Preparation method of high-purity gardenia yellow pigment

Abstract

The invention discloses a preparation method of a high-purity gardenia yellow pigment, and solves the problems of long time consumption, low yield, incapability of separating impurities such as gardenia polysaccharide and the like and reduction of the purity of the gardenia yellow pigment due to solvent crystallization refining in the existing method. The preparation method comprises the following steps: taking gardenia fruits, performing degreasing and impurity removal treatment on gardenia dry powder, and drying to obtain the gardenia yellow pigment. The method comprises the following steps: roughly extracting dry gardenia powder based on a supercritical fluid extraction method in combination with a pre-prepared yellow pigment entrainer, preparing yellow pigment adsorption resin, packing the yellow pigment adsorption resin into a column by a wet method, adsorbing a yellow pigment crude extract on the column, eluting with a 45% ethanol solution, and separating a yellow pigment solution from an impurity solution; when the gardenia yellow pigment is prepared, the gardenia yellow pigment with relatively high purity and color value is obtained by adopting the technical means of degreasing and impurity removal treatment of the gardenia dry powder and adsorption and purification of the yellow pigment crude extract by the yellow pigment adsorption resin, and meanwhile, geniposide and chlorogenic acid can be separated from the gardenia yellow pigment.

Description

Technical Field

[0001] The invention belongs to the technical field of pigment extraction, and particularly relates to a method for preparing high-purity gardenia yellow pigment. Background Art

[0002] Gardenia is a plant resource that is both medicinal and edible. It can be divided into two types: water gardenia is used for pigment extraction, while mountain gardenia is used as medicinal gardenia. At the same time, gardenia is also widely used as a healthy food for food coloring and making porridge and tea. The various chemical components of gardenia have the ability to lower blood sugar levels, lower blood lipids, protect the liver and gallbladder, and promote pancreatic secretion.

[0003] Gardenia yellow is a water-soluble natural pigment mainly extracted from gardenia fruit. Gardenia yellow is orange-yellow in appearance and can be dissolved in water, ethanol and propylene glycol. It has been widely used. The extraction method of gardenia yellow mainly uses solvent to directly extract the active substance; however, the extraction purity cannot be guaranteed using existing methods and the extraction time is relatively long.

[0004] Chinese patent CN102898864B discloses a method for refining gardenia yellow pigment by solvent crystallization, comprising the following steps: adding solvent A to the crude product of gardenia yellow pigment, stirring at 10-30°C to dissolve the crude product of gardenia yellow pigment or heating to 35-100°C to dissolve the crude product of gardenia yellow pigment, filtering and taking the filtrate; the composition of the solvent A is: 70-100% hydrophilic organic solvent, 0-30% water; crystallizing the filtrate, and drying to obtain gardenia yellow. However, the existing method uses solvent crystallization and refining, which takes a long time and has a low yield. At the same time, it is impossible to separate impurities such as gardenia polysaccharides, and the gardenia polysaccharides in the crude product of gardenia yellow pigment will affect the color, quality and activity of gardenia yellow pigment, resulting in a decrease in the purity of gardenia yellow pigment. In view of the above problems, we propose a method for preparing high-purity gardenia yellow pigment. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing high-purity gardenia yellow pigment in view of the shortcomings of the prior art, thereby solving the problems that the prior method uses solvent crystallization refining, which is time-consuming and has a low yield, and is unable to separate impurities such as gardenia polysaccharides, resulting in reduced purity of gardenia yellow pigment.

[0006] The present invention is achieved by providing a method for preparing high-purity gardenia yellow pigment, the method for preparing high-purity gardenia yellow pigment specifically comprising:

[0007] Take gardenia fruit, wash the gardenia fruit with ultrapure water for 3-5 times, place the gardenia fruit in a forced air drying oven at 40° C. and dry for 45 h, grind it into 100-mesh gardenia dry powder in a B-type universal grinder, defatted and impurity-removed gardenia dry powder, and set aside;

[0008] A yellow pigment entrainer is pre-prepared, and the Gardenia dry powder is crudely extracted by supercritical fluid extraction combined with the pre-prepared yellow pigment entrainer, and the yellow pigment entrainer is removed by rotary evaporation, and an equal volume of ultrapure water is added to the yellow pigment crude extract to obtain a yellow pigment crude extract;

[0009] Prepare yellow pigment adsorption resin, take the prepared yellow pigment adsorption resin, wet-load the yellow pigment adsorption resin into a column, take the yellow pigment crude extract onto the column for adsorption, elute with 45% ethanol solution, and separate the yellow pigment solution and the impurity solution.

[0010] Take the impurity solution and prepare a purification extractant, the volume ratio of the purification extractant to the impurity solution is 10:3, mix the purification extractant with the impurity solution, extract and purify the chlorogenic acid in the impurity solution, the extraction time is 3-10 minutes, and then use a stripping agent to perform 2-10 levels of countercurrent stripping to obtain a gardenia glycoside solution with separated chlorogenic acid.

[0011] Preferably, the method for defatting and removing impurities from the Gardenia jasmine dry powder specifically comprises:

[0012] Take the Gardenia powder, suspend it with 10 times the volume of a 1:1 mixture of petroleum ether and n-hexane in an evaporating dish, place the evaporating dish in a constant temperature water bath for 3 hours, maintain the temperature of the constant temperature water bath at 65-70°C, stir manually every 15 minutes, and replace equal volumes of petroleum ether and n-hexane every 30 minutes;

[0013] The Gardenia powder in the suspension in the evaporating dish is filtered through a mesh sieve, the supernatant in the suspension is discarded, and the suspension residue is retained;

[0014] The suspended residue was placed in a 75°C forced air drying oven for 10 min, and then the temperature of the forced air drying oven was lowered to 40°C and dried for 2 h to obtain a pre-defatted dry powder.

[0015] Take the pre-defatted dry powder, grind the pre-defatted dry powder with pre-cooled liquid nitrogen, then place the ground dry powder in a reactor, add 10 times the volume of sodium dodecyl sulfate to the reactor, mix well, add 3 times the volume of phenol, let it stand for 10 hours, mix and extract the mixed liquid in the reactor, discard the organic phase and supernatant, take the dry powder precipitate, and dry the dry powder precipitate in a 60°C forced air drying oven for 20 minutes.

[0016] The dry powder precipitate was placed in a reaction tube, and then 95% ethanol with a mass of 12 times that of the dry powder precipitate was added for soaking for 48 hours. After soaking, the dry powder precipitate was placed in a 60°C forced air drying oven and dried for 50 minutes to obtain defatted and impurity-free gardenia dry powder.

[0017] Preferably, the yellow pigment entrainer comprises the following raw materials in weight percentage:

[0018] Ethanol: 65%;

[0019] Acetone: 10%;

[0020] Ether: 15%;

[0021] Ethyl acetate: 10%;

[0022] Wherein, the method for pre-preparing the yellow pigment entrainer specifically comprises:

[0023] Take ethyl acetate, add acetone to the ethyl acetate under argon protection environment to obtain the first entrainer component;

[0024] Add acetone dropwise to the first group of entrainers at 30°C, stir and mix for 2 minutes, and let stand for 10 minutes to obtain the second group of entrainers;

[0025] Take the second component of the entrainer, add ether to the second component of the entrainer under the protection of inert gas, stir at 10-20r / min for 5 minutes to obtain the yellow pigment entrainer, and store the yellow pigment entrainer at 20°C for later use.

