EP3004299A1

EP3004299A1 - Processes for selective extraction of unsaponifiable materials from renewable raw materials by reactive trituration in the presence of a cosolvent

Info

Publication number: EP3004299A1
Application number: EP14733255.5A
Authority: EP
Inventors: Antoine Piccirilli
Original assignee: Saeml Valagro Carbone Renouvelable Poitou-Charentes
Current assignee: Saeml Valagro Carbone Renouvelable Poitou-Charentes
Priority date: 2013-06-04
Filing date: 2014-06-04
Publication date: 2016-04-13
Also published as: WO2014195637A1; CN105452428A; FR3006327A1; JP2016522293A; FR3006327B1; US20160108013A1; CA2914466A1

Abstract

The invention relates to processes for extraction of an unsaponifiable fraction from a renewable raw material, comprising the reactive trituration of the raw material which has been dehydrated in the presence of at least one polar organic solvent comprising at least one light alcohol, of at least one nonpolar cosolvent which is immiscible with said light alcohol and of at least one catalyst, resulting in the obtaining of a polar organic phase enriched with lipids functionalized with one or more functions chosen from hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions, and of a nonpolar organic phase enriched with lipids containing no or few hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions, then the concentration of the organic phases.

Description

METHODS FOR SELECTIVELY EXTRACTING THE INSAPONIFIABLE REACTIVE TRITURATION-BASED RENEWABLE RAW MATERIALS IN THE PRESENCE OF A

cosolvent

The present invention relates to the field of oleochemistry. More particularly, the invention relates to a process for extracting unsaponifiables from a renewable lipid raw material, in particular from an oleaginous fruit, in particular avocado, from an oleaginous seed or from an animal raw material, algal, fungal or yeast, or microorganism.

By lipids is meant substances of biological origin soluble in non-polar solvents. The lipids may be saponifiable (for example triglycerides) or unsaponifiable (for example steroid skeleton molecules).

The term "unsaponifiable" is intended to mean all compounds which, after total saponification of a fatty substance, that is to say under the prolonged action of an alkaline base, remain insoluble in water and can be extracted by a solvent. organic in which they are soluble. Unsaponifiables are usually a minor fraction in fat.

Five major groups of substances are present in most unsaponifiables of vegetable fats: saturated or unsaturated hydrocarbons, aliphatic or terpene alcohols, sterols, tocopherols and tocotrienols, and carotenoid pigments, especially xanthophylls.

Renewable lipid raw materials contain very variable proportions of unsaponifiable compounds. The contents of unsaponifiable fraction obtained by extraction of different vegetable oils according to various known methods range from 1 to 7% by weight of unsaponifiables in avocado oil, compared with 0.5% in coconut oil and 1% of coconut oil. % in soybean oil or in olive oil.

At present, the conventional processes for extracting unsaponifiables generally use, as lipid raw material, vegetable oils and their derivatives and co-products derived from the lipid extraction industry (vegetable oils, animal fats, marine oils, vegetable oleoresins) from their refining and their transformation. Most often, it involves extracting unsaponifiables of crude, semi-refined or refined vegetable oils, unsaponifiable concentrates of refined oils obtained by molecular distillation or extraction by supercritical fluids. Also, many unsaponifiable fractions such as sterols, squalene, tocopherols or tocotrienols are obtained from vegetable oils deodorization escapements, which are abundant co-products of the chemical or physical refining of vegetable oils. However, other lipid-refining co-products may also be acid oils, neutralization pastes, lipids retained by the bleaching earths used to decolorize the oils, and the soils from the winterization units. may also use co-products derived from the trituration of oleaginous or oleaginous fruits such as oilcakes, cockles or seed kernels, molasses, vegetable waters.

To extract unsaponifiables or their fractions, it is also possible to use co-products resulting from the transformation of lipids such as crude glycerines from biodiesel production units, hydrolysis or saponification of animal or vegetable fats, fatty waters from animal fats processing industries, distillation bottoms of alkyl esters of fatty acids.

Likewise, unsaponifiable fractions, in particular sterols, are produced from industrial co-products such as paper mills, also called tall oil. Similarly, unsaponifiable fractions of co-products derived from beverage industries such as breweries, rum factories, industrial maltings are extracted.

In the same way, it is possible to use, as raw material source of unsaponifiables, vegetable serums (eg tomato, citrus fruits), seeds, oleoresins of oleoresins of oleiferous fruits or not, vegetables, flowers or leaves.

The unsaponifiable extraction processes most often comprise a step of transesterification or esterification of the fat obtained by pressure, and / or a stage of saponification of the fat followed by a liquid-liquid extraction using an organic solvent.

The methods of selective extraction of unsaponifiable fractions are few. The application WO 201 1/048339 describes a process for extracting an unsaponifiable fraction of a renewable raw material, comprising a) the dehydration and conditioning of the renewable raw material, b) the transesterification by reactive trituration of the raw material. lipidic conditioned in the presence of a light alcohol and a catalyst, c) the evaporation of the light alcohol, d) the concentration of the liquid phase so as to obtain a concentrate comprising the unsaponifiable fraction diluted in alkyl esters. fatty acids, e) saponification of the unsaponifiable concentrate, f) extraction of the unsaponifiable fraction of the saponified mixture.

The avocado, because of its high content of unsaponifiable fraction, deserves special attention. It gives access, in a known manner, to particular lipids of furanic type, the main component of which is a linoleic furan denoted H7 of formula:

By furan lipids of avocado is meant according to the invention the components corresponding to the formula: wherein R is a C1-C19 hydrocarbon linear chain, preferably C13-C17 saturated or comprising one or more ethylenic or acetylenic unsaturations. These furanic lipid solids have been described in particular in Farines, M. et al., 1995, J. Am. Oil Chem. Soc. 72, 473. In general, the furan lipids of avocado are unique compounds in the plant kingdom and are especially sought after for their pharmacological, cosmetic, nutritional or even biopesticide properties.

Avocado furan lipids are metabolites of precursor compounds that are initially present in fruit and leaves which, under the effect of heat, dehydrate and cyclize into furan derivatives. For example, linoleic furan H7 is derived from the thermal transformation of the following keto-hydroxylated precursor, denoted P1H7:

Under atmospheric pressure, the precursor P1 H7 is generally converted to linoleic furan H7 at a temperature ranging from 80 to 120 ° C.

It is now well established that the presence of these precursors of furan compounds in the leaves or avocado fruit (including the core) depends not only on the variety (the Hass and Fuerte varieties being the richest in these compounds ) but also how to obtain the oil or another plant extract of avocado (hexanic or ethanolic extract of avocado leaves).

Moreover, certain compounds initially present in the fruit and leaves of the avocado may be in the form of polyhydroxy fatty alcohols most often non acetylated, such as the following compound:

According to the invention, polyhydroxylated avocado fatty alcohol is understood to mean a polyol in the form of a saturated C17-C21 hydrocarbon linear main chain or comprising one or more ethylenic or acetylenic unsaturations, and comprising at least two hydroxyl groups, the groups hydroxyls being generally located on a part of the chain main, preferably to one of the two ends of the main chain, the other part of this main chain thus forming the fatty chain (hydrophobic portion) of the polyol.

The content of polyhydroxy fatty alcohols in the fruit depends mainly on the climatic conditions, the quality of the soil, the season and the ripening of the fruit when it is harvested.

Given the therapeutic interest of the unsaponifiable avocado rich in furan lipids for its beneficial and curative action on connective tissue, especially in inflammatory conditions such as osteoarthritis, periodontitis and scleroderma, and its cost high in general, there is a strong interest in preparing with the best possible yield unsaponifiable fractions of avocado oil, rich in furanic lipids. Similarly, there is a definite interest in valuing the entire fruit with maximum yield in order to improve the overall profitability of the process.

Known techniques for obtaining these specific furan compounds or polyols from the fruit or the fruit of the avocado fruit make it possible to obtain these compounds only in mixture with many other unsaponifiable avocado compounds.

The application FR 2678632 describes a process for obtaining the unsaponifiable fraction of avocado from an avocado oil enriched in one of its fractions, called H, corresponding in fact to these same furan lipids. The preparation of such an unsaponifiable rich in furanic lipids, the content of which can vary from 30 to 60%, is essentially conditioned by controlled heating of the fresh fruits, previously sliced into thin strips, at a temperature of between 80 and 120 ° C. , and for a period preferably chosen between 24 to 48 hours. This heat treatment makes it possible, after extraction, to obtain an avocado oil rich in furanic lipids. Finally, from this oil, obtaining the unsaponifiable fraction is carried out according to a conventional method of saponification, supplemented with a liquid-liquid extraction step with an organic solvent.

