Spirulina-astaxanthin popping bead and preparation method thereof

Abstract

A preparation method of the spirulina-astaxanthin popping bead comprises the following steps: mixing a chitosan solution and a spirulina suspension to obtain a modified spirulina suspension, mixing the modified spirulina suspension with an astaxanthin solution, and carrying out centrifugation, precipitation and freeze drying on the obtained spirulina-embedded astaxanthin solution to obtain spirulina-embedded astaxanthin composite particles; preparing a spirulina-astaxanthin suspension from the spirulina-embedded astaxanthin composite particles, and mixing the spirulina-astaxanthin suspension with a sodium alginate solution in proportion to obtain a spirulina-astaxanthin-sodium alginate mixed solution; and sucking the spirulina-astaxanthin-sodium alginate mixed solution by using an injector, dropwise adding the spirulina-astaxanthin-sodium alginate mixed solution into a calcium chloride solution, slowly stirring, and fishing out to obtain the spirulina-astaxanthin popping bead. According to the spirulina-astaxanthin popping bead disclosed by the invention, the astaxanthin is loaded on the spirulina biological matrix and is embedded by the sodium alginate, so that the effect of double-layer protection of the astaxanthin is achieved, and the illumination stability, the heat stability, the pH stability and the ultraviolet irradiation stability of the astaxanthin are improved.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a spirulina-astaxanthin popping bead and its preparation method. Background Technology

[0002] Astaxanthin (AST) is an oxygenated derivative of carotenoids with strong antioxidant properties. It can scavenge free radicals, fight cancer and inflammation, boost immunity, protect skin from sun damage, prevent cardiovascular diseases, and protect eyesight, showing broad application prospects in the food, cosmetics, and pharmaceutical industries. However, astaxanthin has poor water solubility and is sensitive to light, heat, pH, and ultraviolet radiation, limiting its application in these fields.

[0003] Spirulina contains various active ingredients, such as phycocyanin, carotenoids, and polysaccharides, and is relatively safe for consumption. The surface of spirulina cells typically carries a negative charge, allowing it to load positively charged molecules through electrostatic adsorption. Its helical structure not only makes it easier for intestinal villi to capture it but also allows it to adhere to the intestinal wall, thus protecting the active substances and prolonging their retention time in the intestines. Furthermore, spirulina has a large specific surface area, giving it a highly efficient capacity for loading active substances. Loading astaxanthin with spirulina can improve the stability of astaxanthin; however, how to load it and whether the stability of the astaxanthin active substance can be maintained after loading remains a technical challenge.

[0004] Popping beads are functional foods containing a core material encased in an edible film. Their outer shell has good toughness and sealing properties; when chewed, the beads burst instantly, releasing the inner core material. Popping beads have a unique taste and have gained popularity among consumers in recent years. Currently, most popping beads on the market use fruit juice or probiotics as core materials, resulting in a limited nutritional profile. There are currently no popping beads with spirulina-astaxanthin as the core material.

[0005] Therefore, there is an urgent need to develop a Spirulina-Astaxanthin popping bead to solve the problem that astaxanthin is sensitive to light, heat, pH and ultraviolet light, improve the stability of astaxanthin, and thus improve the commercial value and market application prospects of astaxanthin. Summary of the Invention

[0006] The purpose of this invention is to provide a Spirulina-Astaxanthin Popping Beads and its preparation method, so as to solve the problems mentioned in the background art.

[0007] This invention provides a method for preparing Spirulina-Astaxanthin Popping Beads, comprising the following preparation steps:

[0008] S1. Preparation of modified spirulina suspension: Chitosan solution and spirulina suspension are mixed at a mass ratio of 1:8 to 10 and stirred at 100 to 200 rpm for 10 to 15 minutes to fully combine chitosan and spirulina, thus obtaining modified spirulina suspension.

[0009] S2. Preparation of astaxanthin solution embedded in spirulina: The astaxanthin solution and the modified spirulina suspension were mixed at a mass ratio of 1:9-10 and stirred at 100-200 rpm for 2-8 hours to fully embed the astaxanthin into the spirulina, thus obtaining the astaxanthin solution embedded in spirulina.

