PROTEIN PRODUCTS AND METHODS FOR PRODUCING THEM

FIELD OF THE INVENTION

The present invention relates to methods for preparing drinkable acidified milk protein products. Further, the invention relates to drinkable acidi- fied milk protein products.

BACKGROUND OF THE INVENTION

Raw cow milk contains in addition to water (about 87%), fat (about 4.5%), lactose (about 5%) and protein (about 3.3%) also minerals and trace elements, such as calcium, magnesium, phosphorus, manganese, potassium, sodium, iodine and zinc. Further, milk contains also vitamins, such as A, K, B12, B6 and B2. The amino acid composition of milk proteins has better biological value than any other protein (red or white meat). Milk proteins contain a lot of so-called essential amino acids like lysine, leucine and isoleucine. The proteins of milk belong to casein or whey proteins. Typically the ratio of casein proteins to whey proteins in cow's milk is about 80:20.

Quark is unripened fresh cheese which is made from pasteurized skim milk by adding an acidifier to the milk. Typically, a small amount of rennet is also added. The ratio of casein proteins to whey proteins in quark is about 80:20. Quark has a smooth texture and mild, acid flavour. Quark products presently in the market are typically spoonable and very firm in texture.

Yogurt is a fermented milk product produced by lactic acid bacterial fermentation of milk. The bacteria used to make yogurt are known as "yogurt cultures". Fermentation of lactose by these bacteria produces lactic acid, which acts on milk protein to give yogurt its texture and its characteristic tang. There are both spoonable and drinkable yogurt-based products in the market. However, the protein content of the drinkable ones is typically less than 5%. Further, the drinkable products are usually supplemented or fortified with whey protein, typically in the form of a whey protein concentrate (WPC) or a whey protein isolate (WPI). Accordingly, the protein quality and the composition of proteins in such products are different than that of normal dairy milk.

It has been very challenging to manufacture liquid acidified high protein products, i.e., product containing proteins about 5% or more, in an industrial scale using the methods known in the art. With the current methods, the texture of products has inevitably become solid and thick. This is mainly be- cause of the behaviour of milk proteins in the heat-treatment and acidification, since the most of the whey proteins do denature during a heat-treatment (about 90 to 95 °C for about 2 to 5 min), and form a gel-like thick texture during the lowering of the pH due to the acidification and/or fermentation.

In recent years methods for preparing drinkable acidified milk pro- tein products have been developed and such processes are described in US 2002/0160086 A1 , WO 2012/081982 A2, WO 2009/1 12036 A2, WO 2006/065244 A1 and WO 2008/136671 A1 , for example.

There is a continuous need for protein-rich dairy products, especially drinkable products, in the market. In addition, there is a growing need for methods of preparing protein-rich dairy products in economical and environmentally friendly way.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to a method for producing a drinkable acidified milk protein product, comprising the steps of:

a) providing an acidified dairy mass having a protein content of about 5% to about 12% and a pH of about 4.5 to about 5.3,

b) providing a milk protein concentrate,

c) optionally providing a lactose concentrate,

d) chilling the acidified dairy mass, the milk protein concentrate and optionally the lactose concentrate,

e) combining the chilled acidified dairy mass with the chilled milk protein concentrate and optionally the chilled lactose concentrate,

f) mixing the blend formed in step (e),

g) optionally flavouring the blend,

h) optionally packing the blend.

Alternatively, the present invention relates to a method for producing a drinkable acidified milk protein product, comprising the steps of:

a) providing a chilled acidified dairy mass having a protein content of about 5% to about 12% and a pH of about 4.5 to about 5.3,

b) providing a chilled milk protein concentrate,

c) optionally providing a chilled lactose concentrate,

d) combining the chilled dairy mass with the chilled milk protein concentrate and optionally the chilled lactose concentrate,

e) mixing the blend formed in step d),

f) optionally flavouring the blend g) optionally packing the blend.

The present invention relates also to a drinkable acidified milk protein product having a protein content of about 5 to about 12% and a pH of about 4.5 to about 5.3. The product of the present invention is a high protein product containing milk proteins in a casein:whey protein ratio of about 80:20.

