Preparation method of fructus cannabis protein lycopene emulsion and application of fructus cannabis protein lycopene emulsion in food

Abstract

The invention relates to the field of plant protein extraction and functional food processing, and discloses a preparation method of a fructus cannabis protein lycopene emulsion and application of the fructus cannabis protein lycopene emulsion in food, fructus cannabis protein starch emulsion loaded lycopene is constructed, and the preparation method comprises the following steps: S1, preparing a fructus cannabis protein dispersion liquid; s2, preparing a starch dispersion liquid; s3, mixing the fructus cannabis protein dispersion liquid with the starch dispersion liquid to obtain a fructus cannabis protein and starch blend; s4, adding soybean oil into the fructus cannabis protein starch blend, homogenizing by a high-speed shear apparatus, and performing ultrasonic treatment to obtain a fructus cannabis protein starch emulsion; and S5, dissolving lycopene in soybean oil, stirring to obtain a lycopene mixed solution, and uniformly mixing the fructus cannabis protein starch emulsion with the lycopene mixed solution. The fructus cannabis protein starch emulsion disclosed by the invention can load lycopene, and ingredients such as cane sugar and orange-flavor essence are added, so that a lycopene functional beverage which is good in taste and good in stability is prepared.

Description

Technical Field

[0001] The invention relates to the field of plant protein extraction and functional food processing, and in particular to a preparation method of hemp seed protein lycopene emulsion and application thereof in food. Background Art

[0002] As people pay more and more attention to healthy eating, plant protein has gradually gained attention due to its rich nutritional value and sustainability. Hemp seed is the seed part of the hemp crop, which is rich in nutrients, rich in protein, oil, trace elements and antioxidants. Among them, the amino acid composition of hemp seed protein is rich and balanced. It not only contains all the essential amino acids required by the human body, but also has high levels of arginine and cysteine. It also has multiple biological activities such as hypoglycemic and anti-tumor. Therefore, hemp seed protein is regarded as a new high-quality plant protein source with great potential.

[0003] At present, alkali extraction and acid precipitation is a common method for extracting hemp seed protein, but this method has disadvantages such as long extraction time, low extraction efficiency and protein variability. At the same time, the solubility and emulsification properties of hemp seed protein are poor, which limits its full utilization in the food industry. Therefore, we should actively seek suitable extraction methods to overcome the application defects of hemp seed protein, give full play to its nutritional value and functional characteristics, and promote its wide application in the food field. There are few studies on the application of enzyme-assisted traditional alkali extraction and acid precipitation in the extraction of hemp seed protein. This is a potential new strategy for the high-value utilization of hemp seed protein, which is of great significance in meeting consumers' demand for healthy and nutritious food and promoting the development of the hemp seed protein industry.

[0004] Studies have shown that lycopene is easily affected by the intestinal environment during digestion and has poor stability. The use of a suitable delivery system can improve its susceptible and poor stability and increase its health value. Currently, commonly used delivery systems include emulsions, liposomes, nanostructured liposomes, hydrogels, etc. However, they have limitations such as easy flocculation or aggregation of larger particles, easy precipitation, high content of surfactants, high preparation cost and relatively complex production process, uncertain safety issues, limited stability improvement, and little research in the food field.

[0005] Therefore, there is an urgent need to establish a transportation system that can improve the stability of lycopene, reduce the impact during digestion, and is safe and relatively easy to operate. Summary of the invention

[0006] In view of the above-mentioned deficiencies of the existing hemp seed protein extraction technology and application, the present invention provides a method for preparing a hemp seed protein lycopene emulsion and its application in food. The method optimizes the enzymatic hydrolysis conditions to improve the protein extraction rate, while improving its solubility and interface properties, and further improves the stability of the protein emulsion by adding starch. A hemp seed protein starch emulsion is constructed to load lycopene, and ingredients such as sucrose and orange flavor are added to prepare a lycopene functional beverage with good taste and good stability.

