Process for treating a dairy protein composition to produce a lactose-rich liquid composition.

Abstract

The present invention relates to a process for treating a milk protein composition to obtain a lactose-rich liquid composition comprising an ultrafiltration step ii) for obtaining an ultrafiltration permeate and an ultrafiltration retentate; followed by a treatment step on ion exchange resins (iv) comprising at least one pass comprising percolation on a cationic resin followed by percolation on an anionic resin.

Description

Title of the invention: Process for treating a dairy protein composition for the manufacture of a lactose-rich liquid composition. Technical field

[0001] The present invention relates to the field of the valorization of a dairy protein composition, in particular whey or a milk ultrafiltration permeate, for the manufacture of a lactose-rich liquid composition. Prior art

[0002] The agri-food industry generates, annually, significant quantities of by-products, which can have harmful effects on the environment when they cannot be recovered.

[0003] Whey is a by-product of milk processing, particularly in the cheese industry. It can be used in animal feed, or if it cannot be recovered, it is discarded. Today, and thanks to the various recovery processes, its use in several areas has expanded considerably. Indeed, whey is sought after as a raw material for its components (proteins, lactose and minerals) and thus represents an opportunity for the manufacture of new products.

[0004] Whey (Sérum Lactus), commonly called "serum" or "whey", is a dairy co-product that results either from the coagulation of milk during cheese making, particularly after the separation of casein and fat during milk coagulation, or from a membrane filtration process of milk such as milk microfiltration. This is the liquid part. The solid part is called curd. It is aqueous, translucent and is characterized by a greenish-yellow color.

[0005] There are three types of whey: those produced from the production of caseins or fresh cheeses in an acidic environment (acid whey); those produced from the production of caseins using rennet and cooked or semi-cooked pressed cheeses (sweet whey); and those produced from the microfiltration of milk, called ideal or native serum (this is the microfiltration permeate of milk).

[0006] Whey is mainly formed of water, lactose, proteins, in particular serum proteins, and minerals. Whey can be recovered by isolating the lactose on the one hand, and the proteins on the other. Whey proteins can also be recovered as an ingredient for the manufacture of numerous food products, for example for the manufacture of nutritional and protein drinks.

[0007] It is known to treat non-demineralized whey by ultrafiltration (UF) in order to manufacture dairy protein concentrates (WPC for Whey Protein Concentrate in English) from the ultrafiltration retentate. Ultrafiltration permeates are used in animal feed, in methanization, or in lactose production. These permeates, low in protein, rich in lactose but also in minerals, are difficult to valorize. The production costs of these UF permeates are often supported by the high added value of its co-product, non-demineralized WPC.

[0008] There is thus a need to improve the recovery of milk by-products, in particular whey or milk ultrafiltration permeates, in particular by developing new outlets and by developing efficient treatment processes generating little effluent(s) to be treated because they maximize the recovery of the compounds of interest. Statement of the invention

[0009] The subject of the present invention, according to a first aspect, is a method for treating a dairy protein composition to obtain a lactose-rich liquid composition meeting the aforementioned problems, and comprising the steps: (i)- providing a dairy protein composition; (ii)- ultrafiltration of said dairy protein composition allowing the production of an ultrafiltration permeate and an ultrafiltration retentate; (iii)- an at least partial demineralization step taking place before ultrafiltration step (ii) and / or after ultrafiltration step (ii); (iv)- at least one treatment step on ion exchange resins of the ultrafiltration permeate, at least partially demineralized, comprising at least one pass comprising percolation on a cationic resin followed by percolation on an anionic resin.

[0010] Advantageously, when the milk protein composition passes through the ultrafiltration unit, the serum proteins are retained in the ultrafiltration retentate, and are therefore concentrated in this retentate while the water and the low molecular weight molecules in solution pass through the ultrafiltration membrane(s). The permeation of minerals is not equivalent to the permeation of lactose. Certain minerals are in fact bound to the serum proteins and consequently retained in the retentate.

[0011] The combination of the steps of ultrafiltration (ii), demineralization (iii) and at least one pass on ion exchange resins during step (iv) makes it possible to obtain a liquid composition rich in lactose and demineralized from the milk protein composition of step (i).

[0012] The present invention makes it possible to obtain a liquid composition rich in lactose, in particular with a dry mass fraction of lactose greater than or equal to 90%.

[0013] For dry mass fractions of lactose greater than or equal to 90%, in particular greater than or equal to 95%, it can be considered that it is a liquid lactose.

[0014] Lactose exists in the state of the art in solid form (for example in powder form), and is obtained after treatment in a lactose factory of a liquid composition comprising dry mass fractions of lactose lower than those obtained in the present invention.

[0015] The presentation of lactose in liquid form is new. This form has many advantages for its implementation, particularly for the formulation of dairy products. In addition, this frees manufacturers using the milk protein composition (i) from having to provide a costly and complex lactose factory to implement.

[0016] The lactose obtained by means of the process according to the invention can be recovered in liquid form or in solid form (by implementing a step of evaporation of the water and drying). Step (iii) of demineralization

[0017] The demineralization step (iii) may be any demineralization step known to those skilled in the art making it possible to lower the conductivity (psiemens / cm) and / or the dry mass fraction of minerals and / or ash: of the milk protein composition (i) before the ultrafiltration step (ii), and / or of the ultrafiltration permeate (ii) before the step iv) of treatment on the ion exchange resins. The intensity of this demineralization is a function of the dry mass fraction of minerals of the milk protein composition in step i).

[0018] This demineralization step (iii) can take place before the UF step (ii) in order to at least partially demineralize the dairy protein composition at the inlet of the UF step (ii), and / or after the UF step (ii) in order to at least partially demineralize the ultrafiltration permeate at the inlet of step (iv) comprising at least one pass over ion exchange resins.

[0019] Finally, the ultrafiltration permeate must be highly demineralized at the inlet of step (iv) on the ion exchange resins in order to increase the dry mass fraction of lactose in the lactose-rich liquid composition obtained.

[0020] This demineralization step can be carried out in a non-limiting manner as described in the present text or as described in patent EP 1,053,685 B1 or in WO 2020 / 207894.

[0021] The term “liquid composition rich in lactose obtained” means the composition recovered / collected at the end of step iv), or after a decolorization step described below or a step v) described below to remove in particular the galactose.

[0022] Preferably, the temperature of the dairy protein composition in step (i) and / or at the inlet of step (ii) and / or of the UF permeate obtained in step (ii) and / or of the UF retentate obtained in step (ii) and / or of the UF permeate in step iv) and / or of the lactose-rich liquid composition obtained is greater than 0°C, more particularly less than or equal to 40°C, even more particularly less than or equal to 30°C, in particular less than or equal to 20°C.

[0023] Preferably, the ultrafiltration step (ii) and / or the demineralization step (iii) and / or the step (iv) on the ion exchange resins is / are carried out (i.e. so as to maintain the treated product) at a temperature above 0°C, more particularly less than or equal to 40°C, even more particularly less than or equal to 30°C, in particular less than or equal to 20°C. Milk protein composition

[0024] The dairy protein composition of step (i) may be chosen from, in particular is chosen from the list consisting of: milk, in particular skimmed milk, whey, and a mixture of the latter, optionally partially demineralized.

[0025] The whey according to the invention may be chosen from, in particular is chosen from the list consisting of: a sweet whey; an acid whey; an ideal or native whey, in particular a milk microfiltration permeate; and a mixture of these.

[0026] A sweet whey can be obtained by a physicochemical treatment of the milk (for example precipitation and / or coagulation), in particular using rennet, making it possible to recover on the one hand the caseins and on the other hand the sweet whey.

[0027] An ideal or native whey can be obtained by a physical membrane treatment of the milk, in particular by implementing microfiltration, making it possible to recover on the one hand the casein and on the other hand an ideal whey.

[0028] An acid whey is preferably obtained by an acid treatment of the milk, in particular using lactic acid and / or hydrochloric acid, making it possible to recover on the one hand the caseins, and on the other hand the acid whey.

[0029] The dairy protein composition in step (i), or the dairy protein composition before or after a demineralization step (iii) carried out before the UF step (ii), may be pre-concentrated to increase its total dry mass fraction, mechanically (for example by reverse osmosis or nanofiltration or a combination thereof) and / or thermally (for example by evaporation of water).

[0030] The dairy protein composition in step (i) may be partially demineralized or not, i.e. raw.

[0031] The demineralization step (iii) can thus be a first demineralization when the milk protein composition of step (i) has not undergone demineralization. prior, or a second or nth demineralization step when the milk protein composition of step (i) has already been partially demineralized.

[0032] In one embodiment, the dairy protein composition in step (i), preferably obtained after a demineralization step (iii) carried out before the UF step (ii), has an ash mass fraction, calculated relative to the total dry mass of said dairy protein composition, greater than 0% and less than or equal to 6%, preferably less than or equal to approximately 2.5%.

