Note: Descriptions are shown in the official language in which they were submitted.
t 33432 1
Liquid based comPosition comprisinq a qelling
polysaccharide capable of forming a reversible gel
and a method of preparing such composition
The present invention is concerned with a liquid based
composition comprising at least one gelling
polysaccharide capable of forming a reversible gel and a
method of preparing such a liquid based composition.
Here by a reversible gel is meant a gel that melts when
heated and again forms a gel when cooled down
subsequently. Examples of gelling polysaccharides
capable of forming reversible gels are: agar,
carrageenan, furcelleran, gellan, pectin, etc.
The preparation of reversible gels has extensively been
described in the prior art. One very well known example
is the preparation of agar gels, used to form agar
plates which are a common biological growth support.
Agar plates are conventionally made by pouring a heated
agar solution into petri dishes and leaving the dishes
undisturbed while the solution gels to an immobile
state.
One aspect of the present invention is a liquid based
composition comprising at least one gelling
polysaccharide capable of forming a reversible gel,
which composition is characterized in that, at a
temperature T, it is fluid and substantially less rigid
than the gel formed after heating said composition to
above transition temperature and subsequent cooling
under quiescent conditions to the same temperature T,
the gelling polysaccharide(s) predominantly being
present in the composition as microgels having a mean
equivalent diameter of less than 100 microns, more
preferably of less than 50 microns.
'~
~_ 2 1 33432 t L 7136 (R)
The temperature T preferably is within the range of 0C
to 100C, more preferably in the range of 5C to 50C.
The transition temperature of a particular composition
is the temperature at which, upon slow temperature
increase, the ordered form, be it of microscopical or
macroscopical size, has disappeared completely. The
transition temperature can be measured by means of
differential sc~nn;ng calorimetry. The transition
temperature of the present composition can be somewhat
higher than its gel melting point.
The gel melting point of the present composition can be
determined by measuring the melting point of a gel,
cont~i n ing exactly the same ingredients, obtained by
cooling under quiescent conditions. By cooling under
quiescent conditions is to be understood cooling in the
absence of any agitation. Here the term agitation
encompasses actions such as shearing, stirring and
shaking.
The melting temperature of a gel can suitably be
measured using the following procedure: Pour a sample
into a glass test tube and allow it to set fully at 5C.
Then place the tube in a water jacket connected to a
programmable water bath. Place a steel ball, having a
diameter of approximately 1 mm, on the surface of the
sample and depress slightly in order to minimize surface
tension effects. Equilibrate for one hour at 25C, or a
lower temperature in case of a low melting gel, and then
apply a heating regime of 0.05C/min. The gel melting
point is the temperature at which the ball begins to
sink through the sample. Movement of the ball can be
observed using a travelling microscope.
The fluid composition according to the present invention
offers several advantages. The present composition may
1 33432 1 - L 7136 (R)
be stored indefinitely in its more mobile state, but
can be returned to its normal more rigid state at any
moment, by simply heating through the transition-
temperature of said composition, whereafter the heated
solution will form a normal gel on cooling under
quiescent conditions.
Due to its mobile state, the present fluid composition
equals a pourable fluid, capable of flow and of forming
a level surface. The mobile state of the fluid
composition according to the invention thus enables
easy transportation. The composition is easily pumpable
and can be converted to a stable rigid gel whenever
desired. The rigid gel thus obtained is moreover
indistinguishable from a gel originally prepared from
the same ingredients by heating and subsequent cooling
under quiescent conditions.
The present fluid composition furthermore possesses the
advantageous property that it disrupts at low strain
(e.g. rubbing or mastication) to give a very smooth,
fat-like consistency. This property makes that the fluid
composition can suitably be turned into products such as
skin creams, moisturizer lotions, spreads, etc., by the
inclusion of suitable ingredients (e.g. perfume,
colouring, flavouring). The smooth disruption at low
strain of the present composition is essentially
different from the fracturing observed when rigid gels
are subjected to conditions of strain.
The fluid composition according to the invention can
advantageously be used as a culture medium in e.g.
