Method and apparatus for preparing plant-derived extract

Abstract

In accordance with an embodiment of the present invention, there is provided a method for preparing a plant-derived extract. The method comprises the following steps: applying extraction pressure to a plant source material under the action of liquid carbon dioxide to carry out a supercritical carbon dioxide extraction process so as to obtain an extraction mixture; separating an intermediate extract from the extraction mixture; and feeding the intermediate extract substantially immediately after the separation step to a series of stages for molecular distillation to obtain a plant-derived extract having a level of improved one or more parameters compared to the intermediate extract. The one or more parameters include at least one of density, acid value, refractive index, appearance, or intermiscibility. A preset distillation temperature, a preset vacuum pressure and a preset rotating speed are set in each stage. In one embodiment, the plant-derived extract is an essential oil from a plant. In accordance with other embodiments of the present invention, devices for preparing plant-derived extracts are also provided.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to Singapore Patent Application No. 10202204097S filed on April 20, 2022, the contents of which are incorporated herein by reference in their entirety for all purposes. Technical Field

[0003] Various embodiments are directed to methods and apparatus for preparing plant-derived extracts, and more particularly, for preparing essential oils. Background of the Invention

[0005] Phytogenic extracts are concentrated plant materials containing potent bioactive compounds from different parts of plants, such as petals, flowers, leaves, roots and stems. To obtain phytogenic extracts, extraction is required, i.e. the process of removing one or several desired plant compounds from the plant itself for further analysis and / or processing.

[0006] For example, patchouli (pogostemon cablin) is an aromatic species of the Lamiaceae family originating in Southeast Asia, which contains essential oils with great economic value. Patchouli oil is widely used in perfumes and aromatherapy because of its fragrant and spicy aroma. Essential oils also have many therapeutic properties, which are traditionally obtained by steam distillation of dried patchouli leaves. Typical steam distillation processes involve obtaining essential oils with a yield of 1% to 3% by high temperature and long extraction time (up to 10 hours). Other methods for extracting essential oils can be water distillation and solvent extraction, which have, for example, low yields, the need to use chemicals and solvents, and environmentally unfriendly disadvantages. It is desirable to be able to recover more essential oils in a shorter time, at a lower temperature, and without the need for solvents.

[0007] The extraction of essential oils using supercritical fluid extraction (SCFE) with carbon dioxide (CO2) is a relatively new technology that has not yet been fully developed. SCFE using CO2 can be performed at a critical temperature of 304K and a critical pressure of 7.39MPa to produce a solvent-free extract. However, if the extraction is performed only at the critical point (i.e., at low pressure, low temperature, and low CO2 flow rate), it is found that the yield of essential oil is relatively low and its patchouli alcohol content is also low. In order to maximize the recovery of essential oils and patchouli alcohol, extraction should be performed at higher pressures for longer times. CO2 extracts prepared under high pressure may include high free fatty acids (FFA), pigments, waxes / gels, and other impurities, which make the extracts incomparable to marketable essential oils prepared by other traditional methods such as steam distillation. In other words, SCFE of CO2 may generate undesirable viscous extracts, which require manufacturers to perform a large number of time-consuming, expensive, and labor-intensive post-processing steps (such as centrifugation, winterization, filtration, deacidification, and decolorization) to convert them into high-quality essential oils that can be put on the market.

[0008] Although previous publications describe tailoring patchouli alcohol in the SCFE process, there is no mention or guidance of any post-treatment of the extract to remove impurities such as pigments, waxes, gums, water. In previous publications, there is no attempt to post-treat the viscous SCFE extract to convert it into a marketable absolute.

[0009] Therefore, there is a need for a technology that can solve at least the above-mentioned problems to produce high yield and high quality essential oils and their related products without affecting the yield due to CO2 extraction. Summary of the invention

[0010] According to an embodiment, a method for preparing a plant-derived extract is provided. The method may include applying an extraction pressure to a plant-derived material under the action of liquid carbon dioxide to perform a supercritical carbon dioxide extraction process to obtain an extraction mixture; separating an intermediate extract from the extraction mixture; and feeding the intermediate extract to a series of stages substantially immediately after the separation step for molecular distillation to obtain a plant-derived extract having an improved level of one or more parameters compared to the intermediate extract. The one or more parameters may include at least one of density, acid value, refractive index, appearance, or compatibility. Each stage may be set with a predetermined distillation temperature, a predetermined vacuum pressure, and a predetermined rotation speed.

[0011] According to an embodiment, a device for preparing a plant-derived extract is provided. The device may include a supercritical carbon dioxide extraction module, which is configured to apply extraction pressure to a plant-derived material under the action of liquid carbon dioxide to perform a supercritical carbon dioxide extraction process to obtain an extraction mixture; a separation module in fluid communication with the supercritical carbon dioxide extraction module, the separation module being configured to separate an intermediate extract from the extraction mixture; and a molecular distillation module in fluid communication with the separation module. The molecular distillation module may include a series of stages configured to perform molecular distillation to obtain a plant-derived extract having an improved level of one or more parameters compared to the intermediate extract; and one or more pipelines, each of which is coupled between a stage in a series of stages and a subsequent stage in a series of stages. One or more parameters may include at least one of density, acid value, refractive index, appearance, or compatibility. Each stage may be operated at a predetermined distillation temperature, a predetermined vacuum pressure, and a predetermined rotation speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In the accompanying drawings, like reference characters generally refer to like parts throughout the different views. These drawings are not necessarily drawn to scale, but emphasis is generally placed on illustrating the principles of the invention. In the following description, various embodiments of the invention are described with reference to the following drawings, in which:

[0013] Figure 1A A flow chart of a method for preparing a plant-derived extract according to various embodiments is shown.

