Osmanthus fragrans extraction process

Abstract

The invention relates to the field of natural plant extraction, and particularly discloses an extraction process of sweet osmanthus. The process comprises the following steps: S1, selecting fresh, mildew-free and pollution-free sweet-scented osmanthus, washing and draining to obtain a sweet-scented osmanthus raw material; s2, mixing the osmanthus fragrans raw material with water, homogenizing and crushing, and performing enzymolysis by using a compound enzyme which is composed of cellulase, beta-glucosidase, pectinase and hemicellulase in a mass ratio of 2: 1: 1: 0.5 and has the cellulase activity of 30000-50000 U / g, so as to obtain an osmanthus fragrans flower pulp mixture after enzymolysis; s3, carrying out constant-temperature ultrasonic extraction on the flower pulp mixture, and filtering and centrifuging to obtain a crude extracting solution 1 and a precipitate 1; s4, extracting the precipitate 1 with an ethanol aqueous solution, and performing vacuum rotary distillation and centrifugation to obtain a crude extract 2; and S5, mixing the two crude extracting solutions, and carrying out oil-water separation to obtain the osmanthus fragrans extracting solution and the osmanthus fragrans essential oil. The process has the advantages of synergistic steps, high extraction efficiency, high product purity, stability and economical efficiency, and can be industrially popularized and applied.

Description

Technical Field

[0001] This invention relates to the field of natural plant extraction, and in particular to an extraction process for osmanthus. Background Technology

[0002] Osmanthus fragrans Lour., belonging to the Oleaceae family and the Osmanthus genus, is an evergreen tree or shrub. It has unique growth habits, preferring sunlight but tolerating some shade, favoring warm environments, intolerant of severe cold, and thriving in acidic soil while disliking waterlogging. The history of consuming osmanthus in my country is long and rich. More than two thousand years ago, Qu Yuan wrote in his poem "Nine Songs," "I draw water from the Big Dipper and pour osmanthus wine," indicating that our ancestors had already mastered the art of making fine wine from osmanthus. Today, osmanthus tea, osmanthus cake, and osmanthus wine have become unique traditional foods in my country.

[0003] Osmanthus flowers are rich in polysaccharides, polyphenols, flavonoids, terpenes, pigments, and other active ingredients, giving osmanthus and its products numerous health benefits, including antioxidant, anti-aging, anti-tumor, lipid-lowering, blood pressure-lowering, cough-relieving, phlegm-reducing, halitosis-relieving, and antibacterial effects. Therefore, the ancients praised osmanthus as the "king of all medicines." Based on this, in-depth research into the processing of osmanthus products is undoubtedly of vital importance for promoting the development of the osmanthus cultivation industry and facilitating the development, application, and promotion of osmanthus products.

[0004] Osmanthus hydrosol, an aqueous solution distilled during the distillation of osmanthus essential oil, shares the same main fragrance components as osmanthus essential oil, including linalool and its oxides, γ-decanoic acid lactone, β-ionone, and geraniol. These components are remarkably effective in improving skin condition, such as dullness, roughness, sallowness, and sagging. They also hydrate and moisturize, regulate oil-water balance, reduce skin sensitivity, and enhance skin vitality. Given its highly effective hydrating properties, excellent whitening effects, and good antioxidant properties, osmanthus hydrosol has been widely used in cosmetics development.

[0005] Currently, most methods for extracting the active ingredients from osmanthus flowers employ steam distillation. This method, based on Dalton's Law, involves distilling osmanthus flowers and water together, allowing the volatile components to evaporate along with the steam. After condensation, the essential oil floating on the surface is separated. Steam distillation can be further subdivided into underwater distillation and above-water distillation based on the contact method between the spice raw material and water; and into steam-heated distillation and direct bottom-heated distillation based on the heating method. Modern enterprises commonly use steam-heated underwater distillation. However, this traditional method has certain limitations. On the one hand, steam distillation has a relatively long extraction time, and some heat-sensitive components are easily destroyed during prolonged heating, thus affecting the extraction efficiency and purity of the active ingredients. On the other hand, this method is highly dependent on equipment and consumes a large amount of energy, which increases production costs to some extent. Furthermore, while supercritical fluid extraction has advantages in extracting certain components, it requires extremely sophisticated equipment and has huge acquisition costs, making large-scale application difficult.

