Process of preparing a pasta filata product

Abstract

The present invention relates to a process of preparing a pasta filata product and the pasta filata product obtained hereby having improved functionalities. In particular, the present invention relates to a process of preparing a pasta filata product where a milk starting material used for preparing the pasta filata product 5 is acidified by using electrodialysis with bipolar membrane. The obtained pH adjusted milk starting material is processed into a pasta filata product.

Description

[0001] Process of preparing a pasta filata product

[0002] Technical field of the invention

[0003] The present invention relates to a process of preparing a pasta filata product and the pasta filata product obtained hereby. In particular, the present invention relates to a process of preparing a pasta filata product where a milk starting material used for preparing the pasta filata product is acidified by using electrodialysis with bipolar membrane. The obtained pH adjusted milk starting material is processed into a pasta filata product.

[0004] Background of the invention

[0005] Pasta filata products, such as for example mozzarella, are widely used in many food applications such as topping on pizza. When preparing these types of products, it is desired to obtain a product with good melting and stretching properties.

[0006] Calcium plays an important role during the manufacture of a pasta filata product. The calcium content, for example, is known to have an influence on the melting and stretching properties. Lowering the calcium content in pasta filata cheese enhances its melting and stretching properties. This is because a lower calcium / protein ratio allows for better melt and stretch. However, calcium is also essential for forming a network structure of casein during the coagulation process of milk proteins. A high calcium content can increase the hardness of the cheese.

[0007] Methods of reducing calcium content in a pasta filata product is known, for example by pre-acidification with an organic acid of the milk used for preparing the curd, or by addition of lactic acid producing bacteria or acids during the coagulation step. The acidifying agents will solubilise calcium but also work as a coagulation agent.

[0008] Further, the use of for organic acids, such as for example citric acid, in preparing a pasta filata product, results in contamination of the whey obtained with the organic acid. Further, addition of for example citric acid forms calcium citrate that may result in fouling.

[0009] Therefore, an improved method of preparing a pasta filata product with an improved control of calcium removal would be advantageous, and, in particular, a more efficient method of preparing a pasta filata product without the need of adding organic acid would be advantageous.

[0010] Further, a process of preparing a pasta filata product having improved functionalities would be advantageous.

[0011] Summary of the invention

[0012] Thus, an object of the present invention relates to providing a process of preparing a pasta filata product that has good functional properties such as good blister size, blister coverage, stretch, meltability and texture. In addition, it is an object of the present invention to provide a pasta filata product that has not been prepared by adding any organic acid.

[0013] In particular, it is an object of the present invention to provide a process for preparing a pasta filata product that solves the above-mentioned problems of the prior art.

[0014] Thus, one aspect of the invention relates to a process of preparing a pasta filata product comprising the following steps:

[0015] i) providing a milk starting material;

[0016] ii) adjusting pH of the milk starting material to be in the range of 5.4 to 6.3 by subjecting the milk starting material to electrodialysis using one or more bipolar membrane(s);

[0017] iii) adding one or more coagulating enzyme(s) to the pH adjusted milk starting material of step ii), and

[0018] vi) heating the mixture of step iii) to a temperature in the range of 25°C to 60°C for a time period sufficient to coagulate the mixture and obtain cheese curd and whey;

[0019] v) separating the curd from the whey; vi) subjecting the curd to a heating and stretching step to obtain a pasta filata product.

[0020] Another aspect of the present invention relates to a pasta filata product obtained by the process according to the invention comprising:

[0021] - calcium in an amount of 25 mg per gram protein or less;

[0022] potassium in an amount of 2.8 mg per gram protein or less;

[0023] protein in an amount of 20% by weight or more;

[0024] - does not comprise any organic acid or inorganic acid;

[0025] and the pasta filata product is having a pH in the range of 5.0 to 5.5 while it does not comprise any added organic acid or inorganic acid.

[0026] Brief description of the figures

[0027] Figure 1 shows a schematic overview of an example of the stack used for acidification using electrodialysis with bipolar membrane. The electrodialysis with bipolar membrane in figure 1 comprises CEM and BM. BM refers to bipolar membrane and CEM refers to cationic membrane.

[0028] Figure 2 shows a schematic overview of another example of the stack used for electrodialysis with bipolar membrane. The electrodialysis with bipolar membrane in figure 2 comprises AEM, CEM and BM. BM refers to bipolar membrane, AEM refers to anionic exchange membrane and CEM refers to cationic exchange membrane.

[0029] Figure 3 shows a flow diagram of the process of preparing a mozzarella using electrodialysis with bipolar membrane according to the present invention.

[0030] Figure 4 shows a flow diagram of a process of preparing mozzarella using pH adjustment with citric acid.

[0031] Figure 5 shows blister size and blister coverage of mozzarella made with A) acidification with citric acid to pH 6.15, B) acidification with EDBM to pH 6.15, C) acidification with EDBM to pH 6.0, D) acidification with EDBM to pH 5.80 and E) acidification with EDBM to pH 5.80 followed by ultrafiltration.

[0032] Figure 6 shows a flow diagram of the process of preparing mozzarella using electrodialysis with bipolar membrane according to the invention including an ultrafiltration step before acidification.

[0033] Figure 7 shows the process of the invention. Figure 7A shows the process of the invention where fat standardized milk is used for acidification. Figure 7B shows the process of the invention where skim milk is used for the acidification and fat is added to the curd in the cooker / stretcher.

[0034] The present invention will now be described in more detail in the following.

[0035] Detailed description of the invention

[0036] Definitions

[0037] Prior to discussing the present invention in further details, the following terms and conventions will first be defined:

[0038] All references referred to herein are percentages by weight unless otherwise stated. The term "w / w" also refers to weight percentages. For example, 1% w / w refers to a composition comprising 1% by weight of a compound.

[0039] In the context of the present invention, the term "pasta filata product" refers to a stretched-curd product that makes the product elastic. The term "pasta filata product" covers both pasta filata cheeses but also analogue products that are not categorised as a cheese but is categorised as pizza topping. The analogue pasta filata product is characterised by having vegetable fat added instead of dairy fat. Hence, the term "pasta filata product" covers all type of pasta filata products that are elastic and stretchable. The pasta filata cheese is a type of cheese characterized by its unique production process. The term "pasta filata" translates to "spun paste" or "stretched curd" in Italian. The cheese-making process involves heating the curds until they become pliable, then stretching and kneading them to achieve a smooth, elastic texture. This technique aligns the proteins in the cheese, resulting in its signature stringiness and excellent melting properties. Notable examples of pasta filata cheeses include Mozzarella, Provolone, Burrata and Scamorza

[0040] Milk starting material:

[0041] In the process of preparing the pasta filata product of the present invention, the pasta filata product is prepared from a milk starting material. The term "milk" in "milk starting material" refers to that the milk starting material is in liquid form. Hence, the milk starting material is liquid.

[0042] The type of milk used as starting material is not to be seen as a limitation of the present invention, and in principle, any milk product may be used as the milk starting material.

[0043] However, the milk starting material may for example be selected from the group consisting of whole milk (full-fat milk), low-fat milk, reduced fat milk, fat-free milk, buttermilk, reconstituted milk powder, lactose- reduced milk, low-lactose milk, lactose-free milk, heat treated milk (e.g. pasteurised or UHT treated milk), raw unfiltered milk, homogenised milk, mineral reduced milk, whey protein reduced milk, micellar casein isolate, micellar casein concentrate, an ultrafiltration permeate of milk and combinations thereof.

