Method for improving emulsification capacity of super-spirulina protein by ultrasonic assistance

Abstract

This invention discloses a method for improving the emulsifying ability of Spirulina macrophylla protein. The method involves mixing Spirulina macrophylla protein with deionized water to form a dispersion, fully hydrating it at 4°C for 12 hours, centrifuging for 30 minutes to remove insoluble matter, and then sonicating to obtain a modified Spirulina macrophylla protein solution. The surface tension of this modified Spirulina macrophylla protein solution decreases to 9.33-10.06 mN / m, and after 6 hours of static storage, the average particle size of the emulsion decreases to 4.21-6.00 μm, demonstrating significantly better emulsifying performance than the unmodified protein. This method for improving the emulsifying ability of Spirulina macrophylla protein effectively enhances its interfacial activity and emulsifying properties, expanding its applicability and making it widely applicable in the food industry and pharmaceutical functionalization fields.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical technology, and specifically relates to a method for improving the emulsifying ability of Spirulina macrophylla protein. Background Technology

[0002] The protein content of *Spirulina maxima* ranges from 60.0% to 71.0%. *Spirulina maxima* protein is a complete protein, containing 7 essential amino acids and 10 non-essential amino acids. Its amino acid composition is highly balanced and conforms to the FAO / WHO model. *Spirulina maxima* protein possesses antioxidant and immune-enhancing biological activities. Furthermore, it exhibits significant anti-inflammatory and antiviral effects. However, during the extraction and processing of *Spirulina maxima* protein, methods such as high-temperature sterilization and acid / alkali treatment can cause protein denaturation, weakening its interfacial activity and reducing its emulsifying ability. This significantly limits its functional applications in the food and pharmaceutical industries.

[0003] Chinese patent application CN200810235769.6 describes a method for improving the properties of wheat germ proteins using ultrasound. This method involves extracting albumin and globulin separately from defatted wheat germ powder, and then treating the wheat germ albumin and globulin solutions with ultrasound. This method can significantly improve the solubility, foaming properties, foaming stability, emulsifying properties, and emulsifying stability of wheat germ albumin and globulin. However, this patent primarily focuses on improving the solubility, foaming properties, and emulsifying ability of wheat germ proteins, and does not directly address improving the emulsifying ability of Spirulina macrophylla protein.

[0004] In addition, some studies have explored the effects of ultrasonic treatment on the interfacial tension and emulsifying properties of wheat germ proteins. These studies found that ultrasonic treatment significantly reduced the interfacial tension of wheat germ proteins and significantly improved their emulsifying activity. This indicates that ultrasonic treatment has a significant impact on the emulsifying properties of proteins, but this study did not specifically target Spirulina macrophylla proteins.

[0005] Therefore, developing a method to improve the emulsifying ability of Spirulina macrophylla protein is of great significance for its application in the food industry and the pharmaceutical field. Summary of the Invention

[0006] This invention aims to provide a method for improving the emulsifying ability of Spirulina macrophylla proteins. This method utilizes ultrasonic treatment to significantly enhance the interfacial activity and emulsifying ability of the proteins.

[0007] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0008] A method for improving the emulsifying ability of Spirulina macrophylla protein includes the following steps:

[0009] a. Mix Spirulina macrophylla protein with deionized water at a ratio of 0.5%, shake on a shaker for 3 hours, and then fully hydrate at 4°C for 12 hours to obtain a Spirulina macrophylla protein solution;

[0010] b. Centrifuge the Spirulina macrophylla protein solution at 4°C for 30 minutes to remove insoluble matter, and obtain a clear Spirulina macrophylla protein solution;

[0011] c. The clarified Spirulina macrophylla protein solution is subjected to ultrasonic treatment for 30-60 minutes to obtain a modified Spirulina macrophylla protein solution.

[0012] Furthermore, the Spirulina macrophylla protein is prepared by repeatedly freezing and thawing Spirulina macrophylla raw material and ultrasonic cell disruption, centrifuging to collect the supernatant, extracting the protein by alkaline dissolution and acid precipitation, dialysis purification to remove small molecule impurities, and finally freeze-drying.

[0013] Furthermore, the freeze-thaw treatment involves freezing at -20°C for 12 hours and then thawing at room temperature, repeating the freeze-thaw process 5 times.

[0014] Furthermore, the ultrasonic cell disruption power is 150W, and the cell disruption is performed in an ice bath for 10 minutes.

