Method for extracting high-quality oil by combining supercritical CO2 with molecular distillation

Abstract

A method for extracting high-quality oil by combining supercritical CO2 with molecular distillation is characterized in that raw materials are extracted by a supercritical system, supercritical qualified oil, to-be-separated oil and supercritical unqualified oil are collected, and the to-be-separated oil is immediately fractionated by a molecular distillation system to obtain molecular distillation qualified oil; the supercritical qualified oil is oil which is liquid at normal temperature, free of water and macroscopic impurities, less than 2 mg / g in acid value and less than 0.1% in peroxide value. The qualified molecular distillation oil is immediately combined with the supercritical qualified oil to obtain mixed qualified oil, so that natural antioxidant substances in the supercritical qualified oil are effectively utilized, and disqualification caused by the fact that the acid value and the peroxide value of the qualified molecular distillation oil are increased to exceed the national standard limit due to long-term storage is avoided; the oil yield of the mixed qualified oil is higher than that of conventional supercritical extraction, the quality is stable, the acid value is smaller than 4 mg / g after the mixed qualified oil is placed at normal temperature for 12 months, and the peroxide value is smaller than 0.25%. The utilization value of the raw materials and the economic benefit are improved.

Description

Technical Field

[0001] The invention belongs to the field of natural product extraction, relates to the technical field of processing and utilization of edible oils and fats, and specifically relates to a method for extracting oils and fats from natural products. Background Art

[0002] Supercritical carbon dioxide (CO 2 ) Extraction technology refers to contacting supercritical carbon dioxide with the substance to be separated under supercritical conditions, so that it can selectively extract components of polarity, boiling point and molecular weight in turn. At the same time, the density, polarity and dielectric constant of supercritical carbon dioxide increase with the increase of closed system pressure, and components of different polarities can be extracted step by step by increasing the pressure. The mixed components are obtained by controlling the conditions, and then the supercritical carbon dioxide is turned into gas by reducing pressure and increasing temperature. The extracted substances are automatically and completely precipitated step by step, thereby achieving the purpose of separation and purification, and combining the extraction and separation processes into one. But supercritical CO 2 There are many types of components extracted, including various fatty acids, sterols, unsaponifiable matter, trace amounts of water and other impurities. As the temperature rises and the time increases, the acid value will increase rapidly and the peroxide value will increase slowly, and eventually they will exceed the qualified standards for vegetable crude oil specified in GB 2716 National Food Safety Standard Vegetable Oil, that is, acid value ≤4mg / g, peroxide value ≤0.25%.

[0003] Patented supercritical CO 2 Method for stepwise extraction and separation of coix lacrymate and coix seed oil (CN101863764A) and patented supercritical CO 2 The method for extracting and grading and purifying Ganoderma lucidum spore oil (CN101845361A) uses a step-by-step extraction and graded purification method to separate qualified oil and unqualified oil, and the criteria for judging qualified oil and unqualified oil are based on the color and morphology of the collected material. After that, the oils and fats of some time periods are extracted to detect the acid value and peroxide value. For example, in Table 1 in CN101845361A, the collection time period 0-4.5 hours of separation kettle 1 are all qualified products, and the qualified oleic acid value of separation kettle II is mostly greater than 2 mg / g. It can be seen that the quality of the oil in the separation kettle has a certain continuity, showing a trend of: better-good-better-bad. It was found through testing that when a good quality oil with an acid value of ≥4 mg / g and a peroxide value of <0.25% is mixed with a good quality oil with an acid value of 0-2 mg / g and a peroxide value of 0-0.1%, after long-term storage (180-360 days), the acid value may rise to ≥4 mg / g, and the peroxide value may rise to ≥0.25%, causing the quality of the entire mixed oil to decline and become unqualified oil. Therefore, the quality of the qualified oil produced by the above two patents is unstable.

[0004] Molecular distillation is a special liquid-liquid separation technology. It is different from traditional distillation, which relies on the separation principle of boiling point difference. Instead, it achieves separation by the difference in the mean free path of the molecules of different substances. When the liquid mixture flows along the heating plate and is heated, the light and heavy molecules will escape from the liquid surface and enter the gas phase. Since the free paths of light and heavy molecules are different, the molecules of different substances move different distances after escaping from the liquid surface. If a condensation plate can be properly set, the light molecules will reach the condensation plate and be condensed and discharged, while the heavy molecules will not reach the condensation plate and will be discharged along the mixed liquid. In this way, the purpose of material separation is achieved.

