DE102023115260A1 - EXTRUDER ARRANGEMENT AND METHOD FOR PRODUCING A TEXTURATE - Google Patents

Abstract

The invention relates to an extruder arrangement, having a mixing extruder with an inlet zone for supplying a base mixture which contains at least one protein mixture and water, a mixing zone and an ejection zone; wherein the mixing extruder is designed to produce a multiphase gel from the base mixture across several zones with a temperature increase up to a maximum temperature between 110°C and 160°C. Downstream of this is an ejection nozzle which is designed to treat the multiphase gel thermomechanically during the advance of the multiphase gel to form a viscoelastic multiphase and in particular cohesive gel, and a roller arrangement whose gap is at least partially smaller than a thickness of the ejection nozzle which is designed to exert a pressure on the viscoelastic multiphase gel perpendicular to an advance direction.

Description

The present invention relates to an extruder arrangement and a method for producing a textured product.

BACKGROUND

Plant proteins in the form of isolates or concentrates are now used for a variety of meat substitute products. This is due on the one hand to an increased demand for a vegetarian or vegan diet and on the other hand to consumer desire for sustainable and resource-saving agriculture.

One of the advantages of vegan food products made from plant proteins is that they can be produced from domestically or locally produced raw materials. Pulses in particular, but also other plant-based substances, have the advantage over soy or others that they can be grown in a more resource-efficient way. In contrast, there is a growing demand for various plant-based food products.

Traditionally, vegetable protein-based products are produced by dry or wet extrusion. Dry extrusion is carried out at high temperatures T > 130°C and a moisture content < 30%. A short, narrow die without cooling is used for extrusion. This allows the production of directly expanded products, so-called TVP (textured vegetable proteins). In dry form, they are rather irregular, porous and glassy and, after being rehydrated, are further processed into the final products. The final product has a sponge-like structure without significant anisotropy with either no or very short fibers. They bear little resemblance to the sensory properties of meat analogues and are often used in mixed products (e.g. burger patties, etc.) rather than for whole products.

Moisture-embedded meat extrusion (HME) is the current technology used by the industry to produce fibrous plant-protein-based products. The resulting products often provide a satisfactory base, as they have an anisotropic, meat-like structure, texture and appearance. Such products are manufactured using various technologies.

In such a wet extrusion, the mass is pressed after kneading through an elongated cooling slot die or an extended cooling couette die. In both cases, the protein-based matrix is extruded at relatively high temperatures (T > 130°C) and high water contents (>50%) in the screw section of the extruder and then forced to flow through a subsequent cooling die in which the material is continuously cooled (typically to below <100 °C at the die outlet) in order to avoid expansion, which could destroy the fibrous structures produced in the die section.

Although this method can be applied to a variety of plant-based raw materials to produce fibrous protein-based products that acceptably resemble meat products in appearance and, to some extent, in taste, they lack either long fiber structures or the desired tenderness, both of which are necessary to successfully replicate the properties of cooked meat.

It has been shown that the resulting products have fiber-like structures with only a short length, while real meat consists of longitudinal fibers up to 30 cm long. Depending on the implementation, the length of the fibers in the plant proteins can be increased somewhat, but the resulting end product is very compact, hard and has a very strong elasticity, which does not lead to the desired mouthfeel of the meat products.

There is a need to make further changes to conventional technologies in order to achieve improvements in the products.

SUMMARY OF THE INVENTION

This need is taken into account by the subject matter of the independent patent claims. Further developments and embodiments of the proposed principle are specified in the subclaims.

Previous research assumed that fiber formation in the molded part and the exit nozzle results from multiphase gel formation at high temperatures and the subsequent deformation of this multiphase system by shear stresses in the molded part, with the mass cooled to less than 100° C in order not to destroy the fibers.

Although this method has proven successful in producing fibrous protein-based products that typically resemble meat products, controlling the resulting fiber formation remains a challenge. This requires precise control of gel formation, cooling and shear forces in the molded part, which in turn lead to vary greatly, since such highly elastic materials exhibit wall slip and melt fracture phenomena that significantly affect the deformation history. Wall slip or melt fracture lead to a sudden drop in pressure in the nozzle and thus to an expansion of the mass and, in addition to tearing of the fibers, to unstable behavior.

As a result, many meat products, especially those with long fiber structures, cannot be adequately imitated using this technology. Instead, the products tend to be elastic, with relatively high gel or bite strength. Due to their cohesive structure, these texturates also offer very low water or fat absorption capacity after extrusion, e.g. during cooking, which leaves less room for culinary developments.

In addition, the available die technologies can only texture protein-based matrices with very specific properties. Typically, the suitable protein sources should have a very high gel strength and viscosity after treatment in the screw section of the extruder, as this significantly influences the shear stresses in the die section (low viscosity, low deformation stresses, no fiber formation). This limits the use of many protein resources that could be cheaper, more sustainable or healthier.

definition of protein mixture

For the purposes of this application, the term "protein mixture" includes a plant protein mixture. Such a plant protein mixture is usually obtained from a single plant species in the manufacturing process, although contamination from other plants may occur to a small extent.

Unless otherwise stated, a "plant protein" includes a plant protein mixture from the respective plant, otherwise it is referred to as a "single plant protein". In addition to the actual plant proteins, the mixture can also contain other components such as starch, sugar, fiber, minerals, fats and oils. Individual amino acids can also be part of the protein mixture. The respective amounts are defined in more detail below in the terms concentrate and isolate.

Similarly, a “pea protein” or a pea-based plant protein is a protein mixture which essentially comprises pea, pea components or proteins of the pea plant and has been processed accordingly.

Definition of legume protein

A legume protein is a protein mixture that is obtained from legumes. These include peas and broad beans, but also lentils, chickpeas, white beans and peanuts. Soya is also one of these, but - unless explicitly stated - should also be included under the term legume protein, although the cultivation of soya beans consumes significantly more resources than other legumes.

Definition of other protein mixtures

In addition to protein mixtures from pulses, other protein mixtures can also be produced from other crops. These include wheat and generally all types of grain or more generally all types of proteins from cereals, potatoes, rice, hemp, pumpkin seeds, corn, but also rapeseed, sunflowers and especially protein from mushroom mycelium or mushroom fruiting bodies.

Definition of concentrate and isolate

The terms plant protein isolate and plant protein concentrate each describe plant protein mixtures whose protein content is present in different concentrations. The other components of an isolate or concentrate are, for example, fats, sugars including starch and cellulose, which remain in the mixture when the concentrate or isolate is processed. The individual other components are reduced compared to the original concentration, but residues are still present in the isolate or concentrate in different concentrations due to the different processing options. There is also a small amount of residual moisture in the isolate or concentrate.

A plant protein isolate, for example, is a mixture of a plant protein in which the concentration of the protein in the mixture is in the range of over 85% by weight, for example in the range of 87% to 97% by weight. In a protein concentrate, the weight proportion of the protein is usually in the range of below 80% by weight or below 70% by weight, for example in the range of 40% by weight to 75% by weight or up to around 80% by weight. There is also a transition area that ranges from 75% by weight to 85% by weight depending on the protein mixture and in which, depending on the manufacturer, protein variant or other parameters, it is sometimes referred to as concentrate or isolate.

Depending on the preparation and production process, a concentrate or isolate can be obtained from a plant species. The production process therefore not only significantly influences the concentration of the plant protein mixture, but also the composition of the other components and the residual moisture.

definition of additional ingredients

In some aspects, additional functionality in protein composition, taste, textural composition, visual or tactile properties can be created by various other ingredients. It should be noted here that the above-mentioned protein mixtures from the various fruits are mixed both in terms of the different fruits and in terms of concentration. An example would be mixtures of pea protein and broad bean protein, but also additions of wheat or rice protein to a protein mixture made from soy or pea.

Other ingredients such as salt, spices, but also additional starch, sugar, syrup, fats or oils can also be present. These can be added both as part of the raw mixture at the beginning and during the processing. It has surprisingly been found that sugar, oils and salts and/or in the form of ingredients containing sugar, salt or oil, e.g. grape juice concentrate or soy sauce, can not only lead to an adjustment in taste but also to textural changes.

Another possibility is the addition of functional components, such as flavors, or additional special protein or amino acid sources to adjust certain properties or improve human biocompatibility. In general, the additional mixtures and the substances mentioned above are referred to as additional ingredients or additional components.

definition of basic mixture

A base mix is a combination of a protein mixture, be it a single protein mixture, or mixtures of several plant species, as an isolate, concentrate or a combination thereof, and water that is added before or during processing. Optionally, other protein mixtures or other ingredients and components can be added.

When water is added, the mixture created in this way forms a slurry, which is then further processed in an extruder. Alternatively, the individual components can also be fed into the extruder during extrusion.

