WO1995005084A1

WO1995005084A1 - Production of filled unit food portions

Info

Publication number: WO1995005084A1
Application number: PCT/GB1994/001770
Authority: WO
Inventors: Stephen Favor Parker; Paul Croft Roberts
Original assignee: Sovereign Food Group Limited
Priority date: 1993-08-13
Filing date: 1994-08-12
Publication date: 1995-02-23
Also published as: AU7349994A

Abstract

A method and apparatus for introducing an edible filling into a unit food portion such as a chicken breast fillet. A mould set (1) is described which operates with a sharpened probe (4) for making an aperture in the food portion and an injector for introducing the filling into the aperture. The mould parts involve use of two lids (3, 6), a first of which contains the food during formation of the aperture and the second of which allows for the increased volume due to the filling, and has a hinged section (7) which allows for a further increase in volume due to presence of the injector which increased volume is reduced as the injector is withdrawn. The hinged section then crimps off the end of the food portion to seal the filling in the product.

Description

PRODUCTION OF FILLED UNIT FOOD PORTIONS

The present invention relates to the production of unit food portions. By unit food portions we mean food portions of pre-selected volume size and or weight. Examples of such unit food portions are fishfingers, battered cod steaks, formed chicken drumsticks, unit chicken breast fillets, and various similar meat products made from comminuted or whole muscle meat and of chosen size.

With such unit food portions, the product may be produced to a chosen weight or volume by trimming and may then be frozen or enrobed with batter, or breadcrumbs or chilled or pre-cooked and then packed and/or stored for sale.

In the case of unit portions of chicken breast fillet, it is desirable to add to the product a filling such as garlic butter, sauce, or indeed any other pumpable edible filling. Unit portions of the other food products exemplified above may also need to have such a filling applied.

In producing such a filled product a number of problems arise.

It is generally necessary, particularly with whole muscle, to cut and form a cavity within the unit portion with consistency.

The filling has to be accurately placed within the unit portion and it is desirable to mini-mise any tendency to leaking of the filling during subsequent processing stages such as packing, storing and cooking.

The minimum of manual handling should be achieved both for hygiene and cost considerations.

Operational safety combined with hygiene has to be achieved. EP 0,408,374A discloses an apparatus for injecting additives into a confectionary article such as kiwi fruit. A number of needles form a cavity within the confectionary article either by sucking out material or by displacement which compresses the material of the article within the mould. The additive is then injected into the cavity so formed. However both of these possibilities have problems in practice - sucking out the material requires this material to be disposed of, whereas compressing the material could cause structural damage and hence quality changes to the food material. Moreover there is a limit to the amount of additive that can be accommodated.

The present invention aims to solve these problems and accordingly provides a method of forming a filled food portion comprising the steps of

introducing a selected quantity of the food into a cavity in a mould, and then applying an edible filling into a cavity region within said quantity of food

characterised in that the mould used is an expandible mould having an internal volume which can be expanded in use,

that the cavity within the quantity of food is defined by forming an incision within the food while it is maintained under pressure within the expandible mould

and that the edible filling is injected into said cavity defining incision while the internal volume of said expandible mould is permitted to increase to take up an increase in volume of the filled foodstuff due to displacement caused by said injection of the edible filling.

Preferably on completion of injection a temporary seal will be provided to close off said internal cavity and thereafter the product integrity can be maintained in any of a number of ways known per se. For example the product can be enrobed with batter or breadcrumbs and be flash fried followed by freezing or chilling and then packing; or the product may be directly frozen in uncoated form.

As well as a method of producing such a filled unit food portion, the invention also provides apparatus for production of such a filled unit food portion and filled unit food portions made by the method of the invention or by the apparatus of the invention.

In a preferred form of the method, the internal cavity is formed by insertion of a sharp ended probe into the interior of the contained quantity of food while the food is maintained under constraint within the mould cavity. The sharp ended probe should be located with precision in relation to the mould cavity.

The edible filling may be injected into the internal cavity of the foodstuff by insertion of an injector into the cavity which is then withdrawn as the injection is completed. This should also be located with precision in relation to the mould cavity. Generally injection will take place after removal of the sharp ended probe, however in some situations the two features can be combined with one device performing both functions.

