Preparation method of high-stability safflower yellow pigment preparation

Abstract

The application provides a preparation method of a high-stability safflower yellow pigment preparation, (1) safflower powder is added into an ethanol aqueous solution containing sodium dihydrogen phosphate for extraction, the residue is repeatedly extracted, the filtrates are combined, sodium dihydrogen phosphate is added for dissolution, and the mixture is left to stand, and the upper extraction liquid is concentrated to obtain safflower yellow extract A; (2) the safflower yellow extract A is subjected to silica gel chromatography column elution, and the eluate is collected; (3) the eluate is mixed with a metal chelating agent, an antioxidant protective agent and wall material A, and concentrated to obtain safflower yellow extract B; (4) wall material B in an aqueous solution, safflower yellow extract B and an antioxidant protective agent are mixed and emulsified, and spray drying is carried out to obtain the safflower yellow pigment preparation. In the process of extracting the safflower yellow pigment, the ethanol aqueous solution containing sodium dihydrogen phosphate is combined with silica gel chromatography extraction and purification, which can effectively protect the safflower yellow from degradation in the processing process, reduce the heating time of the safflower yellow in the processing, improve the retention rate of the safflower yellow, and obtain a high-stability, high-color-value safflower yellow powder product.

Description

Technical Field

[0001] This invention relates to the field of pigment extraction technology, and in particular to a method for preparing a highly stable safflower yellow pigment preparation. Background Technology

[0002] Safflower yellow pigment, also known as safflower yellow ( carthamus yellow ) is a plant of the Asteraceae family, safflower ( Carthamus tinctoriusL. The water-soluble components extracted are natural food coloring agents. The safflower yellow pigment obtained through crude extraction contains many other water-soluble impurities, resulting in a low color value for the crude product. Current research on the refining and purification of safflower yellow pigment primarily employs four methods: the first is the traditional water extraction and alcohol precipitation method; the second is chromatography; the third is flocculant removal; and the fourth is membrane separation.

[0003] In the first category of technologies, water extraction and alcohol precipitation is a traditional purification method. This method utilizes the low solubility of macromolecules such as proteins and starch in a certain concentration of ethanol aqueous solution, causing them to adsorb and cross-link with each other, forming impurity particle aggregates that then settle. However, this method has poor selectivity, and a large amount of data has shown that its purification effect is worse than other methods.

[0004] In the second category of technologies, there is relevant literature, "Research and Application of Safflower Yellow Pigment Purification Process - Zhang Chi," and an invention patent (CN99123713.7) shows that total safflower yellow pigment can be prepared using polyamide / silica gel / resin chromatography. Macroporous adsorption resin and other chromatography methods have higher removal capabilities for impurities such as proteins, sugars, and suspended particulate matter than other purification methods, but the recovery rate of safflower yellow pigment using this method is low.

[0005] In the third category of technologies, there is relevant literature titled "Study on Extraction and Purification of Safflower Yellow Pigment and Safflower Red Pigment - Ma Guangting". This paper uses chitosan, gelatin and other flocculants as flocculants to purify safflower yellow pigment. This method has the highest recovery rate of safflower yellow pigment, and is low in cost, simple to operate and does not require special equipment. However, the impurity removal effect is far inferior to that of macroporous adsorption method.

[0006] In the fourth category of technologies, there is relevant literature such as "Study on Extraction, Membrane Separation and Properties of Safflower Yellow Pigment - Guo Ruili". Ultrafiltration membranes have a certain pore size, which can effectively retain large organic molecules such as proteins and suspended solids. However, they also cause serious membrane fouling, resulting in the retention of safflower yellow pigment and loss of content. Moreover, the membrane fouling mechanism is complex and not yet fully understood, which increases the difficulty of solving the membrane fouling problem.

[0007] Furthermore, safflower yellow contains multiple hydroxyl auxochrome groups, including alcoholic and phenolic hydroxyl groups. Phenolic hydroxyl groups are easily oxidized by aldehyde and carboxyl groups, causing safflower yellow to fade. They are also easily oxidized to quinones, turning safflower yellow red or brown. Additionally, phenolic hydroxyl groups can undergo substitution reactions with alkaline substances. Therefore, improper extraction methods can easily lead to fading of safflower yellow. Currently, there is very little literature on color protection for safflower yellow, and research on color protection for most natural pigments, including safflower yellow, is relatively singular, generally falling into three categories: the first involves adding chemical preservatives or natural antioxidants for protection; the second involves microencapsulation of the pigment; and the third combines the effects of the first two categories.

[0008] In the first category of technology, there is an invention patent (CN201510913247.7) showing that high-purity (95%-98%) oxalic acid, and when the ratio of oxalic acid to pigment is 2:1, has a color-protecting effect on a variety of water-soluble pigments under long-term high temperature.

