GB2223926A - Apparatus for, and method of, processing a food product - Google Patents

Abstract

An apparatus for processing a food product comprises an elongate tube 30 having jacket 34 and a processing zone such as 15, 16, 17 having perforations 48 in the tube and at least one carriage 32 for conveying food product through the tube the or each carriage having spaced end portions 60 slidable in the tube. Each zone (15, 16, 17) is divided into an upper hart and a lower half by fins (42), and each zone has an inlet (44) and an outlet (46). As shown fluid entering through an inlet (44) is directed by baffle plates (36, 38) to the lower hart of the associated zone. From the lower half, the fluid passes through holes (48) into the interior of tube (30) before leaving through outlet (44). The apparatus described has product and carriage loading and unloading stations (Figs. 4, 5 not shown). In alternative apparatus the "carriages" are formed by spaces between fins extending from a conveyor belt arranged to pass through the tube (Fig 8. not shown). <IMAGE>

Description

APPARATUS FOR, AND METHOD OF, PROCESSING A FOOD PRODUCT This invention relates to an apparatus for, and a method of, processing a food product prior to distribution and consumption. Food products are commonly subjected to a variety of processes prior to their distribution and consumption. Processes such as boiling, roasting, grilling or frying may be intended to cook whereas processes such as drying, cooling, pasteurizing or sterilizing may be intended to preserve. Sometimes a process will be intended to cook, or partially cook, and also to preserve.

Many food products contain water as a constituent which at normal atmospheric pressure boils at around 100 degrees centigrade. The exact boiling point may be affected by salts dissolved in the water. This boiling point varies directly with pressure and this property is frequently used in the above processes. For example, if the pressure is reduced to below atmospheric pressure, the water consituent may be made to evaporate so as to cool the product by loss of latent heat or to dry the product by direct loss of water. If the pressure is increased to above atmospheric, the boiling point of the water in the product is elevated so the product can be heated to any temperature below the elevated boiling point without water loss. This permits the food product to be cooked or sterilized.For sterilization, it is normally necessary to heat the product above 120 degrees centigrade.

Methods which are presently known for processing food products at pressures other than atmospheric may be divided into four groups and each of these will now be discussed.

In.the first group, the food product, which may be particulate with a liquid or liquid only, is packed into microbiologically secure containers, such as closed cans or heat sealed pouches prior to heating. In this group of methods, the processing is performed at a temperature which is high enough to achieve sterilization. The pressure required is applied externally by enclosing the container in a pressure vessel or by performing the processing at the bottom of a hydrostatic column.

This type of method suffers from the disadvantage that the food is static within its container and so heat transfer to particles in the centre is slow. In order to ensure sterility of food at the centre at the container, particles near the outside may be overcooked. Also liquid may be overcooked while heating the centre of partIcles to the detriment of products having partlcles and liquid. This method suffers from the further disadvantage that each container must be capable of withstanding the process and conducting heat from the outside to food contained inside it. Consequently, the choice of containers which are suitable for this method are limited.

In the second group, the product is placed in a pressure vessel, liquid is added, the vessel is sealed and then heat is supplied. This type of method suffers from several disadvantages. Firstly, for each processing operation, the batch size is restricted. Large vessels are disproportionately expensive, particularly if required to work at high pressures. The rate at which the temperature and pressure within such a large vessel can be raised is low. Where the product is sterilized in such a vessel prior to aseptic packaging, subsequent aseptic handling and metering of the food prior to packaging is difficult to perform.

In the third group, the product is processed at pressures above atmospheric and the food product is carried by a conveyor along a Ushaped tube, the hydrostatic pressure at the bottom of the tube providing the required processing pressure. This type of method also suffers from a number of disadvantages. Because of the geometry of the tube, the pressure builds up slowly and reduces slowly after peaking at the bottom of the tube and this restricts the variety of processes which are available. In the normal U-shaped tube which is used, the dwell time at the position of maximum pressure is very short. Such a U-shaped tube is difficult to build, the hydrostatic pressure cannot be changed after the tube has been built, and the maximum pressure is limited by the structure which is available to support the tube. Processing must be performed in a liquid.

