Textured vegetable protein

Abstract

The invention provides a texturized vegetable protein, said texturized vegetable protein being defined as a fibrous vegetable protein material having a protein content of at least 40 wt.% relative to dry matter, which texturized vegetable protein is prepared by extrusion at a moisture content of 18.1 - 25.9 wt.% of a feed composition comprising a) a source of plant protein from seed, cereal, algae, fruit, leaf or legume comprising at least 65 wt.% plant protein, relative to dry matter; and b) a source of tuber protein, comprising at least 75 wt.% tuber protein, relative to dry matter; and c) a filler. The invention furthermore provides food products comprising the TVP of the invention, as well as methods for obtaining these products, and use thereof for substituting animal-derived meat in food products.

Description

[0001] Title: Textured vegetable protein

[0002] Background

[0003] The technique of extrusion cooking of protein is an upcoming technique in the art of industrial food preparation, which is being developed to ever more sophisticated levels. Extrusion cooking is performed in an extruder. An extruder comprises one or more rotating screws (e.g. single or twin screw, co-rotating or counter-rotating), located in consecutive blocks, which blocks collectively form the barrel. Each block can be heated or cooled independently, as desired. A proteinaceous material fed to the extruder can get plasticized under the influence of heat and shear inside the barrel, which is generally done in the presence of additional water and / or further ingredients.

[0004] The plasticized mass which is formed in the extruder moves through the barrel pushed by the rotation of the screws to an outlet orifice located in the last block, called die, which provides a counter force to the mass flow resulting in a pressure build-up in the barrel. Upon exiting the die, the pressure is released and the plasticized mass quickly equilibrates with room conditions. During this process, the protein and other ingredients undergo a variety of physicochemical modifications, thereby altering the properties of the protein.

[0005] By extrusion cooking, protein material can be provided with enhanced functional, physicochemical and sensory properties. For example, a protein powder may be transformed by extrusion cooking into a protein product of very different size, shape, hardness or elasticity, than the initial product. For example, “fluffy” (foam-like) aerated protein products may be obtained, as well as elastic, crumbly, soft, firm, rubbery or fibrous materials. What type of product is obtained depends to a large extent on the different ingredients which are present during extrusion, as well as on the applied conditions. It is not at present understood why a specific feed composition provides for particular characteristics of the resulting product, under given conditions.

[0006] The presence of fibrous and firm protein material is an important characteristic of meat products. The presence of fibrous and firm protein material is therefore also a desirable attribute when making vegetarian and vegan meat analogues. To this end, non-meat protein, such as plant protein, can be converted into texturized vegetable protein (TVP).

[0007] TVP has been defined as a fabricated palatable food ingredient processed from an edible protein source, optionally with other ingredients, for nutritional or technological purposes. Protein sources often used for such applications include soy protein, pea protein or wheat protein. Although TVP can have many physical characteristics, particularly desired characteristics are fibrosity and firmness.

[0008] Extrusion cooking to obtain texturized vegetable proteins is conventionally classified into two general methods: high moisture extrusion (HME) and low moisture extrusion (LME). High moisture conditions (40 - 80 % moisture inside the barrel) are known to provide for good fibrosity (see e.g. Samard, J. Sci. Food. Agric. 2019, 99, 4922 - 4931), because due to the high moisture content, the extrusion process allows for obtaining a layered structure which transforms to a product with high fibrosity upon exiting the die.

[0009] HME however has the drawback that due to the high moisture content, the solids output of an HME process is low. In addition, the resulting product has high moisture content, for which reason it has a limited shelf-life; it must be used soon after being produced to obtain a usable food product. Alternatively, it may be further processed (e.g. freezing) to allow for storage, which can have a strong influence on the properties of the HME product. Even then, the high moisture content of such products renders transport of the product over longer distances uneconomical. Protein products obtained from extrusion cooking under low moisture conditions (generally less than 35 % moisture) do not suffer from these drawbacks. The obtained product is more or less dry, has high solids content, and is stable for many months even under ambient conditions. An LME product can thus be stored and transported without difficulties.

[0010] However, extrusion under low moisture conditions generally does not lead to fibrous products. Instead, products extruded under low moisture conditions are mostly amorphous, glassy or spongy.

[0011] Some attempts have been made to produce fibrous (texturized) protein products under low moisture conditions. WO 2020 / 038541 describes high-moisture extruded protein material which are predominantly comprised of oat material. US2021 / 329942 describes protein carbohydrate composites obtained under low moisture extrusion conditions, and furthermore describes that such products are often spongy, mushy or rubbery.

[0012] There remains a need to provide for a texturized vegetable protein material of high fibrosity and high firmness, which can be obtained using an LME process. The present invention provides for such a material.

[0013] Summary

[0014] The invention is based on the insight that low moisture extrusion of mixtures of tuber protein and plant protein from seed, cereal, algae, fruit, leaf or legume provides for fibrous and / or firm TVP products also in the presence of a filler, even when pure tuber protein or pure plant protein from seed, cereal, algae, fruit, leaf or legume, extruded under the same conditions, do not provide for fibrous and / or firm TVP products.

[0015] The invention thus provides a texturized vegetable protein, said texturized vegetable protein being defined as a fibrous vegetable protein material having a protein content of at least 40 wt.% relative to dry matter, which texturized vegetable protein is prepared by extrusion at a moisture content of 18.1 - 25.9 wt.% of a feed composition comprising a) a source of plant protein from seed, cereal, algae, fruit, leaf or legume comprising at least 65 wt.% plant protein, relative to dry matter; and b) a source of tuber protein, comprising at least 75 wt.% tuber protein, relative to dry matter; and c) a filler.

[0016] It has been found that the texturized vegetable protein (TVP) of the invention has high fibrosity and high firmness. This TVP has beneficial properties when used in food products such as for example vegetarian and vegan meat substitutes.

[0017] The invention furthermore provides food products comprising the TVP of the invention, as well as methods to prepare the TVP and the food product, and use of the TVP for substituting animal-derived meat in a food product.

[0018] Figures

[0019] Figure 1: fibrosity scoring scale, used to assess fibrosity.

[0020] Detailed description

[0021] Surprisingly, it has been found that above mentioned issues to obtain a texturized vegetable protein (TVP) under LME conditions can be solved by co-extrusion of plant protein from seed, cereal, algae, fruit, leaf or legume and a filler with tuber protein. The additional presence of tuber protein results in an increased fibrosity and / or increased firmness of the resulting TVP. The presence of the filler allows to reduce protein content, so as to attain a material which requires less resources while still having sufficient nutritional value. The TVP of the invention thus has excellent fibrous structure, as well as high firmness. This is surprising, because under identical extrusion conditions, neither the plant protein from seed, cereal, algae, fruit, leaf or legume nor the tuber protein provides a fibrous material. Only when mixed, a fibrous and firm product can be obtained.

[0022] In addition, the water absorption index renders the TVP of the invention appropriate for use in for example a meat substitute. The water absorption index (WAI) is a measure for the quantity of water which can be adsorbed by the TVP, under standardized conditions, as described in example 4. The WAI must be sufficiently high in order to use a TVP in a food product. A TVP of the invention preferably has a WAI of 100 - 1000, more preferably 250 - 750, more preferably 300 - 650, more preferably 350 - 650, more preferably 390 - 650.

[0023] Within this range, the WAI also provides an indication of fibrosity and / or firmness of a TVP product. The lower WAI of a TVP of the invention (containing added tuber protein), relative to the reference materials (without tuber protein), thus is indicative of increased firmness and / or fibrosity.

[0024] The invention thus provides a texturized vegetable protein, said texturized vegetable protein being defined as a fibrous vegetable protein material having a protein content of at least 40 wt.% relative to dry matter, which texturized vegetable protein is prepared by extrusion at a moisture content of 18.1 - 25.9 wt.% of a feed composition comprising a) a source of plant protein from seed, cereal, algae, fruit, leaf or legume comprising at least 65 wt.% plant protein, relative to dry matter; and b) a source of tuber protein, comprising at least 75 wt.% tuber protein, relative to dry matter; and c) a filler.

