阅读说明：本技术 胶质豆类蛋白 (Glial legume proteins ) 是由 C·拉罗切 L·卡尔蒙 于 2020-04-29 设计创作，主要内容包括：本发明涉及一种在中性pH值下具有改进的凝胶强度的豆类蛋白组合物,以及其生产方法。(The present invention relates to a pulse protein composition having improved gel strength at neutral pH, and a method for producing the same.)

1. A pulse protein composition, in particular selected from the group consisting of peas, lupins and fava beans, characterized in that the protein composition according to test A has a gel strength of more than 200 Pa.

2. The pulse protein composition of claim 1, wherein the pulse protein composition is a pulse protein isolate.

3. The pulse protein composition of claim 1 or 2, wherein the pulse plant is pea.

4. The pulse protein composition according to any one of claims 1 to 3, wherein said pulse protein composition has a protein abundance of more than 80%, preferably more than 85%, more preferably more than 90% relative to the total weight of dry matter.

5. The pulse protein composition according to any one of claims 1 to 4, wherein said pulse protein composition has a D90 particle size of less than 20 microns, preferably less than 15 microns, more preferably less than 10 microns.

6. The pulse protein composition according to any one of claims 1 to 5, characterized in that it has a solubility of 30 to 65%, such as 33 to 62%, in particular 38 to 60%, according to test B.

7. Method for producing a pulse protein composition according to any one of claims 1 to 6, characterized in that it comprises the following steps:

1) processing legume seeds, preferably selected from the group consisting of peas, lupins and fava beans;

2) grinding the seeds to form an aqueous suspension;

3) separating the water insoluble fraction by centrifugal force;

4) at 55 deg.C⁺/_-2 ℃ and 65 DEG C⁺/_-Between 2 ℃ and preferably 60 DEG C⁺/_-Coagulating the protein by heating to an isoelectric pH at a temperature of 2 ℃ for a time of between 3.5 minutes and 4.5 minutes, preferably 4 minutes;

5) recovering the coagulated protein floc by centrifugation;

6) adjusting the pH to 6⁺/_-0.5 and 9⁺/_-Between 0.5;

7) as an alternative, heat treatment may be performed;

8) drying the coagulated protein floc;

9) the coagulated protein floc is ground with an air jet mill and dried to obtain particles of D90 particle size of less than 20 microns, preferably less than 15 microns, more preferably less than 10 microns.

8. The method of claim 7, wherein the heat treatment of step 7 comprises a temperature of 100 degrees C⁺/_-2 ℃ to 160 DEG C⁺/_-Heating at 2 ℃ for a conventional proportion of 0.01 to 3 seconds, preferably between 1 and 2 seconds, and then cooling immediately.

9. Method according to any of claims 7 to 8, characterized in that the drying in step 8 is done by atomization, preferably by multi-effect atomization drying.

10. Method according to any one of claims 7 to 9, characterized in that the grinding in step 9 is done by means of an opposed air jet mill.

11. The method according to any one of claims 7 to 10, wherein the gel strength of the protein composition according to test a is at least 150% of the gel strength of the dried protein floe in step 8.

12. Use of a composition according to any one of claims 1 to 6 in a food or pharmaceutical product.

13. Use according to claim 12, wherein the pH of the foodstuff or pharmaceutical product is between 4 and 9, such as between 5 and 8.5, in particular between 6 and 8, even about 7.

14. Use according to claim 12 or 13, wherein the product is a meat or fish substitute.

Technical Field

The present invention relates to the field of vegetable proteins, in particular legume protein isolates, more particularly pea protein isolates.

Background

The daily protein requirement of humans is between 12% and 20% of the food intake. These proteins are provided by animal products (meat, fish, eggs, dairy products) and plant products (cereals, legumes, algae).

In industrialized countries, people take mainly animal proteins. However, many studies have shown that excessive intake of animal proteins, not plant proteins, is one of the causes of increased cancer and cardiovascular disease.

Furthermore, animal proteins have many disadvantages both in terms of allergenicity (especially proteins in milk or eggs) and in terms of environmental protection (associated with the harmful effects of intensive farming).