In the fourth group, the product is carried by a liquid which is pumped under hydraulic pressure through a closed conduit and heat is applied through the wall of the conduit. As the food particles to be processed rely on the liquid both for transport and heat transfer, this method is limited to processes which can be performed in a liquid. In order to achieve rapid and even heating, the crosssection of the conduit must be as small as possible to shorten the heat transfer path and encourage mixing and this imposes a restriction on the size of the particles which can be processed. In this type of method, the transfer speed of food particles through the conduit depends on their size and consequently it is difficult to achieve even heating of all the particles.

It is accordingly an object of this invention to provide a new or improved apparatus for, and a method of, processing a food product in which the above mentioned disadvantages are overcome or reduced.

According this invention there is provided an apparatus for processing a food product said apparatus comprising: an elongate tube having a processing zone extending along at least part of its axial length: a jacket surrounding the tube along at least part of the length of said processing zone: lateral fins extending between the exterior surface of the tube and the interior surface of the jacket and dividing the space between the tube and the jacket into a first part and a second part: means for supplying fluid to the first part of the space between the tube and the jacket:: means for removing fluid from the second part of the space between the tube and the jacf; and at least one carriage for conveying a portion of food along the tube, the or each carriage having a pair of spaced apart end portions arranged to slide along the interior of the tube and the fit of each carriage end portion in the tube being of sufficient closeness to prevent the movement of food particles and to substantially prevent the movement of fluid axially along the tube past the end portions;; in which the tube in said processing zone comprises a perforated part having perforations through the wall of the tube bounded at each axial end of the tube by an unperforated part, the axial length of each unperforated part being equal to, or greater than, the axial separation of the two end portions of one of said carriages, some of said perforations being arranged to supply fluid from the first part of the space between the tube and the jacket into the interior of the tube, and others of said perforations being arranged to remove fluid from the interior of the tube into the second part of the space between the tube and the jacket.

With the apparatus of this invention, the food product is induced to follow a path different to that of the fluid. This provides the important advantage that the fluid and the pressure and temperature of the fluid may be changed as required This invention will now be described in more detail, by way of example, with reference to the drawings in which: : Figure 1 is a front perspective view, partly broken away, of three processing zones and a pair of carriages forming part of an apparatus for processing food embodying this invention; Figure 2 is a front sectional view of the three processing zones of Figure 1; figure 3 is a cross sectional view on the line 3-3 of Figure 2; Figure 4 is a rear sectional view showing a carriage loading station and a product loading station of the apparatus of Figure 1; Figure 5 is a rear sectional view showing a product unloading station and a carriage unloading station of the apparatus of Figure 1; Figure 6 is a block diagram illustrating a fluid circuit forming part of the apparatus of Figure 1; Figure 7 is a block diagram illustrating the relative positions of the loading and unloading stations and the processing zones of the apparatus of Figure 1; and Figure 8 is a diagrammatic front view, partly in cross section, of another apparatus embodying this invent ion.

Referring to Figures 1 - 7, there is shown an apparatus for processing food embodying this invention. The apparatus generally comprises an elongated tube 30 of circular cross section, parts of which are visible in the drawings, a series of carriages 32 for conveying food, a carriage loading station 10 and a product loading station 11 located at one end of the tube 30, and a product unloading station 19 and a carriage unloading station 20 locateS at the other end of the tube 30.

The tube 30 is divided into seven food processing zones and the relative positions of these zones and the stations 10, 11, 19 and 20 are shown in figure 7. The processing zones comprise, in order, a safety zone 12, a pressurizing zone 13, a main processing zone 14, a pressurized cooling zone 15, a pressure reduction zone 16, an unpressurized cooling zone 17, and a safety zone 18. Each of the zones 12 to 18 is of a similar construction and the construction of zones 15 to 17 together with the construction of the carriages 32 will now be described.

Referring now to Figures 1 - 3, the tube 30 is surrounded by a jacket 34, an annular space being defined between the exterior surface of the tube 30 and interior surface of the jacket 34. In each of the zones 15, 16, 17, the annular space is bounded by a pair of baffle plates 36, 38. Each of the baffle plates 36 acts as a barrier whereas each of the baffle plates 38 is provided with an opening 40 in its lower part. In each of the zones 15, 16, 17, a pair of lateral fins 42 extend between the outer surface of the tube 30 and the inner surface of jacket 34 and also between the baffle plates 36 and 38, thereby dividing the annular space into a lower half and an upper half. For each of the zones 15, 16, 17, the jacket 34 is provided with an inlet 44 located between the baffle plates 36 and 38 and an outlet 46.In each of the zones 15, 16, and 17, the tube 30 has a central perforated part provided with holes 48, the central part being bounded by a pair of unperforated parts. Fluid entering through an inlet 44 is directed by the baffle plates 36, 38 to the lower half of the associated zone. From this lower half, the fluid is constrained by the lateral fIns t2 to pass through holes 48 into the interior of the tube 30 which, in use, will contain a number of carriages number 32.