[0025] In the present context, texturized vegetable protein is defined as a fibrous vegetable protein material which is obtained by extrusion at a moisture content of 18.1 - 25.9 wt.%. This is generally considered an LME process, as elsewhere defined. The material is called a texturized vegetable protein, in line with the conventional name for texturized protein, although a TVP of the invention may comprise protein derived from sources not always considered “vegetable”. The word vegetable, in the abbreviation TVP, is to be interpreted as “plant-derived”.

[0026] The moisture content during extrusion is 18.1 - 25.9 wt.%, preferably 19.1 - 24 wt.%, more preferably 19.2 - 22 wt.%.

[0027] The moisture content during extrusion as defined herein has the advantage that the obtained protein material has a high solids content, and does not require further processing in order to attain a long shelflife. Most of the moisture is released when the extrudate exits the die. The shelflife of the obtained product without further processing is at least 3 months, preferably at least 6 months.

[0028] The texturized vegetable protein of the invention has a protein content of at least 40 wt.%, relative to dry matter. Preferably, the protein content is 40 - 88.5 wt.%, more preferably 40 - 84.5 wt.%, more preferably 40 - 69.9 wt.%, more preferably 50 - 69.9, most preferably 60 - 69.9 wt.%, relative to dry matter.

[0029] The texturized vegetable protein of the invention has the further unexpected advantage that it possesses high fibrosity and high firmness.

[0030] High fibrosity is an advantage for TVP products which are to be used as meat replacement proteins in various food products, because fibrosity is a characteristic of meat proteins. The high fibrosity of the present product distinguishes it from prior art products, in particular from low moisture extruded products.

[0031] High firmness, also, is an important characteristic for a TVP product, because the firmness dictates chewability. High firmness provides for a strong bite resembling the bite of animal meat, whereas lower firmness is generally perceived as more elastic, leading to a soft product. The texturized vegetable protein of the invention is prepared by extrusion at a moisture content of 18.1 - 25.9 wt.% of a feed composition comprising protein from seed, cereal, algae, fruit, leaf or legume comprising at least 65 wt.% plant protein, relative to dry matter, a source of tuber protein, comprising at least 75 wt.% tuber protein, relative to dry matter, and a filler.

[0032] The feed composition refers to the mixture which is fed into the extruder. Preferably, the feed composition is a homogenous powder mixture, comprising said source of plant protein from seed, cereal, algae, fruit, leaf or legume, said source of tuber protein, and said filler. The feed composition can be used as a dry mix having a moisture content 1 - 15 wt.%. Preferably, the feed composition is used under standard factory conditions, such as at a moisture content of 5 - 15 wt.%, preferably 5 - 12 wt.%.

[0033] The source of plant protein from seed, cereal, algae, fruit, leaf or legume is preferably provided as a powder. A source of plant protein can be referred to as a concentrate or an isolate, depending on the protein concentration of the powder. A protein concentrate is generally understood to mean a protein source comprising more than 55 wt.% protein and less than 80% wt.% protein, relative to dry matter. A protein isolate is generally understood to mean a protein source comprising at least 80 wt.% protein, relative to dry matter.

[0034] The source of plant protein from seed, cereal, algae, fruit, leaf or legume comprises at least 65 wt.%, preferably at least 66 wt.%, more preferably at least 67 wt.%, more preferably at least 68 wt.%, more preferably at least 69 wt.%, more preferably at least 70 wt.%, more preferably at least 71 wt.%, more preferably at least 72 wt.%, more preferably at least 73 wt.%, more preferably at least 74 wt.%, more preferably at least 75 wt.%, more preferably at least 76 wt.%, more preferably at least 77 wt.%, more preferably at least 78 wt.%, more preferably at least 79 wt.%, more preferably at least 80 wt.% of plant protein, relative to dry matter. The source of plant protein can be a plant protein concentrate (generally having a protein content of up to 80 wt.%), or a plant protein isolate (generally having a protein content of at least 80 wt.%). The source of plant protein is preferably a free flowing powder.

[0035] The source of plant protein from seed, cereal, algae, fruit, leaf or legume is generally commercially available, or can be obtained by methods well known to those skilled in the art.

[0036] Seed protein is preferably obtained from protein rich seed, such as seed used for isolation of plant oil. Preferred examples of seed protein include canola protein, rapeseed protein, flax protein, and hemp protein.

[0037] Typical examples of cereal protein include protein obtained from wheat, rye, barley, oat, rice, sorghum, millet or corn.

[0038] Algae protein can be protein derived from algae, among which macroalgae (“seaweed”) and microalgae (unicellular algae, such as chlorella or spirulina).

[0039] Fruit protein can be derived from any type of fruit, such as orange, lemon, apple, pear or banana.

[0040] Preferred examples of leaf protein are rubisco protein and lemna protein.

[0041] Preferred examples of legume protein are protein from soybean, faba bean, mung bean, haricot, kidney bean, black bean, horse bean, Lima bean pea, cow pea, green pea, yellow pea and chickpea, as well as from peanut, lentil or lupin.

[0042] In much preferred embodiments, the source of plant protein provides a legume protein. The legume protein can be a protein from any type of legume. The skilled person is well aware what type of protein is legume protein; legume protein is protein derived from a plant from the family of Leguminosae, preferably from a seed from such a plant. Legume protein may thus be derived from legume such as a pulse, among which a bean such as soybean, faba bean, mung bean, haricot, kidney bean, black bean, horse bean or Lima bean, a type of pea such as (regular) pea (Pisum sativum), cow pea, green pea, yellow pea and chickpea, as well as from peanut, lentil or lupin. In preferred embodiments, the legume protein is a pulse protein. In further preferred embodiments, the legume protein is a pea protein.

[0043] In order to obtain a non- allergenic product, soy protein is preferably not used as a legume protein. A non-allergenic TVP of the invention prepared from a source of legume protein thus comprises, as legume protein, any pulse protein excluding soy. In preferred embodiments, the source of legume protein comprises a protein from pea, chickpea, faba bean, kidney bean, black bean, mung bean, cow pea, horse bean, Lima bean, green pea, yellow pea or haricot. In further preferred embodiments, the source of legume protein is a source of protein from faba bean, pea, chickpea, peanut, lentil or lupin, preferably of pea, chickpea or faba bean, most preferably of (regular) pea (Pisum sativum).

[0044] In another preferred embodiment the source of legume protein comprises a protein isolated from soy bean, faba bean, pea, or chickpea, preferably from soy bean or pea.

[0045] In another preferred embodiment, a non-allergenic TVP of the invention does not comprise wheat gluten. In a much preferred embodiment, a TVP of the invention is free of gluten and soy.

[0046] The source of plant protein from seed, cereal, algae, fruit, leaf or legume can be a native protein, or a coagulated protein. In preferred embodiments, the plant protein is non-functional. In further preferred embodiments, the plant protein is a coagulated protein. The source of plant protein from seed, cereal, algae, fruit, leaf or legume can be an isolate or a concentrate, such as conventionally obtained by either dry milling and air classification or wet milling after de-hulling (Handbook of Food Proteins, G. O. Phillips and P. A. Williams, Eds. Woodhead Publishing Limited, 2011, chapter 9). Dry milling followed by air classification selecting the fine, protein rich fraction generally provides a protein concentrate with up to 75 wt.% protein, mainly depending on the type of plant.

[0047] During wet milling (or “wet fractionation”), protein is extracted under alkaline or acidic conditions from a plant flour (defined as a source of plant protein comprising less than 55 wt.% of protein), followed by centrifugation or similar technology to separate solubilized protein from the residue. Proteins are recovered by isoelectric precipitation or ultrafiltration, thereby providing a plant protein isolate with up to 95 wt.% protein content on dry weight. The skilled person in the food industry is well aware of sources of plant protein, as such isolates or concentrates are commercially available.

[0048] The source of tuber protein comprises at least 75 wt.%, preferably at least 76 wt.%, more preferably at least 77 wt.%, more preferably at least 78 wt.%, more preferably at least 79 wt.%, more preferably at least 80 wt.%, more preferably at least 81 wt.% of tuber protein, relative to dry matter. The source of tuber protein can be referred to as a tuber protein concentrate (generally having a tuber protein content of up to 80 wt.%), or as tuber protein isolate (generally having a tuber protein content of at least 80 wt.%); the source of tuber protein is preferably a free flowing powder.

