U.S. patent application number 14/409196 was filed with the patent office on 2015-06-18 for mineral fortification process and its uses.
The applicant listed for this patent is MASSEY UNIVERSITY. Invention is credited to Shantanu Das, Ashling Ellis, Vikas Ashok Mittal, Harjinder Singh, Aiqian Ye.
Application Number | 20150164123 14/409196 |
Document ID | / |
Family ID | 49769068 |
Filed Date | 2015-06-18 |
United States Patent
Application |
20150164123 |
Kind Code |
A1 |
Mittal; Vikas Ashok ; et
al. |
June 18, 2015 |
MINERAL FORTIFICATION PROCESS AND ITS USES
Abstract
A mineral-protein complex (Complex I) is provided, including a
mineral and a protein, wherein the protein is derived from a milk
source and wherein the milk source has a ratio of protein to
calcium is equal to or above 45:1, and wherein the mineral-protein
complex includes over 1% w/w bound mineral. A mineral-protein
complex (Complex II) is also provided, including an exogenously
added mineral and a protein, wherein the mineral-protein complex is
soluble in a solution at a physiological pH between 6.6 and 6.9 and
the complex includes exogenous phosphorus.
Inventors: |
Mittal; Vikas Ashok;
(Hamilton, NZ) ; Ellis; Ashling; (Hamilton,
NZ) ; Das; Shantanu; (Hamilton, NZ) ; Ye;
Aiqian; (Hamilton, NZ) ; Singh; Harjinder;
(Hamilton, NZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MASSEY UNIVERSITY |
Palmerston North |
|
NZ |
|
|
Family ID: |
49769068 |
Appl. No.: |
14/409196 |
Filed: |
June 20, 2013 |
PCT Filed: |
June 20, 2013 |
PCT NO: |
PCT/NZ2013/000109 |
371 Date: |
December 18, 2014 |
Current U.S.
Class: |
426/74 ; 426/580;
426/587; 426/588; 426/656 |
Current CPC
Class: |
A23V 2002/00 20130101;
A23V 2002/00 20130101; A23C 9/1522 20130101; A23J 3/10 20130101;
A23L 33/19 20160801; A23V 2250/1592 20130101; A23C 9/146 20130101;
A23V 2250/1618 20130101; A23V 2250/5424 20130101; A23L 33/165
20160801; A23C 9/1526 20130101 |
International
Class: |
A23L 1/304 20060101
A23L001/304; A23C 9/152 20060101 A23C009/152; A23L 1/305 20060101
A23L001/305 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 20, 2012 |
NZ |
600756 |
Claims
1. A milk or concentrated milk product, wherein the milk or
concentrated milk product includes a mineral-protein complex, the
complex comprising: a) a mineral; and b) a milk protein the milk or
concentrated milk product has a ratio of milk protein to calcium
equal to or above 45:1, and wherein the mineral-protein complex
includes over 1% w/w mineral bound to protein.
2. The milk or concentrated milk product as claimed in claim 1
wherein the lactating animal is a mammal.
3. The milk or concentrated milk product as claimed in claim 1
wherein the milk source is bovine milk.
4. The milk or concentrated milk product as claimed in claim 1
wherein the ratio of protein to calcium in the milk source is equal
to or above 58:1.
5. The milk or concentrated milk product as claimed in claim 1
wherein the ratio of protein to calcium in the milk source is
approximately between 58:1 and 640:1.
6. The milk or concentrated milk product as claimed in claim 1
wherein approximately 70% w/v of the calcium has been removed from
the milk source.
7. The milk or concentrated milk product as claimed in claim 1
wherein the mineral-protein complex includes between 1% to 20% w/w
mineral bound to protein.
8. The milk or concentrated milk product as claimed in claim 1
wherein the mineral-protein complex includes between 1% to 7% w/w
mineral bound to protein.
9. The milk or concentrated milk product as claimed in claim 1
wherein the mineral is iron.
10. The milk or concentrated milk product as claimed in claim 9
wherein the iron is ferric and/or ferrous salts of iron.
11. The milk or concentrated milk product as claimed in claim 1
wherein the milk protein is selected from casein and whey protein
or combinations thereof.
12. The milk or concentrated milk product as claimed in claim 1
wherein the protein is casein.
13. The milk or concentrated milk product as claimed in claim 1
wherein the mineral-protein complex includes exogenously added
phosphorus.
14. The milk or concentrated milk product as claimed in claim 1
wherein the mineral-protein complex includes an amount of
phosphorus to provide a ratio of protein to phosphorus in the milk
source of up to 8:1.
15. The milk or concentrated milk product as claimed in claim 14
wherein the mineral-protein complex includes an amount of
phosphorus to provide a ratio of protein to phosphorous in the milk
source of up to 6.25:1.
16. The milk or concentrated milk product as claimed in claim 1
wherein the mineral-protein complex is used as a food additive or
ingredient within a nutritional beverage product, food product,
therapeutic/pharmaceutical composition or animal feed
composition.
17. A method of manufacturing a milk or concentrated milk product,
wherein the milk or concentrated milk product includes a
mineral-protein complex including a mineral and a milk protein, and
wherein the milk or concentrated milk product has a ratio of
protein to calcium equal to or above 45:1 and wherein the
mineral-protein complex includes over 1% w/w bound mineral, the
method comprising the step of: a) adding the mineral to the milk or
concentrated milk product.
18. The method as claimed in claim 17 wherein the milk or
concentrated milk is in liquid form and selected from the group
consisting of whole milk, skimmed milk, low lactose milk,
ultrafiltration retentate concentrated milk and combinations
thereof.
19. The method as claimed in claim 17 wherein the milk is stirred,
or in case of powder source, is dissolved in an amount of water,
and mixed at a temperature between 2-95.degree. C.
20. The method as claimed in claim 17 wherein the method includes
removing an amount of calcium from the milk source.
21. The method as claimed in claim 20 wherein the amount of calcium
removed from the milk source utilises an ion exchange step.
22. The method as claimed in claim 21 wherein the ion exchange step
utilises a weakly acidic cation exchange resin of K.sup.+ form.
23. The method as claimed in claim 21 wherein the amount of resin
used is 0.1-80% w/v.
24. The method as claimed in claim 22 wherein the amount of resin
used is 0.1 to 50% w/v.
25. The method as claimed in claim 17 wherein the method includes
reducing the amount of calcium in the milk source to a ratio of
protein to calcium equal to or greater than 58:1.
26. The method as claimed in claim 17 wherein the method includes
reducing the amount of calcium in the milk source to a ratio of
protein to calcium of approximately 106:1.
27. The method as claimed in claim 17 wherein the method includes
removing the amount of calcium in the milk source by at least 50%
w/w and up to 100% w/w of the calcium from the milk source.
28. The method as claimed in claim 17 wherein the pH is maintained
between 6.0 to 8.5 using at least one pH regulator.
29. The method as claimed in claim 17 wherein the pH is maintained
at approximately 6.5 to 7.5.
30. The method as claimed in claim 17 wherein the calcium is
removed whilst retaining the temperature between approximately
2-10.degree. C.
31. The method as claimed in claim 17 wherein the method includes
adding phosphorus to the milk or concentrated milk.
32. The method as claimed in claim 17 wherein phosphorus is added
to the milk or concentrated milk to provide a ratio of protein to
phosphorus between 64:1 to 8:1.
33. The method as claimed in claim 17 wherein phosphorus is added
to the milk or concentrated milk to provide a ratio of protein to
phosphorus between 30:1 to 8:1.
34. The method as claimed in claim 17 wherein the temperature is
maintained between 2-10.degree. C. when the mineral is added.
