Method for desalting a milk protein composition, a milk protein composition obtained by said method, and equipment for carrying out said method

Abstract

The present invention relates to a method for producing a desalted milk protein composition (MPC2) comprising the steps of: (i) providing a milk protein composition (MPC); (ii) a unit cell (15, 215) containing three compartments (20, 26, 30; 220, 226, 230), and wherein at least one cation in said milk protein composition (MPC) is replaced by at least one hydrogen ion H + to obtain an at least partially desalted and acidified milk protein composition (MPC1); (iii) electrodialyzing the milk protein composition (MPC1) obtained in step (ii); and (iv) recovering the desalted milk protein composition (MPC2).

Description

[Technical Field]

[0001] The present invention relates to a method for desalting a milk protein composition and to the milk protein composition, in particular desalted whey, obtainable by this method.

[0002] The present invention also relates to an installation for carrying out said method for desalting a milk protein composition. [Background technology]

[0003] The milk protein composition may be whey. Whey is the liquid portion resulting from the coagulation of milk. Two types of whey can be distinguished: that resulting in particular from the production of casein or fresh cheese in an acid medium (acid whey), and that resulting from the production of casein and cooked or semi-cooked pressed cheese using rennet (sweet whey).

[0004] Whey is primarily composed of water, lactose, proteins, especially serum proteins, and minerals. Separation of both lactose and proteins can add value to whey. Whey proteins can also have added value as ingredients in the production of infant formula. Demineralized whey, especially lactose, can be used in the production of confectionery, cakes, ice cream, prepared foods, pastries, etc.

[0005] Whey can be desalted through a nanofiltration process, followed by electrodialysis or passage through cation and anion exchange resins to achieve desalting rates of 70-90% or higher. However, ion exchange resins produce large amounts of saline waste, which is difficult and expensive to treat.

[0006] At the same time, consumers are demanding ingredients from the food processing industry that retain their original, natural properties and therefore are not, or at any rate, as little processed and / or denatured as possible. Furthermore, there is a demand for methods of desalting dairy products that limit or even eliminate the presence of exogenous mineral species. Indeed, ion exchange resins function by exchanging mineral species in the composition being processed for exogenous mineral species. However, eliminating one or more passes through the ion exchange resin complicates the production of highly desalted milk protein compositions, e.g., 70%, 80%, or 90% desalted. If the desalting is transferred to other processing systems, there is a risk that the membranes of these systems will clog more quickly due to the high mineral load. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention therefore aims to propose an improved method for desalting milk protein compositions, in particular without the use of ion exchange resins (anionic and / or cationic).

[0008] The present invention also aims to propose a method for desalting a milk protein composition that limits the introduction of exogenous mineral compounds into said milk protein composition. [Means for solving the problem]

[0009] According to a first aspect, the present invention overcomes the aforementioned problems in that it features a method for producing a desalted milk protein composition (MPC2), comprising the following steps, carried out in particular succession:

[0010] (i) providing a milk protein composition (MPC); (ii) a unit cell comprising three compartments, in particular consisting of three compartments, and wherein at least one cation is substituted with at least one hydrogen ion H in said milk protein composition (MPC); +to obtain an at least partially desalted and acidified milk protein composition (MPC1); (iii) electrodialyzing the milk protein composition (MPC1) obtained in step (ii); and (iv) recovering the desalted milk protein composition (MPC2).

[0011] Generally, during electrodialysis, dissolved ionized mineral or organic species, such as salts, acids, or bases, are transported through an ionic membrane under the action of an electric current. An electrodialysis unit may contain parallel, alternating cationic (cation-permeable) membranes (CEMs) and / or anionic (anion-permeable) membranes (AEMs). Under the action of an electric field applied by anodes and cathodes, the CEMs block anions and allow cations to pass, while the AEMs block cations and allow anions to pass. In this way, a concentration compartment (concentrate) and a desalting compartment are created. This most common type of electrodialysis is one in which the basic unit cell contains two compartments. The unit cell corresponds to the minimally repeated pattern of concentration and desalting operations (one compartment corresponds to one concentration or desalting). The solution is renewed within the compartments by circulation parallel to the membrane plane. The application of electric current is provided by two electrodes, parallel to the plane of the membrane and positioned at the ends of the electrodialysis device.

[0012] Advantageously and in a novel manner, the invention comprises the use of an electrodialyzer for carrying out step (ii) comprising three compartments adapted to allow the exchange of cations: thus, in addition to the demineralizing compartment (where ions are lost) and the concentrating compartment (where ions accumulate), the electrodialyzer for step (ii) comprises a cation exchange compartment.

[0013] The milk protein composition (MPC) obtained in step (ii) is thus depleted of cations and therefore acidified (accompanied by a decrease in pH).

[0014] A second electrodialysis (iii) is carried out in an electrodialyzer comprising a cell containing (each consisting of) two compartments: a first compartment receives said milk protein composition (MPC1) to be treated and a second compartment is first subjected to said electrodialysis (iii) of water, the water containing salts of the ions extracted from said milk protein composition (MPC1) to form brine.

[0015] The electrodialysis (iii) allows complete extraction of cations and anions not extracted in the first electrodialysis. The desalination obtained for the recovered milk protein composition (MPC2) is strong and may reach desalination rates of 70% or more, in particular 75% or more, or 80% or 85% or more, and more in particular 90% or more.

[0016] Advantageously, the process according to the invention is less polluting, since it does not produce a regeneration effluent to be treated and does not consume exogenous acid, or consumes very little according to the different variants developed below.

[0017] This method can be said to be partly eco-efficient.

[0018] The milk protein composition obtained in step (ii) has an acidic pH, in particular a pH below the isoelectric point of the proteins (especially serum proteins) of the MPC in step (i), in particular a pH below 6, preferably below 4.

[0019] This provision facilitates the control of microbiological stability. Furthermore, the milk protein composition can be subjected to heat treatment (particularly pasteurization) under conditions of temperature and duration different from those applied in a non-acidic environment, which limits protein denaturation. Thus, the milk protein is advantageously less susceptible to degradation.

[0020] Preferably, the temperature of the milk protein composition in step (ii) and / or step (iii) is below 40° C., in particular above 0° C. The milk protein composition recovered in step (iv) has a pH of above 5, in particular above 6, and even below 6.2, in particular below 8.

[0021] (Milk protein composition)

[0022] Preferably, the milk protein composition is selected from whey, such as sweet whey or acid whey or mixtures thereof, milk ultrafiltration permeate; milk microfiltration permeate (also called ideal or native whey), whey ultrafiltration retentate or permeate, milk microfiltration permeate ultrafiltration retentate or permeate, or mixtures thereof (List I).

[0023] All of the dairy protein compositions listed in List I are considered to be whey or whey derivatives.

[0024] In one embodiment, the milk protein composition (MPC) and / or sweet whey and / or acid whey and / or native whey is unprocessed, i.e. it / they have not been subjected to any manipulation to reduce its / their mineral load. Thus, the whey or milk protein composition (MPC) not precisely referred to may be unprocessed or partially demineralized.

[0025] Sweet whey is preferably obtained by chemical treatment of milk, particularly using rennet, to recover both casein and sweet whey, while acid whey is preferably obtained by acid treatment of milk, particularly using lactic acid and / or hydrochloric acid, to recover both casein and acid whey.

[0026] In particular raw or partially desalted milk protein composition (MPC) and / or in particular raw or partially desalted whey can be pre-concentrated mechanically (e.g. by reverse osmosis or nanofiltration or a combination thereof) or thermally (e.g. by evaporation of water) to increase its dry extract.

[0027] In particular the raw or partially desalted milk protein composition (MPC) and / or in particular raw or partially desalted acid whey and / or in particular raw or partially desalted sweet whey and / or in particular raw or partially desalted milk microfiltration permeate has / has more than 0% dry extractives up to about 16%, in particular up to about 6%.

[0028] In particular, raw or partially desalted milk protein composition (MPC) and / or in particular raw or partially desalted acid whey and / or in particular raw or partially desalted sweet whey and / or in particular raw or partially desalted milk microfiltration permeate may be subjected to a pre-concentration step as defined above to obtain a dry extract of not less than about 8% and not more than about 32%. The milk protein composition according to the invention is liquid at the time of use. This may be obtained by reconstituting a liquid solution from a powder and / or liquid selected in particular from List I above.

[0029] Preferably, the milk protein composition in step (i) is partially desalted, which allows to reduce the size of the three-compartment electrodialyzer in step (ii) and / or the size, i.e. the active membrane surface, of the two-compartment electrodialyzer in step (iii).

