Plant extraction methods

Abstract

To provide: a process for preparation of a plant extract rich in polyphenols and / or substantially free of simple sugars; a plant extract thus obtained; and cosmetic use of the extract to prevent / reduce skin aging and / or to hydrate the skin.SOLUTION: The process comprises a step of fermentation of a plant extract with a yeast belonging to Saccharomyces cerevisiae var. bayanus. A cosmetic composition comprises the plant extract.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for preparing a plant extract that is rich in polyphenols and / or substantially free of monosaccharides. The present invention also relates to a plant extract obtainable by the method according to the invention, as well as to the cosmetic use of this extract for preventing / reducing skin ageing and / or moisturizing the skin. [Background technology]

[0002] Skin is primarily composed of three layers: starting from the top layer, the epidermis, the dermis and the subcutaneous tissue.

[0003] The epidermis is composed in particular of keratinocytes (which make up the majority), melanocytes (responsible for skin pigmentation) and Langerhans cells. Its function is to protect the body from the external environment, ensure its integrity, and in particular to retard the invasion of microorganisms or chemicals and to prevent the evaporation of the water contained in the skin.

[0004] To achieve this, keratinocytes undergo a continuous process of directed maturation, during which keratinocytes located in the basal layer of the epidermis form, at the final stage of their differentiation, completely keratinized dead cells called keratinocytes in the form of a cornified membrane composed of proteins and lipids such as ceramides. During this differentiation process, epidermal lipids are further formed between keratinocytes and then organized into a bilayer (sheet) in the stratum corneum. Together with the aforementioned cornified membrane, they are involved in the barrier function of the epidermis.

[0005] However, the barrier function of the epidermis can be disrupted under certain climatic conditions (e.g., under the influence of cold and / or wind) or also under the influence of stress or fatigue, thus facilitating the penetration of, among other things, allergens, irritants or microorganisms, which can cause dryness of the skin and discomfort such as tightness or redness, and can also alter the radiance of the complexion and the suppleness of the skin.

[0006] To prevent or regulate this phenomenon, it is known to apply cosmetic compositions to the skin that contain hygroscopic agents, such as sugars or polyols, intended to capture the moisture present on the skin and thereby slow down its evaporation. Typically, such compositions also contain active agents that act on one or more biological targets, for example, involved in the skin aging process.

[0007] Due to the increasing consumer preference to turn to natural products containing as few synthetic ingredients as possible, and in view of the increasing heavy regulatory constraints on compounds derived from the chemical industry, active ingredients derived from plant extracts are now preferred.

[0008] The advantage of plant extracts is that they contain many polyols, especially polyphenols, whose antioxidant effects are now widely recognized.

[0009] However, plant extracts also contain many monosaccharides such as glucose, fructose, and galactose (which account for 25-75% by weight of conventional extracts), which have the effect of impairing the biological activity of the plant's active ingredients.

[0010] To reduce the sugar content of plant extracts, the plant extracts are generally treated using purification techniques, such as the use of resins, activated carbon, cellulose, or by distillation, which aim to remove the polar matrix containing monosaccharides.

[0011] However, these techniques are non-specific and also remove other molecules of interest such as amino acids or organic acids. [Prior art documents] [Non-patent literature]

[0012] [Non-Patent Document 1] MH Akin, "Evolution du pH pendant la fermentation" Summary of the Invention

[0013] Therefore, there is a real need for an extraction method to obtain a plant extract containing a large number of polyphenols, now widely recognized for their moisturizing and antioxidant properties, but free of simple sugars such as glucose, fructose and galactose, which are detrimental to the biological activity of the extract.

[0014] The Applicant has succeeded in developing a method for preparing a plant extract that is rich in polyphenols and substantially free of monosaccharides, and has demonstrated that a fermentation step of the plant extract using a yeast of the type Saccharomyces cerevisiae var. bayanus removes the monosaccharides and increases the polyphenol content of said plant extract.

[0015] The applicant has further demonstrated that the specific use of this strain of yeast allows for optimal fermentation rates with rapid and complete consumption of the simple sugars contained in the plant extract.

[0016] The present invention therefore relates to a method for preparing a plant extract that is rich in polyphenols and / or substantially free of monosaccharides, comprising a fermentation step of the plant extract using a yeast belonging to the species Saccharomyces cerevisiae var. bayanus.