35. The use of a milk or concentrated milk as claimed in claim 1
for the manufacture of a fortified product, to help an animal
achieve the dietary mineral intake required for optimum health.
36. An ingredient for use in fortified products to help an animal
meet its mineral requirements for optimum health, the ingredient
consisting of a milk or concentrated milk as claimed in claim
1.
37. The ingredient as claimed in claim 36 wherein the mineral is
selected from iron, zinc, copper, manganese, magnesium, selenium,
chromium, or combinations thereof.
38. (canceled)
39. (canceled)
40. A non-micellar mineral-protein complex comprising: an
exogenously added mineral and a protein, wherein the
mineral-protein complex is soluble in a solution at a physiological
pH between 6.6 to 6.9; and the complex includes exogenous
phosphorus.
41. The complex as claimed in claim 40 wherein the protein is a
phosphoprotein.
42. The complex as claimed in claim 41 wherein the phosphoprotein
is casein.
43. The complex as claimed in claim 40 wherein the casein
containing compound is sodium caseinate, potassium caseinate,
ammonium caseinate, lactic casein and/or derivatives or fractions
of caseins.
44. The complex as claimed in claim 40 wherein the mineral is
iron.
45. The complex as claimed in claim 40 wherein the iron is ferric
iron.
46. The complex as claimed in claim 40 wherein the mineral-protein
complex includes above 1% w/w mineral bound to protein.
47. The complex as claimed in claim 40 wherein the mineral-protein
complex includes between 1% to 20% w/w mineral bound to
protein.
48. The complex as claimed in claim 40 wherein the mineral-protein
complex includes between 1% to 9% w/w mineral bound to protein.
49. A method of manufacturing a mineral-protein complex including
an exogenously added mineral and a protein, wherein the
mineral-protein complex is soluble in a solution at a physiological
pH between 6.6 to 6.9 the method comprises: a) adding exogenous
phosphorus to the protein; and b) adding the exogenous mineral to
the protein to form the complex.
50. The method as claimed in claim 49 wherein the protein used is a
casein containing compound.
51. The method as claimed in claim 49 wherein the casein containing
compound used in the method is sodium caseinate, potassium
caseinate, ammonium caseinate, lactic casein and/or derivatives and
fractions of caseins.
52. The method as claimed in claim 49 wherein the method including
dissolving the protein in water to form a solution.
53. The method as claimed in claim 49 wherein the protein
concentration in the solution is configured to be between 1-12.5%
w/v.
54. The method as claimed in claim 49 wherein the phosphorus is
added to the protein solution prior to the addition of the mineral
component.
55. The method as claimed in claim 49 wherein the source of
phosphorus is K.sub.2HPO.sub.4.
56. The method as claimed in claim 49 wherein an amount of
phosphorus is added to the protein solution such that the ratio of
protein to phosphorus is between 5:1 to 130:1.
57. The method as claimed in claim 49 wherein the ratio of protein
to phosphorus is between 7:1 to 90:1.
58. The method as claimed in claim 49 wherein the mineral is added
to the mixture resulting from step a).
59. The method as claimed in claim 49 wherein the mineral is
iron.
60. The method as claimed in claim 59 wherein the iron is ferric
iron.
61. The method as claimed in claim 59 wherein the ratio of protein
to iron is between 200:1 to 2:1.
62. The method as claimed in claim 59 wherein the ratio of protein
to iron is between 100:1 to 7:1.
63. The method as claimed in claim 59 wherein after step b), the
mineral component, protein and phosphorus are mixed for a period of
time at 2-10.degree. C.
64. A use of a mineral-protein complex as claimed in claim 40 in
the manufacture of a fortified product to help an animal achieve
its dietary mineral intake required for optimum health.
65. The use as claimed in claim 64 wherein the mineral used is
selected from iron, zinc, copper, manganese, magnesium, selenium or
chromium.
66. An ingredient for use in fortified products, to help an animal
achieve the dietary mineral intake required for optimum health, the
ingredient consisting of a mineral-protein complex as claimed in
claim 40.
67. The ingredient as claimed in claim 66 wherein the mineral is
selected from iron, zinc, copper, manganese, magnesium, selenium,
chromium, or combinations thereof.
68. (canceled)
69. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates to mineral-protein complexes
and their uses as fortificants.
BACKGROUND ART
[0002] Essential metals (otherwise known as `minerals` in nutrition
science) iron, zinc, copper, manganese, magnesium, selenium,
chromium are needed for many body functions, and are required by
the body in sufficient quantities to meet its demands in order to
maintain optimum health. These minerals are found in varying levels
in different foods according to the source (i.e. magnesium from
cereal products, iron and zinc from red animal muscle tissue, etc)
and production location (i.e. high or low selenium soils) of that
product. Economic, religious and ethical constraints, or simple
personal food preferences, may result in certain populations or
individuals consuming a diet that does not provide adequate levels
of certain essential minerals for optimum health.
[0003] Fortification technologies provide opportunities to add an
essential mineral(s) to products that would not usually be
significant sources of the mineral(s). This means that a wider
range of food products can contribute to the total dietary intake
of the mineral(s), and thus provides consumers with alternative
means of achieving the intakes required for optimum health.
However, it can be technologically challenging to add minerals to
foods, especially minerals that tend to readily interact with other
food components, such as iron. This is particularly difficult in
liquid food formats, where processing steps such as heating are
involved. At present, fortifying foods or beverages with a
physiologically-relevant level of bioavailable iron without the
development of undesirable taste (metallic) and appearance (colour
changes which can occur either during processing or storage) is a
significant challenge.
[0004] The natural forms of iron in the diet are haem and non-haem.
Haem iron is a constituent of haemoglobin, the molecule that is
responsible for carrying oxygen in the blood of most animals. For
this reason, it is solely of animal origin, and is found in
significant levels in meats such as beef, lamb and pork. It is
highly bioavailable, due to its solubility in the alkaline
conditions of the duodenum and jejunum (West and Oates, 2008),
which allows it to be readily absorbed by the body. However,
despite its high bioavailability, its animal origin presents
difficulties for vegetarian and vegan populations.
[0005] Non-haem iron is naturally found in plant sources in either
the ferrous or ferric form, and has a lower bioavailability due to
low solubility at intestinal pH. The ferrous form of iron can be
easily oxidised to its ferric state in the presence of oxygen, as
is commonly encountered under processing conditions. Ferric salts
of iron are precipitated as ferric hydroxide at pH>3, making
them unavailable for absorption in the duodenum (Conrad and
Umbreit, 2002).
[0006] The general dilemma in iron fortification of liquid and
semi-solid foods (especially milk and dairy products) has been the
issue of product stability. Traditional fortificants like ferrous
sulphate or elemental iron are not suitable for the mass iron
fortification of a range of food products due to lack of
physico-chemical compatibility. Nutritional programmes involving
iron fortification, that target young children and women, have
attempted to fortify milk and dairy products due to their high
nutritional value.
[0007] However, the reactivity of soluble (bioavailable) iron
sources with constituents in liquid milk (caseins, fat and calcium
in milk) has been shown to decrease the bioavailability of Fe both
in vitro and in vivo studies in the past (Edmondson, 1971).
[0008] Reactivity of the iron sources also can translate into
unpalatable products which is a further disadvantage. This reason
has been the main deterrent in using milk as a vehicle for iron
fortification.
[0009] The general consensus is that greater bioavailability is
found in iron ingredients which have increased solubility at the
duodenal pH (6.6-6.9). Compounds like ferric pyrophosphate, which
are poorly soluble, have been used for fortification of dried milk
and dairy products. However, its reported bioavailability is highly
variable (Hurrell, 2002).
