NATURAL VANILLIN COMPOSITIONS

Abstract

A composition comprising natural vanillin, 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde and 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde, the composition having a natural vanillin titer greater than or equal to 90%.

Description

NATURAL VANILLIN COMPOSITIONS This application claims priority over the patent application filed on July 30, 2019 in France under number 1908643, the content of which is incorporated in full by reference. Field of invention The present invention relates to natural vanillin compositions comprising at least one compound selected from 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde and 4hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde. The invention also relates to a process for obtaining natural vanillin compositions according to the invention. Previous technique Vanillin, or 4-hydroxy-3-methoxybenzaldehyde, can be obtained by several methods known to a person skilled in the art, in particular by the following three routes: A natural route based on a biotechnological process comprising, in particular, the cultivation of a microorganism 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 origins, in particular from rice bran or corn bran. A synthetic route involving conventional chemical reactions starting with guaiacol, without the participation of a microorganism. This process results in the preparation of a vanillin called synthetic vanillin. Finally, vanillin can also be prepared according to a route described as bioderivative in which vanillin is obtained from eugenol or lignin; noteworthy examples include US 2745796, DE 1132113 and the article entitled "Preparation of lignin from wood dust as vanillin source and comparison of different extraction methods" by Azadbakht et al., in the International Journal of Biology and Biotechnology, 2004, Volume 1, No. 4, pp. 535-537. When the natural route is used for the industrial production of vanillin, several side reactions can occur, leading to the formation of numerous byproducts that can affect the organoleptic properties of natural vanillin. The chemical synthesis of one of these byproducts is described in particular in EP 2763947. Consequently, preparing a natural vanillin composition with the desired properties is complex, particularly with regard to color and organoleptic properties. The present invention aims at the controlled and efficient preparation of natural vanillin compositions with a controlled and known content of byproducts. Brief description Therefore, a first object of the present invention relates to a composition comprising natural vanillin and further comprising at least one compound selected from 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde and 4-hydroxy3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde. Another aspect relates to a process for preparing a natural vanillin composition according to the invention, comprising a step (a) of fermenting ferulic acid and optionally a step (b) of purifying the natural vanillin composition obtained at the end of step (a). Finally, the present invention relates to the use of a natural vanillin composition as a flavoring in the field of human food and animal feed, in pharmaceuticals, or as a fragrance in the cosmetics, perfumery and detergent industries. Detailed description In the context of the present invention, unless otherwise stated, the expression between ... and ... includes the limits. Unless otherwise stated, percentages and ppm are percentages and ppm by weight. In the context of the present invention, unless otherwise indicated, the term ppm means parts per million. This unit represents a weight fraction: 1 ppm = 1100 mg / kg. In the context of the present invention, unless otherwise indicated, the term "natural vanillin" may denote a flavoring substance in accordance with Article 9.2(c) of Regulation (EC) No 1334 / 2008, that is, a flavoring substance obtained by physical, enzymatic, or microbiological processes from materials of plant, animal, or microbiological origin, either as in the natural state of the material or after processing for human consumption by one or more of the traditional food preparation processes. A natural flavoring substance corresponds to a substance that is naturally present and has been identified in nature. Definitions provided by regulations in force in other countries or regions may also apply.Preferably, the term "natural vanillin" according to the present invention denotes vanillin obtained by a biotechnological process comprising the cultivation of a microorganism capable of converting a fermentation substrate into vanillin. According to the invention, the microorganism may be genetically intact or genomodified, particularly to enhance vanillin production or to prevent the formation of byproducts. Most preferably, this may be a process for the fermentation of ferulic acid, as described in patent application EP 0 885 968. The ferulic acid may be of any origin, particularly from rice bran, beet pulp, wheat bran, bagasse, sugarcane, or corn, particularly corn bran or corn fibers, particularly from starch mills or nixtamalization units. According to a first aspect, the present invention relates to a composition comprising natural vanillin and further comprising at least one compound selected from 4-((410 hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde and 4-hydroxy3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde. [Chemical formula 1] o , -------í, / )------° ,· '' X ' Ú P-----OH OMr f 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde OMe । OH - CH π XXX CMe 4-hydroxy-3-(4-hydroxy-3-methoxyberzyl)-5-methoxybenzaldehyde According to a particular aspect, the composition of 15 according to the present invention comprises 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde and 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde. According to a preferred aspect, the composition according to the present invention further comprises at least one compound selected