[0009] In the second category of technologies, relevant literature shows that they have good effects (research on microencapsulation of natural safflower yellow pigment - Liu Ke), but the amount of wall material added is mostly dozens of times that of pigment, which directly results in a significant reduction in product purity, making it unsuitable for industrial production and lacking practical economic benefits.

[0010] The third type of technology has a relevant invention patent (CN201210154733.1), but its color-protecting formula contains chemically synthesized substances such as alum, which does not conform to the development trend of modern green food, green consumption, and green market. Summary of the Invention

[0011] In view of this, the present invention proposes a method for preparing a highly stable safflower yellow pigment preparation. The method of the present invention can effectively extract safflower yellow, resulting in a high retention rate of safflower yellow, and can also improve the stability of safflower yellow.

[0012] The technical solution of this invention is implemented as follows:

[0013] A method for preparing a highly stable safflower yellow pigment formulation includes the following steps:

[0014] (1) Add safflower powder to an ethanol aqueous solution containing sodium dihydrogen phosphate, extract at 55~65℃ for 1~2h, filter, repeat the extraction 1~2 times on the filter residue, combine all the filtrates, add sodium dihydrogen phosphate to the combined filtrate and stir to dissolve, let stand to separate the layers, take the upper layer extract and concentrate to obtain safflower yellow extract A.

[0015] (2) Add safflower yellow extract A to a silica gel chromatography column and elute with an ethanol-water solution, then collect the eluent;

[0016] (3) The eluent was stirred with metal chelating agent, antioxidant, and wall material A at room temperature. After stirring and mixing, the ethanol aqueous solution was concentrated and recovered to obtain safflower yellow extract B.

[0017] (4) Mix wall material B with water to prepare wall material B aqueous solution, then add safflower yellow extract B and antioxidant protectant, mix well and emulsify, spray dry to obtain the target safflower yellow pigment preparation.

[0018] Furthermore, in step (1), the amount of the ethanol aqueous solution containing sodium dihydrogen phosphate is 5 to 10 times the mass of safflower powder; the amount of the ethanol aqueous solution containing sodium dihydrogen phosphate is 5 to 10 times the mass of safflower powder; the concentration of the ethanol aqueous solution in the ethanol aqueous solution containing sodium dihydrogen phosphate is 1 to 50 v / v, and the mass concentration of sodium dihydrogen phosphate in the ethanol aqueous solution is 0.5 to 2 wt%.

[0019] Furthermore, in step (1), the dry weight ratio of the safflower yellow extract A is 35-60%; the amount of sodium dihydrogen phosphate added is 2.5-40% of the mass of the combined filtrate; the stirring speed is 30-100 r / min and the stirring time is 15-30 min.

[0020] Furthermore, the sodium dihydrogen phosphate-containing ethanol aqueous solution is obtained by dissolving sodium dihydrogen phosphate in an ethanol aqueous solution.

[0021] Further, in step (2), the silica gel chromatography column is obtained through the following process: the silica gel is placed in an oven and activated at 110~120℃ for 100~120 min, then soaked in an aqueous ethanol solution with a concentration of 55~70 v / v%, packed into a chromatography column with a height-to-diameter ratio of (8-10):1 and compacted, and then an aqueous ethanol solution with a concentration of 55~70 v / v% is added to remove air bubbles.

[0022] Furthermore, the silica gel has a particle size of 100-200 mesh and is model XCL.

[0023] Further, in step (2), the specific elution process is as follows: the sample is loaded according to the weight ratio of safflower yellow extract A to silica gel in the silica gel chromatography column of 1:(2~5), the loading flow rate is (1~2) bv / h, after adsorption on the column, elution is carried out with (2-5) bv and (55~70) v / v% ethanol aqueous solution, the elution flow rate is (1~2) vb / h, the eluent is collected in segments, the initial segment of 0-(0.5-1.0) bv of the eluent is discarded, and the eluent of (0.5-1.0)-(2-5) bv of the eluent is collected.

[0024] Furthermore, in step (3), the mass ratio of the eluent, metal chelating agent, antioxidant, and soluble starch is (2000~3000):(0.1-1):(0.1~2):(5~20); the wall material A is one or more of soluble starch, gelatin, xanthan gum, and sodium octenyl succinate starch; and the dry weight ratio of the safflower yellow extract B is 40~55%.

[0025] Furthermore, in step (3), the stirring speed is 500~1000 r / min and the time is 15~30 min.

[0026] Furthermore, in step (4), the mass ratio of safflower yellow extract B, wall material B, and antioxidant is (5~10):(0.5-1.5):(0.05~0.1); the wall material B is one or more of soluble starch, gelatin, xanthan gum, and sodium octenyl succinate starch; the dry weight ratio of the aqueous solution of the wall material B is 30~50%.

