Extraction process of wormwood blue essential oil

Abstract

The invention relates to an extraction process of wormwood blue essential oil, and aims to improve the yield, purity and color stability of essential oil. The process comprises the following steps: taking fresh wormwood, carrying out cold soaking treatment, and adding ethanol to enhance the dissolution of effective components; essential oil is extracted through heating reflux, citric acid is added in the extraction process to adjust the pH value, and the color of the essential oil is stabilized; the oil-water separation adopts a mode of combining standing and centrifugal separation, so that the purity of the essential oil is ensured. Anhydrous sodium sulfate or a molecular sieve is adopted for essential oil dehydration treatment, residual moisture is removed, and the stability of the essential oil is ensured. In addition, the ultrasonic-assisted extraction technology is combined, release of volatile oil is accelerated, the extraction efficiency is improved, the wormwood raw material is refrigerated, and loss of effective components is avoided. The method is simple in process and high in operability, and the obtained essential oil is high in purity and stable in color and has wide application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of wormwood essential oil, in particular to an extraction process of wormwood blue essential oil. Background Art

[0002] Artemisia argyi is a perennial herbaceous plant of the Asteraceae family, widely distributed in many Asian countries, especially in China, South Korea and Japan, with a long history of medicinal and folk use. As a commonly used medicinal material in traditional Chinese medicine, wormwood has attracted much attention due to its rich volatile oil components. Its extracts have multiple biological activities such as anti-inflammatory, antibacterial, and antioxidant. Wormwood is not only widely used in the field of traditional Chinese medicine, but also has important application value in modern cosmetics, food additives and aromatherapy health products. In particular, wormwood essential oil, due to its natural pharmacological activity, is widely used in insect repellent, antibacterial, antiseptic, pain relief and other aspects.

[0003] In recent years, with the increasing attention paid to natural plant extracts, the extraction process of wormwood essential oil has gradually become a research hotspot. However, the traditional extraction method mainly uses steam distillation. Although this method is simple and easy to use, it has problems such as low extraction efficiency and unstable essential oil quality. In particular, the color of the extracted wormwood essential oil is often yellow or light yellow, lacking visual appeal. This color is mainly due to the destruction of certain active ingredients during the extraction process, or the ineffective collection of volatile components, resulting in the lack of antioxidant sesquiterpenoid components in the extracted essential oil, and the inability to form high value-added blue wormwood essential oil.

[0004] As a high-end product among wormwood essential oils, the unique color of blue essential oil comes from specific compounds in the essential oils, especially the stability and content of sesquiterpenoid components. However, due to improper temperature control, unreasonable extraction time, incomplete oil-water separation and other factors in the traditional process during the extraction process, sesquiterpenoid compounds are easily decomposed, thereby affecting the color and quality of the essential oils. In addition, the oil-water separation efficiency during the extraction process is low, resulting in low purity of the essential oils. At the same time, the residual moisture is also easy to cause oxidation or deterioration of the essential oils, further affecting the pharmacological and aroma properties of the essential oils. Therefore, how to improve the extraction efficiency of wormwood essential oils, maintain its natural active ingredients, and enhance the color stability and purity of the essential oils has become a problem to be solved in the current technical field.

[0005] In order to overcome these shortcomings, the present invention provides an extraction process of wormwood blue essential oil. Summary of the invention

[0006] The purpose of the present invention is to provide an extraction process of blue wormwood essential oil in view of the shortcomings of the prior art, so as to solve the problems raised in the background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: a process for extracting blue wormwood essential oil, the process comprising the following steps:

[0008] Step 1: Take the above-ground parts of fresh wormwood, including stems and leaves, weigh them and place them in a volatile oil extraction tank, add 2-4 times the volume of water, and soak them at room temperature for 1 to 3 hours;

[0009] Step 2: heating the wormwood treated in step 1 to 80° C. to 100° C. in an extraction tank, maintaining a constant temperature, and extracting by steam reflux circulation for 3 to 5 hours;

[0010] Step 3: separating the reflux condensate obtained in step 2 into oil and water, and returning the separated water layer to the extraction tank after standing and separating, and collecting the oil layer to obtain the preliminarily extracted wormwood essential oil;

[0011] Step 4: Dehydrate the wormwood essential oil obtained in step 3, and use anhydrous sodium sulfate or a dehydrated molecular sieve as a water absorbent to obtain high-purity wormwood blue essential oil.

