Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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IMPROVEMENTS IN CONFECTIONERY MANUFACTURE
The present invention relates to processes for producing fat-based heat-
meltable confectionery products, particularly chocolate-type
compositions.
Examples of suitable fat-based heat-meltable confectionery products
include chocolate-type compositions and fat-based cremes (e.g. biscuit
cremes, wafer cremes and pralines).
For the avoidance of doubt, "chocolate-type compositions" includes
conventional milk, plain and white chocolate compositions, such
compositions in which at least some of the cocoa butter has been
removed (i.e. low fat chocolate) and/or replaced by other fats/oiis, and/or
having at least some of the sugar removed and/or replaced by bulking
agents (i.e. low calorie chocolate), including such compositions which by
national or international agreement may not be sold as "chocolate". For
clarity, such compositions will hereinafter be referred to as chocolate
compositions, and any references to "chocolate mixture", "chocolate
composition" or "chocolate product" should be construed accordingly.
The pleasurable organoleptic properties of conventional chocolate are to a
significant extent due to the fact that the fat (primarily cocoa butter) which
forms the continuous phase in chocolate melts quickly and smoothly in
the mouth giving a characteristic mouthfeel. This is because cocoa butter
softens at approximately 28°C and is generally completely melted at 32
to
35°C. However, such melting presents problems for storage and
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distribution in regions where ambient temperatures are high (e.g. 30 to
40°C).
As a result, much research effort has been directed towards the production
of so-called "high-temperature tolerant" chocolate products. As used
herein, "high-temperature tolerant" in relation to chocolate products,
refers to those products which retain their shape at higher temperatures
than conventional chocolate. One approach is to replace the cocoa butter
partially or completely with higher melting fats. Although such an
approach does yield products which maintain their shape at relatively
high temperatures, the higher melting fats melt less readily when eaten
and leave an undesirable waxy mouthfeel.
A second approach is to develop a structure of non-fat ingredients in the
chocolate product which remains rigid when the fat starts to melt, such as
a lattice of predominantly sugar particles. A lattice of sugar andlor other
hydrophilic materials may be developed by the addition of water to a
chocolate mixture. To have a satisfactory mouthfeel and texture, the
lattice should dissolve evenly when the chocolate is eaten, and there
should be no large aggregates of non-fat ingredients to impart a gritty
texture. For success, the prior art focuses on the problem of how to
present water to the chocolate mixture. The solutions offered are to form
very small water droplets and/or oillwater emulsions. For example, US
5125160 discloses the use of an aqueous foam and W093112664
discloses the use of water-in-oil microemulsions, the water being in the
form of droplets of size 10 to 1000A.
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Thus, it is an object of a first aspect of the present invention to provide a
process for the manufacture of a fat-based heat-meltable confectionery
product which exhibits improved properties..
According to the first aspect of the present invention, there is provided a
continuous process for the manufacture of a fat-based heat-meltable
confectionery product comprising the steps of:-
(i) . introducing a fat-based heat-meltable confectionery mixture into
a low-shear extruder mixer,
(ii) introducing water into the low-shear extruder mixer,
(iii) mixing the fat-based heat-meltable confectionery mixture and
water as they pass through the mixer to form a fat-based heat meltable
confectionery composition, and
(iv) forming the fat-based heat-meltable confectionery composition
into the fat-based heat-rneltable confectionery product.
The above process enables the confectionery product formed by the
process to retain its shape at a higher temperature than a corresponding
confectionery product formed from the fat-based heat-meltable
confectionery mixture not having undergone the process.
1t will be understood that the basis of the first aspect of the present
invention resides in the surprising discovery that, contrary to accepted
wisdom, the nature of the mixing of the water with the fat-based heat-
meltable confectionery mixture is more significant than the form in which
water is added. None of the prior art makes any specific recommendation
as to the type of mixer to be used. As used herein "low-shear" means a
shear of not more than 1000s'.
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Preferably, said low-shear extruder mixer is a cavity-transfer type mixer,
for example that disclosed in EP 0048590.