[0027] Furthermore, in step (4), the emulsification process is carried out in an emulsification tank with a rotation speed of 4000~8000r / min for 30~60min.

[0028] Furthermore, in step (4), the inlet air temperature during the spray drying process is 130~150℃ and the outlet air temperature is 50~65℃.

[0029] Furthermore, the metal chelating agent is citric acid; the antioxidant is one or more of ascorbic acid, rosemary extract, and sucrose.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] In the extraction process of safflower yellow pigment, this invention uses an ethanol-water solution containing sodium dihydrogen phosphate combined with silica gel chromatography for extraction and purification. The acidic environment can effectively protect safflower yellow from degradation during processing, reduce the heating time during the refining process of safflower yellow, and improve the retention rate of safflower yellow, ultimately obtaining a safflower yellow powder product with high stability and high color value. The first extraction using an ethanol-water solution containing sodium dihydrogen phosphate effectively removes water-soluble impurities such as starch, protein, and sugars, leaving fewer residual impurities in the extract. A second purification using silica gel chromatography further reduces impurities in the column chromatography solution, making the separation of safflower yellow pigment from residual impurities easier to control and resulting in higher purity safflower yellow pigment. Furthermore, the 55-70 v / v% ethanol solution containing safflower yellow obtained from the elution requires a shorter concentration time and can be concentrated at a lower temperature compared to 0-50 v / v% ethanol solutions and aqueous solutions. This effectively reduces the heating time during the refining process of safflower yellow pigment, improving its retention rate and ultimately yielding a highly stable, high-color-value safflower yellow pigment powder. The transfer rate of safflower yellow pigment is also significantly improved. Additionally, the appropriate addition of metal chelating agents, antioxidants, and soluble starch as wall material raw materials during the processing of safflower yellow pigment can effectively protect the molecular structure of safflower yellow pigment, thereby enhancing its stability during processing, storage, and application.

[0032] This invention, through a scientific and reasonable preparation method, can effectively solve the problem of low transfer rate of safflower yellow pigment during the extraction process using simple chromatography, avoid the complex operation of flocculation method, facilitate large-scale continuous production, solve the problem of poor thermal stability of safflower yellow pigment, and improve the storage stability of safflower yellow pigment at room temperature and its thermal stability during application.

[0033] In the extraction process of safflower yellow pigment, the ethanol aqueous solution containing sodium dihydrogen phosphate added in this invention can separate, recover and reuse the safflower yellow extract A during the extraction process, thereby improving the utilization rate of the extraction raw materials and saving resources. Detailed Implementation

[0034] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0035] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0036] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0037] Example 1 - A method for preparing a highly stable safflower yellow pigment formulation

[0038] Includes the following steps:

[0039] (1) Add safflower powder to an ethanol-water solution containing sodium dihydrogen phosphate in 5 times its mass (wherein, the volume concentration of the ethanol-water solution is 40 v / v and the concentration of sodium dihydrogen phosphate is 1.0 wt%), extract at 60℃ for 2 h, filter, repeat the extraction once with the filter residue, combine all the filtrates, add sodium dihydrogen phosphate to the combined filtrate and stir to dissolve (the amount of sodium dihydrogen phosphate added is 10% of the mass of the combined filtrate), stir for 30 min, rotate at 50 r / min, let stand to separate into layers, take the upper layer extract and concentrate to obtain safflower yellow extract A with a dry weight ratio of 35%;

[0040] (2) Add safflower yellow extract A to the silica gel chromatography column and load the sample at a weight ratio of safflower yellow extract A to silica gel in the silica gel chromatography column of 1:2. The loading flow rate is 2bv / h. After adsorption on the column, elute with 3bv and 70v / v% ethanol aqueous solution at a flow rate of 2vb / h. Collect the eluent in segments, discard the initial 0-0.6bv eluent, and collect the first and middle segments of 0.6-3.0bv eluent. The silica gel chromatography column is obtained by the following process: place silica gel with a particle size of 200 mesh and model XCL in an oven and activate it at 110℃ for 120min. Then, wet it with 70v / v% ethanol aqueous solution, pack it into a chromatography column with a height-to-diameter ratio of 8:1 and compact it. Then, add 70v / v% ethanol aqueous solution to remove air bubbles.

[0041] (3) The eluent was mixed with citric acid metal chelating agent, antioxidant (composed of ascorbic acid, rosemary extract and sucrose in a mass ratio of 1:1:1) and soluble starch wall material A at room temperature for 15 min at a stirring speed of 700 r / min. After mixing, the ethanol was concentrated and recovered to obtain safflower yellow extract B with a dry weight ratio of 55%.

