A highly stable, high-brightness, fast-dissolving, dust-free natural blue composite particle, its preparation method, and its application.

Abstract

This invention discloses a highly stable, high-brightness, fast-dissolving, dust-free natural blue composition granules, its preparation method, and its applications, belonging to the field of pigment extraction technology. This natural blue composition uses gardenia blue, butterfly pea flower extract, and phycocyanin extract as the ternary coloring components, compounded with buffers (phosphates) and antioxidants (vitamin C and tea polyphenols), and employs an embedding wall material (β-cyclodextrin and sodium caseinate) for emulsification and embedding. Finally, it is produced into composite granules through spray drying and dry granulation processes. The composition granules exhibit a bright and vibrant color, excellent light and heat resistance, rapid dissolution in water without dust generation, and are environmentally friendly. This invention also provides a method for preparing the composition granules and their application as a colorant in food, pharmaceuticals, and cosmetics, offering a safe, stable, and efficient comprehensive solution to replace petroleum-based synthetic blue pigments.

Description

Technical Field

[0001] This invention belongs to the field of pigment extraction technology, specifically relating to a highly stable, high-brightness, fast-dissolving, dust-free natural blue composition particle, its preparation method, and its application. Background Technology

[0002] With increasing global health awareness and the rise of the Clean Label movement, the food, pharmaceutical, and cosmetic industries have an increasingly urgent need for natural and safe colorants. Petroleum-based synthetic pigments (such as indigo and brilliant blue) are facing increasingly stringent regulations due to potential health risks (including carcinogenicity, neurobehavioral effects, and allergic reactions). In April 2025, the U.S. Department of Health and Human Services (HHS) and the Food and Drug Administration (FDA) jointly announced a phase-out of petroleum-based pigments in food and accelerated approval of natural alternatives, marking a significant policy turning point in the global colorant industry's transition to natural products. Against this backdrop, natural blue pigments have become a key alternative to synthetic blue pigments. Currently, the mainstream natural blue pigments include gardenia blue, butterfly pea flower extract, and phycocyanin extract, all of which have been approved for use by the FDA in recent years.

[0003] Gardenia blue pigment is a natural water-soluble blue pigment derived from the fruit of the gardenia plant (Rubia cordifolia). It is produced by first extracting iridoid compounds (mainly geniposide) from the fruit, then hydrolyzing them using β-glucosidase to obtain the key intermediate genipin. Finally, genipin reacts with specific amino acids or proteins and their hydrolysates to generate the final blue pigment. It has advantages such as good water solubility, strong tinting strength, and high safety, but its lightfastness and heat resistance still need improvement, and its hue brightness is limited. Butterfly pea flower extract mainly refers to a natural water-soluble pigment obtained from the petals of the butterfly pea plant (Butterfly Pea). Its core component is delphinidin anthocyanins, which is why it exhibits a unique and vibrant blue color. It has a bright color and good thermal stability, but it is extremely sensitive to light and easily degrades and discolors, severely limiting its application in transparent packaging and long-shelf-life products. Phycocyanin extract comes from spirulina. Its aqueous solution is a bright sky blue, the brightest among natural blue pigments, but as a protein-bound pigment, it is prone to fading under strong alkaline conditions, and its light stability is also insufficient.

[0004] The aforementioned single natural blue pigments all have their own performance defects: insufficient stability (especially light and heat stability), insufficient brightness and vividness of hue, slow dissolution rate, and the powder form of the product easily generates dust, resulting in a poor operating environment. They are difficult to fully meet the comprehensive requirements of modern industrial production for pigments that are efficient, stable, convenient, and environmentally friendly. Although the industry has tried to improve performance by compounding multiple pigments, existing technologies mostly focus on color mixing (such as mixing butterfly pea flower blue pigment with red pigment to produce purple), or simply extracting through simple physical mixing. They lack synergistic design for the blue pigments themselves, and have not systematically solved the comprehensive problems of stability, solubility, and ease of use. Summary of the Invention

[0005] Addressing the common technical challenges of poor stability (especially insufficient light and heat stability), dull and unbright hues, poor solubility, and dust-prone powder form that hinders the environmentally friendly operation of existing single or simply compounded natural blue pigments, this invention aims to provide a highly stable, high-brightness, rapidly dissolving, dust-free natural blue composition granules, its preparation method, and applications. The composition primarily uses gardenia blue, butterfly pea flower extract, and phycocyanin extract, supplemented with antioxidants such as vitamin C, sodium isoascorbate, tea polyphenols, vitamin E, and rosemary extract, as well as pH buffers such as phosphates. After uniformly mixing the main and auxiliary ingredients, the mixture is emulsified and embedded using an embedding wall material to form a multi-layered protective layer, followed by spray drying into powder. This natural blue composition not only boasts a bright and vibrant color but also significantly improved light and heat resistance, rapid dissolution, and dust-free operation, making it environmentally friendly. It can be widely used in food, beverages, pharmaceuticals, and cosmetics, providing an ideal solution to replace petroleum-based synthetic blue pigments. To achieve the above objectives, the present invention employs the following technical solution: This invention provides a natural blue composition granule, which, by mass parts, consists of the following components: 40-70 parts of gardenia blue, 20-40 parts of butterfly pea flower extract, 10-20 parts of phycocyanin extract; 0.1-5 parts of buffer; 0.05-3 parts of antioxidant; and 50-800 parts of encapsulating wall material. The total number of parts of the gardenia blue, butterfly pea flower extract, and phycocyanin extract is 100 parts; The composition particles are dust-free particles formed by dry granulation, and the pigment components in the gardenia blue, butterfly pea flower extract and phycocyanin extract are embedded in the embedding wall material.

