FR3052064A1 - METHOD FOR OBTAINING STABLE EMULSION FROM OLEO-PROTEAGINOUS ENTITIES, THE EMULSION OBTAINED AND THE COSMETIC COMPOSITIONS COMPRISING THE SAME - Google Patents

Abstract

Process for obtaining an emulsion from whole seeds or from a combination of oleo-proteinaceous unshelled seeds characterized in that it comprises an aqueous fractionation phase jointly by a high-energy thermo-mechanical contacting method and by stirring, leading to a filtrate and a solid cake, and a separation phase of the solid and liquid phase of the filtrate, leading to a range of light emulsions and fat directly usable in cosmetics.

Description

TECHNICAL AREA

The present invention relates to a process for obtaining stable in situ emulsions from whole seeds or oil-protein-rich unshelled seed mixtures, the emulsion obtained and the cosmetic compositions comprising said emulsion. The field of the invention relates to the field of emulsions and more particularly the cosmetics industry, the pharmaceutical industry and the food industry for the formulation of natural compositions.

STATE OF THE ART

An emulsion is a mixture of two immiscible liquid substances that do not mix normally, such as water and oil. The liquid forming the drops is called the internal phase, discontinuous or dispersed, while the liquid surrounding the droplets is called continuous or external phase. In an oil-in-water emulsion, the oil is dispersed in water as small droplets. Whether it is an oil-in-water (O / W) or water-in-oil (W / O) emulsion, an emulsion is typically unstable and tends to separate or coalesce. It can also be multiple emulsions, for example Water / oil / Water or Oil / Water / Oil. Thus, for the mixture of the two immiscible phases to remain stable, an emulsifier is added which reduces the interphase tensions and prevents the melting of the droplets. The basic principle for obtaining an O / W emulsion therefore generally consists of finely dispersing the lipid phase in water in the presence of an emulsifier. Various emulsifying systems have thus been proposed in the literature, mainly based on the use of surfactant compounds.

Among the conventional synthetic emulsifiers are the controversial PEGs (polyethylene glycol), which also act as solvents and are on the list of "twelve ingredients to avoid" in cosmetic formulations defined by the David SUZUKI Canadian Foundation, along with the derived dyes. coal tar, dibutyl phthalate, formaldehyde releasers or parabens.

PEGs show signs of genotoxicity, can cause skin irritation when used on damaged skin and, because they are highly penetrating, allow toxic ingredients to be absorbed through the skin. PEGS are synthesized by polymerization of ethylene oxide, which is a toxic gas, highly reactive, carcinogenic and mutagenic. Its polymerization with a fatty alcohol, at high temperature and under high pressure, makes it possible to form polyethoxylated alcohols. If the final product contains no trace of ethylene oxide, it may be contaminated with a reaction by-product, 1,4-dioxane, formed by dimerization of ethylene oxide and considered carcinogenic to humans by the state of California.

In 2012, the global cosmetics surfactants market was worth more than $ 10 billion.

However, for some applications, we would like to be able to do without emulsifier. In the dermatological and cosmetic field for example, emulsions of the oil-in-water type are now highly valued for their ease of use and freshness. In order to overcome the use of surfactants to stabilize this type of emulsion, the application EP0692237A1 proposes the use of hollow thermoplastic particles expanded with acrylonitrile polymer or copolymer ensuring the dispersion of the oily phase. Another area for which the possibility of preparing emulsions without conventional emulsifiers or stabilizers is of great interest is that of the agri-food industry. The suppression of emulsifiers makes it possible to simplify the recipes and to eliminate the problems of allergy or intolerance related to this type of compounds. The application DE102006032083A1 describes a process for manufacturing microcapsules containing a lipophilic agent. The method involves the implementation of multiple emulsions, including a step of emulsifying an O / W emulsion in a lipid phase by means of ultrasound.

These two processes are therefore complex, employ ultrasonic treatments with cavitation, require multiple manipulations of the phases to be emulsified, in various volumes and incorporate synthetic compounds.

These different emulsifying systems have disadvantages related to the nature of some of their constituents, and specificities that limit their uses.

There is therefore the need for a process which makes it possible to obtain, as simply as possible, a stable and natural emulsion.

SUMMARY OF THE INVENTION

The present invention proposes for this purpose a process for obtaining a range of light or fat emulsions directly usable in cosmetics, obtained from seed or mixtures of whole seeds unshelled, oleo-proteinaceous. By this arrangement of the invention, a stable emulsion is obtained in a single step, in a method advantageously continuous.

