Processing a mass of pumpable foodstuff material

Abstract

A method and installation for processing a mass of pumpable foodstuff material, for example a ground meat mass. The installation comprises a hopper and a positive displacement pump having an inlet and an outlet. A tube structure connects to the outlet of the pump and has a mouth, e.g. leading to a molding device or a sausage machine. A controllable vacuum assembly causes controlled evacuation of air from the mass in the trajectory of the mass from the hopper to a pump chamber. A controllable aeration assembly causes controlled introduction of a gas into the mass at one or more locations in the trajectory of the mass between the pump outlet and the mouth. A gas pressure control device introduces gas into the mass at a controlled pressure that is at least equal to the actual pressure of the mass at the location of introduction of the gas.

Claims

1. A method for processing of a ground meat mass, comprising: depositing a ground meat mass in a hopper, discharging said mass from said hopper to a positive displacement pump having an inlet and an outlet for the mass, the pump having one or more pump chambers that each are successively in communication with the pump inlet for the introduction of mass into the one or more pump chambers and with the pump outlet for the discharge of mass from the one or more pump chambers, expelling the mass from the outlet of the pump into a tube structure that is connected to the outlet of the positive displacement pump, said tube structure having at least one mouth from which said mass is discharged, said mass being shielded by said tube structure from the surrounding atmosphere, using a controllable vacuum assembly to subject the mass to a controlled evacuation of air at one or more locations in the trajectory of the mass starting from and including the hopper to and including one of the pump chambers at a position thereof where it is in communication with the pump inlet, subjecting the mass at one or more locations in the tube structure between the pump outlet and the mouth to a controlled introduction of a gas into the mass by a controllable aeration assembly, said aeration assembly comprising a source of pressurized gas and an aeration member that is disposed in the tube structure between the pump outlet and the mouth, said aeration member being connected to the source of pressurized gas and having one or more orifices from which said gas is emitted, and said aeration assembly comprising a gas pressure control device adapted to regulate said introduction of said gas into the mass at a controlled pressure that is at least equal to the actual pressure of the mass at the location of introduction of the gas into the mass.

2. The method according to claim 1, wherein said aeration assembly comprises an agitator member in the path of the mass and adapted to agitate said mass in order to enhance the introduction and distribution of the gas into the mass.

3. The method according to claim 2, wherein the aeration ember is integrated with the agitator member.

4. The method according to claim 2, wherein said agitator member is movably arranged in the tube structure in order to entrain the mass when the agitator member is in motion and wherein a drive motor is provided for driving said agitator member.

5. The method according to claim 4, wherein the agitator member is embodied as a meat grinder.

6. The method according to claim 1, wherein said aeration member comprises one or more porous members, each forming a multitude of orifices from which said gas is emitted into the mass.

7. The method according to claim 1, further comprising using an electronic control unit operatingly connected at least to the vacuum assembly and to the aeration assembly, wherein said electronic control unit comprises a memory that stores production settings of the evacuation by the vacuum assembly and of the aeration by the aeration assembly.

8. The method according to claim 1, wherein the mass that is discharged from said at least one mouth is fed to a shaping device which shapes the mass into three dimensional products.

9. The method according to claim 1, wherein the mass that is discharged from said at least one mouth is fed to a moulding device which comprises: a frame, a mould member having multiple mould cavities, each having a filling opening for the introduction of foodstuff material into the mould cavity, wherein the mould member is movably supported by the frame, a mould member drive for moving the mould member along a path, said path including a fill position for filling the ground meat mass into one of the mould cavities and a product release position for releasing a moulded product from the mould cavity, a mass feed member, preferably supported by the frame, having said mouth at the fill position along the path of the mould member, said mass feed member being connected to a fill tube of the tube structure and being adapted to transfer the mass into a mould cavity of the mould member when the filling opening thereof is in communication with the mouth at said fill position.

10. The method according to claim 1, wherein the aeration involves the introduction of a mixture of a gas and a liquid into the mass.

11. The method according to claim 1, wherein the mass that is discharged from said at least one mouth is fed to a sausage machine filling the ground meat mass into sausage casing.