[0007] On the one hand, the present invention discloses the application of hemp seed protein in a lycopene delivery system, wherein starch is added to the hemp seed protein to further improve the stability of the protein emulsion, and the constructed hemp seed protein starch emulsion has the ability to load lycopene and has good stability. The method comprises the following steps:

[0008] S1: preparing hemp seed protein into a hemp seed protein dispersion;

[0009] S2: preparing starch dispersion;

[0010] S3: mixing the hemp seed protein dispersion with the starch dispersion to prepare a hemp seed protein / starch blend, and storing the blend at 4° C. overnight;

[0011] S4: adding soybean oil to the hemp seed protein starch blend, homogenizing and then ultrasonically treating to obtain a hemp seed protein starch emulsion;

[0012] S5: Add lycopene to soybean oil, stir at room temperature in the dark to obtain a lycopene mixed solution, and mix the hemp seed protein starch emulsion with the lycopene mixed solution to obtain the hemp seed protein lycopene emulsion.

[0013] Preferably, the hemp seed protein in step S1 is 0.4 g, dispersed in 10 mL of ultrapure water;

[0014] Preferably, after the hemp seed protein is dispersed in ultrapure water in step S1, the pH is adjusted to 7.5-11.5, magnetic stirring is performed for 1.5 hours, and then ultrasonication is performed for 6 minutes (amplitude 30%), and then the pH is adjusted to 7.0;

[0015] Specifically, 1 mol / L NaOH was used to adjust the pH to 7.5-11.5, and 1 mol / L HCl was used to adjust the pH to 7.0;

[0016] Preferably, the starch in step S2 is 0.4 g, dispersed in 10 mL of ultrapure water;

[0017] Preferably, the starch described in step S2 is hydroxypropyl distarch phosphate;

[0018] Preferably, in step S2, the starch is dispersed in ultrapure water, heated to 90° C., magnetically stirred for 0.5 h, and cooled to 50° C.;

[0019] Preferably, the high-speed shear homogenization in step S4 is carried out at 10,000 to 20,000 rpm for 1 to 5 min, and the resulting crude emulsion is ultrasonically treated for 10 min (amplitude 20% to 70%).

[0020] Preferably, the concentration of the lycopene mixed solution is 1 mg / mL; and the stirring time is 3 to 3.5 hours.

[0021] Adding starch can further improve the stability of the protein emulsion, reduce oil droplet agglomeration, and improve the storage stability of the emulsion; the lycopene retention rate of the hemp seed protein starch emulsion loaded with lycopene can reach 55% after 30 days of storage, and the lycopene retention rate exceeds 70% after heating at 60-90°C for 20 minutes, and the light stability is also improved.

[0022] On the other hand, the present invention provides a method for extracting hemp seed protein by alkaline protease-assisted alkali extraction and acid precipitation, which optimizes the enzymatic hydrolysis conditions and improves the protein extraction rate. The method comprises the following steps:

[0023] (1) dissolving the defatted hemp seed powder in an alkaline solution to obtain an alkali-soluble defatted hemp seed powder;

[0024] (2) adding alkaline protease to the alkali-soluble defatted hemp seed powder for enzymolysis to extract hemp seed protein;

[0025] (3) freeze-drying the hemp seed protein to obtain hemp seed protein powder.

[0026] Preferably, the defatted hemp seed powder in step (1) is dissolved in an alkaline solution having a pH of 7.5 to 11.5;

[0027] Preferably, in step (2), the amount of alkaline protease added is 4775.3 U / g, the enzyme activity is 1000-8000 U / g, and the weight ratio of the alkali-soluble defatted hemp seed powder to the alkaline protease is 1000:5-40;

[0028] Preferably, the enzymatic hydrolysis time in step (2) is 30 to 150 min;

[0029] Preferably, in step (2), the pH is adjusted to the isoelectric point (4.5-5.0) to perform acid precipitation, and the protein precipitate is collected by centrifugation;

[0030] Furthermore, the extraction method of the present application combines "alkaline solution dissolution" and "alkaline protease" to achieve better results, which is significantly higher than enzymatic hydrolysis using only one method.

