Food products, such as cakes, biscuits and pastries, having a surface coating such as icing or chocolate are generally manufactured in a three- stage process: (1) a batter is placed in a mould and cooked in an oven, (2) the food product is removed from the mould and allowed to cool, and (3) a coating and other decoration is applied to the surface of the cooked food product. In industrial food production, the same three-stage process is generally carried out by inline processing in which the food product, once cooked and removed from the mould, is coated by an enrobing process.

This conventional method of inline processing has particular disadvantages in the manufacture of coated food products having complex shapes and/or coatings. Where the coating is applied to the food product as a liquid (e. g. chocolate), fine detail in the shape and/or surface of the food product are generally lost, i. e. it is not possible to transfer fine detail from the food product to the coating. The same is true when the coating is applied to the food product as a solid (e. g. icing). Additionally, conventional inline processing is incapable of manufacturing food products having complex coatings, such as those found on novelty cakes. Instead, complex coatings must generally be applied to the food product by hand, which is ultimately time consuming and expensive in terms of labour costs. Even by hand, it can prove extremely difficult to coat a food product in which the food product, the coating or both have very fine surface detail.

Ready-to-cook products for domestic use enable a consumer to quickly and conveniently make a freshly cooked food product. In most cases a dry batter mix is provided and the consumer makes-up the batter, for example by adding an egg and milk before baking. The result of the baking

is a plain cake or biscuit which still requires decoration. Many consumers find manually applying icing and other coatings to a cake or biscuit to be awkward and consumers are often unhappy with the results of their efforts.

An object of the present invention is to provide an alternative method of manufacturing a coated food product. Additionally, it is an object of the present invention to provide a ready-to-cook product which simplifies the addition of a coating such as icing or chocolate to the product.

Accordingly, in a first aspect the present invention provides a method of manufacturing a coated food product comprising the steps of providing a mould ; lining at least a portion of the inner surface of a mould with a coating; placing a food product batter in the lined mould ; volumetrically heating the batter to form a food product; and thereafter removing the food product with its coating from the mould.

The food product and coating are preferably cooled, for example by refrigeration or vacuum cooling, within the mould immediately after heating to prevent any substantial increase in temperature of the coating.

The inner surface of the mould defines the outer (i. e. visible) surface of the coating. The inner surface of the mould may therefore include any number of surface features, such as indentations and projections, according to the desired design of the coating.

The mould preferably includes an undercut and the coating is preferably made to line at least a part of the undercut. This then acts to support the coating during cooking and subsequent cooling so as to prevent, or at least hinder, any sagging of the coating towards the bottom of the mould.

The batter is preferably heated by irradiating the batter with electromagnetic radiation having frequencies in the range 10-3000 MHz.

Cooking of the food product batter may be supplemented by additional forms of heating. Nevertheless, the food product batter is predominantly heated by volumetric heating.

In a second aspect, the present invention provides a ready-to-cook product comprising a mould adapted for use in a volumetric heating oven and shaped to receive a coating along at least a part of an inner wall of the mould, a coating or ingredients for making a coating and a food product batter or ingredients for making a food product batter.

The mould is preferably substantially transparent to microwave radiation so that the ready-to-cook product may be used with a conventional microwave oven. Moreover, the mould is preferably already lined with the coating such that only the batter need be prepared and placed into the lined mould prior to cooking.

Reference to a coated food product should be understood to mean a food product having a substantially solid coating and is not intended to encompass food products having a substantially liquid coating such as sauces.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 illustrates a method of manufacturing a coated food product in accordance with the present invention; Figure 2 is a sectional view of a ready-to-cook product in accordance with the present invention; and Figure 3 is a sectional view of a ready-to-cook product in accordance with an alternative embodiment of the present invention.

Referring to Figure 1, a method of making a coated food product includes the basic steps of providing a mould S1, lining the mould with a coating S2 and placing a food product batter S5 in the lined mould. The mould with the coating and batter is then volumetrically heated S6 so as to cook the batter within the lined mould. After cooking, the coated food product is cooled in the mould S7 and subsequently removed from the mould S10.