[0010] Chelated forms of iron have emerged as a convenient choice,
as they are soluble at a physiological pH and are therefore
available for absorption within the body. As the iron is bound to a
ligand, it is prevented from interacting with other compounds
present in the food matrix. However, despite their benefits from a
functional and bioavailability perspective, chelates such as sodium
ferredetate and ferrous bisglycinate are not presently used as a
mass fortificant because of their reactivity at high temperatures
(especially in the presence of polyphenols), as well as a high cost
of raw materials.
[0011] An alternative that has been explored is to chelate iron
with protein, such as casein, which is naturally present in milk.
However, earlier commercial and research applications of binding
iron to milk proteins (e.g. WO 2000/51446) have not been successful
because of the formation of insoluble precipitates at higher levels
of iron addition (>8 mM). The levels of iron loading in this
earlier patent was therefore unable to exceed 1% of the dried
powder, which represents a ratio of casein to iron in the powder of
approximately 92:1 assuming the protein content to be 92% of the
said powder. Such products cannot be applied to beverages like
milk, fruit juices etc because they could generate haze when added
to transparent beverages and solutions.
[0012] In another example Raouche and co-workers added 20 mM iron
(3.62% of milk protein Dry Matter (DM) basis) to milk at chilling
temperatures, wherein the iron was bound to the caseins in micellar
form. More than 90% of the added iron was bound to the caseins in
the colloidal phase of milk. However, when milk with added iron was
heated at 90.degree. C. for 10 min precipitates were observed
(Raouche et al., 2009).
[0013] All references, including any patents or patent applications
cited in this specification are hereby incorporated by reference.
No admission is made that any reference constitutes prior art. The
discussion of the references states what their authors assert, and
the applicants reserve the right to challenge the accuracy and
pertinency of the cited documents. It will be clearly understood
that, although a number of prior art publications are referred to
herein, this reference does not constitute an admission that any of
these documents form part of the common general knowledge in the
art, in New Zealand or in any other country.
[0014] Throughout this specification, the word "comprise", or
variations thereof such as "comprises" or "comprising", will be
understood to imply the inclusion of a stated element, integer or
step, or group of elements integers or steps, but not the exclusion
of any other element, integer or step, or group of elements,
integers or steps.
[0015] It is an object of the present invention to address the
foregoing problems or at least to provide the public with a useful
choice.
[0016] Further aspects and advantages of the present invention will
become apparent from the ensuing description which is given by way
of example only.
DISCLOSURE OF THE INVENTION
[0017] In the broadest aspect, the present invention relates to the
provision of improved mineral protein complexes. Advantages of the
complexes formed may include an improved solubility and heat
stability, ease and lowered costs in their manufacturing, and wider
applications in food, beverage and therapeutic products.
[0018] The advantages of the mineral protein complexes, methods of
manufacture and uses described herein will become more apparent
with the ensuing description. Two embodiments of the present
invention are outlined below under the Headings "Complex I" and
"Complex II". It should be appreciated that the preferred
embodiments of each complex may be utilised by the other complex,
and vice versa.
[0019] In the following disclosure the contents of calcium, iron
and phosphorus have been described as ratios with respect to the
protein content in the samples. To further clarify; in the case of
normal cow milk there is a concentration of 32 g protein, 1000 mg
phosphorus and 1200 mg of calcium per litre of milk, which will
achieve a ratio of 26:1 (protein:calcium) and 32:1
(protein:phosphorus) respectively. A reduction in the calcium
content will increase this ratio (protein/calcium), while an
increase in the phosphorus will decrease this ratio
(protein:phosphorus). Milk contains negligible amounts of iron and
the external addition of iron is represented in terms of
protein:iron ratio. Understandably, an increase in the
concentration of iron will decrease the ratio of protein:iron.
[0020] Wherever low calcium is said it means a protein/calcium
ratio in milk or sources of milk protein with protein/calcium ratio
greater than 58:1 or a casein/calcium ratio greater than 45:1 (cow
milk contains 32 g protein in which casein constitutes 25 g in 1
litre of milk).
Complex I
[0021] According to one aspect of the present invention there is
provided a mineral-protein complex, the complex including [0022] a)
a mineral component; and [0023] b) a protein characterised in that
the protein is derived from a milk source and wherein the milk
source has a ratio of protein to calcium equal to or above 45:1 and
wherein the mineral-protein complex includes over 1% w/w bound
mineral.
[0024] According to a further aspect of the present invention there
is provided a method of manufacturing a mineral-protein complex as
discussed above,
the method characterised by the step of: [0025] a. adding a mineral
to a milk source with a ratio of protein to calcium equal to or
above 45:1 such that the mineral-protein complex includes over 1%
of bound mineral.
Advantages of Complex I
[0026] The inventors found that by using a milk source with a low
level of calcium for example, as outlined in FIG. 1, an improved
fortification complex may be obtained compared to the prior art,
particularly with regards to heat stability of the complex and the
ability to load equal or higher amounts of the mineral whilst
retaining stability and bioavailability.
[0027] It should be emphasised that the present invention may
utilise a milk source with a low level of calcium which has been
already provided, or may result from processing to remove calcium
from a milk source. There are well-known techniques available to
remove calcium from a milk source, such as ion exchange process,
membrane processes, their combination and the like.
[0028] Without wishing to be bound by theory, the inventors
consider the significant advantages of the present invention are
arising because the calcium, which normally binds with high
affinity to the milk proteins, is being removed thus opening up
binding sites for a mineral(s) to bind to the milk proteins.
Therefore, it is possible that the ability to bind higher amounts
of mineral(s) without certain disadvantages such as precipitation,
for example, may be possible.
[0029] To provide an example using the method as described herein,
the inventors were able to achieve an optimum ratio of protein/iron
of 19.5:1 (equating to about 5.1% w/w loading of iron to protein in
complex I), although higher levels of iron loading were also able
to be achieved. Additionally, the complex was found to be stable in
a soluble form at these ratios and mineral loading, and it is
considered this stability and higher loadings will be beneficial
for inclusion in food and beverage products.
[0030] This is a significant improvement over loading of iron and
stability as reported in WO 2000/5144, namely only 1 w/w iron
loading in final powder (expected protein/iron ratio 92:1). In the
current process, the inventors were able to achieve an optimum
protein/iron 19.5:1 and still provide a very stable product, unlike
as reported in Raouche et al, 2009. This improvement in the higher
loading of the mineral and stability of the complex is thought to
be attributed to the reduced calcium levels in the complex.
[0031] The invention may help to overcome problems associated with
fortification of milk products including precipitation of protein,
decreased stability particularly at the high temperatures
experienced with processing of liquid and semi-solid food products
and limitations to the amount of mineral that can be added during
the fortification process. Furthermore, the preparation of these
soluble mixes may enable iron fortification to liquid beverages,
without affecting the shelf stability of liquid beverages.
[0032] Additionally, the present method results in a complex which
is soluble at physiological pH, unlike many of the prior art
documents. In the past when ferric iron has been bound to casein
through a precipitation process, it has been found that the
bioavailability of the iron from such complexes is similar to that
of ferrous sulphate (Zhang and Mahoney, 1989, Kim et al., 1995),
which is considered to have very good bioavailability for a
non-haem iron source. Given the nature of the present invention is
similar in terms of the binding of a mineral to casein, it is
expected to demonstrate bioavailability of a similar level.
[0033] A further advantage of this method is that it may use
inherently available proteins in milk (such as casein). This may
help to reduce manufacturing time and resources needed and so
forth.
[0034] A further advantage of this process (and its resulting
complex) is that the methods which may be used to remove calcium
have no substantial effect on other constituents in the milk, which
are left substantially unchanged. Again, this helps to keep the end
product closer to the original milk composition.
