Preparation system and method of marigold extract

Abstract

The invention provides a marigold extract preparation system and method.The marigold extract preparation system comprises a pretreatment unit, a mixing unit, a desolventizing unit and a saponification and purification unit, the saponification and purification unit comprises an alkali adding module, a membrane separation module and a secondary treatment module, the alkali adding module is used for adding potassium hydroxide into an extracting solution for saponification to obtain a saponified solution, and the membrane separation module is used for carrying out membrane separation on the saponified solution; the membrane separation module is used for filtering the saponification liquid to obtain relatively pure ultrafiltrate, and the secondary treatment module is used for carrying out water washing, alcohol washing and recrystallization on the ultrafiltrate to obtain lutein crystals. Specific extraction solvent, extraction time, extraction temperature, extraction solvent volume ratio and extraction times are given, a saponification process and a purification process of the xanthophyll extracting solution are optimized to obtain the xanthophyll extract with the purity of 95%, the xanthophyll extract is recrystallized to obtain the xanthophyll crystal with a good form, the purity of the xanthophyll crystal reaches 98.5% or above, and the xanthophyll crystal has a good crystal form. The enrichment degree of the xanthophyll is higher, and membrane holes are not easy to block.

Description

Technical Field

[0001] The invention relates to the technical field of lutein preparation, and in particular to a system and method for preparing a marigold extract. Background Art

[0002] Marigold is an annual herb of the genus Tagetes in the Asteraceae family. The stem branches near the base, the leaves are pinnate, and the lobes are oblong or lanceolate; the ligulate flowers are yellow or dark orange-yellow, with claws at the base, and the corolla of the tubular flowers is yellow; the achenes are linear and slightly hairy. The flowering period is July-September. Marigold is warm, resistant to early frost, semi-shade, and transplanting, has strong resistance, has few diseases and pests, is not strict on soil, grows quickly and is easy to cultivate. Loose artificial media is used for reproduction, and seedlings are raised by bed sowing and box sowing. Marigold is rich in lutein, and the natural yellow pigment can be used as a raw material for food, feed, and medicine. It also has rich medicinal and health value, and is known as the "longevity grass" or "immortal grass". It has a wide range of uses in traditional Chinese medicine and modern pharmacology.

[0003] Marigold is rich in polysaccharides, saponins, polyphenols and other active ingredients, which have obvious antioxidant effects and help to resist the damage of free radicals to cells. Marigold extract can lower blood sugar and blood lipids, and has a certain auxiliary therapeutic effect on diseases such as diabetes and hyperlipidemia. It has the effect of enhancing immune function and helps to improve the body's resistance.

[0004] Lutein is a carotenoid, a flavonoid compound, a nutrient that cannot be synthesized by the human body and must be taken in through food. It is mainly found in some green leafy vegetables, fruits and other plants, such as spinach, rapeseed, cauliflower, corn, etc. Lutein is widely present in nature, especially in the chloroplasts of plants, where it protects the chloroplasts from light damage. The role and health benefits of lutein: Antioxidant effect: Lutein is a powerful antioxidant that can remove free radicals in the body, reduce cellular oxidative damage, and help maintain cell health. Protect the retina: Lutein is mainly concentrated in the retina of the eye, especially in the macula, which can filter and reduce the damage of blue light to the eyes, help protect vision, and prevent eye diseases such as macular degeneration. Reduce the risk of cancer: Studies have shown that the intake of lutein is negatively correlated with the incidence of certain cancers (such as breast cancer, colon cancer, etc.). Anti-inflammatory effect: It has a certain anti-inflammatory effect, which helps reduce the risk of inflammatory reactions and related diseases. Other health benefits: It also includes regulating blood pressure, lowering blood lipids, and enhancing immunity.

[0005] Marigold pigment, also known as "marigold oleoresin", is obtained by granulating marigold flowers before extraction, then extracting with organic solvents, and then desolventizing the extract to obtain a yellow oily liquid, which is then separated and purified to obtain pure lutein. However, the current extraction system does not produce lutein crystals of sufficient purity and needs to be improved. Summary of the invention

[0006] The present invention aims to provide a system and method for preparing marigold extract, which can obtain high-purity lutein crystals.

