Method for treating a composition comprising natural vanillin

Abstract

The present invention relates to a method for treating a composition comprising natural vanillin by isolating the compound having formula (I).

Description

[0001] This application claims the priority of patent application number 1908644 filed in France on July 30, 2019, and the contents of this patent application are incorporated by reference in their entirety. Technical Field

[0002] The present invention relates to a method for treating a composition comprising natural vanillin by isolating the compound having formula (I). Background Art

[0003] Vanillin or 4-hydroxy-3-methoxybenzaldehyde can be obtained by various methods known to those skilled in the art, in particular by the following three routes:

[0004] - A "natural" route based on biotechnological processes, which comprises in particular the cultivation of microorganisms capable of bioconverting a fermentation substrate into vanillin. Such a process, in which the fermentation substrate is ferulic acid, is known in particular from application EP 0 885 968. The ferulic acid used can have various sources, in particular derived from rice bran or corn bran. These processes result in the preparation of vanillin known as "natural vanillin".

[0005] - A "synthetic" route involving conventional chemical reactions starting with guaiacol (but without the involvement of microorganisms). This method results in the preparation of vanillin known as synthetic vanillin.

[0006] Finally, vanillin can also be prepared according to a route described as "biobased", in which vanillin is produced from lignin; mention may in particular be made of documents US 2745796, DE 1132113 and the article by Azadbakht et al., International Journal of Biology and Biotechnology, 2004, Vol. 1, No. 4, pp. 535-537, entitled "Preparation of lignin from wood dust as vanillin source and comparison of different extraction methods", or from eugenol.

[0007] When the "natural route" is used for the industrial production of vanillin, some side reactions may occur, leading to the formation of a large number of by-products, which may affect the organoleptic properties of natural vanillin. These by-products can also react with, in particular, vanillin. As a result, the purification yield of natural vanillin is reduced and the overall yield of natural vanillin production is also reduced. The organoleptic properties of natural vanillin are also prone to degradation.

[0008] Furthermore, natural vanillin can be purified. For example, document WO 2018 / 146210 describes a method for purifying natural vanillin, which method comprises at least one step of stripping a liquid stream containing natural vanillin with an entraining gas and / or a vaporized liquid. Although this method makes it possible to satisfactorily purify natural vanillin, vanillyl alcohol is not satisfactorily removed.

[0009] The present invention aims to provide an effective solution for preventing side reactions with natural vanillin in order to increase the overall yield of natural vanillin purification while maintaining or even improving its organoleptic properties. Summary of the invention

[0010] Therefore, a first subject of the present invention relates to a method for treating a composition (C) resulting from a process for producing natural vanillin comprising natural vanillin and vanillyl alcohol, the process comprising:

[0011] - Step (i) of forming a compound having formula (I) from vanillyl alcohol:

[0012] [Chemical formula 1]

[0013]

[0014] wherein n is equal to 0 or 1, and R is selected from a linear or branched, saturated or unsaturated alkyl group, optionally substituted with at least one hydroxyl, alkoxy or amino group, or R is a group having the formula -(WO) m -X, wherein W is a linear or branched alkyl chain containing from 1 to 4 carbon atoms, and the -(WO) m - the average molecular weight of the group is between 200 and 3000 g / mol, and X is selected from H and units of formula (II)

[0015] [Chemical formula 2]

[0016]

[0017] wherein step (i) is carried out in the presence of natural vanillin and is capable of forming composition (C1) or (C2);

[0018] - a step (ii) of recovering natural vanillin and / or a step of recovering the compound of formula (I) present in composition (C1) or (C2).

[0019] Another aspect relates to a method for purifying a composition comprising natural vanillin and vanillyl alcohol by isolating the compound having formula (I).

[0020] The present invention also relates to a process for preparing a compound of formula (I) in the presence of natural vanillin.

[0021] Finally, the invention relates to the use of a natural vanillin composition in the field of human and animal nutrition, as a flavoring agent in pharmacy, and as a fragrance in the cosmetic, perfume and detergent industries. DETAILED DESCRIPTION

[0022] In the context of the present invention, and unless otherwise stated, the expressions "between ..." include the limit values. Unless otherwise stated, percentages and ppm are percentages and ppm by weight.