[0031] The hemp seed protein extraction rate obtained by this method reaches 81.3%, which is significantly higher than the traditional alkali extraction and acid precipitation method. The solubility, emulsification and foam stability of the obtained protein are improved; the appropriate amount of enzymatic hydrolysis can reduce the protein particle size, increase its surface charge, and make it more stable in the solution; moderate hydrolysis can increase the water holding capacity (6.75g / g) and oil holding capacity (2.15g / g) of the protein, which is expected to enhance its application performance in the food system.

[0032] Enzyme hydrolysis technology has been applied in the extraction and modification of various proteins due to its mild, efficient and safe advantages. It not only improves the extraction efficiency, but also further improves the functional properties of proteins. Application defects such as poor solubility of hemp seed protein can be improved by enzyme modification technology.

[0033] In another aspect, the hemp seed protein starch emulsion of the present invention is loaded with lycopene, and ingredients such as sucrose and orange flavor are added to prepare a lycopene functional beverage with good taste and good stability. The steps include:

[0034] 1) Add lycopene emulsion to citric acid buffer (0.1 mol / L), add sucrose, orange flavor and 0.04% xanthan gum to prepare a beverage;

[0035] 2) The prepared beverage is homogenized for 3 minutes under a certain homogenization pressure and filled into dry and sterile glass bottles;

[0036] 3) Sterilize in water bath, cool and finish.

[0037] Preferably, the amount of lycopene emulsion added in step 1) is 5% of the total volume;

[0038] Preferably, the amount of sucrose added in step 1) is 9% of the total volume;

[0039] Preferably, the amount of orange flavor added in step 1) is 0.2% of the total volume;

[0040] Preferably, the homogenization pressure in step 2) is 20-30 MPa;

[0041] Preferably, the water bath sterilization temperature in step 3) is 85° C. and the sterilization time is 30 min.

[0042] The hemp seed protein / starch loaded lycopene emulsion system was successfully used in the development of lycopene beverages. 5% (v / v) lycopene emulsion was mixed with 9% sucrose and 0.20% orange flavor to produce a better taste; under the homogenization pressure of 20-30MPa, the beverage has good stability and can be stored for a long time below 40°C.

[0043] The beneficial effects of this application are:

[0044] 1. Efficient extraction: Enzyme-assisted alkaline extraction and acid precipitation are used to improve protein extraction rate while avoiding protein denaturation.

[0045] 2. Improvement of functional properties: Improve the solubility, emulsification, water retention and oil retention of protein through enzyme modification.

[0046] 3. Food application expansion: Hemp seed protein can be used as an emulsifier stabilizer in lycopene emulsions and beverages to improve the nutritional value and processing stability of food.

[0047] 4. Sustainability: This application adopts a green enzymatic hydrolysis process to reduce the use of chemical reagents and achieve high-value utilization of protein, which meets the sustainable development needs of the food industry.

[0048] 5. Improve the stability of lycopene: This application constructs a hemp seed protein starch emulsion to load lycopene, thereby improving the stability of lycopene. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The extraction rate of hemp seed protein is the same as that of comparative example 1, comparative example 2 and embodiment 1;

[0050] Figure 2 The particle size and Zeta potential of the hemp seed protein starch emulsion in Example 2; (A is the particle size of the hemp seed protein starch emulsion with different starch ratios; B is the Zeta potential of the hemp seed protein starch emulsion with different starch ratios)

[0051] Figure 3 The microscopic morphology of the hemp seed protein starch emulsion of Example 2; (magnified 400 times under an optical microscope to observe the microscopic morphology of each emulsion of EHSP, EHSP / 50S, EHSP / 100S, and EHSP / 150S)

