Note: Descriptions are shown in the official language in which they were submitted.
L 553 (R)
108388Z
The invention relates to water-in-oil type low fat
spreads.
A problem that is often encountered in emulsions, par-
ticularly those of the so-called low calorie type, is that
an insufficient flavour-release takes place by chewing the
product in the mouth, because a substantial proportlon of wa-
ter droplets - which con~ain flavouring material - do not
reach the papillae in the mouth but remain enveloped with
the continuous fat phase.
An improvement in flavour release can in principle be
achieved by taking care that the product has a coarser emul-
sion structure than conventional products, so as to obtain
a more unstable emulsion, which upon mastication on the
palate will give a better flavour release. From a micro-
biological point of view, however, such emul~ions are dan-
gerous, since upon storage water separation can easily take
place, which may result in unacceptable bacteriological in-
fections of the product.
The present invention provides an emulsion which com-
prises 35 to 65, preferably 50-65% by weight of a dispersed
aqueous phase of a pH value of 4-6 and 65 to 35, preferably
50-35% by wt of a continuous fat phase containing a minor
amount of a partial glyceride emulsifier, the fat having a
solid content of 10-35% at all temperatures from 10-20C, a
difference in solid content at 10 and 20C of no more than
10%, and a solid content at 30C of less than 5%, and
preferably of no more than 0.5, especially no more than
0.1% at 35C, the emulsion having a phase instability tem-
~Xe
-- 2 --
,, . . :
.
, . , . ~ , ,
. .,
' ~ ,' - ~
,, .. . :
:
108388Z L 553 (R)
perature of 10 -40C, preferably at least 15C, particularly
from 20-35C.
In this specification by "phase instability temperature"
(PIT) is understood the temperature at which the emulsion,
under shear conditions similar to those that occur on the
palate and as measured by the "PIT-test",which will herein-
after be described, shows a marked increased tendency to con-
duct electricity.
The terms "dispersed phase" and "continuous phase"
refer to the condition of the emulsion at room temperature,
i.e. about 20C.
In this specification all percentages are by weight
and are calculated on the total weight of the low fat spread
(except the solid contents) unless otherwise indicated. The
solids contents are expressed as percentages by weight and
are calculated on the weight of the fat blend. The solids
contents were measured by the method of Haighton, Vermaas
and Den Hollander as described in J.A.O.C.S. Vol. 48, pages
7-10.
An advantage of the low fat spread of the invention
is that a substantial proportion of the dispersed aqueous
phase is released in the mouth, whereby water-soluble
emulsifiers are freed into the saliva, which causes the
former fat-continuous phase to emulsify into the saliva,
: ?5 thereby giving an oil-in-water emulsion in the mouth. In
the low fat spread of the invention up to 90% or even more
of the dispersed aqueous phase can break out under palate
conditions wlthin about 10 seconds. This will result in a
_ ~ _
~ . ,
,~
,:
1083882 L 553 (R)
rapid flavour release, not only because the water-soluble
flavours are released, but also because of a rapid partition
of essentially oil-soluble flavour components into the saliva,
which become part of the continuous aqueous phase under palate
conditions, due to the high interfacial area of the oil-in-
water emulsion which is formed.
The dilatometric characteristics of the fat blend of the
emulsion of the invention will substantially avoid the forma-
tion of high-melting trisaturated triglycerides through re-
crystallisation on cycling of the temperature of the emulsion
during storage, which glycerides at relatively low levels
would have under palate conditions W/0 emulsion stabilizing
properties.
The dilatometric characteristics of the fat blend also
1~ influence the product instability, especially under condi-
tions of shear as met with on the palate. Preferably a fat
blend is used having a solid content at 10-20C which is
as invariable as possible, e.g. a difference in solid con-
tent between 10 and 20C of no more than 5%. Products con-
taining a fat blend of such a solids/temperature curve will
have a minimum of melting and re-crystallisation of gly-
cerides on cycling of the temperature within the range of
e.g. 10-20C, an improved feel of coolness on the palate
during melting of the glycerides,and a low solids content
at 30C, which will help to avoid a greasy feel on the
palate of the molten product.
The type and proportion of both the emulsifier system
c~ and the fat blend are of importance for ensuring a sufficient
. . .
. .
`
- - '' .. ~ :
L 553 (R)
~083882
degree of product instability at palate conditions. 8uitable
amounts of partial glycerides are from about 0.1 to 0.8% by
weight. Preferably partial glycerides are used that are not
completely saturated, e.g. partial glycerides of fatty acids
with 16-22 carbon atoms and having an iodine value of 20-100,
especially 30-60.
Monoglycerides of an iodine value of 30-60, especially
35-50, e.g. those of unhydrogenated lard or tallow are particu-
larly preferred. The partial glycerides can be present in
proportions within the range indicated above; preferably
however the content of partial glycerides is adjusted to the
fat content of the low fat spread of the invention.
