A method for extracting chamomile volatile oil

Abstract

This application relates to the technical field of fine chemicals, specifically disclosing a method for extracting chamomile volatile oil. The method disclosed in this application includes the following steps: soaking chamomile in a 5-20 wt% ethanol aqueous solution, performing low-temperature extraction, and filtering to discard the extract; soaking the residue in a 50-70 wt% ethanol aqueous solution, then performing ultrasonic extraction, filtering, and collecting the extract; soaking the residue from step S2 in a 70-100 wt% ethanol aqueous solution, then performing ultrasonic extraction, filtering, and collecting the extract; combining the extracts from steps S2 and S3 to obtain a chamomile ethanol extract, which is then subjected to rotary evaporation, salting out, and washing with water to obtain chamomile volatile oil. Using the method of this application, the extraction rate and core component content of chamomile volatile oil are significantly better than traditional steam distillation, and the energy consumption is lower, showing good prospects for industrial application.

Description

Technical Field

[0001] This application relates to the technical field of fine chemicals, specifically to a method for extracting chamomile volatile oil. Background Technology

[0002] Chamomile (Matricaria recutita L.) is an annual plant belonging to the order Asterales, family Asteraceae, and genus Matricaria. Its volatile oil possesses various pharmacological activities, including antibacterial, antiparasitic, anti-inflammatory, and antidepressant effects, and has broad application prospects in the pharmaceutical, cosmetic, and fragrance industries. Currently, common extraction methods for volatile oils mainly include steam distillation, organic solvent extraction, and supercritical fluid extraction. Steam distillation is widely used due to its mature technology and simple equipment, but it suffers from low extraction efficiency (yield typically only around 1.5%) and long heating times (requiring over 6 hours). High-temperature environments can easily damage heat-sensitive components in the volatile oil, leading to a decline in product quality. Organic solvent extraction (such as petroleum ether) has higher extraction efficiency, but it presents safety hazards such as high solvent costs, flammability, explosiveness, and residual impurities, limiting its application in the food and cosmetic fields. Supercritical fluid extraction offers high extraction efficiency and leaves no solvent residue, but it requires specialized high-pressure equipment, resulting in high investment costs and complex operation, making large-scale industrial production difficult.

[0003] Therefore, developing a method for extracting chamomile volatile oil that has a high extraction rate, low cost, simple process, and can retain the active components of the volatile oil has become an urgent technical problem to be solved in this field. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a method for extracting chamomile volatile oil.

[0005] In a first aspect, this application provides a method for extracting chamomile volatile oil, comprising the following steps: S1: Soak chamomile in a 5-20 wt% ethanol aqueous solution and extract at a low temperature of 15-30℃ for 30-90 min. Filter and discard the extract. S2: Soak the residue from step S1 in a 50-70 wt% ethanol aqueous solution, then perform ultrasonic extraction, filter, and collect the extract; S3: Soak the residue from step S2 in a 70-100 wt% ethanol aqueous solution, then perform ultrasonic extraction, filter, and collect the extract; S4: Combine the extracts from steps S2 and S3 to obtain chamomile ethanol extract; subject the chamomile ethanol extract to rotary evaporation, salting out, and water washing to obtain chamomile volatile oil.

[0006] To address the shortcomings of existing technologies, this application combines the component characteristics of chamomile volatile oil, uses ethanol as the extraction solvent, and employs ultrasonic extraction technology to optimize the process parameters. Simultaneously, it utilizes salting-out to achieve efficient separation of volatile oil and ethanol, solving the technical problem of low volatile oil separation efficiency after ethanol extraction, thus providing reliable technical support for the industrial production of chamomile volatile oil.