[0014] Figure 1B A schematic diagram of an apparatus for preparing a plant-derived extract according to various embodiments is shown.

[0015] Figure 2 A flow chart is shown involving a method of post-processing a SCFE extract according to various embodiments.

[0016] Figure 3A A photograph depicting an extract obtained by SCFE using Patchouli is shown according to one embodiment.

[0017] Figure 3B Shown are photographs depicting a stage 2 sample containing low patchouli alcohol (PA) oil, a stage 3 sample containing high PA oil, and an oil containing primarily pigments, iron, waxes / gums / fatty acids, according to one embodiment.

[0018] Figure 4 A photograph depicting a stage 2 sample and a stage 3 sample is shown according to one embodiment - both are absolute oils, and another portion of the stage 3 sample is myristic acid.

[0019] Figure 5Shown are photographs depicting a clove bud extract obtained by SCFE, a stage 2 sample, a stage 3 sample, and another portion of the stage 3 sample, according to one embodiment.

[0020] Fig. 6A A photograph depicting an extract obtained by SCFE using ginger is shown according to one embodiment.

[0021] Figure 6B According to one embodiment, a diagram based on Fig. 6A Photographs of a Stage 2 sample, a Stage 3 sample, and another portion of the Stage 3 sample of the extract. DETAILED DESCRIPTION

[0022] The following specific embodiments relate to the drawings that illustrate the specific details and embodiments that the present invention can be implemented. These embodiments are described in sufficient detail to enable those skilled in the art to implement the present invention. Other embodiments may be used, and structural, logical and electrical changes may be made without departing from the scope of the present invention. Various embodiments are not necessarily mutually exclusive, because some embodiments may be combined with one or more than one other embodiments to form new embodiments.

[0023] Embodiments of a method or an apparatus described above and below are also valid for other methods or apparatuses. Similarly, embodiments of a method described above and below are also valid for an apparatus, and vice versa.

[0024] The features of the embodiments described in the context may be applicable to the same features or similar features in other embodiments accordingly. The features of the embodiments described in the context may be applicable to other embodiments accordingly, even if the features are not explicitly described in these other embodiments. In addition, the addition and / or combination and / or replacement of the features of the embodiments described in the context may be applicable to the same features or similar features in other embodiments accordingly.

[0025] In the context of various embodiments, a feature or element not preceded by a quantifier includes one or more than one of the feature or element.

[0026] In the context of various embodiments, the phrase "substantially" can include "exactly" and reasonable variations.

[0027] In the context of the various embodiments, the term "about" as applied to numerical values ​​includes the exact value and reasonable variation.

[0028] As used herein, the term "and / or" includes any and all combinations of one or more than one of the associated listed items.

[0029] As used herein, a phrase of the form "at least one of A or B" may include A or B or A and B. Accordingly, a phrase of the form "at least one of A or B or C", or including further listed items, may include any and all combinations of one or more of the associated listed items.

[0030] As used herein, the expression "configured to" may mean "built to" or "arranged to."

[0031] Various embodiments can be provided for preparing essential oils and their related products.

[0032] Figure 1A A flow chart of a method 100 for preparing a plant-derived extract according to various embodiments is shown. In step 102, an extraction pressure may be applied to a plant-derived material under the action of liquid carbon dioxide to perform a supercritical carbon dioxide extraction process to obtain an extraction mixture. In step 104, an intermediate extract may be separated from the extraction mixture. In step 106, the intermediate extract is fed to a series of stages substantially immediately after the separation step for molecular distillation to obtain a plant-derived extract having an improved level of one or more parameters compared to the intermediate extract. The one or more parameters may include at least one of density, acid value, refractive index, appearance, or compatibility. Each stage may be set with a predetermined distillation temperature, a predetermined vacuum pressure, and a predetermined rotation speed.

[0033] In other words, the technology relates to a one-step post-processing method of CO2 extracts to produce marketable essential oils and related products after CO2 extraction. In this method, essential oils and related products can be produced by supercritical fluid extraction (SCFE) of plant-derived materials and then post-processed using molecular distillation technology. Molecular distillation refers to a distillation method operated under high vacuum. Here, SCFE, SCFE of CO2, and CO2 extraction can mean supercritical carbon dioxide extraction.

[0034] The proposed solution can be easily implemented by combining existing SCFE technology with continuous molecular distillation post-treatment. Here, a one-step process refers to SCFE combined with molecular distillation. It may also refer to a continuous process, in which SCFE and separation and molecular distillation post-treatment are not performed separately as different batches, so that SCFE and separation are basically followed by molecular distillation post-treatment immediately. It should also be understood that in different embodiments, molecular distillation can be performed in a batch mode of post-treatment after SCFE.

[0035] The technology is capable of producing high-quality essential oils and their derivatives in relatively short extraction times without compromising yields. Various embodiments can provide solutions for essential oil manufacturers struggling to find ways to convert viscous SCFE extracts into marketable absolutes with customizable properties such as functional compounds, acidity, color, viscosity, density, and odor.

