Nozzle for extruding a protein- and water-rich material, and extrusion machine equipped with such a nozzle

Abstract

The nozzle (30) comprises a tubular outer casing (31) centered on an axis (XX), the outer casing being temperature-controlled. For a more compact and efficient design, the nozzle further comprises an inner element (32) coaxially disposed within the outer casing and mounted for rotation about the axis relative to the outer casing, the downstream portion of the inner element extending outside the outer casing and rotating about the axis in conjunction with a drive motor (35), a channel (33) having an annular cross section and centered about the axis being defined between the outer casing and the inner element. The channel has an upstream end (33A) and a downstream end (33B) between which material flows into the channel as it is forced through the nozzle, and moves through the channel from the upstream end to the downstream end as it is forced through the nozzle, thereby causing the material to exit the channel.

Description

[Technical Field]

[0001] The present invention relates to a nozzle for extruding protein- and water-rich materials. Furthermore, the present invention relates to an extrusion machine comprising such a nozzle. Furthermore, the present invention relates to a system for the continuous preparation of extruded food products. [Background technology]

[0002] The present invention is directed to an extrusion machine comprising an internal sleeve of the extruder, with one or more screws, in particular two screws, rotating relative to the extruder, the screws drawing the material to be extruded from an upstream portion of the sleeve to a downstream portion of the sleeve, where the material then flows through an extrusion nozzle provided for shaping, texturing and / or fiberizing the extruded material. Such an extrusion machine applies thermomechanical processing to the material, in the sense that the material is subjected to both essentially mechanical deformation through shear and pressure exerted by the screws, and essentially thermal deformation through temperature regulation along the sleeve.

[0003] More specifically, the present invention relates to the extrusion of protein- and water-rich materials and the associated food processing extrusion machine for continuously preparing textured food products from protein-rich raw materials. The raw material proteins may be of animal and / or plant origin in particular. In all cases, the proteins are mixed with a large proportion of water, and, where appropriate, fats and additives, and the corresponding mixture undergoes a thermomechanical treatment applied by the extrusion machine to heat and gel before being shaped in the nozzle. The texturing of the food product, also known as fiberization, essentially occurs in the nozzle of the extrusion machine, through which the material exiting the machine's sleeve is forced by the machine's screw. The method for preparing food products based on fiberized proteins (in French) is known under the name "CEMH", an acronym for the French expression "Cuisson-Extrusion en Milieu Humide" (Extrusion-cooking in a humid medium), and under the name "HME", an acronym for the English expression "High Moisture Extrusion".

[0004] WO 2003 / 007729 discloses an HME method and an associated extrusion machine in which a nozzle is designed to cool the flowing material in a controlled manner by forcing the material to flow through a channel having both a large length, typically several meters, and a rectangular cross-section, and a temperature profile is applied along the channel to gradually reduce the temperature of the material between the inlet and outlet of the channel. Material in contact with the cooled walls of the channel tends to adhere to the walls, thereby shearing the laminar flow of material within the channel. This shearing leads to the development of flow lines in the material paste, tending to align the modified polymers along the flow direction. In practice, the shear rate and flow pattern are due to the fixed geometry of the channel, and controlled fiberization requires long channels and therefore long processing times at the nozzle.

[0005] In a different field from the present invention, namely the field of plastic or rubber extrusion, French Patent Application Publication No. 2213846 and Japanese Patent Application Publication No. 2002-113764 disclose a "crosshead" nozzle comprising an outer casing with an internal component coaxially arranged therein, defining a flow channel for the extruded material. The internal component is rotated about a common axis from an upstream portion of the internal component, while on the downstream side, the material is formed into a tubular product and exits the nozzle. Similarly, International Publication No. 2020 / 144407 discloses a nozzle having an internal component coupled to rotate with the extruder rotor and defining, relative to a fixed outer annulus of the nozzle, a channel through which the extruded material flows before exiting the nozzle through a radial outlet of the outer annulus. As the material flows along a tortuous path in the different nozzles, which are not structurally suitable for passing the protein and water-rich material, the material gradually gels during its extrusion process with the appearance and development of long fibers. Summary of the Invention [Problem to be solved by the invention]

[0006] The aim of the present invention is to propose a new nozzle for the extrusion of protein and water-rich materials, which is less bulky and more effective with respect to fiberization of the product leaving the nozzle. [Means for solving the problem]

[0007] For this purpose, the subject of the invention is a nozzle as defined in claim 1.

[0008] A further subject of the invention is an extrusion machine as defined in claim 10.