[0017] The present invention also relates to a plant extract obtainable by the above method, which is characterized by being substantially free of monosaccharides and containing a high content of polyphenols, such as flavonoids.

[0018] According to another aspect, the present invention also relates to a cosmetic composition comprising, in a physiologically acceptable medium, at least one plant extract that is rich in polyphenols and / or substantially free of monosaccharides, as described above.

[0019] Finally, the present invention also relates to the use of a yeast of the species Saccharomyces cerevisiae var. bayanus for removing monosaccharides from plant extracts. DETAILED DESCRIPTION OF THE INVENTION

[0020] According to a first aspect, the present invention relates to a method for preparing a plant extract that is rich in polyphenols and / or substantially free of monosaccharides, comprising a fermentation step of the plant extract using a yeast belonging to the species Saccharomyces cerevisiae var. bayanus.

[0021] Polyphenols are molecules that contain at least two phenolic groups, i.e., contain at least two benzene rings with hydroxyl functional groups.Specific examples of polyphenols include hydroxybenzoic acid, hydroxycinnamic acid, and coumarin, naphthoquinone, stilbenoids, or flavonoids.Flavonoids are the most common polyphenols in the plant kingdom, and specifically include flavones, flavonols and dihydroflavonols, flavanones, aurones, chalcones and dihydrochalcones, flavanols, flavandiols, anthocyanidins, and their heterosides.Polyphenols are known for their antioxidant effects, which makes them particularly useful anti-aging active ingredients.In addition, the presence of many hydroxyl groups in polyphenols allows them to capture water present in the skin, thereby slowing down water evaporation.Therefore, polyphenols also have a very beneficial moisturizing effect.

[0022] "Polyphenol-rich" extract is used herein to refer to an extract containing from 5.00 to 100% by weight of polyphenols, particularly from 5.00 to 85.00% by weight of polyphenols, and especially from 55.00 to 85.00% by weight of polyphenols.

[0023] According to the present invention, "monosaccharides" are glucose, fructose, galactose and mannose, but also dimers of glucose, fructose, galactose and mannose.

[0024] In the context of the present invention, an extract that is "substantially free of monosaccharides" is an extract that contains less than 20.00% by weight, in particular less than 10.00% by weight, preferentially less than 5.00% by weight, and even more preferably less than 1.00% by weight of monosaccharides.

[0025] In a particular embodiment, the extract according to the invention is completely devoid of monosaccharides, i.e. comprises 0% by weight of monosaccharides.

[0026] The method of the present invention includes a fermentation step of the plant extract with a yeast strain of Saccharomyces cerevisiae var. bayanus, which reduces or eliminates the monosaccharides contained in the plant extract but also enriches the polyphenol content of the plant extract.

[0027] Applicant has demonstrated that the use of yeast of the species Saccharomyces cerevisiae var. bayanus provides optimal fermentation rates for plant extracts, significantly better than those obtained using other species of yeast (see Examples below). The Saccharomyces cerevisiae var. bayanus yeast specifically reduces the fermentation time of plant extracts, i.e., the time required to consume the sugars in the extract, to less than 24 hours. Thus, the yeast of the present invention rapidly and efficiently consumes the simple sugars contained in the plant extract.

[0028] Yeasts of the variety Saccharomyces cerevisiae var. bayanus are known and used, particularly in the field of enology. Those skilled in the art know how to obtain such yeasts to practice the present invention. In a specific embodiment, the yeast Saccharomyces cerevisiae var. bayanus is selected from among the yeast strains commercially available as IOC Fizz+, IOC Divine, IOC 18-2007, or mixtures thereof. All of these strains are listed by the French Institute of Vine and Wine (Institut Français de la Vigne et du Vin) and are readily accessible to those skilled in the art.

[0029] The IOC Fizz+ yeast strain is a mixture of two yeasts deposited at the Pasteur Institute under numbers LYCC 6022:LA CLAIRE CGC62 and LYCC 6039:LA CLAIRE SP665.

[0030] Strain IOC Divine corresponds to the strain deposited at the Institut Pasteur under number LYCC 7000, and strain 18-2007 corresponds to the strain deposited at the Institut Pasteur under number CNCM I-5320.

[0031] The yeast strain according to the invention may be in dry form, in liquid form or in the form of a yeast cream.

[0032] In certain embodiments, the strain of Saccharomyces cerevisiae var. bayanus is in a dried form.