Petri dishes. A proportioned amount of the fluid
composition can simply be poured into a Petri dish and
act as a culture medium. If a rigid growth support is
desired, a measured amount of the fluid composition can
be poured onto a Petri dish, after which the Petri dish
4 L 7136 (R)
1 334321
is heated to above the gel melting point and left to
cool. Thus a rigid culture medium is formed which is
indistinguishable from a medium obtained via
conventional methods well known in the art.
Another advantage of the present fluid composition is
that it can suitably be used in the preparation of
spreads. The fluid composition according to the
invention, comprising more or less discrete gelled
particles, can advantageously be dispersed in a fat
matrix so as to obtain a stable water-in-oil dispersion.
In this manner dispersions can be prepared that contain
water-soluble ingredients which would hinder the
preparation of a water-in-oil dispersion when using
conventional processing.
The use of the fluid composition according to the
invention in the preparation of water-in-oil emulsions
such as spreads furthermore offers the advantage that
the size of the gelled droplets in the emulsion depends
heavily on the size of the gelled beads in the fluid
composition. Indeed, when the fluid composition
according to the invention is incorporated into a
continuous fat phase, using conventional emulsification
techniques, the mean equivalent diameter of the
microgels before and after emulsification are not
substantially different. Thus the droplet size can be
controlled more easily than in a conventional process in
which the (heated) gelling agent cont~;ning aqueous
phase is emulsified into the fat phase.
The mobile condition of the present composition should
not be confused with the enhancement of mobility which
can be achieved by breaking up a gel into particles
which can roll and slide over one another. The gel
particles thus obtained are of macroscopical size and
are visible to the naked eye, i.e. they have an average
-~ 1 33~2~ L 7136 (R)
size exceeding 100 microns. Thus effectively such a
broken gel is composed of numerous relatively large
fragments, possessing the same properties, e.g.
rigidity, as the original gel. Another noticeable
difference between broken gels and the compositions
according to the invention is that broken gels display a
clear tendency to loose liquid.
As contrasted with broken gels, the present fluid
composition, when viewed under a microscope, is composed
of very small microgels, which microgels have a mean
equivalent diameter not exceeding 100 microns, more
preferably not exceeding 50 microns. Here the mean
equivalent diameter is the number weighted mean
equivalent diameter of the microgels having an
equivalent diameter in the range of 0.1 to 200 microns.
Most preferably the microgels present in the liquid
based composition of the invention have a mean
equivalent diameter in the range of 0.1 to 30 microns.
The equivalent diameter distribution of the microgels
can suitably be established from microscopical images.
Although such may be done by hand, in order to obtain
more reproducible results, it is preferred to determine
the diameter distribution by means of an image analyzing
computer. Of course the magnification applied should be
suitable for properly determining the diameter
distribution. For determining the diameter distribution
in the range of 0.1 to 100 microns a magnification of
800 appeared to be appropriate. Furthermore it should be
observed that the mean equivalent diameter found, when
using an image analyzing computer, may depend on the
particle concentration, since overlapping particles may
not be recognized as separate particles, but instead be
regarded as one larger particle.
Although the polysaccharide microgels in the present
- 6 1 33432 1 L 7136 (R)
composition can have a size of less than 0.1 micron or
more than 200 microns, preferably, more than 90%, more
preferably more than 95% by weight of the
polysaccharides is present in the form of microgels
having an equivalent diameter in the range of 0.1 to 200
microns, more preferably in the range of 0.1 to 100
microns.
The low rigidity of the present composition in
comparison with a gel obtained by quiescently cooling an
identical composition through its gel setting point,
can be illustrated by comparing the shear modulus of
both compositions, at the same temperature. The shear
modulus of the present fluid composition, at a
temperature T, preferably is at least 5 times as low as
the shear modulus of the gel obtained after the heating
and subsequent cooling under quiescent conditions to the
same temperature T.
The shear modulus of a composition can be determined by
using the method described further on in this
application, be it that, in order to establish the shear
modulus at a certain temperature T, the sample is
equilibrated at that temperature without precedent
heating to above the transition temperature.
