Method for manufacturing leguminous protein

Abstract

To provide a method for manufacturing a leguminous plant protein composition, capable of obtaining a leguminous plant protein composition having improved functional characteristics, reduced gelling power and improved emulsification power.SOLUTION: A method for manufacturing a leguminous protein composition, preferably, a pea protein composition comprises steps of dry-heating a leguminous seed for 1-6 minutes at a temperature of 70-130°C; grinding the seed to obtain powder; forming the suspension of the powder in a water solution; and separating a soluble component from the suspension to extract protein from the soluble component. The method can obtain a protein composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention belongs to the field of vegetable proteins. In particular, the present invention relates to a method for producing a leguminous plant protein composition, preferably a protein composition from peas, and to a protein composition obtained by this method.

Background Art

[0002] The daily protein requirement for humans is 12-20% of the food intake. These proteins can be obtained either from animal-derived products (meat, fish, eggs, dairy products) or from plant-derived foods (grains, legumes, seaweeds).

[0003] However, in developed countries, protein intake is mainly made from animal-derived proteins. However, numerous studies have shown that excessive intake of animal-derived proteins and insufficient intake of vegetable proteins are one of the causes of increasing cancer and cardiovascular diseases.

[0004] Furthermore, animal proteins have many drawbacks both in terms of allergenicity, especially for proteins from milk or eggs, and in terms of the environment in relation to the harmful effects of intensive agriculture.

[0005] Therefore, there is an increasing demand from manufacturers for plant-derived compounds that have beneficial nutritional and functional properties but do not have the drawbacks of animal-derived compounds.

[0006] Soybeans are a major plant alternative to animal proteins. However, the use of soybeans presents certain drawbacks. The origin of soybean seeds is, in most cases, not from genetically modified organisms (GMOs), and the production of its proteins proceeds through a degreasing process using solvents.

[0007] Since the 1970s, particularly in Europe, mainly in France, leguminous plants, especially those including broad beans, have developed dramatically as alternative protein sources to animal proteins for animal and human food intake. Broad beans contain approximately 27% by weight of protein. The term "broad bean" is considered in its broadest accepted usage herein, and includes, in particular, all wild varieties of "round broad bean", as well as all mutant varieties of "round broad bean" and "wrinkled broad bean", regardless of their normal intended use (human food, animal feed and / or other uses). These seeds are non-GMO and do not require a solvent-based oil extraction process.

[0008] Broad bean proteins, mainly vicilin, have been industrially extracted and utilized for many years. As an example of a method for extracting broad bean proteins, reference can be made to European Patent No. 1400537. In this process, the seeds are ground in the absence of water to obtain a powder (a process called "dry milling"). The powder is then suspended in water to extract the protein.

[0009] Despite their excellent quality, the proteins extracted from broad beans produce an odor known as "broad bean odor", "beany odor", or "plant odor" when compared to animal proteins. This odor is an undeniable obstacle in many industrial applications, especially in food.

[0010] Particularly in the beverage field, it is particularly difficult to mask the odor of proteins, so improving the sensory profile is essential. That is, by adding additional components, Actually, viscosity adjustment, stability in solution, and / or beverage palatability can be achieved. Furthermore, it is advantageous that the protein has a low gelling power or even lower viscosity, so that the protein content can be increased without the beverage gelling or becoming too viscous.

[0011] As a result of many studies, it has been revealed that one of the main causes of these undesirable odors is due to the action of endogenous lipoxygenase on the lipids remaining during protein extraction, resulting in the synthesis of aldehydes and / or ketones (especially hexanal). Saponins and 3-alkyl-2-methoxypyrazines are also a type of compound that generates these undesirable odors ("Flavor aspects of pulse Ingredients", Wibke S.U.Roland, 2017).

