Title of Invention

PROCESS FOR PRODUCING SEED CRYSTAL SUSPENSIONS BASED ON MELTED FAT AND APPARATUS THEREOF

Abstract The invention relates to a method and to a device for producing seed crystal suspension that are based on melted fat, especially, for producing stable, microdisperse cocoa butler crystal suspensions that have a high ßVI modification share. The invention further relates to the use of said suspensions in the seed crystallization of fat-based suspensions that contain disperse solid particles such as chocolates and chocolate-like masses or the lite where the melts are seeded with the crystal seed suspension. The inventive method facilitates an improved dosability vis-à-vis seeding methods that use crystal powders since it is easier to dose liquids. The inventive mechanic/thermal shearing/extensional flow treatment of the seed crystal suspensions allows the production of substantially smaller seed crystals than according to conventional powder-based seed crystallization methods and thus an improved microhomogeneous mixture and higher seeding efficiency (reduced seed crystal share to obtain an optimum pre-crystallization) as well as an increased share of the highly stable ßVI crystal modification.
Full Text Description
Class
The invention relates to a process for producing seed crystal suspensions based on melted
fat, in particular for generating stable microdisperse cocoa butter crystal suspensions
which have a high ßVI modification share and its use in the seed crystallization of fat-based
suspensions containing disperse solid particles such as chocolate, chocolate-like masses, or
the like.
Furthermore, the invention relates to an apparatus for carrying out the process.
State of the Art
"PROCESS FOR PRODUCING SEED CRYSTAL SUSPENSION BASED ON
MELTED FAT AND APPARATUS THEREOF"
The aim of the so-called precrystallization step in the conventional production of chocolate
or chocolate-like masses is the generation of a sufficiently large number of fat crystal germs
which, after the forming or molding of the mass, initiate the further solidifying
crystallization in the subsequent cooling process. It is of particular importance therein that
the germ crystals generated in the precrystallization step are present in a desired stable
crystal modification. For the cocoa butter fat system these are the so-called ßv and ßvi
crystal modifications in which the principal triglycerides of the cocoa butter (SOS, POP,
SOP, S = stearin, O= olein, P = palmitin) are present arranged in a triclinic crystal lattice.
So-called unstable modifications are the ?-crystal structures (amorphous), a-crystal
structures (hexagonal), and ßrv-crystal structures (orthorhombic). The modification of the
crystal germs determinatively affects the formation of additional crystals during the
cooling and solidification of the molded, precrystallized masses.
To the extent that the germ crystals consist predominantly of unstable modifications, a
predominantly unstable rigid end product results as a consequence after the termination of
the cooling process in the production process. During storage unstable crystals are
converted into stable modifications even at low storage temperatures since they are
thermodynamically more stable and therefore of lower energy. Crystals of unstable
modifications have a less dense hardening structure. This, and the diffusion process
running during the modification conversion, require that, in particular, fat portions with a
low melting point are "transported" to the surface of the chocolate product and there form
a crystal film, so-called bloom. This bloom causes the graying of the chocolate surface and
thereby a clear affect on the quality of the chocolate. If sufficiently stable crystal germs are
generated during the precrystallization, no bloom formation is shown during storage.
Along with the generation of crystal germs which are as stable as possible during the
precrystallization, it is in particular also a goal to minimize as much as possible the total
amount of the generated crystal germs without endangering the effective precrystallization
quality, since this leads to a reduced viscosity during molding or forming of the
precrystallized mass and thereby to processing advantages. Low mass viscosities are a
prerequisite for the uniform forming, for example, in production of coatings for filled
products (production of hollow bodies) in order to insure uniform wall thicknesses.
In traditional precrystallization processes ca. 0.5 to 2% relative to the total fat mass are
solidified in the form of germ crystals. Depending on the origin (provenance) of the cocoa
butter as well as due to the physical/chemical interaction between the triglycerides (fats)
and other components of the formulation (in particular emulsifiers), the crystallization
kinetics can run differently. This necessarily leads, with the largely determined dwelltime
in the industrial process, to sharp deviations in the precrystallization state, which has an
effect on the quality of the product. In the traditional precrystallization technology it is
attempted to realize as optimal a precrystallization as possible by variation of a step-wise
management of the temperature. This requires on the one hand much empirical experience
and on the other hand the adjustability is problematic even for small deviations in
temperature in the precrystallization process (for example, +/-1° C).
The so-called temperature meter process serves to monitor the precrystallization quality in
the traditional process monitoring (offline). In this measurement process a small sample
volume, which is drawn from the precrystallization apparatus at precrystallization
temperature, is introduced into a sample tube, at whose center a temperature sensor in
installed. The sample tube is cooled under defined temperature conditions (water bath) and
the temperature curve measured in the sample. The temperature curve determined reflects
the curve of the solidifying crystallization in the sample. The "inclination toward
crystallization" can be identified in this manner with a certain temperature curve (as a
function of time) due to the precrystallization release of heat of the sample. Depending on
the form of a temperature curve of this type one skilled in the art can make a classification
of "over, under, and well temperature-controlled".
Traditional processes or apparatuses for the precrystallization of chocolates work
according to the principle of a step-wise temperature control. This means that the chocolate
mass arriving at temperatures > 45° C in a temperature controller (precrystallizer) as a
rule is easily precooled in three temperature control zones (temperature control zone 1: ca.
30° C), then supercooled (temperature control zone 2: 25 to 27° C), and finally warmed up
to a processing temperature (temperature control zone 3: 28 to 31° C). The exit
temperature from traditional precrystallizers (temperature controllers) is between 28 and
31° C, in rare cases slightly over 31° C. If a mass is pretemperature-controlled as described,
then the direct analysis of the germ crystals arising, said analysis being performed by
means of a so-called direct DSC (Differential Scanning Calorimetry) measurement on the
mass drawn after the crystallizer, shows a typical crystal modification spectrum. In the
case of cocoa butter as a continuous fatty phase, the predominant share of the crystal
germs consists of ßv-crystals (50-70%), followed by Prv-crystals (20-40%), as well as in
part of remnants of a-crystals (ca. 10%). As a rule a predominant share of Pv-crystals
guarantees that the solidifying crystallization will achieve a sufficient quality of structure to
insure bloom stability and other marks of quality (for example, crisp breaking behavior,
soft melt). Nonetheless, in the case of traditional crystallized chocolate masses, in particular
when fatty shares with a low melting point (for example, milk fat or nut oil) are also
contained, quality deficiencies frequently occur due to the formation of bloom. Partially the
bloom first shows itself after 2-3 months storage (possibly even longer). Chocolates with
bloom cannot be sold or lead to customer returns.
From WO 98/30108 a process for the precrystallization of chocolates is known in which the
melted product is seeded directly with a crystal powder. As will be described further below,
the seeding by means of crystal powders is associated with numerous disadvantages in
practice.
Objective
The objective of the invention is to produce concentrated (crystal share of 5-35% by
volume) seed crystal suspensions which contain microdisperse (particle diameter micrometers (µm)) nearly exclusively (> 95%) thermally highly stable (polymorphous
crystal modification with the highest melting point, for example, ßvi-modification in the
case of cocoa butter) fat crystals and to dose and homogeneously mix them continuously
and uniformly in low concentration (crystal share ca. 0.01-0.2%) into the product flow
previously brought to seed temperature and thereby to improve traditional processes of