By the gel setting point as referred to in this
application is meant the temperature at which, upon
slowly cooling down, an ordered structure if formed. The
gel setting point for a composition according to the
invention can be determined by heating the composition
to above the transition point, splitting it up in a
number of samples which are subsequently equilibrated,
under quiescent conditions, at different temperatures
lying 1 centigrade apart, and dropping a steel ball of
about 1 mm diameter on each of the samples after
equilibration. If the samples are ordered in accordance
~~ 7 1 3 3 4 3 L 7136 (R)
with the temperature at which the samples were
equilibrated, starting from the sample equilibrated at
the highest temperature, the gel setting temperature is
the equilibration temperature of the first sample
through which the steel ball did not sink.
In an even more preferred embodiment, the shear modulus
of the fluid composition according to the invention, at
a temperature T, is less than 200 Pa., more preferably
lo the shear modulus is within the range of 1 to 150 Pa.,
and the shear modulus of the gel obtained after heating
and subsequent quiescent cooling of the composition to
the same temperature T, is at least 100 Pa., more
preferably at least 200 Pa.
The present invention is applicable to gelling
polysaccharides whose solutions naturally form gels
comprising a macroscopical three dimensional network
structure. A number of polysaccharides display this
characteristic in a very pronounced manner, in
particular agar, kappa-carrageenan, iota-carrageenan and
furcelleran.
Although we do not wish to be bound by theory it is
believed that the mobile state of the present fluid
composition may be explained from the absence, on a
macroscopical scale, of a three dimensional network. As
can be seen from figures 1 and 2, respectively
representing a photograph of the microscopical image of
a pourable composition according to the present
invention and a micro-photograph of the same composition
diluted with a factor 10, said pourable composition is
composed of essentially non-aggregated microgels. As
can be derived from figures 1 and 2, the microgels in
the present composition may be of a spherical or
irregular shape.
- 8 1 3343~ 1 L 7136 (R)
The present fluid composition is preferably based on a
polar liquid. More preferably said liquid is selected
from the group consisting of: water, ethanol, iso-
propanol and mixtures thereof. For most purposes water
is the most suitable liquid to be used. Preférably the
present composition, at room temperature, comprises at
least 50 wt.%, more preferably at least 70 wt.% of the
liquid.
The liquid based composition according to the present
invention, besides liquid and gelling polysaccharides,
can also comprise other components. Such additional
components may be immiscible with the liquid in which
the gelling polysaccharide is dissolved. Thus the
present composition can contain two or more distinct
phases. Although, in case the additional immiscible
components account for the major part of the
composition, it may be argued that such a product is not
a liquid based composition, such a composition is
nevertheless encompassed by the present application.
Indeed the presence of a relatively mobile, gelling
polysaccharide cont~;n;ng liquid, is also appreciated in
such products contA;n;ng at least two distinct phases.
An example of a fluid composition according to the
present invention cont~;n;ng a component which is
immiscible with the liquid, is a composition comprising
a continuous aqueous phase cont~;n;ng the gelling
polysaccharide and a fat phase which is dispersed in
said aqueous phase.
The fluid composition according to the present
invention, due to its special rheology and provided the
right ingredients are added thereto, can advantageously
be utilized as a product for personal care including
cosmetic products, such as skin cream, moisturizer
lotion, hair gel, deodorant, anti-perspirant etc., or as
a pharmaceutical product such as ointment. The present
9 1 33432 ~ L 7136 (R)
fluid composition usually forms the bulk of such
pharmaceutical products or products of personal care.
The present composition can beneficially be employed in
both relatively viscous systems such as ointments and
skin creams and less viscous systems such as deodorants.
When utilized in ointments and skin creams the present
composition offers the advantage that an appropriate
rheology can be obtained without the need of using fatty
emulsions which give a persisting greasy skin feel.
When used in, for instance, deodorants, the present
composition offers the advantage that a viscous fluid
composition is obtained by the inclusion of natural
polymers, rather than the synthetic polymers normally
used. The known inclusion of gelling polysaccharides in
deodorants has the disadvantage that a more or less
rigid gel is formed, hampering discharge from the
container the deodorant is held in.