[0049] The source of tuber protein can provide a protein derived from any type of tuber. The term tuber, in the present context, is to be given its regular meaning, and refers to any type of tuber. In particular, tuber in the present definition includes structures which may also be called root. The term “tuber” as herein defined may thus be replaced with the phrase “root or tuber”.

[0050] Preferably, a tuber in the present context is an edible tuber, which may be grown in the context of human food production. Tuber inherently comprises protein; preferred types of tuber are also rich in starch, such as tuber used for starch isolation. Tuber protein is understood to mean a protein from one type of tuber, or a particular protein fraction from one type of tuber, although in special cases, tuber protein may comprise a mixture of protein derived from two or more types of tuber.

[0051] Preferably, tuber in this context comprises potato (Solarium tuberosum), sweet potato (Ipomoea batatas), cassava (including Manilwt esculenta, syn. M. utilissima, also called manioc, mandioca or yuca, and also including M. palmata, syn. M. dulcis, also called yuca dulce), yam (Dioscorea spp), and / or taro (Colocasia esculenta). More preferably, the tuber comprises potato, sweet potato, cassava or yam, even more preferably the tuber comprises potato, sweet potato or cassava, even more preferably the tuber comprises a potato or sweet potato, and most preferably the tuber comprises potato (Solanum tuberosum).

[0052] Preferred tuber protein comprises potato protein, sweet potato protein, cassava protein, yam protein, and / or taro protein. Most preferably, the source of tuber protein can be a tuber protease inhibitor isolate, a tuber patatin isolate, or a tuber isolate comprising a mixture of protease inhibitor and patatin. The source of tuber protein in the present context may be a native tuber protein isolate, or a denatured tuber protein isolate, such as obtainable by coagulation of tuber protein.

[0053] Preferably, the source of tuber protein comprises a native potato protein, such as obtainable following the methods in WO 2014 / 011042, or a coagulated potato protein, such as obtainable by following the methods in WO 2017 / 142406 or in WO 2016 / 133448. Potato protein is a preferred type of tuber protein, because potato protein is known as an excellent source for essential amino acids, having an average DIAAS above 100. Potato protein thus possesses an essential amino acid score close to that of animal protein (Herreman et al. Food Science & Nutrition, 2020, 00:1-13, Comprehensive overview of the quality of plant- and animal sourced proteins based on the digestible indispensable amino acid score). Most preferably, the source of tuber protein comprises a coagulated potato protein.

[0054] Both native tuber protein and coagulated tuber protein, including native potato protein and coagulated potato protein, is commercially available.

[0055] The filler is preferably inert. The filler is preferably a dry flowing powder. The filler can be a monosaccharide, such as glucose, maltose, fructose or glucose. Preferably, the filler comprises a polysaccharide, such as starch or plant fiber, most preferably starch. Starch can be a modified or a native (non-modified) starch. Preferably, the starch is native starch.

[0056] The starch may be a waxy starch, defined as a starch comprising more than 95 wt.% of amylopectin, or a regular starch, defined as a starch comprising between 60 and 90 wt.%, preferably between 65 and 85 wt.%, of amylopectin.

[0057] The starch may be from any origin, including for example wheat starch, maize starch, sweet potato starch, and potato starch. The starch is preferably derived from a source which is different from the source of plant protein. The starch is preferably a starch from a root or a tuber, preferably a tuber starch, most preferably potato starch. In much preferred embodiments, the starch is a waxy or non-waxy native potato starch, most preferably a native potato starch (NPS).

[0058] The filler may also be a plant fiber. Plant fiber, in the present context, refers to a material which is commercially available, generally in the form of a free flowing powder, and which may be added to the feed composition. Many types of plant fiber are generally known in the art. Examples include soy cotyledon fiber, pea fiber, potato fiber, and grain fiber, among which wheat fiber, barley fiber or oat fiber.

[0059] Plant fibers, as referred to herein, generally include various types of indigestible carbohydrates among which pectins, hemi-cellulose, and / or gums, but furthermore comprises non-soluble cell wall components remaining after acid and alkaline hydrolysis.

[0060] Generally, the filler is preferably present in a significant quantity, such as for example at least 11.5 wt.%, preferably at least 15.5 wt.%, more preferably at least 20 wt.%, relative to the dry weight of the feed composition. Filler can be present in the feed composition in a quantity up to 50.0 wt.%, up to 45.0 wt.%, up to 40.0 wt.%, up to 35.0 wt.%, up to 30.0 wt.%, up to 25.0 wt.%, or up to 20.0 wt.%. Preferred quantities of filler include 11.5 - 50.0 wt.%, preferably 15.5 - 45.0 wt.%, more preferably 15.5 - 40.0 wt.%.

[0061] In preferred embodiments, the quantity of tuber protein in the feed composition is 2.5 - 95 wt.%, preferably 3 - 90 wt.%, more preferably 5 - 75 wt.%, more preferably 7 - 50 wt.%, more preferably 8 - 35 wt.%, relative to total protein. In further preferred embodiments, the quantity of tuber protein in the feed composition is 2.5 - 50 wt.%, preferably 2.5 - 40 wt.%, more preferably 5 - 30 wt.%, even more preferably 7.5 - 25 wt.%, relative to the total weight of the feed composition. In preferred embodiments, the quantity of tuber protein in the feed composition is 7.0 - 35 wt.%, relative to the total weight of the feed composition.

[0062] The quantity of plant protein from seed, cereal, algae, fruit, leaf or legume in the feed composition is preferably at least 50 wt.%, more preferably at least 60 wt.%, more preferably at least 70 wt.%, most preferably at least 75 wt.%, relative to total protein. That is, in much preferred embodiments, the quantity of plant protein from seed, cereal, algae, fruit, leaf or legume exceeds the quantity of tuber protein, on a total weight basis (including moisture of the raw materials). The ratio of plant protein from seed, cereal, algae, fruit, leaf or legume to tuber protein in the feed composition is preferably 19 : 1 - 1 : 1, more preferably 19 : 1 - 3 : 1.

[0063] In much preferred embodiments, the feed composition comprises a quantity of protein from seed, cereal, algae, fruit, leaf or legume of at least 50 wt.%, preferably at least 60 wt.%, relative to dry matter. The quantity of tuber protein in the feed composition is preferably 2.5 - 50 wt.%, more preferably 5 - 30 wt.%, relative to dry matter.

[0064] It is a distinct advantage of the present invention that due to the presence of the tuber protein, a fibrous and firm product can be obtained. The product furthermore generally has a water absorption index (WAI) which is appropriate for use as a TVP product in for example meat substitutes.

[0065] In some embodiments, the feed composition preferably comprises less than 15 wt.%, preferably less than 10 wt.%, preferably less than 5 wt.%, most preferably less than 2 wt.% of lipid. In other embodiments, the feed composition preferably comprises at least 1 wt.%, more preferably at least 2 wt.%, more preferably at least 3 wt.%, more preferably at least 4 wt.%, more preferably at least 5 wt.% lipid. A lipid, in this context, is an oil or fat which may naturally present in the raw materials, or which may be added separately to the feed composition.

[0066] A lipid in the present context includes for example free fatty acids, mono-, di, or triglycerides, sucrose fatty acid esters and sorbitan fatty acid esters. The quantity of lipid is defined as the total weight of the fatty acids present in the feed composition.

[0067] In much preferred embodiments, the feed composition comprises no separately added lipids, so that no additional fat or oil is added to the feed composition prior to the extrusion.

[0068] In further preferred embodiments, the source of plant protein from seed, cereal, algae, fruit, leaf or legume applied in the feed composition comprise less than 12 wt.%, preferably less than 10 wt.%, of lipid. In some embodiments, the source of plant protein from seed, cereal, algae, fruit, leaf or legume comprises at least some lipid. In preferred embodiments, the lipid content of the source of plant protein from seed, cereal, algae, fruit, leaf or legume is 3 - 10 wt.%, preferably 4 - 9 wt.%. A source of tuber protein for use in the feed composition preferably comprises less than 6 wt.%, more preferably less than 5 wt.%, more preferably less than 4 wt.%, more preferably less than 3 wt.%, more preferably less than 2 wt.%, more preferably less than 1 wt.% of lipid. In some embodiments, the source of tuber protein comprises at least some lipid. In some preferred embodiments, the lipid content in the source of tuber protein is 0.1 - 5 wt.% lipid.

