Solid polymer material with porphyrin units for sequestering methionine contained in a liquid and method for synthesizing such a material

Abstract

The invention relates to a solid polymer material resulting from the polycondensation of a monofunctional porphyrin derivative with a monocyclic aromatic crosslinking agent and a likewise monocyclic aromatic compound having an ionizable function, followed by complexation with copper. This polymer material is particularly suitable for use in a method for sequestering methionine and / or cysteine molecules contained in a liquid medium, in particular a liquid food product, for the purpose of preventing the development of light-struck taste therein.

Description

[0001] SOLID POLYMER MATERIAL WITH PORPHYRINE PATTERNS FOR THE SEQUESTRATION OF METHIONINE CONTAINED IN A LIQUID AND METHOD FOR SYNTHESIZING SUCH A MATERIAL The present invention relates mainly to the field of liquid processing, in particular beverages intended for human consumption.

[0002] More particularly, the present invention relates to a solid polymer material particularly suited for use in sequestration of methionine molecules contained in a liquid medium, as well as a method for synthesizing such a material. The invention also relates to a method for sequestration of methionine and / or cysteine ​​molecules contained in a liquid medium, as well as a more general method for treating a liquid food product to reduce the risk of developing a light-flavored taste, and a more general method for detecting the presence of methionine and / or cysteine ​​in a liquid, all of these methods using a solid polymer material according to the invention.

[0003] Wines are consumed worldwide, and particular attention is paid to their quality. It should be noted that in this description, the term "wine" refers to both still and sparkling wines.

[0004] Numerous defects can appear in wines, whether during their production or storage. The most well-known aromatic deviation is cork taint, which manifests itself upon opening the bottle. Another equally detrimental defect, known as "light-struck," can develop after wine is exposed to light. This organoleptic alteration, to which white, rosé, and sparkling wines are particularly susceptible, leads to the formation of very unpleasant tastes and odors such as cooked cabbage, rotten egg, garlic, or wet wool. This defect can also be present in other types of alcoholic beverages, such as spirits and brewed goods, or even in dairy products.

[0005] In wines and other alcoholic beverages, the "light-struck" taste is formed following the photooxidation of sulfur-containing amino acids, produced during alcoholic fermentation, by a specific photosensitizer that occurs naturally: riboflavin. This photosensitizer is capable of absorbing light at wavelengths between 300 and 500 nm, wavelengths present in sunlight and artificial light. When riboflavin absorbs light, a singlet excited state is formed. This state is largely transformed into a triplet state by intersystem crossing, and it can then oxidize, via electron transfer, the sulfur-containing amino acids, particularly methionine. These amino acids are thus degraded into volatile sulfur compounds such as methanethiol, dimethyl disulfide, and dimethyl trisulfide, which are marker compounds of light-struck taste.These sulfur compounds have very low perception thresholds, and concentrations in the micromolar range lead to the formation of a light-flavored taste that is detectable by consumers. The product can develop this defect very quickly. For example, exposing a flute of sparkling wine to summer sunlight for just 15 minutes can be enough to cause light-flavored taste. In terms of taste, the product, particularly white and rosé wines and sparkling wines, develops a pronounced bitterness. In dairy products, light-flavored taste is also primarily formed following the degradation of sulfur-containing amino acids, especially methionine, as a result of its reaction with riboflavin in its triplet form. This reaction leads to the formation of malodorous volatile sulfur compounds such as methanethiol and dimethyl disulfide, which are responsible for the appearance of light-flavored taste.

[0006] Currently, there is no way to remove light-induced flavors without altering the taste profile of the beverage. Contaminated liquids must therefore be discarded, representing a cost loss for the industry. To prevent light-induced flavors in liquid products such as wines and dairy products, it is necessary to keep them constantly protected from light, from production to consumption. In practice, this proves difficult to achieve. In particular, the opaque glass used for packaging wines, especially sparkling wines, either does not have sufficiently good light-filtering properties to effectively prevent light-induced flavors, or is very expensive to produce in an industrial setting. Furthermore, the use of highly opaque packaging, which conceals the product, is detrimental to sales.

[0007] To limit the risk of lightstain in wines, prior art has proposed reducing riboflavin concentration through various oenological approaches, specifically either by limiting its release by yeasts during the winemaking process—for example, by using low-riboflavin strains of Saccharomyces for alcoholic fermentation—or by extracting riboflavin from the wine using various inorganic adsorbents, such as activated carbon (Fracassetti et al., Australian Journal of Grape and Wine Research 23, 329–333, 2017). However, reducing riboflavin concentration in wines also results in a reduction of color. Furthermore, treating wine with adsorbents such as activated carbon can also lead to a decrease in the concentration of other aromatic compounds in the wine, particularly polyphenols.Such treatment would therefore alter the wine's aromatic profile and deteriorate its organoleptic properties. Another strategy to limit the formation of light-struck flavors is to add antioxidants to wines to compete with sulfur-containing amino acids during the photooxidation reaction. These antioxidants can be, for example, oenological tannins. It has been shown that the use of oenological tannins reduces the formation of light-struck flavors in model solutions without increasing bitterness (Fracassetti et al., Food Chemistry, 2023, 404, 134563). Nevertheless, the addition of additives to wines raises concerns about consumer acceptance and potential interactions with other wine components.

[0008] An alternative solution proposed by prior art to prevent the appearance of lightsickness due to the formation of volatile sulfur compounds when liquid products containing sulfur amino acids and riboflavin are exposed to light, consists of extracting from these liquid products, not riboflavin, but methionine, a sulfur amino acid primarily responsible, along with riboflavin, for the formation of these deleterious volatile sulfur compounds. In this context, document WO 2023 / 110915 describes a process for sequestration of methionine contained in a liquid medium, in particular a liquid food product such as wine, dairy products or brewed products.This process uses a solid polymer material comprising copper-containing porphyrin monomer units, which effectively sequesters and removes methionine molecules from liquid media, thus significantly reducing the development of light-flavored taste when these liquid media are subsequently exposed to light within the wavelength range that excites riboflavin. This inhibition of light-flavored taste is further achieved without altering the organoleptic properties of the liquid medium, which is highly advantageous in the context of beverages intended for human consumption. A particularly preferred polymer material described in this document is defined by the structure of an average repeating unit of formula (X):

[0009]

[0010] in which M represents an alkali metal, for example sodium, and n is an integer greater than 2, and preferably less than 1000.

[0011] The present invention falls within the field of solid polymer materials comprising porphyrin-based monomer units containing copper, with the capacity to capture methionine molecules contained in a liquid medium.

[0012] The present inventors have now discovered that such polymeric materials, having a specific chemical formula different from that proposed by the prior art, not only exhibit a high capacity for methionine binding, but can also be synthesized in a particularly simple manner, with improved yield and at a lower cost. Furthermore, when placed in contact with a liquid medium, these polymeric materials do not release any substances incompatible with food contact, nor do they alter the other organoleptic properties of that liquid medium.

[0013] Thus, the present invention aims to provide a simple to synthesize, high-yield, low-cost solid polymer material that efficiently sequesters methionine molecules contained in a liquid medium, so as to constitute an effective solution for protecting food liquids, in particular alcoholic beverages such as wines and dairy products, from the appearance of light taste.