Examples of substances that may suitably be included in
the pharmaceutical products and products for personal
care according to the present invention are:
(i) Perfumes, which give rise to an olfactory
response in the form of a fragrance, and deodorant
perfumes, such as those described in US patent 4,278,658
(Lever Brothers & Co) which in addition to providing a
fragrance response, can also reduce body malodour;
(ii) Skin coolants, such as menthol, menthyl lactate,
menthyl pyrrolidone carboxylate N-ethyl-p-menthane-3-
carboxamide and other derivatives of menthol, which give
rise to a tactile response in the form of a cooling
sensation on the skin; and
- `
lo 1 33432 1 L 7136 (R)
(iii) Emollients such as isopropylmyristate, silicone
oils, mineral oils and vegetable oils which give rise to
a tactile ~.s,or-r in the form of an increase in skin
lubricity.
(iv) Deo~Lants other than ~erfumes, whose function
is to reduce the level of or eliminate microflora at the
skin surface, especially those responsible for the
development of body malodour. Precursors of ~oAnrants
other than perfume can also be employed.
(v) Anti~ers~irant actives, whose function is to
reduce or eliminate the appearance of perspiration at
the skin surface.
(vi) Anticholinergic actives, whose function is to
reduce or eliminate the generation of perspiration
before it reA~h~c the skin surface, examples of which
are scopolamine derivatives, such as scopolamine
hydrobromide and esters thereof, such as benzoyl
scopolamine hydrobromide.
(vii) Emulsifiers
Emulsifiers may be nonionic, anionic or cationic.
25 Examples of suitable emulsifiers are:
HLB value
BRIJ 72 (Polyoxyethylene-2-stearyl ether) 4.9
BRIJ 52 (Polyoxyethylene-2-cetyl ether) 5.3
(viii) Activitv Enhancer
The composition according to the invention can also
optionally comprise an activity ~hA~c~r, which can be
chosen from a wide variety of molecules. Particular
classes of activity ~hAn~rs include penetration
e~hAnc~rs and cationic polymers, Reference is ~ade to
European patent publication No. EP O 342 054, in
which various suitable activity e~hAncers are mentioned.
~~ 11 L 7136 (R)
~ 33432 1
(ix) Suncreens
The emulsion according to the invention can also
optionally comprise one or more sunscreen active
ingredients.
The amount of the sunscreen active ingredient that can
optionally be employed in accordance with the invention,
as a therapeutically effective amount, will normally be
from 0.01 to 10%, preferably from 0.1 to 5% and most
preferably from 1 to 5% by weight of the composition.
In addition to the above ingredients conventionally
used in products for personal care, the composition
according to the invention can optionally comprise
ingredients such as a colourant, preservative,
antioxidant, in amounts which are conventional in the
cosmetics, pharmaceutical etc.
The present fluid gelling polysaccharide cont~;n;ng
composition, when having an appropriate rheology and
cont~;n;ng particular ingredients such as flavouring,
colouring, preservative, fat, etc., can suitably
constitute a food product such as a spread, in
particular a low calorie spread.
The composition according to the invention can contain
various other ingredients such as colouring agent,
flavouring, fat, salt, anti-oxidant, emulsifier etc.
Preferably the composition according to the invention
the composition is edible and contains, in combination,
at least 90 wt.% of water and/or fat. Most preferably
the present composition is water-continuous and contains
from 5 to 30 wt.% fat.
The liquid in the present fluid composition preferably
contains gelling polysaccharide(s) in an amount capable
~ 12 L 7136 (R)
1 33~321
of quiescent gelation. Here by the liquid is meant that
liquid phase in the product in which the gelling
polysaccharide dissolves most easily. The amount of
gelling polysaccharide can lie below 12 wt.%, but even
higher concentrations are possible. A more preferred
range of gelling polysaccharide, calculated on the
liquid, is 0.1-15 wt.%. For agar a preferred range is
0.2-5% by weight of the liquid. For carragPPn~nc and
furcelleran a preferred range is 0.5 to 10% by weight of
the liquid. According to a preferred embodiment of the
invention the liquid constitutes a continuous phase in
the present composition.
The composition according to the invention can contain
materials which have the effect of modifying the gel
melting and setting temperature, for example ion-
sources such as salts, which have a strong influence on
the gel melting and setting point.
