Preparation process of lutein ester microcapsule

Abstract

The invention discloses a lutein ester microcapsule preparation process, which comprises: extracting a lutein ester solution, preparing marigold and n-hexane, washing marigold, removing soil and impurities, airing, and grinding into a fine powder with a mesh number of less than 200 mesh after airing. The lutein ester microcapsules are dried in a freeze-drying mode, the activity of the lutein ester microcapsules can be ensured, structural damage and deformation in the drying process are reduced, the embedding rate of the lutein ester microcapsules is increased, the stability and bioavailability of the lutein ester microcapsules can be improved by adding the coenzyme Q10 into the lutein ester solution, and the lutein ester microcapsules can be applied to preparation of capsules. According to the present invention, the lutein ester solution is added to the wall material, the oxidation degradation process of the lutein ester is delayed so as to improve the high temperature resistance, and the surfactant is added during the lutein ester solution and wall material mixing process so as to improve the solubility and the dispersibility of the lutein ester, such that the lutein ester can be well wrapped by the vegetable glue wall material, protection can be achieved, and the light resistance can be improved; and the shelf life is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of lutein ester microcapsule preparation, in particular to a preparation process of lutein ester microcapsule. Background Art

[0002] Lutein is a natural and safe pigment. It has important physiological effects in the human body. The human body cannot synthesize it naturally and is mainly taken in through medicines and foods. Lutein is widely available. Many foods contain lutein, such as cabbage, spinach, lettuce, mung bean, rapeseed, and tea, but the content is relatively low. After research, it was found that the content of lutein in marigold flowers is relatively high. Now most luteins are mainly extracted from marigold flowers. Marigold, also known as stinking hibiscus. Asteraceae, marigold, annual herb, plant height 100-150cm, stem erect, sturdy, multi-branched, smooth surface, leaves opposite, pinnately fissured, leaf margins with shallow serrations, capitula solitary, scape 5-9cm, summer and autumn flowering, long flowering period, large and beautiful flowers, yellow on the upper part, orange on the lower part.

[0003] Microcapsules are a technology that uses natural or synthetic polymer encapsulation materials to encapsulate dispersed solids, liquids, and gases to form tiny particles with semi-permeable or sealed capsule membranes. Due to the differences in core materials, wall materials, and microencapsulation methods, the size, shape, and structure of microcapsules vary greatly. The diameter of microcapsules is generally in the range of 1-1000um. Particles with a diameter less than 1um are called nanoparticles or nanomicrocapsules, and particles with a diameter greater than 1000um are called microparticles or macrocapsules. The shape of microcapsules containing solid particles is similar to the shape of the solid inside the capsule, and the shape of microcapsules containing liquids or gases is generally spherical, but there are also rice-grain, kidney-shaped, block-shaped, needle-shaped, or irregular shapes.

[0004] The lutein ester microcapsules are prepared by extracting a lutein ester solution, mixing the lutein ester solution with a wall material, adding an emulsifier and stirring evenly to form a stable emulsion, slowly adding the emulsion into a container and mixing it with a curing agent, so that the wall material gradually solidifies and solidifies to form a microcapsule structure to encapsulate the lutein ester, and finally removing the moisture by freeze-drying to achieve the preparation of the lutein ester capsules; the lutein ester microcapsules in the prior art only encapsulate and protect the lutein ester during use, but the factors such as temperature and light during the storage process will still have a great influence on the stability of the lutein ester, and then under high temperature or light conditions, the retention rate of the lutein ester will gradually decrease, resulting in failure, thereby limiting its use. Summary of the invention

[0005] The object of the present invention is to provide a preparation process of lutein ester microcapsules, which has the advantages of improving light and high temperature resistance, and solves the problem that the lutein ester microcapsules in the prior art are only wrapped and protected by an outer capsule during use, but the temperature and light and other factors during the storage process still have a great influence on the stability of the lutein ester, and then under high temperature or light conditions, the retention rate of the lutein ester will gradually decrease, resulting in failure, thereby limiting its use.