[0006] In response to the aforementioned technologies, the inventors believe that it is necessary to develop a more efficient extraction method that can overcome the shortcomings of existing technologies and improve the extraction efficiency and purity of the active ingredients in osmanthus. Summary of the Invention

[0007] To address the technical deficiencies of existing technologies, this application provides an extraction process for osmanthus flowers.

[0008] This application provides an extraction process for osmanthus flowers, employing the following technical solution: An extraction process for osmanthus flowers includes the following steps: S1: Select fresh, mold-free, and pollution-free osmanthus flowers, wash off surface impurities with clean water, drain the water, and obtain osmanthus raw materials; S2: Mix the osmanthus raw material with water, homogenize and crush it, and then enzymatically hydrolyze it to obtain an osmanthus flower pulp mixture; The enzyme used in the enzymatic hydrolysis is a complex enzyme, which includes cellulase, β-glucosidase, pectinase and hemicellulase, with a mass ratio of 2:1:1:0.5 and a cellulase activity of 30,000-50,000 U / g. S3: Place the enzymatically hydrolyzed osmanthus flower pulp mixture in a constant temperature water bath, extract it by ultrasound, filter and centrifuge to obtain the supernatant crude osmanthus extract 1 and precipitate 1; S4: After mixing precipitate 1 with an ethanol-water solution, extract the mixture, then perform vacuum rotary distillation and centrifugation to obtain the supernatant crude osmanthus extract 2. S5: Mix crude osmanthus extract 1 and crude osmanthus extract 2, and after oil-water separation, obtain osmanthus extract and osmanthus essential oil.

[0009] By adopting the above technical solution, the compound enzyme system is used to specifically decompose components such as cellulose, pectin, and hemicellulose in the cell wall of osmanthus. Combined with subsequent ultrasonic extraction and soaking processes, the water-soluble and fat-soluble effective components in osmanthus are fully dissolved. At the same time, through step-by-step extraction and purification, the loss of effective components is reduced, ensuring the purity and quality of the final product. The synergistic effect of each step forms a highly efficient and stable osmanthus extraction system.

[0010] Preferably, the amount of water added in step S2 is 3 to 5 times the mass of the osmanthus raw material.

[0011] By adopting the above technical solution, the osmanthus raw material can be fully dispersed in water, providing suitable material flowability for the homogenizer and avoiding insufficient crushing due to excessively viscous material. At the same time, the appropriate amount of water can ensure sufficient contact between the subsequent compound enzyme and the osmanthus raw material, providing a stable reaction environment for the enzymatic hydrolysis reaction. This avoids both insufficient water leading to excessively high enzyme concentration and uneven reaction, and excessive water leading to enzyme dilution and decreased enzymatic hydrolysis efficiency.

[0012] Preferably, the amount of compound enzyme added in step S2 is 0.3 to 0.6% of the mass of the osmanthus raw material.

[0013] By adopting the above technical solution, it can be ensured that the amount of each component in the compound enzyme can meet the decomposition requirements of the osmanthus cell wall components, so that substances such as cellulose and pectin can be effectively degraded and the release of effective components in the cells can be promoted. At the same time, controlling the amount of compound enzyme added within this range can avoid insufficient enzyme dosage leading to incomplete enzymatic hydrolysis and limited dissolution of effective components, as well as the waste of raw materials caused by excessive enzyme dosage and the adverse effects of excessive enzyme residue on the subsequent extraction purification process.

[0014] Preferably, the enzymatic hydrolysis in step S2 is carried out at pH 4.5-5.0 and 50-55℃ for 120-180 min, with stirring at 800-1200 rpm during the process.

[0015] By adopting the above technical solution, the conditions of pH 4.5-5.0 and 50-55℃ are matched with the suitable action conditions of components such as cellulase and β-glucosidase in the compound enzyme, which can maximize the activity of each enzyme component and ensure the efficient enzymatic hydrolysis reaction. The enzymatic hydrolysis time of 120-180 min can ensure that the cell wall components of osmanthus are fully decomposed, avoiding insufficient dissolution of effective components due to insufficient enzymatic hydrolysis time, and also avoiding increased energy consumption and degradation of effective components due to excessively long enzymatic hydrolysis time. The stirring speed of 800-1200 rpm can make the compound enzyme and osmanthus material evenly mixed, reducing the situation of excessively high or low local enzyme concentration, and ensuring that the enzymatic hydrolysis reaction is uniform and sufficient.