[0006] The gardenia blue, butterfly pea flower extract, and phycocyanin extract can be commercially available products that meet food-grade or cosmetic-grade standards. The gardenia blue, butterfly pea flower extract, and phycocyanin extract used in this invention were purchased from Henan Zhongda Hengyuan Biotechnology Co., Ltd.; they can also be prepared through the following steps: (1) Preparation of Gardenia Blue: Gardenia fruit is crushed, extracted with water, enzymatically hydrolyzed (β-glucosidase), reacted with protein and protein hydrolysate or amino acid, purified and dried to obtain Gardenia Blue pigment; (2) Preparation of butterfly pea flower extract: butterfly pea flower petals are extracted with ethanol or water, filtered, concentrated and spray-dried to obtain butterfly pea flower extract; (3) Preparation of phycocyanin extract: Spirulina powder is extracted with water, centrifuged, ultrafiltered, freeze-dried or spray-dried to obtain phycocyanin extract.

[0007] Preferably, the ingredients are 45-65 parts gardenia blue, 30-40 parts butterfly pea flower extract, and 15-20 parts phycocyanin extract.

[0008] More preferably, the ingredients are 50 parts gardenia blue, 30 parts butterfly pea flower extract, and 20 parts phycocyanin extract.

[0009] The buffer is one or more of sodium pyrophosphate, tetrapotassium pyrophosphate, sodium hexametaphosphate, disodium hydrogen phosphate, and dipotassium hydrogen phosphate.

[0010] Preferably, the buffer is sodium pyrophosphate and sodium hexametaphosphate.

[0011] More preferably, the pH value of the sodium pyrophosphate and sodium hexametaphosphate mixed buffer system is 6.0-8.0.

[0012] The antioxidant is one or more of vitamin C, sodium ascorbate, tea polyphenols, and rosemary extract. By simultaneously introducing a buffer (to resist pH changes) and an antioxidant (to resist photo and thermal oxidative degradation), preliminary protection is provided for the three unstable natural pigments from the perspective of the external environment, thus initially improving the overall stability of the composition.

[0013] Preferably, the antioxidant is vitamin C and tea polyphenols.

[0014] The encapsulating wall material is one or more of β-cyclodextrin, gum arabic, sodium caseinate, and hydroxypropyl starch. The encapsulating wall material microencapsulates pigment molecules through methods such as spray drying, forming a physical barrier. This is a key step in significantly improving the light and heat resistance stability of the pigment. Through a dry granulation process, easily dusty powder is transformed into dust-free particles, fundamentally solving the dust pollution problem during the use of powder pigments, improving the operating environment, and achieving "environmental friendliness." Simultaneously, the particle morphology also facilitates "rapid dissolution."

[0015] Preferably, the embedding wall material is β-cyclodextrin and sodium caseinate.

[0016] The color value of the gardenia blue is 5-300, the color value of the butterfly pea flower extract is 2-50, and the color value of the phycocyanin extract is 5-30.

[0017] The ratio of the total weight of the embedding wall material to the total weight of the gardenia blue, butterfly pea flower extract and phycocyanin extract is (0.5:1) to (2:1).

[0018] Secondly, the present invention provides a method for preparing natural blue composition particles, comprising: Gardenia blue, butterfly pea flower extract and phycocyanin extract were dissolved in twice the amount of purified water to obtain a blue mixed solution; Phosphate and antioxidant were added sequentially to the above blue mixed solution to obtain a stable blue buffer mixed solution; The dissolved embedding wall material was added to the above stable blue buffer mixture, stirred and mixed, spray-dried, and then dry-granulated to obtain natural blue composition particles.

[0019] The amount of phosphate added is 0% to 5% of the mass of the blue mixed solution; the amount of antioxidant added is 0.1% to 50% of the mass of the blue mixed solution; and the amount of encapsulating wall material added is 20% to 100% of the mass of the blue mixed solution.

[0020] Preferably, the amount of phosphate added is 0.5% of the mass of the blue mixed solution.

[0021] Preferably, the amount of antioxidant added is 1% to 20% of the mass of the blue mixed solution.

[0022] More preferably, the amount of antioxidant added is 5% of the mass of the blue mixed solution.

[0023] Preferably, the amount of the embedding wall material added is 20% to 100% of the mass of the blue mixed solution.

[0024] More preferably, the amount of the embedding wall material added is 40% to 80% of the mass of the blue mixed solution.

[0025] The spray drying inlet air temperature is 160℃~180℃, and the outlet air temperature is 80℃~90℃.

[0026] The dry granulation process includes: degassing, compressing, and pressing the blue powder with rollers, pressing it into thin sheets with a thickness of 0.5 to 3.0 mm under a pressure of 20 to 100 MPa, and then crushing and granulating it to obtain particles with a particle size of 0.1 to 2.0 mm.

[0027] Preferably, the degassing conditions are: temperature 10℃~40℃, vacuum degree -0.05MPa~-0.08MPa, time 5min~10min; the compression conditions are: extrusion twin-screw speed 10~80rpm; the pressure roller conditions are: pressure 5kN / cm~20kN / cm, speed 40rpm~80rpm, and pressure roller cooling water temperature 0℃~10℃.

[0028] Thirdly, the present invention provides the application of the above-mentioned natural blue composition particles as a colorant in food, pharmaceuticals or cosmetics.