[0007] The specific method for using ethanol as the extraction solvent is as follows: a three-step gradient extraction process of "low-ethanol impurity removal → medium-ethanol pre-extraction → high-ethanol purification" is adopted to achieve targeted screening of impurities and target volatile oils. Specifically: The first step is low-ethanol pre-extraction to remove impurities, aiming to preferentially dissolve water-soluble impurities (such as polysaccharides, small molecule sugars, and water-soluble pigments) while minimizing the dissolution of volatile oils, thus avoiding co-dissolution of impurities and volatile oils and reducing the difficulty of subsequent separation from the source. The second step is medium-ethanol pre-extraction, aiming to initially dissolve some moderately polar volatile oil components while further removing residual moderately polar impurities, laying the foundation for subsequent high-ethanol purification. The third step is high-ethanol purification, aiming to selectively dissolve the remaining volatile oil components (especially the highly lipid-soluble α-bisabolol), maximizing the extraction rate of volatile oils while minimizing the dissolution of impurities.

[0008] Preferably, step S1 is as follows: chamomile is soaked in a 10-15 wt% ethanol aqueous solution at a material-to-liquid ratio of 1:5-15, and extracted at a low temperature of 15-25°C for 30-60 minutes. The extract is then filtered and discarded to obtain the residue.

[0009] Preferably, step S2 is as follows: according to the material-liquid ratio of 1:5 to 15, the residue in step S1 is soaked in a 55 to 65 wt% ethanol aqueous solution for 60 to 180 min, and then ultrasonically extracted for 30 to 90 min under an ultrasonic power of 100 to 300 W. After extraction, the mixture is allowed to stand for 5 to 10 min, filtered, and the extract is collected.

[0010] Preferably, step S3 is as follows: according to the material-liquid ratio of 1:5-15, the residue in step S2 is soaked in an 80-90wt% ethanol aqueous solution for 60-180 minutes, and then ultrasonically extracted for 30-90 minutes under an ultrasonic power of 150-200W. After extraction, the mixture is allowed to stand for 5-10 minutes, filtered, and the extract is collected.

[0011] Preferably, in step S4, the rotary evaporation method is as follows: the chamomile ethanol extract is placed in a water bath at 50-70°C and the pressure is reduced to 20-30 wt%; anhydrous ethanol is added to wash 2-4 times, the washing liquid is combined with the remaining extract, and water is added to adjust the ethanol concentration of the system to 30-50 wt%.

[0012] Preferably, in step S4, the salting-out method is as follows: add 10-20 wt% of a composite salting-out agent to the solution after rotary evaporation and dissolve it, let it stand at room temperature for 6-12 hours, and collect the volatile oil after the volatile oil has completely floated to the surface of the liquid. The composite salting-out agent is a mixture of sodium chloride, anhydrous magnesium sulfate, and potassium dihydrogen phosphate in a weight ratio of 2-3:1-1.5:0.5-1.

[0013] Preferably, the composite salting-out agent is a mixture of sodium chloride, anhydrous magnesium sulfate, and potassium dihydrogen phosphate in a weight ratio of 3-4:1-1.5:0.5-1.

[0014] During the experiment, the applicant discovered that salting out using a composite salt composed of sodium chloride, anhydrous magnesium sulfate, and potassium dihydrogen phosphate can achieve efficient separation of volatile oils and ethanol. Sodium chloride, as a monovalent salt, significantly reduces the miscibility of ethanol and water, initially promoting the precipitation of volatile oils. Anhydrous magnesium sulfate, as a divalent salt, has a strong dehydrating effect, disrupting the oil-water emulsion system, accelerating stratification, and simultaneously adsorbing trace amounts of residual ethanol in the aqueous phase. Potassium dihydrogen phosphate adjusts the ionic strength of the system, further enhancing the salting-out effect, while inhibiting the oxidation of volatile oils. The synergistic effect of these three components, compared to single salting-out, increases the stratification speed, reduces the water content of the oil phase, completely solves the emulsification problem, and synergistically protects the active components of the volatile oils.

[0015] In one specific implementation, the weight ratio of sodium chloride, anhydrous magnesium sulfate and potassium dihydrogen phosphate in the composite salting-out agent can be 3:1:0.5, 4:1:0.5, 3:1.5:0.5, 4:1.5:0.5, 3:1:1, 4:1:1, 3:1.5:1, or 4:1.5:1.

[0016] Experimental analysis shows that using sodium chloride, anhydrous magnesium sulfate, and potassium dihydrogen phosphate in the above weight ratio as a composite salting-out agent can further improve the extraction efficiency of the extraction method and increase the content of effective components in chamomile volatile oil.

