Tower type extraction equipment and process for co-production of lutein and zeaxanthine

Abstract

The invention discloses tower type extraction equipment and technology for co-production of lutein and zeaxanthine, and relates to the technical field of natural product extraction and separation. Ferric chloride and ferrous chloride are added into deionized water, a solution is heated, a stirring device is started for stirring after heating is completed, ammonia water is added after stirring is completed, and a mixture is obtained; the preparation method has the advantages that ferroferric oxide magnetic nano-particles are prepared by adopting a coprecipitation method to serve as magnetic nano-materials, so that the ferroferric oxide magnetic nano-particles have the characteristic of rapid aggregation under the action of an external magnetic field, the magnetic nano-materials can be rapidly aggregated under the action of the external magnetic field in the separation process after demulsification, the two-phase separation process is greatly accelerated, and the separation efficiency is improved. The separation operation is more convenient and efficient, and when an emulsification phenomenon occurs, the surface active ionic liquid in the demulsifier rapidly reduces the interfacial tension and promotes the rapid disintegration of an emulsification structure, so that the extraction efficiency is remarkably improved, and adverse effects on the structures and properties of xanthophyll and zeaxanthine can be effectively avoided.

Description

Technical Field

[0001] The invention relates to the technical field of natural product extraction and separation, in particular to tower extraction equipment and a process for the co-production of lutein and zeaxanthin. Background Art

[0002] Lutein, also known as plant lutein, is a natural pigment widely found in vegetables, flowers, fruits and other plants. It has strong antioxidant properties and can protect cells from free radical damage. In the human body, lutein mainly accumulates in the macula of the retina, which can effectively filter blue light and prevent the occurrence of retinal and macular diseases. It plays a vital role in eye health. Zeaxanthin has a similar structure to lutein and has similar physiological functions. It is also a highly effective antioxidant that can reduce the damage of oxidative stress to the body. In terms of eye health, zeaxanthin and lutein work synergistically to maintain the health of the retina. In the food field, zeaxanthin can be used as a natural pigment, and because of its good stability and safety, it is favored by more and more food companies. In the medical field, studies have shown that zeaxanthin has a potential role in the prevention and treatment of certain chronic diseases, such as the prevention of cardiovascular diseases. The existing technology has certain defects. First, emulsification is easy to occur in the liquid-liquid extraction system. Emulsification will make it difficult to separate the extract phase and the residual phase, reduce the extraction efficiency, and increase the difficulty of subsequent processing. The currently commonly used demulsification methods such as heating and centrifugation have limited effects and may have adverse effects on the structure and properties of lutein and zeaxanthin. If a new type of high-efficiency demulsifier can be developed, it can quickly and gently eliminate the emulsification phenomenon, so that the two phases can be separated smoothly without affecting the quality of the target product. The extraction process will be greatly improved. Secondly, in the crystallization process of lutein and zeaxanthin, the existing methods are often difficult to obtain ideal crystal morphology and particle size distribution. Spontaneous crystallization may cause slow crystal growth and irregular crystal form, affecting the quality of the product and subsequent processing performance. If a new type of seed inducer can be prepared, it can effectively guide lutein and zeaxanthin to form regular and uniform crystals, control the growth rate and particle size of the crystals, improve the crystallization efficiency and product quality, and meet the requirements of product crystal morphology in different application fields. To this end, we propose a tower extraction equipment and process for the co-production of lutein and zeaxanthin. Summary of the invention

[0003] The object of the present invention is to provide a tower extraction device and process for the co-production of lutein and zeaxanthin.

[0004] In order to solve the problems raised in the above background technology, the present invention provides the following technical solution: a tower extraction process for co-production of lutein and zeaxanthin, the tower extraction process comprising the following steps: Step 1, slowly adding ferric chloride and ferrous chloride into deionized water, heating the solution, turning on a stirring device to stir after the heating is completed, adding ammonia water after the stirring is completed, and adding polyvinyl pyrrolidone at the same time, stirring and reacting continuously, after the reaction is completed, washing the precipitate alternately with deionized water and anhydrous ethanol, separating the precipitate by applying an external magnetic field after each washing, and finally placing the separated precipitate in a vacuum drying oven to dry to obtain a magnetic nanomaterial; Step 2: Take N-methylimidazole and dodecane bromide as raw materials, add them to anhydrous ethanol, control the temperature of the reaction system, and then start stirring to obtain an imidazole ionic liquid, then add 1-butyl-3-methylimidazole p-toluenesulfonate to the imidazole ionic liquid and continue to stir and react, after the reaction is completed, add sodium fluoride to the system and continue to react, and after the reaction is completed, remove ethanol using a rotary evaporator to obtain a surface active ionic liquid; Step 3: Mix the prepared magnetic nanomaterial with the surfactant ionic liquid, then add deionized water, and then add the sodium alginate solution, transfer the mixed system to an ultrasonic instrument for ultrasonic dispersion treatment, so that the magnetic nanomaterial and the surfactant ionic liquid are evenly dispersed in the water to obtain a demulsifier; Step 4, weighing terephthalic acid and dissolving it in N,N-dimethylformamide to prepare an N,N-dimethylformamide solution of terephthalic acid, separately dissolving zinc nitrate in deionized water to obtain a zinc nitrate solution, and then stirring, slowly dropping the zinc nitrate solution into the N,N-dimethylformamide solution of terephthalic acid, and adding 2,5-thiophenedicarboxylic acid as a second organic ligand, after the dropwise addition is completed, transferring the mixed solution to a reactor for reaction, and then washing the product with N,N-dimethylformamide and ethanol in turn, centrifuging after each washing, and finally drying the product to obtain a metal organic framework material; Step 5: Select a metal organic framework material and a β-carotene derivative, add them to a mixed solvent containing 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride, N-hydroxysuccinimide and 1,3-dicyclohexylcarbodiimide, dimethyl sulfoxide and N-methylpyrrolidone, and then stir them to react so that the β-carotene derivative and the metal organic framework material undergo a coupling reaction through a covalent bond. After the reaction is completed, transfer the reaction solution to a centrifuge tube for centrifugation, collect the precipitate, and wash the precipitate with dimethyl sulfoxide to obtain a seed inducer; Step 6: pretreat fresh marigold flowers as raw materials, put the pretreated marigold raw materials into a tower extraction equipment, select ethyl acetate and n-butanol mixed solvent as the extractant for extraction, during the extraction process, add a demulsifier to the emulsified system, gently stir and let stand, then apply an external magnetic field to quickly separate the demulsifier, and at the same time, introduce carbon dioxide gas into the extraction system. After the extraction is completed, the extraction phase is treated to reach a supersaturated state of crystallization, then a seed inducer is added to the solution and continued to be stirred to form regular and uniform crystals of lutein and zeaxanthin, followed by filtering, using a microporous filter membrane for vacuum filtration to separate the crystals from the mother liquor, and finally performing a drying operation to obtain high-purity lutein and zeaxanthin products, completing the entire co-production tower extraction and crystallization process.