The water may be introduced into the mixer by itself, or alternatively as an
oil-in-water emulsion, but preferably as a water-in-oil emulsion. if the
water is to be added as an emulsion, an emulsifier such as polyglycerol
polyricinoieate (PGPR) is preferably included.
Preferably, sufficient water is added such that the fat-based heat-meltable
confectionery product has a water content in the range of 1.8 to
3.0°I° by
weight, more preferably in the range of 1.8 to 2.5°I° by weight.
Preferably, steps (i) and (ii) are effected simultaneously.
Preferably, the fat-based heat-meltable confectionery mixture is a
chocolate mixture.
The chocolate mixture may be tempered or unternpered. Surprisingly, the
process of said first aspect of the present invention does not cause
detempering of tempered chocolate mixtures.
Preferably, the water is added to the mixer at 30 to 45°C, and
more
preferably 40°C.
When the fat-based heat-meltable confectionery mixture is chocolate, it is
preferably added to the mixer at 27 to 45°C and, in this case, the
mixer is
preferably maintained at a temperature of 27 to 45°C. However, in the
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case where tempered chocolate is employed, it is preferably added to the
mixer at less than 30°C in order to preserve the temper and the mixer
is
preferably maintained at less than 30°C.
Also according to said first aspect of the present invention, there is
provided a fat based heat-meltable confectionery product prepared in
accordance with the process of said first aspect of the present invention.
A related problem is that refrigeration (which may be required even in
temperate climates during summer months) hardens conventional
chocolate such that it must be held in the mouth for an unacceptably Tong
time in order for it to melt, or it must be chewed. in either event at least
some of the pleasure derived from eating chocolate is lost.
European Patent Application No. 0717931 also discloses a chocolate
composition suitable for consumption at low temperatures. The fat
content of the composition includes at least 40°/° by weight of
fats rich in
2-unsaturated-1,3-disaturated glycerides. Specific fats include fractions of
palm, palm kernel and coconut oils having overall melting points from 21
to 30°C. Despite such relatively high melting points, loss of shape at
ambient temperatures requires the chocolate to be held in a mould.
Thus, it is an object of a second aspect of the present invention to provide
a fat-based heat-meitable confectionery product which, when consumed
directly from a refrigerator or freezer, has superior eating characteristics
to
conventional chocolate consumed in the same way, but which retains its
shape at eating temperatures above that of its storage, for example 8 to
SO°C.
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According to the second aspect of the present invention, there is provided
a process for the manufacture of a fat-based heat-meltable confectionery
product comprising the steps of:-
(i) mixing a fat-based heat-meltable confectionery mixture whose fat
component remains substantially liquid from its melting temperature to a
temperature not exceeding 30°C and water in a mixer to produce a fat-
based heat-meltable confectionery composition, and
(ii) forming the fat-based heat-meltable confectionery composition
into the fat-based heat-meltabie confectionery product.
The confectionery mixture will normally contain, in addition to the fat
component, at least one added sweetener (e.g. sugar) and may also
contain one or more added flavouring ingredients.
The above process enables the product so produced to melt more rapidly
when consumed directly from storage at sub-ambient temperature than a
corresponding confectionery product formed from the fat-based heat-
meltable confectionery mixture not having undergone the process
consumed in the same way, and to retain its shape at ambient
temperatures.
Preferably said fat component referred to in step (i) is liquid at less than
20°C.
Preferably step (i) is effected by a low-shear extruder mixer, and more
preferably, a cavity transfer mixer, for example that disclosed in EP
0048590.
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Preferably, said fat component comprises one or more vegetable oils
which are more preferably selected from the group consisting of
sunflower, maize, groundnut, palm, palm kernel and coconut oils.
Preferably, said fat component oils) accounts) for at least 5% by weight
of the fat-based heat-meltable confectionery mixture; and more preferably
accounts) for between 5% and 55°/° by weight, and most
preferably 15 to
40°/° by weight.
Also according to the second aspect of the present invention, there is
provided a fat-based heat-meltable confectionery product prepared in
accordance with the process of said second aspect of the present
invention.
