Preparation method and application of rosemary extract

Abstract

The invention discloses a preparation method of a rosemary extract. The preparation method comprises the following steps: S1, extracting and separating rosemary essential oil; s2, obtaining carnosic acid; s3, obtaining a rosemary water-soluble component; s4, carnosic acid is prepared into an oil phase; s5, preparing the rosemary water-soluble components into a water phase; s6, obtaining a single-coated nano emulsion; and S7, coating the emulsion for the second time. According to the invention, rosemary components are respectively extracted in an oil-soluble manner and a water-soluble manner and are cooperatively used during use, so that the antioxidant effect of the rosemary extract is improved, the stability during storage and use is relatively high, the single-coated nano-emulsion is prepared by adopting a high-pressure microjet method, a finer and more stable coating effect can be realized, and the anti-oxidation effect of the rosemary extract is improved. The high-temperature and low-temperature storage stability of the product is improved. After secondary coating, the stability and functionality of the product can be further improved, and the product can be dissolved and used in most skin care products and is wide in application range.

Description

Technical Field

[0001] The present invention relates to the field of grooming products, and particularly to a preparation method and application of rosemary extract. Background Art

[0002] People's skin condition is getting worse and worse. Using daily chemical products to block ultraviolet damage and delay skin aging is a common skin care method in modern society. Rosemary contains components with antioxidant and antibacterial effects and is a natural plant antibacterial agent. However, the components of rosemary are complex, the extraction is difficult, and the polysaccharide components in the extract are prone to moisture absorption and decomposition, and carnosic acid has a special smell. Therefore, rosemary extract cannot be directly applied to daily chemical products. Therefore, it is crucial to develop a rosemary extract suitable for daily chemical products.

[0003] Chinese invention patent CN102697692B discloses a rosemary extract, its preparation method and application. Using a Soxhlet extractor for extraction, an extract with an extraction rate of 11.2% can be obtained, which has sunscreen and anti-free radical repair effects. However, the special smell of the extract is not treated and the application range is not wide. Chinese invention patent application CN119385895A discloses a preparation method, product and application of an antioxidant repair rosemary extract. Using extraction solvent A and extraction solvent B, and the combined use of ethyl acetate and acetone in extraction solvent B can significantly improve the extraction rates of rosmarinic acid, carnosic acid and rosmaridiphenol in rosemary, and has significant effects in antioxidant, soothing and repairing the skin. However, the extraction rate is not high and the antioxidant effect of the extract decreases during actual application. Summary of the Invention

[0004] In order to develop a rosemary extract suitable for daily chemical products, the first aspect of the present invention provides a preparation method of rosemary extract, including the following steps:

[0005] S1 Using dried rosemary leaves as raw materials, extracting and separating rosemary essential oil;

[0006] S2 Extracting the dried rosemary leaves from which rosemary essential oil has been separated, then performing a separation process, and then rectifying to obtain carnosic acid;

[0007] S3 Continuing to extract the dried rosemary leaves from which carnosic acid has been separated to obtain water-soluble components of rosemary;

[0008] S4 Preparing carnosic acid into an oil phase;

[0009] S5 Preparing the water-soluble components of rosemary into an aqueous phase;

[0010] S6 mixes the oil phase and the water phase, and obtains a coarse emulsion through dispersion emulsification. The coarse emulsion is homogenized by dynamic high-pressure microfluidics to obtain a single-coated nanoemulsion, which is cooled and reserved for later use;

[0011] S7 uses the single-coated nanoemulsion as the core material and the biocompatible powder as the wall material to obtain a secondary-coated emulsion of rosemary extract through dispersion emulsification.

[0012] As an implementation method, the rosemary dry leaves from which rosemary essential oil is separated by supercritical CO2 extraction and separation in step S1; the specific extraction method is to first perform static extraction and then dynamic extraction.

