Note: Descriptions are shown in the official language in which they were submitted.
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LoW FAT BUTrER
My invention relates to butter having a low fat content,
and a process for the production thereof.
Milk fats contain a relatively high proportion of
glycerides of saturated fatty acids. Such glycerides have relatively
high softening temperatures; as the te~perature of the butter is
decreased by refrigeration, for example, the hardness of the butter
increases greatly whereby it becomes no longer spreadable. It w~uld
be highly desirable to decrease the concentration of these fatty
acids in butter so that the butter is spreadable at lower temperatures,
particularly where this can be achieved whilst retaining the
plastic characteristics of butter at normal ambient temperatures.
It would be further desirable to achieve this decrease in the
concentration of saturated fatty acids as these are considered by
many authorities to be linked to blood cholester~l formation.
The rheological properties of margerin have long been
known to be influenced by varying the fatty acid make-up of the
glycerides and also the water content of the emulsion. Whilst
it would be possible to modify the chemical make-up of butter
fat, e.g. by transesterification, such product would no longer
be a true dairy product.
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It has heretofore been proposed to reduce the fat content
of butter by increasing the water content thereof. In such
proposals butter is first prepared from cream by churning in the
traditional manner, and water is reincorporated as a second step.
It would be economically desirable to produce a low fat product from
cream in a one step process.
E~rthermore, the churning process for the manufacture
of normal butter is essentially a batch process. It would be
desirable to produce butter from cream as a continuous process.
Natural butter comprises a water in oil emulsion of about
80% milk fats, 17% water, 1~ to 2~ milk solids not fat (milk solids)
and up to akout 2~ salt; nunor quantities of other adjuvants may also
be present. It is generally produced by churning dairy cream having
up to about 40~ milk fat, 6% milk solids, with the balance water.
In the churning process a phase inversion occurs with the
separation of buttermilk from the butter produced, and a
concomitent increase in fat content and decrease in milk solids.
Since the milk solids are predominately protein it is apparent that
there is a loss o nutritional value in the formation of natural
butter from cream. It w~uld be desirable to produce a low fat
butter having the nutritional balance in terms of protein to fat
ratio akout equal to that of dairy cream.
It is known to produce low fat dairy spreads directly
from cream. However, in such processes the product is an oil in
water enLlsion. The continuous aqueous phase with its relatively
high protein content forms an excellent medium for the propagation
of micro-organisms, and such products have little commercial
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acceptance for this reason. Even where the aqueous phase is
discontinuous, it may still be conducive to bacterial
propagation, partic~llarly where the protein of the product lS
relatively high as herein. It ~uld be desirable to provide a
nutritional, low fat butter of good keeping quality.
In accordance with the prime aspect of this invention
there is provided low fat butter having good low temperature
spreadability.
In a further aspect of the invention there is provided
a low fat butter of enhanced nutritional value.
In yet a further aspect of the invention there is provided
a low fat butter having an enhanced nutritional value and good
keeping qualities.
In another aspect of this invention, there is provided
a simple, one step process for the production of low fat butter
from cream.
In accordance with one emkodiment of the invention,
a low fat butter is produced from a dairy cream by incorporating
into such dairy cream a relatively small quantity of a non-ionic
emulsifying agent having a hydrophilic-lipophilic ~alance (HLB)
as defined in BECHER, EMULSIONS THEORY AND PRACTIOE, ACS MCNCGRAM
135, 1957, in the range of about 3 to 5 inclusive, and a relatively
small quantity of a hydrocolloid. The cream is subject to
homogenizing conditions so as to produce a relatively fine
emwlsion, following which it is chilled and w~rked whereby phase
inversion takes place without any substantial syneresis occuring.
The resulting product is then tempered by refrigeration, so as to
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induce a gel structure therein.
me cream will generally have a milk fat content equal
to that of the low fat butter to be prepared, and in the range of
about 35% to about 60% by weight, there being no criticality in
respect thereof. Preferably the cream will contain about 40% by
weight miIk fat. Cream of this milk fat content may be readily
separated from whole milk by low speed centrifuging, for example
Cream of higher miLk fat content may be separated from whole milk
by higher speed centrifuging. In addition, a natural cream may be
modified to supplement the milk fat of such natural cream by
other fatty materials. Preferably such fatty materials will be
dairy products such as butter or butter fat; it is also contemplated
that fats from non dairy sources,for example vegetable oils,be
employed to supplement the milk fat. In general the amount of
fat used to modify the cream so as to supplement the milk fat
will not comprise more than about 50% by weight of the total fats
of the modified cream.
