outside of the central pipe 3, one side of the electromagnet 28 is fixedly connected with the mounting seat 31, the lower end of the extension pipe 25 penetrates the mounting seat 31, the upper end of the extension pipe 25 penetrates the fermentation tank 1 and is connected with the water inlet end of the fluid pump 24, the fluid pump 24 is arranged on the top of the fermentation tank 1, the output end of the fluid pump 24 is connected with the sampling pipe 23, the lower end of the extension pipe 25 is connected with the remotely controlled electromagnetic valve 30, the sliding seat 29 slides up and down in the driving pipe 26 by driving the threaded rod 27 with the motor 20, when sliding, the sliding seat 29 drives the electromagnet 28 to slide up and down outside the central pipe 3, the electromagnet 28 drives the mounting seat 31 to be at different depths in the fermentation tank 1, the electromagnetic valve 30 is opened at different depths respectively, the fluid pump 24 sucks the fermentation liquid through the extension pipe 25 and leads out from the sampling pipe 23, the acid-base values at different depths in the fermentation tank 1 are measured, when the acid-base needs to be adjusted, the sampling pipe 23 is connected with the calcium hydroxide solution, the fluid pump 24 reversely leads the calcium hydroxide solution into the fermentation tank 1 through the extension pipe 24, the pH value in the fermentation tank 1 is increased to 5.5-6.0 by the stirring mechanism 34, the setting of sealed sampling and air leakage-free acid-base neutralization makes the lactic acid production green and environmentally friendly, the air does not flow into the fermentation tank 1, the fermentation material is not polluted, the lactic acid fermentation production is more green and environmentally friendly, the setting of multi-point non-contact rapid sampling can accurately control the fermentation condition in the fermentation tank and ensure the lactic acid to be fermented in the best process.

[0023] The top of the fermentation tank 1 is provided with a pressure relief valve and an exhaust valve, and the bottom of the fermentation tank 1 is provided with a discharge port 6.

[0024] Embodiment three: Referring to Figures 1-8 The embodiment of the present application provides a food lactic acid green production process, which comprises the following process steps: Step one, fermentation process: through the feeding port 13, glucose with sugar content of 20%-25% and corn starch mixed solution with 40%-45% are put into the fermentation tank 1, 100 degrees Celsius hot water is introduced into the water tank 2, water vapor higher than 100 degrees Celsius is introduced into the temperature control pipe 35 to keep the water temperature in the water tank 2 boiling at all times, the raw material substrate in the fermentation tank 1 is heated at 100 degrees Celsius for 10 minutes, then the temperature in the fermentation tank 1 is reduced to below 50 degrees Celsius through the water tank 2, then lactic acid bacteria is inoculated into the fermentation tank 1, after inoculation, the electromagnetic valve on the air inlet pipe 22 is opened, the sterile anaerobic gas is introduced into the air inlet pipe 22 through the sterile gas supply assembly through the air inlet 21, the gas is released in the fermentation tank 1 through the connecting pipe 9, the air supply pipe 7 and the venturi tube 8 in turn, after the oxygen in the fermentation tank 1 is gradually squeezed out, the feeding port 13 is sealed by the sealing cover, the water tank 2 is introduced into 40 degrees Celsius warm water, and the fermentation tank 1 is fermented at 30-45 degrees Celsius for 15-20 hours; Step two, stirring management process during fermentation: the motor 14 drives the driving gear 19 and the inner tooth ring 18 to rotate synchronously through the flexible shaft 12, the inner tooth ring 18 drives the rotating shaft 16 to rotate through the synchronous wheel and the synchronous belt 4, the stirring plate 10 on the synchronous belt 4 lifts the fermentation material at the bottom of the fermentation tank 1 from bottom to top, the fermentation raw materials in the fermentation tank 1 are fully mixed and the temperature is balanced, the bacteria decompose the sugar to form lactic acid through slow mixing; Step three, acid-base adjustment process during fermentation: the motor 20 drives the sliding seat 29 to slide up and down in the driving pipe 26 through the threaded rod 27, when sliding, the sliding seat 29 drives the electromagnet 28 to slide up and down outside the center pipe 3, the electromagnet 28 drives the mounting seat 31 to be installed at different depths in the fermentation tank 1, different electromagnetic valves 30 are opened at different depths, the fluid pump 24 draws the fermentation liquid from the sampling pipe 23 through the extension pipe 25, the acid-base value at different depths in the fermentation tank 1 is measured, when the pH value is lower than 5.5, the sampling pipe 23 is connected to 0.15 moles per liter of calcium hydroxide solution, the fluid pump 24 reverses to introduce the calcium hydroxide solution into the fermentation tank 1 through the extension pipe 25, and the pH value in the fermentation tank 1 is increased to 5.5-6.0 through the stirring mechanism 34; Step four, temperature process during fermentation: the internal temperature of the fermentation tank 1 is changed through the water tank 2, the temperature in the water tank 2 is fine-tuned through the temperature control pipe 35, and the temperature loss caused by the fermentation tank 1 and the water tank 2 is compensated; Step five, after the fermentation is completed, the mixture in the fermentation tank 1 is discharged through the discharge port 6 for next step processing.