precrystallization in such a way that even with a clear increase (ca. 2 - 3° C) the mass
temperature over the prior-art precrystallization temperatures (for chocolates previously
at most ca. 31° C) in contradiction to traditionally precrystallized masses the crystal germs
do not melt in such a way that the desired crystallization initiation capacity is lost on
cooling of the mass but is instead preserved to the extent required and that thereby even at
increased molding temperatures of ca. 34° C in the case of chocolates, or greater deviations
of molding temperatures, faultlessly crystallized products with very good quality
characteristics can be produced and moreover the reduction in viscosity setting in at the
high processing temperatures according to the invention can be utilized advantageously in
the production process.
Furthermore, the objective of the invention is to provide an apparatus for carrying out the
process according to the invention.
Accordingly, the present invention provides a process for
producing seed crystal suspensions based on melted fat, in particular for
generating stable microdisperse cocoa butter crystal suspensions with a high ßVI
modification share and for its use in the seed crystallization of fat-based suspensions
containing disperse solid particles such as chocolate, chocolate-like masses, or the like
with adjustable total crystal content (I), share of ßVI-crystal modifications (II) with a
high melting point as well as average crystal size (III) wherein cold-sprayed fat powder
is subjected to a step-wise thermal conditioning in such a manner that without
clumping of the powder particles a modification conversion of the polymorphous fat
system advances so far that the thermally highly stable ßVI-modifications are formed at
a share of > 10%, the fat powder conditioned in this manner is suspended to > 1% in a
crystal-free melted fat temperature-controlled to about l°-2° below the melting
enthalpy peak minimal temperature of the ßVI-crystal modification, and this fat powder
suspension is treated with defined coordination of mechanical and thermal stresses as
well as the dwelltime in a shear/extensional flow until reaching the characteristics set:
total crystal content, ßVI crystal modification share, and average crystal size, and the
seed crystal suspension thus generated is uniformly dosed into the product flow of a
precrystallizing chocolate or chocolate-like masses with seed crystal shares between
0.01 and 0.2% (relative to total mass) and thereafter protectively, homogeneously, and
continuously mixed into the product flow.
The present invention also provides an apparatus consisting
of a cold-spray tower, . a temperature control chamber, a
suspension stirring container, a shear/extensional flow module, a pump, and a static
mixer for carrying out the process as defined herein, . where in the cold-
spray tower the cold-spraying of the melted cocoa butter fat or a mixture of cocoa
butter and other fats can be performed according to the invention in a cold gas flow
which can be set to a temperature of 10°-50° C below the crystallization temperature of
the fat component with the lowest melting point of the sprayed fat system and fat
particles can be generated, by means of a nozzle with spray pressures of 1-500 bar
excess pressure, with diameters conveyed into the temperature control chamber where in a thermal conditioning (10) of
two or more steps with selectable temperature-time curves with plateau temperatures
of preferably -10 and + 25 or + 28° C the controlled modification conversion (formation
of > 10-50% ßVI share) takes place without clumping of the spray particles and
subsequently the powders conditioned in this manner are suspended in a
stirring/mixing container temperature-controlled to ca. 26-32.5° C, which is assembled
with stirring elements mixing homogeneously and protectively at low speeds of rotation,
in a cocoa butter or melted fat mixture supercooled to ca. 26-32.5° C and subsequently
these spray powder fat crystal suspensions are sheared in a shear/extensional flow
module (8), through which there is a continuous axial flow and which according to the
invention preferably consists of a concentric or eccentric cylindrical shearing column
which has a column width adjustable to 5-30° C with setting of the speed of axial flow through the shearing
column to to 2 m/s in such a manner that the exit temperature of the crystal suspension from the
shearing column due to the superimposed viscous energy dissipation through shearing
and heat discharge can be set between 32° and 34.5° C, precise to 0.5° C, and
simultaneously a fine dispersion of the crystals to diameters of (µm) (from a starting size of ca. 50 to 500 u.m) is done and furthermore, as a function of
the shearing, wall temperature, and dwelltime in the shearing column, the exiting
crystal suspension can be controllably and regulably set to a crystal content of 5 to 35%
via the torque transferred to the rotating inner cylinder and thereafter the seed crystal
suspension is dosed continuously in small amounts of kg product into the product flow of a chocolate or chocolate-like mass with temperature
controlled to 32° to 34.5° C with a dosing pump working mechanically protectively
and is mixed homogeneously and protectively into the product flow by means of a static
mixer, "
Several Advantages
In the process according to the invention the production of concentrated (crystal share 5-
35% by volume) seed crystal suspensions, which contain microdisperse (particle diameter 10 micrometers (µm)) exclusively thermally highly stable (polymorphous crystal
modification with the highest melting point 50-95% ßVI-modification in the case of cocoa
butter, rest ßV-modification) fat crystals, is done in a process according to the invention
comprising up to three treatment steps. These three treatment steps are:
1. A cold spray step in which a melted fat (for example, cocoa butter) is sprayed into a
supercooled space and is solidified to form a powder capable of flowing with powder
particle sizes of ca. modifications (for example, ?-modifications, a- modifications, and ßIV modifications in
the case of cocoa butter).
2. A multi-step thermal conditioning step is performed in which a modification
conversion of the fat crystals is done until reaching a ca. 50% share of the most stable
crystal modifications (ßVI modifications in the case of cocoa butter).
3. A shearing/extending treatment step in which with the input of mechanical energy the
crystal powder from step 2 suspended in a melted fat is sheared/extended where
under suitable coordination of the input of mechanical energy, temperature, and
dwelltime a reduction of the suspended crystal particle size through partial melting
and mechanical decomposition processes and a nearly complete (>/+ 95%)
modification conversion into the crystal modification with the highest melting point as
well as a setting of the crystal share to 5-35% by weight takes place. The
shearing/extending treatment step is preferably done in a cylindrical column through
which flow occurs axially with a rotating inner cylinder with adjustable speed of
rotation which can also have a scraping element installed. With respect to the speed of
rotation the degree of shearing and extension can be set substantially independently of
mass flow.
The addition of cold-sprayed (process step I) and conditioned (process step II) powder
containing ca. 50% ßVI-cocoa butter powder is in principle absolutely necessary only in the
first application of the seed crystal suspension. If liquid cocoa butter is added to a remnant
of this suspension, new seed suspension can be generated within a time period of ca > 30-60
minutes (depending of the input of mechanical energy) with temperature and stirring
conditions held constant.
In a particular form of embodiment of the process according to the invention the
generation of a seed crystal suspension can also be done without the process steps I and II,
that is, by direct production of the supercooled melted fat in a shear treatment step.
Therein however, for crystal germ formation initiation, there is the necessity of setting
clearly lowered wall temperatures of the shearing geometry through which flow is to occur
(of ca. 10 to 28° C for cocoa butter) and extending the dwelltimes in the shear flow field
sufficiently, that is to 20 to 500 s, in order to be able to be able to set a desired germ crystal
content of 5 to 35% by weight. In this special case of the restriction on process step III,
however, no ßVI-crystal germ content (in the case of cocoa butter) > 50% can be achieved
with a one-time passage through the shearing treatment step with reduced wall
temperature. Instead of this the lowered wall temperatures necessary for the acceleration
of crystal germ formation and crystal growth kinetics cause additional Pv-germ crystals to
arise (for cocoa butter) to the extent of > 50%. In so far as a multiple passage through the
shearing step is realized, the ßVI share can be increased if as of the 2nd passage there is also
an increase of the wall temperature to 25 - 32° C. A multiple passage through the shearing