[0044] Preferably, the milk starting material is selected from the group consisting of whole milk, low-fat milk, reduced fat milk, fat-free milk, buttermilk, reconstituted milk powder, lactose-reduced milk, low-lactose milk, lactose-free milk, heat treated milk, raw unfiltered milk, homogenised milk, mineral reduced milk, whey protein reduced milk, an ultrafiltration permeate of milk and combinations thereof.

[0045] More preferably, the milk starting material is selected from the group consisting of whole milk, low-fat milk, reduced-fat milk, fat-free milk, lactose reduced milk, low-lactose milk, lactose-free milk, an ultrafiltration permeate of milk, and combinations thereof.

[0046] In an embodiment of the invention, the milk starting material is an ultrafiltration permeate of milk, where the milk is any of whole milk, low-fat milk, reduced fat milk, fat-free milk, lactose- reduced milk, low-lactose milk, and lactose-free milk. Preferably the milk is low-fat milk, reduced-fat milk. Fat-free milk. After ultrafiltration of milk, a permeate and retentate is obtained. The ultrafiltration permeate is acidified using the electrodialysis with bipolar membrane and the acidified ultrafiltration permeate is mixed with the ultrafiltration retentate before further processing, see figure 6.

[0047] Furthermore, the milk starting material provided and used in the process of the present invention for preparing a fermented dairy product may be based on milk from mammals, such as milk from cow, buffalo, goat, sheep, camel, yak, or mixtures thereof. In a preferred embodiment of the present invention, the milk starting material is from cow, such as bovine milk. The term bovine milk and cow's milk refer to the same and may be used interchangeable.

[0048] In a preferred embodiment of the invention, the milk starting material is pasteurised milk, and especially pasteurised bovine milk. When referring to pasteurised milk, it may in principle be any type of the above-mentioned milk starting materials that have been pasteurised, such as for example pasteurised whole milk, low-fat milk, reduced fat milk, fat-free milk, raw unfiltered milk, mineral reduced milk, lactose reduced milk, low-lactose milk, lactose-free milk and ultrafiltration permeate of milk.

[0049] The fat content of the milk starting material is not critical for the invention, and therefore a milk starting material could have either a low or a high fat content depending on the product to be prepared. Hence, the fat content of the milk starting material may be up to 5% by weight, such as up to 3% by weight.

[0050] However, in an embodiment of the present invention, the milk starting material is low in fat and comprises fat in an amount of 0.1% by weight or less. Preferably, the milk starting material comprises fat in an amount of 0.05% by weight or less. However, fat may also be added later in the process. For example, fat may be added to the curd before or during heating and stretching of the curd to a pasta filata product. In another embodiment, the milk starting material being low in fat is fat standardized by adding either dairy fat or vegetable fat to the milk starting material before acidification. The fat in the milk starting material may be adjusted by a process known as fat standardization. Traditionally, standardization of milk has been achieved by removing nearly all the fat (cream) from the starting milk (by separation technique, such as centrifugation) and adding back a known amount of cream thereto to achieve a predetermined protein / fat ratio in the milk. Fat standardization is typically performed by subjecting the milk to centrifugation which separates the cream fraction from the skim milk fraction (reduced fat milk fraction). Fat added to the milk may also be vegetable fat.

[0051] In another embodiment of the invention, the milk starting material has not been subjected to any fat standardization (fat removed) and the fat content is corresponding to the fat content typically present in milk, i.e. about 3.5% by weight.

[0052] In another embodiment of the invention, the milk starting material is a skim milk having a low-fat content, and the acidification with electrodialysis with bipolar membrane is made on the skim milk. Subsequently, in the heating and stretching of curd in step vi) of the process of the invention, fat may be added. The fat added may be any dairy fat or suitable vegetable fat.

[0053] The milk starting material preferably comprises preferably both casein and milk serum protein (whey protein) and preferably the ratio between whey protein and casein in the milk starting material is about the same ratio as found in natural milk, but in principle the whey protein and casein content may be different from the content present in natural milk. However, in the embodiment of the invention where a milk ultrafiltration permeate is used as the milk starting material, the milk starting material does not comprise casein or milk serum protein. The proteins are present in the ultrafiltration retentate and after acidification of the ultrafiltration permeate using EDBM, the acidified ultrafiltration permeate is mixed with the ultrafiltration retentate comprising the proteins to make acidified milk, see figure 6. The casein in the milk starting material is primarily present in the form of casein micelles, similar or even identical to the casein micelles found in e.g. skimmed milk.

[0054] The term "milk serum" refers to the liquid phase of milk in which whey proteins and fat globules are dispersed.

[0055] In the context if the present invention, the terms "milk serum protein" and "serum protein" refer to the protein bound in the milk serum. The milk serum protein may also be referred to as whey protein. The milk serum protein typically include betalactoglobulin, alpha-lactalbumin, bovine serum albumin, immunoglobulin and osteopontin as well as lactoferrin and lactoperoxidase.

[0056] The term "protein" refers in the context of the present invention to polypeptides containing at least 10 amino acids and encompasses both single polypeptides and aggregates of polypeptides.

[0057] The term "non-protein nitrogen" (NPN) refers to nitrogen found in molecules that are not protein. In milk a significant portion of the NPN comes from urea, ammonium, salts and small peptides containing less than 10 amino acids.

[0058] The term "whey" refers to the liquid obtained after casein in milk is precipitated or coagulated.

[0059] In the present invention, precipitation of casein is obtained by using a coagulation enzyme, for example rennet, and not by adding an organic acid. In some embodiments of the invention, the coagulation step may also comprise an acid producing microorganism. The microorganism used is typically a thermophilic or mesophilic microorganism or a combination of both. The whey obtained from precipitation of casein by use of a coagulation enzyme is typically referred to as sweet whey, and the whey obtained from acid precipitation of casein micelles is typically referred to as acid whey or sour whey.

[0060] Where acid whey has limited use, sweet whey can be further processed into various products, e.g. whey protein products or lactose products. The term "curd" refers to the particles obtained after coagulation of caseins in the milk starting material.

[0061] In an embodiment of the invention, the ratio between milk serum protein and casein in the milk starting material is in the range of 10:90 to 30:70, preferably 15:85 to 25:75, more preferably about 20:80. For example, the milk starting material can have a reduced whey protein content as compared to milk.

[0062] In the process of preparing a pasta filata product of the present invention, the casein will curdle / coagulate when the coagulation enzyme is added to make curd. The non-curdled part of the milk starting material is obtained in the whey. The whey can be separated from the curd.

[0063] Therefore, the casein content in the milk starting material should be in the range of 70% to 90% by weight of the total protein content, preferably 75% to 85% by weight and more preferably about 80% by weight of the total protein content.

[0064] In some embodiment of the invention, the milk serum protein of the milk starting material is present in undenatured, native form, i.e. the same form as in raw milk, which has not been subjected to a denaturing heat treatment. It is therefore also preferred that the milk starting material has not been subjected to conditions that have resulted in significant protein denaturation, such as e.g. high temperature for prolonged durations. However, the milk starting material may be pasteurised. Pasteurisation of the milk starting material may take place under standard conditions, namely, heat treatment of the milk starting material at a temperature and time sufficient to kill pathogens, typically at 72°C for 15 seconds.

[0065] In an embodiment of the invention, the milk starting material comprises a total amount of protein in the range of 1-10% (w / w). Preferably, the milk starting material comprises a total amount of protein in the range of 2-8% (w / w), and, even more preferably, the milk starting material comprises a total amount of protein in the range of 3-5% (w / w), such as 3.0-4.6. The solid content of the milk starting material may vary depending on the used feed, but it is typically in the range of 1-30% (w / w). preferably, the solid content of the milk starting material is in the range of 4-25% (w / w). Even more preferably, the solid content of the milk starting material is in the range of 5-15% (w / w).

