Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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CO~r~SrrETCE CONFECllONS
Technical Field of the Invention
The invention relates to ice confections and their method
of preparation. In particular the invention relates to
ice confections which comprise a mass of a milk
containing ice confection, for example ice cream, with at
least one discrete element of water ice which is
preferably present as a surface layer covering the mass
of milk containing ice confection.
Back~round to the Invention
A well known ice confection on the market is a
traditional split product comprising an ice cream core
and an outer layer of water ice on a stick. These
products are produced by filling a mould with a water ice
solution, cooling the mould such that a layer of water
ice is frozen to the mould, removing the still liquid
water ice solution from the centre, filling the centre
with ice cream, inserting a stick and final cooling to
fully freeze the product.
Traditional split products, however, have a number of
disadvantages. Primarily the quality of the water ice
layer provided is poor. The quiescently frozen water ice
layer has large ice crystals which result in a hard icy
texture. Furthermore the shape of the product which can
be achieved is limited because the product must be able
to be removed from the mould, the quality of the ice
cream is poor because in order to dose the ice cream into
a mould the ice cream must have a sufficiently low
viscosity and thus an overrun of greater than 80~ is not
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suitable, in order to de-mould the final product, the
product has to be warmed then re-cooled which further
lowers the final product quality.
In particular the consumer desires a soft water ice layer
of high quality.
To overcome the problems of the traditional split,
WO 95/20883 proposes to produce the water ice layer via a
dipping process, whereby the surface of the ice cream
core is pre-cooled to -15~C or below to effect the quick
freezing of the water ice layer, the water ice layer is
then hardened. This method indeed results in products of
good quality having a soft water ice layer texture.
However a problem with the process disclosed in
WO 95/20883 is that it is generally necessary to dip the
ice-cream core more than once in order to achieve a
water-ice layer of appropriate thickness.
Furthermore the essential requirement in WO 95/20883 to
pre-cool the surface of the ice cream core to -15~C or
below prior to dipping in the water ice solution, raises
the production costs.
EP 500 940 (Kanebo) discloses a process to provide a two
component ice confection having a rugged surface. An ice
confection core is dipped into a semi-frozen ice mixture.
EP 560 052 (Nestle) discloses a process for coating a
frozen confectionery product which comprises applying a
gelatin sol to the confectionery product. The gelatin sol
may contain up to 10~ gelatin and preferably contains
from 1.5 to 3~O by weight based on the total weight of the
gelatin sol. The gelatin sol is applied by a dipping
process, the temperature of the sol being from 10 to 25~C
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during this dipping process. The coated product may
advantageously be re-frozen in a freezing tunnel to
complete the setting process if necessary.
The levels of gelatin taught by EP 560 052 for the
gelatin sol results in a number of well known
disadvantages as described by, for example, US 2,360,559
namely;
(i) The gelatin sol must be at a relatively high
temperature during the dipping process which results in
some melting of the ice confection core, providing a loss
of quality.
(ii) The finished coating has a tendency to become sticky
and adhere to the paper in which the ice confection is
packaged.
(iii) The product has undesirable eating characteristics.
Surprisingly it has been found that if the properties of
the water ice solution are carefully selected this
significantly widens the possible processing conditions
to produce products of high quality having a water ice
which is soft, non-icy and has a substantially reduced
tendency to stick. Furthermore, the product has excellent
eating characteristics.
In particular it has been found if the rheology of the
water ice solution is chosen in a specific range, this
results in a good quality product which can be produced
via a single application step.
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Di~closure of the Invention
Accordingly the invention relates to a process for
producing an ice confection comprising a mass of milk
containing ice confection and a discrete element of water
ice, wherein;
(i) a mass of milk containing ice confection is contacted
with a water ice solution having a rheometry value of
more than about 1.0 to cause the water ice solution to
adhere to the mass of milk containing ice confection; and
(ii) the adhering water ice solution is rapidly cooled to
-15~C or below.
Preferably the water ice solution has a rheometry value
of 1.1 to 1.8, more preferred 1.2 to 1.6. A suitable
method of measuring the rheometry value is described in
the examples.
It is well within the ability of the skilled person to
vary the composition and processing of the water ice
solution such that the required rheometry value is
obtained.
Suitable measures may for example be selected from
variation of type and amount of solids, use of thickeners
or gelling agents, inclusion of other phases e.g.
aeration etc, and mixtures thereof.
Generally speaking the rheometry value will increase if
the solids content of the water ice solution increases.