[0030] Preferably, the salt removal rate of the milk protein composition in step (i) is 30% or more.

[0031] Preferably, the salt removal rate of the milk protein composition in step (i) is 70% or less, preferably 60% or less, for example 50% or less.

[0032] Preferably, the milk protein composition obtained / recovered in step (iv) has a salt removal rate of at least 70%, in particular at least 80% (DM80) or at least 85% (DM85), more in particular at least 90% (DM90).

[0033] In one embodiment, the milk protein composition has a dry extract by mass of more than 1%, preferably not less than 5% and not more than 10%, e.g., it is non-concentrated whey.

[0034] In another embodiment, the milk protein composition has a dry extract by weight of between 10% and 30%, preferably between 15% and 25%, e.g., concentrated whey. Concentration of the whey dry matter can be achieved by reverse osmosis, nanofiltration, or other thermal concentration methods.

[0035] Generally, the milk protein composition may be derived from any dairy female. Preferably, the milk protein composition is derived from milk selected from: cow's milk, goat's milk, sheep's milk, donkey's milk, buffalo's milk, mare's milk, or mixtures thereof, even more preferably selected from: cow's milk, goat's milk and sheep's milk, or mixtures thereof, in particular cow's milk.

[0036] The protein composition comprises milk proteins, particularly serum proteins. The milk protein composition (MPC), particularly whey, comprises serum proteins and does not include casein, which remains in the bulk (coagulated) portion during milk processing and / or in the milk microfiltration residue.

[0037] Preferably, the especially raw sweet whey or especially raw native whey has one of the following properties, alone or in combination: pH between 5.8 and 6.5; the ratio of lactose mass to dry extract mass is greater than or equal to 70%, in particular greater than or equal to 74%; the ratio of the mass of nitrogenous substances to the mass of the dry extract is greater than or equal to 10%, in particular greater than or equal to 12%, in particular less than or equal to 30%; The ratio of the mass of ash to the mass of dry extract is greater than or equal to 8%, in particular less than or equal to 10%; and The ratio of the mass of organic acids to the mass of the dry extract is greater than or equal to 2%, in particular less than or equal to 5%.

[0038] Preferably, the especially unprocessed acid whey has one of the following properties, either alone or in combination: pH below 5, especially below 4.5; the ratio of the mass of lactose to the mass of dry extract is not less than 55%, in particular not more than 65%, in the case of whey resulting from the manufacture of cheese in an acidic medium; the ratio of the mass of lactose to the mass of the dry extract is greater than or equal to 70%, in particular less than or equal to 85%, in the case of whey derived from the production of casein in an acidic medium; The ratio of the mass of total nitrogenous substances (TNM) to the mass of the dry extract is not less than 4%, in particular not more than 12%; the ratio of the mass of ash to the mass of dry extract is not less than 10%, in particular not more than 15%; The ratio of the mass of organic acids to the mass of dry extract is greater than or equal to 10%, in particular less than or equal to 20%, in the case of whey derived from the manufacture of cheese in a lactic acid medium; and The ratio of the mass of organic acids to the mass of dry extract is greater than or equal to 2%, in particular less than or equal to 5%, in the case of whey derived from the production of casein in an acidic medium.

[0039] In one embodiment, the ratio of lactose by weight to the weight of the dried extract of MPC (step (i)) is 50%, or 60%, or 70% or more.

[0040] In one embodiment, the ratio of the mass of total nitrogenous substances to the mass of the dry extract of the MPC (step (i)) is greater than or equal to 5% or 10%, in particular greater than or equal to 12%, and in particular less than or equal to 30%.

[0041] Desalting essentially consists in completely or partially removing the ash present in said milk protein composition, in particular in whey.

[0042] (Definition, measurement method)

[0043] In particular, the ash content (i.e., dry mass fraction of ash) of said milk protein compositions (MPC, MPC1, MPC2) can be determined by standardized method NF V04-208, October 1989 edition, entitled "Milk - Determination of ash content - Reference method", in particular using the incineration method at 525°C.

[0044] In this specification, dry extract weight or total dry weight is understood to mean, for example, the dry weight of said milk protein composition (MPC, MPC1, MPC2) obtained after evaporation of water until a total dry weight is obtained, in particular based on the total weight of said milk protein composition at atmospheric pressure. Dry extract weight can be determined by the standardized method ISO 6731: January 2011 edition "Milk, cream, evaporated milk - Determination of dry matter (Reference method)".

[0045] In the present specification, lactose is understood to mean lactose as defined in Codex Alimentarius, Codex Stan 212-1999: i.e. a natural constituent of milk, usually obtained from whey, in particular having an anhydrous lactose content of 99.0% w / w or more on a dry basis.

[0046] The determination of the lactose or sugar mass content (or dry mass fraction) can be carried out by high performance liquid chromatography, in particular using the standard NF ISO 22662, November 2007 edition.

[0047] The methods that can be used to quantify cations and anions in milk (calcium, magnesium, sodium, potassium, phosphorus / phosphate, citrate) can be chosen from the following: molecular absorption spectrometry, titration / complexometry, electrochemistry, atomic spectrometry, capillary electrophoresis, ion chromatography / conductivity detection, 31P nuclear magnetic resonance, enzymatic methods / UV detection.

[0048] The dry mass fraction of total nitrogenous substances (TNM) can be determined using standard NF EN ISO 8968-1 dated May 2014 (Kjeldahl method).

[0049] The mass content can be determined using the following standards: for example, for chloride: potentiometric titration (NF ISO 21422, February 2019 edition), for example, for total phosphorus: molecular absorption spectrometry (NF ISO 9874, April 2008 edition), for example, for calcium: titration (standard ISO 12081: 2010 edition), for example, for calcium, sodium, potassium and magnesium: atomic absorption spectrometry (standard ISO 8070: 2007 edition) or ion chromatography; for example, for lactic acid / lactate, according to standard ISO 8069 dated 2005.

[0050] As used herein, MPC refers to the milk protein composition according to the present invention.

[0051] Preferably, the milk protein composition (i.e. MPC) in step (i) has a conductivity of at least 1 mS / cm, more preferably at least 3 mS / cm, preferably at least 8 mS / cm, especially at least 10 mS / cm.

[0052] Preferably, the MPC recovered in step (iv) is not more than 2.5% of the dry extract, preferably not more than 1.5% of the dry extract, more preferably not more than 1% of the dry extract, preferably not more than 0.60% of the dry extract.

[0053] Preferably, the milk protein composition comprises the following cations, which are particularly targeted by the desalting method according to the present invention: calcium, magnesium, sodium and potassium.

[0054] Preferably, the milk protein composition comprises the following anions, which are particularly targeted by the desalting method according to the present invention: chloride, phosphate, sulfate, lactate, acetate and citrate.

[0055] In one embodiment, monovalent cations and monovalent anions are at least partially extracted from the MPC in a preliminary desalting step prior to step (i) which comprises a nanofiltration or reverse osmosis step.

[0056] Advantageously, the method comprises cells each comprising three compartments, in particular wherein at least one anion in the milk protein composition, in particular MPC1, is at least one hydroxyl ion OH - Advantageously, the method does not include a substitution step carried out in an electrodialyzer, in particular exclusively for anions.

[0057] Advantageously, the method does not include an anion substitution step carried out in an electrodialyzer comprising a cell containing compartments receiving the milk protein composition MPC1, each of said compartments being separated between two anionic membranes.

[0058] In a variant, the method comprises adding at least one basic solution, in particular at least one solution comprising at least one basic salt, to the milk protein composition during step (iii), in particular during at least part of step (iii) and / or after step (iii).

[0059] In one embodiment, the basic solution is a sodium hydroxide (NaOH) solution or a potassium hydroxide solution, or a mixture of these solutions.

[0060] In one embodiment, the basic solution comprises at least 0.5% by weight, preferably at least 1% or 3% or 5% of the base (e.g., NaOH and / or KOH) relative to its total weight (including water).

[0061] In a first embodiment, a basic solution is added to the milk protein composition after step (iii), and then the pH-adjusted milk protein composition (MPC2) is recovered, which may be standardized. The recovered MPC2 contains ions, particularly cations, of the added basic salt. Depending on the required mineral profile, this MPC2 may be suitable for a particular application. In a second embodiment, optionally in combination with the first embodiment, a basic solution is added to the compartment of the electrodialyzer in step (iii) containing the milk protein composition MPC1. The pH is then preferably increased during the electrodialysis (iii).

