METHOD FOR TREATING WINE TO IMPROVE ITS COLLOIDAL STABILITY AND PREPARATION FOR SUCH TREATMENT

Abstract

The invention relates to a method for treating a wine in order to improve its colloidal stability, in particular with respect to the coloring matter. This method comprises the incorporation of gum ghatti into the wine during its production. A preparation particularly suitable for carrying out such a treatment contains gum ghatti mixed with sulfur dioxide in an aqueous solution.

Description

Title of the invention: METHOD FOR TREATING A WINE WITH A VIEW TO IMPROVING ITS COLLOIDAL STABILITY AND PREPARATION FOR SUCH TREATMENT

[0001] The present invention relates to the field of wine production, particularly red or rosé wines.

[0002] More particularly, the present invention relates to a method for treating a wine in order to improve its colloidal stability, forming part of a more global process for producing said wine. The invention also relates to a preparation based on gum ghatti intended for such treatment, as well as the use of gum ghatti or such a preparation for treating a wine in order to improve its colloidal stability. The invention also relates to a kit for such treatment.

[0003] Wines are a complex mixture of molecules that constantly evolve during aging and are the origin of their organoleptic properties. Among these properties, the color as well as the absence of sediment in the bottles are guarantees of quality required by consumers. Wines, in particular red or rosé wines, must thus retain their color and remain clear not only at the time of bottling, but also during their storage / aging, until their consumption. To this end, it is necessary to treat them in order to improve their colloidal stability, and more particularly to prevent or limit the precipitation / crystallization of the mineral matter, in particular cations and tartaric acid, and of the coloring matter, mainly polyphenols, contained therein.Various technological treatments have been proposed by the prior art for this purpose, these treatments ranging from physical processes to the addition of additives, including the use of technological aids, such as fining products, and being implemented at the end of the winemaking process, at a stage close to the final bottling stage.

[0004] The supplementation of wines with additives contributes to their organoleptic properties by meeting several technical-functional objectives such as the colloidal stabilization of the mineral matter and the coloring matter, the modification of the sensory properties and the improvement of the antioxidant properties.

[0005] Tartaric stabilization of wines before bottling is carried out in order to prevent the precipitation of tartaric acid salts. Prevention of this instability is achieved in particular by the addition of additives such as carboxymethylcellulose, man-noproteins, potassium polyaspartate or metatartaric acid. However, the use of molecules such as carboxymethylcellulose or polyaspartate Potassium can be accompanied by constraints because they can interact with the coloring matter contained in the wine, which induces a reduction in their effectiveness with regard to mineral instability phenomena.

[0006] The stabilization of the coloring matter of red or rosé wines before bottling is ensured in particular by the addition of proteoglycans such as mannoproteins or arabinogalactan proteins (AGPs) from Acacia senegal gum (Ribéreau-Gayon et al., Handbook of Enology, Volume 2: The Chemistry of Wine-Stabilization and Treatments. 2006, John Wiley & Sons). The use of mannoproteins can however be accompanied by possible undesirable effects such as the risk of increased turbidity of the wine in the event of an overdose. In addition, their cost of use is relatively high. Acacia senegal gum is an effective natural additive against these phenomena of instability of the coloring matter (Nigen et al., Food Hydrocolloids, 2019: 105176).However, at the doses used, typically between 10 and 30 g / hl, it can cause filtration problems, and more particularly cause clogging of the filtration membranes.

[0007] In a global perspective of limitation and reduction of additives in the field of oenology, the objectives of the wine industry are currently to reduce the use of additives in wines, by their number and / or their quantity, as well as to promote the use of additives of natural origin while preserving the organoleptic and sensory qualities of the wines.

[0008] The present invention aims to fall within this framework, and to propose an additive for the treatment of wines, in particular red or rosé wines, preferably at the end of the aging stage in the winemaking process, or at the end of the alcoholic fermentation stage for wines whose production does not include an aging stage. The invention aims for this additive to have functional properties making it possible to effectively improve, at low doses, the colloidal stability of these wines, in particular concerning the coloring matter, while being of natural origin and meeting the sensory and technical requirements required for the production of wines. In particular, objectives of the invention are that this additive does not penalize the filterability of the treated wine, and that it does not modify its sensory properties.

[0009] Additional objectives of the invention are that this additive is easy to use, low cost, and of course that it meets the safety requirements in force in the field of food additives.

[0010] To this end, the present inventors were interested in natural biopolymers derived from plant exudates. They discovered that such a specific biopolymer, gum ghatti, incorporated into a red or rosé wine, particularly at the end of aging, has a protective effect which particularly effectively opposes the precipitation of coloring matter particles, and makes it possible to maintain good colloidal stability. of the coloring matter of this wine, durable over time, so that no cloudiness is observed in the wine during its storage, including at low temperatures. Such a result is advantageously obtained at very low doses which do not significantly modify either the sensory qualities of the wine or its filterability characteristics in the presence of sulfur dioxide. Gum ghatti used at such doses does not cause clogging of the filters during the filtration of the wine in which it is incorporated, which makes it possible to meet the constraints linked to winemaking processes, such as the need to carry out a wine filtration step before bottling.

[0011] Thus, according to a first aspect, the present invention relates to a method for treating a wine, in particular a red or rosé wine, with a view to improving its colloidal stability, in particular with respect to the coloring matter contained therein. This method comprises the incorporation of gum ghatti into the wine during its production.

[0012] In the present description, the term wine is understood to mean both wines in themselves, including special wines such as sparkling wines, and beverages based on wine or derived from wine, such as, the references indicated in parentheses being those of the International Code of Oenological Practices of the International Organization of Vine and Wine, 2022 edition: beverages based on wine products (288 / 2010), wine-based beverages (288 / 2010), aromatized wines (OIV-ECO-395-2011), beverages obtained by dealcoholization of wine (OIV-ECO 432-2012) and beverages obtained by partial dealcoholization of wine (OIV-ECO 433-2012).

[0013] The invention proves to be particularly advantageous for the treatment of red or rosé wines as well as beverages based on such wines or derived from such wines.