[0023] In the context of the present invention, and unless otherwise specified, the term "ppm" means "parts per million." This unit represents a fraction by weight: 1 ppm = 1 mg / kg.

[0024] In the context of the present invention, and unless otherwise indicated, the expression "natural vanillin" may denote a flavoring substance according to article 9.2c) of Regulation EC 1334 / 2008, that is to say a flavoring substance for human consumption obtained as is or after its transformation from a material of plant, animal or microbial origin, by one or more conventional methods for the preparation of foods, by physical, enzymatic or microbiological methods. Natural flavoring substances correspond to substances that occur naturally and have been identified in nature. The definitions given by the current regulations of other countries or regions may also be applied. Preferably, the term "natural vanillin" according to the present invention denotes vanillin obtained by a biotechnological process. According to another alternative, the term "natural vanillin" denotes vanillin obtained by a microbiological process, in particular comprising the cultivation of a microorganism capable of converting a fermentation substrate into vanillin. According to the present invention, the microorganism may be wild or genetically modified, in particular in order to improve performance, for example to increase the yield of vanillin, to limit or prevent the formation of by-products, or to increase productivity. Very preferably, it is a process of ferulic acid fermentation, as described in patent application EP 0 885 968. The ferulic acid may be of any origin, in particular derived from rice bran, beet pulp, wheat bran, bagasse, sugar cane or corn, in particular corn bran or corn fiber, in particular derived from a starch factory or an alkalizing wet milling unit.

[0025] In the context of the present invention, the term "alkyl" means a straight or branched, saturated or unsaturated chain. Preferably, the alkyl group comprises from 1 to 10 carbon atoms, preferably from 1 to 8 carbon atoms, and still more preferably from 1 to 6 carbon atoms. The alkyl group may preferably be selected from the group consisting of: methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl and tert-butyl. According to a particular aspect, the alkyl group may be substituted by at least one hydroxyl group. For example, the alkyl group substituted by at least one hydroxyl group may be -CH2-CH(OH)-CH2-OH.

[0026] Therefore, a first subject of the present invention relates to a method for treating a composition (C) resulting from a process for producing natural vanillin comprising natural vanillin and vanillyl alcohol, said treatment comprising:

[0027] - step (i) of forming a composition C1 comprising natural vanillin and a compound of formula (I) from said vanillyl alcohol present in composition (C):

[0028] [Chemical formula 3]

[0029]

[0030] wherein n is equal to 0 or 1, and R is selected from a linear or branched, saturated or unsaturated alkyl group, optionally substituted with at least one hydroxyl, alkoxy or amino group, or having the formula -(WO) m -X, wherein W is a linear or branched alkyl chain containing from 1 to 4 carbon atoms, and the -(WO) m - the average molecular weight of the group is between 200 and 3000 g / mol, and X is selected from H and units of formula (II)

[0031] [Chemical formula 4]

[0032]

[0033] - a step (ii) of recovering natural vanillin and / or a step of recovering the compound of formula (I) present in composition (C1) or (C2). Preferably, n is equal to 0 and / or R is a butyl group.

[0034] Therefore, the present invention particularly relates to a method for treating a composition (C) comprising natural vanillin and vanillyl alcohol, wherein the composition (C) comes from a process for producing natural vanillin, the vanillyl alcohol is converted into the above-mentioned compound of formula I, and wherein the natural vanillin composition is purified.

[0035] According to the present invention, the weight concentration of natural vanillin in composition (C) is between 0.50% and 99%, preferably between 0.50% and 60%, preferably between 5% and 40%, and even more preferably between 10% and 35%, relative to the weight of the natural vanillin composition produced from the method for producing natural vanillin.

[0036] According to the present invention, the composition (C) produced from the method for producing natural vanillin contains vanillin alcohol. Typically, the weight concentration of vanillin alcohol is between 0.1% and 5%, preferably between 0.5% and 4%, and even more preferably between 1% and 2.5%, relative to the weight of the natural vanillin composition (C) produced from the method for producing natural vanillin.

