Iron-fortified dairy food or beverage product

Abstract

METHOD The present invention provides a method of producing an iron-fortified dairy food or beverage product, the method comprising: (a) providing a dairy ingredient composition comprising casein and whey protein; (b) adding iron to the dairy ingredient composition to form an iron- fortified dairy ingredient composition comprising iron-casein complexes; (c) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron-fortified dairy ingredient composition; and (d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60℃ to about 110℃ for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D(4,3) mean diameter.

Description

[0001] IRON-FORTIFIED DAIRY FOOD OR BEVERAGE PRODUCT

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a method for producing an iron-fortified dairy food or beverage product, in particular to methods for producing an iron-fortified dairy food or beverage product comprising (i) agglomerated caseins and whey protein complexes and (ii) iron-casein complexes. The invention also relates to iron-fortified dairy food or beverage products comprising (i) agglomerated proteins comprising caseins and whey proteins and (ii) ironcasein complexes.

[0004] BACKGROUND TO THE INVENTION

[0005] Fortification technologies provide opportunities to add essential minerals to products that would not usually be significant sources of the minerals. This means that a wider range of food products can contribute to the total dietary intake of the minerals, and thus provides consumers with alternative means of achieving the intakes required for optimum health. However, it can be technologically challenging to add minerals to foods. This is particularly difficult in liquid food formats, where processing steps such as heating are involved.

[0006] Micronutrient-fortified dairy food and beverage products are well known in the art. For example, WO2013 / 191568 describes methods for the iron-fortification of dairy products by a method which induces the formation of iron-casein complexes.

[0007] Mouthfeel and creaminess, flavour, colour, as well as reduction of fat, are key considerations for dairy food and beverage products.

[0008] There are particular challenges to increase the mouthfeel / creaminess of dairy food and beverage products, in particular to achieve such increase in mouthfeel / creaminess using allnatural formulations or ideally by acting on the product matrix itself, instead of adding ingredients to the product. This is particularly true in low and no fat products.

[0009] It has been known since the 1980s that a slight pH adjustment of native fresh milk prior to heat treatment results in change of aggregation behaviour between casein micelles and whey proteins. It is also known that the texture and mouthfeel of dairy food and beverage products may be improved by inducing controlled protein aggregation.

[0010] However, there is a need for micronutrient-fortified dairy food and beverage products that provide effective micronutrient supplementation while also delivering a sensory performance (e.g. mouthfeel / creaminess) that is desired by consumers. SUMMARY OF THE INVENTION

[0011] The present inventors have surprisingly found that the addition of iron to a dairy ingredient composition prior to a heat treatment enables the generation of protein aggregates comprising whey protein and casein which contribute to texture and mouthfeel of the product as well as iron-casein complexes that are particularly effective for iron supplementation.

[0012] In particular, the inventors have shown that dairy food and beverage products produced according to the present methods provide a high level of sensory performance desired by consumers (e.g. taste, texture and mouthfeel) whilst also providing a highly effective iron supplementation (e.g. desirable iron bioavailability).

[0013] This was particularly surprising as previous methods aimed at achieving both effects by combining methods for inducing protein aggregation using divalent cations with iron- fortification methods resulted in products with poor sensory performance, in particular a perception of metallic odour and flavour during consumer testing.

[0014] Accordingly, in a first aspect, the present invention provides a method of producing an iron- fortified dairy ingredient composition, the method comprising:

[0015] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0016] (b) adding iron to the dairy ingredient composition to form iron-casein complexes;

[0017] (c) homogenising the dairy ingredient composition; and

[0018] (d) heat treating the dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D(4,3) mean diameter, thereby forming the iron-fortified dairy ingredient composition.

[0019] Suitably, the iron-fortified dairy ingredient composition comprises iron-casein complexes and agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0020] In a further aspect, the present invention provides a method of in-situ complexation of exogenous iron with milk casein in liquid form for producing an iron-fortified dairy ingredient composition comprising iron-casein complexes and agglomerated caseins and whey protein, the method comprising:

[0021] (a) providing a dairy ingredient composition comprising casein and whey protein; (b) adding iron to the dairy ingredient composition to form iron-casein complexes;

[0022] (c) homogenising the dairy ingredient composition; and

[0023] (d) heat treating the dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D(4,3) mean diameter, thereby forming the iron-fortified dairy ingredient composition.

[0024] Suitably, the iron-fortified dairy ingredient composition comprises iron-casein complexes and agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0025] In a further aspect, the present invention provides a method of in-situ complexation of exogenous iron with milk casein in liquid form for (i) fortification in a dairy product with increased bioavailability of the exogenous iron and (ii) formation of agglomerated proteins comprising caseins and whey protein in the dairy product, the method comprising:

[0026] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0027] (b) adding iron to the dairy ingredient composition to form iron-casein complexes;

[0028] (c) homogenising the dairy ingredient composition; and

[0029] (d) heat treating the dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D(4,3) mean diameter, thereby forming the iron-fortified dairy ingredient composition.

[0030] Suitably, the iron-fortified dairy ingredient composition comprises iron-casein complexes and agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0031] Suitably, step (b) and step (c) may be performed in either order.

[0032] Suitably, step (c) is performed prior to step (b).

[0033] Accordingly, in a further aspect, the invention provides a method of producing an iron-fortified dairy ingredient composition, the method comprising: (a) providing a dairy ingredient composition comprising casein and whey protein;

[0034] (b) adding iron to the dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0035] (c) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition; and

[0036] (d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0037] In a further aspect, the invention provides a method of producing an iron-fortified dairy ingredient composition, the method comprising:

[0038] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0039] (b) homogenising the dairy ingredient composition to form a homogenised dairy ingredient composition;

[0040] (c) adding iron to the homogenised dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition comprising iron-casein complexes; and

[0041] (d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0042] The invention also provides an iron-fortified dairy ingredient composition comprising agglomerated proteins comprising casein micelles and whey proteins, the agglomerates having a size of 3 - 50 microns as measured by D<4,3) mean diameter, and iron-casein complexes.

[0043] In another aspect, the present invention provides an iron-fortified dairy ingredient composition produced by the method of the present invention.

[0044] The invention also provides a dairy food or beverage product comprising an iron-fortified dairy ingredient composition according to the invention.

[0045] In a further aspect, the invention relates to an iron-fortified dairy ingredient composition or a dairy food or beverage product according to the present invention for use in iron supplementation in a subject in need thereof. The invention also relates to an iron-casein complex for use in iron supplementation in a subject in need thereof; wherein the iron-casein complex is present in a dairy ingredient composition or a dairy food or beverage product comprising agglomerated proteins comprising caseins and beta-lactoglobulin from whey proteins, the agglomerates having a size of 3 - 50 microns as measured by D<4,3) mean diameter.

[0046] In a further aspect, the invention provides a use of iron to generate agglomerated proteins comprising caseins and beta-lactoglobulin from whey proteins in a dairy ingredient composition, the agglomerates having a size of 3 - 50 microns as measured by D<4,3) mean diameter.

[0047] Food and beverage products of the present invention, such as those produced by the present methods, provide an advantageous combination of sensory performance (e.g. taste, texture, colour and / or mouthfeel), nutritional performance and beneficial iron supplementation effects (e.g. advantageous bioavailability, such as from 90-100% relative bioavailability).

[0048] Further, in some embodiments the present methods and products provide dairy food and beverage products with beneficial sensory performance achieved with reduced milk-fat content. The present methods and products may also achieve the advantageous properties, for example preferred sensory performance (such as increased creaminess or reduced fat with the same creaminess as standard products without reduced fat), in the absence of or with reduced levels of additional thickening agents and / or stabilisers (e.g. hydrocolloids and / or emulsifiers). This is advantageous as a reduction or elimination of such stabilisers is desirable, in particular for clean label food and beverages.

[0049] In addition, without wishing to be bound by theory, the present inventors consider that - in some embodiments - the present methods may an achieve the required generation of agglomerates comprising caseins and whey protein complexes at lower temperatures than prior art methods (e.g. using divalent cations). This may provide further advantages, such as quality improvements including improved nutrition, improved flavour since a higher temperature leads to a more cooked taste (which is less desirable in dairy food or beverage products), energy savings, time savings and operational flexibility; for example.

