Systems and methods for extracting volatile molecules from plant feedstock

Abstract

The present invention relates to the field of production of natural plant extracts, more particularly to the field of capture of volatile compounds and molecules from plant raw materials and in particular from fresh flowers including matt flowers. More specifically, the present invention relates to a system and method for capturing and making available plant odorant substances, in particular in the form of an extract on a carrier, intended to be used in compositions such as perfumes. The invention also relates to such an extract.

Description

Technical Field

[0001] The present invention relates to the field of production of natural plant extracts and more specifically to the field of capturing volatile molecules and compounds from plant raw materials and in particular from flowers, including silent flowers. The invention relates more precisely to a system and a method capable of capturing aromatic plant substances and making them available, in particular in the form of an extract on a carrier, with a view to using them, for example, in the composition of a perfume. The subject of the invention is also such an extract. Background Art

[0002] Various extraction methods are known, some of which are very old, for concentrating the aromatic substances of plants.

[0003] The oldest method is called lipophilia, which involves placing freshly cut flowers on a body of fat (such as animal fat) and then allowing the fat to become saturated with the scent of the flowers. Once this is done, the fat can be used directly or processed before use.

[0004] Also known are processes using steam distillation or hydrodistillation techniques, whereby natural plant extracts are absorbed by steam to obtain essential oils and hydrosols. These processes are currently very widely used, but have the disadvantage that the plants used are degraded and that aromatic substances that represent the original smell of the fresh raw material are not always obtained. Distillation processes also have the disadvantage of very low yields, that is to say that very large amounts of raw material are required to obtain small amounts of the final product. Furthermore, these processes consume particularly large amounts of energy and require large amounts of water.

[0005] Extraction methods using solvents are also known. These methods consist of leaving the plant in a tank filled with a solvent, usually of petrochemical origin, until the solvent permeates the plant's odor. The solvent is then removed by evaporation. These methods have the disadvantage of being time-consuming and requiring large amounts of petrochemical solvents, which are often pollutants and hazardous materials, the presence of which in the finished product is regulated.

[0006] Methods using supercritical CO2 are also known. In the supercritical state, CO2 acts as a solvent and can extract aromatic molecules. Methods using supercritical CO2 generally allow extracts to be obtained that are closer to the smell of the raw material than the above methods. These methods are still expensive to use. In addition, these methods are generally somewhat incompatible with the use of fresh raw materials.

[0007] Finally, document EP 2 644 039 describes a device for extracting aromatic components of plants as an alternative to the liposuction technique. The device comprises an extraction housing containing a container for a plant, such as a flower (jasmine, rose, tuberose, etc.), and having a gas flow through the container. The gas is then directed by a compressor to a collection container, where the aromatic substances contained in the gas are captured by a solvent (which may be a vegetable oil).

[0008] The invention stems from the observation that there is no known method of capturing volatile molecules that would allow obtaining a product whose scent fully represents the scent of a plant, especially its head notes. Furthermore, existing methods are unable to capture the scent of certain plants, especially so-called "silent" plants, such as lily of the valley, hyacinth, lilac, freesia, etc. A flower is generally considered silent if it meets one or both of the following conditions:

[0009] - the yield of the compound of interest extracted by known methods is very low, and

[0010] - The final extract obtained by the known method has poor olfactory quality. Summary of the invention

[0011] The object of the present invention is to remedy the disadvantages of the prior art, in particular the above-mentioned ones, by proposing a system and a method for extracting natural extracts of plants, making it possible to obtain an extract representative of the smell of the raw material. The object of the present invention is also to propose an extraction method and a system that do not use polluting or hazardous materials and have an energy efficiency that is possibly higher than that of known extraction methods.

[0012] To this end, the present invention relates to a system for extracting volatile molecules from plant raw materials, the system comprising:

[0013] - at least one housing comprising a plurality of containers configured to receive plant material, the housing being hermetically sealed to prevent the ingress of gas and comprising an inlet and an outlet disposed at opposite ends of the housing, the housing being configured to generate a gas circulation in the housing through each container, wherein the gas flow of each container is substantially similar or equal,

[0014] - compression means configured to regulate the pressure of the air or gas circulated from the housing to the capture system at a relative pressure greater than or equal to 2 bar,

[0015] The capture system comprises:

[0016] - a first capture device at least partially filled with a first solvent so as to enable an exchange between the first solvent and the compressed gas entrained by the compression device, and

[0017] - a second capture device comprising an inlet connected to the duct so that the air extracted from the first capture device can be sucked into the second capture device, the second capture device being at least partially filled with a second solvent so as to be able to exchange between the second solvent and the compressed gas that has passed through the first capture device.

[0018] The present invention also relates to a method for extracting volatile molecules from plant materials such as flowers, the extraction method comprising the following steps:

[0019] - distributing the plurality of portions of the plant material into an enclosure which is supplied with a gas, such as air, and which is configured to generate a circulation of the gas through each portion of the plant material, wherein the gas flow rate in each portion is close to or equal,

[0020] - extracting the gas that has circulated through all the parts of the plant material and compressing it to a relative pressure greater than or equal to 2 bar,

[0021] - trapping a compressed gas in a first organic solvent, the solubility of which in water is less than or equal to 20% by weight, and separating by condensation the vapor contained in said gas to obtain a depleted gas, a first organic phase and a first aqueous phase,

[0022] - capturing the depleted gas in a second organic solvent having a solubility in water less than or equal to 20% by weight, preferably the same as the first organic solvent, and separating by condensation the vapor contained in the gas in order to obtain a second organic phase, a second aqueous phase and a further depleted gas, which is optionally recycled in step (a),

[0023] - The two organic phases and optionally the organic compounds present in the two aqueous phases are combined to obtain the plant extract.

[0024] The present invention also relates to a plant extract obtained by the above process, in particular an extract obtained from a plant material consisting of silent flowers. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention relates to a method and a device for extracting aromatic compounds from plant material, and to the extracts obtained in this way.

[0027] Plant material refers to fresh plant material, which may have been washed or, after harvest, has been subjected to at least one mechanical treatment (e.g. blowing), chemical treatment (e.g. oxidation) and / or thermal treatment (in particular drying, roasting or freeze drying) and from which aromatic molecules can be extracted. Preference is given to fresh plant material, i.e. freshly picked or cut and undried plants of any type. The plant material may be any part of any plant, in particular consisting of leaves, flowers, fruits, stems, tops, needles, roots or mixtures thereof. More particularly, flowers are used, in particular jasmine, rose, tuberose or perfume flowers and flowers described as silent in the field of perfumery, in particular lily of the valley, hyacinth, lily, honeysuckle, lilac, gardenia, violet, carnation, sweet pea, buddleja or peony.