[0069] The feed composition as defined is processed by low moisture extrusion, as defined above. The low moisture extrusion setup to obtain the TVP of the invention preferably comprises an extruder comprising a barrel section comprising at least 3 blocks, preferably at least 5 blocks, the first block of the barrel section comprising a feed inlet adapted for feeding the feed composition into the extruder, the second block, located downstream of the first block of the barrel section, comprising a water inlet adapted for introducing water into the extruder, and one or more further downstream blocks adapted to setting the temperature along the barrel section to comprise an increasing temperature gradient, said extruder further comprising a die section located downstream of the barrel section, and one or more screw elements adapted to convey the feed composition through the barrel section to the die section.

[0070] The first block in the barrel section comprises a feed inlet, adapted for feeding a feed composition as herein defined into the extruder. The second block in the barrel section, located downstream of the first block, comprises a water inlet, adapted for introducing water into the extruder so as to attain the desired moisture content of between 18.1 and 25.9 wt.%, preferably between 19.1 and 24 wt.% (based on the total weight of the composition) as described elsewhere. The first and the second block are preferably operated under more or less ambient conditions (20 - 30 °C). One or more further downstream blocks in the barrel section are preferably equipped with means for heating and cooling, so as to allow for setting the temperature along the barrel section to comprise an increasing temperature gradient. In preferred embodiments, the temperature increases step wise to a maximum temperature of 100 - 250 °C, preferably 130 - 225 °C, more preferably 142 - 200 °C, most preferably 142 - 180 °C. In much preferred embodiments, the extrusion conditions comprise a minimum temperature in the barrel of at least 142 °C, more preferably at least 145 °C, even more preferably at least 150 °C.

[0071] Although the barrel section must comprise an increasing temperature gradient, it is conceivable that in some setups, the barrel section may comprise one or more barrel parts in which there is a decreasing temperature gradient, or a constant temperature. Such barrel parts may be combined with for example one, two or more barrel parts with an increasing temperature gradient, as the skilled person appreciates.

[0072] The barrel section furthermore comprises a die section located downstream of the barrel section, and one or more screw elements adapted to convey the feed composition through the barrel section to the die section. In preferred embodiments, the barrel section is equipped with a co-rotating twin screw. Further preferably, the screw configuration comprises reversed pitch elements and conveying elements, preferably alternatingly. In further preferred embodiments, the screw configuration comprises 2 - 10 reversed pitch elements. Reversed pitch elements are preferably located of from 10 D to 20 D. In much preferred embodiments, a reversed pitch element, preferably the reversed pitch element furthest downstream, is followed downstream by a kneading block, preferably having a stagger angle of between 35 and 55 °, most preferably between 40 and 50 °. In further preferred embodiments, the die section comprises a die having one, or two or multiple outlets, preferably one or two outlets, through which outlet(s) the extruded feed mass exits the extruder.

[0073] Extrusion conditions for obtaining the TVP of the invention preferably comprise a temperature in the barrel section of 100 - 250 °C, more preferably 130 - 200 °C, even more preferably 142 - 200 °C, most preferably 142 - 180 °C. This value refers to the maximum temperature observed in a temperature gradient.

[0074] Alternatively or additionally, the conditions comprise a pressure at the die, i.e. after the screw before the die of 1.5 - 80 bar, preferably 2 - 50 bar, more preferably 15 - 40 bar; and / or a specific mechanical energy (SME) of 0.05 - 0.35 kWh / kg, preferably 0.10-0.28 kWh / kg, preferably 0.14 - 0.25 kWh / kg.

[0075] The extruder can be operated at 100 - 1800 screw rotations per minute (rpm), preferably 200 - 1250 rpm; alternatively, the extruder can preferably be operated at 250 - 1600 rpm. Higher rotation speeds, such as 500 - 1600 rpm, preferably 900 - 1500 rpm, provide for higher throughput and hence improved production efficiency.

[0076] In an exemplary embodiment, the extruder can be a ZSK 27 extruder (a co-rotating twin-screw extruder marketed by Coperion). In this particular embodiment, further described in the examples, the extruder comprises 6 blocks, having a total length of 24D. The diameter D of the screws is 27 mm. The barrel section, and thus the screws, have a total length of 648 mm, and the screw diameter is 27 mm.

[0077] In this exemplary embodiment, the screw configuration comprises 3 to 7, preferably 4 to 6, most preferably 5 reversed pitch elements alternatingly intertwined with conveying elements. The reversed pitch elements are preferably placed towards the end of the screw starting at position 14 D. The furthest downstream reversed pitch element is preferably followed downstream by a kneading block (about 45° stagger angle) at position 21.5 D and by a conveying element right before the screw tip at position 23D. The die section comprises two conical cavities, comprising cylindrically shaped die holes having a diameter of 3 mm and a length of 2 mm. In this particular embodiment, the temperature in the first (feeding) block and second (water addition) block can be more or less ambient. The third and fourth blocks are operated at a temperature of 50 - 100 °C, preferably 60 - 90 °C. The fifth and sixth blocks are operated at a temperature of 100 - 250 °C, preferably 142 - 200 °C, most preferably 142 - 180 °C, more preferably 150 - 190 °C. A minimum temperature at some point in the barrel of at least 150 °C, preferably at least 160 °C, is preferred.

[0078] The throughput is 15 to 25 kg / h based on total weight (including moisture) and operated at 500 rpm. At higher rotation speed, the throughput can be higher, as the skilled person appreciates. The throughput can be 10 - 100 kg / h, preferably 15 - 80 kg / h. At 800 - 1600 rpm, the throughput can be 40 - 80 kg / h.

[0079] In this particular embodiment, the pressure at the die is 1.5 - 80 bar, preferably 2 - 50 bar, more preferably 10 - 30 bar, and the extruder is operated at a specific mechanical energy (SME) of 0.05 - 0.35 kWh / kg, preferably 0.10 - 0.28 kWh / kg, more preferably 0.14 - 0.25 kWh / kg.

[0080] Using the described feed composition and the low moisture extrusion process described above, the TVP of the invention having high fibrosity and firmness can generally be obtained. The texturized vegetable protein has a moisture content of 1 - 20 wt.%, preferably 5 - 15 wt.%, more preferably 5 - 12 wt.%.

[0081] The texturized vegetable protein preferably comprises, as wt.% relative to dry matter, a) less than 15 wt.%, preferably less than 10 wt.%, more preferably less than 5 wt.% lipid; and / or b) at least 1 wt.%, preferably at least 2 wt.%, more preferably at least 3 wt.%, more preferably at least 4 wt.%, more preferably at least 5 wt.% lipid.

[0082] The texturized vegetable protein further preferably comprises less than 150 ppm, preferably less than 100 ppm, more preferably less than 80 ppm, more preferably less than 50 ppm, more preferably less than 30 ppm of total triglycoalkaloids (TGA).

[0083] The skilled person is capable of adjusting the feed composition so as to obtain a preferred TVP of the invention.

[0084] The TVP of the invention may be further dried to moisture contents of less than 10 wt.%, preferably less than 8 wt.%, more preferably less than 7 wt.% in order to enhance the microbiological stability and / or the shelflife. Additional drying can be achieved by any means known in the art.

[0085] A TVP of the invention is capable of adsorbing moisture. Moisture adsorption can be expressed using the water adsorption index (WAI); the WAI expresses how much water can be adsorbed by dry TVP as a weight equivalent (expressed as %). A TVP of the invention preferably has a WAI of 100 - 1000, more preferably 250 - 750, more preferably 300 - 650, more preferably 350 - 650, more preferably 390 - 650.

[0086] In further preferred embodiments, a TVP of the invention may be provided with additional texturization, flavoring or coloring, in order to mimic real meat fibers even further. To achieve this, suitable flavors, colorants and / or texturizers can be mixed into the feed composition, or be provided with the added water. Suitable texturizers, flavors and colorants include salts, such as sodium or potassium chloride, as well as alkali metal and alkali earth metal salts of hydroxide, carbonate, bicarbonate, phosphate and monohydrogen phosphate. Preferred alkali metal and alkali earth metal hydroxides are sodium, calcium, magnesium and / or potassium hydroxide. Salts furthermore comprise various organic acid salts such as citrate and lactate salts. The group of suitable texturizers, flavors and colorants furthermore includes various food-grade organic acids such as citric acid and lactic acid.