[0014] Additional objectives of the invention are that this material is compatible with food contact, and that it does not alter the sensory profile of the liquid food media with which it is brought into contact.

[0015] These objectives are achieved by a new solid polymer material obtained by random polycondensation of a symmetric porphyrin having phenyl substituents each substituted by a single reactive group, this reactive group being chosen from alcohol, thiol or primary or secondary amine groups, with a crosslinking agent and in the presence of an ionizable compound.

[0016] Thus, according to a first aspect, the present invention proposes a solid polymer material obtainable by a synthesis process comprising the following steps:

[0017] a / preparation of a porphyrin derivative of formula (I):

[0018]

[0019] in which

[0020] - Ri represents a hydrogen atom or a linear or branched alkyl group at C1 to C4, preferably a methyl or ethyl group, and R2 represents an -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group at C1 to C4, preferably a methyl or ethyl group,

[0021] or Ri represents a -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group at C4, preferably a methyl or ethyl group, and R2 represents a hydrogen atom or a linear or branched alkyl group at C4, preferably a methyl or ethyl group,

[0022] - and R3 represents a hydrogen atom or a linear or branched alkyl group in C1 to C4, such as a methyl or ethyl group, R3 preferably representing a hydrogen atom;

[0023] b / polycondensation of said porphyrin derivative of general formula (I) with a compound of general formula (II), which acts in the reaction as a crosslinking agent:

[0024]

[0025] in which:

[0026] - R4 and R7 each represent a carbonitrile group -CN,

[0027] - Rs and Rs, identical or different, each represent a halogen atom, preferably a fluorine atom, a hydrogen atom, or a linear or branched alkyl group at C1 to C4, preferably a methyl or ethyl group, at least one substituent from Rs and Re representing a halogen atom, preferably a fluorine atom,

[0028] - Rs and R9, identical or different, each represent a halogen atom, preferably a fluorine atom, a hydrogen atom, or a linear or branched alkyl group at C1 to C4, preferably a methyl or ethyl group, at least one substituent from Rs and R9 representing a halogen atom, preferably a fluorine atom,

[0029] in the presence of a compound of general formula (III), comprising an ionizable function:

[0030] EJ

[0031] K 14

[0032]

[0033] in which:

[0034] - R10, R11 and R12, identical or different, each represent a hydrogen atom or a group chosen from a sulfonic group or one of its salts, preferably an alkali salt such as sodium, a carboxyl group or one of its salts, preferably an alkali salt such as sodium, an ammonium ion or one of its salts, or a boronic acid group, at least one of R10, R11 and R12 not representing a hydrogen atom, - Ri3 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4, preferably a methyl or ethyl group, and R14 represents an -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group from C1 to C4, preferably a methyl or ethyl group,

[0035] or R13 represents a -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group at C4, preferably a methyl or ethyl group, and R14 represents a hydrogen atom or a linear or branched alkyl group at C4, preferably a methyl or ethyl group,

[0036] so as to form a polymer in which monomer units contain a porphyrin core,

[0037] And

[0038] c / complexation of the porphyrin nuclei of the polymer obtained in step b / with copper.

[0039] In this description, the term "linear or branched C1 to C4 alkyl group" is understood to mean any alkyl group (i.e., of the formula CnH2n+1) comprising 1, 2, 3, or 4 carbon atoms, and whose chain, in the case of a C3 or C4 alkyl group, may be linear or include a branch. Preferably, each linear or branched C1 to C4 alkyl group in the compounds described herein is a methyl or ethyl group.

[0040] In particularly preferred embodiments of the invention, the synthesis process is such that step a / of preparing a porphyrin derivative of formula (I) comprises:

[0041] - a step a1 / of condensation of a compound of general formula (IV):

[0042]

[0043] in which

[0044] - Ri' represents a hydrogen atom or a linear or branched alkyl group at C1 to C4, preferably a methyl or ethyl group, and R2' represents a methoxy group,

[0045] or Ri' represents a methoxy group and R2' represents a hydrogen atom or a linear or branched alkyl group from C1 to C4, preferably a methyl or ethyl group,

[0046] - and R3 represents a hydrogen atom or a linear or branched alkyl group in the C1 to C4 group, in particular a methyl or ethyl group, R3 preferably representing a hydrogen atom,

[0047] with pyrrole, for example in refluxing propanoic acid, so as to form a porphyrin derivative of formula (I'):

[0048]

[0049] in which Ri', R2' and R3 are as defined above,

[0050] - then a step a2 / of hydrolysis of the methoxy groups (Ri' or R2' depending on the configurations) of said porphyrin derivative of formula (I'), for example by treatment with boron tribromide, or a mixture of hydrobromic acid and acetic acid under reflux, in order to obtain a porphyrin derivative of general formula (I) in which:- Ri (then identical to Ri') represents a hydrogen atom or a linear or branched alkyl group from C1 to C4, preferably a methyl or ethyl group, and R2 represents a hydroxyl group -OH,

[0051] where Ri represents a hydroxyl group -OH and R2 (then identical to R2') represents a hydrogen atom or a linear or branched alkyl group from C1 to C4, preferably a methyl or ethyl group,

[0052] - and R3 represents a hydrogen atom or a linear or branched alkyl group in C1 to C4, in particular a methyl or ethyl group, R3 preferably representing a hydrogen atom.

[0053] Preferably, in the general formula (I'):

[0054] - R3 represents a hydrogen atom, and / or

[0055] - Ri' represents a hydrogen atom and R2' represents a methoxy group -OMe, or Ri' represents a methoxy group -OMe and R2' represents a hydrogen atom.

[0056] An example of such a compound is obtained by implementing, in step a1, as a compound of general formula (IV), 4-methoxybenzaldehyde or 3-methoxybenzaldehyde. A porphyrin-derived compound of formula (I') according to the particular invention corresponds to formula (l'a):

[0057] o

[0058]

[0059] (l'a). Thus, preferably, in the general formula (I),

[0060] - R3 represents a hydrogen atom, and / or

[0061] - Ri represents a hydrogen atom and R2 represents an -OH group, or Ri represents an -OH group and R2 represents a hydrogen atom.

[0062] An example of a porphyrin derivative of formula (I) according to the invention corresponds to formula (la):

[0063]

[0064] The solid polymer material according to the invention has a cross-linked structure with random branches. It is advantageously porous, its porosity being linked to its degree of cross-linking, and the latter being easily controlled by controlling the respective proportions of the compounds of formulas (I), (II) and (III) during step b / of polycondensation of the synthesis process.

[0065] Since the solid polymer material according to the invention is of a random type, its exact structure cannot be determined. However, by way of example, for some embodiments of the invention, it is possible to propose the following formula (V) for the structure of an average repeating unit of this polymer: Rs nr

[0066]

[0067] in which:

[0068] - Re and R9, whether identical or different, each represent a halogen atom, preferably a fluorine atom, or a hydrogen atom,

[0069] - and R11 represents a group chosen from a sulfonic group or one of its salts, preferably an alkali salt such as a sodium salt, a carboxyl group or one of its salts, preferably an alkali salt such as a sodium salt, an ammonium ion or one of its salts, or a boronic acid group.