The mould 2 with the coating 3 and food product batter 4 in place is illustrated in Figure 2. In this Figure the coating 3 lines the entire inner

surface 5 of the mould 2. However, it is also envisaged that the coating may line only a part of the inner surface of the mould with the mould specifically shaped to receive the coating at one or more discrete regions.

The mould 2 is a receptacle that is open at only one end and is of a material that is substantially transparent to electromagnetic radiation at the wavelengths used to volumetrically heat food products. Preferably, the material is substantially transparent to electromagnetic radiation having a frequency range within 10-3000 MHz. However, the material used for the mould ultimately depends upon the characteristics of the electromagnetic radiation, in particular the frequency and power of the radiation and the desired exposure of the coating and batter to the radiation.

Where the mould 2 is intended for use in a domestic microwave oven, ideally the mould is substantially transparent to electromagnetic radiation having a frequency of 2450 MHz. In industrial food preparation, microwaves (typically 460-2450 MHz) and radiowaves (typically 10-30 MHz) may be used to volumetrically heat food products. As well as being substantially transparent to the frequency of the radiation used, the mould 2 preferably has a high thermal conductivity so that, when cooked, the coated food product may cool more rapidly in the mould 2. As described in more detail below, rapidly cooling the coated food product immediately after cooking prevents any substantial increase in temperature of the coating 3.

Consequently, substantial deterioration of the coating 3, and in particular melting, may be prevented.

The mould 2 is preferably made of silicone rubber. However, other materials which have been approved by national food agencies for use in microwave/radio wave cooking may alternatively be used, e. g. glass, ceramics, certain plastics and papers.

The mould 2 may be of any shape and need not be limited to simple geometric shapes. For example, where the food product is a cake to celebrate a birthday or anniversary, the mould may be in the shape of a numeral. Alternatively, the mould 2 may be in the shape of a recognisable

object, e. g. car, train or cartoon character. The inner surfaces 5, of the mould 2 need not be smooth or planar but may instead include any number of surface features such as indentations and projections. Accordingly, coated food products of any arbitrary shape are possible. In the embodiment of the mould illustrated in Figure 2, the inner surfaces 5 of the mould 2 include a number of indentations 6 which serve to define the shape of the coating 3.

The mould 2 may be manufactured using conventional moulding techniques including, but not limited to, vacuum moulding, injection moulding, blow moulding, and casting.

The mould 2 may be made in one or more parts depending on the complexity of the product.

The coating 3 comprises one or more layers of an edible material typically used to coat food products including, but not limited to, icing, chocolate and marzipan. The coating 3 is applied to one or more selected regions of the inner surface 5 of the mould 2 by conventional coating methods including, but not limited to, vacuum moulding, pressure moulding, spray moulding and rotational moulding. The coating 3 may initially comprise a liquid or paste material which is subsequently cooled and/or dried. Cooling and drying of the coating 3 may be accelerated by, for example, respectively pre-cooling the mould 2 and lining the mould 2 in a warm and dry environment. For example, chocolate which has been heated so as to melt may be applied by spray or rotational moulding onto a pre- cooled mould 2. Regardless of whether the coating 3 is initially solid or liquid, the coating 3 is, prior to placing the batter 4 in the mould 2, substantially solid so that the coating 3 remains on the lined surfaces of the mould 2.

In the embodiment illustrated in Figure 2, the coating 3 comprises three different layers 7,8, 9. The first layer 7 of coating 3, e. g. black icing, fills only the indentations 6 in the inner surfaces 5 of the mould 2. The second layer 8 of coating 3, e. g. white icing, overlies the first layer 7 of coating 3 and

the remaining exposed surfaces of the inner surfaces 5 of the mould 2.

Finally, the third layer 9 of coating 3, e. g. marzipan, completely covers the second layer 8 of coating 3.

Whilst the coating 3 illustrated in Figure 2 covers all inner surfaces 5 of the mould 2, the coating 3 may alternatively cover only a region of the inner surfaces 5. In particular, the coating 3 may cover only the bottom inner surface so that only the top surface of the eventual food product is coated.

Furthermore, each layer of coating 3 may comprise regions of a different material. For example, the coating 3 may comprise a single layer of icing having regions of different colour. A single layer coating having different regions may be formed, for example, by spraying the coating material through a different mask for each region of the coating.

