FI122602B - Lactose-low and lactose-free milk product and process for making them - Google Patents

Abstract

The invention concerns a low-lactose and lactose-free milk product and a method for their production. Lactose from the milk raw material is hydrolyzed, proteins, minerals and sugars are separated into different fractions using membrane technology and a low-lactose or lactose-free milk product is assembled from the fractions. With the help of the invention, a milk product is obtained, the water in which is derived from the original milk raw material. In addition, the method produces usable by-products.

Description

Low lactose and lactose free milk product and process for their preparation

Field of the Invention

The invention relates to a low-lactose and lactose-free milk product and a process for their preparation. The lactose in the milk raw material is completely or partially hydrolyzed and the proteins, minerals and sugars are separated into different fractions. The invention relates in particular to the use of membrane filtration techniques for the separation of proteins, minerals and sugars.

BACKGROUND OF THE INVENTION There are several known methods based on membrane technology for producing low-lactose and lactose-free milk. Also known in the art is the traditional enzymatic method for lactose digestion, which comprises the step of adding lactose from yeast or yeast to lactose so that more than 80% of the lactose is digested into monosaccharides, i.e. glucose and galactose.

Several membrane filtration method solutions have been proposed for removing lactose from milk raw material. There are generally four basic types of membrane filtration methods: reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF) and microfiltration (MF). Of these, UF is the most suitable for separating lactose from milk. Reverse osmosis is generally applied to concentration, ultra- and microfiltration fractionation, and nanofiltration to both concentration and fractionation. A membrane-based lactose removal process is described, for example, in WO 00/45643, in which lactose is removed by ultrafiltration and diafiltration. The use of filtration methods often results in the generation of side fractions such as permeate or lactose fractions. U.S. Patent Publication No. 2007/0166447 discloses the use of a lactose-containing NF retentate fraction as a side fraction 0 as a raw material for fermentation, e.g., in the manufacture of yoghurt.

g Recent studies have focused on the membrane filtration of milk

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30) and the use of such filtered low-carbohydrate milk for the manufacture of dairy products such as cheese, ice cream and yoghurt. one

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§ for multi-step membrane filtration methods known to you is that the methods include the addition of separate water, not derived from a milk raw material, for example to dilute the milk component pathway and obtain a low carbohydrate content (e.g. lactose). Particularly problematic in the industry is that a product whose liquid content is not entirely derived from the original milk raw material may not be called milk. It is also common to the known methods that residual lactose is removed from the membrane-filtered milk-5 raw material.

It is well known in the art that membrane techniques generally have the problem that in the case of ultrafiltration, in addition to lactose, some of the minerals which have a clear role in the taste of milk and milk products are removed. Mineral management is problematic in the art and the failure of known methods is high and often requires, for example, the restoration or separate addition of minerals.

Membrane processes often also produce side streams containing, for example, sugars and / or minerals, which cannot be effectively utilized and which also increase the effluent load, require further treatment and cost.

WO 2005/074693 describes the use of membrane technology in the manufacture of lactose-free milk. It is typical of the process that the ultrafiltration retentate is diluted with water to give a lactose content of about 3.0%. Residual lactose is hydrolyzed enzymatically.

WO 03/094623 A1 discloses a method of ultrafiltration, nanofiltration and concentration of milk product by reverse osmosis followed by the recovery of the minerals which are removed by ultrafiltration into the UF retentate. The residual lactose of the low-lactose milk product thus obtained is hydrolyzed with the enzyme lactase to the monosaccharides to give a substantially lactose-free milk product. The method provides lactose removed from milk without affecting the organoleptic properties of the milk product being prepared. In a process for preparing a dairy product,

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that does not originate in the different stages of the process. In addition, the process also produces mineral-containing side streams that cannot be utilized in the process and require post-treatment.

| KR20040103818 describes a process for preparing low-lactose σ> milk, wherein lactase-hydrolyzed

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Water is added to partially remove the galactose and glucose and water is added to the nanofiltration retentate to obtain suitable sweetness. Choi et al. (Asian-35 Aust. J. Anim. Sci. 20 (6) (2007) 989-993) describe a process for the preparation of lactose hydrolyzed milk in which raw milk is hydrolyzed with β-galactosidase (5,000 lactase activity units / g, Validase, Valley Research). partially (0.03%; 4 ° C, 24 hours) or 'completely' (0.1%; 40 h), heat treated to inactivate the enzyme (72 ° C, 5 min), cooled to 45-50 ° C, and nanofiltrated at ca. At 9-10 bar (130-140 psi; concentration factor δ 1.6). Water was added to the NF retentate and heat-treated at 65 ° C for 30 min. The processes described in said publications, comprising the hydrolysis step, heat treatment of the enzyme, nanofiltration and addition of water, are not as such suitable for the preparation of a dairy product without the separate addition of water. The method also comprises a separate heat treatment to inactivate the enzyme and to avoid microbiological problems during the filtration step (i.e., NF filtration in the warm). The high hygiene requirements for milk processing also place limits on industrial processes. For the treatment of milk raw material in industrial processes and film processes, a temperature of, for example, 10 ° C is generally desirable to avoid microbiological problems.