[0014] Gum ghatti is an amorphous, translucent exudate of the tree Anogeissus latifolia of the family Combretaceae, native to India and Sri Lanka. It is exuded as rounded tears less than 1 cm in diameter, or as larger worm-like masses. It is an acidic heteropolysaccharide rich in arabinose and galactose and containing a protein moiety, occurring in nature as a mixed salt of calcium, magnesium, potassium, and sodium. The primary structure of this gum is composed of sugars such as L-arabinose, D-galactose, D-mannose, D-xylose, and D-glucuronic acid (Kang, J., et al., Food hydrocolloids, 2011. 25(8): 1984-1990). Gum ghatti is used for its emulsifying properties in oil-in-water emulsions in various fields, particularly in certain beverages such as sodas.

[0015] Surprisingly, it has been discovered by the present inventors that gum ghatti, compared to gum arabic, has colloidal stabilization properties of the coloring matter of wines at much lower doses, notably 10 to 20 times lower depending on the wine. At these doses, its negative impact on the filterability of wines is low, despite the fact that the intrinsic viscosity of gum ghatti is approximately three times higher than that of gum arabic at the same concentration. Nothing in the prior art suggested such performance of gum ghatti used as an additive in wines, particularly red or rosé wines.

[0016] Furthermore, gum ghatti also shows efficacy at much lower doses than gum arabic and other gums of natural origin on the mineral stabilization of calcium chloride in the framework of the test of the international oenological codex OENO 27 / 2000, sheet COEI-l-GOMARA.

[0017] Preferably, the gum ghatti is used as is. In particular, it is not impregnated with any substance, in particular not impregnated with a protein, for example a protein that is substantially insoluble in water.

[0018] The method according to the invention may furthermore meet one or more of the characteristics described below, implemented in isolation or in each of their technically effective combinations.

[0019] In particular embodiments of the invention, the gum ghatti is incorporated into the red wine at a concentration of between 0.05 g / hl and 5 g / hl. Such a concentration range proves to be optimal both in terms of stabilization of the coloring matter of the wine, and of the filterability of the latter containing the gum ghatti. The concentration of gum ghatti introduced into the wine is preferably between 0.25 and 5 g / hl, more preferably between 0.25 and 4 g / hl, preferably between 0.25 and 2.5 g / hl, more preferably between 0.5 and 2.5 g / hl, and even more preferably between 1 and 2.5 g / hl. Such concentration ranges present the best compromises between effectiveness of stabilization of the coloring matter of the wines and filterability of the treated wine.

[0020] In particular embodiments of the invention, the incorporation of gum ghatti into the wine is carried out, in a wine-making process, after an alcoholic fermentation step and before a bottling step. When the wine-making process includes a final filtration step prior to this bottling, the incorporation of gum ghatti into the wine can be carried out after this final filtration step. Preferably, it is carried out before this final filtration step, preferably as late as possible before this step. Furthermore, preferably, when the wine-making process includes an aging step, the incorporation of gum ghatti into the wine is carried out during this aging step, preferably at the end of this aging step, or just after this aging step.

[0021] When the product to be treated is a wine-based or wine-derived beverage, such as defined above, the incorporation of gum ghatti is preferably carried out just before bottling this drink.

[0022] Gum ghatti can be used in raw form, if necessary after grinding to form a more homogeneous powder. Preferably, it is used in atomized form, thus having in particular the advantage of better homogeneity of the material and better control of its quality. The atomized gum can be obtained by a process comprising a first phase of solubilization of the raw gum in water, then several stages of purification of the composition obtained, in particular by vibrating sieving and centrifugation, aimed at removing insoluble foreign particles, before stages of spraying and drying, for example in a conventional atomization tower, to obtain particles of the desired size, for example between 50 and 200 μm.

[0023] The method according to the invention may further comprise the introduction into the wine of any conventional oenological additive in itself, in particular a tartaric acid crystallization inhibitor, such as carboxymethylcellulose or potassium polyaspartate, or any other tartaric acid crystallization inhibitor known to those skilled in the art and compatible with use for human consumption. Such an inhibitor may be introduced into the wine before, after, or substantially simultaneously with the incorporation of gum ghatti therein. Such a combination of gum ghatti and a tartaric acid crystallization inhibitor advantageously ensures particularly high colloidal stability of the treated wine.In particular, the combination of gum ghatti with carboxymethylcellulose and / or potassium polyaspartate reduces the interactions of the latter with the coloring matter contained in red wine, and increases their effectiveness with regard to the stabilization of mineral matter, more particularly tartaric acid.

[0024] The tartaric acid crystallization inhibitor can, for example, be introduced into the wine at a concentration of between 0.5 and 20 g / hl.

[0025] Gum ghatti can be introduced into the wine in the form of solid particles. Preferably, it is incorporated into the wine in the form of a composition containing it in a form dissolved in water. Its concentration in this composition is then between 0.5 and 5% by weight, preferably between 0.5 and 2% by weight, relative to the volume of the composition.

[0026] In particularly preferred embodiments of the invention, in particular from the point of view of the filterability of the treated wine, the incorporation of gum ghatti into the wine is carried out by introducing, into the wine, a preparation containing gum ghatti mixed with sulfur dioxide in an aqueous solution.

[0027] Sulphur dioxide is conventionally used for the sulphiting of musts and wines in order to ensure stabilisation against microbial proliferation, protection against oxidation, and more generally better preservation. Quite surprisingly, it was discovered by the present inventors that the association of sulfur dioxide with gum ghatti, prior to the incorporation of the latter into the wine to be treated, not only does not impact the effects of the gum on the stability of the coloring matter of the wine, but greatly improves the filterability characteristics of the latter.

[0028] Sulphur dioxide may in particular be introduced into the preparation in the form of a sulphurous solution, i.e. an aqueous solution of sulphur dioxide. This sulphurous solution may be obtained by any conventional means in itself, in particular by bubbling gaseous sulphur dioxide into an aqueous solution at acidic pH, for example at pH 1, or by solubilising potassium metabisulphite and gaseous sulphur dioxide in an acidic aqueous solution, for example at pH 4.75. For example, the sulphurous solution may be concentrated to 6 to 10% w / v in sulphur dioxide.

[0029] In particular embodiments of the invention, the preparation introduced into the wine contains 0.5 to 5%, preferably 0.5 to 2%, by weight of gum ghatti relative to the volume of the preparation. It also preferably contains 0.5 to 4 g / L, preferably 0.5 to 2 g / l, of sulfur dioxide.

[0030] The quantity of such a preparation introduced into the wine to be treated is preferably chosen, as a function of its gum ghatti content, to incorporate into the wine a concentration of this gum of between 0.05 and 5 g / hl, preferably between 0.25 and 5 g / hl, more preferably between 0.25 and 4 g / hl, preferentially between 0.25 and 2.5 g / hl, more preferably between 0.5 and 2.5 g / hl, and even more preferably between 1 and 2.5 g / hl.