From the interior of the tube 30, the fluid passes through further holes 48 into the upper half of the annular space before leaving through the respective outlet 46. In each of the zones 15, 16, 17, the jacket 34 is provided with a drain 50 which can be opened to remove any liquid which has collected at the botton of the jacket 34.

Each of the carriages 32 comprises a pair of circular end portions or plates 60 connected together by a pair of rods 62. Each of the carriages 32 is arranged to carry a portion of food product along the tube 30, the end plates 60 together with the wall of tube 30 forming a moving chamber.

The plates 60 are arranged to be a close fit in the tube 30, the closeness of the fit being sufficient to prevent movement of food particles and to substantially prevent the movement of fluid axially along the tube past one of the end plates 60. By way of refinement each of the end plates 60 may be provided with a circumferential seal of engaging the inner surface of the wall of the tube 30. In each carriage 32 the distance between the outer faces of plates 60 defines the length of the carriage.

Referring especially to Figure 2, in each of the zones 15, 16, 17, the tube 30 has a central perforated part bounded at each end by an unperforated part. The length of the unperforated part between adjacent zones has a length equal to or greater than the length of one of the carriages.

Consequently the carriages 32 substantially prevent fluid from passing from one zone to an adjacent zone along the interior of the tube 30. Each of the zones 15, 16, 17, has a length equal to three times the length of one of the carriages and so each zone can accomodate three such carriages. From this it follows that the pitch of the unperforated parts is also equal to three times the length of one of the carriages. More generally, in an apparatus embodying this invention it is particularly convenient to arrange the length of each processing zone so that it is equal to the length or a multiple of the length of one of the carriages.

Referring now to Figure 4, the carriage loading station 10 comprises a chute 70 for delivery of carriages 32 to the end of tube 30. The carriages 32 are driven along the tube 30 by a piston 72 operated by a hand lever 74. By way of alternative, the piston 72 and lever may be replaced by a pneumatic or hydraulic cylinder or by a feed screw for engaging the carriages 32. The carriage loading station 70 includes a non-return pawl 76.

The pawl 76 is moveable between an arresting position, at which it prevents the carriages from moving backwards out of tube 30, and an open position at which it permits the carriages to leave the loading station 10.

Still referring to Figure 4, the product loading station 11 includes a chute 80 for supplying food products for the carriages 32. The food product may be supplied through a metering device so that a pre-determined quantity of food is supplied to each carriage 32.

Referring now to Figure 5, the product unloading station 19 comprises a chute 82 for delivering processed food from each carriage to containers 84. Conveniently, the containers 84 are transported to and from the station 19 on a suitable conveyor. Where the food processing operations performed by the apparatus include sterilization, unloading station 19 together with the associated parts of the conveyor for the containers 84 may be enclosed within a chamber filled with sterile air, thereby permitting the food product te be packaged aseptically.

Still referring to Figure 5, the carriage unloading station 20 includes a chute 86 for delivering the carriages 32 from the tube 30 to a desired position. If desired, the carriages 32 may be conveyed automatically back to the carriage loading station 10.

In the normal operation of the apparatus, the carriages 32 are fed intermittently into the tube 30 so that they remain stationary between each feeding operation. The frequency of feeding the carriages will determine the residence time of the food product in each of the zones 12 to 18. Alternatively, the carriages may be moved continuously along the tube 30 using a feed mechanism such as the feed screw mentioned above.

In each of the zones 12 to 18, the interior of the tube 30 forms part of a fluid circuit.

Referring to Figure 6, such a circuit typically comprises a reservoir 90 of fluid, which may be a gas or liquid, a pump 92, a heating or cooling device 96, the relevant section of the interior of tube 30, and a filter 98 from which the fluid is returned to the reservoir 90. When neither heating nor cooling is required, the device 96 may be omitted. Where the fluid is air, there is no need for a reservoir.