12. An installation for processing of a mass of pumpable foodstuff material, said installation comprising: a hopper adapted to receive a batch of the mass of pumpable foodstuff material, a positive displacement pump configured to move ground meat, the positive displacement pump having an inlet and an outlet for the mass, the pump forming one or more pump chambers that each are successively in communication with the pump inlet for the introduction of mass into the one or more pump chambers and with the pump outlet for the discharge of mass from the one or more pump chambers, a tube structure connected to the outlet of the positive displacement pump, said tube structure having at least one mouth from which said mass is discharged, said mass being shielded by said tube structure from the surrounding atmosphere, a controllable vacuum assembly adapted to cause controlled evacuation of air from the mass at one or more locations in the trajectory of the mass from and including the hopper to and including a pump chamber at a position where it is in communication with the pump inlet, wherein the installation further comprises a controllable aeration assembly adapted to cause controlled introduction of a gas into the mass at one or more locations in the tube structure between the pump outlet and the mouth, said aeration assembly comprising a source of pressurized gas and an aeration member disposed in the tube structure between the pump outlet and the mouth, said aeration member being connected to the source of pressurized gas and having one or more orifices from which said gas is emitted, and said aeration assembly comprising a gas pressure control device that is adapted to regulate the introduction of said gas into the mass at a controlled pressure that is at least equal to the actual pressure of the mass at the location of introduction of the gas into the mass.

13. The installation according to claim 12, wherein said aeration assembly comprises an agitator member in the path of the mass and adapted to agitate said mass in order to enhance the introduction and distribution of the gas into the mass.

14. The installation according to claim 13, wherein the aeration member is integrated with the agitator member.

15. The installation according to claim 13, wherein said agitator member is movably arranged in the tube structure to entrain the mass when the agitator member is in motion and wherein a drive motor is provided for driving said agitator member.

16. The installation according to claim 12, wherein said aeration member comprises one or more porous members, each forming a multitude of orifices from which said gas is emitted into the mass.

17. The installation according to claim 12, comprises an electronic control unit operatingly connected at least to the vacuum assembly and to the aeration assembly, and wherein said control unit comprises a memory adapted to store production settings of the evacuation by the vacuum assembly and of the aeration by the aeration assembly.

18. The installation according to claim 12, wherein the installation further comprises a shaping device that is adapted to shape the mass emerging from the at least one mouth into three dimensional products.

19. The installation according to claim 12, wherein the installation further comprises a moulding device that is adapted to shape the mass emerging from the at least one mouth into three dimensional products, wherein the moulding device comprises: a frame, a mould member having multiple mould cavities, each having a filling opening for the introduction of foodstuff material into the mould cavity, wherein the mould member is movably supported by the frame, a mould member drive for moving the mould member along a path, said path including a fill position for filling the mass into one of the multiple mould cavities and a product release position for releasing a moulded product from one of the multiple mould cavities, a mass feed member having said mouth at the fill position along the path of the mould member, said mass feed member being connected to a fill tube of the tube structure and being adapted to transfer the mass into one of the multiple mould cavities of the mould member when the filling opening thereof is in communication with the mouth at said fill position.

20. The installation according to claim 12, wherein the installation further comprises a sausage machine that is adapted to shape the mass emerging from the at least one mouth into sausages by filling the ground meat mass into sausage casing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 depicts schematically an installation according to the invention having both a vacuum assembly and an aeration assembly,

(3) FIG. 2 schematically depicts a portion of an example of an aeration member of an installation according to the invention,

(4) FIG. 3 schematically depicts a portion of another example of an aeration member of an installation according to the invention,

(5) FIGS. 4 and 5 depict an example of an installation having the layout schematically depicted in FIG. 1,

(6) FIG. 6 schematically depicts another installation according to the invention including a density measurement device,

(7) FIG. 7 depicts the installation of FIG. 6 with an additional foreign objects detection device,

(8) FIGS. 8a and 8b schematically depict yet another installation according to the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

(9) FIG. 1 schematically depicts an installation for the moulding of three dimensional products from a mass of pumpable foodstuff material, for example from a ground meat mass.

