Liquid/liquid extraction with a solvent comprising at least 5 carbon atoms and 1 or 2 oxygen atoms

Abstract

The present invention relates to an extraction process of an unsaponifiable fraction contained in an oil or a vegetable butter, in an oil originating from a micro-organism, in a concentrate of oil or butter or of oil originating from a micro-organism, or in a co-product of the refining industry for vegetable oils, such as deodorization exhaust and distillates of physical refining, or oils originating from micro-organisms, comprising at least: A) a transformation step of said oils, of said butter or said co-product of the refining industry for vegetable oils or oils originating from micro-organisms in hydro-alcoholic solution, especially via a saponification step, and B) an extraction step of the hydro-alcoholic solution in which the fatty fraction is separated from unsaponifiable fraction by liquid/liquid extraction,
said process being characterized in that at least the liquid/liquid extraction step of the step B is performed by using a first solvent system comprising a solvent content selected from the solvents comprising at least 5 carbon atoms and one or two oxygen atoms in the form of either ether function, or ketone function, or ester function, of at least 50% in volume relative to the total volume of the first solvent system, as well as fractions obtained by said process.

Claims

1. A process for extraction of an unsaponifiable fraction contained in an oil or a vegetable butter, in an oil originating from a micro-organism, in a concentrate of oil or vegetable butter or of oil originating from a micro-organism, or in a co-product of the refining industry for vegetable oils or oils originating from micro-organisms, comprising at least the following steps: A) saponifying said oils, said butter or said co-product of the refining industry for vegetable oils or oils originating from micro-organisms to form a hydro-alcoholic solution, A) adjusting alcohol content of the hydro-alcoholic solution obtained in step A to between 10 and 50% by weight, and B) extracting the adjusted hydro-alcoholic solution, wherein the fatty fraction is separated from unsaponifiable fraction by liquid/liquid extraction, wherein at least the liquid/liquid extraction step of the step B is performed with a first solvent system comprising a content in solvent selected from the solvents comprising at least 5 carbon atoms and one or two oxygen atoms in the form of either ether function, or ketone function, or ester function, of at least 50% in volume relative to the total volume of the first solvent system, wherein said solvent comprising at least 5 carbon atoms and one or two oxygen atoms is selected from methylketones, propionates, propylethers, and mixtures thereof.

2. The process according to claim 1, wherein after step A the alcohol content is between 11 and 40% by weight.

3. The process according to claim 1, further comprising after step B a purification step C of the unsaponifiable.

4. The process according to claim 3, wherein purification step C of the unsaponifiable is performed with said first solvent system.

5. The process according to claim 1, wherein the first solvent system has a density less than 1.

6. The process according to claim 1, wherein the solvent comprising at least 5 carbon atoms and one or two oxygen atoms is selected from methyl isobutyl ketone (MIBK), 2-heptanone, ethyl propionate, n-butyl propionate, isoamyl propionate, diisopropyl ether (DIPE), and mixtures thereof.

7. The process according to claim 1, wherein the first solvent system comprises a content in solvent comprising at least 5 carbon atoms and one or two oxygen atoms in the form of ether, ketone or ester function of at least 75% in volume, relative to the total volume of the first solvent system.

8. The process according to claim 1, wherein the first solvent system comprises a content in solvent selected from solvents comprising at least 5 carbon atoms and one or two oxygen atoms in the form of ether, ketone or ester function, selected from methylketones, propionates, propylethers, and mixtures thereof of at least 75% in volume, relative to the total volume of the first solvent system.

9. The process according to claim 1, wherein the first solvent system further comprises hexamethyldisiloxane (HMDS) in a content ranging from 0.1 to 49% in volume relative to the total volume of the first solvent system.

10. The process according to claim 1, wherein the first solvent system comprises a content of Carcinogenic, Mutagenic and Toxic for Reproduction (CMR) solvent(s), present on the list CMR UE1, UE2, and/or US, less than or equal to 0.1% in volume, relative to the total volume of the first solvent system.

11. The process according to claim 1, wherein step A) is performed in a second solvent system comprising a content in solvent selected from C2 to C4 alcohols, 2-methyltetrahydrofuran (MeTHF) and their mixtures, of at least 50% in volume relative to the total volume of the second solvent system.