[0031] In particular embodiments of the invention, the preparation containing gum ghatti and sulfur dioxide is introduced into the wine at a dose of between 1 and 1000 ml / hl, preferably between 2.5 and 500 ml / hl, more preferably between 2.5 and 250 ml / hl, and preferentially between 2.5 and 100 ml / hl.

[0032] Another aspect of the invention relates to a preparation for the treatment of a wine, in particular a red or rosé wine, in particular for the colloidal stabilization, in particular of the coloring matter, of this wine. This preparation contains gum ghatti mixed with sulfur dioxide in an aqueous solution.

[0033] This preparation may meet one or more of the characteristics described above in relation to the method according to the invention, with regard to the preparation which may be implemented therein.

[0034] In particular, it may contain 0.5 to 5%, preferably 0.5 to 2%, by weight of gum ghatti relative to the volume of said preparation.

[0035] It may also contain 0.5 to 4 g / l, in particular 0.5 to 2 g / l, of sulfur dioxide.

[0036] It may also contain any other substance commonly used for the treatment of wines, for example a tartaric acid crystallization inhibitor such as carboxymethylcellulose or potassium polyaspartate.

[0037] The preparation according to the invention may have a dynamic viscosity at 25°C, depending on its gum ghatti content and its sulfur dioxide content, of between approximately 1 and approximately 11 mPa.s. This viscosity is notably much lower than that of aqueous compositions based on gum ghatti alone, free of sulfur dioxide, at equal gum concentrations.

[0038] A method for producing the preparation according to the invention may use, as ingredients: - gum ghatti in raw form, where appropriate ground to reduce the size of the nodules, or in atomized form, in particular to a particle size of between 50 and 200 pm; - and / or gaseous sulfur dioxide and / or an aqueous sulfurous solution, containing for example 6 to 10% v / v of sulfur dioxide, this solution being able for example to have been obtained by bubbling gaseous sulfur dioxide into an aqueous solution at acid pH, or by solubilization of potassium metabisulfite and gaseous sulfur dioxide in an acidic aqueous solution; - as well as, where appropriate, one or more oenological additives known in themselves for the treatment of wine, such as a tartaric acid crystallization inhibitor.

[0039] After mixing these ingredients in water, the preparation can be kept stirring in a closed bottle for several hours, preferably at room temperature, in order to promote complete solubilization of the gum. The preparation can then be filtered, for example on a filter with a porosity of 0.65 μm, in order to remove insoluble particles.

[0040] Another aspect of the invention relates to the use of gum ghatti or a preparation according to the invention, containing gum ghatti, for the treatment of a wine, in particular a red or rosé wine, in particular at the end of its production process. This treatment aims in particular to improve the colloidal stability, in particular the stability of the coloring matter, of said wine.

[0041] The use according to the invention preferably comprises the incorporation of gum ghatti or the preparation according to the invention into the wine to be treated, preferably during the production of the latter, preferably just before its bottling or a possible final filtration step prior to this bottling.

[0042] The use of gum ghatti or a preparation according to the invention for the treatment of a wine according to the invention may meet one or more of the characteristics described above with reference to the method of treating a wine according to the invention, in all their possible combinations, in particular concerning the moment, during the wine-making process, at which the gum ghatti or the preparation according to the invention are incorporated into the wine.

[0043] In particular, the dose incorporated into the wine to be treated may be comprised: - for gum ghatti, between 0.05 and 5 g / hl, preferably between 0.25 and 5 g / hl, more preferably between 0.25 and 4 g / hl, preferentially between 0.25 and 2.5 g / hl, more preferably between 0.5 and 2.5 g / hl, and more preferably still between 1 and 2.5 g / hl: - for the preparation according to the invention, between 1 and 1000 ml / hl, preferably between 2.5 and 500 ml / hl, more preferably between 2.5 and 250 ml / hl, and preferentially between 2.5 and 100 ml / hl.

[0044] Another aspect of the invention relates to a kit for treating a wine, in particular a red or rosé wine, with a view to improving its colloidal stability, in particular the stability of the coloring matter. This kit comprises: - gum ghatti in solid form, in particular in raw form, where appropriate ground, or in atomized form, - an aqueous solution of sulfur dioxide, in particular concentrated at 6 to 10% w / v in sulfur dioxide, - and instructions for producing a preparation according to the invention, in particular according to the production method described above. This kit can also contain any other classic oenological additive in itself, to be integrated into this preparation or to be incorporated into the wine to be treated before, after or substantially simultaneously with the preparation.

[0045] It may further contain instructions for implementing a wine treatment method according to the invention using the preparation formed. The characteristics and advantages of the invention will appear more clearly in the light of the following examples of implementation, provided for purely illustrative purposes and in no way limiting the invention, with the support of figures 1 to 10, in which:

[0046] [Fig.l] [Fig.l] shows a graph representing, for different rubbers (Ghatti, A.senegal, Mesquite, Huizache) in a model hydroalcoholic solution containing tartaric acid, as a function of the gum concentration in this solution, the ratio R corresponding to: the absolute value of the difference in optical densities measured by spectrophotometry at 880 nm, at the time (To) of the introduction of calcium chloride into the solution without gum then 24 h (T24) after the introduction of calcium chloride into the solution with added gum, divided by the difference in optical densities measured at the time of the introduction of calcium chloride into the solution then 24 h later, obtained for a solution without gum.

[0047] [Fig.2] [Fig.2] shows a graph representing, for different erasers (Ghatti, A. senegal, Combretum, Karaya) in a model hydroalcoholic solution containing tartaric acid, depending on the gum concentration in this solution, the Turbiscan stability index (TSI) determined after 24 h at 25 °C after the addition of calcium chloride in the solution.

[0048] [Fig.3] [Fig.3] shows a graph representing, for different erasers (Ghatti, A. senegal) in a model hydroalcoholic solution containing polyphenols, depending on the gum concentration in this solution, the stability index determined by Turbiscan (TSI) after 48 h of incubation at 10 °C.

[0049] [Fig.4] [Fig.4] shows a graph representing the percentage reduction of the instability of the coloring matter contained in a model hydroalcoholic solution treated with a gum, compared to the untreated model solution, after 48 h at 4 °C, as a function of the concentration of gum having been incorporated into this model solution, for a ghatti gum (2971 / 2) and for an A. senegal gum (OF192191).

