Method for preparing zeaxanthin ester and zeaxanthin from Chinese wolfberry fruits
By pretreatment of wolfberry fruit and multi-step extraction, the problems of low extraction efficiency and low purity in existing technologies have been solved, realizing the efficient and green preparation of zeaxanthin esters, which are suitable for industrial production of food and health products.
Patent Information
- Application Number
- CN202511708009.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2026-03-03
AI Technical Summary
Existing technologies for extracting zeaxanthin and its esters from plants suffer from problems such as low extraction efficiency, complex processes, long extraction times, residual organic solvents, or low purity of the target product.
The method employs steps such as pretreatment of wolfberry fruit, separation of pulp from peel and seeds, separation of peel from seeds, peel pretreatment, dehydration and drying, and supercritical carbon dioxide or subcritical fluid extraction, combined with organic solvent method and saponification treatment, to achieve efficient preparation of zeaxanthin esters.
It improves extraction efficiency, shortens extraction time, ensures high purity of the target product with no solvent residue, has good food safety, and maximizes the economic value of wolfberry fruit.
Smart Images
Figure FT_1 
Figure FT_2
Abstract
Description
Technical Field
[0001] This application relates to the field of natural product extraction technology, specifically to a method for efficiently preparing zeaxanthin monopalmitate, zeaxanthin dipalmitate (lycopene) and free zeaxanthin monomer from wolfberry fruit, which is applicable to the industrial production of food, health products and pharmaceutical raw materials. Background Technology
[0002] Goji berries, a traditional plant used for both medicinal and edible purposes, are rich in various bioactive components. Among them, zeaxanthin and its esters (such as zeaxanthin dipalmitate) have significant antioxidant, anti-inflammatory, and vision-protective physiological functions, making them valuable in the food, health product, and pharmaceutical fields. Currently, methods for extracting zeaxanthin and its esters from plants mainly include organic solvent extraction, supercritical fluid extraction, and enzymatic hydrolysis. However, without effective pretreatment, these methods suffer from low extraction efficiency, complex processes, long extraction times, residual organic solvents, or low purity of the target product.
[0003] Therefore, developing an efficient, green, and mild pretreatment method to achieve high-yield extraction of zeaxanthin esters from wolfberry and efficient preparation of zeaxanthin is of great industrial significance and application prospect. Summary of the Invention
[0004] To improve the extraction rate and shorten the extraction time, this application provides a method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit.
[0005] The method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit provided in this application adopts the following technical solution:
[0006] A method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit includes the following steps:
[0007] S1. Pre-processing of wolfberry raw materials: Place fresh or dried wolfberries in 4-20 times (V / W) of water and boil for 30-180 minutes, stirring slowly to obtain a mixture containing pulp, skin and seeds.
[0008] S2. Separation of pulp, peel and seeds of wolfberry fruit: The mixture containing pulp, peel and seeds is filtered by pressure. The collected filtrate is used for the extraction of wolfberry polysaccharides or the preparation of wolfberry juice. The collected residue is a mixture of peel and seeds.
[0009] S3. Separation of the mixture of pericarp and seeds: The pericarp and seeds are separated by gravity water suspension. The mixture of pericarp and seeds is placed in a conical device and the filter residue is dispersed by high-pressure tangential water flow. After standing for 30-90 minutes, the seeds and pericarp are collected in sequence after the layers are separated.
[0010] S4. Pretreatment of wolfberry peel: Collect the peel obtained in step S3, and crush the peel into peel pulp using a colloid mill. The particle size distribution after crushing is: particles larger than 20 mesh < 5% (w / w), particles of 20-40 mesh 40% (w / w), and particles smaller than 40 mesh > 45% (w / w).
[0011] S5. Dehydration of fruit peel pulp: The obtained fruit peel pulp is dried and dehydrated by hot air drying method. The hot air temperature is 45-65℃, and the moisture content of the dried product is controlled at 13-15% (W / W).
[0012] S6. Extraction of zeaxanthin esters from dried wolfberry peel: Extract zeaxanthin esters from dried wolfberry peel powder using organic solvent extraction, supercritical carbon dioxide extraction, or subcritical fluid extraction.
[0013] S7. Preparation of free zeaxanthin from zeaxanthin esters: Saponify the extract obtained in step S6 using KOH or NaOH to obtain a product containing ≥10% (W / W) free zeaxanthin.