[0005] Molecular distillation can effectively reduce the acid value and peroxide value of oils and fats extracted by various methods. However, when the heating temperature is too high, the light molecular fatty acids and bioactive components in the oils and fats are easily decomposed at high temperature and distilled to the condenser together with the light molecules and removed (Study on the process of molecular distillation and refining of Ganoderma lucidum spore oil [J], Zhang Xinxin et al., China Oils and Fats, 2013, 38 (7): 12-25). Molecular distillation will separate natural vitamin E, various plant sterols and other light molecules into unqualified oils while separating oil components, resulting in the lack of these natural antioxidants in the molecular distillation qualified oil to inhibit the increase of peroxide value (Application of molecular distillation in extracting natural VE [J], Bai Qunan, Feed Wide Angle, 2008, (7): 32-41). After stability testing, it was found that the acid value of molecular distillation qualified oil stored alone would rise slowly and the peroxide value would rise rapidly during long-term storage. Especially when the peroxide value of the raw material for molecular distillation, i.e., the supercritical unqualified oil, is ≥0.5%, even at a heating temperature of 250°C and a feed rate of ≤0.5kg / h×m -2 Under the conditions, the peroxide value of the molecular distillation qualified oil cannot be reduced to <0.25%, and the peroxide value of the molecular distillation qualified oil obtained will quickly rise again to ≥0.5% within 30 days.

[0006] Other patents use chemically synthesized vitamin C, vitamin E, adsorbents or organic solvents such as ethanol to synthesize vitamin C and vitamin E in supercritical CO. 2 Treatment of the raw materials or the extracted oil before, during or after extraction to reduce the acid value and peroxide value of the extracted oil. These treatments increase costs and make the oil unable to obtain organic certification. Summary of the invention

[0007] The purpose of the present invention is to overcome the current conventional supercritical CO 2 The color and morphology of the collected products are used as the judging criteria during the extraction and segmentation collection, which leads to the defects of unstable product quality and short shelf life. The present invention provides a supercritical CO extraction method with stable product quality, long shelf life and practical application. 2 Methods of extracting oil.

[0008] The technical solution adopted by the present invention is: a supercritical CO 2 The method for extracting high-quality oil by molecular distillation has the following key points: the raw material is extracted by a supercritical system, supercritical qualified oil, oil to be separated and supercritical unqualified oil are collected, and the oil to be separated is immediately distilled by a molecular distillation system to obtain molecular distillation qualified oil and molecular distillation unqualified oil; the supercritical qualified oil refers to oil that is liquid at room temperature, has no water and impurities visible to the naked eye, has an acid value of less than 2mg / g, and a peroxide value of less than 0.1%.

[0009] The present invention is creative in supercritical CO 2 During extraction, the collected material is divided into three parts: supercritical qualified oil, oil to be separated and supercritical unqualified oil, rather than simply qualified and unqualified parts, and whether the collected material is supercritical qualified oil is evaluated from the perspective of acid value and peroxide value, rather than simply evaluating from color and morphology, so that the evaluation standard of the collected material is changed from human perception to detection data, thereby making the quality of qualified oil more stable, that is, the quality of the qualified oil of the present invention is higher than that of the existing qualified oil determined by perception. A part of poor-quality qualified oil and a part of good-quality unqualified oil are classified as oil to be separated, and molecular distillation qualified oil and molecular distillation unqualified oil are fractionated by a molecular distillation system, and the molecular distillation qualified oil is merged into supercritical qualified oil, thereby improving the extraction oil yield. The present invention creatively performs molecular distillation on the oil to be separated immediately to obtain molecular distillation qualified oil, avoiding that under long-term storage conditions, the peroxide value of the oil to be separated rises to a level that cannot be reduced to the level that meets national standards even if the molecular distillation process is carried out and needs to be discarded, causing unnecessary waste.

[0010] Further design: the molecular distillation qualified oil is immediately combined with the supercritical qualified oil to obtain a mixed qualified oil.