Thus, it is desirable to provide methods that can also manage side streams in the process and recover more efficiently, which also enables novel applications. This will further streamline processes. However, it is very challenging to achieve products that are completely flawless in taste and structure, and which meet consumers' expectations for an organically acceptable dairy product and which are manufactured economically and simply without the addition of water.

Surprisingly, a method has now been invented for the production of low-lactose and lactose-free milk products with organoleptic properties which are completely flawless and at no additional cost. The method 25 according to the invention enables more efficient and simpler management of the milk components than the conventional methods at no extra cost 5 and minimizes losses. There is no need for additional water in the milk product

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^ from. In addition, the process according to the invention does not produce side streams requiring post-treatment, thereby making the process more efficient.

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= 30 Brief Description of the Invention

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The present invention provides a novel solution to avoid the need for separate addition of water to produce low lactose and lactose-free, low-carbohydrate and / or protein-enriched and protein-modified dairy products, as well as the organoleptic properties of such dairy products. problems, the method of hydrolyzing lactose of a milk raw material separates the proteins, sugars, and minerals obtained from the hydrolyzed milk raw material into various fractions by membrane technology. The separated fractions can be used to make the desired milk product without the need for additional water.

The invention provides a process for preparing dairy products of low lactose and lactose towers, which process is characterized in what is stated in the independent claim. The invention also provides a low-lactose and lactose-free milk product prepared from various fractions obtained by the process of the invention. By the process of the invention, the preparation of low-lactose and lactose-free dairy products 10 can be simplified and made more efficient, making separate addition / addition of water, salts and / or protein unnecessary and by-products particularly suitable for multiple applications within the same manufacturing plant.

All by-products 15 obtained in the process of the invention are normal dairy products and the by-products of the process can be further utilized in the process of the invention. The process does not produce products or side streams that should be treated or separated in a special abnormal manner, thus minimizing wastewater load.

In addition, the process of the invention avoids protein and mineral losses typical of lactose-free and low-lactose dairy products, and in particular the recovery of dilute aqueous solutions resulting from the process.

The invention further provides a method which is simple, economical, large scale industrially feasible and does not entail additional costs.

Surprisingly, it was found that by hydrolyzing lactose o in whole or part of the milk raw material and by membrane filtration technology,

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The ratio of proteins to proteins was effectively controlled. The invention thus provides a process for treating the components of hydrolysed skimmed milk milk raw material in a manner that produces streams, e.g. dilute aqueous solutions are efficiently utilized and no separate addition of water is required in the process σ>, The milk product produced by the process of the invention has the desired organoleptic properties, low carbohydrate content and contains at least comparable amounts of nutritional components.

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The invention also provides the use of certain fractions obtained by the process of the invention as a sweetener and in fermentation processes as well as diafiltration in diafiltration.

DETAILED DESCRIPTION OF THE INVENTION In one aspect, the invention relates to a process for preparing a low lactose or lactose-free dairy product comprising: a) hydrolyzing lactose of a milk raw material to obtain a hydrolyzed milk raw material, b) hydrolyzing the milk raw material to c) if desired, one or more of the obtained fractions are further processed by membrane technology and / or evaporation and / or chromatography; d) one or more fractions obtained in step b) and, if desired, one or more fractions obtained in step c) e) if desired, concentrating the product obtained in step d) into a concentrate or powder.

In the context of the present invention, milk raw material refers to milk, whey and milk-whey combinations as such or in concentrated form. The milk raw material may be supplemented with ingredients commonly used in the manufacture of dairy products such as fat, protein or sugar fractions, etc. The milk raw material may thus be e.g. whole milk, cream, skimmed milk or skimmed milk, ultrafiltered milk, diafiltered milk, microfiltrates or by reconstituting milk made with milk powder, organic milk

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£ or a combination of these. Preferably, the milk raw material is skim milk.

In step a) of the process of the invention, lactose of the milk raw material 9 is hydrolyzed to monosaccharides as is known in the art. In one embodiment of the process of the invention, the hydrolysis is carried out completely 30 (full hydrolysis) prior to the membrane filtration step where the milk components are separated. In another embodiment of the process of the invention, the hydrolysis is carried out partially prior to the filtration step and then the residual lactose of the partially hydrolyzed milk raw material is subsequently hydrolysed and substantially simultaneously when the partially hydrolyzed milk raw material is filtered, i.e. the milk components are separated. The membrane filtration of step b) may comprise several membrane filtration steps. In one embodiment of the process of the invention, the hydrolysis is performed substantially during the first membrane filtration. According to one embodiment of the invention, the first membrane filtration is ultrafiltration (UF).

Full hydrolysis means that the hydrolysed milk raw material is lactose-free, with a lactose content of less than 0.5%. Partial hydrolysis means that the hydrolysed milk raw material has a lactose content of> 0.5%.