[0066] The pH of the milk starting material is the same as in natural milk, i.e. typically in the range of 6.7-7.0.

[0067] In an embodiment of the present invention, the milk starting material is an organic milk derived feed derived from an organic milk source. In a preferred embodiment of the invention, the milk starting material is an organic skimmed milk.

[0068] In the context of the present invention, the term "organic milk" refers to milk produced by mammals, such as cattle, raised according to the following: the cattle must have free access to certified organic pasture for the entire grazing season. This period is specific to the farm's geographical climate but must be at least 120 days per year and preferably at least 150 days. Due to the weather, season, or climate, the grazing season may or may not be continuous. Organic cattle diets must contain at least 30 percent dry matter (on average) from certified organic pasture. Dry matter intake (DMI) is the amount of feed an animal consumes per day on moisture-free basis. The rest of its diet must also be certified organic, including hay, grain, and other agricultural products. The livestock should be managed without antibiotics added growth hormones, mammalian or avian byproducts, or other prohibited feed ingredients (e.g. urea or arsenic compounds).

[0069] pH adjustment:

[0070] In the process of the present invention, the milk staring material is pH adjusted to a pH in the range of 5.4 to 6.3 by subjecting the milk staring material to electrodialysis using one or more bipolar membrane(s).

[0071] The pH is preferably adjusted to a pH in the range of from 5.5 to 6.2, more preferably in the range of from 5.7 to 6.15 and most preferably in the range of from 5.8 to 6.0. pH should not be adjusted to a pH below 5.4, because if for example adjusted to pH 5.2, it was not possible to obtain the desired functionality of the obtained pasta filata product, i.e. the pasta filata product obtained when pH adjusting to pH 5.2 resulted in an undesirable product.

[0072] In a particularly preferred embodiment of the invention, pH was adjusted to a pH in the range of from 5.4 to 6.0.

[0073] In the present invention organic acids and inorganic acids have not been added during the process of preparing the pasta filata product, i.e. any organic acids and inorganic acids have not been added to the milk starting material or added during the process of preparing curd for the pasta filata product of the present invention. pH adjustment of the milk starting material is only by subjecting the milk starting material to electrodialysis with bipolar membrane. Hence, in an embodiment of the present invention, the process excludes addition of an organic acid and an inorganic acid to the milk starting material and excludes addition of organic- and inorganic acid in the process of the invention up to formation of the curd that is processed into the pasta filata cheese

[0074] The organic acid that is excluded from being added to the milk starting material or excluded from being added before the curd formation are for example citric acid, lactic acid, acetic acid, malic acid, and glucono-delta-lactone. The inorganic acid excluded to be added may be hydrochloric acid.

[0075] In the process according to the present invention, the pH adjustment results in that calcium bound in the casein micelles disassociate into free calcium. The free calcium will be present in the whey after curd formation. Hence, calcium can be removed from the milk staring material used to prepare the pasta filata product. Further, one advantage of using EDBM is that calcium partially is removed directly by the electrodialysis process since some of the free calcium in the acidified milk is passing the CEM into the water / salt solution. Hence, the EDBM process itself will remove some calcium. In the process according to the present invention, calcium is therefore removed from the milk staring material by adjusting the pH of the milk starting material using electrodialysis with a bipolar membrane.

[0076] Further, it was found by the inventors of the present invention that it is possible to prepare a pasta filata product with efficient and controlled removal of calcium and without addition of any organic acid.

[0077] In prior art, the process of preparing a pasta filata product may involve a preacidification step where an organic acid is added to for example skim milk.

[0078] However, addition of organic acid is not desired as it need to be labelled on the package, and it negatively affects the valorisation of the whey obtained during the process of preparing the pasta filata product. The presence of for example citric acid in the whey results in the formation of calcium citrate and therefore the use of the whey becomes limited.

[0079] In the method of the present invention, the inventors have surprisingly found that a controlled removal of calcium from the milk starting material used to prepare the pasta filata product can be obtained by pH adjusting the milk starting material by using electrodialysis with a bipolar membrane. Thereby, calcium is released as free calcium that can be removed in the drained whey.

[0080] The lower the pH, the more calcium is removed from the milk starting material in the whey draining step.

[0081] By pH adjustment with electrodialysis with bipolar membrane, no acidifying agents are used. Hence, from the process of the present invention provides a controlled removal of calcium, the process also provides a whey that does not comprises any acidifying agents and a pasta filata product without any acidifying agents.

[0082] In addition, it has surprisingly been found by the inventors of the present invention that a pasta filata product obtained by reducing the calcium content in the milk starting material by a pre-acidification step using electrodialysis with bipolar membrane (EDBM) as compared to pre-acidification using an organic acid has improved functional and sensorial properties. For example, it has surprisingly been found out that a pasta filata product obtained from a milk starting material, such as skim milk, that has been acidified using EDBM has improved stretch, meltability, blister size and blister coverage than a pasta filata product obtained after pre-acidification with citric acid.

[0083] Electrodialysis with bipolar membrane:

[0084] In an aspect of the process of the present invention, the milk starting material is subjected to electrodialysis with a bipolar membrane (EDBM) to adjust the pH of the milk starting material to be in the range of 5.4 to 6.3.

[0085] It has surprisingly been found out by the inventors of the present invention that not only acidification of a milk starting material can be obtained by using EDBM, but also a pasta filata product may be obtained from the milk starting material that has been acidified using EDBM with improved functional and sensorial properties.

[0086] EDBM is an electro-membrane process that could be used to split water into hydrogen and hydroxide ions which can subsequently be used to change the pH of a milk starting material (see figure 1).

[0087] Therefore, EDBM allows to change the pH of a milk starting material without adding any organic acids such as citric acid, lactic acid and acetic acid or inorganic acid such as hydrochloric acid. The use of EDBM for acidification allows the solubilisation of calcium from micellar caseins that are subsequently removed during with the whey separation. Some calcium is also directly removed during the EDBM. Further, the use of EDBM for acidification will remove some calcium and monovalent ions such as potassium from the milk starting material. This leads to changes in ionic strength and mineral balance in both serum phase and micellar colloidal phase. The inventors have surprisingly found that the milk starting material having a lower potassium content lead to a cheese product with a lower viscosity and hence to a softer cheese product.

[0088] As shown in figure 1, the EDBM is made of an anode and a cathode. In the configuration of the EDBM shown in figure 1, a cationic exchange membrane (CEM) is placed close to the anode and next to the cathode is also placed a cationic exchange membrane (CEM). In between the CEMs is placed a bipolar membrane (BM). In figure 1, the EDBM is made with 50 cell pairs with 51 CEMs and 50 BMs, but this may vary depending on the scale of production. The EDBM may also be made with one or more anionic exchange membranes (AEMs) and one or more BMs. The EDBM may be also made with one or more AEMs, one or more CEMs and one or more BMs.

[0089] The EDBM may comprise one or more cell pair, preferably 10 or more cell pair and more preferably 20 or more cell pair, such as 50 or more cell pair. The number of cell pair is not critical for the present invention and could be high. However, in an embodiment, the EDBM comprises up to 500 pairs. One pair comprises a bipolar membrane, a compartment with a stream for water and a compartment with a stream for the milk starting material.

[0090] The term "stack refers to all cell pairs placed between anode and cathode. In figure 1 is shown one stack with 50 cell pairs.

