U.S. patent application number 17/382560 was filed with the patent office on 2021-11-25 for low-bacteria milk powders with a high whey protein nitrogen index (iv).
The applicant listed for this patent is DMK Deutsches Milchkontor GmbH. Invention is credited to Torben Wiegers.
Application Number | 20210360939 17/382560 |
Document ID | / |
Family ID | 1000005754763 |
Filed Date | 2021-11-25 |
United States Patent
Application |
20210360939 |
Kind Code |
A1 |
Wiegers; Torben |
November 25, 2021 |
LOW-BACTERIA MILK POWDERS WITH A HIGH WHEY PROTEIN NITROGEN INDEX
(IV)
Abstract
A low-bacteria milk powder with a WPNI of at least 2 is
suggested, obtainable by (a) providing a milk component; (b)
optionally, separating the cream from the milk component; (c)
subjecting the milk component from which the cream had been
optionally separated to microfiltration, obtaining a low-bacteria
permeate P1 and a bacteria-contaminated retentate R1; (d) mixing
the permeate with a liquid lipid phase and a solid active agent
phase; (e) optionally, subjecting the mixture obtained in step (d)
to a temperature treatment; and (f) processing the mixture of step
(d) or (e) that had optionally been temperature-treated, obtaining
a dry powder.
Inventors: |
Wiegers; Torben; (Zeven,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DMK Deutsches Milchkontor GmbH |
Zeven |
|
DE |
|
|
Family ID: |
1000005754763 |
Appl. No.: |
17/382560 |
Filed: |
July 22, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15643575 |
Jul 7, 2017 |
|
|
|
17382560 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A23C 9/142 20130101;
A23C 3/02 20130101; A23C 9/1422 20130101; A23C 2210/252 20130101;
A23C 9/13 20130101; A23C 7/04 20130101; A23C 9/1512 20130101; A23C
2210/208 20130101; A23C 9/16 20130101; A23C 9/148 20130101; A23C
1/12 20130101 |
International
Class: |
A23C 9/15 20060101
A23C009/15; A23C 9/142 20060101 A23C009/142; A23C 9/148 20060101
A23C009/148; A23C 9/13 20060101 A23C009/13; A23C 1/12 20060101
A23C001/12; A23C 3/02 20060101 A23C003/02; A23C 7/04 20060101
A23C007/04; A23C 9/16 20060101 A23C009/16 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 27, 2016 |
EP |
16 190 754.8 |
Claims
1.-15. (canceled)
16. A process for the production of low-bacteria milk powders with
a whey protein nitrogen index of at least 2, comprising the
following steps: (a) providing whole milk; (b) separating cream
from the whole milk to obtain skimmed milk and pasteurizing the
skimmed milk to obtain pasteurized skimmed milk; (c) dissolving
solid active agents containing proteins and water soluble active
agents in water or in skimmed milk to provide a liquid phase, (d)
subjecting the pasteurized skimmed milk of step (b) to
microfiltration together with the liquid phase of step (c) to
obtain a low-bacteria permeate P1 and a bacteria-contaminated
retentate R1; wherein the microfiltration is performed with a
ceramic membrane having a pore size in the range of from 1.3 to 1.4
.mu.m; (e) mixing the low-bacteria permeate P1 with a liquid lipid
mixture containing lipids, vitamins and fat-soluble active agents
to obtain a mixture; (f) concentrating the mixture of step (e) to
obtain a concentrated mixture; and (g) drying the concentrated
mixture of step (f), without prior thermal treatment, to obtain the
low-bacteria milk powder.
17. The process of claim 16, wherein microfiltration is performed
at a temperature in the range from about 6 to about 60.degree.
C.
18. The process of claim 16, wherein the permeate P1 obtained after
microfiltration is concentrated to a dry matter content from 30 to
55% by weight before mixing.
19. The process of claim 16, wherein said liquid phase of step (c)
comprises water, said proteins and said water soluble active
agents.
20. The process of claim 16, wherein said liquid phase of step (c)
comprises skimmed milk, said proteins and said water soluble active
agents.
21. The process of claim 16, wherein microfiltration step (d) is
performed at a temperature in the range from about 6 to about
30.degree. C.