Preferred Embodiments of Complex I
[0035] Throughout this specification the term milk source should be
taken as meaning whole milk or a component thereof sourced from a
lactating animal.
[0036] Preferably, the lactating animal is a mammal. This is
because, as will be outlined further below, all mammals have casein
(a particularly preferred protein) in their milk.
[0037] Preferably, the milk source is from cow's milk.
Alternatively, the milk source could be from human, sheep, buffalo,
goat or another mammal that has relatively high levels of casein in
the milk source or mixtures thereof. For example, casein makes up
approximately 80% of proteins in cow's milk and buffalo milk, and
about 20-50% of the proteins in human milk.
[0038] Throughout this specification the term protein should be
taken as meaning any polypeptide molecule that has been either
synthetically or naturally derived.
[0039] Throughout this specification, the phrase "low level of
calcium" should be taken as meaning a protein/calcium ratio greater
than that in normal milk. Normal milk has approximately 1200 mg of
calcium constituting a protein/calcium ratio of 26.6:1.
[0040] Therefore, the protein/calcium ratio in the milk source is
equal to or above 45:1, and this clearly constitutes a low level of
calcium compared to what is present in normal milk.
[0041] Preferably, the protein/calcium ratio in the milk source is
greater than 58:1. More preferably, the protein/calcium ratio in
the milk source is approximately between 58:1 and 640:1.
[0042] In this embodiment the protein/calcium ratio is, preferably
between 70:1 to 95:1, as an example 83:1.
[0043] This represents a significant decrease (approximately a
decrease of 70%) of calcium present in the milk compared to milk
which has not had calcium removed.
[0044] More preferably, at least 50% of the calcium is removed from
the milk source.
[0045] Most preferably, approximately 70% of the calcium (w/v) has
been removed from the milk source.
[0046] The inventors identified that removing 70% of the calcium
from milk may be sufficient to solubilise more than 95% of the
colloidal milk proteins (e.g. casein micelles). This improved the
heat stability and physico-chemical properties of the milk proteins
favouring the soluble complex formation.
[0047] Throughout this specification, the term mineral should be
considered any mineral which may be of physiological benefit to an
animal (such as a human) and may be delivered to an animal via the
fortified mineral-protein complex. For example, typical minerals of
physiological value considered most applicable to the present
invention include those such as calcium, sodium, potassium, iron,
zinc, copper, manganese, selenium or chromium.
[0048] In the context of the present invention (for both complex I
and II), it should be understood that the fortification process
relies on addition of at least one exogenous mineral. In agreement
with the general understanding in the industry, and within the
context of the present invention, the term exogenous should be
understood to mean that the mineral is externally added and is not
provided endogenously by the protein. It should also be understood
that within the mineral-protein complex, an amount of endogenous
mineral may also be present. To provide an example, endogenous
calcium may still be bound to the casein. Yet in addition, the
protein complex may be fortified with exogenously added iron.
[0049] Preferably, the mineral is iron.
[0050] The preference to fortify the complex with iron comes back
to the clear need to provide soluble inexpensive fortified iron
complexes and to address the problems as outlined previously.
However, the inventors acknowledge that the present concept may be
used to fortify a complex with other minerals beyond iron, such as
zinc, copper, manganese, selenium or chromium. Potentially
inadequate intakes of these minerals in animals present
opportunities to utilise the present invention in a similar
mechanism. One skilled in the art would appreciate other minerals
may be substituted for iron and also bind to many proteins to form
a complex.
[0051] Preferably, the iron is ferric and/or ferrous salts of iron.
For example, ferric chloride may be used. Alternative ferric iron
sources such as ferric sulphate pentahydrate, ferric phosphate,
ferric pyrophosphate, etc. may be used without departing from the
scope of the invention. Ferric iron will bind more efficiently to
caseins than ferrous iron owing to the binding characteristics of
their respective iron oxidation states.
[0052] However, it should not be ruled out that ferrous iron may be
used in the present invention.
[0053] Preferably, the protein from the milk source is selected
from caseins, whey proteins and their individual fractions or
mixtures of the same.
[0054] More preferably, the protein is casein.
[0055] A protein of particular interest is casein, which is
inherently present in milk. In US 2003/0206939, it is outlined how
various micronutrient components (e.g. minerals, enzymes, vitamins)
which have affinity to casein proteins as a result of positive and
negative groups along the length of the casein polypeptide
chain.
[0056] Although casein represents a particularly preferred protein
to be used in the present invention (either naturally or
synthetically derived), it should be understood that many other
proteins from a milk source may be used with Complex I.
[0057] It is known that casein binds calcium from milk to form
colloidal casein micelles.
[0058] The inventors have identified that an advantage of removing
calcium from milk is it may help to break down the casein micelle
structure and thus allow solubilisation of individual caseins which
become available to bind to the mineral (e.g. iron) once added.
[0059] There are many well-known techniques available to remove
calcium from a milk source. On the other hand, many have tried to
fortify milk with micronutrient components such as iron (GAUCHERON,
F. 2000. Iron fortification in dairy industry. Trends in Food
Science & Technology, 11, 403-409.). However, until now it has
not been thought to actually combine these two principles to arrive
at a significantly improved complex.
[0060] The mineral-protein complex includes above 1% w/w bound
mineral.
[0061] More preferably, the mineral-protein complex includes
between 1% to 20% w/w bound mineral.
[0062] Even more preferably, the mineral-protein complex includes
between 4 to 8% w/w bound mineral.
[0063] For both Complex I and II (discussed further below), the
resulting complex was found to be very stable and soluble, and most
likely will portray significantly improved functionality when
incorporated into food and beverage products than the prior art
complexes. Therefore, providing fortified complexes with higher
loading of minerals such as iron (even at 1% w/w) represents a
significant improvement over the prior art.
[0064] Also, these embodiments regarding % w/w of mineral bound
reflect that although amounts lower than 1% w/w may be beneficial
in some circumstances, a higher concentration of bound mineral may
be much more commercially and physiologically useful.
[0065] There is a balance to be optimised with higher mineral
fortification of the complex and ensuring stability of the complex.
Indeed, the inventors have exemplified binding of 7% w/w loading
(see Examples 3-5 with loading of 25 mM iron) while still ensuring
the complex remains stable. It is quite possible that
concentrations of up to 20% w/w mineral bound to the complex may be
achieved. It should be understood that, depending on the
application of the mineral-protein complex, different amounts of
mineral bound to the complex may be developed for use. The
inventors foresee that a 4% w/w loading of mineral is most
applicable towards various commercial uses, such as in milk powder
fortified with iron.
[0066] Preferably, the mineral-protein complex includes additional
phosphorus. The normal ratio of protein to phosphorus in milk is
32:1.
[0067] Preferably, the protein complex includes an amount of
phosphorus which may decrease this ratio of protein:phosphorus to
8:1, or 6.25:1 for casein:phosphorus.
[0068] Below the above ratio, the inventors believe precipitation
of proteins along with iron and phosphorus may occur.
[0069] A discussion of the advantages of adding phosphorus (and
proposed mode of action) is outlined further in the next section.
Any phosphorus containing food grade compound may be used with the
present invention. However, one such example is
K.sub.2HPO.sub.4.
[0070] Preferably, the complex of the present invention is used as
a food additive or ingredient within a nutritional beverage
product, food product, therapeutic/pharmaceutical composition or
animal feed composition.
Preferred Method of Manufacture of Complex I
[0071] A particularly preferred method of manufacture of Complex I
is shown schematically in FIG. 1.
[0072] Preferably, the milk source is a milk in liquid form
inclusive of whole milk, skimmed milk, low lactose milk,
ultrafiltration retentate concentrated milk and or mixtures
thereof.