Therefore, unlike animal-derived compounds, which have various disadvantages, there is an increasing demand in industry for plant-derived compounds with superior nutritional value and functional properties.

Soy has been the most important plant substitute for animal proteins in the past and present. However, the use of soy also has certain disadvantages. Soybean seeds are often transgenic and require de-oiling with solvents to obtain their proteins.

Since the 70's of the nineteenth century, there has been a vigorous development in europe (mainly in france) of seed plants, particularly peas, as a replacement protein resource for animal proteins used in animal and human food. The weight of protein in peas was about 27%. The term "pea" is used in its broadest sense and specifically includes all wild varieties of "rounded pea" ("smooth pea") for various uses (human food, animal feed and/or other uses) as well as all mutant varieties of "rounded pea" and "wrinkled pea". These seeds are non-transgenic and do not require solvent de-oiling.

Pea proteins, mainly pea globulin, have been industrially extracted and processed for many years. Patent EP1400537 can be cited as an example of a pea protein extraction process. In this process, the seeds are subjected to an anhydrous grinding (a so-called "dry-grinding" process) to obtain soy flour. This soy flour is then suspended in water to extract the proteins. Other processes for extracting leguminous proteins are also described in documents US 4060203A, FR2889416 a1 and WO 2011/124862 a 1. Document JP55-131351a describes a process for the manufacture of a soy protein isolate: the fine particulate soy flour is placed in an aqueous solution and the protein fraction is precipitated by bringing the aqueous solution to an acidic pH. The precipitated protein solution is then neutralized and then subjected to a heat treatment (which may also be atomized) to form a soy protein isolate.

However, legume proteins, particularly pea proteins, have much lower gelling properties than soy proteins. As mentioned in "Accessing gelling ability of vegetable proteins using both recombinant and fluorescent technologies" (Bastisaa et al, International Journal of Biological Macromolecules, No. 36 (2005), pp. 135-143, 2005), pea and lupin proteins have a lower gelling capacity than soy proteins.

It would therefore be of value to obtain pulse proteins, in particular pulse protein isolates, even more particularly pea protein isolates having an improved gel strength or gel strength. These pulse proteins can be added to food or pharmaceutical products. The pH of these products varies widely, between 4 and 9. In many applications, such as meat or fish substitutes, the protein is at a "neutral pH", i.e., a pH of about 6 to 8. Taking these meat and fish substitutes as examples, the protein helps to glue together proteins of other textures after gelation. It would therefore be particularly advantageous to provide new and improved pulse proteins having a gel strength above neutral pH.

Attempts have been made to reduce the particle size of protein isolates and concentrates and to study the functional properties of the resulting compositions. For example, the grinding of whey protein concentrates using a nano-bead mill is described in Sun et al (Reduction of particulate size based on superfine grinding: Effects on Structure, rhelogical and gelling properties of human protein concentration, Journal of Food Engineering, No. 186, 2016, pages 69-76). They studied different properties of proteins, including particle size, gel strength at different pH values, staining and infrared structure. In terms of gel strength, the protein composition after milling has a higher gel strength at an acidic pH (4.5) and a lower gel strength at a neutral pH (6.5) and a basic pH (8.5) compared to the protein before milling.

A paper by Hayakawa et al (particulate by Jet milk grinding of Protein Powders and Effects on Hydrophobicity, Journal of Food Science, Vol.58, 1993, 5, p.1026-1029) describes the use of an air Jet Mill to micronize casein and egg white type proteins and soy fiber. The document does not describe legume proteins. This document also does not describe increasing the protein gel strength.

In the paper by Liu et al (Ball-milling changed the physical properties of SPI and its cold-set gels, Journal of Food Engineering, 195 th.2017, page 158-165) it is described that soy protein isolates are ground using a Ball Mill of the planet BM and Mixer Mill MM400 type to slightly reduce their particle size (average size of 80 μm). However, although the gel strength of this isolate under acidic conditions (in the presence of glucose-delta-lactone) can be increased in the case of milling using a Mixer Mill model MM400 Mill, it is still very weak (a maximum increase of about 30%). Furthermore, grinding with a plant Bm type grinder did not result in any difference in the gel strength observed. Likewise, this document does not investigate the protein gel strength at neutral pH.