[0026] Preferably, the method for crudely extracting Gardenia jasminoides dry powder based on supercritical fluid extraction combined with a pre-formulated yellow pigment entrainer specifically comprises:

[0027] Take the defatted and impurity-free Gardenia powder, put it into a supercritical extractor, seal it with a cover, and set the extraction temperature to 50°C;

[0028] Turn on the carbon dioxide cylinder and air compressor, set the extraction pressure to 30MPa, and set the auxiliary microwave power to 300W;

[0029] After the temperature reaches 50°C, stabilize for 5 minutes, introduce carbon dioxide and a pre-prepared yellow pigment entrainer into the supercritical extractor, and circulate the extraction for 15 minutes, wherein the flow rate of carbon dioxide is set to 3-3.5 L / min, and the flow rate of the yellow pigment entrainer is set to 0.4-0.5 mL / min;

[0030] After the extraction, the supercritical extractor was allowed to stand for 10 minutes, the discharge liquid at the material outlet of the supercritical extractor was collected, centrifuged at a speed of 300-350r / min for 15 minutes, the residue at the bottom of the discharge liquid was removed, and then the yellow pigment entrainer in the discharge liquid was removed by rotary evaporation to obtain a crude yellow pigment extract.

[0031] Preferably, the yellow pigment adsorption resin comprises the following raw materials in parts by weight: 10-20 parts of polyvinyl alcohol, 20-60 parts of maleopimaric acid ethylene glycol acrylate, 1-10 parts of initiator, 1-5 parts of porogen, 1-15 parts of surfactant, 100-120 parts of deionized water, and 10-15 parts of hexamethylphosphoric acid triamide;

[0032] The initiator is azobisisovaleronitrile, the surfactant is sodium dodecylbenzenesulfonate, and the porogen is a 1:1 mixture of polyvinyl pyrrolidone and toluene;

[0033] Wherein, the method for preparing yellow pigment adsorption resin specifically comprises:

[0034] Maleopimaric acid ethylene glycol acrylate, polyvinyl alcohol and initiator were placed in a beaker as the oil phase;

[0035] Deionized water, hexamethylphosphoric acid triamide and surfactant are placed in a three-necked flask as the water phase, and then the oil phase and the water phase are mixed and stirred under nitrogen protection at a stirring speed of 200-250r / min, and heated to 85-90°C in an air bath and reacted for 2h;

[0036] Add a porogen to the three-necked flask and continue the reaction for 1 hour. Then use 0.5 mol / L malic acid to adjust the pH value to 6.0-6.5, cool to room temperature, and then add 3 times the volume of anhydrous ethanol to the three-necked flask for 2 hours to remove the residues of the initiator and the porogen. Rotary evaporation is performed to obtain a rosin-based yellow pigment adsorption resin.

[0037] Preferably, the method of taking the crude yellow pigment extract and applying it to a column for adsorption, eluting it with a 45% ethanol solution, and separating the yellow pigment solution and the impurity solution specifically comprises:

[0038] Take the yellow pigment adsorption resin, add equal volumes of oxalyl chloride and anhydrous ethanol to the yellow pigment adsorption resin, stir mechanically at 100-120 r / min for 30 min, add anhydrous aluminum chloride under argon atmosphere, and react at room temperature for 4 h;

[0039] After adding an equal volume of ethanol to wash and filter 3-5 times, add an equal volume of ethanol to soak overnight, dry for 30 minutes, put the yellow pigment adsorption resin into a three-necked flask, add 4 times the weight of dichloroethane and stir to mix, then slowly add 90% concentrated sulfuric acid until the pH is 4.5-5;

[0040] The three-necked flask was heated to 80°C in a water bath and reacted for 4 hours. After the reaction was completed, the yellow pigment adsorption resin in the three-necked flask was transferred to a chromatography column and backwashed with ultrapure water for 3-5 times until it became neutral.

[0041] The yellow pigment adsorption resin was wet loaded on the column, and the crude yellow pigment extract was adsorbed on the column for 6 hours. The loading flow rate of the crude yellow pigment extract was 5 ml / min, and the weight ratio of the crude yellow pigment extract to the yellow pigment adsorption resin was 5:2. The yellow pigment solution and the impurity solution were separated by elution with 45% ethanol solution.

[0042] Preferably, when extracting and purifying chlorogenic acid in the impurity solution, the purification extractant is a mixture of acetone and cocamidopropyl betaine in a weight ratio of 5:1;

[0043] The stripping agent is a mixture of ethanol and malic acid in a volume ratio of 4:1.

[0044] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0045] The present invention provides a method for preparing high-purity gardenia yellow pigment. When preparing gardenia yellow pigment, the gardenia dry powder is defatted and impurities are removed, and a yellow pigment adsorption resin is used to adsorb and purify a crude yellow pigment extract, so as to obtain gardenia yellow pigment with high purity and color value. At the same time, gardenia glycoside and chlorogenic acid can be separated from the gardenia yellow pigment, and the problem of green discoloration and dark color of gardenia yellow pigment caused by gardenia polysaccharides, gardenia glycoside and chlorogenic acid can be significantly reduced.

[0046] The embodiment of the present invention provides a yellow pigment adsorption resin and a preparation method thereof. The prepared yellow pigment adsorption resin is mainly composed of maleopimaric acid ethylene glycol acrylate and is synthesized under the conditions of combining a surfactant, a porogen and an initiator. It can fully adsorb gardenia yellow pigment and assist in improving the color value of gardenia yellow pigment. At the same time, it can also separate other impurities such as gardenia glycoside, chlorogenic acid, etc., thereby improving the purity of the product.

[0047] In the embodiment of the present invention, sodium dodecyl sulfate and phenol are used to desugar the pre-defatted dry powder, thereby avoiding the problem that the presence of gardenia polysaccharide in gardenia yellow pigment increases the viscosity of gardenia yellow pigment, encapsulates gardenia yellow pigment, and thus inhibits the activity of gardenia yellow pigment. At the same time, sodium dodecyl sulfate and phenol can extract gardenia polysaccharide into the organic phase, thereby avoiding the interference of gardenia polysaccharide with the pigment and purity of gardenia yellow pigment. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The present invention is a schematic diagram of the process for preparing the high-purity gardenia yellow pigment.

[0049] Figure 2 The present invention is a schematic diagram of the implementation process of the defatting and impurity removal treatment of the Gardenia jasminoides dry powder provided by the present invention.

[0050] Figure 3 It is a schematic diagram of the implementation process of the preformulated yellow pigment entrainer provided by the present invention.

[0051] Figure 4 The present invention provides a schematic diagram of the implementation process of a method for crudely extracting Gardenia jasminoides dry powder based on a supercritical fluid extraction method combined with a preformulated yellow pigment entrainer.

[0052] Figure 5The present invention provides a schematic flow diagram of the process of taking a crude yellow pigment extract onto a column for adsorption, eluting with a 45% ethanol solution, and separating a yellow pigment solution from an impurity solution.

[0053] Figure 6 It is a schematic diagram of the implementation process of preparing yellow pigment adsorption resin provided by the present invention.

[0054] Figure 7 It is a schematic diagram of the test results of the sugar yield of Gardenia jasminoides polysaccharide in the present invention.