from vanillic alcohol, vanillic acid, acetovanillone, guaiacol, and vinylguaiacol. For example, the composition according to the present invention may comprise acetovanillone and / or vinylguaiacol. [Chemical formula 2] HC. HC, .0 4-(hydroxymethyl:-2-methoxyphenol, 4-hydroxy-3-methoxybenzoic acid, or vanillic alcohol, or vanillic acid, or OH 1-(4-hydroxy-3-methoxyphenyl:ethan-1one or acetovanillone OH 2-methoxyphenol or guaiacol 2-methoxy-4-vinylphenol or vinylguaiacol Preferably, the composition according to the present invention may further comprise at least one compound selected from vanillic alcohol, vanillic acid, and acetovanillone. Advantageously, the composition according to the present invention has a natural vanillin content greater than or equal to 90%, preferably greater than 95%, and very preferably greater than or equal to 99%. According to one particular aspect, the natural vanillin content is greater than or equal to 99.5%. According to a preferred aspect, the weight content of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde, relative to the total weight of the composition, is less than or equal to 10,000 ppm, preferably less than or equal to 8,000 ppm, preferably less than or equal to 7,000 ppm, and most preferably less than or equal to 5,000 ppm. According to another preferred aspect, the weight content of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde, relative to the total weight of the composition, is greater than or equal to 10 ppm, preferably greater than or equal to 200 ppm, preferably greater than or equal to 500 ppm, and very preferably greater than or equal to 100 ppm. Advantageously, the weight content of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde, relative to the total weight of the composition, is between 600 ppm and 2500 ppm. According to a preferred aspect, the weight content of 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde, relative to the total weight of the composition, is less than or equal to 5000 ppm, preferably less than or equal to 2500 ppm, preferably less than or equal to 1000 ppm, and most preferably less than or equal to 900 ppm. According to another preferred aspect, the weight content of 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde, relative to the total weight of the composition, is greater than or equal to 10 ppm, preferably greater than or equal to 100 ppm, preferably greater than or equal to 200 ppm, and very preferably greater than or equal to 300 ppm. Advantageously, the weight content of 4-hydroxy-3-(4hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde, relative to the total weight of the composition, is between 400 ppm and 800 ppm. According to the present invention, the weight content of vanillic alcohol, relative to the total weight of the composition, is less than or equal to 4000 ppm, preferably less than or equal to 2000 ppm, very preferably less than or equal to 1000 ppm, preferably less than or equal to 800 ppm, preferably less than or equal to 600 ppm, and very preferably less than or equal to 500 ppm. According to the present invention, the weight content of vanillic alcohol, relative to the total weight of the composition, is greater than or equal to 1 ppm, preferably greater than or equal to 5 ppm, preferably greater than or equal to 10 ppm, and very preferably greater than or equal to 20 ppm. Advantageously, the weight content of vanillic alcohol, relative to the total weight of the composition, is between 50 ppm and 250 ppm. According to the present invention, the weight content of vanillic acid, with respect to the total weight of the composition, is less than or equal to 1000 ppm, preferably less than or equal to 700 ppm, preferably less than or equal to 500 ppm and very preferably less than or equal to 200 ppm. According to the present invention, the weight content of vanillic acid, with respect to the total weight of the composition, is greater than or equal to 1 ppm, preferably greater than or equal to 5 ppm, preferably greater than or equal to 10 ppm and very preferably greater than or equal to 20 ppm. Advantageously, the weight content of vanillic acid, relative to the total weight of the composition, is between 50 ppm and 100 ppm. According to the present invention, the weight content of acetovanillone, relative to the total weight of the composition, is less than or equal to 1000 ppm, preferably less than or equal to 800 ppm, preferably less than or equal to 600 ppm, and very preferably less than or equal to 500 ppm. According to the present invention, the weight content of acetovanillone, relative to the total weight of the composition, is greater than or equal to 0.1 ppm, preferably greater than or equal to 5 ppm, preferably greater than or equal to 10 ppm, and very preferably greater than or equal to 20 ppm. Advantageously, the weight content of acetovanillone, relative to the total weight of the composition, is between 50 ppm and 400 ppm. According to the present invention, the weight content of guaiacol, relative to the total weight of the composition, is less than or equal to 100 ppm, preferably less than or equal to 50 ppm, preferably less than or equal to 40 ppm, and very preferably less than or equal to 20 ppm. According to the present invention, the weight content of guaiacol, relative to the total weight of the composition, is greater than or equal to 0.01 ppm, preferably greater than or equal to 0.1 ppm, preferably greater than or equal to 1 ppm, and very preferably greater than or equal to 10 ppm. According to another alternative of the present invention, the vanillin composition does not comprise guaiacol. According to the present invention, the weight content of vinylguaiacol, relative to the total weight of the composition, is less than or equal to 100 ppm, preferably less than or equal to 50 ppm, preferably less than or equal to 40 ppm, and very preferably less than or equal to 20 ppm. According to the present invention, the weight content of vinylguaiacol, relative to the total weight of the composition, is