The process provides a stable oil-in-water emulsion having emulsifying properties and can be used alone or in combination for hydration properties in cosmetic compositions. According to another aspect of the invention, there is provided a stable oil-in-water emulsion without emulsifier.

In another aspect, the invention relates to a composition or product for pharmaceutical, dermatological or food cosmetic use comprising an emulsion obtained according to the present process.

Preferably, the composition is intended in particular for the topical application of the skin (body, face) and / or hair, in particular a cosmetic composition. The invention also relates to the use of the emulsion according to the invention for the stabilization of cosmetic composition.

Advantageously, the composition is intended for hydration of the upper layers of the epidermis.

Advantageously, the composition is intended for the radical protection of the epidermis.

Advantageously, the composition is used in the form of milk or moisturizer.

BRIEF DESCRIPTION OF THE FIGURES

The objects, objects, as well as the features and advantages of the invention will emerge more clearly from the detailed description of an embodiment of the latter which is illustrated by the following accompanying figures in which:

Figure 1: Table showing some parameters for the first phase of the method according to one embodiment of the invention.

Figure 2: Table showing the particle size of the emulsions according to one embodiment of the invention.

The figures are given by way of examples and are not limiting of the invention. They constitute representations of principle intended to facilitate the understanding of the invention.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

Before beginning a detailed review of embodiments of the invention, are set forth below optional features that may optionally be used in combination or alternatively. The invention relates to a method for obtaining an emulsion from whole seeds or from a combination of oleo-proteinaceous unshelled seeds, characterized in that it comprises an aqueous fractionation phase jointly by a method of contacting with heat. high energy mechanics and stirring, leading to a filtrate and a solid cake, and a phase of separation of the solid and liquid phases of the filtrate, leading to emulsions in situ.

Advantageously, a twin-screw extruder is used which combines compression and shear effects.

Advantageously, the whole seeds are chosen from hemp, cardoon (also called cynara), rapeseed, pastel, flax, or a mixture of at least two thereof.

Advantageously, the whole seeds consist of a mixture of rapeseed, hemp, cardoon, pastel and flax. Advantageously, the whole seeds consist of a mixture of rapeseed and hemp.

Advantageously, the whole seeds consist of a mixture of hemp and cardoon.

Advantageously, the whole seeds consist of a rapeseed and cardoon mixture.

Advantageously, the whole seeds consist of a rapeseed and pastel mixture.

Advantageously, the whole seeds consist of a mixture of hemp and pastel.

Advantageously, the whole seeds consist of a cardoon and pastel mixture.

Advantageously, the process comprises the addition of linseed.

Advantageously, the process comprises the addition of previously extracted polysaccharide fractions of flax.

Advantageously, the method comprises the addition of flax mucilage solutions.

Advantageously, said flax mucilage solutions comprise a concentration of flax mucilages of between 5 and 20 g / l.

Advantageously, the filtrate undergoes a first filtration giving rise to a first emulsion.

Advantageously, said first filtration is carried out on a square mesh fabric of 100 μm.

Advantageously, the filtrate undergoes a first centrifugation giving rise to a second emulsion.

Advantageously, said first centrifugation is carried out at a speed of 8000 g for a period of 20 minutes at 20 ° C.

In another aspect, the invention relates to an in situ emulsion of a lipid phase in an aqueous phase obtained by the above method.

In another aspect, the invention relates to a cosmetic composition containing an emulsion as described above.

In another aspect, the invention relates to an emulsion for stabilizing a cosmetic composition.

In another aspect, the invention relates to the use of an emulsion for its antioxidant properties in a cosmetic composition.

To be considered as being of natural origin, the surfactants or emulsifiers must contain at least 50% of materials of renewable or sustainable origin, and their chemical modifications must respect the principles of the green chemistry (low environmental toxicity, low consumption of energy and CO2 etc.).

The term "emulsifier" denotes a compound that lowers the interfacial tension between two immiscible phases (for example water / oil) and thus allows a large increase in the specific surface area of the phase to be emulsified. Thus, the mechanical energy necessary to form an emulsion is decreased.

The term "solid cake" refers to the fraction retained by the filter during filtration.