[0087] Furthermore, lipid compounds may be added such as free fatty acids, mono-, di, or triglycerides, sucrose fatty acid esters and sorbitan fatty acid esters, including polyoxyethylene sorbitan fatty acid esters. The quantity of protein in a TVP composition of the invention can be determined by Kjeldahl analysis using a correction factor of 6.25, as is generally known in the art (EC regulation Nr. 152 / 2009, Annex III, Method C, Dairy, equal to NEN-EN-ISO 8968-1).

[0088] The quantity of triglycoalkaloids can be measured by AO AC Official method 997.13.

[0089] The quantity of lipid can be determined by a method comprising acid hydrolysis and subsequent gravimetric determination of the total weight of the fatty acids. Fatty acids, in this context, are all C2 - C26 fatty acids.

[0090] A TVP of the invention is characterized by a high fibrosity and a high firmness, as compared to other low moisture extruded TVP products.

[0091] The fibrosity of a TVP of the invention is determined visually, using a method set forth in the examples. Fibrosity is high when the fibrosity value is 2 or more, preferably 3 or more, more preferably 4 or more, on a 5 point scale. Fibrosity of a TVP prepared from a particular feed composition can be increased, when occasionally needed, by performing the extrusion at a lower moisture content.

[0092] The firmness of a TVP of the invention is determined using a texture analyzer, for example using the Warner Bratzler method, as set forth in the examples. Firmness can be expressed as absolute firmness (in Newton, “N”), or relative to the sample thickness (in Newton per mm, “N / mm”). Sample thickness of a TVP of the invention is generally 5 - 25 mm, preferably 6 - 15 mm, preferably 7 - 12 mm. Sample thickness is the diameter of the sample perpendicular to the fibre direction (i.e. perpendicular to machine direction) as obtained after extrusion and equilibrated to ambient conditions after full hydration.

[0093] Absolute firmness measured in Newton depends on the sample thickness. Absolute firmness of a TVP of the invention produced according to the invention is generally 5 - 30 N, preferably 8 - 25 N, such as for example 8 - 15 N, preferably 9 - 14 N, or 12 - 30 N, preferably 15 - 25 N. Relative firmness takes into account the variation in sample thickness, and is expressed in N / mm. Relative firmness is generally 1.0 - 3.0, such as for example 1.0 - 1.8 N / mm, or 1.5 - 2.3 N / mm. Firmness is considered high when relative firmness is more than 1.0 N / mm, preferably more than 1.1 N / mm, more preferably more than 1.2 N / mm. Absolute and relative firmness of a TVP prepared from a particular feed composition can be increased, when occasionally needed, by performing the extrusion at a higher moisture content.

[0094] The TVP characteristics, including fibrosity and firmness, are determined by the feed composition, as well as by the conditions of the extrusion. The skilled person is capable of balancing fibrosity and firmness of a TVP from a particular feed composition based on the above guidance, in order to obtain a TVP of the invention satisfying intended features.

[0095] The invention furthermore discloses a method for preparing a texturized vegetable protein of the invention comprising a) providing a feed composition as defined above, said feed composition having a moisture content of 1 - 15 wt.%, preferably 5 - 12 wt.%, relative to the total weight of the feed composition; b) introducing the feed composition into an extruder comprising a barrel section comprising at least 3 blocks, preferably at least 5 blocks, the first block of the barrel section comprising a feed inlet adapted for feeding the feed composition into the extruder, the second block, located downstream of the first block of the barrel section, comprising a water inlet adapted for introducing water into the extruder, and one or more further downstream blocks adapted to setting the temperature along the barrel section to comprise an increasing temperature gradient, said extruder further comprising a die section located downstream of the barrel section, and one or more screw elements adapted to convey the feed composition through the barrel section to the die section; c) extruding the feed composition at a moisture content of 18.1 - 25.9 wt.%, preferably 19.1 - 24 wt.%, relative to the total weight of feed composition, under extrusion conditions comprising

[0096] • a temperature in the barrel section of 100 - 250 °C, preferably 130 - 225 °C, more preferably 142 - 200 °C, most preferably 142 - 180 °C; and / or

[0097] • a die pressure of 1.5 - 80 bar, preferably 2 - 50 bar, more preferably 15 - 40 bar; and / or

[0098] • a specific mechanical energy (SME) of 0.05 - 0.35 kWh / kg, preferably 0.10 - 0.28 kWh / kg.

[0099] Extruding, in this context, means that the feed composition is moved through the barrel by the rotating screws toward the die section, and subsequently exits the extruder through the outlet(s) in the die section. The extruded feed composition preferably exits the extruder through the outlet(s) in the die section in the form of an expanded strand. In much preferred embodiments, the expanded strand is subsequently comminuted, for example using a pelletizer (a rotating cutting device), as is known in the art. The expanded strand is preferably comminuted to portions having a length of 0.5 - 7 cm, preferably 2 - 5 cm, in machine direction.

[0100] In further preferred embodiments, the method furthermore comprises a step of drying the expanded strand, or the comminuted portions, to a moisture content of less than 10 wt.%, preferably less than 8 wt.%, more preferably less than 7 wt.%. This further enhances the microbiological stability and / or the shelflife of the TVP of the invention. Said drying can be achieved by any means known in the art.

[0101] All features of the method of the invention have been described above with reference to the TVP of the invention. Any description of a feature described in the context of the TVP of the invention also is applicable to the method of the invention. Uses of TVP

[0102] A TVP of the invention is particularly suitable for use in food products, preferably human food products. The invention thus also provides a food product comprising a texturized vegetable protein as defined above.

[0103] The high fibrosity and high firmness of a TVP of the invention impart a food product of the invention with a palatable structure, without suffering the drawbacks of high moisture extruded products. This increases processability and usability of a TVP of the invention in the food industry. Prior to its use in a food product, the TVP strand, or preferably the comminuted smaller portions thereof, obtained after extrusion, is preferably further comminuted to smaller size particles, such as particles of from 0.1 - 20 mm, preferably 0.5 - 15 mm, more preferably 0.5 - 10 mm, or even 0.5 - 5 mm. The particle size can be determined by sieve analysis, which analysis method is well-known in the art.

[0104] Preferred food products of the invention are food products which at least in part are based on or resemble meat. A food product of the invention is preferably a food product in which a TVP of the invention is used as a substitute for animal derived meat. Animal-derived meat, in this context, pertains to any type of meat, including mammalian meat such as beef, pork, sheep or goat, preferably beef, and also including poultry such as chicken and turkey, as well as fish and crustaceans. The invention thus also provides use of a TVP of the invention as a substitute for animal-derived meat in food products.

[0105] Preferably, a food product of the invention is an extended meat product, a vegetarian or vegan meat substitute, or a vegetarian or vegan meal component.

[0106] An extended meat product, in this context, is a food product which comprises animal-derived meat, but in which part of the animal-derived meat has been substituted for a TVP of the invention. Examples of extended food products include a beefburger, sausage or meat ball, which comprises animal-derived meat in a quantity which is lower than for conventional animal-derived beefburgers, sausages or meatballs, and in which part of the animal-derived meat has been substituted for a TVP of the invention.

[0107] Extended meat products have the advantage of reducing the consumption of animal-derived meat, while retaining animal-derived meat as a taste and structure component.

[0108] A vegetarian or vegan meat substitute is a meat substitute in which animal-derived meat is not present. A vegetarian meat substitute allows for the presence of non-meat animal-derived components (e.g. egg or milk, and, depending on individual preferences, in some cases also fish and / or crustaceans), whereas a vegan meat substitute is fully plant-based, and does not comprise animal-derived components.

[0109] Preferred vegetarian or vegan meat substitutes or extended meat products are (vegetarian or vegan versions of) a burger, meat ball, skewer, nugget, sausage, minced meat, schnitzel, rib, filet, fish ball, or meat chunk.