[0012] As a preferred technical solution of the present invention, the cold soaking time in step 1 is 2 hours, and 0.5%-1% ethanol is added during the cold soaking process to enhance the permeability of the wormwood cell wall and promote the dissolution of the active ingredients.

[0013] As a preferred technical solution of the present invention, during the extraction in step 2, the pH value of the extract in the extraction tank is adjusted to 4-6 by adding 0.1%-0.5% citric acid to stabilize the color of the blue essential oil and prevent it from oxidative discoloration during the extraction process.

[0014] As a preferred technical solution of the present invention, the reflux extraction in step 2 is condensed by increasing the cooling rate of the reflux condensation system to reduce the loss of volatile components in the essential oil, thereby improving the aroma retention and purity of the essential oil.

[0015] As a preferred technical solution of the present invention, the oil-water separation in step 3 adopts a combination of static separation and centrifugal separation. The water layer is firstly removed by static separation, and then the oil-water separation efficiency is further improved by centrifugal separation to ensure the purity of the essential oil layer.

[0016] As a preferred technical solution of the present invention, the wormwood essential oil separated in step 3 is filtered through a 0.22 μm microfiltration membrane before storage to remove fine impurities and improve the purity and stability of the essential oil.

[0017] As a preferred technical solution of the present invention, the amount of anhydrous sodium sulfate or dehydrating molecular sieve used in the dehydration treatment in step 4 is 5%-10% of the weight of the essential oil, the treatment time is 4 to 6 hours, and the essential oil is kept at a constant temperature of 30°C to 40°C during the dehydration process to avoid the loss of volatile components.

[0018] As a preferred technical solution of the present invention, the wormwood is harvested in the early morning before the dew dries up to maintain the high content of volatile oil in the wormwood. After picking, it is immediately refrigerated to avoid the loss of volatile oil components caused by storing the wormwood in a high temperature environment.

[0019] As a preferred technical solution of the present invention, the extraction process in step 2 is combined with ultrasonic-assisted extraction technology, which accelerates the release of wormwood volatile oil through the destruction of wormwood cell walls by ultrasonic frequencies of 20-40kHz, thereby improving the extraction efficiency of the essential oil.

[0020] As a preferred technical solution of the present invention, the obtained wormwood blue essential oil is dark blue and rich in sesquiterpenoid compounds, which have high antioxidant activity. The obtained essential oil has high purity and stable color and is suitable for use in the fields of medicine, cosmetics, aromatherapy, etc.

[0021] Compared with the prior art, the invention has the following beneficial effects: the blue essential oil extraction process of wormwood provided by the invention significantly improves the release efficiency of volatile oil in wormwood through cold soaking treatment, ethanol-assisted extraction, pH value adjustment and other methods, effectively retains key active ingredients such as sesquiterpenes, and ensures that the extracted essential oil has a stable blue color. This improvement makes the extraction efficiency higher and the yield larger, and greatly improves the extraction rate of essential oil and the added value of products compared with traditional processes.

[0022] In addition, the oil-water separation technology in the process uses a combination of static separation and centrifugal separation to ensure the thoroughness of the separation process, thereby greatly improving the purity of the essential oil. At the same time, the dehydration treatment uses anhydrous sodium sulfate or dehydrating molecular sieves to effectively remove residual water, ensure the long-term stability of the essential oil, and avoid oxidation and deterioration caused by residual water. The combination of these steps ensures that the quality of the essential oil is improved in terms of purity, aroma and color.

[0023] Finally, the ultrasonic-assisted extraction and cold storage treatment technology in the present invention further improves the release rate of volatile oils and reduces the loss of effective ingredients of wormwood after collection, thereby maximizing the medicinal and aroma value of the essential oil. This comprehensive extraction process can produce wormwood blue essential oil with high purity, stable color and rich aroma, meeting the market demand for high-quality essential oil products. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The specific implementation of the present invention is described in detail below in conjunction with multiple embodiments.

[0026] Example 1: Implementation of basic extraction process

[0027] Specific steps:

[0028] Materials: Collect the above-ground parts of fresh wormwood, including stems and leaves. In order to ensure the integrity of the essential oil components in wormwood, select freshly harvested wormwood, weigh 500g immediately after collection, and place it in a volatile oil extraction tank. Add 1500ml of distilled water, and control the volume ratio of water to wormwood to 3:1. Cold soak at room temperature for 2 hours to promote the release of active ingredients in wormwood.