[0073] Alternatively, the milk source is one from powder form.
[0074] Types of milk powder which may be used include milk protein
concentrate powder (MPC), calcium depleted MPC powder, whole milk
powder, skim milk powder (SMP) (or lactose reduced SMP), or
phosphocaseinate powder. The protein concentration of the resulting
milk source solution may vary from 1-12.5%.
[0075] Preferably, the milk is stirred, or in case of powder source
is then dissolved, in an amount of water and mixed at a temperature
between 2-95.degree. C. Most preferably, the temperature is between
2-10.degree. C., for reasons which will become apparent later.
[0076] The mixing step may last about 30 minutes.
[0077] After mixing, calcium may be removed if necessary to provide
the low level of calcium as required.
[0078] One may start with a low-level calcium milk source, or may
prepare such from a milk source initially with normal levels of
calcium, as discussed further below.
[0079] Preferably, the method includes removing the calcium from
the milk source using ion exchange.
[0080] In the ion exchange process, Na.sup.+, K.sup.+ or H.sup.+
form of resin may be used individually or in a mixed form. A strong
acidic cation exchange resin, or a mixture of strong and weak forms
may be used. Most preferably, the resin is a weakly acidic cation
exchange resin of K.sup.+ form.
[0081] An advantage of ion exchange is that removal of calcium by
this process may help to result in minimum alteration in the
quantities of minerals present in milk other than calcium. This may
play an important role in the creation of soluble complexes.
[0082] Preferably, the amount of resin used is 0.1-80% w/v.
[0083] More preferably, the amount of resin used is 0.1 to 50%
w/v.
[0084] Preferably, the method includes reducing the amount of
calcium in the milk source to a protein/calcium ratio to be greater
than 58:1.
[0085] More preferably, the method includes reducing the amount of
calcium in the milk source to a protein to Ca ratio of
approximately 106:1.
[0086] Preferably, the method includes removing the amount of
calcium in the milk source by at least 50% w/w and up to 100% w/w
of the calcium from the milk source. Most preferably, the method
includes removing the amount of calcium in the milk source to about
70% of the initial quantity.
[0087] Calcium removal may be monitored through a number of ways.
One such example is a titration method using Patton Reeder reagent
(Patton and Reeder, 1956).
[0088] To stop the ion exchange process, ion exchange resins in
contact with milk may be removed via clarification. A wide variety
of steps may be used to stop the ion exchange process, including
centrifugation and filtration. Other methods may be used without
departing from the scope of the present invention.
[0089] Preferably, the pH is maintained between 6.0 to 8.5 using at
least one pH regulator. More preferably, the pH is maintained at
approximately 6.5 to 7.5.
[0090] The pH may need to be adjusted between 6.5 and 7.5 after ion
exchange due to the change in calcium levels. To increase and
decrease the pH, a pH regulator such as sodium hydroxide or
hydrochloric acid or like, respectively, may be used.
[0091] Additionally certain minerals which may be added, such as
ferric chloride, are highly acidic. These may precipitate the
proteins if they are added to the milk protein. Therefore,
maintaining this preferred pH will therefore help to prevent
precipitation of proteins from the solution.
[0092] Unlike the prior art, the present invention allows
inexpensive ferric compounds to be used and be soluble at a pH well
above 3. Therefore, the present invention provides a soluble
iron-protein complex which may be advantageously retained at a
physiological pH (6.5-7.5) which renders the complex to be
available for absorption within the body. The process could also be
performed anywhere between pH 8.5 and 6.3 with similar results.
[0093] Preferably, the calcium is removed whilst retaining the
temperature between approximately 2-10.degree. C.
[0094] Maintaining the temperature within this range has a number
of advantages. It helps to prevent bacterial growth, and helps to
control the rate of ion exchange. Also, .beta.-casein, a major
casein in milk, exists as a monomer at these temperatures.
Therefore, this temperature may help to release the calcium from
the micelles during the ion exchange process. Calcium phosphate is
more soluble at lower temperature which may aid in ion
exchange.
[0095] In the case of adding minerals such as iron, removing
lactose may allow increasing the concentration of mineral in the
complex.
[0096] A decrease in the ratio of protein:iron may be achieved by
addition of phosphorus source such that the above ratio decreased
from 28:1 (without phosphorus addition) to 19.5:1 (with phosphorus
addition of 1000 mg/litre of milk), with further improvements
expected.
[0097] As discussed previously, a protein:iron ratio of 28:1
equates to approximately 5.1% w/w binding of iron to the
protein.
[0098] Preferably, the method includes an optional step of
phosphorus addition to the low calcium milk source. In one
embodiment, the phosphorus containing compound is an orthophosphate
like K.sub.2HPO.sub.4. However alternative compounds are clearly
envisaged, as discussed further in this specification (Complex
II).
[0099] Preferably, additional phosphorus is added to the milk
source solution.
[0100] More preferably, phosphorus is added to the milk source to
provide a protein:phosphorus ratio between 64:1 to 8:1.
[0101] The inventor found this level of phosphorus was beneficial
to improve increased iron (or other mineral) loading and complex
solubilisation.
[0102] Most preferably this protein:phosphorus ratio is
approximately between 32:1 to 8:1.
[0103] In the embodiment where iron-protein complexes are to be
formed, the method includes slowly adding an iron containing
compound to the calcium depleted milk source. One such iron
containing compound is FeCl.sub.3.6H2O. A solution such as 0.01 to
0.5 M FeCl.sub.3.6H2O may be used for this process.
[0104] Minerals, such as ferric chloride, which may be added to
form the fortified complex may be highly acidic. Subsequently,
alterations in the milk pH may precipitate the proteins if they are
added to the milk source. Therefore, maintaining a preferred pH
between 5.8 to 10.5 (preferably 6.5 to 7.5) may help to prevent
precipitation of proteins from the solution.
[0105] Preferably, the temperature is maintained between
2-8.degree. C. when the mineral (e.g. iron) is added. This again
helps to maintain the protein (e.g. casein) as monomers to promote
complex formation with the mineral.
[0106] Once the mineral is added, the resulting solution may be
mixed for a period of time such as 30 minutes at between
2-8.degree. C. This mixing may help to promote complex
formation.
[0107] The solution may be clarified to remove precipitated or
unwanted matter. The solution may be formulated into a powder by
concentration and any suitable drying process, such as spray
drying. Powder forms of the complex are considered to be
particularly useful to increase shelf life compared to keeping the
complex stored as a solution. Furthermore, powders may be more
easily handled and are versatile when used for the addition to
food/beverage and/or pharmaceutical purposes.
[0108] It should be appreciated that the complex may instead be
kept as a solution until further use.
Complex II
[0109] According to a further aspect of the present invention there
is provided a mineral-protein complex including an exogenously
added mineral and a protein, wherein the mineral-protein complex is
soluble in a solution at a physiological pH between 6.6 and 6.9
characterised in that the complex includes exogenous
phosphorus.
[0110] According to a further aspect of the present invention there
is provided a method of manufacturing a mineral-protein complex as
discussed above,
wherein the method is characterised by the steps of [0111] a.
adding exogenous phosphorus to a protein; and [0112] b. adding an
exogenous mineral to the protein to form the complex.
Summary of Advantages of Complex II
[0113] After developing the invention and advantages of Complex I,
the inventors then devised an alternative embodiment as provided in
Complex II which provided a range of different advantages and very
positive results.
[0114] Similar to the advantages of Complex I, the method of
preparing Complex II is relatively easy and cost effective compared
to prior art techniques. However, as there is no need to remove
calcium from milk, the present method may present an even simpler
process than that of Complex I. This is primarily because the
process may utilise proteins such as sodium caseinate which are
purchased or otherwise provided for in a pre-purified state.
