GB2231624A

GB2231624A - Metering food supply

Info

Publication number: GB2231624A
Application number: GB8911631A
Authority: GB
Inventors: Richard Sperring; Malcolm Shipway; Roger Lambert
Original assignee: Courtalds Films & Packaging; SOUS CHEF Ltd
Current assignee: Courtalds Films & Packaging; SOUS CHEF Ltd
Priority date: 1989-05-19
Filing date: 1989-05-19
Publication date: 1990-11-21
Anticipated expiration: 2009-05-19
Also published as: GB8911631D0; AU5633290A; WO1990014270A1; JPH03506017A; GB2231624B; EP0425636A1

Abstract

Apparatus for metering a predetermined quantity of aseptic food containing particulate matter into a pre-sterilized package includes a pressurized storage tank (7) for the food, the tank (7) being connected via a valve (9) to a metering device (10). An outlet (16) from the device (10) is connected via a control valve (12) to a fill head (13) through which the package is filled. The device (10) includes a piston (14) movable in a cylinder to bring the food into the cylinder or expel it therefrom, the piston (14) being moved by differences in pressure between its opposite faces, pressure to the rear face of the piston (14) being supplied by a sterilized fluid at a lower pressure than that in the tank (7) so that on closing the valve (9) and opening the valve (12), food is expelled from the cylinder. Piston stroke is controlled by pre-settable control means which controls the supply of sterilized fluid to the rear face of the piston (14).

Description

FOOD DISPENSING METHOD & APPARATUS AND NETERING DEVICE THEREFOR This invention relates to a food dispensing method and apparatus and a metering device there for and more particularly to a method and apparatus for processing food containing particulate matter into an aseptic form ready for packaging in a pre-sterilised pack.

Recipe dish quality foods are becoming more commonplace these days. These are currently most commonly sold by the manufacturer to a customer in a frozen or chilled form who then stores them in a refrigerated cabinet ready for sale. Unfortunately, the temperature of the refrigerated cabinet can change without the customer realising and this change in temperature can sometimes be sufficient to cause the food to go off due to the bacteria therein becoming active.

Tinned food of course requires no refrigeration but it does suffer from a major drawback in that the food has to be heated up in the sealed tin to sterilise the contents. Because the centre of the contents of the tin must be heated for at least 2 minutes to a temperature of the order of 121or, the tin has to be heated to a much higher temperature and for a much longer time. Unfortunately, this can cause any 'particulate matter in the food such as lumps of meat or vegetables to break up so the contents of the tin become less visually appealing and appetising when served from the tin.

s new technology for the high temperature sterilisation of food has been developed involving the "ohmic heating" principle in which heat is internally ggenerated in foods by passing an electric current through them as they travel through a vertical column.

A major advantage of this process is that it enables solid material to heat up as quickly as liquid so a high temperature/short time technique became available for processing foods containing particulate matter. Because the particulate material is not subjected to long heating times, it does not break up as had been the case with prior art sterilising methods.

With the ohmic heating process, an electric current is passed through a controlled flow of foodstuff under pressure as it travels up a vertical column, the sterilisation temperature being achieved in a very short time. Due to its uniform effect, the ohmic heating process allows far higher Fo values to be applied without consequent product damage than can be achieved using normal canning techniques. The product is rapidly cooled after sterilisation and then passed to storage tanks from which it can be supplied to a filling head and put into a pre-sterilised package.

Nost particulate foods can be ohmically processed, and because of the gentle nature of the process all foods, especially fish and vegetables, retain excellent flavour and nutritional values, a firm texture and minimum particle breakdown. The quality is comparable to fresh chilled recipe dishes but with the added benefit of long shelf life due to the absence of micro-organisms. Ohmically processed food packaged in a sterilised pack can have a shelf life of up to two years with no refrigeration.

As the ohmic heating process has to be operated under pressure, the aseptic product has to be stored in a vessel under pressure so it cannot be dispensed using known packaging equipment. It is therefore necessary to use two storage tanks connected by a changeover valve. Thus, while one tank is being filled with processed food at a pressure of say four bar (60 p.s.i.), the pressure in the other filled tank can be reduced to a dispensing pressure of say one bar (15 p.s.i.). Duplication of the storage tank facility however doubles the capital cost and the use of large storage tanks also suffers from the disadvantage that the material stored in a fully filled tank tends to settle out into different stratae if allowed to stand for long periods.This makes drawing off food in accordance with the various ingredients of the recipe from the tank very difficult as only food in the strata at or adjacent the tank outlet will be dispensed so there is no control over the consistency of the food actually put into the sterilised package.