[0011] The present invention creatively combines molecular distillation qualified oil into supercritical qualified oil immediately, and utilizes the antioxidant active ingredients in the supercritical qualified oil to inhibit the rapid increase of the peroxide value of the molecular distillation qualified oil, so that the molecular distillation qualified oil can be stored for a long time and becomes a qualified oil in the true sense, while stabilizing the quality of the mixed qualified oil and improving the supercritical CO 2 The oil yield of extraction makes molecular distillation technology effectively applied in vegetable oil extraction.

[0012] The specific operation steps of the present invention are as follows: collecting oil and fat from a supercritical system extraction separation kettle, collecting at intervals of time T, and preliminarily judging the collections by color and morphology; the above collections are separately stored and tested, and supercritical qualified oil and oil to be separated are determined by the test results, and then classified and merged.

[0013] Since the detection of acid value and peroxide value cannot be done in real time online at present, the present invention can only make a preliminary judgment on the collection by color and morphology. The interval time T can be set according to different raw material properties. T can even be different. For example, it can be appropriately shorter in the oil area to be separated. The time of the current batch of products is limited by the test results, thereby reducing the amount of detection while ensuring quality.

[0014] The oil to be separated in the present invention refers to the oil 2 The oil is obtained by extraction, and the test results are as follows: the acid value is 2-20mg / g, the peroxide value is 0.1-0.5%, and it is liquid at room temperature, without water and impurities visible to the naked eye; the qualified oil by molecular distillation refers to the oil obtained by molecular distillation, and the test results are as follows: the acid value is less than 2mg / g, the peroxide value is less than 0.1%, and it is liquid at room temperature, without water and impurities visible to the naked eye, and the room temperature refers to the temperature range of 10-25℃.

[0015] The "immediately" mentioned in the present invention refers to a two-step combined operation performed in a short period of time, wherein the first step is to collect all the oils from the supercritical fluid as the starting point, and the oil to be separated determined by the test result is completely introduced into the molecular distillation system as the end point, and the time is less than 24 hours; the second step is to collect all the oils from the molecular distillation system as the starting point, and the molecular distillation qualified oil determined by the test result is uniformly mixed with the supercritical qualified oil as the end point, and the time is less than 24 hours.

[0016] The oil yield of the mixed qualified oil of the present invention is higher than the oil yield of the supercritical qualified oil obtained by extracting the same batch of raw materials using only a supercritical system.

[0017] The mixed qualified oil of the invention has an acid value of less than 4 mg / g and a peroxide value of less than 0.25% after being placed at room temperature for 12 months.

[0018] The supercritical CO 2 The method of extracting high-quality oil by combining molecular distillation: The process parameters of the molecular distillation system during molecular distillation are vacuum degree ≤ 0.1Pa, heating temperature ≤ 200℃, feed rate ≤ 2kg / h×m -2 .

[0019] The technical solution adopted by the present invention adopts a careful process design, and after repeated tests, specific process parameters are adopted, and its beneficial effects are as follows:

[0020] 1, the present invention uses supercritical segmented collection technology to collect vegetable oil, distinguishes supercritical qualified oil, oil to be separated and supercritical unqualified oil three parts with the detection data of acid value and peroxide value of collection, improves the quality standard of supercritical qualified oil, a part of poor quality qualified oil (acid value and peroxide value can increase in long-term storage) obtained by conventional supercritical technology extraction in the past and a part of good quality unqualified oil (can reduce acid value and peroxide value to qualified range by molecular distillation) are classified as oil to be separated, and molecular distillation qualified oil and molecular distillation unqualified oil are fractionated by molecular distillation system, and molecular distillation qualified oil is merged into supercritical qualified oil, thereby improves extraction oil yield. Finally the present invention does not blindly reduce the acid value and peroxide value of supercritical qualified oil, avoids due to too strict screening criteria, causes the oil yield of supercritical qualified oil to be too low, the amount of natural antioxidant is too low, and finally after merging and mixing, the defect that the peroxide value of mixed qualified oil rises cannot be suppressed.

[0021] 2. The present invention uses molecular distillation technology to process the oil to be separated in a timely manner, thereby preventing the peroxide value of the oil to be separated from rising to a level that cannot be processed to a qualified level even with molecular distillation technology due to long-term storage, thereby avoiding waste and pollution caused by processing the oil to be separated. At the same time, the utilization rate of the supercritical system and the molecular distillation system is improved, and the loss caused by equipment depreciation is reduced.