[0050] DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 - An illustrative manufacturing flow diagram demonstrating a typical process for the manufacture of a powdered milk product using the present process. Iron addition may be performed before or after evaporation. Figure 2 - Addition of iron and calcium during a manufacturing process results in poor sensory performance with perception of metallic odour and flavour. Reduction of calcium decreases the perception of metallic odour and flavor. Addition of 0.8 mM (A) and 0.4 mM (B) iron is shown. Molarity is calculated at the point of addition of iron or calcium and refers to the amount added (i.e. these values do not include the content of the starting fresh milk or reconstituted milk powder. Y-axis shows the difference of metallic intensity to reference (zero metallic). Score of 1 is considered not significantly different to reference.

[0052] Figure 3 - Iron can be added before or after evaporation without notable impacts on sensory performance in the presence of both reduced or no additional calcium. Molarity is calculated at the point of addition of iron or calcium and refers to the amount added (i.e. these values do not include the content of the starting fresh milk or reconstituted milk powder. Y-axis shows the difference of metallic intensity to reference (zero metallic). Score of 1 is considered not significantly different to reference.

[0053] Figure 4 - Addition of iron and calcium during a manufacturing process results in poor sensory performance with perception of metallic odour and flavour. Reduction of calcium decreases the perception of metallic odour and flavor. Molarity is calculated at the point of addition of iron or calcium and refers to the amount added (i.e. these values do not include the content of the starting fresh milk or reconstituted milk powder. Y-axis shows the difference of metallic intensity to reference (zero metallic). Score of 1 is considered not significantly different to reference.

[0054] Figure 5 - (A) Temperature applied to achieve protein agglomeration with a desired particle size distribution (PSD) at various calcium concentrations, including with only iron addition both before evaporation and after evaporation. Various combination of iron and calcium concentration, as well as with only iron addition (at different addition points before and after evaporation) can be performed with variation of operating temperature (90-100°C). (B) PSD at various calcium concentrations, including with only iron addition both before evaporation and after evaporation. Various combination of iron and calcium concentration, as well as with only iron addition (at different addition points before and after evaporation) can be performed to deliver target particle size distribution range for desired sensory outcome.

[0055] Figure 6 - In vitro iron bioavailability showed that inducing protein agglomeration with a desired PSD with iron addition during the present process (iron-casein complex with aggregation) also results in generation of iron-casein complexes with high levels of iron uptake by Caco-2 cells. Also shown are the levels of iron uptake by Caco-2 cells for Fe pyrophosphate and iron-casein complex for iron fortification (i.e. without aggregation).

[0056] DETAILED DESCRIPTION

[0057] In the present context unless otherwise indicated % of a component means the % of weight based on the weight of the composition, i.e. weight / weight %.

[0058] In one aspect, the present invention provides a method of producing an iron-fortified dairy ingredient composition, the method comprising:

[0059] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0060] (b) adding iron to the dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0061] (c) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition; and

[0062] (d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0063] In some embodiments, the method is a method of in-situ complexation of exogenous iron with milk casein in liquid form for producing an iron-fortified dairy ingredient composition comprising iron-casein complexes and agglomerated caseins and whey protein.

[0064] Accordingly, in a further aspect, the present invention provides a method of in-situ complexation of exogenous iron with milk casein in liquid form for producing an iron-fortified dairy ingredient composition comprising iron-casein complexes and agglomerated caseins and whey protein, the method comprising:

[0065] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0066] (b) adding iron to the dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0067] (c) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition; and

[0068] (d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0069] In a further aspect, the present invention provides a method of in-situ complexation of exogenous iron with milk casein in liquid form for (i) fortification in a dairy product with increased bioavailability of the exogenous iron and (ii) formation of agglomerated proteins comprising caseins and whey protein in the dairy product, the method comprising:

[0070] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0071] (b) adding iron to the dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0072] (c) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition; and

[0073] (d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0074] Suitably, step (b) and step (c) may be performed in either order. Thus, step (c) may be performed prior to step (b).

[0075] Accordingly, in one aspect, the present invention provides a method of producing an iron- fortified dairy ingredient composition, the method comprising:

[0076] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0077] (b) homogenising the dairy ingredient composition to form a homogenised dairy ingredient composition;

[0078] (c) adding iron to the homogenised dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition comprising iron-casein complexes; and

[0079] (d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0080] In a further aspect, the present invention provides a method of in-situ complexation of exogenous iron with milk casein in liquid form for producing an iron-fortified dairy ingredient composition comprising iron-casein complexes and agglomerated caseins and whey protein, the method comprising:

[0081] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0082] (b) homogenising the dairy ingredient composition to form a homogenised dairy ingredient composition;

[0083] (c) adding iron to the homogenised dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition comprising iron-casein complexes; and

[0084] (d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0085] In a further aspect, the present invention provides a method of in-situ complexation of exogenous iron with milk casein in liquid form for (i) fortification in a dairy product with increased bioavailability of the exogenous iron and (ii) formation of agglomerated proteins comprising caseins and whey protein in the dairy product, the method comprising:

[0086] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0087] (b) homogenising the dairy ingredient composition to form a homogenised dairy ingredient composition;

[0088] (c) adding iron to the homogenised dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition comprising iron-casein complexes; and

[0089] (d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0090] In some embodiments, the iron-fortified dairy ingredient composition has increased bioavailability of the exogenous iron compared to the corresponding dairy ingredient composition that has not been fortified using exogenous iron.

[0091] Suitably, the formation of the iron-casein complexes promotes the formation of the agglomerated proteins comprising caseins and whey protein. Thus, the iron-casein complexes induce the agglomeration of caseins and whey protein. Dairy ingredient composition

[0092] The present methods comprise the addition of iron to a dairy ingredient composition to form an iron-fortified dairy ingredient composition.

[0093] The dairy ingredient composition provided in step (a) may be a material comprising milk casein and whey proteins. For example, the dairy ingredient composition may be a mammalian milk in liquid or powder form. By way of further example, the dairy ingredient composition may be any whey-based ingredients (including whey protein concentrate, whey protein isolate, and the like) and / or may be any casein-based ingredients (including caseinates, micellar casein, casein concentrate, and the like).

[0094] Suitably, the dairy ingredient composition may comprise: (a) raw or untreated milk; (b) skimmed milk; (c) concentrated milk; (d) reconstituted milk power; (e) evaporated milk; (f) reverse osmosis filtered milk; (g) whey protein concentrate; (h) whey protein isolate; (i) caseinates; (j) micellar casein; (k) casein concentrate; or (I) or a mixture of any of (a) to (k).

[0095] The present invention is typically performed during the initial stages of a milk manufacturing process (i.e. during wet processing, which comprises ingredients dissolution, mixing, homogenization, heat treatment). Accordingly, the present invention is typically performed prior to spray drying.

[0096] Suitably, the dairy ingredient composition may comprise about 1 to about 25 wt. % proteins. Preferably the dairy ingredient composition may comprise about 1 to about 10 wt. %, more preferably about 2 to about 9 wt. % protein.

[0097] Suitably, the dairy ingredient composition may comprise about 12 to about 35 wt. %, preferably about 16 to about 32 wt. % of proteins.

[0098] Suitably, the dairy ingredient composition may comprise milk casein in a micellar structure.

[0099] Suitably, the dairy ingredient composition may comprise milk casein in a non-micellar structure.

[0100] Suitably, the dairy ingredient composition does not include caseinate.

[0101] Suitably, the dairy ingredient composition comprises protein and calcium; wherein the protein comprises whey and milk casein; and the milk has a weight ratio of the protein to the calcium less than 45:1 , preferably between 40:1 and 10:1 , more preferably between 35:1 and 25:1 , most preferably 30:1. Preferably, the dairy ingredient composition has a casein to whey protein ratio of about 90 / 10 to about 60 / 40.

[0102] The content of soluble protein in the ingredient composition may be below or equal to about 30 wt% in relation to the total protein content indicating that the majority of the proteins are in the form of aggregates.

[0103] The definitions and / or characterization of specific milk products may vary between geographical regions and under different regulatory authorities, however the person skilled in the art is nonetheless able to determine what constitutes a specific concentrated milk product based on the components thereof (e.g., milk protein content, etc.).

[0104] The iron-fortified dairy ingredient compositions according to the invention may be used as the basis for the production of other milk products, such as wherein the advantageous properties of the iron-fortified dairy ingredient compositions herein are also beneficial.