[0062] Advantageously, said at least one basic solution can be added continuously or sequentially, in particular until the desired pH and / or target conductivity is obtained.

[0063] Advantageously, said at least one basic solution is food grade.

[0064] Advantageously, increasing the pH during step (iii), in particular to be above the pKa of at least one organic acid of the treatment composition, makes it possible to obtain the anionic form of the organic acid and thus to extract it through the anionic membrane in step (iii), increasing the mobility of the anions and thereby facilitating their extraction.

[0065] This addition can be done by stopping (and thus switching off) the electrodialyzer (iii), then adding the basic solution to the MPC1, and then restarting the electrodialyzer; or concomitantly with the extraction of ions (and thus switching on).

[0066] Advantageously, said basic solution is added during step (iii) when the conductivity (mS / cm) of the milk protein treatment composition has decreased by at least 50%, preferably at least 75% relative to the conductivity of said milk protein composition in step (i).

[0067] In a variant, said addition of said basic solution is carried out simultaneously with the extraction of ions, in particular cations and anions, during at least part of the electrodialysis step (iii).

[0068] In addition to improving the extraction of anions, the inventors have demonstrated that this configuration significantly reduces the extraction of divalent cations (Ca), particularly compared to desalination methods using exclusively cation replacement (ESC) in a three-compartment electrodialyzer followed by conventional ED, and exclusively anion replacement (ESA) in a three-compartment electrodialyzer. 2+ ;Mg 2+ It was observed that the extraction of

[0069] Advantageously, said addition of said basic solution is carried out under the application of an electric field, in particular during at least part of the electrodialysis step (iii), said electric field being generated by applying a voltage (volts) between the electrodes, i.e. the anode and the cathode, of said electrodialyzer (iii).

[0070] In a variant, the addition of the basic solution to the milk protein composition is carried out when the milk protein composition has a conductivity of 1 mS / cm or less and preferably a pH of 3 or greater.

[0071] Advantageously, said addition of said basic solution to said milk protein composition is carried out when said milk protein composition has a conductivity of 0.5 mS / cm or less and preferably a pH of 4 or more.

[0072] In a variant, after said addition of said basic solution, said milk protein composition has a pH of 4.5 or greater, preferably 5.0 or greater.

[0073] In one embodiment, the milk protein composition (MPC2) recovered after step (iii) has a pH of 6 or less.

[0074] Afterwards, if necessary, the pH can be adjusted to 6-7 by adding more basic solution to standardize the MPC2.

[0075] In one embodiment, the milk protein composition (MPC2) recovered after step (iii) has a pH after step (iii) of greater than or equal to 6. The concentration and duration of application of the basic solution in step (iii) are adjusted to achieve this pH.

[0076] In a variant, the electrodialysis step (iii) comprises the extraction of anions and cations.

[0077] In a variant, step (ii) is the only cation exchange step.

[0078] In a variant, the electrodialyzer of step (ii) comprises a cell containing (consisting of) three compartments (each of which comprises) the milk protein composition (MPC) circulates within (each of) said compartments separated between two cationic membranes.

[0079] In a variant, the milk protein composition (MPC2) recovered in step (iv) contains phosphate ions (H2PO4 - , HPO4 2- , PO4 3- ), and the mass of phosphorus is 110 mg or more, preferably 150 mg or more, per 100 g of the total dry mass of the recovered milk protein composition (MPC2).

[0080] Advantageously, the recovered milk protein composition (MPC2) contains phosphate ions (H2PO4 - , HPO4 2- , PO4 3- ), and the mass of phosphorus is 210 mg or less per 100 g of total dry mass of the recovered milk protein composition (MPC2).

[0081] The mass of the phosphate ion is calculated based on phosphorus.

[0082] The ion profile of the recovered MPC2 also contains more phosphate ions than when the method includes, after step (ii), an electrodialysis step to extract anions and cations, followed by an electrodialysis step exclusively for anion replacement.

[0083] In a variant, the milk protein composition (MPC2) recovered in step (iv) comprises sodium or potassium ions in an amount of at least 20 mg, preferably at least 30 mg, per 100 g total dry mass of the recovered milk protein composition (MPC2).

[0084] In a variant, the milk protein composition (MPC2) recovered in step (iv) comprises sodium or potassium ions in a mass of 80 mg or less, preferably 60 mg or less, per 100 g total dry mass of the recovered milk protein composition (MPC2).

[0085] In one embodiment, the milk protein composition (MPC2) includes sodium and / or potassium ions from the at least one added basic solution.

[0086] In a variant, the compartments of the electrodialyzer in step (ii) that receive the milk protein composition (MPC) are each separated between two cationic membranes.

[0087] In a variant, the manufacturing method comprises: the salt derived directly from the electrodialysis step (ii), a salt derived indirectly from the electrodialysis step (ii), the salt derived directly from the electrodialysis step (iii), a salt derived indirectly from the electrodialysis step (iii), salt from a preliminary desalting step performed on the milk protein composition prior to step (i), and A mixture of the latter, and (v) treating at least a portion of the salt(s) selected from Said treatment step (v) is designed to generate, on the one hand, one or more acid salts and / or, on the other hand, one or more basic salts.

[0088] Said salt is directly derived from steps (ii) and / or (iii) and / or (i) is understood to mean that the latter have not been subjected to steps (vi) or (vii) as defined below, in particular a nanofiltration step.

[0089] Said salt is indirectly derived from steps (ii) and / or (iii) and / or (i) is understood to mean that the latter has undergone step (vi) or (vii) as defined below, in particular a nanofiltration step.

[0090] The salts used in the method according to the invention are preferably selected from: chlorides of monovalent cations; chlorides of divalent cations; in particular sodium chloride, potassium chloride and calcium chloride; sulfates of monovalent cations, sulfates of divalent cations; in particular sodium sulfate, potassium sulfate and calcium sulfate; phosphates of monovalent cations, phosphates of divalent cations; in particular sodium phosphate, potassium phosphate and calcium phosphate; and mixtures thereof.

[0091] In a variant, treatment step (v) consists of an electrodialysis step carried out in a bipolar membrane electrodialyzer.

[0092] Advantageously, the bipolar membrane consists of a cation exchange layer and an anion exchange layer separated by a hydrophilic junction.

[0093] In a variant, the bipolar membrane electrodialyzer in step (v) comprises a unit cell containing three compartments A, B and C, compartments A and B being supplied with water and compartment C being supplied with the salt, in particular compartment C being located between compartments A and B.

[0094] Preferably, the one or more salts are sodium chloride and / or potassium chloride (NaCl and / or KCl).

[0095] In one embodiment, each of the unit cells of the electrodialyzer in step (v) comprises a first compartment separated between a bipolar membrane and an anionic membrane, a second compartment separated between an anionic membrane and a cationic membrane, and a third compartment separated between a cationic membrane and a bipolar membrane.

[0096] Preferably, the first compartment and the third compartment are supplied with water, and the second compartment, located between the first and third compartments, is supplied with salt.

[0097] Advantageously, step (v), in particular bipolar membrane electrodialysis step (v), produces an acid, in particular hydrochloric acid and / or sulphuric acid, and a base, in particular sodium hydroxide and / or potassium hydroxide, from the salt stream derived from steps (ii) and / or (iii).

[0098] This arrangement makes it possible to carry out the electrodialysis steps (ii) and / or (iii) using acid or basic salts from the milk protein composition itself. In this way, the method makes it possible to eliminate, or at least very significantly reduce, the introduction of exogenous mineral compounds.

[0099] The salts, in particular sodium chloride salts, may partly originate from the preliminary desalting step, in particular from nanofiltration, applied to the milk protein composition in step (i).

[0100] In a variant, at least a portion of the one or more salts obtained during treatment step (v), in particular the salts of hydrochloric acid and / or sulfuric acid, is fed in step (ii) to one of the three compartments of the electrodialyzer.

[0101] In a variant, the basic solution added comprises at least partly one or more of the basic salts obtained during treatment step (v), in particular sodium hydroxide and / or potassium hydroxide.

[0102] Advantageously, the base used is derived from the MPC itself, thereby avoiding the addition of exogenous bases.

[0103] In a variant, said basic solution is at least partly obtained from recycling the effluents derived from step (ii) and / or step (iii).

[0104] Effluent is understood to be the brine coming from ED(ii) or ED(iii).

[0105] Advantageously, said recycling is carried out by step (v).