[0110] A vegetarian or vegan meal component is a part of a meal which traditionally comprises meat, but which has been developed further to encompass a variant which is free from animal-derived meat (vegetarian, which sometimes may still comprise fish and / or crustaceans), or completely free of animal derived products (vegan), implying absence of both animal derived meat as well as other animal-derived products (among which egg, gelatin, milk and the like).

[0111] Examples include a vegetarian or vegan Bolognese sauce, chili con carne (“chili sin carne”), a pie filling, a taco filling, a burrito filling or a stew. These examples should not be considered limiting, because generally food products which traditionally comprise meat can be made using a TVP of the invention as a substitute for animal-derived meat.

[0112] The invention further provides a method for making a vegetarian or vegan meat substitute as defined above, comprising a) hydrating a texturized vegetable protein as defined above to obtain hydrated TVP; b) combining the texturized vegetable protein with one or more ingredients selected from the group of starch, plant fiber, colorants, flavors, fats, oils, emulsifiers, proteins, probiotics, yeast extracts, binders, and salts, to obtain a raw mix; c) shaping the raw mix to a desired shape.

[0113] In much preferred embodiments, the method for making a vegetarian or vegan meat substitute comprises a step of comminuting the hydrated TVP. Comminution may be done before or after hydration.

[0114] If comminution is done prior to hydration, comminution is preferably to a particle size of 0.1 - 20 mm, preferably 0.5 - 15 mm. If said comminution is performed after hydration, the particle size of the hydrated and comminuted TVP is preferably 0.1 - 20 mm, more preferably 0.5 - 15 mm. The step of comminuting preferably results in a particle size of hydrated TVP which is typical for the type of meat substitute that is made. For example, for a burger, the particle size of a TVP of the invention prior to hydration is typically 0.5 - 5 mm.

[0115] The method reflects preparation methods for making a vegetarian or vegan meat substitute as they are generally known in the art, except that in the present method, a TVP of the invention is used. In short:

[0116] Hydration of the texturized vegetable protein can be achieved by any means known in the art. Preferred means of hydration include soaking the TVP in an aqueous solution, which may comprise further ingredients such as salts or sugars, for a period of at least 5 minutes, preferably at least 15 minutes.

[0117] Hydration is complete when the TVP of the invention is essentially fully equilibrated with moisture, indicating a moisture content of about 40 - 80 wt.%. This may take up to 5 hours, but preferably takes up to two hours, more preferably up to one hour. The second step comprises combining the said hydrated TVP with other food ingredients, thereby providing a raw mix. Lipid may be added as a pre-emulsion or may be emulsified in the presence of said hydrated TVP. Preparation of said pre-emulsion may comprise mixing lipid, water and a binder and / or an emulsifier; emulsification in the presence of said hydrated TVP may comprise preparation of an emulsion comprising said hydrated texturized vegetable protein, a lipid, water, an emulsifier, and / or a binder. In preferred embodiments, the raw mix comprises an emulsion comprising said hydrated texturized vegetable protein, a lipid, an emulsifier and water.

[0118] The lipid can be any lipid, preferably a plant-derived lipid, such as a plant oil, seed oil or fruit oil. In preferred embodiments, the lipid comprises a quantity of triglycerides, relative to the total weight of the lipid, of at least 95 wt.%, preferably at least 98 wt.%. Suitable types of lipid include coconut oil, palm oil, sunflower oil, olive oil, and the like. For vegetarian meat substitutes, butter or cream may also be used.

[0119] Water is preferably clean and suitable for human consumption. In preferred embodiments, the water used in the emulsion is mains water.

[0120] The binder can be any binder which is suitable for binding a vegetarian or vegan meat substitute. Preferred binders include cellulose binders, alginate binders, gums, starch including native and modified starch, or flour. Alternatively the binder may be a protein binder such as (for vegetarian products) gelatin, or (for vegetarian or vegan products) a heat gelling protein such as a native potato protein, preferably a native patatin isolate.

[0121] The emulsion is preferably prepared by high speed mixing of the components. Any order of addition is suitable, as long as it results in a shapeable emulsion. During or after forming the emulsion, optional ingredients such as flavors, colorants, salts, bulking agents and texturizers may optionally be added. The skilled person can decide which optional agents may be suitable for inclusion in which type of vegetarian or vegan meat substitute based on common general knowledge.

[0122] The raw mix, preferably the emulsion, is finally shaped into a desired shape. The shape can be any shape, but is preferably a shape which is customary for the type of vegetarian or vegan meat substitute in question. Thus, a burger, for example, may be provided with a “patty” (flat-disk) shape, whereas a sausage may be provided with an elongated and optionally bent cylindrical shape.

[0123] The invention furthermore provides a method for preparing a food product selected from a vegetarian or vegan meal component, or an extended meat product, comprising providing one or more ingredients for said vegetarian or vegan meal component, or an extended meat product; hydrating a texturized vegetable protein as describe above; and combining said one or more ingredients with the hydrated texturized vegetable protein.

[0124] The method for preparing a vegetarian or vegan meal component or an extended meat product preferably comprises one or more of the steps of providing ingredients, mixing ingredients, heating one or more ingredients, individually or as a mixture, cooling one or more ingredients, individually or as a mixture. Furthermore, the method may comprise executing cooking steps such as kneading, aerating, stirring, baking, frying, boiling, simmering, mashing, resting, shaping, stretching, and / or macerating.

[0125] For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

[0126] The invention will now be illustrated by the following, nonlimiting examples. Experimental section

[0127] Raw materials

[0128] • tuber protein isolate: coagulated potato protein of Avebe, prepared following the methods described in WO 2017 / 142406.

[0129] • legume protein isolate: pea protein isolate obtained from Roquette (trade name Nutralys F85M)

[0130] • plant fibre: pea fibres obtained from Roquette (trade name L50M). Table 1: Compositional analysis of raw materials expressed on dry solids.

[0131] Methodology

[0132] For the raw materials as well as for the extruded products, the following chemical analyses were applied. Textural analysis was only performed for the extruded products. Protein content

[0133] Protein content was determined by Kjeldahl analysis using a correction factor of 6.25 . This method is based on Regulation (EC) No. 152 / 2009, Annex III, Method C, dairy equivalent to NEN-EN-ISO 8968-1. Lipid analysis

[0134] The quantity of lipids was determined by by Soxhlet extraction after acid hydrolysis, using petroleum ether and gravimetric detection (according to EC 152-2009, Annex III, method H, sub-method B).

[0135] Crude fibre

[0136] The quantity of crude fibre was determined by acid and alkaline hydrolysis conform to AO AC 991.43 based on EC regulation Nr. 152 / 2009, Annex III, Method I. Crude fibre refers to the quantity of fibre which is present in a protein starting material, as opposed to plant fibre, which is fibre which can be added as an isolated powder to a feed composition.

[0137] Carbohydrates

[0138] The quantity of carbohydrates was determined by submitting the sample to an acid hydrolysis step that converts polysaccharides into free sugars and determining the amount of sugars by HPLC using a pulsed amperometric detector (PAD). Total carbohydrates are expressed as the weight total of fructose, galactose and glucose after acid hydrolysis. Free sugars are determined by HPLC analysis from an aqueous extract without acid hydrolysis; free sugars include fructose, galactose, glucose, lactose, maltose, and saccharose.

[0139] TGA

[0140] Total glycoalkaloids (TGA) was determined by AO AC Official method 997.13. Fibrosity

[0141] Extruded samples were hydrated by submerging in water for 10 - 15 minutes, and subsequent draining on a sieve for 10-15 minutes. Test samples were selected from the hydrated extruded samples to have uniform size and shape; the size range studied was 3 - 5 cm. Hydrated test samples were protected against dehydration when not undergoing active treatment.

[0142] The hydrated test samples were assessed for fibrosity using a visual scale ranging from 1 - 5. The rating “1” represents an open non- fibrous structure (“honeycomb”), whereas the rating “5” represents a highly fibrous structure (absence of “honeycomb” structures and high fibrosity). The fibrosity scoring scale depicting fibrosity levels 1 - 5 is shown as Figure 1.

[0143] Firmness

[0144] Firmness was determined using the Warner Bratzler method, applying a texture analyser (Shimadzu EZ test EZ-SX). Hydration and selection of samples has been done as described for fibrosity. Prior to assessment, the sample diameter was measured.