[0012] Therefore, those skilled in the art have developed several solutions to improve the odor of commercially available pea protein and give it a neutral taste. The first solution is based on masking the odor by adding compounds selected for this purpose. In this solution, it is necessary to introduce into their formulations compounds that the user may not necessarily want to introduce, as well as compounds that can cause regulatory and / or allergen problems. Another solution is described in U.S. Patent No. 4,022,919, which taught that in the early 1970s, by treating the pea protein with steam, a protein with improved odor could be obtained. However, this method can be criticized for the risk of changing the functional quality of the protein obtained by heat denaturation (e.g., loss of solubility or increase in its hydration capacity), and the need to add a purification step required before use. Therefore, although these solutions are effective, the end-users of the protein need to perform additional purification operations, which may change the characteristics of the pea protein. Therefore, those skilled in the art have clearly tried to directly and simply obtain pea protein with a neutral odor during the extraction process.

[0013] Many potentially possible solutions have been considered, such as selecting pea varieties with low lipoxygenase or pre-germinating peas before protein extraction, but not limited to these. Recently, International Publication No. WO 2017 / 120597, which discloses a method including precipitation by adding salt, multiple washings, and recovery by centrifugation, can be mentioned. Despite complex methods using a large amount of water (up to 30 times the amount of peas), pea proteins have the odors of "bean-like smell" and "bitterness" (see Graphs 18A, B, and C of International Publication No. WO 2017 / 120597).

[0014] Since lipoxygenase and saponin are sensitive to temperature, in International Publication No. WO 2019 / 053387, it was considered to add additional heat treatment, sometimes combined with a quenching process, during the extraction process consisting of heating (blanching) in a humid environment. Unfortunately, these processes involve a large amount of water and generate soluble by-products that need to be recovered. Furthermore, even using this method, proteins with reduced gelling power cannot be produced.

[0015] In the related soybean field, roasting or dry heat (also called toasting) is used. An important problem in the pea field is the preservation of pea starch, which must not be decomposed for industrial use. Since soybeans do not contain starch, in the soybean field, very high heating temperatures can be used to inhibit lipoxygenase without worrying about the starch problem.

[0016] Also, when seeds are heated, functional modification of proteins (such as solubility and emulsifying power) may occur, and specific uses, especially in food, may become impossible.

[0017] Therefore, it is advantageous to obtain an optimized extraction method and guaranteed characteristics, as well as legume proteins with improved odor, especially legume protein isolates, and more specifically, pea protein isolates. Summary of the Invention

[0018] By subjecting seeds to a preliminary heat treatment step of heat-treating them at 70 to 130°C for 1 to 6 minutes, preferably at 100 to 120°C for 2 to 4 minutes, the inventors have shown that it is possible to inhibit the activity of endogenous lipoxygenase while maintaining the functionality of starch and ensuring the extraction yield of various components. By the method developed by the inventors, it is possible to obtain a legume protein composition whose functional properties are particularly suitable for use in protein-enriched beverages, i.e., a legume protein composition with improved sensory properties, reduced gelling power, and improved emulsifying power.

[0019] According to a first aspect of the present invention, a method for producing a legume protein composition is proposed, the method comprising: i) dry heat-treating seeds of a leguminous plant, preferably selected from pea, broad bean, and fava bean, at a temperature of 70 to 130°C, such as 80 to 125°C, particularly 100 to 120°C, for 1 to 6 minutes, such as 1.5 to 5 minutes, particularly 2 to 4 minutes; ii) pulverizing the seeds into powder and suspending the powder in an aqueous solution, preferably at a dry matter concentration of 15 to 25% by weight, more preferably 20% by weight, based on the weight of the suspension; (iii) separating the soluble components of the suspension by centrifugation; (iv) extracting protein from the soluble components.

[0020] In a preferred embodiment, extracting protein from the fraction comprises coagulating the protein in an aqueous solution at pH 4 to 6 and heat-treating the solution at 45 to 65°C, preferably 55°C, particularly for 3.5 to 4.5 minutes, preferably 4 minutes. Preferably, the coagulated protein is recovered, preferably by centrifugation, and suspended in an aqueous solution. Thereafter, the pH of the aqueous solution of the coagulated protein can be adjusted to 6 to 8, preferably 7, and the aqueous suspension can be heat-treated at 130 to 150°C, preferably 140°C, for 5 to 15 seconds, preferably 10 seconds. The method may further comprise drying the aqueous suspension of the coagulated protein.

