[0001] The present invention relates to an ovenable container for foodstuffs which facilitates
the serving of foodstuffs such as frozen or chilled ready meals.
[0002] Convenience foods such as pre-cooked ready meals are becoming increasingly popular,
particularly with the rapid reheating times that are available using microwave or
conventional thermal ovens. Such foods are usually sold in pre-packaged form. However,
reheating of the foodstuffs tends to result in drying out occurring at the edges of
the foodstuffs in the package. Furthermore, good presentation of the reheated foodstuffs
is difficult to achieve upon removal from the package and transfer to a plate.
[0003] The present invention provides an ovenable container for foodstuffs comprising a
base portion and an inwardly-directed lateral flange sealed to the base portion or
an integral part thereof, at or in the vicinity of the mouth of the container, wherein
the lateral flange extends inwardly by an amount sufficient to inhibit loss of liquid
from the container during heating of the foodstuffs in the container when inverted
over a plate, the lateral flange being sufficiently flexible after the heating to
permit removal of the container from the plate without substantial disturbance of
the foodstuffs.
[0004] The lateral flange should extend inwardly by an amount sufficient to inhibit loss
of liquid from the foodstuffs during the heating of the container in its inverted
position without extending so far as to trap some of the footstuffs when the container
is removed from the plate. The width of the flange will depend on the size of the
container and on the type of foodstuffs present in the container. For example, the
larger the container the further inwardly the flange may extend. Similarly, a substantially
liquid foodstuff may be packed in a container having a large flange whereas a more
solid foodstuff would require a smaller flange. Generally the containers will range
from say 10 cm to 30 cm in width with a depth in the region of 3 cm. Preferably, the
lateral flange extends inwardly by at least 5 mm, more preferably by 8 to 20 mm. The
lateral flange may run substantially continuously around the periphery of the container.
Alternatively, part of the lateral flange may be interrupted, for example by slits
provided that at least about 10 mm of the flange extending inwardly runs substantially
continuously around the periphery of the container. Preferably, it is formed by an
endless strip of material sealed to the base portion.
[0005] The loss of liquid is thought to occur by a combination of vapourisation and seepage.
When the foodstuffs are heated, some of the liquid present will be vapourised and
will escape by venting out from between the container and the plate. Additionally,
some liquid will escape by seepage from between the container and the plate. Thus,
a function of the lateral flange is to provide a barrier between the foodstuffs and
the plate so as to inhibit such loss of liquid. The presence of the barrier tends
to produce a degree of sealing between the container and the plate. This may also
reduce heat loss from the foodstuffs and, as a consequence, may increase efficiency
of heating and reduce the time required for cooking. Advantageously, the presence
of the lateral flange may also impart to the base portion additional rigidity or stability.
[0006] The container may be of any conventional shape. For example, in horizontal cross-section
it could be square, rectangular, elliptical or circular. Preferably the container
is substantially circular in horizontal cross-section and preferably has an annular
flange around the periphery. Whatever the horizontal cross-sectional shape of the
container, the base portion may comprise a single compartment or it may comprise a
plurality of compartments, the purpose of which is to keep separate different types
of foodstuffs.
[0007] The container should be constructed from a suitable food grade material. The base
portion may be flexible or semi-rigid whereas the lateral flange is preferably flexible
at room temperature. The choice of materials depends upon the use to which the container
is put. For microwave cooking, metallic materials should not be used. A temperature
resistance of 130°C is preferred for microwave cooking whereas temperature resistance
of 210°C is preferred for thermal oven cooking. Preferably, the base portion is made
of a plastics material such as a polyester or polycarbonate. The method of forming
the base portion is chosen according to the material from which it is made. For example,
where polycarbonate is used the base portion may be thermoformed. The lateral flange
may also be made of a plastics material, preferably a polyester.
[0008] Once foodstuffs have been placed in the container, the container may be overwrapped.
Among the types of overwrapping which may be used are conventional plastics wrapping
or cartoning. Preferably a removable lid is used, more preferably a peelable lid sealed
to the flange so as to form a peelable seal. Because the overwrapping or lid is removed
prior to cooking, there is no need for this to be constructed from an ovenable material.
However, it is preferable for the container and, where applicable, the lid, to be
stable to, for example, -30°C for frozen food applications and to 0°C for chilled
foods. The lid is preferably made from a polyester.
[0009] In the case of microwave heating the plate is preferably a serving plate from which
the meal is to be eaten. In the case of thermal oven heating the plate may be a heat-resistant
serving plate or an oven baking tray or sheet from which the food would have to be
transferred to a serving plate before eating.