The application WO 01/21605 describes a process for extracting polyhydroxylated furan lipid and fatty alcohol compounds from avocado, comprising the heat treatment of the fruit at a temperature of at least 80 ° C. (controlled drying), the extraction of oil by cold pressing, enrichment in unsaponifiable by crystallization by cold or liquid-liquid extraction or molecular distillation, saponification by ethanolic potash, extraction of the unsaponifiable in a column against the current by a organic solvent, followed by filtration steps, washing, desolvation, deodorization and final molecular distillation. This process makes it possible to obtain either a distillate comprising mainly furanic lipids of avocado, or a distillate comprising mainly furanic lipids and polyhydroxy fatty alcohols of avocado. However, this process makes it possible to value only a small portion of the fruit.

In fact, in this type of process, the oil constituting the residue resulting from the step of concentrating the unsaponifiable by molecular distillation, ie approximately 90% of the oil extracted from the fruit, is very difficult to valorize. This highly colored oil has indeed undergone a heat treatment by high temperature distillation, which leads to a systematic and irreversible destruction of chlorophyll pigments and phospholipids very detrimental to the subsequent refining of the distilled crude oil. Only a very refined refining of this oil allows in the best cases, to make it a color more or less suitable. Refining that is very consumer of inputs (eg bleaching earth), energy and remains very martyrisant for unsaturated fatty acids (isomerization). Finally, an addition of exogenous antioxidant is essential for the conservation of this refined oil over a commercially acceptable period. As a result, the oil thus refined can not be valued in human nutrition or in phar- maceutical applications.

Another disadvantage of the process lies in the production of a meal unsuitable for animal feed. The latter indeed contains antinutritional compounds (precursors H toxic and biopesticide activity, furanic lipids) and highly degraded proteins during extraction by mechanical pressure of air-dried fruits (in fact highly oxidized), poor digestibility proteins . Therefore, the meal or its proteins, can not be valued in animal feed and even less human even though the fruit pulp is commonly consumed by man (guacamole, fruit of mouth).

Similarly, the noble polysaccharides of the fruit such as perseitol and nanoheptulose, unique sugars of the vegetable kingdom, with proven pharmaceutical, cosmetic and nutritional properties (eg liver comfort), are partly destroyed by the Maillard reactions and / or caramelization induced by the mechanical pressure of dehydrated fruits, or made very difficult to extract because too strong interaction with the fibrous matrix and protein.

In conclusion, this type of process allows only a minor valuation of the fruit that can be estimated less than 15%.

Therefore, it remains necessary to improve the yield and selectivity of furan lipid extraction processes and / or polyhydroxy fatty alcohols avocado.

There remains therefore a need for a process for selectively extracting fat unsaponifiables while preserving the integrity of the fruit for a better subsequent recovery, the implementation of which is economical and also allows recovery of glyceride co-products at higher levels. high added value that free fatty acids, or proteins and polysaccharides of good nutritional quality. It would be particularly desirable to develop a process for extracting unsaponifiables with high yield depending on the polarity of the fractions that constitute them. It is indeed desirable to have a robust process for selectively producing the desired fractions and non-martyrisant other fractions of interest or other parts of the fruit.

In order to meet them, the subject of the invention is a process for extracting an unsaponifiable fraction from a renewable raw material containing lipids functionalized by one or more functions chosen from hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions, comprising the following steps:

(a) dehydration, possibly preceded or followed by conditioning of the renewable raw material,

b) reactive trituration of the dehydrated lipid raw material and optionally packaged in the presence of at least one polar organic solvent comprising at least one light alcohol, at least one apolar cosolvent immiscible with said light alcohol and at least one catalyst , resulting in the production of a lipid-enriched polar organic phase functionalized by one or more functions chosen from hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functional groups,

c) concentration of the polar organic phase to obtain a mixture enriched in unsaponifiable fraction, optionally preceded, accompanied or followed by a heat treatment at a temperature greater than or equal to 75 ° C, preferably greater than or equal to 80 ° C,

and optionally comprising the following steps:

d) saponification of the mixture enriched in unsaponifiable fraction,

e) extraction of the unsaponifiable fraction of the saponified mixture.

The invention further relates to a method for extracting an unsaponifiable fraction from a renewable raw material comprising the following steps:

b) reactive trituration of the dehydrated lipid raw material and optionally packaged in the presence of at least one polar organic solvent comprising at least one light alcohol, at least one apolar cosolvent immiscible with said light alcohol and at least one catalyst , leading to the production of a lipid-enriched organic apolar phase containing no or only a few hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions; c) concentration of the apolar organic phase to obtain a mixture enriched in unsaponifiable fraction,

and optionally comprising the following steps:

d) saponification of the mixture enriched in unsaponifiable fraction,

e) extraction of the unsaponifiable fraction of the saponified mixture,

the renewable raw material optionally undergoing heat treatment at a temperature greater than or equal to 75 ° C, preferably greater than or equal to 80 ° C, before or during step b), preferably before step a), during step a) or between step a) and step b).

The two processes of the invention differ in that the first process aims to recover an unsaponifiable fraction soluble in an alcoholic polar phase (or whose precursors are soluble in such a phase), while the second process aims to recover the unsaponifiable fraction. soluble in an apolar organic phase (or whose metabolites are soluble in such a phase). In the case of avocado, these two processes, although differing in several steps, have the common purpose of allowing the selective recovery of furanic lipids from the unsaponifiable fraction with a high yield, while allowing to generate valuable co-products of very high quality: alkyl esters of distilled avocado oil, perfectly traced avocado glycerin, cake freed from antinutritional compounds potentially useful as sources of proteins, oligopeptides, perseitol and nanoheptulose, avocado fibers.

In the particular case of avocado, in particular, the raw materials are not heated initially at a high temperature in the first process (they are only after the reactive trituration step), whereas they are heated before reactive trituration step in the second method, so as to reveal the characteristic furan compounds of the heat-treated avocado earlier. In the case of the first process, the reactive trituration step is carried out with avocados which have not undergone such a heat treatment, these containing at this stage furan lipid precursors.

The invention therefore relates to a process for extracting an unsaponifiable fraction of a lipidic renewable raw material, generally vegetable or animal, preferably plant. This raw material can be chosen in particular from oleaginous fruits, oilseeds, oilseed seeds, seed shells, oleaginous almonds, sprouts, fruit cuticles and nuclei, animal raw materials, algal, fungal or yeast of lipid-rich microorganisms.

According to a first embodiment, the raw material used is an oleaginous fruit, which may be, without limitation, olive, shea, amaranth, palm, buritti, tucuman, squash, serenoa repens, the African palm or the avocado.

According to a second embodiment, the raw material is a seed, an almond, a seed, a cuticle or a core of a vegetable raw material chosen from rapeseed, soya, sunflower, cotton, wheat, maize , rice, grapes (pips), walnuts, hazelnuts, jojoba, lupine, camelina, flax, copra, safflower, crambe, copra, peanut, jatropha, castor, neem, chancre, cuphea, lesquerella, inca inchi, perilla, echium, evening primrose, borage, blackcurrant, Korean pine, Chinese wood, cotton, poppy ( seeds), sesame, amaranth, coffee, oats, tomatoes, lentisks, marigolds, karanja, rice bran, Brazil nuts, andiroba, schizandra, ucuhuba, cupuacu, murumuru, piqui, lemon seeds, tangerine, orange, watermelon, watermelon, cucurbita pepo, tomato. The lipidic raw material may also be an animal raw material, an algae, a mushroom, a yeast or a mold. Among the animal raw materials, we prefer the liver and the skin of fish, especially those of shark, cod and chimera, as well as the solid waste of the meat industry (brains, tendons, lanolin ...) . Other vegetable raw materials containing oleoresins rich in unsaponifiable are tomato, tagetes, paprika, rosemary.

Examples of algae containing unsaponifiable compounds of interest are microalgae Duniella salina (rich in beta-carotene) and Hematococcus pluvialis (rich in asthaxanthin). Examples of microorganisms, especially bacteria containing unsaponifiable compounds of interest are mycelia or any other mold and fungus (ergosterol production), Phaffia sp. (producing asthaxanthine), Blakeslea trispora, (producing lycopene and phytoene), Muriellopsis sp. (producing lutein), or are cited in particular in the application WO 2012/159980 (strain of microalgae adapted to the production of squalene), in US Patent 7659097 (bacteria producing in particular farnesol and farnesene), in the publication Pure & Appl . Chem., Vol. 69, No. 10, pp. 2169-2173,1997 (production of carotenoids) or the publication Journal of Biomedicine and Biotechnology, 2012; 2012: 607329, doi: 10.1 155/2012/607329 (production of coenzyme Q10 by biotechnological means).