[0021] According to another aspect, there is provided a leguminous plant protein composition obtained by the method according to the first aspect of the present invention.

[0022] According to a final aspect of the present invention, it is proposed that the protein composition obtained by the method described in the first aspect of the present invention be industrially used, particularly for animal and human foodstuffs.

[0023] The present invention will be better understood from the following detailed description.

Brief Description of the Drawings

[0024]

Figure 1

Embodiments for Carrying Out the Invention

[0025] Thus, according to a first aspect of the present invention, there is proposed a method for producing a leguminous plant protein composition, the method comprising: i) heating seeds of a leguminous plant preferably selected from pea, broad bean, and fava bean at a temperature of 70 to 130 ° C, for example 80 to 125 ° C, particularly 100 to 120 ° C, for 1 to 6 minutes, for example 1.5 to 5 minutes, particularly 2 to 4 minutes; (ii) grinding the seeds into powder and suspending it in an aqueous solution; iii) separating soluble components from the aqueous suspension, preferably by centrifugation; (iv) extracting the protein in the soluble components.

[0026] In this patent application, the term "protein composition" should be understood to mean a composition obtained by extraction and purification, which composition should be understood to mean a protein macromolecule formed from one or more polypeptide chains consisting of a sequence of amino acid residues joined together via peptide bonds. In the specific context of pea protein, the present invention relates more particularly to globulins (about 50 - 60% of pea protein). Pea globulins are mainly classified into three subfamilies: legumin, vicilin, and convicilin.

[0027] In this application, the term "leguminous plant" will be understood to mean the family of dicotyledonous plants of the order Fabales. The Fabaceae is the third largest family of flowering plants in terms of the number of species, after the Orchidaceae and Asteraceae. The Fabaceae includes about 765 genera and over 19,500 species. Some leguminous plants such as soybean, kidney bean, pea, chickpea, broad bean, adzuki bean, cultivated lentil, cultivated alfalfa, various clovers, cowpea, moth bean, licorice, and mung bean are important crop plants.

[0028] According to a preferred embodiment of the present invention, the leguminous plant protein is selected from the group consisting of pea, kidney bean, broad bean, and mixtures thereof, preferably pea.

[0029] The term "pea" includes in particular all wild varieties of "round pea", as well as all mutant varieties of "round pea" and "wrinkled pea".

[0030] When the selected leguminous plant is pea, the pea can be washed (removing unwanted particles such as stones, insect carcasses, soil residues, etc.), which is a well-known step to those skilled in the art, and also the outer fibers can be removed at a temperature of 70 - 130 °C, for example 80 - 125 °C, particularly 100 - 120 °C, for 1 - 6 minutes, for example 1.5 - 5 minutes, particularly 2 - 4 minutes, before the heating and grinding steps of the method according to the present invention.

[0031] The method according to the invention comprises a step i) consisting of heat-treating the seeds at a temperature of 70 to 130 °C, for example 80 to 125 °C, in particular 100 to 120 °C, for a time of 1 to 6 minutes, for example 1.5 to 5 minutes, in particular 2 to 4 minutes. This heat treatment is a dry heat treatment and is carried out in the absence of an aqueous solvent in addition to the aqueous solvent present in the seeds. This dry heat treatment (toasting) differs from microwave treatment in that the heat is supplied by convection. Thereby, the heat treatment (time and temperature) of the seeds can be accurately controlled. This dry heat treatment is particularly advantageous since it can be easily carried out, for example without monitoring the relative humidity. As illustrated in the present application, it is important to consider the intervals of time and temperature in order to maintain the functionality of the starch, ensure the extraction yield of various components and inhibit the activity of internal lipoxygenase.

[0032] By complying with this heat treatment step prior to these specific conditions and by complying with the conditions of the various steps of this method, it is also possible to obtain a protein composition whose functional properties are particularly suitable for protein-enriched beverage applications, i.e., a protein composition with improved sensory properties, reduced gelling power and improved emulsifying power.