[0105] The iron-fortified dairy ingredient composition produced by the methods described herein may be a dairy food or beverage product. Suitably, the iron-fortified dairy ingredient composition may be a dairy food or beverage product as described herein.

[0106] Casein Complexes

[0107] The present methods comprise incubating the iron-fortified dairy ingredient composition to form iron-casein complexes and heating an iron-fortified dairy ingredient composition to form agglomerated proteins comprising caseins and whey protein and having a size of 3 - 50 microns as measured by D<4,3) mean diameter.

[0108] Casein contains a high number of proline amino acids which hinder the formation of common secondary structural motifs of proteins. There are also no disulfide bridges. As a result, casein has relatively little tertiary structure. It is also relatively hydrophobic, making it poorly soluble in water. Casein may be found in milk as a suspension of particles, called casein micelles, which show only limited resemblance with surfactant-type micelles in a sense that the hydrophilic parts reside at the surface and they are spherical. However, in sharp contrast to surfactant micelles, the interior of a casein micelle is highly hydrated. The caseins in the micelles are held together by calcium ions and hydrophobic interactions.

[0109] The isoelectric point of casein is 4.6. Since milk's pH is typically around 6.6, casein has a negative charge in milk. The purified protein is water-insoluble. While it is also insoluble in neutral salt solutions, it is readily dispersible in dilute alkalis and in salt solutions such as aqueous sodium oxalate and sodium acetate. Casein-

[0110] The casein-whey protein agglomerates / agglomerated proteins created by the present methods may have a D<4,3) mean diameter of about 3 to about 50 microns, about 5 to about 50 microns, about 5 to about 30 microns, about 5 to about 20 microns, about 5 to about 15 microns or about 5 to about 10 microns.

[0111] Suitably, the agglomerated proteins may have a D<4,3) mean diameter of about 5-30 microns.

[0112] Suitably, the agglomerates may have a D<4,3) mean diameter of about 5-15 microns.

[0113] Suitably, the agglomerates may have a D<4,3) mean diameter of about 5-10 microns.

[0114] Suitably, the agglomerates may have a D<4,3) mean diameter of 5, 6, 7, 8, 10, 11 , 12, 13, 14 or 15 microns.

[0115] Suitably, the agglomerates may have a D<4,3) mean diameter of 5, 6, 7, 8, or 10 microns.

[0116] Suitably the mean diameter may be a volume based D<4,3) mean diameter.

[0117] Suitably, the agglomerates may have a particle size distribution (PSD) of D10: about 0.5 to 5 pm, D50: about 0.5 to 8 pm and / or D90: about 8 to 30 pm. Suitably, the agglomerates may have a particle size distribution of D10: about 0.5 to 5 pm, D50: about 0.5 to 8 pm and D90: about 8 to 30 pm.

[0118] Suitably, the agglomerates may have a particle size distribution (PSD) of D10: about 0.5 to 3.5 pm, D50: about 0.5 to 8 pm and / or D90: about 8 to 30 pm. Suitably, the agglomerates may have a particle size distribution of D10: about 0.5 to 3.5 pm, D50: about 0.5 to 8 pm and D90: about 8 to 30 pm.

[0119] Suitably, the agglomerates may have a particle size distribution of D10: about 1 to 3.5 pm, D50: about 4 to 8 pm and / or D90: about 10 to 20 pm. Suitably, the agglomerates may have a particle size distribution of D10: about 1 to 3.5 pm, D50: about 4 to 8 pm and D90: about 10 to 20 pm.

[0120] Suitably, the agglomerates may have a particle size distribution (PSD) of D10: about 2.5 to 5.0 pm, D50: about 4 to 8 pm and / or D90: about 10 to 20 pm. Suitably, the agglomerates may have a particle size distribution (PSD) of D10: about 2.5 to 5.0 pm, D50: about 4 to 8 pm and D90: about 10 to 20 pm.

[0121] The agglomerate particle size distribution may be measured using a laser granulometer such as a Mastersizer 2000 (Malvern Instruments, UK). For the measurements a sample may e.g. be dispersed in the Hydro SM measuring cell until an obscuration rate of 9-10% is obtained and then analysed in the Mastersizer.

[0122] As used herein, the term “caseins / whey protein aggregates having a volume based mean diameter value D<4,3)” of a particular value may refer to protein network comprising casein micelles and whey proteins either present in aggregates or covalently associated and having such volume mean diameter D<4,3)., as measured using laser diffraction.

[0123] Suitably, dispersion of the iron-fortified dairy ingredient composition of the present invention may be achieved in distilled or deionised water and measurements of the particle size distribution by laser diffraction using a Malvern Mastersizer 2000 granulometer (Malvern Instruments Ltd, UK). Measurement settings used may a refractive index of 1.46 for fat droplets and 1.33 for water at absorption of 0.01 and samples may be measured at an obscuration rate of 2.0 - 2.5%. The measurement results may be calculated in the Malvern software based on the Mie theory.

[0124] Agglomerates having a size comprised in the above mentioned ranges have the advantage of providing improved texture / mouthfeel to the present dairy products. Such particle size distribution is advantageously present in any kind of dairy food or beverage product according to the invention, such as full fat milk, skim milk or semi-skim milk, with or without thickener. This particle size is responsible for providing an improved mouthfeel to the product compared to a comparison product having the same fat and thickener content but having smaller particles.

[0125] Controlled aggregation with particles in the above mentioned ranges is also advantageous in that it is at the fine balance between thicker texture / mouthfeel and avoidance of excessive sandiness.

[0126] In addition, the agglomerates are preferable stable, i.e. they do not sediment in the milk.

[0127] Suitably, the casein-whey protein complexes are formed between caseins and betalactoglobulin from the whey proteins.

[0128] Iron-casein complexes

[0129] The present methods also generate complexes comprising iron and casein. For example, the iron-casein complexes may comprise iron bound to casein.

[0130] Suitably, the iron-casein complexes comprise at least 0.005% w / w iron bound to casein.

[0131] Suitably, the iron-casein complexes comprise at least 1 % w / w iron bound to casein. Suitably, the iron-casein complexes comprise between about 0.005 % to about 30%, about 0.005 % to about 20%, about 0.005 % to about 15%, about 0.005 % to about 10%, or about 0.01 % to about 5% w / w iron bound to casein.

[0132] Suitably, the iron-casein complexes may comprise a casein : iron ratio of 60-3000 (wt / wt).

[0133] Suitably, the iron-casein complexes may comprise a casein : ferric sulphate ratio of 5-500 (wt / wt). As will be apparent, depending on the application of the iron-casein complex, different amounts of iron bound to the casein may be developed for use.

[0134] Iron-fortification

[0135] The present methods and products provide approaches for iron supplementation through the addition of exogenous iron to form iron-casein complexes.

[0136] Suitably, iron may be added at any stage during the wet processing. For example, iron may be added during ingredients dissolution, mixing, and / or homogenization. Iron may be added prior to or following an evaporation step.

[0137] Iron is added prior to a heat treatment step as described herein.

[0138] Suitably, iron is added during an ingredients dissolution step. Suitably, the addition of iron may be followed by other ingredients addition and prior to a heat treatment step.

[0139] Suitably, iron is added immediately following an ingredients dissolution step and prior to an evaporation step.

[0140] Suitably, the step of adding iron to the dairy ingredient composition to form an iron-fortified dairy ingredient composition further comprises incubating the dairy ingredient composition in order to form iron-casein complexes. Thus, the iron-fortified dairy ingredient composition formed by the addition of iron may comprise iron-casein complexes.

[0141] Suitably, the iron may be added to the dairy ingredient composition prior to an evaporation step.

[0142] The dairy ingredient composition may comprise less than about 35 wt. % total solids when the iron is added. Suitably, the dairy ingredient composition may have a total milk solid content of below or equal to about 30 wt%, when the iron is added. Suitably, the dairy ingredient composition may comprise about 5 wt. % to about 35 wt. %, about 10 wt. % to about 30 wt. % total solids when the iron is added. These levels of total solids typically occur before the evaporation step of the illustrative method shown in Figure 1 . The dairy ingredient composition may be at a temperature of about 1 °C to about 70 °C, when the iron is added prior to an evaporation step.

[0143] The dairy ingredient composition may be incubated for a period of about 5 to about 30 minutes, such as about 5 to about 15 minutes, following the addition of iron. The dairy ingredient composition may be incubated at the same temperature as when the iron is added, i.e. at a temperature of about 1 °C to about 70 °C.

