Lutein ester oil suspension as well as preparation method and application thereof

Abstract

The invention relates to the technical field of food additives, in particular to lutein ester oil suspension as well as a preparation method and application thereof. The lutein ester oil suspension prepared by the preparation method provided by the invention has good stability and coloring effect, the product is uniform and stable in color generation and coloring, and the color and luster of products such as wrapping powder can be remarkably improved; the method does not use an organic solvent, is green and environment-friendly, has the characteristics of simple process, convenience in use and the like, is high in applicability, and is easy for large-scale industrial production, popularization and application.

Description

Technical Field

[0001] The present invention relates to the technical field of food additives, and in particular to a lutein ester oil suspension and a preparation method and application thereof. Background Art

[0002] Lutein is a natural carotenoid that is widely found in various plants, especially in dark vegetables and fruits. Lutein has strong antioxidant properties, which can protect the eyes from blue light damage and reduce the risk of cataracts and macular degeneration. In addition, lutein also has a variety of biological activities such as anti-cancer, anti-inflammatory and immunomodulatory. Therefore, lutein has broad application prospects in the fields of food, medicine and cosmetics. However, lutein has poor stability and is easily oxidized and degraded, which limits its application to a certain extent. To solve this problem, researchers have developed a derivative of lutein, lutein ester, which is a compound formed by lutein and one or two molecules of fatty acids and has better stability. Existing lutein esters are mainly extracted from plants. Generally, lutein esters are made into oils or water suspensions by adding appropriate solvents and emulsifiers for easy use. These lutein ester products are usually used as food additives to improve the color and nutritional quality of products. However, the existing preparation method of lutein ester oil suspension is relatively complicated and requires the use of a large amount of organic solvents, which is not only costly but also pollutes the environment. In addition, lutein ester oil suspension is prone to physical stratification, color change, and loss of active ingredients during storage and use, and its stability still needs to be improved. These problems limit the wide application of lutein ester oil suspension.

[0003] CN201010602338.6 discloses a carotenoid oil suspension with high bioavailability and a preparation method thereof. The method comprises dissolving carotenoids in a mixed manner with an organic solvent and atomizing and concentrating the mixture to obtain the carotenoid oil suspension. The preparation process requires the use of a large amount of organic solvent, which is not only costly but also pollutes the environment.

[0004] CN202211328321.5 discloses a beta-carotene oil suspension and its preparation method and application, which prepares a beta-carotene oil suspension with a content of more than 30% by a grinding and crushing method, has good fluidity, a simple preparation process, and is convenient for large-scale production. However, unlike beta-carotene, lutein esters are unstable when heated after mixing with oils and fats due to their fatty acid structure, and are easily dissolved and separated, and the mechanical force impact force is large during grinding, and lutein ester crystals are also easily precipitated from the system. Therefore, the above method is difficult to be applied to the preparation of lutein ester oil suspensions.

[0005] When lutein esters are used in food and other fields, in addition to ensuring product stability, attention should also be paid to color stability and coloring effect. Although the prior art prepares lutein esters into a certain form of preparation to improve its oil solubility, little attention is paid to the stability and coloring effect of lutein ester preparations. Therefore, it is urgent to develop a lutein ester oil suspension that is stable, non-stratified, and has stable and uniform coloring. Summary of the invention

[0006] In order to overcome the problems existing in the lutein ester oil suspension in the prior art, the present invention provides a lutein ester oil suspension and a preparation method and application thereof.