[0016] Preferably, the temperature of the constant temperature water bath in step S3 is 40–60°C.

[0017] By adopting the above technical solution, a suitable constant temperature water bath can reduce the viscosity of the osmanthus flower pulp mixture, promote the dissolution of the effective components released after enzymatic hydrolysis into the solution, and avoid the slow dissolution rate and reduced extraction efficiency caused by excessively low temperature. In addition, this temperature range can prevent the degradation of heat-sensitive effective components in osmanthus due to high temperature, ensure the stability of effective components, and thus ensure the quality of the final product.

[0018] Preferably, the ultrasonic extraction in step S3 is a dual-frequency pulsed ultrasonic extraction, wherein the dual-frequency pulsed ultrasonic extraction consists of a 20kHz pretreatment for 10 minutes at a power of 300W, followed by a 60kHz main extraction for 30–60 minutes at a power of 600W, with a pulse mode of 5 seconds of operation followed by 3 seconds of intermittent operation.

[0019] By adopting the above technical solutions, 20kHz low-frequency ultrasonic pretreatment can utilize its strong cavitation effect to break the agglomeration structure of osmanthus material after enzymatic hydrolysis, increase the specific surface area of ​​the material, and create favorable conditions for the subsequent main extraction step; 60kHz high-frequency ultrasound can enhance the mass transfer and dissolution process of effective components, and accelerate the diffusion of effective components from the inside of the material into the extract; the main extraction time of 30-60 minutes can ensure that the effective components are fully dissolved and avoid incomplete extraction; the pulse mode (5 seconds of operation and 3 seconds of intermittent operation) can avoid the local overheating phenomenon caused by continuous ultrasound, reduce the degradation loss of heat-sensitive effective components, and at the same time reduce ultrasonic energy consumption and extend the service life of the equipment. All parameters work together to achieve efficient and gentle ultrasonic extraction effect.

[0020] Preferably, the amount of ethanol-water solution added in step S4 is 5 to 10 times the mass of precipitate 1, and the ethanol-water solution is an ethanol-water solution with a volume fraction of 50 to 75%.

[0021] By adopting the above technical solution, an addition of 5 to 10 times can ensure that the residual active ingredients in precipitate 1 can be fully wetted and dissolved by the ethanol aqueous solution, avoiding insufficient addition that would result in the incomplete recovery of residual active ingredients. An ethanol aqueous solution with a volume fraction of 50 to 75% can take into account the dissolution requirements of both fat-soluble and water-soluble active ingredients. Ethanol in this concentration range can reduce the solubility barrier of active ingredients in the solvent, allowing all kinds of residual active ingredients in the precipitate to be fully dissolved, while avoiding incomplete dissolution of some active ingredients due to excessively high or low ethanol concentration, thus ensuring the recovery efficiency of active ingredients in the precipitate.

[0022] Preferably, the extraction in step S4 is ultrasonic-assisted extraction, and the ultrasonic-assisted extraction conditions are 300W, 40kHz ultrasonic-assisted extraction for 30 minutes.

[0023] By adopting the above technical solution, the ultrasonic parameters of 300W and 40kHz can generate suitable cavitation effect and vibration, which can destroy the microstructure of precipitate 1, accelerate the penetration of ethanol aqueous solution into the interior of the precipitate, and promote the rapid dissolution of residual effective components in the precipitate. Compared with ordinary extraction, the extraction time can be significantly shortened and the extraction efficiency can be improved. The extraction time of 30min can ensure that the residual effective components are fully dissolved, avoid the loss of effective components caused by incomplete extraction, and at the same time control the extraction time to reduce energy consumption and process cost.

[0024] Preferably, the vacuum rotary distillation conditions in step S4 are 55°C and -0.08 to -0.09 MPa.

[0025] By adopting the above technical solution, a distillation temperature of 55℃ can achieve the separation and recovery of ethanol at a lower temperature, avoiding the degradation of effective components in the extract caused by high temperature and ensuring the quality of crude osmanthus extract 2; a vacuum degree of -0.08 to -0.09 MPa can lower the boiling point of ethanol, accelerate the distillation separation speed of ethanol, improve distillation efficiency, and at the same time reduce the volatilization loss of effective components during the distillation process, ensuring that the effective components are fully retained. The recovered ethanol can also be recycled, reducing process costs.

[0026] Preferably, the oil-water separation in step S5 is performed by letting the mixture stand in a 40°C constant temperature oil-water separator for 20-30 minutes.