[0042] (4) Take safflower yellow extract B, gelatin wall material B and antioxidant (composed of ascorbic acid, rosemary extract and sucrose in a mass ratio of 1:1:1) according to a mass ratio of 6:1:0.09. Mix gelatin wall material B with water to prepare a wall material B aqueous solution with a dry weight ratio of 33%. Then add safflower yellow extract B and antioxidant and mix well. Add the mixture to an emulsification tank and emulsify at a speed of 8000 r / min for 60 min. Then spray dry under the conditions of inlet air temperature of 150℃ and outlet air temperature of 55℃ to obtain the target safflower yellow pigment preparation.

[0043] Example 2 - A method for preparing a highly stable safflower yellow pigment formulation

[0044] Includes the following steps:

[0045] (1) Add safflower powder to an ethanol-water solution containing sodium dihydrogen phosphate at a mass of 10 times (wherein, the concentration of the ethanol-water solution is 50 v / v and the concentration of the sodium dihydrogen phosphate solution is 1.5 wt%), extract at a temperature of 65℃ for 1 h, filter, repeat the extraction twice with the filter residue, combine all the filtrates, add sodium dihydrogen phosphate to the combined filtrate and stir to dissolve (the amount of sodium dihydrogen phosphate added is 7% of the mass of the combined filtrate), stir for 15 min, rotate at 100 r / min, let stand to separate into layers, take the upper layer extract and concentrate to obtain safflower yellow extract A with a dry weight ratio of 60%;

[0046] (2) Add safflower yellow extract A to the silica gel chromatography column and load the sample at a weight ratio of safflower yellow extract A to silica gel in the silica gel chromatography column of 1:5. The loading flow rate is 1 bv / h. After adsorption on the column, elute with 4 bv and 55 v / v% ethanol aqueous solution at a flow rate of 1 vb / h. Collect the eluent in segments, discard the initial 0-0.9 bv eluent, and collect the first and middle 0.9-4 bv eluent. The silica gel chromatography column is obtained by the following process: place 100 mesh XCL silica gel in an oven and activate it at 120℃ for 100 min, then wet it with 55 v / v% ethanol aqueous solution, pack it into a chromatography column with a height-to-diameter ratio of 8:1 and compact it, and then add 55 v / v% ethanol aqueous solution to remove air bubbles.

[0047] (3) The eluent was mixed with citric acid metal chelating agent, ascorbic acid and rosemary extract (composed of ascorbic acid and rosemary extract in a mass ratio of 1:1), antioxidant protectant, and wall material A (composed of gelatin and sodium octenyl succinate starch in a mass ratio of 2:1) at a mass ratio of 3000:0.4:1.2:15. The mixture was stirred at room temperature for 30 minutes and at a stirring speed of 500 r / min. After mixing, the ethanol was concentrated and recovered to obtain safflower yellow extract B with a dry weight ratio of 40%.

[0048] (4) Take safflower yellow extract B, xanthan gum wall material B, and antioxidant (composed of ascorbic acid and rosemary extract in a mass ratio of 1:1) in a mass ratio of 8:1:0.08. Mix wall material B with water to prepare a wall material B aqueous solution with a dry weight ratio of 40%. Then add safflower yellow extract B and antioxidant and mix well.

[0049] The mixture is added to an emulsification tank and emulsified at 4000 r / min for 50 min. Then, it is spray-dried at an inlet air temperature of 130℃ and an outlet air temperature of 65℃ to obtain the target safflower yellow pigment preparation.

[0050] Example 3 - A method for preparing a highly stable safflower yellow pigment formulation

[0051] Includes the following steps:

[0052] (1) Add safflower powder to an ethanol-water solution containing sodium dihydrogen phosphate (the concentration of the ethanol-water solution is 25 v / v and the concentration of the sodium dihydrogen phosphate solution is 2.0 wt%), extract at 55℃ for 1.5 h, filter, repeat the extraction once with the filter residue, combine all the filtrates, add sodium dihydrogen phosphate to the combined filtrate and stir to dissolve (the amount of sodium dihydrogen phosphate added is 20% of the mass of the combined filtrate), stir for 30 min at 100 r / min, let stand to separate the layers, take the upper layer extract and concentrate to obtain safflower yellow extract A with a dry weight ratio of 50%;

[0053] (2) Add safflower yellow extract A to the silica gel chromatography column and load the sample at a weight ratio of safflower yellow extract A to silica gel in the silica gel chromatography column of 1:4. The loading flow rate is 2bv / h. After adsorption on the column, elute with 4bv and 60v / v% ethanol aqueous solution at a flow rate of 2vb / h. Collect the eluent in segments, discard the initial 0-0.9bv eluent, and collect the first and middle 0.9-4bv eluent. The silica gel chromatography column is obtained by the following process: place silica gel with a particle size of 150 mesh and model XCL in an oven and activate it at 115℃ for 110min. Then, wet it with 60v / v% ethanol aqueous solution, pack it into a chromatography column with a height-to-diameter ratio of 8:1 and compact it. Then, add 60v / v% ethanol aqueous solution to remove air bubbles.

