Method for extracting essential oil of traditional Chinese medicine abelmoschus manihot seeds by squeezing method

Abstract

The invention discloses a method for extracting traditional Chinese medicine abelmoschus manihot seed essential oil by using a squeezing method, and relates to the technical field of plant essential oil extraction, and the method comprises the following steps: (1) raw material pretreatment: selecting dried abelmoschus manihot seeds, removing impurities, cleaning with clear water, and then drying at a low temperature of 40-60 DEG C until the water content is lower than 8%; the dried abelmoschus manihot seeds are stir-fried in stir-frying equipment, the stir-frying temperature is controlled to be 120-180 DEG C, the stir-frying time is 20-40 minutes until the surfaces of the seeds are golden yellow, a double-squeezing technology combining mechanical squeezing and native squeezing is adopted, and the essential oil extraction rate is remarkably increased; the stir-frying process parameters are accurately controlled, so that active ingredients in the seeds are effectively activated; the crushing granularity is optimized, and the oil yield and the oil quality are balanced; no chemical solvent is added, so that the product is purely natural and high in safety; the essential oil is clear and transparent, low in impurity content and stable in quality; active ingredients are completely preserved, and the medicinal value is high.

Description

Technical Field

[0001] This invention relates to the field of plant essential oil extraction technology, specifically a method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method. Background Technology

[0002] Yellow hibiscus (Abelmoschus manihot L.) is a plant of the Malvaceae family. Its seeds are rich in oil and have important medicinal and edible value. Traditionally, yellow hibiscus seed oil is mainly used to treat edema, skin inflammation, and other diseases. It can also be used as a high-quality cosmetic ingredient and edible oil.

[0003] Currently, the main methods for extracting plant essential oils include: solvent extraction, which uses organic solvents such as petroleum ether and n-hexane, and carries the risk of solvent residue; supercritical fluid extraction, which requires large equipment investment and has high operating costs; steam distillation, which is suitable for volatile components but causes significant damage to heat-sensitive components; and traditional pressing, which results in low oil yield and unstable oil quality.

[0004] Existing technologies have the following shortcomings: chemical solvent extraction poses safety risks and does not meet green and environmental protection requirements; traditional pressing methods have low oil yield and poor economic benefits; active ingredients are easily destroyed during the extraction process; the oil is not pure and contains many impurities; and the production process is complex and difficult to scale up. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method. This method solves the technical problems of existing chemical solvent extraction methods, which have safety hazards, do not meet green and environmental protection requirements, have low oil yield and poor economic benefits, are easily destroyed by active ingredients during extraction, have low oil purity and contain many impurities, and have complex production processes that are difficult to scale up.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method, comprising the following steps: (1) Raw material pretreatment: Select dried okra seeds, remove impurities, wash them with clean water, and then dry them at a low temperature of 40-60℃ until the moisture content is less than 8%; (2) Seed roasting: The dried okra seeds are roasted in a roasting equipment. The roasting temperature is controlled at 120-180℃ and the roasting time is 20-40 minutes until the seed surface turns golden yellow. (3) Grinding process: The roasted okra seeds are ground to 30-40 mesh using a grinder to obtain seed powder; (4) Mechanical pressing: The seed powder is put into a mechanical press and pressed for the first time under a pressure of 20-40MPa and a temperature of 40-60℃, and the virgin oil is collected. (5) Traditional pressing: The oil residue after mechanical pressing is pressed a second time using traditional shrink pressing method, with a pressure of 10-20MPa and a duration of 30-60 minutes, and the second pressing oil is collected. (6) Oil filtration: The oil obtained from the two pressings is coarsely filtered through a 200-300 mesh sieve to remove larger particulate impurities; (7) Sedimentation treatment: Place the filtered oil in a sedimentation container and let it stand at 15-25℃ for 20-28 hours to settle; (8) Essential oil separation: The supernatant after precipitation was taken and filtered through a 0.45μm microporous membrane to obtain okra seed essential oil; (9) Product packaging: The filtered essential oil is bottled into glass bottles or food-grade plastic containers and sealed for storage.

[0007] Preferably, the frying equipment in step (2) is an iron pot or a boiler baking oven. The frying process is carried out by slow frying over a low flame, with the temperature controlled at 140-160℃ and the frying time at 25-35 minutes.

[0008] Preferably, the crushing in step (3) is carried out using a hammer mill, and the temperature is controlled not to exceed 50°C during the crushing process, and the particle size is controlled at 32-38 mesh.

[0009] Preferably, the mechanical pressing in step (4) is performed using a screw press with a pressing pressure of 25-35 MPa, a pressing temperature of 45-55℃, and a pressing speed controlled at 50-100 kg / h.

[0010] Preferably, the traditional shrink-pressing method described in step (5) uses hydraulic pressing, with the pressure gradually increasing from 5MPa to 20MPa, and the pressing time is 40-50 minutes.

[0011] Preferably, the precipitation process in step (7) is carried out under light-protected conditions, and the precipitation container is a stainless steel tank or a ceramic tank, with the precipitation temperature controlled at 18-22℃.