(10) A batch of ground meat mass, e.g. of beef, pork, or poultry meat, is commonly prepared with a meat grinding device or a mixer/grinding device. A batch is e.g. loaded into a (wheeled) bin and then transported to the installation. Instead of loading the hopper with bins, the loading may be conducted via a pipe connecting to the hopper.

(11) The installation comprises a hopper 1 that is adapted to receive a batch of the mass of pumpable foodstuff material. The hopper 1 may have a funnel shape but different shaped hoppers are also possible as long as they are able to receive one or more batches of the mass, possibly via a feed conduit directly leading to the hopper.

(12) In this example a feeder assembly 2 is associated with the hopper 1 to assist in discharging the mass from the hopper 1. In this example one or more motor driven augers 3 are mounted at the bottom of the hopper 1.

(13) The installation furthermore comprises a positive displacement pump 5 having an inlet 6 receiving the mass from the hopper 1, here via the auger 3.

(14) The pump further has an outlet 7 for the mass. The pump shown is a vane pump with a rotor having multiples vanes disposed in a pump cavity of the pump housing. Such pumps, e.g. supplied by Risco (Italy) are known for pumping ground meat and other pumpable foodstuff masses. A drive motor (e.g. electric, not shown) is provided for driving the rotor. The pump forms pump chambers, in the figure shown between neighbouring vanes, that each are successively in communication with the pump inlet 6 for the introduction of mass into the pump chamber and with the pump outlet 7 for the discharge of mass from the pump chamber. The effective volume of the pump chamber reduces from the position thereof at the pump inlet to the position thereof at the pump outlet, so that the mass is effectively expelled from the pump chamber when the pump is in operation. An example of such a pump is disclosed in U.S. Pat. No. 4,761,121.

(15) The optional feeder assembly 2 is arranged to aid in transporting the mass from the hopper 1 towards the inlet 6 of positive displacement pump 5.

(16) The pump may instead of a vane pump also be embodied as a different type of pump, e.g. as a piston pump having one or more reciprocating pistons.

(17) A fill tube 10 of a tube structure is connected to the outlet 7 of the pump 5. This tube 10 in this example leads the mass to a moulding device 20.

(18) The moulding device comprises a frame (not depicted here) and a mould member 21 that is movably supported, here a rotating mould drumas is preferred rotating about a horizontal axis, by the frame.

(19) The mould member 21 has multiple mould cavities 22, each having a filling opening for the introduction of foodstuff material into the mould cavity 22. As is preferred in a mould drum embodiment, the cavities are embodied as recesses in the outer surface of the drum body, having a bottom opposite the filling opening of the cavity.

(20) A mould member drive (not shown) is provided for moving the mould member along a path, here a circular path about the rotation axis of the drum mould 21. This path in general includes a fill position for filling the mass into a mould cavity 22 and a product release position for releasing a moulded product from the mould cavity.

(21) A mass feed member 25 is arranged at a fill position, preferably a stationary fill position, preferably supported by the frame of the moulding device. The mass feed member 25 has at least one mouth 26 from which the mass dispensed. The mouth is positioned along the path of the mould member. The mass feed member 25 is connected to the fill tube 10 and forms part of a tube structure.

(22) The mass feed member 25 is adapted to transfer the mass into a mould cavity of the mould member when the filling opening thereof is in communication with the mouth at the fill position. For example the member 25 may have an elongated slot shaped mouth extending generally at right angles to the path of the mould member, e.g. a single slot extending in a longitudinal direction of the rotating drum mould, so that all mould cavities therein come into communication with said mouth when they pass the fill position during rotation of the mould member. As is preferred the mass feed member sealingly engages the surface of the movable mould member 21 in which the cavities are formed, so that substantially no mass may escape between the mass feed member and the mould member.

(23) Preferred details of a mould drum and an associated mass feed member are e.g. disclosed in WO00/30548 and in WO2004/002229.

(24) The pump 5 provides the pressure that urges the mass from the pump towards the mass feed member and out of the mouth of the mass feed member. By suitable control of the pump 5, e.g. of the pump rotor speed, e.g. using a controllable electric drive motor M (see FIG. 5), the flow of mass to the mouth 26 can be controlled.