greater than or equal to 0.01 ppm, preferably greater than or equal to 0.1 ppm, preferably greater than or equal to 1 ppm, and very preferably greater than or equal to 10 ppm. According to another alternative of the present invention, the vanillin composition does not comprise vinylguaiacol; in particular, the vinylguaiacol content is below the detection limits of liquid chromatography methods. Advantageously, the composition according to the present invention is weakly colored. Preferably, the natural vanillin composition has a color 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 even more preferably less than or equal to 20 Hazen. The color is measured in a 10 wt% ethanolic solution. The color measurements are performed using a Konica Minolta CM-5 spectrophotometer with a cuvette having an optical path length of 10 mm. The natural vanillin composition according to the present invention may be in crystalline or amorphous form, preferably crystalline. The natural vanillin composition may be formed as a powder, crystals, beads, nuggets, or flakes. Advantageously, the natural vanillin composition according to the present invention has a conforming organoleptic profile, particularly with regard to its visual appearance, texture, taste, and fragrance. Advantageously, the composition according to the present invention does not exhibit any off-flavors. In particular, the organoleptic profile of the composition according to the present invention is at least equivalent to the organoleptic profile of natural vanillin extracted from the pods. The natural vanillin composition according to the present invention may contain other compounds. These compounds present in said composition are associated with the process for preparing natural vanillin. Particular mention should be made of, but this is not exhaustive, 4(3-hydroxy-4-methoxybenzyl)-2-methoxyphenol, 4,4'-methylenebis(2-methoxyphenol), ferulic acid, and vanillin dimers and / or trimers. Another aspect relates to a process for preparing a natural vanillin composition according to the invention, characterized in that it comprises a step (a) of fermenting ferulic acid and optionally a step (b) of purifying the crude natural vanillin composition obtained at the end of step (a). Step (a): According to the invention, step (a) of the process is a fermentation step of ferulic acid for the production of a crude natural vanillin composition. A crude natural vanillin composition refers to a composition obtained at the end of the ferulic acid fermentation step. Specifically, the crude vanillin composition can be obtained after the treatment of the aqueous fermentation medium. For example, the fermentation medium can be separated from the biomass, and then the aqueous phase can be extracted with a suitable solvent. Thus, the crude natural vanillin composition can be obtained indirectly at the end of the ferulic acid fermentation step. Specifically, during the production of natural vanillin, a liquid composition is typically recovered, comprising natural vanillin, impurities, and a large quantity of solvent, usually a food-grade solvent such as ethyl acetate. Fermentation can be carried out as indicated in document EP 0 885 968. Fermentation is generally carried out in an aqueous medium. Preferably, at the end of step (a) the weight concentration of natural vanillin is between 0.5% and 60%, preferably between 5% and 40% and even more preferably between 10% and 35% relative to the weight of the crude natural vanillin composition. The crude natural vanillin composition used in step (a) may comprise at least one compound selected from 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde and 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde. The crude vanillin composition may further comprise at least one compound selected from vanillic alcohol, vanillic acid, acetovanillone, guaiacol, and vinylguaiacol. Step (b): Step (b) is an optional purification step of the composition obtained at the end of step (a). In one variant, step (b) is not optional. In general, step (b) may comprise a liquid-liquid extraction as described in EP 2 791 098; preferably, the liquid-liquid extraction is carried out using a solvent compatible with food processing applications. Step (b) may also include at least one crystallization step. Alternatively, the purification step may include supercritical CO2 extraction. Finally, according to another alternative, step (b) may comprise a step in which the crude natural vanillin is evaporated as described in EP 2 948 424 or an entrainment separation step as described in WO2018 / 146210. According to a particular aspect of the present invention, step (b) is an evaporation step in a stirred-film evaporator or a falling-film evaporator. Advantageously, this step allows the removal of compounds less volatile than vanillin that are present in the crude natural vanillin composition obtained at the end of step (a). The less volatile compounds are preferably selected from vanillic alcohol, vanillic acid, acetovanillone, and heavy compounds. The term "heavy compounds" refers to compounds that are less volatile than vanillin under the considered temperature and pressure conditions. Among the heavy impurities are vanillin dimers and trimers (i.e., compounds with a main chain containing two or three phenyl groups, respectively) and ferulic acid. This embodiment is particularly advantageous because it makes it possible to purify a crude natural vanillin composition obtained at the end of step (a) and allows the preparation of a natural vanillin composition according to the present invention. The impurity content is particularly well controlled, and the natural vanillin composition is very lightly colored. The process according to the present invention is capable of limiting the content of 4-((4-hydroxy-3-methoxybenzyl)oxy)3-methoxybenzaldehyde and 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde. Furthermore, this embodiment makes it possible to avoid a separation step by entrainment in the presence of a