[0012] Preferably, the fine filtration in step (8) adopts a multi-layer filtration system, which sequentially passes through a 0.45μm microporous membrane, a 0.22μm microporous membrane and an activated carbon filtration layer.

[0013] Preferably, the packaging in step (9) uses brown glass bottles. Before filling, the packaging containers are dry-heat sterilized at 180-200℃ for 30-60 minutes, and nitrogen is immediately filled and sealed after filling.

[0014] Beneficial effects This invention provides a method for extracting essential oil from the seeds of the traditional Chinese medicine Hibiscus syriacus using a pressing method. It solves the technical problems of existing chemical solvent extraction methods, which suffer from safety hazards, failure to meet green and environmental protection requirements, low oil yield, poor economic efficiency, easy destruction of active ingredients during extraction, low oil purity, high impurity content, and complex production processes that hinder large-scale production. This invention employs a dual pressing process combining mechanical and traditional pressing, significantly improving the essential oil extraction rate. Precisely controlled roasting parameters effectively activate the active ingredients in the seeds. Optimized particle size balances oil yield and quality. No chemical solvents are added, resulting in a pure, natural, and highly safe product. The essential oil is clear and transparent, with low impurity content and stable quality. Active ingredients are fully preserved, resulting in high medicinal value. Extraction efficiency is 15-20% higher than traditional single pressing. The production process is simple, requiring less equipment investment. It is suitable for large-scale production, possesses both medicinal and edible value, can be used as a high-quality cosmetic raw material, has significant therapeutic effects on various diseases, is purely physical pressing with no environmental pollution, does not use chemical solvents, has no residue risk, and the production process meets green and environmental protection requirements. Detailed Implementation

[0015] The present invention will be further described in detail below through specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0016] Example 1: A method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method, comprising the following steps: (1) Raw material pretreatment: Select dried okra seeds, remove impurities, wash them with clean water, and then dry them at a low temperature of 50℃ until the moisture content is 7%; (2) Seed roasting: Roast the dried okra seeds over a low heat in an iron pot or boiler oven. The roasting temperature is controlled at 150℃ and the roasting time is 30 minutes until the seed surface turns golden yellow. (3) Grinding treatment: The roasted okra seeds were ground to 33 mesh at 50℃ using a grinder to obtain seed powder; (4) Mechanical pressing: The seed powder is put into a screw press and pressed for the first time under the conditions of pressure of 30MPa, temperature of 50℃ and pressing speed controlled at 80kg / h, and the virgin oil is collected. (5) Traditional pressing: The oil residue after mechanical pressing is pressed a second time using traditional shrink pressing, gradually increasing from 5MPa to 20MPa for 45 minutes, and the second pressing oil is collected. (6) Oil filtration: The oil obtained from the two pressings is coarsely filtered through a 250-mesh sieve to remove larger particulate impurities; (7) Sedimentation treatment: Place the filtered oil in a sedimentation container and let it stand at 20°C for 24 hours to settle; (8) Essential oil separation: The supernatant after precipitation was taken and filtered through a 0.45μm microporous membrane, a 0.22μm microporous membrane and an activated carbon filter layer in sequence to obtain okra seed essential oil; (9) Product packaging: The filtered essential oil is filled into glass bottles or food-grade plastic containers, sealed and stored. Before filling, the packaging containers are sterilized by dry heat at 190°C for 45 minutes. After filling, nitrogen is immediately filled and sealed.

[0017] Example 2: A method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method, comprising the following steps: (1) Raw material pretreatment: Select dried okra seeds, remove impurities, wash them with clean water, and then dry them at a low temperature of 60℃ until the moisture content is 8%; (2) Seed roasting: Roast the dried okra seeds over a low heat in an iron pot or boiler oven. The roasting temperature is controlled at 160℃ and the roasting time is 40 minutes until the seed surface turns golden yellow. (3) Crushing process: The roasted okra seeds were crushed to 38 mesh at 50℃ using a hammer mill to obtain seed powder; (4) Mechanical pressing: The seed powder is put into a mechanical press and pressed for the first time under the conditions of pressure of 35MPa, temperature of 55℃ and pressing speed controlled at 100kg / h, and the virgin oil is collected. (5) Traditional pressing: The oil residue after mechanical pressing is pressed a second time using traditional shrink pressing. The pressure is gradually increased from 5MPa to 20MPa and the duration is 50 minutes. The second pressing oil juice is collected. (6) Oil filtration: The oil obtained from the two pressings is coarsely filtered through a 300-mesh sieve to remove larger particulate impurities; (7) Sedimentation treatment: Place the filtered oil in a stainless steel or ceramic tank and let it stand at 22°C for 28 hours to settle. (8) Essential oil separation: The supernatant after precipitation was taken and filtered through a 0.45μm microporous membrane, a 0.22μm microporous membrane and an activated carbon filter layer in sequence to obtain okra seed essential oil; (9) Fill the filtered essential oil into glass bottles or food-grade plastic containers, seal and store. Before filling, sterilize the packaging container with dry heat at 200°C for 60 minutes, and immediately fill with nitrogen and seal after filling.

[0018] Comparative Example 1 Traditional single pressing method: only mechanical pressing is used, without traditional secondary pressing.