Natural cream containing about 35% about 60% by weight
milk fat will normally contain therein c~bout 4% to about 8% by
weight of milk protein. When cream is modified by the addition of
other fatty materials in the manner indicated above, such modified
cream will have a reduced protein content in comparison to the
natural cream of an equivalent fat content. It is found necessary
to increase the concentration of hydrocolloid as the protein
content decreases so as to produce a product of a given firmness
and spreadability. Preferably the protein content of m~dified
cream is adjusted by the addition of milk or milk powder so as
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to be not less than about 4% by weight of the finished product.
Generally the protein content is maintained in the range of about
4% to about 6% be weight so as to strike a balance between the
nutritional value and taste of the finished product and the
amount of added hydrocolloid.
The non-ionic emulsifier is preferably of the glyceryl
ester type; particularly preferred are those esters of the long
chain, saturated fatty acids such as st OE ic acid and palmitic
acid. Such esters have a higher setting point than those of the
corresponding unsaturated esters, and this is found to ke
conducive to forming liquid crystaline phases (gels) in water
at a scmewhat higher temperture than that for the unsaturated type.
This ability enables them to be used effectively as water binding,
firmung and plasticizing agentS. me non-ionic emulsifier sh~uld
have a HLB value in the range of about 3 to 5 inclusive. Preferably
the HLB value should be about 3. A preferred emulsifier having
the requisite value is distilled glyceryl monostearate having a
ooncentration of the mono ester of at least akout 90% with the
balance being substantially a di ester. A suitable commercial
product of this type is sold under the trade mark DIMONDMN S.
me quantity of the emulsifier will depend to some
extent upon the type of emulsifier used and the level of naturally
occuring emulsifier present in the cream such as the phospholipids.
Generally, when using the preferred emulsifier the concentration
thereof will be within about 0.5% to about 1.5~ by weight, based
on the total weight of the ingredients; preferable when the milk
fat content is about 40% by weight the concentration of the
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emulsifier will be about 0.9%. Where the milk fat is replaced by
blending the cream with other fatty materials as disclosed akove,
the concentration of phospholipids will generally be decreased, and
the concentration of added emulsifier should be proportionately
increased so as to produce a product of ccmparable stability and
firmness.
The hydrocolloids for use in the present invention
function as a firming agent for the low fat butter and increases
the stability of the water in oil emNlsion. Suitable hydrocolloids
are for example derivatives of alginic acid, gelatin and sodium
caseinate. Most preferred is sodium alginate, as this has
enabled a more firm product to be produced, in relation to the
quantity of hydrocolloid employed, than that which results frcm
other hydrocolloids which have so far been employed. From this it
will ke apparent that the concentration of hydrocolloid to be
employed will depend to some extent upon the desired firmness of the
low fat butter, and generally the concentration will be in the range
of about 0.3% to about 1.5~ by weight,based upon the total weight
of the starting ingredients, where sodium alginate is employed,
the other hydrocolloids being utilizable in an amount to give an
equivalent desired effect.
m e sequence of addition of the hydrocolloid and
emulsifying agent has not been found to be critical. Such
additions should be controlled so as to reduce the ca~ing of the
additives and to avoid calcuim reaction. Calcium reaction is
minimized by the use of sequestering agents and peptizing agents
such as sodium tetrapyrophosphate and sodium citrate. It is found that
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the gel strength of the resulting product is improved by the
incorporation of the sequesterin~ agent. About 0.1~ by weight
of each of these additives,based on the total weight of ingredients,
is adequate for the present purposes.
It is found that the method of preparing the product
of the invention has a significant bearing upon the properties
of the finished product, and also interrelates to some extent
with the concentration of emulsifier and hydrocolloid necessary
to yield a product of desirable characteristics. The preferred
method of preparation of the low fat butter is described in
conjunction with the drawings appended hereto, which shows
a flow diagram of such method operated in a continuous manner.
