U.S. patent application number 10/861015 was filed with the patent office on 2005-01-27 for frozen ice confection.
This patent application is currently assigned to Good Humor-Breyers Ice Cream. Invention is credited to Binley, Gary Norman, Bongers, Petrus Martinus, D'Agostino, Tommaso, Wang-Nolan, Wei.
Application Number | 20050019450 10/861015 |
Document ID | / |
Family ID | 8181926 |
Filed Date | 2005-01-27 |
United States Patent
Application |
20050019450 |
Kind Code |
A1 |
Binley, Gary Norman ; et
al. |
January 27, 2005 |
Frozen ice confection
Abstract
A process and apparatus for preparing a frozen ice confection
comprising a frozen composition incorporating inclusions in a
desired distribution by combining a flow of frozen composition with
one or more flows comprising inclusions, in such a way that the
flows comprising inclusions are introduced discontinuously at a
multiplicity of positions in the cross-section of flow of frozen
composition, and extruding the resulting combined flow without
first subjecting the combined flow to any active blending step.
Inventors: |
Binley, Gary Norman;
(Sharnbrook, GB) ; Bongers, Petrus Martinus;
(Hellendoorn, NL) ; D'Agostino, Tommaso;
(Sharnbrook, GB) ; Wang-Nolan, Wei; (Sharnbrook,
GB) |
Correspondence
Address: |
UNILEVER
PATENT DEPARTMENT
45 RIVER ROAD
EDGEWATER
NJ
07020
US
|
Assignee: |
Good Humor-Breyers Ice
Cream
|
Family ID: |
8181926 |
Appl. No.: |
10/861015 |
Filed: |
June 4, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10861015 |
Jun 4, 2004 |
|
|
|
10132645 |
Apr 25, 2002 |
|
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Current U.S.
Class: |
426/100 |
Current CPC
Class: |
A23G 9/48 20130101; A23G
9/285 20130101 |
Class at
Publication: |
426/100 |
International
Class: |
A23G 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 27, 2001 |
EP |
01303884.9 |
Claims
1. A method for preparing a frozen ice confection comprising
inclusions dispersed in a frozen composition, which method
comprises the steps of:--combining a flow of a frozen composition
with one or more flows comprising inclusions, the flows of
inclusions being introduced, discontinuously, at a multiplicity of
positions in the cross-section of flow of the frozen composition to
give a combined flow of inclusions dispersed in a frozen ice
composition, and extruding the resulting combined flow.
2. A method according to claim 1 wherein the frozen composition
comprises sorbet, frozen yoghurt, sherbet, frozen custard, water
ice, ice cream or a mixture thereof.
3. A method according to claim 1 wherein the frozen composition
comprises ice cream prepared by the process of cold extrusion.
4. A method according to claim 1 wherein the inclusions comprise
soft fruit pieces.
5. A method according to claim 4 wherein the inclusions comprise
strawberry pieces.
6. A method according to claim 1 wherein a single flow of
inclusions is introduced into the flow of frozen composition at a
position in the cross-section of said flow which varies with
time.
7. A method according to claim 1 wherein a plurality of flows
comprising inclusions are introduced into the of flow of the frozen
composition.
8. A method according to claim 1 wherein a plurality of separate
flows of frozen composition are used.
9. A method according to claim 1 wherein the flows of frozen
composition and of inclusions are combined at an angle of no more
than 45.degree..
10. A method according to claim 1 wherein the flows are combined
immediately prior to extrusion.
11. A method according to claim 1 wherein the combined flow of
frozen composition and inclusions is passed through static
deflecting means prior to extrusion.
12. An apparatus for preparing a frozen ice confection comprising a
frozen composition incorporating inclusions, said apparatus
comprising: a nozzle having a chamber and an outlet through which
the frozen composition incorporating inclusions is extruded; feeder
means for supplying a flow of frozen composition into the chamber
of the nozzle; and means for supplying one or more flows comprising
inclusions into the flow of frozen composition to give a combined
flow of frozen composition comprising inclusions, means for
regulating the flow comprising inclusions, to allow said inclusions
to be supplied discontinuously, the means for supplying inclusions
discharging at a multiplicity of positions within the cross-section
of flow of the frozen composition.
13. An apparatus according to claim 12 wherein the frozen
composition feeder means discharge frozen composition into the
nozzle chamber laterally with respect to the axis of the
chamber.
14. An apparatus according to claim 12 wherein the inclusion supply
means discharge the inclusions into the nozzle chamber.
15. An apparatus according to claim 14 wherein the frozen
composition feeder means discharge distal to the outlet of the
nozzle.
16. An apparatus according to claim 12 further comprising means for
deflecting the combined flow within the nozzle chamber.
17. An apparatus according to claim 12 further comprising means for
moving the inclusion supply means such that the position of
discharge of the inclusions into the cross-section of flow of
frozen composition in the feeder supply means varies with time.
18. A frozen ice confection comprising soft fruit pieces dispersed
in a frozen composition wherein the average number of fruit pieces
recoverable from a given volume of the frozen confection, after
said confection has been thawed and washed through a sieve having a
mesh size of 1 mm, is at least 80% of the average number of fruit
pieces, capable of being retained in said sieve, used in preparing
said volume of frozen confection.