[0144] The iron may be added for about 5 to about 30 minutes, such as about 5 to about 15 minutes, prior to the heat treatment.

[0145] In another embodiment, the iron may be added to the dairy ingredient composition following an evaporation step.

[0146] Suitably, iron is added following an evaporation step and prior to a heat treatment step.

[0147] The dairy ingredient composition may comprise more than about 40 wt. % total solids when the iron is added. These levels of total solids typically occur after the evaporation step of the illustrative method shown in Figure 1.

[0148] The dairy ingredient composition may be at a temperature of about 1 °C to about 85 °C, when the iron is added prior to an evaporation step.

[0149] The dairy ingredient composition may be incubated for a period of about 5 to about 30 minutes, such as about 5 to about 15 minutes, following the addition of iron. The dairy ingredient composition may be incubated at the same temperature as when the iron is added, i.e. at a temperature of about 1 °C to about 85 °C.

[0150] The iron may be added for about 5 to about 30 minutes, such as about 5 to about 15 minutes, prior to the heat treatment.

[0151] Suitably, the pH of the ingredient composition is about 6 to about 8, or about 6 to about 7.5 when the iron is added.

[0152] The pH of the ingredient composition may be about 6.1 to about 7.1 when the iron is added.

[0153] The pH can be adjusted using any kind of edible acid and / or edible base known to the person skilled in the art. Example of such acids are for example citric acid, lactic acid or phosphoric acid. The amount of acid needed to achieve the desired pH adjustment as described above can also be determined by a skilled person on the basis of his general knowledge.

[0154] Suitably, the iron is ferric salts of iron. For example, ferric chloride may be used. Alternative ferric iron sources such as ferric sulphate, , ferric nitrate, etc. may be used without departing from the scope of the invention. Ferric iron will bind more efficiently to caseins than ferrous iron owing to the binding characteristics of their respective iron oxidation states.

[0155] The iron is preferably added as soluble ferric iron such as ferric sulfate, ferric nitrate and / or ferric chloride.

[0156] The inventors have surprisingly found that not all type of ferric salts can bind efficiently caseins in view of the problem of lack of solubility of ferric phosphate salts such as ferric phosphate, ferric pyrophosphate in the dairy media.

[0157] The final concentration of iron in the dairy ingredient composition should be adjusted according to the amount of total solids in the dairy ingredient composition.

[0158] Suitably, the iron is added such that the final concentration in the dairy ingredient composition is about 0.005 mM to about 20 mM.

[0159] Suitably, the iron is added such that the final concentration in the dairy ingredient composition is about 0.005 mM to about 20 mM, about 0.005 mM to about 15 mM, or about 0.005 mM to about 10 mM.

[0160] Suitably, the iron is added such that the final concentration in the dairy ingredient composition is about 0.1 mM to about 10 mM or about 0.1 mM to about 5 mM.

[0161] Suitably, the iron, preferably ferric iron salts, is added at a concentration of 0.005 wt.% to 1 wt.% of the ingredient composition; preferably at a weight ratio of the phosphorous to the iron between 1 : 1 and 50: 1 , more preferably between 1 : 1 and 20 : 1.

[0162] Suitably the iron (e.g. ferric iron salt, preferably ferric sulphate) is added to the dairy ingredient composition at a concentration of about 0.005 wt.% to 1 wt.%, about 0.01 wt.% to 1 wt.%, or about 0.05 wt.% to 1 wt.%, of the dairy ingredient composition.

[0163] Suitably, the iron is added to the entire batch of a dairy ingredient composition (e.g., as opposed to a sample taken from the dairy ingredient composition).

[0164] Suitably, the addition of iron and subsequent heating may allow the present methods to achieve the required generation of agglomerates comprising caseins and whey protein complexes at lower temperatures than prior art methods (e.g. using divalent cations). This may provide further advantages, such as energy and time savings; for example.

[0165] Further, the provision on iron in the form of iron-casein complexes has beneficial effects for iron supplementation. In particular, the iron-casein complexes have been shown to have advantageous bioavailability properties, such as from 90-100% relative bioavailability. Methods for determining the presence of iron in food and beverage products (e.g. to determine if a product or ingredient composition is fortified with iron) are known in the art. Such examples include, but are not limited to, those described in Kosse et al. (Food Chemistry; 75(3); 371- 376; 2001) and Chen et al. (Analytica Chimica Acta; 470(2); 223-228; 2002).

[0166] Phosphorous

[0167] Preferably, the present methods comprise the step of adding phosphorous to the dairy ingredient composition prior to, or at the same time as, the iron addition. The term “exogenous” means that the phosphorus is externally added and are not provided endogenously by the material comprising the milk casein.

[0168] The typical ratio of protein to phosphorus in milk is 32:1. Suitably, the method may comprise adding phosphorous at an amount which decreases the ratio of proteimphosphorus to 8:1 , or 6.25:1 for casein:phosphorus.

[0169] Suitably, the iron-casein complexes produced in the present methods may comprise a ratio of protein:phosphorus to 8:1 , or 6.25:1 for caseimphosphorus.

[0170] Suitably, the phosphorous is added at a weight ratio of phosphorous to iron of between 1 :1 and 50:1 , suitably between 1 :1 and 20:1.

[0171] In some embodiments, the exogenous phosphorus is added as inorganic phosphate.

[0172] Suitably, at least a portion of the added phosphorus is dipotassium phosphate (K2HPO4).

[0173] Suitably, the pH of the ingredient composition is about 6 to about 8, or about 6 to about 7.5 when the phosphorous is added. The pH of the ingredient composition may be about 6.1 to about 7.1 when the phosphorous is added.

[0174] The dairy ingredient composition may be at a temperature of about 1 °C to about 70 °C when the phosphorous is added.

[0175] Trivalent cations

[0176] The present inventors have surprisingly determined that the formation of protein aggregates comprising whey protein and casein which contribute to texture and mouthfeel of the product can be achieved using iron, which also provides iron-fortification through the formation of ironcasein complexes.

[0177] Without wishing to be bound by theory, the present inventors consider that the binding of iron to casein, and associated increased rigidity of casein structure, promotes whey-casein aggregation. This effect allows for a reduction in the levels of divalent cation required for aggregation. For example, Fe3+(trivalent cation) binding to protein occurs through coordination bonds and may therefore create a stronger (covalent) bond as opposed to ionic interaction of typical divalent cations such as Ca2+.

[0178] Suitably, the present methods comprise adding essentially no divalent cations to the dairy ingredient composition prior to the homogenisation and / or heating steps.

[0179] Suitably, the method may comprise adding divalent cations in an amount such that the divalent cation concentration in the dairy ingredient composition, iron-fortified dairy ingredient composition or homogenised iron-fortified dairy ingredient composition is less than about 4 mmol divalent cation I kg of milk concentrate.

[0180] Suitably, the amount of divalent cations added may be about 1.5 to 4 mmol divalent cation I kg of milk concentrate, about 1.5 to 3 mmol divalent cation I kg of milk concentrate or about 1 .5 to 3 mmol divalent cation I kg of milk concentrate.

[0181] Suitably, the amount of divalent cations added may be less than about 1.5 mmol divalent cation I kg of milk concentrate.

[0182] Suitably, the amount of divalent cations (such as calcium) added may be about 0 to 1.5 mmol divalent cation I kg of milk concentrate, about 0 to 0.75 mmol divalent cation I kg of milk concentrate, about 0 to 0.25 mmol divalent cation I kg of milk concentrate, or 0 mmol divalent cation I kg of milk concentrate.

[0183] Typically, the milk concentrate comprises about 50 % water.

[0184] Typically, the divalent cations are added to the milk concentrate formed after the evaporation step.

[0185] Suitably, the dairy ingredient composition, iron-fortified dairy ingredient composition or homogenised iron-fortified dairy ingredient composition may be at a temperature of about 1 °C to about 70 °C when the divalent cations are added.

[0186] Suitably, the method does not comprise adding a divalent cation to the dairy ingredient composition prior to the homogenisation and / or heating steps.

[0187] Suitably the divalent cation may be calcium and / or magnesium cations. Preferably, the divalent cation is a calcium cation.

[0188] Evaporation

[0189] The present methods may also comprise an evaporation step. Suitably, evaporation may be performed prior to a homogenisation step. In particular, an evaporation step may be performed as the step preceding homogenisation. Suitably, evaporation may be performed following a dissolution or mixing step and prior to a homogenisation step.

