Solid/liquid extraction

Abstract

The invention relates to a method for the solid/liquid extraction of an oil or butter, particularly having a high unsaponifiable content, contained in at least one solid vegetable matter or a micro-organism. The method includes at least the following steps: solid/liquid extraction of at least one solid vegetable matter or a micro-organism using a first solvent system comprising a concentration of solvent selected from among fluorinated aromatic solvents, particularly trifluorotoluene (BTF) and hexafluorobenzene (BHF), tert-butyl ethers, particularly 2-ethoxy-2-methylpropane, also known as ethyl-tert-butyl-ether (ETBE), and 2-methoxy-2-methylpropane or methyl-tert-butylether (MTBE), solvents comprising at least one silicon atom, particularly hexamethyldisiloxane (HMDS) and tetramethylsilane (TMS), methyl-tetrahydrofuran (MeTHF), and mixtures thereof, representing at least 50 vol.-% in relation to the total volume of the solvent system; and, optionally, recovery of a fraction comprising the oil or butter, particularly unsaponifiable enriched. The invention also relates to an unsaponifiable fraction, oil or butter obtained using this method and to compositions containing said oil or fraction.

Claims

1. A method for extracting an oil or butter, contained in at least one solid vegetable matter or an algae, comprising the following steps: solid/liquid extraction of a) an algae or b) at least one solid wherein said solid is obtained from soybean, rapeseed, corn, sunflower, sesame, lupin, cotton, coconut, olive, avocado, cocoa, illipe, shea, palm kernel, peanut, copra, linseed, castor, grape seeds, gourd seeds, blackcurrant seeds, melon seeds, tomato seeds, pumpkin seeds, almond, hazelnut, walnut, evening primrose, borage, safflower, camelina, or poppy seed, using a first solvent system comprising at least 50% by volume, in relation to the total volume of said solvent system, of a solvent selected from the group consisting of ethyl-tert-butyl-ether (ETBE), methyl-tetrahydrofuran (MeTHF), hexafluorobenzene (BHF), tetramethylsilane (TMS), and mixtures thereof, and recovery of a fraction from the solid-liquid extraction, wherein the fraction comprises the oil or butter, wherein said oil or butter comprises at least 1% by mass of unsaponifiable compounds present in the solid vegetable matter or algae.

2. The method according to claim 1, further comprising the following steps: conversion by saponification or esterification of said oil or butter in the recovered fraction into a hydroalcoholic solution, extraction of the hydroalcoholic solution wherein a fat fraction is separated from an unsaponifiable fraction by liquid/liquid extraction.

3. The method according to claim 1, wherein the first solvent system includes a concentration of solvent selected from the group consisting of ethyl-tert-butyl-ether (ETBE), methyl-tetrahydrofuran (MeTHF), hexafluorobenzene (BHF), tetramethylsilane (TMS), and mixtures thereof, of at least 75%, by volume in relation to the total volume of the first solvent system.

4. The method according to claim 1, wherein the first solvent system includes a concentration of a solvent selected from the group consisting of ethyl-tert-butyl-ether (ETBE), methyl-tetrahydrofuran (MeTHF), hexafluorobenzene (BHF), tetramethylsilane (TMS), and mixtures thereof, of at least 90%, by volume in relation to the total volume of the first solvent system.

5. The method according to claim 2, wherein said oil is converted into a hydroalcoholic solution with a second solvent comprising at least one solvent from the first solvent system.

6. The method according to claim 5, wherein the first and second solvent systems comprise methyltetrahydrofuran (MeTHF).

7. The method according to claim 5, wherein the extraction of the hydroalcoholic solution is performed by liquid/liquid extraction with a third solvent system comprising at least one solvent from the first and/or second solvent system.

8. The method according to claim 1, wherein the unsaponifiable compounds are a soybean unsaponifiable, avocado unsaponifiables, avocado unsaponifiables enriched with furan fraction and/or avocado unsaponifiables enriched with sterol fraction, or a mixture of avocado and soybean unsaponifiables (ASU).

9. The method according to claim 1, wherein said oil or butter comprises at least 2% by mass of unsaponifiable compounds present in the solid vegetable matter or algae.