[0054] (3) The eluent was mixed with citric acid metal chelating agent, antioxidant (composed of rosemary extract and sucrose in a mass ratio of 2:1) and xanthan gum wall material A at room temperature for 30 min at a stirring speed of 800 r / min. After mixing, the ethanol was concentrated and recovered to obtain safflower yellow extract B with a dry weight ratio of 50%.

[0055] (4) Take safflower yellow extract B, wall material B (composed of soluble starch and gelatin in a mass ratio of 1:1) and antioxidant (composed of rosemary extract and sucrose in a mass ratio of 2:1) according to a mass ratio of 10:1:0.1. Mix wall material B with water to prepare a wall material B aqueous solution with a dry weight ratio of 50%. Then add safflower yellow extract B and antioxidant and mix well. Add the mixture to an emulsification tank and emulsify at a speed of 6000 r / min for 30 min. Then spray dry under the conditions of inlet air temperature of 140℃ and outlet air temperature of 50℃ to obtain the target safflower yellow pigment preparation.

[0056] Comparative Example 1

[0057] This comparative example is based on Example 1, with adjustments made to step (1). The rest is the same as in Example 1, as detailed below:

[0058] (1) Add safflower powder to an aqueous ethanol solution with a concentration of 40 v / v% at 5 times its mass, extract at 60°C for 2 hours, filter, repeat the extraction once with the residue, combine all the filtrates, concentrate, and obtain safflower yellow extract A with a dry weight ratio of 35%.

[0059] Comparative Example 2

[0060] This comparative example adjusts step (2) based on Example 1, while the rest is the same as in Example 1, as follows:

[0061] (2) Add safflower yellow extract A to the silica gel chromatography column and load the sample at a weight ratio of safflower yellow extract A to silica gel in the silica gel chromatography column of 1:8. The loading flow rate is 0.5bv / h. After adsorption on the column, elute with 3bv and 40v / v% ethanol aqueous solution at a flow rate of 3vb / h. Collect the eluent in segments and collect all the eluent.

[0062] Comparative Example 3

[0063] This comparative example adjusts the mass ratio of eluent, metal chelating agent, antioxidant, and soluble starch wall material A in step (3) to 1200:1:15:6 based on Example 1, while the rest is the same as in Example 1.

[0064] Comparative Example 4

[0065] This comparative example is based on Example 1, but the mass ratio of safflower yellow extract B, gelatin wall material B, and antioxidant in step (4) is adjusted to 12:1:0.01, and the rest is the same as in Example 1.

[0066] Comparative Example 5

[0067] This comparative example adjusts steps (3) and (4) of Example 1 into one step, while the rest is the same as in Example 1. This comparative example includes the following steps:

[0068] (1) Add safflower powder to an ethanol-water solution containing sodium dihydrogen phosphate in 5 times its mass (wherein, the volume concentration of the ethanol-water solution is 40 v / v and the concentration of sodium dihydrogen phosphate is 1.0 wt%), extract at 60℃ for 2 h, filter, repeat the extraction once with the filter residue, combine all the filtrates, add sodium dihydrogen phosphate to the combined filtrate and stir to dissolve (the amount of sodium dihydrogen phosphate added is 10% of the mass of the combined filtrate), stir for 30 min, rotate at 50 r / min, let stand to separate into layers, take the upper layer extract and concentrate to obtain safflower yellow extract A with a dry weight ratio of 35%;

[0069] (2) Add safflower yellow extract A to the silica gel chromatography column and load the sample at a weight ratio of safflower yellow extract A to silica gel in the silica gel chromatography column of 1:2. The loading flow rate is 2bv / h. After adsorption on the column, elute with 3bv and 70v / v% ethanol aqueous solution at a flow rate of 2vb / h. Collect the eluent in segments, discard the initial 0-0.6bv eluent, and collect the first and middle segments of 0.6-3.0bv eluent. The silica gel chromatography column is obtained by the following process: place silica gel with a particle size of 200 mesh and model XCL in an oven and activate it at 110℃ for 120min. Then, wet it with 70v / v% ethanol aqueous solution, pack it into a chromatography column with a height-to-diameter ratio of 8:1 and compact it. Then, add 70v / v% ethanol aqueous solution to remove air bubbles.