The objects of the invention are achieved by methods and products characterized by what is stated in the independent claims. The preferred embodiments of the invention are disclosed in the dependent claims.

DETAILED DESCRIPTION OF THE INVENTION

There is currently a continuous need for acidified high protein products, especially drinkable products, in the market.

The invention thus relates to a method for producing a drinkable acidified milk protein product, comprising the steps of:

a) providing an acidified dairy mass having a protein content of about 5% to about 12% and a pH of about 4.5 to about 5.3,

b) providing a milk protein concentrate,

c) optionally providing a lactose concentrate,

d) chilling the acidified dairy mass, the milk protein concentrate and optionally the lactose concentrate,

e) combining the chilled acidified dairy mass, the chilled milk protein concentrate and optionally the chilled lactose concentrate,

f) mixing the blend formed in step (e),

g) optionally flavouring the blend,

h) optionally packing the blend.

The present invention relates also to a method for producing a drinkable acidified milk protein product, comprising the steps of:

a) providing a chilled acidified dairy mass having a protein content of about 5% to about 12% and a pH of about 4.5 to about 5.3, b) providing a chilled milk protein concentrate,

c) optionally providing a chilled lactose concentrate,

d) combining the chilled dairy mass with the chilled milk protein concentrate and optionally the chilled lactose concentrate, e) mixing the blend formed in step d),

f) optionally flavouring the blend

g) optionally packing the blend. In the present invention, the acidified dairy mass contains milk proteins from about 5% to about 12%. In one embodiment the acidified dairy mass contains milk proteins from about 6.8% to about 10%. The pH of the acidified dairy mass is in the range of about 4.5 to about 5.3. In one embodiment, the pH of the acidified mass is in the range of about 4.75 to about 4.95. In one embodiment, the pH of the acidified mass is in the range of about 4.5 to about 4.8. The acidified dairy mass is composed of a milk protein concentrate (about 50% to about 90% of the weight of the mass), skimmed milk (about 0 % to about 28% of the weight of the mass) and water and/or lactose concentrate (about 10% to about 17% of the weight of the mass). In one embodiment, the acidified dairy mass contains about 55% milk protein concentrate. In another embodiment, the acidified dairy mass contains about 90% milk protein concentrate. In one embodiment, the acidified dairy mass does not contain skimmed milk. In another embodiment, the acidified dairy mass contains about 28% skimmed milk. In one embodiment, the acidified dairy mass contains about 10% water and/or lactose concentrate. In another embodiment, the acidified dairy mass contains about 17% water and/or lactose concentrate. In a certain embodiment, the acidified dairy mass is composed of a milk protein concentrate (about 55%), skimmed milk (about 28%) and water and/or lactose con- centrate (about 17%). In a certain embodiment, the acidified dairy mass is composed of a milk protein concentrate (about 90%) and water and/or lactose (about 10%). In one embodiment, the acidified dairy mass blend is produced by heat-treating and homogenizing the blend of the milk protein concentrate and water. In another embodiment, the acidified dairy mass blend is produced by heat-treating the blend of the milk protein concentrate, skimmed milk and water and/or lactose concentrate and homogenizing it. The heat-treatment is carried out at conditions varying from about 77°C, to about 90°C for about 20 seconds to about 5 minutes, or at about 125°C for about 4 seconds, depending on the desire texture of the acidified mass. In one embodiment the heat- treatment is carried out at about 78°C to 83°C for about 20 seconds. The ho- mogenisation is carried out by a one or a two stage process at a pressure varying from about 0 to about 250 bar depending on the desire texture of the acidified mass. In a certain embodiment the homogenisation of the concentrates is carried out by one stage process at a pressure varying from about 0 to about 250 bar. In a certain embodiment the homogenisation of the concentrates is carried out by a two stage process at a pressure varying from about 0 to about 250 bar in first stage and from 0 to about 125 bar in second stage. The heat-treatment temperature and time as well as the homogenization pressure have influence on the texture of the mass, i.e., the higher the temperature, the longer the time and/or the harder the pressure, the firmer will be the texture of the mass.

