Method for obtaining acetoin
Through hydrophilic membrane permeation, evaporation and dehydration technology, solvent use and impurities problems in separation and purification of yomson's is solved, and efficient and economical separation of yomson's family is achieved, meeting the food industry's demand for high purity and natural labeling.
Patent Information
- Application Number
- CN202380034069.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-04-15
- Filing Date
- 2023-04-13
- Publication Date
- 2024-12-17
AI Technical Summary
The prior art is difficult to effectively isolate and purify Azoon, especially in the fields of food processing and pharmaceuticals, and commonly used solvents such as ethyl acetate are uneconomically used and may produce impurities, making it difficult to label as "natural" products.
The hydrophilic membrane is used to migrate water and hydrophilic compounds into the permeability by osmotic evaporation dehydration technology using negative pressure, retaining the azeotropic mixture in the retention, avoiding the separation difficulties related to solvent use and azeotropic mixture.
It achieves high yield and high purity separation, avoids the generation of impurities, meets the food industry's demand for high purity, and can be marked as "natural" products.
Smart Images
Figure CN119156368A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for obtaining acetoin from a medium containing acetoin, the method comprising a dehydration step by pervaporation using a hydrophilic membrane. The method can separate and purify acetoin satisfactorily in terms of quality and yield. In addition, the method eliminates the use of solvents and prevents the generation of impurities. Background Art
[0002] Acetoin (3-hydroxybutanone) is a chiral organic molecule with the molecular formula C4H8O2, which belongs to the class of hydroxylated ketones and includes two enantiomeric forms. Acetoin has two functional groups, hydroxyl and carbonyl, which makes acetoin particularly easy to react and decompose, especially to decompose into acetaldehyde.
[0003] Acetoin is found in trace amounts in many foods, especially grapes, raspberries, apples, bananas, corn, honey and coffee. The molecule is also present in some cheeses or some meats. Finally, the molecule is also a synthetic intermediate in the sugar metabolism of some microorganisms.
[0004] Acetoin and diacetyl (2,3-butanedione) are among the molecules that give butter its characteristic flavor. Acetoin can be used as a flavoring agent.
[0005] Acetoin is particularly frequently used in the food industry, more particularly in the dairy products, beverages, bread and bakery products and confectionery sectors, to give a "buttery flavor" to products containing acetoin. In the above sectors, regulations require the use of acetoin of high purity, for example at least 95% (according to Regulation (EC) No 1334 / 2008).
[0006] Acetoin is also used in other areas, especially in flavoring, pharmaceuticals, and tobacco use.
[0007] Acetoin can be obtained by chemical synthesis or biological methods.
[0008] The chemical synthesis method can use, for example, 2,3-butanedione and 2,3-butanediol as raw materials.
[0009] Biological methods can use wild microorganisms, selected microorganisms, or recombinant microorganisms.
[0010] Known recombinant microorganisms do not naturally produce acetoin or produce acetoin in too low a yield and / or as a synthetic intermediate. For example, recombinant microorganisms have been obtained from the following microorganisms: Bacillus subtilis, Bacillus pumilus, Bacillus methanolicus, Bacillus licheniformis, Corynebacterium glutamicum, Escherichia coli, Lactococcus lactis, Saccharomyces cerevisiae and Serratia marcescens.
[0011] Regardless of the production method, the quantity and quality of the product obtained may be insufficient, especially for use in food processing and the pharmaceutical field. In addition, when obtained by biological methods, a medium containing impurities, especially acetoin by-products, organic residues (biomass) and other molecules is obtained. Therefore, it is necessary to separate and purify acetoin from the medium containing acetoin.
[0012] Many purification techniques are known, such as distillation, liquid-liquid extraction or salting-out extraction.
[0013] The effectiveness of these techniques (particularly distillation) may be limited by the fact that acetoin forms an azeotropic mixture with water, whereby separation is hindered or limited when the liquid and vapor phases reach the same water / acetoin composition.
[0014] The use of solvents is not recommended, especially when acetoin is used in the food processing industry. In fact, for regulatory reasons, only specific solvents can be used in products containing acetoin and labeled as "natural". Of the available solvents, only ethyl acetate complies with European regulations and is particularly suitable for the purification of acetoin. However, the use of this solvent requires large amounts, which makes this method not economically feasible for efficient extraction on an industrial scale. In addition, this solvent does not allow the use of the NOP (National Organic Program) label in the United States.