step can also be done in principle by performing such shearing steps one after the other.
In the case of chocolate or chocolate-like masses with cocoa butter shares in total fat of >
5% a crystal germ suspension produced as described initially is continuously dosed in
shares with 0.01 to 0.2 % by weight crystal share (relative to the total mass) into the mass
precooled to temperatures between 32 and 34.5° C in the case of pure cocoa butter fat or
between 27 and 34.5° C in the case of masses with shares of fat with a low melting point.
The microhomogeneous mixing is done in a temperature-controlled, static mixer integrated
into the product tube line.
The seeding by means of a germ crystal suspension permits clear advantages to be realized
vis-a-vis direct seeding with crystal powders. These are essentially:
1. Improved dosability since fluid dosing is possible. The exact dosing of fat crystal
powders is comparatively extremely difficult and, with restrictions in the dosing
quality, only possible in open containers. Open containers are not desirable in
continuous industrial processes (hygiene, operational reliability).
2. Better microhomogeneous mixing in the chocolate matrix results due to the presence
of individual seed crystals in the suspension. In the case of dosing of seed crystals in
powdered form a partial conglomeration of the powder particles results as a rule as
soon as, or even before, contact with the fluid phase is produced.
3. Clearly smaller germ crystals (ca. suspension by stressing it mechanically and thermally, in part via so-called secondary
nucleation. By comparison, minimal fat particle sizes of only ca. 20-200 micrometers
can be achieved with cold-sprayed or cold-milled fat powders. Thus a higher
numerical density of crystal germs in the product volume (chocolate) than with
powders can be achieved with shearing-treated seed crystal suspensions with clearly
lower seed crystal mass dosing.
This leads to a faster and more homogeneous solidification of the product on
subsequent cooling in a cooling tunnel.
4. A higher seeding efficiency vis-à-vis crystal powders can be achieved, despite the
reduced total amount of added crystals, with the use of seed crystal suspensions for
setting a comparable precrystallization quality (on the basis of Points 1-3). This has
as a consequence the fact that the processing viscosity of the mass does not increase
after seed crystal dosing in the case of seed crystal suspensions, as in the case of the
addition of seed powders, but rather can be lowered still further. This offers
advantages for the further processing steps (for example, the molding process).
In the solidifying crystallization in the case of chocolate or chocolate-like masses which are
seeded with ßVI-crystals, surprisingly predominantly ßV-crystals as well as, in given cases, a
very small percentage ( precrystallized with ßVI-crystals as a rule do not have a melting spectrum shifted
significantly toward higher melting temperatures in comparison to traditionally well
precrystallized chocolate masses, a-shares are not observed. Since the ßV-modification has
precisely the same crystal lattice structure (triclinic crystal lattice) as the ßVI-modification
(seed germs), the described effect of the ßVI-seeding, that is, the generation of nearly
exclusively Pv-crystals, appears physically completely logical, if surprising.
There is a significant difference between traditional precrystallization and seed
precrystallization with ßVI-germs with regard to the possible exit temperature from the
precrystallization process. In traditional precrystallized masses, which typically are
processed further at temperatures of 28-31° C (molding, forming processes), sufficiently
effective amounts of germ crystals are no longer present at temperatures > ca. 31.5 to 32°
C. The mass then crystallizes without control. In the case of seed crystallization with ßVI-
crystal germ suspensions still sufficient germ crystals are obtained even at mass exit
temperatures (or seed temperatures) of 34° to 34.5° C.
In contradistinction to ßV-crystal germs generated in the conventional precrystallization
process, the cocoa butter ßVI-crystal germs dosed in the case of seed precrystallization have
a melting temperature range (ca. 34° to 39° C) shifted to clearly higher temperatures but
the same crystal lattice structure (triclinic lattice structure). The beginning of melting of
ßVI-seed crystals is ca. 34° C. Traditionally generated germ crystals in the precrystallization
are already nearly completely melted at 32.5° C. Thus for traditional precrystallization a
strong dependence of the precrystallization quality on the exit temperature at the
precrystallizer (usually ca. 29°-31° C) results as a rule. Deviations customary in production
of +/- 0.5° -1° C can already cause sharp differences in precrystallization. Comparable
variations in temperature in the seed precrystallization in the temperature range up to ca.
34° C (average temperature) show no influence on the precrystallization quality.
Additional advantageous characteristics and effects follow from the following description
of the drawing in which the invention is illustrated, in part schematically, by way of
example. Shown are:
Fig. 1 a schematic representation of the process for the production of fat-based seed
crystal suspensions with highly stable fat germ crystals and their use in seed
crystallization with the use of cold-sprayed fat powder,
Fig. 2 a schematic representation of the process for the production of fat-based seed
crystal suspensions with highly stable fat germ crystals and their use in the seed
crystallization without the use of cold-sprayed fat powder,
Fig. 3 a representation of the apparatus for the production of the seed crystal
suspension as well as its dosing and mixing in seed crystallization,
Fig. 4 installed elements in the shearing/extending module for improved crystal
dispersion,
Fig. 5 a detail from Fig. 4 on an enlarged scale, in part in section,
Fig. 6 a detail from Fig. 4 represented broken and on an enlarged scale, also in section,
Fig. 7 geometry of rotating shaft and wall-scraping measurement installed elements for
achieving alternating spreading/extending and wall-scraping processes,
Fig. 8 a comparative investigation of seed-precrystallized and conventionally
precrystallized chocolate by means of differential thermoanalysis,
Fig. 9 the melting temperature spectrum of the pure seed crystal suspensions,
Fig. 10 temperature curves for chocolate masses seed-precrystallized at different
temperatures,
Fig. 11 temperature curves for a chocolate precrystallized conventionally at different
temperatures,
Fig. 12 viscosity of seed-crystallized masses as a function of time,
Fig. 13 melting temperature spectra of seed crystal suspensions generated only in a
shearing/extending module without the use of a cold-sprayed cocoa butter
powder,
Fig. 14 melting temperature spectra of seed crystal suspensions generated in a 2-step
shearing/extending module without the use of a cold-sprayed cocoa butter
powder,
Fig. 15 two-step shearing/extending module (schematic sketch),
Fig. 16 layout of the control/regulation for the setting of exit temperature and seed
crystal content, and
Fig. 17 showing the generated crystal content of a seed crystal suspension between 5 and
22% as a function of the speed of rotation.
Figures 1 and 2 describe schematically the process for the production of fat-based seed
crystal suspensions with highly stable fat germ crystals and its use in seed crystallization.
Figure 1 takes into account the use of cold-sprayed fat powders as starting germ crystals
while Figure 2 describes the particular inventive form of embodiment of the process
without the use of fat powders. Here the starting germ crystals are generated directly in the
melted fat in a shearing treatment step.
In Figure 3 the apparatus for generating concentrated seed crystal suspensions according
to the invention with highly stable, finely dispersed fat crystals is represented.
The reference number 1 denotes a storage container for cocoa butter in which the crystal
suspension is kept at about 32° to 33° C. The reference number 2 denotes in Figure 3 a
storage container with chocolate mass which is kept at a temperature of 50° C.
A static mixer is denoted by 3, while 4 denotes a heat exchanger.
A dosing pump is denoted by the reference number 5 while 6 denotes a process pump with
which the chocolate mass can be conveyed.
7 denotes recirculation thermostats while 8 denotes a so-called shearing/extending module.
9 denotes a suspension feedback formed as a line and 10 denotes a multi-step thermal
conditioning.
The reference number 11 denotes a cold-spray tower in which the fat mass in question is
cold-sprayed at about - 40° to 0° C.
The reference number 12 denotes a cocoa butter tank in which the cocoa butter is kept at
50° to 60° C.
A 3-way cock is denoted by 13, while 14 denotes a torque-measuring apparatus. The
reference number 15 denotes a regulation unit for the shearing/extending module 8.
Figure 4 describes entrained installed elements integrated into the shearing module 8, said