19. A frozen ice confection comprising soft fruit pieces dispersed
in a frozen composition wherein the average weight of fruit pieces
recoverable from a given volume of the frozen confection, after it
has been thawed and washed through a sieve having a mesh size of 1
mm, is at least 60% of the average weight of fruit pieces, capable
of being retained in said sieve, used in preparing said volume of
frozen confection
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a process for preparing a
frozen ice confection, more particularly a process for
incorporating inclusions, particularly soft fruit inclusions, into
a frozen ice composition in a controlled manner to give a frozen
ice confection. The invention further relates to an apparatus for
use in the present process and to a frozen ice confection
comprising soft fruit inclusions.
BACKGROUND TO THE INVENTION
[0002] Frozen ice confections comprising inclusions have hitherto
generally been manufactured by an in-line process involving dosing
the inclusions into the frozen composition using an inclusion
feeder, blending the frozen composition and inclusions together to
distribute the inclusions within the frozen composition and
extruding and cutting the resulting product.
[0003] Similar methods for producing frozen confections comprising
particulate edible material impressed onto the periphery of the
body of a soft freezable confection, such as ice cream, are
disclosed in U.S. Pat. No. 4,447,458.
[0004] A disadvantage of existing methods is the requirement to
blend the individual components together to bring about dispersal
of the inclusions with in the frozen composition. Conventionally,
this is achieved by subjecting the combined materials to an active
blending step, involving moving blending means such as a rotating
paddle element. This blending step exposes the individual
inclusions to significant shear effects, however, placing a
significant restriction on the type of materials which can be
incorporated into the frozen composition and consequently limiting
the types of products which can be produced.
[0005] Where it is desired to produce an ice confection product
comprising hard inclusions, such as nuts or chocolate pieces, for
example, then the current, conventional method of manufacture can
be used without difficulty. Such a method cannot generally suitably
be used to prepare frozen ice confections incorporating dispersed
inclusions of soft matter, such as soft fruit pieces, however, as
the blending step has a detrimental effect on the integrity of the
inclusion, giving an aesthetically unpleasing final product.
[0006] A further problem associated with conventional manufacturing
techniques arises from the tendency of the inclusion to become
dispersed to the outside edge of the mix during blending, as a
result of the difference in viscosities of the components, leading
to a lack of control over the pattern of distribution of the
inclusions and hence to an unacceptably uneven distribution of
inclusions in the final extruded product Additionally, packing
together the inclusions in an inclusion feeder prior to dosing
leads to an increased risk of structural damage to the inclusion,
rendering the method unsuitable for use in situations where
retention of structural integrity of the inclusion is important
(for example, with soft fruit pieces) and hence imposing
limitations on the range of inclusion materials which can be
used.
[0007] Where flows of two components are combined to give a mixed
product, it is typically arranged that the individual flows
converge approximately perpendicularly, in order to aid mixing. It
is also known to blend flows of different materials to obtain
dispersion of one material within the other by passive mixing by
means of localised deflection of the combined flow in a static
mixer. The incorporation of gelled inclusions in a frozen
composition in such a manner is described, for example, in EP-A-0
811 324, Societe Des Produits Nestle S.A.).
[0008] The difficulties associated with processes for incorporating
soft inclusions into frozen ice confections can be well illustrated
by reference to the manufacture of ice cream products incorporating
soft fruit inclusions. Such ice cream products are extremely
popular with consumers and there is therefore considerable
commercial interest in improved methods for their manufacture.
Products incorporating discrete pieces of, or more especially
whole, soft fruits, are particularly desired. Where the fruit
ingredient is incorporated into the ice cream by the method
described above, however, the shear effect to which the fruit is
exposed upon introduction into the relatively higher viscosity ice
cream flow, combined with the effect of the blending step tends to
cause the fruit to break up, forming a pulp or puree, such that the
final product contains very few, if any, distinct fruit pieces.
Commercially available ice cream products comprising soft fruit
inclusions notably tend not to have discrete whole fruits or even
large pieces of fruit but rather have much smaller pieces. The
larger the difference in viscosity between the ice cream and fruit
components, the more this shear effect is exacerbated and so it
would be expected to represent a particular problem where the ice
cream used is higher viscosity ice cream prepared by extrusion at a
temperature lower than is conventional in the art (such as is
described in WO 97/39637 or WO 98/09534, both Unilever).
[0009] Approaches to overcoming the problems associated with
incorporating soft fruit inclusions into ice confections which have
been described in the literature include treating the fruit in some
way before it is incorporated to make it less susceptible to shear
damage. In U.S. Pat. No. 3,671,268 (Blake et al., assigned to Lever
Brothers), for example, there is disclosed a method for preparing
an ice cream product by forming a gelled fruit puree having a
texture which is similar to the texture of fruit at room
temperature and incorporating discrete pieces of this gelled puree
into the ice cream.
[0010] Alternatively, soft fruit inclusions may be transformed into
hard inclusions (for example by freezing and optionally dicing
whole soft fruits) and incorporated into ice confections in the
conventional manner. This is disadvantageous in economic terms as
it involves increases in ingredient costs in addition to increased
handling and processing costs.
[0011] Incorporation of fruit pieces into ice confections by
careful hand mixing may be feasible on a small scale, say by an
individual in the home, but is inappropriate for large scale
industrial production. Even with hand mixing, it is difficult to
produce a satisfactory product acceptable to the consumer in which
the structure of the fruit pieces is not damaged. Controlling the
distribution of fruit pieces in products prepared in this way also
presents real problems.