It is desirable that the raw materials used in the process according to the invention have an acidity level of less than 3 mg KOH / g. In fact, higher levels of free fatty acids in these raw materials lead to the formation of soaps in a basic medium. For the purposes of the present invention, the term "fatty acids" is understood to mean saturated, monounsaturated or polyunsaturated, linear or branched, cyclic or acyclic C4-C28 aliphatic mono-, di- or tricarboxylic acids which may comprise particular organic functions (hydroxyl , epoxides, ...).

The first method of the invention will now be presented in detail.

The raw materials used in the first method of the invention contain lipid constituents functionalized by one or more polar functions, chosen from hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions, such as, for example, avocado. , karanja, jatropha, andiroba, neem, schizandra, lupine shell, cashew, sesame, rice bran, cotton, or raw materials leading to oils rich in phytosterols such as corn, soybean, sunflower, rapeseed, all of which are very rich in such compounds.

These raw materials can be raw materials that are fresh or have undergone prior transformations, for example a first fat extraction step such as pressure or centrifugation. In the case of avocado, mention may be made of avocado milks obtained by pressing pulps, the products of settling partially deoiled pulps by centrifugation, by-products generally present at the output of the centrifugal strainers, the centrifuge pellets produced in separation, avocado cakes, co-produced during the cold pressing of fruits (fresh or dried) or the liquid-solid extraction of avocado oil from fresh or dried fruit, using an organic solvent, the kernels and avocado leaves. This method comprises a first step a) dehydration and optionally conditioning the renewable raw material. Dehydration and conditioning, when carried out at a temperature of less than or equal to 80 ° C, preferably less than or equal to 75 ° C, are said to be controlled (this is mandatory in the case of avocado). Said temperature is preferably greater than or equal to -50 ° C. According to another embodiment (not applicable to avocado), the temperature ranges from 50 to 120 ° C, more preferably from 75 to 120 ° C. Dehydration can be carried out under an inert atmosphere, in particular in the case of raw materials containing fragile compounds that can oxidize during a rise in temperature. It is preferably carried out under atmospheric pressure.

In the case of avocado (which means in this application the fruit, the core, the avocado leaves or their mixtures), the fact of not raising the temperature beyond 75 or 80 ° C avoids the conversion of the precursors of furanic lipids into furanic lipids.

Dehydration can be performed before or after conditioning (when it occurs). As a preference, oleaginous fruits such as avocado are dehydrated before being packaged, while conversely oleaginous seeds are first packaged before dehydration.

Dehydration is understood to mean all the techniques known to those skilled in the art which allow the total or partial elimination of the water of the raw material. These techniques include, but are not limited to, fluidized bed drying, drying under hot air or inert atmosphere (eg, nitrogen), fixed bed, atmospheric pressure or vacuum, as a thick layer or thin layer, in a continuous belt dryer or hot air rotary, but also microwave drying, spray drying, lyophilization and osmotic dehydration in solution (direct osmosis) or solid phase (eg drying in osmotic bags), drying with solid absorbents such as zeolites or molecular sieves.

Very preferably, the drying time and the temperature are chosen so that the residual moisture is less than or equal to 3% by weight, preferably less than or equal to 2%, relative to the mass of the lipidic raw material. obtained at the end of the dehydration step. The residual moisture of the raw material can be determined by thermogravimetry. This drying step is important so that the subsequent transesterification step takes place under the best conditions. It will make the extraction of the lipid constituents more efficient, in particular because it causes the cells of the raw material to burst, as well as the breakage of the oil-in-water emulsion as it is present in this raw material. It can further facilitate the conditioning of the raw material, especially crushing or crushing operations, which will make solvent extraction more efficient due to a gain in the area of contact with the solvents.

In the context of the present process, for reasons of ease of industrial implementation and for reasons of cost, drying in ventilated dryers (drying ovens), thermoregulated, in a thin layer and under a stream of hot air is preferred. The temperature is preferably between 70 and 75 ° C, and the dehydration preferably lasts from 8 to 36 hours.

The objective of the optional conditioning of the raw material is to make the fats as accessible as possible to extraction solvents and catalysts, especially according to a simple phenomenon of percolation. Packaging can also increase the surface area and porosity of the raw material in contact with these reagents. The conditioning of the raw material does not lead to any extraction of fat.

Preferably, the renewable raw material is conditioned by flattening, flaking, blowing or grinding in powder form. For example, the raw material can be toasted or flaked, or conditioned and / or dried by freeze-drying, per- evaporation, atomization, mechanical grinding, cryogrinding, skinning, flash-relaxation (fast drying by vacuum and decompression rapid), conditioned by pulsed electromagnetic fields, by reactive extrusion or not, flattening by means of a mechanical flattener with smooth or corrugated rollers, blowing by introduction of hot air or superheated steam. In the case of avocado, mainly cut avocado fruit will be used, then subjected to the controlled dehydration step, and finally the dried fruit will be conditioned, usually by grinding the fresh pulp.

Once dehydrated and optionally packaged, the raw material undergoes a step b) of reactive trituration in the presence of at least one polar organic solvent comprising at least one light alcohol, at least one apolar cosolvent immiscible with said light alcohol (in the conditions of the reactive trituration operation) and at least one catalyst.

By reactive trituration is meant any operation to transform saponifiable lipids (or fat) (especially triglycerides) into alkyl esters of fatty acids (generally alkyl monoesters of fatty acids) and glycerol, preferably in the presence of one or more reactive elements. In the present case the trituration is carried out in the presence of a light alcohol, an apolar cosolvent and a catalyst. In one embodiment, anhydrous solvents and cosolvents, and preferably solvents having a boiling point low enough to be distilled, will be used.

In another embodiment, water may be added to the binary mixture of solvents in order, in particular, to extract, with greater efficiency, the highly polar compounds, in particular the hydroxylated ones, the quantity of water involved being preferably 0.1. at 20% by weight of the solvent mixture, preferably from 0.5 to 5%.

This step makes it possible on the one hand to extract the fats, in particular the oil from the dehydrated raw material and at the same time to transesterify it, and on the other hand to isolate a fraction enriched in polar lipid constituents, containing a or several functions chosen from the hydroxyl (preferably aliphatic), epoxide, ketone, thiol, aldehyde, ether and amine (free) functions, unsaponifiable or not, and a fraction enriched in constituents low or non-polar lipids, in particular constituents containing no hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions.

The addition of an apolar cosolvent promotes the obtaining of a heterogeneous medium and two lipid phases whose constitutions will be very different. On the one hand, the lipid constituents which are not functionalized by one or more hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions will be found preferentially in the apolar phase, whereas the lipid constituents functionalized by one or more hydroxyl functions, epoxide ketone, thiol, aldehyde, ether or amine will be found preferentially in the polar phase (light alcohol).

This step allows the selective extraction of functionalized lipid components by one or more hydroxyl (preferably aliphatic), epoxide, ketone, thiol, aldehyde, ether or amine (unsaponifiable or non-unsaponifiable) functions, preferably several, which are separated from the mixture of lipid constituents (especially fatty acid esters) having no such functions, present in the medium at the end of the transesterification reaction. Depending on the type of raw material used, these functionalized lipid components may be, without limitation, polyhydroxy fatty alcohols and keto-hydroxyl compounds furan lipid precursors (especially the compound P1 H7 mentioned above, precursor of linolenic furan H7) which are present in the avocado, non-esterified sterols, or esters of the following fatty acids: ricinoleic acid (12-hydroxy cis 9-octadecenoic acid) present in particular in castor oil, lesquerolic acid (acid 14- 11-hydroxy-1-eicosanoic acid), densipolic acid (12-hydroxy-9,15-octadecadienoic acid) and auricolic acid (14-hydroxy-1,1,17-eicosadienoic acid), all of which are present especially in genus Lesquerrella, coriolic acid (13-hydroxy-9,1 1 -octadecadienoic acid), kamlolenic acid (18-hydroxy-9,1 1, 13-octadecathenoic acid) present especially in the oil extracted from the seeds of the tree Kamala, coronaric acid (9,10-epoxy-cis-octadec-12-enanoic acid) present especially in sunflower oil, vernolic acid (cis-12,13-epoxyoleic acid) present in particular in the oil extracted from the seeds of Euphorbia lagascae or plants of the genus Vernonia.

Step b) is carried out under conditions of temperature, stirring and duration sufficient to allow the extraction of triglycerides and other lipid constituents from the raw material and the transesterification of said triglycerides, leading to the obtaining of a mixture comprising in particular fatty acid esters, glycerol, the native unsaponifiable fraction (not modified by this step), and according to the type of raw material used, soluble polysaccharides, phenolic compounds, glucosinolates, isocyanates, polar alkaloids, polar terpenes, glycerol and a cake.