[0091] The stack may be placed in parallel or in series. Further, the pH adjustment in several stacks may be carried out in a continuous mode or in a batch mode. The rate of decreasing the pH in the EDBM is a question on how many stacks are used. The more stacks used, the larger is the surface area, and hence the faster is the acidification process.

[0092] When the electric potential (voltage) is applied to the system, the water molecules present at the interface of cationic and anionic layers of the bipolar membranes are split into hydrogen (H+) and hydroxide ions (OH-). The hydrogen and hydroxide ions are transported towards the cathode and anode respectively. In an embodiment of the invention, the EDBM stack is made with CEMs and BMs.

[0093] However, AEMs can also be used. The use of AEMs between anode and electrolyte solution will avoid the migration of anions toward the concentrate. Figure 2 shows a configuration of the EDBM including AEM. Figure 2 shows a CEM placed close to the cathode and an AEM placed close to the anode. In between the AEM and CEMs are placed bipolar membranes (BMs). In the configuration shown in figure 1, the milk starting material may be circulated to the EDBM stack in between the BM and the CEM, while water or salt solution is circulated to the EDBM in other compartments.

[0094] The hydrogen ion (H+) is transported to the milk starting material which decreases its pH, while the negative charged ions (OH-) is transported to the water or salt solution, which increases its pH. Further, calcium and other minerals are transported through the CEM to other compartments containing water or salt solution. Hereby, the milk starting material will after EDBM treatment have a decreased pH and a lower calcium content.

[0095] The inventors of the present invention have found out that EDBM can be used to acidify a milk starting material resulting in solubilisation of bound calcium (micellar or colloidal calcium) and that this solubilised calcium can be removed in whey during the coagulation step in preparing a pasta filata product. In addition, it was found by the inventors of the present invention that a pasta filata product obtained by acidifying with EDBM and removal of calcium had improved functional and sensorial properties as compared to a pasta filata product obtained by acidification with an organic acid.

[0096] Figure 3 shows a schematic overview of the process on the present invention using EDBM for acidification followed by an optional ultrafiltration step and further processing into the pasta filate product. .

[0097] Figure 4, on the contrary, shows a schematic overview of a process where skim milk has been acidified using citric acid instead of EDBM.

[0098] In an embodiment of the invention, the EDBM further comprises one or more cationic exchange membrane(s), one or more anionic exchange membrane(s) and one or more bipolar membrane(s).

[0099] In an embodiment of the process of the present invention, the electrodialysis with bipolar membrane is carried out at a temperature in the range of 2°C to 40°C, preferably at a temperature in the range of 5°C to 35°C and most preferably at a temperature in the range of 5°C to 25°C. The temperature used during EDBM is dependent on the membrane used. Some membranes work at lower temperatures where other membrane work better at higher temperatures, such as 30-35°C.

[0100] Addition of ultrafiltration retentate:

[0101] In an embodiment of the present invention, where the milk starting material is a milk ultrafiltration permeate, the acidified milk ultrafiltration permeate is mixed with an ultrafiltration retentate before further processing. The ultrafiltration retentate comprises proteins and by mixing with the acidified milk ultrafiltration permeate, the pH of the mixture decreases and hence calcium bound in the casein micelles disassociate into free calcium which can be removed in the whey.

[0102] This particular embodiment of the invention using an ultrafiltration permeate of milk as the milk starting material and subjecting said ultrafiltration permeate to EDBM, followed by mixing with an ultrafiltration retentate and further processing in the pasta filata product is shown in figure 6.

[0103] Further ultrafiltration:

[0104] In an embodiment of the present invention, the pH adjusted milk starting material obtained after EDBM is subjected to ultrafiltration (UF) with an ultrafiltration membrane to provide a UF permeate and a UF retentate, and wherein it is the UF retentate that is subjected to addition of coagulation enzyme(s) in step iii) of the process of the invention. It is the UF retentate that is further processed into a pasta filata product.

[0105] In the present invention, the milk starting material has been subjected to electrodialysis with a bipolar membrane to decrease pH and hence disassociate some calcium into free calcium. Some of the free calcium will be removed in the following process for making a pasta filata product, i.e. in the whey. However, in an embodiment of the invention, ultrafiltration is of the pH adjusted milk staring material is included. The ultrafiltration step will remove the free calcium into the UF permeate. The ultrafiltration step will also concentrate the protein content of the milk used to making the pasta filata cheese. The lower the pH, the more calcium is removed in the ultrafiltration step. The combination of decreasing pH by using EDBM followed by ultrafiltration further controls the reduction of calcium as compared to just removing calcium in whey.

[0106] The ultrafiltration (UF) membrane allows passage of small peptides, minerals and some lactose into the permeate while retaining the milk serum protein, micellar casein, dissolved beta-casein and some lactose. Depending on the concentration factor, typically 50% of the lactose in the milk starting material will be retained in the retentate while approximately 50% penetrates the UF membrane and is present in the permeate. In fresh milk, the lactose content is about 4.4% to 5.0% by weight. After the ultrafiltration step in the process of the present invention, the lactose content in the UF retentate is about 4.0, but with a much higher protein content.

[0107] According to an embodiment of the present invention, the cut-off of the ultrafiltration membrane is in the range of 2000 Da to 50000 Da, preferably 2500 to 30000 Da, more preferably about 20000 Da. In a preferred embodiment of the invention, a polymeric membrane is used having a molecular weight cut-off of 20000 Da.

[0108] The ratio between the casein and milk serum protein will be the same as for the milk starting material used.

[0109] The concentration factor of the ultrafiltration step may for example be in the range of 1.1 to 7.5. Preferably, the concentration factor is in the range of 2.0 to 6.5 and more preferably 2.5 to 6.0. Most preferably, the concentration factor is 2.8 to 5.1.

[0110] A concentration factor in the range of 2.8 to 5.1 corresponds to obtaining a protein content in the ultrafiltration retentate in the range of 9.8% to 18% by weight.

[0111] The calcium content per gram protein in the UF retentate is reduced as compared to the calcium content per gram protein in the milk starting material, since some calcium will be present in the UF permeate and the proteins have been concentrated in the UF retentate. The amount of calcium removed from the milk staring material in the ultrafiltration step is dependent on the concentration factor and the pH.

[0112] In a further embodiment of the invention, the process comprises diafiltration after the ultrafiltration step, i.e. diafiltration of the UF retentate to further reduce the calcium content. The membrane used for the diafiltration is also an ultrafiltration membrane, In an embodiment, the membrane used for ultrafiltration and diafiltration is the same membrane.

[0113] The concentration factor of the diafiltration step is in an embodiment of the invention also in the range of 1.1 to 7.5.

[0114] The concentration factor is defined as the weight ratio between the protein content in the liquid milk starting material to the protein content in the retentate obtained. Hence, if the concentration factor (CF) is 3, the protein content in the UF retentate has been concentrated 3 times as compared to the protein content in the milk starting material. Hence, if the milk staring material has a protein content of 3.5% by weight and a CF of 3, the protein content in the UF retentate is (3.5x3) 10.5% by weight.

[0115] The UF retentate and the DF retentate obtained may in an embodiment of the invention be diluted with a liquid to obtain a diluted UF retentate or diluted DF retentate having a protein content if 5-18% by weight.

[0116] The protein content is measured using the Kjeldahl method (ISO 8968-l:2014 / IDF 20-1).