[0017] Secondly, this application provides a chamomile volatile oil, obtained using the extraction method described above.

[0018] Preferably, the chamomile volatile oil contains the following components in weight percentage: linalool 0.091-0.13%, bisabolol 0.151-0.244%, eugenol 0.189-0.301%, carvone 4.597-5.748%, and limonene 0.079-0.107%.

[0019] Thirdly, this application provides an application of chamomile volatile oil in the fields of medicine, cosmetics, and fragrance.

[0020] In summary, the technical solution of this application has the following effects: This application, taking into account the component characteristics of chamomile volatile oil, adopts a three-step gradient extraction process of "low-alcohol impurity removal → medium-alcohol pre-extraction → high-alcohol refining," combined with ultrasonic extraction technology, to optimize the best process parameters and achieve targeted screening of impurities and target volatile oil. At the same time, it uses salting out to achieve efficient separation of volatile oil and ethanol, solving the technical problem of low separation efficiency of volatile oil after ethanol extraction, and providing reliable technical support for the industrial production of chamomile volatile oil.

[0021] The method described in this application for extracting chamomile volatile oil has significantly better extraction rate and core component content than the traditional steam distillation method, and also has lower energy consumption and simpler process, showing good prospects for industrial application. Attached Figure Description

[0022] Figure 1 The total ion chromatogram of the chamomile volatile oil obtained in Example 1 is obtained by gas chromatography-mass spectrometry.

[0023] Figure 2 The total ion chromatogram of the chamomile volatile oil obtained in Comparative Example 1 is obtained by gas chromatography-mass spectrometry. Detailed Implementation

[0024] The present application will be further described in detail below with reference to embodiments, comparative examples and performance test results. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0025] Example

[0026] Example 1 Example 1 provides a method for extracting chamomile volatile oil.

[0027] The extraction method of chamomile volatile oil in Example 1 is as follows.

[0028] S1: Rinse freshly picked chamomile with clean water to remove impurities and residual moisture. Dry until there are no obvious water stains on the surface, and then weigh accurately. Soak 100g of clean chamomile in a 10wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10. Extract at 25℃ for 60 minutes. Filter and discard the extract to obtain the residue.

[0029] S2: Soak the residue from step S1 in a 65wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 min. Then, perform ultrasonic extraction for 60 min at an ultrasonic power of 150W. After extraction, let it stand for 10 min, filter, and collect the extract.

[0030] S3: Soak the residue from step S2 in a 90wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 min. Then, perform ultrasonic extraction for 60 min at an ultrasonic power of 150W. After extraction, let it stand for 10 min, filter, and collect the extract.

[0031] S4: Combine the extracts from steps S2 and S3 to obtain chamomile ethanol extract; subject the chamomile ethanol extract to rotary evaporation, salting out, and washing with water to obtain chamomile volatile oil.

[0032] The rotary evaporation method is as follows: the chamomile ethanol extract is placed in a 50°C water bath and reduced to 25 wt% under reduced pressure; anhydrous ethanol is added to the rotary evaporation flask to wash three times, each time the amount is 1 to 2 times the weight of the medicinal material, the washing liquid is combined with the remaining extract, and water is added to adjust the ethanol concentration of the system to 30 wt%.

[0033] The salting-out method is as follows: add 15wt% of a composite salting-out agent to the solution after rotary evaporation and dissolve it. Let it stand at room temperature for 12 hours. After the volatile oil completely floats to the surface of the liquid, collect the volatile oil. The composite salting-out agent is a mixture of sodium chloride, anhydrous magnesium sulfate, and potassium dihydrogen phosphate in a weight ratio of 4:1:1.

[0034] The washing method is as follows: wash three times with purified water to remove residual sodium chloride and ethanol, and then dry to obtain chamomile volatile oil.