[0022] 3. The present invention mixes the molecular distillation qualified oil and the supercritical qualified oil in time, effectively utilizing the natural antioxidant substances in the supercritical qualified oil, avoiding the defect that the acid value and peroxide value of the molecular distillation qualified oil rise to exceed the national standard limit due to long-term storage and become unqualified, and cannot be mixed with the supercritical qualified oil, thereby reducing waste and pollution. At the same time, the supercritical CO 2 The oil extraction rate increases the utilization value of raw materials and produces huge economic benefits.

[0023] 4. The quality of the mixed qualified oil of the present invention is stable. After being placed at room temperature for 12 months, the acid value is less than 4 mg / g and the peroxide value is less than 0.25%. Due to the physical treatment such as supercritical and molecular distillation, chemically synthesized vitamin C, vitamin E, adsorbent or the use of organic solvents such as ethanol are avoided, which reduces the cost compared with other conventional treatment technologies, so that the mixed qualified oil can obtain organic certification.

[0024] 5. The mixed qualified oil of the present invention has no significant change in material basis compared with the supercritical qualified oil after liquid phase fingerprint detection, and can be regarded as the same substance, indicating that the combination of supercritical and molecular distillation technology does not bring safety risks. It proves that the present invention is practical and the oil produced can be eaten with confidence. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the flow chart of supercritical-molecular distillation technology

[0026] Figure 2 This is the trend chart of acid value change of Ganoderma lucidum spore oil

[0027] Figure 3 This is the peroxide value trend chart of Ganoderma lucidum spore oil

[0028] Figure 4 It is the liquid fingerprint of Ganoderma lucidum spore oil

[0029] Figure 5 This is the acid value trend chart of coix seed oil

[0030] Figure 6 This is the trend chart of the peroxide value of coix seed oil

[0031] Figure 7 It is the liquid fingerprint of coix seed oil DETAILED DESCRIPTION

[0032] The following examples further illustrate the content of the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and essence of the present invention, the modification or replacement of the method, steps or conditions of the present invention all belong to the scope of the present invention. The raw materials and equipment used in the present invention, unless otherwise specified, are all commonly used raw materials and equipment in the art, and are all from commercially available products. The methods used in the present invention, unless otherwise specified, are all conventional methods known to those skilled in the art.

[0033] like Figure 1 As shown, a supercritical CO 2 The method of extracting high-quality oil by molecular distillation is mainly characterized in that the raw material is extracted by a supercritical system, supercritical qualified oil, oil to be separated and supercritical unqualified oil are collected, and the oil to be separated is immediately distilled into molecular distillation qualified oil and molecular distillation unqualified oil by a molecular distillation system; the supercritical qualified oil refers to oil that is liquid at room temperature, has no water and impurities visible to the naked eye, has an acid value of less than 2mg / g, and a peroxide value of less than 0.1%; the oil to be separated is the collected oil between the supercritical qualified oil and the supercritical unqualified oil, and its sensory perception is: liquid at room temperature, has no water and impurities visible to the naked eye. The test results are acid value 2-20mg / g, and peroxide value 0.1-0.5%. Molecular distillation qualified oil refers to oil that is obtained by molecular distillation, is liquid at room temperature, has no water and impurities visible to the naked eye, and the test results are acid value <2mg / g, and peroxide value <0.1%. The above-mentioned normal temperature refers to a temperature range of 10-25°C.

[0034] The molecular distillation qualified oil is immediately combined with the supercritical qualified oil to obtain a mixed qualified oil.

[0035] The present invention creatively combines molecular distillation qualified oil into supercritical qualified oil immediately, and utilizes the antioxidant active ingredients in the supercritical qualified oil to inhibit the rapid increase of the peroxide value of the molecular distillation qualified oil, so that the molecular distillation qualified oil can be stored for a long time and becomes a qualified oil in the true sense, while stabilizing the quality of the mixed qualified oil and improving the supercritical CO 2 Extraction oil yield.