installed elements on the one hand making possible the scraping of newly formed crystal
from the temperature-controlled (cooled) wall and on the other hand with corresponding
inventive forming of the installed elements (Figure 4, Pos. 3), as represented in Figure 4,
permitting the realization of the generation of extensional flows (laminar flows accelerated
in the direction of flow). Extensional flows are in particular efficient in the fine dispersion
of the crystals or crystal conglomerates.
In Figures 4 to 6 entrained installed elements 16,17,18, and 19 integrated in the shearing
module 8 and formed as shearing/extending elements are represented, said installed
elements being essentially formed as supporting blades and structured running tapered or
conically to a point on one side, which is the same side. As can be seen in particular from
Figure 4, the installed elements 16 and 18 lie with their pointed or tapered edge areas 20, 21
on the inner face 22 of the drum in which a shaft body 23 driven by a motor is coaxially
disposed. The two installed elements 17 and 19 lying diametrically opposite one another are
associated with this shaft body 23, said installed elements being structured in principle like
the installed elements 16 and 18, therefore also having a blade-like extension (Figure 6) and
with their pointed or tapered edge areas 24, 25 lying on the outer periphery 26 of the
container 23. In this manner the installed elements 16 and 18 are in the position of lying on
the inner cylindrical face 22 and thus to accelerate the flow in the column between the
inner cylinder face 22 and the outer edges of the installed elements 16 and 18, while the
installed elements 17 and 19 lie scrapingly on the periphery 26.
From Figure 4 it can furthermore be seen that the installed elements 16 to 19 are each
connected to the container 23 via support elements 27 to 30. The support elements 27 to 30
can be adjusted synchronously or individually and can also be arrested in their respective
positions. Furthermore, it is possible to structure the support elements 27 to 30 so that they
are in the position to adjust or readjust the blade-like installed elements 16 to 19 with
regard to their setting angle in order to position or to arrest the edge areas 20,21 or 24,25
in relation to the respective cylinder face spatially and/or with the required force of
compression. For this purpose a spring element also not represented can be assigned to the
support elements 27 to 30 so that the blade-like installed elements, in given cases, lie on
their associated cylinder faces as elastic springs. This lying as elastic springs can also be
accomplished by a hydraulic cylinder (not represented).
The rotating installed elements 16 to 19 are formed as shearing elements and rotate with
the shaft body 23. The elements 17 and 19 make possible the scraping of newly formed
crystals from the temperature-controlled (cooled) wall. The elements 16 to 18 spread the
fluid mass on the inner cylinder face 22. Furthermore, it follows from Figure 5 that in the
case of the corresponding inventive forming of the installed elements 16 to 19 extensional
flows into the tapering influx cross-sections between the blade-like installed elements 16 to
19 on the one hand and on the other hand the associated cylinder face 26 and laminar flows
accelerated thereby can be realized. Extensional flows of this type are in particular efficient
in the fine dispersion of the crystals or crystal conglomerates as is indicated schematically
and in extract in Figure 5.
For the cold-spraying of the melted fat in the cold-spray tower ll a cold gas flow is
generated which has a temperature of 10° to 50° C below the crystallization temperature of
the sprayed fat system and has fat spray particles with a diameter of micrometers (urn) which are subsequently conveyed into the thermal multi-step
conditioning 10 formed as a temperature control chamber, where in one thermal
conditioning of two or more steps the controlled modification conversion (formation of > 10
to 50% ßVI share) takes place without clumping of the spray powder particles.
Subsequently the conditioned powders are suspended in a melted fat (cocoa butter)
supercooled to 32° to 32.5° C in a temperature-controlled stirring/mixing container and
subsequently thereto these spray suspensions are sheared in the shearing module 8,
through which there is continuous axial flow and which preferably consists of a concentric
cylindrical shearing column which has a column width of the outer wall of the shearing column and therefore of the inner cylinder face 22, with
setting of the axial rate of flow through the shearing column by rotation of the container 23
formed as an inner cylinder in such a manner that the exit temperature of the crystal
suspension from the shearing column due to the superimposed viscous energy dissipation
through shearing and heat discharge can be set between 32° and 34° C, precise to 0.5° C,
and simultaneously a fine dispersion of the crystals to diameters of from a starting size of 100 to 200 µm is done and furthermore, as a function of wall
temperature and dwelltime in the shearing column, the exiting crystal suspension is
controllably and regulably set to a crystal content of 5 to 35 % via the torque transferred to
the rotating inner cylinder 23. Thereafter the seed crystal suspension is dosed continuously
into the product flow with temperature controlled to 32° to 34° C with a dosing pump 5
working mechanically protectively and mixed homogeneously and protectively into the
product flow by means of a static mixer 3.
The dosing pump 5 insures that the axial rate of flow through the shearing module 8
corresponding to the width of the shearing column and the dosing mass flow for the dosing
of a 0.01% to 0.2% crystal share into the product flow is maintained and either, after a
one-time direct passage of the crystal suspension through the shearing module 8, it is dosed
into the product flow or, from the stirring container in which crystal suspension multiply
treated in the shearing module 8 is remixed, this suspension is dosed into the feedback
product flow.
Via the control/regulation unit for the shearing module 8 a coordination of the speed of
rotation of the shaft body 23 formed as the inner cylinder, the wall cooling temperature of
the outer cylinder with its cylinder face 22, and the mass throughput or the dwelltime in
the reaction space of the shearing module 8, is set via the speed of rotation of the dosing
pump 5, and in fact in such a manner that the seed crystal sizes of (µm) can be set and the exit temperature of the suspension in the case of cocoa butter can
be set between 32° to 34.5° C with a precision of +/- 0.25° C.
The static mixer 3 to be integrated into the product flow of the product to be seeded
(chocolate masses or the like) has sufficiently large through-flow columns in which, in the
case of viscosities relevant for chocolate products of ca. 0.1 to 5 Pas and predetermined
mass flows, the local viscous energy dissipation remains sufficiently small to avoid heating
the product to temperatures greater than 34.5° C in the case of pure ßVI cocoa butter
crystal germs. In so doing it is possible to connect an increased number of > 10 to 12 static
mixing elements in tandem in order to insure a minimal mixing quality of 95%.
In Figure 7 an alternative geometry of the rotating inner cylinder is represented which
combines wall-scraping elements according to the invention with "spreading-extending
zones" generated by the oval geometry of the inner cylinder.
In Figure 8 the melting temperature or melting enthalpy spectra plotted by means of
differential thermal analysis DSC are represented by way of comparison for two
precrystallized chocolate masses after completion of precrystallization by means of
conventional and seed crystallization methods. The melting enthalpy spectra shown in
figure 8 are plotted after the solidification process. For the conventional and the seed-
crystallized mass a fat crystal composite consisting predominantly of ßVI crystal shares (ca.
65-75%) was shown. A small peak in the range of 34.5-37° C shows the presence of the
34.5° C ßVI seed crystals.
Furthermore, the melting temperature spectrum of the pure seed crystal suspension is
plotted in Figure 9.
In Figure 10 so-called temperature curves for chocolate masses seed-precrystallized at
different temperatures is represented. These temperature curves describe the curve for the
development of the heat of crystallization in a chocolate mass sample which has been taken
after the precrystallization process and cooled in the water bath at 8° C in a sample tube.
To the extent that sufficient germ crystals are present in the precrystallized mass, the
temperature curve is formed in the form of an S. The temperature curve, plotted for an exit
temperature of 34° C, for seed-precrystallized chocolate masses always shows the
corresponding temperature curve in the form of an S.
By way of comparison Figure 11 shows for a conventionally crystallized chocolate a