[0029] Compared with the prior art, the present invention has the following beneficial effects: The natural blue composition particles provided by this invention utilize a combination of three natural pigments: gardenia blue, butterfly pea flower extract, and phycocyanin extract. Buffers and antioxidants are added as stabilizing aids, and an embedding wall material is used for embedding and forming a solid form. Gardenia blue has a stable but somewhat dark tone; butterfly pea flower extract (anthocyanin) has a bright tone but is pH sensitive and has poor stability; phycocyanin extract has a greenish tone and moderate thermal stability. The three are blended in a specific ratio, achieving visual harmony and providing complementary stabilization in chemical properties. This results in a brighter, more vibrant, and more natural blue than a single pigment, achieving a stable, high-brightness, fast-dissolving, and environmentally friendly natural blue composition. These natural composition particles can replace brilliant blue and indigo, providing a more natural color and significantly reducing the safety and health risks associated with petroleum-based dyes, such as potential carcinogenicity, potential or exacerbation of neurobehavioral problems in children, attention deficit hyperactivity disorder (ADHD), allergic reactions, and metabolic burden, especially affecting children. The combination of several natural blue pigments effectively leverages their respective advantages, creating a complementary effect. Furthermore, the improved stability and dry granulation technology ensure rapid and convenient dissolution and use, making it environmentally friendly. All three are natural ingredients that combine coloring properties with nutritional value. Gardenia blue offers unique advantages in neurocognitive and hepatobiliary health; butterfly pea flower extract, rich in vitamins, excels in skin beauty and cardiovascular protection; phycocyanin extract is known for its high protein content and anti-tumor potential; gardenia blue possesses potent antioxidant, anti-inflammatory, anti-aging, cardiovascular protective, and choleretic effects, and has traditional medicinal value in protecting gallbladder health, calming the nerves, stopping bleeding, and reducing swelling. Butterfly pea flower extract is rich in delphinidin anthocyanins (especially stable anthocyanins acylated with coumaric acid), flavonoids (myricetin, quercetin, kaempferol, etc.), and vitamins A, C, and E, offering beneficial effects such as antioxidant, anti-inflammatory, immune-boosting, cardiovascular protection, skin protection and repair, and beauty enhancement.

[0030] Furthermore, the use of phosphates as a buffer can mitigate the color changes of butterfly pea flower extract due to pH variations, thus stabilizing its color. The addition of antioxidants such as vitamin C and tea polyphenols improves the light and heat stability of gardenia blue, butterfly pea flower extract, and phycocyanin extract. The use of β-cyclodextrin and sodium caseinate for emulsification and encapsulation further significantly enhances the light and heat stability of the blue composition.

[0031] The preparation method provided by this invention systematically integrates the advantages of two technologies: liquid homogenization encapsulation and solid physical molding. First, the pigment, stabilizer, and wall material are uniformly mixed and encapsulated at the molecular level through a solution system. The dry granulation method used solves the previous problems of powder pigment floating and dust, and can integrate them into one. By granulating, it can have better solubility and achieve rapid dissolution.

[0032] The application provided by this invention has multiple advantages, including "natural origin", "high stability", "bright color", "easy to use (instant dissolution and dust-free)" and "additional health benefits (such as antioxidants)". It can fully meet the stringent requirements of the food, pharmaceutical and cosmetic industries for high-end natural colorants, and has become an ideal solution to replace synthetic blue pigments (such as brilliant blue and indigo), with broad commercial application prospects. Attached Figure Description

[0033] Figure 1 This is the initial morphology of the natural blue composition particles in Example 1 of the present invention; Figure 2 This is a dynamic graph showing the rapid dissolution of the natural blue composition particles in Example 1. Figure 3 This is a comparison chart of the thermal stability of the natural blue composition particles from Examples 1-4 and Gardenia Blue, Butterfly Pea Flower Extract, and Phycocyanin Extract. Figure 4 The above are comparison graphs of outdoor light exposure for the natural blue composition particles of Examples 1-4 and Gardenia Blue, Butterfly Pea Flower Extract, and Phycocyanin Extract. Figure 5 Comparative images of the natural blue composition particles from Examples 1-4 and those from Gardenia Blue, Butterfly Pea Flower Extract, and Phycocyanin Extract in a light chamber. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0035] It should be noted that the terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] The present invention will now be described in further detail: I. This invention provides a natural blue composition that is highly stable, has high brightness, is fast-dissolving, and environmentally friendly. Specifically, the following steps are included: (1) Weigh out the gardenia blue, butterfly pea flower extract and phycocyanin extract by weight, add them to purified water and stir to dissolve them. Mix them evenly to obtain a blue mixed solution. Then add the dissolved phosphates while stirring. Add the dissolved antioxidants while stirring. Weigh out the antioxidants (such as vitamin C, tea polyphenols, etc.) by weight and dissolve them completely in purified water. (2) The dissolved embedding wall material is mixed with the blue mixed solution and stirred at high speed for 15 min to 40 min to obtain the embedding material. The embedding material is spray-dried to obtain blue powder. The embedding wall material (such as β-cyclodextrin, sodium caseinate, gum arabic, etc.) is weighed according to the weight, added to pure water, and stirred under heating conditions to completely dissolve the embedding wall material to prepare a saturated aqueous solution. (3) The blue powder is degassed, pre-compressed and pressed into thin sheets by rollers; (4) After the shaped sheet is crushed and granulated, a natural blue composition with high stability, high brightness, fast solubility and environmental friendliness is obtained.

[0037] In a preferred embodiment, step (1) includes the following components by weight: 40-70 parts of gardenia blue, 20-40 parts of butterfly pea flower extract, and 10-20 parts of phycocyanin extract; more preferably, in step (1), the total weight of gardenia blue, butterfly pea flower extract, and phycocyanin extract is 100 parts.

[0038] In a preferred embodiment, step (1) includes the following components by weight: 50 parts gardenia blue, 30 parts butterfly pea flower extract, and 20 parts phycocyanin extract.

[0039] In a preferred embodiment, in step (1), the gardenia blue valence =5~300, preferred gardenia blue price =50.

