PROCESS FOR PRODUCING A MEAT ANALOGUE AND APPARATUS THEREFOR

Abstract

The present invention relates to a process for the production of a meat analogue, comprising the steps of: a) introducing a meat batter comprising protein into a heating unit and heating the meat batter to a temperature above the melting point of the protein to produce a heat-treated product, wherein the heating unit optionally heats the meat batter by Ohmic heating, b) cooling the heat-treated product by moving through a cooling unit, so that the heat-treated product has a temperature below water boiling temperature at ambient pressure when exiting the cooling unit, and c) dividing the cooled heat-treated product into pieces and optionally d) tearing the pieces by passing the pieces through a roll nip (14) between a pair of counter-rotating cylindrical rolls (2, 4) having parallel axes of rotation (10, 12), a plurality of projections (16) being arranged on an outer surface of at least one of the rolls (2, 4).

Claims

1. A process for the production of a meat analogue, comprising the steps of: a) introducing a meat batter comprising protein into a heating unit and heating the meat batter to a temperature above the melting point of the protein to produce a heat-treated product, wherein the heating unit optionally heats the meat batter by Ohmic heating, b) cooling the heat-treated product by moving through a cooling unit, so that the heat-treated product has a temperature below water boiling temperature at ambient pressure when exiting the cooling unit, and c) dividing the cooled heat-treated product into pieces and optionally d) tearing the pieces by passing the pieces through a roll nip (14) between a pair of counter-rotating cylindrical rolls (2, 4) having parallel axes of rotation (10, 12), a plurality of projections (16) being arranged on an outer surface of at least one of the rolls (2, 4).

2. The process as claimed in claim 1 wherein the heating unit comprises at least two sections, wherein the sections are connected in series and each comprises at least one module, which modules are operable by Ohmic heating.

3. The process as claimed in claim 1 wherein the heating unit comprises two sections, wherein the first section into which the meat batter is firstly introduced comprises from 1 to 10 modules, and the second section, to which the meat batter is transferred from the first section, comprises from 1 to 7 modules, wherein the modules in the sections are connected in series.

4. The process for the production of a meat analogue according to claim 1 wherein 60 to 70% of the total electrical power to be applied to the meat batter in the process is applied in the first section, and 30 to 40% of the total electrical energy to be applied to the meat batter in the process is applied in the second section.

5. The process for the production of a meat analogue according to claim 1 wherein the heating in step a) is carried out with electrodes applying an electrical current density of 100-5,000 A/m.sup.2, current/surface area of the electrodes, as an average electrical current density over the heating unit.

6. The process as claimed in claim 1 wherein step b) comprises externally and internally cooling the heat-treated product by moving through a cooling pipe (34) of a cooling unit (30), so that the heat-treated product has a temperature below water boiling temperature at ambient pressure when exiting the cooling unit (30) and wherein the internal cooling comprises cooling by way of an inner cooling lance (40) co-centric to the outer cooling pipe (34) and wherein the external cooling optionally comprises outer jacket cooling.

7. An apparatus for the production of a meat analogue comprising: i) a heating unit operable to heat a meat batter comprising protein, ii) a cooling unit located downstream the heating unit and operable to cool down heat-treated product obtained from the heating unit below water boiling temperature at ambient pressure when exiting the cooling unit, and iii) a dividing unit located downstream the cooling unit suitable for dividing cooled down heat-treated product obtained from the cooling unit into pieces and optionally v) a tearing unit (1) for tearing the pieces, the tearing unit (1) comprising: a pair of rotatable rolls (2, 4) having parallel axes of rotation (10, 12) arranged at a preset distance (d) of each other, the distance (d) defining a width (w) of a roll nip (14) between the rolls (2, 4), each roll (2, 4) being coupled with a motor (6, 8) for rotating the rolls (2, 4) in a counter-rotating movement, a plurality of projections (16) being arranged on an outer surface of a first roll (2) of the pair of rolls (2, 4), a control unit for controlling the heating unit, the cooling unit, the dividing unit and the tearing unit (1).

