LOW SODIUM PROTEIN ISOLATE

Abstract

The present invention relates to a vegetable protein, including isolates and concentrates, preferably legume protein isolates, more preferably pea protein isolates, characterized in that it contains less than 0.6% sodium by dry weight and less than 1% calcium by dry weight. The invention further relates to extraction and purification processes for the vegetable proteins, including isolates and concentrates, preferably legume protein isolates, more preferably pea protein isolates of the invention. Finally, the invention also relates to the application of the vegetable proteins, including isolates and concentrates, preferably legume protein isolates, more preferably pea protein isolates of the invention, in the food, feed, and pharmaceutical industries.

Description

LOW SODIUM PROTEIN ISOLATE QR / ann / Lznz / E / YiAi FIELD OF INVENTION The present invention relates to a vegetable protein, including isolates and concentrates, preferably legume protein isolates, more preferably pea protein isolates, characterized in that it contains less than 0.6% sodium by dry weight and less than 1% calcium by dry weight. The invention further relates to extraction and purification processes for the vegetable proteins, including isolates and concentrates, preferably legume protein isolates, more preferably pea protein isolates of the invention. Finally, the invention also relates to the application of the vegetable proteins, including isolates and concentrates, preferably legume protein isolates, more preferably pea protein isolates of the invention, in the food, feed, and pharmaceutical industries. BACKGROUND OF THE INVENTION Along with carbohydrates and lipids, proteins make up a significant part of our diet. Generally, it is said that the required amount of protein is between 12% and 20% of our daily food intake. Generally, the proteins consumed are of animal origin, such as meat, fish, eggs, and dairy products. Ref. 318957 or of plant origin, which include cereals, oilseed plants and legume plants. In industrialized countries, protein intake comes predominantly from animal sources. It is important to note that many studies show that excessive consumption of animal protein, and significantly less plant-based protein, is a contributing factor to the rise in cancer and cardiovascular disease rates. In addition, animal proteins have many disadvantages, in terms of their allergenicity, particularly regarding milk and egg proteins, along with the degradation of our environment due to the intensive agriculture necessary for the production of animal proteins. Consequently, manufacturers have gradually turned to plant proteins as an alternative to animal proteins; in fact, it is a well-known practice to use plant proteins to replace all or some of the animal proteins in food products. This type of replacement is not always easy, since the functional properties of plant proteins are different from those of animal proteins. In this case, functional properties refer to the physical or physicochemical properties that affect the sensory qualities of food systems that have been generated during technological transformations, storage, or QR / onn / Lznz / E / YiAi domestic culinary preparations. Among plant proteins, the use of legume proteins is a well-established practice. Although milk proteins have a strong nutritional advantage, their high production cost limits their use in large-scale food processing. As an alternative, legume proteins can replace milk proteins. In particular, pea proteins are now considered game-changers in this field. Pea protein isolates are obtained from non-GMO seeds, rather than soy protein isolates. One drawback of certain plant proteins, particularly legume and pea proteins, is their potentially high sodium content. As illustrated below in this application, current commercial protein isolates, especially pea protein isolates, contain more than 1% sodium in their dry matter. Sodium is primarily introduced during the extraction process through the sodium hydroxide used to adjust the pH. As explained in Pea protein isolates: Structure, extraction, and functionality (Lam et al., 2018), sodium hydroxide is commonly used in this type of protein extraction process. QR / ann / Lznz / E / YiAi humid. Sodium is important for many vital metabolic functions, such as nerve impulse transmission and muscle contraction. However, too much sodium in the diet can also have harmful effects, such as heart disease and high blood pressure. The FAO recommends a maximum intake of 2 g per day for adults (see Sodium intake for adults and children, FAO, 2012). Some protein isolates already contain a low level of sodium, achieved by replacing sodium hydroxide. For example, patent no. EP2911524 describes a process in which sodium hydroxide, used primarily in a pea processing method to adjust pH, is replaced with calcium hydroxide. The resulting isolate has a low sodium content, but, as illustrated in the application, its functional properties, including low solubility, are significantly altered. This isolate is well-suited for baking applications but will not be appropriate for other food applications requiring high solubility and gel strength. Lam et al. (2018) clearly state that sulfate, hydrogen phosphate, ammonium, and potassium