[0005] As a further scheme of the present invention: in the step 1, 18mmol-22mmol of ferric chloride and 9mmol-11mmol of ferrous chloride are slowly added to 180mL-220mL of deionized water, and the solution is heated to 80°C-90°C under the continuous protection of nitrogen, and the stirring speed is controlled to 800r / min-1000r / min, and the stirring time is 30min-45min. After the stirring is completed, 45mL-55mL of ammonia water is added, and 0.5mmol-1.5mmol of polyvinyl pyrrolidone is added at the same time, and the reaction is continuously stirred for 1h-2h, and the precipitate is washed 3-4 times, and the precipitate is placed in a vacuum drying oven at 65°C-75°C and dried for 6h-8h.

[0006] As a further scheme of the present invention: in the step 2, 18mmol-22mmol of N-methylimidazole and 21mmol-25mmol of dodecane bromide are taken, and they are added to 130mL-170mL of anhydrous ethanol, the temperature of the reaction system is controlled at 65℃-75℃, the stirring speed is set to 350r / min-450r / min, and the reaction is continued for 16h-20h, 23mmol-27mmol of 1-butyl-3-methylimidazole p-toluenesulfonate is added, the reaction temperature is adjusted to 55℃-65℃, and the stirring reaction is continued for 8h-12h. After the reaction is completed, 5mmol-10mmol of sodium fluoride is added to the system, and the reaction is continued at 40℃-50℃ for 2h-4h. After the reaction is completed, ethanol is removed by a rotary evaporator at 45℃-55℃ and reduced pressure.

[0007] As a further scheme of the present invention: in the step three, the amount of magnetic nanomaterial added is 4g-6g, the amount of surfactant ionic liquid added is 13g-17g, the content of deionized water added is 80mL-120mL, the concentration of sodium alginate solution added is 0.13mol / L-0.3mol / L, the content is 2mL-5mL, the ultrasonic power of the ultrasonic instrument is set to 200W-300W, and the ultrasonic dispersion is 30min-60min.

[0008] As a further scheme of the present invention: in the step 4, terephthalic acid having a content of 13 mmol-17 mmol is weighed and dissolved in 100 mL-140 mL of N,N-dimethylformamide, zinc nitrate having a content of 6.5 mmol-8.5 mmol is dissolved in 50 mL-70 mL of deionized water, and stirred at a speed of 350 r / min-450 r / min, 2,5-thiophenedicarboxylic acid having a content of 3 mmol-7 mmol is added, the reactor is reacted at a temperature of 120°C-140°C for 16h-20h, and after the reaction, the product is washed 3-4 times, and the centrifugal speed is controlled to be 5500 r / min-6500 r / min for centrifugal separation, and the centrifugal time is 10min-14min, and finally the product is dried in a vacuum drying oven at 85°C-95°C for 8h-12h.

[0009] As a further scheme of the present invention: in the step 5, 4g-6g of the metal organic framework material and 2g-3g of the β-carotene derivative are selected and added to 80mL-120mL of a mixed solvent containing 0.4g-0.6g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.3g-0.5g of N-hydroxysuccinimide and 0.2g-0.5g of 1,3-dicyclohexylcarbodiimide and dimethyl sulfoxide and N-methylpyrrolidone in a volume ratio of 1-2:1, the temperature of the reaction system is controlled to be 45°C-55°C, the stirring speed is set to 250r / min-350r / min during stirring, the reaction is continued for 16h-20h, the centrifuge tube is centrifuged at a speed of 6500r / min-7500r / min for 12min-16min, and the precipitate is washed 3-4 times with dimethyl sulfoxide.

[0010] As a further scheme of the present invention: in the step six, the process of pretreating fresh marigold flowers as raw materials is as follows: first, cleaning is performed to remove impurities in the raw materials, and then the cleaned raw materials are crushed. For fresh marigold flowers, a high-speed crusher is used to crush them into particles with a particle size of 2mm-5mm. The crushed marigold particles are placed in a sodium carbonate solution with a mass fraction of 0.5%-1.5%, and the amount of sodium carbonate solution added is 2-3 times the mass of the crushed marigold particles. The raw materials are soaked at 40℃-50℃ for 1h-2h to remove impurities in the raw materials. After soaking, the pretreated solid raw materials are separated by filtration. Then, the solid raw materials are washed with deionized water for 2-3 times to remove the residual sodium carbonate solution. Finally, the washed raw materials are dried at a temperature of 40℃-50℃ for 2h-3h to complete the pretreatment of the marigold raw materials.

[0011] As a further scheme of the present invention: in the step six, the mixed solvent extractant is ethyl acetate and n-butanol mixed in a volume ratio of 1.5-4:1, the added demulsifier accounts for 1.5%-2.5% of the volume of the emulsion, and the mixture is allowed to stand for 8min-12min after stirring. The flow rate of carbon dioxide gas introduced is 50mL / min-100mL / min, so that the pressure in the system is controlled at 0.1MPa-0.3MPa, and the continuous introduction time is 30min-60min. The seed inducer added to the solution accounts for 0.8%-1.2% of the solution mass, the crystallization temperature is controlled to be 18°C-22°C, and the mixture is slowly stirred at a speed of 100r / min-140r / min for 40min-60min. The filtration operation adopts a pore size of 0.22μm-0.45μm, and the drying operation is dried for 8h-12h under the conditions of a pressure of 0.1kPa-0.5kPa and a temperature of 30°C-40°C.

[0012] As a further scheme of the present invention: in the step six, the extraction phase is treated to reach a supersaturated state of crystallization, and the process is as follows: the extraction phase is transferred to a reduced pressure distillation apparatus, and under the conditions of a pressure of 2kPa-5kPa and a temperature of 40°C-50°C, part of the low-boiling point extractant is distilled off to gradually increase the concentration of the solute in the solution. When the density of the solution reaches 1.05g / cm³-1.15g / cm³, the distillation is stopped, and the solution reaches a supersaturated state.

