Note: Descriptions are shown in the official language in which they were submitted.
CA 02262~12 1999-02-02
WO 98/12g37 PCT/EPg7/04879
Frozen me~l
This invention pertains to a process for preparing a frozen
meal.
S
Traditionally, frozen culinary products have two packages,
an inner package such as an aluminium tray or a boiling bag
containing the food product and a box around the tray or
the bag. Usually, there is a dead space between inner and
outer package so that the end product becomes unnecessarily
voluminous and requires much space on the shelves, in the
storage room and during transport. It would therefore be
desirable to put frozen culinary products on the market
which are characterized by a less voluminous package.
A reduction in packaging material would not only be
advantageous from a financial standpoint, but would also be
in line with recent environmental requirements.
The Applicants have surprisingly found that by introducing
a food preparation into moulds and freezing or prefreezing
it there to rectangular bricks it is possible to directly
put the thus obtained frozen bricks into cardboard boxes or
flow packs without having to resort to additional packaging
material.
Freezing foodstuff to brick-shaped forms is known in the
prior art.
Thus, DE-C-1003021 discloses a process of wrapping poultry
into a transparent sheet. The package is then placed in a
mould and pressed into the shape of a brick. The mould with
the packages is then frozen. After that the frozen packages
are put into an outer package such as a cardboard box.
However, there is no disclosure in this document of placing
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the foodstuff directly into the moulds in order to obtain a
final product with only a single package.
GB-A-1041155 relates to a process of packaging fish by
S placing fish pieces into a cardboard box and then pressing
the box into shape. Thereafter, the box is fro2en. Again,
there is no disclosure of placing the foodstuff directly
into moulds and freezing it there. In addition, in order to
permit the air which is entrapped during the compression
step to escape and thus avoid air void formation, the
interior surface of the cardboard boxes used in this
process is specially structured in that depressions are
embossed into the paperboard before the package is formed;
normal cardboard boxes are not suitable.
WO 95/21541 refers to a process for producing pet food
consisting of lu~plike meat pieces and a liquid sauce,
whereby frozen raw meat is cut into pieces and packed with
equally frozen sauce granules into a press where the
mixture is pressformed to a form corresponding to the lower
section of the container into which the thus obtained form
is subsequently emptied. The container, usually a tray or a
tin, is then sealed on the upper side with a foil. By
freezing the liquid constituents of the foodstuff, the
problem of accidentally spilling sauce on the rim of the
container during the filling step is circumvented. If said
rim is contaminated with food traces, the foil will not
tightly adhere to the container and thus an airtight
sealing is prevented which, of course, has a negative
effect on the shelf-life of the product. This document does
not disclose the suitability of normal cardboard boxes or
flow packs as the only package nor does it relate to
freezing the foodstuff when being enclosed in moulds.
Furthermore, the process as disclosed in this document
3~ requires the additional step of formpressing which is not
necessary in the process of the present invention. In view
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of the fact that formpressing is performed with hard frozen
pieces it would appear that the frozen product does not
have a perfectly smooth surface. Finally, the process as
disclosed in this document is not suitable for the
preparation of meal5 with a topping or multilayered food
such as lasagna.
It is therefore an object of this invention to provide for
a process for preparing a frozen meal which can be packaged
into a single package such as a normal cardboard box or a
flow pack.
It is a further object of this invention to provide for a
process for preparing a frozen meal which can be packaged
into a less voluminous package.
It is a still further object of this invention to provide
for a process which does not require a formpressing step as
disclosed in WO 95/2l54l.
It is a further object of this invention to prepare a meal
having the shape of frozen bricks, which require a minimum
of space on the shelves.
It is a still further object of this invention to prepare a
frozen meal having a smooth surface which is appealing to
the customer.
It is a still further object of this invention to provide
for the preparation of frozen meals having a topping or of
multilayered meals such as lasagna.
Surprisingly, the above objectives can be realized by a
process for the preparation of a frozen meal comprising the
following steps:
a~ putting the components of the meal into moulds;
.. . . .