[0190] Suitably, evaporation may be performed following a homogenisation step.

[0191] Suitably, a pre-heating step may be performed. Suitably, evaporation may be performed following a pre-heating step.

[0192] Suitably, evaporation may be performed prior to a heat treatment step. In particular, an evaporation step may be performed as the step preceding heat treatment.

[0193] In a preferred embodiment, evaporation is performed following a homogenisation step and prior to a heat treatment step. Suitably, a pre-heating step may be performed following the homogenisation step and prior to the evaporation step.

[0194] Methods and apparatus for the evaporation of dairy ingredient compositions during manufacturing processes are well known in the art.

[0195] Suitably, the evaporation step may increase the total solids % of the dairy ingredient composition from about 20% or less to greater than 40%.

[0196] Homogenisation

[0197] Methods and apparatus for the homogenisation of dairy products are well known in the art.

[0198] Suitably, homogenization may refer to a process used to mix and disperse milk fat globules in order to prevent a dairy product from separating and to give it a more homogeneous texture. The average diameter of the globules following homogenization may be below 1 m.

[0199] By way of example, homogenisation may be performed using an EmulsiFlex C-5 high pressure, single-stage homogenizer (Avestin®, Canada).

[0200] The homogenization step may further comprise a high shear mixing. In some embodiments, at least one of a fat or an oil may be added to the composition before and / or during the high shear mixing and homogenization thereof.

[0201] Suitably, the homogenisation step may be omitted in the present methods. Heat treatment

[0202] The present methods comprise heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0203] Accordingly, the heat treatment is performed after the iron addition step and results in the generation of the required agglomerated proteins comprising caseins and whey protein and.

[0204] The heat treatment step may be performed at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes.

[0205] The heat treatment may be a direct steam injection (DSI). The DSI may be followed by a holding stage at a desired temperature and time period.

[0206] Suitably, the total solid content of the dairy ingredient composition is above about 30 wt. % during the heat treatment step.

[0207] The heat treatment may be performed at a temperature of about 80°C to about 105°C, about 80°C to about 100°C, about 80°C to about 95°C, about 85°C to about 95°C, or about 90°C to about 95°C.

[0208] The heat treatment may be performed at a temperature of about 80°C to about 105°C, about 90°C to about 105°C, or about 95°C to about 105°C.

[0209] The heat treatment may be performed for a period of about 0.5 to about 3 minutes, about 1 to about 3 minutes or about 2 to about 3 minutes.

[0210] Suitably, the heat treatment may be performed at a temperature of about 80°C to about 105°C, about 80°C to about 100°C, about 80°C to about 95°C, about 85°C to about 95°C, or about 90°C to about 95°C for about 0.5 to about 3 minutes.

[0211] Suitably, the heat treatment may be performed at a temperature of about 80°C to about 105°C, about 90°C to about 105°C, or about 95°C to about 105°C for about 0.5 to about 3 minutes.

[0212] Suitably, the heat treatment may be performed at a temperature of about 80°C to about 105°C, about 90°C to about 105°C, or about 95°C to about 105°C for about 30 seconds to about 60 seconds.

[0213] Suitably, the heat treatment may be performed at a temperature of about 90°C to about 95°C for about 30 seconds to about 60 seconds. Suitably, the heat treatment may be performed at a temperature of about 95°C to about 105°C for about 30 seconds to about 60 seconds.

[0214] Suitably, the total solid content of the dairy ingredient composition may be below or equal to about 30% when the iron is added and the heat treatment may be performed at a temperature of about 90°C to about 95°C for about 30 seconds to about 60 seconds.

[0215] Suitably, the total solid content of the dairy ingredient composition may be above or equal to about 40% when the iron is added and the heat treatment may be performed at a temperature of about 95°C to about 105°C for a period of about 30 seconds to about 60 seconds.

[0216] Suitably, a separate pasteurisation step may be performed following the heat treatment. The pasteurisation may be a non-thermal (e.g. 5°C - 20°C) pasteurisation. For example, the pasteurisation may be a High Pressure Processing (HPP) also known as high pressure pascalization or cold pasteurization.

[0217] In one embodiment, there is provided producing an iron-fortified dairy food or beverage product, the method comprising the steps of:

[0218] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0219] (b) adding iron to the dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0220] (c) evaporating the iron-fortified dairy ingredient composition to form an evaporated iron- fortified dairy ingredient composition;

[0221] (d) homogenising the evaporated iron-fortified dairy ingredient composition to form a homogenised iron-fortified dairy ingredient composition;

[0222] (e) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 90°C to about 95°C for about 30 seconds to about 60 seconds to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0223] In one embodiment, there is provided producing an iron-fortified dairy food or beverage product, the method comprising the steps of:

[0224] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0225] (b) evaporating the dairy ingredient composition to form an evaporated dairy ingredient composition;

[0226] (c) adding iron to the dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0227] (d) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition; (e) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 95°C to about 105°C for a period of about 30 seconds to about 60 seconds to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0228] In one embodiment, there is provided producing an iron-fortified dairy food or beverage product, the method comprising the steps of:

[0229] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0230] (b) adding iron to the dairy ingredient composition with a total solid content below or equal to about 30% to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0231] (c) evaporating the iron-fortified dairy ingredient composition to form an evaporated iron- fortified dairy ingredient composition;

[0232] (d) homogenising the evaporated iron-fortified dairy ingredient composition to form a homogenised iron-fortified dairy ingredient composition;

[0233] (e) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 90°C to about 95°C for about 30 seconds to about 60 seconds to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0234] In one embodiment, there is provided producing an iron-fortified dairy food or beverage product, the method comprising the steps of:

[0235] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0236] (b) evaporating the dairy ingredient composition to form an evaporated dairy ingredient composition, preferably comprising at least about 40% total solids;

[0237] (c) adding iron to the evaporated dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0238] (d) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition;

[0239] (e) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 95°C to about 105°C for a period of about 30 seconds to about 60 seconds to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0240] In one embodiment, there is provided producing an iron-fortified dairy food or beverage product, the method comprising the steps of:

[0241] (a) providing a dairy ingredient composition comprising casein and whey protein; (b) adding iron to the dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0242] (c) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition;

[0243] (d) evaporating the homogenised iron-fortified dairy ingredient composition to form an evaporated iron-fortified dairy ingredient composition;

[0244] (e) heat treating the evaporated iron-fortified dairy ingredient composition at a temperature of about 90°C to about 95°C for about 30 seconds to about 60 seconds to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0245] In one embodiment, there is provided producing an iron-fortified dairy food or beverage product, the method comprising the steps of:

[0246] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0247] (b) adding iron to the dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0248] (c) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition;

[0249] (d) evaporating the homogenised iron-fortified dairy ingredient composition to form an evaporated iron-fortified dairy ingredient composition;

[0250] (e) heat treating the evaporated iron-fortified dairy ingredient composition at a temperature of about 95°C to about 105°C for a period of about 30 seconds to about 60 seconds to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0251] In one embodiment, there is provided producing an iron-fortified dairy food or beverage product, the method comprising the steps of:

[0252] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0253] (b) adding iron to the dairy ingredient composition with a total solid content below or equal to about 30% to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0254] (c) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition;

[0255] (d) evaporating the homogenised iron-fortified dairy ingredient composition to form an evaporated iron-fortified dairy ingredient composition;

[0256] (e) heat treating the evaporated iron-fortified dairy ingredient composition at a temperature of about 90°C to about 95°C for about 30 seconds to about 60 seconds to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0257] In one embodiment, there is provided producing an iron-fortified dairy food or beverage product, the method comprising the steps of:

[0258] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0259] (b) adding iron to the evaporated dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0260] (c) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition;

[0261] (d) evaporating the homogenised iron-fortified dairy ingredient composition to form an evaporated iron-fortified dairy ingredient composition, preferably comprising at least about 40% total solids;

[0262] (e) heat treating the evaporated iron-fortified dairy ingredient composition at a temperature of about 95°C to about 105°C for a period of about 30 seconds to about 60 seconds to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0263] Other steps may be combined with those described above.

[0264] Suitably, the present methods - including those described above - may comprise a drying step, preferably a spray drying step, following the heat treatment. Such a drying step is typically used to produce a powdered product; for example.