[0050] [Fig.5] [Fig.5] shows a graph representing the percentage reduction of the instability of the coloring matter contained in a red wine (“Monségur”) treated with a gum, compared to the untreated wine, after 48 h at 4°C, depending on the concentration of gum having been incorporated into this wine, for ghatti gums (2971 / 2 and BR2971 / 1) and for A. senegal gums (OF192191 and BR180246).

[0051] [Fig.6] [Fig.6] shows a graph representing the percentage reduction of the instability of the coloring matter contained in a red wine treated with a gum-based preparation into which a 6% sulfur dioxide solution has been introduced, compared to this untreated wine, determined after 48 hours of treatment at 4°C, as a function of the sulfur dioxide concentration in the preparation, for a ghatti gum (3008 / 2) and for an A. senegal gum (OF202510).

[0052] [Fig.7] [Fig.7] shows a graph representing the percentage reduction of the instability of the coloring matter contained in a red wine treated with a gum-based preparation into which a 10% sulfur dioxide solution has been introduced, compared to this untreated wine, determined after 48 hours of treatment at 4°C, as a function of the sulfur dioxide concentration in the preparation, for a ghatti gum (3008 / 2) and for an A. senegal gum (OF202510).

[0053] [Fig.8] [Fig.8] shows a graph representing the difference in turbidity (ANTU) between a red wine R17 treated for 48 h at 4 °C with a preparation formed from gum and a 6% sulfur dioxide solution, and this untreated wine, as a function of the concentration of gum introduced into the wine, for a ghatti gum (3008 / 2) and for an A. senegal gum (OF202510).

[0054] [Fig.9] [Fig.9] shows a graph representing the difference in turbidity (ANTU) between a red wine R9 treated for 48 hours at 4°C with a preparation formed from gum and a 6% sulfur dioxide solution, and this untreated wine, depending on the concentration of gum introduced into the wine, for a ghatti gum (3008 / 2) and for an A. senegal gum (OF202510).

[0055] [Fig. 10] [Fig. 10] shows a graph representing the difference in turbidity (ANTU) between a red wine R12 treated for 48 h at 4 °C with a preparation formed from gum and a 6% sulfur dioxide solution, and this untreated wine, as a function of the concentration of gum introduced into the wine, for a ghatti gum (3008 / 2) and for an A. senegal gum (OF202510).

[0056] Samples of the following gums were used for the experiments: - raw gum ghatti, in the form of nodules: “Ghatti BR2971 / 1”, - pre-atomized ghatti gum, with a particle size between 50 and 200 pm, from a first production batch: “Ghatti 2971 / 2”, - pre-atomized ghatti gum, with a particle size between 50 and 200 pm, from a second production batch: “Ghatti 3008 / 2”, - raw Acacia senegal gum, in the form of nodules: “A. senegal BR180246” - pre-atomized Acacia senegal gum, with a particle size between 50 and 200 pm, from a first production batch: “A. senegal OF192191”, - pre-atomized Acacia senegal gum, with a particle size between 50 and 200 pm, from a second production batch: “A. senegal OF202510”, - pre-pulverized Karaya gum, with particle size between 50 and 200 pm: “Karaya OF 180064”, - Combretum gum, in the form of nodules: “Combretum”, - Mesquite gum, in the form of nodules: “Mesquite”, - Huizache gum, in the form of nodules: “Huizache”.

[0057] The gums in the form of nodules were obtained by grinding the raw gum using a Retsch SM 300 knife mill. The conditions used for this purpose were as follows: a speed of 1500 rpm for 10 s and grid #4. The objective of this step is to obtain a powder in order to make the sample more homogeneous.

[0058] The gums in atomized form were obtained by solubilization in water, then purification by vibrating sieving and centrifugation of the composition obtained, and spraying and drying in a conventional atomization tower, under conditions allowing the desired particle size to be obtained.

[0059] For the experiments on the kinetics of stabilization of the mineral fraction on the one hand, and of the coloring matter on the other hand, the gums were solubilized under stirring for 16 h at room temperature in milli-Q water (resistivity 18.2 mQ) at a concentration of 20 gl '. After solubilization, the samples were centrifuged at 12,000 rpm for 10 min at 20 °C, then analyzed. A / Stabilization of the mineral fraction

[0060] This experiment was carried out on the gums Ghatti 2971 / 2, A. senegal OF192191, Combretum, Huizache, Mesquite and Karaya OF180064.

[0061] The effect of the different gums on the colloidal stability of the mineral matter was evaluated on a model mineral hydroalcoholic solution at pH 3.1 (oenological codex test, HAM) with the composition indicated in Table 1:

[0062] [Tables 1] Component Quantity Water Milli-Q 432 ml Tartaric Acid 1.50 g Potassium Sulfate 0.50 g NaOH 1 M 5.5 ml Ethanol 96% 60 ml Potassium Hexacyanoferrate 30 mg Iron Solution (Standard Iron for ASA) 2.5 ml

[0063] Table 1 - Composition of the HAM model solution

[0064] The pH of the solution is 3.1. The solution was filtered with filters having a cut-off threshold of 0.45 pm (GE Healthcare Life Sciences) before use. The hydroalcoholic solution was prepared prior to each measurement.

[0065] The instability of the mineral fraction within the hydroalcoholic solution was generated by the addition of a 22 g / l calcium chloride (CaCl2) solution. The addition of calcium leads to complexation between the hexacyanoferrate, iron and calcium compounds, then the precipitation of the complexes formed. This mineral hydroalcoholic solution therefore constitutes a good model for studying the influence of the addition of gums on the prevention of this mineral instability.

[0066] The gums were solubilized as described above.

[0067] For the gum samples Ghatti 2971 / 2, A. senegal OF192191, Combretum, and Karaya OF180064, stability kinetics were monitored by near-infrared light transmittance measurements (X = 880 nm) through the sample with a Turbiscan Tower device (Formulaction), for different gum concentrations (range between 0 and 1 g / l). For this purpose, the samples were prepared to contain: 30 ml of HAM solution, 1 ml of CaCl 2 solution (final concentration 0.67 g / l) and 0 to 1 g / l of gum.

[0068] Stability measurements were performed at 25°C in the dark. Transmittance scans were acquired over a period of 24 h.