[0036] In various embodiments, before step 102 of applying extraction pressure to the plant-based material under the action of liquid carbon dioxide, method 100 may further include grinding at least a portion of the plant into a powder and granulating the powder to obtain a granular plant-based material. For example, the size of the powder may be about 140 mesh or less, and the average diameter of the granular plant-based material may be about 2 mm to about 10 mm, and the average thickness may be about 2 mm to about 4.5 mm. In different embodiments, the plant-based material may be in the form of leaves from a plant that are not powdered or granulated.

[0037] Prior to grinding at least a portion of the plant material, method 100 may further include drying at least a portion of the plant material to reduce the moisture content to 15% or less.

[0038] In various embodiments, the extraction pressure may be about 100 bar to about 500 bar. The supercritical carbon dioxide extraction process may be performed at an extraction temperature of 40° C. to 60° C. The liquid carbon dioxide may be continued at a flow rate of 5 kg / h to 30 kg / h for about 10 minutes to about 3 hours.

[0039] In various embodiments, the separating step 104 can be performed under reduced pressure conditions of about 40 bar.

[0040] In various embodiments, the step 106 of feeding the intermediate extract may also include heating the intermediate extract to a molten form at a temperature of about 40° C. to 60° C. More specifically, the intermediate extract may be heated to a suitable temperature to facilitate the flow and feeding of the intermediate extract. It should be understood that this heating step may be performed at the initial stage of a series of stages before being exposed to a predetermined distillation temperature, a predetermined vacuum pressure, and a predetermined rotation speed.

[0041] The predetermined distillation temperature may be 30° C. to 110° C. The predetermined vacuum pressure may vary from 0.2 mbar to 1 mbar. The predetermined rotation speed may be 100 rpm to 140 rpm.

[0042] In various embodiments, the step 106 of feeding the intermediate extract may include feeding the intermediate extract at a feed rate greater than 1 L / h. For example, when the method 100 is performed under laboratory test conditions, the feed rate may be 1 L / h to 5 L / h. In a specific embodiment, the feed rate of the intermediate extract in step 106 may be about 3 L / h for 20 minutes. On the other hand, in large-scale manufacturing, the feed rate may be further increased to even more than 20 L / h.

[0043] In various embodiments, the first stage in a series of stages can be set to a predetermined distillation temperature of about 60°C and a predetermined rotation speed of about 100 rpm; the second stage in a series of stages can be set to a predetermined distillation temperature of about 90°C and a predetermined rotation speed of about 140 rpm; and the third stage in a series of stages can be set to a predetermined distillation temperature of about 110°C and a predetermined rotation speed of about 140 rpm.

[0044] The first stage may precede the second stage, and the second stage may precede the third stage. In this series of stages, the first stage may be the initial stage, and the third stage may be the final stage or an intermediate stage, and the subsequent stages may be followed by further refining and obtaining the final plant-derived extract.

[0045] At least part of the plant may include patchouli leaves, clove buds, nutmeg, ginger, cassia bark, cassia bark, black pepper or plant materials containing essential oils. The alcohol content of the plant-derived extract may be about 25% to 50%. Alcohol content may refer to the alcohol content of an essential oil or a spice oil. Alternatively or alternatively, the plant-derived extract may contain one or more than one functional compound, such as terpenes, eugenol, zingiberene, gingerol, myristic ether, etc. For example, not all plant essential oils contain alcohol compounds to provide alcohol content, and such plant essential oils may be referred to as functional compounds. In other words, method 100 may be used to process a variety of plant-derived materials other than patchouli (pogostemon cablin) oil and its related products. For example, plant-derived materials or plant-derived extracts may include essential oils, spice oils such as clove buds, nutmeg, ginger, cassia bark, cassia bark, black pepper or any other plant materials containing essential oils.

[0046] Although the above method is illustrated and described as a series of steps or events, it should be understood that any order of such steps or events should not be interpreted in a limiting sense. For example, in addition to the steps or events illustrated and / or described herein, some steps may occur in a different order and / or occur simultaneously with other steps or events. In addition, not all steps shown can be applied to one or more than one aspect or embodiment described herein. Moreover, one or more than one step described herein can be performed in one or more than one separate action and / or stage.

[0047] Figure 1B A schematic diagram of an apparatus 120 for preparing a plant-derived extract according to various embodiments is shown. The apparatus 120 may include a supercritical carbon dioxide extraction module 122, which is configured to apply an extraction pressure to a plant-derived material under the action of liquid carbon dioxide to perform a supercritical carbon dioxide extraction process to obtain an extraction mixture; a separation module 124 in fluid communication with the supercritical carbon dioxide extraction module 122 (as shown by line 128), the separation module 124 being configured to separate an intermediate extract from the extraction mixture; and a molecular distillation module 126 in fluid communication with the separation module 124 (as shown by line 130). The molecular distillation module may include a series of stages 131, which are configured to perform molecular distillation to obtain a plant-derived extract having an improved level of one or more parameters compared to the intermediate extract; and one or more pipelines 133. Each pipeline 133 may be coupled between one stage of the series of stages 131 and a subsequent stage of the series of stages 131. The one or more parameters may include at least one of density, acid value, refractive index, appearance, or compatibility. Each stage 131 may be operated at a predetermined distillation temperature, a predetermined vacuum pressure, and a predetermined rotation speed.