[0033] In one embodiment, the dairy protein composition in step (i), or obtained after a demineralization step (iii) carried out before step (ii) of UF, has a dry extract greater than or equal to 5% and less than or equal to 35%, more preferably greater than or equal to 10% and less than or equal to 30%.

[0034] The dairy protein composition in step (i) is liquid when it is implemented. It can be obtained by reconstitution of a liquid solution from powder(s) and / or mixed liquid(s), for example by dispersing in water a whey powder, optionally partially demineralized, or a milk powder, optionally partially demineralized and skimmed, and their mixtures.

[0035] In one embodiment, the dairy protein composition in step (i), preferably obtained after a demineralization step (iii) carried out before a UF step (ii), has a demineralization rate greater than or equal to 70%, more preferably greater than or equal to 80%, preferentially greater than or equal to 85%, in particular greater than or equal to 90%.

[0036] Generally speaking, the milk protein composition comes from milk, which milk can come from any dairy female.

[0037] Preferably, the milk protein composition is derived from a milk chosen from: cow's milk, goat's milk, sheep's milk, donkey's milk, buffalo's milk, mare's milk, camel's milk, and a mixture of the latter, more preferably chosen from: cow's milk, goat's milk and sheep's milk and a mixture of the latter, in particular it is cow's milk.

[0038] Whey comprises serum proteins, and preferably does not comprise caseins remaining in the solidified (coagulated) part during milk processing and / or in the microfiltration retentate of the milk.

[0039] In one embodiment, the dairy protein composition in step (i), or obtained after a demineralization step (iii) carried out before step (ii) of UF, is a whey whose ratio of the dry mass of lactose to the total dry mass of said whey is greater than or equal to 50%, preferably greater than or equal to 60%, more preferably greater than or equal to 70%, preferentially greater than or equal to 80%, in particular greater than or equal to 85%.

[0040] In one embodiment, the dairy protein composition in step (i), or obtained after a demineralization step (iii) carried out before step (ii) of UF, is a whey whose ratio of the dry mass of lactose to the total dry mass of said whey is less than or equal to 90%.

[0041] In one embodiment, the dairy protein composition in step (i), or obtained after a demineralization step (iii) carried out before step (ii) of UF, is a whey whose ratio of the dry mass of the total nitrogenous matter (TNM), to the total dry mass of said whey, is greater than 0%, preferably greater than or equal to 1%, more preferably greater than or equal to 3%, preferentially greater than or equal to 5%.

[0042] In one embodiment, the dairy protein composition in step (i), or obtained after a demineralization step (iii) carried out before step (ii) of UF, is a whey, the ratio of the dry mass of the total nitrogenous matter (TNM) to the total dry mass of said whey, is less than or equal to 30%, preferably less than or equal to 25%, preferentially less than or equal to 20%.

[0043] Preferably, the dairy protein composition in step i), or obtained after a demineralization step (iii) carried out before step (ii) of UF, has a conductivity greater than or equal to 0.10 mS / cm, preferably greater than or equal to 0.80 mS / cm, more preferably less than or equal to 15 mS / cm.

[0044] Preferably, the dairy protein composition in step (i), or at the inlet of step (ii) of UF, comprises the following cations: calcium, magnesium, sodium, potassium.

[0045] Preferably, the dairy protein composition in step (i), or at the inlet of step (ii) of UF, comprises the following anions: chloride, phosphate, sulfate, lactate, and citrate, which are in particular the anions targeted by the demineralization process according to the invention.

[0046] In the present text, the term “dairy protein composition at the input of the UF step (ii)” refers to a dairy protein composition which has possibly undergone a demineralization step (iii). Sweet Whey# / Native Whey

[0047] In one embodiment, the dairy protein composition in step (i) is a sweet whey or a native whey or a mixture thereof, optionally at least partially demineralized (for example during a step (iii) before the ultrafiltration step (ii)), which has one of the following properties, alone or in combination: - a pH between 4.7 and 6.9; - the ratio of the dry mass of lactose to the total dry mass of sweet whey, or native whey, is greater than or equal to 70% or 80%, in particular less than or equal to 90% or 85%; - the ratio of the dry mass of the total nitrogenous matter (TNM) to the total dry mass of the sweet whey, or of the native whey, is greater than or equal to 10%, preferably greater than or equal to 12%, in particular less than or equal to 20%; - the ratio of the dry mass of the ash to the total dry mass of the sweet whey, or of the native whey, is greater than or equal to 0.1%, in particular greater than or equal to 0.3%, - when said sweet or native whey is partially demineralized, the ratio of the dry mass of the ash to the total dry mass of the sweet or native whey is less than or equal to 4% or 3%, or - the ratio of the dry mass of the ash to the total dry mass of the sweet or native whey is greater than or equal to 5%, in particular greater than or equal to 7%, in particular less than or equal to 13% (when said sweet or native whey is not demineralized). Acid whey

[0048] In one embodiment, the dairy protein composition in step (i) is an acid whey, optionally at least partially demineralized (for example during a step (iii) before the ultrafiltration step (ii), which has one of the following properties, alone or in combination: - a pH less than or equal to 6.5, in particular greater than or equal to 4, more particularly less than or equal to 6.1; - the ratio of the dry mass of lactose to the total dry mass of the acid whey is greater than or equal to 50% or 60% or 70% or 80%, in particular less than or equal to 90%, in particular less than or equal to 85%, for example in the case of whey resulting from the manufacture of cheeses in an acid medium or caseins in an acid medium; - the ratio of the dry mass of total nitrogenous matter (TNM) to the total dry mass of acid whey is greater than or equal to 5%, in particular less than or equal to 20%, in particular less than or equal to 15%; - when said acid whey is at least partially demineralized, the ratio of the dry mass of the ash to the total dry mass of the acid whey is greater than or equal to 1.5%, in particular less than or equal to 5%, or - the ratio of the dry mass of the ash to the total dry mass of the acid whey is greater than or equal to 5%, in particular greater than or equal to 7%, in particular less than or equal to 13% (when said acid whey is not demineralized). Step (ii) of ultrafiltration

[0049] Advantageously, the ultrafiltration of a whey, in particular one which is partially demineralized, makes it possible to increase the mass fraction of lactose in the permeate. In addition, the mass fraction of ash in the ultrafiltration retentate obtained at step (ii) is close to that of a whey protein isolate (WPI).

[0050] Advantageously, it is noted that the mass fractions of calcium and phosphorus calculated relative to the total dry mass of the UF retentate of an at least partially demineralized whey are reduced. This arrangement makes it possible to limit, or even eliminate, the precipitation of calcium phosphate or proteins on the membranes being concentrated during step (ii).

[0051] Advantageously, the proteins are thermally stabilized in the ultrafiltration retentate thanks to the prior extraction of calcium during the demineralization step (iii) taking place before step (ii).

[0052] These effects are advantageous because ash and organic acids can be problematic for the subsequent processing of whey protein concentrates and for fouling of ultrafiltration membranes over time.

[0053] In addition, permeation flows are improved, and production times versus cleaning time are optimized.

[0054] In one embodiment, the ratio of the dry mass of lactose to the total dry mass of the ultrafiltration permeate obtained in step (ii), or after a demineralization step (iii) carried out after step (ii) on said UF permeate (ii), is greater than or equal to 50%, preferably greater than or equal to 60%, more preferably greater than or equal to 70%, preferentially greater than or equal to 75% or 80%, more preferentially greater than or equal to 85% or 90%.

[0055] In one embodiment, the ratio of the dry mass of lactose to the total dry mass of the ultrafiltration permeate obtained in step (ii), or after a demineralization step (iii) carried out after step (ii) on said UF permeate (ii), is less than or equal to 96%.

[0056] In another embodiment, the ratio of the dry mass of lactose to the total dry mass of the ultrafiltration permeate obtained in step (ii), or after a demineralization step (iii) carried out after step (ii) on said UF permeate (ii), is greater than or equal to 96%.

[0057] In one embodiment, the ratio of the dry mass of the total nitrogenous matter (TNM), to the total dry mass of the ultrafiltration permeate obtained in step (ii), or after a demineralization step (iii) carried out after step (ii) on said UF permeate (ii), is greater than 0%, preferably greater than or equal to 1%, more preferably greater than or equal to 3%.

[0058] In one embodiment, the ratio of the dry mass of the total nitrogenous matter (TNM), to the total dry mass of the ultrafiltration permeate obtained in step (ii), or after a demineralization step (iii) carried out after step (ii) on said permeate of UF (ii), is less than or equal to 20%, preferably less than or equal to 15%, more preferably less than or equal to 10%, preferably less than or equal to 5%.