[0013] As an implementation method, the specific steps of step S1 are as follows: using rosemary dry leaves as raw materials, after crushing and sieving, they are loaded into the extraction kettle, supercritical CO2 is introduced to maintain a pressure of 4-6 MPa for static extraction for 0.5-1 h, then the pressure of the extraction kettle is adjusted to 15-18 MPa, the temperature is 40-50 °C, and continuous cyclic extraction is carried out for 2-4 h, and the pressure is controlled at 4-6 MPa and the temperature is 30-50 °C to separate rosemary essential oil.

[0014] As an implementation method, the particle size of the crushed and sieved material is 60-80 mesh.

[0015] As an implementation method, the rosemary dry leaves from which rosemary essential oil is separated in step S2 are first added with alcohol and CO2 is introduced for static extraction, then supercritical CO2 dynamic extraction is used, and then transferred to the separation process.

[0016] As an implementation method, the addition amount of alcohol in step S2 is 0.3-0.4 times the mass of rosemary dry leaves, and the mass concentration of alcohol is 20-30 wt%.

[0017] As an implementation method, the specific steps of step S2 are as follows: alcohol is first added to the rosemary dry leaves from which rosemary essential oil is separated, sealed and soaked for 1-3 h, then loaded into the extraction kettle, CO2 is introduced to maintain a pressure of 8-12 MPa for static extraction for 1-2 h, then the pressure is adjusted to 22-50 MPa and the temperature is adjusted to 40-70 °C, supercritical CO2 is introduced for continuous cyclic extraction for 2-4 h, a entrainer with a concentration of 50-60 wt% is added during the continuous cyclic extraction process, the addition amount each time is 0.2-0.3 times the mass of rosemary dry leaves, and the addition frequency is once per hour, and then transferred to the separation process.

[0018] Continuous cyclic extraction removes the volatile by-products in the rosemary dry leaves from which rosemary essential oil is separated, and improves the purity and stability of the extract.

[0019] As an implementation manner, the separation process in the step S2 includes a first separation and a second separation. The pressure of the first separation is 8 - 15 MPa, the temperature is 35 - 55 °C, the pressure of the second separation is 4 - 6 MPa, and the temperature is 30 - 40 °C.

[0020] As an implementation manner, the pressure of the rectification in the step S2 is 4 - 15 MPa, and the temperature is 30 - 50 °C.

[0021] As an implementation manner, in the step S3, the dry rosemary leaves are continuously extracted with pure water, and the addition amount of the pure water is 2 - 8 times the mass of the dry rosemary leaves.

[0022] As an implementation manner, the specific steps of the step S3 are as follows: The dry rosemary leaves from which carnosic acid has been separated are added to pure water and soaked for 1 - 3 h, then extracted. The extraction temperature is 60 - 70 °C. After continuous extraction for 4 - 8 h, the aqueous solution is collected, filtered and centrifuged. The centrifugate is concentrated, allowed to stand, and then centrifuged. The precipitate is placed in an oven at 60 °C for drying to obtain water-soluble components such as rosemary polysaccharides and polyphenols.

[0023] As an implementation manner, the oil phase in the step S4 includes, by weight, 30 - 40 parts of carnosic acid, 60 - 70 parts of vegetable oil, 10 - 20 parts of surfactant, and 10 - 20 parts of polyol.

[0024] As an implementation manner, the vegetable oil includes but is not limited to at least one of soybean oil, peanut oil, camellia oil, and olive oil.

[0025] As an implementation manner, the surfactant is a non-ionic surfactant, and the non-ionic surfactant is selected from at least one of Tween and Span.

[0026] As an implementation manner, the polyol includes but is not limited to at least one of propylene glycol, ethylene glycol, and hexylene glycol.

[0027] As an implementation manner, the preparation method of the oil phase is as follows: Dissolve carnosic acid in alcohol, heat to 40 - 60 °C and stir until dissolved, then add vegetable oil. After mixing evenly, heat up to evaporate the alcohol, filter, and take the filtrate and mix it with the surfactant and polyol and stir evenly to obtain the oil phase.