[0027] By adopting the above technical solution, the constant temperature of 40℃ can reduce the viscosity of osmanthus extract and osmanthus essential oil, reduce the interfacial tension between the two, and promote the rapid separation of osmanthus essential oil and extract. The standing time of 20-30 minutes can ensure that the essential oil and extract are fully separated, avoiding the essential oil from mixing into the extract and affecting the purity of the extract, or the extract from mixing into the essential oil and affecting the quality of the essential oil, thus ensuring the separation effect and purity of the two products in the end.

[0028] In summary, this application has the following beneficial effects: 1. This application constructs a synergistic process system by precisely optimizing the process parameters of each step in the osmanthus extraction process. This system integrates compound enzymatic hydrolysis, dual-frequency pulsed ultrasonic extraction, ultrasonic-assisted ethanol extraction, and stepwise purification, specifically addressing the technical pain points of traditional osmanthus extraction processes, such as insufficient dissolution of effective components, low extraction efficiency, and insufficient product purity. The process parameters of each step are highly adaptable and closely integrated. The compound enzyme system, formulated in a specific mass ratio, can efficiently decompose components such as cellulose, pectin, and hemicellulose in the cell walls of osmanthus, completely breaking down the dissolution barrier of effective components and laying a solid foundation for subsequent extraction steps. Dual-frequency pulsed ultrasonic extraction achieves efficient dissolution of effective components through the combination of low-frequency pretreatment and high-frequency main extraction. Ultrasonic-assisted ethanol extraction can fully recover the effective components remaining in the precipitate. The two processes synergistically improve the overall extraction rate of effective components. Vacuum rotary distillation and constant-temperature oil-water separation steps work together to preserve the activity of effective components while achieving efficient separation of the extract and essential oil, further ensuring product purity.

[0029] 2. This application effectively reduces energy consumption and raw material loss by rationally controlling the process parameters at each step, making the entire extraction process efficient, stable, and economical. Compared with traditional extraction processes, this application's process is simple to operate, with controllable parameters, enabling large-scale continuous production. It can stably produce high-purity osmanthus extract and osmanthus essential oil. Both products meet practical application requirements and can be widely used in food, cosmetics, fragrances, and other fields, possessing good industrial application prospects and practical promotion value. Detailed Implementation

[0030] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0031] Example 1 An extraction process for osmanthus flowers, the preparation steps are as follows: S1 Raw Material Pretreatment: Select fresh, mold-free, and pollution-free osmanthus flowers, wash off surface impurities with clean water, drain the water, and obtain osmanthus raw materials.

[0032] S2 compound enzymatic hydrolysis preparation of flower pulp: Osmanthus raw materials are mixed with 3 times their weight of water, crushed by homogenizer, and then a compound enzyme system (cellulase:β-glucosidase:pectinase:hemicellulase=2:1:1:0.5, the total enzyme amount is 0.3% of the osmanthus weight, of which the cellulase activity is 30000U / g) is added. Enzymatic hydrolysis is carried out at pH 4.5 and 50℃ for 120 min, and the mixture is stirred at 800 rpm during the process to obtain an osmanthus flower pulp mixture.

[0033] S3 Dual-frequency pulsed ultrasonic extraction: The enzymatically hydrolyzed flower pulp mixture was placed in a 40℃ constant temperature water bath and subjected to dual-frequency pulsed ultrasonic extraction (20kHz pretreatment for 10min, power 300W; 60kHz main extraction for 30min, power 600W, pulse mode: 5s working, 3s intermittent). After extraction, the mixture was filtered and centrifuged to obtain the supernatant crude osmanthus extract 1 and precipitate 1.

[0034] S4 Ethanol Ultrasonic Extraction and Recovery: Mix precipitate 1 with 5 times its mass of 50% volume fraction ethanol aqueous solution, and perform ultrasonic extraction at 300W and 40kHz for 30min (divided into two 15min intervals). Vacuum rotary distillation is then performed at 55℃ and -0.08MPa, followed by centrifugation to obtain the supernatant crude osmanthus extract 2.

[0035] S5 Mixed Purification Product: Combine crude osmanthus extracts 1 and 2, and first separate them by standing in a 40℃ constant temperature oil-water separator for 20 minutes to obtain high-purity osmanthus extract and osmanthus essential oil.

