WO2019191809A1

WO2019191809A1 - Shredding device for textured protein foodstuff

Info

Publication number: WO2019191809A1
Application number: PCT/AU2019/050296
Authority: WO
Inventors: Charlie Chessari
Original assignee: ProForm Innovation Pty Limited
Priority date: 2018-04-04
Filing date: 2019-04-04
Publication date: 2019-10-10

Abstract

A device for performing size-reduction on an extruded proteinaceous foodstuff, said device including at least a first and a second adjacently mounted shredding roller, said rollers adapted to be co-rotating, said rollers having complementary surfaces adapted to compress and shear said foodstuff as it passes therebetween; wherein the second roller is rotated at a speed equal to or greater than the speed of the first roller.

Description

SHREDDING DEVICE FOR TEXTURED PROTEIN FOODSTUFF

Technical Field

[0001 ] The invention relates to the field of commercial extruded food manufacture. In particular, the invention relates to a device for shredding an extruded high moisture texturised protein food product.

Background of the Invention

[0002] By 2050 the world’s population is projected to reach 9 billion and it has been suggested that 70% more food will be required to sustain this population. Between 1950 and 2000 meat production increased from 45 to 229 million tons and this is expected to further increase to 465 million tons by 2050.

[0003] The relatively inefficient conversion of plant protein into animal protein via animal metabolism makes meat production responsible for a disproportionate share of environmental pressures such as land use, freshwater depletion, global warming and biodiversity loss.

[0004] A solution to reduce the impact of meat production on the environment is offered by partial replacement of meat protein with plant protein products in the human diet. However, there is a desire that these protein products have favourable organoleptic properties, such as flavour and texture, when compared with meat.

[0005] Both the food industry and food scientists have been interested in creating fibrous food textures for several decades. High Moisture Extrusion Cooking (HMEC) technology as a concept has been established since the early 1980’s. It is a technology for texturising protein-rich materials having a moisture content of greater than about 30% by mass.

[0006] In a typical HMEC process according to the prior art, the raw materials are heated under pressure in an extrusion cooker until molten; the resulting melt is cooled and solidified in-situ by a cooling die to produce aligned protein fibres from the melt, giving a product with a meaty internal texture that satisfies organoleptic requirements. [0007] However, for the product to fulfil its purpose of accurately resembling cooked muscle meat to the consumer, there remains the need to expose the internal texture of the product while reducing the extruded‘rope’ to a usable size.

[0008] Simple‘slicing’ technology tends to be unable to satisfactorily expose the internally fibrous texture of the product. Known ‘shredding’ technologies tend to produce an unacceptably high rate of ‘fines’ that result from high-speed tearing of the product. They also tend to produce sizes that are too randomly distributed and uncontrolled, necessitating sieving or the like in order to achieve the target size, whereupon the off-size pieces are wasted.

[0009] Accordingly, it is an object of the invention to provide a size-reduction step for HMEC technology that ameliorates at least some of the problems associated with the prior art.

Summary of the Invention

[0010] The invention is characterised by a shredding device that incorporates relatively low-speed rotors that are run at differential speeds, and which can provide a controlled shredding of the extruded proteinaceous foodstuff.

[001 1 ] According to a first aspect of the invention, there is provided a device for performing size-reduction on an extruded proteinaceous foodstuff, said device including at least a first and a second adjacently mounted shredding roller, said rollers adapted to be counter-rotating, said rollers having complementary surfaces adapted to compress and shear said foodstuff as it passes therebetween; wherein the second roller is rotated at a speed equal to or greater than the speed of the first roller.

[0012] The inventors have fond that the use of a rollers that can compress and grip the extrudate while rotating at relatively low, but differential, speeds can provide the type of controlled ‘tear’ of the material that adequately exposes the internal texturisation without generating an unacceptable level of randomness or excessive fines.

[0013] Preferably, the first roller rotates at a speed in the range of 3 rpm to 14.5 rpm, and the second roller rotates at a speed in the range 6 rpm to 29 rpm. Typically, the ratio of rotational speed of the second roller to rotational speed of the first roller is between 1 .8 and 4.0. [0014] The gearbox ratio governing the speed of the second roller to the first roller is typically a ratio of approximately 2.0. However, independent variation of roller rotational speeds is obtained by variable frequency drive’s (VFD’s) for each roller motor. With both rollers at the same frequency setting, the ratio of rotational speed of the second roller to rotational speed of the first roller is exactly the gearbox ratio of approximately 2.0.

[0015] Preferably, said surfaces include an array of projections outward from the roller that are arranged to allow intermeshing of said projections from the respective first and second rollers. More preferably, said projections are arranged in a series of transverse rows across the surface of said rollers, each row defining a series of peaks and troughs in profile, and wherein the rollers are disposed such that the peaks of the projections of the first roller are co-operatively adjacent the corresponding troughs of the second roller.

[0016] This arrangement has been found to provide the best product appearance, as it allows the extruded protein to be gripped and compressed whilst being separated ‘pulling’ in the direction of rotation of the rollers. Typically, the first roller is placed in a relatively upstream position with respect to the flow of foodstuff. For the best results, the first roller’s position is fixed and the position of the second roller may be adjusted relative to the clearance between the rollers.

[0017] According to another aspect of the invention, there is provided a process for the shredding of extruded proteinaceous foodstuff, including the use of a device as defined above.

[0018] According to another aspect of the invention, there is provided a proteinaceous foodstuff produced by a process according to that described above.