[0106] In a variant, the milk protein composition is selected from the list comprising whey, such as sweet whey or acid whey or mixtures thereof; milk, in particular skim milk, ultrafiltration permeate; milk microfiltration permeate (also called native or ideal whey); whey retentate or ultrafiltration permeate; milk microfiltration permeate ultrafiltration retentate or permeate; or mixtures thereof, preferably whey.

[0107] In a variant, said electrodialysis step (ii) produces a mixture comprising at least one salt of a monovalent cation, in particular a chloride, such as a sodium chloride salt and / or a potassium chloride salt, and at least one salt of a divalent cation, in particular a chloride, such as a calcium chloride (CaCl) salt, said mixture being subjected to a separation step (vi), in particular a nanofiltration step.

[0108] Advantageously, said separation step (vi) allows the separation of said one or more salts of monovalent cations and said one or more salts of divalent cations.

[0109] In a variant, step (iii) comprises electrodialysis of said at least partially desalted and acidified milk protein composition (MPC1) obtained in step (ii) in an electrodialyser comprising unit cells containing (consisting of) two compartments (each of which contains).

[0110] The electrodialyzer comprises a plurality of cells, for example at least five cells, preferably at least five cells, more preferably at least twenty-five cells.

[0111] In a first embodiment, the electrodialyzer comprises at least one unit cell comprising a first compartment separated by a cationic membrane and an anionic membrane, and a second compartment separated by an anionic membrane, in particular the membrane of the first compartment, and a cationic membrane, in particular the membrane of the first compartment.

[0112] Preferably, the first compartment is fed with the partially desalted and acidified milk protein composition (MPC1) obtained in step (ii), and preferably, the second compartment is fed with water.

[0113] This step advantageously allows extraction of both the anions and cations in the MPC1.

[0114] This two-compartment electrodialysis step carried out after step (ii) also makes it possible to obtain removal rates of more than 80%, 85% or 90% of cations and anions, in particular by the addition of sodium hydroxide.

[0115] Step (ii) may be carried out before the heat treatment step (viii) described herein below.

[0116] In a variant, the electrodialysis step (iii) produces a mixture comprising at least one salt of a monovalent anion and / or cation and / or at least one salt of a divalent anion and / or cation, in particular sodium chloride (NaCl) and / or sodium phosphate, which mixture is subjected to a separation step (vii), in particular a nanofiltration step.

[0117] Advantageously, said separation step (vii) allows the separation of said one or more salts of monovalent anions and one or more salts of divalent anions.

[0118] Advantageously, steps (vi) and / or (vii) described herein make it possible to complete the bipolar membrane electrodialysis by avoiding precipitation of divalent cations, in particular calcium and / or magnesium, in the membrane, in particular in the cationic membrane of the bipolar electrodialysis of step (v), in particular when step (ii) is carried out without a selectively permeable membrane.

[0119] In a variant, the salt of a monovalent cation, in particular a chloride salt of a monovalent cation, preferably sodium chloride, collected at the end of said separation step (vi) and / or said separation step (vii) is fed to said electrodialysis step (ii).

[0120] This arrangement applies in particular when step (ii) is carried out using a selectively permeable membrane as defined below.

[0121] In a variant, the salts of monovalent cations, in particular chloride salts of monovalent cations, preferably sodium chloride or potassium chloride, collected at the end of separation step (vi) and / or separation step (vii) are at least partly subjected to treatment step (v).

[0122] This arrangement applies in particular when step (ii) is carried out without a selectively permeable membrane as defined below.

[0123] Advantageously, treatment step (v) allows the production of a basic salt of said monovalent cation, in particular sodium hydroxide or potassium hydroxide.

[0124] Advantageously, the basic salt derived from process step (v) is used, in particular at least in part, as the at least one basic solution according to the invention.

[0125] In a variant, said electrodialyzer of step (ii) comprises at least one membrane selectively permeable to monovalent cations.

[0126] Thus, said membranes selectively permeable to monovalent cations (or monovalent anions) will only allow monovalent cations (or monovalent anions) to pass through, but will not allow anions (or cations) and cations (or anions) of more than one valency, in particular divalent cations (or anions).

[0127] In a variant, the unit cell comprising three compartments of the electrodialyzer of step (ii) comprises at least one unit cell comprising the following compartments, preferably each of the unit cells comprising the following compartments: a first compartment separated by a membrane selectively permeable to monovalent cations and a cationic membrane; a second compartment separated by two cationic membranes; and A third compartment separated by a cationic membrane and a membrane selectively permeable to monovalent cations.

[0128] In another variant, the unit cell comprising three compartments of the electrodialyzer of step (ii) comprises at least one unit cell comprising the following compartments, preferably each of the unit cells comprising the following compartments: a first compartment separated by an anionic membrane and a cationic membrane; a second compartment separated by two cationic membranes; and A third compartment separated between the cationic and anionic membranes.

[0129] Thus, step (ii) of cation exchange can be carried out with or without the use of a selectively permeable membrane.

[0130] In a sub-variant (variant of step (ii)) above), the first compartment is provided with at least one acid salt, preferably hydrochloride salt, the second compartment is provided with the milk protein composition of step (i), and the third compartment is provided with at least one chloride salt of a monovalent cation, preferably sodium, or water.

[0131] In a variant, the method comprises a heat treatment step (viii) carried out after step (ii) and preferably before step (iii).

[0132] Preferably, in step (viii), the milk protein composition is heated at a temperature of at least 70°C and at most 110°C for a time of at least 5 seconds and at most 10 minutes.

[0133] Advantageously, said heat treatment step is a pasteurization step.

[0134] The acidic medium of the dairy protein composition promotes the elimination of bacteria, including those that are more difficult to destroy, such as spore-forming bacteria.

[0135] In a variant, said milk protein composition of step (i) is whey, in particular derived from organic agriculture.

[0136] In a variant, the milk protein composition of step (i) is partially desalted whey, in particular having undergone at least one process selected from a nanofiltration process, a reverse osmosis process, an evaporation process, and combinations thereof.

[0137] These steps also concentrate the MPC, ie, increase the dry extract mass.

[0138] The subject of the present invention, according to a second aspect, relates to a desalted milk protein composition obtainable by any of the embodiment variants with reference to said first aspect of the invention.

[0139] In a variant, the milk protein composition contains phosphate ions (H2PO4) with a mass of phosphorus of at least 110 mg, preferably at least 150 mg, per 100 g total dry mass of the recovered milk protein composition (MPC2). - , HPO4 2- , PO4 3- ), and also comprising sodium or potassium ions, the mass of which is at least 20 mg, preferably at least 30 mg per 100 g total dry mass of the recovered milk protein composition (MPC2), and preferably the sodium and / or potassium ions are at least partially recycled and / or exogenous.

[0140] Advantageously, the milk protein composition contains phosphate ions (H2PO4 - , HPO4 2- , PO4 3- ), the mass of phosphorus is 210 mg or less per 100 g of total dry mass of the recovered milk protein composition (MPC2), and the mass of sodium or potassium ions is 80 mg or less, preferably 60 mg or less, per 100 g of total dry mass of the recovered milk protein composition (MPC2).

[0141] Preferably, said sodium and / or potassium ions are derived at least from said added basic solution, in particular from said basic salt recycled in step (v).

[0142] Preferably, the sodium and / or potassium ions are, at least in part, recycled ions derived from the desalted milk protein composition.

[0143] Preferably, the sodium and / or potassium ions are, at least in part, exogenous to the desalted milk protein composition.

[0144] Recycled ions are understood to be ions extracted from the milk protein composition and added to the latter.

[0145] Exogenous ions are understood to be ions that do not originate from the milk protein composition.

[0146] The milk protein composition has a salt removal rate of 80%, 85%, or 90% or more.

[0147] The subject of the present invention also relates, according to a third aspect, to an installation for carrying out the method according to any of the embodiment variants according to the first and / or second aspect of the invention, said installation comprising: a) a first inlet intended to receive a milk protein composition (MPC) and a first outlet for an at least partially desalted and acidified milk protein composition (MPC1), each of which comprises unit cells containing (consisting of) three compartments, in which at least one cation in said milk protein composition (MPC) is at least one hydrogen ion H + a first electrodialyzer configured to be replaced by b) a second electrodialyzer comprising a first inlet intended to receive said milk protein composition (MPC1) obtained in step (ii) and a first outlet for said milk protein composition (MPC2); Contains:

[0148] The first electrodialyzer allows step (ii) to be carried out, and the second electrodialyzer allows step (iii) to be carried out.