Step b) is, however, carried out at a temperature of less than or equal to 80 ° C., preferably less than or equal to 75 ° C. in the case of avocado in particular, this temperature control avoiding the conversion of furan lipid precursors. in furanic lipids. These therefore remain present in their hydroxylated form (not cyclized to furans) during the reactive trituration.

In other cases, step b) can be carried out without temperature limitation, i.e., the temperature may exceed 75 or 80 ° C. Thus, when the raw material does not derive from the avocado, step b) can be carried out by carrying out heating at a temperature ranging from 40 to 100 ° C. Step b) is generally carried out at room temperature but can also be carried out by carrying out heating, at a temperature preferably of at least 40 ° C and preferably of less than or equal to 80 ° C, preferably lower or equal to 75 ° C.

General titles such as Bailey 's Industrial OR and Fat Products, 6 ^th Edition

(2005), Fereidoon Shahidi Ed, John Wiley & Sons, Inc., and March's Advanced Organic Chemistry. Reactions, Mechanisms, and Structure, 5 ^th Edition (2001), MB Smith, J. March, Wiley-Interscience, describe more in detail the conditions of the transesterification step, as well as the possible step of saponification which will be presented later.

By light alcohol is meant an alcohol (comprising one or more hydroxyl functional groups) whose molecular mass is less than or equal to 150 g / mol, linear or branched, preferably C -C 6, more preferably C ₁ -C ₄ . Preferentially, the light alcohol is a monoalcohol. It is preferably an aliphatic alcohol and ideally an aliphatic monoalcohol, preferably selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, n-pentanol, n-hexanol, ethyl-2-hexanol and their isomers. The use of such a monoalcohol, the preferred being methanol, will lead to the conversion of glycerides to monoesters of fatty acids.

The apolar cosolvent, immiscible with the light alcohol (under the conditions of the reactive trituration operation), is preferably chosen so that the lipid constituents functionalized by one or more hydroxyl functions, epoxide, ketone, thiol, aldehyde , ether or amine that it is desired to extract are not soluble in this cosolvent. Given their chemical nature, these functionalized lipid components will necessarily have more affinity with the light alcohol phase than with the apolar solvent phase in which they are little (preferably not) soluble.

The apolar cosolvent is an organic solvent which may especially be hexane, heptane, benzene, bicyclohexyl, cyclohexane, paraffinic alkanes of plant origin obtained by dehydration of natural alcohols (or their Guerbet counterparts) or by hydrotreatment of lipids or biomasses (hydroliquefaction process) or by decarboxylation of fatty acids, decalin, decane, kerosene, kerdane (hydrocarbon fuel fraction heavier than hexane), gas oil, kerosene, methylcyclohexane, tetradecane, supercritical C0 ₂ , propane or butane pressurized, natural apolar solvents such as terpenes (limonene, alpha and beta pinene, etc.). It is preferably an alkane or a mixture of alkanes, preferably hexane. The preferred polar solvent (light alcohol) / apolar cosolvent pair is the methanol / hexane pair.

The catalyst is preferably a basic catalyst preferably chosen from alcoholic sodium hydroxide, solid sodium hydroxide, alcoholic potassium hydroxide, solid potassium hydroxide, alkali alcoholates such as methylate, ethylate, n-propylate, isopropylate, n-butylate, lithium i-butylate or t-butylate, sodium or potassium, amines and polyamines, or an acid catalyst preferably selected from sulfuric acid, nitric acid, acid paratoluenesulphonic acid, hydrochloric acid and Lewis acids. An acid catalyst will be more particularly used in extreme cases where the free acidity of the fat will be greater than 4 mg KOH / g. This step will lead to the esterification of the free fatty acids, the continuation of the process of continuing the reactive trituration by a base catalyzed transesterification reaction.

Step b) can be carried out in particular in a stirred bed batch reactor or in a continuous continuous conveyor type continuous extractor reactor. In a preferred embodiment, the organic solvent and the apolar cosolvent are introduced in countercurrent to one another in a reactor. In order to optimize the separation of the different lipid constituents between the polar and apolar phases, and / or to obtain a complete transformation of the mono-, di- and triglycerides into (mono) esters (alkyl) fatty acids, the extraction / trituration can be repeated several times by implementing for example several cascading reactors and intermediate withdrawals, as described in the application WO 2010/084276.

The reactive trituration step makes it possible to recover (especially after filtration and washing of the cake with a solvent such as a light alcohol) on the one hand two immiscible lipid liquid phases, glycerol and on the other hand a solvent cake.

Ideally, the resulting mixture of the transesterification step comprises low levels of mono, di or triglycerides. All of these glycerides generally represent less than 3% by weight of the total mass of the mixture, preferably less than 1%.

The solvent cake resulting from the process of the invention can be dried and then directly used, in particular in animal feed, since it does not contain, or at least very little, antinutritional compounds following the reactive trituration step, in contrast to prior methods which involve a mechanical pressure step. The polar phase (alcoholic) in which are soluble especially lipids containing one or more functions selected from the hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions such as polyhydroxy fatty alcohols and furan lipid precursors (in the case of the lawyer) is separated from the apolar phase. Said polar phase also contains, in particular, fatty acid esters. The separation of the various fractions can be done in different ways, in particular by centrifugation, decantation and / or distillation.

Thus the apolar solvent phase can be subjected to a solvent evaporation step carried out under a suitable vacuum and temperature. The vaporized solvent is then condensed to to be recycled. The apolar heavy phase (phase A), consisting mainly of alkyl esters and unsaponifiable (or non-apolar) compounds, can then be used for molecular distillation in order to obtain, on the one hand, purified esters (in the distillate) and on the other hand, a distillation residue enriched in apolar minor compounds. The extraction of these mainly unsaponifiable compounds is carried out according to the methods known to those skilled in the art. For example by carrying out the following sequence: 1) saponification of the alkyl esters, 2) liquid-liquid extraction for separating the unsaponifiable compounds from the soaps, 3) desolvation of the solvent phase enriched in unsaponifiables and 4) final purification of the unsaponifiable .

Another variant consists of directly saponifying phase A and extracting the mainly apolar unsaponifiable compounds by (1) liquid-liquid extraction enabling the unsaponifiable compounds to be separated from the soaps, (2) desolvation of the solvent phase enriched in unsaponifiables and (3) final purification of unsaponifiable.

The light alcohol (polar solvent) is evaporated from the polar phase, in particular under reduced pressure. In the case of avocado, if the evaporation temperature is high (especially of the order of 80 ° C or more), it may occur from this stage cyclization of furan lipid precursors into furan lipids.

The lipid product obtained may undergo a neutralization step (before or after the evaporation of the light alcohol, preferably before), preferably with an acid, then a decantation or centrifugation step which makes it possible to recover residual glycerol from a part and a lipid phase on the other hand, and / or a filtration step. The remaining lipid phase can then be washed with water and dried under vacuum.

The resulting lipid phase (phase containing typically alkyl esters and enriched in unsaponifiable (or not) polar compounds) is then subjected to a step c) of concentration to obtain a mixture enriched in unsaponifiable fraction and optionally heat treatment at a temperature greater than or equal to at 75 ° C, preferably greater than or equal to 80 ° C. The concentration can be implemented before or after the heat treatment, if it takes place, or these two steps can be carried out concomitantly, if the concentration involves heating to a suitable temperature. As a preference, the concentration is carried out before carrying out the heat treatment.

The prior concentration of the unsaponifiable oil makes it possible to reduce the quantity of material involved during the possible subsequent saponification step, and thus to extract.

The concentration step c) can in particular be carried out by liquid-liquid extraction, distillation or by crystallization, in particular crystallization by cold or crystallization by evaporation under vacuum. By distillation is meant any technique known to those skilled in the art in particular, molecular distillation, distillation at atmospheric pressure or vacuum, multi-stage in series (in particular in a scraped or falling film evaporator), distillation azeotropic, hydrodistillation, steam distillation, deodorization in particular in a layer-thin deodorizer operating under vacuum with or without injection of steam or an inert gas (nitrogen, carbon dioxide).

The preferred technique is molecular distillation, term by which is meant fractional distillation under high vacuum at high temperature but with a very short contact time, which avoids or limits the denaturation of heat-sensitive molecules.

This molecular distillation step, as well as all the other molecular distillations that can be carried out in the processes of the invention, is carried out using a short-path distillation unit, preferably a device chosen from centrifugal-type molecular distillers. and molecular devices of scraped film type.

Molecular distillers of centrifugal type are known to those skilled in the art. For example, EP-0 493 144 discloses such a molecular distiller. In general, the product to be distilled is spread in a thin layer on the heated surface (hot surface) of a conical rotor rotating at high speed. The distillation chamber is placed under vacuum. Under these conditions, there is evaporation and not boiling, from the hot surface of the constituents of the unsaponifiable, the advantage being that these fragile products are not degraded during evaporation.