[0059] In one embodiment, the ultrafiltration permeate obtained in step (ii), or after a demineralization step (iii) carried out after step (ii) on said UF permeate (ii), has a demineralization rate greater than or equal to 70%, in particular greater than or equal to 75%, particularly greater than or equal to 80%, more particularly greater than or equal to 85%.

[0060] In one embodiment, the ultrafiltration permeate obtained in step (ii), or after a demineralization step (iii) carried out after step (ii) on said UF permeate (ii), has a demineralization rate greater than or equal to 90%, in particular greater than or equal to 95%.

[0061] In one embodiment, the ratio of the dry mass of the ash to the total dry mass of the ultrafiltration permeate obtained in step (ii), or after a demineralization step (iii) carried out after step (ii) on said UF permeate (ii), is greater than or equal to 0.1%, in particular greater than or equal to 0.3%.

[0062] In one embodiment, the ratio of the dry mass of the ash to the total dry mass of the ultrafiltration permeate obtained in step (ii), or after a demineralization step (iii) carried out after step (ii) on said UF permeate (ii), is less than or equal to 4%, preferably less than or equal to 2%, more preferably less than or equal to 1%.

[0063] In the present text, the term UF permeate (ii) at the inlet of step (iv) of passage through the ion exchange resins refers to a UF permeate which has possibly undergone a demineralization step (iii).

[0064] The UF permeate from step (ii) may be preconcentrated mechanically (for example by reverse osmosis or nanofiltration or a combination thereof) and / or thermally (for example by evaporation of water). This concentration step makes it possible to increase the mass content of dry matter and may be carried out before or after a demineralization step (iii) carried out after step (ii). Step (iv) on ion exchange resins

[0065] Advantageously, step iv) comprising at least one pass over ion exchange resins makes it possible to demineralize, and possibly deacidify, the ultrafiltration permeate from step ii). This step iv) also makes it possible to remove the residual nitrogenous material.

[0066] Step iv) also makes it possible to increase the dry mass fraction of lactose in the UF permeate resulting from ultrafiltration step ii). If this UF permeate is not demineralized or is demineralized but insufficiently so, it is necessary to carry out a demineralization step (iii) before step iv).

[0067] Percolation on a cationic resin also makes it possible to acidify the UF (ii) permeate, preferably before passing it over an anionic resin which makes it possible to raise the pH of the permeate.

[0068] Percolation on a cationic resin is advantageously a cationic substitution step, in particular of divalent and / or monovalent cations by hydrogen ions H+. In particular, this step is an acidification step (i.e. the pH of the UF (ii) permeate is lowered following its passage over the cationic resin).

[0069] Percolation on an anionic resin is advantageously a step of anionic substitution, in particular of divalent and / or monovalent anions by hydroxyl ions, in particular this step is a neutralization step (i.e. the pH of the UF (ii) permeate is raised following its passage on the anionic resin).

[0070] The cationic resin in step (iv) can be strong or weak.

[0071] The anionic resin in step (iv) can be strong or weak.

[0072] Preferably, the percolation on a cationic resin is carried out without the latter being mixed with an anionic resin.

[0073] Preferably, the percolation on an anionic resin is carried out without the latter being mixed with a cationic resin.

[0074] In the present text, percolation on a cationic or anionic resin is understood to mean percolation on at least one column comprising a cationic or anionic resin, preferably the treatment, in particular the circulation, of the product to be treated on a bed of particles (in particular beads) comprising a cationic or anionic resin.

[0075] In a preferred embodiment, step (iv) of treatment on ion exchange resins of the at least partially demineralized ultrafiltration permeate comprises at least one pass comprising a percolation on a strong cationic resin followed by a percolation on a weak anionic resin.

[0076] In particular, the weak or strong anionic resin makes it possible to raise the pH of the ultrafiltration permeate when the latter is acidic before passing over said weak or strong anionic resin.

[0077] Preferably, said strong cationic resin comprises SO3 sulfonate groups.

[0078] Said strong cationic resin in H+ form makes it possible to fix cations linked to strong or weak anions.

[0079] A weak cationic resin in H+ form can only fix cations bound to weak acids.

[0080] Preferably, the cationic resin, in particular strong, has an exchange capacity greater than or equal to 1.8 eq / liter.

[0081] The bed of cationic resin, in particular strong, preferably comprises beads whose size is greater than or equal to 0.45 mm, in particular of strong styrenic cationic resin.

[0082] The bed of anionic resin, in particular weak, preferably comprises beads whose size is greater than or equal to 0.40 mm, in particular of styrenic weak anionic resin.

[0083] Preferably, the anionic resin, in particular weak, has an exchange capacity greater than or equal to 1.6 eq / liter.

[0084] Preferably, the mass water content of at least one column of anionic resin, in particular weak, or of at least one column of cationic resin, in particular strong, is less than or equal to 65%, in particular less than or equal to 60%.

[0085] Preferably, the strong cationic resin during the first pass, and optionally during the second pass and / or the subsequent pass(es), is a strong cationic resin with high porosity.

[0086] Preferably, said weak anionic resin comprises tertiary amine groups, in particular making it possible to fix anions in solution at acidic pH. In contrast, a strong anionic resin makes it possible to fix anions in solution regardless of the pH of said solution.

[0087] Preferably, the weak anionic resin during the first pass, and optionally during the second pass and / or the subsequent pass(es), is a weak anionic resin with high porosity.

[0088] Liquid composition rich in lactose obtained according to the process of the invention

[0089] In one embodiment, the ratio of the total mass of sugar(s) to the total dry mass of the lactose-rich liquid composition obtained is greater than or equal to 90%, preferably greater than or equal to 95%, more preferably greater than or equal to 98%, in particular greater than or equal to 99%.

[0090] In one embodiment, said sugar is lactose.

[0091] In this text, the term sugar(s) means milk monosaccharides and milk polysaccharides, in particular lactose and galactose.

[0092] In the present text, polysaccharides include disaccharides and oligosaccharides.

[0093] In one embodiment, the ratio of the dry mass of total nitrogenous matter to the total dry mass of the lactose-rich liquid composition obtained is less than or equal to 5%, preferably less than or equal to 3%, more preferably less than or equal to 1%, in particular less than or equal to 0.5%.

[0094] In one embodiment, the ratio of the dry mass of glycomacropeptide(s) to the total dry mass of the lactose-rich liquid composition obtained is less than or equal to 2%, preferably less than or equal to 0.5%, more preferably less than or equal to 0.1%, in particular not detectable or in the form of non-significant traces.

[0095] In one embodiment, the lactose-rich liquid composition obtained has a demineralization rate greater than or equal to 90%, preferably greater than or equal to 95%, in particular greater than or equal to 96%, or 97%, or 98%, or 99%.

[0096] In one embodiment, the ratio of the total dry mass of the lactose-rich liquid composition obtained to the total mass of said lactose-rich liquid composition is greater than 0%, preferably greater than or equal to 5%, more preferably greater than or equal to 10%.

[0097] In one embodiment, the ratio of the total dry mass of the lactose-rich liquid composition obtained to the total mass of said lactose-rich liquid composition is less than or equal to 30%, preferably less than or equal to 25%, more preferably less than or equal to 20%.

[0098] The lactose-rich liquid composition preferably comprises water, in particular the mass fraction of which relative to its total mass is between 70% and 95%. Definitions - Measurement Methods

[0099] The mass ash content (or dry mass fraction of ash), in particular of the milk protein composition in step (i), optionally after a demineralization step (iii), of the UF retentate (ii), or of the UF permeate (ii), optionally after a demineralization step (iii), or of the lactose-rich liquid composition obtained, can be determined with the standardized method NF V04-208 October 1989, entitled “Milk - Determination of ash - Reference method”, in particular implementing an incineration method at 525°C.

[0100] In the present text, the term “dry extract by mass” or “total dry mass” means the dry mass, for example, of the milk protein composition, of the UF retentate (ii), or of the UF permeate, or the dry mass of the lactose-rich liquid composition, obtained after evaporation of the water until a stable total dry mass is obtained, relative to the total mass of the milk protein composition, of the UF retentate (ii), or of the UF permeate or of the lactose-rich liquid composition, in particular at atmospheric pressure. The dry extract by mass can be determined using the standardized method ISO 6731: January 2011, “Milk, cream, and unsweetened concentrated milk - Determination of dry matter (Reference method)”.

[0101] In this text, lactose is understood to mean lactose as defined in the Codex Alimentarius, Codex Stan 212-1999: a natural constituent of milk normally obtained from whey, in particular with an anhydrous lactose content greater than or equal to 99% mass / mass on a dry basis.

[0102] The determination of the mass content of lactose or sugar (or dry mass fraction) can be carried out by high-performance liquid chromatography, in particular using the NF ISO 22662 standard, dating from November 2007.