The base mixture is generally given in weight percentages, based on the ingredients added. A base mixture of 50% protein mixture and 50% water is thus produced by mixing equal weight proportions of protein mixture and water. However, the total water content in the base mixture is slightly greater than 50% because the protein mixture itself contains some residual moisture. The same applies to salts, sugars and fats added to the base mixture, as these are also present in the protein mixture in varying amounts.

Accordingly, the individual components in the basic mixture are slightly offset in terms of the proportions added. This is particularly true with regard to the water content, which is usually somewhat higher than the water added in the dough due to the residual moisture in the protein mixture, but can be lower in the finished texturate because some of the water has evaporated.

Definition Extrudate

In the following, the dough mass produced in the extruder by kneading, which is then stretch-formed, is referred to as extrudate or also as viscous or highly viscous mass.

The inventor has recognized that during the manufacturing process of an extrudate, this is formed into a multiphase gel structure by the mixing extruder itself. In this process, the extrusion produces a multiphase gel structure with at least two immiscible components, for example a protein-protein mixture, a protein-polysaccharide mixture and a liquid or oily phase.

By kneading and simultaneously heating these components with water in the mixing extruder, a multiphase biopolymer mass is formed, the protein interaction of which is then further enhanced by an ejection nozzle. This produces a coherent, i.e. cohesive, multiphase and viscoelastic gel, which is also referred to below as extrudate.

Although the shape and design of the ejection nozzle already leads to an improvement in the protein-protein interaction or the protein-polysaccharide interaction, the inventor has recognized that a decoupling between the extrusion part and a later texturing leads to a significant improvement in flexibility with regard to possible various process parameters, selection of raw materials and different textures. As a result, various texturates based on plant proteins can be produced that would otherwise only be possible to process with significantly greater effort.

The improved result is achieved by first creating a cohesive, multiphase and viscoelastic gel from the individual components of a base mixture with water and then subjecting this extrudate to further compression deformation. The deformation of the dispersed phase of the extrudate leads, among other things, to a break in the gel structure in a preferred direction determined by the pressure and forward direction, which creates anisotropy in the gel and thus a layer formation.

In this way, not only the strength of the anisotropy formed can be adjusted over a wide range, but also other parameters such as a change in the hardness of the multiphase viscoelastic gel, a fiber length and others. Accordingly, the mass can be textured largely independently of the process parameters during extrusion and the materials used in the base mixture. In particular, it is possible to adjust the vector of deformation, i.e. both the strength of the pressure or stress applied and the direction, over a wide range independently of the actual extrusion. This leads to an increase in the anisotropy of the extrudate and thus to the desired adjustable fiber formation.

It has been shown in several experiments that the proposed principle also allows texturing of extrudates that were formed with different ejection nozzles, i.e. a different nozzle geometry. This increases flexibility and also allows nozzle geometries to be used in which anisotropy formation does not occur, but is only created later by deformation. Overall, the formation of different anisotropies and the associated layer or fiber formation is possible with different plant proteins in order to create meat-like or fish-like products both in terms of their texture and mouthfeel.

The deformation of the dispersed phase and also the breakage of the multiphase extrudate to form and shape anisotropy is produced by exerting pressure, for example by a roller system, in which the latter exerts a pressure on the viscoelastic mass that is essentially perpendicular to the direction of advance. At the same time, the mass is allowed to deviate in the other direction perpendicular to the direction of advance, which contributes to the formation of anisotropy. The various properties of anisotropy in the finished textured material can be adjusted by the operational parameters of the roller device, for example the gap between the upper and lower rollers, the type of roller rolls, their size, the entry angle, the roller speed and others.

In one aspect, a mixing extruder has an inlet zone for supplying a base mixture, wherein the base mixture contains at least one protein mixture and water. The mixing extruder further comprises a mixing zone and an ejection zone and is designed to produce a multiphase gel from the base mixture and the water across several zones with a temperature increase up to a maximum temperature between 110°C and 160°C. This comprises, among other things, two immiscible components, which include, for example, protein-protein components, protein-polysaccharide components or oil mixtures. The terms extrudate and gel are used synonymously for the purposes of this application.

Connected to the mixing extruder is an ejection nozzle which is designed to treat the multiphase gel thermomechanically during the advancement of the gel to form a viscoelastic multiphase and in particular cohesive gel. An extrudate is therefore present at the outlet of this ejection nozzle. The terms extrudate and viscoelastic multiphase and optionally cohesive gel are used synonymously for the purposes of this application. It is understood, however, that an interaction between individual proteins and protein polysaccharides and other components takes place in the mixing extruder through the kneading and mixing process, which leads to a certain viscoelasticity. The terms multiphase gel or extrudate are therefore also used to indicate the position of the protein-containing mass in the arrangement.

The extrusion arrangement according to the invention also comprises a roller arrangement whose gap is, at least in sections, smaller than the thickness of the ejection nozzle. This ensures that the gap of the roller arrangement is smaller than the thickness of the extrudate discharged through the ejection nozzle. The roller arrangement is also designed to exert pressure on the viscoelastic multiphase gel or extrudate perpendicular to a direction of advance and thus to cause the anisotropy of the extrudate by deformation.

This makes it possible to produce a fibrous textured product, whereby the anisotropy generated by deformation can be adjusted via the parameters of the roller arrangement. In particular, a textured product with longitudinally oriented fibers can be produced from a protein mixture that is difficult to extrude.

Some aspects deal with the roller arrangement and the resulting pressure build-up or deformation on the extrudate or the cohesive viscoelastic and multiphase gel. In some aspects, the roller arrangement comprises at least two rows of roller rollers, each of which is positioned opposite one another. The viscoelastic multiphase gel is fed from the ejection nozzle as extrudate to the two rows of roller rollers, which then exert a corresponding pressing pressure perpendicular to the direction of advance through the selected slot spacing between the roller rollers, thereby leading to deformation. Each of these rows of roller rollers comprises several roller rollers arranged in the forward direction.

In another aspect, instead of the roller rollers, oppositely arranged belt rollers are provided. These comprise materials approved for the food industry, with the belt rollers each comprising a roller belt clamped and driven by at least two rollers. This is also driven by the rollers. For this purpose, the roller belt can be structured accordingly and, for example, designed with a gear ring into which the at least two rollers engage. In addition to the two rollers, further rollers can be provided which, due to their arrangement, exert pressure on the roller belt in the direction of the viscoelastic multiphase gel. In other words, the belt rollers cause the viscoelastic multiphase gel to deform, thus creating anisotropy through the deformation of the dispersed phase and the breaking up of the multiphase structure.

In a further aspect, a belt roller is provided with a roller belt, which is clamped and driven by at least two rollers. On the other side and arranged at a distance from this, there is a row of one or more rollers. When the extrudate is pushed forward through the roller belt, these exert additional pressure on it and thus a deformation, which leads to the desired anisotropy and thus to the formation of the fibrous structure.

The different roller arrangements can be combined as desired to create the desired anisotropy in the extrudate. For example, it is possible to first provide belt rollers and then two rows of roller rolls to direct the anisotropy in a desired direction. It is also possible to specify different roller arrangements in which the pressure and the resulting deformation occur in different directions perpendicular to the direction of advance.

In one aspect, the adjacent rollers of both the rows of rollers and the rollers of the belt roller can have a distance that is less than a diameter or less than a radius of the roller or roller. In other words, the pressure and thus the strength of the deformation on the extrudate is adjusted by the distance from the adjacent rollers. In some aspects, this distance between opposing rollers can be varied, so that a further flexible design is also possible here.

It is also conceivable to adjust not only the distance between two adjacent rollers in a row, but also the distance between two opposing rollers, in order to create a further degree of freedom. This makes it possible, for example, to generate different levels of pressure on the viscoelastic multiphase gel or the extrudate by means of different distances during propulsion through the roller arrangement, in order to thus form pressure sections and rest sections during propulsion through the roller arrangement. In some aspects, it can be provided that the individual rollers are not directly opposite each other, but slightly offset, i.e. with a "gap". This may result in a more even deformation of the extrudate from both sides.

In some aspects, it is provided that at least two adjacent rollers have a different diameter. Alternatively, as previously described, the position of the rollers perpendicular to the direction of advance can also be different. In some aspects, it is provided in particular that a roller that is downstream in the direction of advance has a larger diameter than a roller that is upstream of this roller in the direction of advance. In other words, the diameters of the rollers become larger in the direction of advance, so that the gap between opposing rollers or between the rollers and the roller belt of a belt roller is increasingly reduced in the direction of advance. In the same way, the distance between the two opposing roller belts in the direction of advance can also be reduced. In an alternative embodiment, it is also possible for the rollers at different distances from each other or at different distances perpendicular to the direction of advance.