[0010] S3. Preparation of Spirulina-encapsulated astaxanthin complex particles: The astaxanthin solution encapsulated in Spirulina was centrifuged at 7000-8000 rpm for 5-6 min, the precipitate was collected, the precipitate was washed with deionized water, centrifuged 3 times, and then freeze-dried to obtain Spirulina-encapsulated astaxanthin complex particles.

[0011] S4. Preparation of Spirulina-Astaxanthin-Sodium Alginate Mixture: Spirulina-astaxanthin composite particles were prepared into a Spirulina-Astaxanthin suspension with a mass concentration of 0.1-1% using deionized water; the Spirulina-Astaxanthin suspension and sodium alginate solution were mixed evenly at a mass ratio of 1:4 to obtain the Spirulina-Astaxanthin-Sodium Alginate Mixture.

[0012] S5. Preparation of Spirulina-Astaxanthin Popping Beads: Using a syringe, draw up a mixture of spirulina-astaxanthin-sodium alginate. Position the syringe needle 5-10 cm above the surface of the calcium chloride solution and drop the mixture into the slowly stirred calcium chloride solution at a rate of 20 drops / min. Then, stir slowly for 15-30 minutes, remove the beads, and rinse with deionized water to obtain spirulina-astaxanthin popping beads with a particle size of 2.0-6.0 mm.

[0013] As a preferred technical solution of the present invention, the chitosan solution is prepared by the following method: chitosan is dissolved in an acetic acid solution with a mass concentration of 1.2% at a mass ratio of 1:10, and then deionized water is added to prepare a chitosan solution with a concentration of 1.5 to 150 μg / mL.

[0014] As a preferred technical solution of the present invention, the spirulina suspension is prepared by the following method: take fresh spirulina liquid, centrifuge at a speed of 7000-8000 rpm for 5-6 minutes, collect the precipitate, wash the precipitate with deionized water, centrifuge 3 times to obtain fresh spirulina, and then use deionized water to prepare a spirulina suspension with a concentration of 40-800 μg / mL.

[0015] As a preferred embodiment of the present invention, the astaxanthin solution is prepared by the following method: astaxanthin is dissolved in ethanol at a mass ratio of 1:20, and then deionized water is added to prepare an astaxanthin solution with a concentration of 0.2 to 2 mg / mL.

[0016] As a preferred technical solution of the present invention, the sodium alginate solution is prepared by the following method: sodium alginate is prepared into a mixed solution with a mass concentration of 1-2% by deionized water, and then homogenized in a homogenizer at a speed of 1800-2000 rpm for 20-30 min to obtain the sodium alginate solution.

[0017] In a preferred embodiment of the present invention, the mass concentration of the calcium chloride solution is 1-4%.

[0018] As a preferred embodiment of the present invention, the slow stirring speed is 30-50 rpm.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. This invention uses spirulina bio-matrix to load astaxanthin and encapsulates it with sodium alginate, achieving a double-layer protection for astaxanthin and improving its stability under light, heat, pH, and ultraviolet radiation. Spirulina is rich in antioxidants such as β-carotene and vitamin E, which work synergistically with astaxanthin to more effectively neutralize free radicals, reduce cell damage, and delay aging. The combination of spirulina and astaxanthin not only provides abundant antioxidants but also supplements various basic nutrients, helping to meet the body's daily nutritional needs. Furthermore, the polysaccharides and proteins in spirulina provide additional antioxidant protection, improving the stability of astaxanthin popping beads and thus extending their shelf life. The sodium alginate encapsulation technology stably encapsulates the nutrients of astaxanthin and spirulina in a gel membrane, avoiding the influence of light, oxygen, temperature, and ultraviolet radiation on their activity and improving the stability of astaxanthin.

[0021] 2. This invention modifies the spirulina suspension by mixing and stirring a spirulina suspension with a chitosan solution, and then loads it with astaxanthin. Spirulina is easily deactivated under conditions such as high temperature and light. Spirulina and chitosan form a spirulina-chitosan complex through electrostatic interaction. Furthermore, the spiral structure of spirulina and the linear polysaccharide chain of chitosan can form spatial intercalation, further enhancing the binding stability and reducing the damage to spirulina and astaxanthin caused by environmental factors such as light and temperature. This maintains the stability of the active ingredients of spirulina and astaxanthin. At the same time, chitosan can reduce the oxidative degradation of astaxanthin by metal ions through chelation. In addition, chitosan and sodium alginate can form a composite gel through electrostatic interaction, which enhances the mechanical strength of the popping beads and reduces the risk of breakage during transportation or storage.