[0015] International application WO 2021 / 060334 A1, published on April 1, 2021, discloses a purification method using tangential filtration technology, which is implemented by a nanofiltration step followed by a reverse osmosis step. However, this method is not effective in achieving a residual moisture content below 50%.
[0016] Therefore, there is a real need to provide a method for obtaining acetoin that can be used directly in the preparation of processed foods. There is also a real need to provide a method for obtaining acetoin in high yield and at an affordable cost. There is also a real need to provide a method that can be carried out without the use of solvents, particularly ethyl acetate. There is also a real need to provide a method for obtaining acetoin that can be labeled as "natural". Summary of the invention
[0017] The invention firstly relates to a method for obtaining acetoin from a medium to be treated, said method comprising a dehydration step by pervaporation using a hydrophilic membrane to obtain a dehydrated medium comprising at least 70% acetoin, relative to the total weight of the treated medium.
[0018] In an embodiment, the hydrophilic membrane is selected from the group consisting of a hydrophilic polymer membrane, a hydrophilic inorganic membrane, a hydrophilic two-dimensional material membrane, a hydrophilic mixed matrix membrane, or a membrane derived therefrom.
[0019] In an embodiment, the hydrophilic film is a hydrophilic silicon dioxide film or a hydrophilic film derived therefrom.
[0020] In an embodiment, the hydrophilic silica film is obtained from an organoalkoxysilane precursor.
[0021] In the embodiment, -700×10 5 mPa or greater negative pressure (underpressure).
[0022] In embodiments, the dehydration step is performed in the absence of solvents and / or inorganic salts.
[0023] In an embodiment, the method comprises a pretreatment step of the medium to be treated, which is performed before the dewatering step using a technique selected from centrifugation, frontal filtration, microfiltration and nanofiltration.
[0024] In an embodiment, the method comprises a post-treatment step of the treated medium by distillation after the dehydration step.
[0025] In an embodiment, the medium comprising acetoin is obtained by a biological method using a recombinant microorganism.
[0026] In embodiments, the recombinant microorganism is a yeast belonging to the genus Saccharomyces.
[0027] Secondly, the invention relates to acetoin obtained by the process described hereinafter.
[0028] Thirdly, the present invention relates to the use of a hydrophilic membrane to obtain acetoin as described below.
[0029] The present invention makes it possible to meet the above needs.
[0030] Surprisingly, the inventors have demonstrated that by choosing a hydrophilic membrane, acetoin can be separated and purified satisfactorily from both a quality and a yield point of view. When using such a membrane, only water and hydrophilic compounds migrate through the membrane into the permeate (filtrate), while acetoin remains in the retentate (treated medium), which results in a progressive and satisfactory dehydration of acetoin. This pervaporation dehydration technique also makes it possible to dispense with the separation limitations associated with the formation of azeotropic mixtures.
[0031] The disadvantage of the commonly used liquid-liquid extraction technique is that it requires the use of large amounts of solvents, such as ethyl acetate. In addition, the inventors have shown that this technique leads to the formation of impurities, such as methyl allyl acetate, the reaction product between acetoin and ethyl acetate. In short, this technique does not allow the production of acetoin that can be labeled as "natural".
[0032] According to the technology in application PCT WO 2021 / 060334 A1, the use of solvents can be avoided, but this technology is not economically feasible because a water-acetoin azeotropic mixture is formed and a large amount of acetoin is removed together with the water, so the yield of acetoin is too low.
[0033] According to the present invention, the pervaporation dehydration technology is used, and a hydrophilic membrane is used to avoid the use of solvents to prevent the generation of impurities in the final product, overcome the separation difficulties associated with the formation of azeotropic mixtures, and obtain a satisfactory acetoin yield.
[0034] Furthermore, counterintuitively, the inventors have also demonstrated that the use of hydrophilic membranes can lead to processes with improved performance, namely higher yields and higher degrees of dehydration, compared to processes using organophilic membranes, despite the fact that water initially dominates the medium. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 A graph showing the concentration of acetoin and water in the retentate (mass percent) versus time (minutes);
[0036] Figure 2 The concentration of acetoin in the retentate (mass percent) and the negative pressure on the permeate surface (×10 5 mPa) versus time (minutes). DETAILED DESCRIPTION
[0037] The invention is hereby described in a non-limiting manner and in more detail in the following description.
[0038] In the specification, unless otherwise specified, all percentages expressed are mass percentages.
[0039] In a first aspect, the present invention relates to a method for obtaining acetoin from a medium containing acetoin (medium to be treated), said method comprising a step of dehydration by pervaporation using a hydrophilic membrane.