[0013] In addition, the present invention also provides a tower extraction device for the co-production of lutein and zeaxanthin, which includes a reaction container, a heating device, a stirring device, a nitrogen supply device, a separatory funnel, a centrifuge, a vacuum drying oven, a condensation reflux device, a rotary evaporator, an ultrasonic disperser, a constant pressure dropping funnel, a washing device, a cleaning device, a pulverizer, a soaking container, a filtering device, and a tower extraction device.

[0014] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are: 1. The present invention adopts a coprecipitation method to prepare ferroferric oxide magnetic nanoparticles as magnetic nanomaterials, so that the magnetic nanoparticles have the characteristic of rapid aggregation under an external magnetic field. In the separation process after demulsification, the magnetic nanomaterial can rapidly aggregate under the action of the external magnetic field, which greatly accelerates the two-phase separation process and makes the separation operation more convenient and efficient. The imidazole ionic liquid is prepared by selecting N-methylimidazole and halogenated alkane to react, and then reacts with a sulfonic acid group-containing compound to obtain a surface active ionic liquid with a unique anionic and cationic structure. This structure gives the surface active ionic liquid a strong ability to reduce interfacial tension, so that it has a stronger ability to destroy the emulsified system. Compared with traditional demulsifiers, the surfactant ionic liquid can destroy the emulsion structure more quickly and thoroughly, greatly improving the demulsification efficiency. The magnetic nanomaterials are compounded with the surfactant ionic liquid to prepare a demulsifier. In the liquid-liquid extraction of lutein and zeaxanthin, when emulsification occurs, the surfactant ionic liquid in the demulsifier quickly reduces the interfacial tension, causing the emulsion structure to quickly disintegrate. Moreover, with the help of the characteristics of the magnetic nanomaterials, the demulsifier can be quickly aggregated and separated by an external magnetic field, which not only significantly improves the extraction efficiency, but also effectively avoids adverse effects on the structure and properties of lutein and zeaxanthin, ensuring the high quality of the product. 2. The present invention selects terephthalic acid and zinc nitrate as raw materials to prepare the metal organic framework material, so that it has a highly ordered pore structure and a large specific surface area. This unique structure provides abundant adsorption sites for lutein and zeaxanthin molecules, can adsorb a large number of target molecules, and provides a sufficient material basis for the growth of crystals. By coupling the β-carotene derivatives with similar structures to lutein and zeaxanthin with the metal organic framework material, the biological small molecules can specifically guide the lutein and zeaxanthin molecules to grow in an orderly arrangement in the pores because the biological small molecules and the target molecules have similar chemical structures and interaction modes. The anisotropic guiding effect can effectively control the growth direction and speed of crystals and avoid the disordered growth of crystals. The metal organic framework material coupled with biological small molecules is used as a seed inducer in the crystallization process of lutein and zeaxanthin. The inducer is added after the crystallization solution reaches a supersaturated state. Under its action, the lutein and zeaxanthin molecules can grow in an orderly manner in the pores to form crystals with uniform particle size and good crystal shape. Compared with traditional crystallization methods, the seed inducer significantly improves the crystallization efficiency and reduces the crystal growth time. At the same time, the high-quality crystals obtained improve the quality of the product and meet the strict requirements of different application fields on crystal morphology and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the process steps in the embodiment of the present invention. DETAILED DESCRIPTION

[0016] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0017] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] Please see attached Figure 1 The present invention provides a tower extraction process for co-production of lutein and zeaxanthin, the tower extraction process comprising the following steps: Step 1, slowly adding ferric chloride and ferrous chloride into deionized water, heating the solution, turning on a stirring device to stir after the heating is completed, adding ammonia water after the stirring is completed, and adding polyvinyl pyrrolidone at the same time, stirring and reacting continuously, after the reaction is completed, washing the precipitate alternately with deionized water and anhydrous ethanol, separating the precipitate by applying an external magnetic field after each washing, and finally placing the separated precipitate in a vacuum drying oven to dry to obtain a magnetic nanomaterial; Step 2: Take N-methylimidazole and dodecane bromide as raw materials, add them to anhydrous ethanol, control the temperature of the reaction system, and then start stirring to obtain an imidazole ionic liquid, then add 1-butyl-3-methylimidazole p-toluenesulfonate to the imidazole ionic liquid and continue to stir and react, after the reaction is completed, add sodium fluoride to the system and continue to react, and after the reaction is completed, remove ethanol using a rotary evaporator to obtain a surface active ionic liquid; Step 3: Mix the prepared magnetic nanomaterial with the surfactant ionic liquid, then add deionized water, and then add the sodium alginate solution, transfer the mixed system to an ultrasonic instrument for ultrasonic dispersion treatment, so that the magnetic nanomaterial and the surfactant ionic liquid are evenly dispersed in the water to obtain a demulsifier; Step 4, weighing terephthalic acid and dissolving it in N,N-dimethylformamide to prepare an N,N-dimethylformamide solution of terephthalic acid, separately dissolving zinc nitrate in deionized water to obtain a zinc nitrate solution, and then stirring, slowly dropping the zinc nitrate solution into the N,N-dimethylformamide solution of terephthalic acid, and adding 2,5-thiophenedicarboxylic acid as a second organic ligand, after the dropwise addition is completed, transferring the mixed solution to a reactor for reaction, and then washing the product with N,N-dimethylformamide and ethanol in turn, centrifuging after each washing, and finally drying the product to obtain a metal organic framework material; Step 5: Select a metal organic framework material and a β-carotene derivative, add them to a mixed solvent containing 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride, N-hydroxysuccinimide and 1,3-dicyclohexylcarbodiimide, dimethyl sulfoxide and N-methylpyrrolidone, and then stir them to react so that the β-carotene derivative and the metal organic framework material undergo a coupling reaction through a covalent bond. After the reaction is completed, transfer the reaction solution to a centrifuge tube for centrifugation, collect the precipitate, and wash the precipitate with dimethyl sulfoxide to obtain a seed inducer; Step 6: pretreat fresh marigold flowers as raw materials, put the pretreated marigold raw materials into a tower extraction equipment, select ethyl acetate and n-butanol mixed solvent as the extractant for extraction, during the extraction process, add a demulsifier to the emulsified system, gently stir and let stand, then apply an external magnetic field to quickly separate the demulsifier, and at the same time, introduce carbon dioxide gas into the extraction system. After the extraction is completed, the extraction phase is treated to reach a supersaturated state of crystallization, then a seed inducer is added to the solution and continued to be stirred to form regular and uniform crystals of lutein and zeaxanthin, followed by filtering, using a microporous filter membrane for vacuum filtration to separate the crystals from the mother liquor, and finally performing a drying operation to obtain high-purity lutein and zeaxanthin products, completing the entire co-production tower extraction and crystallization process.