[0103] The methods that can be used to quantify milk cations and anions (calcium, magnesium, sodium, potassium, phosphorus / phosphate, citrate) can be chosen from the following methods: molecular absorption spectrometry, titrimetric / complexometric method, electrochemical method, atomic spectrometry, capillary electrophoresis, ion chromatography / conductometric detection, nuclear magnetic resonance for 31P, enzymatic method / UV detection.

[0104] The dry mass fraction of total nitrogenous matter (TNM) can be determined using the NF EN ISO 8968-1 standard dating from May 2014 (Kjeldhal method).

[0105] The following standards can be used to determine the mass content: for example in chlorides: potentiometric titration method (NF ISO 21422, February 2019); for example in total phosphorus: molecular absorption spectrometry method (NF ISO 9874, April 2008); for example in calcium: titrimetric method (standard ISO 12081:2010); for example in calcium, sodium potassium and magnesium: atomic absorption spectrometric method (standard ISO 8070:2007) or ion chromatography; for example in lactic acid / lactate via the ISO 8069 standard dating from 2005.

[0106] In the present text, the term CPL refers to the dairy protein composition according to the invention.

[0107] UF is used herein to denote ultrafiltration.

[0108] In this text, the term demineralization rate is understood to mean the mass reduction rate of minerals (including cations and anions) measured from the formula: ((dry mass fraction of ash or minerals of the non-demineralized CPL - the mass rate of ash or minerals of the at least partially demineralized target CPL) / ash rate of the non-demineralized CPL)*100).

[0109] The demineralization rate can also be evaluated by replacing the dry mass fraction of minerals or ash with a measurement of conductivity (mS / cm).

[0110] These calculation methods also apply to the UF permeate, the UF retentate, and the lactose-rich liquid composition obtained.

[0111] In the present text, a dry mass fraction in one or more given component(s) is calculated relative to the total dry mass of the liquid composition comprising said component(s).

[0112] In a first variant, step iv) comprises at least two passes.

[0113] This arrangement is optimal for increasing the dry mass fraction of lactose, lowering the ash and / or mineral content and removing the remaining nitrogenous matter.

[0114] In a second variant, the ultrafiltration step (ii) comprises the use of one or more ultrafiltration membrane(s) each having a minimum cut-off threshold greater than or equal to approximately 1000 Daltons, preferably greater than or equal to approximately 3000 Daltons, more preferably greater than or equal to 4000 Daltons.

[0115] Preferably, the ultrafiltration step (ii) comprises the use of one or more ultrafiltration membrane(s) each having a minimum cut-off threshold less than or equal to approximately 10,000 Daltons, preferably less than or equal to approximately 8,000 Daltons, more preferably less than or equal to 7,000 Daltons, preferentially less than or equal to 6,000 Daltons.

[0116] The inventors have discovered that the use of such membranes in ultrafiltration under the conditions of the present invention makes it possible to retain more nitrogenous matter in the retentate and therefore to remove it from the permeate, and avoids leaks of true proteins, in particular avoids leaks of Glycomacropeptides (GMP) which increases the saturation capacity of the resins used downstream in step (iv).

[0117] In a third embodiment variant, the dairy protein composition entering the ultrafiltration step ii) has a demineralization rate greater than or equal to 70%, preferably greater than or equal to 75%, more preferably greater than or equal to 80%, preferentially greater than or equal to 85% or 90%.

[0118] In one embodiment, the dairy protein composition (i) is a whey and the method comprises at least one demineralization step (iii) taking place before the UF step (ii) in order to at least partially demineralize the dairy protein composition (i) until the targeted demineralization rate is reached.

[0119] Preferably, in this embodiment, the method does not comprise a demineralization step (iii) taking place after the UF step (ii) and before step (iv). The demineralization upstream of the ultrafiltration is sufficiently advanced so that the UF steps (ii) and percolation on the resins in step (iv) combined make it possible to achieve a dry mass fraction of lactose between 90% and 100%, in particular between 95% and 100%.

[0120] In a fourth embodiment variant, the ultrafiltration permeate at the inlet of the treatment step on the resins (iv) has a demineralization rate greater than or equal to 80%, preferably greater than or equal to 85%, more preferably greater than or equal to 90%.

[0121] Demineralization must be sufficient before passing through the resins so that the latter do not become saturated too quickly and so that said resins allow the demineralization already initiated to be perfected and increase the dry mass fraction of lactose.

[0122] In one embodiment, the dairy protein composition of step (i) is milk or whey, optionally non-demineralized, and the method comprises a step demineralization (iii) carried out after ultrafiltration step (ii) to demineralize the UF permeate until the target demineralization rate is reached.

[0123] In a fifth embodiment, the demineralization step (iii), at least partial, comprises a step of substitution of the cations (iiia) by hydrogen ions H+.

[0124] This arrangement lowers the pH of the dairy protein composition or UF permeate from step (ii), in particular to a pH between 2 and 4, more particularly to a pH between 2 and 3 (upper and lower limits included).

[0125] Lowering the pH and demineralization facilitate possible downstream nanofiltration and / or electrodialysis step(s) by improving their efficiency and stabilizing the composition to be treated.

[0126] The substituted cations may be divalent cations and / or monovalent cations.

[0127] In one embodiment, the cation exchange step (iiia) with hydrogen ions H+, comprises at least one percolation of the dairy protein composition of step (i) or of the UF permeate of step (ii) on at least one column comprising (consisting of) a cationic resin, in particular weak or carboxylic.

[0128] The cationic resin can be strong or weak, in particular it is a weak cationic resin.

[0129] In one embodiment, the demineralization step (iii) comprises, in particular downstream of step (iiia), a step of substitution of the anions (iiib) by hydroxyl or chloride ions.

[0130] The substituted anions may be divalent anions and / or monovalent anions.

[0131] In one embodiment, the anion exchange step (iiib) with chloride ions comprises, in particular downstream of step (iiia) involving a cationic resin, in particular weak or carboxylic, at least one step of percolation of the dairy protein composition of step (i) or of the UF permeate of step (ii) on at least one column comprising (consisting of) an anionic resin, in particular strong, optionally mixed with a cationic resin, in particular strong (i.e. mixed bed).

[0132] In a sixth variant embodiment, the cation substitution step (iiia) is a substitution electrodialysis step, in particular exclusively cationic, carried out on an electrodialyzer comprising cells each comprising (consisting of) three compartments.

[0133] Preferably, the dairy protein composition (i) or the UF permeate (ii) circulates in a compartment, in particular the central compartment, delimited between two cationic membranes.

[0134] In a seventh embodiment, the demineralization step (iii) comprises a step of substitution, in particular exclusively, of the anions (iiib), by hydroxyl ions, and said step (iiib) is carried out on an electrodialyzer comprising cells each comprising (consisting of) three compartments.

[0135] Said step (iiib) is preferably carried out after step (iiia).

[0136] Preferably, the dairy protein composition (i) or the UF permeate (ii) circulates in a compartment, in particular the central compartment, delimited between two anionic membranes.

[0137] In one embodiment, the demineralization step (iii) comprises: - a step of substitution, in particular exclusively, of the cations (iiia) by hydrogen ions H+, in particular a step of cationic substitution electrodialysis carried out on an electrodialyzer comprising cells each comprising (consisting of) three compartments; then - optionally an electrodialysis step, in particular to extract anions and cations, carried out on an electrodialyzer whose cells comprise (are made up of) two compartments; then - a step of substitution, in particular exclusively, of the anions (iiib), by hydroxyl ions, said step (iiib) is carried out on an electrodialyzer comprising cells each comprising (consisting of) three compartments.

[0138] In an eighth embodiment, the demineralization step (iii), at least partial, comprises an electrodialysis step and / or a nanofiltration step, in particular carried out after step (iiia) and / or after step (iiib).

[0139] This electrodialysis step advantageously allows the extraction of anions and cations.

[0140] Preferably, the choice between the electrodialysis and / or nanofiltration step is made according to the dry mass extract of the dairy protein composition in step (i) or of the UF permeate in step (ii).

[0141] In one embodiment, the demineralization step comprises a nanofiltration step when the mass solids content of the dairy protein composition or the UF permeate is less than or equal to 15%.

[0142] In one embodiment, the demineralization step (iii) preferably comprises only an electrodialysis step, in particular carried out on an electrodialyzer whose cells comprise (are made up of) two compartments, still preferably carried out after the ultrafiltration step (ii).

[0143] In one embodiment, the demineralization step (iii) comprises an electrodialysis step, in particular carried out on an electrodialyzer whose cells comprise (are made up of) two compartments, after the step of substitution of cations (iiia) by hydrogen ions H+, preferably the step of substitution, in particular exclusively, of cations (iiia) is a step of cationic substitution electrodialysis carried out on an electrodialyzer comprising cells each comprising (consisting of) three compartments. Preferably, the milk protein composition (i) or the UF permeate (ii) circulates in a compartment, in particular the central compartment, delimited between two cationic membranes.