[0025] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A green production method of lactic acid for food, characterized by: The following steps are involved: Step S1, mixing a mixture of 20%-25% glucose and 40%-45% corn starch in a volume ratio of 100:15, then introducing the mixture into a fermentation device, and heating the mixture at 100 degrees Celsius for 10 minutes to eliminate bacteria; Step S2, cooling the sterilized fermentation raw materials to below 50 degrees Celsius, inoculating lactic acid bacteria therein, introducing sterile gas into the fermentation equipment and exhausting it, and then fermenting at 30-45 degrees Celsius for 15-20 hours, sampling the fermentation liquid several times during the fermentation process to detect the pH value, and adding 0.15-0.2 mol / L calcium hydroxide solution to adjust the pH to between 5.5 and 6.0 if the pH value is lower than 5.5, and stirring continuously during the fermentation process to fully mix the materials; Step S3: Cooling the fermented raw materials, separating and purifying them, and then filling and refrigerating them to obtain the finished products.

2. A green production equipment for lactic acid for food, which is the fermentation equipment for green production of lactic acid for food mentioned in claim 1, characterized in that: include: A fermentation tank (1), wherein a feeding port (13) is provided at the top of the fermentation tank (1), a sealing cover is provided at the top of the feeding port (13), and an air supply mechanism (33) and a sampling mechanism (11) are provided in the middle of the fermentation tank (1); a temperature control mechanism (32), the temperature control mechanism (32) comprising a water tank (2) and a temperature control tube (35); the water tank (2) is cylindrical and is sleeved on the outside of the fermentation tank (1); a gap for passing hot water is formed between the water tank (2) and the fermentation tank (1); and a plurality of groups of temperature control tubes (35) are arranged in the gap from top to bottom; A driving mechanism (17), the driving mechanism (17) comprising a motor (14), a flexible shaft (12), a driving gear (19), an arc tube (5) and a rotating shaft (16), wherein there are two arc tubes (5), and the two arc tubes (5) are detachably mounted on the upper and lower parts of the fermentation tank (1) through fixing rods (15), the motor (14) is mounted on the top of the sealing cover, the driving end of the motor (14) is fixed to each other through a coupling and the flexible shaft (12), there are a plurality of driving gears (19) and all of them are arranged on the flexible shaft (12), a plurality of rotating shafts (16) are arranged on the arc tube (5), an inner gear ring (18) is arranged on the inner side of the rotating shaft (16) in the upper arc tube (5), and the inner gear ring (18) and the driving gear (19) cooperate with each other; A stirring mechanism (34) includes a synchronous belt (4) and a stirring plate (10). The upper and lower corresponding rotating shafts (16) of the two arc tubes (5) are connected via a synchronous wheel and a synchronous belt (4). Each synchronous belt (4) is provided with a plurality of stirring plates (10).

3. The green production equipment for lactic acid for food according to claim 2, characterized in that: The water tank (2) is provided with a water inlet and a water outlet, and each of the temperature control pipes (35) is provided with a water outlet pipe and a water inlet pipe.

4. The green production equipment for lactic acid for food according to claim 2, characterized in that: The air supply mechanism (33) comprises a central tube (3), an air inlet pipe (22), an air inlet (21), a connecting pipe (9), an air delivery pipe (7) and a venturi tube (8). The central tube (3) is arranged in the middle of the fermentation tank (1) and the top of the central tube (3) passes through the top of the fermentation tank (1). The air delivery pipe (7) is circular. A plurality of venturi tubes (8) are arranged on the air delivery pipe (7). The air delivery pipe (7) is detachably mounted in the lower part of the fermentation tank (1). The air delivery pipe (7) and the connecting pipe (9) are connected. The connecting pipe (9) and the air inlet pipe (22) are connected. The air inlet pipe (22) is arranged on one side of the central tube (3). The top of the air inlet pipe (22) is connected to the air inlet (21). The air inlet (21) is connected to a sterile air supply device. A remotely controllable electromagnetic valve is arranged at the bottom of the air inlet pipe (22) and a waterproof cover is arranged outside the electromagnetic valve.