[0014] Preferably, the moisture content of the dried fruit used in step S1 is in the range of 13-16% (W / W).
[0015] Preferably, the filter screen with a mesh size of 20-40 mesh is used in step S2.
[0016] Preferably, the seeds collected in step S3 are used for oil extraction.
[0017] Preferably, in step S4, the cell wall and membrane are broken by enzymatic hydrolysis, which uses a mixture of enzymes, including cellulase, pectinase, hemicellulase and protease.
[0018] Preferably, the extraction method of the organic solvent method is as follows: extracting zeaxanthin esters from dried wolfberry peel using a water-soluble organic solvent and a water-insoluble organic solvent, with a material-to-liquid ratio of 1:4 (W / V), and an extraction temperature of 25-50℃, to obtain a wolfberry peel extract with a zeaxanthin ester content ≥10% (W / W).
[0019] Preferably, the water-soluble organic solvent is ethanol, methanol, tetrahydrofuran, or acetone, and the water-insoluble organic solvent is ethyl acetate.
[0020] Preferably, the supercritical carbon dioxide extraction method is as follows: the pericarp powder obtained in step S5 is placed in the extraction vessel, supercritical CO2 fluid is introduced and an extraction aid is added, the extraction pressure is controlled at 28-50 MPa, the temperature at 45-70℃, and the time is 1.5-5 h, the extract containing zeaxanthin ester is obtained by depressurization separation, the extraction aid is removed by depressurization, and CO2 is recovered.
[0021] Preferably, the CO2 dosage is 20-60 times the volume of carbon dioxide per material weight; the extraction aid is a low alcohol with food safety properties; and the extraction aid dosage is 5-30% of the volume of the extraction aid per material weight.
[0022] Preferably, the subcritical fluid extraction method is as follows: the fruit peel powder obtained in step S5 is intermittently fed into the extraction vessel, butane in a subcritical state is introduced, the temperature is 45-50℃, the pressure is 10-12Kg, the mixture is continuously stirred, the extraction time is 2-4h, the extract is filtered and collected, and then fed into a vacuum separation vessel to recover butane gas and collect liquid extract.
[0023] In summary, this application has the following beneficial effects:
[0024] 1. This application provides a highly efficient, green, and mild method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit. Through pretreatment and dehydration of the raw materials, some of the bound zeaxanthin esters in the pericarp cells are converted into a free state, significantly improving extraction efficiency, shortening extraction time, and resulting in high purity of the target product.
[0025] 2. The zeaxanthin esters prepared by supercritical carbon dioxide extraction or subcritical fluid extraction in this application are preferably free of any solvent residue and have good food safety.
[0026] 3. The method of this application prepares free zeaxanthin from zeaxanthin esters. This method lays the foundation for the comprehensive processing and utilization of wolfberry fruit, and maximizes the economic value of wolfberry fruit. Attached Figure Description
[0027] Figure 1 This is a flowchart of the method provided in this application.
[0028] Figure 2 This is a schematic diagram of the gravity-water suspension method for separating fruit peel and seeds according to this application. Detailed Implementation
[0029] The following is in conjunction with the appendix Figure 1-2 The present application will be further described in detail with reference to the embodiments.
[0030] Example
[0031] Example 1
[0032] A method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit includes the following steps:
[0033] S1. Pre-treatment of wolfberry raw materials: Place dried wolfberries with a moisture content of 13% (W / W) in 4 times (V / W) of water and boil for 30 minutes, stirring slowly to obtain a mixture containing pulp, skin and seeds.
[0034] S2. Separation of the pulp, peel, and seeds of wolfberry fruit: The mixture containing pulp, peel, and seeds is filtered by pressure. The collected filtrate is used for the extraction of wolfberry polysaccharides or the preparation of wolfberry juice. The collected residue is a mixture of peel and seeds. The filter screen used for pressure filtration has a mesh size of 20 mesh.
[0035] S3. Separation of the mixture of pericarp and seeds: The pericarp and seeds are separated by gravity-fed water suspension. A schematic diagram of the separation equipment is shown below. Figure 2 The mixture of pericarp and seeds is placed in a conical device, and the filter residue is dispersed by high-pressure tangential water flow. After standing for 30 minutes and stratification, the seeds and pericarp are collected in sequence. The collected seeds are used for oil extraction.