[0265] Suitably, the present methods may comprise stirring the homogenised iron-fortified dairy ingredient composition during the heat treatment step. Suitably, in the present context "stirring" means moving the ingredient composition.

[0266] Methods for forming agglomerated proteins in a dairy product are well known in the art. For example, WO 2018114818 A1 , WO 2018002141 A1 , WO 2018114834 A1 and WO 2018114826 A1 describe methods for forming agglomerated proteins in a dairy product using divalent cations such as calcium. Any suitable method for forming agglomerated proteins in a dairy product may be employed in the practice of the present invention and adapted to include iron fortification (i.e. the addition of iron) as described herein.

[0267] Dairy food or beverage product

[0268] The dairy food or beverage product may be a powdered milk, a concentrated milk, an evaporated milk, a medical nutritional product, or a ready to drink (RTD) dessert.

[0269] Preferably the dairy food or beverage product is a powdered milk. In embodiments where the dairy ingredient is processed to a powder, the powdered dairy ingredient composition (e.g. following drying, such as spray drying) may comprise about 5 mg to about 80 mg or about 5 mg to about 50 mg iron per 100 g of powder.

[0270] Suitably, the dairy food or beverage product is a powdered milk comprising about 5 mg to about 80 mg or about 5 mg to about 50 mg iron per 100 g of powder.

[0271] Suitably, the powder dairy ingredient or powdered milk may comprise about 5 mg to about 80 mg or about 5 mg to about 50 mg iron per 100 g of powder.

[0272] Suitably, the powder dairy ingredient or powdered milk may comprise about 0.005 to about 4 % iron (w / w).

[0273] Suitably, the dairy food or beverage product is a low fat product. As will be apparent, the description of a ‘low-fat’ product may differ depending on the product category under consideration. However, the present invention provides dairy food or beverage products with advantageous texture and / or mouthfeel characteristics (e.g. perception of creaminess) achieved with lower fat levels than products which do not comprise the casein-whey protein agglomerates as described herein.

[0274] The present products may provide advantages such as having similar sensory profiles to milk products that comprise similar amounts of milk solids and / or milk proteins but have not been subject to the present heat treatment in the presence of iron. As such, the milk products of the invention are able to retain a sensory profile that is desired by consumers whilst utilizing less raw materials.

[0275] Suitably, the dairy food or beverage product may be a low fat powdered milk. For example, the low fat powdered milk may contain less than 15% milk fat, less than 10% milk fat, less than 5% milk fat, less than 3% milk fat, or about 1 % milk fat.

[0276] Suitably, the dairy food or beverage product may contain about 5 g / 100 mL to about 20 g / 100 mL protein per serving. For example, the dairy food or beverage product may contain about 6 g / 100 mL to about 9 g / 100 mL, about 9 g / 100 mL to about 12 g / 100mL, or about 12 g / 100 mL to about 18 g / 100 mL protein per serving. Suitably, for powdered products for reconstitution in water, the dairy food or beverage product may contain about 9 g / 100 mL to about 12 g / 100mL protein per serving. Suitably, for RTD dairy food or beverage products, the product may contain about 6 g / 100 mL to about 9 g / 100 mL or about 12 g / 100 mL to about 18 g / 100 mL protein per serving. Suitably, the serving size may be from about 100 mL to about 250 mL, such as 120 mL or 200 mL. Suitably, the dairy food or beverage product may be dried into powder by means of freeze drying, spray drying or roller-drying.

[0277] Suitably, the dairy food or beverage product may be dried by spray drying.

[0278] Suitably, the dairy food or beverage product does not comprise non-dairy stabilizers.

[0279] Suitably, the dairy food or beverage product does not comprise additional thickening agents and / or stabilisers (e.g. hydrocolloids and / or emulsifiers).

[0280] Iron Supplementation

[0281] Iron deficiency remains a major global health problem affecting an estimated 2 billion people. Highly soluble compounds of iron, such as ferrous sulfate (relative bioavailability 100%), are desirable food fortificants but cannot be used in many food vehicles because of sensory issues. Thus, potentially less well-absorbed forms of iron commonly are used in food fortification e.g. Iron pyrophosphate (Hurrell et al., Int J Vitam Nutr Res. 2004 Nov; 74(6) 387 - 40).

[0282] The present invention further provides an iron-casein complex for use in iron supplementation in a subject in need thereof; wherein the iron-casein complex is present in a dairy ingredient composition or a dairy food or beverage product comprising agglomerated proteins comprising caseins and beta-lactoglobulin from whey proteins, the agglomerates having a size of 3 - 50 microns as measured by D<4,3) mean diameter.

[0283] The subject may have been determined to have an iron-deficiency or at risk of an iron deficiency.

[0284] The subject may have, or be at risk of, iron deficiency anaemia.

[0285] Iron-deficiency, and iron deficiency anaemia, as well methods of iron supplementation are known in art (see Pasricha et al.-, The Lancet; 397(10270); 233-248; 2020).

[0286] Suitably, the "subject" or “individual” is a mammal, preferably a human.

[0287] Various preferred features and embodiments of the present invention will now be described by way of non-limiting examples. This disclosure is not limited by the exemplary methods and materials disclosed herein, and any methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of this disclosure. The skilled person will understand that they can combine all features of the invention disclosed herein without departing from the scope of the invention as disclosed. It must be noted that as used herein and in the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

[0288] The terms "comprising", "comprises" and "comprised of" as used herein are synonymous with "including", "includes", "containing", or "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or steps. The terms "comprising", "comprises" and "comprised of" also include the term "consisting of".

[0289] Numeric ranges are inclusive of the numbers defining the range. As used herein the term “about” means approximately, in the region of, roughly, or around. When the term “about” is used in conjunction with a numerical value or range, it modifies that value or range by extending the boundaries above and below the numerical value(s) set forth. In general, the terms “about” and “approximately” are used herein to modify a numerical value(s) above and below the stated value(s) by 10%.

[0290] The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that such publications constitute prior art to the claims appended hereto.

[0291] All publications mentioned in the specification are herein incorporated by reference.

[0292] EXAMPLES

[0293] The invention will now be further described by way of examples, which are meant to serve to assist one of ordinary skill in the art in carrying out the invention and are not intended in any way to limit the scope of the invention.

[0294] Example 1 - Addition of iron and calcium during production of a fortified milk product comprising whey-casein protein agglomerates

[0295] Fortified milk powder containing iron was prepared by a milk processing procedure which utilizes calcium to induce whey-casein complexes with a particle size distribution associated with improved sensory characteristics (see Figure 1). Specifically, fresh milk and skimmed milk powder were dissolved at 60 °C - 65 °C and further homogenised. The milk emulsion was further concentrated by two-effect evaporation before heat treatment using direct stem injection (DSI) to induce complex formation. Finally, spray drying was performed to produce the milk powder.

[0296] Initial iterations of the method combined the addition of 0.1-20 mM ferric sulphate and 0.1-10 mM calcium chloride to the wet ingredients following the evaporation step and prior to heat treatment, at a neutral pH and a temperature of about 65°C. However, this was found to result in a final product with a poor taste profile in a panel review, in particular a metallic off-notes (see Figure 2A).

[0297] It was determined that the addition of ferric sulphate to the wet ingredients allowed the calcium concentration to be reduced. Reduction of calcium overcame the poor taste profile (see Figures 2A, 2B and 4). Possible explanation could include that despite ferric ion binds more strongly to casein micelle (equilibration constant of iron-casein 1013log is higher than calcium casein complex 102- 103) it was probable that calcium, if displaced upon iron addition, remain associated with the casein micelle in some way. It has been previously shown that calcium was not released into the non-sedimentable phase of milk even upon addition of > 10 mM iron to milk. Therefore, it is possible that the binding sites of casein were shared by calcium and added iron which my contribute to the alteration of taste profile.

[0298] Ferric sulphate addition was performed either before or after evaporation, without notable impacts on sensory performance in the presence of both reduced or no additional calcium (see Figure 3).

[0299] Example 2 - Addition of iron during production of a fortified milk product enables generation of whey-casein protein agglomerates

[0300] In order to assess particle size distribution (PSD), dispersions and emulsions were analyzed after shearing by dynamic light scattering using a MasterSizer 3000 (Malvern Instruments Ltd®, UK) and HORIBA LA-350 (Horiba Scientific). The emulsion sample was dispersed in the measuring cell until an obscuration rate of 9-10% was obtained. Measures were performed three times and the average of the three replications was reported.