[0055] Figure 8 It is a schematic diagram of the test results of the adsorption rate and elution rate of the porous resin in the present invention.

[0056] Fig. 9 It is a schematic diagram of the OD value test result of the present invention. DETAILED DESCRIPTION

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0058] Example 1

[0059] The embodiment of the present invention provides a method for preparing high-purity gardenia yellow pigment. Figure 1 The schematic diagram of the process flow of the preparation method of high-purity gardenia yellow pigment is shown. The preparation method of high-purity gardenia yellow pigment specifically comprises:

[0060] Step S10, taking gardenia fruits, washing the gardenia fruits with ultrapure water for 3-5 times, placing the gardenia fruits in a forced air drying oven at 40° C. and drying for 45 hours, and grinding the gardenia fruits in a type B universal grinder into 100-mesh gardenia dry powder, defatting and removing impurities from the gardenia dry powder, and setting aside;

[0061] In this embodiment, the gardenia fruit can be water gardenia produced in Fuzhou, Jiangxi Province, the manufacturer of the B-type universal grinder is Changzhou Baokang Drying Machinery Co., Ltd., China, and the manufacturer of the blast drying oven is Mettler-Toledo.

[0062] Step S20, pre-preparing a yellow pigment entrainer, crudely extracting the Gardenia powder by supercritical fluid extraction combined with the pre-prepared yellow pigment entrainer, removing the yellow pigment entrainer by rotary evaporation, and adding an equal volume of ultrapure water to the yellow pigment crude extract to obtain a yellow pigment crude extract;

[0063] Step S30, preparing yellow pigment adsorption resin, taking the prepared yellow pigment adsorption resin, wet-loading the yellow pigment adsorption resin into a column, taking the yellow pigment crude extract onto the column for adsorption, eluting with 45% ethanol solution, and separating the yellow pigment solution and the impurity solution;

[0064] Step S40, taking the impurity solution, preparing a purification extractant, the volume ratio of the purification extractant to the impurity solution is 10:3, mixing the purification extractant with the impurity solution, extracting and purifying the chlorogenic acid in the impurity solution, the extraction time is 3-10 minutes, and then using a stripping agent to perform 2-10 levels of countercurrent stripping to obtain a gardenia glycoside solution with separated chlorogenic acid.

[0065] Among them, when extracting and purifying chlorogenic acid in the impurity solution, the purification extractant is a mixture of acetone and cocamidopropyl betaine in a weight ratio of 5:1. During the extraction, the initial pH of the purification extractant and the impurity solution is 6.5, and malic acid can be used to adjust the pH value of the aqueous phase / organic phase; the stripping agent is a mixture of ethanol and malic acid in a volume ratio of 4:1.

[0066] It should be noted that, in the stripping agent, the ethanol is 75% anhydrous ethanol, and the malic acid is 0.5 mol / L.

[0067] It should be noted that the yellow pigment adsorption resin includes the following raw materials in parts by weight: 10-20 parts of polyvinyl alcohol, 20 parts of maleopimaric acid ethylene glycol acrylate, 1 part of initiator, 1 part of porogen, 1 part of surfactant, 100 parts of deionized water, and 10 parts of hexamethylphosphoric acid triamide;

[0068] In this embodiment, polyvinyl alcohol, surfactants, and hexamethylphosphoric acid triamide are all produced by Sinopharm Chemical Reagent Co., Ltd., maleopimaric acid ethylene glycol acrylate is produced by Guangxi Wuzhou Richeng Forest Products Chemical Co., Ltd., and deionized water is homemade in the laboratory.

[0069] The initiator is azobisisovaleronitrile, the surfactant is sodium dodecylbenzenesulfonate, and the porogen is a 1:1 mixture of polyvinyl pyrrolidone and toluene;

[0070] In the embodiment of the present invention, polyvinyl pyrrolidone and toluene cooperate with each other, so that the specific surface area of ​​the yellow pigment adsorption resin can be significantly improved, thereby increasing the pore size density of the yellow pigment adsorption resin, ensuring the uniformity of the pore size of the yellow pigment adsorption resin, and thus improving the stability of the yellow pigment adsorption resin in adsorbing gardenia yellow pigment.

[0071] Wherein, the method for preparing yellow pigment adsorption resin specifically comprises:

[0072] Step S401, maleopimaric acid ethylene glycol acrylate, polyvinyl alcohol, and an initiator are placed in a beaker as an oil phase;

[0073] Step S402, deionized water, hexamethylphosphoric acid triamide, and a surfactant are placed in a three-necked flask as an aqueous phase, and then the oil phase and the aqueous phase are mixed and stirred under nitrogen protection at a stirring speed of 200-250 r / min, and heated to 85-90° C. in an air bath, and reacted for 2 hours;

[0074] Step S403, add a porogen to the three-necked flask, continue the reaction for 1 hour, then use 0.5 mol / L malic acid to adjust the pH value to 6.0-6.5, cool to room temperature, and then add 3 times the volume of anhydrous ethanol to the three-necked flask for 2 hours to remove the residues of the initiator and the porogen, and rotary evaporate to obtain a rosin-based yellow pigment adsorption resin.

[0075] The embodiment of the present invention provides a yellow pigment adsorption resin and a preparation method thereof. The prepared yellow pigment adsorption resin is mainly composed of maleopimaric acid ethylene glycol acrylate and is synthesized under the conditions of combining a surfactant, a porogen and an initiator. It can fully adsorb gardenia yellow pigment and assist in improving the color value of gardenia yellow pigment. At the same time, it can also separate other impurities such as gardenia glycoside, chlorogenic acid, etc., thereby improving the purity of the product.

[0076] The present invention provides a method for preparing high-purity gardenia yellow pigment. When preparing gardenia yellow pigment, the gardenia dry powder is defatted and impurities are removed, and a yellow pigment adsorption resin is used to adsorb and purify a crude yellow pigment extract, so as to obtain gardenia yellow pigment with high purity and color value. At the same time, gardenia glycoside and chlorogenic acid can be separated from the gardenia yellow pigment, and the problem of green discoloration and dark color of gardenia yellow pigment caused by gardenia polysaccharides, gardenia glycoside and chlorogenic acid can be significantly reduced.

[0077] Example 2

[0078] The embodiment of the present invention provides a method for preparing high-purity gardenia yellow pigment. Figure 1 The schematic diagram of the process flow of the preparation method of high-purity gardenia yellow pigment is shown. The preparation method of high-purity gardenia yellow pigment specifically comprises:

[0079] Step S10, taking gardenia fruits, washing the gardenia fruits with ultrapure water for 3-5 times, placing the gardenia fruits in a forced air drying oven at 40° C. and drying for 45 hours, and grinding the gardenia fruits in a type B universal grinder into 100-mesh gardenia dry powder, defatting and removing impurities from the gardenia dry powder, and setting aside;

[0080] Step S20, pre-preparing a yellow pigment entrainer, crudely extracting the Gardenia powder by supercritical fluid extraction combined with the pre-prepared yellow pigment entrainer, removing the yellow pigment entrainer by rotary evaporation, and adding an equal volume of ultrapure water to the yellow pigment crude extract to obtain a yellow pigment crude extract;

[0081] Step S30, preparing yellow pigment adsorption resin, taking the prepared yellow pigment adsorption resin, wet-loading the yellow pigment adsorption resin into a column, taking the yellow pigment crude extract onto the column for adsorption, eluting with 45% ethanol solution, and separating the yellow pigment solution and the impurity solution;

[0082] Step S40, taking the impurity solution, preparing a purification extractant, the volume ratio of the purification extractant to the impurity solution is 10:3, mixing the purification extractant with the impurity solution, extracting and purifying the chlorogenic acid in the impurity solution, the extraction time is 3-10 minutes, and then using a stripping agent to perform 2-10 levels of countercurrent stripping to obtain a gardenia glycoside solution with separated chlorogenic acid.