[0022] 3. This invention uses spirulina bio-matrix to load astaxanthin and encapsulates it with sodium alginate to create double-protected popping beads. The encapsulated popping beads gradually release nutrients in the gastrointestinal tract, allowing the body to more fully absorb and utilize these beneficial substances. Furthermore, the popping beads' ability to burst upon pressure and spew upon contact with the mouth provides consumers with a unique taste experience and added fun, making them suitable for use in beverages, desserts, and other foods, thus enhancing the commercial value and market competitiveness of astaxanthin. Attached Figure Description

[0023] Figure 1 Image of the Spirulina-Astaxanthin popping beads prepared according to this invention;

[0024] Figure 2 Bar chart showing the effect of soaking popping beads under different pH conditions on DPPH free radical scavenging rate;

[0025] Figure 3 Bar chart showing the effect of placing popping beads at different temperatures on DPPH free radical scavenging rate;

[0026] Figure 4 Line graph showing the effect of light exposure time on DPPH free radical scavenging rate;

[0027] Figure 5 The graph shows the effect of UV irradiation time on DPPH free radical scavenging rate. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0029] All raw materials used in this invention are commercially available food-grade raw materials.

[0030] Example 1:

[0031] A method for preparing spirulina-astaxanthin popping beads includes the following preparation steps:

[0032] S1. Preparation of modified spirulina suspension: (1) Preparation of chitosan solution: Chitosan was dissolved in acetic acid solution with a mass concentration of 1.2% at a mass ratio of 1:10, and then deionized water was added to prepare a chitosan solution with a concentration of 150 μg / mL; (2) Preparation of spirulina suspension: Fresh spirulina liquid was taken, centrifuged at a speed of 8000 rpm for 5 min, the precipitate was collected, and the precipitate was washed with deionized water and centrifuged 3 times to obtain fresh spirulina. Then, the fresh spirulina was prepared into a spirulina suspension with a concentration of 800 μg / mL using deionized water; (3) Preparation of modified spirulina suspension: Chitosan solution and spirulina suspension were mixed at a mass ratio of 1:8 and stirred at a speed of 100 rpm for 15 min to obtain modified spirulina suspension.

[0033] S2. Preparation of astaxanthin solution embedded in spirulina: (1) Preparation of astaxanthin solution: Dissolve astaxanthin in ethanol at a mass ratio of 1:20, and then add deionized water to prepare an astaxanthin solution with a concentration of 2 mg / mL; (2) Preparation of astaxanthin solution embedded in spirulina: Mix astaxanthin solution and modified spirulina suspension at a mass ratio of 1:10 and stir at 200 rpm for 2 h to obtain astaxanthin solution embedded in spirulina.

[0034] S3. Preparation of Spirulina-embedded astaxanthin complex particles: The astaxanthin solution embedded in Spirulina was centrifuged at 8000 rpm for 5 min, the precipitate was collected, washed with deionized water, centrifuged 3 times, and then freeze-dried to obtain Spirulina-embedded astaxanthin complex particles.

[0035] S4. Preparation of Spirulina-Astaxanthin-Sodium Alginate Mixture: (1) Preparation of Sodium Alginate Solution: Sodium alginate was prepared into a 2% mass concentration mixture with deionized water, and then homogenized in a homogenizer at 2000 rpm for 20 min to obtain a sodium alginate solution; (2) Preparation of Spirulina-Astaxanthin-Sodium Alginate Mixture: Spirulina-astaxanthin composite particles were prepared into a 1% mass concentration suspension with deionized water; Spirulina-astaxanthin suspension and sodium alginate solution were mixed evenly at a mass ratio of 1:4 to obtain Spirulina-Astaxanthin-Sodium Alginate Mixture.

[0036] S5. Preparation of Spirulina-Astaxanthin Popping Beads: Using a syringe, a mixture of spirulina-astaxanthin-sodium alginate was drawn up. The syringe needle was positioned 10 cm above the surface of a 4% calcium chloride solution. The mixture was dropped into the slowly stirred calcium chloride solution at a rate of 20 drops / min. The solution was then slowly stirred for 30 minutes. The mixture was then removed and rinsed with deionized water to obtain spirulina-astaxanthin popping beads with a particle size of 2.0–6.0 mm. The stirring speed was 50 rpm.