[0033] Typically, the fermentation step is carried out using a strain of Saccharomyces cerevisiae var. bayanus at between 1 and 5% by weight of the solution to be fermented, in particular between 2 and 3% by weight of the solution to be fermented, and especially at 2% by weight of the solution to be fermented.

[0034] The duration of the fermentation step should be sufficient to obtain a monosaccharide content in the plant extract of less than 20% by weight, in particular less than 10% by weight, preferentially less than 5% by weight, and even more preferably less than 1% by weight. Typically, the fermentation step is carried out over a period of 1 to 72 hours, in particular 12 to 60 hours, preferably 18 to 48 hours.

[0035] In certain embodiments, the fermentation step can be carried out by a fermented dough prepared by fermenting a concentrated plant extract (same plant extract as used in the method of the present invention) with a strain of Saccharomyces cerevisiae var. bayanus. The plant extract used in the fermented dough is typically concentrated to a dry matter content of about 5-30%.

[0036] According to this embodiment, the fermentation step of the method according to the invention is carried out by adding a fermented dough to the plant extract. The use of the fermented dough can initiate fermentation and therefore speed up the fermentation step of the method according to the invention.

[0037] Typically, the fermented dough is prepared by fermenting a plant extract concentrated to between 5 and 50%, particularly between 15 and 30%, dry matter in water with 10% by weight of the dried yeast Saccharomyces cerevisiae var. bayanus for about 2 hours at room temperature (or 37° C.). 1-5% by weight of this fermented dough, preferably 2% by weight of the fermented dough, is added to the plant extract for the fermentation step according to the method of the present invention.

[0038] The plant extract used in accordance with the method of the present invention can be obtained by any extraction method known to those skilled in the art.

[0039] Typically, the method for preparing a plant extract comprises: a) extracting the plant material with at least one alcohol solvent and / or water; b) filtering the mixture obtained in a) to remove plant matter residues, for example by sieving; c) optionally decolorizing the mixture obtained in step b); and d) Removing the solvent and concentrating the extract Includes.

[0040] Thus, according to one embodiment, the present invention provides a method for preparing a plant extract that is rich in polyphenols and / or substantially free of monosaccharides, comprising the steps of: a) extracting the plant material with at least one alcohol solvent and / or water; b) filtering the mixture obtained in a) to remove plant matter residues, for example by sieving; c) optionally decolorizing the mixture obtained from step b); d) concentrating the extract by removing the solvent, for example by evaporation; and e) a fermentation step of the extract obtained from step d) using a yeast belonging to the species Saccharomyces cerevisiae var. bayanus. The present invention relates to a method, including:

[0041] The "plant" used in step a) can be any organism belonging to the kingdom Plantae. The plant is a woody terrestrial plant or a herbaceous plant. Preferably, the plant is a seed plant or a "flowering plant". It can be selected, for example, from lily (Lilium candidum), forget-me-not (Myosotis sylvatica), elderberry (Sambucus sp.), camellia (Camellia sp.), primrose (Primula sp.), tuberose (Polianthes tuberosa), jasmine (Jasminum grandiflorum), plantain (Plantago lanceolata), quince (Cydonia oblonga), apricot (Prunus armeniaca), or frangipani (Plumeria sp.).

[0042] The part of the plant extracted in step a) may be the whole plant or only a part of the whole plant, such as the flower, the leaf, the stem or the root, etc. In a preferred embodiment, the extract is a flower extract.

[0043] The plant material used in step a) may be in "fresh" form, i.e., may be used within 48 hours, particularly within 24 hours, more particularly within 12 hours of harvest.

[0044] The plant material used in step a) may be in dried form. In this case, the fresh plant material is dehydrated under mild conditions, either at room temperature away from light or in a ventilated dryer at a temperature below 35° C. The plant material is preferably dried to a dry matter content of more than 80%, preferably more than 85%.

[0045] Step a) may further comprise grinding the plant matter, typically its flowers and / or leaves, to a particle size of less than 5 cm, preferably less than 2 cm.

[0046] The extraction step is carried out using at least one extraction solvent, including an alcoholic solvent and / or water. The extraction solvent depends on the plant material selected. A typical plant material / solvent ratio is 1 to 10 (w / w).