[0028] As an implementation manner, the specific steps of the step S5 are: Dissolve the water-soluble components of rosemary in water, heat and stir until completely dissolved, filter, and take the filtrate as the aqueous phase.

[0029] As an implementation manner, the specific steps of the step S5 are: Dissolve 35 parts by weight of the water-soluble components of rosemary in 65 parts by weight of water, heat to 50 - 70 °C and stir until completely dissolved, filter, and take the filtrate as the aqueous phase.

[0030] As an implementation manner, the weight ratio of the aqueous phase to the oil phase is (10 - 20):(80 - 90).

[0031] As an implementation manner, the weight ratio of the aqueous phase to the oil phase is 15:85.

[0032] As an implementation manner, in step S6, the dispersion frequency is 15000 - 25000 r / min, and the dispersion time is 1 - 5 min; the homogenization pressure of the dynamic high-pressure microfluidizer is 50 - 70 MPa, and the homogenization is performed for 1 - 5 cycles.

[0033] As an implementation manner, in step S6, the dispersion frequency is 20000 r / min, and the dispersion time is 4 min; the homogenization pressure of the dynamic high-pressure microfluidizer is 60 MPa, and the homogenization is performed for 4 cycles.

[0034] As an implementation manner, in step S7, the weight ratio of the core material to the wall material is (5 - 15):1; in step S7, the dispersion frequency is 15000 - 25000 r / min, the dispersion time is 1 - 5 min, and the emulsification temperature is 40 - 60 °C.

[0035] As an implementation manner, in step S7, the weight ratio of the core material to the wall material is 10:1; in step S7, the dispersion frequency is 20000 r / min, the dispersion time is 4 min, and the emulsification temperature is 50 °C.

[0036] As an implementation manner, the biocompatible powder includes at least one of porous starch, β-cyclodextrin, cellulose, collagen, and chitosan.

[0037] As an implementation manner, the biocompatible powder is a combination of porous starch and β-cyclodextrin, and the weight ratio of the porous starch to the β-cyclodextrin is (0.1 - 1):(0.1 - 1); as an implementation manner, the weight ratio of the porous starch to the β-cyclodextrin is 1:1.

[0038] The inventor found during the experiment that the rosemary extract extracted from rosemary has excellent antioxidant effects. However, after being applied to actual products, the antioxidant effects decreased to a certain extent. The inventor can greatly improve the problem of the decrease in the antioxidant activity of the rosemary extract during actual application by double coating the extracted rosemary extract. It is speculated that the possible reason is that the single-coated nanoemulsion is obtained by co-emulsifying and homogenizing the extracted rosemary oil extract and water extract. The oil phase and water phase components both come from rosemary, and the stability between them is high. When applied, the oil phase components and water phase components coordinate with each other, improving the use stability of the rosemary extract.

[0039] The inventors further found that the single-coated emulsion prepared by high-pressure microfluidization homogenization can be further secondarily coated with starch and cyclodextrin to improve the stability of rosemary extract in actual application products. The reason may be that the water-in-oil rosemary extract emulsion has poor stability in aqueous-phase products. By performing secondary coating, the water solubility of the emulsion can be increased, the application in water-soluble skin care products can be expanded, and the skin feel is fresh and non-greasy.

[0040] Moreover, the emulsion after secondary coating can further reduce the oxidation of the oil-phase components of rosemary extract, thereby improving the antioxidant effect of rosemary extract. When applied to aqueous-phase skin care products, the antioxidant effect is obvious.

[0041] The second aspect of the present invention provides an application of a preparation method of rosemary extract, which is used for preparing rosemary extract, and the prepared rosemary extract is applied to daily chemical products.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) In the preparation method of the rosemary extract of the present invention, the components of rosemary are extracted separately by oil-soluble and water-soluble methods, and are used in a synergistic manner during use, which improves the antioxidant effect of the rosemary extract, and has high stability during storage and use.