[0040] In a preferred embodiment, in step (1), the color value of the butterfly pea flower extract is... =2~50, color value of preferred butterfly pea flower extract =30.

[0041] In a preferred embodiment, in step (1), the color value of the phycocyanin extract is... =5~30, preferred phycocyanin extract color value =20.

[0042] In a preferred embodiment, in step (1), the phosphate is one or more combinations of sodium pyrophosphate, tetrapotassium pyrophosphate, potassium polymethphosphate, sodium hexametaphosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate. The preferred phosphates are sodium pyrophosphate and sodium hexametaphosphate.

[0043] In a preferred embodiment, in step (1), the phosphate is a mixed buffer system of sodium pyrophosphate and sodium hexametaphosphate with pH 6.0-8.0, and the amount of sodium pyrophosphate and sodium hexametaphosphate added by weight is 0% to 5% of the blue mixture in step (1), more preferably 0.5%.

[0044] In a preferred embodiment, in step (1), the antioxidant is one or more of the following: vitamin C, sodium ascorbate, calcium ascorbate, tea polyphenols, tea polyphenol palmitate, vitamin E, rosemary extract, licorice antioxidant, phytic acid, sodium phytate, bamboo leaf antioxidant, rutin, etc.

[0045] In a preferred embodiment, in step (1), the antioxidant is added at a weight of 0.1% to 50% of the blue mixture in step (1).

[0046] In a preferred embodiment, in step (1), the antioxidant is preferably vitamin C, tea polyphenols, or rosemary extract; more preferably, vitamin C and tea polyphenols.

[0047] In a preferred embodiment, in step (1), the content of vitamin C is ≥99.0%, more preferably, the amount of vitamin C added by weight is 1% to 20% of the blue mixture; more preferably, it is 5%.

[0048] In a preferred embodiment, in step (1), the tea polyphenol content is ≥80%, more preferably 0.2% to 5% by weight of the tea polyphenols added to the blue mixture; even more preferably 2%.

[0049] In a preferred embodiment, in step (2), the embedding wall material is one or more combinations of β-cyclodextrin, gum arabic, sodium caseinate, hydroxypropyl starch, etc.

[0050] In a preferred embodiment, in step (2), the amount of the embedded wall material added by weight is 20% to 200% of the blue mixture in step (1).

[0051] In a preferred embodiment, in step (2), the embedding wall material is more preferably β-cyclodextrin and sodium caseinate.

[0052] In a preferred embodiment, in step (2), the β-cyclodextrin in the embedding wall material is added at a weight of 20% to 100% of the blue mixture in step (1), preferably 40% to 80%. The sodium caseinate in the embedding wall material is preferably added at a weight of 0.5% to 10% of the blue mixture in step (1), preferably 2% to 5%.

[0053] In a preferred embodiment, in step (2), the amount of β-cyclodextrin added as the embedding wall material is 60% by weight of the blue mixture in step (1). The amount of sodium caseinate added as the embedding wall material is 2.5% by weight of the blue mixture in step (1).

[0054] In a preferred embodiment, in step (2), the β-cyclodextrin embedded wall material is completely dissolved in hot water at 95°C or higher, and sodium caseinate is completely dissolved in hot water at 45-50°C and then mixed with a stable blue buffer solution. The mixture is stirred at high speed, with a stirring speed of 3000-10000 r / min, more preferably 7000-8000 r / min.

[0055] In a preferred embodiment, in step (2), the embedding wall material (such as β-cyclodextrin, sodium caseinate, etc.) is mixed with a stable blue buffer solution and stirred at high speed for 15 min to 40 min, more preferably 25 min to 30 min.

[0056] In a preferred embodiment, in step (2), the drying method is centrifugal spray drying, with an air inlet temperature of 160℃~180℃ and an air outlet temperature of 80℃~90℃.

[0057] In a preferred embodiment, in step (3), the degassing conditions are: temperature 10℃~40℃, vacuum degree -0.05MPa~-0.08MPa, and time 5min~10min; In a preferred embodiment, in step (3), the pre-compression condition is: the extrusion twin screw speed is 10-80 rpm; In a preferred embodiment, in step (3), the conditions of the pressure roller are: pressure 5-20 kN / cm, rotation speed 40-80 rpm, and cooling water temperature of the pressure roller 0-10℃.

[0058] In a preferred embodiment, in step (4), the natural blue composition particles are dust-free, uniform in size, and environmentally friendly.

[0059] In a preferred embodiment, in step (4), the natural blue composition particles have good solubility and can dissolve completely on their own within 30 seconds without stirring.

[0060] Through extensive experimental research, this invention has found that controlling the raw materials and their content within the aforementioned range is more conducive to dry granulation, reduces energy consumption during degassing and rolling, and improves the stability of the natural blue composition.

[0061] The technical solution of this application will be described in detail below through specific embodiments: Unless otherwise specified, the technical means used in this invention are conventional means well known to those skilled in the art. The main raw materials used in this invention—gardenia indigo, butterfly pea flower extract, and phycocyanin extract—were all purchased from Henan Zhongda Hengyuan Biotechnology Co., Ltd. All other materials, reagents, instruments, and equipment can be purchased commercially or prepared using existing methods.

[0062] In this invention, the weight parts can be weight units known in the art such as μg, mg, g, kg, or multiples thereof, such as 1 / 10, 1 / 100, 10 times, 100 times, etc.

[0063] The gardenia blue, butterfly pea flower extract, and phycocyanin extract used in this invention are all produced by Henan Zhongda Hengyuan Biotechnology Co., Ltd. The gardenia blue is model TH-50; the phycocyanin extract is model ZL-04; and the butterfly pea flower extract is model C05211.

