The present invention relates to a baked food product, more particularly a baked food product having a curved shape, and to a process and apparatus for the production thereof.

It is, of course, well known to produce food products, such as snack food products, by baking, in which a food ingredient mixture is subjected to dry heating, in an oven, at a sufficiently high temperature. On an industrial scale, baked food products are typically produced by depositing discrete portions of a food ingredient mixture, as a liquid batter or semi-liquid dough mixture onto a flat conveyor belt, typically made of a metal such as steel. This belt is passed through an oven where the food mixture is heated at a sufficiently high temperature to provide baked food products. The resulting baked food products will have a flat lower surface, being the surface in contact with the flat conveyor belt during baking, and may have an overall flat appearance.

It is often desirable that baked food products not only have an appealing taste, but also be produced in shapes that appeal to the eye. This presents a problem in that the shaping of the lower surface of baked food products typically requires the use of a baking mould having an appropriately shaped profile. The baked food products produced in this way will typically have a substantially flat upper surface, whereas it may be desirable to produce baked food products having curved lower and upper surfaces. Moreover, the use of baking moulds is not suitable for the production of curved baked food products from food ingredient mixtures that are relatively fluid, since such mixtures when poured into the moulds will run towards the centre of the mould rather than covering the sides and will not, therefore, adopt the desired shape. The present invention therefore seeks to provide a process for producing curved baked food products in a relatively fast and efficient manner.

According to a first aspect of the present invention, there is provided a method of producing a plurality of curved baked food products from a food ingredient mixture, said method comprising the steps of:

depositing a plurality of discrete portions of food ingredient mixture in at least partially unbaked form onto a generally flat flexible belt which may run in a longitudinal direction;

distorting, at least a part of, the belt whereby said belt is curved in the transverse direction such that said discrete portions of food ingredient mixture are held within a trough formed thereby;

feeding the belt in a distorted configuration through a heat source to bake the discrete portions of food ingredient mixture to form curved baked food products; and

releasing the belt from the distorted configuration.

The curved baked food products may be so formed that they are of substantially uniform thickness to the naked eye.

With regard to the heat source, this may, for example, comprise a conventional oven of the type commonly known in the art. However, other types of heat source may be employed, for example an infra red heater.

The viscosity of the food ingredient mixture is an important factor in the production of baked food products by the process according to this aspect of the present invention. In particular, the viscosity of the at least partially unbaked food ingredient mixture at the point of distortion of at least part of the belt to curve the belt in the transverse direction should be sufficiently high to ensure that the food ingredient mixture adopts the form of the curved belt and does not flow into the centre of the trough formed by the curved belt. The food ingredient mixture may therefore be formulated to have a predetermined minimum viscosity such that it retains the desired shape upon distortion of the belt.

Alternatively or additionally, the belt carrying the discrete portions of food ingredient mixture may be passed through a heat source in the flat, undistorted, configuration to heat the food ingredient mixture, thereby driving off water in order to achieve the desired viscosity prior to distortion of the belt. The extent of heating is predetermined, taking into account the temperature of the heat source, velocity of the belt and length of the heat source. The food ingredient mixture may be partially baked by the heat source, and an outer 'crust' may form on each portion of food ingredient mixture. Pre-heating to achieve the required minimum viscosity ensures that when the belt is later distorted, the food ingredient mixture retains the desired shape rather than flowing towards the centre of the trough formed by the curved belt, which can be a significant problem with relatively fluid food ingredient mixtures. Thus, the portions of food ingredient mixture adopt the curved shape of the distorted belt. The heat source used to partially pre-bake the food ingredient mixture may be the same heat source used to fully bake the food ingredient mixture to form the baked food products, wherein the belt is distorted within the heat source. In this way, the food ingredient mixture is partially baked to a predetermined extent prior to distortion of the belt and baking is completed after distortion of the belt to produce curved baked food products. Alternatively, separate heated ovens may be employed for pre-baking on the flat belt and fully baking on the curved belt. The food ingredient mixture may contain a high level of sucrose, for example up to 50%, or other ingredients capable of forming a glass-like structure.

According to a second aspect of the present invention there is provided an apparatus for making curved baked food products, from a food ingredient mixture, comprising:

(i) a generally flat flexible belt which may run in a longitudinal direction;

(ii) means for depositing a plurality of discrete portions of food ingredient mixture in at least partially unbaked form onto said belt;

(iii) means for temporarily distorting at least a part of the belt, whereby said belt is curved in the transverse direction such that said discrete portions of food ingredient mixture are held within a trough formed thereby;

(iv) a heat source; and

(v) means for feeding the belt in a distorted configuration through the heat source whilst the food ingredient mixture is baked to form a curved baked food product.