[0019] In one embodiment of the present invention: in step 1, 18 mmol-22 mmol of ferric chloride and 9 mmol-11 mmol of ferrous chloride are slowly added to 180 mL-220 mL of deionized water, and the solution is heated to 80°C-90°C under continuous nitrogen protection, and the stirring speed is controlled to 800 r / min-1000 r / min, and the stirring time is 30 min-45 min. After stirring, 45 mL-55 mL of ammonia water is added, and 0.5 mmol-1.5 mmol of polyvinyl pyrrolidone is added at the same time, and the reaction is continuously stirred for 1 h-2 h, and the precipitate is washed 3-4 times, and the precipitate is placed in a vacuum drying oven at 65°C-75°C and dried for 6 h-8 h.

[0020] In one embodiment of the present invention: in step 2, 18 mmol-22 mmol of N-methylimidazole and 21 mmol-25 mmol of bromododecane are taken, and they are added to 130 mL-170 mL of anhydrous ethanol, the temperature of the reaction system is controlled at 65°C-75°C, the stirring speed is set to 350 r / min-450 r / min, and the reaction is continued for 16 h-20 h, 23 mmol-27 mmol of 1-butyl-3-methylimidazole p-toluenesulfonate is added, the reaction temperature is adjusted to 55°C-65°C, and the stirring reaction is continued for 8 h-12 h. After the reaction is completed, 5 mmol-10 mmol of sodium fluoride is added to the system, and the reaction is continued at 40°C-50°C for 2 h-4 h. After the reaction is completed, ethanol is removed by a rotary evaporator at 45°C-55°C and under reduced pressure.

[0021] In one embodiment of the present invention: in step three, the amount of magnetic nanomaterial added is 4g-6g, the amount of surfactant ionic liquid added is 13g-17g, the content of deionized water added is 80mL-120mL, the concentration of sodium alginate solution added is 0.13mol / L-0.3mol / L, the content is 2mL-5mL, the ultrasonic power of the ultrasonic instrument is set to 200W-300W, and the ultrasonic dispersion is 30min-60min.

[0022] In one embodiment of the present invention: in step 4, weigh terephthalic acid with a content of 13mmol-17mmol, dissolve it in 100mL-140mL of N,N-dimethylformamide, zinc nitrate with a content of 6.5mmol-8.5mmol, dissolve it in 50mL-70mL of deionized water, stir at a speed of 350r / min-450r / min, add 2,5-thiophenedicarboxylic acid with a content of 3mmol-7mmol, react in the reactor at a temperature of 120℃-140℃ for 16h-20h, wash the product 3-4 times after completion, centrifuge and control the centrifugal speed to 5500r / min-6500r / min, the centrifugal time is 10min-14min, and finally dry the product in a vacuum drying oven at 85℃-95℃ for 8h-12h.

[0023] In one embodiment of the present invention: in step five, 4g-6g of metal organic framework material and 2g-3g of β-carotene derivative are selected and added to 80mL-120mL of a mixed solvent containing 0.4g-0.6g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.3g-0.5g of N-hydroxysuccinimide and 0.2g-0.5g of 1,3-dicyclohexylcarbodiimide and dimethyl sulfoxide and N-methylpyrrolidone in a volume ratio of 1-2:1, the temperature of the reaction system is controlled to be 45°C-55°C, the stirring speed is set to 250r / min-350r / min during stirring, the reaction is continued for 16h-20h, the centrifuge tube is centrifuged at a speed of 6500r / min-7500r / min for 12min-16min, and the precipitate is washed 3-4 times with dimethyl sulfoxide.

[0024] In one embodiment of the present invention: in step six, the process of pretreating fresh marigold flowers as raw materials is as follows: first, clean them to remove impurities in the raw materials, and then crush the cleaned raw materials. For fresh marigold flowers, use a high-speed crusher to crush them into particles with a particle size of 2mm-5mm, put the crushed marigold particles into a sodium carbonate solution with a mass fraction of 0.5%-1.5%, and the amount of sodium carbonate solution added is 2-3 times the mass of the crushed marigold particles. Soak them at 40℃-50℃ for 1h-2h to remove impurities in the raw materials. After soaking, filter and separate to obtain a pretreated solid raw material, then wash the solid raw material with deionized water 2-3 times to remove residual sodium carbonate solution, and finally dry the washed raw material at a temperature of 40℃-50℃ for 2h-3h to complete the pretreatment of the marigold raw material.

[0025] In one embodiment of the present invention: in step six, the mixed solvent extractant is ethyl acetate and n-butanol mixed in a volume ratio of 1.5-4:1, the added demulsifier accounts for 1.5%-2.5% of the volume of the emulsion, and the mixture is stirred and allowed to stand for 8min-12min. The flow rate of carbon dioxide gas introduced is 50mL / min-100mL / min, so that the pressure in the system is controlled at 0.1MPa-0.3MPa, and the continuous introduction time is 30min-60min. The seed inducer added to the solution accounts for 0.8%-1.2% of the solution mass, the crystallization temperature is controlled to be 18°C-22°C, and the mixture is slowly stirred at a speed of 100r / min-140r / min for 40min-60min. The filtration operation adopts a pore size of 0.22μm-0.45μm, and the drying operation is dried for 8h-12h under the conditions of a pressure of 0.1kPa-0.5kPa and a temperature of 30°C-40°C.

[0026] In one embodiment of the present invention: in step six, the extraction phase is treated to reach a supersaturated state of crystallization. The process is as follows: the extraction phase is transferred to a reduced pressure distillation apparatus, and a portion of the low-boiling point extractant is distilled off under the conditions of a pressure of 2kPa-5kPa and a temperature of 40°C-50°C to gradually increase the concentration of the solute in the solution. When the density of the solution reaches 1.05g / cm³-1.15g / cm³, the distillation is stopped, and the solution reaches a supersaturated state.

[0027] In one embodiment of the present invention: in step 1, when ammonia water and polyvinyl pyrrolidone are added for reaction, the reaction system comprises the following reaction: ; At the same time, polyvinyl pyrrolidone (PVP) in the reaction system adsorbs the active sites on the surface of the generated nanoparticles through the polar groups in its molecular structure, thereby controlling Growth and aggregation of nanoparticles.