[0052] Figure 4 The stability of the hemp seed protein / starch stabilized lycopene emulsion of Example 3 during 30 days of storage; (A is the appearance of the hemp seed protein / starch stabilized lycopene emulsion during 30 days of storage; B is the particle size of the hemp seed protein / starch stabilized lycopene emulsion during 30 days of storage; C is the lycopene retention rate of the hemp seed protein / starch stabilized lycopene emulsion during 30 days of storage)

[0053] Figure 5 The thermal stability of the hemp seed protein / starch stabilized lycopene emulsion of Example 3;

[0054] Figure 6 The light stability of the hemp seed protein / starch stabilized lycopene emulsion of Example 3;

[0055] Figure 7The release rate (A) and bioaccessibility of free fatty acids (FFA) during the digestion process of hemp seed protein / starch stabilization in Example 3; [A is the release rate of free fatty acids (FFA) of hemp seed protein / starch stabilization lycopene emulsion during digestion; B is the bioaccessibility of free fatty acids of hemp seed protein / starch stabilization lycopene emulsion during digestion] DETAILED DESCRIPTION

[0056] The technical solution of the present application is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present application is not limited to the following.

[0057] Example 1

[0058] The specific steps of preparing a hemp seed protein are as follows:

[0059] Take defatted hemp seed powder as substrate, add 200mL of deionized water, make substrate concentration 5.31%, adjust pH to 9.48 with 1mol / L NaOH, add 4775.3U / g of enzyme, stir and extract for 87.5min at 45℃, centrifuge for 10min at 4000r / min, retain precipitate and supernatant. Take supernatant and adjust pH to 5.0 with 1mol / L HCl, let stand to make precipitation sufficient, centrifuge (4000r / min, 10min) and retain precipitation. Take precipitate for secondary extraction. Add deionized water (1:20, w / w) to the precipitate, repeat the above steps to extract and collect precipitate. Mix the obtained precipitate, add deionized water, adjust pH to 7.0, freeze-dry to obtain hemp seed protein powder, and the extraction rate is 81.3%.

[0060] Example 2

[0061] The particle size, Zeta potential and microscopic morphology of the hemp seed protein starch emulsion are as follows:

[0062] Take 0.4g alkaline enzyme assisted alkaline extraction of hemp seed protein 1EHSP (enzyme dosage is 4000U / g) and disperse it in 10mL ultrapure water, use 1mol / L NaOH to adjust pH to 10.0, magnetic stirring 1.5h after ultrasonic 6min (amplitude 30%) to fully unfold its structure. Subsequently, the pH of the solution is adjusted to 7.0 with 1mol / L HCl to obtain hemp seed protein dispersion. Then, 0.1, 0.2, 0.4 and 0.6g starch are dispersed in 10mL ultrapure water and heated to 90℃ magnetic stirring for 0.5h, cooled to 50℃, and then mixed with the above-mentioned hemp seed protein dispersion respectively, and stored overnight at 4℃ to ensure hydration. The ratio of starch in the blend is 25%, 50%, 100% and 150% (starch: protein, w / w) respectively.

[0063] 8mL soybean oil was added to the above-mentioned hemp seed protein / starch blend (20mL), homogenized with a high-speed shearing instrument (15000rpm, 2min), and the resulting crude emulsion was ultrasonically treated for 10min (amplitude 30%) to obtain freshly prepared hemp seed protein / starch emulsion system, which was named 1EHSP / 25S, 1EHSP / 50S, 1EHSP / 100S and 1EHSP / 150S according to the starch ratio of 25%, 50%, 100% and 150%, respectively. The hemp seed protein emulsion system without starch was used as the control group, i.e. 1EHSP.