[0070] (3) The eluent was concentrated and ethanol was recovered to obtain safflower yellow extract B with a dry weight ratio of 55%. Gelatin wall material B was mixed with water to prepare a wall material B aqueous solution with a dry weight ratio of 40%. Then, it was mixed with safflower yellow extract B, citric acid metal chelating agent, antioxidant (composed of ascorbic acid, rosemary extract and sucrose in a mass ratio of 1:1:1), and soluble starch wall material A. The mixture was added to an emulsification tank and emulsified at 8000 r / min for 60 min. Then, it was spray-dried at an inlet air temperature of 150℃ and an outlet air temperature of 55℃ to obtain the target safflower yellow pigment preparation. The mass ratio of metal chelating agent, antioxidant, and (soluble starch wall material A + gelatin wall material B) was 1:4:45, and the mass ratio of soluble starch wall material A and gelatin wall material B was 1:1.

[0071] Comparative Example 6

[0072] This comparative example differs from Example 1 in steps (3) and (4) without the addition of metal chelating agents, antioxidants, wall material A, and wall material B, and is combined into one step. The rest is the same as in Example 1. This comparative example includes the following steps:

[0073] (1) Add safflower powder to an ethanol-water solution containing sodium dihydrogen phosphate in 5 times its mass (wherein, the volume concentration of the ethanol-water solution is 40 v / v and the concentration of sodium dihydrogen phosphate is 1.0 wt%), extract at 60℃ for 2 h, filter, repeat the extraction once with the filter residue, combine all the filtrates, add sodium dihydrogen phosphate to the combined filtrate and stir to dissolve (the amount of sodium dihydrogen phosphate added is 10% of the mass of the combined filtrate), stir for 30 min, rotate at 50 r / min, let stand to separate into layers, take the upper layer extract and concentrate to obtain safflower yellow extract A with a dry weight ratio of 35%;

[0074] (2) Add safflower yellow extract A to the silica gel chromatography column and load the sample at a weight ratio of safflower yellow extract A to silica gel in the silica gel chromatography column of 1:2. The loading flow rate is 2bv / h. After adsorption on the column, elute with 3bv and 70v / v% ethanol aqueous solution at a flow rate of 2vb / h. Collect the eluent in segments, discard the initial 0-0.6bv eluent, and collect the first and middle segments of 0.6-3.0bv eluent. The silica gel chromatography column is obtained by the following process: place silica gel with a particle size of 200 mesh and model XCL in an oven and activate it at 110℃ for 120min. Then, wet it with 70v / v% ethanol aqueous solution, pack it into a chromatography column with a height-to-diameter ratio of 8:1 and compact it. Then, add 70v / v% ethanol aqueous solution to remove air bubbles.

[0075] (3) The eluent was concentrated and ethanol was recovered to obtain safflower yellow extract B with a dry weight ratio of 55%. Then it was spray dried with an inlet air temperature of 150°C and an outlet air temperature of 55°C to obtain the target safflower yellow pigment preparation.

[0076] Comparative Example 7

[0077] This comparative example adjusts the conditions of spray drying in step (4) based on Example 1, while the rest is the same as in Example 1. The inlet air temperature for spray drying is 180°C and the outlet air temperature is 90°C.

[0078] This comparative example includes the following steps:

[0079] (1) Add safflower powder to an ethanol-water solution containing sodium dihydrogen phosphate in 5 times its mass (wherein, the volume concentration of the ethanol-water solution is 40 v / v and the concentration of sodium dihydrogen phosphate is 1.0 wt%), extract at 60℃ for 2 h, filter, repeat the extraction once with the filter residue, combine all the filtrates, add sodium dihydrogen phosphate to the combined filtrate and stir to dissolve (the amount of sodium dihydrogen phosphate added is 10% of the mass of the combined filtrate), stir for 30 min, rotate at 50 r / min, let stand to separate into layers, take the upper layer extract and concentrate to obtain safflower yellow extract A with a dry weight ratio of 35%;

[0080] (2) Add safflower yellow extract A to the silica gel chromatography column and load the sample at a weight ratio of safflower yellow extract A to silica gel in the silica gel chromatography column of 1:2. The loading flow rate is 2bv / h. After adsorption on the column, elute with 3bv and 70v / v% ethanol aqueous solution at a flow rate of 2vb / h. Collect the eluent in segments, discard the initial 0-0.6bv eluent, and collect the first and middle segments of 0.6-3.0bv eluent. The silica gel chromatography column is obtained by the following process: place silica gel with a particle size of 200 mesh and model XCL in an oven and activate it at 110℃ for 120min. Then, wet it with 70v / v% ethanol aqueous solution, pack it into a chromatography column with a height-to-diameter ratio of 8:1 and compact it. Then, add 70v / v% ethanol aqueous solution to remove air bubbles.