The mould for use in the invention will generally consist of a first part having a mould cavity to receive the unit food portion and a movable cover to complete encompassment of the cavity to allow for expansion and provide the required constraint.

It is preferred, although not essential, to have two separate covers for the mould cavity one of which is used during the stage of inserting the sharp ended probe to form the cavity and the second of which is used to close the cavity during the stage where the injector injects the filling into the internal cavity.

The first of these covers may be a plate closing off the top of the mould via an inner protrusion which allows for the expansion of the unit food portion during insertion of the sharpened probe and also including some form of locating spigot to ensure that the two parts marry together correctly and remain aligned during the relative movement.

The second form of cover preferably includes a shallow cavity to enlarge the defined cavity created by the first part of the mould to accommodate the added volume of the unit portion when it contains the filling. Preferably this cover also includes an expandible section which can expand to accommodate the filling nozzle and can then be closed down as the filling nozzle is removed. This expandible section is preferably pivoted to the relevant cover section and preferably has a crimping end to establish a seal of the food portion as the injector is finally removed from within the food portion.

Two embodiments of the invention will now be described by way of example with reference to the accompanying diagrammatic drawings in which:- Figure 1 is an exploded perspective view of a mould, first stage lid and knife; and

Figure 2 is an exploded perspective view of a mould, second stage lid and injector.

Figure 3 is a perspective view of a second form of the apparatus embodying the invention which is adapted to cut a cavity in the meat.

Figure 4 is a plan view of the apparatus of Figure 3 in the operative engaged state and with the lid omitted for clarity.

Figure 5 is a perspective view of that part of the apparatus embodying the invention which injects sauce into the cavity cut in the meat by the apparatus of Figure 3; and

Figure 6 is a plan view of the apparatus of Figure 5 in the operative engaged state and with the lid omitted for clarity. Referring to Figure 1, a mould 1 has a cavity 2 of a shape defining the desired unit portion of food, and a top plate or lid 3 which is essentially flat but has on its underside (not shown) a protrusion and locating spigots to ensure that it accurately marries with the mould while allowing for expansion. A sharp ended probe 4 in the form of a knife is located alongside and directed inwards towards an end of the mould cavity. The end wall of the mould 1 has an aperture 5 of slotted and domed cross-section to accommodate the knife 4 and an injector (referred to in Figure 2) . The shaped aperture ensures that the knife and injector are located with precision in relation to the mould cavity; while the protrusion and spigots allow relative movement of the parts when the knife is inserted into material in the mould, thereby causing expansion.

In a first stage of the process, pieces of chicken breast (fillets) were trimmed to a target weight of 125g (other target weights such as lOOg could also be used with a suitably sized mould) . It was found important that the membrane (inner skin) of the fillet should remain intact during the trimming process.

Each piece of fillet was then individually placed into the mould 1, the fillet being placed with its membrane facing into the mould cavity.

The lid or top plate 3 was then put in position to grip the fillet within the mould and was held in position by mechanical pressure so as to provide all round support to the fillet. The knife 4 was then inserted through the end of the mould into the end of the fillet through the aperture 5 which was approximately 5mm above the membrane and parallel to it. The knife was constrained to a calibrated distance of travel within the breast fillet before being automatically withdrawn. The width of the knife is calculated to cut a longitudinal incision that provides sufficient clearance for an injection nozzle to be subsequently inserted without tearing or rupturing of the fillet during that stage. Movement of the top plate 3 outwards and inwards relative to the mould 1 during this stage accommodates the change in volume due to the presence and then absence of the knife.

After forming the incision inside the fillet, the first stage lid or top plate 3 was removed and replaced with a second stage pressure plate.

The second stage pressure plate 6 is shown in Figure 2 and has a shallow cavity on its underside (not shown) to accommodate the overall increase in the volume of the fillet following injection of the filling required, and a hinged section 7 to accommodate the volume of a filling nozzle 8 when this is inserted through the aperture 5 into the cavity within the unit portion. The hinged section 7 also has a crimping end section 9 in the form of a v-section projection.