[0028] The extraction system according to the invention makes use of a gas cycle, in particular an air cycle, the temperature of which is advantageously close to or equal to the ambient temperature, to carry the volatile molecules emitted by the raw material placed in the housing towards the solvent. By avoiding heating the housing (or heating it to too high a temperature) and avoiding premature contact of the raw material with substances (such as steam, solvents or other chemical products) that could degrade some of the volatile molecules responsible for the original odor of the raw material, it is certain that all the emitted volatile molecules can be captured by the extraction system without deterioration (or almost without deterioration). By using a pressurized gas cycle, the system according to the invention makes it possible to increase the exchange between the compressed gas and the solvent contained in the capture device, thereby increasing the efficiency of the capture of the volatile molecules by the one or more solvents. Thus, the efficiency of the extraction system and the extraction yield are increased, in particular making it suitable for use on an industrial scale. The system constituting the object of the invention also makes it possible to treat a plurality of successive quantities of raw material with the same amount of solvent, thereby obtaining a higher concentration of volatile molecules in the solvent. The system according to the invention is particularly suitable for solvents of non-petrochemical origin. Therefore, the extraction system according to the invention is more environmentally friendly than known systems and methods and facilitates compliance of the finished product with legal regulations, in particular in cases involving the presence of residual solvents. Finally, the system according to the invention is compatible with so-called silent flowers.

[0029] The above mentioned objects are achieved in particular by the fact that the housing is configured to generate a gas circulation in the housing through each container, wherein the gas flow rate is equal or almost equal for each container. To this end, various types of configurations can be envisaged.

[0030] In a first embodiment, the housing includes an inlet and an outlet arranged at respective opposite ends of the housing, and the inlet of the housing is connected to a gas or air distribution column passing through the housing, the distribution column including a tubular body, the tubular body including a plurality of perforated longitudinal sections, the plurality of perforated longitudinal sections including a distribution hole near each container, each perforated section being arranged between two adjacent containers, and the cumulative area of ​​the holes of each continuous perforated section decreasing from the inlet to the outlet of the housing.

[0031] In one embodiment, the holes are of the same size and shape, with the number of holes in each successive perforated section decreasing from the inlet to the outlet of the housing.

[0032] In another embodiment, the shell includes an outer envelope and an inner envelope, wherein the inner envelope includes a plurality of perforated longitudinal sections, wherein the plurality of perforated longitudinal sections include a dispensing hole near each container, each perforated section is arranged between two adjacent containers, and the cumulative area of ​​the holes of each consecutive perforated section decreases from the entrance to the exit of the shell.

[0033] In a first variant of this embodiment, the housing comprises a gas or air distribution column comprising a perforated longitudinal portion close to each container and connected to the outlet of the housing.

[0034] In a second variant of this embodiment, the container comprises perforated lower and upper walls.

[0035] In another embodiment, the housing comprises a plurality of containers arranged side by side, and the inlet of the housing is connected to a gas or air distribution column comprising a tubular body comprising a plurality of perforated longitudinal sections comprising distribution holes near each container, the cumulative area of ​​the holes of each consecutive perforated section decreasing along the distribution column from the inlet of the housing. In a further embodiment, the housing comprises a plurality of removable containers around a horizontal axis, the inlet of each container comprising a gas or air distribution hole.

[0036] The supplementary embodiments described below are compatible with each of the embodiments of the housing described above.

[0037] In one embodiment, the compression device comprises an inlet connected to the outlet of the enclosure so as to extract the gas contained in the enclosure, and the compression device comprises an outlet connected to the inlet of the first capture device.

[0038] In one embodiment, the compression device is configured to generate a pressure higher than 2 bar, such as higher than 4 bar.

[0039] In one embodiment, the compression device is configured to generate a pressure between 4 and 6 bar (inclusive).

[0040] In one embodiment, the compression device is configured so that when the volume of the housing is between 100 and 200 liters (inclusive), the flow rate of the circulating gas at the outlet of the housing is greater than 20 liters per minute, preferably less than 100 liters per minute, for example between 30 and 80 liters per minute (inclusive).

[0041] In one embodiment, the compression device is an oil-free compressor.

[0042] In one embodiment, the extraction system comprises two housings, the outlet of each housing being connected to the inlet of the compression device.

[0043] In one embodiment, the extraction system comprises a selection device making it possible to start or stop the gas circulation in each housing, the selection device being able to selectively start the gas circulation in one or the other of the two housings or in both housings simultaneously, the selection device comprising, for example, one or more valves.

[0044] In one embodiment, the selection means is automatically controlled, for example via a timer means.

[0045] In another embodiment, the extraction system comprises two or more housings disposed within a reservoir, each housing comprising one or more gas outlets and one or more gas inlets connected to a single gas outlet of the reservoir.

[0046] In one embodiment, the containers are stacked, each container comprising a bottom wall and preferably a peripheral side wall.

[0047] In one embodiment, the bottom wall and / or the side wall of each container comprises a plurality of gas circulation holes.

[0048] In one embodiment, the solubility of the first solvent in water is less than or equal to 20%, and preferably less than or equal to 10%.

[0049] In one embodiment, the second solvent is the same as the first solvent, or the second solvent is different from the first solvent, and the second solvent is miscible with the first solvent.

[0050] In one embodiment, the solubility of the second solvent in water is less than or equal to 20%, and preferably less than or equal to 10%.

[0051] In one embodiment, the first capture device and / or the second capture device comprises a device for generating bubbles in the first solvent and / or the second solvent, respectively, such as a turbine, a sintered filter, a nebulization system or an ultrasonic probe. Preferably, it is a porous metal filter, such as a sintered metal type filter, so that the gas entering the first capture device passes through the filter before contacting the first solvent, and / or the gas entering the second capture device passes through the filter before contacting the second solvent.

[0052] In one embodiment, the first capture device and / or the second capture device comprise means forming a reservoir for condensed water resulting from condensation occurring during the circulation of gases in the extraction system.

[0053] In one embodiment, the first capture device and / or the second capture device comprises means for draining condensed water, the draining means being optionally automatically controlled.