[0036] Example 2 S1 Raw Material Pretreatment: Select fresh, mold-free, and pollution-free osmanthus flowers, wash off surface impurities with clean water, drain the water, and obtain osmanthus raw materials.

[0037] S2 compound enzymatic hydrolysis preparation of flower pulp: Osmanthus raw materials are mixed with 4 times their weight of water, crushed by homogenizer, and then a compound enzyme system (cellulase:β-glucosidase:pectinase:hemicellulase=2:1:1:0.5, the total enzyme amount is 0.5% of the osmanthus weight, of which the cellulase activity is 40000U / g) is added. Enzymatic hydrolysis is carried out at pH 5.0 and 55℃ for 160 min, and the mixture is stirred at 1000 rpm during the process to obtain an osmanthus flower pulp mixture.

[0038] S3 Dual-frequency pulsed ultrasonic extraction: The enzymatically hydrolyzed flower pulp mixture was placed in a 50℃ constant temperature water bath and subjected to dual-frequency pulsed ultrasonic extraction (20kHz pretreatment for 10min, power 300W; 60kHz main extraction for 45min, power 600W, pulse mode: 5s working, 3s intermittent). After extraction, the mixture was filtered and centrifuged to obtain the supernatant crude osmanthus extract 1 and precipitate 1.

[0039] S4 Ethanol Ultrasonic Extraction and Recovery: Mix precipitate 1 with 7 times its mass of 65% volume fraction ethanol aqueous solution, and perform ultrasonic extraction at 300W and 40kHz for 30min (divided into two 15min intervals). Vacuum rotary distillation was carried out at 55℃ and -0.09MPa, followed by centrifugation to obtain the supernatant crude osmanthus extract 2.

[0040] S5 Mixed Purification Product: Combine crude osmanthus extracts 1 and 2, and first separate them by standing in a 40℃ constant temperature oil-water separator for 25 minutes to obtain high-purity osmanthus extract and osmanthus essential oil.

[0041] Example 3 An extraction process for osmanthus flowers, the preparation steps are as follows: S1 Raw Material Pretreatment: Select fresh, mold-free, and pollution-free osmanthus flowers, wash off surface impurities with clean water, drain the water, and obtain osmanthus raw materials.

[0042] S2 compound enzymatic hydrolysis preparation of flower pulp: Osmanthus raw materials are mixed with 5 times their weight of water, crushed by homogenizer, and then a compound enzyme system (cellulase:β-glucosidase:pectinase:hemicellulase=2:1:1:0.5, the total enzyme amount is 0.6% of the osmanthus weight, of which the cellulase activity is 50000U / g) is added. Enzymatic hydrolysis is carried out at pH 5.0 and 55℃ for 180 min, and the mixture is stirred at 1200 rpm during the process to obtain an osmanthus flower pulp mixture.

[0043] S3 Dual-frequency pulsed ultrasonic extraction: The enzymatically hydrolyzed flower pulp mixture was placed in a 60℃ constant temperature water bath and subjected to dual-frequency pulsed ultrasonic extraction (20kHz pretreatment for 10min, power 300W; 60kHz main extraction for 60min, power 600W, pulse mode: 5s working, 3s intermittent). After extraction, the mixture was filtered and centrifuged to obtain the supernatant crude osmanthus extract 1 and precipitate 1.

[0044] S4 Ethanol Ultrasonic Extraction and Recovery: Mix precipitate 1 with 10 times its mass of 75% volume fraction ethanol aqueous solution, and perform ultrasonic extraction at 300W and 40kHz for 30min (divided into two 15min intervals). Vacuum rotary distillation is then performed at 55℃ and -0.09MPa, followed by centrifugation to obtain the supernatant crude osmanthus extract 2.

[0045] S5 Mixed Purification Product: Combine crude osmanthus extracts 1 and 2, and first separate them by standing in a 40℃ constant temperature oil-water separator for 30 minutes to obtain high-purity osmanthus extract and osmanthus essential oil.

[0046] Comparative Example 1 An extraction process for osmanthus flowers differs from that in Example 1 in that only cellulase is added in step S2 of this comparative example, and the amount added is 0.3% of the total mass of osmanthus flowers.

[0047] Comparative Example 2 An extraction process for osmanthus flowers, which differs from Example 1 in that the ultrasonic extraction in step S3 of this comparative example is ordinary ultrasonic extraction at 800W for 40 minutes.