[0029] Heating extraction: After the cold soaking treatment is completed, the heating system of the extraction tank is started, and the temperature is gradually raised to 90°C and kept constant for 4 hours. In this process, the steam reflux circulation extraction method is adopted. The volatile oil is distilled out with the steam and enters the condensation system for cooling. The volatile oil in the reflux liquid is gradually deposited above the oil layer.

[0030] Oil-water separation: After the extraction is completed, the reflux condensate is introduced into the oil-water separation device, and the water layer and the oil layer are naturally separated by static separation. The separated water layer flows back to the extraction tank to continue to participate in the extraction, while the oil layer is collected in the container, and the preliminary extracted wormwood essential oil is obtained.

[0031] Dehydration treatment: In order to remove the residual water in the essential oil, anhydrous sodium sulfate is used for dehydration treatment. Anhydrous sodium sulfate is added at 8% of the weight of the essential oil, the temperature is controlled at 35°C, and the dehydration time is 5 hours. After treatment, the purity of the essential oil is greatly improved, and high-purity blue wormwood essential oil is obtained.

[0032] Experimental data: In this embodiment, with 500g of wormwood raw material, a total of 20ml of blue wormwood essential oil was obtained after extraction and dehydration. The main components and physical properties of the essential oil were good. The experimental data are shown in Table 1:

[0033] parameter Numeric Raw material (g) 500 Amount of water added (ml) 1500 Extraction time (hours) 4 Essential oil yield (ml / 500g wormwood) 20 Essential oil color Dark Blue Essential oil purity (%) 95.2 odor Rich aroma pH 5.1 Dehydration temperature (℃) 35 Dehydration treatment time (hours) 5

[0034] Example 2: Extraction process using ethanol-assisted cold soaking

[0035] Specific steps:

[0036] Materials: 500 g of fresh wormwood was collected and placed in an extraction tank. In order to enhance the permeability of the wormwood cell wall and promote the dissolution of the active ingredients, ethanol (1%, i.e., 15 ml) was added during the cold soaking process, and the cold soaking time was still 2 hours.

[0037] Heating extraction: After the cold soaking is completed, the temperature of the extraction tank is gradually raised to 90°C and maintained for 4 hours for reflux circulation extraction. During this process, the addition of ethanol can effectively enhance the solubility of the active ingredients in wormwood, thereby improving the extraction efficiency.

[0038] Oil-water separation: After the extraction is completed, the water layer and the oil layer are separated by static separation. In order to further improve the separation efficiency, centrifugal separation is also used to ensure the purity of the essential oil layer. The centrifugal separation parameters are set to 3000rpm and the centrifugal time is 15 minutes.

[0039] Dehydration treatment: Same as in Example 1, using anhydrous sodium sulfate for dehydration, the treatment time is 5 hours, and the dehydration treatment temperature is controlled at 35°C.

[0040] Experimental data: After adding ethanol, the cold soaking process is more effective and the final essential oil yield is increased. The experimental data is shown in Table 2:

[0041] parameter Numeric Raw material (g) 500 Amount of water added (ml) 1500 Amount of ethanol added (ml) 15 Extraction time (hours) 4 Essential oil yield (ml / 500g wormwood) 23 Essential oil color Dark Blue Essential oil purity (%) 97.0 odor The aroma is more intense pH 5.0 Centrifugal separation speed (rpm) 3000 Centrifugation time (minutes) 15

[0042] Example 3: Extraction process of blue essential oil stabilized by pH adjustment

[0043] Specific steps:

[0044] Materials: After collecting 500g of fresh wormwood, add 1500ml of distilled water, and add 0.2% citric acid (3g) during cold soaking to adjust the pH value of the solution to 5. This acidification treatment can prevent the essential oil from changing color due to oxidation during the extraction process, making the blue essential oil more stable.

[0045] Heating extraction: After 2 hours of cold soaking, the extraction tank is heated to 90°C and refluxed for 4 hours. During the extraction process, the pH value adjustment can prevent the decomposition of the sesquiterpenoid components in the essential oil and maintain the blue color.