[0054] As mentioned above, the present invention also relates to an extraction method using the above extraction system.

[0055] The present invention specifically relates to a method for extracting volatile molecules from plant materials such as flowers, the method comprising the following steps:

[0056] - distributing the plurality of portions of the plant material into an enclosure which is supplied with a gas, such as air, and which is configured to generate a circulation of the gas through each portion of the plant material, wherein the gas flow rate in each portion is close to or equal,

[0057] - extracting the gas that has circulated through all the parts of the plant material and compressing it to a relative pressure greater than or equal to 2 bar,

[0058] - trapping a compressed gas in a first organic solvent, the solubility of which in water is less than or equal to 20% by weight, and separating by condensation the vapor contained in said gas to obtain a depleted gas, a first organic phase and a first aqueous phase,

[0059] - capturing the depleted gas in a second organic solvent having a solubility in water less than or equal to 20% by weight, preferably the same as the first organic solvent, and separating by condensation the vapor contained in the gas in order to obtain a second organic phase, a second aqueous phase and a further depleted gas, which is optionally recycled in step (a),

[0060] - The two organic phases and optionally the organic compounds present in the two aqueous phases are combined to obtain the plant extract.

[0061] By "depleted gas" is meant a gas which no longer contains some of the volatile components it contained before entering the first capture device. By "further depleted gas" is meant a gas which no longer contains some of the volatile components it contained before entering the second capture device.

[0062] In a preferred embodiment, the method according to the invention is performed by an extraction system as described above and in the remainder of this specification. Then, the method comprises the following steps:

[0063] - arranging the plant material in the housing,

[0064] - extracting the gas contained in the housing, for example by suction through an outlet of said housing,

[0065] - compressing the extracted gas to a relative pressure greater than or equal to 2 bar,

[0066] - circulating compressed gas in said first capture device,

[0067] - circulating the gases leaving said first capture device in said second capture device.

[0068] In one embodiment, the extraction, compression and circulation steps of the gas are performed in a continuous cycle, the extraction system being stopped between two consecutive operating cycles.

[0069] In one embodiment, the duration of each cycle corresponds to a first predetermined duration, in particular a duration greater than 15 minutes, for example equal to 30 minutes.

[0070] In one embodiment, the time during which the system is stopped corresponds to a second predetermined duration, which is, for example, equal to the first predetermined duration.

[0071] In one embodiment, the duration of each cycle corresponds to the time required for the compressed gas to reach a predetermined relative pressure, for example a relative pressure between 2 and 10 bar (inclusive) or between 4 and 6 bar (inclusive).

[0072] In one embodiment, the time at which the extraction system is stopped corresponds to the time required for the relative pressure of the compressed gas to reach zero.

[0073] In one embodiment, the method employs an extraction system comprising at least two housings, and the extraction steps are performed alternately in each housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] The present invention will be better understood by reading the following detailed description with reference to the accompanying drawings, in which:

[0075] Figure 1 is a schematic diagram of an extraction system consistent with the present invention.

[0076] Figure 2 is a view of the gas distribution column.

[0077] Figure 3 is a schematic diagram of an extraction system according to the invention comprising two housings.

[0078] Figure 4 Represents the steps of the extraction method according to the present invention.

[0079] Figure 5Variants of the extraction system according to the invention are depicted.

[0080] Figure 6 A second variant of the extraction system according to the invention is depicted.

[0081] Figure 7 A third variant of the extraction system according to the invention is depicted.

[0082] Figure 8 is a chromatogram depicting the composition of rose absolute.

[0083] Fig. 9 It is a chromatogram depicting the composition of a rose.

[0084] Fig.10 is a chromatogram depicting the composition of the rose extract obtained according to the present invention.

[0085] Fig.11 It is a chromatogram depicting the composition of lily of the valley.

[0086] Fig.12 is a chromatogram depicting the composition of the lily of the valley extract obtained according to the present invention.

[0087] Figure 1 is a schematic diagram of an example of an extraction system 1 according to the present invention. The extraction system 1 comprises a storage housing 10, making it possible to store aromatic raw materials 2, in particular fresh plant materials, such as flowers 2. The extraction system 1 also comprises a compression device 12 and a capture system 14, 16. In this example, the capture system comprises a first capture device 14 and a second capture device 16. The extraction system 1 is configured to circulate a gas, which may be in particular air, through the housing 10, so as to bring a mixture of gas (or air) and volatile molecules emitted by the raw materials 2 stored in the housing 10 into the capture system 14, 16. In this example, the compression device 12 is arranged between the housing 10 and the capture system 14, 16, so as to suck the gas contained in the housing 10, which gas is air in this example. The sucked air is compressed by the compression device 12 and sucked into the first capture device 14. The passage of the air through the first capture device 14 makes it possible to capture some volatile molecules mixed with the air. The air is then sucked into the second capture device 16. The second capture device 16 makes it possible to capture volatile molecules that have not been captured by the first capture device 14.

[0088] The housing 10 includes an airtight body 100, which in this example is in the general shape of an elongated right cylindrical shape extending along a vertical axis of symmetry. By "airtight" it is meant that the housing 10 is particularly sealed to prevent the ingress of ambient air, except for air that enters the housing 10 through an inlet 102 in the body 100 (in this example through a lower end 104 of the body 100) and an outlet 106 in the body 100 (in this example through an upper end 108). The internal volume of the housing in this example is between 150 and 160 liters (inclusive). The housing 10 includes a plurality of containers 18 configured to store raw materials, such as flowers 2. The housing 10 also includes a gas distribution column 20 disposed in the body 100. The distribution column 20 (described in more detail below) includes a hollow body 200 connected to the air inlet 102 and includes one or more perforated portions 202. The perforated portion 202 enables the gas / air to circulate between the inside and the outside of the body 200, and therefore between the inlet 102 and the internal space of the housing 10 located around the distribution column. Thus, when the compression device 12 draws the air contained in the housing 10, an air circulation is generated from the inlet 102 to the outlet 106 of the housing, and the incoming air (arrow F3) is restricted to pass through the inside of the body 200 of the distribution column 20, then through the perforated portion 202 of the body 200, and then leave the housing 10 through the outlet 106. In this example, the distribution column 20 is arranged in the central part of the body 100 along the axis of symmetry of the body 100. The inlet 102 of the housing 10 is advantageously equipped with a filter, for example a carbon filter, making it possible to filter the air entering the housing 10 so that this air is free from any olfactory contamination.