In a further aspect, the gap of the roller arrangement, i.e. the distance between two opposing roller rolls or opposing belt rollers, can be reduced continuously or in sections. In some further aspects, it is provided in this context that the gap of the roller arrangement remains essentially constant in the direction of advance, at least in sections. This makes it possible, for example, to define pressure or deformation sections and rest sections during advance through the roller arrangement.

Another way to create anisotropy in the multiphase viscoelastic and cohesive gel is by using different rotation speeds for the rollers. For example, it is possible for rollers that are positioned downstream in the direction of advance to have a higher rotation speed than rollers that are positioned upstream in the direction of advance. In other words, in this embodiment, the rotation speed of the individual rollers is increased the further the extrudate is advanced in the roller arrangement.

In another aspect, for example, rollers in one row can have a different rotation speed compared to the rollers in another row. Accordingly, it is also possible for the belt rollers arranged opposite one another to have different speeds, so that in this way the top side of the extrudate experiences a different tension than the bottom side of the extrudate as it advances through the arrangement. This allows the shear forces to be varied; however, it is also possible to change the stretching forces using a suitable arrangement, so that a high degree of flexibility is achieved. In another aspect, it can also be provided that the roller belt moves at a different speed compared to the individual rollers.

All of the above-mentioned aspects of the roller rolls or belt rollers can be combined with each other so that a different anisotropy can be achieved depending on the desired texture and parameters used, such as the composition of the base mixture, the parameters of the extrudate and also the geometry parameters of the ejection nozzle.

In a further aspect, it can also be provided that the surface of the roller roll or the surface of the belt rollers is structured in order to imprint a track on the viscoelastic and multiphase gel as it advances.

Another aspect concerns the expansion and temperature processing by the roller arrangement. During the ejection phase, i.e. while the multiphase viscoelastic and cohesive gel exits the ejection nozzle, further expansion can occur in some aspects, during which any water or moisture still present within the gel evaporates due to the drop in pressure and thus leads to a loosening of the mass. In this context, it can therefore be advantageous to design the roller arrangement so that it can be tempered and, in particular, heated or cooled, in order to also obtain a further degree of freedom.

In this context, it was also determined, among other things, that the deformation caused by the roller arrangement is at least partially reversible under certain parameters, i.e. the viscoelastic mass partially returns to its original shape even after pressure has been applied. Accordingly, it is planned to make the deformation irreversible by adjusting the strength of the pressure, the duration of advancement through the roller arrangement, the slot thickness, as well as other geometric and mechanical parameters and a temperature setting. The term irreversible also means, among other things, that the multi-phase component breaks, resulting in the formation of layers.

A permanent and essentially irreversible anisotropy can be achieved directly by the roller arrangement, for example by the pressure exerted exceeding a threshold value or a threshold range. In another embodiment, this can also be combined with a temperature change during the advance and in particular during the deformation or shortly thereafter. It has surprisingly been found that anisotropy is retained even if the anisotropy is generated at a higher temperature and the mass treated in this way is then cooled before the onset of regression.

Another aspect concerns the design of the ejection nozzle and the differences between the ejection nozzle and the roller arrangement. In the area of the ejection nozzle, it is advisable to generate a transverse or longitudinal tensile stress without further shear forces, since the latter can lead to the destruction of a possible fiber formation or a reduction of anisotropy possibly already generated by the ejection nozzle in the case of Accordingly, it is advisable to reduce adhesion between the surface of the ejection nozzle and the propelled mass, ie the multiphase gel.

In some embodiments, an inner side of the ejection nozzle is therefore coated with a fluoropolymer and in particular Teflon. Alternatively, it can also be provided that an inner side of a first section of the ejection nozzle has a first material and an inner side of a subsequent second section of the ejection nozzle comprises a second material and a material that is different from the first material. In this context, the material of the ejection nozzle or its surface quality can in particular be designed differently than the material of the roller arrangement or its surface quality.

In some aspects, it is expedient in this context that a material of the ejection nozzle has, at least in sections, a lower coefficient of static and/or sliding friction than a material of the roller arrangement. In other words, the surface of the roller arrangement generally has a higher friction than the surface of the ejection nozzle. Accordingly, the extruder arrangement is designed in such a way that static friction in the ejection nozzle is as low as possible, but is greater in the roller arrangement to generate the anisotropy.

In some aspects, the ejection nozzle comprises at least one section in which a decrease in diameter along a first direction perpendicular to the forward direction is greater than a decrease along a second direction perpendicular to the first direction and the advance direction. The ejection nozzle is thus designed as a transverse expansion nozzle in which the mass produced in the mixing extruder is subjected to an expansion stress transverse to the advance direction.

Alternatively, the ejection nozzle can also have at least one section in which the diameter increases along a direction perpendicular to the direction of advance. In this embodiment, too, expansion forces are generated perpendicular to the direction of advance. An input cross-section of the ejection nozzle can in some aspects be larger than an output cross-section. Accordingly, with a constant mass transport through the ejection nozzle, the change in the cross-section leads to the propelled mass being expanded in one direction, for example transversely to the direction of advance.

In another aspect, however, a longitudinal expansion nozzle can also be provided in which, for example, the cross-section of the nozzle decreases over the direction of advance without the ratio of length to width of the nozzle changing. The cross-section of the nozzle thus becomes smaller while retaining its shape over the length of the nozzle.

In a further aspect, the ejection nozzle comprises different sections, at least some of which have a constant cross-section. Accordingly, the ejection nozzle can thus have sections in which the propelled mass is subjected to a transverse or also a longitudinal expansion (or a combination thereof), as well as further sections connected thereto, which are characterized as rest zones and in which the mass is only propelled but is essentially not subjected to any further expansion stress. In a further aspect, transverse and longitudinal stresses can be realized simultaneously by an appropriate geometry of the ejection nozzle or its cross-section.

The nozzle can therefore be designed as a slot nozzle, as a square or rectangular nozzle, or as an oval, round or Couette nozzle, each with a shorter or longer length. In some aspects, the nozzle is longer than its corresponding inlet or outlet cross-section. However, this is not absolutely necessary; it is also possible for the outlet cross-section to be larger in one direction (e.g. in width) than the length of the nozzle.

The proposed principle creates a texture and anisotropy in the extrudate released from the ejection nozzle in that the roller arrangement deforms the extrudate during the advance and thus creates a fracture in the multiphase gel. However, it is not necessary for the roller arrangement to be directly connected to the ejection nozzle; instead, further arrangements for processing the ejected extrudate can be provided. In some aspects, this is, for example, a cutting arrangement arranged between the ejection nozzle and the roller arrangement. The cutting arrangement can be designed to divide the mass released from the ejection nozzle perpendicular to the advance direction into portions of equal length in particular. In another aspect, the cutting arrangement is designed to cut and divide the mass released from the ejection nozzle along the advance direction.

In this way, the roller assembly is not fed with a continuous extrudate, but rather individual pieces or strips. that these pieces, or strips, are irregularly caught by the roller arrangement because, for example, they fall into the roller arrangement from above. This causes the anisotropy to be generated differently for the individual pieces, with the gel breaking or deformation occurring both in the direction (ie along a strip and across it).

In a further aspect, a rest zone can also be provided, which is arranged between the ejection nozzle and the roller arrangement. This is designed, among other things, to transport the viscoelastic multiphase gel or extrudate from the ejection nozzle to the roller arrangement while changing its moisture content. The moisture content can decrease, but can also increase slightly through spraying or other measures. The rest zone can also be temperature-controlled. Other measures such as dusting or coating with an emulsion can also be provided in this.

The cutting arrangement presented here as well as the rest zone are arranged after the roller arrangement in some aspects. In addition, it is possible to provide a cooling device after the roller arrangement in which the viscoelastic multiphase mass, which is now provided with anisotropy, is cooled quickly so that the anisotropy is retained and an irreversible process is created.

Another aspect relates to a method for producing a texturate. In this method, a base mixture is provided which comprises at least a first protein mixture with a weight proportion of between 40 percent by weight and 90 percent by weight based on a base mixture. The protein mixture can, as already explained above, be made from a single protein mixture or a combination of different protein mixtures, both as concentrates and as isolates. Oils, starch, flavors and other substances are either present in the concentrates or are also added in some aspects. Water is also added to the protein mixture, which has a weight proportion of between 10 percent by weight and 50 percent by weight, based on the base mixture, to form a slurry. The slurry is then kneaded and mixed to produce a multi-phase gel at a maximum temperature of between 110°C and 160°C. Depending on the composition, this gel already shows viscoelasticity. Due to the low water content in the base mixture, this is referred to as dry or semi-dry extrusion. During the mixing and kneading process, the higher pressure of several bar and the increased temperature also cause an interaction between the individual components of the mass, i.e., for example, between the proteins themselves or between the starch and the proteins. Following the kneading process, the gel may contain various phases, some of which are present in separate areas.