[0044] (2) In the preparation method of the rosemary extract of the present invention, a single-coated nanoemulsion is prepared by a high-pressure microfluidization method, which can achieve a finer and more stable encapsulation effect and improve the high and low temperature storage stability of the product.

[0045] (3) In the preparation method of the rosemary extract of the present invention, the once-coated nanoemulsion is secondarily coated, which can further improve the stability and functionality of the product, and enable the product to be dissolved and used in most skin care products, with a wide range of applications.

[0046] (4) In the preparation method of the rosemary extract of the present invention, the volatile by-products are dynamically extracted from the dried rosemary leaves from which rosemary essential oil has been separated, and then through two consecutive separation processes and rectification, the purity of the rosemary extract is improved.

[0047] (5) In the preparation method of the rosemary extract of the present invention, a small amount of low-concentration alcohol is added to the dried rosemary leaves from which rosemary essential oil has been separated for static extraction, which can further improve the purity of the rosemary extract and improve its antioxidant effect. Description of the Drawings

[0048] Figure 1 Photos of the rosemary extract prepared in Example 1 stored at -18°C, 0°C, 4°C, 25°C, and 48°C for 1 day;

[0049] Figure 2 Photos of the rosemary extract prepared in Example 1 stored at -18°C, 0°C, 4°C, 25°C, and 48°C for 7 days;

[0050] Figure 3 Photos of the rosemary extract prepared in Example 1 stored at -18°C, 0°C, 4°C, 25°C, and 48°C for 14 days;

[0051] Figure 4 Photos of the rosemary extract prepared in Example 1 stored at -18°C, 0°C, 4°C, 25°C, and 48°C for 21 days;

[0052] Figure 5 Photos of the rosemary extract prepared in Example 1 stored at -18°C, 0°C, 4°C, 25°C, and 48°C for 28 days;

[0053] Figures 1-5 From left to right are 48°C, 25°C, 4°C, 0°C, -18°C. Detailed implementation methods

[0054] Example 1

[0055] A preparation method of rosemary extract, comprising the following steps:

[0056] S1 Using dried rosemary leaves as raw materials, extracting and separating rosemary essential oil;

[0057] S2 Extracting the dried rosemary leaves from which rosemary essential oil has been separated, then performing a separation process, and then rectifying to obtain carnosic acid;

[0058] S3 Continuing to extract the dried rosemary leaves from which carnosic acid has been separated to obtain water-soluble components of rosemary;

[0059] S4 Preparing carnosic acid into an oil phase;

[0060] S5 Preparing the water-soluble components of rosemary into an aqueous phase;

[0061] S6 Mixing the oil phase and the aqueous phase, dispersing and emulsifying to obtain a crude emulsion, and subjecting the crude emulsion to dynamic high-pressure microfluidic homogenization to obtain a single-coated nanoemulsion, which is cooled and reserved;

[0062] S7 Using the single-coated nanoemulsion as the core material and a biocompatible powder as the wall material, dispersing and emulsifying to obtain a secondary-coated emulsion of rosemary extract.

[0063] The specific steps of step S1 are as follows: Using 1 kg of dried rosemary leaves as raw materials, after pulverizing and sieving, they are loaded into an extraction kettle. Supercritical CO2 is introduced to maintain a pressure of 6 MPa for static extraction for 1 h. Then, the pressure of the extraction kettle is adjusted to 17 MPa and the temperature is 45 °C for continuous cyclic extraction for 3 h. The pressure is controlled at 5 MPa and the temperature is 35 °C to separate 44.8 g of rosemary essential oil.

[0064] The particle size of the pulverized and sieved material is 60 mesh.