[0037] Example 2:

[0038] A method for preparing spirulina-astaxanthin popping beads includes the following preparation steps:

[0039] S1. Preparation of modified spirulina suspension: (1) Preparation of chitosan solution: Chitosan was dissolved in acetic acid solution with a mass concentration of 1.2% at a mass ratio of 1:10, and then deionized water was added to prepare a chitosan solution with a concentration of 1.5 μg / mL; (2) Preparation of spirulina suspension: Fresh spirulina liquid was taken, centrifuged at a speed of 7000 rpm for 6 min, the precipitate was collected, and the precipitate was washed with deionized water and centrifuged 3 times to obtain fresh spirulina. Then, fresh spirulina was prepared into a spirulina suspension with a concentration of 40 μg / mL using deionized water; (3) Preparation of modified spirulina suspension: Chitosan solution and spirulina suspension were mixed at a mass ratio of 1:10 and stirred at a speed of 200 rpm for 10 min to obtain modified spirulina suspension.

[0040] S2. Preparation of astaxanthin solution embedded in spirulina: (1) Preparation of astaxanthin solution: Dissolve astaxanthin in ethanol at a mass ratio of 1:20, and then add deionized water to prepare an astaxanthin solution with a concentration of 0.2 mg / mL; (2) Preparation of astaxanthin solution embedded in spirulina: Mix astaxanthin solution and modified spirulina suspension at a mass ratio of 1:9 and stir at 100 rpm for 2 h to obtain astaxanthin solution embedded in spirulina.

[0041] S3. Preparation of Spirulina-encapsulated astaxanthin complex particles: The astaxanthin solution encapsulated in Spirulina was centrifuged at 7000 rpm for 6 min, the precipitate was collected, washed with deionized water, centrifuged 3 times, and then freeze-dried to obtain Spirulina-encapsulated astaxanthin complex particles.

[0042] S4. Preparation of Spirulina-Astaxanthin-Sodium Alginate Mixture: (1) Preparation of Sodium Alginate Solution: Sodium alginate was prepared into a 1% mass concentration mixture with deionized water, and then homogenized in a homogenizer at 1800 rpm for 30 min to obtain a sodium alginate solution; (2) Preparation of Spirulina-Astaxanthin-Sodium Alginate Mixture: Spirulina-astaxanthin composite particles were prepared into a 0.1% mass concentration suspension with deionized water; Spirulina-astaxanthin suspension and sodium alginate solution were mixed evenly at a mass ratio of 1:4 to obtain Spirulina-Astaxanthin-Sodium Alginate Mixture.

[0043] S5. Preparation of Spirulina-Astaxanthin Popping Beads: Using a syringe, a mixture of spirulina-astaxanthin-sodium alginate was drawn up. The syringe needle was positioned 5 cm above the surface of a 1% calcium chloride solution. The mixture was dropped into the slowly stirred calcium chloride solution at a rate of 20 drops / min. The solution was then slowly stirred for 15 minutes. The mixture was then removed and rinsed with deionized water to obtain spirulina-astaxanthin popping beads with a particle size of 2.0–6.0 mm. The stirring speed was 30 rpm.

[0044] Example 3:

[0045] A method for preparing spirulina-astaxanthin popping beads includes the following preparation steps:

[0046] S1. Preparation of modified spirulina suspension: (1) Preparation of chitosan solution: Chitosan was dissolved in acetic acid solution with a mass concentration of 1.2% at a mass ratio of 1:10, and then deionized water was added to prepare a chitosan solution with a concentration of 80 μg / mL; (2) Preparation of spirulina suspension: Fresh spirulina liquid was taken, centrifuged at a speed of 7500 rpm for 5 min, the precipitate was collected, and the precipitate was washed with deionized water and centrifuged 3 times to obtain fresh spirulina. Then, the fresh spirulina was prepared into a spirulina suspension with a concentration of 100 μg / mL using deionized water; (3) Preparation of modified spirulina suspension: Chitosan solution and spirulina suspension were mixed at a mass ratio of 1:9 and stirred at a speed of 150 rpm for 12 min to obtain modified spirulina suspension.

