RU2793288C2 - Method of producing baby food and fermented milk products from milk - Google Patents

Abstract

FIELD: dairy industry.

SUBSTANCE: method of producing of a baby food product and fermented milk product including: (a) processing of milk to a flow of casein, flow of whey protein and flow of lactose by: (i) filtration of fat free animal milk at the filtration stage through a microfiltration membrane with production of de-bacterized milk as a permeate; (ii) filtration of permeate generated at stage (i) at filtration stage through a microfiltration membrane with generation of a casein flow as retentate and permeate including the whey protein; (iii) fractioning of permeate generated at stage (ii) on the flow of whey protein and the flow of lactose, wherein stage (iii) is done by ultrafiltration; (b) combining a portion of casein flow, whey protein flow generated at stage (a) and the source of lactose to obtain a recombined flow, wherein the flow of lactose includes acid whey; (c) preparation of a product for baby food from recombined flow generated at stage (b); (d) preparation of a fermented milk product from a portion of casein flow generated at stage (a).

EFFECT: efficient utilization of dairy production waste.

10 cl, 2 dwg, 1 tbl, 2 ex

Description

The invention relates to the field of milk processing, in particular, the processing of skimmed animal milk. The invention relates to the preparation of baby food products, such as infant formula bases, as well as fermented milk products, from the same starting material. The invention also relates to a baby food product and a fermented milk product, which can be obtained by the method according to the invention.

State of the art

Human milk is considered the "gold standard" for infant nutrition. Processing animal milk, such as cow's milk, to more closely resemble the composition of human milk is known in the art as "humanization" of animal milk. A method for humanizing animal milk includes changing the ratio of casein:whey proteins found in animal milk (e.g., approximately 80:20 for cow's milk) to a desired infant nutritional ratio found in human milk, e.g., 75:25 to 30:70 , or usually around 40:60, which is the ratio found in human milk at 0-6 months postpartum. In addition, the mineral content of animal milk is usually higher than the content found in human milk. Thus, the humanization of animal milk also includes the reduction of minerals.

The preparation of products suitable for use in baby food generally involves mixing, wet or dry, the various separately purified components in appropriate ratios. Existing manufacturing processes require several dairy ingredients from intermediary suppliers, including skimmed milk or its concentrate, including skimmed milk powder, demineralized whey or its concentrate, including demineralized whey powder, whey protein concentrates or isolates, usually in the form of powders, and pure lactose, usually in powder form, for inclusion in a nutritionally balanced infant formula.

Membrane filtration processes in the manufacture of baby food products from milk are known from WO 2013/137714, WO 2015/041529, US 5503865, EP 1133238, WO 2013/068653, WO 2014/163493 and WO 2014/163494. None of them disclose a productive and cost-effective way to reduce waste streams, in particular excess casein, which usually remains when milk is used to make baby food products. In WO 2015/041529 this excess casein is used to produce a food product suitable for infants aged 6-36 months.

There remains a need in the art for a method that will make it possible to efficiently and cost-effectively produce baby food products from milk, which will also reduce some of the waste streams.

The essence of the invention

The invention relates to a method for the simultaneous production of a baby food product and a fermented milk product from skimmed animal milk. The invention also relates to a baby food product obtained by the method according to the invention and a dairy product obtained by the method according to the invention. The method of the present invention includes

(a) converting milk into a casein stream, a whey protein stream and a lactose stream by

(i) filtering the skimmed animal milk in a filtration step through a microfiltration membrane capable of retaining bacteria and passing milk proteins to form debacterized milk as permeate;

(ii) filtering the permeate formed in step (i) in a microfiltration step through a microfiltration membrane capable of retaining casein and passing whey proteins to form a stream of casein as a retentate and a permeate comprising whey protein;

(iii) fractionating the permeate formed in step (ii) into a whey protein stream and a lactose stream;

(b) combining a portion of the casein stream, at least a portion of the whey protein stream formed in step (a), and a lactose source to obtain a recombined stream, the lactose stream comprising acidic whey;

(c) using the recombinant stream generated in step (b) in the manufacture of a baby food product;

(d) using a portion of the casein stream formed in step (a) in the production of a fermented milk product.

The method of the invention elegantly allows all components of the incoming skimmed animal milk to be used and to minimize the amount of waste streams that are generated. According to a preferred embodiment, the method makes it possible to obtain both a baby food product and a fermented milk product from incoming skimmed animal milk as the sole source of protein. Another advantage of the process according to the invention is that both products are produced productively and cost-effectively with minimal enrichment requirements.

Preferred Embodiments

1. A method for producing a product for baby food and a fermented milk product from skimmed animal milk, including

(a) converting milk into a casein stream, a whey protein stream and a lactose stream by

(i) filtering skimmed animal milk in a filtration step through a microfiltration membrane capable of retaining bacteria and passing milk proteins to form debacterized milk as permeate;

(ii) filtering the permeate formed in step (i) in a microfiltration step through a microfiltration membrane capable of retaining casein and passing whey proteins to form a stream of casein as a retentate and a permeate comprising whey protein;

(iii) fractionating the permeate formed in step (ii) into a whey protein stream and a lactose stream;

(b) combining a portion of the casein stream, at least a portion of the whey protein stream formed in step (a), and a source of lactose to obtain a recombined stream, the lactose stream comprising acid whey;

(c) using the recombinant stream generated in step (b) in the manufacture of a baby food product;

(d) using a portion of the casein stream formed in step (a) in the production of a fermented milk product.

2. Process according to embodiment 1, wherein the acid whey used in the combination in step (b) is obtained as a by-product during the production in step (d).

3. Process according to embodiment 1 or 2, wherein the acid whey is obtained as a liquid stream from a separation step during the production of the fermented milk product.

4. The method according to any of the previous embodiments, wherein the acid whey is subjected to demineralization prior to use as a source of lactose in step (b), the demineralization preferably comprising at least one of the steps of salt precipitation, electrodialysis, lactose crystallization and ion exchange, optionally in combination with nanofiltration.

5. A process according to any of the preceding embodiments, wherein at least a portion of the lactose stream formed in step (a) is used as a source of lactose in step (b) and/or is used in production in step (d).

6. The process according to embodiment 5, wherein part, preferably 50-95 wt.% of the total mass of lactose of the lactose stream is used as a source of lactose in stage (b), and part of the lactose stream, preferably the remainder, is used in the production of stage (d ).

7. The method according to any of the preceding embodiments, wherein the acid whey and at least a portion of the lactose stream formed in step (a) are combined and then subjected to demineralization according to embodiment 4 before being used as the source of lactose in step (b).

8. The method according to any of the preceding embodiments, wherein the combination in step (b) is performed such that the weight ratio of whey protein to casein in the recombinant stream is in the range of 90:10-40:60.