Disclosure of Invention

According to a first aspect of the present invention, a legume protein composition is proposed, the legume being in particular selected from the group consisting of peas, lupins and fava beans, characterized in that the protein composition according to test a has a gel strength of more than 200 pa, preferably more than 250 pa, more preferably more than 300 pa, most preferably more than 350 pa. The pulse protein composition is preferably selected from pulse protein isolates, more preferably from pea protein isolates.

According to another aspect of the present invention, there is provided a method of producing a protein composition, the method comprising the steps of:

1) processing legume seeds, preferably selected from the group consisting of peas, lupins and fava beans;

2) grinding the seeds to form an aqueous suspension;

3) separating the water insoluble fraction by centrifugal force;

4) at 55 deg.C⁺/_-2 ℃ and 65 DEG C⁺/_-Between 2 ℃ and preferably 60 DEG C⁺/_-Coagulating the protein by heating to an isoelectric pH at a temperature of 2 ℃ for a time of between 3.5 minutes and 4.5 minutes, preferablyIs 4 minutes;

5) recovering the coagulated protein floc by centrifugation;

6) adjusting the pH to 6⁺/_-0.5 and 9⁺/_-Between 0.5;

7) as an alternative, heat treatment may be performed;

8) drying the coagulated protein floc;

9) the coagulated protein floc is ground with an air jet mill and dried to obtain particles having a particle size D90 of less than 20 microns, preferably less than 15 microns, more preferably less than 10 microns.

According to a final aspect of the invention, it is proposed that a legume protein composition, preferably a legume protein isolate selected from the group consisting of peas, lupins and faba beans, more preferably a pea protein isolate according to the invention, is used industrially for food or pharmaceutical products, in particular for animal and human food products.

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

According to a first aspect of the present invention, a legume protein composition is proposed, the legume being in particular selected from the group consisting of peas, lupins and beans, characterized in that the protein composition according to test a has a gel strength of more than 200 pa, preferably more than 250 pa, more preferably more than 300 pa, most preferably more than 350 pa. The legume is most preferably a pea. For example, the gel strength of a protein composition according to test A may be less than 450 Pa, such as less than 400 Pa. The pulse protein composition is preferably selected from pulse protein isolates, more preferably from pea protein isolates.

The term "protein composition" is understood in the present application to be a composition obtained by extraction and purification, said composition comprising a protein, a macromolecule consisting of one or more polypeptide chains consisting of a number of amino acid residues linked to each other by peptide bonds. In the particular context of pea proteins, the invention relates in particular to globulins (which represent approximately 50-60% of pea proteins). Pea globulin is mainly divided into three subfamilies: bean proteins, cang proteins and j uen proteins.

The term "legume plant" in the present application refers to a dicotyledonous plant of the order Cajanoidales. This plant is one of the most important flowering plant families, the species number of which is second only to orchids and compositae. Including approximately 765 genera, over 19,500 species. Many legume plants are important cultivated plants, including soybeans, beans, peas, chickpeas, fava beans, peanuts, cultivated lentils, cultivated alfalfa, various clovers, fava beans, carob beans, licorice, and lupins.

"gelling power" refers to the ability to form a gel or network from a protein composition while increasing viscosity and producing a functional property of a state of matter between liquid and solid states. The term "gel strength" may also be used. To quantify this gelling power, it is necessary to create such a network and evaluate its strength. For this quantification, test a, described below, is used in the present invention:

1) at 60 DEG C⁺/_-The protein composition to be tested contained 15% at 2 deg.C⁺/_-Solubilisation in 2% dry matter water at a pH of 7;

2) at 60 DEG C⁺/_-Shaking at 2 deg.C for 5 min;

3) cooling to 20 deg.C⁺/_-Stirring at the speed of 350 r/min for 24 hours at the temperature of 2 ℃;

4) preparing a suspension in an applied stress rheometer equipped with concentric columns;

5) the elastic modulus G' and the viscous modulus G ″ were measured by applying the following temperature curves:

a. stage 1: at 20 deg.C⁺/_-After stabilization at 2 ℃ from 20 ℃ in 10 minutes⁺/_-Heating to 80 deg.C at 2 deg.C⁺/_-A temperature of 2 ℃, measurement parameter G' 1;

b. and (2) stage: at 80 deg.C⁺/_-Stabilizing at 2 deg.C for 110 min; c. and (3) stage: from 80 ℃ in 30 minutes⁺/_-Cooling to 20 deg.C at 2 deg.C⁺/_-At a temperature of 2 ℃ and at 20 DEG C⁺/_-G' 2 is measured after stabilization at a temperature of 2 ℃;

6) the calculated gel force is equal to G '2-G' 1.