[0036] The specific operation steps of the present invention are as follows: collecting oil and fat from a supercritical system extraction separation kettle, collecting at intervals of time T, and preliminarily judging the collections by color and morphology; the above collections are separately stored and tested, and supercritical qualified oil and oil to be separated are determined by the test results, and then classified and merged.

[0037] Since the detection of acid value and peroxide value cannot be done in real time online at present, the present invention can only make a preliminary judgment on the collection by color and morphology. The interval time T can be set according to different raw material properties. T can even be different. For example, it can be appropriately shorter in the oil area to be separated. The time of the current batch of products is limited by the test results, thereby reducing the amount of detection while ensuring quality.

[0038] The "immediately" mentioned in the present invention refers to a two-step combined operation performed in a short period of time, wherein the first step is to collect all the oils from the supercritical fluid as the starting point, and the oil to be separated determined by the test result is completely introduced into the molecular distillation system as the end point, and the time is less than 24 hours; the second step is to collect all the oils from the molecular distillation system as the starting point, and the molecular distillation qualified oil determined by the test result is uniformly mixed with the supercritical qualified oil as the end point, and the time is less than 24 hours.

[0039] The oil yield of the mixed qualified oil of the present invention is higher than the oil yield of the supercritical qualified oil obtained by extracting the same batch of raw materials using only a supercritical system.

[0040] The mixed qualified oil of the invention has an acid value of less than 4 mg / g and a peroxide value of less than 0.25% after being placed at room temperature for 12 months.

[0041] The supercritical CO 2 The method of extracting high-quality oil by combining molecular distillation: The process parameters of the molecular distillation system during molecular distillation are vacuum degree ≤ 0.1Pa, heating temperature ≤ 200℃, feed rate ≤ 2kg / h×m -2 .

[0042] For the acid value test method of oils and fats, refer to Test Example 1;

[0043] For the test method of peroxide value of oil, please refer to Test Example 2;

[0044] The liquid fingerprint detection method of oil and fat is shown in Detection Example 3;

[0045] The detection methods of acid value and peroxide value include but are not limited to currently available methods. The time in the definition of "immediately" can be appropriately shortened according to the shortening of the time to obtain the test results.

[0046] Example 1

[0047] The mature spore powder of Ganoderma lucidum was collected, impurities were removed, dried to a moisture content of ≤6%, the spore wall was broken, granulated, dried to a moisture content of ≤6%, fine powder of ≥200 mesh was screened out, 7 kg of spore powder of Ganoderma lucidum was taken, and supercritical CO was used to precipitate the spore powder. 2 Ganoderma lucidum spore oil was prepared by extraction technology. Ganoderma lucidum spore oil was prepared according to the process of the embodiment of the patent (CN101845361A), with an extraction pressure of 25-30 MPa, an extraction temperature of 40-45°C, a separation pressure of 12-8 MPa, a separation pressure temperature of 45-50°C, a flow rate of 110-120 L / h, and the extraction records are shown in Table 1.

[0048] Table 1 Example 1 Extraction Record

[0049]

[0050]

[0051] After the extraction starts, the oil in the separation kettle is collected at intervals of 1.0 h and stored separately. After obtaining the oil from the separation kettle, the oil is quickly heated to 25°C and the acid value and peroxide value are observed and tested.

[0052] The collected oil every 1.0h was divided into three equal parts. The first part collected qualified oil according to the evaluation standard of GB2716, totaling 478.2g, with a yield of 20.50%, recorded as Ganoderma lucidum spore oil I; the second part collected the oil to be separated according to the evaluation standard of the present invention, totaling 200.7g; the third part collected supercritical qualified oil and oil to be separated according to the evaluation standard of the present invention, wherein 463.1g of supercritical qualified oil and 200.7g of oil to be separated, totaling 663.8g.

[0053] The second and third portions of oil to be separated were combined and immediately put into the molecular distillation system for molecular distillation. The molecular distillation vacuum was 0.05 Pa, the heating temperature was 200 ° C, the cooling temperature was 50 ° C, and the feed rate was 2 kg / h×m -2 , distillation area 0.1m 2 , collect heavy molecular oil, detect acid value and peroxide value, and obtain 376.2g of molecular distillation qualified oil with acid value <2mg / g and peroxide value <0.1%. Take half of it, 188.1g, and record it as Ganoderma lucidum spore oil II.