Another aspect of the present invention is a method of
preparing a fluid composition containing a sufficient
amount of at least one gelling polysaccharide to form a
reversible gel on quiescent cooling, wherein a liquid
containing the gelling polysaccharide(s) is subjected to
sufficient shear while cooling the liquid through its
gel setting temperature to obtain a substantially less
rigid composition than would be obtained by quiescent
cooling.
Although it is possible to obtain the advantages of the
present process whilst cooling down through a very
narrow temperature range, preferably shear is applied
while cooling down the liquid containing the gelling
polysaccharide(s) through a temperature range of at
least 10C. More preferably shear is applied while
cooling down the liquid cont~;n;ng the gelling
polysaccharide(s) from at least 10C above the gel
_ 13 1 33432 1 L 7136 (R)
setting point to at least 10C below the gel setting
point.
The following method can be used to determine, for a
given composition and at a certain cooling rate, the
shearing time required to obtain a suitable product:
C Fit a Bohlin VOR Rheometer, or equivalent apparatus,
with a 30 mm plate and 5 degree cone geometry and water
bath. Set the water bath temperature at least 10-C
higher than the transition temperature of the material
to be tested. Place the liquid sample of the
polysaccharide to be tested between the cone and the
plate and set the gap at the plate edge to be 1 mm.
Apply silicone oil to the plate edge to prevent the
sample from drying out.
Allow ten minutes for the sample to equilibrate with
the water bath temperature. Meanwhile, set the frequency
of oscillation (f) to be 1 Hz and the strain to be 7.2
degrees. Set a rate of cooling equal to or at least
similar to that used in the method of preparing the
fluid composition and cool to a temperature of at least
10C below the gel setting temperature of the test
material.
Start continuous sinusoidal oscillation and record
compliant strain at convenient time intervals (t) during
cooling and for at least 1 hour after the lower
temperature has been reached.
Calculate the shear storage modulus (G') from the
relationship:
O o
G' = (~ 2l ) cos
where
~2,=~l/sin~t+d)
2/ / sin ~t
_ 14 1 33 432 1 L 7136 (R)
is the shear stress
~ is the shear strain
and ~ is the phase angle
More detailed information can be found in "Viscoelastic
Properties of Polymers" by J.D. Ferry, Chapter 1, pages
4-16, Std Book Number 471 25774 5, published by J. Wiley
& Sons Inc.
The equilibrium value of G', which can be derived from a
plot of G' versus time, is then characteristic of the
gel formed. An example is given in figure 3 for 50:50
kappa/iota carrageenan (1% w/w) in aqueous NaCl (1.5%
w/w) and potassium sorbate (0.2% w/w) solution.
Referring to the above method of analysis, in the
present method of preparing a fluid composition, the
shearing is preferably started before G' assumes 5%,
more preferably 2% of its equilibrium value, and
shearing is not stopped before the G' assumes 90%, more
preferably 95% of its equilibrium value. In order to get
a useful indication as to the period during which shear
must be applied in the present process, it is crucial
that the cooling regimes applied in the method of
analysis is very similar to the cooling regime applied
in said process.
The present process can be carried out as a batch
process, but it is preferred to carry out the process in
a continuous or semi-continuous manner by, for instance,
continuously passing a (pre-heated) stream of gelling
polysaccharide cont~in;ng liquid through one or more
cooling and shearing units.
The present invention encompasses a process for
preparing a fat-continuous dispersion, cont~ining a
dispersed aqueous phase, by inversion of an oil-in-water
1 33432 t L 7136 (R)
emulsion to a water-in-oil dispersion. In the latter
process an oil-in-water emulsion containing a sufficient
amount of gelling polysaccharide to gel the aqueous
phase, is cooled through the gel setting temperature
under conditions of shear. Thus the continuous aqueous
phase is converted to a fluid composition composed of
microgels. After the formation of the microgels the
cooling and shearing conditions will induce the
inversion of the water-continuous emulsion to a water-
in-oil dispersion.
The present invention also encompasses the application
of more than one gelling polysaccharide. In case the
present gelling polysaccharides containing liquid
comprises two or more gelling polysaccharides at
respective concentration levels exce~ing the critical
concentration of the polysaccharide in said composition,
the liquid must be sheared through the gel setting
points of each of said polysaccharides. The critical
concentration of a gelling polysaccharide in a
particular composition can be calculated from
measurements of the shear modulus of a series of-samples
containing different concentrations of gelling agent, as
described in Br. Polymer J. 17 (1985), 164.