[0037] According to the present invention, composition (C) may further comprise at least one compound selected from the group consisting of vanillic acid, acetylvanillin, guaiacol and vinylguaiacol. Preferably, when composition (C) comprises acetylvanillin, guaiacol is also present.

[0038] The invention may further comprise a preliminary step of fermenting a substrate, preferably ferulic acid, for producing a composition resulting from a process for producing natural vanillin containing vanillyl alcohol. The fermentation may be carried out as described in document EP 0885 968. The fermentation is generally carried out in an aqueous medium. Composition (C) may be obtained from the fermentation medium or directly at the end of the fermentation after treating the aqueous medium, in particular so that the fermentation biomass can be removed.

[0039] The composition (C) used in the treatment process according to the invention is generally obtained at the end of the fermentation step and optionally directly at the end of the fermentation after treatment of the aqueous culture medium.

[0040] The composition (C) may be in an aqueous solution, or in a water / solvent mixture, preferably in a water / organic solvent mixture. The organic solvent is typically a food solvent, in particular a solvent registered on the FEMA GRAS list. For example, ethanol, isopropanol, butanol, isobutanol, glycols and acetates, such as ethyl acetate and propyl acetate, may be mentioned.

[0041] Step (i):

[0042] According to the present invention, step (i) is a step of forming a compound having formula (I) according to the following formula:

[0043] [Chemical formula 5]

[0044]

[0045] wherein n is equal to 0 or 1, and R is selected from a linear or branched, saturated or unsaturated alkyl group, optionally substituted with at least one hydroxyl, alkoxy or amino group, or having the formula -(WO) m -X, wherein W is a linear or branched alkyl chain containing from 1 to 4 carbon atoms, and

[0046] The-(WO) m - the average molecular weight of the group is between 200 and 3000 g / mol, and X is selected from H and units of formula (II)

[0047] [Chemical formula 6]

[0048]

[0049] Usually, -(WO) mThe average molecular weight of the -group is between 200 and 3000 g / mol, preferably greater than or equal to 300 g / mol, more preferably greater than or equal to 350 g / mol. -(WO) m The average molecular weight of the -group is usually less than or equal to 2000 g / mol, preferably less than or equal to 1500 g / mol. -(WO) m The average molecular weight of the - group may be 400 g / mol or 600 g / mol.

[0050] According to a preferred aspect, step (i) is a step of forming a compound having formula (Ia) according to the following formula:

[0051] [Chemical formula 7]

[0052]

[0053] wherein R is selected from a linear or branched, saturated or unsaturated alkyl group, optionally substituted with at least one hydroxyl, alkoxy or amino group, or having the formula -(WO) m -X, wherein W is a linear or branched alkyl chain containing from 1 to 4 carbon atoms, and the -(WO) m - the average molecular weight of the group is between 200 and 3000 g / mol, and X is selected from H and units of formula (II)

[0054] [Chemical formula 8]

[0055]

[0056] According to another preferred aspect, step (i) is a step of forming a compound having formula (Ib) according to the following formula:

[0057] [Chemical formula 9]

[0058]

[0059] wherein R is selected from a linear or branched, saturated or unsaturated alkyl group, optionally substituted with at least one hydroxyl, alkoxy or amino group, or having the formula -(WO) m -X, wherein W is a linear or branched alkyl chain containing from 1 to 4 carbon atoms, and the -(WO) m - the average molecular weight of the group is between 200 and 3000 g / mol, and X is selected from H and units of formula (II)

[0060] [Chemical formula 10]

[0061]

[0062] According to the present invention, group R is preferably selected from ethyl, n-butyl, n-propyl, isopropyl, isobutyl, optionally substituted by hydroxyl group. Advantageously, group R can be selected from ethyl, n-butyl, OH-CH2-CH2-, OH-CH2-CH(CH3)-. In a variant, group R is selected from the above-mentioned group further comprising-CH2-CH(OH)-CH2-OH.