[0081] (3) The eluent was mixed with citric acid metal chelating agent, antioxidant (composed of ascorbic acid, rosemary extract and sucrose in a mass ratio of 1:1:1) and soluble starch wall material A at room temperature for 15 min at a stirring speed of 700 r / min. After mixing, the ethanol was concentrated and recovered to obtain safflower yellow extract B with a dry weight ratio of 55%.

[0082] (4) Safflower yellow extract B and gelatin wall material B (composed of ascorbic acid, rosemary extract and sucrose in a mass ratio of 1:1:1) were mixed in a mass ratio of 6:1:0.09 and added to an emulsification tank. The mixture was emulsified at 8000 r / min for 60 min and then spray-dried at an inlet air temperature of 180℃ and an outlet air temperature of 90℃ to obtain the target safflower yellow pigment preparation.

[0083] Experimental situation

[0084] (a) Color price

[0085] Color value is one of the main quality indicators of natural pigments. To a certain extent, it reflects the level of pigment content and the strength of the product's coloring ability. For individual pigments, it is also one of the important bases for direct price calculation. The color value of safflower yellow pigment samples prepared according to the methods in GB1886.61-2015 National Food Safety Standard for Food Additives (Safflower Yellow) was determined. The experimental results are shown in Table 1 below.

[0086] (II) Stability Assessment

[0087] The stability of safflower yellow pigment samples prepared by the methods in Examples 1-3 and Comparative Examples 1-7 of this invention was investigated. 0.05 g of the safflower yellow pigment samples before and after treatment with the corresponding experimental conditions were diluted with distilled water to 100 g to obtain sample solutions. Then, 1 g of the sample solution was diluted with a buffer solution of disodium hydrogen phosphate and citric acid to 10 g. According to GB 1886.61-2015 National Food Safety Standard for Food Additives Safflower Yellow, the absorbance of the sample solutions before and after treatment at 405 nm was measured, and the retention rate of safflower yellow pigment was calculated as the evaluation index. A higher retention rate and lower degradation rate of safflower yellow pigment indicate that it is relatively stable in this system environment.

[0088] Safflower yellow pigment retention rate W = A1 / A0 × 100%

[0089] Where A0 is the absorbance value of the safflower yellow pigment sample before treatment, and A1 is the absorbance value of the safflower yellow pigment sample after treatment.

[0090] The specific experimental conditions are as follows:

[0091] (1) Temperature

[0092] Take 20g of each of the safflower yellow pigment samples prepared in Examples 1-3 and Comparative Examples 1-7, and place them at 60℃ for 270min to obtain the processed safflower yellow pigment samples.

[0093] (2) Light

[0094] 20g of each of the safflower yellow pigment samples prepared in Examples 1-3 and Comparative Examples 1-7 were placed in a light source with a D65 light source and an illuminance of 5000lx for 10 days to obtain the treated safflower yellow pigment samples. The experimental results are shown in Table 1 below.

[0095] Table 1 Experimental results of safflower yellow pigment

[0096]

[0097] The above results indicate that the safflower yellow pigment products prepared by the methods described in Examples 1-3 of this invention have high color values. Furthermore, the use of appropriate preparation methods and the addition of raw materials such as metal chelating agents, antioxidants, and soluble starch effectively protect the molecular structure of safflower yellow, thereby improving its stability. Compared to Example 1, Comparative Example 1 only used an ethanol-water solution for the first extraction, resulting in increased degradation of safflower yellow during extraction. Without a properly proportioned aqueous two-phase treatment, most water-soluble impurities in the safflower yellow could not be effectively removed. During the secondary purification by silica gel column chromatography, the impurity content increased, leading to decreased stability and reduced retention rate of the final safflower yellow pigment. Comparative Example 2 used an unsuitable ethanol-water solution and dosage during silica gel column chromatography extraction, resulting in ineffective separation of impurities and ineffective extraction of safflower yellow pigment. The color value was reduced after extraction. In Comparative Example 3, the mass ratios of eluent, metal chelating agent, antioxidant, and soluble starch were adjusted. In Comparative Example 4, the mass ratios of safflower yellow extract B, gelatin aqueous solution, and antioxidant were adjusted. The proportions of these protective components of safflower yellow pigment were inappropriate and could not effectively protect the molecular structure of safflower yellow, resulting in a decrease in the stability of safflower yellow pigment and affecting the color value. In Comparative Example 5, the order of addition of protective components such as metal chelating agent and antioxidant was inappropriate, and they failed to form effective protection, which accelerated the degradation of safflower yellow pigment. In Comparative Example 6, direct drying without the addition of wall materials, metal chelating agents, antioxidants, or other protective components yielded safflower yellow pigments with relatively high purity and color value. However, due to the lack of protection from these components, the safflower yellow pigment was easily degraded by hydroxyl oxidation under conditions such as heat and light, resulting in color changes and a significant decrease in stability. Comparative Example 7 altered the spray drying conditions, causing the safflower yellow pigment to degrade rapidly at high temperatures, further reducing its stability. Furthermore, experiments revealed that compared to the preparation methods in Comparative Examples 1-7, the safflower yellow pigments prepared using the methods described in Examples 1-3 of this invention exhibited significantly higher transfer rates.