[0083] Wherein, when extracting and purifying chlorogenic acid in the impurity solution, the purification extractant is a mixture of acetone and cocamidopropyl betaine in a weight ratio of 5:1; the stripping agent is a mixture of ethanol and malic acid in a volume ratio of 4:1.

[0084] It should be noted that the yellow pigment adsorption resin includes the following raw materials in parts by weight: 10-20 parts of polyvinyl alcohol, 60 parts of maleopimaric acid ethylene glycol acrylate, 10 parts of initiator, 5 parts of porogen, 15 parts of surfactant, 120 parts of deionized water, and 15 parts of hexamethylphosphoric acid triamide;

[0085] The initiator is azobisisovaleronitrile, the surfactant is sodium dodecylbenzenesulfonate, and the porogen is a 1:1 mixture of polyvinyl pyrrolidone and toluene;

[0086] Wherein, the method for preparing yellow pigment adsorption resin specifically comprises:

[0087] Step S401, maleopimaric acid ethylene glycol acrylate, polyvinyl alcohol, and an initiator are placed in a beaker as an oil phase;

[0088] Step S402, deionized water, hexamethylphosphoric acid triamide, and a surfactant are placed in a three-necked flask as an aqueous phase, and then the oil phase and the aqueous phase are mixed and stirred under nitrogen protection at a stirring speed of 200-250 r / min, and heated to 85-90° C. in an air bath, and reacted for 2 hours;

[0089] Step S403, add a porogen to the three-necked flask, continue the reaction for 1 hour, then use 0.5 mol / L malic acid to adjust the pH value to 6.0-6.5, cool to room temperature, and then add 3 times the volume of anhydrous ethanol to the three-necked flask for 2 hours to remove the residues of the initiator and the porogen, and rotary evaporate to obtain a rosin-based yellow pigment adsorption resin.

[0090] Example 3

[0091] The embodiment of the present invention provides a method for preparing high-purity gardenia yellow pigment. Figure 1 The schematic diagram of the process flow of the preparation method of high-purity gardenia yellow pigment is shown. The preparation method of high-purity gardenia yellow pigment specifically comprises:

[0092] Step S10, taking gardenia fruits, washing the gardenia fruits with ultrapure water for 3-5 times, placing the gardenia fruits in a forced air drying oven at 40° C. and drying for 45 hours, and grinding the gardenia fruits in a type B universal grinder into 100-mesh gardenia dry powder, defatting and removing impurities from the gardenia dry powder, and setting aside;

[0093] Step S20, pre-preparing a yellow pigment entrainer, crudely extracting the Gardenia powder by supercritical fluid extraction combined with the pre-prepared yellow pigment entrainer, removing the yellow pigment entrainer by rotary evaporation, and adding an equal volume of ultrapure water to the yellow pigment crude extract to obtain a yellow pigment crude extract;

[0094] Step S30, preparing yellow pigment adsorption resin, taking the prepared yellow pigment adsorption resin, wet-loading the yellow pigment adsorption resin into a column, taking the yellow pigment crude extract onto the column for adsorption, eluting with 45% ethanol solution, and separating the yellow pigment solution and the impurity solution;

[0095] Step S40, taking the impurity solution, preparing a purification extractant, the volume ratio of the purification extractant to the impurity solution is 10:3, mixing the purification extractant with the impurity solution, extracting and purifying the chlorogenic acid in the impurity solution, the extraction time is 3-10 minutes, and then using a stripping agent to perform 2-10 levels of countercurrent stripping to obtain a gardenia glycoside solution with separated chlorogenic acid.

[0096] Wherein, when extracting and purifying chlorogenic acid in the impurity solution, the purification extractant is a mixture of acetone and cocamidopropyl betaine in a weight ratio of 5:1; the stripping agent is a mixture of ethanol and malic acid in a volume ratio of 4:1.

[0097] It should be noted that the yellow pigment adsorption resin includes the following raw materials in parts by weight: 10-20 parts of polyvinyl alcohol, 25 parts of maleopimaric acid ethylene glycol acrylate, 2 parts of initiator, 2 parts of porogen, 3 parts of surfactant, 102 parts of deionized water, and 11 parts of hexamethylphosphoric acid triamide;

[0098] The initiator is azobisisovaleronitrile, the surfactant is sodium dodecylbenzenesulfonate, and the porogen is a 1:1 mixture of polyvinyl pyrrolidone and toluene;

[0099] Wherein, the method for preparing yellow pigment adsorption resin specifically comprises:

[0100] Step S401, maleopimaric acid ethylene glycol acrylate, polyvinyl alcohol, and an initiator are placed in a beaker as an oil phase;

[0101] Step S402, deionized water, hexamethylphosphoric acid triamide, and a surfactant are placed in a three-necked flask as an aqueous phase, and then the oil phase and the aqueous phase are mixed and stirred under nitrogen protection at a stirring speed of 200-250 r / min, and heated to 85-90° C. in an air bath, and reacted for 2 hours;

[0102] Step S403, add a porogen to the three-necked flask, continue the reaction for 1 hour, then use 0.5 mol / L malic acid to adjust the pH value to 6.0-6.5, cool to room temperature, and then add 3 times the volume of anhydrous ethanol to the three-necked flask for 2 hours to remove the residues of the initiator and the porogen, and rotary evaporate to obtain a rosin-based yellow pigment adsorption resin.

[0103] Example 4

[0104] The embodiment of the present invention provides a method for preparing high-purity gardenia yellow pigment. Figure 1 The schematic diagram of the process flow of the preparation method of high-purity gardenia yellow pigment is shown. The preparation method of high-purity gardenia yellow pigment specifically comprises:

[0105] Step S10, taking gardenia fruits, washing the gardenia fruits with ultrapure water for 3-5 times, placing the gardenia fruits in a forced air drying oven at 40° C. and drying for 45 hours, and grinding the gardenia fruits in a type B universal grinder into 100-mesh gardenia dry powder, defatting and removing impurities from the gardenia dry powder, and setting aside;

[0106] Step S20, pre-preparing a yellow pigment entrainer, crudely extracting the Gardenia powder by supercritical fluid extraction combined with the pre-prepared yellow pigment entrainer, removing the yellow pigment entrainer by rotary evaporation, and adding an equal volume of ultrapure water to the yellow pigment crude extract to obtain a yellow pigment crude extract;

[0107] Step S30, preparing yellow pigment adsorption resin, taking the prepared yellow pigment adsorption resin, wet-loading the yellow pigment adsorption resin into a column, taking the yellow pigment crude extract onto the column for adsorption, eluting with 45% ethanol solution, and separating the yellow pigment solution and the impurity solution;

[0108] Step S40, taking the impurity solution, preparing a purification extractant, the volume ratio of the purification extractant to the impurity solution is 10:3, mixing the purification extractant with the impurity solution, extracting and purifying the chlorogenic acid in the impurity solution, the extraction time is 3-10 minutes, and then using a stripping agent to perform 2-10 levels of countercurrent stripping to obtain a gardenia glycoside solution with separated chlorogenic acid.