[0006] To achieve the above object, the present invention provides the following technical solution: a preparation process of lutein ester microcapsules, comprising the following steps:

[0007] A. Lutein ester solution extraction:

[0008] A1. First, prepare marigold and n-hexane, then wash the marigold, remove dirt and impurities, and dry it. After drying, grind it into a fine powder with a mesh size of less than 200 meshes;

[0009] A2. The crushed marigold is mixed with a n-hexane solvent, and the marigold and the n-hexane solvent are fully mixed by a stirrer to promote the dissolution and extraction of lutein esters to form a mixture, and the absorbance value is used as an indicator to determine whether the extract contains lutein esters;

[0010] A3, filtering the mixture to separate the marigold residue and the solution, placing the extract in a container after separation, removing the n-hexane solvent in the extract using a rotary evaporator, and concentrating the extract to obtain a lutein ester solution;

[0011] B. Preparation of lutein ester microcapsules: B1. Adding coenzyme Q10 to the lutein ester solution and stirring to allow the lutein ester solution and coenzyme Q10 to recombine to form a lutein ester mixed solution;

[0012] B2, mixing the lutein ester mixed solution, the surfactant and the plant glue wall material, adding an emulsifier, and stirring the mixture evenly with a stirrer to form a stable emulsion;

[0013] B3, slowly adding the formed emulsion into a container containing a curing agent, and then continuously stirring the mixture so that the plant glue wall material gradually solidifies and solidifies to form a microcapsule structure;

[0014] B4. Centrifuge the prepared microcapsule suspension to separate the microcapsules, then wash the microcapsules with a suitable solvent or solution to remove the residual emulsifier and curing agent, and finally dry the microcapsules by freeze drying to obtain lutein ester microcapsules.

[0015] Preferably, the extractant is one of tetrahydrofuran, petroleum ether, n-hexane, chloroform, acetone, ethanol, and ethyl acetate.

[0016] Preferably, the fusion of the crushed marigold and the n-hexane solvent in step A is usually carried out at room temperature or under slightly heated conditions.

[0017] Preferably, the freeze-drying temperature in step B4 is between minus 40 degrees Celsius and minus 50 degrees Celsius, and the time is between 20 and 35 hours.

[0018] Preferably, the temperature during the stirring of the lutein ester solution and coenzyme Q10 in step B1 is 25 degrees Celsius to 40 degrees Celsius.

[0019] Preferably, in step A3, when filtering the mixture, a filter screen with a mesh size of 100 is used.

[0020] Preferably, a desktop centrifuge is used for centrifugal separation in step B4, and its model is Eppendorf5424, and the rotation speed is 2000 to 15000 rpm, and the rotation speed is adjustable.

[0021] Preferably, in step A2, the absorbance value is used as an indicator to determine whether the extract contains lutein esters, which specifically includes the following steps: 1 ml of the lutein ester solution extracted with n-hexane is taken into a 100 ml brown volumetric flask, and the absorption spectrum of the sample is obtained by scanning in the range of 400-500 nm. If the extract has a maximum absorption peak at the same wavelength as the standard and the shape of the absorption spectrum is basically consistent with that of the standard, it can be determined whether the extract contains lutein esters.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention dries the lutein ester microcapsules by freeze drying, which not only ensures the activity of the lutein ester microcapsules but also reduces structural damage and deformation during the drying process, thereby improving the embedding rate of the lutein ester microcapsules. Coenzyme Q10 is added to the lutein ester solution, thereby improving the stability and bioavailability of the lutein ester, delaying the oxidative degradation process of the lutein ester, and improving the high temperature resistance. In addition, a surfactant is added during the mixing process of the lutein ester solution and the wall material to improve the solubility and dispersibility of the lutein ester, so that the plant glue wall material can well wrap the lutein ester to achieve protection, thereby improving the light resistance of the lutein ester and extending the shelf life. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the process of the present invention.

[0025] Figure 2This is a temperature test result diagram of the present invention.

[0026] Figure 3 This is a diagram of the illumination test results of the present invention. DETAILED DESCRIPTION

[0027] Comparison Example

[0028] A preparation process of lutein ester microcapsules comprises the following steps:

[0029] Lutein ester solution extraction, first prepare marigold and n-hexane, then wash the marigold, remove dirt and impurities, and dry it, and then grind it into a fine powder state with a mesh size of less than 200 meshes;

[0030] The crushed marigold is blended with a n-hexane solvent, and the marigold and the n-hexane solvent are fully mixed by using a stirrer to promote the dissolution and extraction of lutein esters to form a mixture, and the absorbance value is used as an indicator;