[0089] The compression device 12 comprises an inlet 120 connected to the outlet 106 of the housing 10 via a first duct 22 and an outlet 122 connected to the first capture device 14 via a second duct 24. The compression device 12 is configured to suck the air contained in the housing 10 and to compress this air, which is loaded with volatile molecules from the raw material 2 stored in the housing 10. The compression device 12 is in this example a dry compressor (ie an oil-free compressor), which avoids contaminating the air circulating in the extraction system 1. In fact, a lubricated compression device 12 is prone to contamination in the extraction system, in particular by releasing lubricant particles into the gas / air circuit, which can compromise the quality of the final product, which may contain lubricant particles (and the lubricant may be contaminated with volatile molecules from previous extractions). The compression device 12 is configured to generate a relative pressure greater than or equal to 2 bars or 3 bars at the outlet. The compression device 12 is advantageously capable of generating a relative pressure between 4 and 5 bars (inclusive) or between 4 and 6 bars (inclusive). Providing a compression device disposed downstream of the housing 10 enables the generation of air circulation in the housing 10 by suction, which is more conducive to entraining volatile molecules from the flowers 2 disposed in the housing 10, compared to air circulation generated by reducing the pressure in the housing 10, which is more likely to generate turbulence, thereby damaging the operation of the system and the raw materials contained in the housing 10. The compression device 12 is configured to generate an air flow (or gas flow) sufficient to entrain the air contained in the housing, and this air flow is kept low enough not to generate excessive turbulence in the housing 10, in particular not to generate turbulence that is prone to moving the raw materials. For example, for a housing 10 with a volume of about 100 to 200 liters, the compression device 12 can be arranged to generate an air flow of between 30 and 100 liters per minute (inclusive) at the inlet of the device and between 10 and 50 liters per minute (inclusive) at the outlet of the device. Also by way of example, for a housing 10 having a volume of approximately 160 liters, the compression device 12 would be designed to produce an air flow of 50 liters per minute at the inlet and 20 liters per minute at the outlet. Of course, the air flow that the compression device is able to produce at the inlet (and therefore at the outlet of the housing 10) will depend, inter alia, on the internal volume of the housing 10.

[0090] The first capture device 14 comprises a body 140 forming a cylindrical reservoir and having an inlet 142 connected to the second duct 24 and an outlet 144 connected to the third duct 26 connecting the first and second capture devices 14, 16. The inlet 142 is arranged at the lower end of the body 140 so that the compressed air from the compression device 12 can enter, while the outlet 144 is arranged at the upper end of the body 140 so that the air can be drawn out to the third duct 26 and thus discharged to the second capture device 16. The body 140 is partially filled with a first solvent S1 and comprises for this purpose a first part 141 which forms a reservoir for the first solvent S1. The first solvent is selected from solvents suitable for preparing perfumes and is preferably a natural and non-polluting solvent. A porous metal filter 146 (for example of sintered metal type) is arranged next to the inlet 142 so that the air entering the body 140 is restricted to pass through the filter 146 before coming into contact with the first solvent. When the air from the compression device 12 enters the first capture device 14, a bubbling phenomenon is generated due to the filter 146, thereby achieving the exchange between the compressed air and the first solvent. This exchange causes the first solvent to capture at least a first portion of the volatile molecules contained in the air. Obviously, another bubble generation system can be used instead of the filter 146. Due to the compression of the air, the exchange between the air and the solvent increases due to the pressure of the air, and the capture efficiency achieved by the air passing through the solvent is improved. In order to optimize the exchange between the compressed air and the first solvent, the porosity of the filter 146 is preferably between 10 and 100 microns (inclusive), preferably between 20 and 60 microns (inclusive), for example, equal to 20 microns. The fine porosity is conducive to the generation of small air (or gas) bubbles and enables a larger exchange area to be provided between the first solvent and the air. In this example, the filter 146 is a sintered stainless steel filter. The volume of the first solvent is advantageously greater than or equal to 400 ml, and in particular between 500 ml and 2000 ml (inclusive) or between 500 ml and 1200 ml (inclusive) or between 600 ml and 1100 ml (inclusive), for example equal to 900 ml. Of course, the volume of the solvent will be determined according to the amount of raw material that can be stored in the housing 10, and therefore according to the volume of the housing 10. In this regard, solvent volumes greater than 2000 ml can of course be envisaged.

[0091] The body 140 of the first capture device 14 advantageously comprises a second part 148 between the first part 141 and the outlet 144, so as to form a reservoir for storing condensed water EC, i.e. water resulting from the condensation of water contained in the air entering the first capture device (from the air entering the housing 10 and from the feedstock 2). The second part 148 is of course in fluid communication with the first part 141. The respective volumes of these two parts are determined so that the first part 141 can accommodate all the first solvent quantities required, and so that the second part preferably has a volume sufficient to receive all the condensed water, for example a volume between 4 and 10 litres.

[0092] The air entering the first capture device 14 is drawn out through the outlet 144 and is entrained in the third duct 26 to the second capture device 16. The second capture device 16 comprises a body 160 forming a cylindrical reservoir and comprising an inlet 162 connected to the third duct 26 and an outlet 164, which can be a free outlet or connected to the fourth duct 28 connecting the second capture device to the inlet 102 of the housing 10. The inlet 162 is arranged at the lower end of the body 160 so that the compressed air that has passed through the first capture device (14) can enter, while the outlet 164 is arranged at the upper end of the body 160 so that the air can be drawn out from the second capture device 16. The body 160 is partially filled with a second solvent S2, which is selected from solvents suitable for preparing perfumes and is preferably a non-polluting natural solvent. In addition, the second solvent is selected to be miscible in the first solvent. A porous metal filter 166 (for example of sintered metal type) is arranged next to the inlet 162 so that the air entering the body 160 is restricted to pass through the filter 166 before reaching the second solvent. When the air from the first capture device 14 enters the second capture device 16, a bubbling phenomenon is generated due to the filter 166. For the first capture device, the air passes through the second solvent, causing the second solvent to capture the volatile molecules contained in the air, and the bubbling system is not limited to the sintered filter. Therefore, the compressed air passes through the second solvent to capture the second part of the volatile molecules from the air and recover these molecules in the second solvent. For the first solvent, due to the compression of the air, the exchange between the air and the solvent increases due to the pressure of the air, and the capture efficiency generated by the air passing through the second solvent is improved. In order to optimize the exchange between the compressed air and the second solvent, the porosity of the filter 166 is preferably between 10 and 100 microns (inclusive), preferably between 20 and 60 microns (inclusive), for example, equal to 20 microns. In this example, the filter 166 is a sintered stainless steel filter. The volume of the second solvent is advantageously greater than or equal to 50 ml, in particular between 50 ml and 300 ml (inclusive), or between 50 ml and 200 ml (inclusive), for example, equal to 100 ml. The body 160 of the second capture device 16 advantageously comprises a compartment in the upper part, in which a condensation device 168 is arranged, which in this example comprises a Raschig ring. The condensation device 168 is capable of optimizing the condensation of volatile molecules mixed with the air and not captured by the solvent. Alternatively, the condensation device 168 may comprise an atomizing device.