[0144] In one embodiment, the demineralization step (iii) comprises an electrodialysis step, in particular carried out on an electrodialyzer whose cells comprise (are made up of) two compartments, after the step of substitution of the cations (iiia) by hydrogen ions H+, and after the step of substitution, in particular exclusively, of the anions iiib). Preferably, steps iiia) and iiib) are percolation steps on ion exchange resins, as described above.

[0145] Said step of substitution, in particular exclusively, of the anions (iiib) can be carried out as described above on ion exchange resins or on an electrodialyzer whose cells each comprise (are made up of) three compartments.

[0146] Said step of substitution, in particular exclusively, of the cations (iiia) can be carried out as described above on ion exchange resins or on an electrodialyzer whose cells each comprise (are made up of) three compartments.

[0147] Generally, during electrodialysis, dissolved ionized, mineral or organic species, such as salts, acids or bases, are transported through ionic membranes under the action of an electric current. An electrodialysis unit may comprise cationic membranes (permeable to cations) MEC and / or anionic membranes (permeable to anions) MEA arranged in parallel and in an alternating manner. Under the action of the electric field applied using an anode and a cathode, the MEC block the anions and allow the cations to pass through, while the MEA block the cations and allow the anions to pass through. Concentration compartments (concentrates) and desalination compartments are then created. This most common type of electrodialysis is an electrodialysis whose basic cellular unit comprises two compartments.The cellular unit corresponds, to the smallest repeating pattern, to the operations of concentration and desalination (one compartment corresponding to one concentration or one desalination). The solutions are renewed in the compartments by a circulation parallel to the plane of the . membranes. The application of a current is ensured by two electrodes parallel to the plane of the membranes and placed at the ends of the electrodialyzer.

[0148] In a ninth embodiment, the method comprises a step, taking place after step iv), comprising at least one pass comprising percolation on an adsorbent resin.

[0149] The pass is carried out on at least one column of adsorbent resin.

[0150] Advantageously, this arrangement makes it possible to remove the color from the treated UF permeate, in particular riboflavin (vitamin B 2).

[0151] The adsorbent resin can be functionalized.

[0152] Preferably, the adsorbent resin is a resin with a porosity of between 10 Å and 1000 Å (angstrom), in particular making it possible to adsorb small organic molecules.

[0153] In a tenth embodiment, the method comprises a nanofiltration step (v) carried out after the treatment step on ion exchange resins (iv).

[0154] The nanofiltration step (v) can be carried out after or before the treatment on an adsorbent resin, preferably after the treatment on an adsorbent resin.

[0155] This nanofiltration step (v) is carried out to remove saccharides other than lactose, in particular monosaccharides such as galactose.

[0156] This nanofiltration step (v) can be implemented when the dry mass fraction of galactose relative to the total dry mass of the lactose-rich liquid composition obtained at the end of step (iv) is greater than or equal to 1%, in particular less than or equal to 15%. This dry mass fraction of galactose can be encountered in the treatment of certain acid wheys.

[0157] Preferably, the nanofiltration membrane(s) have a cut-off threshold greater than or equal to 150 Daltons and less than or equal to 350 Daltons.

[0158] Advantageously, the lactose-rich liquid composition obtained after nanofiltration step v) comprises a dry mass fraction of lactose relative to its total dry mass greater than or equal to 98% or 99%.

[0159] In an eleventh embodiment, the ratio of the dry mass of sugar(s), in particular lactose, to the total dry mass of the lactose-rich liquid composition obtained, is greater than or equal to approximately 90%, preferably greater than or equal to 95%.

[0160] This ratio may be greater than or equal to 96%, 97%, 98% or even 99%.

[0161] When this ratio is greater than or equal to 99%, the lactose-rich liquid composition can be used as edible lactose, or refined lactose.

[0162] This is the lactose-rich liquid composition obtained after step iv) or step v) of nanofiltration.

[0163] In a twelfth embodiment, the method comprises a step of concentration by evaporation (in particular of the water contained in the lactose-rich liquid composition) and drying carried out after the treatment step on the ion exchange resins iv) to obtain sugar(s), in particular lactose, in solid form.

[0164] This step of transforming the lactose-rich liquid composition into a solid can be carried out directly after step iv), or after treatment on an adsorbent resin and / or after step v).

[0165] In one embodiment, the lactose-rich liquid composition is subjected to a concentration step by evaporation, then a drying and atomization step, in particular on an atomization tower, for the manufacture of powdered lactose.

[0166] Advantageously, the liquid composition obtained being very rich in lactose, it allows the manufacture of lactose without going through a lactose factory. This arrangement allows the whey producer to recover the latter without having to invest in a lactose factory which generates large volumes of crystallization mother liquors which are very difficult to recover.

[0167] In a thirteenth embodiment, the method comprises a demineralization step iii) carried out before the ultrafiltration step (ii), and the ultrafiltration retentate obtained at the end of the ultrafiltration step (ii), at least partially demineralized, is stable at a temperature greater than or equal to 100°C.

[0168] The proteins of the ultrafiltration retentate are preferably stable at a temperature greater than or equal to 100°C, greater than or equal to 110°C, in particular greater than or equal to 120°C or 130°C, for at least 1 minute, preferably for at least 5 minutes, more preferably for at least 10 minutes, in particular for at least 20 minutes.

[0169] Preferably, the ultrafiltration retentate (ii) has a pH adjusted to a pH greater than or equal to 6.5, in particular greater than or equal to 7.0.

[0170] In a fourteenth embodiment, the ratio of the dry mass of the Total Nitrogenous Matter (TNM) to the total dry mass of the ultrafiltration retentate obtained in step (ii) is greater than or equal to approximately 50%, preferably greater than or equal to 60% or 70% or 80% or 90%.

[0171] In a fifteenth embodiment, the ratio of the dry mass of the ash to the total dry mass of the ultrafiltration retentate obtained in step (ii) is less than approximately 6%, in particular less than or equal to approximately 5%.

[0172] This ratio is preferably less than or equal to 4%, more preferably less than or equal to 3%.

[0173] In a fifteenth variant, the dairy protein composition of step (i) is chosen from: milk, in particular skimmed milk, whey, and a mixture of the latter.

[0174] In a sixteenth variant, the dairy protein composition of step (i) is chosen from: an acid whey, a sweet whey, a native whey, and a mixture of these.

[0175] The embodiments 1 to 16, and the aforementioned embodiments, may be combined independently with each other, unless otherwise specified.

[0176] The subject of the present invention, according to a second aspect, is a lactose-rich liquid composition capable of being obtained by the process with reference to the first aspect of the invention according to any one of the embodiment variants one to sixteen.

[0177] In a variant, the ratio of the dry mass of sugar(s), in particular lactose, to the total dry mass of said lactose-rich liquid composition is greater than or equal to 90%, preferably greater than or equal to 95%, more preferably greater than or equal to 96% or 97% or 98% or 99%.

[0178] The subject of the present invention, according to a third aspect, is an installation for implementing a method for treating a dairy protein composition to obtain a liquid composition rich in lactose, in particular according to any one of the variant embodiments with reference to the first aspect of the invention, comprising, in particular in series: a- an ultrafiltration unit comprising a first inlet intended to receive a dairy protein composition, a first outlet for an ultrafiltration permeate, and a second outlet for an ultrafiltration retentate; b- a demineralization unit for the at least partial demineralization of the milk protein composition upstream of the ultrafiltration unit, and / or a demineralization unit for the at least partial demineralization of the ultrafiltration permeate downstream of the ultrafiltration unit; c- a treatment unit comprising ion exchange resins, downstream of the ultrafiltration unit for the demineralization of the ultrafiltration permeate previously at least partially demineralized, said unit comprising: - at least one column A comprising a cationic resin and comprising a first inlet intended to receive said ultrafiltration permeate previously at least partially demineralized, and a first outlet for the ultrafiltration permeate PI at least partially demineralized, - at least one column B comprising an anionic resin and comprising a first inlet intended to receive said ultrafiltration permeate PI, and a first outlet for the at least partially demineralized ultrafiltration permeate P2.

[0179] In one embodiment, the ultrafiltration unit comprises a concentration sub-unit for increasing the dry mass fraction of the dairy protein composition (as defined herein) and a diafiltration sub-unit downstream of the concentration sub-unit.

[0180] In one embodiment, the ultrafiltration unit, in particular the diafiltration unit, comprises one or more ultrafiltration membrane(s) each having a minimum cut-off threshold greater than or equal to approximately 1000 Daltons, preferably greater than or equal to approximately 3000 Daltons, more preferably greater than or equal to 4000 Daltons.

[0181] Preferably, the ultrafiltration unit, in particular the diafiltration unit, comprises one or more ultrafiltration membrane(s) each having a minimum cut-off threshold less than or equal to approximately 10,000 Daltons, preferably less than or equal to approximately 8,000 Daltons, more preferably less than or equal to 7,000 Daltons, preferentially less than or equal to 6,000 Daltons.