8. The apparatus as claimed in claim 7 wherein the projections (16) are formed as cylinders, pointed cylinders, cones, truncated cones, pyramids or truncated pyramids, each pyramid having 3, 4, 5, 6 or more sides and optionally the projections are arranged in at least 1, 5, 10, 20, 40 or 50 rows parallel to the axes of rotation (10, 12) and/or along at least 1, 2, 3, 5, 10, 15 or 20 circumferential lines and optionally the projections (16) have a height of between 1% and 30% or between 5% and 10% of an outer diameter of the roll (2, 4) and optionally a cone half angle or a pyramid half angle of the projections (16) is less than 60°, 50°, 45°, 30°, 20° or 10° and optionally a second roll (4) of the pair of rolls (2, 4) is provided with a plurality of projections (16) on an outer surface of the roll (4).

9. The apparatus as claimed in claim 7 comprising a means for adjusting the distance (d) between the axes of rotation (10, 12) in order to adjust the width (w) of the roll nip (14).

10. The apparatus as claimed in claim 7 wherein each roll (2, 4) is derivably connected to a separate motor (6, 8), each motor (6, 8) being operable to drive the rolls (2, 4) to rotate at equal or different speeds.

11. The apparatus as claimed in claim 7 wherein the cooling unit (30) comprises a cooling lance (40) co-cencentric to the cooling pipe (34) for internal cooling and optionally wherein the cooling pipe (34) has a circular cross-section.

12. The apparatus as claimed in claim 11 wherein the cooling pipe (34) is a double-wall pipe for outer jacket cooling, wherein the outer diameter of the double-wall pipe is optionally in a range of 40 to 70 mm, wherein the inner diameter of the double-wall pipe is optionally in a range of 35 to 60 mm and preferably about 50 mm.

13. The apparatus according to claim 11 wherein the cooling lance (40) is shorter than the cooling pipe (34).

14. The apparatus according to claim 11, wherein the cooling lance (40) comprises a coolant supply passage (43) and a coolant return passage (45) that are in fluid communication and a coolant inlet (42) in fluid communication with the coolant supply passage (23) and a coolant outlet (24) in fluid communication with the coolant return passage (25).

15. A tearing apparatus for tearing pieces of meat analogue, comprising: a pair of rotatable rolls (2, 4) having parallel axes of rotation (10, 12) arranged at a preset distance (d) of each other, the distance (d) defining a width (w) of a roll nip (14) between the rolls (2, 4), each roll (2, 4) being coupled with a motor (6, 8) for rotating the rolls (2, 4) in a counter-rotating movement, a plurality of projections (16) being arranged on an outer surface of each roll (2, 4), the projections (16) being formed as cones, truncated cones, pyramids or truncated pyramids, the projections (16) being arranged in rows parallel to the axes of rotation (10, 12) and along circumferential lines, the rolls (2, 4) being positioned in an axial direction such that between each two adjacent circumferential lines of projections (16) of one roll (2), a circumferential line of projections (16) of the opposing roll (4) is positioned.

16. (canceled)

Description

[0066] The invention will be explained with reference to an embodiment and a drawing, where

[0067] FIG. 1 illustrates a process of the invention in general,

[0068] FIG. 2 shows a tearing unit according to the invention,

[0069] FIG. 3 to 5 show different views of rolls used in the tearing device of FIG. 2.