temperature curve plotted for an exit temperature of 32° C with curve form already clearly
without temperature control (deficiency of crystal!). This means the no longer sufficient
presence of germ crystals.
Comparative investigations of the quality characteristics of conventionally and seed-
precrystallized chocolate masses showed in a plurality of different formulations at least
similar quality of the seed-crystallized mass, but many times improved bloom stability of
the seed-crystallized samples. In texture (breaking, firmness of bite) seed-crystallized
masses frequently have a slightly increased strength with respect to conventionally
produced masses. This increase in strength is also evaluated as desirable in most cases.
In particular, masses with shares of foreign fat, which only crystallize late, cannot be
precrystallized, or can only be precrystallized incompletely, in traditional temperature
systems. This has as a consequence that a long cooling tunnel or low cooling temperatures
(with disadvantageous negative consequences for the surface gloss) or long dwelltimes in
the cooling tunnel are necessary. These disadvantages can be clearly reduced by means of
seed precrystallization.
In the case of seed precrystallized masses their sharply reduced viscosity with respect to
those crystallized traditionally is particularly clear, and also accompanying their thereby
improved and longer processibility at process exit temperature (cf. Figure 12). A reduced
viscosity is of particular advantage in the case of further processing. Accordingly
formulations with reduced fat share and nonetheless sufficient flowability for the further
production process can be generated by means of seed precrystallization processes.
Figure 13 shows with the aid of calorimetric measurement curves (melt enthalpy spectra)
that even in the case of general use of a one-step shearing module high shares of Pvi crystal
shares (ca. 50%, rest pv) can be achieved (crystal share corresponds to the surface under
the curve shown).
In Figure 14 it is shown, also with the aid of the melt enthalpy spectra, for a two-step
shearing module with two temperature-controlling zones that the ßVI crystal share with this
embodiment of the shearing module can be increased up to ca. 90% with optimized
coordination of the speed of rotation (Step I: 900 1/min, Step II: Optimum at 800 1/min),
wall temperatures (Step 1:10° C, Step II: 30° C), and dwelltime (Step I: 420 sec, Step II:
420 sec).
Figure 15 shows the schematic layout of a two-step shearing module with two temperature
control and shearing zones. The inner cylinder areas can in addition be embodied with the
installed elements or geometries described in Figure 4 and 7.
In Figure 16 the schematic layout of the control/regulation for the generation of seed
crystal suspensions with defined seed crystal content at a certain exit temperature is
represented. A sensing of the seed crystal content is done indirectly via the torque
measured on the shearing module shaft. This increases with the crystal content of the
suspension and the accompanying increase in viscosity. An increase of the crystal content
can be achieved via a reduction of the wall temperature and an extended dwelltime (=
reduced mass flow). An increase in the speed of rotation accelerates the crystal formation
kinetics up to an optimal speed of rotation. An additional increase in the speed of rotation
causes an increase in temperature due increased energy dissipation and concomitantly a
partial melting of crystals. The optimal speed of rotation thus depends on the wall
temperature. Crystal germ sizes are set with the described optimal conditions (cf. Figure
13,14) to ca. temperature, speed of rotation, and dwelltime (or mass flow) with the target/regulation
indices exit temperature and crystal content can be described from the experimental data
collected in the form of approximate connections by means of approximation equations
which are then implemented as control/regulation algorithms. The use of neuronal network
programming represents a more elegant method which can also "learn" and allow non-
linear relationships between said quantities to be described. The control/regulation is then
realized according to the "learned" pattern.
Figure 17 plots generated crystal contents between ca. 5 and 22% in the seed crystal
suspension, adjustable as a function of the speed of rotation, (here with the use of a two-
step shearing module with wall-scraping installed elements with the following settings: Step
I; n = 900 rpm, coolant water temperature = 10° C, Step II; speed of rotation was varied,
coolant water temperature = 30° C (dwelltimes cr. Figure 17).
The features to be seen in the abstract, in the claims, and in the description, as well as in
the drawings can be significant individually as well as in arbitrary combinations for the
realization of the invention.
List of Reference Numbers
1 Storage container with cocoa butter crystal suspension (32°-33° C)
2 Storage container with chocolate mass (50° C)
3 Mixer, static
4 Heat exchanger
5 Dosing pump
6 Process pump
7 Recirculation thermostats
8 Shearing/extending module, shear/extensional flow module
9 Suspension feedback
10 Thermal conditioning, multi-step
11 Cold-spray tower (- 40° C - 0° C)
12 Cocoa butter tank (50° C - 60° C)
13 3-way cock
14 Torque measurement apparatus
15 Regulation unit for shearing module 8
16 Installed element as shearing element, in the form of a blade
17 " " " "
18 " " " "
19 " " " "
20 Edge area, tapered
21 " " "
22 Cylinder face, inner
23 Container, motor-driven, shaft body
24 Edge area, tapered
25 " " "
26 Periphery of the container 23
27 Support element
28
29
30
M Motors
SKI Shear/extending module 1
SK2 Shear/extending module 2
t Time in minutes
rpm Speed of rotation per minute
o C Degrees Celsius
Ra Radius of the cylinder face
RiII Inner cylinder radius (shearing module Step II)
RiI Inner cylinder radius (shearing module Step I)
PV Crystal modification form with melting range ca. 28° C - 32° C
pVI Crystal modification form with melting range ca. 34° C - 39° C
Pas Pascal-seconds = measure for dynamic viscosity
mJ/(s mg) Specific heat flow (millijoule per second and milligram)
27
References Cited
Claims
1. Process for producing seed crystal suspensions based on melted fat, in particular for
generating stable microdisperse cocoa butter crystal suspensions with a high ßVI-
modification share and for its use in the seed crystallization of fat-based suspensions
containing disperse solid particles such as chocolate, chocolate-like masses, or the like
with adjustable total crystal content (I), share of ßVI-crystal modifications (II) with a
high melting point as well as average crystal size (III) wherein cold-sprayed fat powder
is subjected to a step-wise thermal conditioning in such a manner that without
clumping of the powder particles a modification conversion of the polymorphous fat
system advances so far that the thermally highly stable ßVI-modifications are formed at
a share of > 10%, the fat powder conditioned in this manner is suspended to > 1% in a
crystal-free melted fat temperature-controlled to about l°-2° below the melting
enthalpy peak minimal temperature of the ßVI-crystal modification, and this fat powder
suspension is treated with defined coordination of mechanical and thermal stresses as
well as the dwelltime in a shear/extensional flow until reaching the characteristics set:
total crystal content, ßVI crystal modification share, and average crystal size, and the
seed crystal suspension thus generated is uniformly dosed into the product flow of a
precrystallizing chocolate or chocolate-like masses with seed crystal shares between
0.01 and 0.2% (relative to total mass) and thereafter protectively, homogeneously, and
continuously mixed into the product flow.
2. Process according to claim 1 characterized by the fact that for the production of the
cold-sprayed powder the cold-spraying of a melted cocoa butter in a refrigerated space
(spray tower) is done in such a manner that the melted drops generated with the finest
atomization with a definite drop size distribution from 1 to 200 micrometers are moved
relatively to form a cold gas flow, in which they are sprayed in, and definitely
crystallized by means of defined setting of the temperatures of the cold gas (- 40° C-0°
C) and the melted cocoa butter sprayed in (+ 40° C to + 60° C) as well as of a cold gas
speed (0.1-1 m/s) coordinated to the drop size distribution and subsequently are carried
out at cold gas temperature.
3. Process according to claim 1 characterized by the fact that the powders' thermal
conditioning, performed for the formation/increase of the pvi-share in the cocoa butter
powders cold-sprayed at (- 40° C-0° C), is done in multiple steps, preferably two steps,
in such a manner that the modification conversion from unstable to highly stable
crystal modifications, which is as rapid as possible, is done without clumping of the fat
particles, for which storage in the form of powder is guaranteed, which, for example, is
realized in the case of the two-step combination with 12° C for > two days (Step I) and