[0047] S2. Preparation of astaxanthin solution embedded in spirulina: (1) Preparation of astaxanthin solution: Dissolve astaxanthin in ethanol at a mass ratio of 1:20, and then add deionized water to prepare an astaxanthin solution with a concentration of 1 mg / mL; (2) Preparation of astaxanthin solution embedded in spirulina: Mix astaxanthin solution and modified spirulina suspension at a mass ratio of 1:10 and stir at a speed of 100-200 rpm for 2-8 hours to obtain astaxanthin solution embedded in spirulina.

[0048] S3. Preparation of Spirulina-embedded astaxanthin complex particles: The astaxanthin solution embedded in Spirulina was centrifuged at 7500 rpm for 5 min, the precipitate was collected, washed with deionized water, centrifuged 3 times, and then freeze-dried to obtain Spirulina-embedded astaxanthin complex particles.

[0049] S4. Preparation of Spirulina-Astaxanthin-Sodium Alginate Mixture: (1) Preparation of Sodium Alginate Solution: Sodium alginate was prepared into a mixture with a mass concentration of 1.5% by deionized water, and then homogenized in a homogenizer at a speed of 2000 rpm for 25 min to obtain a sodium alginate solution; (2) Preparation of Spirulina-Astaxanthin-Sodium Alginate Mixture: Spirulina-astaxanthin composite particles were prepared into a Spirulina-Astaxanthin suspension with a mass concentration of 0.8% by deionized water; Spirulina-Astaxanthin suspension and sodium alginate solution were mixed evenly at a mass ratio of 1:4 to obtain Spirulina-Astaxanthin-Sodium Alginate Mixture.

[0050] S5. Preparation of Spirulina-Astaxanthin Popping Beads: Using a syringe, a mixture of spirulina, astaxanthin, and sodium alginate was drawn up. The syringe needle was positioned 6 cm above the surface of a 2% calcium chloride solution. The mixture was dropped into the slowly stirred calcium chloride solution at a rate of 20 drops / min. The solution was then slowly stirred for 20 minutes. The mixture was then removed and rinsed with deionized water to obtain spirulina-astaxanthin popping beads with a particle size of 2.0–6.0 mm. The stirring speed was 40 rpm.

[0051] Comparative Example 1:

[0052] The difference from Example 1 is that the spirulina suspension is not modified with chitosan, and the spirulina suspension is directly mixed with the astaxanthin solution.

[0053] Comparative Example 2:

[0054] The difference from Example 1 is that no modified spirulina suspension was added.

[0055] Comparative Example 3:

[0056] The difference from Example 1 is that sodium alginate solution is not added.

[0057] The popping beads prepared in Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 were tested for their breakage rate, pH stability, temperature stability, light stability, and ultraviolet irradiation stability.

[0058] The breakage rate of probiotic popping beads was determined using a texture analyzer. A P50 cylindrical probe was selected, and the speed was set to 1 mm / s and the trigger force to 1.5 N. The breakage rate of 50 probiotic popping beads under the 1.5 N condition was measured, and the breakage rate was calculated. The test was repeated for three groups, and the average value was taken. The test results are shown in Table 1.

[0059] Table 1: Breakage Rate of Bursting Beads

[0060] As shown in Table 1, the breakage rate of the popping beads in the examples was all below 8.8%. The breakage rates of the popping beads in Comparative Examples 1, 2, and 3 were 65.8%, 76.3%, and 101.3% higher than those in Example 1, respectively. It is evident that by modifying chitosan with spirulina, spirulina and chitosan form a spirulina-chitosan complex through electrostatic interaction. Furthermore, the helical structure of spirulina and the linear polysaccharide chains of chitosan can form spatial intercalation, further improving the quality stability of the popping beads. Additionally, chitosan and sodium alginate can form a composite gel through electrostatic interaction, enhancing the mechanical strength of the popping beads and reducing the risk of breakage during transportation or storage.

[0061] The pH stability test method involves immersing the popping beads prepared in Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 in solutions with pH values ​​of 2.0, 6.0, and 10.0, respectively, for 1.0 h. The DPPH free radical scavenging rate of the popping beads is then tested using a UV spectrophotometer.