The partially or wholly hydrolyzed milk raw material obtained in step b) of the process of the invention is membrane filtered to separate proteins, sugars and minerals into different fractions, varying by membrane filtration method, process conditions and / or different types of membranes. The condition to be changed may be, for example, the filtration temperature, the filtration pressure, the addition of diawater and / or the filtration concentration factor. The conditions can be changed for either one or more variables. In one embodiment of the process of the invention, membrane filtration is performed by ultrafiltration. According to step c) of the process according to the invention, one or more of the retentate or permeate fractions obtained in the previous step b) can be further processed by membrane techniques and / or evaporation and / or chromatography to further enhance the separation of proteins, sugars and minerals. It is essential in the invention that it is possible to carry out further treatment without the addition of water. Examples of membrane techniques suitable for further processing include nanofiltration (NF) and reverse osmosis (RO), in particular nanofiltration. Further processing may comprise several membrane filtration steps. The various separation methods may also be combined in one or more steps as desired.

In one embodiment of the invention, NF permeate obtained by nanofiltration of a hydrolyzed milk feedstock is utilized in the process of the invention as diawater in diafiltration (DF). However, the use of the NF permeate obtained according to the invention is not limited only

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but can also be used in other membrane filtration processes. In a particular embodiment of the invention, the NF-? 30 permeate is derived from the nano-? filtering.

σ> Protein, sugars and minerals from hydrolysed milk raw materials

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It is subjected to membrane methods, preferably ultrafiltration in a first step under conditions where the retention of sugars in the retentate is low.

Suitable ultrafiltration membranes include, for example, HFK-131 (Koch mem brane systems, Inc., USA). Suitable nanofiltration membranes are, for example, DeSal 5 DL (GE Osmonics, USA), Desal 5 DK (GE Osmonics, USA), TFC® SR3 (Koch membrane systems, Inc., USA), FILMTEC ™ NF (Dow, USA). Suitable reverse osmosis membranes include, for example, TFC® HR (Koch membrane systems, Inc., USA) and FILMTEC FT30 (Dow, USA).

5 Concentration factor (K) means the weight ratio of liquid to retentate to be filtered and is defined by the formula: K = feed (kg) / retentate (kg)

In the process of the invention, ultrafiltration is preferably carried out at a concentration factor of K = 1 to 10, more preferably 2 to 6, and nanofiltration is preferably performed at a concentration factor of K = 1 to 10, more preferably K = 2 to 6. When using diafiltration, the concentration factor can be significantly higher.

According to step d) of the process according to the invention, one or more fractions obtained by membrane filtration of the hydrolyzed lactated milk raw material and, if desired, one or more fractions obtained by further processing, form a lactose-free or low-lactose milk product of desired composition. Said fractions may also be formulated as low-carbohydrate and protein-enriched and protein-modified milk products. Other ingredients may also be added to the product. In one embodiment of the invention, the milk product is formulated without substantially adding water, using the fraction or fractions of the hydrolyzed milk raw material obtained in the process of the invention as the liquid required to formulate the product. Particular mention may be made of RO permeate, NF permeate, or condensation water from condensation or evaporation of a hydrolysed milk feedstock. In one embodiment of the invention, the NF permeate is derived from nanofiltration of the UF permeate of the hydrolyzed milk raw material.

° Tap water can also be used partly as a liquid. The term '' substantially without water 'in the context of this invention means that at least 50% of the tap water is replaced by the fraction σ> obtained by the process of the invention.

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If desired, the low-lactose or lactose-free milk product prepared by the process of the invention may be concentrated to a concentrated milk or to a milk powder.

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The milk product produced by the process of the present invention is low-lactose or lactose-free. The term low lactose in the present invention means that the milk product has a lactose content of less than 1%. The term lactose-free means that the milk product has a lactose content of 0.5 g / dose (for example, 0.5 g / 244 g for liquid milk with a lactose content of up to 0.21%), but less than 0.5%. According to the invention, low-carbohydrate milk beverages can also be prepared which are organoleptically flawless. Furthermore, the loss of protein in the milk raw material is minimized and no separate supplementation of minerals and / or protein is required.

The process according to the invention is simple and suitable for large scale production.

The process of the present invention can be applied to both batch and continuous manufacture. Preferably, the process of the invention is carried out in a batch process.

In another aspect, the invention relates to a lactose-free and low-lactose milk product containing one or more fractions of hydrolysed milk raw material obtained from one or more membrane filtrations of the hydrolyzed milk raw material. In one embodiment of the invention, the lactose-20 ton or low-lactose milk product comprises at least one of the fractions UF-retentate, UF-permeate, NF-retentate, NF-permeate, DF-retentate, DF-permeate, RO-retentate and RO-permeate. In a particular embodiment of the invention, the dairy product of the invention is obtained by dipping the protein in the form of DF retentate.