(25) At a release position the formed product, here meat product 15, is released from the mould cavity, e.g. to be transported onward on a conveyor 30. The release from the mould cavity may be assisted by pneumatic pressure, e.g. as the wall of the mould cavity comprises one or more sections of porous material through which pressurized air or gas is forced thereby assisting the release of the product. A mechanical ejector member may also be provided to perform or assist in the release of the product from the mould member.

(26) It is noted that in an alternative embodiment (not shown) the mould member may be plate shaped instead of drum, e.g. in a turret device where the plate revolves about a vertical axis, or e.g. in a reciprocating plate moulding device. In the latter known type of device, a mould plate with multiple moulding cavities that are open both on the top side and the bottom side of the plate member is reciprocated, so that the mould cavities are at a fill position to receive mass from a mass feed member and are later at a release position (commonly provided with a plunger ejector member to punch the formed products out of the cavities).

(27) The installation comprises a controllable vacuum assembly 40, here integrated with the pump 5 as is known in the art, e.g. known for pumps used in stuffing sausage casings. This assembly 40 is adapted to cause controlled evacuation of air from the mass at one or more locations in the trajectory of the mass from the hopper 1 to and including the pump chamber at a position where it is in communication with the pump inlet 6 of the positive displacement pump. As is preferred, this vacuum assembly comprises a vacuum pump 41, e.g. an electrically operated vacuum pump.

(28) As is preferred, a vacuum port 42 is arranged in the pump 5 so as to be effective in establishing a vacuum in the pump chamber that is in communication with the inlet 6 during operation of the pump 5. This vacuum assists in the complete filling of the chamber with a portion of the mass.

(29) As explained above, a vacuum may be created in the hopper 1 as is known in the art. A vacuum may also be created in any passage between the hopper 1 and the pump inlet 6, e.g. in a duct into which one or more augers of a feed assembly extend.

(30) As explained the vacuum assembly 40 allows the evacuation of the mass, e.g. the ground meat mass, so as to reduce the presence of air in the mass. This increases the uniformity of the products when it comes to the weight of mass that is effectively introduced into each of the mould cavities 22, among other advantages.

(31) The installation also comprises a controllable aeration assembly that is adapted to cause controlled introduction of a gas, e.g. air or another gas or gas mixture, e.g. N.sub.2 or CO.sub.2, into the mass at one or more locations in the trajectory of the mass between the pump outlet 7 and the mouth of the mass feed member 25.

(32) In this example wherein a shaping device having one or more mould cavities is connected to the mouth 26, the gas is thus introduced into the mass, before the mass enters the mould cavity in which the product is formed. It is observed that in this trajectory the mass passes through the tube 10, the mass feed member 25 and is in generally within a passage that is closed from the surrounding atmosphere.

(33) The aeration assembly comprises a source of pressurized gas 51, here depicted as a gas bottle, but other embodiments are also possible, e.g. with an air compressor that handles filtered air.

(34) The aeration assembly further comprises a gas pressure control device 52, that allows the introduction of the gas into the mass at a controlled gas pressure that is at least equal to the actual pressure of the mass at the location of introduction of the gas into the mass in order to obtain a reception of the gas in the mass. The gas pressure need not be significantly above the pressure in the mass to obtain an effective introduction of gas into the mass.

(35) Preferably one or more mass pressure sensors are present in this gas introduction trajectory to determine the actual pressure of the mass, the mass pressure sensor being operatingly connected to the gas pressure control device 52, e.g. to obtain a variation in the gas pressure based on the sensed pressure of the mass which may vary over time (e.g. due to the mould cavities coming into and out of communication with the mouth of the mass feed member).

(36) The aeration assembly comprises an aeration member 53 disposed in the path of the mass between the pump outlet 6 and the mouth of the mass feed member 25. This aeration member 53 is connected to the source 51 of pressurized gas and has one or more orifices from which the gas is emitted into the mass.