salts promote ion-water interactions, which disrupt the hydration layers surrounding proteins, leading to the exposure of hydrophobic entities. Consequently, aggregation and precipitation occur, depending on the ionic strength and hydrophobicity level. Those skilled in the technique will readily understand that using such salts as pH reagents can significantly impact the functionality of protein isolates, particularly their solubility. The fractionation process can also supply low-sodium proteins, but it will not produce a high-protein isolate, e.g., with a protein content greater than 80 L Therefore, there remains a need for a protein isolate that has a low sodium content while maintaining its good functional properties compared to a sodium-based isolate. SUMMARY OF THE INVENTION A first aspect of this invention is a vegetable protein, characterized in that its maximum sodium content is less than 0.6% on a dry weight basis, and its calcium content is less than 1% on a dry weight basis. In a preferred embodiment, such vegetable protein isolate contains more than 80% by dry weight of protein richness on a dry matter basis. In a more preferred embodiment, the vegetable protein of the invention is characterized in that its potassium content is between 0.5% and 3% by dry weight of its dry matter. A second aspect of this invention is a process for preparing a vegetable protein, which is described in the first QR / ann / Lznz / E / YiAi aspect of this invention, comprising the following stages: a) provide a plant seed that contains protein; b) grind the above seed and obtain a ground suspension in water; c) extract proteins from the ground suspension; d) adjust the pH between 6 and 9; e) optionally, heat to a temperature of 100 °C to 160 °C and / or pasteurize the proteins obtained; f) optionally, dry the proteins obtained; characterized in that potassium hydroxide is used as a pH reagent in step (d). A third aspect of this invention is the use of vegetable protein, which is described in the first aspect of this invention, in the industrial field comprising food, feed, pharmaceutical, and cosmetic applications. Another aspect of the invention is the use of vegetable protein according to the invention in a food texturizing process. The invention will be better understood in the following chapter of detailed description. DETAILED DESCRIPTION OF THE INVENTION A first aspect of this invention is a vegetable protein, preferably a vegetable protein isolate, more preferably a legume protein isolate, even QR / ann / Lznz / E / YiAi with greater preference a pea protein isolate, characterized in that its maximum sodium content is less than 0.6% on a dry weight basis, preferably less than 0.2%, with greater preference less than 0.1% on a dry weight basis, and its calcium content is less than 1% on a dry weight basis, preferably less than 0.5%, with greater preference less than 0.25%, even with greater preference less than 0.1% on a dry weight basis. In this description, the term "plant protein" refers to any type of protein extracted from any type of plant. "Plants" is understood to mean any of the various photosynthetic, eukaryotic, multicellular organisms of the kingdom Plantae that characteristically contain chloroplasts, have cell walls made of cellulose, produce embryos, and lack the power of locomotion. Plants include trees, shrubs, grasses, ferns, mosses, and certain green algae. Particularly in this application, the term "plant" applies to the legume family, which includes peas and beans. Other preferred types of plants are flax, oats, rice, and lentils. The term "protein," as used in this application, should be understood to refer to molecules consisting of one or more long chains of amino acid residues. In this application, proteins may be native to the plant or modified, including hydrolyzed proteins. These proteins may have different concentrations, including isolates greater than 80% or concentrates greater than 50%. In this application, isolates with a protein content greater than 80% on a dry weight basis are particularly preferred. The term legume, as used in this description, should be understood to refer to plants of the pea family (Leguminosae). These have seeds in pods, distinctive flowers, and typically, root nodules. These nodules contain symbiotic bacteria that are capable of fixing nitrogen. The term "pea" in this description is understood in its broadest and most acceptable sense. In particular, it includes all smooth and wrinkled pea varieties, and all mutant varieties of both. These varieties relate to the uses usually intended for each type of pea (food for human consumption, animal fodder, and / or other uses). In this application, the term "pea" includes pea varieties belonging to the genus Pisum, and more particularly to the species sativum and aestivum. Mutant varieties are, in particular, those known as r mutants, rb mutants, and rug 3 mutants. QR / onn / Lznz / E / YiAi rug 4 mutants, rug 5 mutants and lam killers, as described in the article by CL HEYDLEY et al. entitled Developing novel pea starches, Proceedings of the Symposium of the Industrial Biochemistry and Biotechnology Group of the Biochemical Society, 1996, pp. 77-87. The quantification of sodium is well understood by experts in the fields of chemistry and