[0117] Useful, but not limiting, examples of diluents which can be used for diluting of the UF retentate or the DF retentate are, demineralized water or reverse osmosis (RO) water. The demineralized water may also be referred to as distilled water. The RO water refers in the context of the present invention to any permeate from membrane filtration of milk and tap water that has been subjected t reverse osmosis. Hence, RO water may be a permeate obtained by reverse osmosis of a permeate from ultrafiltration of milk, reverse osmosis of a permeate from nanofiltration of milk, or reverse osmosis of tap water.

[0118] In an embodiment of the present invention, the UF retentate is diluted with RO water to obtain a content of total protein of 5% to 18% by weight.

[0119] In a further embodiment of the invention, the temperature during ultrafiltration (and possible diafiltration) is in the range of 2°C to 15°C, preferably 4°C to 10°C.

[0120] Adding coagulation enzyme:

[0121] One or more coagulation enzyme(s) is / are added to the pH adjusted milk staring material, or optionally to the UF retentate of pH adjusted milk starting material, to coagulate the casein.

[0122] The coagulation enzyme(s) is / are typically added under stirring or mixing to distribute the enzyme(s) evenly throughout the pH adjusted milk starting material (or the UF retentate).

[0123] The coagulation enzyme may be any enzyme that has (kappa)-caseinolytic activity and that when used in an effective amount is capable of coagulating milk starting material such that curd is obtained. For example, the coagulating enzyme may be rennet, chymosin, pepsin, microbial rennet, recombined rennet, any other suitable microbial or vegetable derived protease with caseinolytic activity or a combination thereof. A bacterially derived proteolytic enzyme (fermentation produced enzyme) may be Fromase® XL750 (DSM Food Specialties, Herten, Netherlands) or ChyMax® (Novonesis A / S, Horsholm, Denmark). Naturen® (Novonesis A / S, Horsholm, Denmark) is an example of an animal rennet. One example of a suitable beneficial kappa-caseinolysis enzyme is an enzyme of vegetable origin, namely that obtained from the Card Cardosin. In a preferred embodiment of the invention, the coagulation enzyme(s) is any type of rennet and may therefore be selected from the group of rennet, microbial rennet, and recombined rennet. In another preferred embodiment of the invention, the coagulation enzyme(s) comprise chymosin.

[0124] Rennet is a complex set of enzymes (when describing commercial products) produced in the stomach of ruminant mammals or produced by microorganisms. In the context of the present invention, the term "rennet" refers to rennet obtained from an animal stomach. Microbial rennet is obtained by fermentation by exposing certain microorganisms to rennet-producing genes from animals.

[0125] Microbial rennet may also be referred to as vegetable rennet. The main enzyme in rennet is chymosin which is a protease enzyme cleaving the kappa casein chain. Cleavage causes casein to stick to other cleaved casein molecules and form a network, and hence curdles the casein in milk. The clustering of casein protein is improved in the presence of calcium and phosphate, and therefore it is beneficial that some calcium remained during production of the curd. In addition to chymosin, rennet contains other enzymes such as pepsin and lipase.

[0126] The coagulation enzyme, such as rennet, is typically added to the pH adjusted milk starting material, or UF retentate of pH adjusted milk staring material, in an amount of from 5 mil / 100 kg when having an activity of 200-600 IMCU / ml. IMCU stands for International Milk Clotting Unit as defined in International Standard ISO 11815 (2007).

[0127] After addition of the coagulation enzyme(s), the mixture is heated to a temperature in the range of 25°C to 60°C for a time period sufficient to coagulate the mixture and obtain curd and whey.

[0128] In an embodiment of the present invention, the process involves adding a lactic acid producing culture during step iii). The culture may be any known culture in the art known to be used in the preparation of pasta filata products.

[0129] Preferably, the heating during the coagulation step is at a temperature of 35°C to 55°C and most preferably at a temperature of 40°C to 50°C. As mentioned earlier, coagulation is initiated when the temperature is above 15°C. However, at 15°C the speed of coagulation is very low. Hence, the temperature during the coagulation step should preferably be above 25°C for efficient coagulation. At temperatures above 40°C, the coagulation proceeds very rapidly within seconds and almost instantly. A temperature above 40°C is therefore preferred.

[0130] Further, the temperature during the coagulation step should not exceed 60°C since at a temperature above 60°C unwanted sticking of the obtained curd occurs. Furthermore, the curd begins to stretch at high temperatures which is wished avoided at this point in the process.

[0131] The time period of the coagulation step may vary a lot since the time required for coagulation is dependent on the temperature. Hence, at a temperature of 25°C coagulation takes some time and the time period may therefore be several minutes and up to 60 minutes for efficient coagulation however, if the temperature is 40°C to 60°C, the time period for coagulation is within seconds (0.1-10 seconds) and may be instantly. At temperatures above 40°C, the coagulation starts instantly. The coagulation continuous and complete coagulation is probably after 10-30 seconds. Hence, the time period for the coagulation step should not be seen as a limitation to the present invention. However, typically the time period for the coagulation is 0.1 second to 60 minutes.

[0132] Preferably, the mixture of pH adjusted milk starting material (or optionally the UF retentate) and the coagulation enzyme(s) is stirred during the coagulation step to induce controlled turbulence in the solution and to cause coagulation of the protein into small curd particles within the solution. The liquid obtained after obtaining the curd particles is called whey.

[0133] In an embodiment of the invention, the temperature of the pH adjusted milk starting material or optional the UF retentate of pH adjusted milk starting material is adjusted to be in the range of from 4°C to 15°C before coagulation enzyme is added. At temperatures below 4°C, the coagulation enzyme will not work efficiently and provide a proper coagulation, Furthermore, at temperatures above 15°C, the coagulation will initiate. The warmer the pH adjusted milk starting material is, the faster is the coagulation. Preferably, the temperature is adjusted to be in the range of 5°C to 10°C before adding the coagulation enzyme to avoid spontaneous coagulation. If the temperature is higher than 15°C, the coagulation enzyme is slightly active and there is a risk of the coagulation being initiated. When the coagulation enzyme is added to the pH adjusted milk stating material at a temperature of 4°C to 15°C, it should preferably be stored at that temperature for at least 30 minutes. To allow hydrolysis of the proteins. When the coagulation enzyme(s) is / are added at cold temperatures (4-15°C) it is to control the clotting of the curd (coagulation) and to improve the control of starting / stopping the curd formation process. By adding the coagulation enzyme(s) at cold temperatures, the enzymatic hydrolysis with the coagulation enzyme(s) can occur while no coagulation occurs. The coagulation enzymes cut caseinomacropeptide (CMP) from casein such that casein becomes more hydrophobic and can adhere (stick together) to each other.

[0134] The mixture with coagulation enzyme(s) is stored for a minimum of 30 minutes for the coagulation enzyme to cut the CMP form casein and form curd and whey. In principle, there is no upper limit for the cold storing because the temperature is so low that coagulation does not occur and there is no culture or acidifying agents present. However, for time efficiency, cold storing is up to 48 hours.

[0135] Preferably, the curd is cut before whey is drained. The curd is preferably cut by a curd cutter, such as steel wires stretched over a frame.

[0136] Step v) separating whey from curd:

[0137] In step v) of the process if the present invention, whey is drained from the curd. As earlier mentioned, the free calcium will be removed from the curd with the whey.

[0138] The heating is typically by using direct or indirect heating means to coagulate the protein and form the coagulated curd particles. In the case of direct heating, steam can be injected into the flow of the pH adjusted milk starting material (or UF retentate). In case of indirect heating, a jacketed heater or heat exchanger is associated with the flow path along which the liquid is being pumped. The temperature is increased to an upper limit which will be consistent with the parameters of the process, for example up to 55°C and the flow rate is high causing controlled substantial turbulence into the liquid being passed there along. This prevents any large build-up of curd and means that the protein coagulates into small curd particles.