[0054] Another 188.1 g of molecular distillation qualified oil was immediately combined with the third portion of supercritical qualified oil 463.1 g, a total of 651.2 g, with a yield of 27.91%, and was recorded as Ganoderma lucidum spore oil III.

[0055] Example 2

[0056] The mature coix seeds were harvested, impurities were removed, crushed, and dried to a moisture content of ≤6%. 11 kg of coix seed powder was taken and dried using supercritical CO 2 Coix seed oil was prepared by extraction technology. The coix seed oil was prepared according to the process of the embodiment of the patent (CN101863764A), with an extraction pressure of 25-30 MPa, an extraction temperature of 40-45°C, a separation pressure of 12-8 MPa, a separation pressure temperature of 45-50°C, a flow rate of 110-120 L / h, and the extraction records are shown in Table 2.

[0057] Table 2 Example 2 Extraction Record

[0058]

[0059] After the extraction starts, the oil in the separation kettle is collected at intervals of 1.0 h and stored separately. After obtaining the oil from the separation kettle, the oil is quickly heated to 25°C and the acid value and peroxide value are observed and tested.

[0060] The collected oil every 1.0h was divided into three equal parts. The first part collected qualified oil according to the evaluation standard of GB2716, with a total of 175.6g, a yield of 4.79%, and was recorded as coix seed oil I; the second part collected the oil to be separated according to the evaluation standard of the present invention, with a total of 87.6g; the third part collected supercritical qualified oil and oil to be separated according to the evaluation standard of the present invention, with 157.2g of supercritical qualified oil and 87.6g of oil to be separated, with a total of 244.8g.

[0061] The second and third portions of oil to be separated were combined and immediately put into the molecular distillation system for molecular distillation. The molecular distillation vacuum was 0.05 Pa, the heating temperature was 200 ° C, the cooling temperature was 50 ° C, and the feed rate was 2 kg / h×m -2 , distillation area 0.1m 2 , collect heavy molecular oil, detect acid value and peroxide value, and obtain 150.2g of molecular distillation qualified oil with acid value <2mg / g and peroxide value <0.1%. Take half of it, 75.1g, and record it as coix seed oil II.

[0062] Another 75.1 g of the above-mentioned coix seed molecular distillation qualified oil was immediately combined with the third portion of supercritical qualified oil 157.2 g, a total of 232.3 g, with a yield of 6.34%, which was recorded as coix seed oil III.

[0063] Test Example 1

[0064] Ganoderma lucidum spore oil Ⅰ, Ⅱ and Ⅲ and coix seed oil Ⅰ, Ⅱ and Ⅲ were sampled and the sample solution was prepared according to 5.1.1 of the first method of GB 5009.229 National Food Safety Standard Determination of Acid Value in Food to test the acid value. Another 50mL was bottled, sealed and placed at room temperature (10-25℃) to test long-term stability. The acid value was tested by the same method. The results are shown in the attached Figure 2 and 5 .

[0065] from Figure 2 It can be seen that compared with Ganoderma lucidum spore oil Ⅲ, the acid value of Ganoderma lucidum spore oil Ⅰ has always maintained a slow upward trend within 360 days at room temperature, while the acid value of Ganoderma lucidum spore oil Ⅱ and Ganoderma lucidum spore oil Ⅲ has always remained stable within 360 days at room temperature; Figure 5 It can be seen that the acid value of coix seed oil I has maintained a slow upward trend within 360 days at room temperature. The acid value of coix seed oil II and coix seed oil III has remained stable within 360 days at room temperature.

[0066] Test Example 2

[0067] Ganoderma lucidum spore oil Ⅰ, Ⅱ and Ⅲ and coix seed oil Ⅰ, Ⅱ and Ⅲ were sampled and the sample solution was prepared using 5.1.1 of the first method of GB 5009.227 National Food Safety Standard for the Determination of Peroxide Value in Food to detect the peroxide value. The peroxide value was detected using the same method using the sample packaged in Test Example 1. The results are shown in the attached Figure 3 and 6 .