[0064] II. Examples of the preparation of the above-mentioned natural blue composition particles Example 1 This embodiment provides a natural blue composition granule, and the specific preparation steps are as follows: Weigh out 50g of gardenia blue, 30g of butterfly pea flower extract, and 20g of phycocyanin extract, add 200g of purified water and stir to dissolve, resulting in a uniformly mixed blue solution. Weigh 0.5g of a mixture of sodium hexametaphosphate and sodium pyrophosphate (mixed in a 1:1 mass ratio), dissolve it in 50mL of purified water, and add it to the blue solution while stirring until homogeneous. Weigh 5g of vitamin C, dissolve it in purified water, and add it to the blue solution while stirring until homogeneous. Weigh 2g of tea polyphenols, dissolve them in purified water, and add them to the blue solution while stirring until homogeneous. A preliminary stable blue buffer solution is obtained.

[0065] Weigh 60g of β-cyclodextrin and dissolve it completely in boiling purified water. Weigh 2.5g of sodium caseinate and dissolve it completely in hot water at 45-50℃. Add the two solutions to a pre-stable blue buffer solution and mix them. Place the mixture in a high-speed mixer and mix it at 3000 r / min. Then, quickly increase the speed to 8000 r / min and continue mixing for 30 minutes to obtain a highly homogeneous and stable blue encapsulation emulsion. The above-mentioned blue embedded emulsion was dried by a centrifugal spray dryer, with the inlet air temperature controlled at 165~170℃ and the outlet air temperature at 80~85℃, and the resulting blue powder was collected. The collected blue powder was transferred to a degassing tank, the feed valve was closed, and a vacuum was drawn to -0.05 MPa and maintained for 10 minutes. The temperature was controlled at 15°C. After the degassing tank was depressurized, the degassed blue powder was placed in a horizontal twin-screw extruder. The horizontal twin-screw extrusion motor was turned on and the speed was set to 40 rpm. The discharge hopper door of the degassing tank was opened, and the powder was fed into the horizontal twin-screw channel at a uniform speed. The powder was extruded by the twin screws to form a semi-soft agglomerated cake. The resulting agglomerated cake was fed into the horizontal roller inlet through the twin-screw channel. The pressure motor was turned on, and the roller speed was adjusted to 40 rpm with a pressure of 10 kN / cm. At the same time, 4°C cold water was turned on for cooling to make the sheets uniform and stable, thus obtaining the formed tablets. The formed tablets are granulated into small particles using a gyratory granulator, with the mesh size controlled at 30 mesh, to obtain uniform and consistent natural blue compound particles.

[0066] Example 2 This embodiment, based on Example 1, provides a natural blue composition particle, and the specific preparation steps are as follows: Weigh out 55g of gardenia blue, 25g of butterfly pea flower extract, and 20g of phycocyanin extract, add them to 200g of purified water and stir to dissolve, resulting in a uniformly mixed blue solution. Weigh 0.4g of a mixture of sodium hexametaphosphate and sodium pyrophosphate (mixed in a 1:1 mass ratio), dissolve it in 50mL of purified water, and add it to the blue solution while stirring until homogeneous. Weigh 4g of vitamin C, dissolve it in purified water, and add it to the blue solution while stirring until homogeneous. Weigh 3g of tea polyphenols, dissolve them in purified water, and add them to the blue solution while stirring until homogeneous. A preliminary stable blue buffer solution is obtained.

[0067] Weigh 70g of β-cyclodextrin and dissolve it completely in boiling purified water. Weigh 2g of sodium caseinate and dissolve it completely in hot water at 45-50℃. Add the two solutions to a pre-stable blue buffer solution and mix them. Place the mixture in a high-speed mixer and mix it at 3500 r / min. Then, quickly increase the speed to 8000 r / min and continue mixing for 28 minutes to obtain a highly homogeneous and stable blue encapsulation emulsion. The above-mentioned blue embedded emulsion was dried by a centrifugal spray dryer, with the inlet air temperature controlled at 160~165℃ and the outlet air temperature at 85~88℃, and the resulting blue powder was collected. The collected blue powder was transferred to a degassing tank, the feed valve was closed, and a vacuum was drawn to -0.07 MPa and maintained for 8 minutes. The temperature was controlled at 18°C. The degassed blue powder was placed in a horizontal twin-screw extruder, the horizontal twin-screw extrusion motor was turned on at 45 rpm, the lower discharge hopper door of the degassing tank was opened, and the powder was fed into the horizontal twin-screw channel at a uniform speed. The powder was extruded by the twin screws to form a semi-soft agglomerated cake. The resulting agglomerated cake was fed into the horizontal roller inlet through the twin-screw channel. The pressure motor was turned on, the roller speed was adjusted to 45 rpm, and the pressure was 12 kN / cm. At the same time, 5°C cold water was turned on for cooling to make the sheets uniform and stable, thus obtaining the formed tablets. The formed tablets are granulated into small particles using a gyratory granulator, with the mesh size controlled at 30 mesh, to obtain uniform and consistent natural blue compound particles.

[0068] Example 3 This embodiment, based on Example 1, provides a natural blue composition particle, and the specific preparation steps are as follows: Weigh out 45g of Gardenia Blue, 30g of Butterfly Pea Flower Extract, and 25g of Phycocyanin Extract, add 200g of purified water and stir to dissolve, resulting in a uniformly mixed blue solution. Weigh 0.6g of a mixture of sodium hexametaphosphate and sodium pyrophosphate (mixed in a 1:1 mass ratio), dissolve it in 50mL of purified water, and add it to the blue solution while stirring until homogeneous. Weigh 6g of vitamin C, dissolve it in purified water, and add it to the blue solution while stirring until homogeneous. Weigh 2.5g of tea polyphenols, dissolve them in purified water, and add them to the blue solution while stirring until homogeneous. A preliminary stable blue buffer solution is obtained.