[0301] Figure 5 shows illustrative temperatures utilized to generate whey-casein protein agglomerates with a PSD known to provide a desired sensory performance at various CaCh concentrations, including in the absence of CaCh (i.e. addition of iron only) both at lower total solids (before evaporator stage) and at higher total solids (after the evaporator stage). CaCh was added after the evaporator stage and heat treatment was performed at the heat treatment step shown in Figure 1 for a period of 30-60 seconds. Various combination of iron and calcium concentration, as well as with only iron addition (at different addition points before and after evaporation) can be performed with this variation of operating temperature (90- 100°C) to achieve the desired PSD.

[0302] As shown in Figure 5, generally a lower temperature could be used to achieve the required PSD in the presence of iron. In addition, lower Ca2+could be used to achieve the same PSD effect in the presence of iron. The stronger binding of Fe3+to phosphoserine of casein (as opposed to electrostatic interaction of Ca2+to casein) is thought to contribute to change in the casein protein confirmation, increasing structural rigidity, possibly due to the exposure of hydrophobic regions of caseins towards more polar environment.

[0303] Various combination of iron and calcium concentration, as well as with only iron addition (at different addition points before and after evaporation) can be performed to deliver target particle size distribution range for desired sensory outcome. In particular, all of the tested parameters provide the desired PSD, which is necessary to generate the desired creamy texture and sensory performance (Figure 5B). This evidences that the added iron can induce protein agglomeration with the desired PSD in the presence of reduced levels of calcium or even in the absence of calcium.

[0304] Example 3 - Iron bioaccessibility of casein iron complexes generated by the addition of iron during production of a fortified milk product

[0305] Figure 6 shows in vitro iron bioaccessibility (validated CaCo2 cell model); see, for example, Ariza-Nieto M, Blair MW, Welch RM, Glahn RP, Journal of Agricultural and Food Chemistry 2007 Sep 19;55(19):7950-6; Gangloff, M.B., Glahn, R.P., Miller D.D., and Van Campen D.R., 1996, Nutrition Research 16:479-487; Glahn R.P., Wien E.M., Van Campen D.R. and Miller D.D, 1996, J. Nutr. 126:332-339; Glahn, R.P., Lee, O.A., Yeung, A., Goldman, M.I., and Miller, D.D., 1998, J. Nutr. 128:1555-1561 ; Glahn RP, J Vis Exp, 2022 Apr 28;(182); and Glahn et al. Cornell University, 02 / 2021 , unpublished.

[0306] As shown in Figure 6, the present method inducing casein-iron complexes in combination with whey-casein complexes (“Iron-casein complex with aggregation”) was shown to have similar in vitro bioaccessibility compared to iron chelation alone (“Iron-casein complex”). This shows iron induced protein aggregation can be achieved without affecting its bioavailability. The present method inducing casein-iron complexes in combination with whey-casein complexes (“Iron chelation + heat treatment”) was shown to have significantly higher in vitro bioaccessibility in comparison to ferric pyrophosphate.

[0307] EMBODIMENTS

[0308] Aspects of the present invention are defined in the following numbered paragraphs (paras):

[0309] 1. A method of producing an iron-fortified dairy ingredient composition, the method comprising:

[0310] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0311] (b) adding iron to the dairy ingredient composition to form iron-casein complexes;

[0312] (c) homogenising the dairy ingredient composition; and (d) heat treating the dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D(4,3) mean diameter.

[0313] 2. The method according to para 1 , wherein step (c) is performed prior to step (b).

[0314] 3. A method of producing an iron-fortified dairy ingredient composition, the method comprising:

[0315] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0316] (b) adding iron to the dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;

[0317] (c) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition; and

[0318] (d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0319] 4. A method of producing an iron-fortified dairy food or beverage product, the method comprising:

[0320] (a) providing a dairy ingredient composition comprising casein and whey protein;

[0321] (b) homogenising the dairy ingredient composition to form a homogenised dairy ingredient composition;

[0322] (c) adding iron to the homogenised dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition comprising iron-casein complexes; and

[0323] (d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

[0324] 5. The method according to any preceding para wherein the dairy ingredient composition has a pH of about 6.0 to about 7.5, preferably about 6.1 to about 7.1 , when the iron is added.

[0325] 6. The method according to any preceding para wherein the dairy ingredient composition comprises about 12 to about 35 wt. % of proteins.

[0326] 7. The method according to para 6, wherein the dairy ingredient composition comprises about 16 to about 32 wt. % of proteins. 8. The method according to any preceding para wherein the dairy ingredient composition comprises about 5 - 70 wt. % total solids when the iron is added.

[0327] 9. The method according to any preceding para wherein the dairy ingredient composition has a casein to whey protein ratio of about 90 / 10 to about 60 / 40.

[0328] 10. The method according to any preceding para wherein the casein is micellar casein.

[0329] 11 . The method according to any preceding para wherein the iron is ferric iron.

[0330] 12. The method according to any preceding para wherein the iron is added to the dairy ingredient composition in the form of ferric sulphate.

[0331] 13. The method according to any preceding para wherein the iron is added such that the final concentration in the dairy ingredient composition is about 0.005 mM to about 20 mM, preferably about 0.005 mM to about 10 mM.

[0332] 14. The method according to any preceding para wherein the iron-casein complexes comprise over 0.005% w / w iron bound to casein, preferably over 1% w / w iron bound to casein.

[0333] 15. The method according to any of paras 1 to 3 or 5 to14, wherein the iron is added at a temperature of about 1 °C to about 70 °C.

[0334] 16. The method according to any of paras 1 to 3 or 5 to 15, wherein the method further comprises performing an evaporation step on the homogenised iron-fortified dairy ingredient composition formed in step (c) and prior to the heat treating the evaporated homogenised iron- fortified dairy ingredient composition in step (d).

[0335] 17. The method according to any of paras 1 , 2 or 4 to 14, wherein the iron is added at a temperature of about 1 °C to about 85 °C.

[0336] 18. The method according to any of paras 1 , 2, 4 to 14 or 17, wherein the method further comprises performing an evaporation step on the homogenised dairy ingredient composition formed in step (b) and prior to adding iron to the evaporated homogenised dairy ingredient composition in step (c) to form an evaporated homogenised iron-fortified dairy ingredient composition comprising iron-casein complexes.

[0337] 19. The method according to any preceding para wherein phosphorous is added to the dairy ingredient composition prior to, or at the same time as, the iron addition.

[0338] 20. The method according to para 19 wherein the phosphorous is added in an amount to provide a ratio of casein to phosphorous in the dairy ingredient composition of up to 8:1 . 21. The method according to any preceding para wherein the agglomerated proteins are about 5-30 microns, preferably about 5-10 microns.

[0339] 22. The method according to any preceding para wherein the total solid content of the dairy ingredient composition is (i) less than 30 wt %, or (ii) above 40 wt. when the iron is added.

[0340] 23. The method according to any preceding para wherein the total solid content of the dairy ingredient composition is above 40 wt. when step (d) is performed.

[0341] 24. The method according to any preceding para when step (d) is performed at a temperature of about 75°C to about 110°C for a period of about 20 seconds to about 90 seconds, suitably about 80°C to about 105°C for a period of about 30 seconds to about 60 seconds.

[0342] 25. The method according to any one of paras 1 to 3, 5 to 16, or 19 to 24, wherein the total solid content in the ingredient composition is below or equal to about 30% when the iron is added.

[0343] 26. The method according to para 25 wherein step (d) is performed at a temperature of about 80°C to about 95°C, preferably about 90°C to about 95°C, for a period of about 30 seconds to about 60 seconds.

[0344] 27. The method according to any of paras 1 , 2, 4 to 14, or 17 to 24, wherein the total solid content of the ingredient composition is above or equal to about 40%, when the iron is added.

[0345] 28. The method according to para 27 wherein the heat treatment is performed at a temperature of about 95°C to about 105°C for a period of about 30 seconds to about 60 seconds.

[0346] 29. The method according to any preceding para where step (d) comprises stirring the homogenised iron-fortified dairy ingredient composition during the heat treatment.

[0347] 30. The method according to any preceding para wherein the dairy ingredient composition comprises from about 0-50 wt. % fat, preferably about 1-20 wt. %, more preferably about 3- 15 wt. % of fat, or most preferably 5-10 wt. % of fat.