The mould 2 preferably includes an undercut 11, which comprises a shoulder and a rising wall, and the coating 3 is applied so as to fill or partially fill the undercut 11. The undercut 11 acts as a support for the coating 3 so as to prevent any sagging of the coating 3 that might occur during cooking and subsequent cooling. The uppermost surface 13 of the undercut 11 may then serve as a trimming surface whereby any excess coating and/or cooked food product that extends beyond the trimming surface is removed After lining the mould 2 with the coating 3, there may be unwanted excess coating 3. In particular, there may be coating 3 extending beyond the upper surface of the undercut 13 of the mould 2 and/or on the outer surfaces of the mould 2. Any excess coating 3 is preferably removed from the mould S3 and recycled to the source of coating material S4.

A pre-determined amount of food product batter 4 is then dispensed into the lined mould 2. The amount of batter 4 is preferably such that after volumetric heating, the food product extends beyond the opening in the mould 2. The food product batter 4 may be any batter capable of being cooked by volumetric heating methods, in particular using microwave radiation and radio-wave radiation.

Prior to lining the mould 2 with the coating 3, the inner surfaces 5 of the mould 2 may be lined with a mould-release material to facilitate removal of the coated food product from the mould 2 after heating (not illustrated).

The mould-release material is selected from known mould-release materials used in food production according to the type of mould, coating and food product batter that is used.

After the batter 4 has been dispensed into the mould, the mould and its contents are subjected to volumetric heating S6. Preferably, the volumetric heating is effected by electromagnetic radiation at frequencies and powers conventionally used for microwave cooking or radio wave cooking. Owing to the transparency of the mould 2 to the relevant wavelengths of electromagnetic radiation, the electromagnetic radiation preferentially heats and cooks the batter 4 to form the food product. There may be some cooking of the food product due to thermal flux within the food product, in particular heat transfer from hot spots within the food product.

Indeed, cooking of the batter 4 may comprise periods during which the batter 4 is not subjected to volumetric heating (known as'standing') in order to encourage temperature equalisation within the food product and thus prevent the build up of hot spots. It will be appreciated that length of time during which the mould and its contents is subjected to volumetric heating will depend upon, among other things, the batter material 4, the size and shape of the mould 2, and the frequency and power of the electromagnetic radiation.

Cooking of the food product may be supplemented by additional forms of heating. In particular, conventional infrared radiation may be used to additionally heat and cook the surface of the batter 4 exposed by the opening in the mould 2 to create a firmer base for the food product. Where additional forms of heating are employed, cooking of the food product is nevertheless predominantly by volumetric heating.

As the coating 3 may contain a significant (i. e. non-negligible) amount of fat, sugar and water, the electromagnetic radiation may also heat the

coating 3. Nevertheless, the thickness and dielectric properties of the coating 3 are such that the electromagnetic radiation is predominantly absorbed by the food product batter 4 and consequently no substantial deterioration of the coating 3 occurs during cooking.

Heating of the coating 3 may be hindered by adapting a region of the mould 2 immediately adjacent the coating 3 to shield the coating from incident radiation. In particular, a region of the mould may be made of a radiation reflective material or be coated with a reflective material. For example, where only the bottom surface of the mould 2 is lined with the coating 3, the outer surface of the bottom wall of the mould 2 may have a metal coating to reflect the microwaves.

It is generally not possible in domestic microwave ovens to control the direction of the microwaves, which are reflected around the oven by the metallic walls to ensure even heating. In industrial scale cooking, however, the microwaves or radio waves may be directed so that heating of the coating 3 may be minimised. In particular, the electromagnetic radiation may be directed at those areas of the mould 2 not lined with coating 3, e. g. the top, open end of the mould 2.

After the batter 4 has been cooked, the food product is generally much hotter than the coating 3. Heat will therefore be transferred from the food product to the coating 3 causing the temperature of the coating 3 to increase. This increase in temperature may cause the coating 3 to deteriorate. In particular, the coating may melt or partially melt and, as a result, surface features in the coating 3 may be lost and/or the coating 3 may slide off surfaces of the food product. In order to minimise the build-up of heat in the coating 3 and thereby prevent any substantial deterioration in the coating 3, the food product and coating 3 are cooled S7. The rate and duration of cooling will depend upon, among other things, the size and type of food product, as well as the thickness and material used for the coating.