[0182] The ultrafiltration unit allows step (ii) to be carried out.

[0183] In one embodiment, the treatment unit comprising ion exchange resins comprising at least one chain comprising, in particular in series, at least one column comprising (consisting of) a cationic resin (strong or weak), preferably strong, followed by at least one column comprising (consisting of) an anionic resin (strong or weak), preferably weak.

[0184] The treatment unit comprises ion exchange resins allowing step (iv) to be carried out.

[0185] In one embodiment, the demineralization unit comprises (consists of) an electrodialyzer comprising cells comprising (consisting of) two compartments.

[0186] In one embodiment, the demineralization unit comprises, in particular in series: - an electrodialyzer comprising cells comprising (consisting of) three compartments, preferably each cell comprises a central compartment in which the product to be treated circulates (dairy protein composition / ultrafiltration permeate), said central compartment is delimited between cation exchange membranes (mono and / or divalent), in particular it is a substitution, in particular exclusively, cationic as described above; - optionally an electrodialyzer comprising cells comprising (made up of) two compartments, and - an electrodialyzer comprising cells comprising (consisting of) three compartments, preferably each cell comprises a central compartment in which the product to be treated circulates (dairy protein composition / ultrafiltration permeate), said central compartment is delimited between anion exchange membranes (mono and / or divalent), in particular it is a substitution, notably exclusively, anionic as described above.

[0187] In one embodiment, the demineralization unit comprises, in particular in series: - at least one column comprising a cationic resin, in particular weak or carboxylic, and - at least one column comprising an anionic resin, in particular a strong one, optionally mixed with a cationic resin, in particular a strong one (i.e. mixed beds); and - optionally a nanofiltration unit or an electrodialyzer comprising cells comprising (consisting of) two compartments.

[0188] The demineralization unit allows step (iii) to be carried out.

[0189] In one embodiment, the installation comprises a treatment unit comprising an adsorbent resin, in particular downstream of the treatment unit comprising ion exchange resins c).

[0190] In one embodiment, the installation comprises a nanofiltration unit, in particular downstream of the treatment unit comprising ion exchange resins c), in particular also downstream or upstream of the treatment unit comprising an adsorbent resin.

[0191] The variant embodiments, embodiments, and definitions according to a first aspect may be combined, independently of each other, and optionally with the variants and embodiments according to the second or third aspect of the invention.

[0192] The present invention advantageously makes it possible to obtain a liquid composition rich in lactose which can be ready for use directly or via a transformation step in simple solid form which does not require its treatment by crystallization. Brief description of the drawings

[0193] The invention will be better understood on reading the following description of an embodiment of the invention given by way of non-limiting example, with reference to the appended drawings, in which:

[0194] [Fig-1] [Fig. 1] illustrates the method of treating a dairy protein composition according to the invention;

[0195] [Fig.2] [Fig.2] illustrates the treatment of the ultrafiltration permeate of [Fig.l] on ion exchange resins, step (iv).

[0196] Description of the embodiments without limitation

[0197] In [Fig.l], the dairy protein composition 10 is fed to an ultrafiltration unit 20, in particular comprising a concentration subunit and a diafiltration subunit, to form a UF 30 retentate rich in serum proteins and a UF 40 permeate rich in lactose. The UF membranes have in this specific example a cut-off rate of between 1000 Daltons and 10000 Daltons, preferably between 4000 and 6000 Daltons.

[0198] The milk protein composition (MPC) 10 can be demineralized at least partially during a demineralization step (iii) before the ultrafiltration step (ii).

[0199] The UF 40 permeate obtained in step (ii) may be demineralized, alternatively to the demineralization step taking place before the UF step (ii), or additionally to the latter during a demineralization step (iii) taking place after the UF step (ii) and before step (iv) on the ion exchange resins in order to achieve a satisfactory demineralization rate allowing the recovery of a lactose-rich liquid composition after step iv), in particular whose dry mass fraction of sugar(s), in particular lactose, relative to its total dry mass is greater than or equal to 90%.

[0200] The method according to the invention may also comprise a reverse osmosis step in order to increase the dry mass fraction of the UF permeate (ii), preferably carried out before a demineralization step (iii).

[0201] The UF 40 permeate is percolated as illustrated in [Fig.2] on columns comprising ion exchange resins, in particular in two passes 80 and 90. During the first pass 80, the partially demineralized UF 40 permeate is percolated on a column comprising a cationic resin 50, preferably strong, then is percolated on a column comprising an anionic resin 60, preferably weak. During the second pass, the partially demineralized UF 40 permeate at the outlet of the first pass 80, is again percolated on a column comprising a cationic resin 55, preferably strong, then on a column comprising an anionic resin 65, preferably weak. The UF 40 permeate at the outlet of the two passes 80 and 90 can also undergo percolation on a column comprising an adsorbent resin 70 in order to remove the coloring of the UF 40 permeate, in particular to remove the riboflavin responsible for the coloring.This step does not significantly modify the lactose mass fraction.

[0202] The adsorbent resin may be, for example, a highly porous styrene divinyl benzene matrix adsorbent resin with sulfonic groups, the pore size of which is greater than or equal to 350 Å, and having an exchange capacity of the order of 1.

[0203] A lactose-rich liquid composition is recovered at the end of step iv) and in this specific example after treatment on an adsorbent resin. This lactose-rich liquid composition, and generally sugar-rich, comprises a very high mass fraction of lactose relative to its total dry mass. This composition may in certain cases also comprise galactose depending on the starting milk protein composition. The lactose-rich liquid composition then undergoes a nanofiltration step v) in order to remove or reduce the galactose mass fraction, and thus increasing the lactose mass fraction. This nanofiltration step v) may take place after treatment on the adsorbent resin.

[0204] The strong cationic resins 50 and 55 may be, for example, strong cationic, styrenic, porous resins, the size of the beads of which is 0.45 mm minimum, the water content of which is less than or equal to 58% and the exchange capacity of 1.8 eq / l. It may be a resin supplied by the companies Mitsubishi, Dao, or Purolite.

[0205] The weak anionic resins 60 and 65 may be, for example, weak anionic, styrenic, porous resins, the size of the beads of which is at least 0.40 mm, the water content of which is less than or equal to 58% and the exchange capacity 1.6 eq / L minimum.

[0206] The dairy protein composition may be sweet whey, acid whey, or native whey.

[0207] The milk protein composition may be milk, in particular skimmed milk. In this case, the ultrafiltration retentate 40 in step (ii) is rich in serum proteins and caseins.

[0208] Example 1 according to the invention of treatment of an acid whey _ with partial demineralization (iii) before the UF step (ii)

[0209] a- The acid whey from step i) has undergone a demineralization step (iii) before the ultrafiltration step (ii). The partially demineralized acid whey at the inlet of the ultrafiltration step (ii) has a pH of approximately 6; a conductivity less than or equal to 5 mS / cm, a demineralization rate of 74%, a dry mass extract of approximately 18%, a dry mass fraction in MAT of approximately 13%, an ash mass fraction of approximately 2%, a dry mass fraction in lactose of the order of 86%, a mass fraction in cations (Na+, K+, NH4+, Mg2+, Ca2+) less than or equal to 1.5%, a mass fraction in anions (Cf, NO3, PO43, SO42) less than or equal to 0.5%.

[0210] This partially demineralized acid whey undergoes a UF step ii), then the UF permeate obtained is percolated on ion exchange resins in step iv). The whey feed pressure during UF in step ii) is of the order of 4 bars. The temperature of the partially demineralized whey at the inlet of UF step (ii) is of the order of 10°C, this temperature is maintained during UF step ii) and during step iv) on the ion exchange resins. The preceding mass fractions are calculated relative to the total dry mass of the partially demineralized acid whey at the inlet of UF step (ii).

[0211] b- The UF permeate of the partially demineralized acid whey obtained at the outlet of UF step (ii), has a pH of approximately 6; a dry mass extract of approximately 13%, a conductivity less than or equal to 2 mS / cm, a dry mass fraction in MAT of approximately 4%, an ash mass fraction less than 2%, a mass fraction of cations (Na+, K+, NH4+, Mg2+, Ca2+) less than or equal to 0.9%, a mass fraction of anions (Cf, NO3, PO43, SO42) less than or equal to 0.2%, a lactose mass fraction of the order of 93%. The preceding mass fractions are calculated relative to the total dry mass of the UF permeate of the whey at the outlet of UF step (ii).