[0012] Ice confections containing a plurality of inclusions
prepared by automatically distributing the inclusions through a
fruit feeder into the ice mix and disclosed in WO 98/37770.
[0013] There remains a continuing need to develop an improved
method for incorporating inclusions, especially soft inclusions,
into frozen ice confections which can be employed economically on a
scale appropriate for industrial use. In particular, there remains
a need to develop a method for incorporating fruit especially soft
fruit, inclusions into frozen ice confections wherein the
structural integrity of the fruit inclusion is maintained to give
an aesthetically pleasing product. A method which affords the
possibility of controlling the pattern of distribution of the
inclusions in the frozen ice confection product is particularly
desired.
SUMMARY OF THE INVENTION
[0014] In one aspect, the present invention provides a method for
preparing a frozen ice confection comprising inclusions dispersed
in a frozen composition, which method comprises the steps of:--
[0015] combining a flow of a frozen composition with one or more
flows comprising inclusions,
[0016] the flow of inclusions being introduced, discontinuously, at
a multiplicity of positions in the cross-section of flow of the
frozen composition to give a combined flow comprising inclusions
dispersed in a frozen ice composition, and extruding the resulting
combined flow.
[0017] In another aspect, the invention provides an apparatus for
preparing a frozen ice confection comprising a frozen composition
incorporating inclusions, the apparatus comprising:
[0018] a nozzle having a chamber and an outlet through which the
frozen composition incorporating inclusions is extruded;
[0019] feeder means for supplying a flow of frozen composition into
the chamber of the nozzle; and
[0020] means for supplying one or more flows comprising inclusions
into the flow of frozen composition to give a combined flow of
frozen composition comprising inclusions,
[0021] means for regulating the flow comprising inclusions, to
allow said inclusions to be supplied discontinuously,
[0022] the means for supplying inclusions discharging at a
multiplicity of positions within the cross-section of flow of the
frozen composition.
[0023] The invention further provides novel frozen ice confections
comprising a frozen composition incorporating inclusions.
[0024] An `inclusion` is a discrete, edible piece of a material
which differs in some way (such as in composition, flavour, texture
or colouring, for example) from the frozen composition material
into which it is to be incorporated. Where the inclusion is a fruit
piece, this is either a whole fruit or a discrete piece of
sufficient size that it is distinguishable over fruit pulp. It will
be appreciated that the absolute size of the individual fruit piece
will depend on the type of fruit to be used.
[0025] By `discontinuously` is meant that the flow of inclusions is
not continuous but is interrupted, regularly or not.
[0026] As used herein, a nozzle comprises a chamber into which the
matrix and fruit materials are fed and an outlet through which the
combined product is extruded, the nozzle serving to define the form
of the extrudate.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The invention is based on the finding that an improved
frozen ice confection, comprising a frozen composition
incorporating inclusions in a desired distribution may suitably be
prepared by a process involving combining a flow of frozen
composition with one or more flows comprising inclusions, in such a
way that the flows comprising inclusions are introduced
discontinuously at a multiplicity of desired positions in the
cross-section of flow of frozen composition, and extruding the
resulting combined flow without first subjecting the combined flow
to any active blending step.
[0028] By means of this method, the present inventors have found
that it is possible to obtain a controlled dispersion of inclusions
in the final product, while minimising any damage to the structural
integrity of the inclusions arising from the manufacturing
process.
[0029] Simplifying the manufacturing process by reducing the number
of steps involved clearly has attendant economic advantages for
industrial scale use but perhaps more importantly, it opens up the
possibility of preparing products which cannot satisfactorily be
prepared by existing processes.
[0030] A disadvantage associated with using the existing processes
for preparing frozen ice confections comprising frozen compositions
incorporating inclusions is the damage inflicted on the structural
integrity of the inclusion. This adversely impacts on the aesthetic
appeal of the final product and presents a particular problem where
the inclusion is a soft inclusion, especially where the inclusion
is a soft fruit. Indeed, frozen ice confections incorporating
discrete soft fruit pieces cannot readily be obtained by
conventional methods.
[0031] It is possible to obtain a product containing a reasonable
amount of substantially intact soft inclusions by a conventional
process by dosing in a very large amount of inclusions, since
although many would be damaged there would be a likelihood that a
proportion would survive substantially intact. This is
disadvantageous however, in that there would be a background of
damaged inclusion material mixed into the final product which may
be unappealing. It would also be economically disadvantageous
because of the likely high cost of the increased inclusion dosing
necessary.
[0032] The present invention dispenses with the need for a separate
blending step to disperse the inclusions within the frozen
composition and minimises the time between the dosing of the
inclusions and extrusion of the final confection product in order
to reduce the shear effects to which the inclusions are exposed.
The method of the invention therefore affords the possibility of
preparing aesthetically acceptable products comprising inclusions,
especially soft inclusions such as soft fruit pieces, which have
hitherto not been readily obtainable.
[0033] In a further advantage, the present invention provides a
method for controlling the pattern of dispersion of the inclusions
within the frozen composition to give a visually attractive final
product, for example, one in which the fruit pieces appear randomly
distributed.