[0065] The specific steps of step S2 are as follows: First, alcohol is added to the dried rosemary leaves from which the rosemary essential oil has been separated, and they are sealed and soaked for 2 h and then loaded into an extraction kettle. CO2 is introduced to maintain a pressure of 10 MPa for static extraction for 1 h. Then, the pressure is adjusted to 30 MPa and the temperature is adjusted to 60 °C, and supercritical CO2 is introduced for continuous cyclic extraction for 2 h. During the continuous cyclic extraction process, a 60 wt% entrainer is added, and the addition amount each time is 0.25 times the mass of the dried rosemary leaves, and the addition frequency is once per hour. Then, it is transferred to the separation process.

[0066] In step S2, the addition amount of alcohol is 0.4 times the mass of the dried rosemary leaves, and the mass concentration of alcohol is 20 wt%.

[0067] In step S2, the entrainer is alcohol.

[0068] The separation process in step S2 includes a first separation and a second separation. The pressure of the first separation is 10 MPa and the temperature is 40 °C. The pressure of the second separation is 6 MPa and the temperature is 35 °C.

[0069] The pressure of the rectification in step S2 is 8 MPa and the temperature is 40 °C.

[0070] Before rectification, 5 g of carnosic acid powder A with a purity of 80.24% is obtained; after rectification, 4.6 g of carnosic acid powder with a purity of 93.17% is obtained.

[0071] The specific steps of step S3 are as follows: The dried rosemary leaves from which carnosic acid has been separated are added with pure water and soaked for 2 h and then leached. The leaching temperature is 65 °C. After continuous leaching for 5 h, the aqueous solution is collected, filtered and centrifuged. The centrifugate is concentrated, allowed to stand, and centrifuged again. The precipitate is placed in an oven at 60 °C for drying to obtain water-soluble components such as rosemary polysaccharides and polyphenols.

[0072] In step S3, the dried rosemary leaves are continuously extracted with pure water, and the addition amount of pure water is 5 times the mass of the dried rosemary leaves.

[0073] In step S4, the oil phase includes 35 parts of carnosic acid, 65 parts of vegetable oil, 17 parts of surfactant, and 18 parts of polyol by weight.

[0074] The vegetable oil is soybean oil, purchased from First Grade of Golden Arowana; the surfactant is Tween-80; the polyol is 1,3-propanediol.

[0075] The preparation method of the oil phase is as follows: Dissolve carnosic acid in alcohol, heat to 50 °C and stir to dissolve, then add vegetable oil, mix evenly and then heat up to evaporate the alcohol, filter, and take the filtrate and mix it with the surfactant and polyol and stir evenly to obtain the oil phase.

[0076] The specific steps of step S5 are: Dissolve 35 parts by weight of the water-soluble components of rosemary in 65 parts by weight of water, heat to 60 °C and stir until completely dissolved, filter, and take the filtrate as the water phase.

[0077] The weight ratio of the water phase to the oil phase is 15:85.

[0078] In step S6, the dispersion frequency is 20000 r / min and the dispersion time is 4 min; the homogenization pressure of the dynamic high-pressure microfluidization is 60 MPa and the homogenization is carried out for 4 cycles.

[0079] In step S7, the weight ratio of the core material to the wall material is 10:1; in step S7, the dispersion frequency is 20000 r / min, the dispersion time is 4 min, and the emulsification temperature is 50 °C.

[0080] The biocompatible powder is a combination of porous starch and β-cyclodextrin, and the weight ratio of the porous starch to β-cyclodextrin is 1:1.

[0081] The porous starch is purchased from Suzhou Langfu Biotechnology Co., Ltd., and the model is GF-P10; the β-cyclodextrin is purchased from Zhiyuan Biology.