A DHR 2(TA, instruments) and MCR 301(Anton Paar) model applied stress rheometer with concentric columns is preferably selected. They have a peltier temperature control system. To avoid evaporation problems at high temperatures, paraffin oil was added to the samples.

"rheometer" in the sense of the present invention refers to a laboratory instrument capable of measuring the rheology of a fluid or gel. It exerts a force on the sample. In general, its characteristic dimensions are small (the mechanical inertia of the rotor is low), allowing the mechanical properties of liquids, gels, suspensions, pastes, etc. under the action of an applied force to be studied fundamentally.

The so-called "applied stress" mode allows determining the intrinsic viscoelastic quantity of a material by applying a sinusoidal stress (oscillation mode), such intrinsic viscoelastic quantity being dependent on, inter alia, time (or angular velocity ω) and temperature. In particular, this type of rheometer allows to obtain a complex modulus G, which in turn allows to obtain a modulus G' or elastic part and a G "or viscous part.

The first three steps involve resuspending the protein in water under precise conditions to maximize subsequent measurements.

The water is preferably selected from permeate water, but drinking water may also be used.

The temperature was 60 ℃ at the time of initial resuspension⁺/_-2 deg.C (first and second steps) and then 20 deg.C after 24 hours of dissolution and cooling before measurement⁺/_-2 deg.c (third step). In general, unless otherwise indicated, the temperatures given in this description always include⁺/_-Variation at 2 deg.C, e.g. 20 deg.C⁺/_-2 ℃ or 80 DEG C⁺/_-2℃。

Adding a defined amount of protein to said water to obtain 15%⁺/_-Suspension of 2% dry matter. For this purpose, equipment known to the skilled person is used, such as beakers, magnetic bars. Shake a 50mL volume at 350 rpm for at least 10 hours at room temperature. In general, unless otherwise stated, the dry matter contents given in this description always include⁺/_-2% variation, e.g. 15%⁺/_-2 percent. Adjusting the pH value to 7 by using a pH meter and an acid-base reagent⁺/_-0.5, which is well known in the art.

The fourth step is to introduce the sample into the rheometer and cover it with a thin layer of oil to limit evaporation.

In the fifth step, the following temperature schedule was used: a. stage 1: from 20 ℃ in 10 minutes⁺/_-Heating to 80 deg.C at 2 deg.C⁺/_-A temperature of 2 ℃; b. and (2) stage: at 80 deg.C⁺/_-Stabilizing at 2 deg.C for 110 min; c. and (3) stage: from 80 ℃ in 30 minutes⁺/_-Cooling to 20 deg.C at 2 deg.C⁺/_-A temperature of 2 ℃.

The parameter G' is measured continuously and recorded in this schedule.

The sixth, and final, step of test a is to perform the recording. Two values are to be extracted: g' 1 ═ 20 ℃ at the beginning of stage 1⁺/_-G 'value after stabilization at 2 ℃ and G' 2-20 ℃ at the end of stage 3⁺/_-G' value after stabilization at 2 ℃.

The gel strength is equal to G '2-G' 1.

Preferably, the pulse protein composition according to the invention has a protein abundance of more than 80%, preferably more than 85%, more preferably more than 90% relative to the total weight of dry matter.

Protein abundance is measured by any technique known to those skilled in the art. Preferably, the total nitrogen is measured (as a percentage of the total dry weight of the composition by weight of nitrogen) and the result is multiplied by a factor of 6.25. This process is well known in the field of vegetable proteins, based on the fact that proteins contain on average 16% nitrogen. Any dry matter determination method well known to the skilled person may also be used.