[0007] To achieve the above object, the present invention proposes the following technical solution: a system for preparing marigold extract, comprising:

[0008] A pretreatment unit, the pretreatment unit comprising an automatic cleaning machine, an automatic air drying machine, a crushing device and a grinding device, the automatic cleaning machine is used to clean and remove impurities from marigold flowers, the automatic air drying machine is used to air-dry the washed flowers, the crushing device is used to crush the flowers into particles, and the grinding device is used to grind the particles into marigold powder;

[0009] A mixing unit, the mixing unit comprising a stirring module, a solvent adding module, a heating module, an ultrasonic generating module, and an enzyme adding module, the stirring module is used to mix marigold powder and an extraction solvent to form a mixed solution, the solvent adding module is used to add the extraction solvent to the stirring module, the extraction solvent is a two-component solvent, the heating module is used to heat the stirring module, the ultrasonic generating module is used to ultrasonically crush the mixed solution, the ultrasonic generating module can form a cavitation effect to crush the cell wall of the marigold powder, and the enzyme adding module is used to add cellulase or hemicellulase into the stirring module;

[0010] A desolventizing unit, the desolventizing unit comprising a suction filtration module and a rotary evaporation module, the suction filtration module is used to separate the undissolved part of the mixed solution, and the rotary evaporation module is used to remove the solvent in the mixed solution to obtain an extract;

[0011] The saponification and purification unit includes an alkali adding module, a membrane separation module, and a secondary treatment module. The alkali adding module is used to saponify the extract with potassium hydroxide to obtain a saponified liquid. The membrane separation module is used to filter the saponified liquid to obtain a purer ultrafiltrate. The secondary treatment module is used to wash the ultrafiltrate with water, alcohol and recrystallize it to obtain lutein crystals.

[0012] Furthermore, in the present invention, the two-component solvent includes a mixed solvent of petroleum ether and ethanol, and the ratio of the petroleum ether to the ethanol is 2:5.

[0013] A method for preparing marigold extract, using the above-mentioned system for preparing marigold extract, is characterized by comprising the following steps:

[0014] Step 1, washing, air-drying, crushing and grinding marigold flowers to obtain marigold flower powder;

[0015] Step 2, weighing marigold flower powder, placing it in an extraction bottle, adding a certain volume of a two-component solvent as an extraction solvent, stirring through a stirring module during extraction, controlling the temperature through a heating module, adding cellulase or hemicellulase into the extraction bottle, and using an ultrasonic generator module to emit ultrasound to the mixed solution to assist in extracting lutein esters;

[0016] Step 3, filtering the mixed solution in step 2 and rotary evaporating the solvent to obtain an extract;

[0017] Step 4, saponifying and purifying the extract of step 3, adding the extract and the organic solvent into the reactor, stirring and mixing them thoroughly under a sealed condition at 30-35°C, adding the alkaline solution and mixing them thoroughly, raising the temperature to 40-45°C, reacting for 8-10 hours, stopping the saponification, adding distilled water to the saponified product and stirring evenly, ultrafiltering the crude lutein, eluting the precipitated crude lutein with anhydrous ethanol and n-hexane, respectively, and recrystallizing the eluted high-purity lutein.

[0018] Furthermore, in the present invention, the cleaning time in step 1 is 1-2 hours, the air-drying temperature is 25°C-35°C, the grinding time is 30-50 minutes, and the grinding speed is 200-500r / min.

[0019] Further, in the present invention, the temperature of the heating module in step 2 for temperature control is 50-55°C, the microwave power is 200w-2000w, the microwave time is 3-4 hours, and the solid-liquid ratio is 1:40. In the case of petroleum ether and ethanol (2:5-v / v), the solvent extraction effect is good, and the extraction effect becomes better with the extension of extraction time and the increase of temperature, but the extension of time and the increase of temperature will cause the decomposition of lutein esters. The optimal temperature for lutein extraction is 50-55°C, the extraction time is 3-4h, the solid-liquid ratio is 1:30, and the extraction level is 3 extractions.