biochemistry, who will be familiar with all the appropriate analytical methods for quantifying sodium content. In the context of this application, the use of a flame absorption spectrometer is preferred. In a preferred embodiment, such vegetable protein isolate contains more than 80% protein richness on a dry weight basis, more preferably more than 85% on a dry weight basis. Any reference assay method well known to a person skilled in the art can be used to quantify the protein level. Preferably, a determination of total nitrogen (in % of crude) is made, and the result is multiplied by the coefficient 8.25. This well-established methodology in the field of proteins is based on the observation that proteins contain, on average, 16% nitrogen. Some protein concentrates obtained by air sorting, including pea concentrates, may have a low sodium level, but their QR / ann / Lznz / E / YiAi protein content is much less than 80% on a dry weight basis. This type of product is not suitable for some food applications that require a high protein content. In a more preferred embodiment, the vegetable protein of the invention, preferably vegetable protein isolate, more preferably legume protein isolate, and even more preferably pea protein isolate, is characterized in that its potassium content is between 0.5 and 3% by dry weight of its dry matter, preferably between 1.5 and 2.5%, more preferably between 1.8 and 2.5% by dry weight of dry matter. In a first variant, the vegetable protein of the invention, preferably vegetable protein isolate, more preferably legume protein isolate, even more preferably pea protein isolate, is characterized in that its maximum sodium content is preferably less than 0.2%, more preferably less than 0.1% by dry weight on a dry matter basis and its potassium content is between 0.5 and 3% by dry weight on a dry matter basis, preferably between 1.5 and 2.5%, more preferably between 1.8 and 2.5% by dry weight on a dry matter basis. In a second variant, the vegetable protein of the invention, preferably vegetable protein isolate, more preferably legume protein isolate, even more preferably pea protein isolate, is QR / ann / Lznz / E / YiAi is characterized by having a sodium content between 0.3% and 0.6%, preferably between 0.4% and 0.6%, with greater preference 0.5% on a dry weight basis, and a potassium content between 0.5% and 3% on a dry weight basis, preferably between 1% and 2%, with greater preference between 1.3% and 1.5% on a dry weight basis. The use of potassium hydroxide to replace sodium hydroxide partially or completely in the protein extraction process allows for obtaining a protein rich in potassium and low in sodium. Especially in the pea extraction process, those skilled in the technique would avoid using potassium hydroxide as a pH adjuster, as it is known to directly alter the solubility of the resulting pea isolate. Lam et al. (2018) clearly state that sulfate, hydrogen phosphate, ammonium, and potassium salts promote ion-water interactions, which disrupt the hydration layers surrounding proteins, leading to the exposure of hydrophobic entities. Consequently, aggregation and precipitation occur, depending on the ionic strength and level of hydrophobicity.Surprisingly, the applicant has discovered that using potassium hydroxide to adjust the pH allows for achieving a pea protein isolate with the same solubility as a protein isolate for which sodium hydroxide was used to adjust the pH. QR / onn / Lznz / E / YiAi These protein isolates also allow for extrusion, with good fiber formation and water retention. Other protein isolates with low sodium content, such as calcium-based isolates, lead to poor fiber formation and water retention. A second aspect of this invention is a process for preparing a vegetable protein, preferably a vegetable protein isolate, more preferably a legume protein isolate, and even more preferably a pea protein isolate, described in the first aspect of this invention, comprising the following steps: a) provide a plant seed containing protein, preferably a legume seed, most preferably a pea seed; b) grind the above seed and obtain a ground suspension in water; c) extract proteins from the ground suspension, preferably by thermocoagulation at isoelectric pH; d) adjust the pH between 6 and 9, preferably 7; e) optionally, heat to a temperature of 100 °C to 160 °C and / or pasteurize the proteins obtained; f) optionally, dry the proteins obtained; characterized in that potassium hydroxide is used as a pH reagent in step (d), preferably in the absence QR / ann / Lznz / E / YiAi total sodium hydroxide. In step (a), the seeds of plants suitable for this invention may be selected from a list of food-compatible plant seeds, particularly pea, broad bean, oat, lentil, and flax. Legume plants are preferred. Pea seed is indeed the best and most suitable seed, followed closely by broad bean. The seeds may be cleaned, sorted, and / or roasted or blanched before use in step (b). Step (b) involves grinding the seed into a flour, which can be done using any process known to those skilled in the art. This may include pre-soaking, blanching, or even the well-known roasting step, which is used to inhibit endogenous enzymes such as lipoxygenases. The seed can be ground into a flour before being mixed with water, a process