The particle size D90 of the protein composition is preferably less than 20 microns, more preferably less than 15 microns, most preferably less than 10 microns.

"D90" as used herein refers to the particle size in microns, divided into two populations by number, representing 90% and 10% of the total particle of the protein composition, respectively.

For the D90 measurement, a laser particle sizer is preferably used, more preferably Mastersizer 2000 from malvern. The use parameters were as follows: used in liquid form, dispersed in ethanol; refractive index: 1.52; absorption index: 0.1; ultrasound is not used.

Preferably, the protein composition according to the invention has a high solubility at neutral pH values. To quantify the solubility of the protein composition, test B was used according to the invention. The test comprises the following steps:

150g of distilled water at 20 ℃ +/-2 ℃ are added to a 400mL beaker while stirring with a magnetic bar and 5g of the pulse protein sample to be tested are added precisely. If necessary, the pH is adjusted to 7 with 0.1N NaOH or 0.1N HCl. Make up water to 200 g. Mix at 1000 rpm for 30 minutes and then centrifuge at 3000g for 15 minutes. 25g of the supernatant was collected and placed in a crystallization dish which had been previously dried and de-skinned. The dish was placed in an incubator at 103 ℃ +/-2 ℃ for 1 hour. It was then placed in a desiccator (with dehydrating agent) to cool to room temperature and weighed.

Solubility corresponds to the content of soluble dry matter, expressed as a percentage of its weight on the weight of the sample. The solubility is calculated as follows:

[Math.1]

wherein:

weight of sample (unit: g) 5g

m1 weight of dried crystallizing dish (unit: g)

m2 weight of empty petri dish (unit: g)

Weight of collected sample (unit: g) 25g

Advantageously, according to test B, the solubility of the protein composition of the invention is between 30% and 65%, for example between 33% and 62%, in particular between 38% and 60%.

Another advantage of the present invention is that the gelling properties of pea proteins can be improved while maintaining their solubility. However, these properties seem to be difficult to reconcile: for example, increasing the solubility of a protein by proteolysis is combined with a loss of its gelling properties. Without being bound by any theory, this can be explained by the following facts: generally, to form a protein gel, once the protein aggregates, a network must be formed. The protein that results in gelation is larger, even if replaced back in solution, and therefore generally has lower solubility. However, the present invention is able to reconcile these two characteristics.

According to another aspect of the present invention, there is provided a method for producing a pulse protein composition, comprising the steps of:

1) processing legume seeds, preferably selected from the group consisting of peas, lupins and fava beans;

2) grinding the seeds to form an aqueous suspension;

3) separating the water insoluble fraction by centrifugal force;

4) at 55 deg.C⁺/_-2 ℃ and 65 DEG C⁺/_-Between 2 ℃ and preferably 60 DEG C⁺/_-Coagulating the protein by heating to an isoelectric pH at a temperature of 2 ℃ for a time of between 3.5 minutes and 4.5 minutes, preferably 4 minutes;

5) recovering the coagulated protein floc by centrifugation;

6) adjusting the pH to 6⁺/_-0.5 and 9⁺/_-Between 0.5;

7) as an alternative, heat treatment may be performed;

8) drying the coagulated protein floc;

9) the coagulated protein floc is ground with an air jet mill to obtain particles of D90 particle size of less than 20 microns, preferably less than 15 microns, more preferably less than 10 microns.

The process starts in step 1): processed legume seeds, preferably selected from the group consisting of peas, lupins and fava beans.

When the legume selected is peas, the peas processed in step 1) may have previously undergone steps well known to those skilled in the art, such as washing (elimination of unwanted particles, such as stones, dead insects, soil residues, etc.) or elimination of the outer fibers of the peas (outer cellulose envelope) by the well known "dehulling" step.

Treatments aimed at improving organoleptic properties, such as dry heating (or baking) or wet blanching, may also be experienced. Blanching at 70 deg.C⁺/_-2 ℃ and 90 DEG C⁺/_-Adjusting pH to 8 at 2 deg.C⁺/_-0.5 and 10⁺/_-Between 0.5, preferably 9⁺/_-0.5. These conditions are maintained for 2 to 4 minutes, preferably 3 minutes.