[0212] c- The UF retentate of the partially demineralized acid whey obtained as a result of step (ii) of UF has a pH of between 5.5 and 5.9; a dry mass extract of approximately 15%, a dry mass fraction in MAT of approximately 50%, an ash mass fraction of less than approximately 2.8%, a mass fraction of cations (Na+, K+, NH4+, Mg2+, Ca2+) of less than or equal to 1.5%, a mass fraction of anions (Cl, NO3, PO43, SO42) of less than or equal to 0.3%, a lactose mass fraction of the order of 50%. The preceding mass fractions are calculated relative to the total dry mass of the UF retentate of the whey at the outlet of step (ii) of UF.

[0213] d- After a double pass on the ion exchange resins of the UF permeate during step (iv), such as the double pass 80,90, the lactose-rich liquid composition which is recovered after step iv), and optionally the passage on at least one column of adsorbent resin, has a pH of the order of 6.8, a dry mass extract of approximately 10%, a conductivity less than or equal to 10 pS / cm, a dry mass fraction in MAT less than approximately 0.3%, a mass fraction in ash less than or equal to 0.1%, a mass fraction in cations (Na\K+, NH4+, Mg2+, Ca2+) less than or equal to 0.001%, and a mass fraction in anions (Cf, NO3, PO43, SO42) less than or equal to 0.001%, and a mass fraction in lactose of the order of 99.5%. The above mass fractions are calculated relative to the total dry mass of the lactose-rich liquid composition obtained.

[0214] Example 2 according to the invention of treatment of a sweet whey _ with partial demineralization (iii) before the UF step (ii)

[0215] a- The sweet whey from step i) has undergone a demineralization step (iii) before the ultrafiltration step (ii). The partially demineralized sweet whey entering the ultrafiltration step (ii) and used below has a pH of 6.8; a demineralization rate of 90%, a dry mass extract of approximately 20%, a dry mass fraction in MAT of approximately 13%, a mass fraction of non-protein nitrogenous matter less than 2%, an ash mass fraction of approximately 1%, a lactose mass fraction of 80%. The preceding mass fractions are calculated relative to the total dry mass of the partially demineralized sweet whey entering the UF step (ii).

[0216] This partially demineralized sweet whey undergoes a UF step ii), then the UF permeate obtained is percolated on ion exchange resins in step iv). The feed pressure of the whey during the UF in step ii) is of the order of 4 bars. The temperature of the partially demineralized whey at the inlet of the UF step (ii) is of the order of 10°C, this temperature is maintained during the UF step ii) and during step iv) on the ion exchange resins.

[0217] b- The UF permeate of the partially demineralized sweet whey obtained at the outlet of step (ii) of UF, has a pH of 6.5; a dry mass extract of approximately 13%, a conductivity of the order of 600 qS / cm, a dry mass fraction in MAT of approximately 1%, a mass fraction in non-protein nitrogenous matter less than 1%, a mass fraction in ash less than or equal to 0.6%, a mass fraction in cations (Na+, K+, NH4+, Mg2+, Ca2+) less than or equal to 0.3%, a mass fraction in anions (Cf, NO3, PO43, SO42) less than or equal to 0.1%, a mass fraction in lactose of 91%. The demineralization rate of the UF permeate is of the order of 99%. The above mass fractions are calculated relative to the total dry mass of the whey UF permeate at the outlet of UF stage (ii).

[0218] c- The UF retentate of the partially demineralized sweet whey obtained at the outlet of UF step (ii) has a pH less than or equal to 7; a dry mass extract of approximately 20%, a dry mass fraction of the MAT of approximately 50%, a mass fraction of non-protein nitrogenous matter less than or equal to 5%, a mass fraction of ash less than or equal to approximately 0.5%. The preceding mass fractions are calculated relative to the total dry mass of the UF retentate of the whey at the outlet of UF step (ii).

[0219] d- After a double pass on the ion exchange resins of the UF permeate, such as the double pass 80,90, the lactose-rich liquid composition obtained after step iv), and optionally the passage on at least one column of adsorbent resin, has a pH between 5 and 6, a dry mass extract of approximately 13%, a conductivity less than or equal to 5 iiS / cm, a dry mass fraction in MAT less than or equal to approximately 0.4%, a mass fraction in non-protein nitrogenous matter less than or equal to 0.1%, a mass fraction in ash less than or equal to 0.1%, a mass fraction in cations (Na^K+,NH4+,Mg2+,Ca2+) less than or equal to 0.012%, and a mass fraction in anions (Cf, NO3, PO43, SO42) less than or equal to 0.015%, and a mass fraction in lactose of the order of 99.8%. After a single pass on the 80 resins, the mass fraction in lactose is of the order of 99%, which is lower than the value of 99.8% obtained with a double pass. The extraction rate of Glycomacropeptides and riboflavin is close to 100%. The above mass fractions are calculated relative to the total dry mass of the lactose-rich liquid composition obtained.

[0220] Example 3 according to the invention of treatment of a native whey with demineralization (iii) after the UF step (ii)

[0221] a- A native whey (step i) undergoes an ultrafiltration step (ii) then reverse osmosis to preconcentrate it. The ultrafiltration permeate of the preconcentrated native whey has a pH of 6.0; a conductivity less than or equal to 10.5 mS / cm, a mass dry extract of approximately 15%, a dry mass fraction in MAT of approximately 3%, an ash mass fraction of approximately 9%, a dry mass fraction in lactose of the order of 84%, a mass fraction in cations (Na+, K+, Mg2+, Ca2+) calculated with respect to the total dry mass less than or equal to 3.6%, a mass fraction in anions (Cf, P-PO4, S-SO42) less than or equal to 2.3%. This ultrafiltration permeate (40) undergoes a demineralization step (iii) by electrodialysis iii) (whose cells comprise two compartments), then is percolated on ion exchange resins in step iv).The temperature of the ultrafiltration permeate during the electrodialysis step (iii) is of the order of 30°C, this temperature is lowered to 10°C during step iv) on the ion exchange resins. The preceding mass fractions are calculated relative to the total dry mass of ultrafiltration permeate at the inlet of the demineralization step (iii).

[0222] b- The UF permeate of the partially demineralized native whey obtained at the outlet of step (iii) of electrodialysis, has a pH of approximately 5; a mass solids content of approximately 14%, a conductivity less than or equal to 0.4 mS / cm, a dry mass fraction in MAT of approximately 2%, an ash mass fraction less than 1%, a cation mass fraction (Na+, K, Mg2+, Ca2+) less than or equal to 0.13%, an anion mass fraction (Cf, P-PO43, S-SO42) less than or equal to 0.27%, a lactose dry mass fraction of the order of 97%. The demineralization rate of the UF permeate after step (iii) is of the order of 96%. The preceding mass fractions are calculated relative to the total dry mass of the UF permeate at the outlet of demineralization step (iii).

[0223] c- After a double pass on the ion exchange resins of the UF permeate during step (iv), such as the double pass 80,90, the lactose-rich liquid composition obtained after step iv), and optionally the passage on at least one column of adsorbent resin, has a pH of the order of 5, a dry mass extract of approximately 13%, a conductivity less than or equal to 5 pmS / cm, a dry mass fraction in MAT less than approximately 0.8%, a mass fraction in ash less than or equal to 0.1%, a mass fraction in cations (Na+, K+, Mg2+, Ca2+) less than or equal to 0.001%, and a mass fraction in anions (Cf, PO43, SO42) less than or equal to 0.001%, and a dry mass fraction in lactose of the order of 99.5%. The above mass fractions are calculated relative to the total dry mass of the lactose-rich liquid composition obtained.

[0224] Example 4 according to the invention of treatment of a native whey with demineralization (iii) after the UF step (ii)

[0225] a- The native whey (i) undergoes an ultrafiltration step (ii) and reverse osmosis to preconcentrate it. The ultrafiltration permeate of the preconcentrated native whey has a pH of approximately 6; a conductivity less than or equal to 10.5 mS / cm, a dry mass extract of approximately 17%, a dry mass fraction in MAT of approximately 3%, an ash mass fraction of approximately 9%, a dry mass fraction in lactose of the order of 84%, a mass fraction in cations (Na+, K+, Mg2+, Ca2+) calculated with respect to the total dry mass less than or equal to 3.6%, a mass fraction in anions (Cl, P-PO43 „ S-SO42 ) less than or equal to 2.3%. This ultrafiltration permeate (40) undergoes a demineralization step by electrodialysis iii) in an acidic process, then is percolated on ion exchange resins in step iv).The demineralization step iii) comprises a sequence of three electrodialyses: a three-compartment electrodialysis for substituting cations with hydrogen ions H+ (iiia) (ESC), followed by a two-compartment demineralization electrodialysis, and followed by a three-compartment electrodialysis for substituting anions with hydroxyl ions (iiib) (ESA). The temperature of the ultrafiltration permeate during the electrodialysis step (iii) is around 30°C, this temperature is lowered to 10°C during step iv) on the ion exchange resins. The preceding mass fractions are calculated relative to the total dry mass of ultrafiltration permeate at the inlet of the demineralization step (iii).