[0046] Oil-water separation: The static separation method is also used, and the water layer is recycled for subsequent extraction. The oil layer is separated by centrifugation to improve the purity of the essential oil.

[0047] Dehydration treatment: Dehydration treatment is carried out as in Example 1 to ensure the high purity of the essential oil.

[0048] Experimental data: After pH adjustment, the color stability of essential oils is greatly enhanced. The experimental data are shown in Table 3:

[0049] parameter Numeric Raw material (g) 500 Amount of water added (ml) 1500 Citric acid addition amount (g) 3 pH 5 Extraction time (hours) 4 Essential oil yield (ml / 500g wormwood) 21 Essential oil color Dark blue, stable color Essential oil purity (%) 96.3 odor Rich aroma Centrifugal separation speed (rpm) 3000 Centrifugation time (minutes) 15

[0050] Example 4: Ultrasonic assisted extraction process

[0051] Specific steps:

[0052] Materials: Collect 500g of mugwort and add 1500ml of distilled water.

[0053] Ultrasonic assisted extraction: During the extraction process, ultrasonic assisted extraction technology was used, with the ultrasonic frequency set to 30kHz, the amplitude to 50%, and the processing time to 2 hours. The high-frequency vibration of ultrasound can effectively destroy the cell wall of wormwood and promote the release of volatile oil. Subsequently, conventional reflux extraction was carried out, and the total extraction time was 3 hours.

[0054] Oil-water separation: The condensate after extraction is separated by standing and centrifugation, and the oil layer is collected for subsequent treatment.

[0055] Dehydration treatment: Same as in Example 1, using anhydrous sodium sulfate for dehydration to ensure the purity of the essential oil.

[0056] Experimental data: Ultrasonic assisted extraction significantly improved the extraction efficiency, and the yield and purity of essential oil increased. The experimental data are shown in Table 4:

[0057] parameter Numeric Raw material (g) 500 Amount of water added (ml) 1500 Ultrasonic frequency (kHz) 30 Ultrasonic treatment time (hours) 2 Extraction time (hours) 3 Essential oil yield (ml / 500g wormwood) 27 Essential oil color Dark Blue Essential oil purity (%) 98.1 odor The aroma is more intense Centrifugal separation speed (rpm) 3000 Centrifugation time (minutes) 15

[0058] Example 5: Raw material extraction process after cold storage

[0059] Specific steps:

[0060] Materials collection: In order to retain the volatile oil components in wormwood to the maximum extent, this embodiment selects to collect 500g of fresh wormwood in the early morning when the dew has not dried, and immediately puts it in a 4°C refrigerated environment for 4 hours after picking to prevent the volatile oil components of wormwood from being lost at high temperature. After the refrigeration treatment is completed, the wormwood is placed in a volatile oil extraction tank, 1500ml of distilled water is added, and cold soaking treatment is carried out at room temperature for 2 hours.

[0061] Heating extraction: After the cold soaking, the extraction tank is gradually heated to 90°C, and the volatile oil is extracted by reflux circulation extraction method for 4 hours. During the extraction process, the volatile oil is condensed and collected through the condensation system, and the reflux liquid enters the oil-water separation device.

[0062] Oil-water separation: After the extraction is completed, the condensate is separated into an oil layer and a water layer by static separation. Since the volatile oil content in the wormwood is high after refrigeration treatment, the effective ingredients in the water layer are reduced. After static separation, the water layer is returned to the extraction tank for subsequent extraction, and the oil layer is collected in a container. In order to further improve the purity of the essential oil, centrifugal separation is performed, with a centrifugal parameter of 3000rpm and a centrifugal time of 15 minutes.

[0063] Dehydration treatment: After oil-water separation, anhydrous sodium sulfate is added as a dehydrating agent at 8% of the weight of the essential oil, the temperature is maintained at 35°C, and the dehydration time is 5 hours to ensure the high purity and stability of the essential oil.