The process according to the invention comprises step 2): the seeds are ground and made into an aqueous suspension. If the seeds already have water, the water is retained, but can also be replaced, and the seeds are ground directly. If the grain is dry, soy flour is first prepared and then suspended in water.

Milling is carried out by any suitable technique known to the skilled person, such as ball mills, conical mills, screw mills, air jet mills or rotor/rotor systems.

During the grinding process, water may be added continuously or discontinuously at the beginning, during or at the end of the grinding, so as to obtain at the end of this stage an aqueous suspension of ground peas, the weight of Dry Matter (DM) being between 15% and 25% relative to the weight of said suspension, preferably representing 20% of the weight of dry matter.

At the end of the milling, the pH can be checked. Preferably, at the end of step 2, the pH of the aqueous suspension of ground peas is adjusted to a value between 5.5⁺/_-0.5 and 10⁺/_-Between 0.5, e.g. pH adjusted to 6⁺/_-0.5 to 9⁺/_-0.5. Optionally, the pH is adjusted to 8⁺/_-0.5 and 10⁺/_-Between 0.5, for example, the pH is adjusted to 9. The adjustment of the pH can be carried out by addition of an acid and/or a base, for example sodium hydroxide or hydrochloric acid.

Then, the process according to the invention proceeds with step 3): the water-insoluble fraction is separated by centrifugal force. This is composed mainly of starch and polysaccharides called "internal fibers". The soluble protein in the supernatant was concentrated.

The process according to the invention proceeds with step 4): at 55 deg.C⁺/_-2 ℃ and 65 DEG C⁺/_-Between 2 ℃ and preferably 60 DEG C⁺/_-The protein is coagulated by heating to an isoelectric pH at a temperature of 2 ℃ for a time of between 3.5 minutes and 4.5 minutes, preferably 4 minutes. This is aimed at separating the desired pea proteins from the other constituents of the supernatant in step 3). For example, the applicant's patent EP1400537 describes process examples from paragraph 127 to paragraph 143. Good control of the time/temperature schedule is crucial: as will be illustrated below, these parameters are critical in order to obtain a gelled protein composition according to the invention.

The next step 5) involves recovering the coagulated protein flocs by centrifugation. The solid fraction of concentrated protein is separated from the liquid fraction of concentrated sugar and salt.

In step 6), the floc is resuspended in water and its pH is adjusted to a value between 6⁺/_-0.5 and 9⁺/_-Between 0.5. The dry matter is adjusted to a weight ratio of between 10% and 20%, preferably 15%, relative to the suspension. Any acidic and basic agent is used to adjust the pH. Preference is given to using ascorbic acid, citric acid and potassium salts or sodium hydroxide.

As an alternative, step 7) may be performed: a heat treatment aimed at ensuring the microbiological quality of the protein is carried out. This heat treatment may also be used to functionalize the protein component. Preferably at 100 deg.C⁺/_-2 ℃ to 160 DEG C⁺/_-Heating at 2 ℃ for 0.01 to 3 seconds, preferably 1 to 2 seconds, in the usual ratio, and then immediately cooling.

In step 8), the coagulated protein floc is dried to more than 80%, preferably more than 90% by weight of the dry matter. For this purpose, any technique known to the skilled person may be used, such as freeze-drying or atomisation. Atomization is a preferred technique, in particular multi-effect atomization.

The dry matter content is determined by any method known to the person skilled in the art, preferably using the so-called "drying" method. It consists in determining the quantity of water evaporated by heating a known quantity of sample of known mass: the sample was initially weighed and the mass m1 measured in g; the sample is placed in a heating chamber to evaporate the water until the mass of the sample is stable and the water is completely evaporated (preferably at a temperature of 105 ℃ at atmospheric pressure), and finally the sample is weighed to measure the mass m2 in g. The dry matter is calculated as follows: (m2/m1) × 100.

The last step 9), like the preceding step 4), is critical for obtaining the protein composition according to the invention. Comprising grinding the coagulated protein floc and drying to obtain particles of D90 particle size of less than 20 microns, preferably less than 15 microns, more preferably less than 10 microns. An air jet mill is used in this step of the process of the present invention. Preferably an opposed air jet mill is used, more preferably Netzsch CGS 10. This type of mill is reduced in size by generating collisions: the particles accelerated by the high velocity gas jet are disintegrated by impact.