In general, the term lipid phase (or lipophilic) refers to all oily substances. The term aqueous (or hydrophilic) phase refers to any phase containing water and / or alcohol. We can mention water softened or not, mineral or not, spring water.

The process according to the invention is intended to obtain an emulsion. More preferably, an emulsion of a lipid phase in an aqueous phase.

The process is made from whole seeds.

The term whole seed refers to any seeds that have not undergone any particular preparation process before being introduced into the measuring cup.

Preferably, the whole seeds have a moisture content of 8 to 10%.

The process according to the invention is divided into two phases. A first phase of aqueous fractionation by twin-screw extruder and a second phase of separation.

The first phase of aqueous fractionation begins with the introduction of whole seeds in a twin-screw extruder.

This first phase comprises a step of grinding whole seeds.

Advantageously, this grinding step allows the extraction of oil from the seeds.

The first phase subsequently comprises a step of bringing the ground seeds into contact with water so as to allow extraction of the oil in the water, advantageously in emulsified form. The areas of kneaders located upstream of the introduction of water cause the pressing of the seeds and the extraction of the oil. Advantageously, a pump allowing the introduction of water is connected to the extruder module 5. The oil and the water are then brought into contact, with stirring thanks to the rotation of the screws, allowing mixing of the two phases and the creation of an emulsion This step leads to the formation of an oil-in-water mixture, advantageously emulsified.

The first phase advantageously comprises a liquid / solid separation step. This separation step is carried out on the oil-in-water mixture obtained in the preceding step and containing the crushed seeds and advantageously by filtration. According to one possibility, the filter has a diameter of 1 mm, allowing the flow of the filtrate. The filtration step leads, on the one hand, to the recovery of an oil-enriched filtrate and preferably to bioactive compounds and, on the other hand, to a solid extrudate corresponding to the crushed seeds.

By bioactive compounds are meant proteins, phospholipids and extracted polysaccharides for the stabilization of the emulsion.

According to one embodiment, the first phase comprises the addition of flax mucilages.

Preferably, the flax mucilages are introduced in freeze-dried form, mixed with water in the extruder pump.

Linseed mucilages increase the viscosity of the mixture.

Advantageously, when the seeds introduced are rapeseeds, the mucilage solutions are prepared in water at concentrations of between 5 g / l and 20 g / l, preferably 7.37 g / l for a moderate viscosity and preferentially 14.75 g / L

Advantageously, when the seeds introduced are the hemp / rapeseed mixture, the mucilage solutions are prepared at concentrations of between 5 g / l and 20 g / l, preferably of 9.63 g / l for a moderate viscosity and 19.3 g. / L for a higher viscosity.

According to a preferred embodiment, the first phase of the process according to the invention is carried out in a twin-screw extruder. Preferably, all the steps of this first phase are performed in the twin-screw extruder. The filtrate flows advantageously out of the twin-screw extruder.

According to one possibility, the extruder is divided into 4 zones: a conveying zone in which the seeds are distributed, a mixing zone in which the material is ground or unstructured, a liquid / solid extraction zone, a zone liquid / solid separation. The twin-screw extruder is composed of several independent modules, advantageously seven. The modules are advantageously thermoregulated.

The whole seeds, hereinafter referred to as "vegetable matter", progress advantageously in a linear manner within the twin-screw extruder, from one screw to the other. The screw speed is adapted so that the conveyance of the plant material is effective: avoiding clogging while allowing a residence time of the plant material within each module sufficient for the expected destructuration to be effective. By way of example, the screw rotation speed is 250 rpm, for a seed input rate of 4 kg / h and a water entry rate of 8 kg / h. Under these conditions, the filtrate flows at a rate of 6.3 kg / h and the extrudate at a rate of 5.7 kg / h.

The method according to the invention comprises, after the first phase, a second phase of liquid / solid separation. This second phase is carried out on the filtrate obtained at the end of the first phase.

This second phase advantageously comprises a filtration step of the filtrate. This filtration step makes it possible to obtain a foot corresponding to the solid part and an emulsion corresponding to the liquid part. This first emulsion is called emulsion 1.

The foot corresponds to the solid particles of residual seeds that are passed through the extruder filter during the first phase, instead of being entrained within the extrudate. The filtration step is for example carried out on 100 μm square mesh fabric.

This second phase preferably comprises a subsequent centrifugation step carried out on the liquid part resulting from the preceding filtration step. By way of example, the centrifugation is carried out at a rate of 8000 g for a period of 20 minutes at 20 ° C.