[0149] The first electrodialyzer and / or the second electrodialyzer may comprise any one of the variants / embodiments described above with reference to the first aspect of the invention, in particular with regard to the electrodialyzers of steps (ii) and (iii).

[0150] In a variant, the facility comprises the following devices: c) a device containing a basic solution and configured to be in fluid communication for a predetermined period of time with a compartment of said second electrodialyzer intended to receive said milk protein composition (MPC1), preferably under the application of an electric field.

[0151] Advantageously, said device supplies said at least one basic solution to the compartment of said second electrodialyser receiving MPC1 simultaneously with the extraction of said anions and cations of MPC1 for a predetermined period of time.

[0152] In a variant, the first electrodialyzer comprises a second inlet intended to receive at least one acid salt, in particular a hydrochloride and / or a sulfate, and a third inlet intended to receive water or a salt, in particular a chloride salt of a monovalent cation (NaCl and / or KCl).

[0153] In a variant, the installation comprises a treatment unit (v), in particular an electrodialyzer comprising a cell containing three compartments and a bipolar membrane.

[0154] In a variant, said treatment unit (v) comprises a first inlet for receiving water, a second inlet for receiving monovalent cation salts (NaCl, KCl), a first outlet for acid salts (HCl) and a second outlet for basic salts (NaOH and / or KOH).

[0155] In one embodiment, the basic salt is provided to the device c) containing a basic solution.

[0156] In one embodiment, the acid salt is supplied to the second inlet of the first electrodialyzer a).

[0157] In a variant, the installation comprises a unit for carrying out the separation of salts, in particular step (vi) or step (vii).

[0158] Preferably, the separation unit (vi) or (vii) comprises: a first inlet for receiving at least one salt of a monovalent anion and / or cation and / or at least one salt of a divalent anion and / or cation, in particular sodium chloride (NaCl) and / or sodium phosphate; and if the first inlet receives monovalent and divalent cation salts, a first outlet for the monovalent cation salt and a second outlet for the divalent cation salt; or if the first inlet receives monovalent and divalent anion salts, a first outlet for the monovalent anion salt and a second outlet for the divalent anion salt; Includes:

[0159] Preferably, said separation unit (vi) or (vii) is a nanofiltration unit. [Brief explanation of the drawings]

[0160] The invention will be better understood on reading the following description of embodiments of the invention, given purely by way of non-limiting example, and on referring to the accompanying drawings, in which:

[0161] [Figure 1] 1 is a schematic representation of the various steps of a first example of a process for producing a desalted milk protein composition. [Figure 2] 4 is a schematic representation of a unit cell of a bipolar membrane electrodialyzer implemented in an example of the process step (v) according to the present invention, in particular in the first and second example methods shown in FIGS. 1 and 3. [Figure 3] 1 is a schematic representation of the various steps of a second example method for producing a desalted milk protein composition. DETAILED DESCRIPTION OF THE INVENTION

[0162] A first example of a process for producing a desalted milk protein composition, shown in Figure 1, includes two electrodialyzers (EDs) 5 and 10. The unit cells 15 and 35 each have three compartments. The unit cell 35 of ED 10 has three compartments. A single unit cell 15 of the electrodialyzer 5 is shown in Figure 1. The unit cell 15 includes a first compartment 20 separated by a cation-selectively permeable membrane 22 and a cation membrane 24, a second compartment 26 separated by a cation membrane 24 and a cation membrane 28, and a third compartment 30 separated by a cation membrane 28 and a cation-selectively permeable membrane 32. A single unit cell 35 of the electrodialyzer 10 is shown in Figure 1. The unit cell 35 includes a first compartment 39 separated by a cation membrane 37 and an anionic membrane 41, and a second compartment 43 separated by an anionic membrane 41 and a cation membrane 45.

[0163] Only monovalent cations can cross the cation-selectively permeable membranes 22 and 32. The electrodialyzers 5 and 10 each include a cathode (80, 88) and an anode (78, 90) that generate an electric current through the conductive solution passing through the compartments of the unit cells 15 and 35.

[0164] The method may also comprise a first nanofiltration device 50 for carrying out step (vi) and / or a second nanofiltration device 60 for carrying out step (vii) and / or a bipolar membrane electrodialyzer 70 for carrying out step (v), according to the present invention as particularly shown in Figure 2. This first example method also comprises a heat treatment unit 75 for carrying out said heat treatment step (viii), in particular pasteurization.

[0165] In operation, a milk protein composition MPC, in particular whey, optionally desalted to at least 30%, is provided in step (i) and then fed to the second compartment 26 of the electrodialyzer 5 for the performance of step (ii).

[0166] At the same time, an acidified salt, particularly a hydrochloric acid solution, is fed to the first compartment 20, and a brine, particularly a sodium chloride salt, is fed to the third compartment 30. + Ions cross the cationic membrane 24 and enter the third compartment 30. + ions, which pass through the selectively permeable membrane 32 or 22 under the influence of an electric field. + ions and Ca 2+ Ions cross the cationic membrane 28 in the direction of the cathode 80 under the influence of an electric field, and H + ions. Thus, the milk protein composition MPC1 obtained in step (i) is partially desalted and the cations are replaced by H + The pH of MPC1 is 4 or less. The third compartment 30 contains a mixture of chloride salts, specifically calcium chloride (CaCl) and sodium chloride (NaCl), derived from the milk protein composition MPC. Thus, the monovalent ions (e.g., Na + , K. + ) crosses the cation-selectively permeable membrane 22 or 32 and enters the first compartment 20, while the divalent ions (e.g., Ca 2+ ) remains in the third section 30.

[0167] The acidified milk protein composition MPC1 can be subjected to a heat treatment (heating to 90°C for a few minutes) in step (viii) to improve its bacteriological stability. Advantageously, when the composition MPC1 is acidified, the heat treatment conditions can be stronger than usual and specified so as not to denature the proteins.

[0168] The mixture of salts derived from the third compartment 30 may be subjected to a nanofiltration step (vi) in the nanofiltration unit 50 to increase the purity of the sodium chloride salt derived from the third compartment 30 by retention of divalent salts such as calcium chloride CaCl. The purified sodium chloride salt is then provided to the third compartment 30.

[0169] In particular, the pasteurized composition MPC1 is subjected to a second electrodialysis step (iii) in the electrodialysis device 10 .

[0170] The first compartment 39 is supplied with heated and acidified MPC1. The second compartment 43 receives water. The anions (chloride, phosphate) pass through the anionic membrane 41 and are retained in the second compartment. The cations (sodium, magnesium) pass through the cationic membrane 37 and remain in the brine compartment. The recovered composition MPC2 is thus demineralized and deacidified.

[0171] In the second compartment 43, the mixture of sodium and / or potassium chloride salts (NaCl, KCl) and phosphate salts derived from MPC1 can be subjected to a nanofiltration step (vii), which allows the retention of the phosphate ions to increase the purity of the sodium or potassium chloride salts.

[0172] The method according to the invention, and this example identified as the first example method, can also advantageously comprise a step (v) of treating the sodium chloride salt or potassium chloride salt in a three-compartment bipolar membrane electrodialysis unit 70, whereby the stream of salts, in particular NaCl and / or KCl, derived from the first compartment 20 of cationic electrodialysis step (ii), and / or Optionally, NaCl and / or KCl derived from the preliminary demineralization step carried out upstream to the composition MPC of step (i); and / or food-grade NaCl and / or KCl; and / or a stream of NaCl and / or KCl derived from step (vi) and / or step (vii); from the reaction mixture, allowing the regeneration of the acid, mainly HCl, and the base, mainly sodium or potassium hydroxide.

[0173] Said pre-desalting step preferably consists of a nanofiltration step.

[0174] In a preferred embodiment, said basic salt recycled in step (v) is added to MPC1 in said compartment 39, in particular during the extraction of anions and cations, ie under the influence of an electric field.

[0175] In another embodiment, the electrodialyzer 10 is stopped, then basic salt is added to the MPC1 in compartment 39, and then the electrodialyzer is restarted to continue the desalination.

[0176] In one embodiment, optionally in combination with one or the other of the two previous embodiments, a basic solution is added after step (iii).

[0177] With the exception of the salts used at the start of step (v), the acid and base salts used in carrying out the electrodialysis steps (ii) and (iii) are derived from the milk protein composition MPC1, thereby avoiding the introduction of exogenous mineral compounds.