22. The process of claim 16, wherein microfiltration step (d) is
performed at a temperature in the range from about 8 to about
20.degree. C.
23. The process of claim 16, wherein microfiltration step (d) has a
flow rate of from 200 to 300 l/m.sup.2h.
24. The process of claim 16, wherein the low-bacteria milk powder
has a whey protein nitrogen index of at least 4.
25. The process of claim 16, wherein the low-bacteria milk powder
has a whey protein nitrogen index of at least 6.
26. The process of claim 16, wherein the mixing step (e) is
conducted at a temperature of about 60.degree. C.
27. The process of claim 16, wherein the drying step (g) is
performed at a temperature in the range of from 180 to 260.degree.
C.
28. The process of claim 16, wherein the milk of step (a) and the
skimmed milk of step (c) are cow's milk.
Description
[0001] This application is continuation of U.S. patent application
Ser. No. 15/643,575 which was filed on Jul. 7, 2017, which claims
priority to EP 16190754.8 filed on Sep. 27, 2016, the entire
contents of both of which are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The invention is in the field of dairy products and relates
to novel low-bacteria milk powders with a high whey protein
nitrogen index (WPNI), alternative processes for their production
and their use, specifically for the nutrition of infants and
toddlers.
STATE OF THE ART
[0003] For the production of low-bacteria milk powders, for
example, already pasteurised skimmed milk with a dry matter content
of about 9% is evaporated to a concentration of about 40%. However,
the concentrates still contain a large quantity of heat-resistant
bacteria and spores, which particularly originates from the maize
silage fed to the cows, and which ends up in the raw milk as a
result of insufficient stable hygiene. For this reason, it has been
required to this date to subject the concentrates to high
temperature treatment before spraying, by means of which the
bacteria and spores are quantitatively destroyed, and as a result
of which a bacteria-free and high-quality product is obtained.
[0004] However, high temperature treatment does not only have an
effect on the bacteria and spores, also the valuable whey proteins
are denatured, either completely or to a very large extent, thus
adversely changing the product in its functionality and nutritional
physiology. Whey proteins are in albumins and globulins; they
particularly include alpha-lactalbumin and beta-lactoglobulin,
serum albumin, proteose peptone and the immunoglobulins. From a
nutritional perspective, whey proteins are high-value milk
constituents, which are specifically used to build muscle, for
example, in protein supplements. While untreated skimmed milk has a
so-called whey protein nitrogen index (WPNI) of above 6,
specifically of 6.1, as a parameter for its whey protein content,
this value falls below 1 during regular ultra high temperature
treatment, which is extremely undesired.
[0005] An alternative for this might consist in performing the
temperature treatment at lower temperatures, for example, at about
70.degree. C. instead of more than 100.degree. C. In fact, products
such obtained have a WPNI of above 5, however, the bacterial
contamination is so high that products are obtained which are, at
best, difficult to market.
[0006] In this context, it is referred to CN 2011 1116530 A1, which
discloses a process for the production of low temperature milk
powder, in the process of which skimmed milk is subjected to
microfiltration at between 40 to 50.degree. C., and filtered
through an inorganic membrane with a pore size from 0.8 to 1.4
.mu.m. Subsequently, the microfiltration product is sterilised at
between 72 and 78.degree. C. and concentrated at between 45 and
75.degree. C. in a falling film evaporator. This is followed by
spray drying, in the process of which the temperature at the inlet
is between 180 and 200.degree. C., and between 80 and 105.degree.
C. at the outlet. The document neither specifies the WPNI of the
resulting products, nor does it contain any information on the
bacterial contamination thereof.
[0007] EP 2679098 A1 (DMK) also discloses a process for the
production of low-bacteria milk powders, wherein a microfiltration
step is used to separate the bacteria; this application, however,
does not contain any reference on the production of powders
enriched with active agents.