Three phases emerge from this centrifugation step: a hydrophobic heavy pellet, an aqueous intermediate phase and a higher hydrophobic phase. This upper hydrophobic phase is an emulsion. This second emulsion is called emulsion 2.

According to another embodiment, a mixture consisting of whole seeds previously finely ground in the coffee grinder and water is placed under intense stirring. This stirring is carried out using a bench mixer. This fractionation mode is called batch fractionation.

The mixture is carried out for 5 minutes at 20,000 RPM at room temperature.

The seeds are crushed and the result is a single phase corresponding to water enriched with vegetable oil and bioactive compounds, in which the solid particles from the seed are in suspension. The following steps are similar to the embodiment described above, comprising a bi-screw extrusion aqueous fractionation phase. Indeed, the whole undergoes filtration on canvas in order to get rid of the solid particles from the seed, then a centrifugation to obtain the heavy culott, the aqueous phase and a light emulsion.

The whole seeds used in the present process are advantageously chosen from oil-protein seeds and more specifically from: hemp, cardoon, rapeseed, pastel or a mixture thereof. By way of example, a mixture of 50% by weight of rapeseed and 50% by weight of hemp may be used.

Hemp: The cultivation of hemp, an annual cultivated plant of the cannabaceae family, is allowed for low THC varieties: the maximum THC content for industrial hemp is 0.2%. Its seeds are used for fishing and animal feed and its fibers for the paper industry. Hemp seeds contain a remarkable content of fiber, vegetable oil (30%) and protein (25%). Hemp oil, very rich in polyunsaturated fatty acids, also has a significant cosmetic interest due to its moisturizing, softening, regenerating and revitalizing properties.

Rapeseed: An annual plant with a yellow flower, rapeseed belongs to the brassicaceae family and is widely cultivated for its oil (the world's fifth production of oil, mainly used for agribusiness and biofuel). The rapeseeds have a vegetable oil content of the order of 40%. Many studies have improved the nutritional qualities of rapeseed oil and reduced its erucic acid content, supposed to cause heart lesions in the rat, as well as glucosinolates. The species marketed thus evolved from "traditional oil" (erucic acid content: 59.4%) to "simple zero" (erucic acid content: 0.1%) then "double zero" (erucic acid content: 0 , 02%).

Cardon seeds, flax seeds and pastels are also studied and used for their nutritional and cosmetic properties. The emulsion according to the invention comprises bioactive compounds extracted from the seeds.

The emulsions, object of the invention, find their application in a large number of cosmetic and / or dermatological treatments of the skin, mucous membranes and hair, including the scalp, in particular for the protection, the care, the cleaning and make-up of the skin and mucous membranes for the protection and care of the hair and for the therapeutic treatment of the skin, hair and mucous membranes. The emulsions according to the invention may, for example, be used in skin care or cleansing products in the form of creams or milks or as makeup products (skin and lips) by incorporation of fillers, pigments or dyes. Also, the subject of the invention is also the use of the emulsion as defined above in and / or for the manufacture of a cosmetic and / or dermatological composition intended for the treatment of the skin and / or the hair.

The present emulsion, called emulsion 2, has a stability of several weeks, typically at least one month at room temperature. By way of example, rapeseed emulsions 1 have a stability of one week. Emulsions 1 of hemp / rapeseed have a stability of the order of two months. Emulsions 2 of rapeseed and hemp / rapeseed have a stability of 5 to 6 months. The addition of mucilage allows a better stability, thanks to a decrease in proton mobility.

EXAMPLE 1 The unit employed is an extruder of the Clextral BC 21 type (Ciextral SA, Firminy, France) composed of a fixed bilobed sheath containing two parallel, identical and co-rotating screws.