[0068] from Figure 3 It can be seen that compared with Ganoderma lucidum spore oil III, the peroxide value of Ganoderma lucidum spore oil I has always maintained a slow upward trend within 360 days at room temperature. Compared with Ganoderma lucidum spore oil III, the peroxide value of Ganoderma lucidum spore oil II has rapidly increased to ≥0.25% within 360 days at room temperature. The peroxide value of Ganoderma lucidum spore oil III has always remained stable within 360 days at room temperature; Figure 6 It can be seen that the peroxide value of coix seed oil I kept a slow upward trend within 360 days at room temperature. The peroxide value of coix seed oil II rose rapidly to ≥0.25% within 360 days at room temperature. The peroxide value of coix seed oil III remained stable within 360 days at room temperature.

[0069] Test Example 3

[0070] Ganoderma lucidum spore oil I and III were sampled, and the sample solution was prepared using the characteristic spectrum method under the broken wall Ganoderma lucidum spore powder item of Anhui Province Traditional Chinese Medicine Preparation Specifications 2019 Edition, and the chromatogram was prepared. The results are shown in the attached Figure 4 .

[0071] Coix seed oil I and III were sampled, and the sample solution was prepared using the identification method under Coix seed in the 2020 edition of the Chinese Pharmacopoeia. The chromatogram was prepared and the results are shown in the attached Figure 7 .

[0072] from Figure 4 and Figure 7 It can be seen that there is no significant change in the material basis between Ganoderma lucidum spore oil I and Ganoderma lucidum spore oil III, and between Coix seed oil I and Coix seed oil III, and they can be regarded as the same substance.

Claims

1. A method for extracting high-quality oil by supercritical CO2 combined with molecular distillation, characterized in that: The raw materials are extracted by a supercritical system, and supercritical qualified oil, oil to be separated and supercritical unqualified oil are collected. The oil to be separated is immediately distilled by a molecular distillation system to obtain molecular distillation qualified oil; the supercritical qualified oil refers to oil that is liquid at room temperature, has no water and impurities visible to the naked eye, has an acid value of less than 2mg / g, and a peroxide value of less than 0.1%.

2. The method for extracting high-quality oil by supercritical CO2 combined with molecular distillation according to claim 1, characterized in that: The molecular distillation qualified oil is immediately combined with the supercritical qualified oil to obtain a mixed qualified oil.

3. The method for extracting high-quality oil by supercritical CO2 combined with molecular distillation according to claim 1, characterized in that: Collect the oil from the supercritical system extraction and separation kettle at intervals of time T, and make a preliminary assessment of the collected material based on its color and morphology; The above collected materials are stored separately and tested, and the supercritical qualified oil and the oil to be separated are determined by the test results, and then classified and merged.

4. The method for extracting high-quality oil by supercritical CO2 combined with molecular distillation according to claim 1 or 3, characterized in that: The oil to be separated refers to the oil obtained by supercritical CO2 extraction, with the test results of acid value of 2-20 mg / g, peroxide value of 0.1-0.5%, and liquid at room temperature, without water and impurities visible to the naked eye; the qualified oil for molecular distillation refers to the oil obtained by molecular distillation, with the test results of acid value of less than 2 mg / g, peroxide value of less than 0.1%, and liquid at room temperature, without water and impurities visible to the naked eye, and room temperature refers to the temperature range of 10-25°C.

5. The method for extracting high-quality oil by supercritical CO2 combined with molecular distillation according to claim 1 or 2, characterized in that: The "immediately" mentioned above refers to a two-step combined operation performed in a short period of time, wherein the first step is to collect all the oils from the supercritical fluid as the starting point, and the oil to be separated determined by the test result is fed into the molecular distillation system as the end point, and the time is less than 24 hours; the second step is to collect all the oils from the molecular distillation system as the starting point, and the molecular distillation qualified oil determined by the test result is mixed evenly with all the supercritical qualified oils as the end point, and the time is less than 24 hours.

6. The method for extracting high-quality oil by supercritical CO2 combined with molecular distillation according to claim 2, characterized in that: The acid value of the mixed qualified oil is less than 4 mg / g and the peroxide value is less than 0.25% after being placed at room temperature for 12 months.

7. The method for extracting high-quality oil by supercritical CO2 combined with molecular distillation according to claim 1, characterized in that: The process parameters of the molecular distillation system during molecular distillation are vacuum degree ≤ 0.1Pa, heating temperature ≤ 200℃, feed rate ≤ 2kg / h×m -2 .

Images