(37) As explained above the aeration assembly allows the introduction of gas, e.g. air or another gas, or of a mixture of gasses, possibly a mixture of a gas and a liquid, e.g. with an edible oil or a liquid (anti-)foaming agent, into the mass downstream of the pump before the mass is introduced into the mould cavity. This e.g. allows control of the porosity of the moulded products, thereby e.g. influencing parameters like texture, bite and juiciness of the finally prepared food product, e.g. hamburger, and/or the further preparation process, e.g. the cooking or frying.

(38) As explained the installation allows for example to first evacuate the mass as much as possible in the trajectory between the hopper and the pump 5, thereby enhancing the uniformity of the mass entering the pump chamber and thereby enhancing the weight uniformity of the moulded products. The installation also allows the (re-) introduction of air or another gas into the mass, effectively downstream of the pump, thereby allowing for e.g. increased porosity of the mass before it enters the mould cavity.

(39) As is preferred, the installation comprises an electronic control system operatingly connected to at least to the vacuum assembly 40 and to the aeration assembly 50. This control system preferably comprises a memory adapted to store production settings of the evacuation by the vacuum assembly and of the aeration by the aeration assembly, e.g. for multiple distinct masses and/or distinct products to be moulded from one or more masses.

(40) In order to determine production settings for use in the method for moulding the products with the installation it is envisaged that multiple trial runs may be performed with the installation, the trial runs havingusing the same mass and the same mould memberdifferent settings of the evacuation by the vacuum assembly and of the aeration by the aeration assembly. The formed products can be tested immediately after being so formed, e.g. tested for one or more of the parameters porosity, density, and weight.

(41) It is also envisaged that the formed products are processed further in order to be edible for human consumption, e.g. (oven) cooked and/or fried, e.g. as with a meat product. Then the edible products are tested, e.g. by a test panel. e.g. testing one or more of the parameters texture, bite, juiciness, weight, shape, of the product. Based on the favoured product the setting corresponding to the relevant trial run are then used as production parameters, e.g. stored in a memory of the installation when present.

(42) As explained above the installation can also be employed to remove air from the mass that is introduced into the installation, and to replace the air by another gas or gas mixture, e.g. a gas that promotes the shelf life of the product, e.g. a non-oxygen gas, e.g. carbon dioxide gas or nitrogen.

(43) In a simple embodiment the aeration member 53 comprises a double walled section, with the outer wall being closed and the inner wall having a multitude of orifices. e.g. machined therein or the inner wall being made of porous material. Air or another gas is then supplied in the space between the outer and inner wall, so that the air then is introduced into the mass that passes through the passageway formed by the inner wall.

(44) The aeration member may define a circular cross-section passageway of the mass, but also other cross-sectional shapes, e.g. a rectangular passageway through which a relatively thin layer of mass is transported with opposed main faces into which the air or gas is introduced.

(45) An embodiment of an aeration member 80 is partly shown in FIG. 2. Here a part is shown that is to be arranged in a passageway of the aeration member through which the mass passes. The member 80 includes one or more orificed gas emitting elements 81, 82 to be arranged in the passageway, hereas exampleone or more groups of parallel elongated rod members emitting the gas into the mass. The aeration elements 81, 82 are connected to the source 51 and pressure control assembly 52

(46) In the example shown here a first group of elements 81 is arranged in one direction, whereas another group of elements 82 is arranged in another direction, thereby causing the mass to effectively pass through a grid of gas emitting member 81, 82.

(47) In this example it is illustrated to one or more elements 81, 82 are fully or partially made from porous material, e.g. sintered porous metal, each forming a multitude of fine orifices from which the gas is emitted into the mass.

(48) In this example each element 81, 82 has a leading end 81a, facing the stream of mass indicated with arrow P, that is non-porous, and a trailing end 81b provided with the one or more orifices, e.g. from porous material.

(49) Preferably the effective cross-section for the mass to pass through at the aeration member is at least equal to the cross-section of the pump outlet.

(50) Aeration member elements 81, 82 may be arranged to form a static mixer, so with only static components causing the split up of the stream of mass into substreams that are then reoriented and/or mixed with one another as the mass passes through the static mixer.