[0063] According to a preferred aspect, the compound of formula (Ia) is selected from the group consisting of compounds of formulae A to D:

[0064] [Chemical formula 11]

[0065]

[0066] According to a preferred aspect, the compound of formula (Ib) is selected from the group consisting of compounds of formulae E to H:

[0067] [Chemical formula 12]

[0068]

[0069] According to the present invention, step (i) is an etherification or esterification reaction of vanillin alcohol present in composition (C). The etherification or esterification reaction is carried out in the presence of natural vanillin.

[0070] Advantageously, the etherification or esterification reaction is selective for vanillyl alcohol. The etherification or esterification reaction is advantageously carried out without degrading natural vanillin. In particular, less than 10%, preferably less than 5%, more preferably less than 1%, even more preferably less than 0.1% by weight of the natural vanillin present in composition (C) is degraded. The amount of natural vanillin degraded can be calculated according to the following formula: (amount of natural vanillin initially in composition (C) - amount of natural vanillin remaining after step (i)) / (amount of natural vanillin initially in composition (C)).

[0071] According to the present invention, the etherification or esterification reaction is carried out in a reaction mixture selected from the group consisting of ROH, RCOOH and HO-(WO) m -H, wherein R is selected from a linear or branched, saturated or unsaturated alkyl group, optionally substituted with at least one hydroxyl, alkoxy or amino group, and W is a linear or branched alkyl chain containing from 1 to 4 carbon atoms, and the HO-(WO) m The average molecular weight of the -H compounds is between 200 and 3000 g / mol.

[0072] For example, the etherification reaction may comprise contacting the vanillyl alcohol present in composition (C) with a compound having the formula ROH, R being as defined above. In particular, the etherification reaction may comprise contacting the vanillyl alcohol with a compound having the formula RCOOH, R being as defined above.

[0073] Advantageously, the primary alcohol group of vanillyl alcohol is reacted selectively with a compound of formula ROH or RCOOH to form the corresponding ether or ester of formula (I).

[0074] Therefore, the present invention particularly relates to a method for treating a composition (C), wherein a composition C1 is formed, the composition (C) comprising natural vanillin and vanillyl alcohol, the method comprising:

[0075] - step (i) in which composition (C) is contacted with a compound of formula ROH or RCOOH (R having the above definition) to form a compound of formula (I) as defined above and to obtain composition (C1), said composition (C1) comprising a compound of formula (I) and / or natural vanillin, and

[0076] - a step (ii) of recovering and / or purifying the natural vanillin composition and / or the compound of formula (I) present in the composition of formula (I).

[0077] Preferably, the treatment method according to the present invention is a method wherein step (i) is an etherification reaction carried out in the presence of a compound of formula ROH (R is a butyl group), and wherein step (ii) is a step of recovering natural vanillin and / or recovered compound of formula (I) (wherein n=0 and R is a butyl group).

[0078] Usually, HO-(WO) m The average molecular weight of the -H compound is between 200 and 3000 g / mol, preferably greater than or equal to 300 g / mol, more preferably greater than or equal to 350 g / mol. m The average molecular weight of the -H group is usually less than or equal to 2000 g / mol, preferably less than or equal to 1500 g / mol. m The average molecular weight of the -H group may be 400 g / mol or 600 g / mol.

[0079] According to a particular aspect, the etherification or esterification reaction is carried out in the presence of a compound useful in the agro-food industry.

[0080] According to the invention, the reaction is carried out in the presence of an acid. The acid may be a strong acid. Preferably, the acid is selected from the group consisting of HCl, H2SO4, p-toluenesulfonic acid (p-TsOH). The acid may also be a Lewis acid. Advantageously, sulfuric acid makes it possible to avoid the chlorination reaction of vanillin (which can be observed with HCl).

[0081] According to the invention, the reaction can be carried out in the presence of an inorganic compound in solid form and showing acidic properties, such as a zeolite, in particular titanium silicate, silica zeolite or an oxide of silicon, aluminum, titanium or zirconium. In particular, the reaction can be carried out in the presence of a zeolite described in the document Angew. Chem. Int. Ed. [German Applied Chemistry] 2007, 46, 298-300.

[0082] The reaction can also be carried out in the presence of a cation exchange resin, in particular a cation exchange resin of the Amberlite type described in document CN101165038.

[0083] According to another particular aspect, the etherification or esterification reaction can be performed enzymatically.