[0020] Further, in the present invention, the organic solvent in step 4 is a mixed solvent of tetrahydrofuran and ethanol in a volume ratio of 3:2. The ester derivatives can be completely dissolved in the tetrahydrofuran solution, and KOH can be well dissolved in the ethanol solution, which just meets the requirements. The use of the extract as the saponification system simplifies the saponification process and reduces the volatilization loss of the organic solvent. Therefore, this experiment still uses a mixed solvent of tetrahydrofuran and ethanol as the saponification reaction system.

[0021] Further, in the present invention, the extract in step 2 is subjected to HPLC detection, and the HPLC analysis conditions are as follows: chromatographic column: VP-ODS C 18 Column (150×4.6mm, Φ4um);

[0022] Detection wavelength: 454nm;

[0023] Mobile phase: V(CH 2 Cl 2 ):V(CH 3 OH):V(CH 3 CN):V(H 2 O)=32:29:38:1;

[0024] Flow rate: 0.5 mL / min;

[0025] Injection: 10uL;

[0026] Temperature: Room temperature.

[0027] It can be found that marigold extract has many components, but the relative content of lutein is very high, making it an ideal industrial raw material for extracting and separating lutein. The lutein in marigold mainly exists in the form of esters and requires further saponification separation.

[0028] Furthermore, in the present invention, the membrane separation module is an ultrafilter, an ultrafiltration membrane is arranged in the ultrafilter, the membrane surface area is 0.3m2, the system temperature is 10-40°C, the system P is operated under the condition of <0.1Mpa, and the treatment is 500-20000 ml.

[0029] Furthermore, in the present invention, the membrane separation process is as follows: using an ultrafiltration membrane with a molecular weight cutoff of 30K to 40K, the saponified liquid of lutein ester is subjected to ultrafiltration membrane separation at a temperature of 20-30°C, a liquid flow rate of 2.78×10-5m / s, and a pressure of 0.05Mpa. The ultrafiltrate obtained, after concentration and drying, the purity of the lutein extract obtained reaches more than 95%.

[0030] Furthermore, in the present invention, the recrystallization process is as follows: the lutein extract is washed with water and ethanol respectively, after removing the water and ethanol, the lutein extract is dissolved in tetrahydrofuran to obtain a hot supersaturated solution, and then n-hexane is added dropwise to the saturated solution, while lowering the temperature to precipitate crystals, separating the solvent, and drying in a light-proof vacuum to obtain lutein crystals with a purity of more than 98.5-99.6%.

[0031] Beneficial effects: The technical solution of this application has the following technical effects:

[0032] 1. The present invention extracts lutein esters from marigold based on organic solvents, and provides specific extraction solvents, extraction time, extraction temperature, extraction solvent volume ratio and extraction times. Through single factor experiments, the mixed solvent with a ratio of petroleum ether to ethanol of 2:5 has a good extraction effect. The extraction effect becomes better with the extension of extraction time and the increase of temperature. However, the extension of time and the increase of temperature will cause the decomposition of lutein esters. The optimal temperature for lutein extraction is 50-55°C, the extraction time is 3-4h, the solid-liquid ratio is 1:30, and the extraction stage is 3 extractions. Because the lutein in marigold mainly exists in the form of esters, the present invention further saponifies and separates.

[0033] 2. The present invention optimizes the saponification process and purification process of the lutein extract. Experiments show that, using an ultrafiltration membrane with a molecular weight cutoff of 30K to 40K, a lutein extract with a purity of 95% is obtained at a temperature of 20-30°C, a liquid flow rate of 2.78×10-5m / s, and a pressure of 0.05Mpa. The obtained lutein extract is recrystallized to obtain lutein crystals with good morphology and a purity of more than 98.5%. The lutein is more enriched and is not easy to clog the membrane pores.