[0035] like Figure 1 The figure shows the total ion chromatogram of the chamomile volatile oil obtained in Example 1, acquired by gas chromatography-mass spectrometry. As can be seen from the figure, the chamomile volatile oil contains five key characteristic active components: DL-Limonene: retention time 8.832 min, content 0.093%, belonging to monoterpenes; Linalool: retention time 20.604 min, content 0.122%, belonging to oxygenated monoterpenes, exhibiting significant sedative, anti-anxiety, anti-inflammatory, and antibacterial effects; Pinocarvone: retention time 21.827 min, content 5.763%, belonging to oxygenated monoterpenes; and Eugenol: retention time 49.922 min, content 0.315%, belonging to phenolic compounds. Bisabolol: It includes bisabolol oxide A (retention time 60.682 min, content 0.147%) and bisabolol oxide B (retention time 48.436 min, content 0.092%), with a total content of 0.239%, and has significant anti-inflammatory, analgesic and anti-allergic effects.

[0036] Examples 2-5 Examples 2-5 each provide a method for extracting chamomile volatile oil.

[0037] The difference between the above embodiment and embodiment 1 is that step S1 is different, as shown below.

[0038] In Example 2: Step S1 is as follows: Clean chamomile is soaked in a 15wt% ethanol aqueous solution at a material-to-liquid ratio of 1:8, and extracted at 25°C for 60 minutes. The extract is then filtered and discarded to obtain the residue.

[0039] In Example 3: Step S1 is as follows: Clean chamomile is soaked in a 5wt% ethanol aqueous solution at a material-to-liquid ratio of 1:8, and extracted at 25°C for 60 minutes. The extract is then filtered and discarded to obtain the residue.

[0040] In Example 4: Step S1 is as follows: Clean chamomile is soaked in a 20wt% ethanol aqueous solution at a material-to-liquid ratio of 1:8, and extracted at 25°C for 60 minutes. The extract is then filtered and discarded to obtain the residue.

[0041] In Example 5: Step S1 is as follows: Clean chamomile is soaked in a 15wt% ethanol aqueous solution at a material-to-liquid ratio of 1:8, and extracted at 30°C for 90 minutes. The extract is then filtered and discarded to obtain the residue.

[0042] All other process parameters in the above embodiments are the same as those in Embodiment 1.

[0043] Examples 6-8 Examples 6-8 provide a method for extracting chamomile volatile oil.

[0044] The difference between the above embodiment and embodiment 1 is that steps S2 and S3 are different, as shown below.

[0045] In Example 6: S2: The residue from step S1 was soaked in a 55wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 minutes. After soaking, ultrasonic extraction was performed for 60 minutes at an ultrasonic power of 150W. After extraction, the mixture was allowed to stand for 10 minutes, filtered, and the extract was collected.

[0046] S3: Soak the residue from step S2 in an 80wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 min. Then, perform ultrasonic extraction for 60 min at an ultrasonic power of 150W. After extraction, let it stand for 10 min, filter, and collect the extract.

[0047] In Example 7: S2: The residue from step S1 was soaked in a 50wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 minutes. After soaking, ultrasonic extraction was performed for 60 minutes at an ultrasonic power of 150W. After extraction, the mixture was allowed to stand for 10 minutes, filtered, and the extract was collected.

[0048] S3: Soak the residue from step S2 in a 100wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 minutes. Then, perform ultrasonic extraction for 60 minutes at an ultrasonic power of 150W. After extraction, let it stand for 10 minutes, filter, and collect the extract.

[0049] In Example 8: S2: The residue from step S1 was soaked in a 70wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 minutes. After soaking, ultrasonic extraction was performed for 60 minutes at an ultrasonic power of 150W. After extraction, the mixture was allowed to stand for 10 minutes, filtered, and the extract was collected.

[0050] S3: Soak the residue from step S2 in a 70wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 min. Then, perform ultrasonic extraction for 60 min at an ultrasonic power of 150W. After extraction, let it stand for 10 min, filter, and collect the extract.

[0051] All other process parameters in the above embodiments are the same as those in Embodiment 1.

[0052] Examples 9-12 Examples 9-12 provide a method for extracting chamomile volatile oil.

[0053] The difference between the above embodiments and Embodiment 1 is that the salting-out method is different, as shown below.

[0054] In Example 9: The composite salting-out agent is a mixture of sodium chloride, anhydrous magnesium sulfate and potassium dihydrogen phosphate in a weight ratio of 3:1.5:0.5.