In another aspect, the invention also relates to a lactose-free or low-lactose milk product prepared by a process comprising the steps of:

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^ a) The lactose of the milk raw material is hydrolyzed to obtain a hydrolyzed milk raw material; ^ 30 b) The hydrolyzed milk raw material is membrane-filtered to produce protein, | to separate thighs and minerals into different fractions σ> c) if desired, one or more of the resulting fractions are further processed

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g) film technique and / or evaporation and / or chromatography; od) one or more fractions obtained in step b) and, if desired, one or more fractions obtained in step c) and possibly other ingredients to form a product of the desired composition and sweetness; ) if desired, concentrating the product obtained in step d) to a concentrate or powder.

The invention also relates to the use of NF permeate obtained by nanofiltration of a hydrolyzed milk feedstock as diawater for membrane filtration processes. Said NF permeate can be used in particular for diafiltration or filtration used in the process of the invention. In one embodiment of the invention, the NF permeate is derived from the nanofiltration of the UF permeate of the hydrolyzed milk raw material.

The invention also relates to the use of glucose and galactose sugar fractions obtained by membrane filtration of hydrolysed milk raw material as a sweetening agent or in fermentation processes, for example in the manufacture of sour milk products. In one embodiment of the invention, the sugar fraction is UF permeate obtained by ultrafiltration of hydro-lysed milk raw material or NF retentate obtained by nanofiltration. In one embodiment of the invention, said NF retentate is an NF retentate obtained by ultrafiltration of a hydrolyzed milk raw material. Compared to lactose-containing fractions, these glucose- and galactose-containing fractions resulting from hydrolysis are more readily and directly available for fermentation, for example in the manufacture of sour milk products. Thus, the glucose and galactose fractions obtained by the process of the invention can be used as fermentable sugar or sugars in fermentation processes.

The following examples illustrate the invention but do not limit the invention to the embodiments described.

Example 1. Ultrafiltration of Hydrolysed Skimmed Milk in Cold ™ (K = 1.9) 9 Skimmed milk (40 L) was hydrolyzed (6 ° C, 18 h) with Godo YNL2 lactase phase (Godo Shusei Company, Japan). with 0.15%. Hydro- | Lysed skimmed milk was ultrafiltered with HFK-131 (Koch Membrane Systems, Inc.) at 9-19 ° C and 4.5-5.0 bar. The permeate flow rate was 3.8-6.5 l / m2h. The ultrafiltration was continued to a concentration factor of 1.9, i.e. the volume of UF retentate was then 21 L and UF permeate 191.

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Feed (hydrolyzed skimmed milk), UF retentate and UF permeate were sampled and analyzed for protein, dry matter, glucose, galactose and ash (Table 1).

UF retentate was used in the formulation of the milk beverage (Example 5 8; Tables 9 and 10).

Table 1. Compositions of ultrafiltration feed, retentate and permeate of hydrolyzed skim milk.

Composition Feed (Hydrolysed UF retentate UF permeate __fat milk) ___

Protein (%) __ 3.61__6.34 __: _

Ash (%) __ 078__099__0.45

Glucose (%) __ 049__050__2.62

Galactose (%) __ 024__034__2.40

Dry matter (%) __ 9.07__11.8__5.59_

Example 2. Ultrafiltration of Hydrolysed Skimmed Milk in Warm 10 Mass (K = 4)

Skimmed milk (40 L) was hydrolyzed (6 ° C, 22 h) with Godo YNL2-Lac (Godo Shusei Company, Japan) at a dosage of 0.15%. Hydrolysed skim milk was ultrafiltered with HFK-131 (Koch Membrane Systems Inc., USA) at a temperature of 45-50 ° C and a pressure of 1-3.5 bar. The permeate flow of Perme-15 was 7.8-10.3 l / m2h. The ultrafiltration was continued to a concentration factor of 4, in which case the volume of UF retentate was 10 L and UF permeate 30 L.

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Feed (hydrolyzed skimmed milk), UF retentate and UF permeate were sampled and assayed for protein, dry matter, glucose, 9 galactose and ash (Table 2).

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? 20 UF retentate was used in the preparation of the milk beverage (Example 8; Table 11), in the preparation of the flavored milk beverage (Example 9; Table 12) and in the preparation of the whey protein-containing milk beverage (Example 10; Table 14).

The UF permeate was further processed by nanofiltration (Example 3).

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Table 2. Compositions of ultrafiltration feed, retentate and permeate of hydrolyzed skim milk.

Composition Feed (Hydrolysed UF retentate UF permeate __fat milk) ___

Protein (%) __ 3.64__12.5 __: _

Ash (%) __ 078__750__0.44

Glucose (%) __ 750__2 / 17__2.63

Galactose (%) __ 720__708__2.46

Dry matter (%) __ 9.05__18.4__5.88_

Example 3. Nanofiltration of Ultrafiltration Permeate-5 tin Hydrolysed Skimmed Milk (K = 2)

The experiment of Example 2 was continued by nanofiltration of the ultrafiltration permeate to a concentration factor of 2 on a Filmtec NF film (Dow, USA) and a filtration temperature of 10-16 ° C. The permeate flow was 10l / m2h and the pressure was 11-17 bar. The feed was 29.5 liters, NF retentate 14.5 liters and NF permeate 15 liters.