[0084] According to the invention, the acid is generally used in catalytic amounts. Typically, the amount of acid used is between 0.001 and 0.9 equivalents relative to the amount of vanillyl alcohol present in composition (C).

[0085] According to the invention, the reaction may be carried out at a temperature between 10 and 100°C, preferably between 20 and 80°C, preferably at a temperature lower than or equal to 50°C, and more preferably at a temperature between 25 and 40°C.

[0086] According to the present invention, the reaction is usually carried out under atmospheric pressure.

[0087] According to the invention, at the end of step (i), a composition (C1) is obtained comprising natural vanillin and a compound of formula (I). According to the invention, composition (C1) may also comprise at least one compound chosen from vanillic acid, vanillyl alcohol, acetylvantione, guaiacol and vinylguaiacol.

[0088] Advantageously, composition (C1 ) comprises between 0.1 ppm and 500 ppm of vanillyl alcohol, preferably the composition comprises less than 200 ppm, more preferably less than 100 ppm and even more preferably less than 50 ppm of vanillyl alcohol.

[0089] Advantageously, the weight ratio between vanillyl alcohol and vanillin in composition (C1) is less than or equal to 0.5, preferably less than or equal to 0.2, very preferably less than or equal to 0.1 and even more preferably less than or equal to 0.01.

[0090] According to a particular aspect of the invention, step (i) also enables the formation of a compound of formula (III) according to the following formula from the vanillic acid present in composition (C):

[0091] [Chemical formula 13]

[0092]

[0093] wherein n is equal to 0 or 1, and R is selected from a linear or branched, saturated or unsaturated alkyl group, optionally substituted with at least one hydroxyl, alkoxy or amino group, or having the formula -(WO) m -X, wherein W is a linear or branched alkyl chain containing from 1 to 4 carbon atoms, and

[0094] The-(WO) m - the average molecular weight of the group is between 200 and 3000 g / mol, and X is selected from H and units of formula (IV)

[0095] [Chemical formula 14]

[0096]

[0097] The formation of the compound of formula (III) is carried out in the presence of natural vanillin. The formation of the compound of formula (III) may be carried out simultaneously with the formation of the compound of formula (I).

[0098] According to a particular aspect, at the end of step (i), a composition (C2) is obtained comprising natural vanillin, a compound of formula (I) and / or a compound of formula (III). According to the invention, composition (C2) may also comprise at least one compound chosen from vanillic acid, vanillyl alcohol, acetylvantione, guaiacol and vinylguaiacol.

[0099] Advantageously, composition (C2) comprises between 0.1 ppm and 500 ppm of vanillyl alcohol, preferably the composition comprises less than 200 ppm, more preferably less than 100 ppm and even more preferably less than 50 ppm of vanillyl alcohol. Composition (C2) comprises between 0.1 ppm and 500 ppm of vanillyl alcohol, preferably the composition comprises less than 200 ppm, more preferably less than 100 ppm and even more preferably less than 50 ppm of vanillyl alcohol.

[0100] Advantageously, the weight ratio between vanillyl alcohol and vanillin in composition (C2) is less than or equal to 0.5, preferably less than or equal to 0.2, very preferably less than or equal to 0.1 and even more preferably less than or equal to 0.01.

[0101] Advantageously, the weight ratio between vanillic acid and vanillin in composition (C2) is less than or equal to 0.5, preferably less than or equal to 0.2, very preferably less than or equal to 0.1 and even more preferably less than or equal to 0.01.

[0102] Step (ii):

[0103] According to the present invention, step (ii) is a step of recovering natural vanillin and / or recovering the compound of formula (I) present in composition (C1) or (C2).

[0104] According to the first aspect, step (ii) enables the recovery of natural vanillin. The natural vanillin obtained at the end of step (ii) is purified natural vanillin. In a variant, the natural vanillin obtained at the end of step (ii) is a composition comprising purified natural vanillin.

[0105] According to the invention, the natural vanillin obtained at the end of step (ii) comprises between 0.1 ppm and 500 ppm of vanillyl alcohol, preferably the composition comprises less than 200 ppm, more preferably less than 100 ppm and even more preferably less than 50 ppm of vanillyl alcohol.