[0109] Wherein, when extracting and purifying chlorogenic acid in the impurity solution, the purification extractant is a mixture of acetone and cocamidopropyl betaine in a weight ratio of 5:1; the stripping agent is a mixture of ethanol and malic acid in a volume ratio of 4:1.

[0110] It should be noted that the yellow pigment adsorption resin includes the following raw materials in parts by weight: 19 parts of polyvinyl alcohol, 58 parts of maleopimaric acid ethylene glycol acrylate, 9 parts of initiator, 4 parts of porogen, 12 parts of surfactant, 115 parts of deionized water, and 14 parts of hexamethylphosphoric acid triamide;

[0111] The initiator is azobisisovaleronitrile, the surfactant is sodium dodecylbenzenesulfonate, and the porogen is a 1:1 mixture of polyvinyl pyrrolidone and toluene;

[0112] Wherein, the method for preparing yellow pigment adsorption resin specifically comprises:

[0113] Step S401, maleopimaric acid ethylene glycol acrylate, polyvinyl alcohol, and an initiator are placed in a beaker as an oil phase;

[0114] Step S402, deionized water, hexamethylphosphoric acid triamide, and a surfactant are placed in a three-necked flask as an aqueous phase, and then the oil phase and the aqueous phase are mixed and stirred under nitrogen protection at a stirring speed of 200-250 r / min, and heated to 85-90° C. in an air bath, and reacted for 2 hours;

[0115] Step S403, add a porogen to the three-necked flask, continue the reaction for 1 hour, then use 0.5 mol / L malic acid to adjust the pH value to 6.0-6.5, cool to room temperature, and then add 3 times the volume of anhydrous ethanol to the three-necked flask for 2 hours to remove the residues of the initiator and the porogen, and rotary evaporate to obtain a rosin-based yellow pigment adsorption resin.

[0116] Example 5

[0117] The embodiment of the present invention provides a method for preparing high-purity gardenia yellow pigment. Figure 1 The schematic diagram of the process flow of the preparation method of high-purity gardenia yellow pigment is shown. The preparation method of high-purity gardenia yellow pigment specifically comprises:

[0118] Step S10, taking gardenia fruits, washing the gardenia fruits with ultrapure water for 3-5 times, placing the gardenia fruits in a forced air drying oven at 40° C. and drying for 45 hours, and grinding the gardenia fruits in a type B universal grinder into 100-mesh gardenia dry powder, defatting and removing impurities from the gardenia dry powder, and setting aside;

[0119] Step S20, pre-preparing a yellow pigment entrainer, crudely extracting the Gardenia powder by supercritical fluid extraction combined with the pre-prepared yellow pigment entrainer, removing the yellow pigment entrainer by rotary evaporation, and adding an equal volume of ultrapure water to the yellow pigment crude extract to obtain a yellow pigment crude extract;

[0120] Step S30, preparing yellow pigment adsorption resin, taking the prepared yellow pigment adsorption resin, wet-loading the yellow pigment adsorption resin into a column, taking the yellow pigment crude extract onto the column for adsorption, eluting with 45% ethanol solution, and separating the yellow pigment solution and the impurity solution;

[0121] Step S40, taking the impurity solution, preparing a purification extractant, the volume ratio of the purification extractant to the impurity solution is 10:3, mixing the purification extractant with the impurity solution, extracting and purifying the chlorogenic acid in the impurity solution, the extraction time is 3-10 minutes, and then using a stripping agent to perform 2-10 levels of countercurrent stripping to obtain a gardenia glycoside solution with separated chlorogenic acid.

[0122] Wherein, when extracting and purifying chlorogenic acid in the impurity solution, the purification extractant is a mixture of acetone and cocamidopropyl betaine in a weight ratio of 5:1; the stripping agent is a mixture of ethanol and malic acid in a volume ratio of 4:1.

[0123] It should be noted that the yellow pigment adsorption resin includes the following raw materials in parts by weight: 15 parts of polyvinyl alcohol, 40 parts of maleopimaric acid ethylene glycol acrylate, 5 parts of initiator, 3 parts of porogen, 9 parts of surfactant, 112 parts of deionized water, and 12 parts of hexamethylphosphoric acid triamide;

[0124] The initiator is azobisisovaleronitrile, the surfactant is sodium dodecylbenzenesulfonate, and the porogen is a 1:1 mixture of polyvinyl pyrrolidone and toluene;

[0125] Wherein, the method for preparing yellow pigment adsorption resin specifically comprises:

[0126] Step S401, maleopimaric acid ethylene glycol acrylate, polyvinyl alcohol, and an initiator are placed in a beaker as an oil phase;

[0127] Step S402, deionized water, hexamethylphosphoric acid triamide, and a surfactant are placed in a three-necked flask as an aqueous phase, and then the oil phase and the aqueous phase are mixed and stirred under nitrogen protection at a stirring speed of 200-250 r / min, and heated to 85-90° C. in an air bath, and reacted for 2 hours;

[0128] Step S403, add a porogen to the three-necked flask, continue the reaction for 1 hour, then use 0.5 mol / L malic acid to adjust the pH value to 6.0-6.5, cool to room temperature, and then add 3 times the volume of anhydrous ethanol to the three-necked flask for 2 hours to remove the residues of the initiator and the porogen, and rotary evaporate to obtain a rosin-based yellow pigment adsorption resin.

[0129] In the embodiment of the present invention, Figure 2 As shown, the method for defatting and removing impurities from the Gardenia jasmine dry powder specifically comprises:

[0130] Step S101, taking gardenia dry powder, suspending the gardenia dry powder and 10 times the volume of a 1:1 mixed solution of petroleum ether and n-hexane in an evaporating dish, placing the evaporating dish in a constant temperature water bath for 3 hours, maintaining the temperature of the constant temperature water bath at 65-70° C., manually stirring once every 15 minutes, and replacing equal volumes of petroleum ether and n-hexane every 30 minutes;

[0131] It should be noted that a sterilized glass rod can be used for manual stirring, and the manufacturer of petroleum ether and n-hexane is Shandong Aite Chemical Co., Ltd., and the Hengwei water bath is a SHA-C water bath produced by Shanghai Boxunda Industrial Co., Ltd., China.

[0132] In step S101, the gardenia dry powder can be effectively degreased by the synergistic combination of petroleum ether and n-hexane mixed solution, thereby preventing low-chain and long-chain alkane small molecules from interfering with the purification and separation of gardenia yellow pigment. Petroleum ether and n-hexane have high degreasing efficiency, low cost, simple operation, are relatively environmentally friendly, and help improve product quality.

[0133] Step S102, filtering the Gardenia powder in the suspension in the evaporating dish with a mesh sieve, discarding the supernatant in the suspension, and retaining the suspension residue;

[0134] Step S103, taking the suspended residue and placing it in a 75°C forced air drying oven for 10 minutes, then lowering the temperature of the forced air drying oven to 40°C and drying for 2 hours to obtain a pre-defatted dry powder.