From the feed, NF retentate and NF permeate, dry matter, glucose, galactose and ash were determined. The results are shown in Table 3.

NF permeate was used in Example 5 in the diafiltration step. NF permeate was also used in the formulation of milk drinks (Example 8; Tables 9 and 11).

15 Table 3. Nanofiltration of UF permeate from hydrolyzed skim milk. Composition of feed, retentate and permeate.

C \] ---- o Input c \ j

Composition (Hydrolysed 5 NF retentate NF permeate ^ UF permeate) ^ __ (e.g. 2) ___ ί Ash (%) __ 047__OZ0__0.20 g Glucose (%) __ 755__787__0.21 S Galactose (%) 2.36 4.29 0.15 O ------ § Dry matter (%) 5.7 10.3 0.62

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Example 4. Two-step Nanofiltration of Ultrafiltration Permeate of Hydrolyzed Milk (K = 4, K = 4)

The ultrafiltration permeate of hydrolyzed milk was nanofiltered with a Desal 5 DL membrane to a concentration factor of 4. The filtration temperature was 44-47 ° C, 5 permeate flux 10 l / m2h and pressure 3-6 bar. The feed was 40 liters, NF retentate I 10 liters and NF permeate I 30 liters.

From the feed, NF retentate I and NF permeate I, dry matter, glucose, galactose and ash were determined. The results are shown in Table 4.

Table 4. Nanofiltration of Ultrafiltration Permeate of Hydrolyzed Milk. Composition of feed, retentate and permeate.

Composition Feed (Hydrolyzed NF Retentate I NF Permeate I __UF Permeate) ___

Ash (%) __ 046__087__0.31

Glucose (%) __ 051__021__2,32

Galactose (%) __ 033__005__2.19

Dry matter (%) __ 5.67__8.03__4.83_

The first nanofiltration permeate (NF permeate I) was nanofiltered in a second step on a Filmtec N F film to a concentration factor of 4. The filtration temperature was 10-24 ° C, the permeate flow was 11-3.2 l / m2h and the pressure was 15-11-24 bar. Feed was 28.5 liters, NF retentate II 6 liters and NF permeate II

22.5 liters.

From the feed, NF retentate II and NF permeate II, dry matter, glucose, galactose and ash were determined. The results are shown in Table 5.

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^ Table 5. NF permeate I of UF permeate in hydrolysed milk

9 20 nanofiltrations. Composition of feed, retentate and permeate.

^ ---- ^ Composition Input

x NF retentate II NF permeate II

£ __ (NF-Permeate I) ___ cd Ash (%) __ 029__051__0,19 S Glucose (%) 2,28 7,56 0,20 00 § Galactose (%) __ 2 / M__075__0,18 ^ Powder (%) __ 4 , 56__15,5__0,52_ 13

Two-step nanofiltration gave a purer sugar concentrate as NF retentate II with a lower ash content. Especially of the divalent minerals, calcium and magnesium, 80% remained in the NF retentate I.

NF-Retentate II was used as a sweetener in a flavored milk-5 beverage (Example 9; Tables 12 and 13).

The NF permeate II was further concentrated by reverse osmosis and the resulting RO permeate was used in the preparation of the cocoa milk beverage (Example 9; Table 13).

Example 5. Ultrafiltration (K = 2.2) of hydrolysed skim milk combined with diafiltration

Skimmed milk (40 L) was hydrolyzed (6 ° C, 18 h) with Godo YNL2-Lac (Godo Shusei Company, Japan) at a dosage of 0.15%. Hydrolysed skim milk was ultrafiltered with HFK-131 (Koch Membrane Systems Inc., USA) at a temperature of 8-13 ° C and a pressure of 3.5-4.0 bar. The per-15 meate flux was 5.3-7.5 l / m2h. The skimmed milk was concentrated at a factor of 2.2, i.e. a volume of UF retentate of 181 and a volume of UF permeate of 221. Thereafter, 14 liters of NF permeate of Example 3 was gradually added to the UF retentate. After the diafiltration step, the DF retentate had a volume of 24 liters and the total volume of permeate obtained from diafiltration and ultrafiltration was 30 liters to 20 liters. The combined UF and DF permeate is hereinafter referred to as the permeate in the example.

Feed (hydrolyzed skimmed milk), DF retentate and permeate were sampled and assayed for protein, dry matter, glucose, galactose and ash (Table 6).