[0064] Experimental data: Since the refrigeration treatment delayed the loss of volatile oil components of wormwood, the yield and purity of the extracted essential oil were significantly improved. The experimental data are shown in Table 5:

[0065] parameter Numeric Raw material (g) 500 Amount of water added (ml) 1500 Refrigeration temperature (℃) 4 Refrigeration time (hours) 4 Extraction temperature (℃) 90 Extraction time (hours) 4 Essential oil yield (ml / 500g wormwood) 25 Essential oil color Dark Blue Essential oil purity (%) 96.7 odor Rich aroma Centrifugal separation speed (rpm) 3000 Centrifugation time (minutes) 15 Dehydration temperature (℃) 35 Dehydration treatment time (hours) 5

[0066] Summary and Analysis

[0067] It can be seen from the above examples that different treatment processes have a significant impact on the extraction effect of wormwood blue essential oil. The following is a comparative data table of the extraction effects of each example (Table 6):

[0068]

[0069] From the comparison in Table 6, it can be seen that ultrasonic-assisted extraction (Example 4) and cold storage (Example 5) significantly improved the yield and purity of the essential oil, and the dark blue stability of the essential oil was good. Ethanol-assisted cold soaking (Example 2) and pH adjustment (Example 3) also had a very obvious effect on the optimization of the extraction process. The essential oils obtained in each embodiment have good aroma and color stability, and are suitable for applications in various fields.

[0070] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An extraction process for blue wormwood essential oil, characterized in that: The process includes the following steps: Step 1: Take the above-ground parts of fresh wormwood, including stems and leaves, weigh them and place them in a volatile oil extraction tank, add 2-4 times the volume of water, and soak them at room temperature for 1 to 3 hours; Step 2: heating the wormwood treated in step 1 to 80° C. to 100° C. in an extraction tank, maintaining a constant temperature, and extracting by steam reflux circulation for 3 to 5 hours; Step 3: separating the reflux condensate obtained in step 2 into oil and water, and returning the separated water layer to the extraction tank after standing and separating, and collecting the oil layer to obtain the preliminarily extracted wormwood essential oil; Step 4: Dehydrate the wormwood essential oil obtained in step 3, and use anhydrous sodium sulfate or a dehydrated molecular sieve as a water absorbent to obtain high-purity wormwood blue essential oil.

2. The extraction process of blue wormwood essential oil according to claim 1, characterized in that: The cold soaking time in step 1 is 2 hours, and 0.5%-1% ethanol is added during the cold soaking process to enhance the permeability of the wormwood cell wall and promote the dissolution of the active ingredients.

3. The extraction process of wormwood blue essential oil according to claim 1, characterized in that, During the extraction in step 2, the pH value of the extract in the extraction tank is adjusted to 4-6 by adding 0.1%-0.5% citric acid.

4. The extraction process of wormwood blue essential oil according to claim 1, characterized in that, The reflux extraction in step 2 is performed by increasing the cooling rate of the reflux condensation system to reduce the loss of volatile components in the essential oil.

5. The extraction process of wormwood blue essential oil according to claim 1, characterized in that, The oil-water separation in step 3 is carried out by combining static separation with centrifugal separation. The water layer is initially removed by static separation, and then the oil-water separation efficiency is further improved by centrifugal separation.

6. The extraction process of wormwood blue essential oil according to claim 1, characterized in that: The wormwood essential oil separated in step 3 is filtered through a 0.22 μm microfiltration membrane before storage to remove fine impurities.

7. The extraction process of blue wormwood essential oil according to claim 1, characterized in that: The amount of anhydrous sodium sulfate or dehydrating molecular sieve used in the dehydration treatment in step 4 is 5%-10% of the weight of the essential oil, the treatment time is 4 to 6 hours, and the essential oil is kept at a constant temperature of 30° C. to 40° C. during the dehydration process.

8. The extraction process of wormwood blue essential oil according to claim 1, characterized in that: The best time to harvest mugwort is in the early morning when the dew has not dried yet. After picking, it should be immediately refrigerated to avoid the loss of volatile oil components caused by storing mugwort in a high temperature environment.

9. The extraction process of wormwood blue essential oil according to claim 1, characterized in that: The extraction process in step 2 is combined with ultrasonic assisted extraction technology, which accelerates the release of volatile oil from mugwort through the destruction of mugwort cell walls by ultrasonic frequencies of 20-40kHz, thereby improving the extraction efficiency of essential oils.

10. The extraction process of blue wormwood essential oil according to claim 1, characterized in that: The obtained wormwood blue essential oil is dark blue and rich in sesquiterpenoid compounds, which have high antioxidant activity. The obtained essential oil has high purity and stable color and is suitable for the fields of medicine, cosmetics and aromatherapy.

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