An acidifier, such as a mesophilic or a thermophilic starter or a chemical acidifier, for example, and optionally lactase are added to the heat- treated blend. The blend is allowed to acidify at a temperature of about +24°C to about +40°C for about 4 to about 19 hours until the pH of the mass is about 5.3 or below. After the acidification, the acidified mass is chilled or cooled. In one embodiment, after the acidification, the acidified mass is chilled or cooled to a temperature of about +12°C or below and optionally hydrolysed lactose- free for about 6 to about 8 hours at a temperature of about +12°C or below. In one embodiment, the mass is cooled to a temperature of about +8°C to about +12°C. In one embodiment, the mass is cooled to a temperature at about +10°C or below. The chilling or cooling of the acidified mass is important for the texture of the acidified mass itself as well as for the drinkable acidified product prepared in the present invention. The functional properties of the milk proteins, such as bonding and net formation, which are essential for the for- mation of the texture, are affected by the temperature, for example.

In the present invention the acidified dairy mass may be quark or a quark type acidified mass or a dairy mass acidified with a thermophilic acidifier, such as a yogurt, for example.

In one embodiment, the acidified dairy mass is quark or a quark type acidified mass. In one embodiment the quark is produced by using a biological acidifier, e.g. a bulk starter or DVS starter (direct to vat starter), a chemical acidifier or an organic or inorganic acidifier or a ferment like starter, acids and acidogens, such as gluconodelta-lactone (GDL), lactic acid, citric acid, hydrochloric acid, and oxalic acid. For instance, a mesophilic starter (Lacto- coccus lactis ssp. cremoris, Lactococcus lactis ssp. lactis, Leuconostoc mes- enteroides ssp. cremoris and/or Lactococcus lactis ssp. diacetylactis) is typically used in the preparation of quark. The acidification conditions, such as temperature, time and heat treatments depend on the acidifier used and are commonly known in the field. The temperature at which acidification is carried out can vary within the range of about 4°C to about 45°C, depending on the specific acidifier (starter) used in the method. In one embodiment, the acidifier is gluconodelta-lactone. In another embodiment, the acidifier is a thermophilic starter (Lactobacillus acidophilus, L. bulgaricus, L. delbrueckii subs, bulgaricus, Bifidobacterium lactis).

In a certain embodiment, a quark mass is produced from a base that consists of milk protein concentrate (about 90% of the weight of the mass), and water (about 10 % of the weight of the mass). The quark mass is produced by heat-treating at 90°C for 20 seconds the blend of the milk protein concentrate and water and homogenizing it at a pressure of 100 bar. A mesophilic acidifier and optionally lactase are added and the heat-treated blend is allowed to acidify at a temperature of about +24 °C for about 17 to about 20 hours until the pH of the mass is about 4.8 or below.

In a certain embodiment, a quark mass is produced from a base that consists of milk protein concentrate (about 55% of the weight of the mass), skimmed milk (about 28% of the weight of the mass) and water (about 17% of the weight of the mass). The quark mass is produced by heat-treating at 90°C for 20 seconds the blend of the milk protein concentrate, skimmed milk and water and homogenizing it at a pressure of 100 bar. A mesophilic acidifier and optionally lactase are added and the heat-treated blend is allowed to acidify at a temperature of about +24°C for about 17 to about 20 hours until the pH of the mass is about 4.8 or below.

The quark of the present invention can be produced with a method differing from a typical method for producing quark wherein no rennet is used and no thermization and separation steps are performed in the method.

In a certain embodiment, a dairy mass acidified with a thermophilic acidifier is produced from a base that consists of milk protein concentrate (about 55% of the weight of the mass), skimmed milk (about 28% of the weight of the mass) and water (about 17% of the weight of the mass). The acidified dairy mass blend is produced by heat-treating at 90°C for 20 seconds the blend of the milk protein concentrate, skimmed milk and water and homogeniz- ing it at a pressure of 100 bar. A thermophilic acidifier and optionally lactase are added and the heat-treated blend is allowed to acidify at a temperature of about 40°C for about 4 to about 5 hours until the pH of the mass is about 5.3 or below.