[0047] The extraction solvent is water and / or an alcoholic solvent. In certain embodiments, the alcoholic solvent is an alcohol, such as ethanol, particularly 96° ethanol.

[0048] The extraction solvent can contain 0-100% water and 0-100% alcohol by volume. In certain embodiments, the extraction solvent contains 100% water, and in other embodiments, 100% ethanol. The extraction solvent can also contain 50% water and 50% ethanol by volume.

[0049] In certain embodiments, the water may be deionized water.

[0050] The extraction step lasts for at least 1 hour, preferably at least 2 hours, in particular at least 3 hours, and can be repeated once or twice.

[0051] As mentioned above, the extraction method can include a step of decolorizing the mixture from step b). The purpose of this step is to remove pigments present in the extract, such as chlorophyll and xanthophyll. Those skilled in the art are familiar with several methods for removing these pigments. Decolorization can be achieved, for example, by contacting the mixture with activated carbon. After decolorization, the mixture is filtered to remove residual carbon.

[0052] Typically, step d) involves concentrating the extract to a dry matter to water ratio in the range of 5-30%, preferably 15-30%.

[0053] The plant extract from step d), i.e. the concentrated plant extract, can be used to prepare the leavened dough described above.

[0054] The above method may further comprise step d') between steps d) and e), in which the mixture containing the concentrated extract is microfiltered (typically at 2 μm) to remove particulates and residual bacteria.

[0055] The method may further comprise step f) filtering the fermentation extract and then diluting it to obtain an extract containing 1-10% by weight of dry matter, which may be in the form of a clear, stable aqueous solution.

[0056] In a particular embodiment, the method according to the present invention comprises: a) extracting the flower powder ground to a size of less than 2cm twice with ethanol or water or a mixture of both at 60-75°C for at least 2 hours; b) filtering the mixture to 4 μm; c) subjecting the resulting mixture to decolorization by contact with activated carbon for 1 hour, followed by microfiltration down to 1 μm to remove residual carbon; d) removal of the extraction solvent by evaporation and concentrating the extract until the dry matter content in water is about 5-15% (wt / wt); d') filtering the mixture through 0.2 μm; e) fermentation of the mixture for 24-48 hours at 37°C with 2% by weight of fermented dough obtained by concentrating a portion of the extract obtained before step d) to 30% dry matter in water and adding 10% by weight of dried Saccharomyces cerevisiae var. bayanus yeast for a first fermentation of 2 hours at 37°C; f) then filtering the fermented extract through 1 μm and then diluting it to obtain an extract containing 1-10% by weight of dry matter, to which glycol and / or other preservative systems are added; Includes.

[0057] In another aspect, the present invention relates to a plant extract obtainable by the method described above, i.e. a plant extract rich in polyphenols and / or substantially free of monosaccharides.

[0058] Thus, in this context, the subject of the invention is - 5.00 to 100.00% by weight of polyphenols, in particular 5.00 to 85.00% by weight of polyphenols, especially 55.00 to 85.00% by weight of polyphenols; and / or less than 20.00% by weight, in particular less than 10.00% by weight, preferably less than 5.00% by weight, even more preferably less than 1.00% by weight of monosaccharides The plant extract is characterized by comprising:

[0059] The plant extract according to the invention is used cosmetically to moisturize human skin or to protect it from dryness. Thanks to the antioxidant effect of polyphenols, the extract can also be used to combat signs of aging such as wrinkles and fine lines, loss of firmness and elasticity due to loss of tissue in the epidermis and / or dermis, loss of radiance due to reduced microcirculation and slowed cell renewal in the epidermis, the appearance of pigmented spots associated with dysfunctional melanin synthesis, or dry skin resulting from a weakened barrier function of the stratum corneum and slowed renewal of the epidermis.

[0060] Antioxidants are indeed known for their ability to scavenge free radicals, which are one of the main factors in accelerated skin aging.

[0061] The present invention also relates to a cosmetic composition comprising the above-mentioned plant extract.

[0062] Preferably, the extract is present in the cosmetic or dermatological composition in a proportion of 0.001 to 90% by weight of the total composition, in particular in a proportion of 0.01 to 10%, preferably in a proportion of 0.1 to 10% by weight of the total composition. The cosmetic or dermatological composition may be particularly suitable for topical application.