thereafter at 25° C for > 30 days (Step II).
4. Process according to claim 1 characterized by the fact that in the case of a pure cocoa
butter system the suspension of > 1% of the conditioned spray fat powder is performed
in a substantially crystal-free, supercooled melted fat at a temperature of 26° C-32.5° C.
5. Process arrangement according to claim 1 characterized by the fact that the
thermal/mechanical stress of the spray fat powder suspension is done spatially
homogeneously in a shear/extensional flow field with setting of the effective shifting
stresses or shearing speeds and temperatures in one or multiple steps and by partial
melting of crystal modifications with a low melting point and the mechanical
dispersion/breaking up of the crystals a reduction of the average crystal size from ca.
100 (spray field powder) to with a crystal content in the suspension of 5 to 35% by volume can be set.
6. Process according to claims 1 and 5 characterized by the fact that, in the production of
a seed crystal suspension starting from cold-sprayed and thermally conditioned cocoa
butter particles, these have a share of > 10% of highly stable pVi-crystal modifications
which are subsequently increased to > 95% with the input of increased mechanical
energy in the fat powder/melted fat suspension at about 32° C-34° C.
7. Process according to claims 1 and 6 characterized by the fact that liquid cocoa butter is
added to a remnant of the suspension previously generated, which within a time period
of less than 60 minutes with temperature and stirring conditions held constant is used
for the production of a new seed crystal suspension.
8. Process according to claims 1 and 5 characterized by the fact that in a particular form
of embodiment of the process according to the invention the use of cold-sprayed cocoa
butter (fat) powder as a crystallization promoter is omitted altogether and the entire
seed crystal content in the seed crystal suspension is generated directly in the
mechanical/thermal treatment step in a shear/extensional flow field where the wall
temperature is lowered to 10 to 25° C, the dwelltime is increased to > 150 sec, and fat
crystals formed on the wall are continuously scraped off and mixed with the melted fat.
9. Process according to claims 1 to 8 characterized by the fact that the precooled product
flow is seeded with the crystal suspension at a temperature between 32° and 35° C.
10. Process according to claim 1 or one of the claims following it characterized by the fact
that the seeding is done continuously by dosing and protective, microhomogeneous
mixing in such a manner that a partial melting of the seed crystals in the product flow,
for example, by increased local energy dissipation, is avoided.
11. Process arrangement according to claim 1 or one of the claims following it
characterized by the fact that the seed crystal suspension is continuously fed to the
product flow in shares with 0.01 to 0.2 % of seed crystal relative to the total mass of the
product.
12. Process according to claim 1 or one of the claims following it characterized by the fact
that, instead of the chocolate system based on cocoa butter fat, suspensions with other
fats as the continuous phase are seeded in a comparable manner where the fat crystal
germs to be introduced are triglyceride mixtures with a high melting point and suitable
specifically to the fat system.
13. Apparatus consisting of a cold-spray tower (11), a temperature control chamber, a
suspension stirring container, a shear/extensional flow module, a pump, and a static
mixer (3) for carrying out the process according to claims 1 to 12 where in the cold-
spray tower (11) the cold-spraying of the melted cocoa butter fat or a mixture of cocoa
butter and other fats can be performed according to the invention in a cold gas flow
which can be set to a temperature of 10°-50° C below the crystallization temperature of
the fat component with the lowest melting point of the sprayed fat system and fat
particles can be generated, by means of a nozzle with spray pressures of 1-500 bar
excess pressure, with diameters conveyed into the temperature control chamber where in a thermal conditioning (10) of
two or more steps with selectable temperature-time curves with plateau temperatures
of preferably -10 and + 25 or + 28° C the controlled modification conversion (formation
of > 10-50% ßVI share) takes place without clumping of the spray particles and
subsequently the powders conditioned in this manner are suspended in a
stirring/mixing container temperature-controlled to ca. 26-32.5° C, which is assembled
with stirring elements mixing homogeneously and protectively at low speeds of rotation,
in a cocoa butter or melted fat mixture supercooled to ca. 26-32.5° C and subsequently
these spray powder fat crystal suspensions are sheared in a shear/extensional flow
module (8), through which there is a continuous axial flow and which according to the
invention preferably consists of a concentric or eccentric cylindrical shearing column
which has a column width adjustable to 5-30° C with setting of the speed of axial flow through the shearing
column to to 2 m/s in such a manner that the exit temperature of the crystal suspension from the
shearing column due to the superimposed viscous energy dissipation through shearing
and heat discharge can be set between 32° and 34.5° C, precise to 0.5° C, and
simultaneously a fine dispersion of the crystals to diameters of (µrn) (from a starting size of ca. 50 to 500 µm) is done and furthermore, as a function of
the shearing, wall temperature, and dwelltime in the shearing column, the exiting
crystal suspension can be controllably and regulably set to a crystal content of 5 to 35%
via the torque transferred to the rotating inner cylinder and thereafter the seed crystal
suspension is dosed continuously in small amounts of kg product into the product flow of a chocolate or chocolate-like mass with temperature
controlled to 32° to 34.5° C with a dosing pump (5) working mechanically protectively
and is mixed homogeneously and protectively into the product flow by means of a static
mixer (3).
14. Apparatus according to claim 13 characterized by the fact that the temperature-
controlled conditioning space is assembled with rotating or vibrating installed elements
(16) in order preferably to realize a permanent motion of the powder generated by
rotation or vibration of the installed elements or the mixing chamber itself and thereby
to make possible an accelerated thermal conditioning of the spray powder at increased
temperatures (up to 28° C in the generation of the ßVI-crystal modification) while
avoiding clump formation.
15. Apparatus according to claim 13 characterized by the fact that the shear/extensional
flow module (8) has, entrained with the inner cylinder, installed elements for the
treatment of the spray powder suspensions, said installed elements being disposed
either scrapingly on the inner wall of the cooled outer cylinder and/or forming
narrowed gaps between the inner and outer cylinder wall, or in addition in the installed
elements themselves, in which a local acceleration of the flow occurs and thereby shear
flow effects become active whereby according to the invention an improved fine
dispersion through alternating spreading (= extending + shearing) and scraping of the
fat crystals or fat crystal conglomerates on or from the cooled wall is achieved.
16. Apparatus according to claim 13 characterized by the fact that the shear/extensional
flow module (8) is integrated into a bypass line to form a stirring container so that the
finely dispersed crystal suspensions treated in the shearing module (8) can be remixed
in this stirring container with suspension still not treated mechanically and after several
passages of the stirring container contents through the shearing module (8) changeover
of the operation of the cycle to dosing into the product line is made possible via an
integrated 3-way cock (13).
17. Apparatus according to claim 13 characterized by the fact that, before the shearing
module (8), a dosing pump (5) is connected which permits setting of the axial rate of
flow through the shearing module (8) corresponding to the width of the shearing
column and the dosing mass flow of the crystal concentration in the seed crystal
suspension corresponding to a dosing of 0.01% to 0.2% crystal share into the product
flow and either, after one-time direct passage of the crystal suspension through the
shearing module (8), it is dosed into the product flow or, from the stirring container in
which crystal suspension multiply treated in the shearing module (8) is remixed, this
suspension is dosed into the feedback product flow.
18. Apparatus according to claims 13 and 15 to 17 characterized by the fact that the
shearing module (8) is divided axially into two zones and the first zone represents a
cooling zone which is cooled with water of a temperature of ca. 10 to 15° C and thereby
a strong formation of crystal (mixture of ßIV-, ßV and ßVI-crystal modifications) is
created in the melted cocoa butter fat and where the second zone is temperature-