[0007] The present invention found in the research process that the color of the product prepared by simply mixing and homogenizing lutein ester crystals with oil is unstable. The color gradually changes from red to orange to varying degrees during storage, affecting the coloring effect. The crystals are precipitated and sink after long-term placement, and the oil floats and is easy to stratify. After continuous attempts, the present invention found that by controlling the lutein ester content of the lutein ester crystals and adding an oil-soluble emulsifier compounded with medium-chain triglycerides and glycerol fatty acid esters in the system, the stability of the lutein ester crystals in the system can be significantly improved, and the possibility of precipitation and stratification under normal temperature conditions can be reduced. At the same time, the present invention also found that by adopting program cooling control and supplemented by emulsification and homogenization technology, the particle size and distribution of the lutein ester crystals in the system can be effectively controlled. With the above-mentioned compounded emulsifier, the product color can be controlled, and the stability of the product can be guaranteed, solving the problems of storage stratification and color change. In summary, the lutein ester oil suspension prepared by the preparation method provided by the present invention has both stability and good coloring effect.

[0008] Specifically, the present invention provides the technical solution described below.

[0009] The present invention provides a method for preparing a lutein ester oil suspension, the method comprising: The lutein ester crystals are mixed with the first composition and heated to dissolve the crystals to obtain a second composition, wherein the first composition comprises oil, a composite emulsifier and a composite antioxidant; The second composition is subjected to programmed cooling in two stages to obtain a third composition; emulsifying and homogenizing the third composition; Wherein, the lutein ester content of the lutein ester crystals is 65%-80%; The composite emulsifier comprises medium chain triglyceride and glycerol fatty acid ester in a mass ratio of (60-74):(2-4).

[0010] The present invention proves through verification experiments that the lutein ester content of the lutein ester crystals is controlled between 65% and 80%, and the addition of the above mass ratio of medium-chain triglycerides and glycerol fatty acid esters as emulsifiers can significantly improve the stability, particle size and distribution, and coloring effect of the lutein ester oil suspension. The above raw material improvement combined with programmed cooling after heating and dissolving the crystals can further improve the stability, particle size and distribution, and coloring effect of the lutein ester oil suspension.

[0011] In the above method, lutein ester crystals, oil, composite emulsifier and compound antioxidant are first dissolved and dispersed under certain temperature conditions to obtain an oil solution of lutein ester, and then the temperature is lowered step by step according to a specific cooling program to obtain a suspension, and finally emulsified and homogenized to obtain a uniform and stable lutein ester oil suspension. Among them, the purpose of performing program cooling in two stages after heating to dissolve the lutein ester crystals is to perform low-temperature induced phase transition. The present invention finds that without high-temperature dissolution of crystals or adjusting the two-step program cooling to one-step cooling will cause the color brightness of the prepared oil suspension to be reduced, the particle size is larger and unevenly distributed, and the product stability is reduced.

[0012] The lutein ester content of the lutein ester crystals used in the present invention is preferably between 65% and 75%. The lutein ester crystals with the above content are mixed with oils, emulsifiers, etc. in appropriate proportions to help form a more stable oil suspension.

[0013] Medium chain triglycerides (MCT) are medium chain fatty acid triglycerides, whose main components are saturated caprylic triglycerides, saturated capric triglycerides, and saturated caprylic-capric mixed triglycerides.

[0014] The HLB value of the glycerol fatty acid ester used in the present invention is preferably 3.0-3.5. Low HLB value and appropriate addition ratio of glycerol fatty acid ester can better ensure that the hydrophilic group in the emulsifier does not affect the solubility of lutein ester in oil, and can effectively disperse oil droplets, better ensuring that the product does not stratify during storage.

[0015] Preferably, the glycerol fatty acid ester is at least one selected from glycerol stearate, glycerol distearate, glycerol oleate, and glycerol dioleate.

[0016] In some embodiments of the present invention, the glycerol fatty acid ester is glycerol dioleate.

[0017] Preferably, the mass ratio of medium chain triglycerides to glycerol fatty acid esters is (66-74): (3-4).

[0018] In the above method, the two-stage programmed cooling comprises: The first stage of program cooling: cooling rate 10-20℃ / h, cooling to 25-40℃; And, the second stage of programmed cooling: cooling rate 15-25℃ / h, cooling to 5-15℃.

[0019] Preferably, the first stage of programmed cooling: the cooling rate is 15-20°C / h, and the temperature is lowered to 30-40°C; the second stage of programmed cooling: the cooling rate is 15-25°C / h, and the temperature is lowered to 10-15°C.