[0031] The mixture is filtered to separate the marigold residue and the solution, and after separation, the extract is placed in a container, and the n-hexane solvent in the extract is removed by a rotary evaporator, and the extract is concentrated to obtain a lutein ester solution;

[0032] Preparation of lutein ester microcapsules: B1, stirring the lutein ester solution, mixing the lutein ester solution with the plant glue wall material, adding an emulsifier, and stirring the mixture evenly with a stirrer to form a stable emulsion;

[0033] The formed emulsion is slowly added into a container containing a curing agent, and then the mixture is continuously stirred so that the plant glue wall material gradually solidifies and solidifies to form a microcapsule structure;

[0034] The prepared microcapsule suspension is centrifuged to separate the microcapsules, and then the microcapsules are washed with a suitable solvent or solution to remove the residual emulsifier and curing agent, and the microcapsules are dried to obtain lutein ester microcapsules.

[0035] Embodiment 1:

[0036] A. Lutein ester solution extraction:

[0037] A1. First, prepare marigold and n-hexane, then wash the marigold, remove dirt and impurities, and dry it. After drying, grind it into a fine powder with a mesh size of less than 200 meshes;

[0038] A2, blending the crushed marigold with n-hexane solvent, using a stirrer to fully mix the marigold and the n-hexane solvent to promote the dissolution and extraction of lutein esters to form a mixture, and judging whether the extract contains lutein esters based on the absorbance value as an indicator, specifically comprising the following steps: taking 1 ml of the lutein ester solution extracted with n-hexane and making it constant to a 100 ml brown volumetric flask, scanning in the range of 400-500 nm to obtain an absorption spectrum of the sample, if the extract has a maximum absorption peak at the same wavelength as the standard and the shape of the absorption spectrum is substantially consistent with that of the standard, it can be judged whether the extract contains lutein esters;

[0039] A3, filtering the mixture to separate the marigold residue and the solution, using a filter screen with a 100-mesh mesh, placing the extract in a container after separation, removing the n-hexane solvent in the extract using a rotary evaporator, and concentrating the extract to obtain a lutein ester solution;

[0040] B. Preparation of Example Lutein Ester Microcapsules and Comparative Example Lutein Ester Microcapsules:

[0041] B1. Divide the lutein ester solution into two parts, namely a control example and an example; add coenzyme Q10 to the control example lutein ester solution and stir to compound the lutein ester solution and form a control example lutein ester mixed solution, wherein the temperature during the stirring of the lutein ester solution and the coenzyme Q10 is 25 degrees Celsius;

[0042] B2, by mixing the reference example lutein ester mixed solution, Tween 20 and the plant glue wall material, and adding an emulsifier, stirring the mixture evenly with a stirrer to form a stable emulsion, and at the same time, by mixing the example lutein ester solution with the plant glue wall material, and adding an emulsifier and stirring, forming a stable example emulsion;

[0043] B3, slowly adding the formed emulsion and the embodiment emulsion into a container containing a curing agent, and then continuously stirring the mixture to gradually solidify and solidify the plant glue wall material to form a microcapsule structure;

[0044] B4. Centrifuge the prepared microcapsule suspension to separate the microcapsules, then wash the microcapsules with an appropriate solvent or solution to remove the residual emulsifier and curing agent, and finally dry the microcapsules by freeze drying to obtain lutein ester microcapsules, wherein the freeze drying temperature is minus 40 degrees Celsius and the time is 20 hours.

[0045] The difference between the control example and the example is that no coenzyme Q10 is added to the lutein ester solution, no surfactant is added, and the drying method is ordinary drying.

[0046] The temperature and light tests were performed on the control example lutein ester microcapsules and the example lutein ester microcapsules. The temperature test results of the example lutein ester microcapsules and the control example lutein ester microcapsules are shown in Table 1 below:

[0047]

[0048] It can be seen that the retention rate of the control example lutein ester capsule at 40°C differs from that of the example lutein ester capsule by 13.5%, the retention rate at 60°C differs by 29.7%, the retention rate at 80°C differs by 45.2%, and the retention rate at 100°C differs by 58.8%.