[0008] However, the production of milk powders which are
specifically intended for the nutrition of infants and toddlers is
subject to particularly high requirements: regardless of the fact
that a defined whey protein/casein ratio is desired, the products
must be practically bacteria-free in order to not damage the
developing intestinal flora. At the same time, the powders are also
intended to contain a multitude of further active agents and
additives which are beneficial for the nutrition and development of
the child such as, for example, (milk) fats, vitamins,
carbohydrates, peptides or amino acids, long-chain unsaturated
fatty acids and the like. As these substances are typically neither
produced nor stored under sterile conditions, they exhibit a
considerable bacterial count which leads to an undesired
contamination when mixed with the milk component that had just been
decontaminated by microfiltration. This should to be regarded even
more critically, as, particularly, added powder products often
contain pathogenic bacteria such as Cronobacter Sakazakii,
Salmonella Enterica, Staphylococcus Aureus or Listeria
Monocytogenes, which--as is self-evident--must definitely not be
found in baby food.
[0009] The task of the present invention was therefore to provide
milk powders, in fact, both skimmed milk powders and whole milk
powders, which are both bacteria-free or low-bacteria and only
obtained by high temperature processes to this date, and which also
have a high WPNI of at least 2, specifically at least 4, and
particularly from 5.5 to 6 and above as obtained by low temperature
processes, although these parameters had been running in opposite
directions to this date. Fat-soluble and water-soluble additives
are intended to be added to the powders at the same time without
introducing any further bacteria. In addition, the process should
be performable with little technical effort.
DESCRIPTION OF THE INVENTION
[0010] A first subject-matter of the invention relates to a
low-bacteria milk powder with a WPNI of at least 2, which is
obtainable by [0011] (a) providing a milk component; [0012] (b)
optionally, separating the cream from the milk component; [0013]
(c) subjecting the milk component from which the cream had been
optionally separated to microfiltration, obtaining a low-bacteria
permeate P1 and a bacteria-contaminated retentate R1; [0014] (d)
mixing the permeate P1 with a liquid lipid phase and a solid active
agent phase; [0015] (e) optionally, subjecting the mixture obtained
in step (d) to a temperature treatment; and [0016] (f) processing
the mixture of step (d) or (e), which had optionally been
temperature-treated, obtaining a dry powder.
[0017] Surprisingly, it was found that the process of the invention
particularly allows the production of milk powders with additives,
which are admissible for the nutrition of infants and toddlers,
having a high WPNI of at least 2 and up to 7.5, preferably from
about 3.5 to 6, and particularly from about 4 to about 5 at the
same time, and which are still practically bacteria-free, namely
having a bacterial count with respect to both the thermophilic
bacteria and the mesophilic bacteria of 500 maximum, depending on
the processing even of a total count (thermophilic+mesophilic
bacteria) from about 100 to about 500. According to experience,
products are obtained which do not exhibit any pathogenic bacteria
any more.
BRIEF DESCRIPTION OF THE DRAWING
[0018] The present invention will be described in greater detail
with reference to the accompanying drawing which is a flow chart
illustrating the method according to the present invention.
PROCESS
[0019] A further subject-matter of the invention relates to a first
process for the production of low-bacteria milk powders with a WPNI
of at least 2, comprising the following steps: [0020] (a) providing
a milk component; [0021] (b) optionally, separating the cream from
the milk component; [0022] (c) microfiltration of the milk
component of step (a) or (b), from which the cream had been
optionally separated, obtaining a low-bacteria permeate P1 and a
bacteria-contaminated retentate R1; [0023] (d) mixing the permeate
P1 with a liquid lipid phase and a solid active agent phase; [0024]
(e) optional temperature treatment of the mixture obtained in step
(d); and [0025] (f) processing of the mixture of step (d) or (e),
which had optionally been temperature-treated, obtaining a dry
powder.
[0026] Suitable milk components which can be employed as raw
materials in the process are selected from the group consisting of
whole milk, skimmed milk with a fat content of up to 4% by weight,
low-fat milk, pasteurised milk, high temperature treated milk,
ultra high temperature treated milk, whey, fine whey, soured milk
and mixtures thereof.
[0027] Preferably, whole milk or whey is employed. When components
are used which had already been skimmed, step (b) is omitted.
Separation of Cream
[0028] Skimming of the raw milk is preferably performed in heat
exchangers, whereby, specifically, plate heat exchangers have
proved to be particularly suitable. There is a temperature gradient
at the heat exchangers, which, however, is selected such that the
raw milk is heated to a temperature from about 70 to 80.degree. C.
and particularly from about 72 to 74.degree. C. for a residence
time of a minimum of 20 and a maximum of 60 seconds, preferably
about 30 seconds, thus already being pasteurised once.