[0145] Samples were placed in the centre of the sample holder, paying attention that the Warner Bratzler knife is oriented perpendicular to the fibre direction (if a fibre direction can be observed). The samples were completely cut by moving the Warner Bratzler knife down for 40 mm, making sure the knife moves completely through the plateau. Measurement speed was set at 4 mm / sec.

[0146] The peak force, expressed in Newton, was recorded and used to express absolute firmness. By dividing the firmness in N by the diameter, the relative firmness expressed in N / mm can be calculated. Each trial point was measured in 6-fold and the average number is reported. Extrusion

[0147] Extrusion trials were performed with a Coperion ZSK 27 twin- screw, co-rotating extruder. The ZSK 27 extruder is a food-grade laboratory scale machine (27 mm diameter). The extruder has three peripherals attached to it: water pump feeder (Feeder 1), solid material feeder (Feeder 2) and a pelletizer provided with a compressed air outlet.

[0148] The extruder barrel is composed of 6 modular blocks having a total length of 24D (4D x 6). The diameter D of the screws is 27 mm. The barrel section, and thus the screws, have a total length of 648 mm. The die plate used has two conical cavities. The two conical cavities end into the two cylindrical die holes (“outlet orifices”) having a diameter of 3 mm and a length of 2 mm.

[0149] A screw configuration was used having a series of seven reversed pitch elements intertwined with conveying elements. The reversed pitch elements were placed towards the end of the screw starting at position 14 D. The reversed pitch elements were followed by a kneading block (45° stagger angle) at position 21.5 D and a conveying element right before the screw tip at position 23 D. The screw speed was 500 rpm in all experiments.

[0150] The temperature profile was based on a rather steep temperature increase after the water dosing point (2nd block). The temperature in the third (60 °C) and fourth (90 °C ) blocks was set to 60 to 90 °C. Higher temperatures were reached within the fifth (140 °C) and sixth (160 °C) blocks to further reduce the viscosity of the melt and facilitate the protein cleavage produced by the series of reversed pitches.

[0151] The high temperature at the die results in sudden release of water in the form of steam when exiting the extruder. The steam release resulted in a clear expansion of the extrudate. Without being bound to any theory, it is hypothesized that rearrangement and formation of proteinprotein bonds when exiting the extruder result in a protein-fibrous structure. Table 2: Temperature profile set in the barrel used for extrusion

[0152] Example 1 Pea protein isolate, potato protein isolate, as well as various pea / potato protein mixtures were extruded following the general extrusion setup described above, under different low moisture conditions. For comparative reasons, a series of pea protein / pea fibre (state of the art) was prepared following the same methods. The ratio of the mixtures is on total weight of the raw materials (“asis”).

[0153] A compositional analysis of the extruded protein products is displayed in table 3.

[0154] Table 3: Compositional analysis (g / kg dry matter unless otherwise noted) of extruded products pea = pea protein; fibre = pea fibre; potato = potato protein, faba = faba bean protein (20 % MC). Numbers in the heading represent wt.% in the feed. The extrusion parameters and the textural analysis of the extruded products is displayed in table 4. The results show that despite neither pea protein nor potato protein providing for acceptable fibrosity under the applied extrusion conditions, mixtures of pea protein and potato protein do provide fibrous structures. Extruded mixtures of pea protein and potato protein also have an acceptable firmness. Thus, the addition of potato protein provides fibrosity and firmness. This effect occurs regardless of the presence or absence of a filler (example 3).

[0155] Table 4: Extrusion parameters and results of the visual and textural analysis pea = pea protein; fibre = pea fibre; potato = potato protein; P = die pressure; T = temperature; SME = specific mechanical energy; protein = protein content; A.firm. = absolute firmness; R.firm. = relative firmness.

[0156] Example 2

[0157] Trials were conducted at a throughput of 25 kg / h at 500 rpm using the same screw configuration as in Example 1. Pure pea protein, as well as various pea I potato protein mixtures were extruded following the general extrusion setup described above, under various low moisture conditions. The ratio of the mixtures is on weight of the raw materials as is. For comparative reasons, a series of pea protein I pea fibre (state of the art) was prepared following the same methods.

[0158] Table 5 shows that extruded mixtures of pea protein and potato protein have an acceptable firmness and fibrosity. Extruded pea / fibre or pure pea protein lack either firmness or fibrosity. Thus, the addition of potato protein provides fibrosity and firmness . This effect occurs regardless of the presence or absence of a filler (example 3).

[0159] Table 5: Extrusion parameters and results of the visual and textural analysis

[0160] Example 3

[0161] Pea protein isolate, potato protein isolate, as well as various pea I potato protein mixtures were extruded following the general extrusion setup described above, under different low moisture conditions, in the presence of a varying quantity of filler. The filler was starch (native potato starch, Avebe).

[0162] The screw configuration used for extrusion was “screw configuration 2”. Screw configuration 2 comprised a series of five reversed pitch elements intertwined with kneading- and conveying elements. The first kneading element (45° stagger angle) was placed at position 6D and the second kneading element at position 11D (90° stagger angle). The five reversed pitch elements were placed towards the end of the screw starting at position 16D. The reversed pitch elements were followed by another kneading element (45° stagger angle) at position 2 ID and a conveying element right before the screw tip at position 23D.

[0163] Using screw configuration 2, the feed composition was subjected to extrusion under low moisture conditions as herein defined, using a temperature profile in the barrel section as described above, but applying higher rotation speeds in order to gain higher throughput and production efficiency.

[0164] Quantities refer to the total quantity of filler present in the feed, and the total quantity of pea protein and potato protein, relative to dry matter, obtained by recalculation on the basis of the used quantity of starting materials.

[0165] The results show that in the presence of a filler, at protein contents as low as 65 wt.%, the presence of potato protein in the extruded mixture imparts fibrosity and firmness. Table 6: Extrusion parameters and results of the visual and textural analysis pea = pea protein; fibre = pea fibre; potato = potato protein; P = die pressure; T = temperature; SME = specific mechanical energy; protein = protein content; A.firm. = absolute firmness; R.firm. = relative firmness. WAI = water absorption index as described in Example 4. Fibrosity was evaluated on the basis of a 5-point scale, with 5 representing high fibrosity and 1 representing no fibrosity.

[0166] Firmness was evaluated on the basis of a 5-point scale, with 5 representing high firmness and 1 representing low firmness; 4 and 5 are considered acceptable.

[0167] Color was evaluated on the basis of a 5-point sale, with 5 indicating an appropriate light color, and 1 representing too high (dark) coloring; 4 and 5 are considered acceptable.

[0168] Juiciness was evaluated by sensory evaluation (yes / no).

[0169] Example 4

[0170] Further TVP’s were prepared using screw configuration 2, without filler. The source of plant protein to be combined with the tuber protein prior to extrusion was varied.

[0171] The feed composition comprises potato protein and pea protein mixtures as used in Example 1, and also potato protein (same as above) and faba bean protein mixtures. Faba bean protein was commercially obtained from Univar (Univar 90-C-EU), and had a protein content of 93.4 wt.% on the basis of Kjeldahl analysis. The compositional analysis of the used faba bean protein is reported in table 1.

[0172] The extrusion parameters and the TVP characteristics are shown in table 7. The compositional analysis of the TVP obtained from 75 wt.% faba bean protein and 25 wt.% potato protein at 20 % moisture, is reported in table 3.

[0173] The water absorption index (WAI) is a measure for the quantity of water which is adsorbed by the TVP, under standardized conditions. First, the dry weight of the TVP is determined, by correcting the weight of the TVP asis with the moisture content: mdry= masisx((100-moisture%) / 100). To determine the WAI, about 10 g of TVP is weighted accurately, and submerged using a sieve in a bowl of water for 10 minutes. The sieve with the TVP is removed from the water, and allowed to drip under gravity in order to remove excess, non-adsorbed water. The soaked TVP is then weighted, and the WAI is calculated: WAI = 100 * (msoaked - mdry) / mdry.

[0174] WAI of the present TVP’s is provided in Table 7.