[0048] Comparative Example 3 An extraction process for osmanthus flowers, which differs from that in Example 1, is that the extraction in step S4 of this comparative example is ordinary ethanol extraction for 30 minutes.

[0049] Effect test 1. Test subjects: Osmanthus extract and osmanthus essential oil prepared by the extraction processes of Examples 1-3 and Comparative Examples 1-2 (all using 1000g of osmanthus as raw material).

[0050] 2. Test methods: The extraction efficiency was calculated based on the amount of osmanthus flowers used and the yield of essential oil; the extraction efficiency was also calculated based on the amount of osmanthus flowers and water used and the yield of osmanthus extract; and the purity of osmanthus extract and osmanthus essential oil was analyzed using high performance liquid chromatography.

[0051] Extraction efficiency of osmanthus essential oil (%) = Osmanthus essential oil yield / Osmanthus flowers used × 100%; Extraction efficiency (%) of osmanthus extract = yield of osmanthus extract / (mass of osmanthus used + mass of water used + mass of ethanol aqueous solution) × 100%; 3. Test results: as shown in Table 1.

[0052] Table 1 Results of the effect test

[0053] As shown in Table 1, the yields of osmanthus extract obtained in Examples 1-3 reached 4205g, 5371g, and 6619g, respectively, with extraction efficiencies remaining stable within a narrow range of 88.25%-88.78%, and purity not lower than 93.72%. The yields of osmanthus essential oil were 1.97g-2.57g, with extraction efficiencies of 0.197%-0.257%, and purity above 97.12%. Even though the process parameters for enzymatic hydrolysis and ultrasonic extraction were adjusted in Examples 2 and 3 to increase the yield of the extract, the overall extraction efficiency and purity did not fluctuate significantly, fully demonstrating that the process of this application has good parameter adaptability and implementation stability. In contrast, Comparative Examples 1-3, due to changes in a single technical feature, showed significant deterioration in all test indicators, forming a clear performance gradient. This directly proves the synergistic effect of the three core steps in the process of this application: compound enzymatic hydrolysis, dual-frequency pulsed ultrasonic extraction, and ethanol ultrasonic leaching and recovery; none of these steps can be omitted.

[0054] Among them, Comparative Example 1, which used a single cellulase instead of the complex enzyme system of this application, was the group with the worst performance in all indicators. Its osmanthus extract extraction efficiency was only 67.70% and purity was 82.15%, and its osmanthus essential oil extraction efficiency was 0.163% and purity was 90.12%, which was far lower than all other examples. The reason is that the complex enzyme system of cellulase:β-glucosidase:pectinase:hemicellulase = 2:1:1:0.5 used in this application can specifically decompose multiple structural components such as cellulose, pectin, and hemicellulose in the cell wall of osmanthus. Compared with a single cellulase, it can more fully destroy the cell wall structure and promote the dissolution of effective components in the cell, laying a good material foundation for subsequent extraction steps. In contrast, a single enzyme system can only decompose a single cell wall component, and the dissolution of effective components is limited, which directly leads to a significant decrease in extraction efficiency and purity.

[0055] Comparative Example 2 used 800W conventional ultrasound extraction instead of the dual-frequency pulsed ultrasound extraction of this application. The efficiency and purity of the extract and essential oil were significantly lower than those of Example 1 and inferior to Comparative Example 3. It can be seen that dual-frequency pulsed ultrasound is a key means to improve the extraction effect. This application adopts a dual-frequency mode of 20kHz pretreatment + 60kHz main extraction, combined with a pulse mode of 5s working and 3s intermittent, which can form a more uniform and gentler ultrasonic field. It utilizes the strong cavitation effect of low-frequency ultrasound to break the material agglomeration structure, and enhances the mass transfer and dissolution of effective components through high-frequency ultrasound. The pulse mode can avoid the local overheating problem caused by continuous operation of conventional ultrasound and reduce the decomposition loss of effective components. Conventional ultrasound has no frequency gradient and pulse control, the cavitation effect is uneven and it is easy to cause damage to effective components, so the extraction effect is greatly reduced.