[0029] The separation of solids ("casein dust") and the skimming of
a fat content of about 4% by weight is usually carried out in a
downstream component, preferably a separator. Said components are
adequately known from the state of the art. Separators of the
company GEA Westfalia Separator GmbH, which allow to perform both
steps individually or together
(http://www.westfalia-separator.com/de/anwendungen/molkereitechn-
ik/milchmolke.html), are widely used in the dairy industry.
Corresponding components have also been disclosed, for example, in
DE 10036085 C1 (Westfalia) and are perfectly known to one skilled
in the art. Therefore, no explanations are needed on how to carry
out these process steps, as they are understood to be part of the
general specialist knowledge.
Microfiltration
[0030] Microfiltration is a process for the separation of
substances. The essential difference between microfiltration and
ultrafiltration is in the different pore sizes and in the different
membrane structure, as well as in the materials and filter
materials involved. Filtration through membranes having a pore size
<0.1 .mu.m is usually referred to as ultrafiltration, while
filtration at pore sizes >0.1 .mu.m is commonly referred to as
microfiltration. In both cases, this concerns purely physical,
i.e., mechanical membrane separation methods which apply the
principle of mechanical size exclusion: all particles in the fluids
which are larger than the membrane pores are retained by the
membrane. The driving force in both separation methods is the
differential pressure between the inlet and the outlet of the
filter area, which is between 0.1 and 10 bar. Depending on the area
of application, the filter area material may consist of stainless
steel, synthetic material, ceramics or textile fabric. Filter
elements appear in different forms: candle filters, flat membranes,
spiral coil modules, bag filters and hollow fibre modules, all of
which are, in principle, suitable within the meaning of the present
invention.
[0031] In dairy technology, there has been the prejudice that the
pore size should have a value of no less than 0.5 .mu.m for the
separation of microorganisms and the fat constituents in the raw
milk. This invention, however, includes the finding that a size
within the range of 1.4 .mu.mand less, preferably 1.3 to 1.4 .mu.m,
is completely sufficient for the production of a Class I raw milk,
if the majority of the thermolabile bacteria has been separated by
corresponding thermal treatment before. Combining this comparably
larger pore size with a microfiltration device which substantially
consists of a ceramic membrane solves the problem of frequent
clogging at the same time.
[0032] Microfiltration may, in principle, be performed in the range
from about 6 to about 60.degree. C. However, there is the prejudice
that the separation of bacteria by means of filtration steps
requires a temperature from at least 55.degree. C. to about
60.degree. C., as only these conditions allow sufficient flow
rates, whereas at temperatures of, for example, 20 to 30.degree. C.
flow rates of only 100 l/m.sup.2h maximum are obtained. Filtration
under warm conditions is also possible in the present process,
however, it has the significant disadvantage that the
heat-resistant bacteria and spores start to grow through the
membranes after about 4 hours filtration time, proliferating in the
permeate. Therefore, a particular advantage within the scope of the
process of the invention is performing the filtration under cold
conditions, i.e., from about 6 to about 30.degree. C. and,
preferably, from about 8 to about 20.degree. C., as this manner
prevents the bacteria from growing through while, surprisingly, a
flow rate from 200 to 300 l/m.sup.2h is still achieved.
Concentration
[0033] A low-bacteria to bacteria-free permeate P1 which is further
processed, and a retentate which is usually discharged due to its
high bacterial contamination are obtained during
microfiltration.
[0034] As an optional measure, this may be followed by a step in
which the permeate is dehydrated and concentrated to a dry matter
content from about 30 to 55% by weight, particularly from about 35
to about 45% by weight. Conventional evaporators are particularly
suitable here.
Mixing
[0035] Mixing may be performed in each conventional stirrer,
provided that it can be heated. The permeate phase, optionally
after concentration, is presented and mixed with a lipid phase and
a powder phase. The lipid phase includes lipids, vitamins and
fat-soluble active agents such as long-chain unsaturated fatty
acids and the like. As the fatty phase easily solidifies, it is
recommended to perform the mixture at temperatures in the range of
about 60.degree. C. In contrast with that, the solid active agent
phase contains proteins and water-soluble substances.