[0106] According to the invention, the natural vanillin obtained at the end of step (ii) contains between 0 and 200 ppm of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde or 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde. Preferably, the content of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde or 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde is less than or equal to 100 ppm, preferably less than or equal to 50 ppm and more preferably less than or equal to 20 ppm. Preferably, the content of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde or 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde is greater than or equal to 0.01 ppm and more preferably greater than or equal to 0.1 ppm.

[0107] Advantageously, the treatment process according to the present invention can also increase the overall yield of the treatment process compared to conventional purification processes.

[0108] According to the invention, the process may comprise an additional step (iii) in which the natural vanillin obtained at the end of step (ii) is shaped, in particular in the form of crystals, powder, beads or pearls.

[0109] According to the invention, the natural vanillin titer at the end of step (ii) or (iii) is greater than or equal to 95%, preferably greater than or equal to 97%, very preferably greater than or equal to 99%, even more preferably greater than or equal to 99.5%. Very preferably, the natural vanillin titer at the end of step (ii) or (iii) is greater than or equal to 99.95%.

[0110] According to the invention, the natural vanillin at the end of step (ii) or (iii) is light-colored. Preferably, the natural vanillin at the end of step (ii) or (iii) has a color of less than or equal to 400 Hazen, preferably less than or equal to 200 Hazen, more preferably less than or equal to 100 Hazen, very preferably less than or equal to 50 Hazen and more preferably still less than or equal to 20 Hazen. The color is measured in a 10% by weight ethanol solution. The color measurement is carried out using a Konica Minolta CM-5 spectrophotometer using a cuvette with an optical path length of 10 mm.

[0111] Advantageously, the natural vanillin at the end of step (ii) or (iii) has smooth organoleptic properties, in particular in terms of visual appearance, texture, taste or aroma. Advantageously, the composition according to the invention does not give false indications. Preferably, the organoleptic characteristics of the composition according to the invention are at least equivalent to those of the natural vanillin extracted from the pods.

[0112] According to another aspect, step (ii) enables recovery of the compound of formula (I). According to the invention, the content of natural vanillin in the compound of formula (I) is less than or equal to 200 ppm, preferably less than or equal to 100 ppm. According to the invention, the content of natural vanillin in the compound of formula (I) is greater than or equal to 0.1 ppm.

[0113] According to another aspect, step (ii) enables the recovery of natural vanillin and no recovery of the compound of formula (I). The compound of formula (I) may be degraded during step (ii).

[0114] According to another aspect, step (ii) comprises the recovery of natural vanillin and the recovery of the compound having formula (I). The steps of recovering natural vanillin and the compound having formula (I) may be performed simultaneously or consecutively in any order.

[0115] In particular, step (ii) enables recovery of a compound of formula (I) wherein n=0 and R is a butyl group.

[0116] According to the invention, the purification yield of natural vanillin is greater than or equal to 75%, preferably greater than or equal to 80%, preferably greater than or equal to 90%, even more preferably greater than or equal to 95%, and very preferably greater than or equal to 99%. The purification yield of natural vanillin corresponds to the ratio of the amount of natural vanillin isolated at the end of step (ii) to the amount of natural vanillin in composition (C).

[0117] Step (ii) can be carried out by vacuum distillation, in particular in a falling film evaporator or wiped film evaporator in order to prevent thermal degradation phenomena.

[0118] Step (ii) can be carried out in particular under the conditions described in documents WO 2018 / 146210 or WO 2014 / 114590. In one variant, step (ii) can be carried out according to the conditions described in EP 2 791 098.

[0119] Preferably, when step (i) is carried out in the presence of an acid, the method according to the present invention may include an optional neutralization step at the end of step (i) and before step (ii). In one embodiment, the neutralization step is not optional and / or may be carried out during step (ii). Neutralization may be carried out in the presence of a weak base or a strong base. Preferably, neutralization may be carried out with NaOH, KOH in solid form or in aqueous solution. Alternatively, neutralization may be carried out in the presence of NaHCO3, KHCO3, Na2CO3 in solid form or in aqueous solution.