[0015] Furthermore, the alkaline dissolution and acid precipitation method specifically involves: adjusting the pH to 3.0 with HCl to precipitate the protein, allowing it to stand overnight at 4°C, centrifuging (6500g) for 30 minutes to collect the precipitate, adjusting the pH to 7.0 with NaOH to reconstitute the protein, centrifuging (6500g) for 30 minutes to collect the supernatant.

[0016] Furthermore, the centrifugal force during the centrifugation operation is 6500g.

[0017] Furthermore, the power of the ultrasonic treatment is 240W.

[0018] Furthermore, the surface tension of the modified Spirulina protein solution decreased to 9.33-10.06 mN / m, and after 6 hours of static storage, the average particle size of the emulsion decreased to 4.21-6.00 μm.

[0019] Furthermore, the feed-to-liquid ratio refers to the ratio of the mass of the Spirulina macrophylla protein raw material to the mass of deionized water.

[0020] The beneficial effects of this invention are as follows: This invention provides a method for improving the emulsifying ability of Spirulina macrophylla protein by treating the protein with ultrasound. Ultrasound generates localized high temperature, high pressure, and strong shear force through cavitation, disrupting the intermolecular interactions of the protein molecules, causing their structure to unfold and exposing more hydrophobic groups and active sites. Simultaneously, ultrasound promotes protein molecule depolymerization, increases surface area, and enhances adsorption and encapsulation capabilities at the lipid interface, thereby improving emulsifying activity and stability. Furthermore, ultrasound is a very common physical processing technique in current food processing research, capable of improving the interfacial activity and functional adaptability of proteins. This method, using ultrasound treatment, significantly improves the interfacial activity and emulsifying ability of the protein. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and examples.

[0022] Figure 1 This is a schematic diagram comparing the surface tension of proteins in a method for improving the emulsifying ability of Spirulina macrophylla protein according to the present invention.

[0023] Figure 2 This is a schematic diagram showing the microscopic characterization of proteins in a method for improving the emulsifying ability of Spirulina macrophylla proteins according to the present invention. Detailed Implementation

[0024] In the following detailed description of the embodiments, several specific details are set forth to provide a more thorough understanding of the invention by those skilled in the art. However, it should be understood by those skilled in the art that the implementation of the invention may not be limited to these specific details. In other instances, well-known technical solutions have not been described in detail to avoid ambiguity regarding the relevant details of the following embodiments.

[0025] Example 1:

[0026] Preparation method of modified Spirulina macrophylla protein:

[0027] a. Mix the Spirulina macrophylla raw material with deionized water at a ratio of 1:10, freeze at -20℃ for 12 hours, thaw at room temperature, repeat the freeze-thaw cycle 5 times, treat with an ultrasonic cell disruptor (150W) in an ice bath for 10 minutes, centrifuge (6500g) to collect the supernatant, then adjust the pH to 3.0 with HCl to precipitate the protein, let stand at 4℃ overnight, centrifuge (6500g) for 30 minutes to collect the precipitate, adjust the pH to 7.0 with NaOH to reconstitute the protein, centrifuge (6500g) for 30 minutes to collect the supernatant, then dialysis to purify and remove small molecule impurities, and finally freeze-dry to obtain Spirulina macrophylla protein;

[0028] b. Mix the Spirulina macrophylla protein with deionized water at a ratio of 0.5%, shake on a shaker for 3 hours, and then fully hydrate at 4°C for 12 hours to obtain a Spirulina macrophylla protein solution.

[0029] c. Centrifuge the Spirulina macrophylla protein solution at 4°C for 30 minutes to remove insoluble matter, and obtain a clear Spirulina macrophylla protein solution;

[0030] d. The clarified Spirulina macrophylla protein solution is subjected to ultrasonic treatment for 30 minutes to obtain a modified Spirulina macrophylla protein solution.

[0031] Example 2:

[0032] The preparation method in this embodiment is the same as in Example 1, but in step d, the Spirulina macrophylla protein is subjected to ultrasonic treatment for 60 minutes.

[0033] The surface tension and emulsification stability of the modified Spirulina macrophylla protein prepared in this invention were determined as follows:

[0034] I. Test Methods and Conditions

[0035] 1. Surface tension test: The surface tension of the composite system was determined using a contact angle meter and the pendant drop method. 40 μL of Spirulina macrophylla protein solution was injected into soybean oil, and the droplet morphology changes were recorded over 30 minutes at 25°C. The surface tension value was calculated using the Young-Laplace equation.

[0036] 2. Emulsion stability test: Spirulina macrophylla protein solution and soybean oil were mixed at a mass ratio of 4:1 and homogenized for 5 minutes using a homogenizer at a speed of 10,000 rpm to prepare an emulsion. The distribution of emulsion droplets was then observed using an inverted microscope (100x) for microscopic characterization.