The zones 12 to 18 will now be described in further detail and some alternatives will be mentioned. The zones will be described in order so as to provide an understanding of the processing operations that may be performed on a food product as it passes through the tube.

After leaving the product loading station 11, a carriage passes through the safety zone 12.

The safety zone 12 has a construction similar to zone 15 except that it has a length equal to the length of one of the carriages and no inlet is provided. The outlet is connected to a safe discharge point. Thus, the safety zone prevents leakage from a downstream zone reaching stations 10, 11, thereby preventing such stations from contamination and the operator from possible injury. Where the end plates of carriages 60 are not provided with seals, a seal may be located at each end of the safety zone so as to prevent leakage when -the carriages are stationary.

After leaving the safety zone, the carriage passes through the pressurizing zone 13 and this zone is supplied with air at a pressure at or near to the pressure used in the processing zone 14. By arranging the pressure in the pressurizing zone 13 to be close to the pressure in main processing zone 15, leakage of fluid from the processing zone 14 is minimised. Although some leakage of air may occur from the pressurizing zone 13 to the safety zone 12, this is of little consequence as air is cheap and easily disposable. The pressurizing zone 13 has a construction similar to the zone 16.

After leaving the pressurizing zone 13, the carriage is passed to the main processing zone 14.

The main processing zone 14 has a construction similar to zone 16 but may have a length greater than the length of three carriages so as to increase the residence time of the food product in this zone. In addition, in the preferred arrangement, the fluid inlet and outlet are located adjacent opposite ends of this zone and this zone is divided into sections by pairs of radial fins. Each of these sections has a length of one of the carriages.

The radial fins extend between the exterior surface of the tube 30 and the interior surface of the jacket 34 and they are generally similar to the baffle plates 38. The part of the tube 30 between each pair of radial fins is unperforated and the lateral fins 42 are interrupted between each pair of radial fins. Openings are provided in each of the radial fins so that the fluid is guided circumerfentially around each unperforated part of the tube 30 and thus passes through each carriage, in turn, in the same direction.

Where the main processing zone 14 is intended to receive a gas as a process fluid, a drain is provided in the lower part of the jacket for removing fluid. Where the process fluid is itself a liquid, a drain is provided in the upper part of the jacket for removing unwanted gas.

The fluid supplied to the main processing zone 14 will depend upon the processing operation which it is desired to perform. Examples of possible fluids are hot water, salt solution or broth for boiling, steam for steaming, air for roasting or hot oil for frying. The pressure and temperature of the fluid are selected so as to achieve partial cooking, complete cooking, pasteurisation or sterilization of the product as may be required.

By way of-a modification, heat may be supplied separately from the process fluid. For example, where it is desired to process the product by grilling, heat may be supplied by radiant panels located in the wall of the tube and which emit infrared radiation. Alternatively, radiation may be supplied by microwave transducers located in the wall of the tube. Where the heat is supplied separately from the process fluid, the pressure and nature of the process fluid may be selected so as to control fluid loss or gain from the product. Typical process fluids for use with this modification are air, a mixture of air and steam or an inert gas.

Where it is required to cool or dry the product, the process fluid may be a gas supplied at a pressure below atmospheric pressure.

In another modification the process fluid is an electrolyte and the tube is electrically isolated and provided with electrodes so that heat is generated by the passage of current through the electrolyte.

It is generally desireable to arrange the main processing zone 14 so that fluid enters at the downstream end and leaves from its upstream end.

This will ensure that any micro-organisms picked up by the fluid will be carried away from the downstream end and thus from a position where a food product may be sterile or at least may be free from harmful micro-organisms. Similarly, it is sometimes desirable to operate the apparatus on a slope so that the carriages travel uphill, thereby ensuring that extraneous liquid flows away from the downstream end of this zone.

From the main processing zone 14, the carriages 32 pass through the pressurized cooling zone 15. This zone is supplied with sterile cool fluid (for example, air or water) at a pressure equal to the pressure in the main processing zone. This ensures that the food product can cool without sudden uncontrolled evaporation of its water constituent.

If the product is sterilized in a liquid in the main processing zone 14 and cooled in a gas in zone 15, it may be necessary to insert an additional zone between zones 14 and 15 where the product can be drained under pressure.