The milk protein concentrate used in the present invention contains in liquid form about 10% (w/w) to about 15% (w/w) protein, about 3.5% (w/w) to about 10% (w/w) carbohydrate and up to about 1 % (w/w) fat. In powder form the protein content of the concentrate is up to 90%.

In the present invention, the milk protein concentrate can be produced by membrane filtration of a milk raw material, by chromatographic sepa- ration, by crystallisation, by centrifugation (liquid concentrate), or by further increasing dry weight by evaporation and/or by drying (powder). The milk raw material of the present invention is typically milk obtained from an animal, such as a cow, sheep, goat, camel, mare or any other animal that produces milk suitable for human consumption. The milk raw material may be, for instance, whole milk, skim milk, low-lactose or lactose-free milk. In one embodiment, the milk protein concentrate used in the present invention is produced by ultrafiltration. Thus, in one embodiment, the milk protein concentrate is an ultrafiltration retentate. In one embodiment, the milk protein concentrate is in a liquid form and the proteins are mostly in their native forms. In one embodiment, the milk protein concentrate is in a powder form and the proteins are mostly in their native forms.The ratio of casein proteins to whey proteins in the milk protein concentrate of the present invention corresponds the ratio of casein proteins to whey proteins in cow's milk i.e., the ratio is about 80:20.

The lactose concentrate used in the present invention contains up to about 1 % (w/w) protein in both the powder and liquid concentrates, up to 99.7% (w/w) lactose in the powder concentrate, or about 7% (w/w) to about 17% (w/w) lactose in the liquid concentrate. In one embodiment, the lactose concentrate is liquid.

In one embodiment of the present invention, before combining the milk protein concentrate and optionally the lactose concentrate with the acidified dairy mass, the milk protein concentrate and the lactose concentrate are heat-treated. The heat-treatment is carried out at conditions varying from about 77°C to about 90°C, for about 20 seconds to about 5 minutes, or at about 125°C for about 4 seconds. In one embodiment the heat-treatment is carried out at about 78°C to 83°C for about 20 seconds. The homogenisation of the concentrates is carried out by one or two stage at a pressure varying from about 0 to about 250 bar in the first and from 0 to about 125 in the second stage, after which they are chilled or cooled to a temperature of about +12°C or below and optionally hydrolysed lactose-free for about 6 to about 8 hours at a temperature of about +12°C or below. In one embodiment, the concentrates are chilled or cooled to a temperature of about +8°C to about +12°C. In one embodiment, the concentrates are chilled or cooled to a temperature of about +10°C or below. The chilling or cooling of the concentrates is important for the texture of the concentrates as well as for the drinkable acidified product prepared in the present invention. The functional properties of the milk proteins, such as bonding and net formation, which are essential for the formation of the texture, are affected by the temperature, for example.

In an embodiment, the milk protein concentrate and the lactose concentrate are exposed to a lactose hydrolysis step in which lactose is split into monosaccharides, i.e. glucose and galactose. In an embodiment, a lactase enzyme is used for hydrolyzing the lactose. The lactose hydrolysis may be carried out using lactase enzymes widely used in the dairy field and by means of conventional methods. There are several different commercially available lactase enzymes ([beta]-D-galactosidases) that are suitable for use in the process of the invention. These include for instance enzymes produced with the Kluy- veromyces fragilis strain, such as HA lactase (Chr. Hansen A S, Denmark), or enzymes produced with the Kluyveromyces lactis strain, such as Validase (Valley Research Inc., USA), Maxilact L2000 lactase (DSM, Holland) and Godo YNL (Godo Shusei Company, Japan). An example of mould-based lactase preparations is GLL cone, lactase produced by Aspergillus oryzae (Biocon Ja- pan Ltd, Japan). The optimal hydrolysis conditions depend on the enzyme in question, and they are available from the manufacturers of commercial enzymes.