[0070] FIGS. 6a and 6b illustrate feeding test results for meat analogues prepared according to examples and comparative examples 5 to 8;

[0071] FIG. 7 shows a flow diagram of a process for the production of a meat analogue according to a special embodiment of the invention;

[0072] FIG. 8 shows a side view of a cooling unit of an apparatus according to a special embodiment of the present invention;

[0073] FIG. 9 shows a front view of the cooling unit of FIG. 8;

[0074] FIG. 10 shows a sectional view of the cooling unit of FIG. 8;

[0075] FIG. 11 shows a detail of the cooling unit of FIG. 8 at the left end of a cooling pipe contained in the cooling unit;

[0076] FIG. 12 shows a detail of the cooling pipe of the cooling unit of FIG. 8 further on the right side;

[0077] FIG. 13 shows a detail of the cooling unit of FIG. 8 at the right end of the cooling pipe;

[0078] FIG. 9 shows a perspective view of the cooling unit of FIG. 8;

[0079] FIG. 10 shows a detail of the cooling unit of FIG. 8 at the left end of a cooling pipe contained in the cooling unit;

[0080] FIG. 11 shows a detail of the cooling pipe of the embodiment shown in FIG. 8; and

[0081] FIG. 12 shows a detail of the cooling unit of FIG. 8 at the right end of the cooling pipe.

[0082] FIG. 1 shows a general overview of an embodiment of the process for producing a meat analogue according to the invention. In a mixing step, ingredients used for preparing the meat batter for a particular meat analogue, e.g. wheat gluten, (meat) emulsion and water, including various dry ingredients, are mixed. The material is conveyed and pressurised by pumping. A rotating lobe pump can be used in order to separate the mixing process from the high pressure heating process step. In the heating step, melting of proteins occurs. Pressure preferably is above 7 bar in order to avoid steam formation at temperatures up to about 160° C. to 170° C.

[0083] In another pumping step, the heated material is further conveyed and pressurised, i.g. above 8 bar, towards a cooling unit. In the cooling unit, the heat treated material texturizes and solidifies. The material is cooled down below 100° C. and is divided into pieces, e.g. by cutting.

[0084] In a final tearing step, the pieces or chunks of material are torn in a tearing unit in order to clearly display the inner (fibrous) texture, and to make the individual pieces less regular, i.e. so as not to have regular geometries of the pieces like cubes, cylindrical elements and so on.

[0085] FIG. 2 shows an exemplary embodiment of a tearing unit 1. A hopper 20 for introducing the pieces to be teared is shown folded away in order to show a pair of rotatable rolls 2, 4. A first roll 2 is driven to rotate clockwise by a first electric motor 6, and a second roll 4 is driven to rotate counter-clockwise by a second electric motor 8.

[0086] FIGS. 3 to 5 show further views and details of the pair of rolls 2, 4.

[0087] Axes of rotation 10, 12 of the rolls 2, 4 are parallel to each other and arranged at a distance d from each other which is adjustable by a mechanism not shown in detail. The distance d is at least 0.1 mm, 0.2 mm, 0.5 mm or 1 mm more than a minimum distance. The minimum distance is a distance where both rolls are in touch with each other i.e. cannot be moved further towards each other, and where the width w of a roll nip 14 is a minimum, in particular zero. Preferably, the distance d is 0.2 mm more than the minimum distance, leaving a gap or a width w of the roll nip 14 of 0.2 mm.

[0088] Both rolls 2, 4 are provided with a plurality of projections 16 arranged on an outer surface of the rolls. The projections 16 are each shaped as a pyramid having a square base area and four triangular sides converging in a pointed tip 18. The projections 16 are arranged in rows parallel to the axis of rotation, and along circumferential lines, i.e. circles, perpendicularly to the direction of the rows.

[0089] The arrangement of the rollers 2, 4 is such (FIG. 4) that each circumferential line or circle of projections 16 of one roll is positioned, in an axial direction, between two adjacent circumferential lines of projections of the opposing roll so that when rotating, a meshing or interlocking rotation of the projections occurs.