[0033] In an even more preferred embodiment, the temperature is 110 to 120 °C, for example 120 °C. This choice makes it possible to obtain a very low viscosity of the protein composition, which is a further advantage in certain food applications such as high-protein beverages.

[0034] At the end of this step, in a well-known step also called "peeling", the outer broad bean fiber (cellulose outer shell) is optionally removed.

[0035] The method according to the invention comprises a step ii) of grinding the seeds to produce an aqueous suspension.

[0036] The grinding is carried out by any suitable technique known to those skilled in the art, such as a ball mill, a conical mill, a screw mill, a jet mill or a rotor / rotor system.

[0037] During pulverization, water may be added continuously or discontinuously at the start, during, or at the end of pulverization so as to produce an aqueous suspension of pulverized broad bean with a solid content (SC) of 15% to 25% by weight, preferably 20% by weight, based on the weight of the suspension.

[0038] At the end of pulverization, the pH can be checked. Preferably, the pH of the aqueous suspension of pulverized broad bean at the end of step ii) is adjusted to 8 - 10, preferably pH 9. The pH can be adjusted by adding an acid and / or a base, such as sodium hydroxide or hydrochloric acid. The use of ascorbic acid, citric acid, potassium hydroxide, and sodium hydroxide is preferred.

[0039] Next, the method according to the present invention comprises step iii) of separating soluble components from the aqueous suspension, preferably by centrifugal force. This step makes it possible to separate the soluble fraction from the insoluble fraction of the suspension. The insoluble fraction mainly consists of starch and a polysaccharide called "internal fiber". Proteins are concentrated in the soluble fraction (supernatant).

[0040] Also, by providing a first sieving step for removing the internal fiber of broad bean, starch and fiber can be separated. This first step is necessary because the internal fiber of broad bean binds very easily to the starch and proteins of broad bean. Thereafter, it is necessary to wash these fibers multiple times to extract starch or related proteins. After this sieving step, the suspension from which the internal fiber has been removed is centrifuged to produce a "light phase" mainly containing proteins and a "heavy phase" mainly containing starch.

[0041] The method according to the present invention includes step iv) of extracting proteins from the soluble components. The extraction can be carried out by any suitable method, such as precipitation at the isoelectric point pH of the protein or heat coagulation by heating.

[0042] Preferably, protein extraction consists of a step of coagulating the protein in an aqueous solution at a pH of 4 to 6, preferably 5, followed by heating to a temperature of 45 to 65°C, preferably 55°C.

[0043] The contact time can be from 1 minute to 30 minutes, for example from 1 minute to 10 minutes, preferably from 3 minutes to 5 minutes, and even more preferably 5 minutes. The object of the present specification is to separate the target pea protein from other components of the supernatant in step iv). It is very important to check the time / temperature scale.

[0044] Preferably, the heating is carried out, for example, by indirect steam injection in a double jacketed stirred tank.

[0045] The coagulated protein (also known as coagulated protein flocs) can then be recovered by centrifugation. Thereby, the solid fraction having the concentrated protein is separated from the liquid fraction having the concentrated sugar and salts. Thereafter, the flocs are suspended in an aqueous solution and preferably diluted with water. Thereafter, the solid content is adjusted to a solid content of 10% by weight to 20% by weight, preferably 15% by weight, based on the weight of the suspension.

[0046] Thereafter, the pH of the protein flocs can be adjusted to a value of 6 to 8, preferably 7. The pH is adjusted using any acidic and basic reagents. The use of ascorbic acid, citric acid, potassium hydroxide, and sodium hydroxide is preferred.

[0047] Thereafter, heat treatment can be carried out at 130°C to 150°C, preferably 140°C, for 5 seconds to 15 seconds, preferably 10 seconds.

[0048] The extraction of the protein can preferably be terminated by drying using any technique known to those skilled in the art. In a preferred method, the coagulated protein flocs are dried so as to reach a protein solid content of more than 80% by weight, preferably more than 90% by weight, based on the weight of the solid content. For this purpose, any technique well-known to those skilled in the art, such as freeze-drying or atomization, can be used. Atomization is a preferred technique, particularly multiple-effect atomization.