[0120] Finally, the present invention relates to a method for purifying a composition comprising natural vanillin and vanillyl alcohol by isolating the compound of formula (I).

[0121] The present invention also relates to a process for preparing a compound of formula (I) in the presence of natural vanillin.

[0122] Natural vanillin obtainable by the process according to the invention is also a subject of the present invention.

[0123] The compound of formula (I) obtainable according to the process of the invention is also a subject of the present invention. To this end, the present invention relates to a compound of formula (I) as described above, wherein n=0 and R=butyl and wherein the compound of formula (I) is natural. Advantageously, such a compound is considered natural in legislation, in particular in the United States. The compound of formula (I) as described above (wherein n=0 and R=butyl) can be obtained from a natural compound of formula ROH and natural vanillyl alcohol according to step (i) defined above, R being butyl. At the end of step (i), step (ii) as defined above can be carried out to recover and / or separate the natural compound of formula (I), wherein n=0 and R=butyl.

[0124] The term "natural compound" is understood to mean a compound corresponding to the definition provided for by legislation, which means, for example in the United States, that this compound must be obtained by physical, enzymatic or microbiological processes and exclusively from materials of plant or animal origin.

[0125] The present invention also relates to a composition comprising a compound of formula (I) as described above, wherein n=0 and R=ethyl or butyl, the compound of formula (I) being a natural compound, the composition further comprising less than 200 ppm of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde and / or 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde. For example, the composition comprises between 0 and 200 ppm of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde or 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde. Preferably, the content of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde or 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde is less than or equal to 100 ppm, preferably less than or equal to 50 ppm, and more preferably less than or equal to 20 ppm. Preferably, the content of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde or 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde is greater than or equal to 0.01 ppm, and more preferably greater than or equal to 0.1 ppm.

[0126] Finally, the invention relates to the use of a natural vanillin composition in the field of human and animal nutrition, as a flavoring agent in pharmacy, and as a fragrance in the cosmetic, perfume and detergent industries.

[0127] By reading the following example, the method according to the present invention will be better understood, and this example is a specific embodiment of the method. This example is provided purely for illustration and cannot be interpreted as limiting the present invention. If the disclosure of the patents, patent applications and publications cited by reference herein conflict with the description of the present application to the extent that the terminology may be unclear, this description should be taken as the criterion.

[0128] Examples

[0129] Material

[0130] Ethanol, sulfuric acid, sodium hydroxide solution and also the solvents used for the analysis were from Merck and used without prior purification.High performance liquid chromatography (HPLC) was performed using an Agilent 1260 analytical train with a C18 column.

[0131] After treating the aqueous phase produced by the fermentation of ferulic acid by a microorganism, a composition (C) comprising natural vanillin, vanillyl alcohol and solvent S1 is obtained. The cultivation of the microorganisms was carried out according to the conditions described in EP 0 885 968 and the solvent S1 corresponded to ethyl acetate. Composition (C) was analyzed by HPLC and the results are presented in Table 1.

[0132] In step (i), 349.5 g of composition (C), 21 g of ethanol (ROH) and 0.5 g of 96% H2SO4 were introduced into a reactor. The mixture was stirred at room temperature for 1 hour to form a compound of formula I, wherein R = ethyl, n = 0. A composition (C1) comprising the compound of formula I and natural vanillin was thus obtained and analyzed by HPLC. The results are presented in Table 1.

[0133] Table 1

[0134]

[0135] Composition C1 also contains solvent S1 and "heavy" impurities, ie impurities whose relative volatility is lower than that of natural vanillin under the pressure and temperature conditions considered.The identification of vanillin and vanillyl alcohol is carried out by comparison with commercial standards.

[0136] Thus, thanks to the treatment process according to the invention, vanillyl alcohol is selectively converted into ether. In fact, no loss of vanillin is observed: the content in composition (C) is the same as in composition (C1), and only vanillyl alcohol is converted into ether, namely vanillyl ethyl ether.

[0137] In step (ii), the composition (C1) is concentrated by evaporating part of the solvent S1, thereby obtaining about 270 g of the concentrated composition (C1).