[0062] The temperature stability test method involves placing the popping beads prepared in Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 at 4, 25, 40, and 60°C for 2 hours, respectively, and then using a UV spectrophotometer to test the DPPH free radical scavenging rate of the popping beads.

[0063] The light stability test method involves placing the popping beads prepared in Examples 1, 2, and 3, and Comparative Examples 1, 2, and 3, under a light intensity of 200 W / m². 2 The DPPH free radical scavenging rate of the popping beads was tested using a UV spectrophotometer after irradiation for 7, 14, 21, and 28 days.

[0064] Ultraviolet irradiation stability test: The popping beads prepared in Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 were placed in an environment with 0.5 W / m 2 The DPPH free radical scavenging rate of the popping beads was tested by irradiating them under a UV lamp for 3, 6, 9, and 12 hours, and then using a UV spectrophotometer.

[0065] DPPH is a stable free radical that appears purple in ethanol solution. The color of the solution changes when DPPH reacts with hydrogen atoms provided by an antioxidant. DPPH ethanol solution has the maximum absorbance at 517 nm. Therefore, the absorbance value at 517 nm is used to measure the ability of an antioxidant to scavenge DPPH free radicals.

[0066] Figure 2 The bar chart shows the effect of soaking popping beads under different pH conditions on DPPH free radical scavenging rate. Figure 2As shown, the free radical scavenging rate of the popping beads was relatively low after soaking at pH 2.0 and 10.0 for 1.0 h, indicating that the popping beads are not tolerant to acidic and alkaline conditions. The free radical scavenging rate was relatively high after soaking at pH 6.0 for 1.0 h. Under the same pH treatment conditions, the free radical scavenging rate of the popping beads in the example was higher than that in the comparative example.

[0067] Figure 3 A bar chart showing the effect of placing popping beads at different temperatures on DPPH free radical scavenging rate, as shown. Figure 3 As shown, after being placed at 4℃ and 25℃ for 2 hours, the DPPH free radical scavenging rate of the popping beads was relatively high, while the higher temperatures of 40℃ and 60℃ had a greater impact on the antioxidant activity of the popping beads.

[0068] Figure 4 A line graph showing the effect of different light exposure times on DPPH free radical scavenging rate, as shown. Figure 4 As shown, the DPPH free radical scavenging rate decreased with the extension of light exposure time. After 14 days of light exposure, the DPPH free radical scavenging rate of the popping beads in the comparative examples decreased significantly. After 21 days of light exposure, the DPPH free radical scavenging rates of the popping beads in Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 decreased by 13.5%, 15.1%, 16.8%, 44.2%, 43.5%, and 46.8%, respectively, compared with the 7th day of light exposure.

[0069] Figure 5 The graph shows the effect of UV irradiation time on DPPH free radical scavenging rate. Figure 5 As shown, the DPPH free radical scavenging rate decreased with the extension of ultraviolet irradiation time. After 9 hours of ultraviolet irradiation, the DPPH free radical scavenging rates of the popping beads in Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 decreased by 24.9%, 25.6%, 24.8%, 49.2%, 52.9%, and 51.6%, respectively, compared with 3 hours of ultraviolet irradiation.

[0070] It is evident that loading astaxanthin onto a spirulina biomatrix and encapsulating it with sodium alginate achieves a double-layer protection for astaxanthin, improving its stability under light, heat, pH, and ultraviolet radiation. Sodium alginate encapsulation technology stably encapsulates astaxanthin and the nutrients of spirulina within a gel membrane, preventing the effects of light, oxygen, temperature, and ultraviolet radiation on its activity and enhancing astaxanthin stability. The polysaccharides and proteins in spirulina provide additional antioxidant protection, improving the stability of astaxanthin popping beads and thus extending their shelf life. Spirulina and chitosan form a spirulina-chitosan complex through electrostatic interactions, and the helical structure of spirulina and the linear polysaccharide chains of chitosan can form spatial intercalation, further enhancing binding stability and reducing damage to spirulina and astaxanthin caused by environmental factors such as light and temperature, maintaining the stability of the active ingredients in spirulina and astaxanthin.