[0019] Comparative Example 2 Solvent extraction method: Extraction is performed using n-hexane as a solvent.

[0020] Extraction efficiency comparison Extraction method Oil yield (%) Extraction time (h) Example 1 18.5 2.5 Example 2 19.2 3.0 Comparative Example 1 15.3 2.0 Comparative Example 2 22.6 6.0 Essential oil quality analysis Testing items Example 1 Comparative Example 2 Acid value (mgKOH / g) 1.2±0.2 0.8±0.1 Peroxide value (mmol / kg) 3.5±0.3 2.8±0.2 Impurity content (%) 0.12±0.03 0.08±0.02 Solvent residue Not detected n-Hexane detected Active ingredient analysis The content of the main active ingredients was determined by HPLC. Element Example 1 (mg / g) Comparative Example 2 (mg / g) Total flavonoids 12.5±0.8 15.2±1.2 Phytosterols 8.6±0.5 9.8±0.7 Vitamin E 5.3±0.3 6.2±0.4 Stability test Store at 25°C and 60% relative humidity for 12 months: Storage time Example 1: Change in acid value Comparative Example 2: Changes in Acid Value 0 months 1.2 0.8 6 months 1.8 1.5 12 months 2.5 3.2 Application effect evaluation Sixty patients with skin allergies were selected and the product from Example 1 was used: Overall effectiveness: 91.7% Average time to see results: 2.3 days Adverse reaction rate: 3.3% Sensory evaluation Organize professional perfumers to evaluate the essential oils: Color: Golden and transparent Scent: Pure and refreshing Texture: Refreshing and non-greasy Overall rating: Excellent This invention successfully established a highly efficient and safe process for extracting essential oil from okra seeds through optimized pressing parameters and a unique double-pressing method. Compared with traditional methods, this invention demonstrates significant advantages in extraction efficiency, product quality, and safety, providing reliable technical support for the intensive processing and comprehensive utilization of okra seeds.

[0021] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

Claims

1. A method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method, characterized in that, Includes the following steps: (1) Raw material pretreatment: Select dried okra seeds, remove impurities, wash them with clean water, and then dry them at a low temperature of 40-60℃ until the moisture content is less than 8%; (2) Seed roasting: The dried okra seeds are roasted in a roasting equipment. The roasting temperature is controlled at 120-180℃ and the roasting time is 20-40 minutes until the seed surface turns golden yellow. (3) Crushing process: The roasted okra seeds are crushed to 30-40 mesh using a crusher to obtain seed powder; (4) Mechanical pressing: The seed powder is put into a mechanical press and pressed for the first time under a pressure of 20-40MPa and a temperature of 40-60℃. The virgin oil is collected. (5) Traditional pressing: The oil residue after mechanical pressing is pressed a second time using traditional shrink pressing method, with a pressure of 10-20MPa and a duration of 30-60 minutes, and the second pressing oil is collected. (6) Oil filtration: The oil obtained from the two pressings is coarsely filtered through a 200-300 mesh sieve to remove larger particulate impurities; (7) Sedimentation treatment: Place the filtered oil in a sedimentation container and let it stand at 15-25℃ for 20-28 hours to settle. (8) Essential oil separation: The supernatant after precipitation was taken and filtered through a 0.45μm microporous membrane to obtain okra seed essential oil; (9) Product packaging: The filtered essential oil is bottled into glass bottles or food-grade plastic containers and sealed for storage.

2. The method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method according to claim 1, characterized in that, The frying equipment mentioned in step (2) is an iron pot or a boiler baking oven. The frying process is carried out by slow frying over a low flame, with the temperature controlled at 140-160℃ and the frying time at 25-35 minutes.

3. The method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method according to claim 1, characterized in that, The crushing process in step (3) uses a hammer mill. During the crushing process, the temperature is controlled to not exceed 50°C and the particle size is controlled to be 32-38 mesh.

4. The method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method according to claim 1, characterized in that, The mechanical pressing in step (4) uses a screw press with a pressing pressure of 25-35 MPa, a pressing temperature of 45-55℃, and a pressing speed of 50-100 kg / h.

5. The method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method according to claim 1, characterized in that, The traditional shrink-pressing method described in step (5) uses hydraulic pressing, with the pressure gradually increasing from 5MPa to 20MPa, and the pressing time is 40-50 minutes.

6. The method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method according to claim 1, characterized in that, The precipitation process described in step (7) is carried out under light-protected conditions. The precipitation container is a stainless steel tank or a ceramic tank, and the precipitation temperature is controlled at 18-22℃.

7. The method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method according to claim 1, characterized in that, The fine filtration in step (8) uses a multi-layer filtration system, which sequentially passes through a 0.45μm microporous membrane, a 0.22μm microporous membrane, and an activated carbon filtration layer.

8. The method for extracting essential oil from seeds of the traditional Chinese medicine okra using a pressing method according to claim 1, characterized in that, The packaging described in step (9) uses brown glass bottles. Before filling, the packaging containers are dry-heat sterilized at 180-200℃ for 30-60 minutes. After filling, they are immediately sealed with nitrogen.