[0034] The method of the invention is applicable to any frozen
composition conventional in the frozen ice confection art. Suitably
the composition may be a frozen aerated material such as sorbet,
frozen yoghurt, sherbet, frozen custard or water ice but is
preferably ice cream. The present process finds particular
application in the preparation of frozen confections incorporating
ice cream prepared by the process of cold extrusion. The higher
viscosity of such ice cream means that the mechanical shear on soft
inclusions during normal processing is greater, hence the
motivation to use a process which minimises the adverse impact on
the final product of differences in viscosity between the
constituent ingredients.
[0035] The method of the invention could also be used to produce a
confection comprising more than one type of frozen composition,
with inclusions incorporated into one or more of the frozen
composition components. For example, different frozen compositions
could be fed into the nozzle by separate feeder means, and the
inclusions could be introduced either into the flow of individual
frozen composition components in their individual feeder means or
into the combined flow of frozen compositions in the nozzle.
[0036] Any type of edible, discrete inclusions may be incorporated
into a frozen ice composition by the method of the invention,
provided that they can be supplied in a physical form that is
capable of being pumped, since the method of the invention requires
that a flow of inclusion material is pumped through the apparatus.
For example, pieces of any type of fruit may be incorporated,
provided that they can be introduced in a suitable form, such as in
a suspension with the natural fruit syrup. The method is
particularly applicable to the preparation of frozen ice
confections incorporating soft fruit pieces, such as, for example,
raspberry, blackberry, gooseberry, banana, apricot, peach, orange,
pineapple, plum and especially strawberry.
[0037] It will be appreciated that the method could also be used to
incorporate discrete pieces of a material that is pumped through
its supply means as a continuous phase but that can be cut into
discrete pieces, by a suitable cutter means, at the point where the
flow of said material is combined with a substantially
co-directional flow of frozen composition. For example, discrete
pieces of water ice, sherbet or ice cream could be incorporated in
this way. Since the invention allows for the supply of multiple
flows comprising inclusions, as discussed further below, it is
straightforward to introduce more than one type of inclusion, if
desired, by the method of the invention.
[0038] Combining a single continuous flow of inclusions with a flow
of frozen composition in a fixed spatial relationship would give an
extruded combined flow of final product in which the inclusions are
present in a continuous, essentially columnar region within the
frozen composition. Whilst a product having inclusions dispersed in
a regular pattern might be acceptable, consumers generally find
products in which the inclusions are dispersed throughout the
frozen composition in irregular fashion more pleasing to the eye.
Conventionally, this would be achieved by means of an active
blending step, with its inherent disadvantages for soft inclusions,
but the inventors have found that a good and controllable
distribution can be obtained without the need for such a step by
introducing either a multiplicity of flows of inclusions at points
distributed across the cross-section of flow of the frozen
composition or a single flow at a point in the cross-section of
flow of the frozen composition which varies with time, and by
arranging for the flows of inclusions to be discontinuous.
[0039] In a preferred embodiment of the invention, a plurality of
separate flows comprising inclusions is introduced into the flow of
frozen composition. Preferably, the inclusions are discharged in
substantially parallel adjacent flows, so that the inclusions will
be dispersed over the cross section area of the extruded
product.
[0040] The number and position of discharge of flows comprising
inclusions employed will then depend on the desired visual
appearance of the final product and, in principle, is limited only
by the cross section area of the flow of frozen composition into
which the flows comprising inclusions are to be introduced. In this
way, it is possible to achieve a product having the appearance of a
random distribution of inclusions. Alternatively, by appropriate
choice of number and position of inputs, specific patterns of
inclusions within the frozen composition may be produced.
[0041] According to another embodiment, the distribution of
inclusions within the frozen composition may be controlled by using
an inclusion supply means which is moveable within the flow of the
frozen composition. In this way, the position of input of the
inclusion flow within the cross section of the flow of frozen
composition (and hence the point of discharge of the inclusions
into the frozen composition flow) may be varied. Conveniently, the
inclusion supply means is moveable within the flow of frozen
composition throughout the operation of the process.
[0042] Regardless of the mechanism used to achieve a dispersion of
inclusions in the cross-section of flow of frozen composition, it
is a requirement of the invention that the distribution of
inclusions within the frozen composition is additionally controlled
by intermittent interruption of the flow comprising inclusions into
the flow of frozen composition. The regularity, frequency and
duration of the interruptions will depend, in general, on the
extrusion flow speed, size of the container and on the density and
distribution pattern of inclusions desired in the final product.
Where multiple flows comprising inclusions are provided, the
interruptions may be synchronous or asynchronous depending, again,
on the desired distribution of inclusions in the final product.
[0043] In another embodiment, the inclusions may be further
dispersed in the frozen composition by passing the combined flows
through deflecting means prior to extrusion. In this way, the
distribution of inclusions can be modified to give a final extruded
frozen confection product having a seemingly random distribution of
inclusions while at the same time minimising the mechanical shear
effects on the individual inclusions.
[0044] In order to minimise the shear effects that arise when flows
of materials of different viscosities are combined, the invention
provides that the flow of frozen composition and the flows
comprising inclusions are preferably substantially co-directional
at the points where they are combined. For the purposes of the
invention, this means that the angle between the converging flows
is between 0.degree. and 45.degree., suitably no more than
30.degree., preferably no more than 20.degree.. In a particularly
preferred embodiment, the flows to be combined run in parallel. The
consequence is a reduction in the extent of physical damage to the
inclusions that arises, compared to the conventional situation,
where the flows are oriented substantially perpendicularly at the
point where they are combined.