9. The method according to any of the preceding embodiments, wherein step (d) comprises combining a portion of the casein stream formed in step (a) with a source of whey protein, preferably skimmed animal milk, preferably the weight ratio of protein from the casein stream to protein from whey protein source is in the range of 0.1-9.0, most preferably in the range of 0.5-2.0.

10. A process according to any of the preceding embodiments, wherein 10-50% by weight of the casein stream formed in step (a), relative to the total casein weight, is treated in step (b) and the remainder is treated in step (d).

11. A process according to any of the preceding embodiments, wherein the fraction of the casein stream generated in step (a) that is processed in step (b) and that is used in step (d) is controlled by the desired weight ratio of whey protein to casein in the recombined stream.

12. The method according to any of the preceding embodiments, wherein the volume concentration ratio at which the ultrafiltration step operates is in the range of 20-200.

13. A method according to any of the preceding embodiments, wherein the production in step (c) comprises at least one of drying, concentrating, adding vitamins, minerals, lipids and/or dietary fiber, and packaging.

14. The method according to any of the preceding embodiments, wherein the fermented milk product is selected from the group consisting of fermented dairy products and sour cheeses, preferably the fermented milk product is strained yogurt.

15. The method according to any of the preceding embodiments, wherein skimmed animal milk is the sole source of protein for the infant food product, preferably both the infant food product and the fermented milk product.

16. An infant food product obtained in step (b) of the method according to any one of embodiments 1-15.

17. The fermented milk product obtained in step (d) of the process according to any one of embodiments 1-15.

Detailed description

In the process according to the invention, skimmed animal milk is processed to obtain an infant food product and a fermented milk product. In the method, steps (a)-(c) refer to the production of a baby food product and steps (a) and (d) to the production of a fermented milk product. The present invention integrates a fermented milk product manufacturing process and a baby food product manufacturing process in order to minimize waste streams and at the same time produce both products productively and cost effectively with minimal fortification required. The inventors have surprisingly found that components that are normally discarded as waste in one form of product form excellent components for use in another product, so that waste streams are minimized and the need for fortification with other components is minimized. In other words, the casein that remains when a milk product is made from milk is excellent for use in the production of fermented milk products, and according to a preferred embodiment, the acid whey that remains when a fermented milk product is made from casein according to the present invention is excellent. for use in the manufacture of a baby food product.

The advantage of the present invention lies not only in the discovery that residual casein from the manufacture of a milk baby food product is excellent for the manufacture of fermented milk products, but also in the discovery that the acid whey, a by-product of the latter process, can be effectively used in the manufacture of a baby food product. from milk. Compared to separate processes, the combined process for producing a baby food product as well as a fermented milk product according to the present invention reduces the need for adding ingredients from outside, especially in the production of baby food products, while at the same time essentially all components of the incoming skim milk are used. for valuable products. As such, waste generation is largely avoided.

In a first aspect, the invention relates to a method for the production of a baby food product and a fermented milk product from skimmed animal milk, comprising

(a) converting milk into a casein stream, a whey protein stream and a lactose stream by

(i) filtering skimmed animal milk in a filtration step through a microfiltration membrane capable of retaining bacteria and passing milk proteins to form debacterized milk as permeate;

(ii) filtering the permeate formed in step (i) in a microfiltration step through a microfiltration membrane capable of retaining casein and passing whey proteins to form a stream of casein as a retentate and a permeate comprising whey protein;

(iii) fractionating the permeate formed in step (ii) into a whey protein stream and a lactose stream;

(b) combining a portion of the casein stream, at least a portion of the whey protein stream formed in step (a), and a lactose source to obtain a recombined stream, the lactose stream comprising acidic whey;

(c) using the recombinant stream from step (b) in the manufacture of a baby food product;

(d) using a portion of the casein stream formed in step (a) in the production of a fermented milk product.

This method, including its preferred embodiments which are further defined below, is also referred to as the method of the invention.

In another aspect, the invention relates to an infant food product obtainable in step (c) of the method of the invention. In one embodiment, this aspect of the invention relates to an infant food product obtained in step (c) of the method of the invention.

In another aspect, the invention relates to a fermented milk product obtained in step (d) of the process of the invention. In one embodiment, this aspect of the invention relates to a fermented milk product obtained in step (d) of the process of the invention.

The lactose source used in step (b) comprises or is derived from acid whey, preferably acid whey, obtained as a by-product during production in step (d). As such, acid whey is recycled from the fermented milk product process to the infant formula process, making it particularly efficient to use streams that are typically waste streams. In a preferred embodiment, the source of lactose is acidic whey, which is essentially devoid of minerals and proteins. The acid whey is preferably subjected to demineralization and/or protein removal steps to obtain said acid whey substantially devoid of minerals and proteins.

Here it is preferable that at least part, preferably all of the lactose stream formed in step (a) is used as a source of lactose (or part thereof) in step (b) and/or used in production in step (d). In one embodiment, the lactose source includes at least a portion of the lactose stream formed in step (a) and acid whey, preferably acid whey, obtained as a by-product during production in step (d).

It is preferred here that the entire casein stream generated in step (a) is used in steps (b) and (d). A portion of the casein stream formed in step (a) is used in the production of step (d) and a portion of the casein stream, preferably the remainder, is combined in step (b) and included in the recombined stream.

It is preferred here that the entire whey protein stream generated in step (a) is used in step (b).

In the context of the present invention, whenever a stream or composition is referred to as "formed at" some stage of the process, for example, a recombined stream formed at stage (b), said stream or composition may be a composition that is obtained directly from specified process step. In addition, if such directly obtained stream or composition is processed in one or more additional stages, for example, partial evaporation and/or addition of water or other components, the stream or composition is also considered to be formed at that particular stage of the method. Thus, if the recombined stream from step (b) can be partially stripped off before it enters the baby food product in step (c), the incoming stream to step (c) is still considered to be the recombined stream formed in step (b).

In one embodiment, the casein stream obtained in step (a) is used directly in steps (b) and (d) without significant modification. In one embodiment, the whey protein stream obtained in step (a) is used directly in step (b) without significant modification. In one embodiment, the permeate obtained in step (i) is used directly in step (ii) without significant modification. In one embodiment, the permeate obtained in step (ii) is used directly in step (iii) without significant modification.

In the context of the present invention, the term "flow" refers to a liquid composition, although the presence of some solid material, for example, in the form of a suspension, is not excluded, as long as the composition can be processed in conventional dairies.

The process according to the invention produces two different products: a baby food product and a fermented milk product, both of which are obtained from skimmed milk. In the context of the present invention, the term "baby food product" refers to milk-based nutritional compositions suitable for infant nutrition, which are usually in the form of a reconstituted powder or ready-to-use liquid composition, or refers to infant formula bases that are suitable for the manufacture of infant formula. and which include all or almost all of the necessary ingredients in the amounts required for nutrition of children. Preferably, the present method is a method for making infant formula, growing formula or bases therefor. In the context of the present invention, a baby food product is different from a fermented milk product.