In the method of producing a drinkable acidified milk protein product, the cooled acidified mass and the cooled concentrates are combined to- gether in a ratio of about 3 to about 15% of the milk protein and optionally lactose concentrates and about 85 to about 97% of the acidified mass. Accordingly, in one embodiment in the production of the drinkable acidified milk protein product, the cooled acidified mass and the cooled concentrates are combined together in a ratio of about 3 to about 15% of the milk protein concentrate and about 85 to about 97% of the acidified mass. In another embodiment, in the production of the drinkable acidified milk protein product, the cooled acidified mass and the cooled concentrates are combined together in a ratio of about 3 to about 15% of the milk protein and lactose concentrates and about 85 to about 97% of the acidified mass. In one embodiment, about 5% to about 6% milk protein concentrate, 0% to about 2.5% lactose concentrate and about 92% to about 95% acidified mass is combined. In one embodiment, the acidi- fied mass is combined with the concentrates at a temperature of about +10°C or below. The blend of the acidified mass and the concentrates is mixed to a drinkable acidified milk protein product, which is then optionally flavored and packed.

The method for producing a drinkable acidified milk protein product of the present invention does not comprise a step of adding a stabilizer. Further, as it is evident from above, the blend formed by combining the chilled acidified dairy mass with the chilled milk protein concentrate and optionally with the chilled lactose concentrate is only mixed.

The drinkable acidified milk protein product of the present invention contains about 5 to about 12% protein and about 0 to about 8% fat. The drinkable acidified milk protein product of the present invention contains calcium about 1 50 mg to about 240 mg/100 g and D-vitamin about 1 .5 pg to about 3 pg/100 g. In a certain embodiment, the drinkable acidified milk protein prod- uct of the present invention contains about 6.5 - 7.5% protein. In a certain embodiment the drinkable acidified milk protein product of the present invention contains about 7% to about 10% protein. In a certain embodiment the drinkable acidified milk protein product of the present invention contains about 10- 1 1 % protein. In a certain embodiment, the drinkable acidified milk protein product of the present invention contains about 0% to 0.5% fat. The pH of the product is about 4.5 to about 5.3. In a certain embodiment, pH of the product is about 4.75 to about 4.85. In a certain embodiment, pH of the product is about 4.5 to 4.8. The viscosity of the product at a temperature of +10°C is about 50 to about 90 mPas. In a certain embodiment, the viscosity of the product at a temperature of +10°C is about 60 to about 80 mPas, preferably about 60 to about 70 mPas. In a certain embodiment, the drinkable acidified milk protein product contains protein 7 g/100 g. In a certain embodiment, the drinkable acidified milk protein product contains fat 0.4 g/100g. In a certain embodiment, the drinkable acidified milk protein product contains carbohydrates 3.9 g/100 g. In a certain embodiment, the drinkable acidified milk protein product contains calcium 160 mg/100 g. In a certain embodiment, the drinkable acidified milk protein product contains D-vitamin 2 g/100 g. The ratio of casein proteins to whey proteins in the drinkable acidified product corresponds with the ratio of casein proteins to whey proteins in cow's milk i.e., the ratio is about 80:20. Ac- cordingly, the proteins of the product are about 79 - 80% caseins and about 19 - 20% whey proteins. In one embodiment, the drinkable acidified milk protein product of the present invention contains about 85-97 % based on the total weight of the product of an acidified dairy mass having a protein content of about 5% to about 12% and a pH of about 4.5 to about 5.3. In another embodiment, the drinkable acidified milk protein product contains based on the total weight of the product about 85-97 % of an acidified dairy mass having a protein content of about 5% to about 12% and a pH of about 4.5 to about 5.3, and about 3-15% of a milk protein concentrate and optionally a lactose concentrate. In one embodiment, the milk protein concentrate of the drinkable acidified milk protein product is produced by ultrafiltration of a milk raw material.