(51) The aeration assembly may comprise a movable agitator member in the path of the mass in the tube structure and adapted to agitate the mass in order to enhance the introduction and distribution of the gas into the mass. Such an agitator member could e.g. be arranged downstream of the member depicted in FIG. 2, e.g. with one or more rotating blades. e.g. similar to a boat propeller or a fan, that agitate the mass by operation of a drive motor for driving said agitator member so as to entrain the mass in said motion of the agitator member.

(52) In an example the one or more of the groups of elements 81, 82 may be arranged to rotate about a central axis of the aeration member during operation. This would then be an example of an aeration member that is integrated with the agitator member.

(53) In FIG. 3 an example of an aeration member 90 is depicted, wherein the housing of the member forms a duct wherein the mass, entering the member through a circular opening, is brought into a shape of a flattened layer, the air or gas being introduced into the mass from one or more main faces of the flattened layer.

(54) In this example the aeration member 90 includes a needle member 91 having a multitude of parallel needles 92 that each extend into the passageway for the mass. The needles are hollow or porous so that air or gas can be fed via the needles into the mass.

(55) The needle member 91 in this example, as is optional, is movable by a drive (not shown) allowing to move the needles to different positions within the duct, e.g. reciprocating along their axis within the duct during the passage of the mass. This allows e.g. for an enhanced distribution of air or gas in the mass.

(56) The aeration member, in particular of any agitator member thereof when present, e.g. the needle member 91, may be employed to alter the orientation of any fibres in the mass (e.g. as is present in ground meat) when present, e.g. to alter the orientation of such fibres compared to the orientation when the mass emerges from the pump outlet.

(57) The second aspect of the invention relates to a method for use of an installation as illustrated in FIG. 1 without the presence of an aeration assembly, so in fact a prior art installation. In this method the level of evacuation provided by the vacuum assembly is used as a control mechanism to control the weight and/or porosity of the moulded products. The evacuation is not performed to obtain a maximized evacuation of the mass, but the evacuation is done in a manner to achieve the moulding of a product with a desired weight and/or porosity. Again, it is possible to perform trial runs with the installation to determine the optimal production setting for a particular combination of mass to be handled and mould member used, and store the production setting in a suitable memory of an electronic control unit of the installation when present. The degree of evacuation can then be well below the maximum level of evacuation for the respective mass. e.g. between 40 and 80 percent of the maximum evacuation level (to be determined with the installation when filled with the mass).

(58) It is noted that it is known from e.g. WO00/30548 to have multiple mass feed members positioned at different positions along the path of the mould member, the mould member being embodied such that a multilayer product can be obtained, e.g. having a movable bottom to allow for different volumes of the mould cavity; first to be filed with the first mass, then lowering of the bottom to make space for the second mass.

(59) In this respect it is envisaged that an installation e.g. having two mass feed members may have just one aeration member to aerate the mass flowing to one of the mass feed members and not the mass to one or more other mass feed members, or the installation has multiple, independently controllable aeration members. This e.g. allows to feed masses to these mass feed members that have undergone different aeration processes, e.g. one mass being non-aerated, the other mass being aerated, or masses being aerated differently. The mass can emerge from a common positive displacement pump, e.g. with a splitting manifold behind the pump. The mass can also emerge from different pumps, each having its corresponding hopper and connected to a respective mass feed member. e.g. as the masses are of entirely different composition.

(60) FIGS. 4 and 5 show an embodiment of an installation according to the invention, having the features discussed with reference to the schematic FIG. 1. Therefore parts identical or similar to parts discussed with reference to FIG. 1 have been denoted with the same reference numeral.

(61) The moulding device has a frame 28, here a wheeled frame, supporting the mould drum 21.

(62) The electronic control unit of the installation is depicted at 29.

(63) It will be appreciated that the disclosed technique is also suitable for the production of sausages, wherein the mouth preferably is adapted to introduce the mass into the sausage casing.