[0034] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, may be considered to be part of the inventive subject matter of the present disclosure, provided such concepts are not mutually inconsistent.

[0035] The foregoing and other aspects, embodiments and features of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or learned from the practice of the specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For clarity, not every component is labeled in every figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, in which:

[0037] Figure 1 Schematic diagram of temperature influence of the present invention.

[0038] Figure 2 Schematic diagram of the influence of the material-liquid ratio of the present invention.

[0039] Figure 3 Schematic diagram of microwave power effect of the present invention DETAILED DESCRIPTION

[0040] In order to better understand the technical content of the present invention, specific embodiments are cited and described as follows in conjunction with the accompanying drawings. Various aspects of the present invention are described in this disclosure with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the present disclosure are not necessarily defined to include all aspects of the present invention. It should be understood that the various concepts and embodiments introduced above, as well as those described in more detail below, can be implemented in any of many ways, because the concepts and embodiments disclosed in the present invention are not limited to any implementation. In addition, some aspects disclosed in the present invention can be used alone, or in any appropriate combination with other aspects disclosed in the present invention.

[0041] Example 1

[0042] This embodiment provides a preparation system of marigold extract, including a pretreatment unit, wherein the pretreatment unit includes an automatic cleaning machine, an automatic air-drying machine, a crushing device and a grinding device, wherein the automatic cleaning machine is used to clean and remove impurities from marigold flowers, the automatic air-drying machine is used to air-dry the washed flowers, the crushing device is used to crush the flowers into particles, and the grinding device is used to grind the particles into marigold powder;

[0043] A mixing unit, the mixing unit comprising a stirring module, a solvent adding module, a heating module, an ultrasonic generating module, and an enzyme adding module, the stirring module being used to mix marigold powder and an extraction solvent to form a mixed solution, the solvent adding module being used to add an extraction solvent into the stirring module, the extraction solvent being a two-component solvent, the two-component solvent comprising a petroleum ether and an ethanol mixed solvent, the ratio of the petroleum ether to the ethanol being 2:5, the heating module being used to heat the stirring module, the ultrasonic generating module being used to ultrasonically crush the mixed solution, the ultrasonic generating module being able to form a cavitation effect to crush the cell walls of the marigold powder, and the enzyme adding module being used to add cellulase or hemicellulase into the stirring module;

[0044] A desolventizing unit, the desolventizing unit comprising a suction filtration module and a rotary evaporation module, the suction filtration module is used to separate the undissolved part of the mixed solution, and the rotary evaporation module is used to remove the solvent in the mixed solution to obtain an extract;

[0045] The saponification and purification unit includes an alkali adding module, a membrane separation module, and a secondary treatment module. The alkali adding module is used to saponify the extract with potassium hydroxide to obtain a saponified liquid. The membrane separation module is used to filter the saponified liquid to obtain a purer ultrafiltrate. The secondary treatment module is used to wash the ultrafiltrate with water, alcohol and recrystallize it to obtain lutein crystals.

[0046] Example 2

[0047] A method for preparing marigold extract, using the above-mentioned system for preparing marigold extract, is characterized by comprising the following steps:

[0048] Step 1, washing, air-drying, crushing and grinding marigold flowers to obtain marigold flower powder, the washing time is 1 hour, the air-drying temperature is 25° C., the grinding time is 30 minutes, and the grinding speed is 200 r / min;

[0049] Step 2, weighing marigold flower powder, placing it in an extraction bottle, adding a certain volume of a two-component solvent as an extraction solvent, wherein the two-component solvent includes a petroleum ether and ethanol mixed solvent, and the ratio of the petroleum ether to the ethanol is 2:5, stirring is performed by a stirring module during extraction, and the temperature is controlled by a heating module, and cellulase or hemicellulase is added to the extraction bottle. The ultrasonic generating module emits ultrasound to the mixed solution to assist in the extraction of lutein esters, and the temperature of the heating module is controlled at 50° C., the microwave power is 600 w, the microwave time is 3 hours, and the solid-liquid ratio is 1:40;

[0050] The extract was subjected to HPLC analysis under the following conditions: chromatographic column: VP-ODS C 18 Column (150×4.6mm, Φ4um);

[0051] Detection wavelength: 454nm;

[0052] Mobile phase: V(CH 2 Cl 2 ):V(CH 3 OH):V(CH 3 CN):V(H 2 O)=32:29:38:1;

[0053] Flow rate: 0.5 mL / min;

[0054] Injection: 10uL;

[0055] Temperature: Room temperature.