[0037] II. Test Results

[0038] 1. Test results of Example 1

[0039] (1) Surface tension test results:

[0040] like Figure 1 As shown, the surface tension of the modified Spirulina macrophylla protein (ultrasonicated for 30 minutes) decreased from 10.27 mN / m to 10.06 mN / m, indicating that the modification treatment effectively improved the interfacial activity of the protein.

[0041] (2) Results of emulsification stability test:

[0042] like Figure 2As shown, after 6 hours of static storage, the average particle size of the emulsion decreased to 6.00 μm, indicating that ultrasonic treatment can delay the aggregation process of emulsion droplets and improve the stability of the emulsion, proving the effectiveness of the modification treatment in improving emulsification performance.

[0043] 2. Test Results of Example 2

[0044] (1) Surface tension test results:

[0045] like Figure 1 As shown, the surface tension of the modified Spirulina macrophylla protein (ultrasounded for 60 minutes) decreased from 10.27 mN / m to 9.33 mN / m, which is lower than that of the modified Spirulina macrophylla protein that was sonicated for 30 minutes, indicating that increasing the sonication time can further improve the interfacial activity of the protein.

[0046] (2) Results of emulsification stability test:

[0047] like Figure 2 As shown, after 6 hours of static storage, the average particle size of the emulsion decreased to 4.21 μm, indicating that ultrasonic treatment can delay the aggregation process of emulsion droplets and improve the stability of the emulsion, proving the effectiveness of modification treatment in improving emulsification performance.

[0048] The test results from the examples show that, compared with Spirulina macrophylla protein, the modified Spirulina macrophylla protein exhibits significantly improved interfacial activity and emulsifying ability. This provides important technical support for the application of Spirulina macrophylla protein in the food and pharmaceutical industries.

[0049] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for improving the emulsifying capacity of Spirulina maxima protein, characterized by, Includes the following steps: a. Mix Spirulina macrophylla protein with deionized water at a ratio of 0.5%, shake on a shaker for 3 hours, and then fully hydrate at 4°C for 12 hours to obtain a Spirulina macrophylla protein solution; b. Centrifuge the Spirulina macrophylla protein solution at 4°C for 30 minutes to remove insoluble matter, and obtain a clear Spirulina macrophylla protein solution; c. The clarified Spirulina macrophylla protein solution is subjected to ultrasonic treatment for 30-60 minutes to obtain a modified Spirulina macrophylla protein solution.

2. The method for improving the emulsifying ability of Spirulina macrophylla protein according to claim 1, characterized in that: The Spirulina macrophylla protein is prepared by repeatedly freezing and thawing Spirulina macrophylla raw material and ultrasonic cell disruption, centrifuging to collect the supernatant, extracting the protein by alkaline dissolution and acid precipitation, dialysis purification to remove small molecule impurities, and finally freeze-drying.

3. The method according to claim 2, characterized in that, The freeze-thaw process involves freezing at -20°C for 12 hours, then thawing at room temperature, and repeating this freeze-thaw cycle 5 times.

4. The method according to claim 2, characterized in that, The ultrasonic cell disruption power is 150W, and the cell disruption is performed in an ice bath for 10 minutes.

5. The method according to claim 2, characterized in that, The alkaline dissolution and acid precipitation method is as follows: the pH is adjusted to 3.0 with HCl to precipitate the protein, which is then allowed to stand overnight at 4°C. After centrifugation (6500g) for 30 minutes to collect the precipitate, the pH is adjusted to 7.0 with NaOH to reconstitute the protein. The supernatant is then collected after centrifugation (6500g) for 30 minutes.

6. The method for improving the emulsifying ability of Spirulina macrophylla protein according to claim 1, characterized in that: The centrifugal force during the centrifugation operation is 6500g.

7. The method for improving the emulsifying ability of Spirulina macrophylla protein according to claim 1, characterized in that: The power of the ultrasonic treatment is 240W.

8. The method for improving the emulsifying ability of Spirulina macrophylla protein according to claim 1, characterized in that: The surface tension of the modified Spirulina protein solution decreased to 9.33-10.06 mN / m, and after 6 hours of static storage, the average particle size of the emulsion decreased to 4.21-6.00 μm.

9. The method for improving the emulsifying ability of Spirulina macrophylla protein according to claim 1, characterized in that: The feed-to-liquid ratio refers to the ratio of the mass of Spirulina macrophylla protein raw material to the mass of deionized water.

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