[0069] Weigh 55g of β-cyclodextrin and dissolve it completely in boiling purified water. Weigh 3g of sodium caseinate and dissolve it completely in hot water at 45-50℃. Add the two solutions to a pre-stable blue buffer solution and mix them. Place the mixture in a high-speed mixer and mix it at 4000 r / min. Then, quickly increase the speed to 8000 r / min and continue mixing for 25 minutes to obtain a highly homogeneous and stable blue encapsulation emulsion. The above-mentioned blue embedded emulsion was dried by a centrifugal spray dryer, with the inlet air temperature controlled at 170~175℃ and the outlet air temperature at 82~88℃, and the blue powder obtained from the drying was collected. The collected blue powder was transferred to a degassing tank, the feed valve was closed, and a vacuum was drawn to -0.08 MPa and maintained for 6 minutes. The temperature was controlled at 12°C. The degassed blue powder was placed in a horizontal twin-screw extruder, the horizontal twin-screw extrusion motor was turned on at 35 rpm, the lower discharge hopper door of the degassing tank was opened, and the powder was fed into the horizontal twin-screw channel at a uniform speed. The powder was extruded by the twin screws to form a semi-soft agglomerated cake. The resulting agglomerated cake was fed into the horizontal roller inlet through the twin-screw channel. The pressure motor was turned on, the roller speed was adjusted to 35 rpm, and the pressure was 14 kN / cm. At the same time, 4°C cold water was turned on for cooling to make the sheets uniform and stable, thus obtaining the formed tablets. The formed tablets are granulated into small particles using a gyratory granulator, with the mesh size controlled at 30 mesh, to obtain uniform and consistent natural blue compound particles.

[0070] Example 4 This embodiment, based on Example 1, provides a natural blue composition particle, and the specific preparation steps are as follows: Weigh out 40g of Gardenia Blue, 35g of Butterfly Pea Flower Extract, and 25g of Phycocyanin Extract, add 200g of purified water and stir to dissolve, resulting in a uniformly mixed blue solution. Weigh 0.7g of a mixture of sodium hexametaphosphate and sodium pyrophosphate (mixed in a 1:1 mass ratio), dissolve it in 50mL of purified water, and add it to the blue solution while stirring until well mixed; weigh 7g of vitamin C, dissolve it in purified water, and add it to the blue solution while stirring until well mixed; weigh 4g of tea polyphenols, dissolve them in purified water, and add them to the blue solution while stirring until well mixed. Weigh 50g of β-cyclodextrin and dissolve it completely in purified water heated to boiling. Weigh 4g of sodium caseinate and dissolve it completely in hot water at 45-50℃. Add the two solutions to a pre-stable blue buffer solution and mix them. Place the mixture in a high-speed mixer and mix it at 4500 r / min. Then, quickly increase the speed to 7000 r / min and continue stirring for 26 minutes to obtain a highly homogeneous and stable blue encapsulation emulsion. The above-mentioned blue embedded emulsion was dried by a centrifugal spray dryer, with the inlet air temperature controlled at 168~172℃ and the outlet air temperature at 85~90℃, and the resulting blue powder was collected. The collected blue powder was transferred to a degassing tank, the feed valve was closed, and a vacuum was drawn to -0.06 MPa and maintained for 5 minutes. The temperature was controlled at 20°C. After the degassing tank was depressurized, the degassed blue powder was placed in a horizontal twin-screw extruder. The horizontal twin-screw extrusion motor was turned on and the speed was set to 45 rpm. The discharge hopper door of the degassing tank was opened, and the powder was fed into the horizontal twin-screw channel at a uniform speed. The powder was extruded by the twin screws to form a semi-soft agglomerated cake. The resulting agglomerated cake was fed into the horizontal roller inlet through the twin-screw channel. The pressure motor was turned on, and the roller speed was adjusted to 45 rpm with a pressure of 15 kN / cm. At the same time, 1°C cold water was turned on for cooling to make the sheets uniform and stable, thus obtaining the formed tablets. The formed tablets are granulated into small particles using a gyratory granulator, with the mesh size controlled at 30 mesh, to obtain uniform and consistent natural blue compound particles.

[0071] The above embodiments are merely illustrative of preferred technical solutions of the present invention. Those skilled in the art will understand that, without departing from the core concept of the present invention, buffers, antioxidants, and embedding wall materials can be replaced with other conventional, functionally equivalent alternatives as described in the claims and specification. For example, rosemary extract can be used to replace some tea polyphenols, or gum arabic can be combined with β-cyclodextrin, etc., to achieve the same objective of the present invention.

[0072] III. Performance Verification Examples The main performance indicators of the natural blue composition particles prepared in Examples 1-4 were tested, and the results are shown below: 1. Solubility Dissolution rate test: Take 1g of natural blue composition particles, use a 500mL graduated cylinder to take 750mL of pure water, sprinkle the natural blue composition particles on the water surface, the particles immediately start the rapid dissolution and sinking process after contact with the water surface, the whole process is completed within 30 seconds, the aqueous solution turns into a uniform blue, and there are no visible insoluble particles left.