[0056] Step 3, filtering the mixed solution in step 2 and rotary evaporating the solvent to obtain an extract;

[0057] Temperature is an important factor affecting the extraction results. For most substances, increasing temperature can increase the solubility of the substance; and as the temperature increases, the viscosity of the solution decreases, the diffusion rate of the substance increases, thereby increasing the speed. However, if the temperature is too high, impurities will be easily dissolved and some active ingredients will be destroyed. Therefore, this example compares the extraction conditions at different temperatures from 40°C to 60°C. Other conditions are fixed, such as Figure 1 shown.

[0058] The solid-liquid ratio is an important factor in the extraction process. From the perspective of mass transfer rate, it is mainly reflected in the concentration difference between the solid phase and the liquid phase, that is, the mass transfer driving force. The larger the solid-liquid ratio, the smaller the concentration difference between the two phases, and thus the smaller the mass transfer driving force. Secondly, the size of the solvent ratio will affect the mixing of the two phases. The increase in the solvent ratio will inevitably increase the mass transfer driving force to a greater extent, but it will also increase the production cost and the difficulty of subsequent processing, so the solvent ratio should not be too high. In the experiment, solid-liquid ratios of 1:20, 1:30, 1:40, 1:50, and 1:60 were used to discuss the effect of the solid-liquid ratio on the extraction results. Other conditions are the same, and the results are as follows Figure 2 .

[0059] Depend on Figure 3 It can be seen that the absorbance value of marigold lutein is different under different microwave powers. The reason is that different types of substances have different absorption capabilities for microwaves. This characteristic of the substance can be expressed by the dissipation factor, which can be changed by controlling the microwave power, so that the microwave absorption of a certain extracted component can be maximized. Figure 3 It shows that when the microwave power is 600w, the extraction efficiency of marigold lutein reaches the maximum.

[0060] Example 3

[0061] The difference from Example 1 is that the two-component solvent includes a mixed solvent of petroleum ether and ethanol, and the ratio of the petroleum ether to the ethanol is 1:5.

[0062] Example 4

[0063] The difference from Example 1 is that the two-component solvent includes a mixed solvent of petroleum ether and ethanol, and the ratio of the petroleum ether to the ethanol is 3:5.

[0064] Example 5

[0065] The difference from Example 1 is that the two-component solvent includes a mixed solvent of petroleum ether and ethanol, and the ratio of the petroleum ether to the ethanol is 4:5.

[0066] Example 6

[0067] The difference from Example 1 is that the two-component solvent includes a mixed solvent of petroleum ether and ethanol, and the ratio of the petroleum ether to the ethanol is 1:1.

[0068] Example 7

[0069] The difference from Example 1 is that the two-component solvent includes a mixed solvent of petroleum ether and ethanol, and the ratio of petroleum ether to ethanol is 6:5.

[0070] Serial number Solvent ratio Maximum absorption wavelength (nm) Lutein ester absorbance Example 6 The ratio of petroleum ether to ethanol is 1:1 443 0.645 Example 2 The ratio of petroleum ether to ethanol is 2:5 456 0.667 Example 3 The ratio of petroleum ether to ethanol is 1:5 453 0.643 Example 4 The ratio of petroleum ether to ethanol is 3:5 447 0.621 Example 5 The ratio of petroleum ether to ethanol is 4:5 446 0.658 Example 7 The ratio of petroleum ether to ethanol is 64:5 441 0.638

[0071] In the case of petroleum ether and ethanol (2:5-v / v), the solvent extraction effect is good, and the extraction effect becomes better with the extension of extraction time and the increase of temperature, but the extension of time and the increase of temperature will cause the decomposition of lutein esters. The optimal temperature for lutein extraction is 50-55℃, the extraction time is 3-4h, the solid-liquid ratio is 1:30, and the extraction stage is 3 extractions.