In the context of the present invention, the term “fermented milk product” refers to fermented dairy products (e.g. yoghurts) and sour cheeses during the production of which acid whey is produced as a by-product, such as homemade cheeses, strained yoghurts or Greek yoghurts. Fermented milk products, during the production of which sour whey is formed as a by-product during their manufacture, are particularly preferred, since sour whey is advantageously used as a source of lactose in step (b) of the process according to the invention.

In a preferred embodiment, the fermented milk product is a strained fermented milk product. Methods for obtaining strained fermented dairy products are known in the art, for example from WO 2014/114970 or WO 2014/169171. As used herein, the term "sour cheese" refers to sour-type cheeses or "acid-coagulated cheeses" such as house cheese or similar types of cheese. As is known in the art, sour cheeses are those which provide acid whey as a by-product during their manufacture. In other words, in the production of sour cheeses, acids are used to form coagulates. Such methods for the production of sour cheeses are well known in the art. In one embodiment, the sour cheese is selected from cottage cheese and sour milk cheese. Preferably, the fermented milk product in connection with the present description is a product whose production process includes a step in which the whey is separated from the coagulum. Such separation may include centrifugation, filtration and/or straining.

The method of the present invention uses milk as a starting material in step (a) and optionally in step (d). The skimmed animal milk is processed in step (a) and can be used in combination with at least a portion of the casein stream in the production of step (d). In the context of the invention, the term "skimmed milk" refers to milk with a reduced fat content compared to whole milk. Typically the fat content of skimmed milk is in the range of 0-2 wt.%, preferably 0-1 wt.%, more preferably 0-0.2 wt.%, most preferably 0-0.05 wt.% relative to the total weight of skimmed milk. In one embodiment, the skimmed milk is skimmed milk. The method of the present invention uses animal milk that is not human milk, preferably cow's milk. Most preferably skimmed cow's milk is used. In one embodiment, the method includes the step of skimming the milk to produce skimmed animal milk, which is then processed in step (a). In this case, full-fat animal milk, or animal milk or whole animal milk, is treated in a skimming step. The skimming step produces skimmed animal milk.

While heat-treated milk can be used as the incoming milk in the process according to the invention, it is preferable that the incoming skimmed animal milk is not heat-treated. In one embodiment, the process of the invention does not include any step of treating the liquid stream with pasteurization or sterilization, preferably no heat treatment prior to drying, typically spray drying, at the end of step (c). As such, the native state of the proteins is preserved in the final products as much as possible, which is beneficial for children.

Stage (a)

In step (a), the skimmed animal milk is processed or fractionated into a casein stream, a whey protein stream and a lactose stream. Here, the casein stream is a liquid composition comprising casein that is enriched in casein compared to the casein content of incoming skimmed animal milk, the whey protein stream is a liquid composition comprising whey protein that is enriched in whey protein compared to the whey protein content of incoming skim milk. animal milk, and the lactose stream is a liquid composition comprising lactose that is enriched in lactose compared to the lactose content of incoming skimmed animal milk. In the context of the present invention, "enriched" means that the enriched component, on a dry weight basis, is increased in one stream compared to another. Thus, the casein stream is casein enriched, i.e., has a higher casein content, on a dry weight basis, compared to the incoming skimmed animal milk.

Step (a) uses membrane filtration techniques and includes a combination of microfiltration and ultrafiltration. Suitable membrane filtration methods are known in the art, such as those disclosed in WO 2013/068653, WO 2013/137714 and WO 2015/041529.

Stage (a) includes

(i) filtering the skimmed animal milk in the filtration step through a microfiltration membrane capable of retaining bacteria and passing milk proteins to form debacterized milk as permeate;

(ii) filtering the permeate formed in step (i) in a microfiltration step through a microfiltration membrane capable of retaining casein and passing whey proteins to form a stream of casein as a retentate and a permeate comprising whey protein; And

(iii) fractionating the permeate formed in step (ii) into a whey protein stream and a lactose stream.

In step (i), skimmed animal milk is debacterized by microfiltration through a microfiltration membrane capable of retaining bacteria and passing milk proteins to form debacterized milk as permeate. Such bacterial filtration to remove bacteria is known in the art.

In the microfiltration step (ii) the skimmed animal milk is fractionated into two different streams, each enriched with a certain type of protein; casein enriched MF retentate (MFR) and whey protein enriched MF permeate (MFP) are produced. The MF in step (ii) is performed through a membrane which allows the fractionation of casein and whey protein. Such a membrane typically has a porosity of 0.05-0.35 microns. Preferably, a ceramic membrane or a spiral (organic) membrane is used.

According to a preferred embodiment, the microfiltration in step (ii) is enhanced by diafiltration (DF). Diafiltration can be performed by diluting the MF retentate at least once with some water, or by diluting the incoming skim milk with some water and subjecting the diluted animal milk to MF. The DF water may be added to the incoming animal skimmed milk or MFR once, or the total amount of DF water may be added in multiple additions. After each addition of water for DF to incoming animal skimmed milk or MFR, the diluted liquid composition is subjected to MF.

During ultrafiltration in step (iii), most of the liquid and few solutes end up in the UF permeate (UFP), while the UF retentate (UFR) includes substantially all of the whey protein in a smaller volume. Small molecules that permeate the UF membrane are, for example, lactose, monovalent and polyvalent ions. The ultrafiltration in step (iii) can be performed with any UF membrane known in the art, including ceramic membranes, tubular membranes, and organic helical membranes. Preferably the UF membrane is an organic helical membrane. The UF membrane cuts off the molecular weight that allows proteins, preferably whey proteins, to remain in the retentate and allows low molecular weight solutes such as lactose to pass through the membrane. The UF in step (iii) is preferably carried out with a membrane having a molecular weight cutoff of at most 25 kDa, preferably at most 10 kDa, and preferably at least 2.5 kDa, preferably at least 5 kDa. The UF in step (iii) is preferably carried out with a volume concentration factor (VCF) in the range of 20-200, preferably 50-150, which is found to provide the most optimal results in terms of UF retentate composition.

In the context of the invention, the term "volume concentration factor" or "VCF" is the ratio by which a liquid composition is concentrated after filtration, i.e., the total volume of the incoming stream before filtration divided by the total volume of the retentate after filtration, regardless of the total solids content substances. Thus, when 5 L of liquid composition is fractionated through an ultrafiltration membrane into 4 L of permeate and 1 L of retentate, such a UF process operates with a VCF of 5/1=5.