[0073] The initial morphology of the blue particles and their rapid dissolution dynamics in water are shown in the attached figure. Figure 1-2 As shown, the particles act immediately upon being sprinkled onto the water surface. Within 5 seconds, a clear dissolution and diffusion phenomenon is observed, with the blue color rapidly spreading to the surrounding water, indicating rapid hydration of the particle surface and the immediate initiation of the dissolution process. Within 5-10 seconds, the particles rapidly disintegrate, and the blue area continues to expand and deepen. No large undissolved residues are observed in the water, proving that the internal structure of the particles facilitates rapid water penetration and simultaneous release of components. In images taken between 15 and 25 seconds, the particle morphology completely disappears, and the blue color is uniformly distributed throughout the observed water body, resulting in a homogeneous solution. This dynamic dissolution process strongly confirms the key characteristics of this blue composite particle: rapid dissolution and uniform dispersion. The entire dissolution process is completed efficiently within 30 seconds, with no visible residue, providing intuitive visual evidence and performance assurance for its practical application in scenarios requiring rapid dissolution (such as instantaneous staining and rapid dispersion of functional components).

[0074] 2. Color difference analysis Table 1 shows a comparison of photographs of the natural blue composition particle samples prepared in Examples 1-4 and their corresponding color difference (CIELAB color space) data.

[0075] Table 1: Color difference comparison of different sample photo sets

[0076] As shown in Table 1, the blue particles prepared in Examples 1-4 exhibit a high brightness, stability, and strong blue-green hue. All samples have L values ​​between 70 and 73, indicating high brightness and a bright visual effect. All a values ​​are negative (approximately -17.5 to -19.8), clearly indicating a greenish tint. All b values ​​are negative (approximately -32.1 to -32.3) and stable, clearly indicating a strong blue tint. While there are slight, adjustable variations in the green component (a value) among the different examples, the core blue saturation (b value) and overall brightness (L value) maintain a high degree of consistency and stability, proving that this preparation process can produce blue particle products with uniform color and reliable performance. The color characteristics reflected in the above data can be visually verified by combining sample photographs.

[0077] 3. Thermal stability test The natural blue composition particles from Examples 1-4, commercially available gardenia blue, butterfly pea flower extract, and phycocyanin extract were each prepared into solutions with equal absorbance (Abs) using purified water. These solutions were then sealed and placed in a 90°C water bath for 2 hours. Samples were taken every 30 minutes to measure absorbance and calculate pigment retention rate. The results are shown in Table 2. Figure 3 As shown.

[0078] Table 2: Pigment retention rate of different samples during heating at 90℃

[0079] From Table 2 and Appendix Figure 3 It can be seen that after heating at 90℃ for 2 hours, the pigment retention rates of each sample, from highest to lowest, are as follows: Example 1 > Example 2 > Example 3 > Example 4 > Gardenia Blue ≈ Butterfly Pea Flower Extract > Phycocyanin Extract. After heating for 120 minutes, the pigment retention rates of Examples 1-4 remained above 90%, with Example 1 having the highest (94%), indicating that the blue particles prepared by this invention have significantly better thermal stability than the control natural pigments. The retention rates of Gardenia Blue and Butterfly Pea Flower Extract decreased to approximately 78% and 73% respectively in the initial heating stage (30 minutes). Although there were slight fluctuations later, the final retention rates were only about 76% and 66%, indicating significant thermal degradation. Phycocyanin Extract had the worst thermal stability; after heating for 30 minutes, the retention rate had dropped to 16%, and after 120 minutes, only 6.17% remained, indicating that it is extremely susceptible to heat damage. All samples showed a gradual decrease in retention rate over time during heating, but the decrease in the examples of this invention was much smaller than that of the control samples, indicating that its structure or formulation can effectively slow down heat-induced pigment degradation.

[0080] The natural blue composition particles provided by this invention (Examples 1-4) exhibit excellent thermal stability under high temperature conditions (90°C, 2 hours), and the pigment retention rate is significantly higher than that of commercially available natural blue pigments. They are suitable for food, pharmaceuticals, cosmetics and other fields that require heat processing or high temperature treatment, and have good application prospects.

[0081] 4. Light stability test To evaluate the lightfastness of the natural blue composition particles prepared in this invention (Examples 1-4), they were compared with commercially available common natural blue pigments (gardenia blue, butterfly pea flower extract, and phycocyanin extract). Each sample was prepared into a solution with equal absorbance (Abs) using purified water, sealed, and exposed to strong sunlight outdoors (ambient temperature 20–36°C) for 4 consecutive days. Samples were taken at 0, 0.5, 1, 2, 3, and 4 days to measure absorbance and calculate pigment retention rate. The results are shown in Table 3. Figure 4 As shown.

[0082] Table 3: Pigment retention rate of different samples under strong outdoor light irradiation

[0083] From Table 3 and Appendix Figure 4 It can be seen that under four consecutive days of strong sunlight exposure, the pigment retention rate of all samples showed a decreasing trend, indicating that light has a significant degradation effect on natural blue pigments. The overall retention rate of Examples 1-4 of this invention was consistently higher than that of the control samples, showing superior lightfastness. After 0.5 days of irradiation, the retention rate of Examples 1-4 was still as high as 80% or more (84.59% for Example 1), while that of Gardenia Blue and Phycocyanin extracts had decreased to 72% and 42% respectively, and that of Butterfly Pea Flower Extract was 74%. This indicates that the degradation rate of the blue particles of this invention was significantly lower than that of most controls in the early stages of light exposure. After four days of irradiation, the retention rate of Examples 1-4 remained between 36% and 41%, while the highest retention rate among the control samples, Gardenia Blue, was only 28.71%, Butterfly Pea Flower Extract was 25.74%, and Phycocyanin Extract had been severely degraded to 5.07%. Example 1 consistently showed the highest retention rate throughout the entire testing period; Gardenia blue exhibited rapid degradation in the initial stage (0.5 days), followed by a slower degradation rate in the later stages, with a final retention rate similar to that of Butterfly Pea Flower Extract and Example 4, but its overall stability was lower than that of the embodiments of this invention; Butterfly Pea Flower Extract's final retention rate was comparable to that of Gardenia Blue; Phycocyanin Extract showed the worst photostability, with its retention rate plummeting to 42.23% after only 0.5 days and remaining at only 5.07% after 4 days, indicating almost complete decomposition, demonstrating its extreme light intolerance. In summary, the natural blue composition particles provided by this invention (Examples 1-4) exhibit significantly better photostability than commercially available common natural blue pigments (Gardenia Blue, Butterfly Pea Flower Extract, Phycocyanin Extract) under strong sunlight. Especially during the initial stage of irradiation, degradation was slow, and a high pigment retention rate was maintained even after long-term exposure. This indicates that the product is more suitable for applications requiring exposure to light or high color durability, such as some beverages and outdoor products, possessing better practicality and storage stability.