[0072] The volume ratio of petroleum ether and ethanol is 2:5, which can effectively dissolve lutein ester compounds during the extraction process. The optimal extraction temperature is 50-55℃. Within this temperature range, the solubility of lutein is high, which is conducive to improving the extraction efficiency. The recommended extraction time is 3-4 hours. Too short extraction time may lead to incomplete extraction of lutein, while too long extraction time may lead to decomposition of lutein esters. The solid-liquid ratio is 1:30, that is, 30 units of raw materials are corresponding to each unit volume of solvent. This ratio helps to achieve the appropriate concentration in the solvent and improve the solubility and extraction efficiency of lutein. Extraction stage: 3 extractions. Multiple extractions can further improve the recovery rate of lutein and ensure that the lutein concentration in the solvent reaches the maximum.

[0073] Time and Temperature: While longer extraction times and higher temperatures will improve extraction results, they will also increase the risk of lutein ester decomposition. Therefore, it is very important to perform the extraction within the set optimal conditions and balance the extraction efficiency and compound stability. The conditions of the above examples provide a basic framework that will help to effectively extract lutein in research or industrial production. Ensuring accurate temperature control and appropriate time during the experiment can maximize the extraction efficiency and quality of lutein.

[0074] The invention extracts lutein ester from marigold based on organic solvent, provides specific extraction solvent, extraction time, extraction temperature, extraction solvent volume ratio and extraction times, and through single factor experiment, the extraction effect of the mixed solvent with the ratio of petroleum ether to ethanol being 2:5 is good, and the extraction effect becomes better with the extension of extraction time and the increase of temperature, but the extension of time and the increase of temperature will cause the decomposition of lutein ester, the optimal temperature for lutein extraction is 50-55 DEG C, the extraction time is 3-4h, the solid-liquid ratio is 1:30, and the extraction stage is 3 extractions, and because the lutein in marigold mainly exists in the form of ester, the invention further performs saponification separation.

[0075] Example 8

[0076] On the basis of Example 2, step 4 is added, the extract of step 3 is saponified and purified, the extract and the organic solvent are added to the reactor, the organic solvent is a mixed solvent of tetrahydrofuran and ethanol in a volume ratio of 3:2, and the mixture is fully stirred and mixed under a sealed condition at 30°C, an alkaline solution is added and fully mixed, the temperature is raised to 40°C, the reaction is carried out for 8 hours, the saponification is stopped, distilled water is added to the saponified product and stirred evenly, and the crude lutein is ultrafiltered. The process of ultrafiltration membrane separation is as follows: an ultrafiltration membrane with a molecular weight cutoff of 30K is used, at a temperature of 20°C, a feed liquid flow rate of 2.78×10-5m / s, and a pressure of 0.05Mpa under the condition Under the following conditions, the saponified liquid of lutein ester is separated by ultrafiltration membrane, and the ultrafiltrate obtained is concentrated and dried to obtain a lutein extract with a purity of more than 95%. The precipitated lutein crude product is eluted with anhydrous ethanol and n-hexane respectively, and the eluted high-purity lutein is recrystallized. The recrystallization process is as follows: the lutein extract is washed with water and ethanol respectively, and after removing the water and ethanol, the lutein extract is dissolved in tetrahydrofuran to obtain a hot supersaturated solution, and then n-hexane is added dropwise to the saturated solution, and the temperature is lowered at the same time to precipitate crystals, and the solvent is separated. After drying in a vacuum in the dark, lutein crystals can be obtained, and the purity can reach more than 98.5-99.6%.