[0048] The device 120 may include Figure 1A For example, one or more parameters and a series of stages 131 described in the context of apparatus 120 may be the same as or similar to the method 100 shown. Figure 1A The illustrated method 100 is similar or identical to those described above.

[0049] In the context of various embodiments, the term "coupled" may refer to attached or connected. The expression "in fluid communication" may refer to coupling.

[0050] In various embodiments, separation module 124 may be further configured to perform separation under reduced pressure conditions of about 40 bar.

[0051] The apparatus 120 may further include a heating module configured to heat the intermediate extract to a molten form at a temperature of about 40° C. to about 60° C. The intermediate extract heated to a molten form may be easily fed through the molecular distillation module 126 .

[0052] The predetermined distillation temperature may be 30° C. to 110° C. The predetermined vacuum pressure may vary from 0.2 mbar to 1 mbar. The predetermined rotation speed is 100 rpm to 140 rpm.

[0053] In various embodiments, one or more conduits 133 may be arranged to be heated to about 50° C. This may be so that the intermediate extract processed in each stage 131 is in molten form when it moves through conduit 133 to the subsequent stage 131 .

[0054] In various embodiments, the series of stages 131 may include a first stage configured to operate at a predetermined distillation temperature of about 60° C. and a predetermined rotation speed of about 100 rpm; a second stage configured to operate at a predetermined distillation temperature of about 90° C. and a predetermined rotation speed of about 140 rpm; and a third stage configured to operate at a predetermined distillation temperature of about 110° C. and a predetermined rotation speed of about 140 rpm. For example, the first stage may precede the second stage, and the second stage may precede the third stage. In one embodiment, the series of stages 131 may include three stages.

[0055] Various embodiments may provide for Figure 1A The plant-derived extract prepared by the method 100 is shown. The alcohol content of the plant-derived extract may be about 25% to about 50%, or preferably about 29% to about 31%, or more preferably about 40% to about 50%. The plant-derived extract may be an essential oil.

[0056] Hereinafter, an example of a method for preparing essential oil and related products based on post-processing of SCFE extract to convert viscous SCFE extract into pure essential oil will be described.

[0057] Figure 2 A flow chart of a method 200 for post-processing a SCFE extract is shown according to various embodiments. The method 200 may include or involve Figure 1A Methods and Figure 1B The same or similar elements or components of the device 120 are assigned the same ending numbers, and similar elements can be just as in Figure 1A Methods and Figure 1B The present invention is described in the context of the device 120, and thus the corresponding description may be omitted here.

[0058] like Figure 2 As shown, method 200 includes the following steps. Plant or plant-derived material 205 (e.g., patchouli) can be fed to a SCFE extractor 222 (e.g., Figure 1B The supercritical carbon dioxide extraction module 122 is used to extract the carbon dioxide at an optimal pressure, temperature and flow rate (e.g., Figure 1A and step 102 and step 104) and passed through a molecular distillation system 226 (e.g., Figure 1B In one embodiment, the SCFE separator 224 (e.g., Figure 1B The separation module 124) can be arranged between the SCFE extractor 222 and the SCFE extractor 222 including various stages 231a, 231b, 231c (e.g., Figure 1B A series of stages 131) of the molecular distillation system 226 are provided between the stages via pipelines 233 (e.g., Figure 1B The SCFE extract 207 (e.g., patchouli extract) may be preheated to maintain its molten state and then pumped into the molecular distillation system 226 using a feed pump 235 to separate water 209, alcohol, plant oil 211 with a low phytol content, plant oil 213 with a high phytol content, and finally a viscous liquid 215 containing all impurities, waxes, and pigments. Taking patchouli as a specific example of a plant or plant source material 205, the plant oil 211 with a low patchouli alcohol content has a patchouli alcohol content of about 30% or less, and the plant oil 211 with a patchouli alcohol content of less than 1% may be called a terpene. The plant oil 213 with a high patchouli alcohol content may have a patchouli alcohol content of about 40% to 50%. The viscous liquid 215 may also contain vegetable oil containing up to 60% patchouli alcohol, depending on the percentage of initial patchouli alcohol content in the feed.

[0059] In various embodiments, the molecular distillation system 226 may include a molecular evaporator, a degassing system, a feeding system, a heating system, a vacuum cooling system, and a control system. The core component of the molecular distillation device may be a molecular evaporator, which mainly has three types, namely, falling film type, scraped film type, and centrifugal type.

[0060] Depending on the type of plant material 205 and the parameters used for each stage 231a, 231b, 231c, the percentage value of plant alcohol may be different from the above example values ​​and / or ranges. However, it should be understood that because the parameters set for one stage (e.g., 231b) are different from the parameters set for another stage (e.g., 231c), the plant oil of this stage (e.g., 231b) may have a different percentage of plant alcohol content than the plant oil of another stage (e.g., 231c), thereby allowing comparison of low plant alcohol content and high plant alcohol content (e.g., 231b, 231c) between different stages.

[0061] Can be used Figure 2Method 200 is based on patchouli to prepare essential oils and related products thereof. In this case, the plant alcohol oil may be patchouli alcohol (PA) oil. It should be understood that method 200 can be used to process a variety of plant-derived materials other than patchouli oil and related products thereof. Some embodiments may include spice oils such as clove buds, nutmeg, ginger (which will be discussed in more detail later for illustration and comparison purposes), as well as cassia bark, cassia bark, black pepper, and the like.