[0009] A further object of the present invention is a system for the continuous preparation of extruded food products as defined in claim 12.

[0010] One of the concepts underlying the present invention is to design an extrusion nozzle that provides good heat exchange with the flowing material and can be used to adjust the shear rate applied to the material flow within the nozzle by allowing the shear rate to be adjusted as a nozzle control parameter. To this end, the nozzle defines a channel through which the material flows. The channel has an annular cross section and is defined by the coaxial arrangement of a tubular outer casing and an internal component. The outer casing is temperature-controlled so that the inner surface of the outer casing, against which the material flows in the channel, can be made cooler than the temperature of the material, meaning that the material tends to adhere to the inner surface of the outer casing. Due to the extended cylindrical contact surface between the material and the inner surface of the outer casing, there is a considerable amount of heat exchange between the outer casing and the material flowing through the channel. At the same time, the internal component is rotatably mounted around the central axis of the nozzle. By rotating the internal component relative to the outer casing, the material flowing through the channel tends to wrap around the outer surface of the internal component. The material flowing through the channel is thus intensely sheared between the cooled inner surface of the outer casing and the rotating outer surface of the inner component, at a shear rate that can be adjusted by varying the speed and / or direction of rotation of the inner component and / or by adjusting the temperature regulation of the outer casing. The nozzle according to the invention can therefore be used to obtain and finely control the fiberization of the material flowing in the channel, and thus of the product exiting the nozzle, i.e., the extruded food product continuously prepared by the system according to the invention, while the nozzle is compact, i.e., takes up little space in the direction of its central axis.

[0011] Further advantageous features of the invention are specified in the other claims.

[0012] The invention will be better understood on reading the following detailed description, given purely by way of example and made with reference to the drawings in which: [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view of an extrusion machine according to the present invention; [Figure 2] 2 is a view similar to FIG. 1 showing a portion of the extrusion machine shown in FIG. 1 equipped with a nozzle according to the invention; [Figure 3] 2 is a partial schematic longitudinal section of the extrusion machine shown in FIG. 1, taken in plane III of FIG. 1; [Figure 4] 4 is a cross section taken along line IV-IV shown in FIG. 3. [Figure 5] 4 is a cross section taken along line VV shown in FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0014] 1 to 5 show a schematic diagram of an extrusion machine 1. FIG.

[0015] The extrusion machine 1 is designed for food processing extrusion by continuously extruding food products intended for human and / or animal consumption from raw materials rich in protein and water.

[0016] More specifically, the extrusion machine 1 is designed for extruding protein- and water-rich materials by continuously preparing textured food products, in other words fiber products. More precisely, the raw materials, i.e. all ingredients processed by the extrusion machine 1 to form the food product, and the extruded material, i.e. the material obtained at the outlet of the extrusion machine 1, contain mainly water and protein and, to a small or trace extent, dietary fiber and / or starch, and possibly fats and additives.

[0017] The extruded material thus contains 25-90 wt%, preferably 50-85 wt%, of water and further contains 20-90 wt% of protein based on the total dry material. The protein is of plant and / or animal origin and / or at least one other source. Vegetable proteins are derived, for example, from legumes, cereals and / or protein crops (soybeans, wheat, peas, corn, chickpeas, lentils, etc.). Proteins of animal origin are derived, for example, from fish, meat, milk and / or eggs. One or more other sources of protein are, for example, mushrooms, algae, insects, cultured meat, etc.

[0018] The extruded material further comprises 0-50 wt% dietary fiber and 0-50 wt% starch, based on the total dry matter, the total dietary fiber and / or starch being greater than 0.01%. The dietary fiber may be, for example, a fiber of plant origin, and the starch may be, for example, of plant origin, originally in a pre-gelatinized or modified state.

[0019] The extruded material may further comprise 0-20% fat, especially fat of vegetable and / or animal origin, and / or functional ingredients such as lecithin, caseinate or other ingredients.

[0020] The extrusion machine 1 comprises a sleeve 10 having an elongated shape, which extends along and is centred on a geometric axis XX. Inside the sleeve 10, two screws 20 are received in complementary longitudinal cavities of the sleeve, which extend parallel to and are centred on the axis X--X. In practice, in a manner known per se, each screw comprises, for example, a central screw shaft 21 to which a set of screw elements 22 is attached. As can be clearly seen in FIG. 2, in which the screws 20 are omitted, the screws extend on both sides of the axis X--X and therefore penetrate into cavities of the sleeve which have a two-lobed lateral profile.