[0071] In summary, the spirulina-astaxanthin popping beads prepared by this invention utilize spirulina bio-matrix to load astaxanthin and are encapsulated with sodium alginate to achieve a double-layer protection of astaxanthin. This improves the light stability, heat stability, pH stability, and ultraviolet radiation stability of astaxanthin. The spirulina-astaxanthin popping beads prepared by this invention can be applied in the fields of food, medicine, and cosmetics, and have high commercial value and market application prospects.

[0072] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A method for preparing Spirulina-Astaxanthin popping beads, characterized in that, The preparation steps include the following: S1. Preparation of modified spirulina suspension: Chitosan solution and spirulina suspension were mixed and stirred at 100-200 rpm for 10-15 min to obtain modified spirulina suspension; S2. Preparation of astaxanthin solution embedded in spirulina: The astaxanthin solution and the modified spirulina suspension were mixed and stirred at 100-200 rpm for 2-8 hours to obtain the astaxanthin solution embedded in spirulina. S3. Preparation of Spirulina-embedded astaxanthin complex particles: The astaxanthin solution embedded in Spirulina was centrifuged at 7000-8000 rpm for 5-6 min, the precipitate was collected, the precipitate was washed with deionized water, centrifuged 3 times, and then freeze-dried to obtain Spirulina-embedded astaxanthin complex particles. S4. Preparation of Spirulina-Astaxanthin-Sodium Alginate Mixture: Spirulina-embedded astaxanthin composite particles were prepared into a Spirulina-Astaxanthin suspension with a mass concentration of 0.1-1% using deionized water; the Spirulina-Astaxanthin suspension and sodium alginate solution were mixed evenly at a mass ratio of 1:4 to obtain the Spirulina-Astaxanthin-Sodium Alginate Mixture. S5. Preparation of Spirulina-Astaxanthin Popping Beads: Using a syringe, draw up a mixture of spirulina-astaxanthin-sodium alginate. Position the syringe needle 5-10 cm above the surface of the calcium chloride solution and drop the mixture into the slowly stirred calcium chloride solution at a rate of 20 drops / min. Then, stir slowly for 15-30 minutes, remove the beads, and rinse with deionized water to obtain spirulina-astaxanthin popping beads with a particle size of 2.0-6.0 mm.

2. The method for preparing Spirulina-Astaxanthin Bursting Beads according to claim 1, characterized in that, The chitosan solution was prepared by dissolving chitosan in a 1.2% acetic acid solution at a mass ratio of 1:10, and then adding deionized water to prepare a chitosan solution with a concentration of 1.5–150 μg / mL.

3. The method for preparing Spirulina-Astaxanthin Bursting Beads according to claim 1, characterized in that, The spirulina suspension was prepared by the following method: fresh spirulina liquid was taken and centrifuged at 7000-8000 rpm for 5-6 minutes. The precipitate was collected, washed with deionized water, and centrifuged 3 times to obtain fresh spirulina. Then, the fresh spirulina was prepared into a spirulina suspension with a concentration of 40-800 μg / mL using deionized water.

4. The method for preparing Spirulina-Astaxanthin Bursting Beads according to claim 1, characterized in that: In S1, the chitosan solution and spirulina suspension are mixed in a mass ratio of 1:8 to 10. In S2, the astaxanthin solution and the modified spirulina suspension are mixed in a mass ratio of 1:9 to 10.

5. The method for preparing Spirulina-Astaxanthin Bursting Beads according to claim 1, characterized in that, The astaxanthin solution was prepared by dissolving astaxanthin in ethanol at a mass ratio of 1:20, and then adding deionized water to prepare an astaxanthin solution with a concentration of 0.2–2 mg / mL.

6. The method for preparing Spirulina-Astaxanthin Bursting Beads according to claim 1, characterized in that, The sodium alginate solution was prepared by the following method: sodium alginate was prepared into a mixture with a mass concentration of 1-2% using deionized water, and then homogenized in a homogenizer at a speed of 1800-2000 rpm for 20-30 min to obtain the sodium alginate solution.

7. The method for preparing Spirulina-Astaxanthin Bursting Beads according to claim 1, characterized in that, The mass concentration of the calcium chloride solution is 1-4%.

8. The method for preparing Spirulina-Astaxanthin Bursting Beads according to claim 1, characterized in that, The slow stirring speed is 30-50 rpm.

9. A type of spirulina-astaxanthin popping bead, characterized in that, It is prepared by the preparation method of any one of claims 1 to 8.

Images