[0139] The coagulated curd can be separated from the whey by use of a separator, such as for example a decanter, a sieve, a filter or other means suitable for separating curd from whey. The whey will comprise free calcium. If an ultrafiltration has been performed, most of the free calcium is in the UF permeate, but some calcium is further removed in the whey. However, the bound calcium is present in the curd.

[0140] Processing of curd into a pasta filata product:

[0141] The curd obtained may be stored before further processing but may also be processed immediately while still fresh into the pasta filata product. The curd could for example be frozen or dried, and subsequently thawed and / or reconstituted before further processing into the pasta filata product.

[0142] In an embodiment of the present invention, the pasta filata product is a mozzarella, but is may also be a mozzarella-like product such as a pizza topping. A mozzarella is made with addition of dairy fat, while a pizza topping is made with addition of vegetable fat.

[0143] When processing the curd into the pasta filata product, the curd is subjected to heating and stretching. This is preferably in a cooker-stretcher.

[0144] In an embodiment of the invention, the heating and stretching in step vi) is by using a dry cooker-stretcher or a wet cooker-stretcher.

[0145] Fat can be added in the process various places. For example, fat can be added to the milk starting material before subjecting to EDBM, this is disclosed as method A in figure 7. Figure 7 shows addition of fat as cream but is may in some embodiments also be by addition of vegetable fat.

[0146] Fat may also be added later in the process, for example to the curd before or during the heating and stretching step vi). This is shown in figure 7B.

[0147] Preferably, the curd used for preparing the pasta filata product comprises a fat content of 0.1% by weight or below, such that curd with low fat content is prepared. After separation of the whey from the curd, but before heating and stretching, the curd is mixed with fat to a fat content of 5-30% by weight.

[0148] The fat added may either be a dairy fat, such as cream, or it may be a vegetable fat. Any vegetable fat suitable for making a mozzarella like product could be used. Suitable vegetable fats are rape seed oil, palm oil, coconut oil, sunflower oil and other neutral flavoured vegetable oils. In an embodiment, minerals, lactose, emulsifier, and water may also be added before or during step v) of the process. Minerals, including sodium chloride may be added in an amount of 0.1-2.5% by weight of the cheese curd, preferably 1-1.5% by weight.

[0149] When the curd particles in step vi) is heated and stretched, the curd is heated to a temperature of 50°C to 90°C, preferably 60°C to 75°C, and mechanically stretched into a homogeneous plastic mass. The equipment for heating / stretching is equipment common in the art, such as single or twin-screw stretcher / extruder type device or steam jacketed and / or infused vessels equipped with mechanical agitation. The heating is performed either by use of direct heating or indirect heating by steam.

[0150] In an embodiment of the present invention, the heating and stretching in step vi) is by using a cooker-stretcher.

[0151] The heated and stretched pasta filata product is transferred into moulds for forming and shaping the pasta filate product obtained. The form may be any shape, such as sheets, shreds, blocks, dices, or any other shape. Afterwards, the pasta filata product is cooled by a rapid cooling step. The cooling can be done by various cooling methods and the present invention should not be limited to the cooling method. The cooling may for example be by rapid brine solution, cold water, ice water or cold air.

[0152] As mentioned earlier, it is important for the present invention that a substantial amount of calcium is removed in the whey and optionally also in a UF permeate. In the process of the present invention, the calcium content per gram protein in the pasta filata product is typically reduced by up to 75% by weight as compared to the calcium content per gram protein in the milk starting material. The amount of calcium per gram protein reduced by the present invention is typically 30% to 75% by weight. However, it is also important that not all calcium is removed, since the removal of too much calcium will result in no coagulation of casein. Further, if the amount of calcium per gram protein is reduced with more than 75%, no gelation occurs, and the curd cannot be formed. If too much calcium is removed, the obtained product has undesirable cheese functionalities. With the present invention, the removal of calcium can efficiently be controlled. With the present invention, a pasta filata product obtained has a calcium content of about 2500-5000 mg / kg product and a protein content of about 23-25g / 100g product. This corresponds to a calcium content of 10-22 mg per gram protein.

[0153] Hence, after subjecting a milk staring material to EDBM, the calcium content in the final pasta filata product is typically less than 25 mg per gram protein, and typically less than 22 mg per gram protein. If the pH adjusted milk starting material has been ultrafiltrated, the calcium content may be even lower.

[0154] If for example skim milk is used as the milk starting material, the calcium content is typically about 1200-1400 mg / kg and the protein content is about 35 g / kg. This corresponds to a calcium content of 1.2 to 1.4g per 35g protein (in 1 kg milk) which is equal to 34-40mg calcium per gram protein.

[0155] The lower the pH is after EDBM, the more calcium is removed.

[0156] Calcium is measured using the standard method ICP-OES (DS / EN ISO 11885m:2009)

[0157] Pasta filata product:

[0158] In an aspect, the present invention relates to a pasta filata product obtained by the process according to the invention comprising:

[0159] - calcium in an amount of 25 mg per gram protein or less,

[0160] potassium in an amount of 2.8 mg per gram protein or less,

[0161] protein in an amount of 20% by weight of more,

[0162] and wherein the pasta filata product is having a pH in the range of 5.0 to 5.5 while it does not comprise any added organic acid or inorganic acid.

[0163] In the pasta filata product of the present invention, it is important that it does not comprise any added organic acid or inorganic acid, i.e. no added chemical acidifying agent. The only pH adjustment that has been made during processing of the pasta filata product is from subjecting the milk starting material to electrodialysis with a bipolar membrane. When the patent filata product of the present invention does not comprise any organic acid or inorganic acid, it is understood as no chemical acidifying agent is present. However, acid producing microorganisms can be present because acid producing microorganisms are in the present invention not to be considered as an organic acid or inorganic acid.

[0164] Organic acids are for example citric acid, lactic acid, acetic acid, malic acid, and glucono-delta-lactone. An example of an inorganic acid is hydrochloric acid.

[0165] In an embodiment, the pasta filata product comprises fat in an amount of from 5% to 30%.

[0166] The fat added may either be a dairy fat, such as cream, or it may be a vegetable fat. Any vegetable fat suitable for making a mozzarella like product could be used. Suitable vegetable fats are rape seed oil, palm oil, coconut oil, sunflower oil and other neutral flavoured vegetable oils.

[0167] The pH of the pasta filata product is preferably in the range of 5.1 to 5.5 and more preferably in the range of 5.2 to 5.45.

[0168] In also an embodiment of the invention, the solid content of the pasta filata product is in the range of 45% to 55% by weight, such as 47% to 52% by weight.

[0169] In an embodiment of the invention, the pasta filata product comprises potassium in an amount of 2.5 mg per gram protein or less, such as 2.20 mg per gram protein, preferably 2.10 mg per gram protein.

[0170] In a further embodiment of the invention, the pasta filate product comprises potassium in an amount in the range of 1.5 to 2.8 mg per gram protein, such as in the range of 1.7 to 2.5 mg per gram protein, preferably in the range of 1.8 to 2.2 mg per gram protein. The potassium content in the pasta filata product is typically about 2.0 mg per gram protein.

[0171] The calcium content in the pasta filata product of the present invention is typically in the range of 10 to 25 mg per gram protein, preferably in the range of 13 to 22 mg per gram protein, more preferably 15 to 21 mg per gram protein. The pasta filata product of the present invention typically comprises protein in an amount on the range of 20% to 30% by weight, preferably in the range of 22% to 28% and more preferably in the range of 23% to 26% by weight.