[0056] Comparative Example 3, which replaced the ultrasonic extraction and recovery of ethanol in this application with ordinary ethanol extraction, showed the best performance among the comparative examples, but still did not reach the level of the Example. This indicates that the introduction of ultrasonic assistance can effectively enhance the dissolution mass transfer efficiency of ethanol on the residual effective components in the precipitate, making up for the shortcomings of ordinary extraction such as slow mass transfer rate and insufficient recovery of residual effective components, further improving the overall extraction efficiency, and ensuring the purity of the recovered components. In addition, Example 1, as the preferred combination of process parameters in this application, has the highest extraction efficiency (0.257%) and purity (98.96%) of osmanthus essential oil among all examples, and the extraction efficiency (88.53%) and purity (95.61%) of osmanthus extract are also at a high level. It takes into account the extraction effect of both extract and essential oil, and is the optimal solution that balances extraction efficiency, product purity and process economy.

[0057] In summary, this application creates the basic conditions for the dissolution of effective components through the precise formulation of a complex enzyme system and the regulation of the enzymatic hydrolysis process. Combined with the high-efficiency dissolution advantage of dual-frequency pulsed ultrasonic extraction, and then through ethanol ultrasonic immersion extraction to fully recover the residual effective components in the precipitate, and finally through constant-temperature oil-water separation purification, each step is interconnected and works synergistically. From the dissolution, extraction to recovery and purification of effective components, a complete technical system is formed, which ultimately achieves a dual improvement in the extraction efficiency and purity of osmanthus extract and osmanthus essential oil. Compared with processes improved by a single technical means, it has significant technical advantages and implementation value.

[0058] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An extraction process for osmanthus flowers, characterized in that, Includes the following steps: S1: Select fresh, mold-free, and pollution-free osmanthus flowers, wash off surface impurities with clean water, drain the water, and obtain osmanthus raw materials; S2: Mix the osmanthus raw material with water, homogenize and crush it, and then enzymatically hydrolyze it to obtain an osmanthus flower pulp mixture; The enzyme used in the enzymatic hydrolysis is a complex enzyme, which includes cellulase, β-glucosidase, pectinase and hemicellulase, with a mass ratio of 2:1:1:0.5 and a cellulase activity of 30,000-50,000 U / g. S3: Place the enzymatically hydrolyzed osmanthus flower pulp mixture in a constant temperature water bath, extract it by ultrasound, filter and centrifuge to obtain the supernatant crude osmanthus extract 1 and precipitate 1; S4: After mixing precipitate 1 with an ethanol-water solution, extract the mixture, then perform vacuum rotary distillation and centrifugation to obtain the supernatant crude osmanthus extract 2. S5: Mix crude osmanthus extract 1 and crude osmanthus extract 2, and after oil-water separation, obtain osmanthus extract and osmanthus essential oil.

2. The extraction process of osmanthus according to claim 1, characterized in that: In step S2, the amount of water added is 3 to 5 times the mass of the osmanthus raw material.

3. The extraction process of osmanthus according to claim 2, characterized in that: The amount of compound enzyme added in step S2 is 0.3 to 0.6% of the mass of the osmanthus raw material.

4. The extraction process of osmanthus according to claim 3, characterized in that: The enzymatic hydrolysis in step S2 is carried out at pH 4.5-5.0 and 50-55℃ for 120-180 min, with stirring at 800-1200 rpm during the process.

5. The extraction process of osmanthus according to claim 1, characterized in that: The temperature of the constant temperature water bath in step S3 is 40–60°C.

6. The extraction process of osmanthus according to claim 5, characterized in that: The ultrasonic extraction in step S3 is a dual-frequency pulsed ultrasonic extraction, which consists of a 20kHz pretreatment for 10 minutes at a power of 300W, followed by a 60kHz main extraction for 30–60 minutes at a power of 600W, with a pulse mode of 5 seconds of operation followed by 3 seconds of intermittent operation.

7. The extraction process of osmanthus according to claim 1, characterized in that: The amount of ethanol-water solution added in step S4 is 5 to 10 times the mass of precipitate 1, and the ethanol-water solution is an ethanol-water solution with a volume fraction of 50 to 75%.

8. The extraction process of osmanthus according to claim 7, characterized in that: The extraction in step S4 is an ultrasonic-assisted extraction, and the ultrasonic-assisted extraction conditions are 300W, 40kHz ultrasonic-assisted extraction for 30 minutes.

9. The extraction process of osmanthus according to claim 8, characterized in that: The vacuum rotary distillation conditions in step S4 are 55°C and -0.08 to -0.09 MPa.

10. The extraction process of osmanthus according to claim 1, characterized in that: The oil-water separation in step S5 is performed by letting the mixture stand in a 40°C constant temperature oil-water separator for 20-30 minutes.

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