[0082] Example 2

[0083] A preparation method of rosemary extract, comprising the following steps:

[0084] S1 Using dry rosemary leaves as raw materials, extracting and separating rosemary essential oil;

[0085] S2 Extracting the dry rosemary leaves from which rosemary essential oil has been separated, then carrying out a separation process, and then rectifying to obtain carnosic acid;

[0086] S3 Continuing to extract the dry rosemary leaves from which carnosic acid has been separated to obtain the water-soluble components of rosemary;

[0087] S4 Preparing carnosic acid into an oil phase;

[0088] S5 Preparing the water-soluble components of rosemary into a water phase;

[0089] S6 mixes the oil phase and the water phase, disperses and emulsifies them to obtain a crude emulsion, subjects the crude emulsion to dynamic high-pressure microfluidic homogenization to obtain a single-coated nanoemulsion, and cools it for later use;

[0090] S7 uses the single-coated nanoemulsion as the core material and the biocompatible powder as the wall material, disperses and emulsifies them to obtain a secondary-coated emulsion of rosemary extract.

[0091] The specific steps of step S1 are as follows: Using 1 kg of dried rosemary leaves as raw materials, after crushing and sieving, they are loaded into an extraction kettle, supercritical CO2 is introduced to maintain a pressure of 6 MPa for static extraction for 1 h, then the pressure of the extraction kettle is adjusted to 16 MPa and the temperature is 40 °C for continuous cyclic extraction for 2 h, and the pressure is controlled at 5 MPa and the temperature is 45 °C to separate 45.6 g of rosemary essential oil.

[0092] The particle size of the crushed and sieved material is 80 mesh.

[0093] The specific steps of step S2 are as follows: Alcohol is first added to the dried rosemary leaves from which rosemary essential oil has been separated, sealed and soaked for 2 h, then loaded into an extraction kettle, CO2 is introduced to maintain a pressure of 10 MPa for static extraction for 1 h, then the pressure is adjusted to 45 MPa and the temperature is adjusted to 50 °C, supercritical CO2 is introduced for continuous cyclic extraction for 2 h, and a 50 wt% entrainer is added during the continuous cyclic extraction process, with each addition amount being 0.3 times the mass of the dried rosemary leaves and the addition frequency being once per hour, and then it is transferred to the separation process.

[0094] In step S2, the addition amount of alcohol is 0.3 times the mass of the dried rosemary leaves, and the mass concentration of alcohol is 30 wt%.

[0095] In step S2, the entrainer is alcohol.

[0096] The separation process in step S2 includes a first separation and a second separation. The pressure of the first separation is 9 MPa and the temperature is 45 °C, and the pressure of the second separation is 5 MPa and the temperature is 30 °C.

[0097] In step S2, the pressure of rectification is 8 MPa and the temperature is 45 °C.

[0098] After rectification, 4 g of carnosic acid powder with a purity of 90.58% is obtained.

[0099] The specific steps of step S3 are as follows: The dried rosemary leaves from which carnosic acid has been separated are added to pure water, soaked for 2 h and then leached. The leaching temperature is 65 °C. After continuous leaching for 5 h, the aqueous solution is collected, filtered and centrifuged. The centrifugate is concentrated, allowed to stand, centrifuged again, and the precipitate is placed in an oven at 60 °C for drying to obtain water-soluble components such as rosemary polysaccharides and polyphenols.

[0100] In step S3, the dried rosemary leaves are continuously extracted with pure water, and the addition amount of pure water is 5 times the mass of the dried rosemary leaves.

[0101] In step S4, the oil phase includes 35 parts by weight of carnosic acid, 65 parts by weight of vegetable oil, 16 parts by weight of surfactant, and 19 parts by weight of polyol.

[0102] The vegetable oil is soybean oil, purchased from First Grade of Golden Arowana; the surfactant is Tween-80; the polyol is 1,3-propanediol.

[0103] The preparation method of the oil phase is as follows: Dissolve carnosic acid in alcohol, heat to 50 °C and stir to dissolve, then add vegetable oil, mix evenly and then heat up to evaporate the alcohol, filter, and take the filtrate and mix it with the surfactant and polyol and stir evenly to obtain the oil phase.

[0104] The specific steps of step S5 are: Dissolve 35 parts by weight of water-soluble components of rosemary in 65 parts by weight of water, heat to 60 °C and stir until completely dissolved, filter, and take the filtrate as the water phase.