The invention is further illustrated by means of the
following examples:
Example 1
A formulation was prepared consisting of 1 wt.% agar
(OxoidTM Lll) and 99 wt.% deionised water. The agar was
dissolved in the water at 80C after which the solution
was warmed to 95C and then allowed to cool slowly in a
glass beaker while stirring vigorously with a magnetic
stirrer. Cooling was continued until the stirred
solution reached a temperature of 13C. For cooling
below room temperature the solution the beaker was
- 16 1 33432 1 L 7136 (R)
immersed in ice water.
The solution was allowed to warm to 20C. Both at 13C
and 20C the solution was a pourable liquid. It was
found that this liquid was stable and could be stored at
room temperature for six months without apparent change
in its condition. Other materials could additionally be
stirred into the liquid, again without change in its
condition.
A sample of the liquid was reheated to 95 D C and then
allowed to cool without agitation. It cooled to a rigid
gel which was indistinguishable from the gel obtained by
cooling, under quiescent conditions, a sample of the
original heated solution of agar. The shear modulus of
the rigid gel obtained after reheating is more than 5
times as high as the shear modulus of the pourable
liquid obtained through sheared cooling.
Example 2
Example 1 was repeated but after dissolving the agar and
warming the solution to 95C it was cooled in a
continuous process with throughput of 25g per minute.
The solution was cooled during passage through four
units of apparatus. In the first, third and fourth units
(known as VotatorsR) the solution was subjected to shear
by scraping over a cooled surface. In the second unit
(called a C-unit) the solution passed through the
annular space between a rotor bearing radially
projecting pins and a surrounding cooled jacket from
which pins projected radially inwardly towards the
rotor. The jackets of all four pieces of apparatus were
cooled by water at 10C.
The agar solution obtained by cooling with this
continuous process was again a stable pourable liquid
which could be stored and which could be converted to a
1 334321
`~ 17 L 7136 (R)
rigid gel by heating to 95C and then allowing to cool
without disturbance. The shear modulus of the rigid agar
gel obtained after reheating the pourable liquid is more
than 5 times as high as the shear modulus of the
pourable liquid obt~;n~ through sheared cooling.
Example 3
Example 2 was repeated using a formulation consisting of
2% agar and 98% deionised water and cooling under shear
in a single C-unit to a pourable liquid which could be
converted to a self supporting rigid gel by reheating to
95 D C and allowing to cool undisturbed. The shear modulus
of the rigid gel obtained after reheating is more than 5
times as high as the shear modulus of the pourable
liquid obtained through sheared cooling.
The pourable liquid was viewed under a microscope at a
magnification of x320. A photograph of the image
obtained is represented in figure 1. The pourable liquid
was subsequently diluted by a factor 10 with deionised
water after which a sample was taken and viewed under a
microscope at magnification x400. A photograph of the
image is represented in figure 2.
The mean equivalent diameter of the microgels present
in the sample obtained a~ter dilution was determined by
C means of a Quantimet 970 particle size analyzer. The
mean equivalent diameter, having measured 514
microgels, was found to be about 10 microns. Less than
5% of the particles appeared to have an equivalent
diameter of more than 25 microns. In fact the true mean
equivalent diameter was even less than lo microns as
some overlap between microgels was observed.
~Tro_Je,~~ o ~k
~ 18 1 33432 I L 7136 (R)
Example 4
A formulation was used consisting of:
1.3% carrageenan
0.41% sodium chloride
1.05% potassium sorbate
-- balance deionised water --
The carrageenan was kappa and iota carrageenan in a
weight ratio of 70:30.
The carrageenan and the salts were dissolved in the
deionised water at 80C and briefly heated to 95-C. The
solution was allowed to cool to 66C and then cooled
from 66C to 30C while applying shear. Cooling while
applying shear was carried out by passing the solution
through a cooled VotatorR.
The cooled composition was a thick pumpable liquid
which, when heated slowly, showed a rapid loss of
viscosity at approximately 55C. The shear modulus of
the rigid gel obtained after reheating to 95C and
subsequent cooling is more than 5 times as high as the
shear modulus, measured at the same temperature, of the
pourable liquid obtained through sheared cooling.
