GB2308800A - Preserving cakes in a cooking tin - Google Patents

Description

1 A Method of Making Non-Perishable Baked Items 2308800 The invention

relates to a method of making non-perishable baked items from a cake mixture, wherein a cake tin is filled with the cake mixture, the cake tin is closed by a lid and the cake mixture is heated together with the cake tin and lid, wherein the resulting gases are released, the cake mixture is cooled together with the cake tin, and a vacuum, sealing the cake tin in an air-tight manner by means of the lid without additional aid, is generated inside the cake tin as a result of the cooling of the baked item.

A method of making non-perishable baked items of this type is known from EP 406 213 B 1. Using this method, it is possible to bake items such as cakes in a tin and then to use the cake tin as a transportation container for the cake. The method described ensures that the lid seals tightly on the cake tin by means of the decreasing internal pressure generated during cooling.

However, depending on the cake mixture or baking mix to be used, an internal pressure or vacuum can build up to a level which on the one hand necessitates very strong lids and on the other hand impedes opening thereof. This can have undesirable effects similar to an implosion, in particular during the opening process. The result of all this is that the method does not give satisfactory results with certain cake mixtures and with a certain construction of the cake tin or the lid.

An object of the invention is to develop a method of making nonperishable baked items of the aforesaid type in such a manner that the lid can be simply constructed and opened easily and safely.

The invention provides a method as set out in claim 1 and a lid as set out in claim 10.

The method according to the invention is distinguished by a number of considerable advantages.

1? The negative pressure in the range from 0.3 to 0.5 bar, provided according to the invention, firstly ensures that the lid closes sufficiently tightly and secondly that the lid can be opened by the individual consumer without difficulty. There is no danger of injury due to implosion or sudden deformation of the lid. Furthermore, the lid itself can be less sturdily constructed; for example, only a relatively low metal thickness is necessary. In addition, the lid is prevented from deforming and losing its tight closing function during transportation as a result of the considerable negative pressure.

In a particularly advantageous further development of the invention, it is provided that cooling takes place in at least two stages and that, after a first cooling stage, the negative pressure generated up to that point is negated.

With the known method, depending on the cake mixture used, a negative pressure in the range from 0.93 to 0.96 bar can arise when the cake tin with the cake mixture inside has been completely cooled. Therefore, according to the invention, there is only half or a third the amount of negative pressure, proving advantageous in the manner already described. By means of the multi-stage cooling process, it is possible to control the negative pressure generated or to predetermine the negative pressure in the completely cooled cake tin.

The negative pressure is preferably negated by supplying gases to the interior of the cake tin. It is particularly advantageous if inert gases are supplied, for example nitrogen or carbon dioxide.

There are many possible ways of supplying the gases, it is particularly advantageous if the gases can flow into the interior of the cake tin through an opening in the lid, the opening being closed after negation of the negative pressure and before further cooling. The opening can be formed by piercing the lid, for example, and the opening can be closed by a drop of glue or plastics or by similar means.

In an advantageous further development of the invention, it is provided that the negative pressure is negated at a level of substantially 0.5 bar, which is produced by the cooling process. After baking, the cake tin with the baked item 3 inside is therefore cooled until attaining a negative pressure of 0.5 bar. With a knowledge of the composition of the cake mixture, it is easily possible to ascertain the corresponding cooling value.

It goes without saying that various intermediate stages in the stated negative-pressure value can be advantageous, depending on the composition of the cake mixture and the dimensions of the cake tin and the lid. With the method described in the European patent 406 213, it has proved advantageous if the negative pressure in the completely cooled cake tin is 0.3 bar.

The invention also makes it possible to open the lid easily and safely, in that the lid has means for controlled opening. It can be particularly advantageous if a ring pull is provided on the edge of the lid. It can either be formed in one piece with the lid, or it can also be connected to the lid by means of a joining process.

In order to ensure that the lid tears in a particular manner, it can furthermore be advantageous if the edge of the lid has at least one tearing notch adjacent the ring pull. This notch serves to tear the lid and open it in the region of the seal provided thereon. This avoids only the edge of the lid being deformed while the region provided with the seal remains in contact with the edge of the cake tin. It can also be advantageous if the lid is provided with a prestamped tearing line, ensuring that the lid is tom open in a controlled manner. The tearing line can be formed on one side of the lid only, and can be curved, straight or similarly formed.

The ring pull, the tearing notch and the tearing line ensure the controlled opening of the lid and eliminate the danger of injury.

The invention is described in the following with reference to embodiments in conjunction with the drawings which show:

Fig. 1: a schematic side view of an embodiment of a cake tin according to the invention'.

Fig. 2: a schematic side view of an embodiment of a lid according to the invention, 4 Fig. 3.. a plan view of an embodiment of a lid according to the invention with a ring pull and a tearing line; Fig. 4.. a plan view of a further embodiment of a lid according to the invention, and Fig. 5: a perspective view of the opening process.

Figs. 1 and 2 show side views of a cake tin and a lid respectively. The formation of the cake tin, the baking process itself and the essential features of the formation and method of operation of the lid are described in EP 406 213 B I, to which reference is hereby made. In order to avoid repetition, the disclosure of this specification forms part of the present description.