If the product is sterilized in a liquid in the main processing zone 14 and cooled under pressure in a liquid in zone 15, it may be necessary to insert an additional zone after zone 15 where the product can be drained under pressure.

After leaving the pressurized cooling zone 15, the carriages pass through the pressure reduction zone 16 and this zone is supplied with sterile air at atmospheric pressure.

After leaving the pressure reduction zone 16, the carriages pass to the unpressurized cooling zone 17, which is supplied with cool sterilized fluid at ambient pressure.

From the zone 17, the carriages pass through the safety zone 18, which is similar to the safety zone 12, and from this zone they pass to the product unloading station 19.

Where the process performed in the main processing zone 14 is sterilization, it may be desireable to provide an additional zone between the product unloading station 19 and the carriage unloading station 20. This then can be supplied with sterile fluid, such as air, to provide a positive barrier between the sterile product and the mechanical parts of the carriage unloading station station 20.

For some food products, it may be desired to pasteurize or sterilize a product in the main processing zone 14 and then provide extra cooking of the product at atmospheric pressure. In order to achieve this, an additional zone may be inserted between zones 16 and 17.

In the case of products which are not harmed by partial loss of their water constituent, the pressurized cooling zone 15 may be omitted.

Where sterilized food products are unloaded aseptically into sterilized containers, it is sometimes desireable to eliminate oxygen from the products and its surrounds prior to packaging. In order to do this, the apparatus may include an additional zone immediately before the product unloading station 19, this zone being provided with a gas containing no oxygen. This gas will then replace the oxygen in the carriage prior to packaging.

In order to provide agitation to the product in the main processing zone 15, it is desireable to arrange this zone so that the fluid passes through each carriage in an upward direction.

In general, the number and construction of the processing zones may be selected as required. For certain food products satisfactory processing may be achieved in an apparatus in which the tube is provided with a single processing zone.

The apparatus which has been described above presents a number of important advantages. Because the apparatus is relatively small, it can be designed to operate over a wide range of pressures. For example, a range of pressures between full vacuum and ten bar may be easily achieved.

Because the food product is induced to follow a different path from the processing fluids, the fluids, and their pressures and temperatures, may be changed as required without restriction. It is also possible to subject a food product to processing by a series of different fluids.

The food product may be delivered to the packaging containers in pre-metered amounts and in a dry state and this is particularly advantageous in the case of products which are packaged aseptically.

Referring to Figure 8, there is shown another apparatus embodying this invention. This apparatus includes a-tube divided into a series of processing zones and surrounded by a jacket, a combined tube and jacket being indicated by reference numeral 100. The tube and jacket have a construction generally similar to that described above with reference to Figures 1 to 7. A conveyor belt 101 passes through the tube and around a drive wheel 102 and a free wheel 103. The conveyor belt 101 carries a series of spaced apart fins, one of which is indicated by reference numeral 104, and which define a series of carriages. The fins 104 act as the end walls of the carriages and each of the fins 104 has a shape complementary to the internal cross section of the tube. The conveyor belt 101 is arranged to carry a series of portions of a food product from a product loading station 105 to a product unloading station 106.

Claims (23)

1. An apparatus for processing a food product said apparatus comprising: an elongate tube having a processing zone extending along at least part of its axial length; a jacket surrounding the tube along at least part of the length of said processing zone; lateral fins extending between the exterior surface of the tube and the interior surface of the jacket and dividing the space between the tube and the jacket into a first part and a second part; means for supplying fluid to the first part of the space between the tube and the jacket; means for removing fluid from the second part of the space between the tube and the jacket; and; at least one carriage for conveying a portion of food along the tube, the or each carriage having a pair of spaced apart end portions arranged to slide along the interior of the tube and the fit of each carriage end portion in the tube being of sufficient closeness to prevent the movement of food particles and to substantially prevent the movement of fluid axially along the tube past the end portions;; in which the tube in said processing zone comprises a perforated part having perforations through the wall of the tube bounded at each axial end of the tube by an unperforated part, the axial length of each unperforated part being equal to, or greater than, the axial separation of the two end portions of one of said carriages, some of said perforations being arranged to supply fluid from the first part of the space between the tube and the jacket into the interior of the tube, and others of said perforations being arranged to remove fluid from the interior of the tube into the second part of the space between the tube and the jacket.

2. An apparatus as claimed in Claim 1, in which each carriage end portion is provided with a circumferential seal for engaging the inner surface of the wall of the tube.