[0020] Preferably, stirring is performed during the two-stage programmed cooling, wherein the stirring speed of the first stage programmed cooling is 30-50 rpm, and the stirring speed of the second stage programmed cooling is 80-120 rpm.

[0021] Preferably, the stirring time of the first stage programmed cooling is 1-2 hours, and the stirring time of the second stage programmed cooling is 1.5-2 hours. If the time for cooling to the terminal temperature is less than the stirring time, the terminal temperature is maintained after cooling to the terminal temperature and stirring is continued for the stirring time.

[0022] Preferably, the starting temperature of the first stage programmed cooling is 50-70° C. (preferably 60-70° C.) The starting temperature of the second stage programmed cooling is the end temperature of the first stage programmed cooling.

[0023] In the above method, the conditions for heating and dissolving the crystals are: temperature 50-70°C (preferably 60-70°C), stirring speed 200-300 rpm.

[0024] Preferably, the heating and dissolving time is 1-4 hours.

[0025] The oil used in the present invention is preferably a vegetable oil, and more preferably at least one selected from soybean oil, sunflower seed oil, corn oil, and peanut oil.

[0026] In some embodiments of the present invention, the oil is soybean oil.

[0027] The compound antioxidant used in the present invention is preferably vitamin E and rosemary extract.

[0028] Preferably, the mass ratio of vitamin E to rosemary extract is 2:(0.5-1).

[0029] Preferably, the vitamin E is natural vitamin E.

[0030] In the above method, the mixing ratio of the first composition and the lutein ester crystals is: 12.5-23 parts of lutein ester crystals, 5-10 parts of oil, 62-78 parts of composite emulsifier, and 2-4 parts of composite antioxidant.

[0031] Preferably, the mixing ratio of the first composition and the lutein ester crystals is: 13.5-20 parts of lutein ester crystals, 6-8 parts of oil, 69-78 parts of composite emulsifier, and 2-4 parts of composite antioxidant.

[0032] In the above method, the emulsification conditions are preferably: emulsification rate 3000-4000 rpm, emulsification time 30-40 min.

[0033] In the above method, the homogenization pressure is preferably 320-380 bar.

[0034] The lutein ester oil suspension preparation system provided by the present invention introduces a specific composite emulsifier, which can effectively improve the solubility and stability of lutein ester in oils and fats, and the lutein ester and other components in the system form a suspension by inducing phase transition at low temperature, and then the stability and uniformity of the oil suspension are further improved by emulsification and homogenization. The lutein ester oil suspension product prepared by the method has good stability and color tone, and has the characteristics of golden color when used in food such as breading.

[0035] The present invention also provides a lutein ester oil suspension prepared by the above-mentioned method for preparing the lutein ester oil suspension.

[0036] Preferably, the lutein ester oil suspension has a lutein ester content of 10%-15%. The particle size D50 of the lutein ester oil suspension is between 8-10 μm, and the span (PDI) is less than 0.5.

[0037] The preparation method of the present invention can control the D50 particle size of lutein ester in the system to 8-10 μm, with a span of less than 0.5, so that the product presents a uniform and stable orange-yellow oil suspension state. The appearance hue value of the prepared lutein ester oil suspension is L*=45-55, a*=30-40, b*=30-50 (wherein, L* represents brightness, 0 is black, 100 is white, and the larger the L* value, the higher the brightness; a* represents red and green, positive values ​​are red, and negative values ​​are green; b* represents yellow and blue, positive values ​​are yellow, and negative values ​​are blue). In addition, the lutein ester oil suspension prepared by the method of the present invention has good stability, and the shelf life (6 months) stability is greater than 95% (stability=upper oil layer height / total height*100%).

[0038] The present invention provides application of the above-mentioned lutein ester oil suspension in the preparation of food, medicine, cosmetics or feed.

[0039] Exemplarily, the food is breaded.