The multiphase gel thus obtained is then subjected to a first thermomechanical treatment to further increase the viscoelasticity, so that after this step the viscoelastic multiphase gel is in the form of an extrudate. The first treatment is carried out in particular at a temperature above 100°C and a high pressure of several bar, so that a vapor transfer of water present in the mass with the generation of an expansion of the viscoelastic multiphase gel is excluded during the first thermomechanical treatment.

In particular, the mechanical treatment is designed in such a way that expansion of the multiphase gel is restricted in both directions perpendicular to the forward direction. The term "restriction of expansion" is understood to mean that the multiphase gel can only expand slightly in one of the two directions perpendicular to the forward direction and that this expansion is restricted. In other words, the first thermomechanical treatment is carried out in such a way that mass flow is constant during this treatment and the flow rate of the multiphase gel either remains the same or is increased during the treatment to increase the viscoelasticity. In the first case, the volume flow is not changed, in the second case the volume flow is restricted so that an increased flow rate results with a constant mass flow.

Subsequently, in order to form anisotropy of the viscoelastic multiphase gel treated in this way, a deformation is caused by exerting pressure on it in a direction perpendicular to the forward direction while at the same time allowing essentially unrestricted expansion in the other direction perpendicular to the forward direction. The formation of anisotropy breaks up the structure of the viscoelastic multiphase gel or extrudate and in particular deforms the dispersed phase. In this respect, it can also be said that the dispersed phase of the extrudate is deformed and a break is created in the extrudate, whereby a layered and fibrous structure is formed or an existing one is strengthened. By appropriately controlling various parameters, the strength of the anisotropy as well as its direction can be determined. adjustment of the tension and structure over a wide range.

In some aspects, the viscoelastic multiphase gel or extrudate to be treated is a cohesive gel. The cohesion remains even after deformation and the creation or enhancement of anisotropy, i.e. the texturate forms a coherent structure.

The formation or strengthening of anisotropy is achieved, among other things, by rolling the viscoelastic multiphase gel, for example, through two rows of opposing rollers. These exert a propulsion on the multiphase viscoelastic gel through rotation and simultaneously generate a pressure running perpendicular to it, whereby the rollers still allow expansion in the second direction running perpendicular to the forward direction.

Alternatively, this anisotropy can also be achieved by rolling the treated viscoelastic multiphase gel through two opposing belt rollers. The roller belts are each clamped by at least two rollers and are driven by these. Of course, several rollers are also possible, so that the pressure on the viscoelastic multiphase mass remains as constant as possible during the advance or can be adjusted in sections via the various rollers across the roller belt. In another aspect, the treated viscoelastic multiphase gel is rolled over a roller belt that is clamped and driven by at least two rollers and opposite which is a row of several rollers.

In some aspects, the anisotropy is formed by breaking the viscoelastic multiphase gel or extrudate into at least two phases of different viscosity and/or composition. One phase can have a higher proportion of water or oil or fat than the other. In some aspects, anisotropy can also be formed by compressing the treated viscoelastic multiphase gel or extrudate in sections or continuously during propulsion. In some aspects, the anisotropy of the treated viscoelastic gel or extrudate can be formed or reinforced by rolling, in which different sized rollers are used. Alternatively, it is also possible to form or reinforce the anisotropy by rolling at different rotational speeds. In this context, the anisotropy is formed by compressing the extrudate. At the same time, the extrudate is propelled forward, whereby in some aspects rollers can be used for this purpose that rotate at different rotational speeds. Likewise, the individual belt rollers can have different speeds.

In some aspects, structuring is also carried out during the formation of the anisotropy of the treated viscoelastic multiphase gel, which in particular comprises embossing the surface of the extrudate. The embossing is at least partially irreversible, so that the embossed structure is retained afterwards.

Due to the rolling process, the thickness of the extrudate is initially greater and then less after the application or reinforcement of an existing anisotropy. In order to prevent revision of the anisotropy created, i.e. a "shrinkage" or "change" of the shape caused by the viscoelasticity, heat treatment or heating or cooling during or shortly after the formation of the anisotropy is provided in some aspects.

The treated viscoelastic multiphase gel is cut in some aspects prior to rolling, for example perpendicular to the direction of advance. In other words, in this aspect, several individual pieces or strips of the viscoelastic multiphase gel or extrudate are subjected to compression or rolling. This rolling can be carried out both along the main direction of the individual extrudate pieces or strips, but also transversely to this.

It is also possible to reduce the moisture content before or after rolling, for example by allowing the product to rest for a longer period of time and then subjecting it to heat treatment so that the moisture still contained in it evaporates. In some aspects, the surface of the textured product produced in this way can be coated with a spice, salt or emulsion layer after rolling.

SHORT DESCRIPTION OF THE DRAWINGS

• 1 zeigt eine Ausgestaltung einer Extruderanordnung mit einem Mischextruder, wie er für das vorgeschlagene Verfahren nach dem vorgeschlagenen Prinzip einsetzbar ist;
• 2 stellt eine erste Ausführung einer Walzenanordnung in Querschnittansicht nach dem vorgeschlagenen Prinzip dar;
• 3 zeigt eine weitere Ausgestaltung einer Walzenanordnung nach dem vorgeschlagenen Prinzip;
• 4 zeigt eine weitere Ausgestaltung einer Walzenanordnung nach dem vorgeschlagenen Prinzip in Querschnittansicht;
• 5 stellt eine vierte Ausführung einer Walzenanordnung in Querschnittansicht nach dem vorgeschlagenen Prinzip dar;
• 6 stellt eine fünfte Ausführung einer Walzenanordnung in Querschnittansicht nach dem vorgeschlagenen Prinzip dar;
• 7 zeigt eine weitere Ausgestaltung einer Walzenanordnung nach dem vorgeschlagenen Prinzip;
• 8 zeigt eine weitere Ausgestaltung einer Extruderanordnung nach dem vorgeschlagenen Prinzip,
• 9 stellt eine Ausgestaltung einer Ausstoßdüse mit einem transversalen sich ändernden Querschnitt dar zur Erläuterung einiger Aspekte des vorgeschlagenen Prinzips;
• 10A und 10B zeigen zwei Simulationen einer transversalen Dehnungsdüse, wie sie in einer Extruderanordnung nach dem vorgeschlagenen Prinzip einsetzbar ist;
• 11 ist ein Beispiel eines Verfahrens zur Erzeugung eines Texturats;
• 12A bis 12B zeigen eine weitere Ausgestaltung einer Extruderanordnung nach dem vorgeschlagenen Prinzip mit entsprechenden Abbildungen eines Texturats nach jeder Walze;
• 13 zeigt Schnittansichten des Texturats der 12B;
• 14 bis 16 zeigen weitere Ausgestaltungen einer Walzenanordnung, wie sie bei dem Verfahren und in der Extruderanordnung nach dem vorgeschlagenen Prinzip zum Einsatz kommen kann;
• 17 zeigt weitere verschiedene Beispiele von möglichen Rollen in einer Walzenanordnung.

Further aspects and embodiments according to the proposed principle will become apparent with reference to the various embodiments and examples which will be described in detail in connection with the accompanying drawings.

• 1 shows an embodiment of an extruder arrangement with a mixing extruder, as it can be used for the proposed method according to the proposed principle;
• 2 shows a first embodiment of a roller arrangement in cross-sectional view according to the proposed principle;
• 3 shows a further embodiment of a roller arrangement according to the proposed principle;
• 4 shows a further embodiment of a roller arrangement according to the proposed principle in cross-sectional view;
• 5 shows a fourth embodiment of a roller arrangement in cross-sectional view according to the proposed principle;
• 6 shows a fifth embodiment of a roller arrangement in cross-sectional view according to the proposed principle;
• 7 shows a further embodiment of a roller arrangement according to the proposed principle;
• 8 shows a further embodiment of an extruder arrangement according to the proposed principle,
• 9 shows a design of an ejection nozzle with a transversely varying cross-section to illustrate some aspects of the proposed principle;
• 10A and 10B show two simulations of a transverse expansion nozzle as it can be used in an extruder arrangement according to the proposed principle;
• 11 is an example of a process for producing a texture;
• 12A to 12B show a further embodiment of an extruder arrangement according to the proposed principle with corresponding images of a texture after each roller;
• 13 shows sectional views of the texture of the 12B ;
• 14 to 16 show further embodiments of a roller arrangement as it can be used in the method and in the extruder arrangement according to the proposed principle;
• 17 shows further different examples of possible roles in a roller arrangement.