[0226] b- The UF permeate from the whey undergoes a first ESC electrodialysis (iiia) which allows the cations to be replaced by protons and thus to work in an acidic way. The whey at the outlet of the ESC (iiia) has a pH of approximately 1.5; a dry mass extract of approximately 16%, a conductivity of approximately 12 mS / cm, a dry mass fraction in MAT of approximately 2%, a mass fraction in cations (Na+, K+, Mg2+, Ca2+) less than or equal to 0.8%, a mass fraction in anions (Cf, P-PO43, SO42) less than or

[0227] equal to 1.9%, a lactose mass fraction of the order of 95%. The acidified whey then undergoes demineralization of approximately 90% by conventional two-compartment ED electrodialysis. The whey leaving the ED has a pH of approximately 2.6; a dry mass extract of approximately 16%, a conductivity of approximately 1 mS / cm, a dry mass fraction in MAT of approximately 2%, a mass fraction in cations (Na+, K+, Mg2+, Ca2+) less than or equal to 0.13%, a mass fraction in anions (Cl, P-PO43, SO42) less than or equal to 0.19%, a dry mass fraction in lactose of the order of 97%. The partially demineralized whey then undergoes approximately 96% demineralization by anionic substitution electrodialysis ESA (iiib).The whey leaving the ESA (iiib) has a pH of approximately 8; a dry mass extract of approximately 16%, a conductivity of approximately 0.4 mS / cm, a dry mass fraction in MAT of approximately 2%, a mass fraction in cations (Na+, K+, Mg 2+, Ca2+) less than or equal to 0.13%, a mass fraction in anions (Cl, P-PO43, SO4 2 ) less than or equal to 0.15%, a dry mass fraction in lactose of the order of 98%.

[0228] c- After a double pass on the ion exchange resins of the UF permeate during step (iv), such as the double pass 80,90, the lactose-rich liquid composition obtained after step iv), and optionally the passage on at least one adsorbent resin, has a pH of the order of 5, a dry mass extract of approximately 13%, a conductivity less than or equal to 5 pmS / cm, a dry mass fraction in MAT less than approximately 0.8%, a mass fraction in ash less than or equal to 0.1%, a mass fraction in cations (Na+, K+, Mg2+, Ca2+) less than or equal to 0.001%, and a mass fraction in anions (Cf, PO43, SO42) less than or equal to 0.001%, and a dry mass fraction in lactose of the order of 99.5%. The above mass fractions are calculated relative to the total dry mass of the lactose-rich liquid composition obtained.

[0229] The demineralization step (iii) carried out in examples 1 and 2 may be any demineralization step known to those skilled in the art making it possible to demineralize the dairy protein composition at the inlet of the UF step (ii) and / or after the UF step (ii) in order to lower the dry mass fraction of minerals in the UF permeate at the inlet of step (iv) comprising at least one pass over ion exchange resins. This demineralization step may be carried out in a non-limiting manner as described in this text or as described in the EP patent 1,053,685 B1 or WO 2020 / 207894 or as described in examples 3 and 4.

Claims

Claims

1. Process for treating a dairy protein composition to obtain a lactose-rich liquid composition, characterized in that it comprises the steps: (i)- providing a dairy protein composition; (ii)- ultrafiltration of said dairy protein composition allowing an ultrafiltration permeate and an ultrafiltration retentate to be obtained; (iii) an at least partial demineralization step taking place before the ultrafiltration step (ii) and / or after the ultrafiltration step (ii);(iv)- a step of treatment on ion exchange resins of said at least partially demineralized ultrafiltration permeate comprising at least two passes, each pass comprising a percolation on a cationic resin followed by a percolation on an anionic resin, in that the percolation on a cationic resin is a step of substitution of the divalent and / or monovalent cations by hydrogen ions H+, and the percolation on an anionic resin is a step of substitution of the divalent and / or monovalent anions by hydroxyl ions, and in that the ultrafiltration permeate of the dairy protein composition at the inlet of the treatment step on the ion exchange resins (iv) has a demineralization rate greater than or equal to 80%.;

2. Method according to claim 1, characterized in that step (iv) of treatment on ion exchange resins of the at least partially demineralized ultrafiltration permeate comprises at least two passes each comprising a percolation on a strong cationic resin followed by a percolation on a weak anionic resin.

3. Method according to either of claims 1 and 2, characterized in that the ultrafiltration step (ii) comprises the use of one or more ultrafiltration membrane(s) each having a minimum cut-off threshold greater than or equal to 1000 Daltons, preferably less than or equal to 10000 Daltons.

4. Process according to any one of claims 1 to 3, characterized in that the dairy protein composition at the inlet of the ultrafiltration step ii) has a demineralization rate greater than or equal to 70%.

5. Method according to any one of claims 1 to 4, characterized in that the demineralization step (iii), at least partial, comprises a step of substitution of the cations (iiia) by hydrogen ions H+.

6. Method according to claim 5, characterized in that the cation substitution step (iiia) is a cation substitution electrodialysis step carried out on an electrodialyzer comprising cells each comprising three compartments.

7. Method according to either of claims 5 and 6, characterized in that the demineralization step (iii) comprises a step of substitution of the anions (iiib) by hydroxyl ions OH, and in that said step (iiib) is carried out on an electrodialyzer comprising cells each comprising three compartments.

8. Method according to any one of claims 1 to 7, characterized in that the demineralization step (iii), at least partial, comprises an electrodialysis step and / or a nanofiltration step.

9. Method according to any one of claims 1 to 8, characterized in that it comprises a step, taking place after step iv), comprising at least one pass comprising percolation on an adsorbent resin.

10. Method according to any one of claims 1 to 9, characterized in that it comprises a nanofiltration step (v) carried out after the treatment step on ion exchange resins (iv).

11. Method according to any one of claims 1 to 10, characterized in that the ratio of the dry mass of sugar(s), in particular lactose, to the total dry mass of the lactose-rich liquid composition obtained is greater than or equal to approximately 90%, preferably greater than or equal to 95%.

12. Process according to any one of claims 1 to 11, characterized in that it comprises a demineralization step iii) carried out before the ultrafiltration step (ii), and in that the ultrafiltration retentate obtained at the end of the ultrafiltration step (ii), at least partially demineralized, is stable at a temperature greater than or equal to 100°C.

13. A method according to any one of claims 1 to 12, characterized in that the ratio of the dry mass of the Total Nitrogenous Matter (MAT) on the total dry mass of the ultrafiltration retentate obtained in step (ii) is greater than or equal to approximately 50%.

14. Process according to any one of claims 1 to 13, characterized in that the ratio of the dry mass of the ash to the total dry mass of the ultrafiltration retentate obtained in step (ii) is less than 6%.

15. Process according to any one of claims 1 to 14, characterized in that the dairy protein composition of step (i) is chosen from: milk, in particular skimmed milk, whey, and a mixture of the latter.

16. Method according to claim 15, characterized in that the dairy protein composition is chosen from: an acid whey, a sweet whey, a native whey, and a mixture of these.

17. Process according to any one of claims 1 to 16, characterized in that it comprises a step of concentration by evaporation and drying carried out after the step of treatment on the ion exchange resins iv) to obtain sugar(s), in particular lactose, in solid form.

18. Installation for implementing the method for treating a dairy protein composition to obtain a lactose-rich liquid composition according to any one of claims 1 to 16, characterized in that said installation comprises, in particular in series: a- an ultrafiltration unit comprising a first inlet intended to receive a dairy protein composition, a first outlet for an ultrafiltration permeate, and a second outlet for an ultrafiltration retentate; b- a demineralization unit for the at least partial demineralization of the dairy protein composition upstream of the ultrafiltration unit, and / or a demineralization unit for the at least partial demineralization of the ultrafiltration permeate downstream of the ultrafiltration unit;c- a treatment unit comprising ion exchange resins, downstream of the ultrafiltration unit for the demineralization of the ultrafiltration permeate previously at least partially demineralized, said treatment unit comprising at least one chain, said chain comprising:; - at least one column A comprising a cationic resin and comprising a first inlet intended to receive said ultrafiltration permeate previously at least partially demineralized, and a first outlet for the at least partially demineralized ultrafiltration permeate PI, - at least one column B comprising an anionic resin and comprising a first inlet intended to receive said at least partially demineralized ultrafiltration permeate PI, and a first outlet for the at least partially demineralized ultrafiltration permeate P2, and - in that said treatment unit comprises at least two chains, in that said at least one column A comprising a cationic resin is a step of substituting divalent and / or monovalent cations with hydrogen ions H+, in that said at least one column B comprising an anionic resin is a step of substituting divalent and / or monovalent anions with hydroxyl ions, and in that the ultrafiltration permeate of the dairy protein composition entering the treatment unit comprising the ion exchange resins (iv) has a demineralization rate greater than or equal to 80%.

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