[0040] The lutein ester oil suspension provided by the present invention is used for coating powder. When the addition amount is 2.5‰ (the addition amount is based on 10% of the lutein ester oil suspension content), the hue value of the coating powder is L*=90-94, a*=0-3, b*=30-35, and is golden yellow.

[0041] The beneficial effects of the present invention include at least: the lutein ester oil suspension prepared by the preparation method provided by the present invention has good stability and coloring effect, the product coloring and coloring are uniform and stable, and the color of the powder-coated products can be significantly increased; the method does not use organic solvents, has no waste discharge, and is green and environmentally friendly; the method also has the characteristics of simple process and easy use, strong applicability, and is easy to be industrialized on a large scale and promoted for application. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The medium chain triglycerides and other raw materials used in the following examples can be purchased from commercial sources.

[0044] Example 1 The present embodiment provides a lutein ester oil suspension, the raw materials of which are as follows: 13.5 kg of lutein ester crystals (total lutein ester content 75%), 6 kg of soybean oil, 73.5 kg of medium chain triglycerides, 4 kg of glycerol dioleate, 2 kg of vitamin E, and 1 kg of rosemary extract.

[0045] This embodiment further provides a method for preparing the lutein ester oil suspension, and the specific steps are as follows: 1) dissolving soybean oil, medium chain triglyceride, glyceryl dioleate, vitamin E and rosemary extract uniformly at 60° C. to obtain composition 1; 2) adding lutein ester crystals to composition 1, stirring and dissolving at 60° C. and 300 rpm for 2.5 hours to uniformly disperse the lutein ester in the system, to obtain composition 2; 3) subjecting composition 2 to two-stage programmed cooling to obtain composition 3; wherein, the first stage programmed cooling has a cooling rate of 15°C / h, the temperature is lowered to 30°C, the stirring speed is 50 rpm, and the stirring time is 2 hours; the second stage programmed cooling has a cooling rate of 20°C / h, the temperature is lowered to 10°C, the stirring speed is 100 rpm, and the stirring time is 1.5 hours; 4) The composition 3 was shear-emulsified at an emulsification speed of 4000 rpm and an emulsification time of 30 min, and finally homogenized at 350 bar to obtain a lutein ester oil suspension.

[0046] Example 2 The present embodiment provides a lutein ester oil suspension, the raw materials of which are as follows: 20 kg of lutein ester crystals (total lutein ester content 75%), 8 kg of soybean oil, 66 kg of medium chain triglycerides, 3 kg of glycerol dioleate, 2 kg of vitamin E, and 1 kg of rosemary extract.

[0047] This example also provides a method for preparing the lutein ester oil suspension, which is the same as the preparation method in Example 1.

[0048] Example 3 The present embodiment provides a lutein ester oil suspension, the raw materials of which are as follows: 15.4 kg of lutein ester crystals (total lutein ester content 65%), 6 kg of soybean oil, 71.6 kg of medium chain triglycerides, 4 kg of glycerol dioleate, 2 kg of vitamin E, and 1 kg of rosemary extract.

[0049] This embodiment also provides a method for preparing the lutein ester oil suspension, which is the same as the preparation method in Example 1.

[0050] Example 4 The present embodiment provides a lutein ester oil suspension, the raw materials of which are as follows: 13.5 kg of lutein ester crystals (total lutein ester content 75%), 6 kg of soybean oil, 73.5 g of medium chain triglycerides, 4 g of diolein, 2 g of vitamin E, and 1 g of rosemary extract.