[0135] Step S104, taking the pre-defatted dry powder, grinding the pre-defatted dry powder with pre-cooled liquid nitrogen, and then placing the ground dry powder in a reactor, dropping 10 times the volume of sodium dodecyl sulfate into the reactor, adding 3 times the volume of phenol after mixing, and standing for 10 hours, mixing and extracting the mixed solution in the reactor, discarding the organic phase and the supernatant, taking the dry powder precipitate, and drying the dry powder precipitate in a 60° C. forced drying oven for 20 minutes;

[0136] It should be noted that in the embodiment of the present invention, sodium dodecyl sulfate and phenol are used to desugar the pre-defatted dry powder, thereby avoiding the problem that the presence of gardenia polysaccharide in gardenia yellow pigment increases the viscosity of gardenia yellow pigment, encapsulates gardenia yellow pigment, and thus inhibits the activity of gardenia yellow pigment. At the same time, sodium dodecyl sulfate and phenol can extract gardenia polysaccharide into the organic phase, thereby avoiding gardenia polysaccharide interfering with the pigment and purity of gardenia yellow pigment, overcoming the problems of the existing method using solvent crystallization refining that is time-consuming and has a low yield, and at the same time, it is impossible to separate impurities such as gardenia polysaccharide, thereby affecting the purity of gardenia yellow pigment.

[0137] Step S105, placing the dry powder precipitate in a reaction tube, then adding 95% ethanol with a mass of 12 times that of the dry powder precipitate for soaking, the soaking time is 48 hours, after soaking, placing the dry powder precipitate in a 60°C forced air drying oven and drying for 50 minutes to obtain defatted and impurity-free gardenia dry powder.

[0138] The organic phase obtained in step S104 of the defatting and impurity removal process of the gardenia powder in Examples 1-5 of the present invention was taken, and the composition of the gardenia polysaccharide in the organic phase in Examples 1-5 was determined by liquid chromatography. The gardenia polysaccharide contained rhamnose, arabinose, mannose, glucose and galactose. The sugar yield of the gardenia polysaccharide in the organic phase in Examples 1-5 was determined by colorimetry combined with ultraviolet-visible spectrophotometer. The test results are as follows: Figure 7 And as shown in Table 1.

[0139] Table 1

[0140] Group Example 1 Example 2 Example 3 Example 4 Example 5 Sugar yield / % 24.82 23.55 24.08 23.15 24.06

[0141] It can be seen from Table 1 that when the gardenia dry powder of Examples 1-5 of the present invention is defatted and impurity-removed, the gardenia polysaccharide in the pre-defatted dry powder can be fully recovered, thereby ensuring the purity and color of the gardenia yellow pigment.

[0142] It should be noted that, in this embodiment, the yellow pigment entrainer includes the following raw materials in terms of weight percentage:

[0143] Ethanol: 65%;

[0144] Acetone: 10%;

[0145] Ether: 15%;

[0146] Ethyl acetate: 10%;

[0147] In the embodiment of the present invention, the yellow pigment entrainer is a mixture of ethanol, ether, acetone and ethyl acetate. Compared with ethanol in the prior art, the yellow pigment entrainer has the characteristics of fast extraction speed, high efficiency and simple operation. At the same time, it can ensure that there is no organic solvent residue in the product, and the extracted effective ingredients have the maximum biological activity.

[0148] Among them, Figure 3 As shown, the method for pre-preparing the yellow pigment entrainer specifically comprises:

[0149] Step S201, taking ethyl acetate, and adding acetone to the ethyl acetate under an argon protection environment to obtain a first entrainer component;

[0150] Step S202, adding acetone dropwise to the first group of entrainers at 30° C., stirring and mixing for 2 minutes, and standing for 10 minutes after the addition is completed, to obtain the second group of entrainers;

[0151] Step S203, taking the second component of the entrainer, adding ether to the second component of the entrainer under the protection of inert gas, stirring at 10-20 r / min for 5 minutes to obtain the yellow pigment entrainer, and storing the yellow pigment entrainer at 20° C. for later use.

[0152] like Figure 4 As shown, the method for crudely extracting Gardenia jasminoides dry powder based on supercritical fluid extraction combined with a preformulated yellow pigment entrainer specifically comprises:

[0153] Step S301, taking the defatted and impurity-removed gardenia powder, placing the gardenia powder in a supercritical extractor, sealing it with a cover, and setting the extraction temperature to 50° C.;

[0154] Step S302, turning on the carbon dioxide cylinder and the air compressor, setting the extraction pressure to 30 MPa, and setting the auxiliary microwave power to 300 W;

[0155] Step S303, after the temperature reaches 50°C, stabilize for 5 minutes, introduce carbon dioxide and a pre-prepared yellow pigment entrainer into the supercritical extractor, and circulate the extraction for 15 minutes, wherein the flow rate of carbon dioxide is set to 3-3.5 L / min, and the flow rate of the yellow pigment entrainer is set to 0.4-0.5 mL / min;

[0156] Step S304, after the extraction is completed, the supercritical extractor is allowed to stand for 10 minutes, the discharge liquid at the material outlet of the supercritical extractor is collected, centrifuged at a speed of 300-350r / min for 15 minutes, the residue at the bottom of the discharge liquid is removed, and then the yellow pigment entrainer in the discharge liquid is removed by rotary evaporation to obtain a crude yellow pigment extract.

[0157] In this embodiment, the supercritical extractor is a SFE-4 supercritical CO 2 The extraction was carried out using a Microfuge 16 micro-table centrifuge at a speed of 300-350 r / min.

[0158] In an embodiment of the present invention, the gardenia dry powder is crudely extracted based on the supercritical fluid extraction method combined with a pre-formulated yellow pigment entrainer. At the same time, when extracting the gardenia dry powder, microwave extraction is assisted, which can increase the movement frequency and speed of the gardenia yellow pigment molecules, increase the penetration of the yellow pigment entrainer, and ensure the activity of the gardenia yellow pigment, which is suitable for the rapid extraction of natural yellow pigment.

[0159] In the embodiment of the present invention, Figure 5 As shown, the method of taking the crude yellow pigment extract and adsorbing it on a column, eluting it with a 45% ethanol solution, and separating the yellow pigment solution and the impurity solution specifically comprises:

[0160] Step S501, taking a yellow pigment adsorption resin, adding equal volumes of oxalyl chloride and anhydrous ethanol to the yellow pigment adsorption resin, mechanically stirring at 100-120 r / min for 30 min, adding anhydrous aluminum chloride under an argon atmosphere, and reacting at room temperature for 4 h;

[0161] In step S501 of this embodiment, equal volumes of oxalyl chloride and anhydrous ethanol are added to the yellow pigment adsorption resin, and at the same time, the catalyst anhydrous aluminum chloride is used to introduce methylene chloride groups into the yellow pigment adsorption resin, thereby enhancing the affinity of the yellow pigment adsorption resin for the functional group of gardenia yellow pigment, improving the adsorption capacity of the yellow pigment adsorption resin, and reducing the nonspecific adsorption of other molecules in the crude yellow pigment extract.

[0162] Step S502, add an equal volume of ethanol to wash and filter 3-5 times, then add an equal volume of ethanol to soak overnight, dry for 30 minutes, put the yellow pigment adsorption resin into a three-necked flask, add 4 times the weight of dichloroethane, stir and mix, and then slowly add 90% concentrated sulfuric acid until the pH is 4.5-5;

[0163] Step S503, the three-necked flask is heated to 80° C. in a water bath and reacted for 4 hours. After the reaction is completed, the yellow pigment adsorption resin in the three-necked flask is transferred to a chromatography column and backwashed with ultrapure water for 3-5 times until it becomes neutral.