In the drawing, the numeral 10 represents a steam jacketed tank which
is charged through a line 12 with cream. Such cream may have a
milk fat content equal to that of the desired low fat butter,
or the milk fat content may be supplemented by the addition of
butter in which case tank 10 is desirably equipped with an
agitator 14. The temperature of tank 10 is such to render the milk
fat liquid, and will normally be maintained at about 50C. The
"water soluble" additives such as the hydrocolloid,the sequestering
agent~together with an antifungicide such as potassium sorbate~salt~
and water soluble butter flavour where desired are added
to the cream by an in line funnel arrangement 15 when dry blended
therewith, at circulating pump 16. Alternatively these additives
may be dlssolved in milk or water to form a paste or solution
prior to addition to the cream if desired, such alternative
method further tending to reduce calcium reaction. The outlet
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from pump 16 is in part recirculated to tank 10 through valve
17 and line 18, and part is transferred to steam ~acketed tank ~0.
Here the temperature is further increased to about 70 C. At
this temperature the glyceryl monostearate emulsifier is molten,
and is readily incorporated into the cream b~ metering in at
pump 22.~ Other oil soluble additives such as carotene,butter
flavour and colourant may be incorporated at this stage, serving
additionally to mollify and dissolve the emulsifier. The output
from pump 22 is in part recirculated to tank 20 through valve 24
and line 26, and in part transferred through line 28 to a tw~
stage hcmogenizer 30. The blended cream at about 70C is
subject to homDgenization at an initial pressure of 500 PSIG and
a final pressure of akout 2000 PSIG. Homogenization is found to
have an important effect in retarding microbial growth in the
finished product, both by decreasing the size of the water
droplets (to about 2 to 3 microns), and also by enhancing the
protein absorption of the fat particles (and correspondingly
reducing the concentration of protein in the aqueous phase).
It is further found that the reduced p~rticle size increases the
ease of the later phase inversion step and lessens the tendency
of phase separation which might otherwise occur in such step.
It will be appaent that the hom~gerlization step will
assist in incorporating the various additives in the cream.
However, if desired such step may take place prior to blending
of the additives although this sequence is less preferred.
~ he outlet from homogenizer 30 is transferred through
line 32 to multiplate pasteurizer 40 where the homDgenized cream
is subject to a temperature of about 93C to 95 C for a short
time pasteurization so as to reduce any microbioal activity.
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Standard plate counts of the fresh finished product generally
range fram less than 100 to not more than 1000 p~r gram of product.
It is generally undesirable to maintain the admixed cream at the
above temperatures, particularly where it is desired that the
finished product be printable, as it is found that such heating
weakens the gel strength of the butter. It is surmized that this
may be due to the depolymerization~ of the hydrocolloid, although
this is by no means certain. A residence time of some 30 seconds
is found to be adequate for the purpose of pasteurization.
The output from pasteurizer 40 is passed via line 42
to plate cooler 44 where the temperature is rapidly reduced to
akout 32& to 35C, and thence via line 46 to a cold jacketed
balance tank 48. Balance tank 48 is equip~ped with a slowly
rotating paddlè 49 so as to ~rcmote further cooling and initiate
5 the solidification of milk fat whilst avoiding syneresis.
m e output from balance tank 48 is transferred by pump 50
and line 52 to a continuous throughput tw~ sweep surface heat
exchanger arrangement 54 such as a Votator ~ unit. Here the
cooled mixture is rapidly chilled to a temperature in the range
of about 9C to about 12C, and the chilled mixture is mechanically
w~rked, thereby inducing phase inversion but without any appreciable
accompanying syneresis. The resulting plastic, water in-oil
emulsion is then normally packaged, preferably in tubs, at
packaging unit 56 following which it is refrigerated at 2C to 4&
at refrigeration unit 58 for akout 36 hours to complete the gel
formation and temper the product. If desired, for example
when the low fat butter has a well defined solid form that may be
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wrapped, the refrigerating and packaging stations may be reversed
in sequence.
It is found that the low fat butter produced in
accordance with the above process has excellent keepi~g properties.