[0077] Example 9

[0078] On the basis of Example 2, step 4 is added, the extract of step 3 is saponified and purified, the extract and the organic solvent are added to the reactor, the organic solvent is a mixed solvent of tetrahydrofuran and ethanol in a volume ratio of 3:2, and the mixture is fully stirred and mixed under a sealed condition at 35°C, an alkaline solution is added and fully mixed, the temperature is raised to 45°C, the reaction is carried out for 10 hours, the saponification is stopped, distilled water is added to the saponified product and stirred evenly, and the crude lutein is ultrafiltered. The membrane separation process is as follows: an ultrafiltration membrane with a molecular weight cutoff of 40K is used, at a temperature of 30°C, a feed liquid flow rate of 2.78×10-5m / s, and a pressure of 0.05Mpa under the condition Under the following conditions, the saponified liquid of lutein ester is separated by ultrafiltration membrane, and the ultrafiltrate obtained is concentrated and dried to obtain a lutein extract with a purity of more than 95%. The precipitated lutein crude product is eluted with anhydrous ethanol and n-hexane respectively, and the eluted high-purity lutein is recrystallized. The recrystallization process is as follows: the lutein extract is washed with water and ethanol respectively, and after removing the water and ethanol, the lutein extract is dissolved in tetrahydrofuran to obtain a hot supersaturated solution, and then n-hexane is added dropwise to the saturated solution, and the temperature is lowered at the same time to precipitate crystals, and the solvent is separated. After drying in a vacuum in the dark, lutein crystals can be obtained, and the purity can reach more than 98.5-99.6%.

[0079] The organic solvent in step 4 is a mixed solvent of tetrahydrofuran and ethanol in a volume ratio of 3:2. The ester derivatives can be completely dissolved in tetrahydrofuran solution, and KOH can be well dissolved in ethanol solution, which just meets the requirements. The extraction liquid is used as the saponification system to simplify the saponification process and reduce the volatilization loss of the organic solvent. Therefore, this experiment still uses a mixed solvent of tetrahydrofuran and ethanol as the saponification reaction system. This embodiment optimizes the saponification process and purification process of the lutein extract. The experiment found that using an ultrafiltration membrane with a molecular weight cutoff of 30K to 40K, at a temperature of 20-30°C, a liquid flow rate of 2.78×10-5m / s, and a pressure of 0.05Mpa, a lutein extract with a purity of 95% was obtained. The obtained lutein extract was recrystallized to obtain lutein crystals with good morphology, and its purity reached more than 98.5%. The enrichment of lutein is higher and it is not easy to block the membrane pores.

[0080] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A system for preparing marigold extract, characterized in that: include: A pretreatment unit, the pretreatment unit comprising an automatic cleaning machine, an automatic air drying machine, a crushing device and a grinding device, the automatic cleaning machine is used to clean and remove impurities from marigold flowers, the automatic air drying machine is used to air-dry the washed flowers, the crushing device is used to crush the flowers into particles, and the grinding device is used to grind the particles into marigold powder; A mixing unit, the mixing unit comprising a stirring module, a solvent adding module, a heating module, an ultrasonic generating module, and an enzyme adding module, the stirring module is used to mix marigold powder and an extraction solvent to form a mixed solution, the solvent adding module is used to add the extraction solvent to the stirring module, the extraction solvent is a two-component solvent, the heating module is used to heat the stirring module, the ultrasonic generating module is used to ultrasonically crush the mixed solution, the ultrasonic generating module can form a cavitation effect to crush the cell wall of the marigold powder, and the enzyme adding module is used to add cellulase or hemicellulase into the stirring module; A desolventizing unit, the desolventizing unit comprising a suction filtration module and a rotary evaporation module, the suction filtration module is used to separate the undissolved part of the mixed solution, and the rotary evaporation module is used to remove the solvent in the mixed solution to obtain an extract; The saponification and purification unit includes an alkali adding module, a membrane separation module, and a secondary treatment module. The alkali adding module is used to saponify the extract with potassium hydroxide to obtain a saponified liquid. The membrane separation module is used to filter the saponified liquid to obtain a purer ultrafiltrate. The secondary treatment module is used to wash the ultrafiltrate with water, alcohol and recrystallize it to obtain lutein crystals.