[0040] Dehydration step
[0041] The dehydration step includes bringing the medium to be treated into contact with the first surface of the hydrophilic membrane and applying negative pressure to the permeate surface (second surface) of the hydrophilic membrane.
[0042] The negative pressure applied to the permeation surface of the hydrophilic membrane is -700 x 10 5 mPa or higher, preferably -300 x 10 5 mPa to -0.1 x 10 5 mPa, very preferably -100 x 10 5 mPa to -10 5 mPa.
[0043] Negative pressure is defined relative to the pressure on the surface in contact with the medium to be dehydrated.
[0044] The temperature applied to the feed is 150°C or lower, preferably from 5°C to 100°C, very preferably from 30°C to 90°C.
[0045] Thus, a permeate (medium to be removed) comprising water and hydrophilic compounds migrating through the hydrophilic membrane is gradually formed, whereas the remaining medium comprising acetoin forms the retentate (treated medium).
[0046] Hydrophilic membrane
[0047] "Hydrophilic membrane" refers to a membrane that preferentially allows the permeate, water, and hydrophilic molecules to pass through.
[0048] The hydrophilic membrane can be selected from hydrophilic polymer membranes, hydrophilic inorganic membranes, membranes based on hydrophilic two-dimensional materials (two-dimensional membranes), hydrophilic mixed matrix membranes or hydrophilic membranes derived therefrom; preferably, the hydrophilic membrane is an inorganic membrane or a hydrophilic membrane derived therefrom.
[0049] The hydrophilic inorganic membrane can be selected from a hydrophilic zeolite membrane, a hydrophilic silica membrane, a hydrophilic metal-organic framework (MOF) membrane, a hydrophilic covalent organic framework (COF) membrane or a hydrophilic membrane derived therefrom; preferably, the hydrophilic inorganic membrane is a hydrophilic silica-based membrane or a hydrophilic membrane derived therefrom; very preferably, the hydrophilic inorganic membrane is a hydrophilic silica-based hydride membrane. Silica hydrogenated membranes are indiscriminately referred to as organic-inorganic silica membranes, organic silica membranes or organic silica hydride membranes.
[0050] The hydrophilic silica hydride membrane may be selected from a silica hydride membrane having hydrophilic side groups ("pendant-type organic silica membrane") or a hydrophilic bridged silica hydride membrane ("bridged-type organic silica membrane"); preferably a hydrophilic bridged silica-based hydride membrane.
[0051] Silica hydride membranes are known (see X. Ren's review entitled "Organosilica-based membranes in gas and liquid-phase separation", Membranes, 2019, 9, 107; the book entitled "Pervaporation, vapor permeation and membrane distillation-principles and applications", Ed. Woodhead Publishing Series in Energy, 2015, including Chapter 5 entitled "Next-generation pervaporation membranes: recent trends, challenges and perspectives", 107-141; G. Liu's article entitled "Pervaporation membrane materials: Recent trends and perspectives", Journal of Membrane Science, 2021, 636).
[0052] The bridged organic silica film can be obtained from an organic alkoxysilane precursor (monomer), ie, an alkoxysilane precursor containing an organic moiety.
[0053] The organoalkoxysilane precursor may be selected from organoalkoxysilane precursors containing one, two, three or more than three silicon (silica) atoms.
[0054] The organic alkoxysilane precursor containing silicon atoms can be selected from methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), phenyltriethoxysilane (PhTES), hydroxymethyl (triethoxy) silane (HMTES), (3-aminopropyl) triethoxysilane (APTES) and mixtures thereof.