[0069] The data were analyzed and processed with TowerSoft-1.0.1.27 software (Formulation). The transmittance scans acquired during the measurements can be analyzed by calculating the Turbiscan Stability Index (TSI) according to the equation below:

[0070] [Math.l] TSI 22 (^) ~ H

[0071] in which H is the height (zone defined by the experimenter) of the sample analyzed and h is the variation in transmittance or backscattering at each measurement point over the entire height H of the sample.

[0072] The TSI calculation is done directly from the raw data. The TSI corresponds to the sum of the transmittance variations over the height H of the sample (the entire sample or area defined by the experimenter) between the scan; and the scan, h The higher the calculated TSI value, the more pronounced the destabilization process within the sample. Calculating the TSI over time therefore provides access to destabilization kinetics.

[0073] For the samples of Ghatti 2971 / 2, A. senegal OF192191, Huizache and Mesquite gum, the stability kinetics were established by spectrophotometry, for different gum concentrations (range between 0 and 1 g / l). The samples were prepared for this purpose to contain: 1.82 ml of HAM solution, 0.06 ml of CaCl2 solution (final concentration 0.67 g / l) and 0 to 1 g / l of gum.

[0074] The optical density (OD) was measured just after the addition of the CaCl2 solution. This measurement corresponds to time 0 (To). The cuvettes were left to incubate in an oven at 25°C for 24 h in the dark and then the optical density was measured again to determine the OD at 24 h (T24). The reading was taken at 880 nm using an Ultrospec 2000 UV / VIS spectrophotometer (Pharmacia Biotech). The absolute value of the differences in optical densities (Tg^eia gum-free solution-T24 of each sample), divided by the (To-T24) of the cuvette without gum (hereinafter referred to as the R ratio), was plotted as a function of the gum concentration.

[0075] The results obtained are shown in [Fig.l], for the spectrophotometric analysis, and in [Fig.2], for the Turbiscan analysis at a temperature of 25°C. It is observed that gum ghatti is much more effective than the other gums for the stabilization of the mineral matter of the model solution.

[0076] The critical concentration (CC), corresponding to the minimum concentration of use of the gum necessary for the stabilization of the mineral fraction of the model solution, is determined for each of the gums tested. The results obtained are indicated in Table 2 (the same critical concentrations are obtained for the ghatti and Acacia senegal gums regardless of the method of measure used):

[0077] [Tables2] Gum Critical concentration (g / hl) A. senegal OF192191 9.0 ± 0.003 Ghatti 2971 / 2 0.2 ± 0.0005 Mesquite 4.0 ± 0.0007 Huizache 5.0 + 0.01 Karaya OF 180064 20.0 + 0.36 Combretum 210.0 + 0.07

[0078] Table 2 - Critical concentrations of gums for the stabilization of mineral matter in HAM solution

[0079] The critical concentration of gum ghatti (0.2 g / hl) is particularly low. To stabilize the model solution, 40 times less gum ghatti than A. senegal gum is required. B / Stabilization of coloring matter

[0080] These experiments were carried out for the gums ghatti 2971 / 2, and A. senegal OF192191.

[0081] B. 1 / Stabilization of polyphenols

[0082] The effect of gums on the colloidal stability of the coloring matter was evaluated on a model hydroalcoholic solution containing polyphenols (PAH), prepared from the hydroalcoholic solution of composition indicated in Table 3:

[0083] [Tables3] Component Quantity Water Milli-Q 434 ml Tartaric acid 1.36 g Potassium sulfate 0.45 g NaOH 1 M 6 ml Ethanol 96% 60 ml

[0084] Table 3 - Composition of the PAH model solution (excluding polyphenols)

[0085] The polyphenols (in the form of grape marc) were solubilized at a concentration of 24 g.l1 in this hydroalcoholic solution

[0086] The pH of the solution is 3.5. The solution is filtered with filters having a cut-off threshold of 0.45 pm (GE Healthcare Life Sciences) before use.

[0087] The instability of polyphenols in the hydroalcoholic matrix was induced by cold at 10°C. The influence of gums on the stability of polyphenols was studied for a final polyphenol concentration of 3 g.l1 and a gum concentration range between 0 and 1 gl. The samples were prepared to contain: 2 ml of gum solution (final concentration 0 to 1 g / l), 2.5 ml of polyphenol solution (final concentration 3 g / l) and the sufficient quantity of the hydroalcoholic solution shown in Table 2 to obtain a total volume of 20 ml.

[0088] The stability kinetics analyses were carried out using a Turbiscan Tower device as indicated in part A / above relating to mineral stabilization, at a temperature of 10°C, with the exception of the acquisition time of the transmittance scans which was 48 h.

[0089] The results obtained are shown in [Fig.3]. A decrease in the TSI value is observed when the gum concentration is increased. The CC determined for the A. senegal OF192191 and Ghatti 2971 / 2 gums are 0.045 g / 1 and 0.006 g / 1 respectively. The critical concentration for the ghatti gum is thus 7.5 times lower than that of the A. senegal gum.

[0090] B.2 / Stability of coloring matter

[0091] The effect of gums on the colloidal stability of the coloring matter was evaluated on a hydroalcoholic solution model S29-SO2 of composition indicated in table 4. The appearance of a more or less significant cloudiness after cold incubation of such a solution provides information on the instability of the coloring matter of the wine.

[0092] [Tables4] Component Quantity Purified Water QSP 1000 ml Tartaric Acid 4g Iron Solution (standard iron for AAS) at 1 g / l 3 ml Copper Solution (standard copper for AAS) at 1 g / l 0.3 ml Grape Marc 3g Bovine Serum Albumin (BSA) 100 mg Sodium Hydroxide IN 25 ml Potassium Chloride 0.6 g 10% SO2 Solution 0.3 ml Ethanol 96% 120 ml

[0093] Table 4 - Composition of the model solution S29-SO2

[0094] The 10% SO2 solution was previously obtained by solubilization of meta- potassium bisulfite and SO2 gas in an aqueous solution at pH 4.75.

[0095] After dissolving each constituent, the flask was duly completed and left under magnetic stirring for 24 h, then the solution was filtered on a polyethersulfone (PES) filter with a cut-off threshold of 0.45 μm.