The drinkable acidified milk protein product is acidified using a thermophilic or a mesophilic starter culture or a chemical acidifier. The acidifier is chosen based on the knowledge of the person in the art. In a certain embodiment, the drinkable acidified milk protein product is acidified using a thermophilic starter culture. In a certain embodiment, the drinkable acidified milk pro- tein product is acidified using a thermophilic starter culture such as Lactobacillus acidophilus, L. bulgaricus, L. delbrueckii subs, bulgaricus, Bifidobacterium lactis, for example. In a certain embodiment, the drinkable acidified milk protein product is acidified using a mesophilic starter culture. In a certain embodiment, the drinkable acidified milk protein product is acidified using a mesophilic start- er culture, such as Lactococcus lactis ssp. cremoris, Lactococcus lactis ssp. lactis, Leuconostoc mesenteroides ssp. cremoris and/or Lactococcus lactis ssp. diacetylactis, for example. Accordingly, the drinkable acidified milk protein product may be a drinkable quark or a quark type product acidified with a mesophilic acidifier or acidified mass or a drinkable yogurt product acidified with a thermophilic acidifier.

The drinkable acidified milk protein product of the present invention is free from stabilizers i.e., it does not contain any stabilizer.

The following examples are presented to further illustrate the invention without limiting the invention thereto. EXAMPLE 1 A - PREPARATION OF QUARK

The quark was composed of a milk protein concentrate (about 55% of the weight of the mass), skimmed milk (about 28% of the weight of the mass) and water (about 17% of the weight of the mass). The quark mass blend was produced by heat-treating the blend of the milk protein concentrate, skimmed milk and water at 90°C for 20 seconds and homogenizing it at 100 bar. A mesophilic acidifier (CHN1 1 , Chr. Hansen) and lactase (Maxilact, DSM) were added and the heat-treated blend was allowed to acidify at a temperature of 40°C for about 4 to 5 hours until the pH of the mass was about 4.8. After the acidification, the acidified mass was cooled to a temperature at about +10°C or below.

The acidified dairy mass contains milk proteins about 6.8% (w/w) to about 6.9% (w/w). The ratio of casein proteins to whey proteins in the dairy mass corresponds with the ratio of casein proteins to whey proteins in cow's milk i.e., the ratio is about 80:20.

EXAMPLE 1 B - PREPARATION OF QUARK

The quark was composed of a milk protein concentrate (about 55 % of the weight of the mass), skimmed milk (about 28 % of the weight of the mass) and water (about 17 % of the weight of the mass). The quark mass blend was produced by heat-treating the blend of the milk protein concentrate, skimmed milk and water at 90 °C, for 20 seconds and homogenizing it at 100 bar. A mesophilic acidifier (XT cultures, Chr. Hansen) and lactase (Maxilact, DSM) were added and the heat-treated blend was allowed to acidify at a temperature of 40 °C for about 4 to 5 hours until the pH of the mass was about 4.8. After the acidification, the acidified mass was cooled to a temperature at about + 10 °C or below.

The acidified dairy mass contains milk proteins about 6.8 % (w/w) to about 6.9 % (w/w). The ratio of casein proteins to whey proteins in the dairy mass corresponds with the ratio of casein proteins to whey proteins in cow's milk i.e., the ratio is about 80:20.

EXAMPLE 2A - PREPARATION OF A DRINKABLE QUARK PRODUCT

A milk protein concentrate and a lactose concentrate were heat- treated at 90°C for 20 seconds after which they are exposed to lactose hydrolysis for 6 to 8 hours at about + 10°C.

The quark (92%) produced in Example 1A was then combined with the milk protein concentrate (5.5%) and lactose concentrate (2.5%). This blend was mixed thoroughly with a mixer (YTRON ^® ) and packed.

The drinkable quark product contains milk proteins about 7%, and has a pH of about 4.8 and a viscosity of 70 mPas at + 10°C. The proteins of the product are about 79 - 80% caseins and about 19 - 20% whey proteins. EXAMPLE 2B - PREPARATION OF A DRINKABLE QUARK PRODUCT

A milk protein concentrate and a lactose concentrate were heat- treated at 90°C for 20 seconds after which they are exposed to lactose hydrolysis for 6 to 8 hours at about + 10°C.