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b) subjecting the thus filled moulds to a freezing step;
c) demoulding the frozen product; and
d) packaging the deep frozen product.
The process of the present invention can be carried out in
conventional moulds such as plastic or metallic moulds.
Plastic moulds have the advantage of being less rigid and
less adhesive than metallic moulds so that demoulding is
facilitated by simply knocking or twisting the moulds.
Basically, both vertical and horizontal moulding is
feasible, horizontal moulding is preferred, however, as a
wider variety of products can be obtained with this
technique. Thus, with this technique it is possible to
process both viscous and liquid products, no matter whether
lS large pieces are contained in the meal or not. It is
equally possible to produce meals having a topping or even
multi-layered meals.
The frozen meal of this invention is preferably formed to a
rectangular shape such as a brick. With such a shape, the
volume of the package as well as the dead space can be kept
at a minimum, in addition, multi-packs can be easily
formed. This form of packaging would meet the needs of
catering services and would also be in line with the eating
2~ habits of families where the different members do not have
the same eating hours. Alternatively, the product can also
be offered as a single portion.
The size of the individual portion is not particularly
limited and can be adjusted to the individual needs.
Preferably, the weight of a frozen brick is in the range of
from about 50 g to 1 kg. The bricks are most preferably
portioned to 150 g each. Such an amount of food roughly
corresponds to a complete meal for a child and for an
elderly person, while adults would be expected to consume 2
....
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portions per meal. The portions are most preferably sized
to bricks of about llO x 75 x 20 mm each.
The process as claimed in this application is not limited
S to particular food, basically any meal can be prepared. The
frozen bricks may contain all the constituents of a
complete meal such as meat, pasta, vegetables, rice, sauce
etc. Neither is the process limited to a particular
consistency of the food: meals comprising lump-like pieces
of meat can equally well be processed as more liquid or
saucy meals. "Chili con carne", "riz cantonais", "moussaka"
or multi-layered meals such as "lasagna" are most
preferably prepared with the claimed process.
The freezing step may be performed by any suitable
technology and may include e.g. cryogenic freezing or
crusting, i.e. passing the meal through a liquid nitrogen
tunnel, air blast freezing or contact freezing in a
mechanically refrigerated tunnel. The meal may be deep
frozen in one step or frozen at the surface, demoulded and
deep frozen with cold air. Alternatively, the meal can be
frozen by liquid freezing, i.e. by dipping the moulded meal
into a brine bath at low temperature.
In a preferred first embodiment of the freezing step
including cryogenic freezing, the meal is filled in plastic
or in metallic moulds and then partially frozen (= crusted)
in a liquid nitrogen tunnel. After demoulding, the bricks
are deep frozen in an air blast tunnel and subsequently
packaged. The empty moulds are washed (if necessary) and
conveyed back to the filling station for the next cycle.
In a preferred second embodiment of the freezing step
including liquid freezing in a brine bath, the moulds are
filled with the meal and dipped into a cold brine. Maximum
heat transfer efficiency is achieved when all the brine is
_, ,
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recirculated with high speed through the brine distribution
piping. In order to accelerate the freezing of the upper
surface, cold air is blown over the moulds. The frozen
bricks are demoulded and transferred to the packaging
units. The empty moulds are washed and conveyed back to the
filling station.
Demoulding can be facilitated by blowing warm air on the
moulds, or, in case of the brine process, by defrosting
with warm brine.
The process of this invention is not limited to a
particular packaging material. Preferably, plastic films,
paperboard, or coated paperboard are used. With regard to
environmental considerations, the paperboard and coated
paperboard materials are the most preferred packaging
materials.
Both individual portions and multi-packs are packaged in
flow packs or reclosable paperboards with multipacks
contained in reclosable paperboards being the most
preferred product.