[0010] Means for holding the container may also be present on the base portion for the purpose
of aiding lifting of the container from the plate after cooking. For example, the
base portion may have holding tabs and these tabs may extend laterally from the base
portion.
[0011] The invention will now be further described, by way of example only, with reference
to the drawings in which:
Figure 1 is a vertical sectional view of one embodiment of the base portion of the
container;
Figure 2 is a plan view of an annular ring which is sealable to the base portion shown
in Figure 1;
Figure 3 is a plan view of a lid for use with the annular ring of Figure 2;
Figure 4 shows a vertical sectional view of a schematic representation of this embodiment
of the assembled container in which foodstuffs are placed; and
Figure 5 shows a further embodiment of the container lifted from the foodstuffs after
cooking.
[0012] The drawings relate to embodiments of the container having a circular cross-section.
The container is manufactured by forming base portion 1 to a thickness of at least
12 microns from a polyester (Melinex-ICI) by drawing the material into a suitably-sized
pocket. This is then filled with the foodstuffs. The diameter of base portion 1 at
the periphery of rim 7 is the same as that of annular ring 2, typically 190 mm. The
annular ring 2 is made from a polyester (Mylar 100 XM963 - Du Pont) and forms a 20mm
wide strip. This is weld sealed to the rim 7, which is typically 10 mm wide so as
to form an inwardly-directed lateral flange of 10 mm. The depth of the container is
30 mm. Lid 3 is also made from a polyester (Mylar 100 OL - Du Pont). This is sealed
to the upper surface of annular ring 2 and is shown in Figure 3 with a tab portion
8. In the further embodiment illustrated in Figure 5, the base portion 1 has holding
taps 10 extending laterally therefrom. The finished product may be frozen or chilled
as is appropriate.
[0013] For the purpose of microwave heating, the lid is peeled off and the ready meal placed
on a serving plate 6. Where the ready meal is frozen, simple inversion of the container
onto the plate 6 is sufficient. However, where the ready meal is chilled, the plate
6 should preferably be placed upside-down over the mouth of the container and then
the container and plate inverted together to prevent spillage of the foodstuffs 5.
During heating of the filled container in a microwave oven, inwardly-directed lateral
flange 9 inhibits loss of liquid from the container by acting as a barrier between
the plate 6 and the foodstuffs 5. Once heating has finished, the container 1 is simply
lifted from the plate 6 preferably by the holding tabs. Because the lateral flange
9 is flexible, the foodstuffs remain on the plate 6 virtually undisturbed thereby
improving their presentation. Similarly, the container may be heated in a conventional
thermal oven instead of a microwave oven.
1. An ovenable container (4) for foodstuffs (5) comprising a base portion (1) and an
inwardly-directed lateral flange (9) sealed to the base portion or an integral part
thereof, at or in the vicinity of the mouth of the container (4), wherein the lateral
flange (9) extends inwardly by an amount sufficient to inhibit loss of liquid from
the container (4) during heating of the foodstuffs (5) in the container (4) when inverted
over a plate (6), the lateral flange (9) being sufficiently flexible after the heating
to permit removal of the container (4) from the plate (6) without substantial disturbance
of the foodstuffs (5).
2. An ovenable container as claimed in claim 1, wherein the lateral flange (9) extends
inwardly by at least 5 mm.
3. An ovenable container as claimed in claim 2, wherein the lateral flange (9) extends
inwardly by 8 to 20 mm.
4. An ovenable container as claimed in any of the preceding claims, wherein the lateral
flange (9) forms a substantially continuous strip around the mouth of the container
(4).
5. An ovenable container as claimed in any of the preceding claims wherein the lateral
flange (9) is made of a plastics material.
6. An ovenable container as claimed in claim 5 wherein the plastics material of the lateral
flange (9) is a polyester.
7. An ovenable container as claimed in any of the preceding claims wherein the lateral
flange (9) is formed by an endless strip of material (2) sealed to the base portion
(1).
8. An ovenable container as claimed in any of the preceding claims, wherein the container
(4) is substantially circular in horizontal cross-section.
9. An ovenable container as claimed in any one of the preceding claims, wherein the base
portion (1) is made of a plastics material.
10. An ovenable container as claimed in claim 9, wherein the plastics material of the
base portion (1) is a polyester or polycarbonate.
11. An ovenable container as claimed in any one of the preceding claims which further
comprises a removable lid (3).
12. An ovenable container as claimed in claim 11, wherein the lid (3) is a peelable lid
which is sealed to the flange (9).
13. An ovenable container as claimed in any of the preceding claims wherein the base portion
(1) has holding tabs (10) for facilitating removal of the container (4) from the plate
(5).