[0070] Preferably, in formula (V), R11 represents a carboxylate ion or one of its salts, in particular an alkali salt and preferably a sodium salt. Thus, in particular embodiments of the invention, the solid polymer material comprises at least one monomer unit of formula (V) as defined above.

[0071] A particular example of such a monomer unit corresponds to the general formula (Va):F

[0072]

[0073] In particular embodiments of the invention, the solid polymer material comprises n repetitions of copper-containing porphyrin monomer unit(s), n being an integer greater than 2, and preferably less than 1000. In particular, the polymer material according to the invention may comprise 2 to 1000 repetitions of monomer units, the average structure of which is illustrated by formula (V) above. For example, it may comprise 2 to 1000 repetitions of monomer units, the average structure of which is illustrated by formula (Va) above.

[0074] The solid polymer material according to the invention can advantageously be prepared very simply, by a synthesis protocol comprising only four steps, namely steps a1 and a2 for the preparation of the porphyrin derivative of formula (I), respectively ensuring the synthesis of the porphyrin core and the hydrolysis of the methoxy substituents; step b for the formation of a polymer whose monomeric units contain a porphyrin core; and step c for the metallation of the porphyrin cores of this polymer with copper. Furthermore, the yield of step a for the preparation of the porphyrin derivative of general formula (I) is particularly high compared to the yields of prior art synthesis reactions of porphyrin derivatives, due to the presence of a single reactive function on the phenyl groups branched to the porphyrin core.As an example, the synthesis of the compound with a symmetrical porphyrin nucleus bearing phenol substituents has a yield 30% higher than that of the synthesis of the equivalent compound in which the porphyrin nucleus bears catechol substituents, as recommended by the prior art.

[0075] Furthermore, the presence of a single reactive function on the phenyl rings of the porphyrin nuclei advantageously improves step a2 / of the synthesis process, as it reduces by half the amount of reagent required for the demethylation of the methoxy groups, compared to prior art compounds with two reactive functions on the phenyl rings. This advantageously results in a reduction in the cost of the reaction. In the case where the reagent used for demethylation is hydrobromic acid (HBr), a highly corrosive compound and therefore complex to handle in large quantities, the process according to the invention proves doubly advantageous, as it also improves the safety of the reaction, thus facilitating the scale-up of the polymer synthesis process.For example, by favouring phenol substituents over catechol substituents, it is possible to halve the amount of HBr to be used, which allows the synthesis to be carried out more safely.

[0076] While simpler, safer, and less expensive to prepare, the polymer material according to the invention is no less effective for methionine capture than porphyrin-based polymer materials such as those proposed in the prior art, particularly those with an average repeating unit of formula (X) mentioned above. The polymer material according to the present invention exhibits good methionine capture capacity, as well as that of sulfur-containing amino acids in general, for example, cysteine, and proves perfectly suited for use in a process for sequestering methionine molecules, and more generally, sulfur-containing amino acids such as cysteine, from a liquid medium. Used in such a sequestration process, the polymer material according to the invention thus constitutes an effective solution for protecting wines, even after production, against the development of light-induced off-flavors.

[0077] Such a capacity for the capture of methionine, and of sulfur-containing amino acids in general, for example cysteine, by the solid polymer material according to the invention is particularly surprising, and nothing would have led those skilled in the art to anticipate it. Indeed, the spacer arms located between the porphyrin rings in the polymer chain, and the side chains attached to these porphyrin rings, are much more flexible than those of polymer materials proposed by the prior art, due to the absence within these spacer arms and side chains of condensed rings (such condensed rings being, for example, visible in formula (X) presented above). Now, it is well known to those skilled in the art that the porosity of a solid material (and therefore its capacity to adsorb compounds) is very sensitive to the rigidity of its subunits.This is demonstrated in particular in the publications of Budd et al., Chemical Communications, 2004, 2, 230, and McKeown et al., Chemical Communications, 2002, 23, 2782-2783. It is clear from these prior art works, and as is well known to those skilled in the art, that the more rigid a polymer is, the higher its adsorptive capacity. High rigidity prevents the polymer from occupying all the surrounding space and therefore leaves a larger free space for adsorbed molecules. In the specific case of porphyrin-based polymer materials according to the present invention, however, this general rule is surprisingly not verified.In particular, methionine binding tests conducted on a polymer material according to the invention, with an average monomer unit represented by the formula (Va) above, and on a prior art polymer material, with an average monomer unit of the formula (X) above, show that, although the polymer material according to the invention exhibits greater flexibility (absence of condensed rings between the porphyrin nuclei), it has a methionine-binding capacity equivalent to that of the prior art polymer material. Nothing in the prior art or in the general knowledge of those skilled in the art could have predicted such equivalence of effectiveness. The solid polymer material according to the invention is even more effective than the prior art polymer materials in protecting sparkling wines and milk from light-induced off-flavors.

[0078] The solid polymer material according to the invention offers further advantages over prior art polymer materials. In particular, its structure can be modulated more easily due to a greater number of substitutable positions on the phenyl rings branched to the porphyrin nuclei in the derivative of general formula (I), as well as on the crosslinking agent (II). This provides more possibilities for modulating the material's physicochemical properties, such as its hydrophilicity or absorption capacity.

[0079] Furthermore, the solid polymer material according to the invention is advantageously compatible with contact with food products and complies with the provisions of European regulations on materials in contact with foodstuffs. It does not release any compounds incompatible with food contact, even when the spacer arms connecting the porphyrin cores, or the side chains carried by these cores, are subjected to hydrolysis.

[0080] Copper, in addition to its strong binding capacity to the sulfur atom of methionine, offers the advantages of being abundant, reasonably priced, and low in toxicity to living organisms. For example, the maximum permitted level of copper in foodstuffs in contact with plastic materials is high, at 5 mg / L. Thus, when the liquid medium is a beverage, and this beverage comes into contact with the polymer material according to the invention, the copper does not generate any toxicity in the beverage, after its separation from the polymer material, that would prevent its subsequent consumption.

[0081] The solid polymer material according to the invention is also insoluble, particularly in aqueous and hydroalcoholic media, so that it is easily separated from any liquid medium containing it by simple filtration. No solid residue of this material, at least in significant quantities, is found in the liquid medium after such filtration, even after a long contact time of the material with the liquid, for example, as long as the aging time of a wine in a barrel.

[0082] In particular embodiments of the invention, the synthesis process is such that, in the general formula (II), Rs, Re, Rs, and R9 each represent a halogen atom, preferably a fluorine atom. The compound of general formula (II) then preferably corresponds to the formula (Ha):

[0083]

[0084] In particular embodiments of the invention, the synthesis process is such that, in the general formula (III), Rio and R12 each represent a hydrogen atom and R11 represents a group selected from a sulfonic group or one of its salts, preferably an alkali salt such as a sodium salt, a carboxyl group or one of its salts, preferably an alkali salt such as a sodium salt, an ammonium ion or one of its salts, or a boronic acid group.

[0085] Furthermore, in the general formula (III), preferably R13 represents a hydrogen atom and R14 represents an -OH group.