[0090] When used herein, the terms “roller” and “roll” are interchangable. The rollers can be controlled to rotate at equal or different speeds. Preferably the rollers rotate at different speeds. The ratio of the revolutions per minute of the rolls, can be at least 0.01, e.g. at least 0.03, 0.1, 0.5, 0.7, 0.8, 0.9, 0.95, 0.98 or 0.99 thereby leading to a combined effect of compression and tearing (creation of shear forces). The ratio of the revolutions per minute of the rolls, is suitably from about 1:1 to about 1:91; from about 1:1 to about 1:75; from about 1:1 to about 1:50; from about 1:1 to about 1:25; from about 1:1 to about 1:10; from about 1:1 to about 1:9; from about 1:1 to about 1:8; from about 1:1 to about 1:7; from about 1:1 to about 1:6; from about 1:1 to about 1:5; from about 1:1 to about 1:4; from about 1:1 to about 1:3; from about 1:1 to about 1:2; from about 1:1 to about 1:1.5. Suitable ratios are about 1:10; 1:20; 1:30; 1:40; 1:50; 1:60; 1:70; 1:80 and 1:90. Processes in which the rollers operate at different speeds is provided, preferably the rollers operate at the above ratios. Apparatus in which the rollers can be set to operate at different speeds is also provided, preferably the rollers can be set to operate at the above ratios.

[0091] FIG. 7 shows the flow diagram of a process for the production of a meat analogue according to a special embodiment of the invention. Said process comprises several steps in the order from left to right. The number and/the sequence of said steps can vary dependent on the tasks to be achieved. According to this special embodiment said process comprises mixing of recipe ingredients like powders and fluids. Thereafter the mixed recipe ingredients are conveyed and pressurized by pumping. Then by way of heating proteins are melted. By way of pumping the hot product melt is conveyed and pressurized. Thereafter the hot melt products cooled for texturization and solidification. Then the cooled-down heat-treated product is divided into pieces by cutting. The pieces are torn to provide or improve the visibility of the inner fibrous texture and to irregularize individual pieces.

[0092] FIGS. 8 to 11 show different views of a cooling unit of an apparatus for the production of a meat analogue according to a special embodiment of the invention. Said apparatus comprises a heating unit (not shown) operable to heat a meat better comprising protein for example by Ohmic heating, a cooling unit 30 located downstream the heating unit and operable to cool down heat-treated product obtained from the heating unit below water boiling temperature at ambient pressure when exiting the cooling unit 30, and a dividing unit (not shown) located downstream the cooling unit 30 suitable for dividing cooled down heat-treated product obtained from the cooling unit into pieces.

[0093] The cooling unit 30 comprises a frame 32 and a cooling pipe 34 that is supported by the frame 32. As shown in detail in FIG. 11, a feed hopper 36 is provided at the inlet end 38 of the cooling pipe 34. By way of process pumps (not shown) and the feed hopper 16 hot product melt is conveyed into the cooling pipe 34. As can be seen in FIGS. 11 and 12, the cooling pipe 34 is a double-wall pipe. By way of the two walls an annular cross-sectional area is provided for a coolant, for example water, for outer jacket cooling of the hot product melt. The hot product melt is also cooled in the centre by way of a cooling lance 40 that extends centrally in length direction of the cooling pipe 34. In the present embodiment the cooling lance 40 does not extend over the whole length of the cooling pipe 34. The cooling lance 40 (see also FIG. 13) is mounted co-centrically within the cooling pipe 34 by way of at least one mount or support 41. The cooling pipe 34 is segmented into several coolant segments with respective coolant inlets 50 and coolant outlets 52.

[0094] As can be seen in detail in FIG. 11, in an embodiment the cooling lance 40 is divided in length direction in two passages for coolant supply and coolant return. In FIG. 11 for example there is an upper coolant inlet 42 in fluid connection with the coolant supply passage 43 and a lower coolant outlet 44 in fluid connection with the coolant return passage 45. As can be seen in more detail in FIG. 12, there might by at least one temperature and/or pressure sensor 46 for measuring the temperature and/or the pressure of the hot product melt in the cooling pipe 34. Furthermore, as can be also seen in FIGS. 11 and 12, there is a helical-shaped guiding element 48 between the two walls of the cooling pipe 34 for guiding the coolant helically for improving the cooling by enlarging the jacket area involved in cooling. The coolant for the outer jacket cooling by way of the cooling pipe 34 and/or the coolant for the cooling lance can run in a respective coolant loop.