The protein fraction of the casein stream formed in step (a) in the form of a microfiltration retentate usually contains some whey protein, preferably less than 15% by weight, more preferably less than 10% by weight of the protein fraction of the casein stream, and a lot of casein. Preferably the protein fraction comprises at least 85% by weight of casein, more preferably the protein fraction comprises at least 90% by weight of casein. The total solids content of the casein stream typically ranges from 5 to 30 wt.%, preferably ranges from 7 to 30 wt.%, most preferably from 17 to 24 wt.% of the total weight of the casein stream. The casein stream is preferably a microfiltration retentate (MFR). Casein flow can also be referred to as casein concentrate, casein isolate, micellar casein concentrate, or micellar casein isolate (MCI).

The whey protein stream is typically a liquid composition having a total solids content of 5-35 wt%, preferably 10-30 wt%, most preferably 20-30 wt%, and typically comprises 25-90 wt%, preferably 60 -85 wt.% whey proteins relative to the total dry weight. The whey protein stream is preferably an ultrafiltration retentate (UFR). A whey protein stream may also be referred to as an aqueous composition comprising whey proteins.

Although the whey protein stream is enriched in whey protein compared to the incoming skimmed milk, it may still contain significant amounts of casein depending on the stringent conditions under which casein and whey protein fractionation is performed, typically ultrafiltration. In one embodiment, the whey protein stream comprises at most 40% by weight, preferably 5-20% by weight casein, based on total protein weight. Such changes in fractionation conditions and accompanying changes in whey protein flux are known in the art. Depending on the amount of casein present in the whey protein stream, the amount of casein used in the combining step (b) can be adapted such that the infant formula has a whey protein:casein ratio that lies in the preferred ratio of 90:10-40: 60.

The lactose stream is typically a liquid composition with a total solids content of 3-30% by weight, preferably 5-22% by weight. The lactose content of the lactose stream formed in step (a) is typically at least 75 wt.%, preferably at least 90 wt.% or even at least 95 wt.% of the total dry matter.

Demineralization

The process according to the invention preferably includes a demineralization step in which the source of lactose or one or more of its components is demineralized before being processed in step (b). Therefore, at least a portion of the lactose stream formed in step (a) and/or the acid whey formed in step (d) is usually demineralized, preferably at least the acid whey formed in step (d) is subjected to demineralization before being processed to step (b). Demineralization is especially preferred in the production of baby food products, which usually require a lower mineral content compared to incoming milk.

Thus, in one embodiment, the acid whey, preferably the acid whey formed in step (d), is demineralized before being used as (part of) the source of lactose in step (b). Similarly, in one embodiment, at least a portion of the lactose stream formed in step (a), preferably the UFR formed in step (iii), is demineralized before being used as (part of) the source of lactose in step (b).

In the case where the lactose stream formed in step (a) is not subjected to the treatment of step (b), but, for example, in step (d), demineralization of the lactose stream is usually not required, since the desired mineral content in fermented milk products is usually more than or less consistent with the mineral content of incoming milk. In the case where a portion of the lactose stream formed in step (a) is treated in step (b) and a portion is treated in step (d), preferably only the portion that is treated in step (b) is demineralized first.

In a preferred embodiment, the acid whey that is formed in step (d) is processed in step (b) as a source of lactose (or part thereof) and then processed in step (c) to produce a baby food product. Thus, it is preferred that the acid whey is demineralized before step (b). Therefore, in a preferred embodiment, the acid whey formed in step (d) is combined with a portion of the lactose stream formed in step (a), if any, and the combined lactose source is demineralized prior to being processed in step (b).

Demineralization of the lactose source can be accomplished by any method known in the art such as electrodialysis, ion exchange, salt precipitation, lactose crystallization, membrane filtration techniques such as nanofiltration, optionally enhanced by diafiltration, or a combination thereof. In a preferred embodiment, demineralization comprises at least one of salt precipitation, electrodialysis, lactose crystallization and ion exchange, optionally in combination with nanofiltration, more preferably, demineralization comprises nanofiltration in combination with at least one of salt precipitation, electrodialysis, lactose crystallization and ion exchange. In a preferred embodiment, demineralization comprises at least electrodialysis and/or salt precipitation. In one preferred embodiment, demineralization comprises at least nanofiltration in combination with electrodialysis and/or salt precipitation. The inventors have found that when only nanofiltration is used for demineralization, in particular for demineralization of ultrafiltration permeate as a source of lactose in the production of baby foods, the content of divalent ions such as calcium ion and phosphate ion is usually not reduced enough to obtain the final product for baby food in accordance with regulatory requirements.

Demineralization is preferably carried out so that at least 20 wt.% or preferably 50 wt.%, more preferably at least 70 wt.% or at least 80 wt.%, most preferably at least 90 wt.% polyvalent ions are removed, and/or so that at least 20 wt.% of monovalent ions are removed, preferably at least 35 wt.% or at least 50 wt.%, most preferably at least 60 wt.% of monovalent ions present in the stream are removed lactose, for example UFR formed in step (iii).

Step (b)

In step (b), a portion of the casein stream, at least a portion of the whey protein stream formed in step (a), and the source of lactose are combined to form a recombined stream. This recombinant stream is used to manufacture the baby food product in step (c). The combination in step (b) gives a composition with a protein fraction comprising both casein and whey protein in a specific weight ratio.

The combination is preferably carried out so that the weight ratio of whey protein to casein in the recombined stream is in the range of 90:10-40:60, more preferably in the range of 80:20-50:50, even more preferably in the range of 75:25-50:50, most preferably in the range of 70:30-55:45. In one embodiment, the weight ratio of whey protein to casein in the recombinant stream is about 60:40. The exact ratio is usually determined by the type of baby food product being produced and can be adjusted as is known in the art. In addition, much attention in technology is paid to the amino acid profile of baby food products. The method of the invention provides optimal flexibility in achieving the specific desired amino acid profile, for example by adjusting the ratio in which the whey protein and casein streams are combined, or by changing the specific conditions of the microfiltration process in step (a). As such, optimal amino acid profiles similar to those found in human milk can be obtained using the method of the invention.

Since infant formulas typically need to be lower in casein and higher in whey protein than are present in the skimmed animal milk that is processed in step (a), not all of the casein stream is required to recombine with the whey protein stream. In the present invention, this remaining casein, which is currently discarded in most cases, is transferred for useful use in production in step (d).

Typically, the entire casein stream generated in step (a) is used in step (b) and step (d) so that no casein remains or remains unused either. In other words, the casein stream formed in step (a) is preferably divided between steps (a) and (d). Thus, it is preferable that part of the casein stream formed in step (a) is used in the production of step (d), and part of the casein stream, preferably the remainder, is combined in step (b) and included in the recombined stream.

In one embodiment, 10-50 wt.%, preferably 12-25 wt.% of the total mass of casein in the stream of casein formed in stage (a), is subjected to the processing stage (b). Most preferably, about 16 wt.% of the total mass of casein in the stream of casein formed in stage (a) is subjected to processing in stage (b). Most preferably, the remainder is processed in step (d). The amount of casein stream formed in step (a) that is processed in step (b) is advantageously controlled by the desired weight ratio of whey protein to casein in the recombinant stream.