DETAILED DESCRIPTION

The following embodiments and examples show various aspects and their combinations according to the proposed principle. The embodiments and examples are not always to scale. Likewise, various elements can be shown enlarged or reduced in size to emphasize individual aspects. It goes without saying that the individual aspects and features of the embodiments and examples shown in the figures can easily be combined with one another without affecting the inventive principle. Some aspects have a regular structure or shape. It should be noted that in practice, slight deviations from the ideal shape can occur without, however, contradicting the inventive idea.

In addition, the individual figures, features and aspects are not necessarily shown in the correct size, nor are the proportions between the individual elements necessarily always correct. Some aspects and features are emphasized by showing them in an enlarged manner. However, terms such as "top", "above", "below", "below", "larger", "smaller" and the like are correctly shown in relation to the elements in the figures. This makes it possible to infer such relationships between the elements from the illustrations.

1 shows part of an extruder arrangement according to the proposed principle. The extruder arrangement is designed with a mixing extruder 1 with a twin worm gear, in which the supplied mass is kneaded by means of two worm gears and driven forwards towards an outlet of the mixing extruder. For this purpose, the mixing extruder 1 comprises a motor with gear 10, to which the two worm gears are anchored. Connected to this are several sections 11a, 11b, 11c, 11d and 11e of the mixing extruder.

The respective sections are mechanically tightly connected to one another via flanges or in some other way. In this way, the mixing extruder shown can either be lengthened by adding individual sections or shortened by removing them. The screw sections 12a, 12b and 12c are designed in a similar way so that they can also be lengthened or shortened by adding or removing individual screw elements.

In particular, the mixing extruder 1 according to the proposed principle comprises two inlet sections 11a with associated screw elements 12b. The inlet sections 11a have an opening for supplying the base mixture or water. In detail, in the embodiment shown, the base mixture is introduced via a funnel 14 into a first section 11a of the mixing extruder 1. Subsequently, via a The water is also added to the inlet 15, so that the first two extruder sections 11a serve primarily for initial mixing to form a slurry from the water and the supplied base mixture.

A number of further sections 11b, 11c and 11d are connected to the first sections 11a, some of which are filled with different screw elements 12a. As shown in the illustration of the 1 As can be seen, the screw elements serve on the one hand to propel the dough, but also to knead the dough by increasing pressure and temperature.

For this purpose, the individual sections are equipped with several heating elements (not shown here) that can be controlled separately and independently of one another. This allows different temperature profiles and thus different temperatures of the dough to be advanced to be set in the individual sections 11a to 11e. Furthermore, the individual screw elements in the respective sections are also designed differently. Some screw elements are used to knead the mass from the base mixture and the added water in order to produce a dough with a continuous phase. At the same time, the pressure in these areas is increased to between 15 bar and 20 bar by kneading and further advancing the fed base mixture.

If the temperature is increased at the same time or a high temperature, for example in the range of 120°C to 160°C and a pressure of several bar, the protein mixture polymerizes with the water and the other components, resulting in a gel-like, highly viscous mass. This is kneaded in different ways by the individual screw elements 12a and is pushed forward in small pieces to an exit section 11e of the mixing extruder 1.

The outlet section 11e of the mixing extruder 1 has a slightly conical shape on the outlet side with an ejection zone 13, to which an ejection nozzle is connected either directly or via an intermediate piece. This nozzle will be described below in relation to the 9 explained by way of example. The ejection nozzle is designed not only to provide propulsion but also to enhance further interaction between proteins and proteins and polysaccharides.

In this embodiment, the ejection nozzle 20 is designed with a constant cross-section and drives the mass forward at a temperature of over 100°C and a pressure of more than 10 bar. Upon exit, the mass expands and is transported to a roller arrangement 30 via a short conveyor.

The roller arrangement creates or reinforces an anisotropy of the extrudate that has already formed in the ejection nozzle, so that a desired structure is established at the outlet. The term anisotropy describes, for example, the formation of fibers or layers in the extrudate.

A possible design of a roller arrangement to explain some aspects for the production of a textured product with a longitudinal anisotropy is shown in the 2 . In this case, the roller arrangement comprises two opposing belt rollers 31 and 32. These are arranged opposite each other. However, the two roller belts 300 of the belt rollers 31, 32 are not aligned parallel+, but as in the 1 shown cross-sectional view is V-shaped, with a wider inlet and a thinner outlet. In other words, the distance between the two roller belts 300 decreases in the forward direction, ie in the direction towards the outlet of the roller arrangement.

Each roller belt 300 is driven by a plurality of rotating rollers 310, the direction of rotation of the rollers being counterclockwise for the upper roller belt 300 and clockwise for the lower roller belt 31. This results in a uniform forward speed of the two roller belts 300 for the belt rollers 31 and 32, respectively.

The viscoelastic mass provided by the mixing extruder and the discharge nozzle 20 is now fed to the roller arrangement 30 in its inlet area. The mass is captured by the two roller belts 300 of the belt rollers and is driven forward due to the existing static friction. The rotation speed of the two roller belts 300 can be designed to be somewhat greater than that given by the mass flow of the discharge nozzle 20. The static friction between the viscoelastic mass of the extrudate 40 and the roller belts 300 results in an elongation stress which, while simultaneously reducing the thickness or the distance between the two roller belts 300, creates an anisotropy in the forward direction. This deforms the dispersed phase of the coherent multiphase and viscoelastic mass and aligns the individual protein-protein or protein-polysaccharide chains with respect to one another and along the direction of advance. Due to the pressure built up on the mass, the individual phases are subjected to varying degrees of stress or tension. This leads to a localised application of shear or tensile stress. Tensile stress and subsequent layer formation, which is also known as gel fracture or gel break.

In contrast to the ejection nozzle 20, in which the static friction and thus the build-up of a possible shear stress should be low, in the roller arrangement a static friction is deliberately brought about between the roller belts 300 and the material being driven forward in order to subject the individual phases to a shear and/or tensile stress and thus to reinforce an already existing anisotropy and/or to generate this in the form of gel fracture and thus layer formation.

3 shows a further embodiment, with two belt rollers 31, 32 each with a roller belt 300 and several rollers 310 and 311 provided for driving the roller belt. Similar to the 2 Here too, the diameter of the individual rollers 310 and 311 is the same.

In contrast to the previous example, however, the belt roller 32 is planar and the belt roller 31 is provided with an incline. In this respect, the planar belt roller 32 can also be used as a transport means and can be extended accordingly, so that the mass coming from the ejection nozzle is transported along the belt roller 32 to the beginning of the second upper roller belt. This results in a gap between the two belt rollers 31 and 32 that becomes smaller in the forward direction with the second belt roller 31. In addition, some roller rollers 311 are provided with a temperature control device, so that the advanced mass can also be subjected to additional heating or cooling in successive steps. This allows a further degree of freedom, so that the temperature of the advanced mass can be adjusted during the generation of the gel fracture and the deformation.

In addition, the individual rollers 310 and 311 are designed with an additional gear ring that engages in the corresponding roller belts 300. This enables an intimate connection and prevents slipping on the individual roller rollers when pressure is exerted on the mass 40. By using several rollers 310, 311 per roller belt 300, i.e. more than two, continuous pressure can also be exerted on the propelled mass along the entire propulsion section. This is particularly useful if the propulsion section is somewhat longer overall or the roller belt itself is designed to be elastic. By designing and arranging the individual rollers and the roller belts relative to one another, a defined pressure can be exerted on the viscoelastic mass in order to achieve the desired gel fracture and thus the desired anisotropy.

4 shows a further embodiment of the proposed principle of a roller arrangement 30. In this case, the roller arrangement comprises a planar belt roller, which is opposed by a plurality of rotating individual roller rollers. In contrast to the previous embodiments, the necessary pressure and the corresponding tension are not generated by a roller belt per se, but by a plurality of rotating rollers 33 connected in series. The distance between the individual rollers 33 and the roller belt 300 becomes smaller as the direction of advance increases.

The distance between the individual rollers is significantly smaller than the corresponding diameter or radius of these individual rollers, so that when the compressed mass is transferred between the individual roller belts, there is no major recoil and thus no dissolution of the anisotropy generated. In other words, this also ensures that the existing gel fracture generated by the compression in the roller arrangement 30 does not heal again.

In the previous embodiments, the individual rollers are directly aligned with each other, i.e. they are directly opposite each other. At the same time, the rollers are also the same size. However, both aspects are not necessary and can be varied. For example, it is possible (not shown here) to align the individual rollers with a gap between them and thus not directly opposite each other. Instead, each roller is arranged in its extension in the middle of two adjacent opposite rollers. The rollers in the belt roller can also be aligned in this way. Such a "gap" structure can, among other things, lead to improved pressure application and thus to more continuous tension generation and deformation of the propelled mass.