In an advantageous method of the invention, the gel strength of the protein composition according to test a is at least 150%, advantageously at least 200%, for example at least 300% of the gel strength of the protein floc dried in step 8. The gel strength of the protein composition according to test a may, for example, be at most 600% of the gel strength of the protein floc dried in step 8.

As described above, one advantage of the present invention is that protein solubility can be maintained during the milling step. Advantageously, the solubility of the protein composition according to test B is at least 75%, advantageously at least 90%, of the solubility of the protein floc dried in step 8.

An advantage of the present invention is that the protein composition of the invention may exhibit a higher gel strength at different pH values, in particular at neutral pH values, such as the conditions of test a. The use of the protein composition according to the invention in any type of food and pharmaceutical products is advantageous: the pH of the food or pharmaceutical product may be between 4 and 9, such as between 5 and 8.5, in particular between 6 and 8, or even about 7.

According to a final aspect of the invention, it is proposed that a legume protein composition, preferably a legume protein isolate selected from the group consisting of peas, lupins and faba beans, more preferably a pea protein isolate according to the invention, is used industrially, in particular for animal and human food.

Due to the improved gelling power, the protein composition according to the invention is particularly suitable for food applications, such as vegetable yoghurts or meat-imitation products ("meat-analogues" in english). It is particularly useful as a substitute for meat or fish. It is particularly useful as a binding agent, for example as a binding agent useful in the manufacture of meat or fish substitutes. Thus, another aspect of the invention is for making a meat or fish substitute comprising the protein composition of the invention.

The invention will be better understood by the following non-limiting examples.

Examples

Example 1: production of the pulse protein composition according to the invention

After the external fibers were dehulled in a hammer mill, the pea seeds were ground into bean flour. It is then soaked in water at a final concentration of 25% dry matter by weight of the suspension, at a pH of 6.5, for 30 minutes at room temperature. The suspension of soy flour, with a mass fraction of dry matter of 25%, is then fed to a hydrocyclone to separate a light phase consisting of a mixture of proteins, internal fibres (pulp) and dissolved matter, and a heavy phase containing starch. The light phase leaving the hydrocyclone was then lifted to 10.7% dry matter by weight of the suspension. The internal fibers were separated by a model WESTFALIA centrifugal decanter. The light phase at the outlet of the centrifugal decanter contains a mixture of protein and solubles, while the heavy phase contains pea fibres.

The protein was coagulated at its isoelectric point by adjusting the pH of the light phase at the outlet of the centrifuge decanter to 4.6 and heating the solution at 60 ℃ for 4 minutes. After coagulation of the protein, the protein floc can be recovered. The protein flocs were resuspended in drinking water to form a suspension, the mass of dry matter being 15.1% relative to the mass of the suspension. The suspension was adjusted to pH 7 with caustic potash. Finally, heat treatment was carried out at 130 ℃ for 0.4 second, followed by flash cooling. Then the suspension is atomized on a NIRO MSD multi-effect atomizer, the air inlet temperature is 180 ℃, and the air outlet temperature is 80 ℃. The mass of the powder obtained, relative to the total weight of dry matter, was 92.3%, of which 85.5% was protein. Such powders are referred to as "binders for the compositions according to the invention".

The powder was then milled using a Netzsch CGS10 opposed air jet mill to give a D90 particle size of 7.3 microns.

The resulting powder protein composition is referred to as "micronized protein composition according to the invention".

Example 2: comparative example aimed at demonstrating the effect of a heating table of a protein composition during its coagulation

This example is intended to demonstrate the effect of the coagulation profile on the function of the protein composition according to the invention.

After the external fibers were dehulled in a hammer mill, the pea seeds were ground into bean flour. It was then soaked in water at a final concentration of 25.1% dry matter by weight relative to the suspension and at a pH of 6.5, for 30 minutes at room temperature. The suspension of soy flour, with a mass fraction of dry matter of 25%, is then fed to a hydrocyclone to separate a light phase consisting of a mixture of proteins, internal fibres (pulp) and dissolved matter, and a heavy phase containing starch. The light phase leaving the hydrocyclone was then lifted to 11.2% dry matter by weight of the suspension. The internal fibers were separated by a model WESTFALIA centrifugal decanter. The light phase at the outlet of the centrifugal decanter contains a mixture of protein and solubles, while the heavy phase contains pea fibres.