[0049] The solid content is measured by any method known to those skilled in the art. Preferably, the "dehydration" method is used. It consists of measuring the amount of water evaporated by heating a known amount of a sample of known weight. The sample is first weighed and its mass m1 is measured in grams, the sample is placed in a heating chamber to evaporate the water until the sample mass stabilizes, the water is completely evaporated (preferably, the temperature is 105 °C under atmospheric pressure), and the final sample is weighed and its mass m2 is measured in grams. The solid content is determined by the following calculation: (m2 / m1)*100.

[0050] Therefore, according to a second aspect of the present invention, a leguminous plant protein composition is proposed, in which the leguminous plant is particularly selected from pea, broad bean, and fava bean, and the composition can be obtained by the method described in the first aspect of the invention.

[0051] Preferably, the leguminous plant protein composition according to the present invention has a protein content of more than 80% by weight, preferably more than 85% by weight, and even more preferably more than 90% by weight, based on the total weight of the solid content.

[0052] The protein content is measured by any technique well-known to those skilled in the art. Preferably, the total nitrogen is assayed (as the weight percentage of nitrogen relative to the total dry weight of the composition) and the result is multiplied by a factor of 6.25. This well-known methodology in the field of vegetable proteins is based on the observation that proteins contain on average 16% nitrogen. Any dry matter assay method well-known to those skilled in the art can also be used.

[0053] As exemplified below, the protein composition according to the present invention is innovative because its sensory profile, in particular the components of "plant odor" or "bean-like odor", has been improved. This component is evaluated according to the practice by a taste test panel using the sensory organs. This difference can also be identified by analyzing volatile compounds using gas chromatography equipped with a mass spectrometer.

[0054] Further, this composition can also be characterized in that its gelling power is optimized in that it is reduced by about half compared to a legume protein composition obtained by a production method that does not include a step of heat-treating legume seeds.

[0055] The term "gelling power" consists of the ability of a protein composition to form a gel or network, and means a functional property that increases viscosity and produces a state of matter between the liquid state and the solid state. The term "gel strength" may also be used. In order to quantify the gelling power, it is necessary to generate this network there and evaluate its strength. In order to perform this quantification, in the present invention, Test A is used and will be described below. 1) Solubilization at 60°C ± 2°C of the protein composition tested in water at a solids content of 15% ± 2% and pH 7 2) Stirring at 60°C + / - 2°C for 5 minutes 3) Cooling to 20°C + / - 2°C and stirring at 350 rpm for 24 hours 4) Performing suspension using a controlled stress rheometer equipped with concentric cylinders 5) Performing the following temperature profile: a. Phase 1: Heating from a temperature of 20°C ± 2°C to a temperature of 80°C ± 2°C in 10 minutes, b. Phase 2: Stabilization at a temperature of 80°C ± 2°C for 120 minutes, c. Phase 3: Cooling from 80°C ± 2°C to a temperature of 20°C ± 2°C in 30 minutes. 6) Measuring the gelling power expressed in Pa units.

[0056] Preferably, the imposed stress rheometer is a TA Instruments AR2000 model equipped with a Duvet geometry and a Peltier temperature control system. To avoid problems of evaporation at high temperatures, liquid paraffin is added on top of the sample.

[0057] For the purposes of the present invention, a "rheometer" is a test machine for obtaining measurements relating to the rheology of fluids or gels. The rheometer applies a force to the sample. Generally speaking, with respect to characteristic small dimensions (the very small mechanical inertia of the rotor), the rheometer enables a basic investigation of the mechanical properties of liquids, gels, suspensions, pastes, etc., which respond to the applied force.

[0058] The so-called "controlled stress" model can measure the intrinsic viscoelastic values of substances that are particularly dependent on time (or angular velocity ω) and temperature by the application of a sinusoidal stress (vibration mode). Specifically, this type of rheometer provides access to the complex elastic modulus G*, which itself provides access to the elastic modulus G' of the elastic part or the elastic modulus G" of the viscous part.

[0059] Also, this composition can be characterized in that the emulsifying power is optimized in that it is improved by about two times compared to a legume protein composition obtained by a production method not including a step of heat-treating legume seeds.