[0045] In order to reduce further the shear effect on the
inclusions resulting from combining their flow with that of the
frozen composition, the flows are preferably combined close to the
point of extrusion in a nozzle, conveniently within a distance of
no more than 2 metres, preferably no further than 1 metre away from
the nozzle. More preferably, the frozen composition and the
inclusion material are supplied separately to, and combined within,
the nozzle chamber immediately prior to extrusion. The shape of the
nozzle is not critical to the invention but preferably is chosen so
as to achieve the objectives of maximising the cross-section area
and minimising the length of the combined flow, in order to
minimise the shear forces acting on the fruit and the length of
time during which said forces are effective.
[0046] The method of the invention provides for one of more flows
of frozen composition to be used but preferably a plurality of
separate flows of frozen composition is used. Where a plurality of
flows is employed, it is preferred that these all have the same
flow velocity. According to a particularly preferred embodiment,
the frozen composition is discharged into the nozzle, distal to the
nozzle outlet, while the inclusions are discharged at a more
proximal position within the nozzle, so that the frozen composition
is already flowing towards the nozzle outlet at the point when the
flow comprising inclusions is combined with it.
[0047] Also provided according to the invention is an apparatus for
preparing a frozen ice confection comprising a frozen composition
incorporating inclusions, the apparatus comprising:
[0048] a nozzle having a chamber and an outlet through which the
frozen composition incorporating inclusions is extruded;
[0049] feeder means for supplying a flow of frozen composition into
the chamber of the nozzle; and
[0050] means for supplying one or more a flows comprising
inclusions into the flow of frozen composition to give a combined
flow of frozen composition comprising inclusions,
[0051] means for regulating the flow comprising inclusions, to
allow said inclusions to be supplied discontinuously,
[0052] the means for supply inclusions discharging at a
multiplicity of positions within the cross-section of flow of the
frozen composition.
[0053] The chamber of the nozzle should be of sufficiently large
cross-sectional area compared to the frozen composition feeder
means and the inclusion supply means that the pressure within the
chamber, and therefore the forces acting on the inclusions as a
result of the flow of the combined materials, are reduced. The
nozzle outlet may have a somewhat smaller cross-section area than
the chamber of the nozzle but should be of larger cross-sectional
area than the feeder means and supply means. The size of the nozzle
outlet is not critical to the invention and depends on the size of
the container into which the final product is to be extruded and
the desired appearance of the product.
[0054] Conveniently, the nozzle comprises two or more reversibly
detachable sections so as to allow it to be disassembled for
cleaning purposes. This has the additional advantage of enabling
the section containing the outlet to be exchanged, affording the
possibility of achieving a different extrusion pattern in the
product if desired. Typically, the nozzle is made of any material
suitable for use with food, hereinafter referred to as food grade
material and is suitably stainless steel.
[0055] The flow of frozen composition is supplied by means of one
or more feeder means discharging into the chamber of the nozzle.
Preferably, these feeder means discharge, separately, into the
nozzle chamber laterally with respect to the axis of the chamber.
It is particularly preferred to provide tubes supplying the frozen
composition in two separate flows discharging laterally with
respect to the axis of the chamber and from opposing sides. This is
advantageous in the factory operation as it helps to produce a
constant weight distribution of the final product when it is
extruded into a container of some type. It is also beneficial in
terms of the visual appearance of the resulting product.
[0056] The inclusions are introduced either by multiple supply
means discharging at points distributed across the cross-section of
flow of the frozen composition, or by a single such supply means
the point of discharge of which, in the cross-section of flow,
varies with time. Preferably the supply means are arranged so that
the flow comprising the inclusions is substantially co-directional
with the flow of frozen composition, at the point where the flows
are combined. The point at which the flows are combined may be
within the frozen composition feeder means but in a preferred
embodiment of the invention, the inclusion supply means discharge
into the nozzle chamber, preferably substantially in parallel. The
arrangement of the frozen composition feeder means and the
inclusion supply means is preferably such that the frozen
composition is discharged distal to the outlet of the nozzle, while
the means for supplying the inclusions extend into the chamber and
are directed towards the nozzle outlet, so that the inclusions are
discharged at a more proximal position within the chamber of the
nozzle, thereby ensuring that the flow of said inclusions within
the chamber is substantially co-directional with that of the frozen
composition.
[0057] Means are provided to allow the flow in each of the
inclusion supply means to be regulated in a controlled fashion by
intermittent interruption. Suitable regulator means are well known
in the art. Conveniently, for example, regulation is achieved by
means of changeover valves, positioned upstream of the points where
the flows comprising inclusions are combined with the flow of
frozen composition. Where multiple inclusion supply means are
provided, these may be regulated individually or two or more
supplies may be coupled so that they can be regulated by a single
valve.
[0058] The feeder means for the frozen composition and the
inclusion supply means suitably comprise pipes constructed from a
food grade material, which may be flexible or hard. Food grade
stainless steel is an especially suitable material.
[0059] In one embodiment, the apparatus further comprises moving
means for moving the terminal part of the tube supplying the
inclusions such that the position of discharge of the flow
comprising inclusions into the cross-section of the flow of frozen
composition varies with time. Conveniently, the moving means
comprise a motor driven device which moves the terminal section of
the inclusion supply means within the nozzle or within the frozen
composition feeder means, as appropriate.