[0105] The weight ratio of the water phase to the oil phase is 15:85.

[0106] In step S6, the dispersion frequency is 20000 r / min and the dispersion time is 4 min; the homogenization pressure of the dynamic high-pressure microfluidizer is 60 MPa and homogenization is carried out for 4 cycles.

[0107] In step S7, the weight ratio of the core material to the wall material is 10:1; in step S7, the dispersion frequency is 20000 r / min, the dispersion time is 4 min, and the emulsification temperature is 50 °C.

[0108] The biocompatible powder is a combination of porous starch and β-cyclodextrin, and the weight ratio of the porous starch to β-cyclodextrin is 0.53:0.47.

[0109] Comparative Example 1

[0110] A preparation method of rosemary extract, the specific implementation manner is the same as that of Example 1, the difference is that the specific steps of step S2 are as follows: Introduce CO2 to maintain a pressure of 10 MPa for static extraction for 1 h, then adjust the pressure to 30 MPa and the temperature to 60 °C, introduce supercritical CO2 for continuous circulation extraction for 2 h, add 60 wt% of entrainer during the continuous circulation extraction process, the addition amount each time is 0.25 times the mass of the dried rosemary leaves, the addition frequency is once per hour, and then transfer to the separation process to obtain 7.8 g of carnosic acid with a purity of 51.31%.

[0111] In step S4, the oil phase includes 25 parts by weight of carnosic acid, 65 parts by weight of vegetable oil, 17 parts by weight of surfactant, and 18 parts by weight of polyol.

[0112] The specific steps of step S5 are as follows: Dissolve 45 parts by weight of water-soluble rosemary components in 55 parts by weight of water, heat to 60 °C and stir until completely dissolved, filter, and take the filtrate as the aqueous phase.

[0113] Comparative Example 2

[0114] A preparation method of rosemary extract, the specific implementation manner is the same as that of Example 2, the difference is that the specific steps of step S2 are as follows: First, add alcohol to the dried rosemary leaves from which rosemary essential oil has been separated, seal and soak for 2 h, then load it into the extraction kettle, introduce CO2, keep the pressure at 10 MPa for static extraction for 1 h, then adjust the pressure to 30 MPa and the temperature to 60 °C, introduce supercritical CO2 for continuous circulation extraction for 2 h. During the continuous circulation extraction process, add 60 wt% of the entrainer, the addition amount each time is 0.25 times the mass of the dried rosemary leaves, and the addition frequency is once per hour. Then transfer it to the separation process for separation to obtain 8.5 g of carnosic acid with a purity of 63.83%.

[0115] There is no step S7.

[0116] Performance test

[0117] 1. Purity of carnosic acid: Refer to GB 1886.172-2016 National Food Safety Standard Food Additive Rosemary Extract to test the purity of carnosic acid after step S2.

[0118] 2. Antioxidant property: Use a Metrohm 892 oxidation induction tester to test the antioxidant property. The test results are shown in Table 1.

[0119] Table 1

[0120] Purity of carnosic acid / % Oxidation induction time / h Example 1 93.17 14.12 Example 2 90.58 13.11 Comparative Example 1 51.31 10.51 Comparative Example 2 63.83 9.7

[0121] Compared with Example 1, in Comparative Example 1, the low-concentration alcohol soaking and rectification purification extraction liquid were not used, and the purity of the carnosic acid powder decreased significantly. And the antioxidant activity of the product obtained by reducing carnosic acid decreased, but since the water-soluble components can undertake part of the oxidation effect, the effect only decreased partially.

[0122] Compared with Example 2, in Comparative Example 2, soaking the raw materials with low-concentration alcohol is beneficial to improving the purity of carnosic acid, but not using rectification purification will also cause a significant reduction in the purity of the carnosic acid powder. And the product without the double coating process is vulnerable to the external environment (high and low temperatures, etc.), and cannot protect the active components of rosemary and prevent the flavor from dissipating.