[0060] "Emulsifying power" or further "emulsifying ability" refers to the maximum amount of oil that can be dispersed in an aqueous solution containing a defined amount of emulsifier before the emulsion decomposes into phases or becomes inverse-phase (Sherman, 1995). To quantify it, the applicant has developed a test for easy, rapid, and reproducible quantification: Disperse 0.2 g of the product sample in 20 mL of water, Homogenize the solution at a speed of 9,500 rpm for 30 seconds using an Ultraturax IKA T25, Add 20 mL of corn oil under homogenization under the same conditions as in step 2 above, Perform centrifugation at 3,100 g for 5 minutes, When a good emulsion is obtained, increase the amounts of water and corn by 50% and repeat the test at Point 1. When a poor emulsion is obtained (phase shift), decrease the amounts of water and corn by 50% and repeat the test at Point 1. In this way, the maximum amount of oil that can be emulsified (Qmax (mL)) can be repeatedly determined. Therefore, the emulsifying ability is the maximum amount of corn oil that can be emulsified per 1 g of the product. Emulsifying ability = (Qmax / 0.2) * 100

[0061] According to the last aspect of the present invention, there is proposed an industrial use of the leguminous plant protein composition according to the present invention, preferably a leguminous plant protein isolate selected from pea, broad bean, and fava bean, and even more preferably a pea protein isolate, particularly for use in animal and human foods.

[0062] As exemplified below, the protein composition obtained by implementing the method according to the present invention has an improved sensory profile and can be characterized in that the gel strength is at least halved and the emulsifying power is at least doubled as compared with the leguminous plant protein composition obtained without heat-treating the seeds of the leguminous plant. These characteristics are particularly suitable for protein-enriched beverages such as RTD ("Ready-to-Drink"), plant-based alternative milks, or powdered mixed beverages.

[0063] What is important for the end consumer is the improvement in the sensory profile, but the decrease in the gelling power enables an increase in the protein content without resulting in an overly viscous beverage. Finally, the emulsifying power is also noted, for example, for stabilizing essential fatty acids.

[0064] The present invention will be better understood by the following non-limiting examples.

Example

[0065] Example 1: Influence of heating parameters of leguminous plant seeds in the protein production method.

[0066] In this example, clean yellow pea seeds (Pisum Savitum) from which foreign matter such as small stones has been removed are used.

[0067] Several heat treatment techniques are applied for comparison: Ventilated oven, 2 - 10 minutes, 80° - 120°C Microwave oven, 30 seconds - 3 minutes, 1000W Autoclave, 5 - 15 minutes, 100°C - 120°C Next, the following methods for protein and starch extraction are applied: Separate the outer fiber from the cotyledon of the pea. Grind the cotyledon of the pea using a mortar. Suspend the powder in water at a solid content (SC) of 17%, 20°C ± 2°C, and pH 7 ± 1. Shake for 30 minutes. Centrifuge at 1,000G for 5 minutes to separate insoluble matter (starch and internal fiber). Adjust the supernatant to pH 5. Heat and stir at 55°C for 20 minutes in a container equipped with a double jacket. Recover the protein composition by centrifugation at 5,000G for 5 minutes. Adjust the pH to 7 with 1N NaOH. Perform heat treatment by direct injection at 140°C for 10 seconds. Perform spray drying. Perform several measurements to verify and compare different methods: Modified state of starch by DSC and enthalpy measurement Calculation of protein recovery rate (amount of extracted protein / total amount of protein). Odor by taste test. This component is evaluated using a taste test panel of sensory organs.

[0068] The results are shown in Table 1 below.

Table 1

[0069] By performing pretreatment with dry heat, the functionality of starch can be maintained, the extraction yield of various components can be guaranteed, and the odor of the resulting protein can be improved.

[0070] Example 2: An example for demonstrating the effect of dry heat treatment on the quality of the obtained protein composition.