[0036] S4. Pretreatment of wolfberry peel: Collect the peel obtained in step S3, break the cell walls and enzymes by enzymatic hydrolysis, add a mixture of enzymes, and pulverize the peel into peel pulp using a colloid mill. The particle size distribution after pulverization is: particles larger than 20 mesh < 5% (w / w), particles of 20-40 mesh 40% (w / w), and particles smaller than 40 mesh > 45% (w / w). The mixture of enzymes includes cellulase, pectinase, hemicellulase, and protease.
[0037] S5. Dehydration of fruit peel pulp: The obtained fruit peel pulp was dried and dehydrated by hot air drying at a temperature of 45°C. The moisture content of the dried product was controlled at 13% (W / W).
[0038] S6. Extraction of zeaxanthin esters from dried wolfberry peel: Zeaxanthin esters were extracted from dried wolfberry peel using an organic solvent method.
[0039] The extraction method of the organic solvent method is as follows: using water-soluble organic solvent and water-insoluble organic solvent to extract zeaxanthin esters from dried wolfberry peel powder, with a material-to-liquid ratio of 1:4 (W / V) and an extraction temperature of 25℃, to obtain wolfberry peel extract with a zeaxanthin ester content ≥10% (W / W).
[0040] The water-soluble organic solvent is preferably ethanol or methanol, and the water-insoluble organic solvent is preferably ethyl acetate.
[0041] S7. Preparation of free zeaxanthin from zeaxanthin esters: Saponify the wolfberry peel extract obtained in step S6 using KOH or NaOH to obtain a product with a free zeaxanthin content ≥10% (W / W).
[0042] See Figure 1After the above process steps, the products obtained are: new food raw material (1) = new food raw material rich in zeaxanthin esters; new health food raw material (1) = new health food raw material rich in zeaxanthin esters; new food raw material (2) = new food raw material rich in free zeaxanthin; new health food raw material (2) = new health food raw material rich in free zeaxanthin.
[0043] Example 2
[0044] A method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit includes the following steps:
[0045] S1. Pre-treatment of wolfberry raw materials: Place dried wolfberries with a moisture content of 13% (W / W) in 20 times (V / W) of water and boil for 180 minutes, stirring slowly to obtain a mixture containing pulp, skin and seeds.
[0046] S2. Separation of the pulp, peel, and seeds of wolfberry fruit: The mixture containing pulp, peel, and seeds is filtered by pressure. The collected filtrate is used for the extraction of wolfberry polysaccharides or the preparation of wolfberry juice. The collected residue is a mixture of peel and seeds. The filter screen used for pressure filtration has a mesh size of 40 mesh.
[0047] S3. Separation of the mixture of pericarp and seeds: The pericarp and seeds are separated by gravity-fed water suspension. A schematic diagram of the separation equipment is shown below. Figure 2 The mixture of pericarp and seeds is placed in a conical device, and the filter residue is dispersed by high-pressure tangential water flow. After standing for 90 minutes and stratification, the seeds and pericarp are collected in sequence. The collected seeds are used for oil extraction.
[0048] S4. Pretreatment of wolfberry peel: Collect the peel obtained in step S3, break the cell walls and enzymes by enzymatic hydrolysis, add a mixture of enzymes, and pulverize the peel into peel pulp using a colloid mill. The particle size distribution after pulverization is: particles larger than 20 mesh < 5% (w / w), particles of 20-40 mesh 40% (w / w), and particles smaller than 40 mesh > 45% (w / w). The mixture of enzymes includes cellulase, pectinase, hemicellulase, and protease.
[0049] S5. Dehydration of fruit peel pulp: The obtained fruit peel pulp was dried and dehydrated by hot air drying at a temperature of 65℃, and the moisture content of the dried product was controlled at 15% (W / W).
[0050] S6. Extraction of zeaxanthin esters from dried wolfberry peel: Zeaxanthin esters were extracted from dried wolfberry peel using an organic solvent method.
[0051] The extraction method of the organic solvent method is as follows: zeaxanthin esters are extracted from dried wolfberry peel powder using water-soluble organic solvents and water-insoluble organic solvents at a material-to-liquid ratio of 1:4 (W / V) and an extraction temperature of 50℃, to obtain wolfberry peel extract with a zeaxanthin ester content ≥10% (W / W).