[0064] By measuring the particle size and Zeta potential of hemp seed protein starch emulsions with different starch ratios, the stability of the emulsion is related to the particle size and Zeta potential. Usually, when the particle size is small, the emulsion is more stable, such as Figure 2 As shown in (A), the particle size of 1EHSP / 25S is the smallest, the particle size of 1EHSP / 50S and 1EHSP / 100S is similar to that of the control 1EHSP, and the particle size of 1EHSP / 150S is larger. It is speculated that the emulsions of 1EHSP / 50S and 1EHSP / 100S are more stable. The absolute value of Zeta potential increases with the increase of starch solution concentration. The larger the absolute value of Zeta potential, the stronger the electrostatic repulsion between particles and the more stable the emulsion. Figure 3 The microscopic morphology of hemp seed protein starch emulsions with different starch ratios was analyzed. From the perspective of particle size, EHSP particles were the largest, and 1EHSP / 100S particles were smaller; from the results of uniform distribution, the particle sizes of 1EHSP / 50S and 1EHSP / 150S were quite different, and there may be aggregation or separation phenomena, and the emulsion structure was unstable, while the particle sizes of 1EHSP / 100S were relatively close, and the distribution was uniform, and the solution was relatively stable; from the aggregation phenomenon, EHSP and 1EHSP / 150S aggregated into larger clusters, which may have poor stability, while 1EHSP / 100S particles were well dispersed, indicating that the emulsion stability was better.

[0065] Example 3

[0066] The stability test steps and results of the hemp seed protein starch stabilized lycopene emulsion are as follows:

[0067] Lycopene was dissolved in soybean oil (1 mg / mL), and stirred for 3 hours at room temperature (25°C) in the dark to make it evenly dispersed as the oil phase. Hemp seed protein / starch blends with different starch ratios were used as the water phase. The water phase and the oil phase were mixed and evenly mixed as above. According to the starch ratio of 25%, 50%, 100% and 150%, the above hemp seed protein / starch stabilized lycopene emulsions were named 1EHSP / 25S-L, 1EHSP / 50S-L, 1EHSP / 100S-L and 1EHSP / 150S-L, respectively, and the hemp seed protein emulsion system without starch was used as the control group, namely EHSP-L.

[0068] Depend on Figure 4 As shown in A, the appearance of the hemp seed protein starch stabilized lycopene emulsion stored for 30 days showed that at 0 day, there was no significant difference among the three groups, and no obvious stratification occurred; at 5 days, 1EHSP / 50S-L showed slight stratification, while the other treatments showed no stratification; at 10 days, 1EHSP / 50S-L had precipitated and obvious stratification occurred, and at 15-30 days, 1EHSP / 50S-L showed obvious stratification, 1EHSP / 100S-L had slight stratification, and 1EHSP / 150S-L showed no obvious stratification. During the storage period, 1EHSP / 100S-L and 1EHSP / 150S-L were relatively stable.

[0069] Depend on Figure 4 As shown in Figure B, the particle size changes of hemp seed protein starch stabilized lycopene emulsions stored for 30 days. The particle sizes of the three treatments showed an upward trend with the increase of storage days. The larger the particle size, the lower the stability. At all storage periods, the particle size of 1EHSP / 50S-L was significantly larger than that of 1EHSP / 100S-L and 1EHSP / 150S-L in the same time period. At all storage periods, 1EHSP / 100S-L was larger than 1EHSP / 150S-L, but the difference between 1EHSP / 100S-L and 1EHSP / 150S-L was small.

[0070] Figure 4 As shown in Figure C, the retention rate of lycopene stabilized by hemp seed protein starch after storage for 30 days shows a decreasing trend with increasing storage time. At 5 days, the retention rate of 1EHSP / 100S-L was the highest, and the retention rate of 1EHSP / 50S-L was the lowest. During the storage process of 10 to 30 days, the retention rates of lycopene of 1EHSP / 150S-L and 1EHSP / 100S-L were significantly higher than those of 1EHSP / 50S-L, indicating that 1EHSP / 150S-L and 1EHSP / 100S-L have good protection effects on lycopene, the emulsion is highly stable, and lycopene is not easily degraded.