[0021] The screw 20 is designed to be rotated about its central axis by a drive unit, not shown, which is engaged with the upstream end of the screw, i.e., the right-hand end in FIG. 1, and extends outside the sleeve 10.

[0022] The screws 20, due to their threaded profile, are designed to transport raw material inside the sleeve 10 along the axis X--X inside the central longitudinal cavity of the sleeve 10 from the upstream part of the sleeve 10 where the material components are introduced to the downstream end of the sleeve 10, the terms "upstream" and "downstream" being oriented along the direction of advance of the material inside the sleeve under the action of the screws 20, the direction of advance being from right to left in Figures 1 to 4.

[0023] The sleeve 10 comprises a plurality of modular elements 11 successively arranged along an axis X--X, each of which defines a corresponding portion of a central longitudinal cavity of the sleeve 10 therein, the portions of which are aligned with one another along the axis X--X in the assembled state of the elements 11, as shown. In practice, the elements 11 are assembled in pairs by means of a fixing collar 12.

[0024] In the example of embodiment considered in the figures, the most upstream of the elements 11 can be used to insert ingredients of the raw material inside its central hollow portion. For this purpose, in a manner known per se and not shown in detail here, the most upstream of the elements 11 is provided with a through-hole 11A opening out transversely to the axis XX and outside its central hollow portion. More generally, it is understood that one or more of the different elements 11 of the sleeve 10 make it possible to insert, inside the central longitudinal cavity of the sleeve 10, solid and / or liquid ingredients of the material to be extruded by the extrusion machine 1.

[0025] As described in the introductory section of this document, the screw 20 is designed to shear and compress the material being extruded, in addition to moving along it, to deform the material in an essentially mechanical manner. Because these aspects of the extrusion machine 1 are well known in the art, they will not be discussed further herein. Similarly, as described in the introductory section, the sleeve 10 is designed to regulate the temperature of the material being extruded along the sleeve, to deform the material in an essentially thermal manner. To this end, all or some of the elements 11 of the sleeve 10 may be temperature regulated, allow for the injection of fluid into the sleeve, and / or allow for the degassing of the material being extruded into the sleeve. Here again, such aspects of the extrusion machine 1 are well known in the art and will not be discussed further herein. More generally, the sleeve 10 and the screw 20 are designed to apply a thermomechanical treatment to the raw material as it progresses from the upstream end of the sleeve to the downstream end of the sleeve.

[0026] At its downstream end, the sleeve 10 comprises an end plate 13, commonly referred to in the art as a "front plate." The end plate 13 is directly attached to the downstream end of the most downstream of the elements 11 of the sleeve 10 in a fixed manner, for example by a fixing collar 14. As can be clearly seen in FIGS. 3 and 4, the end plate 13 defines therein a through-hole 15, extending along the axial continuation of the central cavity and centered on the axis X--X, the portion of the most downstream of the elements 11, which receives the downstream end of the screw 20. The cavity 15 is suitable for conveying the material pushed downstream by the screw 20 to provide an appropriate filling rate and pressurization of the central longitudinal cavity of the sleeve 10. For this purpose, the cavity 15 may, for example, be at least partially blocked downstream and provided with a transverse grid 16. Since such aspects of the extrusion machine 1 do not limit the scope of the present invention, they will not be described further below.

[0027] The extrusion machine 1 further comprises a nozzle 30, which, in the assembled state of the extrusion machine 1, is arranged at the downstream end of the sleeve 10. The nozzle 30 is designed to pass the material processed by the extrusion machine 1 for the purpose of extruding the material. Thereby, in the assembled state of the extrusion machine 1, the material exiting the sleeve 10 is forced to flow through the nozzle 30 under the action of the screw 20.

[0028] As can be clearly seen in Figures 3 to 5, the nozzle 30 mainly comprises an outer casing 31 and an internal component 32. The outer casing 31 is tubular and has a geometric axis that coincides with the axis XX in the assembled state of the extrusion machine 1 and is therefore referred to hereinafter as the axis XX. The internal component 32 has an elongated shape and a geometric axis that coincides with the axis XX in the assembled state of the extrusion machine 1 and is therefore referred to hereinafter as the axis XX. The internal component 32 is coaxially arranged inside the outer casing 31, and a channel 33 is defined radially between the outer casing 31 and the internal component 32 in a transverse cross section, i.e., a cross section cut perpendicular to the axis XX. The channel 33 is annular and is centered on the axis XX. The channel 33 therefore extends along the axis XX from an upstream end 33A of the channel 33, which is bent toward the sleeve 10, to a downstream end 33B of the channel facing the sleeve 10. 5, the channel 33 extends continuously around the axis XX, i.e., over 360 degrees. In operation, material coming from the sleeve 10 and passing through the nozzle 30 flows into the channel 33 and progresses therethrough from the upstream end 33A to the downstream end 33B.