known as dry milling. However, milling can also be done while the seeds are suspended in water, also known as the wet milling process. Step (c) consists of extracting proteins from ground seeds. The wet extraction process is particularly suitable for this invention. Favorably, the aqueous flour suspension is processed to separate the internal fibers and starch, preferably with the aid of a combination of a decanter centrifuge and hydrocyclones. This allows for the removal QR / onn / Lznz / E / YiAi the pea fiber fraction and starch in a dry fraction, leaving other compounds including proteins in a wet fraction. Extraction is favorably carried out in the presence of water. In wet milling, water is added before milling. In dry milling, the flour is added with water at a concentration of 20 to 30% by dry weight, preferably 25% by dry weight. When suspending flour in water, it is advantageous to choose flour with an average particle size of 100 µm or less. The pH of the solution is not a limiting factor, but it is more advantageous not to adjust the pH of the suspension, meaning working within a pH range of 6.2 to 7. The proteins can then be easily isolated from the wet fraction by precipitation at their isoelectric pH, which is approximately 4.5 for pea proteins. The pH is favorably adjusted between 4 and 5, preferably 4.5. The use of mineral acid is preferred, with hydrochloric acid being the most preferred. A preferred method is to use a combination of isoelectric pH and thermal coagulation of proteins, called thermocoagulation. In this case, the temperature is favorably selected within the range of 50 °C to 90 °C, including 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, and 85 °C. 70 °C is preferred. The contact time at this temperature will vary from 1 to 20 minutes, depending on the QR / onn / Lznz / E / YiAi temperature. The objective here is to coagulate the globulin fraction to separate it from other, more soluble compounds. After coagulation, the globulin proteins are readily removed from the remaining soluble compounds by any known method, including centrifugation and filtration. Step (d) consists of adjusting the pH between 6 and 9, preferably to approximately 7 at a neutral level, considering that it has been acidified in the previous step. In a first embodiment, step (d) of the process of the invention is carried out in the total absence of sodium hydroxide. Pure potassium hydroxide is then favorably used to completely replace the sodium hydroxide. The preferred concentration of potassium hydroxide ranges from 0.5 to 2 M, preferably approximately 1 M. Before adjusting the pH, water may be added to the globulin fraction to achieve a dry matter content of between 30% and 10%, preferably approximately 20% dry weight on a dry matter basis. In an alternative method, a mixture of sodium and potassium hydroxide can be used to adjust the pH. For this method, the molar ratio of sodium hydroxide to potassium hydroxide can vary from 10 / 90 to 90 / 10, preferably from 20 / 80 to 40 / 60, with greater preference from 30 / 70 to 40 / 60, and even more preferably the molar ratio of sodium hydroxide to potassium hydroxide is 35 / 65. QR / onn / Lznz / E / YiAi depending on the desired sodium and potassium levels in the final protein product. The potassium hydroxide and sodium hydroxide mixture can be achieved by blending them together before pH adjustment, or by using them simultaneously during pH adjustment. Finally, another option is to blend the resulting protein isolate with potassium hydroxide and sodium hydroxide. The process of the invention then optionally includes a step (e) of heating to a temperature of 100 °C to 160 °C and / or pasteurizing the proteins obtained after step (d). This heating step can be carried out using any method known to the person skilled in the art, such as, for example, an HTST treatment consisting of dispersing the proteins in steam water at a temperature between 100 °C and 160 °C for 0.1 seconds. The process of the invention then optionally includes a step (f) of drying the obtained proteins to stabilize them, preferably with the aid of a spray dryer, more preferably a multi-stage spray dryer. Before drying, optional homogenization of the obtained protein can be carried out using a shear pump, and also a commonly known process such as pasteurization or the introduction of auxiliary compounds. QR / ann / Lznz / E / YiAi food grade. A third aspect of this invention is the use of vegetable protein, preferably isolated from vegetable protein, more preferably isolated from legume protein, even more preferably isolated from pea protein, which is described in the first aspect of this invention in the industrial field comprising food, feed, pharmaceutical and cosmetic applications. In particular, the protein isolate of the invention can be used in a food texturizing process, preferably by means of a food extrusion process, more preferably by means of a dry extrusion process. Food extrusion is a form of extrusion used in food processing. It is a process by which a mixture of ingredients is forced through an opening in a perforated plate or die with a design specific to the food, and then cut to a specific size by blades. Through this extrusion process, protein isolate can be transformed into textured vegetable