[0049] The illumination test results of the lutein ester microcapsules of the embodiment and the lutein ester microcapsules of the control example are shown in Table 2 below:

[0050] Photometric status Natural Light Protect from light Example retention rate 90.1％ 95.2％ Control case retention rate 57.6％ 61.5％ Retention rate 32.5％ 33.7％

[0051] It can be seen that the retention rate of the control example lutein ester capsule under natural light is 32.5% different from that of the example lutein ester capsule, and the retention rate is 33.7% different under light-proof state.

[0052] Embodiments Coenzyme Q10 is added to the lutein ester solution, thereby improving its stability and bioavailability, delaying the oxidative degradation process of lutein ester, and improving its high temperature resistance. Further analysis shows that coenzyme Q10 may play a variety of roles in the process of extracting lutein esters, including antioxidant effects. Coenzyme Q10 is a powerful antioxidant that can help protect lutein esters from oxidative damage. During the extraction process, lutein esters are easily oxidized with oxygen, causing them to lose activity or degrade. Coenzyme Q10 can prevent or slow down the occurrence of such oxidation reactions, which helps to maintain the stability and activity of lutein esters. It also helps to enhance the solubility of the extraction solvent for lutein esters. Coenzyme Q10 can also enhance the stability of cell membranes, help protect plant cell structures, and reduce cell rupture and damage that may occur during the extraction process, thereby facilitating the extraction and protection of lutein esters. Coenzyme Q10 may participate in chemical reactions as a co-catalyst during the extraction process to promote the release and extraction of lutein esters.

[0053] When making lutein ester microcapsules, Tween 20 can help stabilize the formation of lutein ester microcapsules, prevent uneven distribution or aggregation of microcapsules during preparation, storage and use, and maintain their stability and uniformity. Tween 20 can increase the solubility of lutein esters in solvents, promote their dissolution and mixing, and help achieve uniform dispersion of lutein esters and encapsulating materials during microcapsule preparation. Tween 20 can further reduce the interfacial tension between lutein esters and encapsulating materials, help form a stable encapsulating film during microcapsule preparation, and promote the formation of lutein ester microcapsules.

[0054] Freeze drying can maintain the stability of the ingredients. During the freeze drying process, the sample is kept in a low temperature environment and is carried out under vacuum conditions, which is conducive to maintaining the stability of the active ingredients in the lutein ester microcapsules, avoiding the thermal sensitivity and oxidation reactions that may occur under high temperature or oxidative conditions, and helping to maintain the activity and bioavailability of the lutein esters in the microcapsules. It can reduce thermal stress. During the freeze drying process, the sample is directly converted from a frozen state to a dry state, avoiding the thermal stress caused by the increase in temperature in traditional thermal drying, and reducing the damage to the structure and ingredients of the microcapsules. Freeze drying can also improve solubility. The freeze-dried microcapsules have a higher solubility because the water in them has been frozen and removed through the sublimation process, making the lutein esters inside the microcapsules easier to release and dissolve in water. Since the water is removed during the freeze drying process, the conditions for microbial growth are reduced, and the shelf life of the lutein ester microcapsules can be extended, making them more stable and long-lasting. Helps to maintain the morphology of microcapsules: Freeze drying can better maintain the morphology and particle structure of the microcapsules, which is conducive to maintaining the appearance and quality of the microcapsules, and is also convenient for subsequent packaging and use

[0055] Embodiment 2:

[0056] A. Lutein ester solution extraction:

[0057] A1. First, prepare marigold and n-hexane, then wash the marigold, remove dirt and impurities, and dry it. After drying, grind it into a fine powder with a mesh size of less than 180 meshes;

[0058] A2, blending the crushed marigold with n-hexane solvent, and fully mixing the marigold and the n-hexane solvent by using a stirrer. The blending of marigold and the n-hexane solvent is usually carried out at room temperature or slightly heated to promote the dissolution and extraction of lutein esters to form a mixture, and judging whether the extract contains lutein esters by using the absorbance value as an indicator, which specifically comprises the following steps: taking 1 ml of the lutein ester solution extracted with n-hexane and making it constant to a 100 ml brown volumetric flask, scanning in the range of 400-500 nm to obtain an absorption spectrum of the sample, if the extract has a maximum absorption peak at the same wavelength as the standard and the shape of the absorption spectrum is substantially consistent with that of the standard, it can be judged whether the extract contains lutein esters;

[0059] A3, filtering the mixture to separate the marigold residue and the solution, using a filter screen with a 100-mesh mesh, placing the extract in a container after separation, removing the n-hexane solvent in the extract using a rotary evaporator, and concentrating the extract to obtain a lutein ester solution;