Table 6. Compositions of ultra- and diafiltration feed, retentate and permeate of hydrolyzed skimmed milk.

o Composition Feed c \ j (Hydrolysed DF Retentate Permeate = __ skimmed milk) ___

Protein (%) __ 3,58__5,51 __: _ § Ash (%) __ 077__079__0,46 § Glucose (%) __ 745__738__2,36 ° Galactose (%) __ 738__737__2,35

Dry matter (%) __ 8.95__8.76__5.27_14

Recycling the ultrafiltration permeate nanofiltration permeate from Example 3 back into the ultrafiltration retentate yields a protein-enriched lactose-free milk drink as DF retentate. DF retentate was also evaluated organoleptically and found to be good and full-bodied.

Example 6 Ultrafiltration and Hydrolysis During Filtration of Partially Hydrolyzed Skimmed Milk (K = 2.2)

Skimmed milk (40 L) was hydrolyzed (50 ° C, 1 h) with Lactoles L3 lac (Biocon Ltd., Japan) at a dosage of 0.18%. Partially hydrolysed skimmed milk was ultrafiltered with HFK-131 (Koch Membrane Systems 10 Inc., USA) at a temperature of 43-45 ° C and a pressure of 1.0-3.5 bar. The permeate flow rate was 10 l / m2h. The skimmed milk was concentrated at a factor of 2.2, i.e. the volume of UF retentate was then 18 L and that of UF permeate was 22 I. The UF permeate was then recycled back into the UF retentate. During the concentration and recycling, the progress of the hydrolysis was followed. Filtration was continued for two hours.

At the beginning of the filtration, the milk had a lactose content of 0.24% and at the end of filtration less than 0.01%.

After feeding (hydrolyzed skimmed milk) and after filtration, UF retentate and UF permeate were sampled and analyzed for protein, dry matter, glucose, galactose, lactose and ash (Table 7).

Table 7. Compositions of ultrafiltration feed, retentate and permeate of hydrolyzed skim milk.

Composition Input (Hydrolysed UF Retentate UF Permeate __Fat Milk) ___ ™ Protein (%) __ 3.53__7 / M__: _ ™ Ash (%) __ 077__1 ^ 8__0.48 9 Glucose (%) __ 732__758__2.59 c \ i Galactose ) __ 713__750__2.47 £ Lactose (%) __ 024 __ <0.01 __- ^ Powder (%) __ 8,95__12,5__5,72_ o 00 tn o The results show that it is possible to continue the hydrolysis of lactose during filtration.

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Example 7. Nanofiltration of Hydrolyzed Whey (K = 7)

The peeled spun whey (401) was hydrolyzed (9 ° C, 20 h) with Godo YNL2 lactase (Godo Shusei Company, Japan) at a dosage of 0.1% and nanofiltrated on a Desal 5 DL membrane (GE Osmonics, USA) at 46-51 ° C and a pressure of 3-6.5 bar. The permeate flow was 10.0-13.5 l / m2h. The Na-filtration was continued to a concentration factor of 7, i.e. the volume of NF retentate was 5.5 L and NF permeate 34.5 L.

Feed (hydrolyzed whey), NF retentate, and NF permeate were sampled and assayed for protein, dry matter, glucose, galactose, and ash (Table 8).

Table 8. Compositions of nanofiltration feed, retentate and permeate of hydrolyzed whey.

Feed NF Retentate NF Permeate Composition (Hydrolyzed Whey) ___

Protein (%) __ 0.61__4.59 __: _

Ash (%) __ 034__1J52__0.28

Glucose (%) __ 005__069__1.97

Galactose (%) __ 090__068__1.84

Dry matter (%) __ 5,02__10,20__4,10_

The NF permeate isolated from the hydrolyzed whey corresponded quite well to the NF permeate I which had been separated from the milk ultrafiltration permeate in a similar composition (Example 4; Table 4). If desired, the nano filtration of the whey may be continued in the second step in the same manner as described in Example 4.

NF retentate was used to formulate a whey protein containing milk beverage (Example 10; Table 14).

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cm Example 8. Composition of a milk beverage from ultrafiltration retentate of hydrolysed skim milk and nanofiltration permeate of ultrafiltration permeate.

The lactose-free milk drink 1 was composed of the ultrafiltration retentate of hydrolyzed skimmed milk of Example 1 and the nanofiltration permeate of the ultrafiltration permeate of Example 3. In lactose-free milk beverage 2, the ultrafiltration permeate nanofiltration permeate of Example 3 was replaced by water.

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The lactose-free milk beverage 3 was composed of the ultrafiltration retentate of hydrolyzed skim milk of Example 2 and the nanofiltration permeate of the ultrafiltration permeate of Example 3 and skim milk. In addition, the milk salt of EP 1061811 B1 was used in the compositions.

5 The compositions and proportions of the fractions in the formulations and the compositions of the lactose-free milk drinks are shown in Tables 9-11. The formulations of lactose-free skimmed milk drinks are similar to regular milk, except for carbohydrates. The ultrafiltration permeate nanofiltration permeate was able to replace all the water needed in the beverages as well as part of the milk salt addition need.

Table 9. Composition of lactose-free skimmed milk beverage 1 from ultrafiltration retentate of hydrolysed skimmed milk and ultrafiltration permeate nanofiltration permeate.