[0096] 3 concentrations of gum in the model solution S29-SO2 were studied: 0.05, 0.1 and 0.2 g / l. Each point of the range was carried out in duplicate according to the quantities shown in Table 5:

[0097] [Tables5] Final concentrations in g / 1 of gum 0 (Control) 0.05 0.1 0.2 Volume of model solution S29-SO2 (ml) 25 25 25 25 Volume of gum solution at 20 g / 1 (ml) 0 0.075 0.15 0.3 Model solution S29-SO2 (ml) QSP 30 QSP 30 QSP 30 QSP 30

[0098] Table 5 - Modalities tested for the dye stability test

[0099] The turbidity of each modality above is then measured with a turbidimeter 2100Q portable HACH (Turbl). After 24 hours at room temperature, the samples are placed at +4°C for 48 hours. After this time, the bottle is removed and shaken vigorously to resuspend any deposit that may have formed, then placed at room temperature for 10 minutes before measuring the turbidity again (Turb2). From this, the % reduction in the instability of the coloring matter contained in the treated model hydroalcoholic solution is deduced, compared to the untreated model solution, after these 48 hours at 4°C. The impact of the product is considered effective if this % reduction is greater than or equal to 50%.

[0100] The results obtained, in terms of percentage reduction in the instability of the coloring matter, compared to the untreated solution, are shown in [Fig.4]. These results show that gum ghatti is very effective from 0.05 g / l with a reduction in instability of approximately 65%, while A. senegal gum shows a reduction at 0.05 g / l of only 29%, less than half of the reduction obtained at this concentration with gum ghatti.

[0101] These results complete the demonstration that gum ghatti is effective at much lower doses than Acacia senegal gum for the stabilization of the coloring matter in this model solution. C / Crystallization test

[0102] The effect of Ghatti 2971 / 2 gum in combination with polyaspartate potassium (KPA) or CMC (CarboxyMethylCellulose, Celstab) on the colloidal stability of the coloring matter and the salts of tartaric acid was evaluated on the hydroalcoholic solution model S29-SO2 described in part B.2 / above.

[0103] The crystallization test provides information on the presence or absence of a crystalline deposit and therefore on an instability with respect to the cold of the salts of tartaric acid in the model solution, the behavior of which is similar to that which could be observed in red wines. It consists of observing the presence or absence of residues of coloring matter and potassium bitartrate in this solution after being placed in the cold for 6 days at -4°C. 10 min after removal from the cold, a turbidity measurement is carried out on the model solution and then filtration is carried out to allow the possible observation of crystals. This test makes it possible to evaluate both the stability of the coloring matter and that of the salts of tartaric acid.

[0104] The gum samples were prepared as indicated in part B.2 / above.

[0105] 3 concentrations of gum in the model solution S29-SO2 were studied: 0.05, 0.1 and 0.2 g / l. The concentration of KPA or CMC was further set at 0.1 g / l.

[0106] For each of the modalities, after 24 h at room temperature, the treated solutions were placed for 6 days at -4°C. Each sample was then shaken vigorously and left for 10 min at room temperature. After this time, a turbidity measurement was carried out and then the composition was completely filtered on a glass fiber filter with binder with a pore size of 2.0 qm and a diameter of 47 mm (AP2504700, Merck Millipore). An observation of the filters was carried out to detect the presence of crystals and / or coloring matter (color, coloring matter residue and crystal residue). An untreated control was also carried out. Model solutions containing only KPA or CMC were also subjected to the same test.

[0107] The results obtained are shown in Table 6:

[0108] [Tableauxô] Turbidity (NTU) Crystals on the filter Colouring matter on the filter Untreated control 994 Very strong presence Very strong presence KPA alone 915 Absence Very strong presence CMC alone > 1000 Absence Very strong presence Ghatti 0.05 g / 1 + KPA 615 Absence Absence Ghatti 0.1 g / 1 + KPA 670 Absence Absence Ghatti 0.2 g / 1 + KPA 510 Absence Absence Ghatti 0.05 g / 1 + CMC 390 Absence Absence Ghatti 0.1 g / 1 + CMC 375 Absence Absence Ghatti 0.2 g / 1 + CMC 305 Absence Absence

[0109] Table 6 - Results of the crystallization test

[0110] In the control, in the absence of gum and KPA or CMC, the formation and deposition on the filter of crystals and residues of coloring matter are observed. The positive controls with the usual crystallization inhibitors, potassium polyaspartate and CMC, show the absence of crystals but the presence of residues of coloring matter on the filter.

[0111] For combinations of CMC or potassium polyaspartate (KPA) with gum ghatti, good colloidal stability of the solutions was obtained for both the coloring matter and the tartaric acid salts. D / Tests on red wine

[0112] These tests were carried out on samples of red Bordeaux wine “Les vignerons réunis de Monségur”, for the gums Ghatti BR2971 / 1, Ghatti 2971 / 2, A. senegal BR180246, A. senegal OF192191 and A. senegal OF202510.

[0113] D. 1 / Clogging index

[0114] This test was carried out for the gums Ghatti BR2971 / 1, Ghatti 2971 / 2, A. senegal BR180246, A. senegal OF192191.

[0115] Before the final filtration of a wine on a membrane, it is necessary to assess the latter's filterability, that is to say, its ease of being filtered. This is achieved by determining its clogging index (CI).

[0116] The wine used was previously filtered on a fiberglass prefilter with binder for a nominal porosity of 2.5 pm, then on an EPS membrane with a pore size of 0.45 pm, in order to achieve a wine turbidity less than or equal to 1 NTU. The wine was distributed in 450 ml bottles and then treated with the gums, at different concentrations between 0.01 and 10 g / hl, by introducing into the wine the appropriate quantity of a 2% w / v gum solution with SO26%, prepared as follows: 2 g of gum (as dry matter) were solubilized under stirring for 16 h at room temperature in tap water (90 ml) in the presence of SO26% (6 ml). After solubilization, the samples were centrifuged at 5000 rpm for 10 min at 20 °C. A 6% SO2 solution marketed by the company Laffort under the name Solution Sulfureuse 6 was used.

[0117] After 24 h of contact at room temperature, the IC was measured for each modality, by filtration of 450 ml of wine on a Pall Ultipor N membrane (porosity 0.65 qm, nylon filter media and diameter 25 mm) at 2 bars of pressure and at a temperature of 20 °C.

[0118] Using a stopwatch, the time elapsed for 200 ml of filtered wine (T2, in s) and the time elapsed for 400 ml of filtered wine (T4, in s) were measured. The clogging index is then calculated by the formula: IC = (T4 - 2xT2) x 1.66. A control without gum was also subjected to the same test.