[0071] The purpose of this example is to demonstrate the effect of dry heat treatment on the quality of the obtained protein composition. Three seed pretreatments are considered: a. Without pretreatment b. Ventilated oven, 4 minutes, 100 °C b. Ventilated oven, 2 minutes, 120 °C Separate the outer fiber from the cotyledon of the pea. Grind the cotyledon of the pea using a mortar. Suspend the powder in water at SC17%, 20 °C ± 2 °C, pH 7 ± 1. Shake for 30 minutes. Separate the insoluble matter (starch and internal fiber) by centrifugation at 1,000 G for 5 minutes. Adjust the supernatant to pH 5. Heat and stir at 55 °C for 20 minutes in a container equipped with a double jacket. Recover the protein composition by centrifugation at 5,000 G for 5 minutes. Adjust the pH to 7 with 1 N NaOH. Perform heat treatment by direct injection at 140 °C for 10 seconds. Perform spray drying.

[0072] Perform several measurements to verify and compare different tests: Solid content measured by drying. Protein content measured by measuring total nitrogen and multiplying the result by a factor of 6.25. Protein recovery rate (amount of extracted protein / total amount of protein) Emulsifying activity measured by the test developed by the applicant above. The gel strength measured in the above Test A.

[0073] The results are shown in Table 2 below.

Table 2

[0074] The protein composition according to the present invention has an emulsifying ability that is approximately doubled and a decreased gel strength.

[0075] The viscosity of the protein composition is measured using a TA Instrument AR2000 rheometer equipped with a Duvet geometry and a Peltier temperature control system. The measurement is carried out at a temperature of 20°C and a shear rate of 0.006 for 600 s -1 for 3 minutes.

[0076] Also, the protein composition according to the present invention prepared at a temperature of 120°C has a decreased viscosity (Figure 1).

[0077] Furthermore, by replacing the grinding of the cotyledons of broad beans using a mortar with the wet grinding of the cotyledons of broad beans as described in Example 1 of International Publication No. WO2019 / 053387, a method similar to the method for producing protein composition a. (obtained without pretreatment) is implemented. This grinding consists of putting the cotyledons of broad beans into an aqueous solution at 80°C, heat-treating for 3 minutes while maintaining the temperature of the solution, recovering, then immersing in water adjusted to 7°C and cooling to 10°C, and then grinding in the solution. At the end of this method, a comparative protein composition with a gel strength that is not decreased compared to protein composition a is obtained.

Claims

1. 1. A method for producing a legume protein composition comprising the steps of: i) subjecting legume seeds to a dry heat treatment at a temperature of 70 to 130° C., for example 80 to 125° C., particularly 100 to 120° C., for 1 to 6 minutes, for example 1.5 to 5 minutes, particularly 2 to 4 minutes; ii) grinding the seeds into a flour and suspending the flour in an aqueous solution; iii) separating the soluble components of said suspension, preferably by centrifugal force; iv) extracting proteins from said soluble components.

2. 2. A method according to claim 1, characterized in that the powder of step ii) is introduced into the aqueous suspension at a concentration of 15-25% by weight solids, preferably 20% by weight solids, relative to the weight of the suspension.

3. Step iv) of extracting proteins comprises 3. The method according to claim 1 or 2, characterized in that it comprises the steps of coagulating the protein in an aqueous solution of pH 4-6 and heat treating the solution at 45°C to 65°C, preferably 55°C.

4. recovering the coagulated protein, preferably by centrifugation and suspending the protein in an aqueous solution; adjusting the pH of the aqueous protein solution to 6 to 8, preferably 7; The method according to claim 3, further comprising the step of heat treating the aqueous protein solution at 130°C to 150°C, preferably 140°C, for 5 to 15 seconds, preferably 10 seconds.

5. The method of any one of claims 1 to 4, further comprising the step of drying the aqueous suspension of the protein.

6. The method according to any one of claims 1 to 5, characterized in that the seeds of the legume family are selected from the group consisting of pea, prickly pear and fava bean.

7. The method according to claim 6, characterized in that the seeds of the legume family are pea seeds.

8. A legume protein composition obtainable by the method according to any one of claims 1 to 7.

9. Use of a legume protein according to any one of claims 1 to 7 in the manufacture of a foodstuff.

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