A further design is shown in the 5 , in which a belt roller 31 is designed with several rollers for generating a driving speed of the roller belt 300. A large number of further roller rollers 312 are now arranged opposite the roller belt 300, the diameter of these roller rollers 312 being significantly different from the roller roller 310 and in particular being smaller. Smaller roller rollers that are arranged closer to each other have the advantage that they exert a uniform force on the extrudate and thus produce improved anisotropy and irreversibility. In this embodiment of the roller arrangement, too, the distance between the individual rollers 312 and the belt roller 31 decreases as the advance distance increases, down to a defined starting gap.

6 shows a further combination in which different belt rollers 31, 32 and 32' are used. The lower planar belt roller 31 comprises a roller belt 300', which is provided with a surface structure which is impressed onto the surface of the extrudate as the mass is advanced over the roller arrangement. In this embodiment, the two upper belt rollers 32, 32' comprise several rollers 313 with a smaller diameter than the rollers 310 of the belt roller 31. In addition, one of the two belt rollers 32, 32' is arranged parallel to the belt roller 31, so that the distance between them does not change or only changes insignificantly during advancement. This does cause advancement, but without any further significant deformation, so that this section can also be referred to as a rest section. The second belt roller 32' is again inclined relative to the lower belt roller 31, so that a wider inlet zone and a narrower outlet zone are formed, the distance between which corresponds to the distance between the belt roller 32 and the belt roller 31.

In addition, it is also possible to provide individual rollers with different diameters in order to reduce the thickness of the propelled mass. 7 shows such a design in which a first roller arrangement 320 is opposite a belt roller 31. The first roller arrangement 320 is inclined relative to the belt roller 31 and comprises several individual roller rollers 312, 313, 314, and 315 arranged one behind the other, which in turn have an increasing diameter in the forward direction. As a result, the distance is reduced during the advance of the viscoelastic mass and the extrudate is deformed to generate the anisotropy. Then further advancement takes place via a roller belt 32, the advance rollers 311 of which are each tempered. In this way, the anisotropy generated by the arrangement 320 can be frozen in the textured material so that it is irreversible.

The roller arrangements presented here make it possible to impart additional anisotropy to an otherwise isotropic extrudate. Anisotropy that may already be present can also be increased. Accordingly, protein mixtures can also be textured in this way, the extrudate of which is hardly or only slightly structured when pushed through a corresponding nozzle.

According to the proposed principle, the roller arrangement can be combined with various ejection nozzles, including a special stretching nozzle, which also applies a transverse or longitudinal stretching stress (or a combination thereof) to the extrudate and the propelled mass.

8 shows such an embodiment, in which a cutting arrangement 41 is also provided. The mixing extruder in the proposed arrangement corresponds to the mixing extruder in the embodiment of the 1 . A special expansion nozzle 20 is connected to the outlet area 13 of the mixing extruder. This is designed as a transverse expansion nozzle and in the 9 explained in more detail below. The protein mixture kneaded in the mixing extruder and mixed with water is further processed through the expansion nozzle 20. The transverse and/or longitudinal expansion stress present in the expansion nozzle 20 leads to an increased molecular interaction of the protein-protein and protein-polysaccharide chains during propulsion, which creates a slight anisotropy when a protein mixture is selected accordingly.

After being ejected through the nozzle 20, the extrudate is fed to a cutting machine 41. This has one or more knives 401, which are arranged perpendicular to the direction of advance and cut the extrudate into strips of essentially the same length. Additional knives can also cut the extrudate strips again lengthwise so that they are narrower. The pieces are then fed to the roller arrangement.

In these designs, the roller arrangement is essentially planar, i.e. the extrudate is fed flat to the roller arrangement. However, this is not necessary; instead, the extrudate or the extrudate strips can fall into the roller arrangement and be caught and pushed forward by the roller belt or rollers. This may be useful for strips or pieces of extrudate, i.e. if the size is already determined by cutting the extrudate into strips or pieces. It is also useful if an anisotropy is already predetermined or if this can be easily reinforced or created by the roller arrangement. The cutting arrangement 41 can also be used as a rest arrangement and suitably tempered to improve the imprinting of the anisotropy.

In the nozzle of the 9 Another aspect is addressed that contributes to gel formation can, namely that the inlet cross-section does not decrease uniformly over the length of the nozzle (this is a possible design), but the inlet reduces in one preferred direction, while in the other direction it actually increases in relation to the outlet. This forms an outlet that forms a slot, whereby the ratio of width to height and also the shape of the side surfaces can be different.

9 shows in this regard an embodiment in which the entrance 23 with its area A1 remains essentially the same in relation to the exit area 24 with its area A2, but its shape is changed. In particular, in the 9 a square entrance area is provided. By steadily decreasing the height and at the same time increasing the width, an elongated, narrow transverse slot is created in the exit area 24, which is approximately twice as wide as the entrance. Its height has, however, decreased by more than half.

The expansion nozzle therefore leads to a decreasing ratio of H/B over the length of the expansion nozzle. For example, the width can increase by a factor of 3, while the height H decreases by the same factor. However, other factors are also possible in this context, whereby the cross-sectional area of the output area 24 also decreases compared to the input area 23. In the present example of the 9 the height of the nozzle at the outlet decreases significantly more than the width increases. As a result, the overall area of the outlet is smaller than the cross-sectional area at the inlet. Accordingly, in this embodiment, there is not only a transverse flow velocity and thus an expansion of the mass perpendicular to the forward direction, but also a longitudinal expansion.

The 10 shows in the upper part of figure A a simulation of the occurring tensile stresses with adhesion and friction effects along the inside. The propulsion direction is now along the Y-axis, the Z-axis corresponds to the width B of the nozzle in 10 . Due to friction, the speed at the edge only increases insignificantly over the length shown here, but a broadening of the speed profile in the width can be seen, since the height of the nozzle also decreases steadily in the X direction. However, due to friction, the maximum increase in speed occurs in the middle of the width (since only half the nozzle is shown here, this must be included for reasons of symmetry).

The lower part B of the 10 shows the simulation through the nozzle without friction on the inner walls. Here a significant increase in speed occurs at the edge, ie in the Z direction, which causes the tensile stresses.

The individual elements of the roller arrangement shown here in the various designs can be combined as desired with regard to their individual sections, geometries, structure and wall coatings in order to control the anisotropy and fiber formation and prepare it for the desired end product. In particular, a combination of ejection nozzle and roller arrangement can achieve a high degree of flexibility with regard to the strength, direction and shape of the anisotropy.

The 14 , 15 and 16 show further embodiments of a corresponding roller arrangement. In 14 a plate element 150 is provided which is stationary and at the same time arranged at an angle relative to a belt roller 31, so that a gap in the direction of advance becomes smaller and smaller. The angle between the roller belt 300 and the plate can be adjusted in some aspects. The extrudate mass is advanced by the belt roller 31 with a roller belt 300 in the direction of the outlet, so that a very thin, but widened textured material is pressed out as a strip. The plate element 350 is designed with heating or cooling elements so that the temperature of the textured material can be adjusted. In addition, the surface of the plate 350 can comprise different materials in order to adjust a static friction and/or a sliding friction between the extruded material and the plate 350. In this embodiment, the plate 350 achieves a uniform and continuous linear reduction of the extruded material in the direction of the outlet.

15 shows, in contrast, a slightly different design in which several plate elements 355 adjustable in height are arranged one behind the other. The two plate elements 355a following the first plate element 355 each have a beveled or curved surface facing the entrance, which is followed by a surface running parallel to the roller belt. Accordingly, a transition from a first distance to a second distance through these curved areas is essentially continuous and even, i.e. occurs without major breakage. In this exemplary embodiment too, the distance between the belt roller 31 with its roller belt 300 and the undersides of the plate elements 355 adjustable in height is reduced, whereby the extrudate is subjected to transverse and longitudinal stress and the desired texturing is thus created.

The adjustable height elements 355 and 355a make it possible to exert different transverse and longitudinal stresses on the extrudate in order to be able to make adjustments when the recipe changes and to achieve the desired text control. The plate shapes shown here can also be designed differently, for example with different gradients, and not, as shown here, with a curved entry area, to which a surface is positioned parallel to the roller belt 300.

16 shows opposite the 14 a kinematically reversed embodiment, in which the plate element 350 is arranged straight and the belt roller 31 with its roller belt is arranged obliquely due to differently sized rollers 312, 313 and 314. This also leads to a reduction in the distance between the roller belt 300 and the underside of the plate 350, whereby the propulsion is again achieved by the rotation of the belt roller. However, due to the different geometry between the 14 and 16 set a different texturing so that flexible texturing is ensured by the geometric arrangement and design between the plate element and the belt roller.