controlled with coolant water of a higher temperature of 25 to 30° C in order to melt the
unstable ßVI cocoa butter crystal suspensions, to increase the ßVI modification share,
and to set the viscosity, where then the generated cocoa butter crystal suspension with a
10 to 30% crystal share with shares of 0-50% ßV-crystal modification and 50 to 100%
Pvi-crystal modification is uniformly dosed, by means of a dosing pump (5), directly
into the product flow of a precrystallizing chocolate or chocolate-like mass with seed
crystal shares between 0.01 and 0.2% (relative to total mass) and thereafter
protectively, homogeneously, and continuously mixed into the product flow.
19. Apparatus according to claim 18 characterized by the fact that the shearing column
between the outer wall of the rotating inner cylinder and the inner wall of the
temperature-controlled outer cylinder is small in the first cooling step (Ri/Ra > 0.8) and
is large in the second step (Ri/Ra cooling step with greater cooling are rapidly converted into stable ßV and ßVI-crystals
due to the greater shearing (shearing stresses: 1000-2000 Pa) and in the second cooling
step shearing is reduced by the increase of the shearing column in order to keep
sufficiently small any additional local heating, by viscous energy dissipation, of the
crystal suspension enriched with crystals.
20. Apparatus according to claim 13 characterized by the fact that via a control/regulation
unit for the shearing module (8) a coordination of the speed of rotation (control
parameter 1) of the inner cylinder (in given cases with installed elements), of the wall
cooling temperature (control parameter 2) of the outer cylinder, and [sic] to the mass
throughput (control parameter 3) or the dwelltime in the reaction space of the shearing
module (8), the latter set via the speed of rotation of the dosing pump (5), is done in
such a manner that the exit temperature of the suspension (target/regulation parameter
1) in the case of cocoa butter can be set between 30 and 34.5° C with a precision of +/-
0.25° C and the crystal content of the suspension (target/regulation parameter 2) can be
set between 10 and 30% (+/-1%) where by the particular shearing/extending of the
crystal suspension determined via the column geometry and speed of rotation seed
crystal sizes of 21. Apparatus according to claim 19 characterized by the fact that in addition a torque
measurement signal measured on the shaft of the shearing module (8) is fed to the
control/regulation unit, said measurement signal, with given settings for speed of
rotation, mass flow, and wall cooling temperature, permitting a direct correlation with
the generated seed crystal concentration and thereby permitting a monitoring or
control of the exit crystal concentration to be realized.
22. Apparatus according to claim 13 characterized by the fact that the static mixer (3) to be
integrated into the product flow of the product to be seeded (chocolate product) has
sufficiently large through-flow columns in which, in the case of viscosities relevant for
chocolate products (of ca. 0.1 to 5 Pas) and predetermined mass flows, the local viscous
energy dissipation remains sufficiently small to avoid local heating of the product to
temperatures greater than 34.5° C (in the case of pure ßVI cocoa butter crystal germs)
and for an increased number of > 10 to 12 static mixing elements to be connected in
tandem in order to insure a minimal mixing quality of 95%.
[The numbers at the left margin correspond to those on the accompanying key for Figure
1.]
1 PRODUCTION PROCESS FOR CRYSTAL SUSPENSIONS
2 SEED CRYSTALLIZATION
3 Melted cocoa butter
(ca. 50° C)
4 Cold-spraying of the Melted Fat
CB Powder : Particle Size: up to ca. 200 µm
Modifications: ßIV, a, ?
5 Therm. Conditioning of the Spray Powder
6 STEP I : 10-12° C/ca. 12 hours
CB Powder : Particle Size: up to ca. 200 µm
Modifications: ßIV, ßIV
7 STEP II : 25-28° C/> 10 days
CB Powder : Particle Size: up to ca. 200 µm
Modifications: ßIV, ßIV (ca. 40%)
8 Suspension of the Conditioned Powder
in melted fat (cocoa butter) at 32-32.5° C
[Figure 1 Key continued]
9 Shearing/Dispersion of the Crystal Suspension
thermal/mechanical ßVI maximization (setting of > 95%
modification share), fine dispersion (setting of crystal sizes
ca. 5 and 30%) by coordination of:
shear speed ?, temperature v, and dwelltime tv
for example,
(shear rates ca. ? = 300-3500 I/s, temperature: ca. v =
32-33° C, dwelltime: ca. tv = 5-25 minutes)
10 Dosing (0.01-0.2 % Crystal Share / Product)
11 Cont. Homogeneous Mixing (Stat. Mixer)
[The numbers at the left margin correspond to those on the accompanying key for Figure
2.]
1 PRODUCTION PROCESS FOR CRYSTAL SUSPENSIONS
2 SEED CRYSTALLIZATION
3 Melted cocoa butter
(ca. 50° C)
4 1 or 2 STEP SHEARING TREATMENT
5 STEP I : Wall Cooling 5-15° C/ca. 100-500 sec.
Shearing: 200-1000 1/sec.
Rapid generation of ca. 5-20% by weight starting
crystal germs (ßIV, ßV, ßVI)
6 STEP II : 25-35° C/ca. 250-500 sec.
Shearing: 200-10001/sec.
thermal/mechanical ßVI maximization
(setting of > 50% PVI modification share),
fine dispersion (setting of crystal sizes
ca. increase of crystal concentration (settable
between 5 and 30%) by coordination of:
shear speed y, temperature v, and dwelltime tv
[Figure 2 Key continued]
7 Feedback in temperature-controlled container or direct feed into the
chocolate flow
8 Dosing (0.01-0.2 % Crystal Share / Product)
9 Cont. Homogeneous Mixing (Stat. Mixer)
[The numbers at the left margin correspond to those on the accompanying key for Figure
3.]
1 SEED CRYSTAL SUSPENSION PRODUCTION
2 Precrystallized
Chocolate mass
(ca. 0.01-0.2%
crystals (> 95% pvi)
32-35° C
[The numbers at the left margin correspond to those on the accompanying key for Figure
4.]
1 Narrowing inflow cross-section
(? extensional flow formation)
2 Wall scraping
[The numbers at the left margin correspond to those on the accompanying key for Figures
5 and 6.]
1 Installed element
2 Narrowing inflow cross-section
(? extensional flow formation)
3 Crystal conglomerate
4 Forces of extension
[The numbers at the left margin correspond to those on the accompanying key for Figure
7.]
1 Spreading (= extending) of the mass
2 Wall scraping
[For Figure 8 see English translation in the German original.]
[For Figure 9 see English translation in the German original.]
[For Figure 10 see English translation in the German original.]
[For Figure 11 see English translation in the German original.]
[For Figure 12 see English translation in the German original.]
[The numbers at the left margin correspond to those on the accompanying key for Figure
13.]
1 Spec, heat flow in mJ/(s mg)
2 Temperature / ° C
3 Dwelltime: 1.4 min
Dwell time: 2.3 min
Dwelltime: 7.0 min
[The numbers at the left margin correspond to those on the accompanying key for Figure
14.]
1 Spec, heat flow in mJ/(s mg)
2 Temperature / ° C
[The numbers at the left margin correspond to those on the accompanying key for Figure
15.]
1 Temperature control zone I
2 Temperature control zone II
3 Mass outlet
4 Mass inlet
[The numbers at the left margin correspond to those on the accompanying key for Figure
16.]
1 Temp.
Wall
(theoretical)
2 Mass
Flow
(theoretical)
3 Speed of Rotation
(theoretical)
4 Torque
Out (actual)
5 Crystal Share
Out
(actual)
6 Temp. - Out
(actual)
[Figure 16 Key, 1st continued Page]
7 Control /
Regulation
Determination of the
Connections of the
Control Parameters 1,2 with 3,4,5
from process model or
neuronal network progr.
8 Torque
Out (theoretical)
9 Crystal Share
Out
(theoretical = 10-30%)
10 Temp. - Out
(theoretical = 32-34° C)
11 Target/Regulation Parameters
12 Temp.
Wall
(actual)
[Figure 16 Key, 2nd continued Page]
13 Mass
Flow
(actual)
14 Speed of Rotation
(actual)
[The numbers at the left margin correspond to those on the accompanying key for Figure
17.]
1 Generated Seed Crystal content in Suspension / %
2 Speed of Rotation [rpm]
3 Dwelltime in SK1: 7 Minutes and in SK2: 7 Minutes
4 Dwelltime in SK1: 2.3 Minutes and in SK2: 2.3 Minutes
The invention relates to a method and to a
device for producing seed crystal suspension that are based
on melted fat, especially, for producing stable, microdisperse
cocoa butler crystal suspensions that have a high ßVI
modification share. The invention further relates to the use
of said suspensions in the seed crystallization of fat-based
suspensions that contain disperse solid particles such as
chocolates and chocolate-like masses or the lite where the
melts are seeded with the crystal seed suspension. The inventive
method facilitates an improved dosability vis-à-vis seeding
methods that use crystal powders since it is easier to dose
liquids. The inventive mechanic/thermal shearing/extensional
flow treatment of the seed crystal suspensions allows the
production of substantially smaller seed crystals than according
to conventional powder-based seed crystallization methods
and thus an improved microhomogeneous mixture and higher
seeding efficiency (reduced seed crystal share to obtain an
optimum pre-crystallization) as well as an increased share of
the highly stable ßVI crystal modification.