[0063] Advantageously, said cosmetic or dermatological composition may be in the form of a powder, emulsion, microemulsion, nanoemulsion, suspension, solution, lotion, cream, aqueous or aqueous alcoholic gel, foam, serum, solution or dispersion for aerosol, or dispersion of lipid vesicles.

[0064] In the case of an emulsion, this can be a water-in-oil or an oil-in-water emulsion.

[0065] The cosmetic or dermatological composition according to the invention may also contain a solvent that is selected according to the various ingredients and the form of administration.

[0066] Examples include water (preferably demineralized water), alcohols such as ethanol, or diethylene glycol ethers such as ethoxydiglycol or diethylene glycol monomethyl ether.

[0067] Said cosmetic composition may also comprise, in addition to the extract according to the invention, at least one additive conventional in the art, such as, for example, at least one compound chosen from emollients or humectants, gelling and / or thickening agents, surfactants, oils, active agents, dyes, preservatives, antioxidants, active agents, organic or inorganic powders, sunscreens and fragrances.

[0068] In particular, the composition may contain: one or more emollients or humectants, which may be chosen, for example, from glycerin, glycol, water-soluble silicones such as those sold under the name KF6011 (Shin Etsu) and water-soluble jojoba such as those sold under the name Resplanta Jojoba (Res Pharma). The emollient or moisturizing agent may be present in the composition in a content ranging from 0 to 30% by weight, preferably from 2 to 10% by weight relative to the total weight of the composition. one or more gelling agents and / or thickening agents for the aqueous phase, chosen, for example, from cellulose derivatives, gums of plant origin (guar, locust bean, alginates, carrageenan, pectin), gums of microbial origin (xanthan), clays (laponite), materials certified by the INCI names "Ammonium acryloyldimethyltaurate / vp copolymer" and "Ammonium acryloyldimethyltaurate / beheneth-25 methacrylate copolymer" (such as those sold under the names Aristoflex AVC and HMB by Clariant). The gelling agent and / or thickening agent may be present in the composition in a content ranging from 0 to 10% by weight relative to the total weight of the composition. one or more surfactants, preferably nonionic, present in a content ranging from 0 to 8% by weight, and preferably from 0.5 to 3% by weight, relative to the total weight of the composition; one or more fats, commonly known as oils, liquid at room temperature, volatile or non-volatile, hydrocarbon or silicone, linear, cyclic or branched, such as isododecane, cyclopentadimethylsiloxane, dimethicone, isononyl isononanoate or pentaerythrityl tetraisostearate, preferably in an amount of 0 to about 10% by weight, preferably 0.5 to 5% by weight, relative to the total weight of the composition. one or more active agents of natural or synthetic origin, having biological activity, selected from, for example, vitamins, trace elements, allantoin, plant proteins, plant extracts, moisturizers, anti-aging agents, antioxidants, gloss enhancers, and mixtures thereof, such as vanilla (Vanilla planifolia) fruit water, niacinamide, hyaluronic acid and its derivatives, yeast extract, and mixtures thereof; one or more water-soluble dyes, such as ponceau disodium salt, alizarin green disodium salt, quinoline yellow, amaranth trisodium salt, tartrazine disodium salt, rhodamine monosodium salt, fuchsin or xanthophyll disodium salt, preferably in an amount of 0 to about 2% by weight relative to the total weight of the composition.

[0069] Other additives normally used in cosmetics may also be present in the compositions according to the invention, such as preservatives, antioxidants or fragrances well known in the art.

[0070] Of all these possible additives, one skilled in the art can select both the nature and the amounts to be added to the composition so that the composition retains all of its properties.

[0071] Finally, in another aspect, the present invention also relates to the use of a yeast of the variety Saccharomyces cerevisiae var. bayanus for removing monosaccharides from a plant extract.

[0072] The invention will now be illustrated by the following non-limiting examples. [Brief explanation of the drawings]

[0073] [Figure 1]Linear regression of total sugars consumed during fermentation for each of the strains studied (Saccharomyces cerevisiae reference strain [ref], not belonging to the bayanus variety, and Saccharomyces cerevisiae var. bayanus strain 18-2007, Fizz+, and Divine). [Example]