[0028] In one embodiment of the present invention: In step three, during the ultrasonic dispersion treatment, the ultrasonic action not only promotes the uniform dispersion of the magnetic nanomaterial and the surfactant ionic liquid, but also triggers some physical and chemical reactions. The cavitation effect generated by the ultrasound causes a local high temperature and high pressure environment to be generated in the solution, resulting in the breaking of some glycosidic bonds in the sodium alginate molecules, generating free radicals with higher reactivity. These free radicals react with the active groups on the surface of the magnetic nanomaterial and the surfactant ionic liquid, thereby enhancing the interaction between the three and forming a more stable dispersion system.

[0029] In one embodiment of the present invention: In step 4, during the preparation of the metal organic framework material, the reaction system of terephthalic acid, zinc nitrate and 2,5-thiophenedicarboxylic acid comprises the following reaction: ; in represents terephthalic acid, represents 2,5-thiophenedicarboxylic acid, and in the reaction process, by controlling the reaction temperature and time, the generated It has a specific crystal structure and pore size to meet the adsorption requirements of lutein and zeaxanthin molecules.

[0030] In one embodiment of the present invention: in step six, after adding the seed inducer, the lutein and zeaxanthin molecules undergo a crystallization reaction under the action of the seed inducer, and the crystallization process can be described as follows: the lutein and zeaxanthin molecules are first adsorbed on the pore surface and active sites of the seed inducer (metal organic framework material coupled with biological small molecules), and then under certain temperature and stirring conditions, the molecules gradually grow in an orderly manner through interactions such as van der Waals forces and hydrogen bonds to form crystals, and during the crystallization process, the growth rate and crystal morphology of the crystals can be adjusted by controlling the stirring speed and crystallization temperature to obtain lutein and zeaxanthin crystals with more uniform particle size and more regular crystal shape.

[0031] In one embodiment of the present invention: in step 1, the precipitate is washed 3-4 times alternately with deionized water and anhydrous ethanol, and the precipitate is separated by an external magnetic field after each washing. The specific process is as follows: a container containing a mixture of washing liquid and precipitation is placed on a stable operating table, and a suitable permanent magnet (magnetic field strength is 0.5-1.0T) is prepared. The permanent magnet is placed close to one side of the container and the position is kept fixed. Since the ferroferric oxide magnetic nanomaterial has paramagnetism, under the action of the magnetic field, the magnetic nanomaterial will quickly gather to the side of the container wall close to the magnet. Wait for 3-5 minutes to allow the magnetic nanomaterial to fully gather and settle. Then, the upper clear liquid in the container is carefully poured out slowly, and care is taken to avoid pouring out the gathered magnetic nanomaterial. After the pouring is completed, the permanent magnet is removed, and an appropriate amount of washing liquid (deionized water or anhydrous ethanol) is added to the container. The next washing operation is performed, and the above steps are repeated until all washing times are completed.

[0032] Example 1, please refer to the attached Figure 1, 22mmol of ferric chloride and 11mmol of ferrous chloride were slowly added to 220mL of deionized water. Under the continuous protection of nitrogen, the solution was heated to 90°C. After heating, the stirring device was turned on for stirring. The stirring speed was controlled to be 1000r / min and the stirring time was 45min. After stirring, 55mL of ammonia water was added and 1.5mmol of polyvinyl pyrrolidone was added at the same time. The stirring reaction was continued for 2h. After the reaction was completed, the precipitate was washed 4 times alternately with deionized water and anhydrous ethanol. After each washing, the precipitate was separated by an external magnetic field. Finally, the separated precipitate was placed in a vacuum drying oven at 75°C and dried for 8h to obtain a magnetic nanomaterial. 22mmol of N-methylamidite was taken. azole and 25mmol of brominated dodecane, add them to 170mL of anhydrous ethanol, control the temperature of the reaction system at 75°C, then start stirring, set the stirring speed to 450r / min, and continue the reaction for 20h to obtain an imidazole ionic liquid. Then, add 27mmol of 1-butyl-3-methylimidazole p-toluenesulfonate to the imidazole ionic liquid, adjust the reaction temperature to 65°C, continue stirring and react for 12h, after the reaction is completed, add 10mmol of sodium fluoride to the system, and continue to react at 50°C for 4h. After the reaction is completed, use a rotary evaporator at 55°C and reduced pressure to remove ethanol to obtain a surfactant ionic liquid. 6g of the prepared magnetic nanomaterial and 17g of the surfactant ionic liquid are mixed. The mixture was mixed, and then 120 mL of deionized water was added, and then 5 mL of a sodium alginate solution with a concentration of 0.3 mol / L was added. The mixed system was transferred to an ultrasonic instrument, and the ultrasonic power was set to 300 W. Ultrasonic dispersion was performed for 60 min to uniformly disperse the magnetic nanomaterial and the surfactant ionic liquid in water to obtain a demulsifier. 17 mmol of terephthalic acid was weighed and dissolved in 140 mL of N, N-dimethylformamide to prepare a terephthalic acid N, N-dimethylformamide solution. 8.5 mmol of zinc nitrate was taken and dissolved in 70 mL of deionized water to obtain a zinc nitrate solution. Then, the zinc nitrate solution was slowly added dropwise to the terephthalic acid N, N-dimethylformamide solution at a stirring speed of 450 r / min. The mixture was added with 7 mmol of 2,5-thiophenedicarboxylic acid as the second organic ligand. After the addition was completed, the mixed solution was transferred to a reactor and reacted at 140°C for 20 hours. After the reaction was completed, the product was washed 4 times with N,N-dimethylformamide and ethanol in turn. After each washing, the product was centrifuged at a speed of 6500 r / min and a centrifugal time of 14 minutes. Finally, the product was dried in a vacuum drying oven at 95°C for 12 hours to obtain a metal organic framework material. 6 g of the metal organic framework material and 3 g of β-carotene derivative were selected and added to a mixture containing 0.6 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.5 g of N-hydroxysuccinimide and 0.5g of 1,3-dicyclohexylcarbodiimide and 120mL of a mixed solvent of dimethyl sulfoxide and N-methylpyrrolidone (volume ratio 2:1), the temperature of the reaction system is controlled to 55°C, and then it is stirred at a stirring speed of 350r / min, and the reaction is continued for 20h to allow the β-carotene derivative to undergo a coupling reaction with the metal organic framework material through a covalent bond. After the reaction is completed, the reaction solution is transferred to a centrifuge tube and centrifuged at a speed of 7500r / min for 16min, and then the precipitate is collected and washed 4 times with dimethyl sulfoxide to obtain a seed inducer. Marigold flowers are selected as raw materials. First, the raw materials are cleaned to remove impurities, and then the cleaned raw materials are crushed. For fresh marigold flowers, they are crushed into particles with a particle size of 5 mm using a high-speed crusher. The crushed marigold particles are placed in a sodium carbonate solution with a mass fraction of 1.5%. The amount of sodium carbonate solution added is 3 times the mass of the crushed marigold particles. They are soaked at 50°C for 2 hours to remove impurities in the raw materials. After soaking, they are filtered and separated to obtain the pretreated solid raw materials. Then, the solid raw materials are washed 3 times with deionized water to remove the residual sodium carbonate solution. Finally, the washed raw materials are dried at 50°C for 3 hours. , complete the pretreatment of marigold raw materials, put the pretreated marigold raw materials into a tower extraction equipment, select ethyl acetate and n-butanol mixed solvent with a volume ratio of 4:1 as the extractant for extraction, during the extraction process, add a demulsifier accounting for 2.5% of the volume of the emulsion to the emulsified system, gently stir and stand for 12 minutes, then apply an external magnetic field to quickly separate the demulsifier, and at the same time, introduce carbon dioxide gas into the extraction system at a flow rate of 100mL / min to control the pressure in the system at 0.3MPa, and continue to introduce it for 60min. After the extraction is completed, the extract phase is treated to achieve a crystallization process. Saturated state, then add 1.2% of the solution mass of seed inducer to the solution, control the crystallization temperature to 22℃, slowly stir at 140r / min for 60min, so that lutein and zeaxanthin form regular and uniform crystals, then filter, use a microporous filter membrane with a pore size of 0.45μm to perform vacuum filtration to separate the crystals from the mother liquor, and finally dry, transfer the filtered crystals to a vacuum drying oven, dry them for 12h at a pressure of 0.5kPa and a temperature of 40℃, and obtain high-purity lutein and zeaxanthin products, completing the entire co-production tower extraction and crystallization process. .