Scraped film type molecular stills, also known to those skilled in the art, include a distillation chamber with a rotating scraper, which allows continuous spreading on the evaporation surface (hot surface) of the product to be distilled. . The product vapors are condensed through a refrigerated finger placed in the center of the distillation chamber. Peripheral supply and vacuum systems are very similar to those of a centrifugal distiller (feed pumps, vane vacuum pumps and oil diffusion pumps, etc.). The recovery of residues and distillates in glass balloons is by gravitational flow.

The molecular distillation is preferably carried out at a temperature ranging from 100 to

260 ° C maintaining a pressure ranging from 10 ³ to 10 ^{~ 2} mm Hg and preferably of the order of 10 ^{~ 3} mm Hg. These conditions are milder than those of previous processes involving a distillation of triglycerides rather than of monoesters of fatty acids, which makes it possible to avoid the decomposition of colored pigments resulting in a quasi-irreversible coloration of the residue.

The unsaponifiable concentration of the distillate can reach 60% by weight. In the case of avocado, even though the contact time of the compounds with the heated zone is very short, some furan lipid precursors can be cyclized to furan lipids at this stage. This phenomenon, however, remains marginal. It is also possible to resort to conventional distillation which, in the case of avocado, would allow complete cyclization of furan lipid precursors via heating at 75 ° C or higher, preferably at 80 ° C or higher. .

Distillation generally makes it possible to obtain a light fraction (first distillate) comprising esters (typically alkyl) of high purity fatty acids separated from the unsaponifiable fraction, and at least one heavier fraction (second distillate or residue), comprising the unsaponifiable fraction diluted in (typically alkyl) esters of residual fatty acids.

The fraction containing high purity fatty acid esters, that is to say generally clear and colorless esters preferably having an ester content greater than 98% by weight and an unsaponifiables content preferably less than 1% , better than 0.1% by weight, can be used directly, especially in cosmetics or pharmacy. If the purity of the ester fraction obtained at the end of the concentration step is insufficient, this fraction can be refined to improve its purity, in particular by molecular distillation.

In the case of avocado, the concentrate enriched in unsaponifiable fraction (and depleted in fatty acid esters) contains at this stage precursors of furanic lipids (not very volatile) and / or furanic lipids (which are less volatile than monoesters of fatty acids), if the heat treatment step which will now be described has taken place before or during the concentration step.

In the case of avocado, the heat treatment step at 75-80 ° C or more of the lipid phase having or not already been concentrated is mandatory. It is intended to achieve the cyclization of furan lipid precursors into furan lipids. This step can be carried out before or after the saponification step (if it takes place), preferably before, otherwise the saponification would transform the furan lipid precursors into modified unsaponifiable derivatives (i.e. other than furan compounds), which are of less interest. The duration of this treatment is usually 0.5 to 5 hours, depending on the heating method used. The temperature employed for the treatment is generally less than or equal to 150 ° C, preferably less than or equal to 120 ° C. It is of course understood that the temperature and the reaction time are two parameters related to each other as to the expected result of the heat treatment which is to promote the cyclization of furan lipid precursors.

Advantageously, this heat treatment is carried out under an inert atmosphere, in particular under a continuous stream of nitrogen. It is preferably carried out under atmospheric pressure.

The heat treatment step may be carried out in the presence or absence of an acid catalyst. The term "acid catalyst" means the so-called homogeneous inorganic and organic catalysts such as hydrochloric, sulfuric, acetic or para-toluenesulphonic acids, but also, and preferably, heterogeneous solid catalysts such as silica, alumina, silica-aluminas, zirconias. , zeolites, acid resins. In particular, acidic aluminas with large specific surface areas, ie at least equal to 200 m ² / g, will be chosen. The catalysts of the acidic alumina type are preferred for carrying out the process of the invention. The concentrate that has optionally undergone the heat treatment can then be subjected to steps d) saponification of the mixture enriched in unsaponifiable fraction and e) extraction of the unsaponifiable fraction of the saponified mixture, depending on the type of raw material used. In the case of the avocado, in particular, steps d) and e) are carried out in order to separate the glycerides. In other cases, it is possible not to perform steps d) and e) and to isolate an oil containing the unsaponifiable fraction accompanied by other compounds such as (mono) esters of fatty acids.

Saponification is a chemical reaction transforming an ester into a water-soluble carboxylate ion and alcohol. In the present case, the saponification converts in particular the fatty acid esters to fatty acids and to alcohol, the liberated alcohol being mainly the light alcohol used during the reactive trituration step to carry out the transesterification.

The saponification step may be carried out in the presence of potassium hydroxide or sodium hydroxide in an alcoholic medium, preferably an ethanolic medium. Typical experimental conditions are a reaction in the presence of 12N potassium hydroxide under reflux of ethanol for 4 hours. At this stage and optionally, a cosolvent may be advantageously used to improve in particular the kinetics of the reaction or to protect the unsaponifiable compounds sensitive to basic pH. This cosolvent may especially be selected from terpenes (limonene, alpha and beta pinene, etc.), alkanes, especially paraffins.

The unsaponifiable fraction of the saponified mixture is then extracted one or more times. Preferably, this step is carried out by liquid-liquid extraction using at least one appropriate organic solvent, that is to say immiscible with the alcoholic or hydroalcoholic solution resulting from the saponification. It makes it possible to separate the salts of fatty acids (soaps) formed during the saponification of the unsaponifiable fraction.

The organic solvent may in particular be an organic synthesis solvent chosen from optionally halogenated alkanes (especially petroleum ether or dichloromethane), aromatic solvents (especially trifluorotoluene, hexafluorobenzene), haloalkanes, ethers ( especially diethyl ether, diisopropyl ether, methyl tert-butyl ether, methyl tetrahydrofuran, 2-ethoxy-2-methylpropane), ketones (in particular methyl isobutyl ketone, 2-heptanone), propionates (especially ethyl propionate, n-butyl propionate, isoamyl propionate), hexamethyldisiloxane, tetramethylsilane, diacetone alcohol, 1-butoxymethoxy butane, 3-methoxy-3-methyl-1-butanol (MMB) or a organic solvent of natural origin selected from terpenes such as limonene, alpha pinene, beta pinene, myrcene, linalool, citronellol, geraniol, menthol, citral, citronellol, or derivatives thereof oxygenated organic compounds of natural origin, especially ethers, aldehydes, alcohols and esters such as, for example, furfural and furfurol. Preferably one will choose a terpene. The extraction can be performed on a co- or countercurrent extraction column or using a battery of mixer settlers, extractors-columns or centrifugal extractors. For preparation on an industrial scale, it will be possible to carry out a continuous extraction in a continuous liquid-liquid extraction apparatus such as a pulsed column, a settling mixer or the like.

Once extracted, the unsaponifiable fraction is preferably purified, in particular by centrifugation (removal of soaps), desolvation, washing, drying, filtration and / or deodorization under vacuum. More specifically, the purification step may in particular be carried out by implementing one or more of the following substeps:

centrifugation of the solvent phase so as to extract the residual soaps, then filtration,

washing with water, possibly saturated with sodium chloride, of the solvent phase to eliminate the residual traces of alkalinity,

drying by evaporation of the extraction solvent by distillation under vacuum, by hydrodistillation or by azeotropic distillation,

- Vacuum deodorization of the unsaponifiable fraction to extract under deodorization conditions, any contaminant remaining including the extraction solvent, pesticides, polycyclic aromatic hydrocarbons.

The first process according to the invention makes it possible to obtain an unsaponifiable fraction of high purity enriched in polar compounds (with the notable exception, in the case of avocado, of furan lipids, because these, of a slightly polar nature, are present in the unsaponifiable fraction isolated by the first method of the invention because they were formed in situ from polar precursors after the step of selective extraction of the polar compounds). In a non-exhaustive manner, the unsaponifiable compounds obtained after the implementation of this process in the finally isolated fraction may be, depending on the nature of the raw material used, the optionally polyhydroxylated fatty alcohols, the furan lipids (in the case of avocado), non-esterified (free) or non-glycosylated sterols and triterpene alcohols, free and glycosylated polyphenols, free or sulphated cholesterol, lignans, phorbols esters, triterpene acids (eg ursolic acid), polar terpenes (mono, di and sesquiterpenes, with alcohol function), free alkaloids, polycosanols, limonoids, xanthophylls (lutein, astaxanthin, zeaxanthin), gossypol, karanjine, shizandrin, azadirachtin, coenzyme Q10, aflatoxins, especially B1 and B2, isoflavones, caffeine, theobromine, yohimbine, sylimarine, lupeol, allantoin.