[0060] In another embodiment, the apparatus additionally comprises
means for deflecting the combined flow during its passage through
the nozzle chamber towards the nozzle outlet. These deflecting
means have the effect of causing the inclusions to become
redistributed within the frozen composition without imparting
significant shear forces on them. Conveniently, the deflecting
means are static mixers (baffles), such as are well known in the
art. The baffles should be positioned within the chamber so as to
deflect the combined flow of inclusions and frozen composition,
leading to distribution of the inclusions within the frozen
composition and reducing localisation of the inclusions in the
extruded product. Preferably, the baffles are arranged peripherally
on the inside wall of the chamber and are suitably made of the same
food grade material as the nozzle chamber. The size and shape of
the baffles used is chosen so as to minimise the shear effect
whilst allowing for sufficient flow of material. Suitably, the
static mixer element has an open area with multiple fingers.
[0061] As mentioned above, the method of the invention can suitably
be used with any type of inclusions that are capable of being
pumped, whether hard or soft, but is particularly advantageous for
preparing frozen ice confections comprising discrete pieces of soft
inclusions, especially soft fruits, such as strawberries, which
cannot readily be prepared by other means.
[0062] Accordingly, in another aspect the invention provides novel
frozen ice confections comprising soft inclusions dispersed in
frozen composition. Suitably the soft inclusions are soft fruit
pieces, preferably strawberries or strawberry pieces.
[0063] For the purpose of defining this aspect of the invention it
is convenient to establish a parameter by means of which it is
possible to compare the relative softness of various inclusions
independently of the size and volume of individual inclusions. The
present inventors have found that a suitable parameter is the
average energy, per unit volume, required to cause a decrease of
30% in the length of the inclusion sample along a given axis, when
a force is applied in the direction of this axis. For convenience
this is referred to hereinafter as the `total energy` per unit
volume. This can readily be measured by means of a plate
compression test (for example, using a Textural Analyzer, Texture
Technologies Corp., Scarsdale, N.Y., USA). The inventors have found
that a total energy per unit volume of 400 J/m.sup.3 represents the
lower limit of processability for fruit inclusions in conventional
blending processes. Below this limit, conventional methods for
incorporating fruit pieces into frozen ice confections lead to
damage to the structural integrity of the fruit pieces.
Accordingly, as used herein, a `soft` inclusion is an inclusion for
which the total energy per unit volume is less than 400
J/m.sub.3.
[0064] Using the method of the invention, it is possible to produce
frozen ice confections incorporating inclusions, especially soft
fruit pieces, wherein the structural integrity of the inclusions in
the final product is retained to a greater degree than in products
prepared by conventional processes. The structural integrity of the
inclusions following processing can conveniently be established by
assessing whether or to what extent they are recoverable intact
from the final product. This can conveniently be determined, for
example, by a method involving rinsing the thawed final product
through a sieve of such a mesh size that only substantially intact
inclusions will be retained, while damaged inclusions, for example
pureed material, and thawed frozen composition pass through, and
observing whether any inclusions remain on the sieve. The inventors
have found that a mesh size of 1 mm is suitable for determining
whether structural integrity is retained and so in distinguishing
novel products according to the invention over known products.
[0065] Also provided are frozen ice confections comprising soft
fruit pieces dispersed in a frozen composition wherein the average
number of fruit pieces recoverable from a given volume of the
frozen confection, after said confection has been thawed and washed
through a sieve having a mesh size of 1 mm, is at least 80% of the
average number of fruit pieces, capable of being retained in said
sieve, that were used in preparing said volume of frozen
confection.
[0066] Further provided are frozen ice confections comprising soft
fruit pieces dispersed in a frozen composition wherein the average
weight of fruit pieces recoverable from a given volume of the
frozen confection, after it has been thawed and washed through a
sieve having a mesh size of 1 mm, is at least 60% of the average
weight of fruit pieces, capable of being retained in said sieve,
that were used in preparing said volume of frozen confection.
[0067] Having described the invention in general terms, preferred
embodiments will be described in detail as an aid to understanding
the invention. These embodiments are illustrated in FIGS. 1 to
3.
[0068] FIG. 1 shows a side view of a nozzle, with its accompanying
feeder pipes, according to the invention.
[0069] FIG. 2 shows a longitudinal section in the plane AA, through
the nozzle of FIG. 1.
[0070] FIG. 3 shows a longitudinal section through an alternative
nozzle, comprising a static mixer element.
[0071] The main body of the nozzle shown in FIGS. 1 and 2 is in the
form of a vertically mounted barrel, closed at the top by means of
a flat plate (1) and having an outlet (2) through which the
combined product is extruded, at the other end. The side walls of
the nozzle are constructed, in this particular embodiment, of four
sections (3-6) bolted together.
[0072] Two feeder pipes (7) suitable for conducting the frozen
composition, discharge laterally and from opposite sides into the
chamber of the nozzle (8). These pipe outlets are located in the
top section (3) of the nozzle wall, distal to the nozzle outlet. A
plurality of feeder pipes (9), suitable for the introduction of
inclusions, pass through holes in the top plate (1) and extend into
the chamber of the nozzle so that they discharge at a position
closer to the nozzle outlet (2) than do the pipes (7) that carry
the frozen composition.