[0348] 31. The method according to any preceding para wherein the method further comprises pasteurising the heat-treated homogenised iron-fortified dairy ingredient following step (d).

[0349] 32. The method according to any preceding para wherein the method comprises adding essentially no divalent cations to the dairy ingredient composition prior to the homogenisation, heat treatment, pasteurisation and / or stirring steps. 33. The method according to any of paras 1 to 30 wherein the method further comprises adding divalent cations in an amount such that the divalent cation concentration in the dairy ingredient composition, iron-fortified dairy ingredient composition, homogenised dairy ingredient composition or homogenised iron-fortified dairy ingredient composition is less than about 4 mmol Ca / kg of milk concentrate, suitably about 1.5 to 4 mmol Ca / kg of milk concentrate.

[0350] 34. The method according to any preceding para wherein the method does not comprise adding a divalent cation to the dairy ingredient composition prior to the homogenisation, pasteurising and / or stirring steps.

[0351] 35. The method according to any preceding para wherein the method further comprises adding the heat-treated homogenised iron-fortified dairy ingredient composition to a dairy food or beverage product following step (d) or following the pasteurisation step.

[0352] 36. The method according to para 35 wherein the dairy food or beverage product is a powdered milk, a concentrated milk, an evaporated milk, a medical nutritional product, or a RTD dessert.

[0353] 37. The method according to para 36 wherein the dairy food or beverage product is a powdered milk.

[0354] 38. The method according to para 36 or 37 wherein the dairy food or beverage product is a low-fat dairy food or beverage product.

[0355] 39. An iron-fortified dairy ingredient composition comprising agglomerated proteins comprising casein micelles and whey proteins, the agglomerates having a size of 3 - 50 microns as measured by D<4,3) mean diameter and iron-casein complexes.

[0356] 40. The iron-fortified dairy ingredient composition according to para 39 wherein the dairy ingredient composition comprises a concentration of about 3% to about 25 wt. % of proteins.

[0357] 41 . The iron-fortified dairy ingredient composition according to para 39 or 40 wherein the dairy ingredient composition has a casein to whey protein ratio of about 90 / 10 to about 60 / 40.

[0358] 42. The iron-fortified dairy ingredient composition according to any of paras 39 to 41 wherein the iron is ferric iron.

[0359] 43. The iron-fortified dairy ingredient composition according to any of paras 39 to 42 wherein the iron-casein complexes comprise over 0.005% w / w iron bound to casein, preferably over 1% w / w iron bound to casein. 44. The iron-fortified dairy ingredient composition according to any of paras 39 to 43 wherein the iron-casein complexes comprise phosphorous; optionally wherein the phosphorous is in an amount to provide a ratio of casein to phosphorous in the dairy ingredient composition of up to 8:1 .

[0360] 45. The iron-fortified dairy ingredient composition according to any of paras 39 to 44 wherein the agglomerated proteins are about 5-30 microns as measured by D<4,3) mean diameter, preferably about 5-10 microns.

[0361] 46. The iron-fortified dairy ingredient composition according to any of paras 39 to 45 wherein the dairy ingredient composition comprises from about 0-50 wt. % fat, preferably about 1-20 wt. %, more preferably about 3-15 wt. % of fat, or most preferably 5-10 wt. % of fat.

[0362] 47. An iron-fortified dairy ingredient composition produced by the method of any of paras 1 to 38.

[0363] 48. A dairy food or beverage product comprising an iron-fortified dairy ingredient composition according to any of paras 39 to 46.

[0364] 49. The dairy food or beverage product according to para 48 wherein the dairy food or beverage product is a powdered milk, a concentrated milk, an evaporated milk, a medical nutritional product, or a RTD dessert.

[0365] 50. The dairy food or beverage product according to para 48 or 49 wherein the dairy food or beverage product is a low-fat dairy food or beverage product

[0366] 51. The dairy food or beverage product according to any of paras 48 to 50 wherein the dairy food or beverage product does not comprise non-dairy stabilizers.

[0367] 52. An iron-fortified dairy ingredient composition or a dairy food or beverage product according to any of paras 39 to 51 for use in iron supplementation in a subject in need thereof.

[0368] 53. An iron-casein complex for use in iron supplementation in a subject in need thereof; wherein the iron-casein complex is present in a dairy ingredient composition or a dairy food or beverage product comprising agglomerated proteins comprising caseins and betalactoglobulin from whey proteins, the agglomerates having a size of 3 - 50 microns as measured by D<4,3) mean diameter.

[0369] 54. An iron-fortified dairy ingredient composition, a dairy food or beverage product or an iron-casein complex for use according to para 52 or 53 wherein the subject has been determined to have an iron-deficiency or at risk of an iron deficiency. 55. The iron-fortified dairy ingredient composition, a dairy food or beverage product or an iron-casein complex for use according to para 52 or 53 wherein the subject has, or is at risk of, iron deficiency anaemia.

[0370] 56. Use of iron to generate agglomerated proteins comprising caseins and beta- lactoglobulin from whey proteins in a dairy ingredient composition, the agglomerates having a size of 3 - 50 microns as measured by D<4,3) mean diameter.

[0371] All publications mentioned in the above specification are herein incorporated by reference. Various modifications and variations of the described methods and system of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as paraed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in molecular biology or related fields are intended to be within the scope of the preceding paras.

Claims

CLAIMS1. A method of producing an iron-fortified dairy ingredient composition, the method comprising:(a) providing a dairy ingredient composition comprising casein and whey protein;(b) adding iron to the dairy ingredient composition to form an iron-fortified dairy ingredient composition comprising iron-casein complexes;(c) homogenising the iron-fortified dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition; and(d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

2. A method of producing an iron-fortified dairy ingredient composition, the method comprising:(a) providing a dairy ingredient composition comprising casein and whey protein;(b) homogenising the dairy ingredient composition to form a homogenised dairy ingredient composition;(c) adding iron to the homogenised dairy ingredient composition to form a homogenised iron- fortified dairy ingredient composition comprising iron-casein complexes; and(d) heat treating the homogenised iron-fortified dairy ingredient composition at a temperature of about 60°C to about 110°C for a period of about 20 seconds to about 3 minutes to form agglomerated proteins comprising caseins and whey protein and having a size of about 3 to about 50 microns as measured by D<4,3) mean diameter.

3. The method according to claim 1 or claim 2 wherein the dairy ingredient composition has a casein to whey protein ratio of about 90 / 10 to about 60 / 40.

4. The method according to any preceding claim wherein the casein is micellar casein.

5. The method according to any preceding claim wherein the iron is ferric iron.

6. The method according to any preceding claim wherein the iron is added such that the final concentration in the dairy ingredient composition is about 0.005 mM to about 20 mM, preferably about 0.005 mM to about 10 mM.

7. The method according to any preceding claim wherein phosphorous is added to the dairy ingredient composition prior to, or at the same time as, the iron addition.

368. The method according to any preceding claim wherein the agglomerated proteins are about 5-30 microns, preferably about 5-10 microns.

9. The method according to any preceding claim wherein the total solid content in the ingredient composition is below or equal to about 30% when the iron is added and wherein step (d) is performed at a temperature of about 90°C to about 95°C for a period of about 30 seconds to about 60 seconds.

10. The method according to any of claims 1 to 8 wherein the total solid content in the ingredient composition is equal to or above about 40% and wherein step (d) is performed at a temperature of about 95°C to about 105°C for a period of about 30 seconds to about 60 seconds.11 . The method according to any preceding claim wherein the method comprises adding essentially no divalent cations to the dairy ingredient composition prior to step (d).

12. An iron-fortified dairy ingredient composition comprising agglomerated proteins comprising casein micelles and whey proteins, the agglomerates having a size of 3 - 50 microns as measured by D<4,3) mean diameter, and iron-casein complexes.

13. An iron-fortified dairy ingredient composition produced by the method of any of claims 1 to 11 .

14. A dairy food or beverage product comprising an iron-fortified dairy ingredient composition according to any of claims 12 or 13.

15. An iron-fortified dairy ingredient composition or a dairy food or beverage product according to any of claims 12 to 14 for use in iron supplementation in a subject in need thereof.

16. Use of iron to generate agglomerated proteins comprising caseins and betalactoglobulin from whey proteins in a dairy ingredient composition, the agglomerates having a size of 3 - 50 microns as measured by D<4,3) mean diameter.37

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