(64) FIG. 6 shows the installation of FIG. 1 wherein an in-line determination of the mass density by a mass density measurement device 60 is envisaged, e.g. based on X-ray, Coriolis effect, air bubbles, or otherwise. The device 60 is arranged to measure the density of the pumped mass as it passes through the tube structure 10 from the pump to mouth 26. As explained this is also possible in an installation that is not equipped with a moulding device having mould cavities that pass along the mouth, e.g. as shown here or in a reciprocating plate type moulding device. The mass could then e.g. exit directly from the mouth. e.g. onto a conveyor belt, into a container, etc. As explained the mass may be a ground meat mass. Neither is it necessary that an aeration assembly 50 is employed. This is, however, a preferred feature.

(65) The device 60 is adapted, e.g. programmed in a computerized device, to provide a signal that is representative of the mass density. This signal is here shown to be used by a control unit 71 (possibly integrated in the overall control system of the installation) which is in turn linked to at least one of: the pump 5, the vacuum assembly 40, the aeration assembly 50, in order to contribute to the operation thereof, primarily in view of the desire to be able to control the density of the mass, which ultimately has noticeable effect on the food product.

(66) For example the control unit 71 is embodied to compare the determined density with a desired density that has been provided by an operator, e.g. based on a stored menu for the production of a certain type of food product, and provides a suitable feedback signal.

(67) FIG. 7 shows the installation of FIG. 6, wherein it is illustrated that an X-ray device 75 is arranged between the pump 5 and the aeration member 53 in order to detect the presence of foreign objects in the pumped mass. This allows for a complete or maximum evacuation of a meat mass or other air containing mass by the vacuum assembly 40 to minimized the presence of air bubbles in the mass as it passes the X-ray device 75. As explained this enhances the detection of foreign objects compared to a situation wherein more air is present in the mass. The aeration member 53, downstream of the device 75 in the tube structure allows for a controlled aeration of the mass. e.g. with air or another gas. This approach is also beneficial in installations wherein no moulding device is present, and is in particular considered advantageous when handling ground meat.

(68) In FIG. 7 the mass density measurement device 70 is also shown, which is done to illustrate the option to measure the mass density in the tube structure 10 at a position downstream of the aeration member 53, e.g. to control this aeration. As explained also an embodiment is envisaged wherein an X-ray device, e.g. device 70 and/or device 75, is embodied, e.g. programmed, to detect foreign objects as well as to determine mass density.

(69) When a foreign object is detected by device 70 or 75 in the mass passing through the tube structure one can envisage a preprogrammed routine wherein a batch of formed products 15 that are made of mass near the detected object is labelled as non-suitable for further use. In another approach a discharge tube is branched from the tube structure with a valve downstream of the respective measurement device, so that a portion of mass near the detected object is led away from the path towards the mouth and discharged as rejected mass. These approaches are also possible in installation having no aeration assembly as disclosed herein.

(70) FIGS. 8a and b illustrate an installation having components similar to the installation of FIG. 1, wherein a sample of a predetermined volume is taken from the stream of mass passing through the tube structure 10. The sampling and density determination device 110 here comprises a valve 111 adjoining at an inlet side thereof the tube structure 10 and at the other side thereof a sample chamber 112. This chamber 112 here is delimited by a cylinder wall 113 and a piston 114. With the piston 114 in a known initial position, the chamber 112 has a known initial sample volume. Care is taken that the chamber 112 is empty at the start of the process, possibly evacuated. Then the valve 111 is opened and the sample portion of mass streams into the chamber 112, The sample in the chamber 112 is still subjected to the pressure in the tube structure as it enters and fills the sample chamber 112. Then the valve 111 is closed, so that the sample chamber 112 and sample therein are no longer in communication with the tube structure 10. Then the sample is allowed to expand as the volume of the chamber is expanded and is connected to the atmosphere such that the sample is under atmospheric pressure. This is done here by releasing the piston 114 from its initial position so that the piston is allowed to move under the influence of the expanding sample of the mass. The degree of expansion of the sample, e.g. measured by the final position of the piston 114, compared to the initial sample volume is representative for the presence of air in the mass and thus for the density of the mass as the air will expand due to the reduced pressure acting on the sample. After the measurement the chamber 112 is emptied and readied for taking a new sample with the piston 114 again in its initial position.