3. An apparatus as claimed in Claim 1 or Claim 2, in which said unperforated parts of the tube are arranged at a pitch equal to the length, or a whole number multiple of the length, of one of said carriages.

4. An apparatus as claimed in any one of the preceding claims further including a fluid inlet for the space between the tube and the jacket located adjacent one end of said processing zone, a fluid outlet for said space located adjacent the other end of said processing zone, a plurality of radial fins extending between the exterior surface of the tube and the interior surface of the jacket for dividing said space into a plurality of sections each of which has a length equal to the length of one of said carriages, and apertures formed in said radial fins, whereby, when an individual carriage is located at each of said sections, fluid entering through said inlet is constrained to pass through each carriage in turn before leaving through said outlet.

5. An apparatus as claimed in Claim 4, in which each pair of adjacent sections of said space are separated by a pair of radial fins, the part of the tube between the two radial fins of each such pair being unperforated and the apertures in each pair of fins being located so that the pair of radial fins are arranged to guide fluid circumferentially around the associated unperforated part of the tube, whereby the fluid is constrained to pass through each successive carriage in the same direction.

6. An apparatus as claimed in Claim 5, in which the apparatus is oriented so that the fluid passes upwardly through each carriage.

7. An apparatus as claimed in any one of the proceding claims, which is capable of operation with fluid at pressures other then atmospheric pressure.

8. An apparatus as claimed in any one of the proceding claims, including a plurality of axially aligned processing zones each of which has an individual fluid supplying means and an individual fluid removing means.

An apparatus as claimed in any one of the preceding claIms, including means for supplying electro-magnetic radiation to the interior of the tube.

10. An apparatus as claimed in Claim 9, in which said electro-magnetic radiation is infrared radiation.

11. An apparatus as claimed in Claim 9, in which sal a electro-magnetic radiation is micro-wave radiation.

12. An apparatus as claimed in any one of the preceding claims, further including a carriage feeding station located at one end of the tube, said carriage feeding station comprising a first chute for feeding a carriage into the tube, a second chute for feeding a product to be processed into a carriage, and means for driving the carriage into and along the tube.

13. An apparatus as claimed in Claim 12, further including a non-return pawl mounted at the carriage feeding station so as to engage the end portion of the carriage, the pawl being moveable from an arresting position, which prevents carriages from sliding backwards out of the tube, to allow a carriage to pass into the tube.

14. An apparatus as claimed in any one of Claims 1 to 11, further including a continuous conveyor belt passing through the tube, said conveyor belt carrying a series of spaced apart fins extending laterally thereof to define a series of carriages, said fins acting as end portions of the carriages.

15. A method of processing a food product with an apparatus as claimed in any one of the preceding claims, said method comprising the steps of: continuously supplying fluid into the first part of the space between the tube and the jacket; continuously removing fluid from the second part of the space between the tube and the jacket; feeding a portion of food into a carriage; passing the carriage through the tube; and removing the portion of food from the carriage.

16. A method as claimed in Claim 15, in which the fluid is heated, whereby the food is cooked, or partially cooked, during passage through the tube.

17. A method as claimed in Claim 16, in which the temperature and pressure of fluid and the residence period of the food product in the tube are selected so that the product is sterilized during passage through the tube.

18. A method as claimed in Claim 15, in which the fluid is at a temperature below ambient temperature, whereby the product is cooled during passage through the tube.

19. A method as claimed in Claim 15, in which the pressure of the fluid is below atmospheric pressure, whereby the water constituent of the product is caused to evaporate during passage trough the tube thereby causing the product to be cooled and dried.

20. A method as claimed in Claim 15, in which the fluid contains no oxygen whereby the fluid replaces the oxygen in the carriage during passage through the processing zone.

21. A method as claimed in Claim 15, in which the tube has a plurality of processing zones spaced axially along its length, said method including the further step of: continuously supplying an individual fluid into the interior of the tube at each processing zone: and continuously removing each of said fluids from the interior of the tube at the associated processing zone.

22. An apparatus for processing a food product substantially as hereinbefore described with reference to Figures : to 6, or Figure 7, or Figure 8 of the accompanying drawings.

23. A method of processing a food product is hereinbefore described with reference to Figures 1 to 6, or Figure 7, or Figure 8 of the accompanying drawings.