[0073] The nozzle is tapered in the third section (5) so that the
bottom section (6), proximal to the nozzle outlet, is narrower than
the upper part. The cross section of this bottom section is
constant throughout its length and is designed to provide the
combined product in an extrusion of a shape suitable for
accommodation in a receptacle (not shown) located below the nozzle
outlet. Means for cutting off appropriately sized portions of
extrudate (not shown) are provided immediately downstream of the
nozzle outlet.
[0074] The flows of frozen composition and of inclusions are driven
through their separate feeder pipes by means of suitable pumps (not
shown). In a preferred embodiment, the flow of inclusions through
the feeder pipes (9) is regulated by means of changeover valves,
located at a point before the pipes enter the nozzle.
[0075] The construction of the nozzle in the alternative embodiment
shown in FIG. 3 is very similar, with the additional feature that
there are provided, mounted on the inside of the nozzle wall, below
the point at which the inclusions are discharged into the chamber,
two static mixer elements (10). Each of these comprises a plurality
of baffles that serve to deflect the flow of material within the
nozzle and thereby alter the distribution of inclusions in the
extruded product.
[0076] The following examples are provided by way of illustration
only.
EXAMPLE 1
Analysis of Softness of Fruit Inclusions
[0077] Fruit pieces of types commonly used as ice cream inclusions
were subjected to textural analysis. The pieces were packed in
sealed plastic containers and stored at +2.degree. C. until they
were ready to be tested. Just before the textural analysis, the
sealed containers were open and a small quantity of inclusions was
taken out and transfers to the room for analysis. One sample of
strawberries was frozen and kept at -25.degree. C., then thawed out
overnight in a refrigerator before textural analysis.
[0078] Textural analysis was done at room temperature
(.about.22.degree. C.). 4 to 6 representative pieces of each fruit
were selected for testing. The fruit pieces were separated from
syrup and laid out on a white-coloured flat surface. Pictures were
taken before the pieces were tested to record their sizes and
shapes. A ruler was positioned in the picture as a reference. From
the pictures, the areas of the fruit pieces were determined and
used in the data analysis to correct for the non-uniform size and
shape. The area of the fruit pieces was measured by imaging
analysis software (Scion Corporation, Frederick, Md., U.S.A) from
the pictures of the fruit pieces. The pixel size on each picture
was calibrated by using the ruler in the picture. The boundaries of
fruit pieces were determined by eye, drawn in by hand and the areas
of the fruit pieces were then calculated by the software.
[0079] Experiments were conducted by plate compression using a
Textural Analyzer (Texture Technologies Corp., Scarsdale, N.Y.,
U.S.A). The plate diameter was 40 mm, which was larger than the
largest fruit piece size (20 mm in length). The crosshead speed was
60 mm/min and a 2 kg load cell was used. As the plate moved down to
compress the specimen, the data collection started as soon as the
force exceeded 0.05 N. For each fruit piece, a force and
displacement plot was produced. FIG. 4 shows two representative
force and displacement curves. The force and displacement curve for
Sample 1 has a relative maximum at a displacement of 3.7 mm. This
relative maximum indicates a failure such as a fracture in the
fruit piece or a breakdown in the cellular structure. As force data
beyond the displacement at which failure occurs cannot be compared
with the force data from fruit pieces that did not fail (Sample 2),
only the force data before a failure were analyzed. Examination of
all force and displacement curves revealed that the minimum
displacement at which a failure occurred, for any of the fruit
pieces studied, was 2 mm. Thus, only force data up to 2 mm
displacement were analyzed. The force and displacement curves for
the fruit pieces were fitted to a third-order polynomial
(R.sup.2>0.99). From the fitted polynomial equations, the forces
at 2 mm displacement were calculated.
[0080] In addition, the fitted polynomial equations were also used
to produce stress and stain plots, where stress is the force
divided by the area of fruit piece and strain is the displacement
divided by the original height of the piece. The stress/strain
plots are independent of dimensional factor unlike the
force/displacement plots. By examining all stress and strain plots,
the minimum strain at which any failure occurred was found to be
30%. Thus the stress of the fruit pieces was compared at a strain
of 30%. The area under the stress and strain curves, which is the
total energy per unit volume required to produce a given strain,
was calculated up to 30% strain for each sample. The stiffness,
which is a measure of the hardness of fruit piece, was calculated
from the gradient of stress and strain curve at 30% strain.
[0081] The textural analysis results are summarised in the table
below. It is clear that the strawberry samples (from different
sources and whether or not they had been frozen and thawed) had the
lowest total energy per volume and stiffness. The next softest
fruit studied was the blackberry, which was found to have a total
energy per unit volume around 2.5 times greater than even the most
robust of the strawberries. This correlated well with the
observation that attempts to incorporate these strawberries into a
flow of ice cream using a conventional fruit feeder at -15.degree.
C. resulted in severe damage to the integrity of the fruit. By
contrast, no significant problems were encountered with
incorporating substantially intact pieces of any of the other
fruits studied using a conventional feeder.