For example a low amount of sugar in the formulation will
provide low rheometry values, while an increase in sugar
level will increase this parameter. Also the inclusion of
high levels of fruit puree or other solids result in an
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increase.
Specific minor ingredients can also be used for
increasing the rheometry value. In particular one or more
thickeners or gelling agents can be used. Examples of
suitable ingredients are for example locust bean gum,
xanthan, agar, guar, carrageenan, alginate, pectin,
microcrystalline cellulose, gelatin, maltodextrin etc.
Levels of these ingredients may be selected to obtain the
desired rheometry values. For gelling agents suitable
levels are from 0.5 to 1.5 wt~, more preferred 0.65 to
1.2 wto.
Also the processing conditions of the water ice solution
can be adapted to influence the rheometry index. For
example aeration of the water ice solution may lead to a
higher rheometry value.
The water ice solution is preferably maintained at a
temperature at or below 8~C, preferably at or below 5~C.
The maintenance of a low temperature has two advantages.
Firstly any melting of the surface of the mass of milk
containing ice confection on application of the water ice
solution is minimised and thus a high quality product is
provided. Secondly it is hygienically advantageous to
process at cooler temperatures.
In a gelled system the requirement to maintain the water
ice solution at a temperature of at or below 8~C, whilst
still being able to apply the water ice solution to the
mass of milk containing ice confection, is achieved by
producing a smooth paste of the gel. The smooth paste is
provided by shearing the water ice mixture either during
or after gelation. Examples of suitable shearing devices
include scraped surface heat exchangers, stirred vessel,
spray driers followed by rehydration, static mixers and
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colloid mills.
Preferably the total soluble solids level of the water
ice solution is between 1 and 70 wt~o, most preferred 2-60
wt~. Low soluble solids levels may for example
advantageously be used for the formulation of isotonic
water ice solutions. While higher soluble solids levels
result in more traditional water ice solutions.
Preferably the water ice solution is chosen such that it
forms a smooth layer on the mass of milk containing ice
confection. For example preferably the water ice solution
is substantially liquid and does not contain ice
crystals. Typically the water ice solution will be at a
lS temperature above its freezing point. The smooth layer
formed on the mass of milk containing ice confection
preferably has a thickness of 0.5 to 6 mm, more preferred
1 to 5, most preferred 2 to 4 mm. Also preferably the
layer is a single layer and not a composite layer e.g.
produced by multiple applications.
The mass of milk containing ice confection contains
proteins and this class of products includes, ice cream,
frozen yoghurt, sherbet, sorbet, ice milk and frozen
custards. The usual form of protein will be animal milk,
but vegetable sources e.g. soy milk are also usable. The
level of fat in the mass of milk containing ice
confection may vary in a broad range, for example 0-3 wt%
for zero to low fat products, 3 to 6 wt% for medium fat,
6-10 wt% for creamy products and above 10wt~o for super-
premium products.
Preferably the mass of milk containing ice confection is
aerated to an overrun of 30 to 300~, more preferred 40 to
200~, most preferred 50 to 150~o.
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As stated above, a problem of known ice confection
coatings (for example as described in EP 560 052) is that
they have a tendency to become sticky and adhere to the
inner surface of the wrapper in which the ice confection
is packaged. Thus the consumer of the product has
difficulty unwrapping the product for consumption.
It is an advantage of the present process that a product
is provided that has both excellent eating
characteristics and an essentially non-sticky water ice.
In order to achieve the desired water ice properties of
softness and reduction of stickiness, it is essential
that after contact with the water ice solution, the
adhered water ice solution is subjected to a rapid
cooling step such that a temperature of -15~C or below is
achieved throughout the water ice. By rapid cooling is
meant that the cooling environment has a temperature of
-50~C or below (inclusive of wind chill factor),
preferably -60~C or below (inclusive of wind chill
factor), most preferably -70OC or below (inclusive of
wind chill factor). Such rapid cooling may be achieved by
for example dipping in a liquid cryogen, such as liquid
nitrogen, or cooling in a blast freezer. Preferably the
rapid cooling is achieved by dipping in liquid nitrogen.
The wind chill factor may be calculated using the
following formulation (as used by the US National Weather
Service);
TWC = 0.045 (5.27.V~s + 10.45 - 0.28.V).(T - 33) + 33
where TWC is the wind chill (oc)~ T is the actual
temperature (oc) and V is the wind speed (km/hr). This
formula is only applicable at wind speeds above about
7km/hr. Below this speed the actual temperature should be
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used.