Suitable weight ratios of fat : partial glycerides are
e.g. from (50:1) to (500:1), preferably from (100:1) to (300:1).
Preferably the emulsion further comprises oil-in-water
promoting emulsifiers, e.g. phosphatides, especially partly
hydrolyzed phosphatides, and synthetic emulsifiers e.g. fatty
acid sugar esters, Tweens (trade mark), etc. e.g. in a propor-
tion of 0.01, preferably 0.02 to 0.6 percent by weight. If
phosphatides are used in the low fat spreads of the present
invention, they preferably contain some 5-25% of mono-acylglycero
phosphatides, particularly a-mono acylglycerides phosphatides,
calculated on the total weight of phosphatides. Such phospha-
tides can be prepared by synthesis or by chemical hydrolysis or
by enzymatic hydrolysis of diacylglycerophosphatides under
conditions known per se (cf British patent Specification
lc
.
~08~8Z L 553 (R)
1,215,868).
Proteins can similarly be used as oil-in-water promoting
emulsifiers.
Although no more than 0.01-0.6 per cent by weight there-
of is sufficient for effectlng phase inversion of the low
fat spread under palate conditions, proportions up to 12%,
preferably up to 8% can be used, since the excess proteins
do not destabilize the emulsion under normal processing and
storage conditions, provided that a suitable proportion of
partial glycerides is present. Such oil-in-water promoting
emulsifiers therefore assist in counterbalancing the water-
in-oil promoting properties of the partial glycerides under
palate conditions, without effecting destabilisation of the
emulsion at normal storage, use and transport conditions.
Whole vegetable phosphatides, i.e. non-chemically
treated or fractionated phosphatides derived e.g. rrOm soya-
bean, rapeseed or corn preferably need a more solid fat blend
than emulsifiers of higher HLB values such as lysolecithin
containing partially hydrolysed phosphatides, proteins etc.
Such lower HLB emulsifiers probably need the grinding action
of more solid fat crystals in the initial stage of mastica-
tion in order to promote the destabilisation of the low fat
spread on the palate.
Suitably whole vegetable phosphatides are used in low
fat spreads containing a fat blend having a solids content
of 26-35% at 10C and preferably 18-25% at 20C.
Emulsifiers which like whole phosphatides are less
`~ efficient oil-in-water emulsifiers, i.e. those of HLB
- 6 -
.
'
,' ' : :~ ,: . :
.. ' ~: - : .:
108388Z L 553 (R)
values of about 10-16, are preferably also used together
with a fat blend of high solids content at 10 and 20C.
Particularly proteinaceous water-soluble emulsifiers
are preferred, since they are very potent counter-emulsifiers
and furthermore they will protect the fat blend against oxi-
dation. Finally such emulsifiers can contain natural flavours,
e.g. those obtained through culturing.
When a fat blend of suitable solids content is used, the
desired phase instability temperature can be obtained by
properly balancing the following factors:
1. The nature and proportion of fat-soluble partial gly-
ceride emulsifiers.
2. The nature and proportion of water-soluble emulsifiers.
Preferably the emulsion further comprises hydrocolloids
in the aqueous phase for raising the interfacial stability
and also enhancing the emulsion-stabilising properties of
the fat crystals under use and storage conditions. The con-
centration of hydrocolloids should be chosen in such a way
that a proper balance in viscosity of the continuous fat
phase and the dispersed aqueous phase is obtained. A suita-
ble hydrocolloid content can vary from about 0.1 to 1.5%
by weight.
Further advantages of using hydrocolloids, particularly
locust bean gum, are its hardness-decreasing influence on
the plastic emulsions of the invention and it also helps
to control the palate sensation of the released aqueous
phase in terms of viscosity.
-~ It has surprisingly been observed that locust bean gum
108388Z
and milk proteins have a synergistic effect on the lncrease of
viscosity.
PIT-Test
A Haake Rotovisko (trade mark) is equipped with the MV
measuring system. The Haake MVII (trade mark) bob is used at
speed 1, under which conditions the shear rate being applied
to the sample is 441 sec 1, which is a high but representative
figure for the conditions on the palate.
Electrodes, made from aluminium foil, are inserted between
the MVII bob and the Haake measuring cup wall. (The electrodes
are 1 cm. wide and 15 cm. long). Those parts of the electrodes
which can come into contact with the cup wall were insulated
with a layer of glue identified by the trade mark "Araldite".
The electrodes are co~nected to a conductivity bridge, for
measuring the conductivity of the emulsion under test.
Measurements of conductivity and viscosity are made at
5C intervals starting e.g. from 20 or lower to the PIT, which
is the temperature at which conductance increases markedly,
i.e. with at least 10 Mhos, or to 70C if no inversion (thus no
marked increase in conductivity~ can be detected. The emulsion
is maintained at each temperature for 15 minutes, to ensure
that equilibrium has been reached, and the Rotovisko bob is kept
rotating at speed 1 throughout the experiment.