The present invention also pertains to the frozen meals
obtained by the process as described above. The concept of
freezing a complete meal to a bricklike structure and
packaging said brick directly into a simple flow pack or
cardboard box, realized by freezing or crusting said meal
while being contained in moulds, is unknown in the prior
art. Therefore, the meals of this invention can be
distinguished from those of the prior art by a much simpler
packaging. In addition, the frozen meals of this invention
are characterized by a very smooth surface, in particular
as far as the lateral and the bottom sides of the brick are
concerned which are in direct contact with the inner
surfaces of the moulds. Smooth surfaces are appealing to
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the customer on the one hand. On the other hand, they are
mandatory for reducing the aforementioned dead space and,
as a consequence, the volume of the packaging to a minimum.
Again, such smooth surfaces are only feasible with the
process as described above, they cannot be obtained with
the method as disclosed in WO 95/21541 wherein already
frozen particles are pressformed to a particular shape.
Within the scope of the present invention it is also
possible to provide for an embodiment where the surface of
the product is irregular. This product conception consists
in the piling up of sauces (several dosing may be
performed), garnish (vegetables, noodles or rice, for
example) and finally at the top a piece of fish or meat.
The main advantage of this concept is to gain an appealing
product when looked at from above, either in or out of the
package. The latter should keep the visual aspect intact
and could be a flow-pack or the darfesh system for
refrigerated products (plastic film wrapped around the
portion to make a skin), for example.
The moulds used for this embodiment may still be of
rectangular or brick shape, but any shape that can be made
in thermoformable material (high density polyethylene, for
example) can be provided for. The mould set up offers
flexibility for having new shapes faster and at a lower
cost, or for changing quickly the whole set of moulds.
The demoulding step can be carried out by spraying warm
water (10 to 20~C, especially 13 to 15~C, for example) on
the outside of the mould in order to unstick the product
from the mould, and then by pushing the bottom of the mould
so as to lead the product out of the mould, for example.
Such an easy and efficient (no product left in the mould)
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way of demoulding the product is feasible because of the
ability of plastic to stand deformation.
The moulds may then travel back to the start of the line.
S They may be washed both on the inside and the outside and
dried. A dosing equipment may be provided for to put both a
sauce and a solld garnish into the mould automatically, for
example.
The freezing equipment may comprise a brine bath at a
temperature of from -~0 to -30~C approximately below a
conveyor of moulds, and a freezing tunnel on top of the
products, for example. A cold source for the freezing
tunnel may be blasted air cooled with ammonia or freon or
liquid nitrogen, or liquid nitrogen sprayed directly at the
surface of the product.
The invention will now be described by way of the following
examples:
~0
Example 1 (cryogenic freezing)
The tests have been performed with meals of different
textures. In particular, "riz cantonais", "chili con carne"
and "moussaka" have been used. Moulds yielding bricks of
llO x 75 x 20 mm, corresponding to a weight of l50 g were
selected. The meal was filled in aluminium moulds and in
thermoformed polycarbonate. The moulds were then introduced
into a cryogenic air liquid tunnel (Zip Freeze, supplied by
Air Liquid, France). At a temperature of about -120~C, the
crusting time (minimum time to permit demoulding and
handling of the brick without sticking and deforming) is in
the range of from 3 to 3.5 min for metallic moulds and from
3.5 to 4 min for the plastic moulds, respectively. The
moulds are subsequently emptied. Demoulding can optionally
be facilitated, particularly in case of the rigid metal
.
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WO98/12937 PCT~P97/04879
moulds, by blowing warm air before the moulds are emptied.
~he prefrozen bricks are then subjected to deep freezing
and directly packaged into cardboard boxes.
Example 2 (brine process)
The tests were again performed with "riz cantonais~, "chili
con carne" and "moussaka". Moulds having the dimensions as
those described in Example l were used. The filled moulds
were introduced into the brine bath. The lower and lateral
parts of the moulds were in direct contact with the brine
at a temperature of about -38~C. In order to reduce the
freezing time, especially of the upper surface which is not
in direct contact with the brine, an air blast cooling
tunnel generating an air temperature of -20~C was installed
on top of the brine bath. With this additional cooling
equipment the freezing time is about 15 min. The bricks
were then extracted from the moulds by means of suction
cups after defrosting with warm brine and further
processed.