[0095] In the embodiment shown in FIGS. 8 to 12 the frame 32 is like the embodiment shown in the figures 7 to 13 also provided with wheels 34 for movement of the whole cooling unit 30, but the frame is divided into three subframes 36. As can be seen in particular in FIG. 11, the cooling pipe 34 is segmented into cooling pipe segments 35. Said cooling pipe segments 35 are held together by way of holding plates 38. As can be seen in particular in FIGS. 10 and 12, the cooling lance 40 is constructed in a different way than the cooling lance of the embodiment shown in FIGS. 7 to 13. In particular, the coolant supply passage 43 and the coolant return passage 45 are realised by way of a pipe-in-pipe assembly.

[0096] In a special embodiment, at 250 kg/h stream process pump feeds the cooling pipe. Preferably an even cooling gradient is maintained along the cooling pipe and capped constant across the cooling pipe to avoid preferential pressures and flows. This may be achieved by specifying the cooling parameters (cooling water flow and temperature per section) and a dedicated cooling pipe design. In a further special embodiment the process pump controls the system pressure of the heating unit by a control loop (PID) based on the pressure at the discharge of the heating process. Managing the pressure during cooling to avoid steam formation is important for product texture formation. Preferably the cooling pipe is designed to deliver enough cooling capacity to cool the product melt below product melting temperature and below 100° C. in a consistent condition to avoid preferential flow in the cooling pipe and further cool the product below designed outlet temperature to avoid product expansion which is impacting the chunk quality.

[0097] Due to the high cooling water amount it is recommended to re-use the cooling water (for example, in circulation with retorting water) and not to waste it. Preferably the cooling pipe is supplied with at least one cooling water loop for outer jacket cooling. Preferably the process pressure of the process pump(s) is above 7 bar and between 8 and max 40 bar. A minimum pressure is required to achieve the corresponding target temperature. Preferably the cooling pipe inlet pressure is lower than 40 bar. Principally it should be equal to or greater than the process pump set point the cooling pipe inlet pressure has impact on consistence of flow. Preferably the viscosity of the hot product melt at the inlet of the cooling pipe is 10 to 15 Pas (for example the viscosity of the melt is 12 Pas at 160° C.) and at the outlet of the cooling pipe the viscosity of the product is >50 Pas or >150 Pas or >1000 Pas or >5000 Pas or >100000 Pas at temperature <100° C. For example, at the outlet of the cooling pipe the material may be nearly solid. Preferably the velocity of the movement of the hot product melt is in a range of 2.95 m/sec to 3.25 m/sec and more preferably 3 m/sec. By way of an example the hot product melt at the inlet of the cooling pipe has a temperature in a range between 150° C. and 170° C., e.g. 157° C.

[0098] The cooling pipe suitably has an outer pipe diameter of about 40 to 70 mm, about 40 to 65 mm, about 40 to 60 mm, about 40 to 55 mm, about 40 to 50 mm, about 40 to 45 mm, about 45 to 70 mm, about 45 to 65 mm, about 45 to 60 mm, about 45 to 55 mm, about 45 to 50 mm, about 50 to 70 mm, about 50 to 65 mm, about 50 to 60 mm, about 50 to 55 mm. The cooling pipe suitably has an inner pipe diameter of less than about 100 mm, less than about 90 mm, less than about 80 mm or less than about 70 mm, e.g. suitably about about 60 mm, about 55 mm, about 55 mm, about 50 mm, about 45 mm, about 40 mm, about 35 mm or about 30 mm e.g. about 35 to 60 mm, about 35 to 55 mm, about 35 to 40 mm, about 40 to 60 mm, about 40 to 55 mm, about 40 to 50 mm, about 40 to 45 mm, about 44 to 60 mm, about 45 to 55 mm, about 45 to 50 mm, about 50 to 60 mm, about 50 to 55 mm.