The invention will now be illustrated by the following
examples in which all proportions and percentages are by weight
and are calculated on the weight of the low fat spread, unless
otherwise indicated.
-- 8 --
'C .
" ,,
.
: . , ' . ' ' . .: . ~:
1083882 L 553 (R)
xample I
A fat phase consisting of palm oil mid-fraction (30 parts)
and sunflower oil (70 parts) was prepared, refined and deo-
dorised. The solid content of this blend was: at 10 C 24%,
at 20C 17%, at 30 C 2% and at 35C 0%. The palm mid-fraction
was obtained by acetone fractionation of palm oil as follows:
(a) 300 g. of refined deodorised palm oil of I.V. 53.4
were mixed with 1~ litres of acetone and the mixture warmed
until a clear solution was obtained (30C). The solution was
then cooled to 6.5 C over ~ hour whilst being gently stirred
with a glass rod. It was allowed to stand for ~ hour at
6.5C and then filtered through a cooled Buchner funnel with
vacuum. The cake was pressed with a glass plunger, and then
washed twice on the filter with 250 ml. acetone at ~C, for
each wash, the cake being pressed between each wash. It wa~
then removed from the fil'cer and the residual acetone dis-
tilled off under vacuum. The yield was 93.9 g. of a frac-
tion having an I.V'. of 28.9.
(b) To 80 g. of the product of stage (a) were added
80 ml. o~ acetone and the mixture warmed to 45 C. To this
were added 400 ml. of acetone at 19C with stirring and
the final'temperature of the mixture adjusted to 26C. It
was allowed to stand at this temperature for 20 minutes and
then filtered through a Buchner ~unnel, pressed and washed
on the filter with 250 ml. acetone at 26C. The filtrate
and wash liquor were combined and the acetone removed by
distillation under vacuum. The yield was 67.5 g. Its
characteristics are given in the following table:
. : . . . ~
.: :
' ~ ' ' ' , .
.
.: :.. . . - : ,
: , ~
1083882 L 553 (R)
Component/character1stics Palm
Mid-Fraction
.~
Iodine value 34.4
Melting point (C) 33.4
Refractionation index N 5D 1.4 468
f.f.a. (%) 0.1
Monoglycerides (%) traces
Diglycerides (%) 1.5
Triglycerides ~ (%) 98.5
S3 (% of triglyceri~es) 3.1
S2U (% of triglycerides) 83.6
SU2 (% of triglycerides) 9.8
U3 (% of triglyceride~) 3.5
Fatty acid composition ~
C 14 : 0 0.4
C 16 : 0 57.1
C 16 : 1
C 17 : 0
C 18 : 0 7.5
C 18 : 1 32.0
C 18 : 2 3.0
C 20 : 0 traces
C 20 : 1
_ _ _ _ _
S = saturated; U = unsaturated
e.g. C 18 : 1 = mono-unsaturated C18 fatty acid.
l , .
-- 10
... . . . ... . . . . . . .
.:. , :.: . .:
' .: ~ ' ~ ' . ' . ' ' ,
: ~
: ~ . . I .
:: . : ;: ~ ~ .
10838~2
39.8% of the palm mid/sunflower oil blend was melted under
nitrogen, at 40C, and into this 0.2% of commercial mono-
glyceride of unhydrogenated lard of an iodine value of 44
was dissolved.
To the above mixture oil-soluble flavours and colour
were also added.
The water phase of the product was prepared by dissolving
1.75% sodium chloride in 58.25% water.
0.05% of a water-soluble lecithin fraction, obtained
through partial hydrolysis with phospholipase A of soyabean
phosphatides as described in British Patent Specification
1,215,868, was then dispersed in the water phase. (The content
of a-monoacylglycero phosphatides was about 12% of the total
phosphatide content.)
A viscosity raising agent was added to the water phase,
i.e., 0.75% locust bean gum.
The pH of the water phase was adjusted to a value of 4.5
to 5.5 by citric acid.
An emulsion of the aqueous phase in the fat phase was
prepared by slowly adding the water phase to the fat phase,
with gentle stirring, at 35C.
The emulsion formed was then processed through a conven-
tional Votator (trade mark), consisting of two A-units
tscraped surface coolers) in~which the product was worked and
cooled to 15-20C, and one P.C.U. (post-crystallising unit).
The PIT was about 28C.
Example II
A fat phase consisting of 32.15% soyabean oil (hardened
-- 11 --
tC
: ~ ' ' "' ' '
108388Z
to m.pt. 35C), 21.53% partially hardened rapeseed oil, 9.32%
soyabean oil (hardened to m.pt. 42C) and 37.0~ sunflower oil,
was refined and deodorised (~ calculated on the weiyht of the
fat blend).