[0029] Due to its tubular shape, the outer casing 31 has an inner side 31A, i.e., a surface curved towards the axis XX, which defines the channel 33 and forms the outer surface of the channel 33 from its upstream end 33A to its downstream end 33B. The internal component 32 has an outer side 32A, i.e., a surface curved away from the axis XX, which defines the channel 33 and forms the inner surface of the channel 33 from its upstream end 33A to its downstream end 33B. In the example embodiment considered in the figures, the inner side 31A of the outer casing and the outer side 32A of the internal component 32 are each cylindrical with a circumferential base centered on the axis XX, as a result of which the annular cross section of the channel 33 is constant from its upstream end 33A to its downstream end 33B.

[0030] The outer casing 31 will now be described in more detail, before the internal components 32 are shown in detail hereinafter.

[0031] The outer casing 31 is thermoregulated, i.e. designed to control the temperature of the outer casing 31 and maintain it at a predetermined value, at least locally, and advantageously adjustable regardless of heat exchange between the outer casing 31 and the immediate environment of the outer casing 31. In particular, the outer casing 31 is therefore designed to influence the temperature in the channels 33, and more precisely in the material flowing through the channels 33, by heat exchange between that material and the outer casing 31 via the inner surface 31A of the outer casing 31.

[0032] For temperature regulation purposes, in the example embodiment considered in Figures 1 to 5, the outer casing 31 comprises two conduits 31.1 and 31.2 for circulating a temperature regulation fluid, e.g., water, under pressure. Each conduit 31.1, 31.2 has an annular shape centered on the axis XX, surrounds a channel 33, and is separated from the channel 33 by a heat-conducting wall of the outer casing 31, which supports an inner surface 31A. The conduits 31.1 and 31.2 are separate from each other and are parallel to each other along the axis XX: conduit 31.1 surrounds the upstream part of the channel 33, extending from the upstream end 33A to the level of the mid-axis of the channel, while conduit 31.2 surrounds the downstream part of the channel 33, extending from the aforementioned mid-axis level to the downstream end 33B of the channel. In practice, as shown in the figure, the conduits 31.1 and 31.2 are each integrated into a separate module of the outer casing 31 and are arranged side by side and parallel to one another along the axis XX. During operation, each of the conduits 31.1 and 31.2 is supplied with a temperature-conditioning fluid which flows generally along the direction of the axis XX to apply a temperature profile along the portion of the channel 33 surrounded by the corresponding conduit and, in particular, to cool the material flowing through the channel 33 as it progresses along the channel. Naturally, the nozzle 30 comprises, for each of the conduits 31.1 and 31.2, a temperature-conditioning fluid inlet for feeding the conduit from outside the outer casing 31 and a temperature-conditioning fluid outlet for discharging the temperature-conditioning fluid to the outside of the outer casing, the inlets and outlets for the temperature-conditioning fluid from the respective conduits not being shown. Insofar as conduits 31.1 and 31.2 are separate, the conduits can advantageously apply respective temperature profiles that differ from one another, for example if the material flowing through channel 33 is cooled more by heat exchange with the temperature-regulating fluid flowing through conduit 31.1 than by heat exchange with the temperature-regulating fluid flowing through conduit 31.2, or vice versa.

[0033] Of course, the embodiment described here in relation to conduits 31.1 and 31.2 is merely one possible embodiment of a temperature adjustment means for casing 31 that is more generally suitable for applying a temperature profile along channel 33 from upstream end 33A to downstream end 33B, and in particular for cooling material flowing through the channel as it progresses through the channel.

[0034] Furthermore, the outer casing 31 is designed to be fixedly connected to the sleeve 10, in the sense that in the assembled state of the extrusion machine 1, the sleeve 10 and the outer casing 31 are connected in a fixed manner. In practice, the outer casing 31, in particular the upstream part of the outer casing 31, is for such purpose rigidly attached, either directly or indirectly, to the downstream part of the sleeve 10, in particular to the end plate 13 of the sleeve 10.

[0035] Thus, according to a possible embodiment implemented in the example considered in the figures, the end plate 13 is extended towards its downstream end by a divergent nozzle 17 which provides a fixed connection between the outer casing 31 and the end plate 13. The outer casing 31 is, for example, rigidly mechanically attached to the divergent nozzle 17 by any suitable means, in particular the divergent nozzle 17 being attached to the interior of the outer casing 31 at its upstream end, while the divergent nozzle 17 is axially continuous with the end plate 13 and is pressed against it directly and held in a fixed manner relative to the end plate 13 by a fixing collar 18.