2. The system for preparing marigold extract according to claim 1, characterized in that: The two-component solvent includes a mixed solvent of petroleum ether and ethanol, and the ratio of the petroleum ether to the ethanol is 2:

5.

3. A method for preparing a marigold extract, using the system for preparing a marigold extract according to claim 1, characterized in that: The steps include: Step 1, washing, air-drying, crushing and grinding marigold flowers to obtain marigold flower powder; Step 2, weighing marigold flower powder, placing it in an extraction bottle, adding a certain volume of a two-component solvent as an extraction solvent, stirring through a stirring module during extraction, controlling the temperature through a heating module, adding cellulase or hemicellulase into the extraction bottle, and using an ultrasonic generator module to emit ultrasound to the mixed solution to assist in extracting lutein esters; Step 3, filtering the mixed solution in step 2 and rotary evaporating the solvent to obtain an extract; Step 4, saponifying and purifying the extract of step 3, adding the extract and the organic solvent into the reactor, stirring and mixing them thoroughly under a sealed condition at 30-35°C, adding the alkaline solution and mixing them thoroughly, raising the temperature to 40-45°C, reacting for 8-10 hours, stopping the saponification, adding distilled water to the saponified product and stirring evenly, ultrafiltering the crude lutein, eluting the precipitated crude lutein with anhydrous ethanol and n-hexane, respectively, and recrystallizing the eluted high-purity lutein.

4. The system for preparing marigold extract according to claim 3, characterized in that: The cleaning time in step 1 is 1-2 hours, the air-drying temperature is 25° C.-35° C., the grinding time is 30-50 minutes, and the grinding speed is 200-500 r / min.

5. The method for preparing a marigold extract according to claim 3, characterized in that: In step 2, the temperature of the heating module for temperature control is 50-55°C, the microwave power is 200w-2000w, the microwave time is 3-4 hours, and the material-liquid ratio is 1:

40.

6. The method for preparing a marigold extract according to claim 3, characterized in that: The organic solvent in step 4 is a mixed solvent of tetrahydrofuran and ethanol in a volume ratio of 3:

2.

7. The method for preparing a marigold extract according to claim 3, characterized in that: The extract of step 2 is subjected to HPLC detection, and the HPLC analysis conditions are as follows: chromatographic column: VP-ODS C 18 Column (150×4.6mm, Φ4um); Detection wavelength: 454nm; Mobile phase: V(CH2Cl2):V(CH3OH):V(CH3CN):V(H2O)=32:29:38:1; Flow rate: 0.5 mL / min; Injection: 10uL; Temperature: Room temperature.

8. The method for preparing a marigold extract according to claim 3, characterized in that: The membrane separation module is an ultrafilter, which is provided with an ultrafiltration membrane with a membrane surface area of ​​0.3 m2, a system temperature of 10-40°C, and a system P < 0.1 MPa, and the treatment volume is 500-20000 ml.

9. The method for preparing a marigold extract according to claim 8, characterized in that: The membrane separation process is as follows: using an ultrafiltration membrane with a molecular weight cutoff of 30K to 40K, the saponified liquid of lutein ester is ultrafiltration separated at a temperature of 20-30°C, a liquid flow rate of 2.78×10-5m / s, and a pressure of 0.05Mpa. The ultrafiltrate obtained, after concentration and drying, the purity of the lutein extract obtained reaches more than 95%.

10. The method for preparing a marigold extract according to claim 9, characterized in that: The process of recrystallization is as follows: the lutein extract is washed with water and ethanol respectively, after removing the water and ethanol, the lutein extract is dissolved in tetrahydrofuran to obtain a hot supersaturated solution, and then n-hexane is added dropwise to the saturated solution, while the temperature is lowered to precipitate crystals, the solvent is separated, and after light-proof vacuum drying, lutein crystals can be obtained, and the purity can reach more than 98.5-99.6%.

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