[0033] Example 2, please refer to the attached Figure 1, 18mmol of ferric chloride and 9mmol of ferrous chloride were slowly added to 180mL of deionized water. Under the continuous protection of nitrogen, the solution was heated to 80°C. After heating, the stirring device was turned on for stirring. The stirring speed was controlled to be 800r / min and the stirring time was 30min. After stirring, 45mL of ammonia water was added and 0.5mmol of polyvinyl pyrrolidone was added at the same time. The stirring reaction was continued for 1h. After the reaction was completed, the precipitate was washed alternately with deionized water and anhydrous ethanol for 3 times. After each washing, the precipitate was separated by an external magnetic field. Finally, the separated precipitate was placed in a vacuum drying oven at 65°C and dried for 6h to obtain a magnetic nanomaterial. 18mmol of N-methylimidazole was taken. and 21mmol of bromododecane, add them to 130mL of anhydrous ethanol, control the temperature of the reaction system at 65°C, then start stirring, set the stirring speed to 350r / min, and continue the reaction for 16h to obtain an imidazole ionic liquid. Then, add 23mmol of 1-butyl-3-methylimidazole toluenesulfonate to the imidazole ionic liquid, adjust the reaction temperature to 55°C, continue stirring and react for 8h, after the reaction is completed, add 5mmol of sodium fluoride to the system, and continue to react at 40°C for 2h. After the reaction is completed, use a rotary evaporator at 45°C and reduced pressure to remove ethanol to obtain a surfactant ionic liquid. Mix 4g of the prepared magnetic nanomaterial with 13g of the surfactant ionic liquid. The mixture was mixed, and then 80 mL of deionized water was added, and then 2 mL of a sodium alginate solution with a concentration of 0.1 mol / L was added. The mixed system was transferred to an ultrasonic instrument, and the ultrasonic power was set to 200 W. Ultrasonic dispersion was performed for 30 min to uniformly disperse the magnetic nanomaterial and the surfactant ionic liquid in the water to obtain a demulsifier. 13 mmol of terephthalic acid was weighed and dissolved in 100 mL of N, N-dimethylformamide to prepare a terephthalic acid N, N-dimethylformamide solution. 6.5 mmol of zinc nitrate was taken and dissolved in 50 mL of deionized water to obtain a zinc nitrate solution. Then, the zinc nitrate solution was slowly added dropwise to the terephthalic acid N, N-dimethylformamide solution at a stirring speed of 350 r / min. At the same time, 3 mmol of 2,5-thiophenedicarboxylic acid was added as the second organic ligand. After the addition was completed, the mixed solution was transferred to a reactor and reacted at 120°C for 16 hours. After the reaction was completed, the product was washed three times with N,N-dimethylformamide and ethanol in sequence. After each washing, it was centrifuged at a speed of 5500 r / min and a centrifugal time of 10 min. Finally, the product was dried in a vacuum oven at 85°C for 8 hours to obtain a metal organic framework material. 4 g of the metal organic framework material and 2 g of β-carotene derivative were selected and added to a mixture containing 0.4 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.3 g of N-hydroxysuccinimide and 0.2g of 1,3-dicyclohexylcarbodiimide and 80mL of a mixed solvent of dimethyl sulfoxide and N-methylpyrrolidone (volume ratio 1:1), the temperature of the reaction system was controlled to 45°C, and then it was stirred at a stirring speed of 250r / min, and the reaction was continued for 16h to allow the β-carotene derivative to undergo a coupling reaction with the metal organic framework material through a covalent bond. After the reaction was completed, the reaction solution was transferred to a centrifuge tube and centrifuged at a speed of 6500r / min for 12min, and then the precipitate was collected and washed with dimethyl sulfoxide 3 times to obtain a seed inducer. Marigold flowers were selected as raw materials. First, clean the raw materials to remove impurities, and then crush the cleaned raw materials. For fresh marigold flowers, use a high-speed crusher to crush them into particles with a particle size of 2 mm. Put the crushed marigold particles into a sodium carbonate solution with a mass fraction of 0.5%. The amount of sodium carbonate solution added is twice the mass of the crushed marigold particles. Soak them at 40°C for 1 hour to remove impurities in the raw materials. After soaking, filter and separate to obtain the pretreated solid raw materials. Then, wash the solid raw materials with deionized water twice to remove the residual sodium carbonate solution. Finally, dry the washed raw materials at 40°C for 2 hours. , complete the pretreatment of marigold raw materials, put the pretreated marigold raw materials into a tower extraction equipment, select ethyl acetate and n-butanol mixed solvent with a volume ratio of 1.5:1 as the extractant for extraction, during the extraction process, add a demulsifier accounting for 1.5% of the volume of the emulsion to the emulsified system, gently stir and stand for 8 minutes, then apply an external magnetic field to quickly separate the demulsifier, and at the same time, introduce carbon dioxide gas into the extraction system at a flow rate of 50mL / min to control the pressure in the system at 0.1MPa, and continue to introduce it for 30min. After the extraction is completed, the extract phase is treated to achieve crystallization. Supersaturated state, then add 0.8% of the solution mass of seed inducer to the solution, control the crystallization temperature to 18℃, slowly stir at 100r / min for 40min, so that lutein and zeaxanthin form regular and uniform crystals, then filter, use a microporous filter membrane with a pore size of 0.22μm to perform vacuum filtration to separate the crystals from the mother liquor, and finally dry, transfer the filtered crystals to a vacuum drying oven, dry them at a pressure of 0.1kPa and a temperature of 30℃ for 8h, and obtain high-purity lutein and zeaxanthin products, completing the entire co-production tower extraction and crystallization process. .