[0071] like Figure 5As shown in the figure, the retention rate of lycopene in hemp seed protein / starch stabilized lycopene emulsion at different temperatures, at 60℃, the retention rate of each treatment is relatively high, but at 70℃~90℃, the retention rate of 1EHSP / 100S-L is the highest, indicating that 1EHSP / 100S-L has the ability to protect lycopene at high temperatures, and 1EHSP / 100S-L loaded lycopene has good thermal stability.

[0072] like Figure 6 As shown in the figure, the retention rate of lycopene under different ultraviolet irradiation, there was no significant difference in the retention rate among the treatments when the ultraviolet irradiation was 8-12 hours, and the retention rate of 1EHSP / 150S-L and 1EHSP / 100S-L was higher when the light was irradiated for 24-36 hours, indicating that they have a strong light protection effect on lycopene.

[0073] like Figure 7 As shown in (A), the FFA release rate of 1EHSP / 50S-L began to increase first, and the peak order of release efficiency was 1EHSP / 150S-L>1EHSP / 100S-L>1EHSP / 50S-L. The addition of different amounts of starch improved the emulsion structure to varying degrees and promoted lipid hydrolysis.

[0074] like Figure 7 As shown in (B), the conversion stability of 1EHSP / 150S-L and 1EHSP / 100S-L is relatively high, significantly higher than that of 1EHSP / 50S-L; the bioaccessibility of 1EHSP / 150S-L and 1EHSP / 100S-L is also relatively high, significantly higher than that of 1EHSP / 50S-L, indicating that 1EHSP / 150S-L and 1EHSP / 100S-L may have the potential to be easily absorbed.

[0075] Example 4

[0076] Application of hemp seed protein lycopene emulsion in food:

[0077] 5% (v / v) lycopene emulsion was added to a citric acid buffer (0.1 mol / L) at pH = 4.0, and 9% sucrose, 0.2% orange flavor and 0.04% xanthan gum were added, homogenized at a homogenization pressure of 30 MPa for 3 minutes, filled into dry sterile glass bottles, and then sterilized in a water bath at 85°C for 30 minutes, and finally cooled. The sensory score was 85 points, and there was no color change or oil ring floating after storage at 30°C, maintaining good stability.

[0078] Comparative Example 1

[0079] A hemp seed protein was prepared, and the specific steps were as in Example 1, except that only alkaline solution was used for dissolution, and alkaline protein was not used for extraction, as follows:

[0080] Take 10g of defatted hemp seed powder, add 200mL of deionized water, adjust the pH to 9.48 with 1mol / L NaOH, stir and extract for 87.5min at 45°C, centrifuge at 4000r / min for 10min, and retain the precipitate and supernatant. Take the supernatant and adjust the pH to 5.0 with 1mol / L HCl, let it stand to precipitate fully, centrifuge (4000r / min, 10min) and retain the precipitate. Take the precipitate for secondary extraction. Add deionized water (1:20, w / w) to the precipitate, repeat the above steps to extract and collect the precipitate. Mix the obtained precipitates, add deionized water, adjust the pH to 7.0, and freeze-dry to obtain hemp seed protein powder. The hemp seed protein extraction rate obtained under this condition is 57.5%.

[0081] Comparative Example 2

[0082] A hemp seed protein is prepared, and the specific steps are as in Example 1, except that only alkaline protease is used for extraction, and no alkaline solution is used for dissolution, as follows:

[0083] Take 10g of defatted hemp seed powder, add 200mL of deionized water, add 4775.3U / g of alkaline protease, stir and extract at 45°C for 87.5min, centrifuge at 4000r / min for 10min, and retain the precipitate and supernatant. Take the supernatant and adjust the pH to 5.0 with 1mol / L HCl, let it stand to make the precipitation sufficient, centrifuge (4000r / min, 10min) and retain the precipitate. Take the precipitate for secondary extraction. Add deionized water (1:20, w / w) to the precipitate, repeat the above steps to extract and collect the precipitate. Mix the obtained precipitates, add deionized water, adjust the pH to 7.0, and freeze-dry to obtain hemp seed protein powder. The hemp seed protein extraction rate obtained under this condition is 60.1%.