Thus such coliform, mould and yeast organisms as may be present
in the finished product in accordance with the above defin~d
range showed little or no grawth over an extended period, and
a shelf life of some three months for the product is entirely
feasible. Where long keeping quality is not a problem, lower
pasteurization temperatures may be used or the step may be
omitted.
In the above illustrated embodiment the blending stage
of the process is shown as being operated in a continuous manner.
It may, of course be operated batchwise, in which case tank 20
may be amitted and the output fram line 19 connected directly
to homogenizer 30. The te~perature of the cream in tank 10 is raised
fram ambient to about 70C and the various additives incorporated
by metering through pump 16 at appropriate temperatures.
me follawing examples, in which the parts are hy weight
further illustrate the invention;
EX~MPLE 1
97 parts of a natural cream containing 40% milk
fats and 8% milk with solids comprising about 65%
milk protein is heated to about 50C to render the solid milk fat
content liquid; a dry mixture consisting of 0.5 parts sodium alginate,
0~1 parts each of sodium tetrapyrophosphate, sodium citrate and
potassium sorbate, together with 1.2 parts of butter salt is
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admixed with the heated cream in an in-line funnel arrangement.
me temperature of the admixture is raised to about 70C, when
~-~ 0.9 parts of Dimondan S distilled monoglycerides is incorporated
together with minor amounts of oil soluble colourant and flavouring.
The hot cream is then homogenized in a tWD stage hcmogenizer
wherein the second valve is set at 500 PSIG and the first valve
at about 2000 PSIG, thereby forming a emulsion having a particle
size about 2-3 microns. The homogenized cream is pasteurized for
about 30 seconds at a temperature of 95C, following which it is
cooled to 35C in a plate cooler, avoiding vigorous mechanical
agitation. m e cooled mixture is slowly stirred to initiate
crystallization of the solid milk fats whilst avoiding syneresis.
me cooled mixture is passed into a tWD sweep surface heat exchanger,
operating at a~out 10C, wherein phase inversion took place with
no syneresis. The resulting product is packaged in tubs and
tempered for 36 hours at akout 2 - 4C. The tempered product
has average penetrometer readings as shown in Table 1.
Penetrcmeter Values 10 1 mm. at
Sample 2C 10C 13 C
20Normal Butter 27 45 69
-
Low Fat Butter 149 183 200
TABLE 1: CoMPARISON OF PENE~'R~METER VALUES FOR LCW FAT
BUTTER OF EXAMPLE 1 and NORMAL BUTTER
From the above it may be seen that the spreadability of
the low fat butter of the instant invention is much greater than
that of natural butter, and it will be appreciated from these
values that the low fat butter is easily spreadable even at very
low refrigeration temperatures. Additionally, the p~rcentage change
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in the speadability of the 1QW fat butter is relatively small over
the range of tem~erature normally encountered in domestic
refrigerators.
EAMPLES 2 - 3
S The procedure of Example 1 is repeated, whilst varying
the milk solids level of the cream by the addition of milk p~wder.
me protein concentration of the cream is taken as being about
65% that of the milk solids. The amount of sodium alginate
necessary to achieve a product having penetrometer values
approximately in acoordance with those given in Example 1 is
shown in Table 2 below, with Example 1 being shown as a
control.
Example Control 2 3
Protein content
of cream % 3.9 5.2 6.5
~ sodium alginate
additive 0.70 o.50 0.40
.
TABLE 2: MILK PRorEIN - HYDRDCOLLOID RELATIONSHIP
EXAMPTE,~ 4 - 7
The procedure of Example 1 is followed but using natural
cream of different milk fat content and maintaining the miLk
solids with the range of about 8 - 10~. The quantity of
emLlsifying agent (Dimondan S) necessary to achieve penetrometer
values for the low fat butter approximately in accordance with those
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given in Example 1 (Control) is shown in Table 3 below:
Example Control 4 5 6 7
_
Milk Fat % 40 35 45 50 55
5 Emulsifying
A~ent ~ 0.90 1.00 0.85 0.75 0.60
TPBLE 3: MILR FAT - EMULSIFIER RELATICNSHIP
It will be appreciated that many changes from the above
description as c e within known or customary practice in the
art may ke made without departing from the principles of the
invention, the essential features of which are set forth in the
appended claims.
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