5. The green production equipment for lactic acid for food according to claim 4, characterized in that: The sampling mechanism (11) comprises a driving tube (26), an electromagnet (28), a mounting seat (31), a slide seat (29), an extension tube (25) of a solenoid valve (30), a fluid pump (24), a sampling tube (23), a threaded rod (27) and a motor (20), wherein the driving tube (26) is arranged on a side away from the air inlet pipe (22) in the center tube (3), the threaded rod (27) is rotatably connected in the driving tube (26), the motor (20) is mounted on the top of the driving tube (26), the upper end of the threaded rod (27) and the driving end of the motor (20) are connected via a coupling, the slide seat (29) is slidably connected in the driving tube (26), and the slide seat (29) is slidably connected in the driving tube (26). The seat (29) and the threaded rod (27) are threadedly connected. The slide seat (29) is made of iron. The slide seat (29) is provided with an electromagnet (28) on the outer sliding sleeve corresponding to the simmered central tube (3). One side of the electromagnet (28) and the mounting seat (31) are fixed to each other. The lower end of the extension tube (25) passes through the mounting seat (31). The upper end of the extension tube (25) passes through the fermentation tank (1) and is connected to the water inlet end of the fluid pump (24). The fluid pump (24) is installed on the top of the fermentation tank (1). The output end of the fluid pump (24) is connected to the sampling tube (23). The lower end of the extension tube (25) is connected to a remotely controllable electromagnetic valve (30).

6. The green production equipment for lactic acid for food according to claim 2, characterized in that: A pressure relief valve and an exhaust valve are provided at the top of the fermentation tank (1), and a feed outlet (6) is provided at the bottom of the fermentation tank (1).

7. A green production process for lactic acid for food, wherein the equipment used in the green production process for lactic acid for food is the green production equipment for lactic acid for food described in any one of claims 2 to 6, characterized in that: The process steps include: Step 1, fermentation process: a mixture of glucose with a sugar content of 20%-25% and corn starch with a sugar content of 40%-45% is added into the fermentation tank (1) through the feeding port (13), 100 degrees Celsius hot water is introduced into the water tank (2), and water vapor with a temperature higher than 100 degrees Celsius is introduced into the temperature control pipe (35) so that the water temperature in the water tank (2) is always in a boiling state without losing temperature. The raw material base material in the fermentation tank (1) is fully heated at 100 degrees Celsius for 10 minutes, and then the temperature in the fermentation tank (1) is reduced to 50 degrees Celsius through the water tank (2). Next, lactic acid bacteria are inoculated into the fermentation tank (1). After inoculation, the solenoid valve on the air inlet pipe (22) is opened, and sterile oxygen-free gas is introduced into the air inlet pipe (22) through the air inlet (21) using a sterile air supply assembly. The gas is released into the fermentation tank (1) through the connecting pipe (9), the air supply pipe (7) and the venturi tube (8) in sequence. After the oxygen in the fermentation tank (1) is gradually squeezed out, the feeding port (13) is sealed with a sealing cover, and 40°C warm water is introduced into the water tank (2). The fermentation tank (1) is fermented at a temperature between 30°C and 45°C for 15-20 hours. Step 2: Stirring management process during fermentation: the motor (14) drives the driving gear (19) and the inner gear ring (18) to rotate synchronously through the flexible shaft (12); the inner gear ring (18) causes the rotating shaft (16) to drive the synchronous belt (4) to rotate through the synchronous wheel; the stirring plate (10) on the synchronous belt (4) lifts the fermentation material at the bottom of the fermentation tank (1) upward from bottom to top; the fermentation material in the fermentation tank (1) is fully mixed and the temperature is balanced; the bacteria are fully decomposed into sugar to form lactic acid after slow mixing; Step 3, acid-base adjustment process during fermentation: the motor (20) causes the slide (29) to slide up and down in the drive tube (26) through the threaded rod (27). When sliding, the slide (29) drives the electromagnet (28) to slide up and down on the outside of the central tube (3). The electromagnet (28) drives the mounting seat (31) to different depths in the fermenter (1). The solenoid valve (30) is opened at different depths. The fluid pump (24) draws the fermentation liquid from the sampling tube (23) through the extension tube (25) to measure the pH value at different depths in the fermenter (1). If the pH value is lower than 5.5, the sampling tube (23) is connected to a 0.15 mol / L calcium hydroxide solution. The fluid pump (24) reversely passes the calcium hydroxide solution through the extension tube (25) into the fermenter (1). The pH value in the fermenter (1) is raised to between 5.5 and 6.0 through the stirring mechanism 34. Step 4: Temperature process during fermentation: changing the internal temperature of the fermentation tank (1) through the water tank (2), and fine-tuning the temperature in the water tank (2) through the temperature control tube (35) to compensate for the loss of temperature caused by the fermentation tank (1) and the water tank (2); Step 5: After fermentation is completed, the mixture in the fermentation tank (1) is discharged through the discharge port (6) for further processing.

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