Another problem with packaging food including particulate material under pressure is that sometimes there can be a build up of the particulate material at the outlet nozzle in the filling head which can clear suddenly, thereby creating possibly another inconsistency in the makeup of the food actually put into the sterilised pack.

It is an object of the present invention to overcome or substantially reduce the above discussed disadvantages.

According to one aspect of the invention, there is provided apparatus for metering a predetermined quantity of aseptic food containing particulate matter into a pre-sterilised package comprising: (a) a pressurised storage tank for the aseptic food to be dispensed and packaged, (b) said tank being connected to a valve controlled inlet of a metering device, the metering device having an outlet connected to a filling head, the output of which is controlled by a valve, (c) the metering device comprising a piston and cylinder arrangement operable so that food under pressure from the storage tank is forced into the cylinder on opening the inlet valve thereto whereby the piston retracts, (d) the metering device also including means for supplying a sterilised fluid to the rear of the piston and maintaining said fluid at a pressure slightly less than that in the storage tank whereby on opening the filling head valve and closing the inlet valve to the piston and cylinder arrangement, the piston moves along the cylinder towards its outlet to expel the food therefrom, (e) the length of the expelling stroke of the piston being controlled by pre-settable control means operably associated with the means for supplying the sterilised fluid to the rear of the piston.

Preferably the contents of the storage tank are maintained at a pressure of substantially four bar, the sterilised fluid, preferably steam, being supplied to the rear of the piston at a pressure of approximately 3.5 bar. Sterlised air could however be used.

Preferably the piston fully retracts on opening the inlet valve to the metering device.

In the preferred embodiment, the piston has a shaft extending rearwardly therefrom, the pre-settable control means comprising adjustable limit switches operable to sense the position of the shaft on movement of the piston during its return stroke whereby the supply of fluid under pressure to the rear of the piston is cut off when the shaft reaches a pre-set position. Conveniently, a trigger is mounted on the shaft to cooperate with the limit switches which are slidably arranged alongside the shaft. With this arrangement, by altering the position of the limit switches, the stroke of the piston can be varied and thus the output from the cylinder can be accurately pre-set.

Preferably the operation of the supply of the sterilised fluid to the rear of the piston is controlled by a valve, the operation of this valve, the filling head outlet valve and metering device inlet valve being controlled by central control means such as a computer.

In a preferred embodiment, the piston is provided with an annular groove which cooperates with the cylinder wall to provide a steam barrier or seal when steam is supplied thereto.

According to a further aspect of the invention, there is provided a method of metering a predetermined quantity of aseptic food containing particulate material from a storage tank under pressure to a pre-sterilised package comprising the steps of: (a) opening a first valve to admit food from the storage tank into a metering device comprising a piston reciprocable in a cylinder whereby the piston is forced back by the food under pressure, a sterilised medium being supplied to the rear of the piston at a pressure less than that in the storage tank, (b) closing a valve to cut off the further supply of food to the cylinder, (c) opening a second valve downstream of the metering device whereby the piston is forced back under the pressure of the sterilised medium to expel food from the cylinder, (d) the length of the return stroke of the piston being controlled by pre-settable control means whereby a predetermined volume of food is dispensed from the metering device to the pre-sterilised package. According to yet another aspect of the invention, there is provided a metering device for dispensing a predetermined volume of foodstuff containing particulate matter supplied under pressure to the device in a sterilised condition. This device is particularly suited for use in the method and apparatus of the present invention.The metering device of the invention comprises a piston reciprocable in a cylinder1 an inlet to the cylinder controlled by a valve, an outlet from the cylinder, means for supplying a sterilised medium under pressure to the rear of the piston, the supply of said sterilised medium being controlled by a valve and pre-settable means controlling the axial displacement of the piston in the cylinder towards the outlet, the arrangement being such that when the inlet to the device is connected to a supply of food under pressure and the inlet valve is opened, foodstuff is admitted to the cylinder to push it back until it reaches its fully withdrawn position when the inlet valve closes, sterilised medium under pressure then being admitted to the rear of the piston to push it back along the cylinder until it reaches its limit position determined by the pre-settable means whereby the exact volume of food displaced by movement of the piston is dispensed through the outlet.