Accordingly the invention also provides an ice confection
comprising a mass of milk containing ice confection and a
discrete element of water ice, wherein the water ice is
essentially non-sticky and has a composition which in the
form of a water ice solution has a rheometry value of
more than about 1Ø
Preferably the surface of the mass of milk containing ice
confection has a temperature of less than -5~C when
contacting with the water ice, more preferred less than
-8~C, most preferred less than -10~C. Generally the
temperature will be more than -40~C, more preferred more
than -25~C. Especially preferred for low cost production
are temperatures of more than -14 ~C, more preferred more
than -12~C.
The mass of milk containing ice confection can be
contacted with the water ice solution in any convenient
manner, for example spraying, dipping, smearing, rolling
etc. Most preferred is the dipping of the mass of milk
containing ice confection into the water ice solution.
Also prefera~ly the core is provided with a stick which
can act as a grip during the dipping operation. The
discrete element of water ice is preferably present as a
layer, most preferably as a surface layer. It is
particularly preferred that the water ice solution is
contacted with the mass of milk containing ice
confection in such a way that a water ice layer is
produced which predominantly covers the mass of milk
containing ice confection without leaving substantial
uncoated areas.
Ice confections according to the invention may contain a
number of optional ingredients normally present in ice
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cream or water ice. Examples of such ingredients are
flavouring materials, emulsifiers, stabilisers, colorants
etc.
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ExamPles
The invention will now be illustrated by means of the
following examples:
Example I
A water ice solution having the following composition was
prepared by mixing the ingredients into water at 60~C
under gentle stirring:
Ingredient wt%
tropical fruit puree 40
sucrose 17.5
glucose 3 9
additives see below
colouring 0.1
citric acid 0.2
water balance
The pick-up (in grams) of various formulations was tested
by cooling a shaped block of ice-cream of 52 grams to
-34 ~C and dipping it for 5 seconds in the mix which was
kept at 2~C.
Generally a higher pick-up is indicative of a higher
rheometry value. Thus pick-up amounts of approximately 20
to 50g, more preferably approximately 25 to 40g,
typically correspond to rheometry values according to the
invention. In order to provide a definite answer as to
whether a composition has the required rheometry value,
the rheometry value can be measured as shown in Example
II.
The following additives were tested:
ll l
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Test additives weight total pick-
ratio amount up ~g)
wt~
1 LBG/Carrageenan 3:1 0.4 15
2 LBG/Carrageenan 1:1 0.4 15
3 LBG/Carrageenan 1:3 0.4
4 LBG/Carrageenan 3:1 1.0 31
LBG/Carrageenan 1:1 1.0 28
6 LBG/Carrageenan 1:3 1.0 36
7 LBG/Xanthan 3:1 O.O1 10
8 LBG/Xanthan 1:1 0.01 10
9 LBG/Xanthan 1:3 0.01 10
Xanthan - 0.01 11
11 Pectin - 0.01 16
12 LBG - 1.0 28
13 LBG/Carrageenan 1:2 1.0 35
14 LBG/Carrageenan 1:5 1.0 43
LBG/Carrageenan 1:7 1.0 43
16 Carrageenan - 1.0 48
17 LBG/Xanthan 1:1 0.05 10
18 Guar - 1.0 24
19 Agar - 1.0 11
gelatin - 1.0 22
21 Pectin - 1.0 12
22 LBG/Xanthan 1:1 0.2 16
23 LBG/Carrageenan 1:5 0.8 46
24 LBG/Carrageenan 1:7 0.8 38
Carrageenan - 0.8 30
26 L8G/Xanthan 1:1 0.6
27 LBG/pectin 1:1 1.5 31
28 LBG/Carrageenan 1:7 0.75 37
29 LBG/Carrageenan 1:7 0.75 44
LBG/Carrageenan 1:7 0.75 34
31 L8G/Xanthan 1:7 0.6 31
32 Xanthan - 0.6 17
33 Guar/Xanthan 1:7 0.6 18
~otes:
test 11 high methoxy pectin; test 21 medium methoxy pectin
test 27 low ~ethoxy pectin
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Example II
The rheometry value can be determined as follows:
A solid stainless steel cylinder having a length of 80mm
and a diameter of 38 mm was provided with 1.2 pitch
diamond knurl grooves of depth 0.5mm extending for 40mm
along the length of the cylinder A 1.2 pitch knurl
defines that the distance between the grooves is 1.2mm.