[0099] The length of the cooling pipe is suitably about 2 to 10 m, about 3 to 9 m, about 4 to 8 m or about 5 to 7 m, e.g. about 3 m, about 4 m, about 5 m, about 6 m, about 7 m or about 8 m. The cooling lance diameter is suitably 10 to 30 mm, 10 to 25 mm, 10 to 20 mm, 15 to 30 mm, 25 to 25 mm 15 to 20 mm, e.g. about 15 mm, about 20 mm or about 25 mm. The length of the cooling lance in suitably about 2 to 4 m, about 2.5 to 4 m, about 3 to 4 m, about 3.5 to 4 m, about 2 to 3.5 m, about 2.5 to 3.5 m, about 3 to 3.5 m, about 3 to 4 m, about 3.5 to 4 m, e.g. about 2.5 m, about 2.6 m, about 2.7 m, about 2.8 m, about 2.9 m, about 3 m, about 3.1 m, about 3.2 m, about 3.3 m, about 3.4 m or about 3.5 m, preferably about 3.1 m.

[0100] The process (or melt) pumps, preferably lobe pumps, ensure delivering the higher pressures required for conveying the melt through the cooling pipe where it turns into a solid. Especially to manage starts after short line stops these pumps are essential.

REFERENCE INDICATORS

[0101] 1 tear unit

[0102] 2 first roll

[0103] 4 second roll

[0104] 6 first electric motor

[0105] 8 second electric motor

[0106] 10 axis of rotation (of 4)

[0107] 12 axis of rotation (of 4)

[0108] 14 roll nip

[0109] 16 projection

[0110] 18 tip

[0111] 20 hopper

[0112] 30 cooling unit

[0113] 32 frame

[0114] 34 cooling pipe

[0115] 35 cooling pipe segments

[0116] 36 feed hopper

[0117] 38 inlet end

[0118] 40 cooling lance

[0119] 41 mount/support

[0120] 42 coolant inlet

[0121] 43 coolant supply passage

[0122] 44 coolant outlet

[0123] 45 coolant return passage

[0124] 46 temperature/pressure sensor

[0125] 48 guiding element

[0126] 50 coolant inlet

[0127] 52 coolant outlet

[0128] 54 wheels

[0129] 56 subframes

[0130] 58 holding plates

[0131] d distance (between 10 and 12)

[0132] w width (of 14)

[0133] The invention is further illustrated by the following non-limiting examples:

Example 1: A Tearing Apparatus Having Rollers Arranged to Provide a Roller Nip of about 0.5 mm

[0134] A tearing apparatus was constructed with two rollers arranged as shown in FIGS. 3 to 5. The axes of rotation 10, 12 of the rolls 2, 4 being parallel to each other and adjustably arranged to touch each other and to provide a roll nip of about 0.5 mm. The rollers 2, 4 having a plurality of projections 16 arranged on an outer surface of each roller, shaped as a pyramid having a square base area and four triangular sides converging in a pointed tip 18. The projections 16 being arranged in rows parallel to the axis of rotation, and along circumferential lines, i.e. circles, perpendicularly to the direction of the rows. The rollers 2,4 were arranged as shown in FIG. 4 so that each circumferential line or circle of projections 16 of one roll was positioned, in an axial direction, between two adjacent circumferential lines of projections of the opposing roll so that when rotating, a meshing or interlocking rotation of the projections occurred. The rollers were set to rotate at different speeds. The ratio of the revolutions per minute of the rolls was set at about 1:60.

Example 2: A Process for Preparing Improved Meat Analogues Using the Tearing Apparatus of Example 1

[0135] The apparatus of Example 1 was used in the process shown in FIG. 1 to prepare meat analogues with improved visual appearance compared to analogues prepared by the same process using the hammermill. The appearance of the meat analogues produced was closer to the appearance of real meat chunks. Analogues having a less ‘synthetic’ appearance were produced. Moreover, the process produced material having fewer fines (very small pieces of meat analogue), which further enhanced the appearance of the product. The reduction in fines produced also improved the process by reducing the potential of the fines to interrupt the equipment. The process can therefore be performed more continuously than previously known processes and cleaning of the apparatus is more efficient.