[0062] Patchouli

[0063] Preparation of Patchouli SCFE Extract

[0064] Patchouli leaves can be obtained from Indonesia and ground into a 40-200 mesh powder. The powder can be further granulated to convert into particles having a diameter of about 2 mm to about 10 mm and a thickness of about 2.0 mm to about 4.5 mm. The particles are then loaded into a SCFE extractor 222 and extracted with carbon dioxide (CO2) at a pressure of 100 to 300 bars, a temperature of 40° C. to 60° C., and a flow rate of 5 kg / h to 30 kg / h for 10 minutes to 3 hours. The supercritical CO2 can then be depressurized to a pressure of about 40 bars to separate the gaseous CO2 and the SCFE extract 207 into a SCFE separator 224. At the end of the process (e.g., at Figure 1A The total SCFE extract 207 is collected in steps 102 and 104, which may contain essential oils, water, pigments, waxes and gums.

[0065] The SCFE extract 207 collected at the end of the process may be viscous, sticky and dark green with an overall yield of about 1% to 10%. The SCFE extract 207 may then be heated to a temperature of 40° C. to 60° C. to melt all waxes, gums and homogenize prior to treatment with molecular distillation (e.g., as Figure 1A 106).

[0066] Post-treatment of SCFE extracts by molecular distillation (MD)

[0067] The SCFE extract can be molecularly distilled (MD) to remove water, pigments, waxes, and any other impurities carried by the SCFE, and to obtain clean oil and related products. To this end, the viscous SCFE extract 207 prepared by SCFE extraction by the SCFE extractor 222 and the SCFE separator 224 can be fed by the feed pump 235 of the molecular distillation system 226, heated to 40°C to 60°C, and the water 209 is removed by the first container (e.g., stage 1 231a), and then the essential oils (e.g., 211, 213) of different qualities are separated by different stages (e.g., stage 2 231b and stage 3 231c) of the molecular distillation system 226. It should be understood that the feed rate, which can be interchangeably referred to as the flow rate, may depend on the production scale unit and may be 1L / h or higher than 1L / h. In some cases, at a large production scale, the feed rate may even exceed 20L / h. Alternatively, lower feed rates of 1 L / h (liters per hour) to 5 L / h may also be used, for example during laboratory tests.

[0068] The distillation temperature can be controlled to be 30°C to 110°C, preferably 30°C to 70°C, the vacuum degree can be varied in the range of 20Pa to 100Pa (meaning that at least without any pressure changing device, the vacuum pressure is not fixed, but varies with the experiment), and the rotation speed is 100rpm to 140rpm. Figure 1B Device 120) can first separate lighter compounds (0% to 5% patchouli alcohol) or terpenes, then patchouli oil with a patchouli alcohol content of 5% to 40% (e.g., 211), and finally patchouli oil with a patchouli alcohol content of 40% to 60% (e.g., 213). The last sample after all the early samples have been collected may be the remaining pigments, wax gums, essential oils and impurities (e.g., 215), which appear as a heavy viscous product and can be further purified to obtain pure patchouli alcohol, which may generally contain a very high patchouli alcohol content of 50% to 70%. Further purification may involve subsequent stages of controlled temperature, controlled vacuum pressure, and controlled rotation speed (e.g., after stage 3 231c), which are not described in detail here.

[0069] Specific examples and experimental data of preparing essential oil and related products from patchouli will be shown below.

[0070] Patchouli leaves were ground, filtered with a 2 mm screen and pelletized. The pellets (2 kg) were then loaded into a SCFE extraction vessel (e.g., SCFE extractor 222) and extracted for 2 hours at a pressure of 300 bar, a temperature of 50° C., and a CO2 flow rate of 15 kg / h. The total SCFE extract 207, which contained any water, pigments, waxes, and gums and impurities, was collected at the end of the process. A total of 20 kg of material was extracted using SCFE, and 1.4 kg of extract (total yield 7%) was obtained. Before being treated with molecular distillation, the extract 207 was heated to 50° C. and homogenized. A 30 g sample was taken to check the patchouli alcohol (PA) percentage and acid value of the extract. Water was removed from the extract by a peristaltic pump and collected in a separate bottle. During post-treatment using molecular distillation, the bottle was heated to 60° C. by a heating stirrer to keep the extract 207 in a molten state. 1 kg of homogenized extract was used as feed and post-treated using a molecular distillation system 226.

[0071] A peristaltic pump was used to feed the homogenized SCFE extract (1 kg) to stage 1231a for molecular distillation at a flow rate of 3 L / h in about 20 minutes. The rotation speeds of stage 1 231a and stage 2 231b were each 100 rpm, and the rotation speed of stage 3 231c was 140 rpm. The temperature of pipeline 233 was 50°C. In the molecular distillation system 226, stage 1 231a was designed to separate any solvent or water 209, stage 2 231b was used to separate low PA oil 211, and stage 3 231c was used to separate high PA oil 213 from oil 215 containing impurities such as pigments, waxes, and gums. The temperature of stage 1 231a was 60°C, the temperature of stage 2 231b was 90°C, and the temperature of stage 3 231c was 110°C. At the end of the process, 4 samples were collected in stage 1 231a, stage 2 231b, and stage 3 231c. Samples of stage 1 231a contain trace amounts of water 209, samples of stage 2 231b contain low PA% oil (29% to 31%) 211, samples of stage 3 231c contain high PA oil (40% to 50%) 213 and oil containing mainly pigments, iron, waxes / gums / fatty acids 215.