[0086] Preferably, in the general formula (III), R10, R12, and R13 each represent a hydrogen atom, R11 represents a carboxyl group or an alkali salt, particularly a sodium carboxylate salt, and R14 represents a hydroxyl group (-OH). The compound with general formula (III) is then 4-hydroxybenzoic acid, with general formula (III), which has, among other advantages, wide commercial availability and low cost:

[0087] M

[0088] C rOO J H (Ilia)

[0089] Each of the steps in the process of synthesizing the solid polymer material according to the invention can be implemented under conventional operating conditions for a person skilled in the art.

[0090] Step a / of preparation of the porphyrin derivative of formula (I) can for example be carried out by step a1 / of condensation of 4-methoxybenzaldehyde with pyrrole, for example in refluxing propanoic acid, to form the first porphyrin derivative of formula (I'). This compound of formula (I') can then be subjected to the step a2 / of demethylation, for example by treatment with bromine tribromide, or a mixture of hydrobromic acid and acetic acid under reflux, in order to obtain a porphyrin derivative of formula (I) in which Ri represents a hydroxyl group -OH and Fb represents a hydrogen atom or a linear or branched alkyl group at C4, preferably a methyl or ethyl group, or Ri represents a hydrogen atom or a linear or branched alkyl group at C4, preferably a methyl or ethyl group, and R2 represents a hydroxyl group -OH.

[0091] Step b / of polycondensation of the porphyrin derivative of formula (I) with the compound of formula (II), in the presence of the compound of formula (III), leading to the formation of a random crosslinked polymer, can, for example, be carried out by combining the different reagents with an excess of base. Preferably, the base is potassium hydroxide (KOH). Thus, in preferred embodiments of the invention, step b / of the synthesis process is carried out in the presence of an excess of potassium hydroxide, for example, at a ratio of 30 molar equivalents relative to the compound of formula (I).

[0092] Furthermore, the synthesis process is preferably such that, in step b / , the molar ratio of the compounds of respective formulas (I), (II) and (III) is between 1 / 3 / 1 and 1 / 3 / 2.

[0093] Step c / of the synthesis process, metallation of the polymer obtained at the end of step b / , can for example be carried out by contacting this polymer with an excess of hydrated copper acetate Cu(OAc)2.

[0094] In particular embodiments of the invention, the solid polymer material according to the invention can be obtained by a synthesis process comprising successive steps of:

[0095] - a1 / condensation of 4-methoxybenzaldehyde, with formula (IVa):

[0096]

[0097] with pyrrole, to form a porphyrin derivative of formula (l'a) as described above;

[0098] - a2 / hydrolysis of the methoxy groups of said porphyrin derivative of formula (l'a) in order to obtain a porphyrin derivative of formula (la):

[0099] HO

[0100]

[0101] - b / polycondensation of said porphyrin derivative of formula (la) with a compound of formula (Ha):

[0102] C IM

[0103]

[0104] in the presence of a compound of formula (Ilia): a

[0105] COO H 01 |Q) ■

[0106]

[0107] so as to form a polymer whose monomer units contain a porphyrin core, and whose average monomer unit can be represented by the formula (Via):

[0108] F

[0109]

[0110] (Via) this polymer preferably comprising 2 to 1000 repetitions of monomer unit(s) whose average structure is illustrated by formula (Via); and c / complexation of the porphyrin cores of the polymer obtained in step b / with copper, to form the solid polymer material according to the invention, the structure of an average monomer unit of which is represented by formula (Va) above.

[0111] Such a polymer material exhibits a particularly strong and selective methionine sequestration capacity. In particular, its methionine association constant is greater than 10 5 M' 1 Its methionine adsorption capacity is estimated at approximately 235 mg / g of polymer material.

[0112] An example of a reaction scheme for obtaining such a crosslinked solid polymer material is shown in Figures 1 and 2, respectively for steps a1 / , a2 / and b / , and for step c / .

[0113] In addition to the general advantages described above, such a solid polymer material can be obtained with high yield and a high degree of purity without the need for one or more costly purification steps involving a chromatographic column. Overall, the synthesis process described above advantageously allows this solid polymer material to be obtained by reducing synthesis costs by 40% compared to porphyrin-core polymer materials proposed in the prior art, from an overall cost of approximately €2.97 / g of material to approximately €1.80 / g of material for the solid polymer material according to the invention. Another aspect of the invention relates to a process for synthesizing a solid polymer material according to the invention. This process comprises the steps of: a / preparing a porphyrin derivative of formula (I):

[0114]

[0115] in which

[0116] - Ri represents a hydrogen atom or a linear or branched alkyl group at C4 and Fb represents an -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group at C4,

[0117] or Ri represents a -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group from C1 to C4, and R2 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4,

[0118] - and R3 represents a hydrogen atom or a linear or branched alkyl group in C1 to C4, in particular a methyl or ethyl group, R3 preferably representing a hydrogen atom;

[0119] b / polycondensation of said porphyrin derivative of general formula (I) with a compound of general formula (II):

[0120]

[0121] - R4 and R7 each represent a carbonitrile group -CN,

[0122] - Rs and Rs, whether identical or different, each represent a halogen atom, a hydrogen atom, or a linear or branched alkyl group from C1 to C4, at least one of Rs and Re representing a halogen atom,

[0123] - Rs and R9, whether identical or different, each represent a halogen atom, a hydrogen atom, or a linear or branched alkyl group from C1 to C4, at least one of Rs and R9 representing a halogen atom,

[0124] in the presence of a compound with general formula (III):

[0125]

[0126] Rl4 (III)

[0127] in which:

[0128] - R10, R11 and R12, whether identical or different, each represent a hydrogen atom or a group chosen from a sulfonic group or one of its salts, a carboxyl group or one of its salts, an ammonium ion or one of its salts, or a boronic acid group, at least one of R10, R11 and R12 not representing a hydrogen atom,

[0129] - R13 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4 and R14 represents an -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group from C1 to C4,

[0130] or R13 represents a -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group from C1 to C4, and R14 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4,

[0131] so as to form a polymer in which monomer units contain a porphyrin core,

[0132] And

[0133] c / complexation of the porphyrin nuclei of the polymer obtained in step b / with copper.

[0134] This synthesis process according to the invention may further meet the definition described above, that is to say, one or more of the characteristics described above, with reference to the solid polymer material according to the invention, with regard to the synthesis process by which it can be obtained. A further object of the invention is a process for sequestering methionine and / or cysteine ​​molecules contained in a liquid medium, comprising contacting this liquid medium with a solid polymer material according to the invention, as defined above.

[0135] The term "liquid medium" here includes yogurts and low-viscosity soft cheeses.

[0136] The contacting of the liquid medium with the solid polymer material can be carried out according to any conventional method in itself for the contacting of a solid with a liquid.