In the preferred metering device the piston has a shaft extending rearwardly therefrom, the pre-settable means comprising means on the shaft which cooperate with adjustable limit stops operably associated therewith to control the length of the return stroke of the piston.

Preferably the piston includes an annular groove around the perimeter thereof to provide an edge seal between the piston and cylinder wall, said groove having a supply duct connected thereto by means of which a sterilising medium such as steam can be supplied to the annular groove. Conveniently, an exhaust duct venting to atmosphere is also connected to the annular groove.

In a preferred embodiment, the shaft is a hollow tube through which, in use, the sterilising medium is fed to the supply duct and hence to the annular groove in the piston. Preferably the piston has a central section made of a plastics material in which the annular duct and the supply and exhaust ducts are formed.

Preferably the bottom of the cylinder is provided with a recess adjacent the inlet and outlet thereto into which the end of the piston fits when it has travelled along the whole length of the cylinder, the end of the piston fitting into said recess so as to leave a space between its front face and the bottom of the recess.

The purpose of this recess is to ensure that any particulate material left in the cylinder at the end of a stroke is not compressed and therefore damaged by the piston on its next stroke.

A preferred process, apparatus and metering device of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which Figure 1 is a diagrammatic view of a food processing system incorporating the present invention; Figure 2 is a schematic view of a part of the apparatus shown in Figure 1; and Figure 3 is a cross section through the metering device shown in Figures 1 and 2.

Referring to Figure 1 of the drawings, there is shown a food processing system comprising a pre-mix container 1 into which the raw recipe ingredients are placed and cooked. Depending on the final product, the ingredients may be completely cooked ready for packaging or alternatively they may be partially cooked for packaging in a partially-cooked condition because they may then be supplied to a manufacturer who will complete the cooking cycle. For instance, steak and kidney can be partially cooked and packed in a pre-sterilised pack ready for supply to a manufacturer of steak and kidney pies who will place the partially cooked food in a pastry envelope which will then itself be cooked.This later cooking cycle will subject the partially cooked steak and kidney to the completion of its cooking process so that when the final product leaves the steak and kidney manufacturer and is delivered to the customer, the contents in the pastry envelope are fully cooked.

After completion of the cooking cycle, or at least the cooking of the ingredients to the desired level in the pre-mix container 1, the cooked ingredients pass through duct 2 into a pump 3 which is preferably a "MARLEN" pump of known type. The pump 3 forces the cooked ingredients upwardly through an ohmic column 4 where heat is internally generated in the ingredients by the passage of an electric current through them using electrodes 4a whereby the sterilisation temperature is achieved in a very short time. The actual temperature and heating times will vary depending on the product being processed. As the solids heat as quickly as the liquids, this method is extremely useful for processing foods containing particulate material such as steak and kidney, curry, spaghetti bolognaise, chilli, etc. With prior art methods, it was found to be very difficult to heat products containing particulate matter because the liquid would heat up much quicker than the particulate matter so there was no guarantee that the whole of the product had been heated to a temperature which would kill off the relevant micro-organisms.

By way of example, if the ohmic column 4 is approximately 6 metres high and has four electrodes 4a spaced along its length, the pre-cooked product could enter the bottom of the column at a temperature of approximately 700C and, by the time it leaves the top of the column, the temperature could have been increased to 1420C. The heating rate applied to the product as it passes through the column is preferably approximately 10C rise in temperature per second but this will vary depending on the product being processed. Accordingly, it takes approximately 70 seconds for the pumped pre-cooked food to be sterilised completely by the time it leaves the top of the column in the illustrated example. Food to be processed by the system of the present invention always involves the use of a liquid as a carrier for the particulate material.

The liquid can take the form of gravy or a sauce. As the food has to be heated to about 1420C to ensure that it is sterilised completely by the time it leaves the top of the column, it will be appreciated that the liquid would normally boil off. The system, therefore, is pressurised to a pressure of 60 p.s.i. (four bar) to lower the effective boiling point of the carrier liquid and thereby avoid this evaporation.