The solid content of this blend was: at 10C 32%, at
20C 24%, at 30C 2.5% and at 35C 0%.
39.7% of the above blend was melted under nitrogen at
40C, and into this 0.3% of commercial monoglycerides of
unhydrogenated lard of an iodine value of 44 was dissolved.
To the above mixture oil-soluble flavours were added.
The water phase of the product was prepared by dissolving
0.5% buttermilk powder in 53.8% water.
The buttermilk solution was heated to 95C and into this
1.75% salt, 0.1% sodium tripolyphosphate, 0.1% potassium
sorbate and 0.75% locust bean gum were dissolved.
The solution was cooled to 45C and 3% cultured butter-
milk was added.
The pH of the mixture was adjusted to 4.5 to 5.Q with
tartaric acid.
An emulsion of the aqueous phase in the fat phase was
prepared by slowly adding the aqueous phase to the oil with
gentle stirring.
The emulsion was then processed through a conventional
Votator (trade mark) system consisting of an A-unit (scraped
surface cooler) and a P.C.U. (post-crystallising unit).
The product was packed into tubs at 15C.
The PIT was about 20C.
- 12 -
r~
.. , ... , .. , ... , .. . ~ 1 .;
. . .. .. . .
- : :
.
. , . . .: .
1~8~32
Example III
A fat phase consisting of palm oil mid-fraction (25%)
with sunflower oil (75%) was prepared, refined and deodorised.
The palm oil mid-fraction was prepared as descri~ed in
Example I. The solid content of the fat blend was at 10C 19%,
at 20C 12%, at 30C 1%, at 35C 0%.
39.7~ of the palm mid/sunflower oil blend was melted at
40C, and into this 0.2% of commercial monoglyceride of
unhydrogenated lard with an iodine value of 44 and 0.1% whole
soyabean phosphatides were dissolved.
The water phase of the product was then prepared by
dissolving 1.75% sodium chloride in 58.25% water.
The pH of the water phase was adjusted to a pH of 4.5 to
5.5, using citric acid.
An emulsion of the aqueous phase in the fat phase was
prepared by slowly adding the water phase to the fat phase
with gentle stirring at 35C.
The emulsion was then processed through a conventional
Votator (trade mark~, consisting of two A-units (scraped
surface coolers~ and one P.C.U. CPost crystalliser working unit).
The product was packed at 10-15C into tubs.
The amount of aqueous phase released under simulated
palate conditions (440 secs 1, 37C, 10 secs.) was 70%.
The PIT was about 26C.
Example IV
The fat phase of Example III was used.
38% of the palm mid/sunflower oil blend was melted under
nitrogen at 45C and into this 0.5~ of commercial . . . . . .
- 13 -
:
' , '` . ~
10838~2
L 553 (R)
monoglyceride of unhydrogenated lard of an iodine value of
44 was dissolved.
56.75% of water was heated to 95C and into this 1.0%
of salt and 0.75~ of locust bean gum was dissolved using
vigorous stirring to ensure complete solution of the gelling
agent.
The mixture obtained was cooled to 45C, and 3% cultured
buttermilk was added to the mix.
The pH of the mix was adjusted to 4.5-5.0 with tartaric
acid, an acid which allows a considerable drop in pH value
without imparting too acid a taste to the product.
An emulsion of the aqueous phase in the fat phase was
prepared by slowly adding the aqueous phase to the fat phase
with gentle stirring at 45C.
The emulsion was then processed through a conventional
Votator consisting of an A-unit (scraped surrace cooler)
and a P.C.U. (post-crystalliser working unit).
The product was packed at 10-15C into tubs.
The amount of aqueous phase released under simulated
palate conditions (440 sec 1, 37C, 10 secs.) was 90%.
The PIT was: about 20C.
Example V
A low fat spread was prepared as described in Example
I using 59% of the same fat blend as was used in Example I
and furthermore:
monoglycerides from unhydrogenated lard (I.V. 44) 0.2%
water 32.4%
sodium caseinate 6.2%
- 14 - ~
,, . :. , . , . . ::
. .
.
.~ ' . .
~ . . . :. - . .. ~ . : . ,
.
1083882 L 553 (R)
salt 1.5%
potassium sorbate 0.1%
sodium tripolyphosphate 0.1%
loc~st bean gum 0.5%
The pH was adjusted to 5.8with citric acid.
~The PIT was 20C.
Example VI
Example I was repeated, except that the rat blend of
Example II was used, that the partially hydrolysed phospha-
tides were replaced by whole soyabean phosphatides (0.05%)
and that the monoglyceride content was raised to 0.3%.
The proportion of water was correspondingly adjusted.
The PIT was just over 30C.
,
- ~ .
' ` . ~ ' . `'
; . ' ' . ' - ~