[0072] Figure 3A An extract 307 (eg, Figure 2 Photo 301 of SCFE207). Figure 3B A photograph 303 depicting a sample of stage 2 231b containing low PA oil 311, a sample of stage 3 containing high PA oil 313, and a sample of stage 3 containing primarily pigment, iron, wax / gums / fatty acids 315 is shown. The contents of the samples 311, 313, 315 can be viewed in relation to Figure 2 211, 213, and 215 are described in similar contexts.

[0073] The samples obtained through different stages of SCFE extraction and molecular distillation were analyzed according to the Indonesian National Standard (SNI) for color, appearance (e.g. Figure 3A and Figure 3B The samples were characterized by %PA, refractive index, acid value, density, and compatibility in ethanol, and the results are shown in Table 1. Other characteristics of the samples may also be evaluated, but are not shown here.

[0074] Table 1 - Comparison of properties of SCFE extracts and neat oils post-treated by molecular distillation process

[0075]

[0076]

[0077] SCFE extract 307 failed most of the tests conducted on the samples, while samples 311 and 313 obtained after molecular distillation passed all the tests and showed excellent results in terms of density, acid value, refractive index, appearance, and compatibility in ethanol and patchouli alcohol.

[0078] As shown in Table 2 below, after post-treatment with molecular distillation, the weights of all samples in different stages 231a, 231b, and 231c were measured, and their recoveries were calculated respectively.

[0079] Table 2 - Sample results obtained from SCFE extracts by molecular distillation based on one experiment

[0080]

[0081] The same plant material was extracted by steam distillation for 8 hours using a laboratory scale steam distillation system, obtaining a 2% yield. The yield of SCFE extract from the same plant material was 7%, and a total of 3.5% of essential oil was recovered after post-processing in a molecular distillation system. Another viscous liquid sample 315 is an oil mainly containing pigments, iron, wax / gums / fatty acids recovered from stage 3 (another part) 231c, which can be further post-processed to obtain a pure oil with significantly high patchouli alcohol. The further post-processing (not described in detail here) may be able to convert the product into other high quality products, such as oleoresins, absolute oils, concrete, patchouli alcohol crystal powders with a purity of 99% or higher.

[0082] Currently, using existing methods, absolute oils are prepared by solvent extraction of plant materials rather than by SCFE or MD processing. Here, a combined SCFE and MD process (e.g. Figure 1A Method 100 and Figure 2 The byproduct (e.g., another sample 315) of the method 200 can be used to convert into a clean oil. For example, the byproduct (e.g., 315) can be subjected to an ethanol post-treatment. The ethanol post-treatment can include the following steps: dissolving the byproduct (e.g., 315) or interchangeably referred to as the oil component in ethanol at a ratio of 1:10, winterizing at a low temperature to precipitate wax, separating the wax by filtration and then removing the ethanol by vacuum evaporation to recover the clean oil. In short, the related products of patchouli oil may include terpenes (PA less than 30%), ordinary PA oil (PA about 30%), high PA (50% to 70%), patchouli perfume (hydrosol), and other related products that can be generated by further processing, such as oleoresins, clean oils, extracts, patchouli crystals (greater than or equal to 99% PA), patchouli wax, etc.

[0083] The proposed combined technique (i.e., Figure 1A Method 100 and Figure 2 Method 200 of using molecular distillation for continuous post-treatment of SCFE extracts) clearly demonstrates several advantages over steam distillation in terms of yield, oil quality, and patchouli alcohol content. Essential oils can also be fractionated into oils of different qualities and converted into various marketable products by simple blending to meet the specific requirements of customers. PA can still be customized during the molecular distillation process (for example, in step 106). In other words, during the molecular distillation process, the PA% of each stage can be changed by changing the parameters of that particular stage. For example, a higher temperature may evaporate more PA in that stage, resulting in less PA entering the next stage, and vice versa. If the PA of the essential oil coming out of the molecular distillation stage does not fully meet the customer's requirements, the low PA oil can be manually blended with the high PA oil to obtain the desired PA%.

[0084] More specifically, since SCFE utilizes high pressure, it often produces viscous extracts, and researchers usually reduce the pressure to a minimum pressure near the critical point of CO2 (>72 bar) to extract purer wax-free oils. Meanwhile, MD is often used to increase the PA% of low PA (<30%) steam-distilled oils to more than 30%, as this is the main criterion for determining the price of essential oils in the market. In the proposed technology, for example, Figure 1A Method 100 and Figure 2 As described in method 200, the MD module (e.g., 126) can be customized to include more steps to process the viscous SCFE extract, thereby making the MD process (e.g., Figure 1A 126) can process viscous SCFE extracts (e.g. Figure 2207). The MD module may include a settling tank for separating water from the SCFE extract, a heater for increasing the temperature of the SCFE extract (40°C to 60°C) to maintain it in a molten and free-flowing form, and an evaporator for removing or at least minimizing any trace amounts of ethanol present in the SCFE extract due to equipment cleaning.

[0085] nutmeg

[0086] Specific examples and experimental data for preparing essential oil and related products from nutmeg will be shown below.