[0084] 5. Accelerated photostability test To further quantify the photostability of the natural blue composition particles prepared in this invention (Examples 1-4), accelerated light irradiation experiments were conducted under controlled conditions. Each sample was prepared into a solution with isoabsorbance (Abs) using purified water, sealed, and placed in a light chamber (temperature 37°C, illuminance 21000 LUX) for continuous irradiation for 9 days. Samples were taken on the initial day, days 1, 3, 5, 7, and 9, and their absorbance was measured. The pigment retention rate was calculated, and the results are shown in Table 4. Figure 5 As shown.

[0085] Table 4: Pigment retention rate of different samples under accelerated light irradiation (37℃, 21000 LUX)

[0086] From the appendix Figure 5As shown in Table 4, after 9 days of accelerated light exposure, the pigment retention rates of each sample, from highest to lowest, were: Example 1 > Example 2 > Example 3 > Example 4 > Butterfly Pea Flower Extract > Gardenia Blue > Phycocyanin Extract. All examples of this invention showed significantly better photostability than the control samples. Throughout the 9-day test period, the pigment retention rates of Examples 1-4 remained high. Example 1 still maintained a retention rate of 69.28% after 9 days, significantly higher than all control samples. The photodegradation rates of all example samples were gradual, indicating that their pigment structures or formulation systems could effectively resist decomposition caused by strong light exposure. Phycocyanin extract exhibited the worst photostability, with a retention rate that dropped sharply to 60% on day 1, decreased to 20% on day 5, and remained at only 11% after 9 days, indicating its extreme instability under strong light. Butterfly pea flower extract and gardenia blue showed relatively good photostability, with retention rates of 28.4% and 39.93% respectively after 9 days, but still significantly lower than the examples of this invention (above 49%). Under controlled accelerated light conditions (37°C, 21000 LUX), the natural blue composite particles provided by this invention (Examples 1-4) exhibited extremely excellent photostability, with significantly higher pigment retention rates than commercially available common natural blue pigments (Gardenia Blue, Butterfly Pea Flower Extract, and Phycocyanin Extract). This indicates that the product can better withstand light exposure and is suitable for applications requiring high color durability and photostability, such as transparently packaged beverages, food stored under light, and cosmetics, demonstrating outstanding market application potential and stability advantages.

[0087] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A natural blue composition granule, characterized in that, The product, by weight, consists of the following components: 40-70 parts gardenia blue, 20-40 parts butterfly pea flower extract, 10-20 parts phycocyanin extract; 0.1-5 parts buffer; 0.05-3 parts antioxidant; and 50-800 parts embedding wall material. The total number of parts of the gardenia blue, butterfly pea flower extract, and phycocyanin extract is 100 parts; The composition particles are dust-free particles formed by dry granulation, and the pigment components in the gardenia blue, butterfly pea flower extract and phycocyanin extract are embedded in the embedding wall material.

2. The natural blue composition particles according to claim 1, characterized in that, The buffer is one or more of sodium pyrophosphate, tetrapotassium pyrophosphate, sodium hexametaphosphate, disodium hydrogen phosphate, and dipotassium hydrogen phosphate.

3. The natural blue composition particles according to claim 1, characterized in that, The antioxidant is one or more of vitamin C, sodium ascorbate, tea polyphenols, and rosemary extract.

4. The natural blue composition particles according to claim 1, characterized in that, The embedding wall material is one or more of β-cyclodextrin, gum arabic, sodium caseinate, and hydroxypropyl starch.

5. A natural blue composition particle according to any one of claims 1-4, characterized in that, The color value of the gardenia blue is 5-300, the color value of the butterfly pea flower extract is 2-50, and the color value of the phycocyanin extract is 5-30.

6. The natural blue composition particles according to claim 1, characterized in that, The ratio of the total weight of the embedding wall material to the total weight of the gardenia blue, butterfly pea flower extract and phycocyanin extract is (0.5:1) to (2:1).

7. A method for preparing natural blue composition particles according to any one of claims 1 to 6, characterized in that, include: Gardenia blue, butterfly pea flower extract and phycocyanin extract were dissolved in twice the amount of purified water to obtain a blue mixed solution; Phosphate and antioxidant were added sequentially to the above blue mixed solution to obtain a stable blue buffer mixed solution; The dissolved embedding wall material was added to the above stable blue buffer mixture, stirred and mixed, spray-dried, and then dry-granulated to obtain natural blue composition particles.

8. The method for preparing natural blue composition particles according to claim 7, characterized in that, The spray drying inlet air temperature is 160℃~180℃, and the outlet air temperature is 80℃~90℃.

9. The method for preparing natural blue composition particles according to claim 7, characterized in that, The dry granulation process includes: pressing the blue powder into thin sheets with a thickness of 0.5 mm to 3.0 mm under a pressure of 20 MPa to 100 MPa, and then crushing and granulating them to obtain natural blue composition particles with a particle size of 0.1 mm to 2.0 mm.

10. The use of the natural blue composition particles according to any one of claims 1-6 as a colorant in food, pharmaceuticals or cosmetics.

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