carrier gas and / or a vaporized liquid. Therefore, this process is of interest from an industrial perspective as it is economically viable. The temperature of the heat transfer fluid at which step (b) is carried out is generally greater than or equal to 130°C, preferably greater than or equal to 145°C. In general, the temperature of the heat transfer fluid is less than or equal to 230°C, preferably less than or equal to 180°C. The pressure at which step (b) is carried out is generally greater than or equal to 0.4 mbar, preferably greater than or equal to 1 mbar. In general, the pressure is less than or equal to 75 mbar, preferably less than or equal to 8 mbar, and most preferably less than or equal to 4 mbar. Advantageously, the weight concentration of natural vanillin in the crude natural vanillin composition used in step (b) is greater than or equal to 10%, preferably greater than or equal to 20%, more preferably greater than or equal to 30%, and even more preferably greater than or equal to 50%, and very preferably greater than or equal to 70%, with respect to the total weight of the crude natural vanillin composition. The process may comprise a step of concentrating the crude natural vanillin composition. According to a preferred embodiment, step (b) is carried out in the presence of at least one engineering aid, for example, a flow agent. Therefore, according to a specific embodiment of the present invention, a flow agent authorized by food regulations may be added to natural vanillin. The flow agent may be added before step (b), in particular between step (a) and step (b). According to another embodiment, the flow agent may be added during step (b). The fluidizing agent can be selected from white mineral oils, in particular food-grade white mineral oils, polyethylene glycols, in particular with an average molecular weight of between 200 and 3000 g / mol, preferably between 600 and 1500 g / mol, or castor oil. Preferably, step (b) is carried out in an inert atmosphere, particularly in argon, nitrogen, or mixtures thereof. Step (b) can also be carried out in oxygen-free air. In general, the oxygen content is less than or equal to 1%. The evaporator makes it possible to recover a gaseous effluent containing the evaporated natural vanillin composition, which is then condensed to recover a condensate of the natural vanillin composition according to the invention. Advantageously, the natural vanillin content is greater than or equal to 90%, very preferably greater than 95%, and even more preferably greater than or equal to 99%. According to one particular aspect, the vanillin content is greater than or equal to 99.5%. Advantageously, the natural vanillin condensate obtained at the end of the natural vanillin purification step (b) is lightly colored. Advantageously, the natural vanillin condensate obtained at the end of step (b) is a natural vanillin composition according to the present invention. Advantageously, this natural vanillin condensate, obtained at the end of step (b), has organoleptic properties that are consistent with, and at least equivalent to, those of natural vanillin extracted from pods or synthetic vanillin. According to one particular aspect, the purification step (b) does not include an entrainment separation step. According to one particular aspect, the process of the invention does not include a step of melting the natural vanillin composition before the evaporation step in a falling-film or agitated-film evaporator. According to one particular aspect, the natural vanillin composition does not crystallize between step (a) and step (b). The process may also comprise an optional step (c) of forming the natural vanillin composition obtained at the end of step (b), preferably by crystallization, more preferably by crystallization in a solvent identified by the FEMA GRAS™ program. In a preferred embodiment, the natural vanillin composition is crystallized or recrystallized in water or in a water / alcohol mixture, particularly ethanol. The process according to the invention can be carried out in continuous mode or in discontinuous mode. The invention also relates to a natural vanillin composition that can be obtained according to the process described in the present invention. Finally, the present invention relates to the use of a natural vanillin composition as a flavoring in the field of human food and animal feed, in pharmaceuticals, or as a fragrance in the cosmetics, perfumery and detergent industries. The following examples are intended to illustrate the invention but not to limit it. In the event that the disclosure of patents, patent applications and publications cited herein by way of reference contradicts the description in this application to the point that there is a risk that a term may not be clear, the present description shall prevail. Example Example 1: A crude natural vanillin composition is prepared from a fermentation carried out in accordance with the procedure described in application EP 0 885 968. Apart from the solvent, the crude vanillin composition comprised the compounds in Table 1. [Table 1] Natural vanillin 21% by weight Vanyl alcohol 2.7% by weight Vanillic acid 0.2% by weight Acetovanillone Not measured 4-((4-hydroxy-3-methoxybenzyl)oxy)-3- Not detected methoxybenzaldehyde 4-hydroxy-3-(4-hydroxy-3methoxybenzyl)-5methoxybenzaldehyde Not detected Example 2: A crude natural vanillin composition obtained according to the process of application EP 0 885 968 is subjected to purification by vacuum evaporation in the presence of castor oil, in a stirred film evaporator. Properties of the natural vanillin composition according to the invention: [Table 1] Natural Vanillin 99.7% by weight 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde 1000 ppm 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde 400 ppm Color (Hazen) (10% by weight ethanolic solution) 20 It is hereby stated that, as of this date, the best method known to the applicant for putting the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