[0034] According to the contents of the above examples 1 and 2, it can be concluded that by adopting the coprecipitation method to prepare the magnetic nanomaterial with the characteristic of rapid aggregation under an external magnetic field, and selecting raw materials such as N-methylimidazole to prepare the surface active ionic liquid with unique anionic and cationic structure and strong ability to reduce interfacial tension, and compounding the two into a demulsifier, in the liquid-liquid extraction of lutein and zeaxanthin, when emulsification occurs, the demulsifier can quickly break up the emulsified structure, and achieve rapid separation with the help of an external magnetic field, which significantly improves the extraction efficiency, and effectively avoids the adverse effects on the structure and properties of lutein and zeaxanthin, ensuring the high quality of the product. In addition, by selecting terephthalic acid and zinc nitrate, a highly ordered pore structure and a large specific surface area are prepared. The metal-organic framework material is then coupled with a β-carotene derivative to obtain a seed inducer. During the crystallization process of lutein and zeaxanthin, the addition of the inducer can make the target molecules grow in an orderly manner in the pores to form crystals with uniform particle size and good crystal shape. Compared with the traditional crystallization method, the crystallization efficiency is significantly improved, the crystal growth time is reduced, the product quality is improved, and the strict requirements of different application fields on crystal morphology and quality are met. With the help of the coordinated cooperation of the characteristics of the materials and the preparation process in the above steps, the co-production tower extraction and crystallization of lutein and zeaxanthin can be efficiently realized to obtain high-purity products. This process has significant technical advantages and broad application prospects in the field of extraction and preparation of lutein and zeaxanthin.

[0035] Although the present invention is disclosed as above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A tower extraction process for the co-production of lutein and zeaxanthin, characterized in that: The tower extraction process comprises the following steps: Step 1, slowly adding ferric chloride and ferrous chloride into deionized water, heating the solution, turning on a stirring device to stir after the heating is completed, adding ammonia water after the stirring is completed, and adding polyvinyl pyrrolidone at the same time, stirring and reacting continuously, after the reaction is completed, washing the precipitate alternately with deionized water and anhydrous ethanol, separating the precipitate by applying an external magnetic field after each washing, and finally placing the separated precipitate in a vacuum drying oven to dry to obtain a magnetic nanomaterial; Step 2: Take N-methylimidazole and dodecane bromide as raw materials, add them to anhydrous ethanol, control the temperature of the reaction system, and then start stirring to obtain an imidazole ionic liquid, then add 1-butyl-3-methylimidazole p-toluenesulfonate to the imidazole ionic liquid and continue to stir and react, after the reaction is completed, add sodium fluoride to the system and continue to react, and after the reaction is completed, remove ethanol using a rotary evaporator to obtain a surface active ionic liquid; Step 3: Mix the prepared magnetic nanomaterial with the surfactant ionic liquid, then add deionized water, and then add the sodium alginate solution, transfer the mixed system to an ultrasonic instrument for ultrasonic dispersion treatment, so that the magnetic nanomaterial and the surfactant ionic liquid are evenly dispersed in the water to obtain a demulsifier; Step 4, weighing terephthalic acid and dissolving it in N,N-dimethylformamide to prepare an N,N-dimethylformamide solution of terephthalic acid, separately dissolving zinc nitrate in deionized water to obtain a zinc nitrate solution, and then stirring, slowly dropping the zinc nitrate solution into the N,N-dimethylformamide solution of terephthalic acid, and adding 2,5-thiophenedicarboxylic acid as a second organic ligand, after the dropwise addition is completed, transferring the mixed solution to a reactor for reaction, and then washing the product with N,N-dimethylformamide and ethanol in turn, centrifuging after each washing, and finally drying the product to obtain a metal organic framework material; Step 5: Select a metal organic framework material and a β-carotene derivative, add them to a mixed solvent containing 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride, N-hydroxysuccinimide and 1,3-dicyclohexylcarbodiimide, dimethyl sulfoxide and N-methylpyrrolidone, and then stir them to react so that the β-carotene derivative and the metal organic framework material undergo a coupling reaction through a covalent bond. After the reaction is completed, transfer the reaction solution to a centrifuge tube for centrifugation, collect the precipitate, and wash the precipitate with dimethyl sulfoxide to obtain a seed inducer; Step 6: pretreat fresh marigold flowers as raw materials, put the pretreated marigold raw materials into a tower extraction equipment, select ethyl acetate and n-butanol mixed solvent as the extractant for extraction, during the extraction process, add a demulsifier to the emulsified system, gently stir and let stand, then apply an external magnetic field to quickly separate the demulsifier, and at the same time, introduce carbon dioxide gas into the extraction system. After the extraction is completed, the extraction phase is treated to reach a supersaturated state of crystallization, then a seed inducer is added to the solution and continued to be stirred to form regular and uniform crystals of lutein and zeaxanthin, followed by filtering, using a microporous filter membrane for vacuum filtration to separate the crystals from the mother liquor, and finally performing a drying operation to obtain high-purity lutein and zeaxanthin products, completing the entire co-production tower extraction and crystallization process.

2. The tower extraction process for co-production of lutein and zeaxanthin according to claim 1, characterized in that: In the step 1, 18 mmol-22 mmol of ferric chloride and 9 mmol-11 mmol of ferrous chloride are slowly added to 180 mL-220 mL of deionized water, and the solution is heated to 80° C.-90° C. under a nitrogen continuous protection environment, and the stirring speed is controlled to 800 r / min-1000 r / min, and the stirring time is 30 min-45 min. After the stirring is completed, 45 mL-55 mL of ammonia water is added, and 0.5 mmol-1.5 mmol of polyvinyl pyrrolidone is added at the same time, and the stirring reaction is continued for 1 h-2 h, and the precipitate is washed 3-4 times, and the precipitate is placed in a vacuum drying oven at 65° C.-75° C. and dried for 6 h-8 h.