[0052] The water-soluble organic solvent is preferably tetrahydrofuran or acetone, and the water-insoluble organic solvent is preferably ethyl acetate.
[0053] S7. Preparation of free zeaxanthin from zeaxanthin esters: Saponify the wolfberry peel extract obtained in step S6 using KOH or NaOH to obtain a product with a free zeaxanthin content ≥10% (W / W).
[0054] Example 3
[0055] A method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit includes the following steps:
[0056] S1. Pre-treatment of wolfberry raw materials: Place fresh wolfberries in 4 times (V / W) of water and boil for 30 minutes, stirring slowly to obtain a mixture containing pulp, skin and seeds.
[0057] S2. Separation of the pulp, peel, and seeds of wolfberry fruit: The mixture containing pulp, peel, and seeds is filtered by pressure. The collected filtrate is used for the extraction of wolfberry polysaccharides or the preparation of wolfberry juice. The collected residue is a mixture of peel and seeds. The filter screen used for pressure filtration has a mesh size of 20 mesh.
[0058] S3. Separation of the mixture of pericarp and seeds: The pericarp and seeds are separated by gravity-fed water suspension. A schematic diagram of the separation equipment is shown below. Figure 2 The mixture of pericarp and seeds is placed in a conical device, and the filter residue is dispersed by high-pressure tangential water flow. After standing for 30 minutes and stratification, the seeds and pericarp are collected in sequence. The collected seeds are used for oil extraction.
[0059] S4. Pretreatment of wolfberry peel: Collect the peel obtained in step S3, break the cell walls and enzymes by enzymatic hydrolysis, add a mixture of enzymes, and pulverize the peel into peel pulp using a colloid mill. The particle size distribution after pulverization is: particles larger than 20 mesh < 5% (w / w), particles of 20-40 mesh 40% (w / w), and particles smaller than 40 mesh > 45% (w / w). The mixture of enzymes includes cellulase, pectinase, hemicellulase, and protease.
[0060] S5. Dehydration of fruit peel pulp: The obtained fruit peel pulp was dried and dehydrated by hot air drying at a temperature of 45°C. The moisture content of the dried product was controlled at 13% (W / W).
[0061] S6. Extraction of zeaxanthin esters from dried wolfberry peel: Zeaxanthin esters were extracted from dried wolfberry peel powder using supercritical carbon dioxide extraction.
[0062] The specific operation method is as follows: Supercritical CO2 fluid is produced from gaseous CO2. The fruit peel powder obtained in step S5 is placed in the extraction vessel, supercritical CO2 fluid is introduced and an extraction aid is added. The extraction pressure is controlled at 28 MPa, the temperature at 45℃, and the time at 1.5 h. The extract containing zeaxanthin ester is obtained by vacuum separation. The extraction aid is removed by vacuum, and CO2 is recovered.
[0063] CO2 dosage: 20 times the volume of carbon dioxide per material weight; the type of extraction aid is a low alcohol with food safety properties; the dosage of the extraction aid is 5% of the volume of the extraction aid per material weight.
[0064] S7. Preparation of free zeaxanthin from zeaxanthin esters: Saponify the wolfberry peel extract obtained in step S6 using KOH or NaOH to obtain a product with a free zeaxanthin content ≥10% (W / W).
[0065] See Figure 1 After the above process steps, the products obtained are: new food raw material (1) = new food raw material rich in zeaxanthin esters; new health food raw material (1) = new health food raw material rich in zeaxanthin esters; new food raw material (2) = new food raw material rich in free zeaxanthin; new health food raw material (2) = new health food raw material rich in free zeaxanthin.
[0066] Example 4
[0067] A method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit includes the following steps:
[0068] S1. Pre-treatment of wolfberry raw materials: Place fresh wolfberries in 20 times (V / W) of water and boil for 180 minutes, stirring slowly to obtain a mixture containing pulp, skin and seeds.
[0069] S2. Separation of the pulp, peel, and seeds of wolfberry fruit: The mixture containing pulp, peel, and seeds is filtered by pressure. The collected filtrate is used for the extraction of wolfberry polysaccharides or the preparation of wolfberry juice. The collected residue is a mixture of peel and seeds. The filter screen used for pressure filtration has a mesh size of 40 mesh.