Temperature Treatment
[0036] In order to avoid that the mixed product is undesirably
contaminated by bacteria via the lipid and powder phases again, the
product is usually subjected to temperature treatment. ment. This
may be a common pasteurisation, preferably, however, an ultra high
temperature treatment in which the mixture is heated to
temperatures from 90 to 140.degree. C. for a period from about 1 to
about 5 seconds. Under these conditions the thermal load is strong
enough to reduce the bacterial count according to specification
without denaturing the delicate whey proteins.
[0037] Drying
[0038] After the temperature treatment, the heated concentrate is
transferred to a dry powder. To this end, belt drying, freeze
drying, and spray-drying in particular are suitable. Typically, the
mixtures are supplied to the tower at temperatures from 180 to
260.degree. C. and, preferably, at about 200.degree. C.; after
passing various heat exchanger units, they will leave it at a
temperature in the range from 25 to 35.degree. C.
[0039] The powders typically contain a residual moisture from 1 to
5, preferably 2 to 3% by weight, in which fat is more or less
evenly distributed in the fat-free dry substances in the form of
inclusions, i.e., in the proteins, sugars and salts.
Alternative Processes 1 and 2
[0040] On the one hand, the pasteurisation step following the
mixing step is required to kill the new bacteria that have been
introduced by the additives; on the other hand, this is
particularly energy-intensive so that there had been a particular
interest within the meaning of an additional task to embody the
process of the invention such that any thermal post-treatment
becomes unnecessary.
[0041] Therefore, two process variants are shown in the following,
by means of which the additional task may be solved without leaving
the scope of the common inventive idea. In doing so, particularly
the finding is considered that the lipid phase practically does not
cause any danger of contamination and that only the powder phase
should be regarded critically, and in this it is, particularly, the
phase when, among other things, whey proteins, so-called WPC (whey
protein concentrates), are added.
[0042] A further subject-matter of the invention therefore relates
to a first alternative process for the production of low-bacteria
milk powders with a WPNI of at least 2, comprising the following
steps: [0043] (a) providing a milk component; [0044] (b)
optionally, separating the cream from the milk component; [0045]
(c) providing a liquid phase, containing dissolved active agents;
[0046] (d) common microfiltration of the milk component of step (a)
or (b), from which the cream had been optionally separated, with
the liquid active agent phase of step (c), obtaining a low-bacteria
permeate P1 and a bacteria-contaminated retentate R1; [0047] (e)
mixing the permeate P1 with a liquid lipid phase; [0048] (f)
processing of the mixture of step (d) or (e) that had optionally
been temperature-treated, obtaining a dry powder.
[0049] In contrast to the original process, this variant involves
dissolving the powder fraction in water or in skimmed milk and
adding it to the microfiltration step. In doing so, the bacteria
contained in the powder are removed in this step so that any
thermal post-treatment is not required. A concentration step may,
certainly, also be included in this process.
[0050] A further subject-matter of the invention further relates to
a first process for the production of low-bacteria milk powders
with a WPNI of at least 2, comprising the following steps: [0051]
(a) providing a first milk component; [0052] (b) optionally,
separating the cream from the first milk component; [0053] (c)
providing a skimmed milk component; [0054] (d) microfiltration of
the skimmed milk component, obtaining a whey protein-rich permeate
P1* ("ideal whey") and a casein-rich retentate R1*; [0055] (e)
microfiltration of the milk component of step (a) or (b), from
which the cream had been optionally separated, with the permeate
P1* of step (d), obtaining a low-bacteria permeate P1 and a
bacteria-contaminated retentate R1; [0056] (f) mixing of the
permeate P1, a liquid lipid phase and, optionally, a solid active
agent phase; [0057] (g) processing of the mixture of step (f),
obtaining a dry powder.
[0058] In this process variant, adding the important whey proteins
via the powder phase is omitted. Those are directly produced from a
skimmed milk instead and supplied to the microfiltration step of
the milk component as a further liquid permeate phase 1*. Thus, the
permeate P1 produced this way already contains the whey proteins,
whereby the bacteria contained in the whey protein phase are also
separated via the retentate 1. As described above, the lipid phase
and, if required, also the powder phase can be added to the liquid
phase. Also in this case, no thermal post-treatment is
required.