[0087] Nutmeg fruit (10 kg) was powdered, filtered through a 1 mm sieve, and then extracted with SCFE at 300 bar, 60°C and a flow rate of 15 kg / h for about 2 hours. A total of 2.5 kg of powder was loaded per run and a crude extract of about 25% was produced. A total of 2.5 kg of crude extract was prepared by homogenization by heating in a 60°C water bath and refilled into 1 L bottles. (Table 3)

[0088] A simulated nutmeg extract was prepared for MD post-treatment by mixing commercially available steam distilled nutmeg oil with nutmeg lipid isolated from a crude extract in a ratio of 60% oil and 40% lipid. The mixed extract was heated to 60°C in a hot water bath and treated by molecular distillation. The parameters selected for MD treatment of the extract were as follows: the temperature of stage 1 231a was 60°C, stage 2 231b was 60°C and stage 3 231c was 110°C. As mentioned above, the flow rate and other parameters were the same as those selected for treating the crude extract of Patchouli. Reference may be made to Table 6 below.

[0089] Figure 4 A photograph 403 depicting a stage 2 sample 411 and a stage 3 sample 413 is shown according to one embodiment - both are absolute oils, and another portion of the stage 3 sample 415 is nutmeg. The contents of the samples 411, 413, 415 can be in the same Figure 2 211, 213, and 215 are described in similar contexts.

[0090] Table 3 shows the characteristics of the SCFE extract of Myristica fragrans and the samples processed at different stages.

[0091]

[0092] Clove Buds

[0093] The following is a specific example and experimental data of preparing essential oil and related products from clove buds.

[0094] Clove buds (30 kg) were powdered, filtered through a 2 mm sieve, and then extracted with SCFE at 300 bar, 50°C, and a flow rate of 15 kg / h for 2 hours. 2.7 kg of powder was charged per run to produce a total extract of about 19% to 20%. A total of 5 kg of extract was prepared and homogenized by heating on a 60°C water bath and refilled into 1 L bottles for MD post-processing.

[0095] The mixed extract was heated to 60°C in a hot water bath and treated by molecular distillation. The parameters selected for the MD treatment of the extract were as follows: the temperature of stage 1 231a was 60°C, stage 2 231b was 100°C and stage 3 231c was 110°C. As mentioned above, the flow rate and other parameters were the same as those selected for the treatment of the crude extract of Patchouli. Reference may be made to Table 6 below.

[0096] Figure 5 An extract 507 obtained by SCFE is shown according to one embodiment (in Figure 2 207), a stage 2 sample 511 and a stage 3 sample 513, and a photograph 503 of another portion of a stage 3 sample 515. The contents of the samples 511, 513, 515 can be seen in the same context as Figure 2 211, 213, and 215 are described in similar contexts.

[0097] Table 4 shows the characteristics of clove bud SCFE extract and samples processed at different stages.

[0098]

[0099] ◆ The low eugenol content in the final processed oil may be due to the low quality of the feed, where the original eugenol content was already low (about 77%).

[0100] ginger

[0101] The following is a specific example and experimental data of preparing essential oil and related products from ginger.

[0102] Ginger (Zingiber officinale) (100 kg) was extracted by SCFE at 300 bar, 50°C and a flow rate of 15 kg / h for 2 hours. A total of 5.6 kg of extract was obtained from 100 kg of ginger (yield 5.6%). The extract was homogenized by heating on a 60°C water bath and refilled into 1 L bottles for MD post-processing.

[0103] Ginger extract (1 kg) was heated to 60°C in a hot water bath and treated by molecular distillation. The parameters selected for the MD treatment of the extract were as follows: the temperature of stage 1 231a was 60°C, stage 2 231b was 90°C and stage 3 231c was 120°C. As mentioned above, the flow rate and other parameters were the same as those selected for the treatment of the crude extract of Patchouli. Reference may be made to Table 6 below.

[0104] Fig. 6A An extract 607 obtained by SCFE is shown according to one embodiment (in Figure 2 Photo 601 of SCFE207 described in the same context). Figure 6B A photograph 603 depicting a sample 611 at stage 2, a sample 613 at stage 3, and another portion of a sample 615 at stage 3 is shown. The contents of the samples 611, 613, 615 may be viewed in relation to Figure 2 211, 213, and 215 are described in similar contexts.

[0105] Table 5 shows the characteristics of the ginger SCFE extract and the samples processed at different stages.

[0106]

[0107]

[0108] As shown in Tables 1, 3, 4 and 5, the SCFE crude extracts of various exemplary spices failed the SNI test, while the samples of stage 2 and stage 3 (a portion) obtained after MD treatment, i.e., the sample of molecular distillation stage 2 and the sample of molecular distillation stage 3 (a portion), respectively passed the SNI test.

[0109] Table 6 is a comparison table of parameters for all four products in material handling / feed preparation, SCFE extraction and molecular distillation post-processing.

[0110]

[0111]

[0112] For comparison purposes, Table 7 summarizes the results of samples (nutmeg, clove buds, and ginger) obtained from molecular distillation treatment of the respective SCFE extracts based on one experiment for each sample and reflects the yield of the respective SCFE extracts after MD treatment.

[0113]

[0114] It is worth noting that for experiment No. MDT59, the nutmeg SCFE extract was blended with commercial oil only to increase the fluidity of the extract for the equipment used during the laboratory test. It should be understood that this blending does not affect the comparative data shown in Table 7.

[0115] Although the present invention has been specifically shown and described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made in form and detail without departing from the spirit and scope of the present invention as defined in the appended claims. Therefore, the scope of the present invention is represented by the appended claims, and therefore, all changes within the equivalent meaning and equivalent range of the claims are included.