[0055] The organoalkoxysilane precursor containing two silicon atoms can be selected from bis(triethoxysilyl)methane (bis(triethoxysilyl)methane, BTESM), 1,2-bis(triethoxysilyl)ethane (1,2-bis(triethoxysilyl)ethane, BTESE), 1,3-bis(triethoxysilyl)propane (1,3-bis(triethoxysilyl)propane, BTESP), 1,8-bis(triethoxysilyl)octane (1,8-bis(triethoxysilyl)octane, BTESO), 1,2-bis(triethoxysilyl)ethylene (1,2-bis(triethoxysilyl)ethylene s(triethoxysilyl)ethylene, BTESEthy), 1,2-bis(triethoxysilyl)acetylene, BTESA), 1,4-bis(triethoxysilyl)diacetylene, BTESDA), bis(trimethoxysilyl)norbornane, BTMS-Nor, 1,2-bis(triethoxysilyl)benz ene, BTESB), 2,5-bis[2-triethoxysilyl]ethyl]-1,4-dioxane (BTES-ED), bis[3-(triethoxysilyl)propyl]amine (BTESPA), 1,6-diacetoxy-3,4-bis(triethoxysilyl)hexa-2,4-diene (BTES-Ac), 4,6-bis(triethoxysilyl)hexa-2,4-diene (BTES-Ac), (3-triethoxysilyl-1-propoxy)-1,3-pyrimidine (4,6-bis(3-triethoxysilyl-1-propoxy)-1,3-pyrimidine, BTPP), bis(triethoxysilyl-dimethyl / dipropyl-N,N'-oxalylurated, BTESMOU / BTESMPU) and mixtures thereof; preferably, the organoalkoxysilane containing two silicon atoms is selected from BTESM, BTESE and mixtures thereof; very preferably, the organoalkoxysilane containing two silicon atoms is BTESE.
[0056] The organic alkoxysilane precursor can be selected from TTESPT, TESE-POSS, MTMS, MTES, PhTES, HMTES, APTES, BTESM, BTESE, BTESP, BTESO, BTESEthy, BTESA, BTESDA, BTMS-Nor, BTESB, BTES-ED, BTESPA, BTES-Ac, BTPP, BTESMOU / BTESMPU, TTESPT, TESE-POSS and mixtures thereof; preferably, the organic alkoxysilane precursor is selected from BTESM, BTESE and mixtures thereof; very preferably, the organic alkoxysilane precursor is BTESE.
[0057] The organic moiety may be used to functionalize the alkoxysilane precursor.
[0058] The organic group used to form an organic bridge between the organoalkoxysilane precursors can be selected from methane (CH4), ethane (CH3-CH3), propane (CH3-CH2-CH3), hexane (CH3-(CH2)4-CH3), octane (CH3-(CH2)6-CH3), phenyl, ethylene (CH2=CH2), acetylene (CHCH), diethylenedioxane, norbornane, triazine, pyrimidine and mixtures thereof. For example, organic bridges such as -CH2-, -CH2-CH2-, -CH2-CH2-CH2-, -(CH2)6-, -(CH2)8, phenyl, -CH=CH-, acetylene bridge, diethylenedioxane bridge, norbornane bridge, triazine bridge, pyrimidine bridge and mixtures thereof can be obtained.
[0059] The silicon dioxide based hydride films can be subjected to additional treatments, for example with metals.
[0060] Hydrophilic membranes are commercially available, for example from The name is membrane.
[0061] Medium to be processed
[0062] The medium to be treated corresponds to a starting product (untreated medium) or alternatively to an intermediate product which has previously undergone a pretreatment step (pretreated medium).
[0063] The terms "medium", "composition", "solution" and "matrix" may be used indiscriminately to refer to the medium to be treated (and, where appropriate, the treated medium).
[0064] The medium to be treated may contain 2% to 50%, preferably 6% to 30%, of acetoin, based on the total weight of the medium. For example, the medium to be treated may contain 1% to 5%, or 5% to 10%, or 10% to 15%, or 15% to 20%, or 20% to 25%, or 25% to 30%, or 30% to 35%, or 35% to 40%, or 40% to 45%, or 45% to 50% of acetoin, based on the total weight of the medium.
[0065] Acetoin may be present in the form of its (3R)-3-hydroxybutanone enantiomer (the natural enantiomer), its (3S)-3-hydroxybutanol enantiomer, or a mixture of both enantiomers (including a racemic mixture).
[0066] The medium to be treated is an aqueous medium. The medium to be treated may contain at least 15%, preferably at least 45%, very preferably at least 65% of water, based on the total weight of the medium.
[0067] The medium to be treated can be obtained by chemical synthesis or biological methods.
[0068] Treated media
[0069] After carrying out a dehydration step, a treated medium (corresponding to the retentate) is obtained.
[0070] The treated medium may contain at least 70% (70% to 99%), preferably at least 80% (80% to 99%), very preferably at least 90% (90% to 99%) acetoin, based on the total weight of the medium. For example, the dehydrated medium may contain 70% to 75%, or 75% to 80%, or 80% to 85%, or 85% to 90%, or 90% to 95%, or 95% to 99% acetoin, based on the total weight of the medium.
[0071] Accordingly, the treated medium may contain 30% or less (from 1% to 30%), preferably 20% or less (from 1% to 20%), very preferably 10% or less (from 1% to 10%) of water and other compounds (impurities), based on the total weight of the medium.