The whole seeds are introduced into a hopper via a KCL type KT 20 dispenser (KTRON, USA). The two screws will, firstly, allow to grind the material and extract the oil, and then bring into contact the oil, the milled material and water to allow solid liquid extraction. The liquid / solid separation is then carried out by means of a 1 mm diameter filter, allowing the flow of the filtrate enriched with oil and bioactive compounds. The twin-screw extruder is composed of 7 independent and thermoregulated modules: 1st module: a section of trapezoidal screws with double thread, also called T2F corresponding to a trapezoidal screw section, having a screw thread of 50 mm allowing conveying of the raw material introduced. 2 '™ module: a section of double-threaded conjugate screw, also called C2F corresponding to a twin threaded screw section with a thread pitch of 33 and 25 mm for conveying the plant material to the next module. 3rd module: • a first series of single-pitch (+ 45 °) single-blade kneading discs allowing the compression, shearing and destructuring of the plant material, • a double-threaded conjugate screw section of C2F type, with a pitch of screw of 33 mm allowing the conveyance of the vegetable matter towards the following module. 4th module: • a section of double-threaded C2F type screw, with a 25 mm thread pitch for conveying the plant material, • a first series of single-pitch (-45 °) single-pitch kneading discs allowing compression, shearing and destructuring of the plant material, more restrictive than the third module at (+ 45 °). 5th module: • a section of double-threaded C2F type screw, with a pitch of 33 and then 25 mm allowing the conveyance of plant material, • a pump allowing the entry of water into the extruder twin-screw, 6th module: • a section of double-threaded C2F-type screw, with a pitch of 25 and then 16 mm allowing the conveyance of the plant material, • a filter allowing the flow of the filtrate opposite this module. 7th module: • a section of double-threaded C2F type screw, with a 16 mm thread pitch, for conveying plant material outside the extruder. A section of CFC2 screw of the counter-thread type allowing the formation of a dynamic plug which allows the filtrate to flow at the level of the filter of the preceding module; a section of conjugated double-threaded screw of C2F type having a pitch 33 mm screw, the output of the destructured plant material, called extrudate, is observed at the output of this module.

The second phase of the process is carried out by filtration on 100μ square cells and centrifugation at a speed of 8000 g for a period of 20 minutes at 20 ° C.

The parameters of the invention are visible in the following tables: Table given in FIG. 1: example of parameters for the first phase of the process according to the invention: T2F: section of trapezoidal screws with double thread; C2F: conjugated screw section with double thread; Mal 0: areas of the mixer where the plant material undergoes physical constraints; CFC2: cross-thread screw section. Table given in FIG. 2: Granulometry of emulsions.

Claims (19)

1. Process for obtaining an emulsion from whole seeds or combination of oil-protein-rich unshelled seeds characterized in that it comprises an aqueous fractionation phase jointly by a high-temperature thermomechanical contacting method. This is followed by stirring and stirring, leading to a filtrate and a solid cake, and a phase of separation of the solid and liquid phases of the filtrate, leading to emulsions in situ. 2. Method according to the preceding claim wherein using a twin-screw extruder which combines compression and shear effects. 3. Method according to any one of the preceding claims wherein the whole seeds are selected from hemp, cardoon, rapeseed, pastel, flax, or a mixture of at least two thereof. 4. Process according to any one of the preceding claims, wherein the whole seeds consist of a rapeseed and hemp mixture. 5. Process according to claims 1-3, wherein the whole seeds consist of a mixture of hemp and cardoon. The method of claims 1-3, wherein the whole seeds consist of a rapeseed and cardon mixture. The method of claims 1-3, wherein the whole seeds consist of a rapeseed and a pastel blend. The method of claims 1-3, wherein the whole seeds consist of a hemp and pastel blend. 9. The method of claims 1-3 wherein the whole seeds consist of a cardon and pastel mixture. 10. Method according to any one of the preceding claims, characterized in that it comprises the addition of linseed. 11. Method according to any one of the preceding claims, characterized in that it comprises the addition of flax mucilage solutions. 12. Method according to the preceding claim, characterized in that said flax mucilage solutions comprise a concentration of flax mucilages of between 5 and 20 g / l. 13. Method according to any one of the preceding claims, characterized in that the filtrate undergoes a first filtration giving rise to a first emulsion. 14. Process according to the preceding claim, characterized in that said first filtration is carried out on a 100 μm square mesh fabric. 15. Process according to any one of the preceding claims, characterized in that the filtrate undergoes a first centrifugation giving rise to a second emulsion. 16. Method according to the preceding claim, characterized in that said first centrifugation is carried out at a speed of 8000g for a period of 20 minutes at 20 ° C. 17. Emulsion in situ of a lipid phase in an aqueous phase obtained by the process according to any one of the preceding claims. 18. Cosmetic composition containing an emulsion according to the preceding claim. 19. Use of an emulsion according to claim 17 for its antioxidant properties in a cosmetic composition.