[0070] S3. Separation of the mixture of pericarp and seeds: The pericarp and seeds are separated by gravity-fed water suspension. A schematic diagram of the separation equipment is shown below. Figure 2 The mixture of pericarp and seeds is placed in a conical device, and the filter residue is dispersed by high-pressure tangential water flow. After standing for 90 minutes and stratification, the seeds and pericarp are collected in sequence. The collected seeds are used for oil extraction.
[0071] S4. Pretreatment of wolfberry peel: Collect the peel obtained in step S3, break the cell walls and enzymes by enzymatic hydrolysis, add a mixture of enzymes, and pulverize the peel into peel pulp using a colloid mill. The particle size distribution after pulverization is: particles larger than 20 mesh < 5% (w / w), particles of 20-40 mesh 40% (w / w), and particles smaller than 40 mesh > 45% (w / w). The mixture of enzymes includes cellulase, pectinase, hemicellulase, and protease.
[0072] S5. Dehydration of fruit peel pulp: The obtained fruit peel pulp was dried and dehydrated by hot air drying at a temperature of 65℃, and the moisture content of the dried product was controlled at 15% (W / W).
[0073] S6. Extraction of zeaxanthin esters from dried wolfberry peel: Zeaxanthin esters were extracted from dried wolfberry peel powder using supercritical carbon dioxide extraction.
[0074] The specific operation method is as follows: Supercritical CO2 fluid is produced from gaseous CO2. The fruit peel powder obtained in step S5 is placed in the extraction vessel, supercritical CO2 fluid is introduced and an extraction aid is added. The extraction pressure is controlled at 50 MPa, the temperature at 70℃, and the time at 5 h. The extract containing zeaxanthin ester is obtained by depressurization separation. The extraction aid is removed by depressurization and CO2 is recovered.
[0075] CO2 dosage: 60 times the volume of carbon dioxide per material weight; the type of extraction aid is a low alcohol with food safety properties; the dosage of the extraction aid is 30% of the volume of the extraction aid per material weight.
[0076] S7. Preparation of free zeaxanthin from zeaxanthin esters: Saponify the wolfberry peel extract obtained in step S6 using KOH or NaOH to obtain a product with a free zeaxanthin content ≥10% (W / W).
[0077] Example 5
[0078] A method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit includes the following steps:
[0079] S1. Pre-treatment of wolfberry raw materials: Place dried wolfberries with a moisture content of 16% (W / W) in 4 times (V / W) of water and boil for 30 minutes, stirring slowly to obtain a mixture containing pulp, skin and seeds.
[0080] S2. Separation of the pulp, peel, and seeds of wolfberry fruit: The mixture containing pulp, peel, and seeds is filtered by pressure. The collected filtrate is used for the extraction of wolfberry polysaccharides or the preparation of wolfberry juice. The collected residue is a mixture of peel and seeds. The filter screen used for pressure filtration has a mesh size of 20 mesh.
[0081] S3. Separation of the mixture of pericarp and seeds: The pericarp and seeds are separated by gravity-fed water suspension. A schematic diagram of the separation equipment is shown below. Figure 2 The mixture of pericarp and seeds is placed in a conical device, and the filter residue is dispersed by high-pressure tangential water flow. After standing for 30 minutes and stratification, the seeds and pericarp are collected in sequence. The collected seeds are used for oil extraction.
[0082] S4. Pretreatment of wolfberry peel: Collect the peel obtained in step S3, break the cell walls and enzymes by enzymatic hydrolysis, add a mixture of enzymes, and pulverize the peel into peel pulp using a colloid mill. The particle size distribution after pulverization is: particles larger than 20 mesh < 5% (w / w), particles of 20-40 mesh 40% (w / w), and particles smaller than 40 mesh > 45% (w / w). The mixture of enzymes includes cellulase, pectinase, hemicellulase, and protease.
[0083] S5. Dehydration of fruit peel pulp: The obtained fruit peel pulp was dried and dehydrated by hot air drying at a temperature of 45°C. The moisture content of the dried product was controlled at 13% (W / W).
[0084] S6. Extraction of zeaxanthin esters from dried wolfberry peel: Zeaxanthin esters were extracted from dried wolfberry peel powder using subcritical fluid extraction.