[0119] From the results obtained for the IC, the intensity of variation of the clogging index (IVIC) was calculated for each modality with the following formula: IVIC = (IC obtained with the treated wine / IC of the control wine). A product is considered to be slightly clogging, and filterable for bottling, if the value of the IVIC is less than 3. The IVIC of the control is by definition equal to 1.<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0120] The results displayed on the table 7:<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0121] [Tables?]<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> Gomme et concentration IC IVIC Ghatti 2971 / 2 - 0.01 g / hl 44.8 1.1 Ghatti 2971 / 2 - 0.05 g / hl 43.2 1.0 Ghatti 2971 / 2 - 0.25 g / hl 48.1 1.2 Ghatti 2971 / 2 - 0.5 g / hl 49.8 1.2 Ghatti 2971 / 2- 1 g / hl 51.5 1.9 Ghatti 2971 / 2 - 2.5 g / hl 53.1 2.0 Ghatti 2971 / 2- 5 g / hl 66.4 2.5 Ghatti 2971 / 2- 10 g / hl 127.8 4.8 Ghatti BR2971 / 1 - 0.01 g / hl 41.5 1.0 Ghatti BR2971 / 1 - 0.05 g / hl 46.5 1.1 Ghatti BR2971 / 1 - 0.25 g / hl 48.1 1.2 Ghatti BR2971 / 1 - 0.5 g / hl 49.8 1.2 Ghatti BR2971 / 1 - 1 g / hl 58.1 1.4 Ghatti BR2971 / 1 - 2.5 g / hl 89.6 2.3 A. senegal OF192191 - 5 g / hl 58.1 1.4 A. senegal OF 192191 - 10 g / hl 73.1 1.7 A. senegal BRI80246 - 5 g / hl 134.5 3.2 A. senegal BRI80246 - 10 g / hl 148.6 3.7<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0122] Tableau 7 - Results from the colmatage test<h2 style=";text-align:left;direction:ltr">

[0123] As can be observed, for concentrations less than or equal to 5 g / hl, we obtain for gum ghatti, raw or atomized, an IC less than 90 and an IVIC less than 3, testifying to good filterability of the wine and an absence of clogging of the filtration membrane.

[0124] D.2 / Stability of the coloring matter after filtration

[0125] The filtered wine samples obtained at point Dl / above were subjected to a coloring matter stability test as described at point B.2 / above.

[0126] The results obtained are shown in Table 8:

[0127] [Tables8] <h2 style=";text-align:left;direction:ltr">Gomme and concentration % of the reduction of the color installation in the color Ghatti 2971 / 2 - 0.01 g / hl 11.6+1.1 Ghatti 2971 / 2 - 0.05 g / hl 26.1+0.6 Ghatti 2971 / 2 - 0.25 g / hl 48.9+0.3 Ghatti 2971 / 2 - 0.5 g / hl 62.4+0.5 Ghatti 2971 / 2 - 1 g / hl 75.1+0.2 Ghatti 2971 / 2 - 2.5 g / hl 83.1+0.1 Ghatti 2971 / 2 - 5 g / hl 88.1+0.3 Ghatti 2971 / 2 - 10 g / hl 93.6+0.4 Ghatti BR2971 / 1 - 0.01 g / hl 13.5+0.5 Ghatti BR2971 / 1 - 0.05 g / hl 24.6+0.0 Ghatti BR2971 / 1 - 0.25 g / hl 49.6+0.3 Ghatti BR2971 / 1 - 0.5 g / hl 61.6+0.9 Ghatti BR2971 / 1 - 1 g / hl 70,5+1,0 Ghatti BR2971 / 1 - 2,5 g / hl 82,6+0,2 Ghatti BR2971 / 1 - 5 g / hl 86,2+0,6 Ghatti BR2971 / 1 - 10 g / hl 93,2+0,1 A. senegal OF192191 - 0.5 g / hl 12.7+0.5 A. senegal OF192191 - 1 g / hl 23.4+1.8 A. senegal OF192191 - 2.5 g / hl 40.3+0.1 A. senegal OF192191 - 5 g / hl 59.3+1.1 A. senegal OF192191 - 10 g / hl 74.9+1.3 A. senegal BRI80246 - 0.5 g / hl 13.5+0.6 A. senegal BRI80246 - 1 g / hl 26.5+1.3 A. senegal BRI80246 - 2.5 g / hl 44.0+1.2 A. senegal BRI80246 - 5 g / hl 64.2+0.9 A.senegal BRI80246 - 10 g / hl 77.2+0.1.

[0128] Table 8 - Results of the test for stabilization of the coloring matter after filtration of the wine

[0129] These results show that ghatti gums exhibit acceptable performance from 0.05 g / hl with a reduction in instability greater than 20%, are effective from 0.25 g / hl, with a reduction in instability of approximately 50% and more, and very effective for concentrations greater than or equal to 1 g / hl, with a reduction in instability of approximately 70% and more. A. senegal gums exhibit a much lesser reduction in instability at equivalent doses.

[0130] This difference in the effectiveness of the ghatti and A. senegal gums in reducing the instability of the coloring matter in wine is clearly visible in [Fig.5], which shows the results obtained for the atomized gums Ghatti 2971 / 2 and A. senegal OF192191.

[0131] D.3 / Tasting

[0132] A blind tasting of samples of filtered wines obtained as described in D.2 / above, for gum concentrations of 10 g / hl, well above the minimum concentration of gum ghatti necessary for the colloidal stabilization of the coloring matter of the wine, by a panel of non-expert tasters, was carried out to evaluate the organoleptic impact (visual, aromatic, gustatory) of the addition of gum ghatti to the wine.

[0133] The panel found no visual difference in color, and for the majority no difference in aroma, between the different samples tested. The wine added with raw gum ghatti was particularly well perceived in terms of taste.

[0134] All of these results demonstrate that, under the conditions used, gum ghatti effectively stabilizes the coloring matter of red wine at low doses, much lower than those required for A. senegal gums, doses at which they do not significantly impact the filterability of the wine, nor its organoleptic properties.

[0135] E / Impact of sulfur dioxide on the efficiency and filterability of red wine treated with gum ghatti

[0136] These experiments were carried out for Ghatti 3008 / 2 gum and the same red wine as in example D / .