The present invention provides a relatively quick and efficient process for the production of a multiplicity of curved baked food products, which may be of regular size and shape. Advantageously, the process obviates the need for multiple loading and unloading steps. The process may be used in the production of baked food products of any suitable composition, for example, sugar wafers, cheese wafers, etc., the recipe for the food ingredient mixture being chosen accordingly.

Typically, the at least partially unbaked food ingredient mixture will be in liquid or semi-liquid form, ideally in the form of a liquid batter, such that said food ingredient mixture readily adopts the shape defined by the curved trough formed by the belt in the distorted configuration. The viscosity of the food mixture may therefore be predetermined in order to ensure that the desired curvature is achieved upon distortion of the flexible belt. In one embodiment, the food ingredient mixture is partially pre-baked on the flat belt to form a 'crust', which avoids the food ingredient mixture flowing into the middle of the curved trough. The viscosity of the food ingredient mixture on deposit onto the belt, at 2O0C, as measured on a Bohlin CVO, may be in the range from 10 to 200 Pas at a shear rate of 1.13 1/s. It will be appreciated, however, that other viscosities may be suitable. Moreover, as hereinbefore described, the food ingredient mixture may be heated on the flat belt in order to increase the viscosity of said food ingredient mixture prior to distortion of said belt. Clearly, therefore, the viscosity of the food ingredient mixture at the point of deposit onto the belt may differ from its viscosity at the point of distortion of said belt.

The discrete portions of food ingredient mixture in at least partially unbaked form may be deposited onto the belt in any appropriate manner. The discrete portions may be of a predetermined volume, and may be of substantially uniform volume, whereby the resultant baked food products are of substantially uniform size. It will be appreciated, however, that the discrete portions of food ingredient mixture may vary in size, such that the baked food products differ in size from one another. It may be desirable that the discrete portions of food ingredient mixture be deposited onto the belt in a generally regular manner in order to produce baked food products having substantially identical dimensions and curvature. One way in which this may be achieved, for example, is to pass the food ingredient mixture in at least partially unbaked form through a stencil such as a sheet having a plurality of substantially uniformly sized and shaped perforations therethrough. The food ingredient mixture passing through the stencil is deposited onto the belt in discrete portions of substantially the same shape. The quantity of food ingredient mixture delivered through the stencil is may be controlled in order to provide discrete portions of substantially uniform volume.

The stencil may be generally flat and may be positioned above the belt such that food ingredient mixture may be delivered generally vertically through perforations in said stencil and onto said belt. A scraper in the form of a knife or similar implement may be secured closely adjacent the stencil in order to level off the discrete portions of food mixture delivered through the stencil.

In one embodiment, however, the food ingredient mixture is delivered into a stencil in the form of a rotatable hollow drum having a plurality of spaced-apart holes through the circumference of its body. The holes may be of any desired size and shape. The holes may be of substantially uniform dimensions, or may vary in size and shape. The drum may have at least one partially open end, the food ingredient mixture being delivered into the interior of the hollow drum through said at least partially open end thereof. The drum may be at least partially open at both ends.

The rotatable drum is ideally positioned such that it sits above a first portion of the flexible belt and makes contact with said portion, the drum being aligned with its axis across the belt. A further portion of the belt upstream from the first portion extends around a portion of the drum, making contact therewith.

The drum may be rotated by any suitable driving means, such as a driving motor. In this embodiment, the flexible belt comprises an endless conveyor belt and is also driven, either independently or by means of the drum with which it makes contact. It is essential that the peripheral velocity of the rotating drum and the linear velocity of the flexible belt are substantially equal.

With this arrangement, food ingredient mixture in at least partially unbaked form may be delivered at a suitable rate into the interior of the hollow rotating drum, for example by means of a supply line, whereupon said food ingredient mixture passes through the boles in the body of the drum as the drum rotates and leaves contact with the adjacent moving flexible belt below. Prior to this point, the holes are sealed by contact with the flexible belt. Thus, a plurality of discrete portions of food ingredient mixture is deposited onto the moving flexible belt, the shape of the discrete portions being representative of the shape of the corresponding holes through which they were delivered.

In order to ensure generally uniform delivery of the food ingredient mixture onto the flexible belt a non-rotating doctor blade, in the form of a knife or a similar implement may be secured closely adjacent to an interior bottom section of the drum. The doctor blade functions to level off the discrete portions of food ingredient mixture as they emerge through the holes in the body of the rotating drum. Thus, a substantially equal volume of food ingredient mixture is delivered through each hole. It will be appreciated that with this arrangement, the depth of the discrete portions of food ingredient mixture deposited onto the flexible belt maybe varied by varying the thickness of the body of the rotating drum. The drum may be formed from a rigid material, since this allows for optimal interaction between drum and belt. For example, the drum may be formed from a metal, such as stainless steel or aluminium, or from any other rigid material.