[0175] Table 7: Extrusion parameters and results of the visual and textural analysis

[0176] Example 5

[0177] A TVP sample according to the invention (Inv 2) was applied in meat alternative of the type “raw” meat burger. The burger was prepared using the ingredients listed in table 8. Prior to preparing the burger, the TVP samples were comminuted to obtain particles with size of 0.5 - 5 mm.

[0178] Table 8: Recipe for making a raw meat type meat substitute burger (wt. ratio)

[0179] Preparation of the meat substitute:

[0180] 1. Mix the TVP and water in a thermomix and mix for 15 minutes at speed setting 2;

[0181] 2. Combine all the dry powder ingredients and make a powder blend;

[0182] 3. Once the hydrated TVP has fallen apart, add the powder blend and blend for 30 seconds (speed setting 3);

[0183] 4. Mix the sunflower oil into the dough and blend for 1 minute (speed setting 4);

[0184] 5. Shape the mixture into burger patties. The burgers were fried in a frying pan until a core temperature of 75-80 °C. Prior to frying, the burgers may be stored for up to one year in a freezer at -18°C. The burgers obtained were cohesive both before and after cooking.

[0185] The mouthfeel was a pleasant and non-crumbly, with a distinct meat -like texture. This observation supports the conclusion that both high fibrosity and high firmness are required for a TVP product, which can be attained by low moisture extrusion of mixtures of legume protein and tuber protein with a filler, as herein disclosed.

Claims

Claims1. A texturized vegetable protein, said texturized vegetable protein being defined as a fibrous vegetable protein material having a protein content of at least 40 wt.% relative to dry matter, which texturized vegetable protein is prepared by extrusion at a moisture content of 18.1 -25.9 wt.% of a feed composition comprising a) a source of plant protein from seed, cereal, algae, fruit, leaf or legume comprising at least 65 wt.% plant protein, relative to dry matter; and b) a source of tuber protein, comprising at least 75 wt.% tuber protein, relative to dry matter; and c) a filler.

2. A texturized vegetable protein according to claim 1, wherein the quantity of filler is at least 11.5 wt.%, preferably at least 15.5 wt.%, relative to the dry weight of the feed composition.

3. A texturized vegetable protein according to claim 1 or 2, wherein the filler comprises starch or plant fiber, preferably starch.

4. A texturized vegetable protein according to any of claims 1 - 3, wherein the protein content is 40 - 88.5 wt.%, preferably 40 - 84.5 wt.%, preferably 40 - 69.9 wt.%, more preferably 50 - 69.9, more preferably 60 -69.9 wt.%, relative to dry matter.

5. A texturized vegetable protein according to any of claims 1 - 4, prepared from a feed composition comprising a quantity of tuber protein of 2.5 - 95 wt.%, preferably 5 - 90 wt.%, more preferably 7.5 - 75 wt.%, more preferably 10 - 50 wt.%, relative to total protein.

6. A texturized vegetable protein according to any of claims 1 - 5, prepared from a feed composition comprising a quantity of plant protein from seed, cereal, algae, fruit, leaf or legume of at least 50 wt.%, preferably at least 60 wt.%, more preferably at least 70 wt.%, most preferably at least 75 wt.%, relative to total protein.

7. A texturized vegetable protein according to any of claims 1 - 6, said texturized vegetable protein having a moisture content of 5 - 12 wt.%.

8. A texturized vegetable protein according to any of claims 1 - 7, comprising, as wt.% relative to dry matter, a) less than 15 wt.%, preferably less than 10 wt.%, more preferably less than 5 wt.%, more preferably less than 2 wt.% lipid; and / or b) at least 1 wt.%, preferably at least 2 wt.%, more preferably at least 3 wt.%, more preferably at least 4 wt.%, more preferably at least 5 wt.% lipid.

9. A texturized vegetable protein according to any of claims 1 - 8, comprising less than 150 ppm, preferably less than 100 ppm, more preferably less than 80 ppm, more preferably less than 50 ppm, more preferably less than 30 ppm of total triglycoalkaloids (TGA).

10. A texturized vegetable protein according to any of claims 1 - 9, wherein the source of plant protein comprises legume protein.

11. A texturized vegetable protein according to any of claims 1 - 10, obtainable by a process comprising a) providing a feed composition as defined in any of claims 1 - 10, said feed composition having a moisture content of 1 - 15 wt.%, preferably 5 - 12 wt.%, relative to the total weight of the feed composition; b) introducing the feed composition into an extruder comprising a barrel section comprising at least 3 blocks, preferably at least 5 blocks, the first block of the barrel section comprising a feed inlet adapted for feeding the feed composition into the extruder, the second block, located downstream of the first block of the barrel section, comprising a water inlet adapted for introducing water into the extruder, and one or more further downstream blocks adapted to setting the temperature along the barrel section to comprise an increasing temperature gradient, said extruder further comprising a die section located downstream of the barrel section, and one or more screw elements adapted to convey the feed composition through the barrel section to the die section;c) extruding the feed composition at a moisture content of 18.1 - 25.9 wt.%, preferably 19.1 - 24 wt.%, relative to the total weight of feed composition, under extrusion conditions comprising• a temperature in the barrel section of 100 - 250 °C, preferably 130 - 225 °C, more preferably 142 - 200 °C, most preferably 142 - 180 °C; and / or• a die pressure of 1.5 - 80 bar, preferably 2 - 50 bar, more preferably 15 - 40 bar; and / or• a specific mechanical energy (SME) of 0.05 - 0.35 kWh / kg, preferably 0.10 - 0.28 kWh / kg.

12. A method for preparing a low-moisture extruded texturized vegetable protein as defined in any of claims 1 - 11, comprising a) providing a feed composition as defined in any of claims 1 - 7, said feed composition having a moisture content of 1 - 15 wt.%, preferably 5 - 12 wt.%, relative to the total weight of the feed composition; b) introducing the feed composition into an extruder comprising a barrel section comprising at least 3 blocks, preferably at least 5 blocks, the first block of the barrel section comprising a feed inlet adapted for feeding the feed composition into the extruder, the second block, located downstream of the first block of the barrel section, comprising a water inlet adapted for introducing water into the extruder, and one or more further downstream blocks adapted to setting the temperature along the barrel section to comprise an increasing temperature gradient, said extruder further comprising a die section located downstream of the barrel section, and one or more screw elements adapted to convey the feed composition through the barrel section to the die section; c) extruding the feed composition at a moisture content of 18.1 - 25.9 wt.%, preferably 19.1 - 24 wt.%, relative to the total weight of feed composition, under extrusion conditions comprising• a temperature in the barrel section of 100 - 250 °C, preferably 130 - 225 °C, more preferably 142 - 200 °C, most preferably 142 - 180 °C; and / or• a die pressure of 1.5 - 80 bar, preferably 2 - 50 bar, more preferably 15 - 40 bar; and / or• a specific mechanical energy (SME) of 0.05 - 0.35 kWh / kg, preferably 0.10 - 0.28 kWh / kg.

13. A food product comprising a texturized vegetable protein as defined in any of claims 1 - 11.

14. A food product according to claim 13, which food product is an extended meat product, or a vegetarian or vegan meat substitute, which extended meat product, vegetarian or vegan meat substitute is preferably a burger, meat ball, skewer, nugget, sausage, minced meat, schnitzel, rib, filet, fish ball, or meat chunk, or which food product is a vegetarian or vegan meal component, preferably chili con carne, bolognese sauce, pie filling, taco filling, burrito filling or stew.

15. A method for making a vegetarian or vegan meat substitute as defined in claim 14, comprising, a) hydrating a texturized vegetable protein as defined in any of claims 1 - ii; b) combining the hydrated texturized vegetable protein with one or more ingredients selected from the group of starch, plant fiber, colorants, flavors, fats, oils, emulsifiers, proteins, probiotics, yeast extracts, binders, and salts, to obtain a raw mix; c) shaping the raw mix to a desired shape.

16. A method for preparing a vegetarian or vegan meal component, or an extended meat product, comprising• providing one or more ingredients for said vegetarian or vegan meal component, or an extended meat product;• hydrating a texturized vegetable protein as defined in any of claims 1 - 11;• combining said one or more ingredients with the hydrated texturized vegetable protein.

17. Use of a texturized vegetable protein as defined in any of claims 1 - 11 as a substitute for animal-derived meat in a food product.

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