[0115] Compared to the prior art, Complex II is a significantly
improved mineral fortification complex as it is again highly
soluble and is not prone to precipitation or aggregation. These are
important advantages as they allow for easier storage and use for
various commercial products. Similar to Complex I, Complex II is
stable at physiological pH, unlike many of the prior art complexes.
Furthermore, a higher concentration of mineral bound to casein may
be achieved in the final powder e.g. final ingredient could contain
8% by wt of iron, and again these preliminary results are expected
to be improved upon. This is a major improvement to prior art
complexes which report loading of only 1% w/w iron in powder form
(protein/iron 92:1).
[0116] A higher concentration of mineral such as iron allows the
complex to be used for a wide variety of uses. For instance, it may
allow a greater dose of iron in a lower volume/mass of a food
product.
[0117] Many other advantages of these complexes are listed and
discussed within this specification.
[0118] Complex II relies on the addition of exogenous phosphorus to
the protein to be used for forming the complex. For simplicity, we
again refer primarily to casein as the protein. However, it should
be understood that other proteins may be used with the present
invention without departing from the scope thereof.
[0119] The inventors identified that the added phosphorus plays an
important role in the formation of these stable, soluble complexes.
Without wishing to be bound by theory, it is thought that
phosphorus may act by increasing the surface charge on the complex
thereby preventing the aggregation and consequent precipitation of
the protein.
[0120] Caseins are known to be mineral chelators, which bind
minerals such as iron mainly through the coordination complexes
formed between the mineral and oxygen of the clusters of
phosphoserine residues available throughout the structure of
caseins. However, binding of iron to these caseins results in a
decrease in the surface charge, thereby causing aggregation and
precipitation of proteins. It may be possible that phosphorus acts
by increasing these surface charges through mechanisms still
unknown thereby preventing the aggregation of proteins.
[0121] Furthermore, the preferred process of making both complex I
and II is conducted at temperatures of about 2-10.degree. C. where
proteins such as casein exist partly as monomers due to absence of
hydrophobic interactions at such temperatures. The existence of
casein in the monomeric form might further provide binding sites
for minerals such as iron thereby increasing the amount of minerals
that could be bound to caseins.
[0122] These results could not have been logically predicted. This
is because in past studies when phosphorus and calcium have been
added to sodium caseinate, it had caused precipitation of the
protein. Therefore, one skilled in the art would have assumed that
upon on addition of iron in place of calcium, substantial
precipitation and/or loss of stability would also have
occurred.
Preferred Features of Complex II
[0123] Preferably, the protein is a phosphoprotein.
[0124] Preferably, the phosphoprotein is casein.
[0125] However, the inventors acknowledge that other proteins such
as egg phophovitin have similarities to casein which suggest a
comparable level of binding and stabilisation would occur following
phosphorylation of the protein.
[0126] Other proteins such as soy protein, cereal protein and algal
protein may also be used, albeit potentially with varied levels of
phosphorylation and/or binding to produce a soluble and stable iron
protein complex.
[0127] Preferably, the casein containing compound is sodium
caseinate, potassium caseinate, ammonium caseinate, lactic casein
and/or derivatives or fractions of caseins.
[0128] Preferably, the mineral is iron. Preferably, the iron is
ferric iron. For example, ferric chloride may be used. Alternative
ferric iron salts such as ferric sulphate pentahydrate, may be used
without departing from the scope of the invention. Similarly, a
ferrous iron source may be used. The preference to fortify the
complex with iron comes back to the clear need to provide soluble
inexpensive fortified iron complexes.
[0129] However, the inventors acknowledge that the present
invention may be used to fortify a complex with other minerals
beyond iron, such as zinc, manganese, selenium or chromium.
Requirements for all these minerals in animals present
opportunities to utilise the present invention in a similar
mechanism. One skilled in the art would appreciate other minerals,
or mixtures of minerals, may be substituted for iron.
[0130] Preferably, the mineral-protein complex includes above 1%
w/w mineral bound to protein.
[0131] More preferably, the mineral-protein complex includes
between 1% to 20% w/w mineral bound to protein.
[0132] Even more preferably, the mineral-protein complex includes
between 1 to 9% w/w mineral bound to protein.
[0133] The advantages of these loadings of mineral have been
previously discussed in relation to Complex I, and the same
reasoning applies for Complex II.
[0134] It should be appreciated that in the case of casein for
example, .alpha..sub.s1, .alpha..sub.s2 and .beta. caseins are
highly phosphorylated, whereas other variants of casein such as
.kappa.-casein are sparsely phosphorylated. The phosphorylation
patterns of casein subtypes are well documented, for example as
outlined on page 1 of US 2003/0206939, which is herein incorporated
by reference. This is also the case for many other proteins which
may be used according to the present invention.
Preferred Method of Manufacture of Complex II
[0135] A particularly preferred method of manufacture of Complex II
is shown schematically in FIG. 2.
[0136] The method is discussed more generally below.
[0137] Preferably, the protein used is a casein containing
compound.
[0138] Preferably, the casein containing compound used in the
method is sodium caseinate, potassium caseinate, ammonium
caseinate, lactic casein and/or derivatives and fractions of
caseins. Such compounds may be readily obtainable from suppliers in
a pre-purified state. As discussed previously, this avoids the need
for processing or purification steps as used in the preparation of
Complex I.
[0139] Preferably, the method includes dissolving the protein in
water to form a solution. This dissolving step may be performed at
a relatively higher temperature such as between 40-60.degree. C. to
aid in the dissolving process. Once dissolved, the solution may
preferably be chilled to a lower temperature, preferably between
2-10.degree. C. for reasons discussed previously. However, the
process may be performed at temperatures between 2-95.degree.
C.
[0140] Preferably, the protein concentration in the solution is
configured to be between 1-12.5% w/v. Most preferably, the protein
concentration in the solution is configured to be between 1-5%
w/v.
[0141] After the protein solution is chilled, this is a convenient
point at which phosphorus may then be added to the protein
solution.
[0142] Most preferably, the phosphorus is added to the protein
solution prior to the addition of the mineral. This may help to
prime the protein solution for effective binding of the
mineral.
[0143] The source of phosphorus may be food grade orthophosphate or
polyphosphate or linear phosphate salt, as mono, di, trisodium,
potassium, ammonium, magnesium or calcium phosphates, as well as
phosphoric acid and/or mixtures thereof.
[0144] Preferably the source of phosphorus is K.sub.2HPO.sub.4 The
normal ratio of casein to phosphorus is 65:1. A lower ratio than
this is required to achieve the aforementioned benefits.
[0145] Preferably, an amount of phosphorus is added to the protein
solution such that the ratio of protein to phosphorus is between
5:1 to 30:1. Most preferably, the ratio of protein (e.g. casein) to
phosphorus is between 12:1 to 22:1.
[0146] Preferably, the mineral is added to the protein solution
after the addition of phosphorus.
[0147] Preferably, the mineral is iron. However, it has already
been emphasised that many other types of minerals may be used in a
similar manner to bind to proteins such as casein.
[0148] Preferably the iron is ferric iron. One such source of
ferric iron is FeCl.sub.3, although others are clearly
envisioned.
[0149] Preferably the ratio of protein to iron (e.g. casein) is
between 200:1 to 2:1.
[0150] Most preferably, the ratio of protein to iron (e.g. casein)
is between 100:1 to 10:1.
[0151] As previously discussed, as ferric iron is acidic, it may be
appropriate to again adjust pH to within the preferred range using
suitable pH regulator(s).