Documents:

IN-PCT-2001-885-KOL-CORRESPONDENCE.pdf

IN-PCT-2001-885-KOL-FORM 27.pdf

IN-PCT-2001-885-KOL-FORM-27.pdf

in-pct-2001-885-kol-granted-abstract.pdf

in-pct-2001-885-kol-granted-assignment.pdf

in-pct-2001-885-kol-granted-claims.pdf

in-pct-2001-885-kol-granted-correspondence.pdf

in-pct-2001-885-kol-granted-description (complete).pdf

in-pct-2001-885-kol-granted-drawings.pdf

in-pct-2001-885-kol-granted-examination report.pdf

in-pct-2001-885-kol-granted-form 1.pdf

in-pct-2001-885-kol-granted-form 18.pdf

in-pct-2001-885-kol-granted-form 3.pdf

in-pct-2001-885-kol-granted-form 5.pdf

in-pct-2001-885-kol-granted-gpa.pdf

in-pct-2001-885-kol-granted-reply to examination report.pdf

in-pct-2001-885-kol-granted-specification.pdf


Patent Number 224161
Indian Patent Application Number IN/PCT/2001/885/KOL
PG Journal Number 40/2008
Publication Date 03-Oct-2008
Grant Date 01-Oct-2008
Date of Filing 28-Aug-2001
Name of Patentee MAESTRANI SCHOKOLADEN AG
Applicant Address ST. GEORGENSTRASSE 105, CH-9011 ST. GALLEN
Inventors:
# Inventor's Name Inventor's Address
1 WINDHAB ERICH IM SCHANZGRABEN 142, CH-8261 HEMISHOFEN
2 ZENG YUANTONG LERCHENHALDE 39/06 CH-8046 ZURICH
PCT International Classification Number A23G 1/18
PCT International Application Number PCT/EP99/03734
PCT International Filing date 1999-05-29
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 1900-01-01 Not Applicable