[0137] In particular embodiments of the invention, the contact between the liquid medium and the solid polymer material is achieved by incorporating the material into the liquid medium and maintaining the material in this liquid medium, preferably under agitation, for a contact time sufficient to allow the formation of bonds between the polymer material and the methionine and / or cysteine ​​molecules contained in the liquid medium. This contact time, which may vary depending on the specific application, may in particular be at least 30 minutes. For example, it may be 1 day.In particular embodiments of the invention, the polymer material is introduced into the liquid medium containing methionine and / or cysteine, or likely to contain methionine and / or cysteine, at a dose that depends on the amount of methionine and / or cysteine ​​to be sequestered, and which may, for example, be between 0.01 and 50 g / l, in particular between 0.1 and 10 g / l, and especially between 0.2 and 2 g / l. By way of example, when the liquid medium is sparkling wine, particularly during production and in the alcoholic fermentation phase, and the compound to be sequestered is methionine, the dose of polymer material introduced into the liquid medium may be approximately 0.2 g / l, or more.

[0138] The contact between the liquid medium and the polymer material is preferably carried out under agitation.

[0139] The process according to the invention preferably includes, after a contact time sufficient to allow the trapping of methionine and / or cysteine ​​molecules by the polymer material, a step of separating the liquid medium and the polymer material sequestering the methionine and / or cysteine.

[0140] This separation step can be carried out by any solid-liquid separation method known to those skilled in the art, for example, filtration, decantation, disgorging during the secondary fermentation of sparkling wines, etc. After separation from the liquid medium, the polymer material can advantageously be regenerated for subsequent reuse. Thus, to this end, the process according to the invention may include a final step of separating the methionine and / or cysteine ​​molecules from the polymer material.

[0141] Such a step may, for example, consist of treating the polymer material with an alkaline washing solution, for example at pH 10, optionally assisted by ultrasonication. After separating the solid polymer material from the washing solution and rinsing with water, a regenerated polymer material is obtained, again exhibiting a high adsorption capacity for methionine and / or cysteine. Alternatively, this step may consist of washing the polymer material with an acidic solution (hydrochloric acid HCl, for example) to demetallize the polymer in order to desorb the methionine and / or cysteine, followed by treatment with a copper solution (copper acetate, for example) to remetallize the polymer material, thus enabling its regeneration. The polymer material according to the invention can advantageously be recycled at least five times without significant loss of its methionine and / or cysteine ​​uptake capacity.

[0142] The process of sequestration of methionine and / or cysteine ​​molecules contained in a liquid medium has applications in many fields.

[0143] One application for which it proves particularly suitable is the treatment of food liquids, especially those intended for human consumption, in order to prevent the appearance of light taste in these liquids following their exposure to light, the compound to be sequestered being specifically methionine.

[0144] Thus, one aspect of the invention relates to a method for treating a liquid food product, in particular a beverage intended for human consumption, in order to reduce, or even completely eliminate, the occurrence of light-flavored taste. This method comprises implementing, on this liquid food product, a process for sequestering methionine molecules contained in a liquid medium according to the invention, for the sequestration of methionine molecules likely to be contained in this liquid food product, the contact of the liquid food product with the polymer material being carried out for at least 30 minutes, preferably at least 1 day, in particular for a contact time of between 2 hours and 36 months, for example between 1 day and 36 months, and being followed by a step of separating the polymer material, sequestering the methionine, from the liquid food product.

[0145] The liquid food product is preferably chosen from wines, especially white and rosé wines, as well as sparkling wines, brandies, dairy products such as milk and its liquid derivatives, brewed products such as beers and ciders, and any other liquid food containing methionine and likely to contain riboflavin, in which a light taste could appear.

[0146] As explained above, the inventors have discovered that removing methionine molecules from such liquid products using the solid polymer material according to the invention makes it easy and effective to prevent the formation of volatile sulfur compounds responsible for the appearance of light-flavored taste, without detectably altering the product's organoleptic profile. Furthermore, the solid polymer material according to the invention advantageously exhibits high selectivity for methionine, such that, when the liquid medium is a beverage, the adsorption of compounds contributing to the beverage's properties, and in particular its sensory profile, by the polymer material is very limited.

[0147] In the context of such a treatment application for beverages to prevent the development of light-induced off-flavors, the contact time between the liquid food product and the polymer material can range from one day to several months. For example, it can be approximately 18 months for sparkling wines.

[0148] Advantageously, in the case of wines aged on lees and rosé wines, the polymer material can be introduced directly into the aging barrel and maintained there throughout the alcoholic fermentation process. In the case of sparkling wines, contact with the polymer material can be made during the secondary fermentation, also in the barrel, and maintained throughout this stage. The inventors have notably observed that the polymer material according to the invention, and in particular the specific polymer materials described above, can be left in contact with food liquids, and especially alcoholic solutions, for periods as long as several months, for example, 18 to 24 months, without degrading or releasing undesirable residues into the product that cannot be easily separated.

[0149] The method for sequestering methionine molecules from a liquid medium according to the invention can also be implemented in liquid media containing methionine, in order to remove the latter, for example, for consumption by individuals who are allergic to it. The method for sequestering methionine molecules from a liquid medium can also be applied in any field where it may be necessary to detect the presence of methionine in a liquid, or even to quantify the methionine content of a liquid. The same applies to cysteine.

[0150] Thus, one aspect of the invention relates to a method for detecting the presence of methionine and / or cysteine ​​in a liquid, which comprises:

[0151] - the implementation, on a sample of this liquid, of a process for sequestration of methionine and / or cysteine ​​molecules contained in a liquid medium according to the invention, the contact of the liquid sample with the polymer material being carried out for at least 30 minutes, in particular between 30 minutes and 1 day, and being followed by a step of separation of the polymer material, sequestering where appropriate methionine and / or cysteine, and of the liquid sample,

[0152] - then the analysis of the polymer material thus separated for the presence of methionine and / or cysteine.

[0153] The analysis of the polymer material for the presence of methionine and / or cysteine ​​can be carried out by any method known to those skilled in the art. In the case of methionine, for example, it can be performed by suspending the polymer in a solution of methionine in D2O. After stirring for 12 hours, the polymer material is isolated from the medium, notably as described above, for example by filtration, and the filtrate is analyzed by infrared spectroscopy or proton magnetic nuclear resonance (NMR) spectroscopy. 1 H), to detect the possible presence of signals representative of methionine, for example respectively at 2.15 ppm, 2.65 ppm and 3.85 ppm under conditions of 300 MHz, D2O and 298 K.

[0154] Optionally, the analysis of the polymer material for the presence of methionine and / or cysteine ​​may include the quantification of the methionine and / or cysteine ​​contained in that polymer material.

[0155] EXAMPLES

[0156] The features and advantages of the invention will become clearer in light of the following implementation examples, provided by way of illustration only and in no way limiting the invention, with the support of Figures 1 to 4, in which:

[0157] Figure 1 represents an example of a reaction scheme for the first steps a1 / , a2 / and b / of the synthesis of a polymer material according to the invention.

[0158] Figure 2 represents an example of a reaction scheme for the last step c / of the synthesis of a polymer material according to the invention.

[0159] Figure 3 shows a graph of the total concentration of methanethiol (MeSH), dimethyl disulfide (DMDS), and dimethyl trisulfide (DMTS) in samples of white wine ("Wine") and sparkling Champagne ("Champagne") respectively, that were irradiated (12 min at 250 W / m²). 2 ) after being exposed to a polymer material according to the invention (“PC”) at 0.2 g / l for 1 week, or not (“Control”) - the dotted line represents the perception threshold by a panel of experts of a light taste in irradiated samples of this type of sparkling wine.