[0123] 3. Stability test: The rosemary extract prepared in Example 1 was divided into 6 portions and stored at -18°C, 0°C, 4°C, 25°C, 48°C, and in the dark at room temperature (counted as the blank sample) for 1 day, 7 days, 14 days, 21 days, and 28 days. The photos after the test are shown in Figures 1-5 . From left to right are 48°C, 25°C, 4°C, 0°C, -18°C. The test results are shown in Table 2.

[0124] Table 2

[0125]

[0126]

Claims

1. A preparation method of rosemary extract, characterized in that, It includes the following steps: S1: Using dried rosemary leaves as raw materials, extract and isolate rosemary essential oil; S2: Extract the dried rosemary leaves from which rosemary essential oil has been isolated, then carry out a separation process, and then rectify to obtain carnosic acid; S3: Continue to extract the dried rosemary leaves from which carnosic acid has been isolated to obtain water-soluble components of rosemary; S4: Prepare the carnosic acid into an oil phase; S5: Prepare the water-soluble components of rosemary into an aqueous phase; S6: Mix the oil phase and the aqueous phase, disperse and emulsify to obtain a crude emulsion, and subject the crude emulsion to dynamic high-pressure microfluidic homogenization to obtain a single-coated nanoemulsion, which is cooled and reserved; S7: Using the single-coated nanoemulsion as the core material and a biocompatible powder as the wall material, disperse and emulsify to obtain a secondary-coated emulsion of rosemary extract.

2. The preparation method of rosemary extract according to claim 1, characterized in that, In step S1, dried rosemary leaves from which rosemary essential oil is extracted and isolated by supercritical CO2 are used; the specific extraction method is to first carry out static extraction and then dynamic extraction.

3. The preparation method of rosemary extract according to claim 1, characterized in that, In step S2, the dried rosemary leaves from which rosemary essential oil has been isolated are first added with alcohol and CO2 is introduced for static extraction, then supercritical CO2 dynamic extraction is used, and then transferred to the separation process.

4. The preparation method of rosemary extract according to claim 3, characterized in that, In step S2, the separation process includes the first separation and the second separation. The pressure of the first separation is 8 - 15 MPa, the temperature is 35 - 55 °C, the pressure of the second separation is 4 - 6 MPa, and the temperature is 30 - 40 °C.

5. The preparation method of rosemary extract according to claim 1, characterized in that, In step S3, the dried rosemary leaves are continuously extracted with pure water, and the addition amount of pure water is 2 - 8 times the mass of the dried rosemary leaves.

6. The preparation method of the rosemary extract according to claim 1, wherein, In step S4, the oil phase includes 30 - 40 parts by weight of carnosic acid, 60 - 70 parts by weight of vegetable oil, 10 - 20 parts by weight of surfactant, and 10 - 20 parts by weight of polyol.

7. The preparation method of rosemary extract according to claim 1, characterized in that, The specific steps of step S5 are: dissolve the water-soluble components of rosemary in water, heat and stir until completely dissolved, filter, and take the filtrate as the aqueous phase.

8. The preparation method of rosemary extract according to claim 1, characterized in that, In step S6, the dispersion frequency is 15000 - 25000 r / min, and the dispersion time is 1 - 5 min; the homogenization pressure of the dynamic high-pressure microfluidic is 50 - 70 MPa, and the homogenization is carried out for 1 - 5 cycles.

9. The preparation method of rosemary extract according to claim 1, characterized in that, In step S7, the weight ratio of the core material to the wall material is (5 - 15):1; the dispersion frequency in step S7 is 15000 - 25000 r / min, the dispersion time is 1 - 5 min, and the emulsification temperature is 40 - 60 °C.

10. Use of the preparation method of rosemary extract according to any one of claims 1-9, characterized in that, It is applied to the preparation of rosemary extract, and the prepared rosemary extract is applied to daily chemical products.

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