In general, the average composition of an unsaponifiable avocado obtained as a result of these different steps (including steps d) and e)) is as follows, in percentages by weight relative to the total mass of the product. unsaponifiable:

- furanic lipids 50-75%

- polyhydroxy fatty alcohols 5-30%

- squalene 0.1 -5%

- sterols 0.1 -5%

- other 0-15% According to the invention, the unsaponifiable product obtained as described can then be subjected to a (second) distillation stage in order to further improve its purity, preferably a molecular distillation, preferably carried out at a temperature ranging from 100 to 160 ° C. preferably from 100 to 140 ° C, preferably from 10 ³ to 5 × 10 ^-2 mm Hg. According to another embodiment, the temperature employed varies from 130 to 160 ° C.

The temperature and pressure chosen during this distillation influence the constitution of the recovered distillate. Thus, this (second) distillation can make it possible to obtain a distillate comprising, in the case of the avocado, avocado furan lipids, the purity of which may exceed 90% by weight, when the distillation temperature varies from 100.degree. at 140 ° C. When the distillation temperature varies from 130 to 160 ° C, a distillate comprising predominantly avocado furan lipids and to a lesser extent polyhydroxy avocado fatty alcohols, the combined content of which can exceed 90% by weight, is generally obtained.

This first method of the invention thus makes it possible to obtain a selective extraction not only of the furan lipids of avocado, but also of the polyhydric fatty alcohols of avocado if they are desired.

Moreover, the unsaponifiable compounds obtained at the end of the implementation of this process in the fraction isolated from the apolar solvent phase, in fine may be, according to the nature of the raw material used, the sterol esters, esterified triterpene alcohols, cholesterol esters, tocopherols (and corresponding tocotrienols), sesamolin, sesamin, sterenes, squalene, paraffinic hydrocarbons, terpeno-polar to apolar terpenes (aldehyde-functional mono, di and sesquiterpenes); and / or ketone), esterified xanthophylls (lutein, astaxanthin, zeaxanthin), carotenoid pigments (beta-carotene, lycopene), waxes, calciferol, cholecalciferol, pongamol.

The second method of the invention will now be presented essentially explaining the differences with respect to the first method of the invention. It should be noted that the reader will be able to refer to the description of the first method of the invention with respect to all other features, which are common to both methods.

The renewable raw materials used in the second process of the invention are not particularly limited and optionally contain lipid constituents functionalized with one or more hydroxyl, epoxide, ketone, thiol, aldehyde, ether or amine functions. They necessarily contain lipid constituents which are not functionalized by any of the aforementioned functions (or at least by few of these functions), these being the most common in nature.

This method comprises a first step a) dehydration and optionally conditioning the renewable raw material. Dehydration and conditioning are not necessarily performed at a temperature of less than or equal to 80 ° C or 75 ° C. Said temperature is preferably greater than or equal to -50 ° C. When heating is involved, the temperature generally varies from 50 to 120 ° C., more preferably from 75 to 120 ° C.

As with the first method, dehydration can be carried out before or after conditioning (when it occurs). It lasts preferably from 8 to 36 hours.

The renewable raw material optionally undergoes (in the case of avocado in particular) a heat treatment as described in particular in the patent application FR 2678632, at a temperature greater than or equal to 75 ° C, preferably greater than or equal to 80 ° C, before or during step b), preferably before step a), during step a) or between step a) and step b) of reactive trituration. Ideally, the heat treatment and the dehydration of the raw material take place simultaneously and constitute one and the same step.

In the case of avocado, this step of heat treatment at 75 ° C or more of the raw material whether or not already conditioned and / or dehydrated is mandatory. As for the first method described, it is intended to promote the cyclization of furan lipid precursors into furan lipids. The duration of this treatment is usually 8 to 36 hours, depending on the heating method used. The temperature employed for the treatment is generally less than or equal to 150 ° C, preferably less than or equal to 120 ° C. Advantageously, this heat treatment is carried out under an inert atmosphere, in particular under a continuous stream of nitrogen. It is preferably carried out under atmospheric pressure.

Once dehydrated and optionally packaged, the raw material undergoes a step b) of reactive trituration in the presence of at least one polar organic solvent comprising at least one light alcohol, at least one apolar cosolvent immiscible with said light alcohol and d at least one catalyst. As in the first method, these solvents and cosolvents can be anhydrous or not, water can be added to the extraction solvent mixture.

This step makes it possible on the one hand to extract the fats, in particular the oil from the dehydrated raw material and at the same time to transesterify it, and on the other hand to isolate a fraction enriched in lipid constituents containing (or little) no hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions, and a fraction enriched in polar lipid constituents, in particular functionalized by one or more hydroxyl functions (preferably aliphatic), epoxide, ketone, thiol, aldehyde, ether or amine.

The addition of an apolar cosolvent promotes the obtaining of a heterogeneous medium and two lipid phases whose constitutions will be very different. On the one hand, the lipid constituents which are not functionalized by one or more hydroxyl, epoxide, ketone, thiol, aldehyde, ether or amine functions will be found preferentially in the apolar phase, while the most polar lipid constituents, in particular those functionalized by a or several hydroxyl functions, epoxide, ketone, thiol, aldehyde, ether and amine, will be found preferentially in the polar phase (light alcohol).

This step allows the selective extraction of lipid constituents that are little or not polar (unsaponifiable or not), which are not functionalized by any of the hydroxyl functions, epoxide, ketone, thiol, aldehyde, ether and amine (or at least a few of these functions), which are separated from the mixture of lipid constituents comprising one or more of these functions, preferably several (for example the polyols), present in the medium following the transesterification reaction.

Depending on the type of raw material used, these non-polar or little polar lipid constituents may be, without limitation, fatty acid esters containing no hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions, furan lipids ( in the case of avocado, furan lipid precursors have already been converted to furanic lipids before the beginning of the reactive trituration step, these furanic lipids being non-hydroxylated), weakly polar alcohols such as tocopherols, squalene , xanthophylls and ester sterols.

Step b) is carried out under conditions of temperature, stirring and duration sufficient to allow the extraction of triglycerides and other lipid constituents from the raw material and the transesterification of said triglycerides, leading to the obtaining of a mixture comprising in particular fatty acid esters, glycerol, the native unsaponifiable fraction (not modified by this step) and a cake. This step b), unlike that of the first process, is carried out without limitation as to the temperature, that is to say that it can exceed 75 or 80 ° C in all cases. Step b) is generally carried out at room temperature but can also be carried out by carrying out heating at a temperature ranging from 40 to 100 ^° C.

The apolar cosolvent, immiscible with the light alcohol (under the conditions of reactive trituration), is preferably chosen such that the lipid constituents functionalized with one or more hydroxyl, epoxide, ketone, thiol, aldehyde, ether or amine which one does not wish to extract are not soluble in this cosolvent. Given their chemical nature, these functionalized lipid components will necessarily have more affinity with the light alcohol phase than with the apolar solvent phase in which they are little (preferably not) soluble.

The reactive trituration step makes it possible to recover (especially after filtration and washing of the cake with a solvent such as a light alcohol) on the one hand two immiscible lipid liquid phases, glycerol and on the other hand a solvent cake. The polar phase (alcoholic phase A) in which the lipids functionalized with hydroxyl groups (preferably aliphatic) and / or epoxide groups such as polyhydroxy fatty alcohols are soluble is separated from the apolar phase. In addition, said apolar phase contains a high proportion of fatty acid esters. The separation of the various fractions can be done in different ways, in particular by centrifugation, decantation and / or distillation.

Thus the polar solvent phase can be subjected to a solvent evaporation step carried out under a suitable vacuum and temperature. The vaporized solvent is then condensed for recycling. The polar phase (phase A), once separated from the glycerol by decantation (followed or not water washes), consisting mainly of alkyl esters and unsaponifiable (or not) polar compounds can then be engaged in molecular distillation to obtain on the one hand, purified esters (in the distillate) and d on the other hand, a distillation residue enriched in polar minor compounds. The extraction of these mainly unsaponifiable compounds is carried out according to the methods known to those skilled in the art. For example by carrying out the following sequence: 1) saponification of the alkyl esters, 2) liquid-liquid extraction for separating the unsaponifiable compounds from the soaps, 3) desolvation of the solvent phase enriched in unsaponifiables and 4) final purification of the unsaponifiable . Another variant consists of directly saponifying phase A and extracting the mainly polar unsaponifiable compounds by 1) liquid-liquid extraction allowing the unsaponifiable compounds to be separated from the soaps, 2) desolvation of the solvent phase enriched in unsaponifiables and 3) final purification of unsaponifiable.

The apolar cosolvent is evaporated from the apolar phase enriched in lipids not containing hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions (or few of these functions) (unsaponifiable or not), especially under reduced pressure. The lipid product obtained may undergo a neutralization step (before or after the evaporation of the apolar cosolvent, preferably before), preferably with an acid, then a decantation or centrifugation step which makes it possible to recover residual glycerol on the one hand and a lipid phase on the other hand, and / or a filtration step. The remaining lipid phase can then be washed with water and dried under vacuum.