Example 5
A formulation was prepared containing:
1.3% carrageenan (70:30 kappa:iota)
0.41% sodium chloride
0.15% potassium sorbate
-- balance deionised water --
The solids were dissolved in the water at 80-C and then
cooled while shearing as described in example 4. After
cooling the product was a thick liquid which, upon
slowly heating, displayed rapid ~h;nn;ng at 35C.
_ 19 1 33432 1 L 7136 (R)
ExamPle 6
Examples 4 and 5 were both repeated using a carrageenan
which was a blend of equal parts of kappa and iota
carrageenan. Very similar results were obtained but it
was found necessary to apply more vigorous shear to the
solution during cooling.
Example 7
A formulation was prepared consisting of:
4% carrageenan (kappa:iota 85:15)
0.41% sodium chloride
1.05% potassium sorbate
-- balance deionised water --
The solids were dissolved in deionised water at 80C and
then cooled while applying shear as in example 4. The
product after cooling was liquid with a rather thick
consistency.
Example 8
A formulation was prepared consisting of:
4% kappa carrageenan
9% hydrolysed starch
0.41% sodium chloride
1% potassium sorbate
-- balance deionised water --
The procedure of Example 4 was again followed. The
product after cooling with shear had a consistencyresembling petroleum jelly. Aggregation of the
hydrolysed starch in the product had increased the
light scattering of the solution so that the product had
an opaque appearance.
Example 9
Example 4 was repeated using 1% carrageenan which was a
- 20 1 33432 1 L 7136 (R)
blend of 60:40 kappa:iota carrageen~n~. Essentially
similar results were obtained.
Example 10
A moisturizer lotion was made on the basis of the
following ingredients:
Ingredient wt.%
Kappa-carrageenan X6960 1 1.05
Iota-carrageenan X6955 0.45
Glycerol 3.00
Sodium chloride 0.60
NipagenTM M 2o.10
Colouring agent 0.03-0.06
15 Flavouring 0.10
Water balance
1 ex Copenhagen Pectin Factory, Copenhagen, Denmark
2 Sodium methyl para benzoate, preservative, ex NIPA
Laboratories, LLantwit Fadre, Pontypridd, Wales
Four different samples were made in the same manner as
described in Example 4, using different colouring agents
and flavouring, namely:
Sample Colouring Agent Flavour
(a) Pink 0.05% Natural Pink Raspberry oil
(b) Blue 0.06% Indigo Carmine Cherry oil
(c) Yellow 0.06% Crocin Eucalyptus
Citriodora oil
(d) Green 0.03 Copper Chlorophyll Apple oil
The lotions obtained when rubbed over the skin,
appeared to be both cating and moisturizing. After a
short period of rubbing the skin appeared to be very
smooth and non-greasy.
Example 11
A moisturizer cream was made on the basis of the
following ingredients:
- 21 1 33432 t L 7136 fR)
Ingredient wt.%
Kappa-carrageenan X6960 0.840
Iota-carrageenan X6955 0.360
5 Glycerol BP 3.000
Sodium chloride 0.410
Potassium chloride 0.045
Colouring agent 0.03-0.06
Flavouring 0.10
10 Water balance
Four different samples were made in the same manner as
described in Example 4, using different colouring agents
and flavouring, namely:
Sample Colouring Aqent Flavour
(a' Pink 0.05% Natural Pink Raspberry oil
(b Blue 0.06% Indigo Carmine Cherry oil
20 (c,, Yellow 0.06% Crocin Eucalyptus
Citriodora oil
(d) Green 0.03 Copper Chlorophyll Apple oil
The moisturizer creams were found to have a clear
smoothening and moistering effect when rubbed over the
skin.
Example 12
A cleanser gel was prepared in the same manner and from
the same ingredients as in Example 11, with the
exception that instead of glycerol, the starting
material contained 7.5 wt.% Brij 58 (Nonionic
surfactant ex. Sigma Chemicals Ltd., Poole, Dorset BH17
7NH, England).