[0059] It is also possible to combine the alternative processes I
and II.
INDUSTRIAL APPLICATION
[0060] A further subject-matter of the invention relates to the use
of the milk powder of the invention, and of the milk powder
obtained according to the processes of the invention for the
nutrition of infants and toddlers, in particular.
EXAMPLES
Comparision Example V1
[0061] Solid components were removed from raw milk in a manner
known per se, it was pasteurised and skimmed so that a skimmed milk
having a dry matter content of about 9% by weight was obtained.
This mixture was intensely mixed with a lipid phase containing milk
fat, vitamins and lactose at 60.degree. C., as well as with a
water-free powder phase in which whey proteins were present.
Subsequently, the mixture was carefully evaporated to a dry matter
content of about 40% by weight. The concentrate such obtained had a
WPNI of 6.1 and was subjected to high temperature treatment at
120.degree. C. for a period of about 5 seconds, in the process of
which spores and other bacteria were quantitatively destroyed. A
bacteria-free concentrate was obtained that was subsequently
sprayed via a tower. A practically bacteria-free, high temperature
skimmed milk powder with a WPNI of only 1.3 was obtained.
Comparision Example V2
[0062] Example V1 was repeated, however, instead of the high
temperature treatment at 105.degree. C., a temperature treatment at
70.degree. C. was performed for 5 seconds. After spraying, a low
temperature skimmed milk powder with a WPNI of 5.9 was obtained
which, however, was contaminated with bacteria (thermophilic and
mesophilic bacteria, each >1,000) and was, therefore, suitable
for consumption to a limited degree only.
EXAMPLE 1
[0063] Example V2 was repeated, however, before the evaporation
step, the skimmed milk was subjected to microfiltration at
55.degree. C. using a ceramic membrane having a pore size of 1.3
.mu.m. The retentate was discharged, the permeate was mixed with
both the lipid phase and the powder phase as described above, and
evaporated. Subsequently, the concentrate was thermally treated at
about 120.degree. C. for 5 seconds and sprayed. A skimmed milk
powder having a WPNI of 6.8 was obtained, which was practically
bacteria-free (thermophilic and mesophilic bacteria,
each<500).
EXAMPLE 2 (Alternative I)
[0064] Example 1was repeated, however, the powder phase was
dissolved in water and subjected to microfiltration together with
the skimmed milk at 55.degree. C., using a ceramic membrane having
a pore size of 1.3 .mu.m. The retentate was discharged, the
permeate was mixed with the lipid phase as described above, and
evaporated. Subsequently, the concentrate was sprayed without any
further temperature treatment. A skimmed milk powder having a WPNI
of 7.0 was obtained, which was bacteria-free (thermophilic
bacteria<100 and mesophilic bacteria<400).
EXAMPLE 3 (Alternative II)
[0065] Skimmed milk was subjected to microfiltration at 55.degree.
C. using a ceramic membrane having a pore size of 0.1 .mu.m, and a
protein-rich permeate and a casein-rich retentate were obtained.
The permeate was subjected to a second microfiltration step
together with a further untreated skimmed milk fraction using a
ceramic membrane having a pore size of 1.3 .mu.m. The retentate was
discharged, the permeate was mixed with the lipid phase and with a
powder phase which substantially consisted of vitamins and lactose,
as described above, and evaporated. Subsequently, the concentrate
was sprayed without any further temperature treatment. A skimmed
milk powder having a WPNI of 7.0 was obtained, which was also
bacteria-free (thermophilic bacteria<100 and mesophilic
bacteria<400).
[0066] Examples 1 to 3 are further explained in a flow chart (FIG.
1). The abbreviations have the following meanings: [0067]
SEP=separator [0068] MF1=microfiltration with a 1.3 .mu.m membrane
[0069] MF2=microfiltration with a 0.1 .mu.m membrane [0070]
CONC=evaporator/concentrator [0071] MIX=mixer [0072] UHT=ultra high
temperature treatment device [0073] ST=spray tower
* * * * *
References