[0160] Figure 4 shows a graph of the total concentration of methanethiol (MeSH), dimethyl disulfide (DMDS), and dimethyl trisulfide (DMTS) in samples of different beverages (sparkling wines, white wines, rosé wines, spirits, and skimmed milk) that were irradiated (12 min at 250 W / m²).2 ) after being exposed to either a polymer material according to the invention (“PC”) at 0.2 g / L for 1 week, or a polymer material not according to the invention (“CS”) at 0.2 g / L for 1 week, or no polymer material (“Control”).

[0161] A / Synthesis of polymer materials

[0162] A.1Z Polymer material according to the invention

[0163] A polymer material according to the invention, named PC, whose structure is schematically represented by the formula (Vila):

[0164]

[0165] — (Vila) in which n is an integer between 3 and 999,

[0166] is prepared in 4 steps according to the reaction scheme shown in figures 1 and 2, as follows.

[0167] A.1.a / Step a1 - Porphyrin formation

[0168] Tetra-(5,10,15,20-(4-methoxyphenyl))porphyrin, with formula (l'a):

[0169] O

[0170]

[0171] is prepared according to the following protocol.

[0172] One equivalent of 4-methoxybenzaldehyde (129 mmol; 15.7 mL) is dissolved in 300 mL of propanoic acid. Then, 7 mL of nitrobenzene is added to the solution. One equivalent of freshly distilled pyrrole (130 mmol; 9 mL) is added dropwise. The mixture is stirred at 130°C for 1.5 hours. The solution is cooled to room temperature and left to stir overnight in the dark. Next, 400 mL of methanol is added to the mixture. The solution is stirred for 4 hours at room temperature. The suspension is cooled in an ice bath and filtered under vacuum to obtain a purple solid. This solid is resuspended in 100 mL of methanol and stirred for 2 hours. The suspension is cooled in an ice bath and filtered under vacuum to obtain a purple solid.The solid is washed several times with cold methanol, then dried under vacuum to obtain the porphyrin derivative (l'a), in the form of a purple solid, with sufficient purity (9.83 g; 41%) ([C44H30N4O4], molar mass: 678.75 g. mol. -1 ).

[0173] 1 H NMR (300 MHz, 298 K, CDCI3): 58.86 (s, 8H, Ha), 8.14 - 8.11 (m, 8H, Hb and Hc), 7.29 (d, 4H, J = 9 Hz Hd), 4.10 (s, 12H, He), -2.75 (s, 2H, Ht)

[0174] 13 C NMR J-MOD (CDCI3): 5 159.9, 135.7, 134.6, 119.8, 112.4, 58.8, 55.9, 18.6 A.1.b / Step a2 - Hydrolysis

[0175] The porphyrin derivative of formula (l'a) is hydrolyzed according to the following operating procedure, to form tetra-(5,10,15,20-(4-hydroxyphenyl))porphyrin, of formula (la):

[0176] OH

[0177]

[0178] One equivalent of tetra-(5,10,15,20-(4-methoxyphenyl))porphyrin (I-a) (5 g; 6.8 mmol) is dissolved in glacial acetic acid (58 mL) and 48% hydrogen bromide (H₂Br) (32 mL). The green solution is stirred for 3 days at 110°C. Then, 10 mL of a saturated Na₂CO₃ solution is added. The solution is cooled in an ice bath, and solid Na₂CO₃ is added to largely neutralize the acids (until the vigorous reaction decreases). 20 mL of the solution is transferred to a separatory funnel. Then, 200 mL of a saturated NaHCO₃ solution is added to completely neutralize the acids. The aqueous phase is extracted with ethyl acetate (2 × 300 mL). The organic phases are combined, washed with water (300 mL) and brine (300 mL) and dried with MgSCk (these steps are repeated until all the crude reaction material has been treated).The solvent is evaporated to obtain a dark purple solid of sufficient purity (3.86 g; 84%) ([C44H30N4O4]; molar mass: 678.75 g. mol. -1 ).

[0179] 1 H NMR (300 MHz, 298 K, acetone D6): 58.92 (s, 7H, Ha), 8.87 (s, 3H, Ht), 8.07 (dd, 8H, J = 9 Hz, 2 Hz, H b and H c ), 7.31 (dd, 8H, J = 9 Hz, 2 Hz, He and H d ), -2.69 (s, 2H, H g )

[0180] A.1.c / Step b - polymerization of hydrolyzed porphyrin

[0181] From tetra-(5,10,15,20-(4-hydroxyphenyl)) porphyrin of formula (la), a polymer is formed, whose structure is schematically represented by the formula (Villa):

[0182]

[0183] in which n is an integer between 3 and 999.

[0184] One equivalent of tetra-(5,10,15,20-(4-hydroxyphenyl))porphyrin (3 g; 4.42 mmols), one equivalent of 4-hydroxybenzoic acid (611 mg; 4.42 mmols), and 30 equivalents of potassium hydroxide (KOH) (7.44 g; 132.6 mmols) are combined in a round-bottom flask under an inert atmosphere (nitrogen) and equipped with an air condenser. 60 mL of anhydrous DMF are added to the flask. The dark solution is heated to 80°C with stirring. After a few minutes at 80°C, three equivalents of 2,3,5,6-tetrafluoroterephthalonitrile (2.65 g; 13.26 mmols) in 30 mL of anhydrous DMF are added by slow dropwise (10–20 min). The solution is stirred for 3 days at 80°C.

[0185] Once cooled to room temperature, the suspension is diluted in 200 mL of water and then filtered under reduced pressure or centrifuged (30 min, 3900 rpm) to recover the solid. The material is rinsed successively with water and acetone to give a purplish solid. The solid is oven-dried. Once dry, the solid is ground into a powder using a mortar. The powder is again rinsed successively with a 1 M HCl solution, a saturated NaHCO3 solution, water, and acetone, and then oven-dried under reduced pressure to give a purple powder (4.37 g; 69%) ([C84H42F6NiO10]n, molar mass: 1435.24 g / mol -1 ).

[0186] A.1.d / Step c - copper metallization

[0187] The porphyrin-based polymer with the schematic structure represented by formula (Villa) (3.6 g; 2.32 mmols) is suspended in 50 mL of water in the presence of 5 equivalents of copper acetate (2.32 g; 11.6 mmols). The suspension is vigorously stirred for 1 day at 50°C. The polymer is recovered by vacuum filtration and then washed several times with water and acetone. The resulting resin is oven-dried to obtain the final copper-coated polymer material PC (3.7 g; 98%), which has a dark purple appearance ([C84H4oF6NiOiOCu]). n molar mass: 1496.77 g / mol -1 ).

[0188] A.2 / Comparative polymer material

[0189] A polymer material not conforming to the invention, named CS, whose structure is schematically represented by the formula (Xa):

[0190]

[0191] in which n is an integer between 3 and 999,

[0192] is prepared according to the protocol described in document WO 2023 / 110915 (PR1 crosslinked polymer).