[0060] B. Preparation of Example Lutein Ester Microcapsules and Comparative Example Lutein Ester Microcapsules:

[0061] B1. Divide the lutein ester solution into two parts, namely a control example and an example; add coenzyme Q10 to the control example lutein ester solution and stir to compound the lutein ester solution and form a control example lutein ester mixed solution, wherein the temperature during the stirring of the lutein ester solution and the coenzyme Q10 is 40 degrees Celsius;

[0062] B2, by mixing the reference example lutein ester mixed solution, Tween 20 and the plant glue wall material, and adding an emulsifier, stirring the mixture evenly with a stirrer to form a stable emulsion, and at the same time, by mixing the example lutein ester solution with the plant glue wall material, and adding an emulsifier and stirring, forming a stable example emulsion;

[0063] B3, slowly adding the formed emulsion and the embodiment emulsion into a container containing a curing agent, and then continuously stirring the mixture to gradually solidify and solidify the plant glue wall material to form a microcapsule structure;

[0064] B4. Centrifuge the prepared microcapsule suspension to separate the microcapsules, then wash the microcapsules with an appropriate solvent or solution to remove the residual emulsifier and curing agent, and finally dry the microcapsules by freeze-drying to obtain lutein ester microcapsules, wherein the freeze-drying temperature is minus fifty degrees Celsius and the time is thirty-five hours.

[0065] Embodiment 3:

[0066] A. Lutein ester solution extraction:

[0067] A1. First, prepare marigold and n-hexane, then wash the marigold, remove dirt and impurities, and dry it. After drying, grind it into fine powder with a mesh size of 100.

[0068] A2, blending the crushed marigold with n-hexane solvent, and fully mixing the marigold and the n-hexane solvent by using a stirrer. The blending of marigold and the n-hexane solvent is usually carried out at room temperature or slightly heated to promote the dissolution and extraction of lutein esters to form a mixture, and judging whether the extract contains lutein esters by using the absorbance value as an indicator, which specifically comprises the following steps: taking 1 ml of the lutein ester solution extracted with n-hexane and making it constant to a 100 ml brown volumetric flask, scanning in the range of 400-500 nm to obtain an absorption spectrum of the sample, if the extract has a maximum absorption peak at the same wavelength as the standard and the shape of the absorption spectrum is substantially consistent with that of the standard, it can be judged whether the extract contains lutein esters;

[0069] A3, filtering the mixture to separate the marigold residue and the solution, using a filter screen with a 100-mesh mesh, placing the extract in a container after separation, removing the n-hexane solvent in the extract using a rotary evaporator, and concentrating the extract to obtain a lutein ester solution;

[0070] B. Preparation of Example Lutein Ester Microcapsules and Comparative Example Lutein Ester Microcapsules:

[0071] B1. Divide the lutein ester solution into two parts, namely a control example and an example; add coenzyme Q10 to the control example lutein ester solution and stir to compound the lutein ester solution and form a control example lutein ester mixed solution, wherein the temperature during the stirring of the lutein ester solution and the coenzyme Q10 is 30 degrees Celsius;

[0072] B2, by mixing the reference example lutein ester mixed solution, Tween 20 and the plant glue wall material, and adding an emulsifier, stirring the mixture evenly with a stirrer to form a stable emulsion, and at the same time, by mixing the example lutein ester solution with the plant glue wall material, and adding an emulsifier and stirring, forming a stable example emulsion;

[0073] B3, slowly adding the formed emulsion and the embodiment emulsion into a container containing a curing agent, and then continuously stirring the mixture to gradually solidify and solidify the plant glue wall material to form a microcapsule structure;

[0074] B4. Centrifuge the prepared microcapsule suspension to separate the microcapsules, then wash the microcapsules with an appropriate solvent or solution to remove the residual emulsifier and curing agent, and finally dry the microcapsules by freeze drying to obtain lutein ester microcapsules, wherein the freeze drying temperature is minus 45 degrees Celsius and the time is thirty hours.

[0075] The lutein ester microcapsules of Example 3 were tested at 40°C, 60°C, and 100°C. The test results are as follows: Figure 2 Example 3 Lutein ester microcapsules test results under sunlight, 25w, 50w lighting conditions are as shown Figure 3 shown.