[0138] The concentrated C1 medium is brought to pH 7 with sodium hydroxide solution. The mixture obtained is washed with water. The organic phase is then removed using a rotary evaporator and the residue obtained is purified in a wiped film evaporator to obtain natural vanillin with a titer greater than 99% and a coloration of 19 Hazen.

Claims

1. A method for treating a composition (C) resulting from a method for producing natural vanillin and comprising natural vanillin and vanillyl alcohol, the weight concentration of vanillyl alcohol being between 0.1% and 5%, the method comprising: - step (i) of forming a composition (C1) comprising natural vanillin and a compound having formula (I) from said vanillin alcohol present in composition (C), and said step (i) is an etherification or esterification reaction of said vanillin alcohol present in composition (C), and said etherification or esterification reaction is carried out in the presence of natural vanillin and in the presence of a compound selected from the group consisting of ROH and RCOOH, wherein R is selected from a linear or branched, saturated or unsaturated hydrocarbon group containing 1 to 6 carbon atoms: wherein n is equal to 0 or 1, and R is selected from a linear or branched, saturated or unsaturated hydrocarbon group containing 1 to 6 carbon atoms, - a step (ii) of recovering the natural vanillin and / or recovering the compound of formula (I) present in composition (C1).

2. The processing method according to claim 1, wherein: Step (i) can also form, from the vanillic acid present in composition (C), a compound of formula (III) according to the following formula: wherein n is equal to 0 or 1, and R is selected from a linear or branched, saturated or unsaturated hydrocarbon group containing 1 to 6 carbon atoms.

3. The processing method according to claim 1, wherein: Step (i) is an etherification reaction carried out in the presence of a compound having the formula ROH, R is a butyl group, And wherein step (ii) is a step of recovering natural vanillin and recovering a compound having formula (I) wherein n=0 and R is a butyl group.

4. The processing method according to claim 1, wherein: The natural vanillin obtained at the end of step (ii) contains less than 500 ppm of vanillyl alcohol.

5. The processing method according to claim 1, wherein: The composition of natural vanillin obtained at the end of step (ii) comprises less than 200 ppm of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde or 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde.

6. The treatment process according to claim 1, comprising an additional step (iii) in which the natural vanillin obtained at the end of step (ii) is shaped.

7. The treatment process according to claim 1, comprising an additional step (iii) in which the natural vanillin obtained at the end of step (ii) is shaped in the form of crystals, beads or powder.

8. The treatment process according to claim 1, comprising an additional step (iii) in which the natural vanillin obtained at the end of step (ii) is shaped in the form of pearls.

9. The treatment process according to claim 1, which has a purification yield greater than or equal to 90% relative to the amount of natural vanillin in composition (C).

10. The processing method according to claim 1 or 6, wherein: The vanillin titer in the natural vanillin composition obtained at the end of step (ii) or (iii) is greater than or equal to 95%.

11. The processing method according to claim 1 or 6, wherein: The natural vanillin obtained at the end of step (ii) or (iii) has a color less than or equal to 400 Hazen.

12. The processing method according to claim 1 or 6, wherein: The vanillin titer in the natural vanillin composition obtained at the end of step (ii) or (iii) is greater than or equal to 97%.

13. The processing method according to claim 1 or 6, wherein: The vanillin titer in the natural vanillin composition obtained at the end of step (ii) or (iii) is greater than or equal to 99%.

14. The processing method according to claim 1 or 6, wherein: The vanillin titer in the natural vanillin composition obtained at the end of step (ii) or (iii) is greater than or equal to 99.5%.

15. The processing method according to claim 1 or 6, wherein: The natural vanillin obtained at the end of step (ii) or (iii) has a color less than or equal to 200 Hazen.

16. The processing method according to claim 1 or 6, wherein: The natural vanillin obtained at the end of step (ii) or (iii) has a color less than or equal to 100 Hazen.

17. The processing method according to claim 1 or 6, wherein: The natural vanillin obtained at the end of step (ii) or (iii) has a color less than or equal to 50 Hazen.

18. The processing method according to claim 1 or 6, wherein: The natural vanillin obtained at the end of step (ii) or (iii) has a color less than or equal to 20 Hazen.

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