[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a highly stable safflower yellow pigment formulation, characterized in that, Includes the following steps: (1) Add safflower powder to an ethanol aqueous solution containing sodium dihydrogen phosphate, extract at 55-65℃ for 1-2 hours, filter, repeat the extraction 1-2 times on the filter residue, combine all the filtrates, add sodium dihydrogen phosphate to the combined filtrate and stir to dissolve, let stand to separate the layers, take the upper layer extract and concentrate to obtain safflower yellow extract A. (2) The sample was loaded with safflower extract A at a weight ratio of 1:(2~5) to silica gel in the silica gel chromatography column. The loading flow rate was (1~2) bv / h. After adsorption on the column, the sample was eluted with an aqueous solution of (2-5) bv and (55~70) v / v% ethanol at a flow rate of (1~2) vb / h. The eluent was collected in segments. The initial eluent of 0-(0.5-1.0) bv was discarded, and the eluent of (0.5-1.0)-(2-5) bv was collected. (3) The eluent is stirred with the metal chelating agent, antioxidant, and wall material A at room temperature. After mixing, the ethanol aqueous solution is concentrated and recovered to obtain safflower yellow extract B. The mass ratio of the eluent, metal chelating agent, antioxidant, and wall material A is (2000~3000):(0.1-1):(0.1~2):(5~20). The wall material A is one or more of soluble starch, gelatin, xanthan gum, and sodium octenyl succinate starch. The metal chelating agent is citric acid. The antioxidant is one or more of ascorbic acid, rosemary extract, and sucrose. (4) Mix wall material B with water to prepare an aqueous solution of wall material B, then add safflower yellow extract B and antioxidant protectant, mix well and emulsify, spray dry to obtain the target safflower yellow pigment preparation; the mass ratio of safflower yellow extract B, wall material B and antioxidant protectant is (5~10):(0.5-1.5):(0.05~0.1); the wall material B is one or more of soluble starch, gelatin, xanthan gum and sodium octenyl succinate starch.

2. The method for preparing the highly stable safflower yellow pigment formulation according to claim 1, characterized in that, In step (1), the amount of the ethanol aqueous solution containing sodium dihydrogen phosphate is 5 to 10 times the mass of safflower powder; the concentration of the ethanol aqueous solution containing sodium dihydrogen phosphate is 1 to 50 v / v, and the mass concentration of sodium dihydrogen phosphate in the ethanol aqueous solution is 0.5 to 2 wt%.

3. The method for preparing the highly stable safflower yellow pigment formulation according to claim 1, characterized in that, In step (1), the dry weight ratio of the safflower yellow extract A is 35-60%; the amount of sodium dihydrogen phosphate added is 2.5-40% of the mass of the combined filtrate; the stirring speed is 30-100 r / min and the stirring time is 15-30 min.

4. The method for preparing the highly stable safflower yellow pigment formulation according to claim 1, characterized in that, In step (2), the silica gel chromatography column is obtained through the following process: silica gel is placed in an oven and activated at 110~120℃ for 100~120 min, then soaked in an aqueous ethanol solution with a concentration of 55~70 v / v%, packed into a chromatography column with a height-to-diameter ratio of (8-10):1 and compacted, and then an aqueous ethanol solution with a concentration of 55~70 v / v% is added to remove air bubbles.

5. The method for preparing the highly stable safflower yellow pigment formulation according to claim 1, characterized in that, In step (3), the dry weight ratio of the safflower yellow extract B is 40-55%.

6. The method for preparing the highly stable safflower yellow pigment formulation according to claim 1, characterized in that, In step (3), the stirring speed is 500~1000 r / min and the time is 15~30 min.

7. The method for preparing the highly stable safflower yellow pigment formulation according to claim 1, characterized in that, In step (4), the dry weight ratio of the wall material B aqueous solution is 30~50%.

8. The method for preparing the highly stable safflower yellow pigment formulation according to claim 1, characterized in that, In step (4), the emulsification process is carried out in an emulsification tank with a rotation speed of 4000~8000r / min for 30~60min; the inlet air temperature of the spray drying process is 130~150℃ and the outlet air temperature is 50~65℃.

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