[0055] In Example 10: The composite salting-out agent is a mixture of sodium chloride, anhydrous magnesium sulfate and potassium dihydrogen phosphate in a weight ratio of 5:1:0.2.

[0056] In Example 11, sodium chloride was used instead of the compound salting-out agent.

[0057] In Example 12: the composite salting-out agent is a mixture of sodium chloride, anhydrous magnesium sulfate and potassium dihydrogen phosphate in a weight ratio of 2:2:1.

[0058] All other process parameters in the above embodiments are the same as those in Embodiment 1.

[0059] Comparative Example Comparative Example 1 Comparative Example 1 provides a method for extracting chamomile volatile oil.

[0060] The extraction method for chamomile volatile oil in Comparative Example 1 was steam distillation, as detailed below.

[0061] S1: Rinse the freshly picked chamomile with clean water to remove impurities and residual moisture, and let it dry until there are no obvious water stains on the surface before weighing it accurately.

[0062] S2: Soak 100g of clean chamomile in an aqueous solution at a material-to-liquid ratio of 1:10 for 30 minutes. Heat the solution in an electric thermostatic water bath until it just boils and continue distilling for 6 hours. Stop heating when the amount of oil in the measuring device no longer increases. Let it stand for 30 minutes, collect the volatile oil and weigh it to obtain 1.55g of volatile oil, with an extraction rate of 1.55%.

[0063] like Figure 2 The figure shows the total ion chromatogram of chamomile volatile oil obtained in Comparative Example 1, acquired by gas chromatography-mass spectrometry. As can be seen from the figure, chamomile volatile oil contains three key characteristic active components: limonene (DL-Limonene): retention time 8.832 min, content 0.077%, a monoterpene; linalool: retention time 20.604 min, content 0.045%, belonging to oxygenated monoterpenes; and pinocalcinone: retention time 21.827 min, content 3.550%, belonging to oxygenated monoterpenes.

[0064] Comparative Example 2 Comparative Example 2 provides a method for extracting chamomile volatile oil.

[0065] S1: Rinse the freshly picked chamomile with clean water to remove impurities and residual moisture, and let it dry until there are no obvious water stains on the surface before weighing it accurately.

[0066] S2: Soak the residue from step S1 in a 65wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 min. Then, perform ultrasonic extraction for 60 min at an ultrasonic power of 150W. After extraction, let it stand for 10 min, filter, and collect the extract.

[0067] S3: Soak the residue from step S2 in a 90wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 min. Then, perform ultrasonic extraction for 60 min at an ultrasonic power of 150W. After extraction, let it stand for 10 min, filter, and collect the extract.

[0068] S4: Combine the extracts from steps S2 and S3 to obtain chamomile ethanol extract; subject the chamomile ethanol extract to rotary evaporation, salting out, and washing with water to obtain chamomile volatile oil.

[0069] The rotary evaporation method is as follows: the chamomile ethanol extract is placed in a 50°C water bath and reduced to 25 wt% under reduced pressure; anhydrous ethanol is added to the rotary evaporation flask to wash three times, each time the amount is 1 to 2 times the weight of the medicinal material, the washing liquid is combined with the remaining extract, and water is added to adjust the ethanol concentration of the system to 30 wt%.

[0070] The salting-out method is as follows: add 15wt% of a composite salting-out agent to the solution after rotary evaporation and dissolve it. Let it stand at room temperature for 12 hours. After the volatile oil completely floats to the surface of the liquid, collect the volatile oil. The composite salting-out agent is a mixture of sodium chloride, anhydrous magnesium sulfate, and potassium dihydrogen phosphate in a weight ratio of 2:1:1.

[0071] The washing method is as follows: wash three times with purified water to remove residual sodium chloride and ethanol, and then dry to obtain chamomile volatile oil.

[0072] Comparative Examples 3-5 Comparative Examples 3-5 each provide a method for extracting chamomile volatile oil.

[0073] The difference between the above comparative example and Example 1 is as follows:

[0074] In Comparative Example 3: Step S1 is as follows: Rinse freshly picked chamomile with clean water to remove impurities and residual moisture, and air dry until there are no obvious water stains on the surface, then weigh accurately. Soak 100g of clean chamomile in the aqueous solution at a material-to-liquid ratio of 1:10, extract at 25℃ for 60 minutes, filter and discard the extract to obtain the residue.