[0085] The specific operation method is as follows: the fruit peel powder obtained in step S5 is intermittently fed into the extraction vessel, subcritical butane is introduced, the temperature is 45℃, the pressure is 10Kg, the stirring is continuous, the extraction time is 2h, the extract is filtered and collected, and then fed into the vacuum separation vessel to recover butane gas and collect liquid extract; the residue in the extraction vessel is condensed under reduced pressure to recover butane, and the residue is discharged.
[0086] S7. Preparation of free zeaxanthin from zeaxanthin esters: Saponify the wolfberry peel extract obtained in step S6 using KOH or NaOH to obtain a product with a free zeaxanthin content ≥10% (W / W).
[0087] See Figure 1 After the above process steps, the products obtained are: new food raw material (1) = new food raw material rich in zeaxanthin esters; new health food raw material (1) = new health food raw material rich in zeaxanthin esters; new food raw material (2) = new food raw material rich in free zeaxanthin; new health food raw material (2) = new health food raw material rich in free zeaxanthin.
[0088] Example 6
[0089] A method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit includes the following steps:
[0090] S1. Pre-treatment of wolfberry raw materials: Place dried wolfberries with a moisture content of 16% (W / W) in 20 times (V / W) of water and boil for 180 minutes, stirring slowly to obtain a mixture containing pulp, skin and seeds.
[0091] S2. Separation of the pulp, peel, and seeds of wolfberry fruit: The mixture containing pulp, peel, and seeds is filtered by pressure. The collected filtrate is used for the extraction of wolfberry polysaccharides or the preparation of wolfberry juice. The collected residue is a mixture of peel and seeds. The filter screen used for pressure filtration has a mesh size of 40 mesh.
[0092] S3. Separation of the mixture of pericarp and seeds: The pericarp and seeds are separated by gravity-fed water suspension. A schematic diagram of the separation equipment is shown below. Figure 2 The mixture of pericarp and seeds is placed in a conical device, and the filter residue is dispersed by high-pressure tangential water flow. After standing for 90 minutes and stratification, the seeds and pericarp are collected in sequence. The collected seeds are used for oil extraction.
[0093] S4. Pretreatment of wolfberry peel: Collect the peel obtained in step S3, break the cell walls and enzymes by enzymatic hydrolysis, add a mixture of enzymes, and pulverize the peel into peel pulp using a colloid mill. The particle size distribution after pulverization is: particles larger than 20 mesh < 5% (w / w), particles of 20-40 mesh 40% (w / w), and particles smaller than 40 mesh > 45% (w / w). The mixture of enzymes includes cellulase, pectinase, hemicellulase, and protease.
[0094] S5. Dehydration of fruit peel pulp: The obtained fruit peel pulp was dried and dehydrated by hot air drying at a temperature of 65℃, and the moisture content of the dried product was controlled at 15% (W / W).
[0095] S6. Extraction of zeaxanthin esters from dried wolfberry peel: Zeaxanthin esters were extracted from dried wolfberry peel powder using subcritical fluid extraction.
[0096] The specific operation method is as follows: the fruit peel powder obtained in step S5 is intermittently fed into the extraction vessel, subcritical butane is introduced, the temperature is 50℃, the pressure is 12Kg, the stirring is continuous, the extraction time is 4h, the extract is filtered and collected, and then sent to the vacuum separation vessel to recover butane gas and collect liquid extract; the residue in the extraction vessel is condensed under reduced pressure to recover butane, and the residue is discharged.
[0097] S7. Preparation of free zeaxanthin from zeaxanthin esters: Saponify the wolfberry peel extract obtained in step S6 using KOH or NaOH to obtain a product with a free zeaxanthin content ≥10% (W / W).