Example 3: A Tearing Apparatus Having Rollers Arranged to Provide a Roller Nip of about 0.7 mm

[0136] A tearing apparatus as described in Example 1 was constructed having rollers arranged to provide a gap (roll nip) of about 0.7 mm.

Example 4: A Process for Preparing Improved Meat Analogues Using the Tearing Example 3

[0137] The process described in Example 2 was repeated using the apparatus of Example 3. Meat analogues were prepared having an appearance close to real meat and with even fewer fines. The product and the process were further improved over previously known processes using the hammer mill.

Example 5

[0138] Three parts of a batter containing 90.8% meat and animal derivatives substantially based on chicken, 4.7% water, and 4.5% of at least one of vitamins, minerals, palatants, colorants, etc. (all percentages are weight percentages based on the total weight of to slurry) as to achieve a nutritionally complete cat food finished product were mixed with one part vegetable protein powder containing min. 75% protein (vital wheat gluten) to form a single solid mixture containing 30.5% crude protein, 59% moisture and 4.5% fat (all percentages of the semi-solid mixture are based on the total weight of the semi-solid mixture).

Example 6

[0139] Three parts of a batter containing 90.8% meat and animal derivatives substantially based on tuna, 4.7% water, and 4.5% of at least one of vitamins, minerals, palatants, colorants, etc. (all percentages are weight percentages based on the total weight of the slurry) as to achieve a nutritionally complete cat food finished product were mixed with one part vegetable protein powder containing min. 75% protein (vital wheat gluten) to form a single solid mixture containing 30.5% crude protein, 59% moisture and 4.5% fat (all percentages of the semi-solid mixture are based on the total weight of the semi-solid mixture).

Example 7

[0140] The mixtures as obtained in Example 5 and Example 6 were each fed by means of a first positive displacement pump into an Ohmic heating unit. 5 modules with a maximum electrical power of 20 kW each have been used in this heating unit. In this Ohmic heating unit, the meat batter was transferred between electrodes having a diameter of 52 mm and a length of 105 mm to result in a surface area of 171.5 cm.sup.2. The average current density across the 5 modules was observed to be 650 A/m.sup.2. The pressure in the heating unit was 1,200 kPa. The outlet temperature of a material from this Ohmic heating unit was between 158-160° C. The material was then directed to a cooling area by a second positive displacement pump through which its temperature was brought down to below 80° C. The solid material obtained was cut to produce meat analogues/fish analogues with internal fibrosity.

Comparative Example 8

[0141] The mixtures of Examples 5 and were individually fed by means of a first positive displacement pump to a single heating unit comprising a single scraped surface heat exchanger (SSHE) with a volume of approximately 17 l and a surface to volume ratio of 60 m.sup.2/m.sup.3 under 1,200 kPa product pressure. The SSHE unit was continuously supplied with steam at a temperature between 166-168° C. and the shaft operated at 200 rpm-300 rpm. The outlet temperature of the material from this heating unit was between 158-160° C. The material was then directed to a cooling area by a second positive displacement pump through which its temperature was brought down to below 80° C. The solid material obtained was cut to produce meat analogues/fish analogues with internal fibrosity.

[0142] A feeding test, both for the chicken and the tuna recipe, and as prepared utilizing the Ohmic heating unit according to the invention and the scraped surface heat exchanger according to the prior art has been conducted, and the results are summarized in FIG. 6a (chicken recipe) and FIG. 6b (tuna recipe). In FIG. 6a, “OH” is the cat food prepared by Ohmic heating, while “SSHE” is the product prepared by SSHE. In FIG. 6b, “OH” is the cat food obtained by Ohmic heating, while “SSHE” is the cat food obtained by SSHE. As can be taken from both FIGS. 6a and 6b, almost parity between both recipes, either prepared by Ohmic heating or SSHE, is obtained.