[0075] In Comparative Example 4: Step S1 is as follows: Rinse freshly picked chamomile with clean water to remove impurities and residual moisture, and air dry until there are no obvious water stains on the surface, then weigh accurately. Soak 100g of clean chamomile in a 30wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10, extract at 25℃ for 60min, filter and discard the extract to obtain the residue.

[0076] In Comparative Example 5: S2 was as follows: the residue from step S1 was soaked in 90wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 min, and then ultrasonically extracted for 60 min at an ultrasonic power of 150W. After extraction, the mixture was allowed to stand for 10 min, filtered, and the extract was collected.

[0077] S3 is as follows: Soak the residue from step S2 in a 90wt% ethanol aqueous solution at a material-to-liquid ratio of 1:10 for 90 min. After soaking, perform ultrasonic extraction for 60 min at an ultrasonic power of 150W. After extraction, let stand for 10 min, filter, and collect the extract.

[0078] All other process parameters in the above comparative examples are the same as those in Example 1.

[0079] Performance testing (1) Extraction rate The extraction rates of chamomile volatile oil in each example and comparative example were calculated using the following formula, and the results are shown in Table 1.

[0080] Extraction rate = (Total mass of chamomile volatile oil / Total mass of chamomile) × 100%.

[0081] (2) Analysis and detection of effective components The chemical composition of the chamomile volatile oil extracted in the examples and comparative examples was analyzed using gas chromatography-mass spectrometry (GC-MS). The GC and mass spectrometry parameters are as follows: Gas chromatography parameters: Column: Agilent HP-INNOWAX (60m column length, 0.25μm inner diameter, 0.25mm film thickness); Carrier gas: Helium (99.999% purity); Column flow rate: 1.5mL / min; Injector temperature: 250℃; Injection volume: 0.1μL; Split ratio: 40:1; Injection method: Direct injection; Temperature program: Initial temperature 60℃, increased to 100℃ at a rate of 4℃ / min, increased to 200℃ at a rate of 2℃ / min, held for 5min, increased to 240℃ at a rate of 4℃ / min, held for 30min.

[0082] Mass spectrometry parameters: Interface temperature: 250℃; Ion source temperature: 230℃; Ionization mode: EI; Solvent delay: 2 min; Scan mode: Full scan (FULLSCAN), scan range 28.5-300 amu.

[0083] Qualitative analysis was performed by searching the NIST spectral library, and quantitative analysis was performed by area normalization. The comparison results of the contents of the main core components are shown in Table 1.

[0084] Table 1. Extraction rate and active ingredient detection results of chamomile volatile oil in the examples and comparative examples.

[0085] As can be seen from the test results in Table 1 above, the extraction rate and core component content of chamomile volatile oil using the technical solution provided in this application are significantly better than those of the traditional steam distillation method (Comparative Example 1), and the energy consumption is lower, showing good prospects for industrial application.

[0086] Comparing the test results of Examples 1-5 and Comparative Examples 2-4, it can be seen that Comparative Example 2 did not use a low-concentration ethanol aqueous solution to remove impurities from chamomile, while Comparative Example 3 used an aqueous solution to remove impurities from chamomile, resulting in a lower content of the core components in the extracted chamomile volatile oil. Comparative Example 4 used a higher concentration of 30wt% ethanol aqueous solution to remove impurities from chamomile, resulting in a poor extraction rate of chamomile volatile oil. In contrast, this application utilizes a 5-20wt% ethanol aqueous solution to remove impurities from chamomile, significantly improving the extraction effect of chamomile volatile oil.