The second stage pressure plate 6 was placed in position on the mould 1 and then the nozzle 8 which is attached via a flexible hose to a positive displacement pump was pushed through the mould aperture 5 into the cavity in the breast fillet to a position where pumping of the filling could start. The nozzle was then withdrawn at a controlled speed while the filling was being pumped in. The hinged section 7, which is at least as wide as the knife and hence as the internal cavity within the fillet, applied pressure to the outside of the fillet as the nozzle began to be withdrawn and then crimped off the end of the unit portion as the nozzle was finally withdrawn so as to contain the filling within the unit food portion.

After removal of the nozzle, the second stage pressure plate 6 was lifted from the mould, the mould was then inverted and then the filled breast fillet was ejected pneumatically (or by equivalent mechanical means) onto a turning device which positioned the fillet, membrane side down, on a conveyor. Thereafter, the filled unit portion could be prepared for storage and/or sale by either freezing or chilling in uncoated form or (possibly but not necessarily after enrobement with pre-dust and/or batter, and/or breadcrumbs and/or other edible coating) by being flash fried or otherwise cooked and then frozen or chilled. These conventional later processing steps generally have the advantage of maintaining the product integrity and ensuring against leakage of the filling.

The second embodiment will now be described.

The apparatus as illustrated in Figure 3-6 comprises a holder 101 having a socket 102 adapted to receive a selected portion of meat, which in the illustrated example, suitably comprises a fillet of breast of chicken. The size and shape of chicken breasts are generally uniform within broad categories dependent upon chicken breed and growth characteristics. Different sizes of holder 101 are suitably constructed for different categories of meat portion shape and size.

The holder 101 is suitably formed as an extrusion of acetal or nylon or other rigid robust plastics material. A lid 120 having a formation 121 on its underside which is shaped to complement the socket 102 of the holder 101 is suitably formed of the same material as the holder 101. The purpose of this lid is to constrain the meat placed within the" socket 102, evenly compressing the meat therewithin so that the meat is firmly and uniformly held within the chamber formed by the cooperating lid protrusion 121 and holder socket 102. An actuating mechanism is suitably provided to bring the lid 120 into play and variably adjust the position for compression of the meat to allow for differences in shape and size between meat portions.

The moulding which forms the holder 101 is provided with three channels 103a, 103b, 104 extending into the holder 101 from one end thereof.

One of these channels 104 is broadly centralized and extends a short distance from the end of the holder 101 into the socket 102 and, when the lid 120 is closed over the socket 102 provides substantially the only passage into the chamber thus formed. The outer pair of channels 103a, 103b extend substantially the full length of the holder 101 and are of small diameter.

The purpose of the passage 104 is to provide an entrance hole for insertion of a blade 106 which is mounted to a header block 107 and guided into and from the holder 101 by co-operative engagement of guide rods 108a, 108b extending from the header block 107 into and along the guide channels 103a, 103b in the holder 101 (see Figure 2). The blade 106 header block 107 and guide rods 108a, 108b together comprise a blade module 105.

The blade 106 is of a girth and extent sufficient to form an incision which enables establishment of a useful working cavity within the meat operatively held within the chamber of the holder 101.

The insertion and removal of the blade 106 is a swift, efficient procedure that is readily effected by pneumatic, hydraulic or other actuating mechanisms giving the reliable control necessary for automation of the process.

Referring to Figures 5 and 6, the second stage of the process, in which the sauce is injected into the cavity formed within the meat portion by the blade 106, is achieved by means of an injector module 110 which co-operatively engages with the holder 101 in a fashion closely similar to the co-operation of the blade module 105 with the holder 101.

The injector module 110 has a header block 113 carrying a pair of guide rods 114a, 114b corresponding to the header block 107 and guide rods 108a, 108b of the blade module 105. However, in place of the blade 106, the injector module 110 has a fluid feed pipe 112 which extends through the header block 113 to form an injector stem 111 which widens and tapers towards its tip to form injector nozzle 115.

The injector stem 111 vertically tapers toward the nozzle 115 to facilitate penetration into the cavity formed by the blade 106 within the meat portion. The lateral widening of the stem 111 of the injector toward the nozzle 115 compensates for the tapering to maintain the rate of fluid delivery from the injector.

A sauce, or other edible filling, is supplied through the feed pipe 112 into the cavity formed within the meat via the nozzle 115 as the injector is gradually retracted from the meat.