UF Retentate NF Permeate Milk Salt Lactose-free (Example 1) (Example 3) non-fat _____ milk drink

Share (%) __ 51 ^ 9__47,8__037__

Composition_____

Protein (%) __ 6.34 __-__ 9.12__3.3

Glucose (%) __ 050__021__23__1.5

Galactose (%) 2.34__015__22__1.4

Ash (%) __ 099__020__41__0.8

Dry matter (%) __ 11.8__0.62__96__6.8

Table 10. Formulation of lactose-free skimmed milk beverage 2 from 15 hydrolysed skimmed milk ultrafiltration retentate and water-2.

° ----- ^ UF-Retentate Water Milk Salt Lactose-Free o (Example 1) Skimmed _____ Milk Drink x Proportion (%) __ 51 ^ 3__48 / 1__061__ ^ Composition_____ g Protein (%) __ 034__0__012__3.3 S Glucose (%) __ 050__0__ (%) 2.34__0__22__1.3 w Ash (%) __ 099__0__41__0.8

Dry matter (%) __ 11.8__0__96__6.6 17

Table 11. Composition of a lactose-free skimmed milk beverage 3 from ultrafiltration retentate of hydrolysed skim milk and nanofiltration permeate of ultra-filtration permeate.

UF-NF- Milk Salt Non-fat Lactose-free retentate permeate non-fat milk __ (example 2) (example 3) ____ milk drink

Share (%) __ 12J__37J3__0,29__500__

Composition______

Protein (%) __ 12.50 __: __ 012__058__3.3

Glucose (%) __ 017__021__23__045__1.6

Galactose (%) 2.08__015__22__038__1.6

Ash (%) __ 050__020__41__0J7__0.8

Dry matter (%) __ 18.4__0.62__96__8.95__7.2 Example 9 Use of Nanofiltration Retentate of Ultrafiltration Permeate as a Sweetener in Cocoa Milk Beverage

The lactose-free cocoa milk drink was composed of lactose-free milk (1% fat content), Example 4 nanofiltration retentate II, Example 2 hydrolysed skimmed milk ultrafiltration retentate, sucrose, 10 low lactose cream and cocoa powder. The low lactose cocoa milk drink was composed of the RO permeate of Example 4, the nanofiltration retentate II of Example 4, the low lactose skimmed milk powder, sucrose, lactose-free cream and cocoa powder. The compositions and proportions of the fractions in the beverages and the compositions of the cocoa milk beverages are shown in <M 15 in Tables 12 and 13.

o Both cocoa milk drinks were organoleptically good and full-bodied. The lactose-free cocoa milk drink was able to rl. to replace 30% of the sucrose required by the nanofiltration reten of Example 4

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Table 12. Preparation of lactose-free cocoa milk beverage.

Lak- NF- UF- Precipitation- Lak- Cocoa- Lactose-free reten- terosis-free powdered milk-free milk tartarate II cocoa cream 1.0% (eg 4) (eg 2) milk ___drink

Share (%) __ 53.6 30.2 11.2 3.1__1J__OjJ__

Composition________

Protein (%) __ 3J5 __: __ 12 £ __: __ 2 $ __: __ 3.3

Fat (%) __ LO __: __: __: __ 38 __: __ 0.9

Glucose (%) __ 2.3 7.56 2.17 __: __ 1_A __: __ 3.5

Galactose (%) __ 2.3 6.75 2.08 __: __ 1_A __: __ 3.8

Lactose (%) __: __: __: __-__: __; __ 0

Sucrose (%) __: __: __-__ 100 __: ___ 3.1

Ash (%) __ 0.7 0.51 1.5 __: __ 0J __: __ 0.7

Dry matter (%) 10 15.5 18.4 100 43 100 16.5

Table 13. Preparation of low lactose cocoa milk beverage.

RO- NF- Low- Salt- Lak- Cocoa- Low- Family- lactation. rose lactose free lactose.

meaatate II fat-free cream cocoa (eg 4) (eg 4) milk milk powder ____ powder

Proportion (%) __ 65.6 19.4 8.4 3.5 2.3 0.80__ cvj Composition________ cm Protein (%) __: __: __ 35 __: __ 2I0 __: __ 3.0 5 Fat (%) __: __-__ LO__ : __ 38 __: __ 0.9 i

Glucose (%) __ <0.1 7.56 21 __: __ L4 __: __ 3.3 x Galactose (%) <0.1 6.75 21 __: __ L4 __: __ 3.2 ^ Lactose (%) __-__-__ 10 __: __ ; __; __ 0.9

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§ Sucrose (%) __-__-__; __ 100 __: ___ 3.5 § Ash (%) __ <0.1 0.51 7.7 __-__ 0.5 __: __ 0.9 w | Dry matter (%) <0.1 15.5 96 100 43 100 16.9 19

Example 10. Composition of a lactose-free whey protein-containing milk beverage from membrane filtration fractions of hydrolysed whey and skimmed milk

The lactose-free whey protein-containing milk beverage was composed of the NF hydrolyzed whey protein of Example 7, the hydrolyzed skim milk, water, and the UF retentate of the hydrolyzed skim milk of Example 2. The composition and proportions of the fractions in the composition and the composition of the lactose-free whey protein-containing milk beverage are shown in Table 14. The lactose-free whey protein-containing milk beverage contained less carbohydrates than normal milk and 10% whey protein with 50% protein.