[0036] Regardless of the particular divergent nozzle 17, the divergent nozzle 17 provides a fixed connection between the nozzle 30 and the sleeve 10, and advantageously, the divergent nozzle 17 defines a distribution chamber 17A for material flowing to the junction between the sleeve 10 and the nozzle 30. In the assembled state of the extrusion machine 1, the distribution chamber 17A connects the downstream end of the cavity 15 in the end plate 13 to the upstream end 33A of the channel 33. The distribution chamber 17A therefore directs material exiting the end plate 13 to the upstream end 33A of the channel 33 about the axis XX. For material entering the upstream end 33A of the channel 33 to be distributed over the entire extent of the upstream end 33A about the axis XX, the distribution chamber 17A is shaped to distribute the material to the upstream end 33A of the channel 33 about the axis XX. For this purpose, in the example shown, the distribution chamber 17A is provided with a frustoconical surface 17B, which is centered on the axis XX, widens downstream and connects the upstream end of the distribution chamber 17A to the inner surface 31A of the outer casing 31.

[0037] Unlike the outer casing 31, the internal component 32 is not intended to be fixed relative to the sleeve 10, but is mounted in the nozzle 30 such that the internal component 32 is rotatable about the axis XX relative to the outer casing 31, and is intended to rotate about the axis XX, whereby the outer surface 32A of the internal component 32 rotates about itself, about the axis XX.

[0038] According to the advantageous embodiment embodied in the figures, the internal component 32 comprises two separate parts 32.1 and 32.2 defining respective portions of the channel 33, the two separate parts 32.1 and 32.2 being contiguous with each other along the axis XX. Thereby, the part 32.1 defines the upstream part of the channel 33 and supports a corresponding part of the outer surface 32A of the internal component 32, while the part 32.2 defines the downstream part of the channel 33 immediately adjacent to the aforementioned upstream part of the channel and supports the remainder of the outer surface 32A. Each of the parts 32.1 and 32.2 can rotate independently of the other part, that is, the parts 32.1 and 32.2 can rotate about the axis XX at respective speeds different from each other and / or in respective directions opposite to each other.

[0039] In the example of embodiment considered in the figures, portion 32.1 comprises both a central shaft 32.3, centered on axis XX, with its upstream portion located inside the outer casing 31, while its downstream portion is located outside the outer casing 31, and a staging portion 32.4, rigidly attached to the upstream portion of the central shaft 32.3 and located inside the outer casing 31. The staging portion 32.4 supports a corresponding portion of the outer surface 32A of the internal component 32, thereby defining the aforementioned upstream portion of the channel 33. Portion 32.2 comprises both a tubular shaft 32.5, centered on axis XX, with an upstream portion of the tubular shaft 32.5 located inside the outer casing 31, while a downstream portion of the tubular shaft 32.5 is located outside the outer casing 31, and a staging portion 32.6, located inside the outer casing 31 and rigidly attached to the upstream portion of the tubular shaft 32.5. The staging portion 32.6 supports a corresponding portion of the outer surface 32A of the inner component 32, thereby defining the aforementioned downstream portion of the channel 33. The central shaft 32.3 extends inside the tubular shaft 32.5 at a radially intermediate position of one or more journal bearings 32.7 between the shafts 32.3 and 32.5, in particular between the respective upstream portions of the shafts 32.3 and 32.5 and between the respective downstream portions of the shafts 32.3 and 32.5. The staging portions 32.4 and 32.6 are immediately adjacent to one another along the axis XX, with an axially intermediate position separating the interface between the staging portions, if applicable, not shown.

[0040] Regardless of the embodiment of the internal component 32, the nozzle 30 advantageously comprises a motorization 35, in particular an electric motor, suitable for rotating the internal component 32 about the axis XX. The invention is not limited to a specific technical motorization 35. In the example embodiment considered in the figures, the motorization 35 comprises two motors 35.1 and 35.2, respectively specific to the sections 32.1 and 32.2 of the internal component 32. Thereby, the motor 35.1 is designed to rotate the section 32.1 about the axis XX. For this purpose, the output of the motor 35.1 is coupled, for example, to the downstream section of the central shaft 32.3. The motor 35.2 is designed to rotate the section 32.2 about the axis XX. The output of the motor 35.2 is coupled, for example, to the downstream section of the tubular shaft 32.5.