[0093] The first solvent is advantageously hydrophobic so as to prevent it from dissolving (or to dissolve it only in very limited amounts) in the water contained in the air circulating in the extraction system 1 or in the water condensed in the first capture device 14. The solubility of the first solvent in water is preferably less than or equal to 20% by weight, preferably less than or equal to 10% by weight, or again less than or equal to 5% by weight. The first solvent is an organic solvent that can be selected by a person skilled in the art according to the plant material to be extracted, and advantageously comprises: at least one alkyl ester, at least one triglyceride (in particular C8 / C10 acid triglycerides); at least one fatty acid, for example C12-C22 carboxylic acid; at least one fatty alcohol, for example of the C6-C20 type, and mixtures thereof. Preferably, an alkyl ester is used, in particular triethyl citrate (TEC). If a certain amount of solvent is found dissolved in the condensed water EC in the reservoir 148 of the first capture device 14, the solvent dissolved in the water can be recovered after use of the extraction system 1, also including some of the captured volatile molecules.

[0094] The second solvent is advantageously also hydrophobic and preferably has a solubility in water of less than or equal to 20%, or less than or equal to 10%, or again less than or equal to 5%. The second solvent is an organic solvent that can be selected by a person skilled in the art according to the plant material to be extracted and advantageously comprises: at least one alkyl ester, at least one triglyceride (in particular C8 / C10 acid triglycerides); at least one fatty acid, for example C12-C22 carboxylic acids; at least one fatty alcohol, for example of the C6-C20 type, and mixtures thereof. Preferably, alkyl esters are used, in particular triethyl citrate (TEC). The second solvent may be identical to or different from the first solvent. The first and second solvents are preferably identical. When the second solvent is different from the first solvent, as described above, the second solvent is selected so as to be miscible with the first solvent so that, after capturing the molecules contained in the air circulating in the extraction system 1 , the two solvents can be mixed, thus providing a product that can be used directly by the perfume manufacturing industry.

[0095] The extraction system 1 preferably comprises means 13 for measuring the relative pressure, which in this example is arranged at the outlet of the compression device 12. The extraction system 1 advantageously comprises means, such as a needle valve, for regulating the maximum pressure at the outlet of the compression device 12. Additionally or alternatively, the extraction system 1 may comprise pressure regulating means.

[0096] When the extraction system 1 comprises a fourth duct 28 arranged at the outlet of the second capture device 16, the fourth duct 28 is connected to the inlet 102 of the housing 10 via the inlet device 30. The inlet device 30 is configured to produce a mixture comprising a portion of the air coming from the second capture device 16 and a portion of the air coming from outside the extraction system 1. The proportion of air coming from the second capture device 16 can advantageously be adjusted, preferably varying in a range between 0% and 100%. Thus, the inlet device 30 enables the air entering the housing 10 to be completely air coming from outside the extraction system 1, or the air entering comprises some air that has already circulated through the extraction system 1.

[0097] The following will refer to Figure 1 and 2 An embodiment of the housing 10 and the suction column 20 is described. As described above, the housing 10 includes a plurality of containers 18 in which the flowers 2 can be stored. In this example, the containers 18 are stacked and each container has an overall shape that is adapted to the shape of the body 100 of the housing 10. Thus, in this example, the containers 18 have an overall shape that exhibits rotational symmetry about an axis of symmetry of the body 100. Figure 1 As shown, the dimensions of the containers 18 are advantageously selected so that a space is defined between the periphery of each container 18 and the inner side wall of the body 100 of the housing 10. Thus, when the extraction system 1 is in operation, a vertical circulation of air (or gas) can be generated along the inner wall of the body 100 (arrow F1).

[0098] Each container 18 includes a bottom wall 180, which forms a surface for storing flowers. The bottom wall 180 can be a solid wall, or a perforated wall to allow air to flow through the bottom wall. The two end containers (i.e., the containers adjacent to the inlet 102 and the outlet 106, respectively) have a solid bottom wall 180, while all containers located between the two end containers have a perforated bottom wall 180. This configuration makes it possible to facilitate the vertical circulation of the above-mentioned air.

[0099] The containers 18 may include a peripheral side wall 182 so that each container forms a reservoir. When the containers 18 include a side wall 182, the side wall 182 is preferably perforated so as to include a plurality of holes distributed over all or part of the periphery of the respective container 18. Therefore, whether or not the containers 18 include a side wall 182, they are configured to allow air to circulate through each container in a direction perpendicular to the axis of symmetry of the body 100 and therefore parallel to the respective bottom wall 180 (arrow F2).