12. The process according to claim 11, wherein the second solvent system comprises a content in solvent selected from C2 to C4 alcohols, 2-methyltetrahydrofuran (MeTHF) and their mixtures, of at least 60% in volume, relative to the total volume of the second solvent system.

13. The process according to claim 11, wherein the second solvent system comprises a content of CMR solvent(s) present on the list CMR UE1, UE2 and/or US, less than or equal to 0.1% in volume, relative to the total volume of the second solvent system.

14. The process according to claim 1, wherein the titre of alcohol of the hydro-alcoholic solution is comprised between 10 and 50% in mass.

15. The process according to claim 1, wherein: the vegetable oil or the oil originating from micro-organism used in the present process is selected from soy oil, quinoa, rapeseed, maize, sunflower, sesame, lupin, cotton, coconut, olive, palm, wheat germ, lucern, avocado, palm nut, peanut, copra, flax, castor, grape pips, squash seeds, blackcurrant seeds, melon seeds, tomato seeds, pumpkin seeds, almond, hazelnut, walnut, evening primrose, borage, safflower, camelina, poppy, macro-algae, micro-algae, and/or originate from micro-organisms, and their mixtures, and the vegetable butter is selected from cocoa butter, illipe butter, shea butter, and their mixtures.

16. The process according to claim 1, wherein the unsaponifiable obtained is selected from an unsaponifiable of soy, an unsaponifiable of avocado, an unsaponifiable of avocado rich in furanic fraction or an unsaponifiable of avocado rich in sterolic fraction.

17. The process according to claim 2, wherein after step A the alcohol content is between 12 and 28% by weight.

18. The process according to claim 1, wherein the first solvent system comprises a content in solvent comprising at least 5 carbon atoms and one or two oxygen atoms in the form of ether, ketone or ester function of at least 90% in volume, relative to the total volume of the first solvent system.

19. The process according to claim 1, wherein the first solvent system comprises a content of methylketones or propionates of at least 90% in volume, relative to the total volume of the first solvent system.

20. The process according to claim 8, wherein the solvent comprising at least 5 carbon atoms and one or two oxygen atoms is selected from methyl isobutyl ketone (MIBK), 2-heptanone, ethyl propionate, n-butyl propionate, isoamyl propionate, diisopropyl ether (DIPE), and mixtures thereof.

21. The process according to claim 11, wherein the C2 to C4 alcohols are ethanol, n-propanol, iso-propanol and/or butanol.

22. The process according to claim 12, wherein the C2 to C4 alcohols are ethanol, n-propanol, iso-propanol and/or butanol.

23. The process according to claim 15, wherein said micro-algae is Chorella.

Description

EXAMPLES

Example 1: Extraction of Unsaponifiable of Avocado with DCE (Reference 1)

(1) The first step consists of saponifying a concentrate prepared by molecular distillation of avocado oil.

(2) For this purpose, a given mass of fatty matter of avocado (15.6 g) then ethanol (36.6 mL), potash at 50% (5.2 mL) and a few grains of pumice stone are successively introduced in a balloon of 100 ml provided with a refrigerant.

(3) The system is then brought to reflux for 3 h30 then, after cooling, diluted with demineralised water which modifies the titre of alcohol of the solution saponified at 21% mass.

(4) The resulting diluted hydro-alcoholic solution contains unsaponifiable (or fraction of unsaponifiable) in solution. This unsaponifiable is then extracted by a first solvent system, in this case DCE.

(5) Several successive extractions (560 mL) are carried out; the organic phases collected in this way are then combined and washed in water (5150 mL) to neutrality.

(6) The resulting solvent phase is dried on anhydrous sodium sulfate then filtered; unsaponifiable is then recovered by evaporation of the solvent in the rotary evaporator at a temperature of 60 C. and pressure of the order of 300 mbar; it is then dried under high vacuum.

(7) The extracted unsaponifiable is weighed and stored in a pill dispenser in inert atmosphere. The results are presented in Table 1 hereinbelow.

Example 2: Extraction of Unsaponifiable of Avocado with 2-Heptanone

(8) Extraction is performed according to the operating method of Example 1 which, after optimisation to adapt it to the new solvent system, corresponds to: a dilution step for adjusting the titre of alcohol to 21% mass; an extraction step with 560 ml of 2-heptanone; a washing step of the organic phases with 6150 mL of water.