[0137] Sulfur dioxide added to gums at different concentrations comes from: - a 6% sulfurous solution marketed by the company Laffort under the name Solution Sulfureuse 6, - or a 10% sulfurous solution marketed by the company Laffort under the name Solution Sulfureuse 10, having been obtained by solubilization of potassium metabisulfite and gaseous SO2 in an aqueous solution at pH 4.75.

[0138] The gum was solubilized at 2% w / v in tap water (pH 7.19) without or with different volumes of sulfurous solution to obtain different sulfur dioxide concentrations between 0.5 and 4 g / l in the preparation as well obtained. The resulting preparations were mechanically stirred for 24 h and the pH was measured. The addition of sulfur dioxide caused acidification of the solutions.

[0139] E. 1 / Clogging index

[0140] Monségur red wine was treated with each of the above preparations, in an adequate quantity to introduce a concentration of 1 g / hl of gum. A measurement of the clogging index was carried out on each preparation after 48 h of treatment at room temperature. The results of the clogging indices IC and IVIC obtained are presented in Table 9:

[0141] [Tables9] Modality IC IVIC Control without gum 39 1 Gum + 0.5 g / 1 SO2 (6%) 49.8 1.4 Gum + 1 g / 1 SO2 (6%) 56.4 1.4 Gum + 2 g / 1 SO2 (6%) 53.1 1.3 Gum + 4 g / 1 SO2 (6%) 43.2 1.1 Gum + 0.5 g / 1 SO2 (10%) 54.8 1.4 Gum + 1 g / 1 SO2 (10%) 54.8 1.4 Gum + 2 g / 1 SO2 (10%) 53.1 1.5 Gum + 4 g / 1 SO2 (10%) 56.4 1.4

[0142] Table 9 - Results of the clogging test on red wine treated with gum ghatti and SO2

[0143] It is observed that the red wine treated with the preparation containing the gum and SO2 in the concentration range of 0.5 to 4 g / l has a low clogging power, whatever the origin of the SO2 (6% sulfurous solution or 10% sulfurous solution).

[0144] E.2 / Stability of coloring matter

[0145] A stability analysis of the coloring matter was carried out, according to the protocol indicated in point B.2 / above, on the red wines treated with preparations based on gum ghatti and sulfur dioxide. For comparison, the same experiment was carried out with the gum A. senegal OF202510.

[0146] The results obtained, expressed in terms of % reduction in the instability of the coloring matter, are shown in [Fig.6] for the preparations based on 6% SO2 and in [Fig.7] for the preparations based on 10% SO2.

[0147] It is observed that the sulfiting of the gum ghatti solution, by a solution of SO2à 6%, does not have a negative impact on its stabilizing power of the coloring matter of red wine. The percentage of reduction of instability is maintained around 89% regardless of the concentration of SO2 tested. This percentage is always higher than that obtained with Acacia senegal gum. In the case of sulfiting using the 10% SO2 solution, a slight decrease in the stabilizing power of gum ghatti is observed at concentrations above 2 g / l. F / Tests on other red wines

[0148] The effectiveness of Ghatti gum 3008 / 2 and A. senegal gum OF202510 on the stability of the coloring matter was evaluated for three different red wines from the Ducourt vineyards: wines R9 and R17 are 2020 vintages, and wine R12 is a 2021 vintage.

[0149] For this purpose, the Ghatti 3008 / 2 gum was solubilized at a concentration of 2% w / v in tap water sulphated at 2.0 g / l (by a 6% sulphur solution), and the A. senegal OF202510 gum was solubilized at a concentration of 10% w / v in tap water sulphated at 2.0 g / l (by a 6% sulphur solution). In order to obtain maximum solubilization, the preparations were left for several hours in a closed bottle and under stirring, then filtered on a Sartorius® cartridge with a porosity of 0.65 pm.

[0150] The preparations were introduced into the wines in adequate doses to obtain concentrations of gum ghatti of 0.01, 0.05, 0.1, 0.25, 0.5, 1 and 5 g / hl respectively, or of gum A. senegal of 1, 5 and 10 g / hl respectively.

[0151] The treatment time was 24 h at room temperature, then a test of stability of the coloring matter was carried out according to the following protocol: the turbidity of the wine filtered on a membrane with a porosity of 0.45 pm (PES) was measured before and after passing at +4°C for 48 h. The difference between these 2 turbidities (ANTU) represents the degree of instability of the coloring matter of the wine. The analyses were carried out in duplicate.

[0152] The results obtained are shown in [Fig.8] for wine R17, [Fig.9] for wine R9 and in [Fig. 10] for wine R12. They confirm that gum ghatti has a stabilization efficiency of the coloring matter of red wines equivalent to that of A. senegal gum at concentrations 10 to 20 times lower.

Claims

Claims

1. A method of treating a wine with a view to improving its colloidal stability, comprising the incorporation of gum ghatti into said wine during its production, characterized in that the gum ghatti is incorporated into said wine at a concentration of between 0.25 and 2.5 g / hl.

2. A method according to claim 1, wherein the gum ghatti is incorporated into said wine at a concentration of between 1 and 2.5 g / hl.

3. A method according to claim 1 or 2, wherein said incorporation of gum ghatti into said wine is carried out, in a process of producing said wine, after an alcoholic fermentation step and before a bottling step.

4. A method according to any one of claims 1 to 3, comprising introducing into said wine a tartaric acid crystallization inhibitor.

5. A method according to any one of claims 1 to 4, wherein the incorporation of gum ghatti into said wine is carried out by introducing into said wine a preparation containing gum ghatti in admixture with sulfur dioxide in an aqueous solution.

6. A method according to claim 5, wherein said preparation contains 0.5 to 5% by weight of gum ghatti relative to the volume of said preparation.

7. Method according to claim 5 or 6, according to which said preparation is introduced into said wine at a dose of between 2.5 and 500 ml / hl.

8. A method according to any one of claims 5 to 7, wherein said preparation contains 0.5 to 4 g / l of sulfur dioxide.

9. Preparation for the treatment of a wine, characterized in that it contains gum ghatti mixed with sulfur dioxide in an aqueous solution, said preparation containing 0.5 to 5% by weight of gum ghatti relative to the volume of said preparation and 0.5 to 4 g / l of sulfur dioxide.

10. Use of gum ghatti or a preparation according to claim 9 for the treatment of a wine with a view to improving its colloidal stability, the concentration of gum ghatti incorporated in said wine being between 0.25 and 2.5 g / hl.

11. Use according to claim 10, for improving the stability of the coloring matter of said wine.

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