Surprisingly, it has been found that such a fat-based heat-meltable
confectionery product is capable of retaining its shape at ambient
temperatures (e.g. 8 to 50°C) even when the entire fat component
consists
of a low temperature melting fat such as sunflower oil (melting point
-16°C).
Embodiments of the invention will now be described, by way of example,
with reference to the accompanying drawing which is a schematic
representation of an apparatus for performing a process in accordance
with the first aspect of the present invention.
Referring to the drawing, an apparatus for performing the process of the
present invention comprises a Silverson high-shear mixer 2, first and
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second thermostatically controlled holding tanks 4a,4b, a pair of fiow-
control pumps 6a,6b, a cavity transfer mixer 8 (sold under the tradename
CTM under license from the Rubber and Plastics Research Association), a
forming station 10 and a cooling tunnel 12. The cavity transfer mixer 8
has first and second inlets 8a,8b and a single outlet 8c.
A flow path exists between the Silverson high shear mixer 2, the first
holding tank 4a and the first inlet 8a of the cavity transfer mixer 8. A flow
path also exists between the second holding tank 4b and the second inlet
8b of the cavity transfer mixer 8. The outlet 8c of the cavity transfer mixer
8 is connected to a forming station 10 linked by conveyor to the cooling
tunnel i 2.
In use, an oil/water emulsion (either water-in-oil or oil-in water) is
prepared in the Silverson high shear mixer 2 and passed into the first
holding tank 4a. A pre-prepared fat-based heat-meitable confectionery
mixture is transferred to the second holding tank 4b, with both holding
tanks 4a,4b being maintained at the respective desired temperature. The
pumps 6a,6b ace activated, causing the oil/water emulsion and the fat-
based heat-meitabie confectionery mixture to be passed via the respective
inlets 8a,8b into the cavity transfer mixer 8. The relative flow rates of the
pumps 6a,6b are adjusted so that a fat-based heat-meltable confectionery
composition having a desired water content will be formed. The oiUwater
emulsion is mixed into the fat-based heat-meltable confectionery mixture
as it passes through the cavity transfer mixer 8 until a substantially
homogeneous fat-based heat-meltable confectionery composition emerges
from the outlet 8c of the cavity transfer mixer 8. The composition is
formed into bars of a desired size and shape. The bars are passed by
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conveyor to the cooling tunnel 12 where they are cooled. If the pre-
prepared tat-based heat-meltable confectionery mixture is chocolate, it
may be tempered before passing into the cavity transfer mixer 8.
Alternatively, the chocolate composition formed in the cavity transfer
mixer 8 may be tempered after having passed therethrough.
It will be understood that if water rather than an emulsion is to be
supplied to the first inlet 8a of the cavity transfer mixer 8, then the
Silverson high shear mixer 2 is not required.
In the following Examples, al) percentages are weight percentages unless
specified otherwise.
Example 1
Water (1 %) was added at 40°C to the first inlet 8c of the cavity
transfer
mixer 8 and a tempered milk chocolate mixture (milk solids 24.1
°I°, sugar
(sucrose) 47.4%, cocoa mass 11.6°/°, cocoa butter 11.3%,
vegetable fat
4.9°/°, emulsifier 0.6°I° and flavouring 0.1 %,
with moisture content 1.0°/°)
at 28°C to the second inlet 8b. The chocolate composition which
emerged from the outlet 8c of the cavity transfer mixer was slightly more
viscous than the chocolate mixture, but was substantially homogeneous
and not detempered (as determined by vis~oa! inspection).
Comparative Examples 1A and 1B
A tempered chocolate mixture of the same composition as used in
Example 1 was stirred at 28°C in a Hobart planetary mixer (Example
1A)
and a Winkworth Z-blade mixer (Example 1 B). The direct addition of
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water (1 %) caused in each case the formation of a viscous, detempered,
gritty mass, unsuitable for product formation.
The above Examples demonstrate the importance of the choice of mixer
for the water to be successfully incorporated into the chocolate mixture,
and the fact that, if the cavity transfer mixer is used, even the addition of
water itself does not cause detempering of tempered chocolate.