protein (TVP), which can be used in the baked goods or meat analogue industries. The vegetable protein isolate of the invention allows obtaining TVP with good properties, in particular, fiber content and water retention, with low sodium content. QR / ann / Lznz / E / YiAi Use of low sodium protein from the previous technique as calcium-based protein concentrates or protein isolates produces low sodium protein and low fiber TVP, respectively. Therefore, the invention further relates to a food texturization method, preferably a food extrusion method, more preferably a dry extrusion method, comprising a step of feeding an extrusion apparatus with a vegetable protein, preferably a vegetable protein isolate, more preferably a legume protein isolate, even more preferably a pea protein isolate according to the invention, optionally with a vegetable fiber, preferably a legume fiber, more preferably a pea fiber. The invention will now be better understood with the following examples. Examples Example 1: Pea protein isolate obtained using the state-of-the-art process First, dried, shelled, and sorted yellow peas were ground to obtain a flour. The resulting flour was then mixed with distilled water at a ratio of 1:4 (w / v) pea flour to water. The flour slurry was then centrifuged at 3000 g for 15 minutes to QR / ann / Lznz / E / YiAi removed the starch and internal fiber, yielding a protein solution. The protein solution was then precipitated by adjusting the pH to 4.5 with 30% HCl and heating at 70 °C for 15 min to coagulate the proteins. The coagulated solution was then centrifuged at 3000 g for 15 min to recover the protein curd. The protein curd was resuspended in distilled water to obtain approximately 20% dry weight on a dry matter basis and neutralized to pH 7.0 with 1 M NaOH. The resulting protein was finally treated with HTST (115 °C, 1 s) and spray-dried to achieve 95% dry weight on a dry matter basis. The sample was obtained using the previous technique – Sodium. Example 2: Pea protein isolate obtained using the state-of-the-art process First, dried, shelled, and sorted yellow peas were ground to obtain a flour. The resulting flour was then mixed with distilled water at a 1:4 (w / v) ratio of pea flour to water. The flour slurry was then centrifuged at 3000 g for 15 minutes to remove starch and internal fiber, yielding a protein solution. The protein solution was then precipitated by adjusting the pH to 4.5 with 30% HCl and heating to 70 °C for 15 minutes to coagulate the proteins. The coagulated solution was then centrifuged at [aβ / αηη / ίζηζ / E / γίΛΐ] 3000 g were soaked for 15 minutes to recover the protein curd. The protein curd was resuspended in distilled water to obtain approximately 20% dry weight on a dry matter basis and neutralized to pH 7.0 with 1 M Ca(OH)₂. The resulting protein was then treated with HTST (115 °C, 1 s) and spray-dried to achieve 95% dry weight on a dry matter basis. The sample was obtained using the previous technique – Calcium. Example 3: Pea protein isolate obtained using the process of the invention First, dried, shelled, and sorted yellow peas were ground to obtain a flour. The resulting flour was then mixed with distilled water at a 1:4 (w / v) ratio of pea flour to water. The flour slurry was then centrifuged at 3000 g for 15 minutes to remove starch and internal fiber, yielding a protein solution. The protein solution was precipitated by adjusting the pH to 4.5 with 30% HCl and heating to 70 °C for 15 minutes to coagulate the proteins. The coagulated solution was then centrifuged at 3000 g for 15 minutes to recover the protein curd. The protein curd was resuspended in distilled water to obtain approximately 20% dry weight of protein and neutralized to pH 7.0 with 1 M KOH. The resulting protein was finally treated with HTST QR / ann / Lznz / E / YiAi (115 °C, 1 s) and spray dried to achieve 95% dry weight on a dry matter basis. The sample obtained was Invention - Potassium. Example 4: Pea protein isolate obtained using the process of the invention First, dried, shelled, and sorted yellow peas were ground to obtain a flour. The resulting flour was then mixed with distilled water at a 1:4 (w / v) ratio of pea flour to water. The flour slurry was then centrifuged at 3000 g for 15 minutes to remove starch and internal fiber, yielding a protein solution. The protein solution was then precipitated by adjusting the pH to 4.5 with 30% HCl and heating to 70 °C for 15 minutes to coagulate the proteins. The coagulated solution was then centrifuged at 3000 g for 15 minutes to recover the protein curd. The protein curd was resuspended in distilled water to obtain approximately a dry weight content of 20% on a dry matter basis and neutralized to a pH of 7.0 with a 1 M mixture of KOH and NaOH, in a respective mass ratio of 65 / 35.The protein obtained was then treated with HTST (115 °C, 1 s) and spray-dried to achieve 95% dry weight on a dry matter basis. The resulting sample was the Invention - Sodium and Potassium Mixture. QR / ann / Lznz / E / YiAi Example 5: Analysis of different protein isolates obtained in Examples 1 to 4 All protein isolates obtained in Examples 1 to 3 were analyzed using the following protocols: - Dry matter was measured by drying with the help of a scale and an oven - Protein was quantified by