[0098] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. A method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit, characterized in that, Includes the following steps: S1. Pre-processing of wolfberry raw materials: Place fresh or dried wolfberries in 4-20 times (V / W) of water and boil for 30-180 minutes, stirring slowly to obtain a mixture containing pulp, skin and seeds. S2. Separation of pulp, peel and seeds of wolfberry fruit: The mixture containing pulp, peel and seeds is filtered by pressure. The collected filtrate is used for the extraction of wolfberry polysaccharides or the preparation of wolfberry juice. The collected residue is a mixture of peel and seeds. S3. Separation of the mixture of pericarp and seeds: The pericarp and seeds are separated by gravity water suspension. The mixture of pericarp and seeds is placed in a conical device and the filter residue is dispersed by high-pressure tangential water flow. After standing for 30-90 minutes, the seeds and pericarp are collected in sequence after the layers are separated. S4. Pretreatment of wolfberry peel: Collect the peel obtained in step S3, and crush the peel into peel pulp using a colloid mill. The particle size distribution after crushing is: particles larger than 20 mesh < 5% (w / w), particles of 20-40 mesh 40% (w / w), and particles smaller than 40 mesh > 45% (w / w). S5. Dehydration of fruit peel pulp: The obtained fruit peel pulp is dried and dehydrated by hot air drying method. The hot air temperature is 45-65℃, and the moisture content of the dried product is controlled at 13-15% (W / W). S6. Extraction of zeaxanthin esters from dried wolfberry peel: Extract zeaxanthin esters from dried wolfberry peel powder using organic solvent extraction, supercritical carbon dioxide extraction, or subcritical fluid extraction. S7. Preparation of free zeaxanthin from zeaxanthin esters: Saponify the extract obtained in step S6 using KOH or NaOH to obtain a product containing ≥10% (W / W) free zeaxanthin.
2. The method for preparing zeaxanthin ester and zeaxanthin from wolfberry fruit according to claim 1, characterized in that: The moisture content of the dried fruit used in step S1 is in the range of 13-16% (W / W).
3. The method for preparing zeaxanthin ester and zeaxanthin from wolfberry fruit according to claim 1, characterized in that: The filter screen used in step S2 has a mesh size of 20-40.
4. The method for preparing zeaxanthin ester and zeaxanthin from wolfberry fruit according to claim 1, characterized in that: The seeds collected in step S3 are used for oil extraction.
5. The method for preparing zeaxanthin ester and zeaxanthin from wolfberry fruit according to claim 1, characterized in that: In step S4, the cell walls and membranes are broken by enzymatic hydrolysis. Enzymatic hydrolysis uses a mixture of enzymes, including cellulase, pectinase, hemicellulase and protease.
6. The method for preparing zeaxanthin ester and zeaxanthin from wolfberry fruit according to claim 1, characterized in that: The extraction method of the organic solvent method is as follows: zeaxanthin esters are extracted from dried wolfberry peel using a water-soluble organic solvent and a water-insoluble organic solvent, with a material-to-liquid ratio of 1:4 (W / V) and an extraction temperature of 25-50℃, to obtain wolfberry peel extract with a zeaxanthin ester content ≥10% (W / W).
7. A method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit according to claim 6, characterized in that: The water-soluble organic solvent is preferably ethanol, methanol, tetrahydrofuran, or acetone, and the water-insoluble organic solvent is preferably ethyl acetate.
8. The method for preparing zeaxanthin ester and zeaxanthin from wolfberry fruit according to claim 1, characterized in that: The supercritical carbon dioxide extraction method is as follows: the pericarp powder obtained in step S5 is placed in the extraction vessel, supercritical CO2 fluid is introduced and an extraction aid is added, the extraction pressure is controlled at 28-50 MPa, the temperature at 45-70℃, and the time is 1.5-5 h, the extract containing zeaxanthin ester is obtained by vacuum separation, the extraction aid is removed by vacuum, and CO2 is recovered.
9. A method for preparing zeaxanthin esters and zeaxanthin from wolfberry fruit according to claim 8, characterized in that: The CO2 dosage is 20-60 times the volume of carbon dioxide per material weight; the extraction aid is a low alcohol with food safety properties; the extraction aid dosage is 5-30% of the volume of the extraction aid per material weight.
10. A method for preparing zeaxanthin ester and zeaxanthin from wolfberry fruit according to claim 1, characterized in that: The subcritical fluid extraction method is as follows: the fruit peel powder obtained in step S5 is intermittently fed into the extraction vessel, butane in a subcritical state is introduced, the temperature is 45-50℃, the pressure is 10-12Kg, the mixture is continuously stirred, the extraction time is 2-4h, the extract is filtered and collected, and then fed into a vacuum separation vessel to recover butane gas and collect the liquid extract.