Additional ingredients may be added to the discrete portions of at least partially unbaked food ingredient mixture after they have been deposited onto the flexible belt and before said belt is passed through the heat source. This addition may be achieved using any suitable delivery or distribution means. For example, a hopper may be provided above the belt from which said additional ingredients may be dispersed onto the discrete portions of food ingredient mixture on the belt. Such an arrangement may be desirable, for instance, if a topping is to be added to the food ingredient mixture.

With regard to the flexible belt, this may comprise an endless conveyor belt. The endless conveyor belt may be disposed around a frame having a table top, the conveyor belt being guided such that an upper part of the belt is situated above the table and a return part of the belt is below the table. The belt may be formed from any suitable flexible material. Typically, the belt will be formed from a plastics material, for example PTFE. The material may be reinforced, for example, with glass fibres. The belt should be sufficiently flexible to permit curved distortion in the transverse direction and sufficiently elastic to return to the generally flat configuration upon release.

The belt may be distorted in any appropriate manner. For example, a bending former may be provided, said bending former having opposed fixed side walls, the distance between which narrows in the direction of movement of the flexible belt. The bending former is positioned adjacent the flexible belt such that side edges of the flexible belt engage the opposed walls of the bending former. As a result, as the flexible belt is passed through the bending former, it is made to distort in the transverse direction to form a U-shaped, curved trough. The degree of curvature of the curved baked food products formed by the process may be varied by varying the width of the flexible belt and/or the configuration of the bending former. The bending former may be fixed above a flexible conveyor belt, and have an inverse U-shaped cross- section, narrowing in the longitudinal direction of movement of the flexible belt.

The flexible belt is held in the distorted configuration whilst being passed through the heat source wherein the discrete portions of food ingredient mixture are baked. The baked food products emerging from the heat source have the curved form of the distorted belt. The baked food products retain their curved shape after the belt is released from the distorted configuration. Once the food ingredient mixture has been baked, therefore, the flexible belt is released from distortion whereupon it returns to its previous generally flat configuration. The curved baked food products are thereafter readily available for collection.

In one embodiment of the present invention, a plurality of flexible belts is used in substantially parallel arrangement. A rotating drum is positioned across the plurality of flexible belts, said drum having axially spaced series of holes appropriately arranged to deliver food mixture onto the plurality of belts. The belts are driven at the same velocity as one another, being substantially the same as the peripheral velocity of the drum. The preferred features of each belt are as hereinbefore described. Each of the belts is may be provided with a bending former as hereinbefore described.

In a one embodiment of the method of the invention, particles are added to each discrete portion of food ingredient mixture prior to baking. The particles may interact with said food mixture to increase the strength of said curved baked food product. The particles may, for example, comprise fruit-containing pieces, including fruit confectionery pieces.

According to a third aspect of the present invention there is provided a curved baked food product having a substantially uniform thickness in the range from 0.7 to 2 mm and having fruit-containing pieces located therein.

The thickness may be in the range from 0.8 to 1.2 mm.

The curved baked food product may be unleavened and may also be generally U-shaped. The curved baked food product may take the form of a curved disc, although other curved shapes are possible.

The curved food product may be formed from a food ingredient mixture comprising a batter.

The fruit-containing pieces may, for example, comprise fruit confectionery pieces or fruit puree. Different fruit purees may be used individually or in combination according to the desired flavour. The fruit- containing pieces may further comprise a gelling agent, such as pectin. A flavouring and/or colouring may also be included.

In addition to fruit-containing pieces, other food ingredients having appropriate properties and being of appropriate size might be included.

By way of example, the curved baked food product may be formed from a food ingredient mixture containing additional fruit products, for example, fruit powders. Thus, the fruit-containing pieces and other fruit products may be selected according to the desired flavour. EXAMPLE

A non-limiting example of a typical food ingredient mixture for use in the present invention is shown below, the food ingredient mixture being an unbaked batter. Sucrose 38.54% Liquid egg white 29.86% Wheat flour 28.90% Butter 2.50% Vanillin crystal 0.10% Salt 0.10%

The invention will now be described further by way of example only with reference to the accompanying drawings, in which:

Fig. 1 is a diagrammatic perspective view of one embodiment of apparatus according to an aspect of the present invention;

Fig. 2 is a diagrammatic side view of the apparatus shown in Fig. 1 ; and

Fig. 3 is a diagrammatic side view showing in detail the drum as shown in Figs. 1 and 2.