[0072] Filter (not present)
[0073] The dehydration step is carried out in the absence of a solvent, such as ethyl acetate, methyl tert-butyl ether, butyl acetate, dimethyl carbonate, diethyl ether, diethyl carbonate, ethanol, methanol, acetone, isopropanol, acetonitrile, dichloromethane and / or chloroform. More specifically, the dehydration step is carried out in the absence of ethyl acetate.
[0074] The dehydration step is performed in the absence of inorganic salts, such as ammonium sulfate, magnesium sulfate, sodium sulfate, copper sulfate, calcium chloride, potassium hydrogen phosphate (dipotassium phosphate), potassium pyrophosphate, sodium carbonate and / or potassium carbonate.
[0075] Preprocessing steps
[0076] The method may include a step of pre-treatment of the medium to be treated prior to the dehydration step. In such an embodiment, the medium to be treated is pre-treated and the pre-treated medium thus obtained is subsequently dehydrated.
[0077] A pretreatment step may be used to remove suspended solids in the medium to be treated. More specifically, a pretreatment step may be used when acetoin is produced by biological methods and the medium to be treated therefore comprises biomass.
[0078] When the medium comprising acetoin is obtained from a biological method, it may include biomass. "Biomass" refers to organic matter of bacterial or fungal, plant or animal origin, preferably organic matter of bacterial or fungal origin. When using bacteria or fungi (including yeast) to obtain the medium from a biological method, biomass may include all microorganisms (alive or dead), the residues of microorganisms (residues such as nuclei, organelles, cytoplasm, membranes) and the molecules (proteins, carbohydrates, lipids, etc.) produced therefrom. According to the gross weight of the medium, the medium to be treated (not pretreated) may include 1% to 20%, preferably 1% to 10% dry biomass.
[0079] The pretreatment step makes it possible to remove at least 80%, preferably at least 90% of the dry biomass contained in the medium to be dewatered.
[0080] The pretreatment step may be selected by centrifugation, prefiltration, microfiltration, ultrafiltration, nanofiltration or any other conventional clarification technique.
[0081] Post-processing steps
[0082] The method may include the step of post-treating the treated medium (retentate) after the dewatering step.
[0083] A work-up step may be used to increase the purity of the acetoin.
[0084] The work-up step can be carried out by distillation.
[0085] The process according to the invention is particularly advantageous since it avoids the difficulties associated with the formation of a water-acetoin azeotrope in a direct distillation process.
[0086] Chemical Synthesis Method of Acetoin
[0087] The medium containing acetoin can be obtained by chemical synthesis.
[0088] Biological methods for obtaining acetoin
[0089] The medium containing acetoin can be obtained by biological methods.
[0090] The biological method can be performed using microorganisms, in particular wild microorganisms, selected microorganisms or recombinant microorganisms.
[0091] Wild microorganisms are microorganisms that naturally produce acetoin in usable concentrations. Selected (non-transgenic) microorganisms are microorganisms that have improved properties in producing acetoin.
[0092] The recombinant (transgenic) microorganism - which does not naturally produce acetoin or produces it in too low a yield and / or as a synthetic intermediate - can be selected from the group consisting of: Bacillus subtilis, Bacillus pumilus, Bacillus methanolicus, Bacillus licheniformis, Corynebacterium glutamicum, Escherichia coli, Lactococcus lactis, Serratia marcescens and yeasts of the genus Saccharomyces, preferably microorganisms of the genus Saccharomyces, very preferably Saccharomyces cerevisiae.
[0093] Acetoin
[0094] The process according to the invention makes it possible to obtain a product comprising at least 70% of acetoin, relative to the total weight of the treated medium.
[0095] Example
[0096] According to an embodiment of the present invention: a method for obtaining acetoin using a hydrophilic membrane
[0097] Material
[0098] Medium to be purified: Aqueous solution containing 10% acetoin based on the total weight of the aqueous solution
[0099] Hydrophilic membrane: Sales AR film
[0100] Dehydration device: PTU-044 device
[0101] Parameters of the pervaporation dehydration step
[0102] Medium temperature: 100℃
[0103] Linear velocity of feed in medium (speed): 1-2m / s
[0104] Negative pressure of permeate (vacuum pressure): -20.10 5 mPa
[0105] Parameters of post-distillation work-up steps
[0106] Distillation method: Batch
[0107] Distillation column: 20 stages
[0108] Applied vacuum: 150mbar
[0109] Steam temperature: 44℃ to 86℃
[0110] Reflux ratio: between 1 and 5
[0111] Water content measurement
[0112] The water content in the retentate and the filtrate was measured by Karl Fischer filtration (KF titration).