The resulting lipid phase (phase containing typically alkyl esters and enriched in unsaponifiable (or not) apolar compounds) then undergoes a step c) of concentration to obtain a mixture enriched in unsaponifiable fraction. As for the first method, the preferred concentration technique is molecular distillation.

Distillation generally makes it possible to obtain a light fraction (first distillate), comprising esters (typically alkyl) of high purity fatty acids, and at least one heavier fraction (second distillate or residue), comprising the unsaponifiable fraction diluted in esters (typically alkyl) fatty acids, present in a significant amount.

In the case of avocado, the concentrate enriched in unsaponifiable fraction (and depleted in fatty acid esters) contains at this stage furan lipids (generally at a content of the order of 10-15% by weight), which are less volatile than monoesters of fatty acids. These furan compounds are present only in trace amounts in the light fraction essentially comprising fatty acid esters.

The concentrate is then optionally subjected to stages d) saponification of the mixture enriched in unsaponifiable fraction and e) extraction of the unsaponifiable fraction of the saponified mixture. Once extracted, the unsaponifiable fraction is preferably purified, using the same techniques as those described for the first method of the invention. The second method according to the invention makes it possible to obtain an unsaponifiable fraction of high purity, enriched in low polar to apolar compounds. Non-exhaustively, the unsaponifiable compounds obtained after the implementation of this process in the isolated fraction in fine may be, according to the nature of the raw material used, furan lipids (in the case of avocado ), sterol esters, esterified triterpene alcohols, cholesterol esters, tocopherols (and corresponding tocotrienols), sesamolin, sesamin, sterenes, squalene, paraffinic hydrocarbons, terpeno-polar to nonpolar terpenes (mono-, di and sesquiterpenes with an aldehyde and / or ketone function), esterified xanthophylls (lutein, astaxanthin, zeaxanthin), carotenoid-type pigments (beta-carotene, lycopene), waxes, calciferol, cholecalciferol, pongamol.

In general, the average composition of an unsaponifiable avocado obtained as a result of these different steps (including steps d) and e)) is as follows, in percentages by weight relative to the total mass of the product. unsaponifiable is:

- furanic lipids 60-80%

- squalene 1 -7%

- other 5-20% (hydrocarbons, tocopherols, fatty ketones, heavy pigments ...)

polyhydroxy fatty alcohols 0.1 -10%

According to the invention, the unsaponifiable product obtained as described can then be subjected to a (second) distillation stage in order to further improve its purity, preferably a molecular distillation, preferably carried out at a temperature ranging from 100 to 160 ° C. more preferably from 100 to 140 ° C, preferably at a pressure of from 10 ³ to 5 × 10 ^-2 mm Hg. This (second) distillation may make it possible to obtain a distillate comprising mainly, in the case of avocado, lipids avocado furans, the purity of which may exceed 90% by mass.

This second method of the invention thus makes it possible to obtain a selective extraction of the furan lipids from the avocado, with the exception of the polyhydric fatty alcohols of avocado which have been extracted in the polar phase during the reactive trituration step .

Moreover, the unsaponifiable compounds obtained at the end of the implementation of this process in the fraction isolated from the polar solvent phase, in fine may be, according to the nature of the raw material used, the furan lipids (in the case of avocado), optionally polyhydroxy fatty alcohols, furanic lipids (in the case of avocado), non-esterified (free) or non-glycosylated sterols and triterpene alcohols, free and glycosylated polyphenols, free cholesterol or sulphated, lignans, phorbols esters, triterpenic acids (eg ursolic acid), polar terpenes (mono, di and sesquiterpenes, alcohol-based), alkaloids, polycosanols, limonoids, xanthophylls (free lutein, astaxanthin, zeaxanthin), gossypol, karanjine, shizandrin, azadirachtin, coenzyme Q10, aflatoxins, especially B1 and B2, isoflavones, caffeine, theobromine, yohimbine, sylimarine, lupeol, allantoin. The invention has many advantages over existing conventional methods used for extraction from oils or deodorization escapes. First of all, the method according to the invention is economical because it does not require the heavy investments of conventional methods. In terms of investment, the process according to the invention makes it possible to dispense with mechanical trituration tools such as a screw press or a hexane extractor, and refining tools (degumming, neutralization). In addition, unlike mechanical trituration or evaporation with hexane, and refining, the reactive trituration according to the invention does not involve high energy consumption. It also requires less freshwater consumption compared to crude oil refining operations.

In addition, the invention is very advantageous in terms of co-valorization, since the implementation of the methods according to the invention leads to high value-added coproducts such as:

esters, generally alkyl esters, of high purity, directly valued in cosmetics or pharmaceuticals (unlike previous processes involving a distillation step on a mixture containing triglycerides, such a distillation generating a highly colored oil and difficult to purify because requiring a higher temperature than that possibly used in the invention, which relates to a mixture containing monoesters of fatty acids from transesterification, lighter than triglycerides),

glycerol, which has applications in cosmetics, pharmacy, hygiene, antifreeze fluids, etc.,

cakes freed from toxic or antinutritional compounds that may be present in the starting biomass and directly used in animal or human nutrition, or cakes that are sources of oligopeptides and / or oligosaccharides of interest, polysaccharides and polyphenols that have been valorized; in cosmetics, pharmacy and animal and human nutrition.

From an economic and environmental point of view, the processes of the invention allow not only an almost total recovery of the fruit unlike current processes and in fact a saving of biomass, or even cultivated land, but they also make it possible to improve the whole. value chain, from the farmer upstream to the downstream user, said unsaponifiables. Finally, it is in line with the key principles of biorefinery models currently under development for multiple uses, in particular energy and industrial.

The unsaponifiable fractions obtained by the processes of the invention have a composition very similar to, or even identical to that of the unsaponifiable material present in the raw material before treatment.

Advantageously, these unsaponifiable fractions and these co-products according to the invention do not contain toxic residual solvent and therefore have a much better safety and regulatory acceptability than the products obtained by implementing processes. classics. These particular characteristics allow a more suitable use of unsaponifiable fractions obtained by the processes of the invention and / or co-products obtained in cosmetic, medicinal, food or food additive or food additive compositions for humans and / or animals.

Similarly, the process according to the invention will make it possible to separate and / or concentrate, according to their polarity, the contaminants that may be present in plant or animal biomasses: polycyclic aromatic hydrocarbons (PAHs), pesticides, polychlorinated biphenyls (PCBs), dioxins, agents brominated fireproof, pharmaceutical products, ....

The unsaponifiable fraction of the avocado obtained by the processes of the invention may especially be used for the manufacture of a medicament intended for example for the treatment of disorders of the joints, more particularly the treatment of osteoarthritis and the treatment of arthritis ( ie rheumatoid arthritis, psoriatic arthritis, Lyme arthritis and / or any other type of arthritis). The drug thus prepared may be intended for the treatment of periodontal diseases, and in particular for the treatment of periodontitis. This medicine can also be used to treat osteoporosis. In addition, this drug may be intended to modulate the differentiation of nerve cells induced by NGF (Nerve Growth Factor). Finally, this drug may be intended for tissue repair, and in particular for skin tissue repair, particularly in the context of a dermatological application.

The unsaponifiable fraction of the avocado resulting from the processes of the invention can also be used in cosmetic compositions, in particular dermo-cosmetic compositions, for the cosmetic treatment of the skin, neighboring mucous membranes and / or integuments (aging, scars, etc.). .), hair fibers or hair bulb, in the presence of an excipient and / or cosmetically acceptable vehicle.

Similarly, the process co-products such as proteins and carbohydrates can, depending on their nature, be used as such or after processing to produce active ingredients or excipients intended in particular for pharmaceuticals, cosmetics and nutrition. to the man or the animal.

EXAMPLES

Selective extraction of unsaponifiable compounds from avocado

40 kg of avocados of the Haas variety are cut whole (core included) in slices of thickness of up to 0.5 cm. 20 kg of slices are then dried in a ventilated oven at 70 ° C. for 16 hours (batch A). After drying, 1254 g of dried avocado are obtained.

The other 20 kilograms are dried at 90 ° C for 16 hours to reach a residual moisture of 2% (Lot B). After drying, 1327 g of dried avocado are obtained. The amounts of lipids present in the ground materials A and B are then determined according to the standardized method (NF EN ISO 659)

Lot A is then subject to the following actions:

1) coarse powder grinding (particle size between 0.3 and 0.8 cm in diameter). 2) introducing the ground material into a fixed bed percolation column (1100 g);

3) A two-phase mixture of ethanol (1100 g) / hexane (1100 g) and 3.6 g of scale soda as catalyst (sodium hydroxide solution dissolved in ethanol) is then sent to the bed of flakes for 30 minutes. at 40 ° C.