[0074] Example 1 - Extraction method of lilies according to the present invention: 1) Fresh lily flowers were extracted twice with 96° ethanol at 60°C for a minimum of 2 hours, with a plant matter / solvent ratio of 1:10 (wt / wt); 2) The mixture is sieved through 100 μm to remove plant residues, then left to stand overnight and filtered again through 4 μm; 3) subjecting the resulting mixture to decolorization by contact with activated carbon for 1 hour to remove pigments such as chlorophyll and xanthophyll; 4) Separating the decolorized mixture from the residual carbon fraction by microfiltration (up to 1 μm); 5) The extract ethanol is removed by evaporation. The extract is concentrated to a dry matter content of about 5% (w / w) in water; 6) The mixture is filtered at 0.2 μm to remove particulates and residual bacteria; 7) To prepare the fermented dough for the fermentation of the extract, a portion of the extract obtained before step 6) is concentrated to 30% dry matter in water, and then 10% by weight of dry yeast Saccharomyces cerevisiae var. bayanus is added. The mixture is stirred for 2 hours at 37°C. This mixture constitutes the fermented dough. 8) Add 2% by weight of fermented dough to the mixture from step 6); 9) After 24-48 hours of fermentation in the dark with stirring at 37°C, the fermented extract is allowed to settle overnight to remove any air bubbles that form; 10) The fermented extract is then filtered through 1 μm and then diluted to obtain an extract containing 1% of dry matter. For better preservation, 0.7% phenoxyethanol or 20% 1,3-propanediol is added and the whole is filtered through 0.2 μm.

[0075] The contents of the lily flower extract are shown in Table 1 below.

[0076] [Table 1]

[0077] As demonstrated above, the method according to the present invention completely removes monosaccharides from the lily flower extract and significantly increases the polyphenol content of the extract.

[0078] Example 2 - Fermentation rates of dried yeasts Saccharomyces cerevisiae var. bayanus Fizz+, Divine, and 18-2007 allow for optimal fermentation of flower extracts.

[0079] To determine which yeast was more efficient, a fermentation kinetics study was performed.

[0080] In general, the fermentation of floral extracts can be divided into three successive steps (MH Akin, "Evolution du pH pendant la fermentation alcoolique de mouts de raisins: modelisation et interpretation metabolique ["Change in pH during alcoholic fermentation of grape musts: modelling and metabolic interpretation"] (2008) 136): - Step 1: Hydrolysis of sucrose to fructose and glucose (lasts between 15 and 30 minutes) - Step 2: Start consuming glucose (lasts up to 5 hours) - Step 3: Start consuming fructose and other simple sugars (varies by strain)

[0081] To select a yeast strain capable of optimal fermentation, the consumption rate of total sugars from lily extract in step 3 was evaluated using various commercially available yeast strains.

[0082] The slope was obtained by linear regression of the relative content of total sugars: the smaller the slope, the greater the reaction rate (Figure 1).

[0083] [Table 2]

[0084] Therefore, the results in Figure 1 and Table 2 show that the Fizz+, Divine, 18-2007, and reference (ref.) strains consumed 6.8%, 5.3%, 4.7%, and 2.1% of the total sugars in the lily flower extract per hour, respectively.

[0085] This comparison then makes it possible to classify the four strains according to their rate of sugar consumption in the following manner: Fizz+>Divine>18-2007>Reference non-bayanus.

[0086] The reference strains, which do not belong to the cultivar Saccharomyces cerevisiae var. bayanus, consume total sugars one-half to one-third slower than the Fizz+, Divine, and 18-2007 strains, which belong to the cultivar Saccharomyces cerevisiae var. bayanus.

[0087] The use of Saccharomyces cerevisiae var. bayanus yeast allows for optimal fermentation rates of plant extracts.

[0088] Example 3: Cosmetic Composition The following compositions can be prepared by conventional methods for those skilled in the art. The amounts indicated below are expressed in weight percent. Components in capital letters are identified according to their INCI names.