10. The method according to claim 1, wherein the algae is macroalgae or microalgae.

11. The method according to claim 10, wherein the algae is Haematocococcus, Dunaliella, Spirulina, or Chorella.

Description

EXAMPLES

(1) In all the examples, a reference test using hexane was carried out.

Example 1: Extraction from Dried Avocados

(2) Extraction from dried avocados was carried out with hexane (reference) and with the following solvents: HMDS, MeTHF, BTF, BHF, MTBE, ETBE.

(3) Dried avocado is ground and introduced into a cellulose cartridge (30 to 40 g). The extraction is carried out in a Soxhlet type device (BUCHI B-811). Four extractions are then launched in parallel and each consists of 20 extraction/siphoning cycles. Once the extraction has been finalised, the extraction solvent is evaporated and the residue from which solvent has been removed is weighed. The mass yields are then compared. The results are given in table 1.

(4) TABLE-US-00001 TABLE 1 Unsaponifiable Extraction oil content solvent Oil yield (% m/m) (% m/m) Hexane 61.1 1.88 ETBE 59.7 2.75 MeTHF 61.3 3.05 HFB 59.3 2.32 BTF 64.0 2.41 HMDS 60.5 1.92 MTBE 65.3 1.92

(5) This demonstrates that the solvents according to the invention have an equivalent extraction capacity to that of hexane.

(6) The unsaponifiable content of the extracted oil is higher for the solvents according to the invention than for hexane; it is increased by 50% in the case of ETBE and MeTHF.

Example 2: Extraction from Freeze-Dried Avocado Pulp Powder

(7) Freeze-dried avocado pulp powder was extracted according to the method described in example 1 with hexane (reference) and with the following solvents: HMDS, MeTHF, BTF, MTBE, ETBE. The results are given in table 2.

(8) TABLE-US-00002 TABLE 2 Unsaponifiable Extraction oil content solvent Oil yield (% m/m) (% m/m) Hexane 70.1 2.15 ETBE 69.6 2.25 MeTHF 71.7 3.02 BTF 67.3 2.22 HMDS 68.8 2.22 MTBE 70.1 2.35

(9) This demonstrates that the solvents according to the invention have an equivalent extraction capacity to that of hexane.

(10) The unsaponifiable content of the extracted oil is higher for the solvents according to the invention than for hexane; it is increased by 50% in the case of 50% in the case of MeTHF.

Example 3: Oil Extraction from Dried Avocados

(11) Extraction from dried avocados is carried out with hexane (reference) and the following solvents: BTF and ETBE.

(12) Dried avocado is ground and introduced into a cellulose cartridge (30 to 40 g). The extraction is carried out in a Soxhlet type device (BUCHI B-811). Four extractions are then launched in parallel, the first consisting of 5 extraction cycles, the second of cycles, the third of 15 cycles and the fourth of 20 cycles. Once the extraction has been finalised, the extraction solvent is evaporated and the residue from which solvent has been removed is weighed. The mass yields are then compared.

(13) The results are given in table 3 below.

(14) TABLE-US-00003 TABLE 3 Solvent Hexane ETBE BTF Cycles 5 10 15 20 5 10 15 20 5 Oil yield 18.3% 31.3% 33.1% 40.9% 17.6% 26.8% 30.2% 40.3% 39.0% (% m/m)

(15) The mass yields obtained with ETBE are similar to those obtained with the hexane reference: ETBE thus offers an alternative to the use of hexane in solid/liquid extraction methods.

(16) The extraction power of BTF is suitable for obtaining, in only 5 extraction cycles, the same yield as those obtained in 20 extraction cycles with hexane or ETBE. BTF thus offers a satisfactory alternative to the use of hexane suitable for reducing the quantity of solvent and/or contact time involved significantly.

Example 4: Extraction from Dried Chorella

(17) Extraction from dried Chorella powder was carried out according to the method described in example 1 with hexane (reference) and with the following solvents: BTF and MTBE. The results are given in table 4.

(18) TABLE-US-00004 TABLE 4 Unsaponifiable Extraction oil content solvent Oil yield (% m/m) (% m/m) Hexane 70 3.0 MTBE 65.4 3.7 BTF 72 3.4

(19) This demonstrates that the solvents according to the invention have an equivalent extraction capacity to that of hexane.

(20) The unsaponifiable content of the extracted oil is higher for the solvents according to the invention than for hexane.