[0051] This embodiment further provides a method for preparing the lutein ester oil suspension, and the specific steps are as follows: 1) dissolving soybean oil, medium chain triglyceride, glyceryl dioleate, vitamin E and rosemary extract uniformly at 60° C. to obtain composition 1; 2) adding lutein ester crystals to composition 1, stirring and dissolving at 70° C. and 300 rpm for 2 h to uniformly disperse the lutein ester in the system, to obtain composition 2; 3) subjecting composition 2 to two-stage programmed cooling to obtain composition 3; wherein, the first stage programmed cooling has a cooling rate of 20°C / h, the temperature is lowered to 30°C, the stirring speed is 50 rpm, and the stirring time is 2 hours; the second stage programmed cooling has a cooling rate of 15°C / h, the temperature is lowered to 10°C, the stirring speed is 100 rpm, and the stirring time is 1.5 hours; 4) The composition 3 was subjected to shear emulsification at an emulsification speed of 4000 rpm and an emulsification time of 30 min, and finally homogenized at a pressure of 350 bar to obtain a lutein ester oil suspension.

[0052] Example 5 The present embodiment provides a lutein ester oil suspension, the raw materials of which are as follows: 13.5 kg of lutein ester crystals (total lutein ester content 75%), 6 kg of soybean oil, 74 kg of medium chain triglycerides, 4 kg of glycerol dioleate, 2 kg of vitamin E, and 0.5 kg of rosemary extract.

[0053] This embodiment further provides a method for preparing the lutein ester oil suspension, and the specific steps are as follows: 1) dissolving soybean oil, medium chain triglyceride, glyceryl dioleate, vitamin E and rosemary extract uniformly at 60° C. to obtain composition 1; 2) adding lutein ester crystals to composition 1, stirring and dissolving at 60° C. and 300 rpm for 1 hour to uniformly disperse the lutein ester in the system, to obtain composition 2; 3) subjecting composition 2 to two-stage programmed cooling to obtain composition 3; wherein, the first stage programmed cooling has a cooling rate of 20°C / h, the temperature is lowered to 40°C, the stirring speed is 40 rpm, and the stirring time is 1.5 h; the second stage programmed cooling has a cooling rate of 25°C / h, the temperature is lowered to 15°C, the stirring speed is 120 rpm, and the stirring time is 2 h; 4) The composition 3 was subjected to shear emulsification at an emulsification speed of 3000 rpm and an emulsification time of 40 min, and finally homogenized at a pressure of 380 bar to obtain a lutein ester oil suspension.

[0054] Comparative Example 1 This comparative example provides a lutein ester oil suspension, which differs from the lutein ester oil suspension of Example 1 in that the raw material composition is: 11.9 kg of lutein ester crystals (total lutein ester content 85%), 7.6 kg of soybean oil, 73.5 kg of medium-chain triglycerides, 4 kg of glycerol dioleate, 2 kg of vitamin E, and 1 kg of rosemary extract.

[0055] The preparation method of the lutein ester oil suspension is the same as that of Example 1.

[0056] Comparative Example 2 This comparative example provides a lutein ester oil suspension, which differs from the lutein ester oil suspension of Example 1 in that the raw material composition is: 16.3 kg of lutein ester crystals (total lutein ester content 62%), 3.2 kg of soybean oil, 73.5 kg of medium-chain triglycerides, 4 kg of glycerol dioleate, 2 kg of vitamin E, and 1 kg of rosemary extract.

[0057] The preparation method of the lutein ester oil suspension is the same as that of Example 1.

[0058] Comparative Example 3 This comparative example provides a lutein ester oil suspension, which differs from the lutein ester oil suspension of Example 1 in that the raw material composition is: 13.5 kg of lutein ester crystals (total lutein ester content 75%), 6 kg of soybean oil, 69.5 kg of medium-chain triglycerides, 8 kg of glycerol dioleate, 2 kg of vitamin E, and 1 kg of rosemary extract.

[0059] The preparation method of the lutein ester oil suspension is the same as that of Example 1.

[0060] Comparative Example 4 This comparative example provides a lutein ester oil suspension, which differs from the lutein ester oil suspension of Example 1 in that the raw material composition is: 13.5 kg of lutein ester crystals (total lutein ester content 75%), 6 kg of soybean oil, 73.5 kg of medium-chain triglycerides, 4 kg of Span 80, 2 kg of vitamin E, and 1 kg of rosemary extract.