As can be seen in Figure 5, the lid 130 of the holder 101 which is used for the injection stage has been modified from the form 120 illustrated in Figure 3. The modified lid 130 is provided with a trap-door-like arrangement which both allows for expansion of the meat within the chamber as a result of the presence of the injector during filling of the meat with the sauce and severs the portion of sauce from the end of the nozzle at the precise time that the sauce pump stops and before the nozzle is withdrawn from the meat. The trap-door-like arrangement also nips the punctured end of the meat closed when the injector has been withdrawn. The trap door is formed by a door element 132 mounted via a pivot bar 133 to the lid 130 within a doorway 135 formed in the lower projecting surface 131 of the lid 130.

The end of the door element 132 remote from the pivot bar 133 has a wedge-shaped head 134 formed thereon which when the door element 132 is pressed downwardly into the cavity of the holder socket 102 gradually squeezes the meat therewithin to separate the sauce from the nozzle inside the fillet.

Throughout this latter stage the pressure applied to the trap door 132 is gradually increased such that the wedge 134 fully comes into effect before the injector module 110 has been withdrawn from the holder 101.

Both above described stages of the process can be fully automated and it is envisaged that the holder 101 will be filled with a portion of meat and advanced by a conveyor belt or other drive system from a position adjacent the blade module 105 to a position adjacent the injector module 110 in succession. Although described above with respect to a preferred embodiment in which the blade and the injector are separate elements which operate successively the process may be completed in a single stage by use of a combined blade and injector element but possibly with some reduction in the efficiency of the system and the quality of end products.

Another convenient modification to either of the described embodiments is to provide two cavities in an existing mould set (1 and 3; or 101 and 130) and provide a pair of injectors and probes for insertion at opposing ends into the mould set. Conveniently a double production line can then be provided where common mechanical components are shared.

Claims

CLAIMS:

1. A method of forming a filled food portion comprising the steps of

introducing a selected quantity of the food into a cavity in a mould,

and then applying an edible filling into a cavity region within said quantity of food

2. A method according to claim 1 in which said incision is made by insertion of a sharp ended probe into the interior of said supported quantity of food while the food is maintained under pressure within the mould cavity.

3. A method according to claim 1 in which the edible filling is injected into the internal cavity of the food by insertion of an injector which is then withdrawn after completion of injection.

4. A method according to claim 1 or claim 2 in which the mould includes a first part having a mould cavity to receive the quantity of food and a lid which is movable in relation to the first part to permit an expansion of the internal volume of said mould.

5. A method according to claim 4 in which the mould is both movable to permit expansion to accommodate forming the incision and has an expandible section to accommodate the foodstuff after the filling has been injected into the internal cavity.

6. A method according to claim 5 in which a lid is provided which includes a hinged section which accommodates the added volume due to presence of the injected edible filling.

7. A method according to claim 6 in which said hinged section has a crimping end section to crimp down on the food as the injector is removed from within the food.

8. Apparatus for forming a filled food portion characterised by mould parts defining an expandible mould cavity to contain a selected quantity of the food and provide all round support to the food quantity a probe for forming an incision to define an internal cavity in the contained quantity of food, and

an injector for injecting an edible filling into the cavity formed by insertion of the probe while allowing the mould cavity to expand.

9. Apparatus according to claim 8 in which the mould includes a first part having a mould cavity to receive the quantity of food and a movable lid which closes off the mould cavity to contain the food while allowing the mould cavity to expand to accommodate insertion of the probe into the food portion in the mould cavity.

10. Apparatus according to claim 8 or 9, which includes a movable lid for use when the filling has been injected into the food, said lid having an expandible section to accommodate the increased volume due to presence of the injector and filling within the quantity of food.

11. Apparatus according to claim 10 in which the lid for accommodating the foodstuff and filling includes a hinged section which accommodates an extra volume due to presence of the injector and injected edible filling.

12. Apparatus according to claim 11 in which the hinged section has a crimping end section to crimp down on the food as the injector is removed from within the food.

13. Apparatus according to any of claims 9 to 12 comprising two lids one to accommodate expansion of the mould cavity when the probe is inserted in the mould cavity, and the other to accommodate expansion of the mould cavity when the injector and the edible filling are introduced into the mould cavity.