4) the biphasic miscella (solvent phase resulting from the liquid-solid extraction) is then withdrawn. The bed of flakes is then washed with 5 successive washes with the ethanol / hexane mixture at 40 ° C. (5 minutes per wash).

5) the biphasic miscella is then centrifuged so as to separate the ethanolic and hexane phases. The solvents of the 2 recovered organic phases are then evaporated under a vacuum of 20 mbar at 90 ° C. for 20 minutes. The glycerol is then separated from the ex-ethanolic lipid phase by simple centrifugation.

6) The lipids obtained after evaporation of their respective solvent (ethanol or hexane), accompanied or not by insoluble gums (oil-insoluble products extracted from the flake during the process), are washed to neutrality by adding water. hot and centrifugation. Finally, they are dried under a vacuum of 20 mbar at 90 ° C for 5 minutes. 412 g of lipids resulting from the hexane phase and 176 g coming from the ethanolic phase respectively are obtained.

The lipids of the hexane phase are then analyzed:

saponification number (NF IS03657 method): 186.4 mg KOH / g

acid number (NFT method 60-204): 2.1 mg KOH / g

unsaponifiable content (modified NF ISO 3596 method in which the extraction solvent is dichloroethane): 0.32%.

Thin layer chromatographic analysis indicates that lipids contain only a few traces of polyhydroxy fatty alcohols from avocado and furan precursors.

Therefore, the process results in an apolar lipid phase depleted of unsaponifiable polar compounds of avocado.

The lipids resulting from the ethanolic phase are then heated in a flask equipped with a Dean-stark at 120 ° C. for 12 hours. After this thermal treatment, thin layer chromatographic analysis (TLC) indicates that the lipids contain in large quantities the polyurethane furan compounds and polyhydric fatty alcohols, these compounds having characteristic spots on TLC.

The lipids of the ethanolic phase are analytically characterized:

saponification number (method NF IS03657): 171 mg / kg

acid number (NFT method 60-204): 3.3 mg KOH / g unsaponifiable content (modified NF ISO 3596 method in which the extraction solvent is dichloroethane): 6.1%.

In view of the analytical characterizations, the extraction process used makes it possible to selectively extract the polar compounds from the unsaponifiable dried avocado (TLC spots characteristic of polyhydroxy fatty alcohols and the presence of furan lipids resulting from the cyclization of the furan precursors resulting from the heat treatment) and this, with an excellent yield (unsaponifiable content much higher than 4%).

The unsaponifiable fraction is then washed, dried, concentrated by molecular distillation, saponified, extracted and purified according to the same protocol as that of Example No. 2 of the application WO 201 1/048339.

A TLC analysis of the unsaponifiable reveals the characteristic spots of furan lipids (very intense spots), hydroxylated fatty alcohols (less intense spots) and phytosterols (less intense spots). Lot B is then subject to the following actions:

1) coarse powder grinding (particle size between 0.3 and 0.8 cm in diameter).

2) introducing the ground material into the fixed bed percolation column;

5) the biphasic miscella is then centrifuged so as to separate the ethanolic and hexane phases. The 2 recovered organic phases are then evaporated under a vacuum of 20 mbar at 90 ° C. for 20 minutes. The glycerol is separated from the ex-ethanolic lipid phase by simple centrifugation.

The lipids of the hexane phase are then analyzed:

saponification number (NF IS03657 method): 179.5 mg KOH / g

- acid number (NFT 60-204 method): 0.9 mg KOH / g

unsaponifiable content (modified NF ISO 3596 method in which the extraction solvent is dichloroethane): 5.3%. A thin layer chromatographic analysis indicates that the lipids of the hexane phase consist mainly of furanic lipids and some traces of polyhydric fatty alcohols.

Therefore, the process results in an apolar lipid phase enriched in furan lipids and depleted in unsaponifiable avocado polar compounds such as polyhydric fatty alcohols.

Lipids from the ethanolic phase are analyzed by thin layer chromatography (TLC). This analysis indicates that this phase contains in large quantities the polyhydroxy fatty alcohols of the avocado as well as traces of furan lipids.

The lipids of the ethanolic phase are analytically characterized:

saponification number (NF IS03657 method): 176.1 mg KOH / g

acid number (NFT method 60-204): 3.1 mg KOH / g

unsaponifiable content (modified NF ISO 3596 method in which the extraction solvent is dichloroethane): 1.2%.

In view of the analytical characterizations, the extraction process used makes it possible to extract the polar compounds selectively from the unsaponifiable dried avocado (TLC spots characteristic of polyhydroxy fatty alcohols).

The unsaponifiable fraction of the lipids resulting from the hexane phase is then washed, dried, concentrated by molecular distillation, saponified, extracted and purified according to the same protocol as that of Example No. 2 of the application WO 201 1/043339.

A TLC analysis of the unsaponifiable material obtained reveals the characteristic spots of furan lipids (very intense spots), hydroxylated fatty alcohols (very weak spots) and phytosterols (very weak spots).

The solvent cakes resulting from the transformation of batches A and B of dried fruit are then desolvated in an oven at 70 ° C for 16 hours. Their respective lipid contents determined by the standardized method NF EN ISO 659 are as follows:

- seed cake A: 0.7% / dry matter

- seed cake B: 0.6% / dry matter

Therefore, the process leads to delipid cake enriched in fact, proteins and polysaccharides sources of active principles and / or excipents or can still be used as such in human and animal nutrition.

Claims

1. A process for extracting an unsaponifiable fraction from a renewable raw material containing lipids functionalized by one or more functions chosen from hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions, comprising the following steps: a) dehydration possibly preceded or followed by packaging of the renewable raw material,

b) reactive trituration of the dehydrated raw material and optionally conditioned in the presence of at least one polar organic solvent comprising at least one light alcohol, at least one apolar cosolvent immiscible with said light alcohol and at least one catalyst, resulting in the production of a lipid-enriched polar organic phase functionalized by one or more functions chosen from hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functional groups,

c) concentration of the polar organic phase to obtain a mixture enriched in unsaponifiable fraction, optionally preceded, accompanied or followed by a heat treatment at a temperature greater than or equal to 75 ° C, preferably greater than or equal to 80 ° C, and optionally including the following steps:

d) saponification of the mixture enriched in unsaponifiable fraction,

e) extraction of the unsaponifiable fraction of the saponified mixture,

2. Process for extracting an unsaponifiable fraction from a renewable raw material comprising the following steps:

b) reactive trituration of the dehydrated raw material and optionally conditioned in the presence of at least one polar organic solvent comprising at least one light alcohol, at least one apolar cosolvent immiscible with said light alcohol and at least one catalyst, leading to the production of a lipid-enriched organic apolar phase containing no or little hydroxyl, epoxide, ketone, thiol, aldehyde, ether and amine functions,

c) concentration of the apolar organic phase to obtain a mixture enriched in unsaponifiable fraction,

and optionally comprising the following steps:

d) saponification of the mixture enriched in unsaponifiable fraction,

e) extraction of the unsaponifiable fraction of the saponified mixture,

the renewable raw material optionally undergoing heat treatment at a temperature greater than or equal to 75 ° C, preferably greater than or equal to 80 ° C, before or during step b).

3. Method according to claim 2, characterized in that said heat treatment is performed, and concomitantly with step a) of dehydration.

4. Method according to claim 2 or 3, characterized in that the renewable raw material is selected from the fruit, the core, the avocado leaves and mixtures thereof, and in that said heat treatment is carried out.

5. Process according to claim 1, characterized in that the renewable raw material is chosen from among the fruit, the core, the avocado leaves and their mixtures, in that the said heat treatment is carried out, and in that the steps ) and b) are carried out at a temperature of less than or equal to 80 ° C, preferably less than or equal to 75 ° C.

6. Method according to any one of the preceding claims, characterized in that the dehydration is carried out so as to achieve a residual moisture less than or equal to 3% by weight relative to the mass of the raw material obtained at the end of the dehydration step.

7. Process according to any one of the preceding claims, characterized in that the light alcohol is chosen from methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol and ethyl. -2-hexanol and their isomers.

8. Method according to any one of the preceding claims, characterized in that the apolar cosolvent is an alkane or a mixture of alkanes.

9. Process according to any one of the preceding claims, characterized in that the catalyst is a basic catalyst.

10. Process according to any one of the preceding claims, characterized in that the concentration of the organic phase is carried out by molecular distillation.

1 1. Process according to any one of the preceding claims, characterized in that it comprises the steps d) and e), the extraction of the unsaponifiable fraction of the saponified mixture being carried out by liquid-liquid extraction using at least an organic solvent.