[0164] Step S504, wet-loading the yellow pigment adsorption resin column, taking the yellow pigment crude extract onto the column for adsorption for 6 hours, the loading flow rate of the yellow pigment crude extract is 5 ml / min, the weight ratio of the yellow pigment crude extract to the yellow pigment adsorption resin is 5:2, eluting with 45% ethanol solution to separate the yellow pigment solution and the impurity solution.

[0165] It should be noted that when eluting with 45% ethanol solution, the elution flow rate is 4 ml / min. The separated yellow pigment solution is concentrated to one eighth of the original volume by vacuum rotary evaporation, placed in a -60°C refrigerator for 24 hours, and then placed in a vacuum freeze-drying under 0.02 mbar conditions to obtain a high-purity yellow pigment powder.

[0166] Comparative Example 1

[0167] The method and steps of this comparative example are similar to those of Example 5. The difference from Example 5 is that the yellow pigment adsorption resin raw materials in this comparative example do not include polyvinyl alcohol, surfactant, and polyvinyl pyrrolidone, and the other raw materials are the same as those in Example 5.

[0168] Comparative Example 1

[0169] The method and steps of this comparative example are similar to those of Example 5. The difference from Example 5 is that the yellow pigment adsorption resin raw material in this comparative example does not include polyvinyl alcohol and surfactant, and the other raw materials are the same as those in Example 5.

[0170] Comparative Example 2

[0171] The method and steps of this comparative example are similar to those of Example 5. The difference from Example 5 is that the yellow pigment adsorption resin raw materials in this comparative example do not include polyvinyl alcohol, surfactant, and polyvinyl pyrrolidone, and the other raw materials are the same as those in Example 5.

[0172] Comparative Example 3

[0173] The method and steps of this comparative example are similar to those of Example 5. The difference from Example 5 is that the yellow pigment adsorption resin raw material in this comparative example does not include surfactant and polyvinyl pyrrolidone, and the other raw materials are the same as those in Example 5.

[0174] Comparative Example 4

[0175] The method and steps of this comparative example are similar to those of Example 5. The difference from Example 5 is that in this comparative example, a commercially available porous resin product LSA-10 is used to replace the yellow pigment adsorption resin.

[0176] Comparative Example 5

[0177] The method and steps of this comparative example are similar to those of Example 5. The difference from Example 5 is that in this comparative example, a commercially available porous resin product LX-60 is used to replace the yellow pigment adsorption resin.

[0178] Comparative Example 6

[0179] The method and steps of this comparative example are similar to those of Example 5. The difference from Example 5 is that in this comparative example, a commercially available porous resin product HPD100A is used to replace the yellow pigment adsorption resin.

[0180] Performance Test:

[0181] 1) The porous resin adsorption rate and elution rate of Examples 4-5 and Comparative Examples 1-6 of the present invention were tested respectively, and the yellow pigment crude extract solution A before and after adsorption and before and after elution was determined by spectrophotometry. 440nm The absorbance, porous resin adsorption rate and elution rate test results are as follows Figure 8 And as shown in Table 2.

[0182] Table 2

[0183]

[0184] It can be seen from Table 2 that the adsorption rate and elution rate of Examples 4 and 5 of the present invention are higher than those of the porous resin in Comparative Examples 1-6. The preparation method of high-purity gardenia yellow pigment provided by the present invention can extract high-purity gardenia yellow pigment.

[0185] 2) The color value and OD value of Examples 4-5 and Comparative Examples 1-6 of the present invention were tested respectively. The OD value test results are as follows: Fig. 9 As shown, Table 3 shows the OD value and color value test results.

[0186] Table 3

[0187]

[0188] As can be seen from Table 3, the OD values ​​of Examples 4-5 of the present invention are lower than those of Comparative Examples 1-6. The color value is higher, the quality of the Gardenia yellow pigment extracted from the surface is purer, and the content of Gardenia glycoside and chlorogenic acid in the impurities is lower, Gardenia glycoside and chlorogenic acid have less effect on Gardenia yellow pigment, and the quality of Gardenia yellow pigment is guaranteed. Compared with Comparative Examples 1-6, the Gardenia yellow pigment extracted from Examples 1-5 of the present invention can effectively prevent the phenomenon of green discoloration and color dullness.

[0189] In summary, the present invention provides a method for preparing high-purity gardenia yellow pigment. The present invention provides a method for preparing high-purity gardenia yellow pigment. When preparing gardenia yellow pigment, the gardenia dry powder is defatted and impurities are removed, and the yellow pigment crude extract is adsorbed and purified by a yellow pigment adsorption resin, so as to obtain gardenia yellow pigment with high purity and color value. At the same time, gardenia glycoside and chlorogenic acid can be separated from the gardenia yellow pigment, and the problem of green discoloration and dark color of gardenia yellow pigment caused by gardenia polysaccharides, gardenia glycoside and chlorogenic acid can be significantly reduced.

[0190] It should be noted that, for the above-mentioned embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should know that the present invention is not limited to the described order of actions, because according to the present invention, some steps may be performed in other orders or simultaneously.

[0191] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field can still combine, add, delete or make other adjustments to the features in the various embodiments of the present invention according to the circumstances without conflict, without making creative work, so as to obtain different other technical solutions that do not deviate from the concept of the present invention in essence, and these technical solutions also belong to the scope of protection of the present invention.

Claims

1. A method for preparing high-purity gardenia yellow pigment, characterized in that: The method for preparing the high-purity gardenia yellow pigment specifically comprises: Take gardenia fruit, wash the gardenia fruit with ultrapure water for 3-5 times, place the gardenia fruit in a forced air drying oven at 40° C. and dry for 45 h, grind it into 100-mesh gardenia dry powder in a B-type universal grinder, defatted and impurity-removed gardenia dry powder, and set aside; A yellow pigment entrainer is pre-prepared, and the Gardenia dry powder is crudely extracted by supercritical fluid extraction combined with the pre-prepared yellow pigment entrainer, and the yellow pigment entrainer is removed by rotary evaporation, and an equal volume of ultrapure water is added to the yellow pigment crude extract to obtain a yellow pigment crude extract; Prepare yellow pigment adsorption resin, take the prepared yellow pigment adsorption resin, wet-load the yellow pigment adsorption resin into a column, take the yellow pigment crude extract onto the column for adsorption, elute with 45% ethanol solution, and separate the yellow pigment solution and the impurity solution.

2. The method for preparing the high-purity gardenia yellow pigment according to claim 1, characterized in that: The method for preparing the high-purity gardenia yellow pigment specifically further comprises: Take the impurity solution and prepare a purification extractant, the volume ratio of the purification extractant to the impurity solution is 10:3, mix the purification extractant with the impurity solution, extract and purify the chlorogenic acid in the impurity solution, the extraction time is 3-10 minutes, and then use a stripping agent to perform 2-10 levels of countercurrent stripping to obtain a gardenia glycoside solution with separated chlorogenic acid.