[0100] As described above, the distribution column 20 is arranged in the central part of the main body 100. In this example, the distribution column 20 includes a tubular hollow main body 200. The main body 200 has an overall shape that presents rotational symmetry around the symmetry axis of the main body 100. The main body 200 is open at a first end or lower end 201 to connect to the inlet 102 of the housing 10. The opposite end or upper end 203 of the main body 200 is closed. The main body 200 includes a plurality of perforated longitudinal portions 202, and adjacent perforated portions 202 are separated by non-perforated portions 205. Each perforated portion 202 includes a plurality of distribution holes 204, and each hole 204 provides fluid communication between the inside and outside of the main body 200. The number of perforated portions 202 included in the distribution column 20 is as many as the number of containers 18 included in the housing 10. The distribution column 20 is configured so that each perforated portion 202 is positioned above the level of the bottom wall 180 of the corresponding container 18 (each bottom wall is positioned by a non-perforated portion 203). Therefore, the hole 204 of the perforated portion 202 is arranged between the bottom wall 180 of two adjacent containers 18. The cumulative area of ​​the hole 204 of each continuous perforated portion 202 decreases from the lower end 201 to the upper end 203, and therefore decreases from the inlet to the outlet of the housing 10. Therefore, the farther the perforated portion 202 is from the outlet 106 of the housing 10 (therefore, the farther the negative pressure source is), the easier it is for air to pass through the main body 200. This configuration enables the air flow through the distribution column 20 to be relatively uniformly obtained along the distribution column. In other words, each container 18 provides an equal air flow. The distribution holes 204 preferably have the same size and shape, and in this example, the holes 204 have a circular cross section. The number of the distribution holes in each continuous perforated portion 202 decreases from the inlet to the outlet of the housing 10, that is, from the lower end 201 of the distribution column 20 to the upper end 203.

[0101] To facilitate the loading of the raw material 2 into the housing, the containers 18 are advantageously removable. Each container is preferably engaged around the body 200 of the distribution column 20, for which purpose it comprises an opening in the bottom wall 180, the shape of the opening being complementary to the cross-sectional shape of the body 200, in this embodiment a circular opening.

[0102] Figure 3 express Figure 1A variant of the extraction system 1 in which the system comprises two similar housings 10. The provision of two housings 10 makes it possible to store twice the amount of flowers. The air contained in the housings 10 can be extracted simultaneously or advantageously alternately. When the extraction system 1 comprises two housings 10, the selection means 32 comprises, for example, at least one valve, preferably capable of selecting from which housing 10 the air is to be extracted when the extraction system 1 is in operation. The selection means 32 is preferably capable of extracting the air in one or the other of the housings 10 or in both housings 10 simultaneously. The selection means 32 can be automatically controlled, for example via a timer device. When the extraction system comprises two housings, the extraction of air can advantageously be performed alternately in each housing, for example each housing is operated for the same predetermined time.

[0103] Figures 5 to 7 Other embodiments of extraction systems according to the present invention are depicted.

[0104] Figure 5 The system shown in the invention comprises a housing (10) provided with an air inlet (102) and an air outlet (106), the housing enclosing a series (here five) of containers (40) arranged side by side. The inlet of the housing (10) is connected to a gas or air distribution column (20) comprising a tubular body comprising a plurality of perforated longitudinal sections comprising distribution holes (not shown) close to the bottom wall of each container (40) so that the air flow (F3) circulates at the same flow rate in each container. To this end, the cumulative area of ​​the holes of each consecutive perforated section decreases along the distribution column from the inlet (102) of the housing (10).

[0105] exist Figure 6 In the variant shown, the housing (10) comprises an outer envelope corresponding to the body (100) and an inner envelope (41), the inner envelope (41) comprising a plurality of perforated longitudinal sections comprising a dispensing hole (not shown) adjacent to each container (not shown), each perforated section being arranged between two adjacent containers, the cumulative area of ​​the holes of each consecutive perforated section decreasing from the inlet (102) to the outlet (106) of the housing (10).

[0106] In this variant, the air can be extracted in two different ways. One way is that the housing comprises a gas or air distribution column having a perforated longitudinal section close to each container, wherein the distribution column is connected to the outlet of the housing. Thus, the air circulates in the distribution column from the inlet of the housing to the outlet. Another way is that the container comprises a perforated lower wall and an upper wall. Thus, the air or gas circulates from the bottom of the housing through the various containers to the outlet.

[0107] exist Figure 7In another variant shown, the housing (not shown) comprises a plurality of containers (42) movable about a horizontal axis (43), the inlet of each container (42) comprising a gas or air distribution hole (not shown) in one of its vertical walls, suitable for passing gas or air (F3) through the container (42).

[0108] In this variant, the air or gas can likewise be extracted in two different ways. In the first way, the shaft constitutes a gas or air distribution pipe provided with a perforated longitudinal section, and the distribution column is connected to the outlet of the container. Thus, the air or gas passing through the plant material enters the distribution column and circulates from the inlet to the outlet of the housing. In another way, the container comprises a second vertical perforated wall opposite the first vertical perforated wall.

[0109] Figure 4 An extraction method according to the invention using an extraction system according to the invention is presented.

[0110] The method comprises a first step 200 in which plant material, such as flowers 2 , is arranged in one or more housings 10 .

[0111] The method then comprises a step 202 of extracting the gas or air obtained in the housing 10. In this example, the extraction is achieved by sucking air through the housing outlet by means of a compression device 12.

[0112] The method then comprises a step 204 of compressing the extracted air to a relative pressure greater than or equal to 2 bar, and advantageously to a pressure between 3 and 5 bar, inclusive.

[0113] The method then comprises a step 206 of circulating the compressed air in the first capture device 14, during which the compressed air passes through the first solvent, which enables the first solvent to capture some of the volatile molecules mixed with the air.

[0114] The method then comprises a step 208 of circulating the air extracted from the first capture device 14 in the second capture device 16, during which the air passes through the second solvent, which enables the second solvent to capture some of the volatile molecules mixed with the air.

[0115] The extraction, compression and circulation steps of air (or gas) are advantageously performed in a continuous cycle, with the system stopped between cycles. Each cycle can be defined by a predetermined duration, for example a duration of 30 minutes. In this case, the method is performed intermittently, with the extraction system running for a first predetermined duration and then stopped for a second specific duration (e.g. equal to 30 minutes). Alternatively, each cycle can be defined by the duration required to obtain a first predetermined pressure, and the cycle is interrupted when the predetermined pressure is reached. The predetermined pressure can be, for example, between 4 and 5 bars (inclusive). The extraction system then remains stopped for the time required for the relative pressure to reach a second predetermined pressure, for example equal to 0.

[0116] The above-described systems and methods are particularly suitable for use in industrial settings, both in terms of extraction yield (i.e., the amount of product extracted from a given amount of feedstock), productivity (the amount of material that can be processed in a given time), processing capacity (the amount of feedstock that the system can accept in one use), and energy efficiency, as the system consumes very little energy.

[0117] The volume of the housing is advantageously greater than 100 or even 150 litres, and is typically between 100 and 1000 litres, inclusive, in particular between 100 and 500 litres, inclusive, for example between 120 and 200 litres, inclusive. The use of two or more housings further enables the total processing capacity of the system to be increased, or a given processing capacity to be achieved using housings of smaller size.