[0082] Textural Analysis of Fruit Pieces
1 Ave Force Ave Stress Total engery Stiff- at 2 mm displacement STD
at 30% STD per volume STD ness STD Inclusions (supplier) (N) (N)
strain (Pa) (Pa) (J/m{circumflex over ( )}3) (J/m{circumflex over (
)}3) (Pa) (Pa) strawberry, small (Kibon) 0.25 0.14 347.93 175.69 57
20 1,083 507 strawberry, large (Kibon) 0.31 0.22 488.81 378.60 62
47 1,544 1,174 strawberry (Ola) 0.16 0.12 996.19 707.09 138 91
3,028 2,362 strawberry (Ola) 0.21 0.06 1607.29 691.49 202 80 5,016
2,224 blackberry (Ola) 0.34 0.10 3242.96 639.01 503 92 9,216 2,381
banana (Ola) 0.72 0.45 4672.89 2804.05 606 269 14,549 9,482
pineapple (Ola) 1.71 0.93 5467.25 3045.11 646 299 15,031 8,758
mango (Ola) 1.01 0.59 6169.70 3351.05 739 416 19,388 10,715 apricot
(Ola) 2.18 2.02 8522.02 6135.62 753 426 25,618 19,942 forest fruits
(Ola) 0.49 0.23 6017.26 2364.92 862 322 18,505 7,448 banana (Miko)
0.91` 0.20 10323.22 2026.62 1,018 213 34,282 6,797 blackberry (Ola)
0.65 0.34 7801.99 4061.59 1,055 471 24,047 13,251 Note: STD:
standard deviation
EXAMPLE 2
Validation of Multi-Injection Soft Fruit Inclusion Trials at the
Factory Scale
[0083] The incorporation of fruit pieces into vanilla ice cream
using a variety of nozzle configurations according to the invention
was investigated.
[0084] A 5-litre multi-injection nozzle was mounted onto an in-line
filler. Ice cream was extruded and cut by heated blades, samples
were collected for evaluation. A number of experiments were
conducted with no static mixers, one or two static mixers in the
nozzle. Two types of static mixers, with different baffle
arrangements, were tested. When there was no static mixer element,
the same flanges used to hold the static mixers remain in the
nozzle, so the nozzle overall height was unchanged throughout all
experiments. In most of experiments conducted, the fruit feeding
pipes into the nozzle were straight. In some experiments, however,
one or more of the fruit pipes were bent to test whether change of
the pipe position can alter fruit distribution within the
nozzle.
[0085] A progressive cavity pump was used to pump fruit pieces. The
pump was capable of delivering the fruit at a rate of between 20
kg/hr and 70 kg/hr. At 950 l/hr ice cream premix flow rate, the
total amount of fruit introduced into ice cream was about 7%.
[0086] In order to try to achieve a good dispersion of fruit in the
product, the flow of pieces into the nozzle was switched on and off
as a function of time, by means of changeover valves. Each of the
individual fruit feeder pipes had a valve, only one of them being
open at one time and all of them having the same open and closed
time intervals.
[0087] Most of the experiments were carried out using strawberry
pieces, about 2 mm in length. The inclusion material supplied to
the nozzle contained about 60% strawberry pieces and 40%
syrup/juice. Some experiments were also carried out with apricot
inclusions. The pieces were much smaller but firmer than the
strawberry ones, about 1 mm cube size. The distribution patterns
obtained were found to be very similar to those obtained with
strawberry. The results described below are those obtained for
strawberry inclusions.
[0088] Results
[0089] In the absence of static mixer elements, the regular array
of pipes supplying the fruit pieces was closely reflected in a very
regular distribution of fruit pieces in the extruded product. The
incorporation process caused very little apparent damage to the
fruit pieces.
[0090] Variation of the timing of the changeover valves regulating
the supply of fruit pieces affected the distribution of pieces in
the product, as well as its quality. The best strawberry
distribution and appearance were obtained with a valve timing of
0.1 second open/1.0 second closed without any static mixer elements
inside the nozzle. This provided a product in which, though there
was only 6% of strawberry pieces by weight, every scoop of ice
cream had strawberry pieces. This result was not achievable using a
conventional fruit feeder and a similar dosing of strawberries.
Changing the timing to 0.1 second open/0.6 second closed, resulted
in the appearance of small voids in the product, as the ice cream
did not fill in all the holes created by the intrusion of the fruit
piece supply pipes as effectively as it did when a longer gap was
left between valve openings.
[0091] Under the same processing conditions, bending two of the
fruit supply pipes had the desired effect of making the strawberry
distribution less regular in the product, without causing any
evident impairment of the quality of the pieces.
[0092] When one or two static mixer elements were placed in the
nozzle, to deflect the flow of the combined ice cream and
strawberry pieces, it was found that the pattern of the included
pieces was more random and no longer obviously reflected the
pattern of the supply pipes. However there was a tendency for an
excessive proportion of strawberry pieces to became concentrated in
the middle of the tub.
EXAMPLE 3
Estimation of the Recovery Rate of Fruit Inclusions from Ice
Cream
[0093] A sample of 500 g of ice cream containing fruit pieces was
placed in a sieve (1 mm mesh size) and rinsed under warm running
water, with very gentle agitation. After all of the ice cream had
been washed away, the fruit pieces left in the sieve were
collected, counted and weighed. The amount of fruit pieces (by
weight or by number) recovered divided by the amount originally
incorporated into this quantity of ice cream is the recovery
rate.
[0094] Results
2 Recovery rate Recovery rate Preoduct (by weight) (by number) Ice
cream with strawberry inclusions .about.50% .about.70% produced by
using a conventional fruit feeder and -5.degree. C. ice cream Ice
cream with strawberry inclusions .about.70% .about.90% produced by
using a process according to the invention and -15.degree. C. ice
cream
* * * * *