In addition to the roller rolls 310, 312, 313 and 314 shown here in different sizes, other designs and in particular other shapes of rollers are also possible. 17 shows various designs in this regard, which, due to their different geometry, do not exert uniform pressure, but rather a different pressure on a roller belt or on the extrudate depending on the rotation position. This makes it possible to achieve a flexible design with different pressure profiles for producing a textured product. Accordingly, the different shapes of roller rolls shown can also be combined with round roller rolls without this detracting from the inventive concept. Accordingly, the individual roller arrangements with the various elements can also be combined with one another and adapted to the respective recipe.

12A to 12C show a further embodiment. Here, the extruder arrangement after the expansion nozzle comprises several roller rolls arranged one behind the other, which together form a roller arrangement according to the proposed principle. The individual roller rolls are marked with the numbers 1 to 5, whereby the first roller roll 1 is the roll closest to the expansion nozzle. The numbering serves, among other things, to 12B and 12C to show the effect of the respective rollers on the extrudate. For this purpose, the viscoelastic multiphase gel emerging from the expansion nozzle is marked with the number 0. Pressure is then exerted by the individual rollers perpendicular to the direction of advance, whereby at the same time the thickness of the gel strand becomes increasingly smaller, ie the distance between two opposing rollers decreases as described above.

The 12B shows a top view of several strands and their surface finish after each roll. In the 13 the same strands are shown in their respective cross-sections. The increase in fibrous consistency across the various rollers is clearly visible. This consistency is evident both in the surface and in the cross-section. The fibrous structure runs along the strands and its length corresponds to the length of the strands. The roller arrangement thus allows a transverse and longitudinal tension to be generated by adjusting the number of rollers and the pressure exerted by them, which textures the extrudate and forms it with a long and fibrous structure. The dispersion between the individual phases is broken up in this way and, in the present example, flat fibrous textures are produced from the round pieces.

The 11 shows, by way of example, the steps of a process for producing a texturate according to the proposed principle, as can be produced using one of the mixing extruders with a downstream roller arrangement shown in the explanations. The process takes advantage of the fact that a dough mixture with a lower water content leads to an increased interaction between the individual proteins and polymers during kneading of the dough in the extruder arrangement, so that the resulting dough has a significantly increased viscosity while at the same time being elastic. By adding sugar and salt, as well as a suitable two-stage thermomechanical treatment using the proposed extruder arrangement (e.g. the use of a two-axis screw drive), the viscoelasticity can first be adjusted and, with the downstream roller arrangement, this can be used to impose a defined deformation and thus anisotropy on the multi-phase system or the extrudate. In this process, the dispersed phases of the extrudate are specifically deformed and a fracture of the extrudate is deliberately induced so that the desired anisotropy is achieved in the form of layers and/or fibers.

In step S1, a protein mixture is provided. This comprises a protein concentrate from wheat and a protein concentrate from pea protein. The proportions of the proteins in the respective Concentrates are around 45% by weight, with a residual moisture content of around 25% by weight and other components such as starch, oils and others. Vegetable fibers are also present in the concentrates in this embodiment. The two concentrates are mixed in roughly equal proportions and make up around 70% by weight of the base mixture. 10% by weight of vegetable oil is also added to the mixture, as well as salt in the range of 1% by weight and sugar in the range of 5% by weight. Flavors and spices are in the range of 2% by weight. The solid and oily components therefore make up 88% by weight, with the residual moisture in this mixture being around 17.5% by weight (0.70% * 0.25%).

Water is added to the mixture in step S2 in the range of 12% by weight and mixed to a light slurry. This results in approximately 30% by weight of water in the resulting slurry.

The mash is then kneaded into a dough in step S3 under pressure and by increasing the temperature. The dough is kneaded in sections and then slightly advanced. In the first sections, the temperature is quickly increased from room temperature to over 100°C and then kept in a range of 130°C for the remaining kneading and advancement steps. The pressure here is over 5 to 6 bar.

The mass is transferred directly into an expansion nozzle in the discharge zone of the mixing extruder. The expansion nozzle comprises a short inlet section in which the cross-section remains essentially the same, an elongated expansion section and an outlet section.

In this embodiment, in step S4, the mass is subjected to transverse expansion at a temperature of approximately 125°C, the expansion stress of which results from a change in the width of the nozzle while the nozzle is simultaneously reduced. In this embodiment, only the shape of the inlet changes in relation to the outlet, but their areas are the same, so that the mass flow through the nozzle is also constant. In the middle section of the expansion nozzle, the static friction is reduced by a suitable coating, so that the dough does not get stuck or no major shear forces occur that could lead to wall slippage or breakage of the dough.

The temperature does not change significantly during the expansion deformation, i.e. the extrudate has a temperature of approximately 125°C at the end of the expansion die. At the outlet, rapid expansion occurs due to the drop in pressure. This creates a porous structure in the extrudate without destroying any existing structure caused by the expansion stress.

The extrudate is then fed in step S5 to a roller arrangement which has two opposing belt rollers. The belts grip the extrudate and push it forward due to their static friction. Due to the rotation speed of the belt rollers and the decreasing gap between them, a pressure is exerted vertically while simultaneously driving forward. Due to the static friction, strong forces are created in the material. The protein-protein interaction and protein-polysaccharide interaction during kneading and the ejection nozzle to form elongated fibers and a layer-like structure. The stretching that occurs here leads to a splitting of this possibly isotropic structure (any anisotropy that may be present can also be increased as a result) and to anisotropy. This is at least partially reversible due to the above-mentioned interaction, provided that the pressure and duration are not too great. The roller arrangement now exerts pressure of sufficient strength and duration so that the anisotropy applied in the roller arrangement is retained. The finished textured material

Another example of a method for producing a textured material with a fibrous structure whose length may be greater than 10 cm is described below, again with reference to 11 shown.

In step S1, a protein mixture is also provided here. In the example, this includes a protein concentrate made from a vegetable protein. The pure protein content in the concentrate is in the range of 55% by weight. The remaining 45% by weight in the concentrate is divided into a residual moisture content of 15% by weight, vegetable oils and fats at around 10% by weight and starch in the range of 10% by weight. The remaining 10% by weight are fibers and other residual vegetable components, such as salts and minerals.

For the basic mixture, the protein concentrate is mixed with 25% water at a weight ratio of 75%. No other components are added in this example. This results in the following proportions for the basic mixture: 41% pure protein, 36% water, 7.5% oils and fats, 7.5% starch and approximately 7.5% fiber.

In step S2, this essentially dry mixture is added to a mixing extruder and slowly add the water in successive stages under pressure and increasing temperature. In other words, the water is not added all at once, but in several parts during the kneading process. The water is heated as it is added, so that there is no or only a slight temperature gradient and the dough is kept at a high or increasing temperature during the kneading process. The maximum temperature during the kneading process is in the range of approx. 145°C.

In step S3, the kneaded matrix, as a viscoelastic gel, is subjected to a tensile stress. The dough mass is pushed forward in sections without tensile stress and stretched in sections. The latter is done by increasing the flow rate of the dough at the same mass flow. The stretched deformation in sections and the resting sections form a reversible structure so that only a slight anisotropy develops. The length of the advance, in which the flow rate is increased in sections, is significantly larger than the diameter of the inlet cross-section. In addition, in this design, the increase in the flow rate in the tapered sections of the expansion nozzle is different. In particular, the flow rate is only increased slightly at the beginning, but is increased further during the advance. This prevents the fiber formation from breaking.

In section S4, the product is suddenly relaxed at the exit. At the same time, however, the temperature does not drop suddenly, but rather slowly to below 100°C. This causes some of the water bound in the matrix to evaporate, which leads to the formation of pores. The extrudate is then cut into several longitudinal strips and then falls into a roller arrangement in step S5. The roller arrangement comprises two oppositely arranged belt rollers, each of which has several rollers on gaps. Gravity carries the extrudate strips towards the belt rollers until they are caught by a roller belt. The two roller belts exert a strong pressure perpendicular to gravity and transport the extrudate strips further through static friction. The roller belts are open at the sides, i.e. the mass of the extrudate strips can deviate perpendicular to the direction of advance and the direction of pressure during the advance, so that a tensile stress is exerted in this direction and in the forward direction, which leads to anisotropy and layering of the mass.