[0118] The first capture device and / or the second capture device can advantageously comprise means for extracting the condensed water. Such means comprise, for example, a valve which can be controlled manually or automatically. The automatically controlled condensed water evaporation device is able to automatically extract the condensed water while the extraction system is running. Thus, the operation of the extraction system does not need to be interrupted in order to prevent the condensed water from possibly reaching an excessive volume.

[0119] At least a portion of the housing 10 may advantageously be translucent or transparent so as to allow light to penetrate into the housing. In fact, depending on the type of flower that one wishes to treat using the extraction system, it may be useful that the flower is not in darkness (darkness would negatively affect the evolution of the flower and the quantity and quality of the volatile molecules emitted by the flower).

[0120] The housing 10 can advantageously be equipped with a heating and / or temperature regulation system, for example to keep the interior of the housing at a given temperature, for example a temperature between 10°C and 50°C (inclusive), preferably between 10°C and 30°C (inclusive), in particular between 20°C and 30°C (inclusive).

[0121] The use of naturally derived and non-polluting solvents is described above. However, it can be said that the system according to the present invention is compatible with the use of petrochemical solvents and the use of adsorbents as alternatives to the first and second solvents.

[0122] The use of an extraction system with air circulation is described above, but it is conceivable to circulate other types of gas in the extraction system, in particular inert gases such as nitrogen. If a gas other than air is used, the extraction system can be configured to operate in a closed circuit or in an open circuit (in which case continuous gas replenishment must be provided).

[0123] The invention also relates to a plant extract obtained by the above method. The plant extract can constitute a food flavoring or preferably a perfume ingredient. The perfume ingredient can be used in particular for making an accord, ie a combination of several perfume ingredients, or for producing a perfume containing a more complex combination of perfume ingredients. DETAILED DESCRIPTION

[0124] Example 1 : Extracted from flowers

[0125] Figure 3 The extraction system according to the invention depicted in is used to obtain extracts from flowers.

[0126] The freshly harvested flowers are set in two different extraction cylinders. They are evenly distributed in the baskets and spread over the entire height of the cylinders.

[0127] The same extraction solvent was placed in two trap columns at a weight ratio of 90:10.

[0128] The system is activated so that the air flow alternates into one or the other cylinder for a period of 15 to 60 minutes, preferably 30 minutes.

[0129] The flowers are left in the cylinder for a suitable period of time to properly preserve the flowers, generally 8 to 48 hours, preferably 24 hours. At the end of this period, the flowers are removed and replaced with fresh flowers.

[0130] This step is repeated until an appropriate flower / solvent weight ratio of 20 / 1 to 200 / 1 is reached, depending on the olfactory capacity of the flower being treated.

[0131] Once this ratio is reached, the solvent contained in the extraction column is taken out together with the condensed water. The aqueous and organic phases are separated by condensation and the aqueous phase is treated chemically (saturated with salt) or physically (centrifuged) to recover the portion of the solvent dissolved in the water, which is then mixed with the organic phase. The resulting mixture is dried to obtain the extract according to the invention.

[0132] Example 2 :Analysis of rose extract

[0133] Using triethyl citrate as the first and second solvents, a rose (Rosacentifolia) flower extract (Extract 1) was obtained as described in Example 1. The extract was analyzed and compared with the same rose absolute commonly used in the perfumery field and the headspace fraction from fresh flowers.

[0134] 2A – Chromatography

[0135] Comparative studies of the chemical composition of VOCs (volatile organic compounds) between fresh flowers, ingredients according to the invention and classic perfume ingredients (such as absolutes) were performed by gas chromatography (GC) using an Agilent GC7890B system coupled to an MSD 5977B mass spectrometer (MS). The samples were prepared in the headspace using the HiSorb (Markes International) technology. The HiSorb probe consists of a 75 mm inert stainless steel rod covered with a small area and an adsorption phase consisting of polydimethylsiloxane (PDMS). The extraction and / or desorption steps of the probe were automated on a Centri (Markes International) extraction and enrichment platform.

[0136] In the case of flower analysis, freshly cut flowers were placed in a bottomless 1-liter clear glass flask, closed with a silicone septum stopper, and placed outdoors in sunlight for 2 hours before the HiSorb probe was introduced for VOC extraction.

[0137] Once the VOCs are extracted, the probe is thermally desorbed at 270°C for 15 minutes, sending 2.5% of the inlet gas flow to a trap to concentrate the analytes before GC injection. The trap corresponds to a glass tube containing a porous polymer-based absorbent (Tenax®). The trap is desorbed by rapid heating to 300°C for 5 minutes and the gas flow is sent to the GC column for VOC analysis.

[0138] In the step before the desorption of the HiSorb probe, the VOC extraction was performed automatically by the Centri extraction and enrichment platform. 500 mg of sample was introduced into a 20 ml glass vial. This vial was first pre-incubated for 5 min at 40 °C with stirring at 500 rpm to equilibrate the flask at the extraction temperature. The HiSorb probe was then placed in the vial and the VOCs were extracted for 15 min at 40 °C with stirring at 500 rpm. The HiSorb probe was then desorbed under the same conditions as for the capture of VOCs from flowers (15 min, 270 °C).

[0139] Chromatographic separation was performed on a 30 x 0.25 m (0.25 µm) DB1-MS (Agilent) nonpolar column using the following temperature gradient: 250°C isothermal, 5 min; 3°C / min gradient to 120°C; 5°C / min gradient to 250°C; 250°C isothermal, 5 min. The carrier gas used was helium at a constant flow rate of 1.6 ml / min. For mass spectrometry detection, the transfer line temperature was set to 250°C, the ionization source temperature was set to 230°C, and the MS Quad temperature was set to 150°C. The ion scan range was between m / z 35 and m / z 550.

[0140] The results of these tests are listed in Figures 8 to 10 middle.

[0141] As shown in these figures, the compounds present in the top fraction of rose ( Figure 8 ) in Extract 1 ( Fig. 9 ) than in the neat oil ( Fig.10 ), especially sabinene, β-pinene, myrcene, α-phellandrene and γ-terpinene.

[0142] 2B – Sensory Analysis

[0143] The analysis was performed by a trained panel. The extract obtained according to the invention is fresher than the traditional rose extract and closer to the olfactory characteristics of the flower, with lychee notes and honey and powdery notes typical of rose (Rosa centifolia).