[0113] Measurement of acetoin content
[0114] Acetoin content was measured by HPLC and gas chromatography.
[0115] Dehydration method
[0116] The process aims at permeating water from the medium to be treated through a hydrophilic membrane into the permeate, thereby achieving a corresponding dehydration of acetoin (retentate).
[0117] like Figure 1 As shown, the figure shows a graph of the concentration of acetoin and water in the retentate (mass percentage) as a function of time (minutes), the concentration of water in the retentate (white squares) decreases over time, on the other hand, the concentration of acetoin in the retentate (black circles) increases over time. After 485 minutes of treatment, the water concentration decreases to about 1.1% of the total weight of the retentate, while the acetoin concentration increases to about 77%, a difference corresponding to organic residues other than acetoin.
[0118] A work-up step by distillation gave acetoin with a purity of 98.5% and a yield of 80.5%.
[0119] Comparative Example: Method for obtaining acetoin using organophilic membrane
[0120] Material
[0121] Medium to be purified: Aqueous solution containing 10% acetoin based on the total weight of the aqueous solution
[0122] Organic-philic membrane: PDMS-FS membrane for sale
[0123] Extraction device: PTU-044 device
[0124] parameter
[0125] Medium temperature: 55℃
[0126] Medium feed rate: 200L / h
[0127] Infiltration vacuum pressure: 20x10 5 mPa to 4x10 5 mPa
[0128] Liquid-Liquid Extraction
[0129] The method aims at causing acetoin to permeate from an acetoin-containing medium through an organophilic membrane into the filtrate.
[0130] like Figure 2 As shown, it shows the concentration of acetoin in the retentate (left coordinate, mass percentage) and the negative pressure of the permeate surface (right coordinate, Xⅹ10 5 mPa) versus time (min), the filtration was not sufficiently selective because, despite the organophilic properties of the membrane used and the application of increasing negative pressure (white circles), acetoin (black circles) migrated through the membrane along with water. This insufficient selectivity did not allow for an effective level of acetoin dehydration to be achieved.
[0131] in conclusion
[0132] The tests performed showed that acetoin can be effectively purified by selecting a hydrophilic membrane. On the other hand, counterintuitively, the tests performed with organophilic membranes did not give convincing results in the absence of sufficient selectivity.
Claims
1. A method for obtaining acetoin from a medium to be treated which contains acetoin, the method comprising a dehydration step by pervaporation using a hydrophilic membrane to obtain a treated medium containing at least 70% acetoin, based on the total weight of the treated medium.
2. The method for obtaining acetoin according to claim 1, wherein the hydrophilic membrane is selected from the group consisting of a hydrophilic polymer membrane, a hydrophilic inorganic membrane, a hydrophilic two-dimensional material membrane, a hydrophilic mixed matrix membrane or a hydrophilic membrane derived therefrom.
3. The method for obtaining acetoin according to one of the preceding claims, wherein the hydrophilic membrane is a hydrophilic silica-based membrane or a hydrophilic membrane derived therefrom.
4. The method for obtaining acetoin according to claim 3, wherein the hydrophilic silica-based film is obtained from an organic alkoxysilane precursor.
5. A method for obtaining acetoin according to one of the preceding claims, wherein -700×10 5 mPa or greater negative pressure.
6. Process for obtaining acetoin according to one of the preceding claims, wherein the dehydration step is carried out in the absence of solvents and / or inorganic salts.
7. The method for obtaining acetoin according to one of the preceding claims, comprising a pretreatment step of the medium to be treated, before the dehydration step, using a technique chosen among centrifugation, prefiltration, microfiltration and nanofiltration.
8. Process for obtaining acetoin according to one of the preceding claims, comprising a post-treatment step of the treated medium by distillation after the dehydration step.
9. Method for obtaining acetoin according to one of the preceding claims, wherein the medium comprising acetoin is obtained by a biological method using recombinant microorganisms.
10. The method for obtaining acetoin according to claim 9, wherein the recombinant microorganism is a yeast belonging to the genus Saccharomyces.
11. Acetoin obtained according to the method of any one of the preceding claims.
12. Use of the hydrophilic membrane according to any one of claims 1 to 10 for obtaining acetoin.