[0178] 2 shows the electrodialyzer 70 and its unit cell 105, which includes a first compartment 110 defined between a bipolar membrane 112 and an anionic membrane 114, a second compartment 116 defined between the anionic membrane 114 and a cationic membrane 118, and a third compartment 120 defined between the cationic membrane 118 and a bipolar membrane 122. The salt, in particular sodium chloride or potassium chloride, is fed to the second compartment 116. The chloride ions pass through the anionic membrane 114 in the direction of the anode 125 under the influence of an electric field, while the Na + , K. +Ions pass through the cationic membrane in the direction of the cathode 127 under the influence of an electric field. This step (v) allows the regeneration of the acidic and basic salts, in particular hydrochloric acid and sodium hydroxide, which are then fed to the first compartment of the unit cell 15 or 215 of step (ii) for the acidic salts and / or to the first compartment 39 or 239 of the unit cell 35 or 235 of step (iii) for the basic salts during the step of adding at least one basic solution according to the invention.

[0179] The second example of a method for producing a desalted milk protein composition, shown in Figure 3, includes two electrodialyzers 200 and 205. The electrodialyzer 200 includes unit cells 215 each containing three compartments. The electrodialyzer 205 includes unit cells 235 each containing two compartments. A single unit cell 215 of the electrodialyzer 200 is shown in Figure 3. The unit cell 215 includes a first compartment 220 separated by an anionic membrane 222 and a cationic membrane 224, a second compartment 226 separated by the cationic membrane 224 and the cationic membrane 228, and a third compartment 230 separated by the cationic membrane 228 and the anionic membrane 232.

[0180] A single unit cell 235 of the electrodialyzer 205 is also shown in Figure 3. The unit cell 235 includes a first compartment 239 separated by a cationic membrane 237 and an anionic membrane 241, and a second compartment 243 separated by an anionic membrane 241 and a cationic membrane 249.

[0181] The electrodialyzers 200 and 205 each comprise an anode (278, 290) and a cathode (280, 288) for generating an electric current through the conductive solution passing through the compartments of the unit cells 215 and 235. The method may also comprise a first nanofiltration device 250 for performing step (vi), and / or a second nanofiltration device 260 for performing step (vii), and / or a three-compartment bipolar membrane electrodialyzer 70, particularly detailed in Figure 2, for performing step (v). Furthermore, the method may comprise a heat treatment unit 275 for performing the heat treatment step (viii), particularly pasteurization.

[0182] In operation, a milk protein composition MPC, particularly whey desalted to at least 30%, is fed to the second compartment 226 of the electrodialyzer 200. At the same time, an acidified salt, particularly a hydrochloric acid solution, is fed to the first compartment 220 and water is fed to the third compartment 230. + Only ions cross the cationic membrane 224 to the second compartment 226 and toward the cathode 280, while the chloride ions cross the anionic membrane 232 to the third compartment 230 and toward the anode 278. In the second compartment 226, Na + and Ca 2+ The monovalent or divalent cations, such as + The milk protein composition MPC1 obtained in step (ii) is thus partially desalted and the cations are replaced by H + The third compartment 230 contains a mixture of CaCl2 and NaCl derived from the milk protein composition MPC. Chloride ions from the first compartment 220 pass through the anionic membrane 222 or 232 and enter the third compartment 230.

[0183] The acidified milk protein composition MPC1 is preferably subjected to a heat treatment in step (viii), in particular a thermization step (heating to 90°C for several minutes), in order to improve its bacteriological stability. Advantageously, since the composition MPC1 is acidified, the conditions of the heat treatment can be determined so that the proteins are not denatured.

[0184] The mixture of salts derived from the third compartment 230 may be subjected to a nanofiltration step (vi) in the nanofiltration unit 250 to increase the purity of the sodium chloride salts derived from the third compartment 230 by extraction of divalent salts such as calcium chloride, CaCl. This step may optionally be followed by treatment with a chelating resin to achieve the 3-5 ppm input specification of step (v).

[0185] In particular, the heat-treated composition MPC1 is subjected to a second electrodialysis step (iii) in the electrodialyzer 205 .

[0186] The first compartment 239 is supplied with heated and acidified MPC1. The second compartment 243 receives water. The anions (chloride, phosphate) pass through the anionic membrane 241 and are retained in the second compartment 243. The cations (sodium, magnesium) pass through the cationic membrane 237 and remain in the brine compartment (243). Thus, the composition MPC2 recovered in step (iv) is demineralized and deacidified.

[0187] In the second compartment 243, the mixture of sodium and / or potassium chloride salts (NaCl, KCl) and phosphate salts derived from MPC1 can be subjected to a nanofiltration step (vii) to increase the purity of the sodium chloride salts by retaining the phosphate ions.

[0188] Said method according to the invention, and in particular this second method example, can also advantageously comprise a step (v) of treating said sodium or potassium chloride salt in a three-compartment bipolar membrane electrodialysis unit, in particular the electrodialyzer 70 shown in FIG. 2 and previously described, whereby a salt, in particular NaCl and / or KCl, stream derived from the preliminary desalting step carried out upstream of the composition MPC of step (i); and / or food-grade NaCl and / or KCl; and / or a stream of NaCl and / or KCl derived from step (vi) and / or step (vii); from the reaction mixture, allowing the regeneration of the acid, mainly HCl, and the base, mainly sodium or potassium hydroxide.

[0189] Said pre-desalting step preferably consists of a nanofiltration step.

[0190] In a preferred embodiment, said basic salt recycled in step (v) is added to MPC1 in said compartment 239, in particular during the extraction of anions and cations, ie under the influence of an electric field.

[0191] In another embodiment, the electrodialyzer 205 is stopped, then a basic salt is added to the MPC1 in compartment 239, and then the electrodialyzer 205 is restarted to continue the desalination.

[0192] In one embodiment, optionally in combination with one or the other of the two previous embodiments, a basic solution is added after step (iii).

[0193] With the exception of the salts used at the start of step (v), the acid and base salts used in carrying out the electrodialysis steps (ii) and (iii) are derived from the milk protein composition MPC1, thereby avoiding the introduction of exogenous mineral compounds.

[0194] The second exemplary process differs from the first exemplary process by the use of a selectively permeable membrane in step (ii).

[0195] The cation exchange step (ii) can be carried out in either electrodialyzer 5 (FIG. 1) or 200 (FIG. 3).

[0196] To carry out the tests described below, a milk protein composition MPC was made by preparing a 16% dry mass dispersion of (raw) sweet whey powder in demineralized water. The dispersion was mechanically stirred until a homogeneous mixture was obtained. The MPC therefore exhibited the following parameters: mass percentage in dry matter: 15.9% (powder mass / total mass); pH = 5.95; initial conductivity: 10.95 mS / cm; ash mass content: 8.1%; lactose mass content: 73.5%; cation (especially Na, NH4, K, Ca, Mg) mass content: 3.79%; anion (especially Cl, NO3, PO4, SO4) mass content: 3.64%. The various mass percentages (except in the case of dry matter) were calculated by relating the total mass of one or more compounds to the total mass of said dry matter.

[0197] 1. Cation substitution in electrodialyzer 200 (Figure 3)

[0198] The electrodialyzer 200 comprises, for example, five to fifteen cells 215. The first compartment 220 is supplied with an HCl solution having a conductivity of 100 mS / cm or more, in particular 150 mS / cm or more. The second compartment 226 is supplied with the MPC exemplified above. The third compartment is initially supplied with an NaCl solution having a conductivity of 50 mS / cm or less, in particular 25 mS / cm or less, in this particular example 15 mS / cm or less. A current (I) of 1 ampere or more, in particular 2 amperes or less, is applied to the electrodialyzer 200, the voltage preferably remaining open. During electrodialysis (ii), the conductivity of the MPC decreases, indicating its desalination, and the cations contained therein are then converted to H +The conductivity increases due to the substitution of cations with HCl. The pH of the resulting MPC1 is about 1, and the conductivity of the MPC1 is about 12 mS / cm. The conductivity of the acidic solution, i.e., HCl, at the outlet of the first compartment 220 decreases by about 74%, and the conductivity of the brine, i.e., NaCl, obtained at the outlet of the third compartment 230 increases by about 234%. The cation removal rate is about 84%.