[0193] B / Suitability for food contact

[0194] The food contact suitability test consists of suspending the PC polymer material according to the invention, at 150 mg / L, in a simulating liquid which is an aqueous solution comprising 20% ​​v / v ethanol and 3% v / v acetic acid (standard conditions for materials in contact with alcoholic beverages between 6° and 20°). The suspension is agitated for 10 days at 60°C. The polymer is then removed, and the presence of contaminants in the simulating liquid, released by the polymer (migration), is quantified by liquid chromatography coupled with mass spectrometry (LC-MS).

[0195] The results obtained for the different compounds likely to be released by the polymer material are shown in Table 1. This table also indicates, for each of these compounds, the maximum limit allowed by Regulation (EC) No 1935 / 2004 of the European Parliament and of the Council of 27 October 2004 on materials and articles intended to come into contact with food and Commission Regulation (EU) No 10 / 2011 of 14 January 2011 on plastic materials and articles intended to come into contact with food.

[0196] Compounds Observed Migration Maximum Permissible Migration (mg / kg) (mg / kg) 5, 10, 15, 20- Tetrakis (4- < 0.01 0.01

[0197] hydroxyphenyl)-21 H,23H

[0198] porphyrin

[0199] Tetrafluoroterephthalonitrile < 0.0075 0.01

[0200] Copper 1.5 5

[0201] 4-Hydroxybenzoic acid 0.018 60

[0202]

[0203] Table 1 - Migration of the different compounds of the PC polymer material to the simulator liquid

[0204] For each of the compounds that could be released by the PC polymer according to the invention, the observed migration is well below the maximum permitted limit. The PC polymer material therefore complies with European Union food contact standards.

[0205] C / Methionine binding test

[0206] The ability of the PC polymer material according to the invention to absorb methionine was evaluated by proton nuclear magnetic resonance (NMR) spectroscopy. 1 H.

[0207] A 2 mM solution of methionine in D2O was analyzed by NMR 1H. Then, 0.25 equivalents of polymer material were added to the suspension, which was left overnight under agitation. After one night, the suspension was again analyzed by NMR. 1 H. The spectra were superimposed using the residual water peak as an internal standard, and the decay of methionine signals was measured. A decay of methionine signals indicates that the polymer material is capable of capturing methionine in solution. In the case of the PC material, a 53% reduction in signals was observed.

[0208] It is also possible to measure the ability of the polymer material to capture methionine in solution by UV-visible spectroscopy. A 1 mM solution of methionine coupled to a UV-visible group, such as coumarin or fluorenyl methoxycarbonyl (Fmoc), is prepared in absolute ethanol. 2.5 mL of acidic water at pH 3 (HCl) and 0.5 mL of the methionine solution are added to a UV cuvette. The absorbance of this solution is measured by UV-visible spectrometry (at 324 nm for coumarin, 300 nm for Fmoc). Then, 0.458 mg of the polymer material is suspended in the cuvette. The suspension is stirred for 1 day. After settling, a new absorbance measurement is taken to determine the remaining free methionine concentration. It is then possible to estimate the capture capacity of the polymer material.With the PC polymer material according to the invention, a reduction in the free concentration of methionine of 58% is observed, in the case of Fmoc-methionine.

[0209] DI Protection of beverages - elimination of volatile sulfur compounds D.1Z Treatment of sparkling wine and white wine

[0210] The ability of the PC polymer material to reduce the formation of volatile sulfur compounds under light irradiation was tested on a sparkling wine meeting the controlled designation of origin Champagne and on a basic white wine.

[0211] Samples of these wines were exposed to the PC polymer at a concentration of 0.2 g / L for one week. Samples without the polymer were also prepared as controls.

[0212] After a week of stirring, the suspensions were filtered, and then the filtrates were irradiated using the Qsun-1000 solar simulator for 12 min at 250 W / m²2 The solutions obtained were analyzed by solid-phase microextraction coupled with gas chromatography with pulsed flame photometry detection (SPME-GC-PFPD) in "splitless" mode, to determine the concentrations of volatile sulfur compounds which are the markers of the following light tastes: methanethiol (MeSH), dimethyl disulfide (DMDS) and dimethyl trisulfide (DMTS).

[0213] Furthermore, previously, a panel of experts established, on a range of sparkling wines with controlled designation of origin Champagne, irradiated at different times, a threshold for the perception of light tastes equal to 1.7 pg / L.

[0214] The results obtained are shown in Figure 3. The perception threshold of a light taste by the panel of experts is illustrated by a dotted line on the figure.

[0215] It is observed that the reduction in volatile sulfur compounds responsible for lightsickness is 62% in the base wine and 67% in the sparkling wine. In the case of sparkling Champagne, the use of the polymer material limits the appearance of lightsickness to below the sensory threshold established by experts. This demonstrates that the PC polymer material according to the invention is capable of complexing methionine in still white wines and sparkling wines such as those bearing the Champagne appellation d'origine contrôlée (AOC).

[0216] D.2 / Processing of various beverages

[0217] The ability of the PC polymer material to reduce the formation of volatile sulfur compounds under light irradiation was tested on various drinks: - sparkling wines: Crémant d'Alsace, Crémant de Bordeaux, Prosecco; - white wines produced from different grape varieties: Pinot Gris, Sauvignon, Gewurztraminer, Bourgogne Aligoté;

[0218] - rosé wines: rosé wine from Bordeaux, rosé wine from Provence;

[0219] - wine-based spirits: Cognac brandy, Armagnac brandy; - skimmed milk.

[0220] The wines were selected for their resemblance to sparkling Champagne wine and / or for their floral aromatic profile, which reflects a complex matrix.

[0221] For comparison, the prior art CS polymer material, which is not in accordance with the invention, was also tested.

[0222] Samples of these beverages were exposed to either the PC polymer or the CS polymer at a concentration of 0.2 g / L for one week. Samples without the polymer were also prepared as controls.

[0223] After a week of stirring, the suspensions were filtered, and then the filtrates were irradiated using the Qsun-1000 solar simulator for 12 min at 250 W / m² 2 The solutions obtained were analyzed by SPME-GC-PFPD in "splitless" mode to determine the concentrations of MeSH, DMDS and DMTS.

[0224] The results obtained are shown in Figure 4. It can be observed that, overall, both polymers reduce the production of volatile sulfur compounds under light irradiation by 50 to 80%, with their overall effectiveness being similar. The PC polymer material is thus capable of capturing methionine in a wide range of beverages susceptible to the development of light-induced off-flavors, thereby protecting them from this defect. This capacity applies to various types of alcoholic beverages, as well as to milk, for which the PC polymer material has a more pronounced effect than the CS polymer material of the prior art. The PC polymer material according to the invention thus constitutes an advantageous solution for protecting milk from the formation of light-induced off-flavors.