[0087] Comparing the test results of Examples 1, 6-8, and Comparative Example 5, it can be seen that the extraction efficiency of chamomile volatile oil was poor in Comparative Example 5, which used a high-concentration 90wt% ethanol aqueous solution for ultrasonic extraction. In contrast, this application utilizes a medium-concentration 50-70wt% ethanol aqueous solution followed by a high-concentration 70-100wt% ethanol aqueous solution for ultrasonic extraction of chamomile, resulting in a significant improvement in the extraction efficiency of chamomile volatile oil. By comparing the test results of Examples 1, 9-12, it can be seen that in the salting-out method, the present application uses a compound salting-out agent composed of sodium chloride, anhydrous magnesium sulfate and potassium dihydrogen phosphate in a weight ratio of 3-5:1-2:0.2-1, which further improves the extraction effect of chamomile volatile oil.

[0088] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for extracting chamomile volatile oil, characterized in that, Includes the following steps: S1: Soak chamomile in a 5-20 wt% ethanol aqueous solution and extract at a low temperature of 15-30℃ for 30-90 min. Filter and discard the extract. S2: Soak the residue from step S1 in a 50-70 wt% ethanol aqueous solution, then perform ultrasonic extraction, filter and collect the extract; S3: Soak the residue from step S2 in a 70-100 wt% ethanol aqueous solution, then perform ultrasonic extraction, filter, and collect the extract; S4: Combine the extracts from steps S2 and S3 to obtain chamomile ethanol extract; subject the chamomile ethanol extract to rotary evaporation, salting out, and washing with water to obtain chamomile volatile oil.

2. The method for extracting chamomile volatile oil according to claim 1, characterized in that, Step S1 is as follows: Soak chamomile in a 10-15 wt% ethanol aqueous solution at a material-to-liquid ratio of 1:5-15, extract at a low temperature of 15-25℃ for 30-60 minutes, filter and discard the extract to obtain the residue.

3. The method for extracting chamomile volatile oil according to claim 1, characterized in that, Step S2 is as follows: Soak the residue from step S1 in a 55-65 wt% ethanol aqueous solution at a material-to-liquid ratio of 1:5-15 for 30-180 min. Then, perform ultrasonic extraction for 30-90 min at an ultrasonic power of 100-300 W. After extraction, let it stand for 5-10 min, filter, and collect the extract.

4. The method for extracting chamomile volatile oil according to claim 1, characterized in that, Step S3 is as follows: Soak the residue from step S2 in an 80-90 wt% ethanol aqueous solution at a material-to-liquid ratio of 1:5-15 for 30-180 min. Then, perform ultrasonic extraction for 30-90 min at an ultrasonic power of 150-200 W. After extraction, let it stand for 5-10 min, filter, and collect the extract.

5. The method for extracting chamomile volatile oil according to claim 1, characterized in that, In step S4, the rotary evaporation method is as follows: the chamomile ethanol extract is placed in a water bath at 50~70℃ and the pressure is reduced to 20~30wt; anhydrous ethanol is added to wash 2~4 times, the washing liquid is combined with the remaining extract, and water is added to adjust the ethanol concentration of the system to 30~50wt.

6. The method for extracting chamomile volatile oil according to claim 1, characterized in that, In step S4, the salting-out method is as follows: add 10-20 wt% of a composite salting-out agent to the solution after rotary evaporation and dissolve it, let it stand at room temperature for 6-12 hours, and collect the volatile oil after the volatile oil has completely floated on the liquid surface. The composite salting-out agent is a mixture of sodium chloride, anhydrous magnesium sulfate, and potassium dihydrogen phosphate in a weight ratio of 3-5:1-2:0.2-1.

7. The method for extracting chamomile volatile oil according to claim 1, characterized in that, In step S4, the composite salting-out agent is a mixture of sodium chloride, anhydrous magnesium sulfate, and potassium dihydrogen phosphate in a weight ratio of 3-4:1-1.5:0.5-1.

8. A chamomile volatile oil, characterized in that, Obtained using the extraction method described in any one of claims 1 to 7.

9. The method for extracting chamomile volatile oil according to claim 8, characterized in that, The chamomile volatile oil contains the following components by weight percentage: linalool 0.091-0.13%, bisabolol 0.151-0.244%, eugenol 0.189-0.301%, carvacrol 4.597-5.748%, and limonene 0.079-0.107%.

10. The application of chamomile volatile oil as described in any one of claims 8 to 9 in the fields of medicine, cosmetics, and fragrance.

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