[0061] The preparation method of the lutein ester oil suspension is the same as that of Example 1.

[0062] Comparative Example 5 This comparative example provides a lutein ester oil suspension, which differs from the lutein ester oil suspension of Example 1 in that the raw material composition is: 13.5 kg of lutein ester crystals (total lutein ester content 75%), 6 kg of soybean oil, 77.5 kg of glycerol dioleate, 2 kg of vitamin E, and 1 kg of rosemary extract.

[0063] The preparation method of the lutein ester oil suspension is the same as that of Example 1.

[0064] Comparative Example 6 This comparative example provides a lutein ester oil suspension, which has the same raw material composition as the lutein ester oil suspension of Example 1, and the difference in the preparation method is: 1) dissolving soybean oil, medium chain triglyceride, glyceryl dioleate, vitamin E and rosemary extract uniformly at 40° C. to obtain composition 1; 2) adding lutein ester crystals to composition 1, stirring and dissolving at 40° C. and 300 rpm for 3 h to uniformly disperse the lutein ester in the system, to obtain composition 2; 3) Composition 2 was directly subjected to shear emulsification at an emulsification speed of 4000 rpm and an emulsification time of 30 min, and finally homogenized at a pressure of 350 bar to obtain a lutein ester oil suspension.

[0065] Comparative Example 7 This comparative example provides a lutein ester oil suspension, which has the same raw material composition as the lutein ester oil suspension of Example 1, and the difference in the preparation method is: 1) dissolving soybean oil, medium chain triglyceride, glyceryl dioleate, vitamin E and rosemary extract uniformly at 60° C. to obtain composition 1; 2) adding lutein ester crystals to composition 1, stirring and dissolving at 60° C. and 300 rpm for 2.5 hours to uniformly disperse the lutein ester in the system, to obtain composition 2; 3) subjecting composition 2 to programmed cooling at a cooling rate of 25°C / h to 25°C, with a stirring speed of 100 rpm and a stirring time of 3 h, to obtain composition 3; 4) The composition 3 was subjected to shear emulsification at an emulsification speed of 4000 rpm and an emulsification time of 30 min, and finally homogenized at a pressure of 350 bar to obtain a lutein ester oil suspension.

[0066] Comparative Example 8 The raw material formula and preparation method disclosed in Example 1 of Chinese patent CN202211328321.5 were adopted, and lutein ester crystals were used as raw materials to prepare lutein ester oil suspension.

[0067] Experimental example The quality evaluation of the lutein ester oil suspension of each embodiment and comparative example is as follows: (1) Particle size: tested using an image particle analyzer (Bai Te, Dandong); (2) Span PDI: Calculated based on the particle size test results: PDI = (D90-D10) / D50; (3) Product color tone: After the sample is shaken well, its appearance color is measured using a spectrophotometer using the reflectance method; (4) Application color tone: Taking 10% lutein ester oil suspension as an example, add 2.5‰ and mix with the coating powder and knead evenly, test the color tone, and convert the addition amount when the oil suspension content changes; (5) Stability: The lutein ester oil suspension was placed on the shelf for 6 months and the stratification was evaluated. Stability = upper oil layer height / total height × 100%.

[0068] The results are shown in Table 1.