[0041] According to a possible arrangement shown in the figures, the upstream end of the internal component 32 is at least partially disposed in the divergent nozzle 17 and defines a distribution chamber 17A together with the divergent nozzle 17. In the example assumed in the figures, the upstream end of the internal component 32 is formed by a staging portion 32.4 of the portion 32.1 of the internal component 32 and has a conical surface 32.4A centered on the axis XX and flaring downstream. The conical surface 32.4A is disposed within the frustoconical surface 17B of the divergent nozzle 17 so as to match and define the distribution chamber 17A between the surfaces 32.4A and 17B.

[0042] According to another possible arrangement, which is also implemented in the embodiment considered in the figures, the nozzle 30 comprises an outlet deflector 36 that is fixedly connected to the internal component 32. The outlet deflector 36, together with the internal component 32, is thereby rotatable about the axis XX relative to the outer casing 31. The invention is not limited to embodiments in which there is a fixed connection between the outlet deflector 36 and the internal component 32. In the embodiment considered in the figures, the outlet deflector 36 is integrated into the staging portion 32.6 of the portion 32.2 of the internal component 32.

[0043] The outlet deflector 36 is arranged at the downstream end 33B of the channel 33 so as to exert a counterpressure on the flow of material exiting the channel 33. In practice, along the axis XX, the deflector 36 may either be exactly at the same position as the downstream end 33B of the channel 33, or slightly offset downstream of the downstream end 33B, as in the example envisaged in the figures. In all cases, the outlet deflector 36 is designed to physically interfere with the material exiting the channel 33 via the downstream end 33B of the channel 33, along the direction of the axis XX. In other words, the outlet deflector 36 creates an axial resistance to the flow of material exiting the channel 33. According to a practical embodiment implemented in the example considered in the figures, the outlet deflector 36 is provided with a substantially frustoconical surface 36A centered on the axis XX and widening downstream, towards which the material exiting the channel 33 flows.

[0044] The operation of the extrusion machine 1 will now be described.

[0045] The raw material components to be extruded are introduced into the sleeve 10 through at least one of its elements 11 and then carried downstream by the screw 20 while being deformed under the effect of the thermomechanical treatment applied by the sleeve and the screw. The material exiting the most downstream of the elements 11 of the sleeve 10 is pushed successively through the end plate 13, the divergent nozzle 17, and the nozzle 30. After passing through the distribution chamber 17A, the material enters the nozzle 30 and is advantageously distributed around the axis XX by the divergent nozzle 17. Inside the nozzle 30, the material flows through the channel 33 from its upstream end 33A to its downstream end 33B. The material leaves the nozzle 30 by escaping from the downstream end 33B of the channel 33, advantageously after being received by counterpressure under the effect of the outlet deflector 36.

[0046] As the material flows along the channel 33, it is sheared by two distinct shear components: a first shear component caused by adhesion of the material to the inner surface 31A of the outer casing 31 due to cooling applied by the outer casing 31 to the material passing through the inner surface 31A, and a second shear component caused by bending of the material around the outer surface 32A of the inner component 32 due to rotation of the inner component 32 about axis XX by motorization 35. This results in substantial fiberization of the material flowing through the channel 33, fiberization occurring under the dual effects of cooling of the material, controlled by temperature regulation of the outer casing 31, and bending of the material flow caused by the rotation of the inner component 32. This results in the material exiting the downstream end of the channel 33 exhibiting qualitative and quantitative texturing, even if, due to the limited axial dimension of the channel 33, the processing time of the material in the nozzle 30 is shorter, especially compared to conventional nozzles used to obtain similar texturing. Thus, the extrusion machine 1 can be used to continuously prepare food products of different fiber structures from raw materials and from extruded material rich in protein and water.

[0047] By manipulating the respective speed and / or direction of rotation of portions 32.1 and 32.2 of internal component 32 and / or by manipulating the respective temperature profiles applied by conduits 31.1 and 31.2 of outer casing 31, it is possible to vary the shear rate applied to the material flowing through channel 33, and thus the fiberization characteristics. Thereby, by controlling the temperature regulation provided by outer casing 31 and / or the rotation of internal component 32, nozzle 30 can be controlled in a controlled and reproducible manner, in the sense that the nozzle can be used to obtain food products with different textures.