Preferably, the entire whey protein stream formed in step (a) is pooled in step (b). Likewise, it is preferred that all of the acid whey formed in step (d) be treated in step (b). This use of the whey protein formed in step (a) and the acidic whey formed in step (d) minimizes the amount of waste that is discarded in the process and gives optimum utilization of all components of the incoming milk.

The presence of lactose is generally required for both the manufacture of the baby food product in step (c) and the production of the fermented milk product in step (d), especially when the dairy product is yogurt. Therefore, in the process according to the invention, it is preferable that at least part of the lactose stream, preferably the entire stream formed in step (a), is treated in step (b) and/or in step (d). In a preferred embodiment, the lactose stream formed in step (a) is divided between steps (b) and (d). Thus, in one embodiment, at least a portion of the lactose stream formed in step (a) is treated in step (b). In this embodiment, step (b) includes combining a portion of the casein stream and at least a portion of the whey protein and lactose streams from step (a) and at least a portion of the acid whey from step (d) into a recombined stream.

In one embodiment, 0-50 wt.%, preferably 5-25 wt.% of the total mass of lactose in the lactose stream formed in stage (a) is treated in stage (b) as a source of lactose (or part of it). Most preferably, the remainder is processed in step (d). The amount of lactose stream formed in step (a) that is treated in step (b) as a source of lactose (or part thereof) is predominantly controlled by the amount of lactose required for step (d). In the event that the amount of lactose in the lactose stream formed in step (a)(iii) which is processed in step (b) may not be sufficient to produce a baby food product, additional lactose which is present in acid whey can be used, formed in step (d). It follows that not all of the lactose from the lactose stream may be required to provide the desired lactose content in the recombinant stream, so that the remaining lactose can be advantageously used in step (d) as an additive during the production of the fermented milk product, which also reduces waste.

In one embodiment, a portion of the casein stream is combined with the entire whey protein stream, a portion of the lactose stream, and all acid whey. In one embodiment, a portion of the casein stream is combined with the entire whey protein stream, the entire lactose stream, and the entire acid whey stream. In one embodiment, a portion of the casein stream is combined with the entire whey protein stream and the entire acid whey without the lactose stream.

In one embodiment, a portion of the MFR generated in step (ii) is combined with at least a portion of the UFR generated in step (iii) and the acid whey generated in step (d).

In step (b), two or more streams are recombined into one stream. Such recombination can occur once (streams are combined simultaneously) or in stages (streams are combined sequentially). In one embodiment, the acid whey formed in step (d) is combined with the lactose stream formed in step (iii) prior to demineralization so that they can both be demineralized before being combined with the casein and whey protein streams. The combination can be performed as wet blending or dry blending or even as a combination of both. Preferably, the combination takes place as wet mixing, in which the liquid compositions are mixed in appropriate amounts.

Stage (s)

In step (c), the recombinant stream generated in step (b) is used to manufacture a baby food product. Such production is known in the art and typically includes one or more of drying, concentration, addition of vitamins, minerals, lipids and/or dietary fiber, heat treatment, homogenization, packaging. In a preferred embodiment, step (c) does not include heat treatment and includes one or more of drying, concentrating, adding vitamins, minerals, lipids and/or dietary fiber, and packaging. Preferably step (c) includes at least a drying step, most preferably all of the above steps.

Although one or more separate streams may be dried prior to being combined in step (b), it is preferable to dry the recombined stream formed in step (b), preferably by spray drying. As such, only one drying step is needed in the manufacture of a baby food product. In addition, drying generally reduces the native protein content, and performing multiple drying steps in this manner results in a reduced native protein content in the final baby food product. In a preferred embodiment, the process of the invention comprises only one drying step, where the recombinant stream is dried in step (c), preferably by spray drying. Due to the inherent limited heat load imposed on the liquid nutritional composition by spray drying, significant amounts of protein remain native during this stage so that the native protein content of the final infant formula product is as high as possible.

In one embodiment, the recombinant stream is preferably concentrated prior to drying. Such concentration can be performed by any means known in the art, such as reverse osmosis (RO), nanofiltration (NF) and/or evaporation.

Heat treatment is known in the art and may be, for example, pasteurization such as HTST, ESL or UHT, or sterilization such as dry hot air sterilization or steam sterilization. Since debacterization takes place during step (i), it is preferred that no further heat treatment is required in the production of step (c).

Depending on the type of baby food product desired, the addition of certain components such as vitamins, minerals, lipids and/or dietary fiber may be desirable. This addition can be done before, during or after the combination in step (b), and/or optionally before or after the drying step. The specialist knows the requirements for certain types of baby food products, for example, from EU Directive 91/321/EEC or EU Directive 2006/141/EC, or from the US Food and Drug Administration, 21 CPR Ch 1 part 107, and is able to adjust the composition of the recombined stream in order to meet these requirements.

In one aspect, the present invention relates to a baby food product obtainable by the method of the invention, i.e., obtainable in step (c). The inventors have found that the digestibility of the protein fraction in the baby food product according to the invention, i.e., which can be obtained by the method according to the invention, is improved compared to the protein fractions of known baby food products. In the present description, improved digestibility refers to digestibility that is closer to the digestibility of human milk. Digestibility is generally referred to as the rate of digestion, preferably the rate of protein digestion. In addition, the whey protein produced by the method of the present invention constitutes an economically attractive source for inclusion in infant formulas.

In one aspect, the present invention relates to whey protein as present in the whey protein stream obtained by the method of the invention, i.e., obtained in step (a)(iii), which is included in the baby food product obtained in step (c) . Said protein product exhibits improved digestibility also in dry form. Said whey protein is preferably present with casein in a whey protein:casein ratio in the range of 90:10-40:60, more preferably in the range of 80:20-50:50, even more preferably in the range of 75:25-50:50, most preferably in the range 70:30-55:45. The whey protein obtained according to the present invention shows digestion kinetics closer to human milk than existing commercial infant formula.

The expert can determine the degree of digestibility, for example, from Van de Braak et al. ( Clin. Nutr., 2013 , 32, 765-771). The preferred method for determining digestibility is the method according to the following digestibility test.