The diamond knurl defines that the grooves intersect to
form a diamond pattern The included angle at the top and
bottom apex is 60~, whilst the included angle between is
120~ The grooves are at an angle of 30~ to the vertical.
The cross-section of the groove is triangular, with a
right angle at the tip. The total depth is 0.5mm. The
remaining 40mm length of the cylinder was smooth.
The cylinder was cooled to 2~C and the patterned end of
the cylinder was dipped into the water ice solution at 2~C
for 5 seconds. The depth of dipping was 40 mm (i.e. for
the full extent of the grooves). The bottom surface was
wiped clean and the cylinder was weighed to determine the
amount of water ice solution adhered to it. From the
surface area of the cylinder (exclusive of grooves), the
weight of pick-up and the density of the water ice
solution, the average layer thickness adhering to the
cylinder is calculated in mm's. This is the rheometry
value.
Example Calculation
For a 38mm diameter cylinder of height 40mm, the surface
area (excluding the grooves) is 4780mm2 If 7g of water
ice solution of density 1.1 g cm~3 is adhered, the volume
of water ice is 6360mm3. Therefore the rheometry value is
1 3
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Exa~nple III
An ice cream formulation was prepared of the following
composition:
Ingredient wt~
skimmed milk powder 7.7
sucrose 15.3
butter 8.1
flavour/colour 0.1
Cremodan SE019
(ex Danisco) 0.4
whey powder 2.5
water balance
The ice cream was prepared with an overrun of 60~ and
extruded through a shaped nozzle to give a cylinder of
52g and a stick was inserted. The ice cream was frozen in
a blast freezer such that the surface temperature was
- 1 0 ~ C .
The ice cream was then dipped for 5 seconds into water
ice solutions at 2~C having the following formulations;
Formulation (~wt) A B C -
Fruit puree 40.0 45.0 40.0
sucrose 18.0 18.0 17.5
glucose monohydrate 4.0 4.0 3.9
locust bean gum 0.3 0.09 0.14
carrageenan 0.1 0.66
guar gum - - 0.06
citric acid 0.2 0.25 0.2
sodium citrate - 0.05
water - balance -
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Formulation B was gelled at 2~C. Therefore a smooth paste
was produced prior to dipping ~y shearing the gel in a
domestic food blender for approximately 30 seconds.
The adhering water ice solution was then rapidly cooled
in a blast freezer operating between -32~C and -34~C (wind
speed factor of 5 ms~l) for 15 minutes (cooling
environment of the blast freezer was therefore -51~C
inclusive of wind chill factor).
The pick-up of the formulations was measured as in
Example I. For formulation A the pick-up was 16 g, for
formulation B this was 34 g, and for formulation C this
was 8g.
The rheometry value for each formulation was measured as
in Example II. For formulation A the rheometry value was
0.8, for formulation B 1.4, and for formulation C 0.8.
Formulation B resulted in highly preferred products
having a smooth appearance, good thickness of the single
water ice layer and with a soft attractive texture.
Formulations A and C resulted in a layer which was too
thin after the single dip in water ice solution.
Example IV
Example III was repeated except that the ice cream was
cooled to -12~C prior to dipping in the water ice
solution.
The pick-up of formulation A (measured as in example I)
was 11 g, while for formulation B this was 32 g and for
formulation C ~his was 12g.
~1 ~
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Formulation B resulted in highly preferred products
having a smooth appearance, good thickness of the single
water ice layer and with a soft attractive texture.
Formulations A and C resulted in a layer which was too
thin after a single dip in the water ice solution.
Example V
A water ice solution of formulation B in Example III was
produced and cooled to 2~C. The water ice solution
provided was a soft gel-type substance. This gel was
sheared for approximately 30 seconds in a domestic
blender to form a smooth flowable paste.
Ice cream prepared as in Example III was frozen in a
blast freezer such that the surface temperature was
-goc~ The ice cream was then dipped for 5 seconds in the
water ice solution at 3~C. The adhering water ice
solution was then rapidly cooled by immersion in liquid
nitrogen for 12 seconds. The product was then wrapped in
a waxed paper wrapper and stored at -25~C.
The product did not significantly adhere to the wrapper.
Comparative Example A
Example V was repeated except that the product was not
rapidly cooled after immersion in the water ice solution
but cooled in a cold store at -25~C.
The resulting product adhered to the wrapper making it
difficult to remove the product from its packaging.