[0019] Now will be described, by way of a specific, non-limiting example, a preferred embodiment of the invention with reference to the drawings.

Brief Description of the Drawings

[0020] Figure 1 is a photograph of a device according to the invention.

[0021 ] Figure 2 is a photograph of the device of figure 1 , viewed from above. [0022] Figure 3 is a diagram of a roller adapted for use in a device according to the invention.

[0023] Figure 4 is a diagram of two rollers adapted for use in a device according to the invention.

Detailed Description of the Invention

[0024] The invention may be embodied as a commercial scale shredding device, having at least two co-operating counter-rotating rollers between which cooled, extruded protein passes. The rollers operate at differential rotational speeds and simultaneously tear and compress the protein in order to produce a controlled size distribution of protein pieces with exposed internal fibrous texture.

[0025] Turning to figure 1 , there is shown a device 5 according to an embodiment of the invention. This device is capable of shredding at least 1000 kg/hr of cooled, extruded protein from a FIMEC process.

[0026] The device 5 has two rollers: a first roller 10 and a second roller 15 (one not visible). A feed hopper 20 and two electric motors 25 and 30 attached to each roller. The cooled extruded protein‘rope’ is fed into the hopper 20 and passes between the rollers.

[0027] Turning to Figure 2, there is shown a view of the device 5 of figure 1 , as seen from above the feed hopper 20. The two rollers (10, 15) are visible and the gap 35 between the rollers is also visible. The rollers each have several projections (or ‘teeth’) 40 that extend outwardly and are formed such that they can be seen to resemble a series of peaks 45 and troughs 50 in profile. It will also be seen that the rollers are arranged such that the peaks of the projections of one roller will‘mesh’ with the troughs between projections of the other roller. This is seen in clearer detail in Figure 3.

[0028] In this example, the projections have peaks 45 are approximately 38mm apart across the roller, and there are 14 rows of these projections 40 arranged around the circumference of the rollers.

[0029] In profile, as seen in Figure 3, the projections are asymmetrical: the leading, or‘cutting’, face 55 of each projection 40 is rendered in a plane that is approximately co-planar with the centre-line 60 of the roller, whereas the trailing face 65 of the projection forms an approximate 60° angle with the adjacent leading face 55.

[0030] The views of two co-operating rollers (10, 15) in Figure 4 illustrates the relative positioning of the first and second rollers in operation. It will be noted that the leading face 55 of the projections 40 are arranged to face forward in the direction of rotation when in operation.

[0031 ] The rollers and/or projections are preferably made from 316 stainless steel, but could also be made from other suitable materials, such as a hard FDA-approved food grade plastic as shown in the figures.

[0032] In operation, the first roller 10 is located in an‘upstream’ position relative to the flow of the extrudate towards the device, and the second roller 15 is located in a relatively‘downstream’ position. The first roller 10 is set to rotate at a speed that is slower than the second roller 15, typically at around half of the speed of the second roller, or less. In the present example, the first roller rotates at about 8 rpm and the second roller rotates at about 23 rpm. These can each be adjusted to anywhere in the range 3rpm to 14.5 rpm for the first roller and between 6rpm to 29 rpm for the second roller.

[0033] Typically, the ratio of first roller to second roller rotational speed would be at least 1 :2 but may be set as high as 1 :4 for different products.

[0034] The actuation of the rollers is preferably done by conventional mechanical coupling to dedicated variable speed electric motors for each roller. The direction of rotation is indicated by the curved arrows in Figure 4.

[0035] It is this speed differential that allows the device to shred the extrudate into pieces of a relatively controlled size, whilst exposing the internal fibrous texture created in the FIMEC process.

[0036] The first roller 10 is preferred to have a fixed position, while the second roller’s position relative to the first roller can be adjusted, to modify the gap between the rollers. This will allow different shredding effects to be created and controlled.

[0037] It will be appreciated by those skilled in the art that the above described embodiment is merely one example of how the inventive concept can be implemented. It will be understood that other embodiments may be conceived that, while differing in their detail, nevertheless fall within the same inventive concept and represent the same invention.

Claims

1 . A device for performing size-reduction on an extruded proteinaceous foodstuff, said device including at least a first and a second adjacently mounted shredding roller, said rollers adapted to be co-rotating, said rollers having complementary surfaces adapted to compress and shear said foodstuff as it passes therebetween; wherein the second roller is rotated at a speed equal to or greater than the speed of the first roller.

2. The device of claim 1 , wherein the first roller rotates at a speed in the range of 3 rpm to 14.5 rpm, and the second roller rotates at a speed in the range 6 rpm to 29 rpm.

3. The device of claim 2, wherein the ratio of rotational speed of the second roller to rotational speed of the first roller is between 1 .8 and 4.0.

4. The device of any preceding claim wherein said surfaces include an array of projections outward from the roller that are arranged to allow intermeshing of said projections from the respective first and second rollers.

5. The device of claim 4, wherein said projections are arranged in a series of transverse rows across the surface of said rollers, each row defining a series of peaks and troughs in profile, and wherein the rollers are disposed such that the peaks of the projections of the first roller are co-operatively adjacent the corresponding troughs of the second roller.

6. The device of any preceding claim, wherein the first roller is placed in a relatively upstream position with respect to the flow of foodstuff.

7. The device of claim 6, wherein the first rollers position is fixed and the position of the second roller may be adjusted relative to the clearance between the rollers.

8. A process for the shredding of extruded proteinaceous foodstuff, including the use of a device as defined in any preceding claim.

9. A proteinaceous foodstuff produced by a process according to claim 8.