[0089] [Table 3] The present invention includes the following embodiments. [1] A method for preparing a plant extract that is rich in polyphenols and / or substantially free of monosaccharides, comprising a step of fermenting the plant extract using a yeast belonging to the species Saccharomyces cerevisiae var. bayanus. [2] before the fermentation step, a) extracting at least one plant material with at least one alcohol solvent and / or water; b) filtering the mixture obtained in a) to remove plant matter residues; c) optionally decolorizing the mixture obtained in step b), and d) removing the solvent and concentrating the resulting extract The method according to [1] above, comprising preparing a plant extract by [3] The method according to [1] or [2], wherein the yeast of the variety Saccharomyces cerevisiae var. bayanus is selected from the group consisting of yeast strains IOC Fizz+, IOC Divine, IOC 18-2007, and mixtures thereof. [4] The method according to [3] above, wherein the yeast of the variety Saccharomyces cerevisiae var. bayanus is a yeast of the IOC Fizz+ strain. [5] The method according to [3], wherein the yeast of the variety Saccharomyces cerevisiae var. bayanus is a yeast of the IOC Divine strain. [6] The method according to [3], wherein the yeast of the variety Saccharomyces cerevisiae var. bayanus is a yeast of the IOC 18-2007 strain. [7] The method according to any one of [1] to [6] above, wherein the plant extract is an extract of a plant, preferably a flowering plant, more preferably a flower. [8] The method according to [7] above, wherein the flower is a flower of a lily (Lilium candidum), forget-me-not (Myosotis sylvatica), elderberry (Sambucus sp.), camellia (Camellia sp.), primrose (Primula sp.), tuberose (Polianthes tuberosa), jasmine (Jasminum grandiflorum), plantain (Plantago lanceolata), quince (Cydonia oblonga), apricot (Prunus armeniaca), or frangipani (Plumeria sp.). [9] The method according to any one of [1] to [8], wherein the fermentation step is carried out using a fermented dough prepared from the fermentation of a concentrated plant extract using a strain of Saccharomyces cerevisiae var. bayanus.

[10] A plant extract obtainable by the method according to any one of [1] to [9] above.

[11] - 5.00 to 100.00% by weight of polyphenols, in particular 5.00 to 85.00% by weight of polyphenols, especially 55.00 to 85.00% by weight of polyphenols, and / or less than 20.00% by weight, in particular less than 10.00% by weight, preferentially less than 5.00% by weight, and even more preferably less than 1.00% by weight of monosaccharides A plant extract comprising:

[12] - 5.00 to 100.00% by weight of polyphenols, in particular 5 to 85% by weight of polyphenols, in particular 55 to 85% by weight of polyphenols, and less than 20.00% by weight, in particular less than 10.00% by weight, preferentially less than 5.00% by weight, and even more preferably less than 1.00% by weight of monosaccharides The plant extract according to

[11] above, comprising:

[13] The plant extract according to

[11] or

[12] , which does not contain monosaccharides.

[14] A cosmetic composition comprising the plant extract described in any one of

[10] to

[13] above.

[15] The use of yeast of the variety Saccharomyces cerevisiae var. bayanus to remove monosaccharides from plant extracts.

Claims

1. 1. A method for preparing a cosmetic flower extract, comprising: The cosmetic flower extract comprises: - 5.00 to 100% by weight of polyphenols, and less than 20.00% by weight of sugars selected from the group consisting of glucose, fructose, galactose and mannose, and dimers thereof Including, The method comprises: a) extracting at least one flower with at least one alcoholic solvent and / or water; b) filtering the mixture obtained in step a) to remove flower residues; c) removing the solvent and concentrating the resulting extract; and d) fermenting the flower extract obtained in step c) using a yeast belonging to the species Saccharomyces cerevisiae var. bayanus.

2. 10. The method of claim 1, further comprising the step of decolorizing the mixture obtained in step b) prior to step c).

3. 3. The method of claim 1 or 2, wherein the flower is a lily (Lilium candidum), forget-me-not (Myosotis sylvatica), elderberry (Sambucus sp.), camellia (Camellia sp.), primrose (Primula sp.), tuberose (Polianthes tuberosa), jasmine (Jasminum grandiflorum), plantain (Plantago lanceolata), quince (Cydonia oblonga), apricot (Prunus armeniaca), or frangipani (Plumeria sp.) flower.

4. 4. The method according to any one of claims 1 to 3, wherein step d) is carried out with a fermented dough prepared from the fermentation of a concentrated plant extract with a strain of Saccharomyces cerevisiae var. bayanus.

5. The cosmetic flower extract is - 5.00 to 85% by weight of polyphenols, and less than 10.00% by weight of sugars selected from the group consisting of glucose, fructose, galactose and mannose, and dimers thereof; 5. The method of claim 1, comprising:

6. 6. The method according to claim 1, wherein the cosmetic flower extract does not contain sugars selected from the group consisting of glucose, fructose, galactose and mannose, and dimers thereof.

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