In the illustrated example, the food leaves the top of the ohmic column, it passes into a holding tube 5 where it is stabilised for a period of approximately 60 seconds. During this stabilisation period, the temperature drops to about 1400C and the product is then passed through a multiple cascade cooler 6 for a period of 15-20 minutes where its temperature is lowered to 250C. On leaving the cooler 6, the product enters storage tank 7 blanketed with an inert gas (preferably nitrogen) at a pressure of four bar (60 p.s.i.).

The storage tank 7 has an outlet duct 8 closed by a first valve 9. The outlet duct 8 supplies sterilised food from the tank 7 to a metering device 10 having an outlet 11 leading to a filling head 13 by means of which the sterilised food is put into a pre-sterilised package (not shown). Control of the output of the filling head 13 is governed by means of second valve 12.

The process illustrated in Figure 1 operates on a continuous basis in that the sterilised food can be dispensed from the filling head 13 into pre-sterilised packs (not shown) using the metering device 10 of the invention to be described in more detail hereafter. A major advantage of the illustrated process is that it only requires one storage tank 7 rather than the two tanks of the prior art processes. Also, only a relatively small quantity of sterilised food needs to be stored in the tank 7 because of the novel metering device 10 of the invention working in conjunction with the filling head 13 so the product is not in the storage tank 7 long enough to separate out into separate stratified layers. Another advantage is that the product can be dispensed directly from the storage tank 7, even though it is maintained at a pressure of four bar owing to the novel metering device 10.

Referring now to Figure 2, there is illustrated in more detail the part of the equipment shown in Figure 1 which forms the subject of the present invention. As can be seen more clearly in Figure 2, the storage tank 7 in which the sterilised food is held under a pressure of four bar has its outlet 8 connected to inlet 15 of the metering device 10. The inlet to the metering device 10 is closed by the valve 9. The metering device 10 has an outlet 16 connected to duct 11 leading to filling head 13. The valve 12 controlling the output from the filling head 13 is provided in the duct 11.

The metering device 10 comprises a piston 14 reciprocable within a cylinder. A sterilised medium, preferably steam, is supplied to the rear of the piston 14 at a pressure of 3.5 bar through valve controlled inlet 17 and is exhausted therefrom via valve controlled outlet 18. A tube 19 projects from the rear of the piston 14 and has a trigger 36 mounted thereon which cooperates with limit switches 20 and 21. The operation of the valves 9, 12, 17, 18 and limit switches 20, 21 and 36 is controlled by a central control means 22, preferably a computer. The pressures mentioned above are preferred. Other pressures may be used if desired.

The operating cycle of the apparatus shown in Figure 2 will be described in more detail hereafter following a description of the metering device 10 with reference to Figure 3.

Referring now to Figure 3, there is shown the metering device 10 which comprises a piston and cylinder arrangement. The valve 9 is provided in the inlet 15 to the cylinder. The outlet 16 from the cylinder is connected to duct 11 leading to the filling head 13 (not shown). The inlet 15 and outlet 16 open into a recess 52 having an annular bevelled edge 51 which cooperates with a corresponding bevelled edge 50 provided around the bottom of the piston 14. The vertical axial distance between the top and bottom of the chamfered edge 50 of the piston is less than the axial depth of the chamber 52 so that there is a small gap between the bottom of the piston and the bottom of the chamber 52 when the bottom of the piston fits within the chamber 52.In the preferred embodiment, this gap will be approximately one inch and the purpose thereof is to avoid damage to any particulate food left in the cylinder 10 on the completion of an operating cycle which would otherwise be crushed and damaged if it were not for this clearance.

The piston 14 in the preferred illustrated embodiment is made up from three separate parts held together by means of bolts 48. Upper and lower parts 41, 40 are made of metal whereas central portion 42 is preferably made of a plastics material. The piston could be made completely of metal but this would substantially increase the weight and cost of manufacture.

The central section 42 of the piston is provided with a duct 47 extending radially outwardly from the centre thereof to communicate with an annular groove 46 provided around its periphery. The central duct 47 communicates via tube 33 with a steam supply and it will be seen that when steam is fed through the tube 33, a steam barrier will be provided at the edge of the piston between its front and rear faces. The piston 14 additionally includes known sealing O-rings 44 and 45.

The ends of the cylinder 10 are closed by end caps 39a and 391it including respective O-ring seals 43a and 43b.