Refrigeration is the preferred method of cooling. However, other known

methods of cooling, including vacuum cooling and air blasting, may also be used.

The food product and coating 3 are preferably cooled within the mould 2 such that movement of the coating 3, which might otherwise occur in the absence of the mould 2, is minimised. In particular, by cooling the coated food product in the mould 2, fine details formed in the surface of the coating 3 by the mould 2 are generally retained. The mould 2 preferably has a relatively high thermal conductivity so that cooling of the coated food product is not substantially hampered by the mould 2.

Prior to removal of the coated food product from the mould S10, any excess food product may be removed S8 and recycled S9. In particular, that part of the food product extending beyond the trimming surface 13 of the mould 2 may be cut and removed so as to produce a food product having a flat base. Any excess food product that is removed is returned to the batter source. S9 Removal of the coated food product from the mould S10 may be aided by injecting air between the coated food product and the mould. The mould is then cleaned S13 before being re-used in a further batch.

After removal from the mould S10, and prior to any packaging S12, the coated food product may receive additional decoration S11.

Figure 3 illustrates an alternative embodiment of the present invention in which the mould 2 includes an insert 10. The insert 10 is preferably made of the same material as that of the mould 2 and may be coated with a mould- release material. The insert 10 may be formed as a separate element, as illustrated in Figure 3, which is placed over the opening in the mould 2 either before or after the batter 4 has been dispensed. The insert 10 may be secured to the mould 2, for example, by clips 12 or other clamping means.

Alternatively, the insert 10 may be part of and integral with the mould 2. The insert 10 serves to provide one or more indentations in the surface of the cooked food product, i. e. that surface which serves as the base of the food product. The indentation in the food product formed by the insert 10 may

then be filled with an edible filling such as butter icing, cream and jam before having a further food product placed over this surface so as to create a food product having a centred filling.

As the size, or more accurately the thickness, of the food product increases, the time required to fully cook the batter 4 also generally increases. As a result, the coating 3 is increasingly susceptible to over- heating, which may result in deterioration of the coating 3. By employing an insert 10, the thickness of the food product is reduced whilst the overall size is maintained. Accordingly, the time required to cook the food product batter 4 is reduced. Large-sized food products are therefore possible without over- heating of the coating. The indentation (s) in the cooked food product formed by the insert 10 may be filled by the same food product, i. e. a smaller food product shaped/moulded to fit inside the indentation, and/or by a filling such as butter icing, cream and jam.

The mould 2 with the coating 3 and food product batter 4 illustrated in Figures 2 and 3 may also serve as a ready-to-cook product fo r domestic use.

Accordingly, a coated food product may be produced in the home simply by heating the ready-to-cook product in a conventional microwave oven. This then obviates the need to separately coat the food product after cooking.

The batter and/or coating may perish after a relatively short period of time making the ready-to-cook product unsuitable for retail purposes.

Accordingly, the ready-to-cook product may comprise the ingredients for the batter and/or coating so that the batter and/or coating may be prepared as and when necessary. The ingredients may be supplied as a dry mix to which is added ingredients such milk, water and/or eggs etc.

With the method of the present invention, the manufacture of coated food products having complex shapes and/or complex coatings is made possible.

In particular, by volumetric heating a batter in a mould I ined with a coating, it is now possible to coat food products having complex shapes and surfaces features that would otherwise have proven impossibl e, or at the

very least extremely difficult, to coat by automated means or by hand.

Additionally, by employing a reusable mould to define the appearance of the coating, coatings having high-definition, three-dimensional features can be quickly, easily, and consistently reproduced. By adding flavourings and/or scents to the food product and/or coating, it is possible to create novelty food products which not only appear but also taste and/or smell of a particular article, e. g. a bottle shaped cake flavoured with a spirit such as brandy, or a cake having the appearance and scent of a rose.

The method of the present invention can also be realised using inline processes. Accordingly, it is now possible to manufacture coated food products having shapes and coatings that would not otherwise have been contemplated using conventional inline processes.

Additionally, the ready-to-cook product of the present invention allows domestic users to prepare a coated food product merely by heating the product in microwave oven, without the need to separately prepare and add the coating after the food product has been cooked.