The protein was coagulated at its isoelectric point by adjusting the pH of the light phase at the outlet of the centrifuge decanter to 4.6 and heating the solution at 70 ℃ for 4 minutes. After coagulation of the protein, the protein floc can be recovered. The protein flocs were resuspended in drinking water to form a suspension with a dry matter mass ratio of 14.9% relative to the mass of the suspension. The suspension was adjusted to pH 7 with caustic potash. Finally, heat treatment was carried out at 130 ℃ for 0.4 second, followed by flash cooling. Then the suspension is atomized on a NIRO MSD multi-effect atomizer, the air inlet temperature is 180 ℃, and the air outlet temperature is 80 ℃. The mass of the powder obtained, relative to the total weight of dry matter, was 91.9%, of which 84.9% was protein. This powder is referred to as "base for comparative protein composition No. 1".

The powder was then milled using a Netzsch CGS10 opposed air jet mill to give a D90 particle size of 8.2 microns.

The resulting powder protein composition is referred to as "micronized comparative protein composition No. 1".

Example 3: comparison of the different protein fractions obtained in example 1 and example 2

For comparison of protein content, the aforementioned test a was used, as well as dry matter and protein abundance.

[ Table 1]

Table 1 above clearly shows that the synergistic effect of the condensation thermometer and the reduction of particle size to less than 10 microns of particle D90 is of paramount importance in order to maximize the gelling force. The gelling force of the micronized protein composition according to the present invention was approximately 4-fold higher than the base of the protein composition according to the present invention, the base of comparative protein composition No. 1, and comparative micronized protein composition No. 1.

Example 4:production of the pulse protein composition according to the invention

After the external fibers were dehulled in a hammer mill, the pea seeds were ground into bean flour. It is then soaked in water at a final concentration of 25% dry matter by weight of the suspension, at a pH of 6.5, for 30 minutes at room temperature. The suspension of soy flour, with a mass fraction of dry matter of 25%, is then fed to a hydrocyclone to separate a light phase consisting of a mixture of proteins, internal fibres (pulp) and dissolved matter, and a heavy phase containing starch. The light phase leaving the hydrocyclone was then lifted to 10% dry matter by weight of the suspension. The internal fibers were separated by a model WESTFALIA centrifugal decanter. The light phase at the outlet of the centrifugal decanter contains a mixture of protein and solubles, while the heavy phase contains pea fibres.

The protein was coagulated at its isoelectric point by adjusting the pH of the light phase at the outlet of the centrifuge decanter to 5.0 and heating the solution at 60 ℃ for 4 minutes. After coagulation of the protein, the protein floc can be recovered. The protein flocs are resuspended in drinking water to form a suspension, the mass of dry matter being 18% relative to the mass of the suspension. The pH of the suspension was adjusted to 7 using sodium hydroxide. Finally, heat treatment was carried out at 130 ℃ for 0.4 second, followed by flash cooling. Then the suspension is atomized on a NIRO MSD multi-effect atomizer, the air inlet temperature is 180 ℃, and the air outlet temperature is 80 ℃. The mass of the powder obtained, relative to the total weight of dry matter, was 93.2%, of which 80.7% was protein. This powder is referred to as "base 2 of the protein composition according to the invention"

This powder was then subjected to two different grindings using a Netzsch CGS10 opposed air jet mill to give a first powder with a D90 particle size of 16.9 microns and a second powder with a D90 particle size of 7.9 microns. The resulting powder protein compositions are referred to as "micronized protein composition 2 according to the invention" and "micronized protein composition 3 according to the invention", respectively.

To compare protein composition, the aforementioned test a and test B, as well as dry matter and protein abundance, were used.

[ Table 2 ]]

Table 2 above further shows that it is possible to maximize the gelling force. The gelling power of the micronized protein composition according to the invention is more than 2 times higher. In addition, protein solubility can be maintained.