[0084] Comparative Example 1 was dissolved in an alkaline solution, and alkaline protease was not used for auxiliary extraction, and its extraction rate did not reach 60%. Comparative Example 2 was not dissolved in an alkaline solution, and only alkaline protease was used for auxiliary extraction, and its extraction rate was 60.1%. The result of Example 1 was compared with Comparative Examples 1 and 2, and the extraction efficiency of hemp seed protein was significantly improved, indicating that the present application utilizes alkaline solution dissolution, and the extraction of hemp seed protein by alkaline protease-assisted alkali extraction and acid precipitation method can significantly improve the extraction rate of hemp seed protein.

[0085] The above is only a preferred embodiment of the present application. It should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge in the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present application, and shall be within the scope of protection of the claims attached to the present application.

Claims

1. A method for preparing hemp seed protein lycopene emulsion, characterized in that: The preparation steps include: S1: preparing hemp seed protein dispersion; S2: preparing starch dispersion; S3: mixing the hemp seed protein dispersion and the starch dispersion and letting them stand to obtain a hemp seed protein starch blend; S4: adding soybean oil to the hemp seed protein starch blend, homogenizing and then ultrasonically treating to obtain a hemp seed protein starch emulsion; S5: taking soybean oil and adding lycopene, stirring at room temperature to obtain a lycopene mixed solution, and mixing the hemp seed protein starch emulsion and the lycopene mixed solution to obtain the hemp seed protein lycopene emulsion.

2. The preparation method according to claim 1, characterized in that: In S1, the step of preparing the hemp seed protein dispersion includes: adding the hemp seed protein to ultrapure water, adjusting the pH to 7.5-11.5, magnetically stirring and then ultrasonicating, adjusting the pH to 7.0, to obtain the hemp seed protein dispersion.

3. The preparation method according to claim 1, characterized in that: The step of preparing the starch dispersion in S2 includes: adding starch into ultrapure water, heating to 90° C., magnetically stirring and then cooling.

4. The preparation method according to claim 1, characterized in that: In S3, the mass ratio of the hemp seed protein dispersion to the starch dispersion is 1:0.25-1.5; And / or, the standing temperature is 4° C., and the standing time is 8 to 12 hours.

5. The preparation method according to claim 1, characterized in that: In S4, the volume ratio of the soybean oil to the hemp seed protein is 1-4:6-9, the high-speed shearing instrument homogenization speed is 10000-20000 rpm for 1-5 min, and the ultrasonic treatment amplitude is 20%-70%.

6. The preparation method according to claim 1, characterized in that: In S5, the concentration of the lycopene mixed solution is 1 mg / mL; and the stirring time is 3 hours.

7. The preparation method according to claim 1, characterized in that: The preparation method of the hemp seed protein comprises the following steps: (1) dissolving the defatted hemp seed powder in an alkaline solution to obtain an alkali-soluble defatted hemp seed powder; (2) adding alkaline protease to the alkali-soluble defatted hemp seed powder for enzymolysis to extract hemp seed protein; (3) freeze-drying the hemp seed protein to obtain hemp seed protein powder.

8. The preparation method according to claim 7, characterized in that: The pH of the alkaline solution in step (1) is 7.5-11.5; and / or the weight ratio of the alkali-soluble defatted hemp seed powder to the alkaline protease in step (2) is 1000:5-40; And / or, the activity of the alkaline protease is 1000-8000 U / g; And / or, the temperature of the enzymatic hydrolysis is 20°C to 60°C, and the time of the enzymatic hydrolysis is 30 to 150 minutes.

9. The hemp seed protein lycopene emulsion obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the hemp seed protein lycopene emulsion obtained by the preparation method according to any one of claims 1 to 8 or the hemp seed protein lycopene emulsion according to claim 9 as a food additive, characterized in that: The food additives include beverage additives.

Images