A hollow tube 19 is connected to the rear of the piston 14 and extends outwardly from the cylinder through the end cap 39b. The end of this hollow tube is closed by a plug 34. The smaller diameter hollow tube 33 passes through the plug 34 and is sealed with respect thereto by means of known sealing rings 37. This hollow tube is connected to the duct 47 leading to the annular groove 46 which provides the steam barrier and steam is provided to the annular duct 46 via this tube. Steam exhausts from the annular groove 46 via exhaust duct 53 communicating with the interior of the hollow tube 19 and venting to atmosphere via duct 55 and steam outlet 35. O-ring seals 49 are provided in end cap 39b to make a fluid tight seal with the exterior of the hollow tube 19 which moves relative to the end cap 39b on movement of the piston 14.

Pre-settable control means are also mounted on the cap 39b and comprise pillar 30 connected by bridge 31 to rod 32. Pillar 30 and rod 32 are fixably mounted in the end cap 39b. Limit switches 20, 21 are slidably mounted on the rod 32. A trigger 36 is attached to the plug 34 closing the end of the hollow tube 19 by screws in known manner. The limit switch 20 senses the fully raised or withdrawn position of the piston 14 illustrated in Figure 3. The lower switch 21 is adjustable and can be set to a position corresponding to the volume of food which is to be dispensed from the cylinder 10 on the return downward stroke of the piston 14.

The operation of the apparatus is as follows : (1) at the start of a cycle, the piston 14 is at its lowest position dictated by limit switch 21. The product inlet valve 9 is closed. Sterilised medium is supplied via inlet 17 to the rear of the piston until a pressure of 3.5 bar is reached. Outlet valve 18 is closed.

(2) On opening the product inlet valve 9, product at a pressure of 4 bar forces the piston to retract against the 3.5 bar pressure at the rear of the piston, this pressure being slowly bled off to atmosphere using restrictor valve 18 which is now open. As valve 17 is now closed, the piston withdraws slowly because a pressure differential of only 0.5 bar is now being applied to it rather than 4 bar.

(3) When the piston reaches its fully withdrawn or raised position, trigger 36 contacts limit switch 20 to close the product inlet valve 9. Inlet valve 17 is now opened and exhaust valve 18 is closed so that the sterilised medium can again be applied to the rear of the piston. Once this pressure has been reached, valve 12 associated with the filling head is opened so the piston 14 moves downwardly to expel product from the cylinder.

(4) When the trigger 36 reaches limit switch 21, the piston will have reached the limit of its downward stroke required to dispense the pre-set volume of product so the product inlet valve 9 is closed again, together with the product outlet valve 12, the inlet valve 17 is closed and the restrictor valve 18 opened and the cycle repeats.

The sterilised medium supplied to the rear of the piston 14 through valve controlled inlet 17 is preferably steam, although some other sterile fluid such as air or nitrogen could be used. Steam is preferred because it cannot contaminate food in the cylinder. Also, using steam as the medium supplied to the annular groove 46 has the same effect, so a very sterile environment is provided. It is a novel feature of the illustrated device that the piston is moved on its upward stroke under the pressure of the food supplied to the cylinder and it is returned by supplying a sterilised medium to the rear of the piston 14 through the valve controlled inlet 17.

It will be appreciated from the foregoing description that the processed product can be very accurately metered into the pre-sterilised packs at a substantially constant density and pressure so the process provides a considerable improvement over known prior art processes.

Claims

1. Apparatus for metering a predetermined quantity of aseptic food containing particulate matter into a pre-sterilised package comprising a pressurised storage tank for the aseptic food to be dispensed and packaged, said tank being connected to a valve controlled inlet of a metering device, the metering device having an outlet connected to a filling head, the output of which is controlled by a valve, the metering device comprising a piston and cylinder arrangement operable so that food under pressure from the storage tank is forced into the cylinder on opening the inlet valve thereto whereby the piston retracts, the metering device also including means for supplying a sterilised fluid to the rear of the piston and maintaining said fluid at a pressure slightly less than that in the storage tank whereby on opening the filling head valve and closing the inlet valve to the piston and cylinder arrangement, the piston moves along the cylinder towards its outlet to expel the food therefrom the length of the expelling stroke of the piston being controlled by pre-settable control means operably associated with the means for supplying the sterilised fluid to the rear of the piston.

2. Apparatus as claimed in Claim 1 wherein the contents of the storage tank are maintained at a pressure of substantially four bar, the sterilised fluid being supplied to the rear of the piston at a pressure of approximately 3.5 bar.