Digestibility Test

Conditions in the stomach and intestines are successfully simulated in serial bioreactors in a system of parallel bioreactors. In each reactor, the conditions are dynamic in the sense that the pH follows a predetermined curve and fresh artificial digestive juices are continuously added. Biochemical conditions in the stomach and intestines, i.e., enzyme activity, bile concentration and pH, are adjusted to mimic conditions found in infants given a 200 ml dose of infant formula. Digestion in the stomach is simulated by adding a pepsin/lipase solution (dose 10 ml + 0.5 ml/min) containing 37.5 mg of lipase (DF Amano 15) and 15 mg of pepsin (Sigma P7012) per 300 ml, at the same time time gradually lower the pH to 4.3 by adding HCl over 2 hours. Intestinal digestion is simulated at neutral pH (7.2) after addition of sodium hydroxide/sodium carbonate and pancreatin/bile extract mixture (dose 45 ml+1 ml/min) containing 7.5 g pancreatin (4×USP, Pfizer) and 2.5 g bile extract (pig bile powder, Sigma B8631) per 500 ml, in 2 hours. Samples are taken at regular intervals to monitor protein digestion over time. The samples are subjected to chemical analysis, including analysis of substrate consumption by SDS-page, generation of primary amino groups by OPA, formation of small peptides by SEC-HPLC and formation of free amino acids by UPLC. Using such a protocol, one can easily compare the digestion rate of one component, such as a protein source, or food product containing a protein source, with the digestion rate of another protein source, or food product containing a protein source.

In another preferred embodiment, the present invention relates to an infant formula obtained in step (c) containing the milk proteins obtained by the method of the present invention, i.e., obtained in step (a). Said milk proteins preferably comprise whey protein and casein, preferably present in a ratio in the range of 90:10-40:60, more preferably in the range of 80:20-50:50, even more preferably in the range of 75:25-50:50, most preferably in interval 70:30-55:45. Whey protein and casein obtained according to the present invention show digestion kinetics closer to human milk than existing commercial infant formula. Preferably the casein and whey proteins produced according to the present invention show digestion kinetics when after two hours of digestion, preferably gastric digestion, more than 70% of the total casein and whey protein administered initially is still intact. More preferably, said digestion kinetics are such that after two hours of digestion, more than 80% of the casein and whey protein initially administered are still intact. Preferably, said digestion kinetics correspond to the digestion test set forth in Example 2.

Preferably, the whey proteins prepared according to the present invention show digestion kinetics when, after two hours of digestion, preferably gastric digestion, more than 70% of the total whey protein administered initially is still intact. More preferably, said digestion kinetics are such that after two hours of digestion, more than 80% or even 90% of the initially administered whey protein is still intact. Preferably, said digestion kinetics correspond to the digestion test set forth in Example 2.

In one aspect, the invention relates to a method or use for improving the digestibility of a protein fraction included in an infant food product, comprising obtaining an infant food product by the method of the present invention. In one aspect, the invention relates to a method or use for feeding an infant, preferably an infant aged 0-6 months, comprising administering to said infant an infant formula according to the invention.

In one embodiment, the invention relates to the use of the protein fraction obtained in step (a) of the method of the invention, in particular the whey protein stream obtained in step (iii), to improve digestibility as defined herein, and typically relates to improved digestion kinetics , i.e., digestion kinetics closer to the digestion kinetics observed for human milk. According to the present aspect, the whey protein obtained in step (a)(iii) of the method of the invention is used as part or all of the protein fraction in the baby food product. Preferably, the protein fraction is obtained in step (a) and part of step (b), where the casein stream is combined with the whey protein stream. The present inventors have found that the whey protein stream of the invention, particularly when combined with the casein stream of the invention, exhibits improved digestibility.

The use of the present invention can also be formulated as an infant food product comprising a protein fraction as defined herein for use in improving digestibility, or as a method for improving digestibility comprising administering to a subject in need thereof, typically an infant, a product comprising a protein fraction , defined in the present description, or as the use of a protein fraction, defined in the present description, for the manufacture of an infant food product to improve digestibility. The use, method, or product for infant formula for use in accordance with this aspect may be medical or non-medical.

Stage (d)

In step (d), a portion of the casein stream is further processed to produce a fermented milk product. In a preferred embodiment, acidic whey is produced as a by-product. The fermented milk product is produced from at least a portion of the casein stream formed in step (a) and optionally skimmed animal milk. Preferably the skimmed animal milk is the same animal milk that is subjected to the treatment in step (a), and preferably it goes through the same pre-treatment steps, if any.

Acid whey, also called sour whey, is a by-product of the normal process of making fermented milk products and is usually discarded as waste. Acid whey includes valuable compounds such as lactose. With the rapidly increasing demand for fermented milk products, in particular yoghurts, the increasing stream of acid whey waste is becoming a major problem for the dairy industry, which the present invention elegantly solves. Preferably, part or all of the lactose stream formed in step (a) is used in the production of step (d). Any methods known in the art for the production of fermented milk products can be used in step (d), for example, a method for the production of yoghurts or a method for the production of sour cheeses. Step (d), as is known in the art, typically includes a process for the production of sour cheese or yogurt, preferably blended or strained yogurt, from casein.

Step (d) typically includes a pooling step in which the casein stream formed in step (a) is combined with one or more whey protein sources (e.g. milk, whey protein concentrate (WPC), whey protein isolate (WPI)), cream , minerals and lactose. Here, the milk is preferably skimmed animal milk, preferably the same skimmed animal milk that is processed in step (a). Here the lactose may come from step (a), from the demineralization step, preferably from the demineralization step of the present invention, or from an external source, most preferably the lactose at least partially comes from step (a). The minerals are preferably added, most preferably in the form of the lactose stream formed in step (a), which has not been demineralised. Most preferably, the casein stream formed in step (a) is combined with at least a source of whey protein, preferably skimmed animal milk. Preferably, such a combination is the first step in the production of step (d). In other words, the fermented milk product is produced from a mixture comprising at least a portion of the casein stream formed in step (a) and a whey protein source, preferably skimmed animal milk. Thus, in one embodiment, the production of the fermented milk product in step (d) uses at least a portion of the casein stream formed in step (a) and skimmed animal milk. The combination is preferably performed such that the weight ratio of protein from the casein stream to protein from the whey protein source is in the range of 0.1-9.0, most preferably in the range of 0.5-2.0.

The presence of a whey protein source ensures that whey protein and lactose are present during the production of the fermented milk product. An additional source of lactose can also be used in the production in step (d), such as the lactose stream (or part thereof) formed in step (a), and preferably in step (d) it is combined with the casein stream formed in step (a) , and skimmed animal milk.

Step (d) preferably includes a centrifugation step in which the solids, which eventually form the fermented milk product, are separated from the liquid stream, which is obtained as acid whey. In a preferred embodiment, the acid whey used in the lactose stream is obtained as a liquid stream from the centrifugation step during production in step (d). The combination of casein, whey protein and lactose for the production of fermented milk products is known in the art and can be carried out as the expert believes.

Typically, the entire casein stream generated in step (a) is used in either step (b) or step (d) so that no excess casein remains. In one embodiment, based on the total weight of casein, 50-90% by weight, preferably 75-88% by weight of the casein stream formed in step (a) is treated in step (d). Most preferably, based on the total weight of casein, about 84% by weight of the casein stream formed in step (a) is processed in step (d). Most preferably, the residue is treated in step (b).