[0199] 2. Cation substitution in electrodialyzer 5 (Figure 1)

[0200] The electrodialyzer 5 comprises, for example, five to fifteen cells 15. The first compartment 20 is supplied with an HCl solution having a conductivity of 100 mS / cm or more, in particular 150 mS / cm or more. The second compartment 26 is supplied with the MPC exemplified above. The third compartment is initially supplied with an NaCl solution having a conductivity of 50 mS / cm or less, in particular 25 mS / cm or less, in this particular example 15 mS / cm or less. A current (I) of 1 ampere or more, in particular 2 amperes or less, is applied to the electrodialyzer 5, the voltage preferably remaining open. At the start of electrodialysis (ii), the conductivity of the MPC decreases, indicating its desalination, and then the cations contained therein are converted to H + In the acidic compartment 20, H + The conductivity decreases due to ion depletion and production of less conductive NaCl. The cations extracted from the MPC migrate to the brine compartment 30, which is enriched in polyvalent cations that are more conductive than NaCl. The resulting MPC1 has a pH of about 1 and a conductivity of about 12 mS / cm. The conductivity of the acidic solution at the outlet of the first compartment 220 decreases by about 35%, while the conductivity of the brine obtained at the outlet of the third compartment 30 increases by about 25%. The cation removal rate is about 82%.

[0201] For the implementation of step (iii), the MPC1 used can be either that from electrodialyzer 5 or 200, since the latter have the same performance in terms of cation removal rate.

[0202] To carry out the tests described below, a milk protein composition MPC" was made by preparing a dispersion of 17% dry weight of (raw) sweet whey powder in demineralized water. The dispersion is mechanically stirred until a homogeneous mixture is obtained. MPC" therefore exhibits the following parameters: mass percentage of dry matter: 17% (powder mass / total mass); pH = 5; initial conductivity: 12 mS / cm; ash mass content: 8%; lactose mass content: 74%; cation (in particular Na, NH4, K, Ca, Mg) mass content: 5%; anion (in particular Cl, NO3, PO4, SO4) mass content: 3%; the various mass proportions (excluding those of the dry matter) are calculated by relating the total mass of one or more compounds to the total mass of said dry matter.

[0203] 3. Cation substitution in the electrodialyzer 200 (ESC) (Figure 3)

[0204] The electrodialyzer 200 comprises, for example, five to fifteen cells 215. The first compartment 220 is supplied with an HCl solution having a conductivity of 100 mS / cm or more, in particular 150 mS / cm or more. The second compartment 226 is supplied with the MPC" exemplified above. The third compartment is supplied with an NaCl solution having a conductivity of 50 mS / cm or less, in particular 25 mS / cm or less, in this particular example 15 mS / cm or less. A current (I) of 2 amperes or more, in particular 3 amperes or less, is applied to the electrodialyzer 200, the voltage preferably remaining open. During electrodialysis (ii), the conductivity of the MPC" decreases, indicating its desalination, and the cations contained therein are then converted to H + The conductivity of the acid solution, i.e., HCl, at the outlet of the first compartment 220 decreases by about 53%, and the conductivity of the brine, i.e., NaCl, obtained at the outlet of the third compartment 230 increases by about 292%. The removal (or replacement) rate of cations is about 77%. The proportion of anions is substantially the same for MPC'' and MPC1''.

[0205] 4. Conventional Two-Compartment Electrodialysis (ED) (Anionic Membrane / Cationic Membrane) (e.g., step (iii) 10 or 205 in Figures 1 or 3)

[0206] The electrodialyzer comprises, for example, five to fifteen cells. The first compartment is supplied with the MPC1" and the second compartment is initially supplied with a salt, in particular sodium chloride, having a conductivity of 5 mcS / cm or more and 15 mcS / cm or less. During the test, a voltage of 10 V or more and 20 V or less, in particular 15 V or less, is applied to the two-compartment electrodialyzer, and the current (I) is left open. During the test, the conductivity of the MPC1" decreases, indicating its desalination. H + Since some of the ions are extracted in the brine compartment, the pH of MPC1" (ESC+ED) at the outlet increases, especially above 2.5, especially above 3. The final conductivity of MPC1" (ESC+ED) is reduced by approximately 90% compared to MPC by this conventional electrodialysis. The cation (Na, NH4, K, Ca, Mg) rejection rate in MPC1" (ESC+ED) is above 90% (compared to MPC1" obtained at the outlet of the cation-exchanged ED, Figure 3). The anion (Cl, NO3, PO4, SO4) rejection rate in MPC1" (ESC+ED) is above 80% (compared to MPC1" obtained at the outlet of the cation-exchanged ED, Figure 3).

[0207] A basic solution (eg, 5% m / m sodium hydroxide solution) can be added to the recovered MPC2 to adjust the pH to the desired pH.

[0208] It is also possible to add the basic solution to the compartment of the electrodialyzer in step (ii) that receives MPC1 simultaneously with the extraction of cations and anions, thus under the application of an electric field. This route allows the pH to be increased while desalting MPC1. Furthermore, a synergistic effect was observed, as the extraction of phosphate ions, and calcium and magnesium ions was improved compared to desalting using ED without the addition of a base.

[0209] To carry out the tests described below, the milk protein composition MPC(A) was provided at 23% dry mass. The milk protein composition was sweet whey pre-concentrated by evaporation. MPC(A) therefore exhibited the following parameters: dry matter content: 23% (dry mass / total mass); pH=6.04; initial conductivity: 12.2 mS / cm; ash mass content: 7.6% (% ash mass / total dry mass); TNM mass content: 15.7% (% TNM mass / total dry mass); Na 541 mg / 100 g total dry matter; K 2269 mg / 100 g total dry matter; Ca 513 mg / 100 g total dry matter; Mg 104 mg / 100 g total dry matter; Cl 1357 mg / 100 g total dry matter; and phosphorus 640 mg / 100 g total dry matter.

[0210] 5. Cation substitution in the electrodialyzer 200 (ESC) (Figure 3)

[0211] The electrodialysis device 200 comprises, for example, five to twenty-five cells 215. The first compartment 220 is supplied with an HCl solution having a conductivity of at least 100 mS / cm, in particular at least 150 mS / cm. The second compartment 226 is supplied with the MPC(A) exemplified above. The third compartment is supplied with water. A current (I) of at least 2 amperes, in particular at most 10 amperes, is applied to the electrodialysis device 200, the voltage preferably remaining open. During electrodialysis (ii), the conductivity of the MPC(A)' decreases, indicating its desalination, after which the cations contained therein are converted to H + The conductivity of the acid solution, i.e., HCl, at the outlet of the first compartment 220 decreases, and at the outlet of the third compartment 230, the water is loaded with ions and contains brine at the outlet. The following profile is obtained for the cations of MPC1(A): Na 166 mg / 100 g total dry matter; K 378 mg / 100 g total dry matter; Ca 314 mg / 100 g total dry matter; Mg 79 mg / 100 g total dry matter. The concentrations of anions are substantially the same between MPC(A) and MPC1(A).

[0212] 6. Conventional Two-Compartment Electrodialysis (ED) (Anionic Membrane / Cationic Membrane) (e.g., electrodialyzer 10 or 205 in Figures 1 or 3)

[0213] The electrodialyzer contains, for example, 5 to 50 cells. The first compartment is supplied with the above-mentioned MPC1(A), and the second compartment is supplied with water. During the test, a voltage of 10 V to 50 V, in particular 40 V, is applied to the two-compartment electrodialyzer, and the current (I) is left open. During the test, the conductivity of MPC(A) decreases, indicating its desalination. The H + Some of the ions are extracted in the brine compartment, increasing the pH of MPC1(A) at the outlet.

[0214] In one embodiment, the addition of a basic solution at 5% (m / m) is performed to MPC2 after step (iii) rather than during step (iii).

[0215] In this case, the pH of MPC2 obtained at the end of step (iii) (before the addition of sodium hydroxide) is about 4.5. The MPC2 at the outlet of step (iii) has a conductivity of about 0.3 mS / cm. The following ion profile is obtained: Na approximately 0 mg / 100 g total dry matter; K 0 mg / 100 g total dry matter; Ca 35 mg / 100 g total dry matter; Mg 19 mg / 100 g total dry matter; Cl 14 mg / 100 g total dry matter; and Phosphorus 206 mg / 100 g total dry matter. The cation removal rate is 98%, and the anion removal rate is 89%.

[0216] In another embodiment, the addition of the basic solution is carried out to MPC1 during step (iii) simultaneously with the extraction of anions and cations under the application of an electric field. 5% (m / m) sodium hydroxide solution (NaOH) is added in the compartment of the electrodialyzer in step (iii) containing MPC1. Preferably, this addition is carried out after the conductivity observed in ED(iii) has decreased by about 75%. Preferably, the addition of sodium hydroxide is carried out when MPC1 has a conductivity of 1 mS / cm or less, in this embodiment around 0.5 mS / cm, and / or when the pH is 3 or greater, particularly 4 or greater.