Example 2
An oil-in-water emulsion (47.5% water; 47:.5% cocoa butter; 5% Soya
lecithin) was prepared in the Silverson high--shear mixer 2 and added to
the tempered milk chocolate mixture of Example 1 in the manner
described in Example 1 to give a final added water content of
1.2°!°. The
chocolate composition emerging from the cavity transfer mixer 8 was
formed into bars and cooled.
Exampte 3
Example 2 was repeated using a water-in-oil emulsion
(47.5°I° water;
47.5°I° cocoa butter; 5°/° PGPR) to give a
chocolate product with a final
added water content of 1.2°/°. The hardness of the bars,
measured as the
average force in grams required to compress the chocolate conditioned
and held at 35°C by 4mm, is given in Table 1.
Comparative Examples 3A and 3B
Comparative examples 1A and 1 B were repeated using the water-in-oil
emulsion of Example 3 (a total water content of 2.2°/°) in place
of the
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water. The chocolate composition was formed into bars. The hardness
values are given in Table 1.
Table 1: Effect of mixer on hardness of chocolate product at 35°C
Example 3 Example 3A Example 3B
Hardness 1760 305 520
(grams force)
Example 4
Example 3 was repeated using untempered milk chocolate of the same
composition as in Example 3 maintained at 40°C.
Thus, it will be clear that the process of the present invention offers
distinct advantages in terms of the hardness of the chocolate product. The
hardness values reflect the relative abilities of the products to retain their
shape at a given temperature. By comparison, the same milk chocolate
having no water or water emulsion added has a hardness of < 60g. In
addition, the texture and mouthfeel of the chocolate of Example 3 was
superior to that of Comparative Examples 3A and 3B.
The following Examples are illustrative of the second aspect of the present
i nvention:-
Example 5
Sugar (50 kg), skimmed milk powder (22.6 kg) and low fat cocoa powder
(6.1 kg) were premixed and milled at ambient temperature using an
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Alpine classifier (mill speed 7000 rpm, classifier speed 3000 rpm) such
that 90% of the resultant particles were less than 30 microns in diameter.
The above milled powder (4 kg) was conched with butterfat (460 g),
sunflower oil (1 kg) and Lecithin (54 g) for 4 hours at speed 1 in a Hobart
mixer jacketed at 40°C. The resultant mixture was transferred to a Z-
blade
mixer and a water-in-oil emulsion at 3°/° of the mix was slowly
added at
30°C. The emulsion contained water (47.5°I°), cocoa
butter (47.5%) and
PGPR (5.0°/°). Mixing was continued until the emulsion was
dispersed.
The chocolate mixture was put into moulds, stored in a refrigerator and
demoulded after cooling. Demoulded product had structural integrity at
ambient temperature. Chocolate from the refrigerator or the deep freeze
melted readily in the mouth to deliver a typical chocolate flavour.
Example 6
2.5 kg milk chocolate crumb (16°/° fat) was blended with 0.236
kg
butterfat and passed through a refiner. 2.68 kg of the refined material was
blended in a Hobart mixer with 0.149 kg sunflower oii and 0.016 kg Soya
lecithin dispersed in cocoa butter for about 2 hours at 40°C until a
smooth
homogeneous mix was obtained. A water-in-oil emulsion as in Example 1
at 3% of the stirred mix was added and blended. The chocolate was put
into moulds and stored in a refrigerator before demoulding. The product
was similar in structural integrity at ambient temperature to the product of
Example 5.
Example 7
Powder mix as in Example 5 (1.6 kg) was blended in a Hobart mixer at
40°C with butterfat (184 g) and soy lecithin (22 g) followed by
blending
with groundnut oil (400 g). This blend was fed to the cavity transfer mixer
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8 at 40°C while water-in-oil emulsion was pumped to the inlet 8a of the
mixer at a rate to give a final moisture content of 2.2% in the chocolate.
The chocolate emerging from the mixer was formed into bars and cooled.
The product had improved structural integrity at ambient temperature
compared with chocolate of Examples 5 and 6, while being at least equal
in sensory qualities.
Surprisingly, the chocolates of Examples 5 to 7 retained their structural
integrity at ambient temperature, despite the fat component being
substantially liquid.