Similarly, it is preferred that the entire lactose stream generated in step (a) is used in either step (b) or step (d) so that no excess lactose remains. In one embodiment, based on the total weight of lactose, 50-100% by weight, preferably 75-95% by weight of the lactose stream formed in step (a) is treated in step (d). Most preferably, the residue is treated in step (b).

In a preferred embodiment, skimmed animal milk is the sole source of protein for both products that are produced by the process of the invention. Preferably all the protein in the fermented milk product that is obtained in step (d) comes from the casein stream and optionally from the same animal skimmed milk that is processed in step (a). Essentially, skimmed animal milk is the only source of protein for a fermented milk product.

Any other additive or component known in the art suitable for the production of fermented milk products may be added to the casein stream, animal milk, or a combination thereof. Suitable additives include milk fat, stabilizers, sweeteners, flavors, and the like. The use of milk that is enriched with such additives for the production of fermented milk products is known in the art.

In a preferred embodiment, the production of the fermented milk product in step (d) produces acid whey as a by-product, which is generally discarded as waste. Acid whey is known in the art and is the name given to the whey stream that is obtained in the production of fermented milk products such as yoghurts and sour cheeses. Acid whey is usually a liquid composition having a pH of at most 5.5 or even 5.1. Acid whey usually contains, on a total dry weight basis, 50-90 wt.%, preferably 60-75 wt.% lactose and 0-20 wt.%, preferably 10-15 wt.% whey protein. Acid whey also typically includes minerals, including calcium, potassium, magnesium, sodium, chloride, and phosphate. The total amount of ash in acid whey is typically in the range of 8-20 wt.%, preferably 10-15 wt.% of the total dry weight.

The acid whey that is formed in step (d) is preferably combined in step (b) for use as a source of lactose (or part thereof) in the manufacture of a baby food product. The ash content of the acid whey can be undesirably high and is therefore preferably reduced by demineralization before being combined in step (b) with the whey protein stream and possibly part of the casein stream formed in step (a). In one embodiment, the acid whey formed in step (d) is combined with the lactose stream prior to demineralization of the combined lactose and acid whey streams. In the event that demineralization of the lactose stream may not be required, the acid whey may be demineralized before being combined with the lactose stream without it. Such demineralization can be carried out by any method known in the art.

figures

Figure 1 shows a preferred embodiment of the method according to the invention. Dashed arrows show preferred embodiments. MF1=microfiltration stage (i); MF2=microfiltration stage (ii); UF=ultrafiltration; Deminer = demineralization; AD = fermented milk product; IF=baby food product; L=source of lactose. The various streams are represented by numbers 1-9: 1=skimmed animal milk; 2=debacterized milk; 3=microfiltration retentate; 4=microfiltration permeate; 5=ultrafiltration retentate; 6=ultrafiltration permeate; 7=recombined stream; 8=acid whey; 9=demineralized lactose.

Figure 2 shows the results obtained in example 2, from which it was found that the protein fraction of the infant formula according to the invention (solid line) is digested more slowly than conventional formula (dotted line). Int=intensity of pooled protein bands in SDS-PAGE gel, in % relative to intensity at t=0 min.

Examples

Example 1

Processing skimmed milk into a native whey protein stream

Whole raw milk (purchased from Dairygold) is processed into WPC fraction in the following way. Milk and subsequent fractions are stored at 4°C throughout the production. Whole milk is separated using a GEA Westfalia separator at 55°C and cooled to 4°C. The skimmed milk is subjected to microfiltration to separate casein from both whey and lactose. The membrane used for microfiltration is a 0.08 µm Synder FR spiral membrane (PVDF 800 kDa). However, any microfiltration membrane can be used, as long as the casein remains while the whey/lactose/soluble minerals pass through efficiently. The microfiltration retentate is retained as a casein fraction. The microfiltration permeate is retained as a whey and lactose fraction.

The operating temperature is 10°C and the concentration factor (CF) is 3. The achieved CF is related to the desired final concentration of casein protein in the microfiltration retentate. The microfiltration permeate is then subjected to ultrafiltration to separate whey protein from lactose at an operating temperature of 10° C. with a VCF of 90. The achieved CF ratio is related to the desired final concentration of whey protein in the ultrafiltration retentate. In this sample, WPC 70 is obtained.

The ultrafiltration membrane used is a 10 kDa ST (PES 10 kDa) Synder spiral membrane. However, any ultrafiltration membrane can be used, as long as whey proteins remain while lactose and minerals pass through efficiently. Diafiltration medium is added to improve the performance of the membranes (200% of the initial volume of the original skimmed milk). The concentrated liquid WPC 70 (DM 11%) is stored at 4°C.

The WPC 70 liquid is heated to 30° C. and spray dried at 11% DM. The spray dryer used is a single-stage pilot dryer operating at an inlet temperature of 185°C and an outlet temperature of 90°C. The dried WPC 70 is then recombined with a source of casein, lactose and minerals to match their infant formula formulations.

Purchase commercially available infant formula (Frisolac Gold, casein 4.2 g/100 g dry or 0.55 g/100 ml ready-to-drink, whey protein 6.4 g/100 g dry or 0.83 g/100 ml ready to use) and used in comparison with a composition comprising whey proteins obtained according to the method described in example 1 above.

Example 2

Digestibility Test

This protocol describes the simulation of digestion processes using a batch multi-fermenter from DasGip. The conditions used are designed specifically to mimic the digestion of a 200 ml serving of infant formula by a child aged 6-12 months. The volumes described in this protocol are all reduced by a factor of 0.175 to allow the use of 0.1 L overhead magnetic stirrer reactors with an initial volume of 35 ml infant formula (IF).

Getting solutions

Fresh stock solutions, which are used during the digestibility test, are obtained before the start of the test. A concentrated 20× gastric electrolyte solution with a density of 1.05438 g/ml is prepared in demineralized water by dissolving 62 g NaCl, 22 g KCl, 3 g CaCl ₂ ·2H ₂ O with stirring in a volume of demineralized water to reach a volume of 1000 ml. Prepare 1 liter of saliva electrolyte (1x) in demineralized water by dissolving 6.2 g NaCl, 2.2 g KCl, 0.3 g CaCl ₂ ·2H ₂ O and 1.2 g NaHCO ₃ and adjusting the pH to 6.3 concentrated HCl. Use sodium acetate buffer pH 5.0 at 0.93 M/L. A concentrated 25× small intestine electrolyte solution (SIES) with a density of 1.09275 g/ml is prepared by adding 125 g NaCl, 15 g KCl and 7.5 g CaCl ₂ ·2H ₂ O and adjusting the pH to 7 with concentrated NaOH solution. The intestinal protease inhibitor solution contains an inhibitor of trypsin and chymotrypsin ( Glycine max, SIGMA, T9777) dissolved in milliQ water at 0.58 mg/mL. 2 ml is used per intestinal sample. Hydrochloric acid (Merck, Substrate A) is used at 0.25 M. A NaHCO ₃ /NaOH solution (substrate B) is prepared by dissolving 84 g NaHCO ₃ and 40 g NaOH.