In another alternative example not shown in the figures, a protein mixture is produced from a field bean concentrate and a soy protein isolate by mixing them in proportions of 60% to 40% by weight. In addition to a protein content of 45% by weight, the field bean concentrate also contains 25% by weight of starch and sugar, 10% by weight of residual moisture and 20% by weight of fibers, oils and other components. The soy protein isolate has a protein content of 93%, 3% by weight of residual moisture, 2% by weight of starch and the rest of oils and fats.

The mixture specified above results in protein contents in the range of 64.2% by weight, sugar and starch in the range of 16% by weight, a residual moisture content of 7.2% by weight, and 13% by weight of remaining components.

This mass can now be mixed with water to produce the base mixture, for example, whereby 20 parts of water fall into 80% by weight of this mixture. This results in a total of 51.4% by weight of proteins and around 27% by weight of water. The rest is made up of around 22% by weight of starch and sugar as well as the other components. This base mixture can be further processed using the proposed process.

The processes described here produce an intermediate extrudate with a moisture content lower than the water content in the base mix during dough kneading. This is due to the loss of water during expansion at the outlet of the stretching die after the stretch forming step, especially when the temperature of the dough and the pressure are maintained above the vapor pressure of the water at that temperature.

Claims (27)

Extruder arrangement, comprising: - a mixing extruder with an inlet zone for supplying a base mixture which contains at least a protein mixture and water, a mixing zone and an ejection zone; wherein - the mixing extruder is designed to produce a multiphase gel from the base mixture across several zones with a temperature increase up to a maximum temperature between 110°C and 170°C; - an ejection nozzle which is connected to the ejection zone and is designed to treat the multiphase gel thermomechanically during propulsion of the multiphase gel to form a viscoelastic multiphase and in particular cohesive gel; - a roller arrangement, the gap of which is at least partially smaller than a thickness of the ejection nozzle, which is designed to exert a pressure on the viscoelastic multiphase gel perpendicular to a propulsion direction. Extruder arrangement according to claim 1 , wherein the roller arrangement comprises at least one of the following elements: - two rows of roller rollers which are opposite one another, each row comprising a plurality of roller rollers arranged in the forward direction; - two belt rollers arranged opposite one another, each of which comprises a roller belt clamped and driven by at least two rollers; - a belt roller comprising a roller belt clamped and driven by at least two rollers and a row of at least one roller roller opposite the roller belt. Extruder arrangement according to claim 2 , in which a distance between two adjacent rollers of a row is smaller than a diameter and in particular smaller than a radius of the rollers. Extruder arrangement according to one of the Claims 2 until 3 , in which at least two adjacent roller rollers have a different diameter, wherein in particular one roller roller has a smaller diameter than a roller roller arranged downstream of this roller roller in the direction of advance. Extruder arrangement according to one of the Claims 2 until 4 , in which the roller arrangement is designed to bring about different rotational speeds of the roller rollers; and in particular to bring about a lower rotational speed for a roller roller in a row than for a roller roller in the row arranged downstream of this roller roller in the direction of advance. Extruder arrangement according to one of the Claims 2 until 5 , in which the roller arrangement is designed - to bring about a different speed between the oppositely arranged rows of roller rollers; or - to bring about a different speed between the oppositely arranged belt rollers or between the belt roller and the oppositely arranged roller roller. Extruder arrangement according to one of the Claims 2 until 6 , in which a surface of the rollers facing the viscoelastic multiphase gel or a surface of the roller belt facing the viscoelastic multiphase gel is structured, in particular has an embossed surface. Extruder arrangement according to one of the preceding claims, wherein an input-side gap of the roller arrangement is larger than an output-side gap. Extruder arrangement according to one of the preceding claims, in which the gap of the roller arrangement is reduced at least in sections in the advancing direction. Extruder arrangement according to one of the preceding claims, in which the gap of the roller arrangement in the advancing direction remains substantially constant at least in sections. Extruder arrangement according to one of the preceding claims, in which the roller arrangement is designed to be temperable, in particular heatable, in particular the roller rolls and/or the roller belts are separately temperable. Extruder arrangement according to one of the preceding claims, in which - an inner side of the ejection nozzle is coated with a fluoropolymer, in particular Teflon; or - an inner side of a first section of the ejection nozzle has a first material, and an inner side of a subsequent second section of the ejection nozzle has a second material that is different from the first material. Extruder arrangement according to one of the preceding claims, wherein - the ejection nozzle has at least one section in which a decrease in diameter along a first direction perpendicular to the direction of advance is greater than a decrease along a second direction perpendicular to the first direction and the direction of advance; and/or - the ejection nozzle has at least one section in which an increase in diameter occurs along a direction perpendicular to the direction of advance, wherein an inlet cross section of the ejection nozzle is larger than an outlet cross section of the ejection nozzle; - the ejection nozzle has at least a first section with a constant cross section, at least a second section with a decreasing cross section and at least a third section with a constant cross section; and/or optionally - a material of a section with a constant cross section is different from a material of a section with a decreasing cross section. Extruder arrangement according to one of the preceding claims, in which - a material of the ejection nozzle which is in contact with the multiphase gel is at least partially different from a material of the roller arrangement which is in contact with the viscoelastic multiphase gel; and/or in which - a material of the ejection nozzle has at least partially a lower coefficient of static friction than a material of the roller arrangement. Extruder arrangement according to one of the preceding claims, further comprising: - a cutting arrangement arranged between the ejection nozzle and the roller arrangement; and/or - rest zone arranged between the ejection nozzle and the roller arrangement and designed to transport the viscoelastic multiphase gel while reducing a moisture content. Method for producing a texturate, comprising the steps: - providing a protein mixture which comprises at least a first protein mixture with a weight proportion of between 40% by weight and 90% by weight based on a base mixture; - adding water with a weight proportion of between 10% by weight and 50% by weight based on the base mixture to form a slurry; - extruding the slurry to form a viscoelastic multiphase gel at a maximum temperature between 110°C and 160°C; - applying a first thermomechanical treatment to the viscoelastic multiphase gel, in particular at a temperature above 100°C, wherein expansion of the viscoelastic multiphase gel is restricted in both directions perpendicular to the forward direction; - inducing anisotropy in the treated viscoelastic multiphase gel by exerting pressure on the treated viscoelastic multiphase gel in one direction perpendicular to the forward direction while allowing substantially unrestricted expansion of the treated viscoelastic multiphase gel in the other direction perpendicular to the forward direction. procedure according to claim 16 in which the treated viscoelastic multiphase gel is a cohesive gel after subjecting it to a first thermomechanical treatment. Method according to one of the Claims 16 until 17 , wherein the formation of anisotropy comprises breaking the viscoelastic multiphase gel into at least two phases of different viscosity. Method according to one of the Claims 16 until 18 , wherein the formation of anisotropy of the treated viscoelastic multiphase gel comprises a section-by-section or continuous compression of the treated viscoelastic multiphase gel during propulsion. Method according to one of the Claims 16 until 19 , in which the step of forming an anisotropy is carried out by - rolling the treated viscoelastic multiphase gel through two rows of opposing rollers; and/or - rolling the treated viscoelastic multiphase gel through two opposing belt rollers, each comprising a roller belt clamped and driven by at least two rollers; - rolling the treated viscoelastic multiphase gel through a belt roller, which comprises a roller belt clamped and driven by at least two rollers and a row of at least one roller roller opposite the roller belt. Method according to one of the Claims 16 until 20 , wherein forming anisotropy of the treated viscoelastic multiphase gel comprises rolling the treated viscoelastic multiphase gel with rollers of different sizes; and/or rolling the treated viscoelastic multiphase gel with rollers of different rotational speeds. Method according to one of the Claims 16 until 21 , wherein forming an anisotropy of the treated viscoelastic multiphase gel comprises compression, wherein two oppositely arranged rows of roller rolls each have a different speed; or wherein two oppositely arranged belt rollers each have a different speed; or wherein a belt roller and at least one oppositely arranged roller roll have a different speed. Method according to one of the Claims 16 until 22 , in which the formation of an anisotropy of the treated viscoelastic multiphase gel comprises structuring, in particular embossing, the surface of the treated viscoelastic multiphase gel. Method according to one of the Claims 16 until 23 , in which a thickness of the treated viscoelastic multiphase gel is larger than a thickness of the gel after the formation of anisotropy. Method according to one of the Claims 16 until 24 , wherein the formation of anisotropy comprises heating or heat treating the treated viscoelastic multiphase gel. Method according to one of the Claims 16 until 25 , further comprising: - cutting the treated viscoelastic multiphase gel substantially perpendicular to the direction of advance; and/or - reducing a moisture content of the treated viscoelastic multiphase gel, in particular before generating anisotropy. Method according to one of the Claims 16 until 25 , further comprising treating the surface of the textured product, in particular coating it with a spice, a salt, or an emulsion layer.

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