1. A composition comprising natural vanillin and further comprising at least one compound selected from 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde and 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5-methoxybenzaldehyde, the composition having a natural vanillin titer greater than or equal to 90%.

2. The composition as claimed in claim 1, further comprising at least one compound selected from vanillic alcohol, vanillic acid, acetovanillone, guaiacol and vinylguaiacol, preferably selected from vanillic alcohol, vanillic acid and acetovanillone.

3. The composition as claimed in claim 1 or 2, wherein the natural vanillin content is greater than 95%, very preferably greater than or equal to 99%, and even more preferably greater than or equal to 99.5%.

4. The composition as claimed in any one of claims 1 to 3, wherein the weight content of 4-((4-hydroxy-3-methoxybenzyl)oxy)-3-methoxybenzaldehyde, relative to the total weight of the composition, is less than or equal to 10,000 ppm and greater than or equal to 10 ppm.

5. The composition as claimed in any one of claims 1 to 4, wherein the weight content of 4-hydroxy-3-(4-hydroxy-3-methoxybenzyl)-5 ML / a / ZUZZ / UU I Ί 00 methoxybenzaldehyde, relative to the total weight of the composition, is less than or equal to 5000 ppm and greater than or equal to 10 ppm.

6. The composition as claimed in any one of claims 1 to 5, characterized by a color 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 even more preferably less than or equal to 20 Hazen.

7. A process for preparing a natural vanillin composition as defined in claims 1 to 6, comprising a step (a) of fermenting ferulic acid and optionally a step (b) of purifying the natural vanillin composition obtained at the end of step (a).

8. The process as claimed in claim 8, wherein step (b) is an evaporation step in a stirred film evaporator or an evaporation step in a falling film evaporator, optionally carried out in the presence of a technical aid.

9. The process as claimed in claim 8, wherein step (b) comprises a liquid / liquid extraction or a supercritical CO2 extraction.

10. The use of a natural vanillin composition as claimed in any one of claims 1100 to 6 as a flavoring in the field of human food and animal feed, in pharmaceuticals, or as a fragrance in the cosmetics, perfumery and detergent industries.