APPARATUS AND METHOD FOR OBTAINING PROTEIN-ENRICHED FRACTIONS FROM BREAST MILK

Abstract

A device for obtaining protein-enriched fractions from human or animal milk comprises a delipidating unit for reducing a lipid content in the human or animal milk to obtain delipidated milk and a filtering unit for increasing a protein concentration of the delipidated milk to obtain the protein-enriched fraction, comprising a replaceable filter having a nominal molecular weight limit of 2 kDa or more, in particular of 5 kDa or more.

Claims

1. A device for obtaining protein-enriched fractions from human or animal breast milk, comprising a) a delipidating unit for reducing a lipid content in the human or animal breast milk to obtain delipidated milk, wherein the delipidating unit comprises a filter; and b) a filtering unit for increasing a protein concentration of the delipidated milk to obtain the protein-enriched fraction, comprising a replaceable filter having a nominal molecular weight limit of 2 kDa or more.

2. The device of claim 1, wherein the delipidating unit comprises a replaceable filter.

3. The device of claim 2, wherein the filter of the delipidating unit is a glass microfiber filter.

4. The device of claim 2, wherein the filter of the delipidating unit has a pore size of less than 0.5 μm.

5. The device of claim 1, further comprising a pasteurizing unit for pasteurizing the delipidated milk.

6. The device as claim 1, further comprising a suction system and/or a pump system cooperating with the delipidating unit and/or the filtering unit.

7. The device of claim 1, wherein the delipidating unit and the filtering unit are arranged in a closed system wherein the delipidated milk is transferred from the delipidating unit to the filtering unit.

8. The device of claim 1, wherein a reservoir is provided in fluid connection with an output of the delipidating unit and with an input of the filtering unit.

9. The device of claim 8, wherein the reservoir has a volume of 5 L or less.

10. A method for obtaining protein-enriched fractions from human or animal breast milk, comprising: a) reducing a lipid content in the human or animal breast milk by filtration to obtain delipidated milk; and b) increasing a protein concentration of the delipidated milk to obtain the protein enriched fraction by filtering the delipidated milk using a filter having a nominal molecular weight limit of 2 kDa or more.

11. The method of claim 10, wherein the lipid content is reduced by microfiltration, employing a filter having a pore size of less than 0.5 μm.

12. The method of claim 10, comprising the step of pasteurizing the human or animal breast milk prior to reducing the lipid content.

13. The method of claim 10, comprising the step of pasteurizing the delipidated milk.

14. The method of claim 10, wherein a total volume of the protein-enriched fraction obtained from an initial volume of the human or animal breast milk is less than a fifth of the initial volume.

15. (canceled)

16. (canceled)

17. The device of claim 1, wherein the filter of the filtering unit has a nominal molecular weight limit of 5 kDa or more.

18. The device of claim 4, wherein the filter of the delipidating unit has a pore size of less than 0.35 μm.

19. The device of claim 9, wherein the reservoir has a volume of 2.5 L or less.

20. The method of claim 10, comprising filtering the delipidated milk using a filter having a nominal molecular weight limit of 5 kDa or more.

21. The method of claim 11, wherein the lipid content is reduced by microfiltration employing a filter having a pore size of less than 0.35 μm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings used to explain the embodiments show:

[0041] FIG. 1A schematic illustration of an embodiment of the inventive method; and

[0042] FIG. 2 a schematic view of an embodiment of the inventive device.

[0043] In the figures, the same components are given the same reference symbols.

PREFERRED EMBODIMENTS

[0044] The FIG. 1 is a schematic illustration of an embodiment of the inventive method.

[0045] The starting product is human breast milk 1. It flows through a first filter 2 having a pore size of 0.2 μm (microfiltration step 10). The filter 2 is a 3-layer glass microfiber filter (GMF), available e. g. from GE Whatman. The filter 2 separates lipids from the rest of the human milk. Due to the small pore size, milk is also partially sterilized as most of the bacteria have a size of 0.5 μm or more. Nevertheless, it is advisable to pasteurize the starting product (or the intermediate product) due to bacteria with irregular shape, spores, etc.

[0046] Lipids precipitate on the first filter 2, the intermediate product (permeate) 3 is further treated by application of a second filter 4, having a nominal molecular weight limit of 10 kDa (nanofiltration step 20). Thereby, the concentration of proteins in the intermediate product 3 is increased. The result is a protein enriched fraction 5. Experiments have shown that the protein fraction does not precipitate and remains soluble.

[0047] The process is supported by a vacuum applied (as shown in more detail below, in connection with FIG. 2), as indicated by arrow 6. It can be further supported by air pressure. Instead, the driving force for squeezing the liquid through the first filter 2 and/or the second filter 4, centrifugation may be employed.

[0048] Both filters 2, 4 are single-usage. They are changed after each batch to avoid bacterial contamination.

[0049] The process is applied to batches of milk having a volume of 1.5 l (or less). The desired concentration factor is 10, i. e. the total volume of the protein-enriched fraction obtained from an initial volume of the human or animal milk is about a tenth of the initial volume. This yields a protein-enriched fraction with a protein amount of about 10 g/l.

[0050] Laboratory experiments have shown that the delipidation does not cause any significant loss of the total protein content since the filter has a very low unspecific binding capacity, i.e. proteins do not stick to the surface but freely pass the membrane.

[0051] The FIG. 2 is a schematic view of an embodiment of the inventive device. The device comprises a first reservoir 51 with a volume of 1.5 l. It may be provided in the form of a bag. The reservoir is connected to the aforementioned replaceable first filter 2, where a valve 52 is arranged in the flow line between the first reservoir 51 and the first filter 2.

[0052] The output of the filter 2 is connected to a lid 53 of a second reservoir 54. A vacuum source 55 is also connected to the lid 53 in order to support the flow of the milk through the first filter 2, passing a valve 56. The second reservoir 54 has a volume of 0.5 l. It is connected to a third reservoir 57 with a volume of 0.5 l, the aforementioend second filter being arranged in the passage 58 between the second reservoir 54 and the third reservoir 57. A further connection connects the vacuum source 55 to the passage 58, passing another valve 59. This supports the extraction of the filtrate collected in the third reservoir 57 from the intermediate product stored in the second reservoir 54.

[0053] The invention is not limited to the embodiments described above. In particular, the inventive device may be supplemented with further elements to simplify the operation, in particular with respect to the supply and removal of educts and products. The vacuum system may be supplemented or replaced by an air pressure system and/or a pump system, e. g. based on a peristaltic pump. A stirring device, e. g. a magnetic stirrer, may be used to prevent accumulation of proteins on the surface of the membrane of the second filter.

[0054] Details of the components, such as filter materials and/or pore sizes, may be adapted.