Table 14. Composition of Lactose-Free Skimmed Whey Protein Milk Beverage from Nanofiltration Fractions and Skimmed Milk.

NF- Hydrolyzed Water UF- Lactose-free retentate non-fat retentate non-fat (whey, milk (milk, whey protein eg 7) eg 2) ______ milk drink

Share (%) __ 27.3__402__200__05__

Composition______

Protein (%) __ 4 ^ 9__039__0__105__3,3

Glucose (%) __ 099__027__0__017__1.6

Galactose (%) 1.80__023__0__008__1.5

Ash (%) __ 1 £ 2__076__0__1 £ Q__0.8

Dry matter (%) 10.20 8.78 0 18.4 7.3

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Claims (17)

A process for the preparation of a lactose-free or low-lactose milk product, characterized in that 5 a) lactose of the milk raw material is hydrolyzed to obtain a hydrolyzed milk raw material, and the hydrolyzed milk raw material is membrane filtered, b) one or more of the fractions obtained in c) if desired, one or more of the fractions obtained in step a) and / or step b) are subjected to further evaporation and / or chromatography to separate the proteins, sugars and minerals into different fractions, d) from one or more fractions obtained in step b) and optionally a) and / or one or more fractions and other ingredients obtained in step c) form a product of the desired composition and sweetness without substantially adding water, e) optionally concentrating the product obtained in step d) into a concentrate or powder. Process according to claim 1, characterized in that in step a) the membrane filtration is ultrafiltration. Process according to Claim 2, characterized in that the UF permeate obtained by ultrafiltration is further treated with nanofiltration to obtain NF retentate and NF permeate. Process according to Claim 3, characterized in that the NF permeate is used in step a) and / or b) for diafiltration of the diavete CM 5 Method according to one of the preceding claims, characterized in that the lactose of the milk raw material is partially hydrolyzed. c \ l Process according to Claim 5, characterized in that the lactose hydrolysis of the partially hydrolysed milk raw material continues while the partially hydrolysed milk raw material is separated into membranes containing proteins, sugars and minerals. 7. A method according to any one of the preceding claims, characterized in that the liquid dairy product is made up of reverse osmosis (RO) permeate obtained from a membrane filtration step or steps of a hydrolysed milk raw material, a nanofiltration (NF) permeate or a hydrolysed milk froth. 8. A method according to claim 7, characterized in that the liquid used is NF permeate derived from nanofiltration of ultrafiltration permeate of hydrolysed milk raw material. 9. A process for preparing a lactose-free or low-lactose milk product, characterized in that a) the lactose of the milk raw material is hydrolyzed to obtain a hydrolyzed milk raw material and the hydrolyzed milk raw material is membrane filtered, b) if desired one or more of the - is subjected to evaporation and / or chromatography to separate the proteins, sugars and minerals into different fractions, c) one or more fractions obtained in step a) and possibly one of several fractions obtained from step b) and other ingredients to produce a product of the desired composition and sweetness; substantially without adding water; d) optionally concentrating the product obtained in step c) into a concentrate or powder. Process according to Claim 9, characterized in that the membrane filtration in step a) is ultrafiltration. 11. A process according to claim 9 or 10, characterized in that the lactose of the milk raw material is partially hydrolyzed. A process according to claim 11, characterized in that the lactose hydrolysis of the partially hydrolysed milk raw material is continued while the partially hydrolysed milk raw material is separated into fractions containing proteins, sugars and minerals. (M The process according to any one of claims 9 to 12, characterized in that the liquid dairy product is prepared by using reverse osmosis (RO) permeate, nanofiltration (NF) permeate or hydrolysed in the membrane filtration step (s) of the hydrolysed milk raw material. condensation water from evaporation of milk raw material, o A process according to claim 13, characterized in that the liquid used is NF permeate derived from nanofiltration of ultrafiltration permeate of hydrolysed? 35 milk raw material. 15. A lactose-free or low-lactose milk product, characterized in that the milk product is substantially free of added water and comprises two fractions of hydrolysed milk raw material obtained from one or more membrane filtrations of the hydrolyzed milk raw material. Dairy product according to claim 15, characterized in that said fraction is selected from ultrafiltration UF retentate and UF permeate, nanofiltration NF retentate and NF permeate, diafiltration DF retentate and DF permeate, inverse RO retentate from RO and permeate RO. Dairy product according to claim 16, characterized in that it comprises DF retentate. CM δ CM O CM X cc CL σ> o oo LO oo o o CM