[0048] Furthermore, various adjustments and modifications of the above-described extrusion machine 1 are possible, examples of which include: The internal component 32 may be provided with a tool for shredding the material exiting the nozzle 30 in the downstream part of the internal component 32 extending outside the outer casing 31; the nozzle 30 envisaged in the figures is provided with such a cutting tool, which is numbered 37 and which only acts on the material exiting the channel 33 using the rotation of the internal component 32, although the specific embodiment is not limited thereto; and / or A reversible mechanical coupling means may be provided between the downstream part of the internal component 32, which extends outside the outer casing 31 and is associated with the motorization 35, and the remainder of the internal component 32; in this way, the downstream part of the internal component 32 may be temporarily removed from the remainder of the nozzle 30, for example for the purposes of cleaning or maintenance of the nozzle. The following embodiments can be given as examples of the present invention. (Appendix 1) A nozzle (30) for extruding the protein and water rich material, a tubular, temperature-controlled outer casing (31) centered on an axis (XX); an internal component (32) coaxially disposed within the outer casing (31) and mounted to rotate relative to the outer casing (31) about the axis (XX); Equipped with a downstream portion of said internal component extending outside said outer casing (31) and associated with a motorization (35) suitable for rotating said internal component about said axis (XX); and a channel (33) is defined between the outer casing and the internal component, the channel (33) having an annular cross section centered on the axis (XX), the channel having an upstream end (33A) and a downstream end (33B), the upstream end (33A) and the downstream end (33B) being axially opposite one another, the material flowing into the channel between the upstream end (33A) and the downstream end (33B), the material progressing through the channel from the upstream end to the downstream end as the material is forced through the nozzle, and through which the material exits the channel in an axial direction; nozzle. (Appendix 2) 2. The nozzle of claim 1, wherein the outer casing (31) is provided with temperature adjustment means (31.1, 31.2) suitable for applying a temperature profile along the channel (33) between the upstream end (33A) and the downstream end (33B). (Appendix 3) 3. The nozzle of claim 2, wherein the temperature profile applied by the temperature adjustment means (31.1, 31.2) is for cooling the material flowing through the channel (33) as it progresses through the channel. (Appendix 4) 4. The nozzle according to claim 2 or 3, wherein the temperature regulation means (31.1, 31.2) are integrated into two separate modules, arranged side by side and parallel to each other along the axis (XX). (Appendix 5) 5. The nozzle according to any one of claims 1 to 4, wherein the internal component (32) comprises at least two separate parts (32.1, 32.2) defining respective portions of the channel (33), the at least two separate parts (32.1, 32.2) being contiguous with one another along the axis (XX) and rotatable about the axis independently of one another. (Appendix 6) 6. The nozzle according to claim 5, wherein the motorization (35) comprises a plurality of motors (35.1, 35.2) corresponding to respective portions (32.1, 32.2) of the internal component (32). (Appendix 7) 7. The nozzle of any one of claims 1 to 6, wherein the nozzle (30) comprises an outlet deflector (36), the outlet deflector (36) being connected in a fixed manner to at least one portion (32.2) of the internal component (32) and being positioned at the downstream end (33B) of the channel (33) so as to exert a counter pressure against the flow of the material exiting the channel (33). (Appendix 8) 8. The nozzle of any one of claims 1 to 7, wherein the internal component (32) comprises a cutting tool (37) arranged outside the outer casing (31) to act on the material exiting the channel (33). (Appendix 9) 9. The nozzle according to any one of appendixes 1 to 8, wherein the cross section of the channel (33) is constant between the upstream end (33A) and the downstream end (33B) of the channel. (Appendix 10) a sleeve (10) within which at least one screw (20) is actuated to apply a thermomechanical treatment to the protein and water rich material; A nozzle (30) according to any one of claims 1 to 9, wherein the outer casing (31) is fixedly connected to the sleeve (10) such that the material leaving the sleeve (10) is forced by the at least one screw through the nozzle. An extrusion machine (1). (Appendix 11) an end plate (13) attached directly to the downstream end of said sleeve (10) in a fixed manner and defining therein a through cavity (15), said through cavity (15) being centered on said axis (XX) and carrying said material pushed by said at least one screw (20); a divergent nozzle (17), the divergent nozzle (17) fixedly connecting the end plate (13) and the outer casing (31) and defining a distribution chamber (17A) connecting the through cavity (15) of the end plate and the upstream end (33A) of the channel (33), the distribution chamber shaped to distribute the material into the upstream end of the channel about the axis (XX); 11. The extrusion machine (1) of claim 10, further comprising: (Appendix 12) an extrusion machine according to appendix 10 or 11; A raw material that is rich in protein and water and is subjected to a thermomechanical treatment after being inserted into the sleeve (10); 1. A system for the continuous preparation of extruded food products, comprising:

Claims

1. A sleeve (10), At least one screw (20) that is actuated to apply a thermomechanical treatment to the protein and water rich material inside the sleeve (10); a nozzle (30) for extruding said protein and water rich material, An outer casing (31), It is tubular with the axis (X-X) as its center, Temperature-controlled, and a nozzle (30) connected in a fixed manner to the sleeve (10) such that the material exiting the sleeve (10) is forced by the at least one screw (20) through the nozzle (30); outer casing (31), An internal component (32) comprising: the internal component (32) is coaxially disposed within the outer casing (31) and is mounted to rotate relative to the outer casing (31) about the axis (X-X); A channel (33) is defined between the outer casing (31) and the inner component (32); the channel (33) has an annular cross section centered on the axis (X-X), The channel (33) has an upstream end (33A) bent toward the sleeve (10) and a downstream end (33B) facing away from the sleeve (10), the upstream end (33A) and the downstream end (33B) are axially opposed to each other, and the material flows into the channel between the upstream end (33A) and the downstream end (33B); As the material is forced through the nozzle (30), the material exits the sleeve (10) and travels through the channel (33) from the upstream end (33A) to the downstream end (33B) through which it exits the channel (33) in an axial direction; the internal component (32) comprises a downstream portion extending outside the outer casing (31); an internal component (32); and Motorization (35), the downstream portion of the internal component (32) is associated with the motorization (35); said motorisation (35) being adapted to rotate said internal component (32) about said axis (X-X); Motorization (35) a nozzle (30) comprising: An extrusion machine (1) comprising:

2. 2. An extrusion machine (1) according to claim 1, wherein the outer casing (31) is provided with temperature regulating means (31.1, 31.2) suitable for applying a temperature profile along the channel (33) between the upstream end (33A) and the downstream end (33B).

3. 3. An extrusion machine (1) according to claim 2, wherein the temperature profile applied by the temperature regulating means (31.1, 31.2) is for cooling the material flowing through the channel (33) as it progresses through the channel.

4. 4. Extrusion machine (1) according to claim 2 or 3, wherein the temperature regulation means (31.1, 31.2) are integrated into two separate modules of the outer casing (31), arranged side by side and parallel to each other along the axis (X-X).

5. 5. The extrusion machine (1) according to any one of claims 1 to 4, wherein the internal component (32) comprises at least two separate parts (32.1, 32.2) defining respective portions of the channel (33), the at least two separate parts (32.1, 32.2) being contiguous with one another along the axis (X-X) and rotatable about the axis (X-X) independently of one another.

6. 6. Extrusion machine (1) according to claim 5, wherein the motorization (35) comprises a plurality of motors (35.1, 35.2) corresponding to respective portions (32.1, 32.2) of the internal component (32).

7. 7. The extrusion machine (1) according to any one of claims 1 to 6, wherein the nozzle (30) comprises an outlet deflector (36), the outlet deflector (36) being connected in a fixed manner to at least one part (32.2) of the internal component (32) and being arranged at the downstream end (33B) of the channel (33) so as to exert a counter pressure on the flow of the material exiting the channel (33).

8. 8. The extrusion machine (1) according to any one of claims 1 to 7, wherein the internal component (32) comprises a cutting tool (37) arranged outside the outer casing (31) so as to act on the material exiting the channel (33).

9. An extrusion machine (1) according to any one of the preceding claims, wherein the cross section of the channel (33) is constant between the upstream end (33A) and the downstream end (33B) of the channel (33).

10. An extrusion machine (1) as described in any one of claims 1 to 9, wherein the internal component (32) has an outer surface (31A) configured such that, by rotating the internal component (32) relative to the outer casing (31), the material flowing through the channel (33) surrounds the outer surface (31A).

11. an end plate (13) attached directly to the downstream end (33B) of the sleeve (10) in a fixed manner and defining therein a through cavity (15), the through cavity (15) being centered on the axis (X-X) and carrying the material pushed by the at least one screw (20); a divergent nozzle (17), the divergent nozzle (17) fixedly connecting the end plate (13) and the outer casing (31) and defining a distribution chamber (17A) connecting the through cavity (15) of the end plate (13) and the upstream end (33A) of the channel (33), the distribution chamber (17A) being shaped to distribute the material into the upstream end (33A) of the channel (33) about the axis (X-X); An extrusion machine (1) according to any one of claims 1 to 10, further comprising:

12. An extrusion machine (1) according to any one of claims 1 to 11, a raw material that is rich in protein and water and that is subjected to a thermomechanical treatment after being inserted into the sleeve (10); 1. A system for the continuous preparation of extruded food products, comprising:

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