[0144] Example 3: Analysis of Lily of the Valley Extract

[0145] An extract of Convallaria japonica was obtained using triethyl citrate as the first and second solvents as described in Example 1. The extract was analyzed using the method described in Example 2 and compared with the headspace fraction of fresh flowers.

[0146] Flowers ( Fig.11 ) and the composition according to the invention ( Fig.12 ) showed that all the olfactory components of the flower (except myrcene) were present in the extract according to the invention.

Claims

1. A system (1) for extracting volatile molecules from plant materials such as flowers, the system (1) comprising: - at least one housing (10), the housing (10) comprising a plurality of containers (18) configured to receive plant material, the housing (10) being hermetically sealed to prevent the ingress of gas and comprising an inlet (102) and an outlet (106) disposed at both ends of the housing, the housing being configured to generate a gas circulation in the housing through each container, wherein the gas flow of each container is substantially similar or equal, - compression means (12) configured to regulate the pressure of the air or gas circulating from the housing (10) to the capture system (14, 16) at a relative pressure greater than or equal to 2 bar, The capture system comprises: - a first capture device (14) at least partially filled with a first solvent so as to enable an exchange between the first solvent and the compressed gas entrained by the compression device (12), and - a second capture device (16), said second capture device (16) comprising an inlet (162) connected to the duct (26) so that air extracted from said first capture device (14) can be sucked into said second capture device (16), said second capture device being at least partially filled with a second solvent so as to enable an exchange between said second solvent and the compressed gas that has passed through said first capture device (14).

2. An extraction system (1) according to the preceding claim, wherein the compression device (12) comprises an inlet (120) connected to the outlet (106) of the housing (10) in order to suck the gas contained in the housing, and the compression device (12) comprises an outlet (122) connected to the inlet of the first capture device (14).

3. An extraction system (1) according to claim 1 or 2, wherein the housing includes an inlet (102) and an outlet (106) arranged at respective opposite ends of the housing, the inlet (102) being connected to a gas or air distribution column (20) passing through the housing, the distribution column (20) comprising a tubular body (200), the tubular body (200) comprising a plurality of perforated longitudinal sections (202), the plurality of perforated longitudinal sections (202) comprising a distribution hole (204) adjacent to each container (18), each perforated section (202) being arranged between two adjacent containers (18), the cumulative area of ​​the holes (204) of each consecutive perforated section (202) decreasing from the inlet to the outlet of the housing (10).

4. The extraction system (1) according to claim 3, wherein the holes (204) have the same size and shape, the number of holes in each consecutive perforated section (202) decreasing from the inlet to the outlet of the housing (10).

5. Extraction system (1) according to any of the preceding claims, wherein the compression device (12) is configured to provide a pressure greater than 2 bar, such as greater than 4 bar, preferably between 4 and 6 bar.

6. Extraction system (1) according to any one of the preceding claims, comprising two housings (10), the outlet (106) of each housing being connected to the inlet of a compression device (12).

7. An extraction system (1) according to the preceding claim, comprising a selection device (32) for each housing (10) making it possible to start or stop the gas circulation, the selection device being able to selectively start the gas circulation in one or the other of the two housings or in both housings simultaneously, the selection device (32) comprising, for example, one or more valves.

8. The extraction system (1) according to any one of the preceding claims, wherein the containers (18) are stacked, each container comprising a bottom wall (180) and preferably a peripheral side wall (182).

9. Extraction system (1) according to the preceding claim, wherein the bottom wall (180) and / or the side wall (182) of each container (18) comprises a plurality of gas circulation holes.

10. The extraction system (1) according to any one of the preceding claims, wherein the solubility of the first solvent in water is less than or equal to 20%, and preferably less than or equal to 10%.

11. The extraction system (1) according to any of the preceding claims, wherein the second solvent is the same as the first solvent, or the second solvent is different from the first solvent, the second solvent being miscible with the first solvent.

12. Extraction system (1) according to the preceding claim, wherein the solubility of said second solvent in water is less than or equal to 20%, and preferably less than or equal to 10%.

13. An extraction system (1) according to any one of the preceding claims, wherein the first capture device (14) and / or the second capture device (16) comprises a device for generating bubbles in the first solvent and / or the second solvent, such as a turbine, a sintered filter, a nebulization system or an ultrasonic probe, preferably a porous metal filter (146, 166), so that the gas entering the first capture device (14) is restricted to pass through the filter (146) before contacting the first solvent, and / or the gas entering the second capture device (16) is restricted to pass through the filter (166) before contacting the second solvent.

14. Extraction system (1) according to any of the preceding claims, wherein the first capture device (14) and / or the second capture device (16) comprises means forming a reservoir for condensed water resulting from condensation occurring in the circulation of gases in the extraction system.

15. A method for extracting volatile molecules from plant materials such as flowers, the method comprising the following steps: - distributing the plurality of portions of the plant material into an enclosure which is supplied with a gas, such as air, and which is configured to generate a circulation of the gas through each portion of the plant material, wherein the gas flow rate in each portion is close to or equal, - extracting the gas that has circulated through all the parts of the plant material and compressing it to a relative pressure greater than or equal to 2 bar, - trapping a compressed gas in a first organic solvent, the solubility of which in water is less than or equal to 20% by weight, and separating by condensation the vapor contained in said gas to obtain a depleted gas, a first organic phase and a first aqueous phase, - capturing the depleted gas in a second organic solvent having a solubility in water less than or equal to 20% by weight, preferably the same as the first organic solvent, and separating by condensation the vapor contained in the gas in order to obtain a second organic phase, a second aqueous phase and a further depleted gas, which is optionally recycled in step (a), - The two organic phases and optionally the organic compounds present in the two aqueous phases are combined to obtain the plant extract.

16. The method according to claim 15, characterized in that The method uses the extraction system (1) according to any one of claims 1 to 14, and the method comprises the following steps: - placing plant material (200) in the housing, - extracting (202) the gas contained in the housing, for example by suction through an outlet of the housing, - compressing (204) the extracted gas to a relative pressure greater than or equal to 2 bar, - circulating compressed gas in said first capture device (206), - circulating the gas leaving the first capture device in the second capture device (208).

17. A plant extract obtainable by the method according to claim 15 or 16.

18. The plant extract according to claim 17, characterized in that The plant material consists of silent flowers.

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