(9) The measurements are taken as in Example 1 and the results are presented in Table 1 hereinbelow.

Example 3: Extraction of Unsaponifiable of Avocado with Isoamyl Propionate

(10) Extraction is performed according to the operating method of Example 1 which, after optimisation to adapt it to the new solvent system, corresponds to: a dilution step for adjusting the titre of alcohol to 22% mass; an extraction step with 560 ml isoamyl propionate; a washing step of the organic phases with 6150 mL of water.

(11) The measurements are taken as in Example 1 and the results are presented in Table 1 hereinbelow.

Example 4: Extraction of Unsaponifiable of Avocado with n-Butyl Propionate

(12) Extraction is performed according to the operating method of Example 1 except that the quantities of materials used are divided by 2.

(13) After optimisation to adapt it to the new solvent system, the operating method used corresponds to: a dilution step for adjusting the titre of alcohol to 22% mass; an extraction step with 530 mL of isoamyl propionate; a washing step of the organic phases with 675 mL of water.

(14) The measurements are taken as in Example 1 and the results are presented in Table 1 hereinbelow.

(15) TABLE-US-00001 TABLE 1 Delta of yield between the reference process (extraction on DCE - Example 1) and the processes described in Examples 2 to 4 Unsaponifiable mass yield (%) Yield gain (%) Example 1 38.7 0 Example 2 47.6 +23 Example 3 48.4 +25 Example 4 51.7 +34

(16) The unsaponifiable mass yield is calculated as follows:
R=100(mass of extracted unsaponifiable/mass of concentrate used)

(17) The yield gain is calculated as follows:
G=100[(R linked to the solvent SR linked to the reference solvent)/R linked to the reference solvent]

(18) The results show that unsaponifiable mass yield of the processes according to the invention is improved relative to the process involving DCE.

Example 5: Extraction of Unsaponifiable of Soy with DCE (Reference 2)

(19) The first step consists of saponifying a deodistillate of soy.

(20) For this purpose, a given mass of deodistillate of soy (10 g) then ethanol (23.3 mL), potash at 50% (1.7 mL) and a few grains of pumice stone are successively introduced to a balloon of 100 ml provided with a refrigerant.

(21) The system is then brought to reflux for 3 h00 then, after cooling, diluted with demineralised water, which modifies the titre of alcohol of the solution saponified at 23% mass.

(22) The hydro-alcoholic solution diluted obtained contains unsaponifiable (or fraction of unsaponifiable) in solution. This unsaponifiable is then extracted by a first solvent system, in this case DCE.

(23) Several successive extractions (536 mL) are carried out; the collected organic phases are then combined and washed in city-supply water (590 mL) to neutrality.

(24) The resulting solvent phase is dried on anhydrous sodium sulfate then filtered; unsaponifiable is then recovered by evaporation of the solvent in the rotary evaporator at a temperature of 60 C. and pressure of the order of 300 mbar; it is then dried under high vacuum.

(25) The extracted unsaponifiable is weighed and stored in a pill dispenser in inert atmosphere. The results are presented in Table 2 hereinbelow.

Example 6: Extraction of Unsaponifiable of Soy with MIBK

(26) Extraction is performed according to the operating method of Example 6 which, after optimisation to adapt it to the new solvent system, corresponds to: a dilution step for adjusting the titre of alcohol to 23% mass; an extraction step with 2105 mL of MIBK; a washing step of the organic phases with 6105 mL of water.

(27) The measurements are taken as in Example 5 and the results are presented in Table 2 hereinbelow.

Example 7: Extraction of Unsaponifiable of Soy with Ethyl Propionate

(28) Extraction is performed according to the operating method of Example 6 which, after optimisation to adapt it to the new solvent system, corresponds to: a dilution step for adjusting the titre of alcohol to 23% mass; an extraction step with 560 mL of ethyl proprionate; a washing step of the organic phases with 6150 mL of water.

(29) The measurements are taken as in Example 5 and the results are presented in Table 2 hereinbelow.

Example 8: Extraction of Unsaponifiable of Soy with a Mixture of MIBK and HMDS 90/10 v/v

(30) Extraction is performed according to the operating method of Example 5 which, after optimisation to adapt it to the new solvent system, corresponds to: a dilution step for adjusting the titre of alcohol to 24% mass; an extraction step with 2105 mL of a mixture MIBK/HMDS 90/10 v/v; a washing step of the organic phases with 6105 mL of water.