[0152] Preferably, the resulting protein solution is mixed for a
period of time at 5-10.degree. C. This may help to allow time for
the mineral to bind to the protein to form the complex. Again, the
preferred temperature is thought to help this binding process.
[0153] After this incubation step, the solution may then be
clarified to remove unwanted material such as any minor amounts of
precipitate.
[0154] Similar to as described with Complex I, the solution may
then be concentrated and spray dried before further use.
Method of Use
[0155] The mineral-protein complex may be added to food and
beverage products; or as the base for any product to be consumed
orally, in order to provide a source of an essential mineral. This
means that animals may get the essential minerals from alternative
sources to help reach the intake required for optimum health.
[0156] Most preferably, the mineral that is to be provided via the
food product is selected from iron, zinc, copper, manganese,
magnesium, selenium or chromium.
Outline of Further Advantages of the Present Invention
[0157] Liquid milk and food products may be fortified with minerals
using the complexes of the present invention. In the case of iron
for example, sodium ferredetate and ferrous bisglycinate are
available to do this, but it is very expensive to do on a large
scale. [0158] Ease of mixing powder of the complexes with
food/beverages. A flowable powder with low bulk density will mix
better than high density iron fortificants e.g. sodium ferredetate
and ferrous bisglycinate. [0159] A wide range of mineral (e.g.
iron) fortification in beverages is possible without affecting
taste, colour and shelf-life. [0160] Complex I is milk based, and
complex II is preferably casein based. This means the complexes may
be applicable to standardised dairy foods with no substantial
regulatory challenges. [0161] The complexes I and II are soluble at
physiological pH (6.6 to 6.9). [0162] Unlike the prior art, the
complexes of the present invention advantageously do not undergo
substantial aggregation, are not prone to precipitation, are heat
stable at up to 90.degree. C. for 30 min or even 140.degree. C. for
5 seconds, are translucent and/or are highly stable. This
temperature stability exceeds that achieved by existing products,
such as ferrous bisgycinate. [0163] For iron (as an example), a
creamish-white coloured powder may be produced by the method of
manufacture. This may give a transparent solution at 25% daily
requirement levels as listed in example 3 [0164] The complexes will
not cause changes in pH of milk or other neutral products. [0165]
The complexes may be mixed with liquid and powdered food products.
Concentrated small batches may be prepared and added to bulk milk
without sophisticated mixing equipment. [0166] The manufacturing
process of Complex I may be performed continuously from milk.
BRIEF DESCRIPTION OF DRAWINGS
[0167] Further aspects of the present invention will become
apparent from the following description which is given by way of
example only and with reference to the accompanying drawings in
which:
[0168] FIG. 1 A preferred method for manufacture of complex I;
[0169] FIG. 2 A preferred method for manufacture of complex II;
[0170] FIG. 3 Effect of iron addition on the levels of soluble
protein;
[0171] FIG. 4 Effect of iron addition on the levels of soluble
iron;
[0172] FIG. 5 Effect of iron addition on the turbidity of sodium
caseinate solution;
[0173] FIG. 6 Photograph 1 to illustrate the advantages of complex
II;
[0174] FIG. 7 Photograph 2 to illustrate the advantages of complex
II;
[0175] FIG. 8 Effect on protein solubility upon iron fortification
using complex I;
[0176] FIG. 9 Effect on iron solubility upon iron fortification
using complex I; and
[0177] FIG. 10 Effect of protein solubility upon exogeneous
phosphorus addition.
BEST MODES FOR CARRYING OUT THE INVENTION
Example 1
Physico-Chemical Properties and Composition of 70% Calcium Removed
Milk (Used for Complex I)
TABLE-US-00001 [0178] Parameters Specification Colour Greenish
translucent liquid pH 6.80 Total solids 10% w/w Viscosity
(20.degree. C.) 1.28 Pascal seconds (50 shear) % Ca removed 70% w/w
Heat stability Heat Stable (90.degree. C. for 30 min or 140.degree.
C. for 5 seconds) Protein 3.12% w/w Soluble protein 96% w/w Zeta
potential (100 X -45.58 dilution) Z-avg diameter value 173 nm Ca
300-350 mg/kg Mg 40.7 mg/kg K 2500 mg/kg P 940 mg/kg Na 642
mg/kg
Example 2
Physico-Chemical Properties and Composition of an Exemplary Soluble
Mineral Protein Complex from a Milk-Derived Liquid Source
TABLE-US-00002 [0179] Parameters Specification Colour Yellowish
liquid pH 6.80 Total solids 10% w/w Viscosity (20.degree. C.) 1.33
Pascal seconds (50 shear) % Ca removed 70% w/w Heat stability Heat
Stable (90.degree. C. for 30 min or 140.degree. C. for 5 seconds)
Protein 3.10% w/w Soluble protein 93% w/w Zeta potential (100 X
dilution) -48 Z-avg diameter value 120 nm Ca 300-350 mg/kg Mg 40.7
mg/kg Fe 1675 mg/kg Fe/Protein Ratio % 3.3% K 2500 mg/kg P 2000
mg/kg Na 1400 mg/kg
Example 3
Examples to Illustrate the Amount of Each Complex Needed to Achieve
Maximum Iron Fortification Levels According to RDI's
[0180] The table below outlines existing permission for iron
fortification in different foods.
TABLE-US-00003 Quantity of Iron-protein complex 1 or 2 powder
Reference Maximum claim per to be added Food quantity reference
quantity (% RDI) Complex 1 Complex 2 Amount of Iron in -- -- 1.8%
7.5% powder Biscuits containing 35 g 3.0 mg (25%) 166 mg 40 mg not
more than 200 g/kg fat & 50 g/kg sugar Cereal Flours 35 g 3.0
mg (25%) 166 mg 40 mg Bread 50 g 3.0 mg (25%) 166 mg 40 mg Pasta 35
g 3.0 mg (25%) 166 mg 40 mg uncooked Extracts of meat, 5 g 1.8 mg
(15%) 100 mg 24 mg vegetables or yeast Analogues of meat 100 g 3.5
mg (30%) 194 mg 100 mg derived from legumes Formulated 600 ml 3.0
mg (25%) 166 mg 47 mg Beverages Formulated meal One meal 4.8 mg
(40%) 266 mg 64 mg replacements servings Formulated One serving 6.0
mg (50%) 333 mg 80 mg supplementary foods Formulated One day 12 mg
(100%) 666 mg 160 mg supplementary quantity sports foods
[0181] The recommended daily intake (RDI) for iron is 12 mg.
[0182] The table also illustrates the amount of each complex which
is required to be added (in powder form) to the food to achieve the
maximum iron fortification for each product. This exemplified the
versatility of the complexes and their use. It also shows the
advantage of being able to load higher amounts of iron into the
complexes, as less powder is needed to achieve high iron
fortification in the food.
Example 4
Effect of Phosphorus Addition to the Complex
[0183] FIGS. 3 to 5 illustrate the effect of adding phosphorus to
the complex.
[0184] FIG. 3 shows how the protein solubility is affected as iron
levels increase from 1 to 20 mM (equivalent to 6.9% iron). As
illustrated, as phosphorus levels are increased from 0 mg/kg
through to 2000 mg/kg, the protein solubility is significantly
improved, regardless of the increase in iron loading.
[0185] FIG. 4 similarly shows the effect on solubility of the iron
in a sodium caseinate solution. Again, as phosphorus levels are
increased, the solubility of iron is improved significantly.
[0186] FIG. 5 illustrates the advantages of the invention, wherein
an increase in turbidity indicates a reduction in stability due to
the formation of small particulates/precipitates. As the amount of
phosphorus is increased, the turbidity can be reduced close to
baseline even upon loading up to 25 mM (6.9%) iron, indicating that
all the protein is remaining in a soluble and stable form.