Prepare fresh working solutions as described below.

50 ml of saliva is prepared by adding 30 mg of α-amylase (Sigma A-6211) to 50 ml of saliva electrolyte, of which 5.8 ml is added to each reactor before inoculation. 300 ml of gastric juice is obtained by adding 15 ml of the original concentrated gastric electrolyte and 3 ml of 1 M sodium acetate buffer, pH=5.0, to 282 ml of demineralized water, of which 12.3 ml are required per reactor. The solution is cooled on ice and enzymes are added when the temperature reaches below 8°C. Then add 37.5 mg of DF Amano lipase 15 and 15 mg of pepsin (Sigma P7012-109) and mix for 10 minutes. Keep on ice. Prepare 500 ml of intestinal juice by adding 2.5 g of powdered porcine bile extract (Sigma) to 250 ml, gradually dissolving in 250 ml of cold demineralized water, and dissolving in 150 ml of cold demineralized water 7.5 g of pancreatin (Pfizer), and combining 115 ml of cold demineralized water with 250 ml of bile solution and 125 ml of pancreatin solution with 10 ml of concentrated stock SIES to a total volume of 500 ml. During the experiment, the solution is kept on ice and constantly stirred. Use 31.5 ml per reactor.

Instrumentation and Sample Testing

The test products from Example 1 are placed in batch multi-fermenter reactors (DasGip) and the apparatus is operated according to the manufacturer's instructions. A magnetic stirrer is used at 200 rpm to stir the acid and enzymes during digestion. Briefly, 38 ml of the test sample is added to the reactors, and at various times (from t=0 minutes to t=130 minutes) a predetermined amount of sample is extracted (3 ml at t=0 and 2 ml at subsequent times), immediately frozen and stored for further SDS-PAGE analysis and signal quantification from various protein bands.

Scheme for the introduction of solutions

SIM time Past tense pH Time of sampling Sample volume Notes 00:00 0 6.8 0 3 ml 00:05 5 6.8 - - Start adding gastric juice 00:15 15 10' 2 ml 00:25 25 6.5 - - 00:35 35 thirty' 2 ml 00:45 45 6.2 - - 01:05 65 5.8 60' 2 ml 01:35 95 5.0 90' 2 ml 02:05 125 4.3 120' 2 ml Stop adding gastric juice 02:10 130 5.4 - - 02:15 135 6.5 - - Start adding intestinal juice 02:17 137 122' 2 ml 02:21 141 6.7 126' 2 ml 02:25 145 130' 2 ml

Gastric juice is injected in a stream at a rate of 40.25 ml/hour for 3 minutes from the time SIM 00:05:01 to 00:08:01, then injected in a stream at a rate of 5.25 ml/hour until 2:04: 59. Intestinal juice is injected in a stream at a rate of 80.5 ml/hour for 9 minutes from the time SIM 2:15:00 to 2:23:59, then injected in a stream at a rate of 10.5 ml/hour during the rest of the test . The first column shows the SIM time used by the SIM machine. The second column shows the elapsed time of the experiment. The times in the fourth column (sampling time) correspond to the times shown in Figure 2 and are adapted to the injection system. The gastric phase runs from sampling time t=0 to sampling time t=130.

Following such an established protocol mimics the digestion kinetics of milk protein found in typical infant formulas.

It is observed that the whey protein fraction prepared according to the method in Example 1 shows slower digestion kinetics than the commercially available infant formula tested. Rapid digestion kinetics similar to commercially available infant formula are observed when the whey protein fraction obtained in Example 1 is subjected to a heat treatment, such as a treatment in which WPC 70 is treated for 10 minutes at 80°C. It is also observed that the presence of fat in infant formula does not prevent delayed improved digestion kinetics, as similar results are obtained with or without fat in the test composition.

Since slower digestion of proteins is known to be beneficial to infants and occurs in human milk compared to commercially available infant formula, it is desirable to produce an infant formula in which at least the protein fraction, in particular the whey proteins contained therein, exhibit the kinetics digestion, which is more consistent with the digestion of human milk.

Claims (17)

1. A method for producing a product for baby food and a fermented milk product from skimmed animal milk, including: (a) converting milk into a casein stream, a whey protein stream and a lactose stream by: (i) filtering the skimmed animal milk in a filtration step through a microfiltration membrane configured to retain bacteria and pass milk proteins to form debacterized milk as permeate; (ii) filtering the permeate formed in step (i) in a microfiltration step through a microfiltration membrane configured to retain casein and pass whey proteins to form a casein retentate and permeate stream comprising whey protein; (iii) fractionating the permeate formed in step (ii) into a whey protein stream and a lactose stream, where step (iii) is carried out by ultrafiltration; (b) combining a portion of the casein stream, the whey protein stream formed in step (a) and the source of lactose to obtain a recombined stream, the lactose stream comprising acid whey; (c) obtaining a baby food product from the recombinant stream formed in step (b); (d) obtaining a fermented milk product from a portion of the casein stream formed in step (a). 2. Process according to claim 1, wherein the acid whey is obtained as a liquid stream from the separation step during the production of the fermented milk product. 3. The method according to any one of the preceding claims, in which the acid whey is demineralized before being used as a source of lactose in step (b), the demineralization preferably comprising at least one of the steps of salt precipitation, electrodialysis, lactose crystallization and ion exchange, optionally combinations with nanofiltration. 4. The process of claim 3 wherein the acid whey and the lactose stream from step (a) are combined and then demineralized before being used as the source of lactose in step (b). 5. Process according to any of the preceding claims, wherein 0-50% by weight of the total mass of lactose in the lactose stream formed in step (a) is treated in step (b) as a source of lactose. 6. The method according to any one of the preceding claims, wherein the combination in step (b) is performed such that the weight ratio of whey protein to casein in the recombined stream is in the range of 90:10-40:60. 7. A process according to any of the preceding claims, wherein the entire whey protein stream formed in step (a) is pooled in step (b). 8. The method according to any one of the preceding claims, wherein the volume concentration ratio at which the ultrafiltration step in step (iii) operates is in the range of 20-200. 9. The method according to any one of the preceding claims, wherein the production in step (c) comprises at least one of the steps of drying, concentrating, adding vitamins, minerals, lipids and/or dietary fiber, and packaging. 10. The method according to any one of the preceding claims, wherein the skimmed animal milk is the sole source of protein for the infant food product, preferably both the infant food product and the fermented milk product.

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