3. The tower extraction process for co-production of lutein and zeaxanthin according to claim 1, characterized in that: In the step 2, 18 mmol-22 mmol of N-methylimidazole and 21 mmol-25 mmol of bromododecane are added to 130 mL-170 mL of anhydrous ethanol, the temperature of the reaction system is controlled at 65° C.-75° C., the stirring speed is set to 350 r / min-450 r / min, the reaction is continued for 16 h-20 h, 23 mmol-27 mmol of 1-butyl-3-methylimidazole p-toluenesulfonate is added, the reaction temperature is adjusted to 55° C.-65° C., the stirring reaction is continued for 8 h-12 h, after the reaction is completed, 5 mmol-10 mmol of sodium fluoride is added to the system, the reaction is continued at 40° C.-50° C. for 2 h-4 h, and after the reaction is completed, ethanol is removed by a rotary evaporator at 45° C.-55° C. under reduced pressure.

4. The tower extraction process for co-production of lutein and zeaxanthin according to claim 1, characterized in that: In the step three, the amount of magnetic nanomaterial added is 4g-6g, the amount of surfactant ionic liquid added is 13g-17g, the content of deionized water added is 80mL-120mL, the concentration of sodium alginate solution added is 0.13mol / L-0.3mol / L, the content is 2mL-5mL, the ultrasonic power of the ultrasonic instrument is set to 200W-300W, and the ultrasonic dispersion is 30min-60min.

5. The tower extraction process for co-production of lutein and zeaxanthin according to claim 1, characterized in that: In the step 4, terephthalic acid having a content of 13 mmol-17 mmol is weighed and dissolved in 100 mL-140 mL of N,N-dimethylformamide, zinc nitrate having a content of 6.5 mmol-8.5 mmol is dissolved in 50 mL-70 mL of deionized water, and the mixture is stirred at a speed of 350 r / min-450 r / min, 2,5-thiophenedicarboxylic acid having a content of 3 mmol-7 mmol is added, the reaction kettle is reacted at a temperature of 120° C.-140° C. for 16 h-20 h, and after the reaction, the product is washed 3-4 times, and the centrifugal separation is controlled at a centrifugal speed of 5500 r / min-6500 r / min, and the centrifugal time is 10 min-14 min, and finally the product is dried in a vacuum drying oven at 85° C.-95° C. for 8 h-12 h.

6. The tower extraction process for co-production of lutein and zeaxanthin according to claim 1, characterized in that: In the step 5, 4g-6g of the metal organic framework material and 2g-3g of the β-carotene derivative are selected and added to 80mL-120mL of a mixed solvent containing 0.4g-0.6g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.3g-0.5g of N-hydroxysuccinimide and 0.2g-0.5g of 1,3-dicyclohexylcarbodiimide and dimethyl sulfoxide and N-methylpyrrolidone in a volume ratio of 1-2:1, the temperature of the reaction system is controlled to be 45°C-55°C, the stirring speed is set to 250r / min-350r / min during stirring, the reaction is continued for 16h-20h, the centrifuge tube is centrifuged at a speed of 6500r / min-7500r / min for 12min-16min, and the precipitate is washed 3-4 times with dimethyl sulfoxide.

7. The tower extraction process for co-production of lutein and zeaxanthin according to claim 1, characterized in that: In the step six, the process of pretreating the fresh marigold flowers as raw materials is as follows: first, cleaning is performed to remove impurities in the raw materials, and then the cleaned raw materials are crushed. For the fresh marigold flowers, a high-speed crusher is used to crush them into particles with a particle size of 2mm-5mm. The crushed marigold particles are placed in a sodium carbonate solution with a mass fraction of 0.5%-1.5%, and the amount of sodium carbonate solution added is 2-3 times the mass of the crushed marigold particles. The raw materials are soaked at 40°C-50°C for 1h-2h to remove impurities in the raw materials. After soaking, the pretreated solid raw materials are separated by filtration. Then, the solid raw materials are washed with deionized water for 2-3 times to remove the residual sodium carbonate solution. Finally, the washed raw materials are dried at a temperature of 40°C-50°C for 2h-3h to complete the pretreatment of the marigold raw materials.

8. The tower extraction process for co-production of lutein and zeaxanthin according to claim 1, characterized in that: In the step six, the mixed solvent extractant is ethyl acetate and n-butanol mixed in a volume ratio of 1.5-4:1, the added demulsifier accounts for 1.5%-2.5% of the volume of the emulsion, and the mixture is allowed to stand for 8min-12min after stirring. The flow rate of the carbon dioxide gas introduced is 50mL / min-100mL / min, so that the pressure in the system is controlled at 0.1MPa-0.3MPa, and the continuous introduction time is 30min-60min. The seed inducer added to the solution accounts for 0.8%-1.2% of the solution mass, the crystallization temperature is controlled to be 18°C-22°C, and the mixture is slowly stirred at a speed of 100r / min-140r / min for 40min-60min. The filtration operation adopts a pore size of 0.22μm-0.45μm, and the drying operation is dried for 8h-12h under the conditions of a pressure of 0.1kPa-0.5kPa and a temperature of 30°C-40°C.

9. The tower extraction process for co-production of lutein and zeaxanthin according to claim 1, characterized in that: In the step six, the extraction phase is treated to reach a supersaturated state of crystallization. The process is as follows: the extraction phase is transferred to a reduced pressure distillation apparatus, and a portion of the low-boiling point extractant is distilled off under the conditions of a pressure of 2kPa-5kPa and a temperature of 40°C-50°C, so that the concentration of the solute in the solution gradually increases. When the density of the solution reaches 1.05g / cm³-1.15g / cm³, the distillation is stopped, and the solution reaches a supersaturated state.

10. A tower extraction device for co-producing lutein and zeaxanthin applicable to the tower extraction process for co-producing lutein and zeaxanthin according to any one of claims 1 to 9, characterized in that: The equipment includes a reaction container, a heating device, a stirring device, a nitrogen supply device, a separating funnel, a centrifuge, a vacuum drying oven, a condensation reflux device, a rotary evaporator, an ultrasonic disperser, a constant pressure dropping funnel, a washing device, a cleaning device, a pulverizer, a soaking container, a filtering device, and a tower extraction device.

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