Claims

1. A method for preparing a plant-derived extract, the method comprising: applying extraction pressure to the plant-derived material under the action of liquid carbon dioxide to perform a supercritical carbon dioxide extraction process to obtain an extraction mixture; separating an intermediate extract from the extraction mixture; as well as feeding the intermediate extract substantially immediately after the separation step to a series of stages for molecular distillation in order to obtain a plant-derived extract having an improved level of one or more parameters compared to the intermediate extract, One or more of the parameters include at least one of density, acid value, refractive index, appearance or compatibility, and A predetermined distillation temperature, a predetermined vacuum pressure and a predetermined rotation speed are set for each stage.

2. The method according to claim 1, further comprising, before the step of applying extraction pressure to the plant-derived material under the action of liquid carbon dioxide, grinding at least part of the plant into powder and granulating the powder to obtain the plant-derived material in granular form.

3. The method according to claim 2, wherein the size of the powder is about 140 mesh or less, and the average diameter of the plant-derived material in the form of particles is about 2 mm to about 10 mm, and the average thickness is about 2 mm to about 4.5 mm.

4. The method according to claim 2 or 3, further comprising drying at least part of the plant to reduce its moisture content to 15% or less before grinding at least part of the plant.

5. The method according to any one of claims 1 to 4, wherein the extraction pressure is from about 100 bar to about 500 bar.

6. The method according to any one of claims 1 to 5, wherein the supercritical carbon dioxide extraction process is carried out at an extraction temperature of 40°C to 60°C.

7. The method according to any one of claims 1 to 6, wherein the liquid carbon dioxide is continued at a flow rate of 5 kg / h to 30 kg / h for about 10 minutes to about 3 hours.

8. The process according to any one of claims 1 to 7, wherein the separation step is carried out under reduced pressure of about 40 bar.

9. The method according to any one of claims 1 to 8, wherein the step of feeding the intermediate extract further comprises heating the intermediate extract to a molten form at a temperature of about 40°C to about 60°C.

10. The method according to any one of claims 1 to 9, wherein the predetermined distillation temperature is from 30°C to 110°C.

11. The method according to any one of claims 1 to 10, wherein the predetermined vacuum pressure varies from 0.2 mbar to 1 mbar.

12. The method according to any one of claims 1 to 11, wherein the predetermined rotation speed is 100 rpm to 140 rpm.

13. The method according to any one of claims 1 to 12, wherein the first stage of a series of stages sets a predetermined distillation temperature of about 60°C and a predetermined rotation speed of about 100 rpm; the second stage of a series of stages sets a predetermined distillation temperature of about 90°C and a predetermined rotation speed of about 140 rpm; and the third stage of a series of stages sets a predetermined distillation temperature of about 110°C and a predetermined rotation speed of about 140 rpm.

14. The method of claim 13, wherein the first stage precedes the second stage, and the second stage precedes the third stage.

15. The method of any one of claims 1 to 14, wherein the alcohol content of the plant-derived extract is from about 25% to about 50%.

16. The method according to any one of claims 1 to 15, wherein at least part of the plant comprises patchouli leaves, clove buds, nutmeg, ginger, cassia bark, cinnamon, black pepper or plant material containing essential oils.

17. A device for preparing a plant-derived extract, the device comprising: a supercritical carbon dioxide extraction module configured to apply extraction pressure to the plant-derived material under the action of liquid carbon dioxide to perform a supercritical carbon dioxide extraction process, thereby obtaining an extraction mixture; a separation module in fluid communication with the supercritical carbon dioxide extraction module, the separation module being configured to separate an intermediate extract from the extraction mixture; as well as A molecular distillation module in fluid communication with the separation module, the molecular distillation module comprising: a series of stages configured to perform molecular distillation to obtain a plant-derived extract having an improved level of one or more parameters compared to the intermediate extract; and one or more pipelines, each pipeline coupled between one stage in the series of stages and a subsequent stage in the series of stages, One or more of the parameters include at least one of density, acid value, refractive index, appearance or compatibility, and Each stage operates at a predetermined distillation temperature, a predetermined vacuum pressure, and a predetermined rotation speed.

18. The apparatus of claim 17, wherein the separation module is further configured to perform separation under reduced pressure conditions of about 40 bar.

19. The apparatus according to claim 17 or 18, further comprising a heating module configured to heat the intermediate extract to a molten form at a temperature of about 40°C to 60°C.

20. Apparatus according to any one of claims 17 to 19, wherein the one or more conduits are arranged to be heated to about 50°C.

21. An apparatus according to any one of claims 17 to 20, wherein the series of stages includes a first stage configured to operate at a predetermined distillation temperature of about 60°C and a predetermined rotation speed of about 100 rpm; a second stage configured to operate at a predetermined distillation temperature of about 90°C and a predetermined rotation speed of about 140 rpm; and a third stage configured to operate at a predetermined distillation temperature of about 110°C and a predetermined rotation speed of about 140 rpm.

22. The apparatus of claim 21, wherein the first stage precedes the second stage, and the second stage precedes the third stage.

23. A plant-derived extract prepared by carrying out the method according to any one of claims 1 to 16.

24. The plant-derived extract according to claim 23, wherein the alcohol content of the plant-derived extract is from about 25% to about 50%, or preferably from about 29% to about 31%, or more preferably from about 40% to about 50%.

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