According to the method of the invention, the cake tin 1 is filled with a cake mixture, the composition, the dimensions and the filling level having been described in the aforementioned European patent specification. The lid 2 is placed loosely on the cake tin and is provided with a seal (not shown) on its inner circumferential edge, the seal resting on one edge 6 of the cake tin 1 and promoting the sealing action of the lid by means of the negative pressure arising during the baking process.

The lid 2 is provided with a deformable edge region 7. After the cake mixture or baking mix (not shown) has been poured into the cake tin 1, the edge region 7 of the lid can be deformed until it engages in the circumferential annular groove 8 of the cake tin 1. In this way, the lid 2 is fixed in position, but is still sufficiently loosely attached to allow the gases formed during the baking process to escape from the interior of the cake tin 1.

Figs. 3 and 4 schematically show plan views of two embodiments of the lid 2 according to the invention. The lid 2 is provided with a ring pull 3 which, as shown in Fig. 5, can be grasped by a finger. At least one tearing notch 4 is provided adjacent the ring pull 3 and causes the lid 2 to tear when the ring pull 3 is pulled up. A tearing line 5 extends from the tearing notch 4 and can be formed in various ways, for example as shown in Fig. 4.

It can be seen from Fig. 5 that the ring pull 3 does not pierce the lid when the lid 2 is opened., instead, the tearing process begins at the tearing notch 4.

In this way, it is ensured that the interior of the cake tin 1 is slowly aerated, resulting in controlled, easy openi%.ithout the danger of implosion.

As a result of the reduced internal pressure provided according to the invention, it is possible to manufacture the lid from a relatively thin material and to provide it with the tearing line described. This would not be possible with greater negative pressure since there would always be the danger of the lid deforming or tearing open in an undesirable manner.

The controlled formation of the vacuum in the completely cooled cake tin, which is possible according to the invention, ensures that the lid closes the cake tin permanently and tightly. Depending on the baked item to be made, there is a negative pressure in the cake tin of approximately 0.4 to 0.46 bar, for example. An adequate closing force is ensured as from a pressure of 0.3 bar, guaranteeing that the closed cake tin is sold without the risk of damage. According to the invention, the lid is at no time subjected to a pressure greater than 0. 5 bar and therefore metal thicknesses of 0. 18 mm are possible for the lid, which can be manufactured from a soft AI-Fe alloy. As a result the opening of the lid is made substantially easier.

One may summarise as follows:

The invention relates to a method of making non-perishable baked items from a cake mixture, wherein a cake tin 1 is filled with the cake mixture, the cake tin 1 is closed by a lid and the cake mixture is heated together with the cake tin 1 and lid 2, wherein the resulting gases are released, the cake mixture is cooled together with the cake tin 1, and a vacuum, sealing the cake tin 1 in an air-tight manner bv means of the lid 2 without additional aid, is generated inside the cake tin 1 as a result of the cooling of the baked item, characterised in that negative pressure in the range from 0.3 to 0.5 bar is produced in the completely cooled cake tin 1.

6

Claims (1)

1.

3.

A method of making non-perishable baked items from a cake mixture, wherein a cake tin is filled with the cake mixture, the cake tin is closed by a lid and the cake mixture is heated together with the cake tin and lid, wherein the resulting gases are released, the cake mixture is cooled together with the cake tin, and a vacuum, sealing the cake tin in an airtight manner by means of the lid without additional aid, is generated inside the cake tin as a result of the cooling of the baked item, characterised in that negative pressure in the range from 0.3 to 0. 5 bar is produced in the completely cooled cake tin.

A method according to claim 1, characterised in that cooling takes place in at least two stages and that, after the first cooling stage, the negative pressure generated up to that point is negated.

A method according to claim 2, characterised in that the negative pressure is negated by supplying gases to the interior of the cake tin.

A method according to claim 3, characterised in that nitrogen is supplied.

A method according to claim 3, characterised in that carbon dioxide is supplied.

6.

A method according to any one of claims 3 to 5, characterised in that, for the supply of gases, an opening is formed in the lid and is closed after negation of the negative pressure and before further cooling.

A method according to any one of claims 2 to 6, characterised in that the negative pressure is negated at a level of substantially 0.5 bar, which is produced by the cooling process.

7 8. A method according to any one of claims 1 to 7, characterised in that the negative pressure in the completely cooled cake tin Is at least 0.3 bar.

9.

A method of making non-perishable baked items from a cake mixture substantially as hereinbefore described with reference to the accompanying drawings.

10.

A lid for carrying out the method according to any one of claims 1 to 9 characterised in that a ring pull is provided on the edge of the lid.

11. A lid according to claim 10, characterised in that the edge of the lid has at least one tearing notch adjacent the ring pull.

A lid according to claim 10 or 11, characterised in that the lid is provided with a prestamped tearing line.

13.

A lid according to claim 12, characterised in that the tearing line is formed on one side of the lid only.

14. A lid substantially as hereinbefore described with reference to the accompanying drawings.