Referring to Figs. 1 to 3, an apparatus 10 comprises an endless conveyor device 11 having a number of substantially parallel individual endless flexible conveyor belts 12 disposed around a frame 13 with a table top 14. The conveyor belts 12 are guided by cylinders 16, 17, 18 such that an upper part 21 of each belt is situated above the table 14 and a return part 22 of each belt is below the table 14. The flexible belts 12, which run in a longitudinal direction, may be formed from a flexible plastics material, for example, glass fibre- reinforced PTFE. A hollow rotatable drum 23 is positioned at one end of the conveyor device 11, the axis of said rotatable drum 23 being aligned with its axis across the belts 12. The drum is formed from a rigid material having a number of axially spaced series of generally circular boles 24, each series of holes 24 being regularly radially spaced around the drum 23. The holes 24 are arranged in axial rows to correspond with the flexible belts 12. The drum 23 is positioned such that it sits above the belts 12 and makes contact with a first portion 26 thereof. A further portion 27 of the belts upstream from the first portion 26 extends around a portion of the drum 23, making contact therewith. The drum 23 is partially open at both ends, each end being provided with a circumferential flange 28. a non-rotating doctor blade 29 is secured closely adjacent to a bottom interior section of the drum 23, the doctor blade 29 comprising a plate extending between first and second sides of the drum 23.

The belts 12 and drum 23 are driven by a driving motor, the linear velocity of the flexible belts 12 being substantially equal to the peripheral velocity of the drum 23.

A heat source comprising an oven 31 is provided downstream from the drum 23. The oven may be divided into separately controlled heating zones. Each belt 12 is provided with a corresponding bending device comprising a bending former 32 having opposed fixed side walls, the distance between said walls narrowing away from the drum 23. The bending formers 32 are fixed within the oven 31 above the belts 12 such that side edges of the belts 12 engage the opposed walls of a respective bending former 32 so as to urge the belts 12 to curve in the transverse direction into a distorted configuration, each of the bending formers 32 having an inverse U-shaped cross-section narrowing in the downstream direction. The bending formers 32 extend longitudinally within the oven 31. A hopper 36 is provided above the belts 12 downstream from the drum 23. Additional ingredients such as toppings may be delivered via the hopper 36.

In use, a food ingredient mixture comprising a liquid batter is delivered into the drum 23 through an open side thereof. The liquid batter may be pumped into the drum via, for example, a delivery tube. The drum 23 is rotated by the driving motor, the belts 12 being driven in the longitudinal direction. A reservoir of liquid batter 37 lies within the bottom portion of the drum 23. The flanges 28 prevent the liquid batter from exiting the sides of the drum 23, whilst the level of the reservoir of liquid batter 37 may be monitored and controlled by means of an electronic sensor linked to the delivery pump.

Each time a row of holes 24 in the rotating drum passes the liquid batter reservoir 37, the holes 24 are filled with liquid batter. The doctor blade 29 levels off the discrete portions of liquid batter filling each of the holes 24, which are sealed at this point by corresponding contacting belts 12. As the flexible belts 12 are released from the drum 23, discrete portions of liquid batter 40 are deposited onto the belts 12, the shape of said discrete portions 40 being generally circular in plan view owing to the generally circular shape of the holes 24.

As the discrete portions of liquid batter 40 are carried in the downstream direction on the flat belts 12, a topping or other additional ingredients may be added via the hopper 36.

The discrete portions of liquid batter 40 are carried into a heated tunnel oven 31 for baking. Depending upon the viscosity of the liquid batter, it may be necessary or desirable to pre-heat the discrete portions of liquid batter 40 before distortion of the flexible belts 12 carrying said discrete portions 40 by the bending formers 32, in order to achieve the correct viscosity such that said liquid batter does not readily flow towards the centre of the trough formed by the curved belt. The bending formers 32 may, therefore, engage the belts 12 some way downstream of the entrance to the heated oven 31. The pre-heating requirements of the process will depend upon the nature of the liquid batter.

The flexible belts 12, carrying discrete portions of liquid batter of appropriate viscosity, are engaged by the bending formers 32 within the oven 31, whereupon said belts 12 are distorted into generally U-shaped curved troughs. The discrete portions of liquid batter 40 are curved accordingly before being fully baked within the heated oven 31 to form baked food products. Upon leaving the heated oven 31, the baked food products 41 have the curved form of the distorted belts 12 and retain their shape. Thus, the belts 12 are released from bending distortion after baking is complete. The baked food products 41 emerging from the oven are generally U-shaped curved discs.

At the downstream end of the conveyor device 11, the curved baked food products 41 lying loosely upon the belts 12 are collected.

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiment, which are provided by way of illustration only.

Where the terms "comprise", "comprises", "comprised", or "comprising" are used in this specification, they are to be interpreted as specifying the presence of the stated features, integers, steps or components referred to, but not to preclude the presence or addition of one or more other feature, integer, step, component or group thereof.