The quark (92%) produced in Example 1 B was then combined with the milk protein concentrate (5.5%) and lactose concentrate (2.5%). This blend was mixed thoroughly with a mixer (YTRON ^® ) and packed.

The drinkable quark product contains milk proteins about 7%, and has a pH of about 4.8 and a viscosity of 70 mPas at + 10°C. The proteins of the product are about 79 - 80% caseins and about 19 - 20% whey proteins.

EXAMPLE 3 - PREPARATION OF QUARK

The quark was composed of a milk protein concentrate (about 90% of the weight of the mass) and water (about 10% of the weight of the mass). The quark mass blend was produced by heat-treating the blend of the milk pro- tein concentrate and water at 90°C for 20 seconds and homogenizing it at 100 bar. A mesophilic acidifier (CHN1 1 , Chr. Hansen) and lactase (Maxilact, DSM) were added and the heat-treated blend was allowed to acidify at a temperature of 24°C for about 17 - 20 hours until the pH of the mass was about 4.8 or below. After the acidification, the acidified mass is cooled to a temperature at about +10°C or below.

The acidified dairy mass contains milk proteins about 10% (w/w) to about 1 1 % (w/w). The ratio of casein proteins to whey proteins in the dairy mass corresponds the ratio of casein proteins to whey proteins in cow's milk i.e., the ratio is about 80:20. EXAMPLE 4 - PREPARATION OF A DRINKABLE QUARK PRODUCT

A milk protein concentrate was heat-treated at 90°C, for 20 seconds after which it was exposed to lactose hydrolysis for 6 to 8 hours at about +10°C.

The quark produced in Example 3 (95%) is then combined with the milk protein concentrate (5%). This blend is mixed thoroughly with a mixer (YTRON ^® ) and packed.

The drinkable quark product contains milk proteins about 10% (w/w) to about 1 1 % (w/w) and has a pH of about 4.8 and a viscosity of 70 mPas at +10°C. The proteins of the product are about 79 - 80 % caseins and about 19 - 20% whey proteins.

EXAMPLE 5 - PREPARATION OF YOGURT

The yogurt was composed of a milk protein concentrate (about 55% of the weight of the mass), skimmed milk (about 28% of the weight of the mass) and water (about 17% of the weight of the mass). The mass blend was produced by heat-treating the blend of the milk protein concentrate, skimmed milk and water at 90°C for 20 seconds and homogenizing it at 100 bar. A thermophilic acidifier (Lactobacillus acidophilus, L. bulgaricus, L. delbrueckii subs. bulgaricus, Bifidobacterium lactis) and lactase were added and the heat- treated blend wass allowed to acidify at a temperature of 40°C for about 4 - 5 hours until the pH of the mass was about 4.5. After the acidification, the acidified mass was cooled to a temperature at about + 10°C or below.

The acidified dairy mass contains milk proteins about 6.8 % (w/w) to about 6.9% (w/w). The ratio of casein proteins to whey proteins in the dairy mass corresponds with the ratio of casein proteins to whey proteins in cow's milk i.e., the ratio is about 80:20.

EXAMPLE 6 - PREPARATION OF A DRINKABLE YOGURT PRODUCT

A milk protein concentrate and a lactose concentrate were heat- treated at 90°C for 20 seconds after which they are exposed to lactose hydrolysis for 6 to 8 hours at about +10°C.

The yogurt (92%) produced in Example 5 was then combined with the milk protein concentrate (5.5%) and lactose concentrate (2.5%). This blend was mixed thoroughly with a mixer (YTRON ^® ) and packed.

The drinkable product contains milk proteins about 7%, and has a pH of about 4.5 and a viscosity of 60 mPas at + 10°C. The proteins of the product are about 79 - 80% caseins and about 19 - 20% whey proteins.

It will be obvious to a person skilled in the art that, as the technology advances the inventive concept can be implemented in various ways. The in- vention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.