(31) The measurements are taken as in Example 5 and the results are presented in Table 2 hereinbelow.

(32) TABLE-US-00002 TABLE 2 Delta of yield between the reference process (extraction on DCE - Example 5) and the processes described in Examples 6 to 8 Unsaponifiable mass yield (%) Yield gain (%) Example 5 46.2 0 Example 6 50.4 +9 Example 7 50.0 +8 Example 8 45.0 3

(33) The unsaponifiable mass yield, is calculated as follows:
R=100(mass of extracted unsaponifiable/mass of concentrate used)

(34) The gain in yield is calculated as follows:
G=100[(R linked to the solvent SR linked to the reference solvent)/R linked to the reference solvent]

(35) Examples 6 and 7 show that unsaponifiable mass yield of the processes according to the invention is improved relative to the process involving DCE.

(36) By remaining within a range of unsaponifiable mass yield close to the target Example 8 also gains in dephasing quality and therefore in overall extraction time.

Example 9: Extraction of Unsaponifiable from Avocado Counter-Current with DCE

(37) The assay described in Example 1 was transposed to pilot scale by conducting counter-current extraction in an agitated column. The titre of the hydro-alcoholic solution was adjusted to 24% after saponification via a dilution step. On start-up of extraction the column was filled with solvent (continuous phase) and the ratio between the flow rates of the solvent or organic phase and DHS or diluted hydro-alcoholic solution was fixed at 1.2.

(38) The weight yield of this extraction was calculated and was 42%.

Example 10: Extraction of Unsaponifiable from Soy Counter-Current with DCE

(39) The assay described in Example 5 was transposed to pilot scale by conducting counter-current extraction in an agitated column. The titre of the hydro-alcoholic solution was adjusted to 23% after saponification via a dilution step. On start-up of extraction the column was filled with solvent (continuous phase) and the ratio between the flow rates of the solvent or organic phase and DHS or diluted hydro-alcoholic solution was fixed at 1.2.

(40) The weight yield of this extraction was calculated and was 40%.

Example 11: Extraction of Unsaponifiable from Avocado Counter-Current with MIBK

(41) The assay described in Example 6 was transposed to pilot scale on avocado matrix by conducting counter-current extraction in an agitated column. The titre of the hydro-alcoholic solution was adjusted to 14% after saponification via a dilution step. On start-up of extraction the column was filled with solvent (continuous phase) and the ratio between the flow rates of the solvent or organic phase and DHS or diluted hydro-alcoholic solution was fixed at 0.9.

(42) The weight yield of this extraction was calculated and was 50%.

Example 12: Extraction of Unsaponifiable from Avocado Counter-Current with MIBK

(43) The assay described in Example 6 was transposed to pilot scale on avocado matrix by conducting counter-current extraction in an agitated column. The titre of the hydro-alcoholic solution was adjusted to 14% after saponification via a dilution step. On start-up of extraction the column was filled with hydro-alcoholic solution (continuous phase) and the ratio between the flow rates of the solvent or organic phase and DHS or diluted hydro-alcoholic solution was set at 0.38.

(44) The weight yield of this extraction was calculated and was 45%.

Example 13: Extraction of Unsaponifiables from Soy Counter-Current with MIBK

(45) The assay described in Example 6 was transposed to pilot scale by conducting counter-current extraction in an agitated column. The titre of the hydro-alcoholic solution was adjusted to 24% after saponification via a dilution step. On start-up of extraction the column was filled with solvent (continuous phase) and the ratio between the flow rates of the solvent or organic phase and DHS or diluted hydro-alcoholic solution was fixed at 1.2.

(46) The weight yield of this extraction was calculated and was 39%.

(47) The table below summarises the results obtained:

(48) TABLE-US-00003 Soy Avocado Solvent DCE MIBK DCE MIBK MIBK Example N.sup.o 10 13 9 11 12 Continuous phase Solvent Solvent Solvent Solvent Aqueous Alcohol titre 23% 24% 24% 14% 14% Flow rate ratio 1.2 1.2 1.2 0.90 0.38 Yield 40% 39% 42% 50% 45%

(49) The assays carried out show that the choice of DHS alcohol titre has an influence on phase partitioning and allows the extraction yield to be optimised.