3. The method for preparing the high-purity gardenia yellow pigment according to claim 1, characterized in that: The method for defatting and removing impurities from the Gardenia jasmine dry powder specifically comprises: Take the Gardenia powder, suspend it with 10 times the volume of a 1:1 mixture of petroleum ether and n-hexane in an evaporating dish, place the evaporating dish in a constant temperature water bath for 3 hours, maintain the temperature of the constant temperature water bath at 65-70°C, stir manually every 15 minutes, and replace equal volumes of petroleum ether and n-hexane every 30 minutes; The Gardenia powder in the suspension in the evaporating dish is filtered through a mesh sieve, the supernatant in the suspension is discarded, and the suspension residue is retained; The suspended residue was placed in a 75°C forced air drying oven for 10 min, and then the temperature of the forced air drying oven was lowered to 40°C and dried for 2 h to obtain a pre-defatted dry powder.

4. The method for preparing the high-purity gardenia yellow pigment as claimed in claim 3, characterized in that: The method for defatting and removing impurities from the Gardenia jasmine dry powder specifically further comprises: Take the pre-defatted dry powder, grind the pre-defatted dry powder with pre-cooled liquid nitrogen, then place the ground dry powder in a reactor, drop 10 times the volume of sodium dodecyl sulfate into the reactor, mix well, add 3 times the volume of phenol, let stand for 10 hours, mix and extract the mixed liquid in the reactor, discard the organic phase and supernatant, take the dry powder precipitate, and dry the dry powder precipitate in a 60°C forced air drying oven for 20 minutes; The dry powder precipitate was placed in a reaction tube, and then 95% ethanol with a mass of 12 times that of the dry powder precipitate was added for soaking for 48 hours. After soaking, the dry powder precipitate was placed in a 60°C forced air drying oven and dried for 50 minutes to obtain defatted and impurity-free gardenia dry powder.

5. The method for preparing high-purity gardenia yellow pigment according to claim 1, characterized in that: The yellow pigment entrainer comprises the following raw materials in percentage by weight: Ethanol: 65%; Acetone: 10%; Ether: 15%; Ethyl acetate: 10%; Wherein, the method for pre-preparing the yellow pigment entrainer specifically comprises: Take ethyl acetate, add acetone to the ethyl acetate under argon protection environment to obtain the first entrainer component; Add acetone dropwise to the first group of entrainers at 30°C, stir and mix for 2 minutes, and let stand for 10 minutes to obtain the second group of entrainers; Take the second component of the entrainer, add ether to the second component of the entrainer under the protection of inert gas, stir at 10-20r / min for 5 minutes to obtain the yellow pigment entrainer, and store the yellow pigment entrainer at 20°C for later use.

6. The method for preparing the high-purity gardenia yellow pigment according to any one of claims 2 to 5, characterized in that: The method for crudely extracting Gardenia jasminoides dry powder based on supercritical fluid extraction combined with a preformulated yellow pigment entrainer specifically comprises: Take the defatted and impurity-free Gardenia powder, put it into a supercritical extractor, seal it with a cover, and set the extraction temperature to 50°C; Turn on the carbon dioxide cylinder and air compressor, set the extraction pressure to 30MPa, and set the auxiliary microwave power to 300W; After the temperature reaches 50°C, stabilize for 5 minutes, introduce carbon dioxide and a pre-prepared yellow pigment entrainer into the supercritical extractor, and circulate the extraction for 15 minutes, wherein the flow rate of carbon dioxide is set to 3-3.5 L / min, and the flow rate of the yellow pigment entrainer is set to 0.4-0.5 mL / min; After the extraction, the supercritical extractor was allowed to stand for 10 minutes, the discharge liquid at the material outlet of the supercritical extractor was collected, centrifuged at a speed of 300-350r / min for 15 minutes, the residue at the bottom of the discharge liquid was removed, and then the yellow pigment entrainer in the discharge liquid was removed by rotary evaporation to obtain a crude yellow pigment extract.

7. The method for preparing high-purity gardenia yellow pigment according to claim 1, characterized in that: The yellow pigment adsorption resin comprises the following raw materials in parts by weight: 10-20 parts of polyvinyl alcohol, 20-60 parts of maleopimaric acid ethylene glycol acrylate, 1-10 parts of initiator, 1-5 parts of porogen, 1-15 parts of surfactant, 100-120 parts of deionized water, and 10-15 parts of hexamethylphosphoric acid triamide; The initiator is azobisisovaleronitrile, the surfactant is sodium dodecylbenzenesulfonate, and the porogen is a 1:1 mixture of polyvinyl pyrrolidone and toluene; Wherein, the method for preparing yellow pigment adsorption resin specifically comprises: Maleopimaric acid ethylene glycol acrylate, polyvinyl alcohol and initiator were placed in a beaker as the oil phase; Deionized water, hexamethylphosphoric acid triamide and surfactant are placed in a three-necked flask as the water phase, and then the oil phase and the water phase are mixed and stirred under nitrogen protection at a stirring speed of 200-250r / min, and heated to 85-90°C in an air bath and reacted for 2h; Add a porogen to the three-necked flask and continue the reaction for 1 hour. Then use 0.5 mol / L malic acid to adjust the pH value to 6.0-6.5, cool to room temperature, and then add 3 times the volume of anhydrous ethanol to the three-necked flask for 2 hours to remove the residues of the initiator and the porogen. Rotary evaporation is performed to obtain a rosin-based yellow pigment adsorption resin.

8. The method for preparing high-purity gardenia yellow pigment according to claim 1, characterized in that: The method of taking the crude yellow pigment extract and applying it to a column for adsorption, eluting it with a 45% ethanol solution, and separating the yellow pigment solution and the impurity solution specifically comprises: Take the yellow pigment adsorption resin, add equal volumes of oxalyl chloride and anhydrous ethanol to the yellow pigment adsorption resin, stir mechanically at 100-120 r / min for 30 min, add anhydrous aluminum chloride under argon atmosphere, and react at room temperature for 4 h; After adding an equal volume of ethanol to wash and filter 3-5 times, add an equal volume of ethanol to soak overnight, dry for 30 minutes, put the yellow pigment adsorption resin into a three-necked flask, add 4 times the weight of dichloroethane and stir to mix, then slowly add 90% concentrated sulfuric acid until the pH is 4.5-5; The three-necked flask was heated to 80°C in a water bath and reacted for 4 hours. After the reaction was completed, the yellow pigment adsorption resin in the three-necked flask was transferred to a chromatography column and backwashed with ultrapure water for 3-5 times until it became neutral.

9. The method for preparing high-purity gardenia yellow pigment according to claim 8, characterized in that: The method of taking the crude yellow pigment extract and applying it to a column for adsorption, eluting it with a 45% ethanol solution, and separating the yellow pigment solution and the impurity solution also includes: The yellow pigment adsorption resin was wet loaded on the column, and the crude yellow pigment extract was adsorbed on the column for 6 hours. The loading flow rate of the crude yellow pigment extract was 5 ml / min, and the weight ratio of the crude yellow pigment extract to the yellow pigment adsorption resin was 5:

2. The yellow pigment solution and the impurity solution were separated by elution with 45% ethanol solution.

10. The method for preparing high-purity gardenia yellow pigment according to claim 2, characterized in that: When extracting and purifying chlorogenic acid in the impurity solution, the purification extractant is a mixture of acetone and cocamidopropyl betaine in a weight ratio of 5:1; The stripping agent is a mixture of ethanol and malic acid in a volume ratio of 4:1.

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