assessing the total nitrogen level and multiplying it by 6.25 - The sodium and potassium contents were quantified using a flame ionization spectrometer - Water and oil retention was determined by: 10 g (=P1) of protein and 10 g of oil or water in a 50 ml test tube; 5 h under agitation; Centrifugation 10 min at 10000 G and removal of the supernatant; Weighing the pellet (=P2); Water / oil retention = ((P2— Pl) / Pl) * 100 - Emulsifying capacity or introduction of 0.2 g of protein sample into 20 ml of water, or homogenization with the help of Ultraturax IKA T25 for 30 seconds at 9500 rpm, or addition of 20 ml of corn oil under homogenization under the same conditions as in the previous stage, QR / ann / Lznz / E / YiAi centrifugation for 5 minutes at 3100 g. • a. In the case of a good emulsion (without breaking or inversion of the emulsion), a new experiment is carried out after increasing the amount of water and oil from 50%. • b. In the case of a bad emulsion (breakage or inversion of the emulsion), a new experiment is carried out after reducing the amount of water and oil by 50%. or the maximum amount of oil (called Qmax, in mi) that can be emulsified is thus determined iteratively. o Emulsifying capacity = (Qmax / 0.2)*100 Stability / Foaming ability - Solubility or 2.0 g of sample and 100 g of distilled water are placed in a 400 ml test tube at 20 °C. The pH is adjusted with 1 N HCl and / or 1 N NaOH and the mixture is made up to exactly 200.0 g with distilled water. This mixture is stirred for 30 minutes and then centrifuged for 15 minutes at 3000 g. After centrifugation, exactly 25.0 g of supernatant is extracted into a crystallization dish (mi). The dish is placed in an oven at 103 °C until it reaches a constant mass (m2). or Solubility = ( (m2 - mi) / 25)**100 QR / ann / Lznz / E / YiAi Invention - Potassium Invention Sodium and Potassium Mixture Prior Art - Calcium Prior Art - Sodium Dry Matter % 94 93 93 94 Protein %DM 85.9 86.0 84.3 85.2 Sodium %DM 0.09 0.4 0.10 1.25 Potassium %DM 1.97 1.4 0.07 0.06 Calcium %DM 0.07 0.06 1.45 0.05 Water Retention g / g 5.4 5.5 2.3-2.9 5.4 Oil Retention g / g 2.6 2.4 2.3-2.8 2.2 Emulsifying Capacity (ml of oil / g) 600 650 <50 650 Foaming Stability % -73 -70 -87 -66.7 Foaming Capacity % 100 100 100 100 Solubility (pH 8) g / 100 g brut 51.4 51.5 13 59.7 Solubility (pH 7) g / 100 g brut 33 41.4 12 49 Solubility (pH 6) g / 100 g brut 18 19.1 9.8 23.1 Solubility (pH 5) g / 100 g brut 10.7 11.1 11.6 11.6 Solubility (pH 4) g / 100 g brut 15 15 14.5 14.9 Solubility (pH 3) g / 100 g brut 53 52.4 20.3 61.4 PH 7.6 7.4 6.9 7.5 The results show that the protein of the invention has the same functional properties as the sodium-based proteins of the prior art, especially solubility, which is quite unexpected. The following table provides an overview of the most common pea protein isolates. QR / onn / Lznz / E / YiAi competition: NUTRALYS S85F NUTRALYS F85M NUTRALYS BF PEAS PROTEIN ISOLATE PISANE 09 PISANE F9 PISANE B9 ROQUETTE ROQUETTE ROQUETTE SHANDONG JIANYUAN COSU- CRA COSU- CRA COSU- CRA Dry matter % 7.7 6.8 7.7 5.8 7.8 5.0 3.9 Protein (N 6.25) 7o dm 85.6 85.2 86.6 83.3 83.6 91.1 85.4 Potassium 7o dm 0.32 0.29 0.35 0.23 0.29 0.22 0.17 Sodium 7o dm 1.25 1.32 0.15 0.78 1.80 0.97 1.00 Calcium 7° dm 0.06 0.07 1.40 0.65 0.04 0.06 0.05 Solubility pH3 7° 37.8 36.1 20.3 19.6 22.3 20.1 10.6 Solubility pH4 7° 13.9 13.3 14.5 12.4 14.9 11.4 7.6 Solubility pH5 7° 10.8 10.6 11.6 10.4 12.5 9.7 7.2 Solubility pH6 7° 28.2 23.2 9.8 10.0 20.4 14.0 10.4 Solubility pH7 7° 61.8 37.0 11.5 13.9 26.5 21.6 14.6 Solubility pH8 7o 75.2 52.0 13.0 16.1 29.1 24.9 19.0 PISANE B9 PISANE M9 PROPULSE PEA PROTEIN PURIS 870 CTH PEA PURIS PROTEIN 870H PEA PURIS PROTEIN 870 PEA PROTEIN TE 80 7o COSUCRA COSUCRA NUTRI-PEA PURIS PURIS PURIS YANTAI ORIEN- TAL Dry matter % 3.9 7.4 5.9 4.0 4.3 4.6 7.2 Protein (N 6.25) 7o dm 85.4 84.6 82.3 83.2 85.2 80.7 83.2 Potassium 7o dm 0.17 0.23 0.38 0.40 0.30 0.52 0.32 Sodium 7o dm 1.00 1.78 0.85 0.57 0.80 0.91 1.08 Calcium % dm 0.05 0.05 0.24 0.30 0.45 0.41 0.08 Solubility pH3 % 10.6 21.9 18.3 37.5 33.0 24.0 15.7 Solubility pH4 % 7.6 13.0 13.5 28.0 22.8 14.8 12.7 Solubility pH5 % 7.2 11.8 11.9 27.1 21.9 14.5 11.4 Solubility pH6 % 10.4 21.1 15.2 41.2 29.4 15.7 14.2 Solubility pH7 % 14.6 29.3 18.1 43.7 34.3 25.5 15.5 Solubility pH8 % 19.0 33.8 20.8 47.5 36.9 34.8 16.9 QR / ann / Lznz / E / YiAi Any expert in the technique will see that the isolate of the invention has a very unique salt profile compared to the more common isolates available commercially. Example 6: Use of protein isolates obtained in Examples 1 to 4 in a dry extrusion process A mixture of 87% by weight of protein isolates obtained from Examples 1 to 4 and 13% by weight of pea fiber (150 M from ROQUETTE) with respect to the total weight of the mixture is fed into a Leistritz / ZSE 27MAXX-80D twin-screw extruder. The twin-screw extrusion apparatus is operated with the aim of providing good fiber formation in textured proteins. The average operating conditions are: or 40 kg / h of dry mix and 6.85 kg / h of water or 1150 tr / min - specific energy 240 kW / kg Two analyses are performed: o Observation of the quality of fiber formation (visual) - Water retention analysis without grinding or Approximately 10 g of textured protein is placed in a test tube (weight = ml) or 100 ml of distilled water is added and 20 mins are waited or residual water is removed by centrifugation 3000 g 15 min or Weigh the remaining hydrated textured protein or Water retention = (m2 - mi) / mi - Water retention analysis with grinding or Approximately 10 g of textured protein is placed in a test tube (weight = ml) or 100 ml of distilled water is added and 20 mins are waited or the residual water is removed by centrifugation 3000 g 15 min or The remaining hydrated textured protein is ground with a Kenwood mixer, 2 min at maximum speed or 100 ml of distilled water is added and left for 20 min or residual water is removed by centrifugation 3000 g 15 min or The remaining hydrated textured protein is weighed or Water retention = (m2 -mi) / mi Invention - Potassium Prior technique - Calcium Prior technique - Sodium Water retention without grinding 2.9 1.2 3.2 Water retention with grinding 4.7 1.9 4.8 Fiber formation +4-4- — +++ The expert in the technique will immediately learn that our invention will be a good alternative for producing textured protein with low sodium content. • Fiber formation is very comparable between Invention - Potassium, Invention - Sodium and Potassium Mixture, and Prior Art - Sodium. Prior Art - Calcium does not provide good texturization. Despite some trials (modifications of water inlet, modifications of twin-screw speed, etc.), we were unable to achieve fiber formation in the textured proteins. • The water retention without grinding is slightly lower than the sodium-rich reference: this may allow the food producer to use it in food applications where the water retention without grinding must be lower. • Invention - Mixture of sodium and potassium allows the production of a textured protein more similar to the previous technique with sodium, especially the apparent density which is slightly lower with the invention - potassium. Example 7: This example aims to compare two embodiments of the present invention described in Examples 3 and 4, respectively, Invention - Potassium and Invention - Sodium and Potassium Mixture, when used in dry protein texturization. This was done in comparison with Technique QR / onn / Lznz / E / YiAi previous - Complete Sodium of Example 1. A mixture of 87% by weight of protein isolates obtained in Examples 1, 3, and 4 and 13% by weight of pea fiber (150 M from ROQUETTE) relative to the total weight of the mixture is fed into a Coperion ZSK-25 twin-screw extruder with 9 zones. Zones 1 and 2 consisted of transport elements, zone 3 consisted of mixing elements, zones 4-5 consisted of transport elements, zones 6-7 consisted of mixing elements, and finally zones 8-9 consisted of transport elements. The twin-screw extrusion unit is operated to provide good fiber formation in textured proteins. The average operating conditions are: dry feed rate 22 kg / h and water feed rate 6.6 kg / h. Screw speed - 1100 and specific mechanical energy 560-595 Kw.h / kg Three analyses are performed on the protein textures obtained: - Observation of the quality of fiber formation (visual) - Apparent density of the textured protein o A 1000 ml graduated cylinder is weighed empty (weight QR / onn / Lznz / E / YiAi = mi) or The graduated cylinder is filled with textured protein or The weight of the cylinder is recorded (weight = m2) or Apparent density = m2 - mi (expressed in g / 1). - Water retention analysis without grinding or Approximately 10 g of textured protein is placed in a test tube (weight = ml) or 100 ml of distilled water is added and 20 mins are waited or residual water is removed by centrifugation 3000 g 15 min or Weigh the remaining hydrated textured protein or Water retention = (m2 - mi) / mi - Water retention analysis with grinding or Approximately 10 g of textured protein is placed in a test tube (weight = ml) or 100 ml of distilled water is added and 20 mins are waited or the residual water is removed by centrifugation 3000 g 15 min or The remaining hydrated textured protein is ground with a Kenwood mixer, 2 min at maximum speed or 100 ml of distilled water is added and left for 20 min or residual water is removed by centrifugation 3000 g 15 min or Weigh the remaining hydrated textured protein or Water retention = (m2 - mi) / mi QR / ann / Lznz / E / YiAi Potassium Invention - Sodium and Potassium Mixture Prior Art Sodium Apparent Density 64.2 79.7 81.8 Water Retention without Crushing 5.6 5.2 5.6 Water Retention with Crushing 6.3 6.3 6.4 Fiber Formation +++ +++ +++ The expert in the technique will see from these results that both isolates made from the invention supply a textured protein that has good fiber formation and good water retention. Invention – Full Potassium provides a textured protein that is significantly lower in terms of bulk density compared to Prior Art – Sodium (approximately 20%). This makes this product perfect for applications such as snacks, where airy textured products are desired. Invention – A mixture of sodium and potassium provides a textured protein that is very similar in terms of bulk density compared to the prior art – sodium. This makes this product ideal for applications such as meat analogues. It is hereby stated that, as of this date, the best method known to the applicant for putting the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