Claims

38 DEMANDS 1. A solid polymer material obtainable by a synthesis process comprising the steps of: a / preparation of a porphyrin derivative of formula (I): R if) in which - Ri represents a hydrogen atom or a linear or branched alkyl group from C1 to C4 and R2 represents an -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group from C1 to C4, or Ri represents a -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group from C1 to C4, and R2 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4, - and R3 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4; b / polycondensation of said porphyrin derivative of general formula (I) with a compound of general formula (II): 39 in which: - R4 and R7 each represent a carbonitrile group -CN, - Rs and Re, whether identical or different, each represent a halogen atom, a hydrogen atom, or a linear or branched alkyl group from C1 to C4, at least one of Rs and Re representing a halogen atom, - Rs and R9, whether identical or different, each represent a halogen atom, a hydrogen atom, or a linear or branched alkyl group from C1 to C4, at least one of Rs and R9 representing a halogen atom, in the presence of a compound with general formula (III): in which: - R10, R11 and R12, whether identical or different, each represent a hydrogen atom or a group chosen from a sulfonic group or one of its salts, a carboxyl group or one of its salts, an ammonium ion or one of its salts, or a boronic acid group, at least one of R10, R11 and R12 not representing a hydrogen atom, - R13 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4 and R14 represents an -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group from C1 to C4, or R13 represents a -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group at C4, and R14 represents a hydrogen atom or a linear or branched alkyl group at C4,40 c / complexation of the porphyrin nuclei of the polymer obtained in step b / with copper.

2. Solid polymer material according to claim 1, said synthesis process being such that, in the general formula (I), - Ri represents a hydrogen atom and R2 represents an -OH group, or Ri represents an -OH group and R2 represents a hydrogen atom. - and R3 represents a hydrogen atom.

3. Solid polymer material according to claim 1 or 2, said synthesis process being such that step a / of preparation of a porphyrin derivative of formula (I) comprises: - a step a1 / of condensation of a compound of general formula (IV): (IV) in which - Ri' represents a hydrogen atom or a linear or branched alkyl group from C1 to C4 and R2' represents a methoxy group, where Ri' represents a methoxy group and R2' represents a hydrogen atom or a linear or branched alkyl group from C1 to C4, - and R3 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4, with pyrrole, so as to form a porphyrin derivative of formula (I'): in which Ri, R2' and R3 are as defined above, - then a step a2 / of hydrolysis of the methoxy groups of said porphyrin derivative of formula (I') in order to obtain a porphyrin derivative of general formula (I) in which: - Ri represents a hydrogen atom or a linear or branched alkyl group from C1 to C4 and R2 represents an -OH group, where Ri represents an -OH group and R2 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4, - and R3 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4.

4. Solid polymer material according to any one of claims 1 to 3, said synthesis process being such that, in the general formula (II), Rs, Re, Rs and R9 each represent a halogen atom, preferably a fluorine atom.

5. Solid polymer material according to any one of claims 1 to 4, said synthesis process being such that, in the general formula (III), R10 and R12 each represent a hydrogen atom and R11 represents a group selected from a sulfonic group or one of its salts, a carboxyl group or one of its salts, an ammonium ion or one of its salts, or a boronic acid group.

6. Solid polymer material according to any one of claims 1 to 5, said synthesis process being such that, in the general formula (III), R13 represents a hydrogen atom and R14 represents an -OH group.

7. Solid polymer material according to any one of claims 1 to 6, said synthesis process being such that the compound of general formula (III) is 4-hydroxybenzoic acid.

8. Solid polymer material according to any one of claims 1 to 7, said synthesis process being such that step b / is carried out in the presence of an excess of potassium hydroxide.

9. Solid polymer material according to any one of claims 1 to 8, said synthesis process being such that, in step b / , the molar ratio of the compounds of respective formulas (I), (II) and (III) is between 1 / 3 / 1 and 1 / 3 / 2.

10. Solid polymeric material according to any one of claims 1 to 8, comprising at least one monomer unit of formula (V): in which - Re and R9, whether identical or different, each represent a halogen atom or a hydrogen atom, - R11 represents a group chosen from a sulfonic group or one of its 43 salts, a carboxyl group or one of its salts, an ammonium ion or one of its salts, or a boronic acid group.

11. Solid polymer material according to claim 10, comprising at least one monomer unit of formula (Va): F (Go).

12. A process for synthesizing a solid polymer material according to any one of claims 1 to 11, comprising the steps of: a / preparation of a porphyrin derivative of formula (I): 44 in which - Ri represents a hydrogen atom or a linear or branched alkyl group from C1 to C4 and R2 represents an -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group from C1 to C4, or Ri represents a -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group from C1 to C4, and R2 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4, - and R3 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4; b / polycondensation of said porphyrin derivative of general formula (I) with a compound of general formula (II): in which: - R4 and R7 each represent a carbonitrile group -CN, - Rs and Rs, whether identical or different, each represent a halogen atom, a hydrogen atom, or a linear or branched alkyl group from C1 to C4, at least one of Rs and Re representing a halogen atom, - Rs and R9, whether identical or different, each represent a halogen atom, a hydrogen atom, or a linear or branched alkyl group from C1 to C4, at least one of Rs and R9 representing a halogen atom, in the presence of a compound with general formula (III): in which: 45 - Rio, Ru and R12, whether identical or different, each represent a hydrogen atom or a group chosen from a sulfonic group or one of its salts, a carboxyl group or one of its salts, an ammonium ion or one of its salts, or a boronic acid group, at least one of Rio, R11 and R12 not representing a hydrogen atom, - R13 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4 and R14 represents an -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group from C1 to C4, or R13 represents a -OH, -SH, -NH2 or -NHR group where R represents a linear or branched alkyl group from C1 to C4, and R14 represents a hydrogen atom or a linear or branched alkyl group from C1 to C4, And c / complexation of the porphyrin nuclei of the polymer obtained in step b / with copper.

13. Synthesis process according to claim 12, meeting the definition of the synthesis process described in any one of claims 2 to 9.

14. A method for sequestration of methionine and / or cysteine ​​molecules contained in a liquid medium, comprising bringing said liquid medium into contact with a solid polymer material according to any one of claims 1 to 11.

15. Sequestration method according to claim 14, wherein said solid polymer material is introduced into said liquid medium at a dose of between 0.01 and 50 g / l.

16. Sequestration method according to claim 14 or 15, comprising a step of separating said liquid medium and the polymer material sequestering methionine and / or cysteine.

17. Sequestration method according to any one of claims 14 to 16, comprising a final step of separating the methionine and / or cysteine ​​molecules from said polymer material.

18. A process for treating a liquid food product to reduce the occurrence of light taste, characterized in that it comprises implementing on said liquid food product a process for sequestration of methionine molecules contained in a liquid medium according to one of46 any of claims 14 to 17, the contact of said liquid food product with the polymer material being carried out for at least 30 minutes, and being followed by a step of separating said polymer material and said liquid food product.

19. A process for treating a liquid food product according to claim 18, wherein said liquid food product is selected from wines, spirits, dairy products and brewery products.

20. A method for detecting the presence of methionine and / or cysteine ​​in a liquid, characterized in that it comprises: - the implementation, on a sample of said liquid, of a process for sequestration of methionine and / or cysteine ​​molecules contained in a liquid medium according to any one of claims 14 to 17, the contact of said liquid sample with the polymer material being carried out for at least 30 minutes, and being followed by a step of separation of said polymer material and said liquid sample, - then the analysis of said polymer material for the presence of methionine and / or cysteine.

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