[0187] Based on these preliminary results, the inventors foresee
that a particularly optimal level of mineral loading (e.g. iron)
may be about 15 mM (4%). This may provide the best balance between
stability and loading for many commercial applications. However,
increases beyond 15 mM (4%) are clearly possible and may be viable
for particular applications as discussed in Example 3 above.
Example 5
Visual Representation of Effect of Phosphorus Addition to Sodium
Caseinate
[0188] FIGS. 6 and 7 visually illustrate how addition of phosphorus
improves the solubility and stability of the complex. Even when the
iron is loaded up to 25 mM, the composition remains in solution.
Without the phosphorus, the protein and/or iron precipitates even
at lower levels of iron (5-10 mM).
[0189] Aspects of the present invention have been described by way
of example only and it should be appreciated that modifications and
additions may be made thereto without departing from the scope of
the appended claims.
Example 6
Testing of Other Minerals
Zinc
[0190] We have compared the effect of zinc sulphate addition on the
precipitation of proteins in sodium caseinate using our
technology.
[0191] Upon addition of zinc sulphate to sodium caseinate solution
(2% protein), not more than 5 mM of zinc could be added without
gross precipitation of proteins at pH 6.8.
[0192] However, as exemplified with the concept of complex II, we
could add 18 mM of zinc to the sodium caseinate (2% protein
solution) without any precipitation of proteins.
Copper
[0193] The sodium caseinate solution (2% protein) precipitated upon
addition of 1.5 mM copper as copper sulphate. Again using the
concept of complex II, we could add 4 mM without noticeable
precipitation at pH 6.8.
Example 7
Heat Stability and Sensory Analysis of Complex I
[0194] An iron-protein complex according to "Complex I" was added
to whole milk powder (WMP) at a level equivalent to 37.5 mg iron
per 100 g WMP. This was then reconstituted to 12% solids using
water, equivalent to natural milk. This provided a final iron
concentration of 4.5 mg per 100 ml serving, equivalent to 25% of
the RDA for menstruating women or 56% of the RDA for adult males
and postmenopausal women.
[0195] The reconstituted WMP was then pasteurised at 75.degree. C.
for 15 seconds, filled into plastic bottles (1 litre) and stored at
4.degree. C. for 7 days. It was then assessed for functional and
sensory characteristics as follows: [0196] Fortified milk and
un-fortified control milk had no difference in colour as measured
by Minolta. Sensory assessment found no difference in colour or
taste between the fortified and control products. [0197] Tea: a tea
bag was brewed for 4 min in 180 ml boiling water. 20 ml cold milk
was added and stirred. Sensory assessment found no difference in
colour or taste between the tea made with the fortified or
un-fortified control milk. [0198] Dark coffee: 2 scoops ground
plunger coffee was brewed for 2 min in 300 g boiling water. 20 g of
this brewed coffee was then added to 50 g boiling milk. Sensory
assessment found no difference in taste between the dark coffee
made with the fortified or un-fortified control milk. However,
there was a significant change in colour between the two milks,
with the fortified milk causing the coffee to turn a dark grey.
[0199] Milky coffee: 2 scoops ground plunger coffee was brewed for
2 min in 300 g boiling water. 20 g of this brewed coffee was then
added to 100 g boiling milk. Sensory assessment found no difference
in taste between the milky coffee made with the fortified or
un-fortified control milk. However, there was a significant change
in colour between the two milks, with the fortified milk causing
the coffee to turn a dark grey.
[0200] In an additional study, the reconstituted WMP was UHT
processed at 140.degree. C. for 5 seconds, filled into plastic
bottles (1 litre) and stored at 4.degree. C. for 7 days. Sensory
testing on the milk showed a small difference in taste between the
fortified and un-fortified control products, but this was not rated
as an unpleasant difference. There was no difference in colour. The
fortified product could also be added to tea and dark coffee
without any differences in taste, although there was a small
negative effect on the taste of milky coffee. There were
significant colour differences in the coffee products.
[0201] Separately, chocolate mix (Nestle Nesquik) was added to the
reconstituted WMP at a concentration of 6 g Nesquik in 100 g milk.
The chocolate-flavoured milks were then pasteurised at 75.degree.
C. for 15 seconds, filled into plastic bottles (1 litre) and stored
at 4.degree. C. for 2 days. Sensory assessment showed a small but
acceptable change in colour and no difference in flavour between
the fortified and un-fortified control milks. In addition, the
chocolate-flavoured milks were UHT processed at 140.degree. C. for
5 seconds, filled into plastic bottles (1 litre) and stored at
4.degree. C. for 2 days. Sensory assessment showed a noticeable but
acceptable change in colour and no significant difference in
flavour between the fortified and un-fortified control milks.
Example 8
Heat Stability and Sensory Analysis of Complex II
[0202] An iron-protein complex according to "Complex II" was added
to whole milk powder (WMP) at a level equivalent to 37.5 mg iron
per 100 g WMP. This was then reconstituted to 12% solids using
water, equivalent to natural milk. This provided a final iron
concentration of 4.5 mg per 100 ml serving, equivalent to 25% of
the RDA for menstruating women or 56% of the RDA for adult males
and postmenopausal women.
[0203] The reconstituted WMP was then pasteurised at 75.degree. C.
for 15 seconds, filled into plastic bottles (1 litre) and stored at
4.degree. C. for 7 days. It was then assessed for functional and
sensory characteristics as follows: [0204] Fortified milk and
un-fortified control milk had no difference in colour as measured
by Minolta. Sensory assessment found no difference in colour or
taste between the fortified and control products. [0205] Tea: a tea
bag was brewed for 4 min in 180 ml boiling water. 20 ml cold milk
was added and stirred. Sensory assessment found no difference in
colour or taste between the tea made with the fortified or
un-fortified control milk. [0206] Dark coffee: 2 scoops ground
plunger coffee was brewed for 2 min in 300 g boiling water. 20 g of
this brewed coffee was then added to 50 g boiling milk. Sensory
assessment found no difference in colour or taste between the dark
coffee made with the fortified or un-fortified control milk. [0207]
Milky coffee: 2 scoops ground plunger coffee was brewed for 2 min
in 300 g boiling water. 20 g of this brewed coffee was then added
to 100 g boiling milk. Sensory assessment found no difference in
taste between the milky coffee made with the fortified or
un-fortified control milk. There was only a very slight difference
in colour between the products, but this was not noticeable unless
they were directly compared.
[0208] In an additional study, the reconstituted WMP was UHT
processed at 140.degree. C. for 5 seconds, filled into plastic
bottles (1 litre) and stored at 4.degree. C. for 7 days. Sensory
testing on the milk showed a small difference in taste between the
fortified and un-fortified control products, but this was not rated
as an unpleasant difference. There was no difference in colour. The
fortified product could also be added to tea, milky coffee and dark
coffee without any differences in taste, although there were
significant colour differences in the coffee products.
[0209] Separately, chocolate mix (Nestle Nesquik) was added to the
reconstituted WMP at a concentration of 6 g Nesquik in 100 g milk.
The chocolate-flavoured milks were then pasteurised at 75.degree.
C. for 15 seconds, filled into plastic bottles (1 litre) and stored
at 4.degree. C. for 2 days. Sensory assessment showed a small but
acceptable change in colour and no difference in flavour between
the fortified and un-fortified control milks. In addition, the
chocolate-flavoured milks were UHT processed at 140.degree. C. for
5 seconds, filled into plastic bottles (1 litre) and stored at
4.degree. C. for 2 days. Sensory assessment showed a noticeable but
acceptable change in colour and no significant difference in
flavour between the fortified and un-fortified control milks.
* * * * *