Having described the invention as above, the following claims are claimed as property:

1. Vegetable protein, preferably a vegetable protein isolate, more preferably a legume protein isolate, even more preferably a pea protein isolate, characterized in that its maximum sodium content is less than 0.6% on a dry weight basis, and its calcium content is less than 1% on a dry weight basis.

2. Vegetable protein, preferably a vegetable protein isolate, more preferably a legume protein isolate, even more preferably a pea protein isolate, according to claim 1, characterized in that it contains more than 80% by dry weight of protein content on a dry matter basis.

3. Vegetable protein, preferably a vegetable protein isolate, more preferably a legume protein isolate, even more preferably a pea protein isolate, according to claim 1, characterized in that its potassium content is between 0.5 and 3% by dry weight of its dry matter.

4. Vegetable protein, preferably a vegetable protein isolate, more preferably a legume protein isolate, even more preferably a pea protein isolate, according to claim 1 or 2, characterized in that its maximum sodium content is preferably less than 0.2%, more preferably less than 0.1% by dry weight on a dry matter basis and its potassium content is between 0.5 and 3% by dry weight on a dry matter basis, preferably between 1.5 and 2.5%, more preferably between 1.8 and 2.5% by dry weight on a dry matter basis.

5. Vegetable protein, preferably a vegetable protein isolate, more preferably a legume protein isolate, even more preferably a pea protein isolate, according to claim 1 or 2, characterized in that its sodium content is between 0.3% and 0.6%, preferably between 0.4% and 0.6%, more preferably 0.5% on a dry weight basis, and its potassium content is between 0.5% and 3% on a dry weight basis, preferably between 1% and 2%, more preferably between 1.3% and 1.5% on a dry weight basis.

6. A process for preparing a vegetable protein according to any one of claims 1 to 5, comprising the following steps: a) providing a plant seed containing protein; b) grinding the above seed and obtaining a ground suspension in water; c) extracting proteins from the ground suspension; d) adjusting the pH between 6 and 9; e) optionally heating to a temperature of 100 °C to 160 °C and / or pasteurizing the obtained proteins; f) optionally drying the obtained proteins; characterized in that potassium hydroxide is used as a pH reagent in step (d).

7. Process according to claim 6, characterized in that step d) is carried out in the total absence of sodium hydroxide.

8. Process according to claim 6, characterized in that a mixture of sodium hydroxide and potassium hydroxide is used to adjust the pH in step d), wherein the molar ratio between the sodium hydroxide and the potassium hydroxide varies from 10 / 90 to 90 / 10, preferably from 20 / 80 to 40 / 60, more preferably from 30 / 70 to 40 / 60, even more preferably the molar ratio between the sodium hydroxide and the potassium hydroxide is 35 / 65.

9. Use of the vegetable protein in accordance with any of claims 1 to 5, wherein industrial comprising food, feed, pharmaceutical and cosmetic applications.

10. Use of vegetable protein according to any of claims 1 to 5 in a food texturization process.