[0172] It should be noted that embodiments and features described in

[0173] the context of one of the aspects of the present invention also apply to the other aspects of the invention.

[0174] The invention will now be described in further details in the following non-limiting examples.

[0175] Examples

[0176] Example 1: Process of preparing a pasta filata product according to the present invention

[0177] Raw milk was centrifuged to separate the milk into skim milk and a fat rich fraction (cream). The skim milk was pasteurised at 72°C for 15 seconds and afterwards the pasteurised skim milk was acidified using electrodialysis with a bipolar membrane (EDBM) to pH 6.15.

[0178] For the EDBM process, 430 kg skim milk acted as diluate and 250 kg of a 0.5% (w / v) sodium chloride solution was used as the concentrate. The electrodialysis was conducted at a constant DC voltage of 75V.

[0179] The acidified milk (250 kg) was either transferred directly to the cheese vats or ultrafiltered (molecular weight cut-off of 10,000 Da) to reach a protein content of approximately 4.5% (w / w).

[0180] After EDBM and / or ultrafiltration, the milk was pasteurised at 72°C for 15 seconds and cooling to 35°C.

[0181] The obtained acidified skim milk was subjected to a process of making a pasta filata product (here a pizza topping). 200 kg of the pasteurised acidified milk was added to the cheese vat and maintained at a temperature of 35°C. Culture was added at 1.5% (w / w) and stirred for 35 minutes at a speed of 8 r.p.m. Rennet (10 g Chymax 200® from Novonesis A / S) was added, followed by coagulation for 35 minutes. After the curd was set, it was cut using a curd cutter producing 10x10x10 mm cubes. The cheese vat stirring speed varied from 5 to 12 r.p.m. starting with a low speed and increased to the high speed. The stirring was for 12 minutes before heating by hot water in jacket to 38.5°C and stirring maintained until pH reached 5.80.

[0182] The obtained curd (14 kg) was separated from whey by using a draining vat / belt. The drained curd was pressed by gravity until a block was formed and subsequently cut into loafs of approximately 40x15 cm and left in the draining vat to further acidify until a target pH of 5.10. The acidified curd was then cut into 5x5x5 chunks before transferred to a cooker-stretcher (Karl Schnell Cooker-Stretcher).

[0183] The obtained curd was further processed into a pizza topping by first mixing with further ingredients (vegetable fat, salt and water) at 35°C. The temperature during processing was increased to 65°C during mixing.

[0184] The obtained pizza topping is stored at 5°C.

[0185] Example 2: Methods of analysis:

[0186] Example 2 shows the methods used for quantification of different nutrients, see table 1 below.

[0187] Table 1: Methods used for quantification of different nutrients

[0188] Analysis Unit Method

[0189] Total solids g / lOOg Gravimetric (ISO 6731:2010 / IDF 21)

[0190] Protein g / lOOg Kjeldahl (ISO 8968-1:2014 / 1 DF 20-1)

[0191] Fat g / lOOg Gravimetric ISO 1735:2004 / IDF 5 mod.

[0192] Moisture % Gravimetric (ISO 6731:2010 / IDF 21)

[0193] Calcium mg / kg ICP-OES (DS / EN ISO 11885m:2009)

[0194] Magnesium mg / lOOg ICP-OES (DS / EN ISO 11885m:2009)

[0195] Phosphorous g / lOOg ICP-OES (DS / EN ISO 11885m:2009)

[0196] Potassium mg / lOOg ICP-OES (DS / EN ISO 11885m:2009)

[0197] Salt g / lOOg Titrimetry ISO 5943:2006 / 1 DF88 mod.

[0198]

[0199] Example 3 - Comparing the nutritional composition of different pizza toppings An example was made where the nutritional composition of a pizza topping prepared by the process according to the invention was compared to pizza topping prepared with addition of citric acid.

[0200] The pizza topping according to the invention was prepared as disclosed in example 1. The analysis involved double analysis of the acidification with EDBM.

[0201] A pizza topping prepared by using citric acid for acidification was also prepared by using the method of example 1, but instead of acidifying with EDBM, the acidification was by addition of citric acid to pH 6.15

[0202] No major differences in preparing the pizza topping based on acidification with EDBM acidified or citric acid were observed during the cheesemaking (renneting, whey drainage, cutting, or heating). All three samples showed clear whey during the draining step.

[0203] In table 2 below is the nutrient content of the three cheese samples (EDI, ED2 and CA). The term "EDI" and "ED2" refers to sample 1 and 2 prepared with acidification using EDBM (no ultrafiltration), while the term "CA" refers to acidification with citric acid. The nutrient content was measured for the final pizza topping obtained. The nutrient content is also shown for raw milk and skim milk 84754PC01

[0204] 30

[0205] Table 2:

[0206] Total Protein Fat Moisture pH Calcium Magnesi Phospho Potassiu Salt solids um rous m

[0207] g / lOOg g / lOOg g / lOOg % mg / kg mg / 100 g / lOOg mg / 100 g / lOOg kg g

[0208] Raw milk 12.97 3.54 3.85

[0209] Skim milk 9.93 3.63 0.09 6.82 1313.3 1795.3

[0210] Pizza 47.21 23.46 21.14 53.26 5.35 4700 14.0 0.291 47.1 1.33 topping

[0211] (EDI)

[0212] Pizza 49.25 24.12 21.31 51.21 5.36 4800 17.1 0.339 47.9 1.42 topping

[0213] (ED2)

[0214] Curd (CA) 41.81 35.60 0.60 N / A 5.07 6500 22.3 0.508 95.9 <0.15 Pizza 49.49 23.92 21.97 50.97 5.31 4600 16.2 0.311 78.5 1.38 topping

[0215] (CA)

[0216]

[0217] • the term "N / A" refers to that the data was not measured. Hence, table 2 shows that a pizza topping prepared from either pH acidification with EDBM or citric acid has about the same amount of solid content, protein and fat.

[0218] The calcium content in the pizza topping made with citric acid and the pizza topping made with EDBM is similar. Furthermore, table 2 shows that the potassium content in the pizza topping made with EDBM is significantly lower than the pizza topping made with citric acid.

[0219] Example 4: Analysis of functionality

[0220] An analysis of the functional properties of a pizza topping prepared with acidification with EDBM was compared to the pizza topping prepared with acidification with citric acid, both to a pH of 6.15. Further samples of pizza topping were made with acidification to different pH values (pH 6.40, 6.15, 6.00, 5.80, 5.40 and 5.20). In addition, a sample of pizza topping was made where the pH was adjusted to pH 5.80 with EDBM, but the obtained pH adjusted skim milk was subjected to ultrafiltration (UF) with a spiral would membrane (GR73 / 48mill PP from Alfa Laval AB). This pizza topping was made according to example 1 with ultrafiltration. The membrane has a cut-off value of 10.000 Da. The CF was 2.8.

[0221] The samples were made according to example 3.

[0222] The sample of pizza topping made with pH adjustment with EDBM to pH 6.40 was not analysed for functionality, because it was found that the sample with acidification to pH 6.4 with EDBM did not remove enough calcium and hence no effect on functionality.

[0223] The sample of pizza topping made with pH adjustment with EDBM to pH 5.20 was not analysed for functionality, since the curd obtained was very different from typically made curd and the pizza topping obtained lacked the desired functionality.

[0224] The sample of pizza topping made with pH adjustment with EDBM to pH 5.40 was also not analysed for functionalities, but it was observed that it was possible to acidify to pH 5.40 and obtain a pizza topping with okay functional properties, however, not the preferred properties.