3. Apparatus as claimed in Claim 1 or Claim 2 wherein the piston is operable to fully retract when the inlet valve to the metering device is opened.

4. Apparatus as claimed in any of the preceding claims wherein the piston has a shaft extending rearwardly therefrom, the pre-settable control means comprising adjustable limit switches operable to sense the position of the shaft on movement of the piston during its return stroke whereby the supply of fluid under pressure to the rear of the piston is cut off when the shaft reaches a pre-set position.

5. Apparatus as claimed in Claim 4 wherein, a trigger is mounted on the shaft to cooperate with the adjustable limit switches arranged alongside the shaft, the position of said switches being adjustable to vary the operating stroke of the piston.

6. Apparatus as claimed in any of the preceding claims wherein the supply of the sterilised fluid to the rear of the piston is controlled by the valve, the operation of this valve, the filling head outlet valve and metering device inlet valve being controlled by central control means.

7. lpparatus as claimed in any of the preceding claims wherein the piston is provided with an annular groove around its periphery, said groove being connected to a supply of steam and the arrangement being such that, in use a steam barrier or seal is provided between the piston and cylinder wall when steam is supplied to said groove.

8. A method of metering a predetermined quantity of aseptic food containing particulate material from a storage tank under pressure to a pre-sterilised package comprising the steps of opening a first valve to admit food from the storage tank into a metering device comprising a piston reciprocable in a cylinder whereby the piston is forced back by the food under pressure, a sterilised medium being supplied to the rear of the piston at a pressure less than that in the storage tank, closing a valve to cut off the further supply of food to the cylinder, opening a second valve downstream of the metering device whereby the piston is forced back under the pressure of the sterilised medium to expel food from the cylinder, the length of the return stroke of the piston being controlled by pre-settable control means whereby a predetermined volume of food is dispensed from the metering device to the pre-sterilised package.

9. A metering device for dispensing a predetermined volume of foodstuff containing particulate matter supplied under pressure to the device in a sterilised condition comprising a piston reciprocable in a cylinder, an inlet to the cylinder controlled by a valve, an outlet from the cylinder, means for supplying a sterilised medium under pressure to the rear of the piston, the supply of said sterilised medium being controlled by a valve and pre-settable means controlling the axial displacement of the piston in the cylinder towards the outlet, the arrangement being such that when the inlet to the device is connected to a supply of food under pressure and the inlet valve is opended, foodstuff is admitted to the cylinder to push it back until it reaches its fully withdrawn position when the inlet valve closes, sterilised medium under pressure then being admitted to the rear of the piston to push it back along the cylinder until it reaches its limit position determined by the pre-settable means whereby the exact volume of food displaced by movement of the piston is dispensed through the outlet.

10. A metering device according to Claim 9 wherein the piston has a shaft extending rearwardly therefrom, the pre-settable means comprising means on the shaft which cooperate with adjustable limit stops operably associated therewith to control the length of the return stroke of the piston.

11. A metering device as claimed in Claim 9 or Claim 10 wherein the piston includes an annular groove around the perimeter thereof to provide an edge seal between the piston and cylinder wall, said groove having a supply duct connected thereto for the supply of sterilising medium

12. A metering device as claimed in Claim 11 wherein an exhaust duct venting to atmosphere is also connected to the annular groove.

13. A Metering Device as claimed in Claim 11 or Claim 12 wherein the shaft is a hollow tube through which, in use, the sterilising medium is fed to the supply duct and hence to the annular groove in the piston

14. A metering device as claimed in Claim 12 or Claim 13 wherein the piston has a section intermediate its ends made of a plastics material in which the annular duct and the supply and exhaust ducts are formed.

15. A metering device as claimed in any of Claims 9 13 wherein the bottom of the cylinder is provided with a recess adjacent the inlet and outlet thereto into which the end of the piston fits when it has travelled along the whole length of the cylinder, the end of the piston fitting into said recess so as to leave a space between its front face and the bottom of the recess.

16. Apparatus substantially as herein described with reference to the accompanying drawings.

17. A method of metering a predetermined quantity of aseptic food containing particulate material from a storage tank under pressure to a pre-sterilised package substantially as herein described with reference to the accompanying drawings.

18. A metering device substantially as herein described with reference to the accompanying drawings.