ExamPle 13
A water-continuous vaseline-like product was prepared
from the following ingredients:
40 Ingredient wt.%
Kappa carrageenan X6960 4.00
Sodium chloride 0.41
Potassium sorbate1.05
Glycerol 3.00
45 Water balance
22 f 33432 1 L 7136 (R~
The above composition was processed by passing the hot
mixture held at 93C, through a scraped surface heat
exchanger (VotatorTM) operating as follows:
Unit speed 4200 rpm
Jacket temperature 16C
Inlet temperature 68C
Exit temperature 38C
Feed rate 50 g/min
The product so obtained appeared to have a gel melting
point of about 55C and had a viscosity and skin feel
very similar to vaseline.
Example 14
A water-continuous spread was prepared on the basis of
the following formulation:
20 Ingredient wt.%
Kappa Carrageenan X6960 2
Palm kernel oil (hardened to a
slip melting point of 38C) 24
Sunflower oil 16
25 Sodium chloride 0.5
Potassium sorbate 1.05
Sodium caseinate 0.6
Flavour & beta carotene
Water to 100
The formulation was selected to give a gel melting
temperature of 49C. The formulation was made up by
dissolving the water soluble ingredients to which the
melted fat was added and then homogenised at 2000 psi
using a CrepecoTM homogeniser. The pH was then adjusted
to 5.8 using lactic acid.
The mixture was then processed by passing it through a
cooled scraped surface heat exchanger (VotatorTM)
running at 3000 rpm, with the jacket temperature set to
decrease the temperature from 90 to 30C at a throughput
of lOOg/min.
1 33432 1
~ 23 L 7136 (R~
A second product was made using a fat phase of 60 wt.%
hycoa 5, 40 wt.% sunflower oil and an aqueous phase of
3.3 wt.% kappa carrageenan, 1.75% potassium sorbate and
0.85 wt.% sodium chloride. This gave a gel melting
temperature of 67C. Both products were smooth and
spreadable with no oiling off even when the temperature
was cycled between 45C and 35C for 1 month. Thus
products of this type are very suited for production and
sale in tropical countries.
Example 15
A fat-continuous spread was prepared from the following
formulation:
Aqueous phase
Sodium chloride 1.0 wt.%
Potassium sorbate 0.08 wt.%
Agar 1.2 wt.%
Water 57.72 wt.%
pH adjusted 5.5 with lactic acid
Fat phase
Hardstock 17.6 wt.%
Sunflower oil 22 wt.%
Monoglycerides 0.2 wt.%
25 Lecithin 0.2 wt.%
Colouring and flavouring
The aqueous phase, having an initial temperature of
90C, was sheared and cooled in two cooled C-units, both
running at 1400 rpm and with a final exit temperature of
approximately 20C. The microgels in the product so
obtained had a volume weighted mean diameter of 10
microns and was stored at 4C overnight. After storage
the aqueous phase was heated to 40C and mixed with the
fat phase. A spread was made using a sequence consisting
of a scraped surface heat exchanger, a C-unit, a second
scraped surface heat exchanger and a second C-unit. The
througput employed was 50 g/min with shaft speeds of
approximately 1000 rpm. The dispersed aqueous phase was
found to have a volume weighted mean diameter of 9
microns.
24 1 334321 L 7136 (R)
Similar results were obtained when the agar
concentration in the aqueous phase was reduced from 1.2
wt.% to 0.6 wt.%, with no holding overnight.
Example 16
A growth support medium was prepared from the following
formulation:
Ingredient wt.%
OxoidlM Lll Agar
OxoidTM Broth No 2 2.5
Water to 100
The ingredients were dissolved into the water at 90C. A
sequence of four cooled shearing devices (a scraped
surface heat exchanger (A-unit) followed by a C-unit, a
second scraped surface heat exchangers and a second C-
unit) were washed with ethanol and then agar and broth
were passed through. The processing conditions employed
were as follows:
Processing unitrPm exit temperature
A-unit 1 4000 23C
C-unit 4000 24C
A-unit 2 1500 21C
C-unit 3 1500 12C
A smooth pourable liquid was obtained at a throughput of
5Og/min, which pourable liquid did not form a rigid gel
on holding at 5C for weeks.