[0225] The functionality of the pizza toppings was analysed by analysing the blister size of a baked pizza topping, the blister coverage, the colour, stretch, meltability and texture. In table 3 below is the analysis of the different functionality shown.

[0226] For blister size: The lower value, the better.

[0227] For Blister coverage: The lower value, the better.

[0228] For colour: The lower value, the better. Colour is determined using L* value, a* value and b* value.

[0229] For stretch: The higher value, the better (100% is stretch of 30 cm)

[0230] For meltability: The higher value, the better.

[0231] For texture, The lower value, the better.

[0232] Table 3:

[0233] Blister Blister Colour Stretch Meltabilit Texture size coverage y

[0234] Mozzarella 50% 50% 50% 85% 50% 50% CA

[0235] Mozzarella 50% 40% 50% 100% 50% 60% EDBM PH 6.15

[0236] Mozzarella 40% 50% 50% 100% 60% 40% EDMB

[0237] pH 6.0

[0238] Mozzarella 40% 40% 50% 100% 70% 35% EDBM PH 5.80

[0239] Mozzarella 15% 25% 25% 100% 75% 30% EDBM

[0240] pH

[0241] 5.80+UF

[0242] Range 10-50% 15-50% 20-50% 85-100% 40-60% 35-55%

[0243]

[0244] Hence, table 3 shows that the functionality of a pizza topping produced by acidifying with EDBM is improved as compared to acidifying with citric acid. In particular, table 3 shows that the blister size, colour, stretch, meltability and texture are improved when preparing a pizza topping by acidifying with EDBM as compared to a pizza topping prepared by acidifying with citric acid.

[0245] In addition, table 3 shows that applying ultrafiltration to the pH adjusted skim mil that has been pH adjusting using EDBM results in further improved functional properties of the pizza topping obtained.

[0246] Furthermore, this analysis shows that using EDBM for acidification result in an improved pizza topping when acidification is to a pH of 5.4 or more and the pH is below 6.4. Further, the analysis shows that the lower pH, the better is the functionalities. The functionalities are best when acidification with EDBM is to a pH of 5.8 to 6.00.

[0247] Figure 4 (A-E) shows the blister size and blister coverage of the different samples of the mozzarella where the figures show as follows:

[0248] - figure 4A shows the melting of a mozzarella made from acidifying with citric acid to pH 6.15

[0249] - figure 4B shows the melting of a mozzarella made form acidifying with EDBM to pH 6.15

[0250] - figure 4C shows the melting of a mozzarella made form acidifying with EDBM to pH 6.00

[0251] - figure 4D shows the melting of a mozzarella made form acidifying with EDBM to pH 5.80

[0252] - figure 4E shows the melting of a mozzarella made form acidifying with EDBM to pH 5.80 followed by ultrafiltration.

[0253] From figure 4A-E is it also clear that a mozzarella prepared by using EDBM for acidification results in improved blister size and blister coverage. Further, the figures 4A-E clearly show that the mozzarella made using acidification with EDBM followed by ultrafiltration results in even further improved functionalities, i.e. the blister size and blister coverage is very low. Example 5: Analysis of calcium content in pizza toppinQ acidified to different pH An example was made where the calcium content of pizza toppings prepared by acidifying using EDBM according to the process of the invention to different pH values was analysed.

[0254] The pizza topping according to the invention was prepared as disclosed in example 1 and pizza toppings were made with acidification to the pH values 6.40, 6.15, 6.00, 5.80, and 5.78. The calcium content is measured as mentioned in example 2.

[0255] The calcium content in the pizza toppings is shown in table 4 below, where "pH after EDBM" refers to the pH of the milk staring material after having been subjected to EDBM.

[0256] Table 4:

[0257] pH after EDBM Calcium content (mg / kg)

[0258] Sample 1 6.4 N / A

[0259] Sample 2 6.15 4700

[0260] Sample 3 6.00 3800

[0261] Sample 4 5.80 3300

[0262] Sample 5 5.78 2900

[0263]

[0264] *N / A refers to the calcium content was not measured because it was not possible to emulsify vegetable fat into the curd

[0265] From table 4, it is clear that the calcium content in the final product decreases as the pH of the milk starting material after EDBM decreases.

Claims

Claims1. A process of preparing a pasta filata product comprising the following steps: i) providing a milk starting material;ii) adjusting pH of the milk starting material to be in the range of 5.4 to 6.3 by subjecting the milk starting material to electrodialysis using one or more bipolar membrane(s);iii) adding one or more coagulating enzyme(s) to the pH adjusted milk starting material of step ii) to obtain a mixture, andvi) heating the mixture of step iii) to a temperature in the range of 25°C to 60°C for a time period sufficient to coagulate the mixture and obtain cheese curd and whey;v) separating the curd from the whey;vi) subjecting the curd to a heating and stretching step to obtain a pasta filata cheese.

2. The process according to claim 1, wherein the method further comprises subjecting the pH adjusted milk starting material of step ii) to ultrafiltration (UF) with an ultrafiltration membrane to provide a UF permeate and a UF retentate, and wherein the ultrafiltration retentate is subjected to addition of coagulation enzyme(s) in step iii).

3. The process according to any of the claims 1 to 2, wherein the pH adjustment by using electrodialysis using one or more bipolar membrane(s) of the milk starting material in step ii) is at a temperature in the range of 2°C to 40°C.

4. the process according to any of the claims 1 to 3, wherein the process does not comprise addition of an organic acid or inorganic acid.

5. The process according to any of the claims 1 to 4, wherein the pH adjustment in step ii) is adjusting the pH of the milk starting material to be in the range of 5.7 to 6.15.

6. The process according to any of the claims 1 to 5, wherein a source of fat is added to the curd before or during the heating and stretching step vi).

7. The process according to claim 6, wherein the source of dairy is selected from the group of dairy fat and vegetable fat.

8. The process according to any of the claims 1 to 7, wherein the heating and stretching in step vi) is by using a dry cooker-stretcher or a wet cooker.

9. The process according to any of the claims 1 to 8, wherein the process involves that a lactic acid producing culture is added during step iii).

10. The process according to any of the claims 1 to 9, wherein the electrodialysis with bipolar membrane comprises one or more cationic exchange membrane(s), one or more anionic exchange membrane(s), and one or more bipolar membrane(s).

11. The process according to any of the claims 1 to 10, wherein the milk starting material is selected from the group consisting of whole milk, low-fat milk, reduced fat milk, fat-free milk, buttermilk, reconstituted milk powder, lactose- reduced milk, low-lactose milk, lactose-free milk, heat treated milk, raw unfiltered milk, homogenised milk, mineral reduced milk, whey protein reduced milk, micellar casein isolate, micellar casein concentrate, ultrafiltration permeate of milk and combinations thereof.

12. The process according to any of the claims 1 to 11, wherein the milk starting material comprises fat in an amount of 0.1% by weight or less.

13. The process according to any of the claims 1 to 12, wherein the milk starting material is an ultrafiltration permeate of milk and the acidified ultrafiltration permeate of step ii) is mixed with an ultrafiltration retentate before further processing in step iii).

14. A pasta filata product obtained by the process according to any of the claims 1 to 13 comprising:- calcium in an amount of 25 mg per gram protein or less;potassium in an amount of 2.8 mg per gram protein or less;protein in an amount of 20% by weight or more;and the pasta filata product is having a pH in the range of 5.0 to 5.5 while it does not comprise any added organic acid or inorganic acid.

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