[0217] In this case, the pH of the MPC2 obtained at the end of step (iii) is around 5.2. The MPC2 at the outlet of step (iii) has a conductivity of around 0.3 mS / cm. The following ion profile is obtained: Na approx. 53 mg / 100 g total dry matter; K 0 mg / 100 g total dry matter; Ca 24 mg / 100 g total dry matter; Mg 13 mg / 100 g total dry matter; Cl 9 mg / 100 g total dry matter; and Phosphorus 160 mg / 100 g total dry matter. The ash content is 0.50% (% ash mass / total dry mass). The cation rejection is 97% and the anion rejection is 92%.

[0218] The addition of a basic solution in said ED(iii) under the application of an electric field makes it possible to improve the extraction of phosphate ions and divalent cations compared to ED(iii) without the addition of said basic solution.

[0219] In a comparative embodiment, step (ii) does not involve the addition of a basic solution, and the desalting method comprises a step of exclusively anion substitution in an electrodialyzer, the cell of which comprises a three-compartment MPC2(A) as described herein, carried out after step (ii). In this case, the pH of the resulting milk protein composition is around 5.4, with a conductivity of around 0.2 mS / cm. The following ion profile is obtained: Na -19 mg / 100 g total dry matter; K -2 mg / 100 g total dry matter; Ca -39 mg / 100 g total dry matter; Mg -37 mg / 100 g total dry matter; Cl -11 mg / 100 g total dry matter; and Phosphate -110 mg / 100 g total dry matter. The ash content is 0.40% (% ash mass / total dry mass). The mass fraction of divalent cations is greater than that obtained above compared to step (iii) during the period in which the basic solution is added.

[0220] The step (iii) in combination with step (ii) in which a base is added during the latter under an electric field allows for an improvement in extraction of divalent cations of about 30% and phosphate extraction of about 20% compared to step (iii) in combination with (ii) in which no sodium hydroxide is added during the latter, and allows for an improvement in extraction of divalent cations of about 44% compared to the comparative embodiment.

[0221] The step (iii) described in point 6 can also be applied to MPC1 obtained in point 1 or point 2 to obtain MPC2.

Claims

1. 1. A method for producing a desalted milk protein composition (MPC2), comprising: (i) providing a milk protein composition (MPC); (ii) electrodialyzing the milk protein composition (MPC) in an electrodialyzer, the electrodialyzer comprising a plurality of unit cells, each unit cell comprising three compartments, the compartments of the unit cells receiving the milk protein composition (MPC) being separated by two cationic membranes, and each unit cell converting at least one cation in the milk protein composition (MPC) into at least one hydrogen ion H ＋ to obtain an at least partially desalted and acidified milk protein composition (MPC1); (iii) electrodialyzing the milk protein composition (MPC1) obtained in step (ii), which comprises removing anions and cations in the milk protein composition (MPC1); and (iv) recovering the desalted milk protein composition (MPC2); Including, The method comprises adding at least one basic solution to the milk protein composition during and / or after step (iii).

2. The manufacturing method described in claim 1, wherein the at least one basic solution contains at least one basic salt.

3. 3. The process of claim 1 or 2, wherein said addition of said basic solution is carried out simultaneously with said removal of ions during at least a portion of electrodialysis step (iii).

4. 4. The method of any one of claims 1 to 3, wherein the adding of the basic solution to the milk protein composition is carried out when the milk protein composition has a conductivity of 1 mS / cm or less.

5. The manufacturing method described in claim 4, wherein the addition of the basic solution to the milk protein composition is carried out when the milk protein composition has a pH of 3 or higher.

6. 6. The method of any one of claims 1 to 5, wherein after the addition of the basic solution, the milk protein composition has a pH of 4.5 or greater.

7. The manufacturing method described in claim 6, wherein after the addition of the basic solution, the milk protein composition has a pH of 5.0 or higher.

8. The milk protein composition (MPC2) recovered in step (iv) contains phosphate ions (H ２ P.O. ４ - , H.P.O. ４ ２- , P.O. ４ ３- 8. The method according to claim 1, wherein the mass of phosphorus is 110 mg or more per 100 g of total dry mass of the recovered milk protein composition (MPC2).

9. The production method described in claim 8, wherein the milk protein composition (MPC2) recovered in step (iv) contains phosphate ions (H2PO4-, HPO42-, PO43-), and the mass of phosphorus is 150 mg or more per 100 g of total dry mass of the recovered milk protein composition (MPC2).

10. 10. The production method according to any one of claims 1 to 9, wherein the milk protein composition (MPC2) recovered in step (iv) contains sodium ions or potassium ions, the mass of which is 20 mg or more per 100 g of the total dry mass of the recovered milk protein composition (MPC2).

11. The method for producing a milk protein composition (MPC2) according to claim 10, wherein the milk protein composition (MPC2) recovered in step (iv) contains sodium ions or potassium ions, the mass of which is 30 mg or more per 100 g of the total dry mass of the recovered milk protein composition (MPC2).

12. the salt directly resulting from the electrodialysis step (ii), salts derived indirectly from the electrodialysis step (ii), the salt directly resulting from the electrodialysis step (iii), a salt derived indirectly from the electrodialysis step (iii), salt from a preliminary desalting step carried out on the milk protein composition prior to step (i); and mixtures thereof, and (v) treating at least a portion of the salt selected from The treatment step (v) is configured to produce, on the one hand, one or more acid salts and / or, on the other hand, one or more basic salts by an electrodialysis step carried out in a bipolar membrane electrodialyzer. The method according to any one of claims 1 to 11.

13. 13. The method according to claim 12, wherein the bipolar membrane electrodialyzer in step (v) comprises a plurality of unit cells, each unit cell comprising three compartments A, B and C, wherein compartments A and B are supplied with water, and compartment C is supplied with one or more salts.

14. A manufacturing method as described in claim 13, wherein compartment C is arranged between compartment A and compartment B.

15. 15. The process according to claim 14, wherein at least a portion of the one or more salts obtained during treatment step (v) is fed to one of the three compartments of the electrodialyzer in step (ii).

16. The method of claim 15, wherein at least a portion of the one or more salts is hydrochloric acid or sulfuric acid or a mixture thereof.

17. 17. The process according to any one of claims 12 to 16, wherein the basic solution comprises, at least in part, one or more basic salts, which are sodium hydroxide and / or potassium hydroxide, obtained during treatment step (v).

18. 18. The process according to any one of claims 1 to 17, wherein the basic solution comprises at least partly recycled effluent obtained through recycling of the effluent from step (ii) and / or step (iii) by an electrodialysis step carried out in a bipolar membrane electrodialyser.

19. 19. The method of any one of claims 1 to 18, wherein the milk protein composition is selected from the list comprising: whey; milk ultrafiltration permeate; milk microfiltration permeate; whey ultrafiltration retentate or permeate; milk microfiltration permeate ultrafiltration retentate or permeate; or mixtures thereof.

20. The manufacturing method described in claim 19, wherein the milk protein composition is whey.

21. A method for producing a product according to claim 19 or 20, wherein the whey is selected from the list including sweet whey, acid whey and mixtures thereof.

22. An installation for carrying out the method according to any one of claims 1 to 21, comprising: a) a first electrodialyzer comprising a first inlet intended to receive a milk protein composition (MPC) and a first outlet for an at least partially desalted and acidified milk protein composition (MPC1), the first electrodialyzer comprising a plurality of unit cells, each unit cell comprising three compartments, the compartments of the unit cells of the first electrodialyzer of step (ii) receiving the milk protein composition (MPC) being respectively separated between two cationic membranes, each unit cell being separated by at least one cation in the milk protein composition (MPC) being converted into at least one hydrogen ion H ＋ a first electrodialyzer configured to be replaced by b) a second electrodialyzer comprising a first inlet intended to receive the milk protein composition (MPC1) obtained in step (ii) and a first outlet for the milk protein composition (MPC2), said second electrodialyzer comprising a plurality of unit cells, each unit cell comprising a plurality of compartments, one of said compartments intended to receive the milk protein composition (MPC1), said second electrodialyzer making it possible to carry out step (iii) of removing anions and cations in the milk protein composition (MPC1); c) a device containing said basic solution, said basic solution being configured to be added for a predetermined period of time to the compartment of said second electrodialyzer intended to receive said milk protein composition (MPC1); Facilities including.

23. The equipment described in Claim 22, wherein the device containing the basic solution is configured so that, under the application of an electric field, the basic solution is added to the compartment of the second electrodialyzer for a predetermined period of time.

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