[0076] In the above-mentioned Examples 1-3, the lutein ester microcapsules are dried by freeze-drying, which not only ensures their activity but also reduces structural damage and deformation during the drying process, thereby improving the embedding rate of the lutein ester microcapsules. By adding coenzyme Q10 to the lutein ester solution, its stability and bioavailability can be improved, the oxidative degradation process of the lutein ester is delayed, and its high temperature resistance is improved. In addition, a surfactant is added during the mixing process of the lutein ester solution and the wall material to improve the solubility and dispersibility of the lutein ester, so that the plant glue wall material can wrap the lutein ester well to achieve protection, thereby improving its light resistance and extending the shelf life.

[0077] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0078] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for preparing lutein ester microcapsules, characterized in that: The method comprises the following steps: A. extracting lutein ester solution; A1. First, prepare marigold and extractant, then wash the marigold, remove dirt and impurities, and dry it. After drying, grind it into fine powder with a mesh size of less than 200 meshes; A2. The crushed marigold is blended with an extractant solvent, and the marigold and the extractant solvent are fully mixed by a stirrer to promote the dissolution and extraction of lutein esters to form a mixture, and the absorbance value is used as an indicator to determine whether the extract contains lutein esters; A3, filtering the mixture to separate the marigold residue and the solution, placing the extract in a container after separation, removing the extractant solvent in the extract using a rotary evaporator, and concentrating the extract to obtain a lutein ester solution; B. Preparation of lutein ester microcapsules; B1. Adding coenzyme Q10 to the lutein ester solution and stirring to allow the lutein ester solution and coenzyme Q10 to recombine to form a lutein ester mixed solution; B2, mixing the lutein ester mixed solution, the surfactant and the plant glue wall material, adding an emulsifier, and stirring the mixture evenly with a stirrer to form a stable emulsion; B3, slowly adding the formed emulsion into a container containing a curing agent, and then continuously stirring the mixture so that the plant glue wall material gradually solidifies and solidifies to form a microcapsule structure; B4. Centrifuge the prepared microcapsule suspension to separate the microcapsules, then wash the microcapsules with a suitable solvent or solution to remove the residual emulsifier and curing agent, and finally dry the microcapsules by freeze drying to obtain lutein ester microcapsules.

2. The process for preparing lutein ester microcapsules according to claim 1, characterized in that: The extractant is one of tetrahydrofuran, petroleum ether, n-hexane, chloroform, acetone, ethanol and ethyl acetate.

3. The preparation process of lutein ester microcapsules according to claim 2, characterized in that: In the step A, the fusion of the crushed marigold and the n-hexane solvent is usually carried out at room temperature or under slightly heated conditions.

4. The process for preparing lutein ester microcapsules according to claim 1, characterized in that: The freeze-drying temperature in step B4 is between minus 40 degrees Celsius and minus 50 degrees Celsius, and the time is between 20 and 35 hours.

5. The preparation process of lutein ester microcapsules according to claim 1, characterized in that: In step B1, the temperature during the stirring of the lutein ester solution and coenzyme Q10 is 25 degrees Celsius to 40 degrees Celsius.

6. The process for preparing lutein ester microcapsules according to claim 1, characterized in that: In the step A3, when filtering the mixture, a filter screen with a mesh size of 100 is used.

7. The process for preparing lutein ester microcapsules according to claim 1, characterized in that: In step B4, a desktop centrifuge is used for centrifugal separation, and its model is Eppendorf5424, and the rotation speed is 2000 to 15000 rpm, and the rotation speed can be adjusted.

8. The process for preparing lutein ester microcapsules according to claim 1, characterized in that: The surfactant is selected from one of Tween 20, Tween 80, Span 80 or sodium lauryl sulfate.

9. The process for preparing lutein ester microcapsules according to claim 2, characterized in that: In step A2, the absorbance value is used as an indicator to determine whether the extract contains lutein esters, which specifically includes the following steps: 1 ml of the lutein ester solution extracted with n-hexane is taken into a 100 ml brown volumetric flask, and the absorption spectrum of the sample is obtained by scanning in the range of 400-500 nm. If the extract has a maximum absorption peak at the same wavelength as the standard and the shape of the absorption spectrum is basically consistent with that of the standard, it can be determined whether the extract contains lutein esters.

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