[0069] Table 1 Product hue value, particle size and stability results

[0070] From the results in Table 1, it can be seen that the lutein ester oil suspension prepared by the embodiments of the present invention using specific raw material compositions and preparation methods has a small particle size, uniform distribution, good stability, and a golden color when applied to breading, with a good coloring effect. In Comparative Example 1, high-content lutein ester crystals are used as raw materials, and the prepared product has large particle size and poor shelf life stability; in Comparative Example 2, low-content lutein ester crystals are used as raw materials, the crystal ratio is high, the product is viscous and not easy to stratify, but the crystals have large particle size and uneven distribution in the system, and the PDI is relatively large; in Comparative Example 3, the product prepared by changing the ratio of the composite emulsifier is not bright yellow enough and has poor stability; in Comparative Example 4, the type of emulsifier is changed, and the stability of the oil suspension decreases; in Comparative Example 5, glycerol fatty acid ester is used as an emulsifier without adding medium-chain triglycerides, crystals are precipitated in the system, and the oil suspension is severely stratified after being placed for 2 months; in Comparative Example 6, the product is directly prepared at low temperature without high-temperature dissolution and programmed cooling steps. In Comparative Example 7, there is no programmed cooling, and the temperature is directly cooled in one step. The prepared product is dark in color, not bright yellow enough, and the product has large particle size, uneven particle distribution, and poor stability. Comparative Example 8 was prepared using the method of patent CN202211328321.5, and lutein ester crystals precipitated and the color was not yellow enough. It can be seen that the method provided by the invention is not suitable for preparing lutein ester oil suspension.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a lutein ester oil suspension, characterized in that: The method comprises: The lutein ester crystals are mixed with the first composition and heated to dissolve the crystals to obtain a second composition, wherein the first composition comprises oil, a composite emulsifier and a composite antioxidant; The second composition is subjected to programmed cooling in two stages to obtain a third composition; emulsifying and homogenizing the third composition; Wherein, the lutein ester content of the lutein ester crystals is 65%-80%; The composite emulsifier comprises medium chain triglyceride and glycerol fatty acid ester in a mass ratio of (60-74):(2-4).

2. The method for preparing the lutein ester oil suspension according to claim 1, characterized in that: The HLB value of the glycerol fatty acid ester is 3.0-3.5; And / or, the glycerol fatty acid ester is at least one selected from glycerol stearate, glycerol distearate, glycerol oleate, and glycerol dioleate.

3. The method for preparing the lutein ester oil suspension according to claim 1 or 2, characterized in that: The two-stage programmed cooling includes: The first stage of program cooling: cooling rate 10-20℃ / h, cooling to 25-40℃; And, the second stage of programmed cooling: cooling rate 15-25℃ / h, cooling to 5-15℃; Preferably, stirring is performed during the programmed cooling process, wherein the stirring speed of the first stage programmed cooling is 30-50 rpm, and the stirring speed of the second stage programmed cooling is 80-120 rpm; Preferably, the stirring time of the first stage programmed cooling is 1-2 h, and the stirring time of the second stage programmed cooling is 1.5-2 h.

4. The method for preparing the lutein ester oil suspension according to any one of claims 1 to 3, characterized in that: The conditions for heating and dissolving the crystals are: temperature 50-70° C., stirring speed 200-300 rpm.

5. The method for preparing the lutein ester oil suspension according to any one of claims 1 to 4, characterized in that: The oil is vegetable oil; preferably at least one selected from soybean oil, sunflower oil, corn oil and peanut oil.

6. The method for preparing the lutein ester oil suspension according to any one of claims 1 to 5, characterized in that: The compound antioxidant is vitamin E and rosemary extract; Preferably, the mass ratio of vitamin E to rosemary extract is 2:(0.5-1).

7. The method for preparing the lutein ester oil suspension according to any one of claims 1 to 6, characterized in that: The mixing ratio of the first composition and the lutein ester crystals is: 12.5-23 parts of lutein ester crystals, 5-10 parts of oil, 62-78 parts of composite emulsifier, and 2-4 parts of composite antioxidant.

8. The method for preparing the lutein ester oil suspension according to any one of claims 1 to 7, characterized in that: The emulsification conditions are: emulsification rate 3000-4000rpm, emulsification time 30-40min; And / or, the homogenization pressure is 320-380 bar.

9. The lutein ester oil suspension prepared by the method for preparing the lutein ester oil suspension according to any one of claims 1 to 8; Preferably, the lutein ester content of the lutein ester oil suspension is 10%-15%; and / or the particle size D50 of the lutein ester oil suspension is between 8-10 μm, and the span is less than 0.

5.

10. Use of the lutein ester oil suspension according to claim 9 in the preparation of food, medicine, cosmetics or feed.

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