Wheat gluten pellets

Abstract

The present invention relates to protein pellets including wheat gluten, characterized in that the gluten has: a water retention capacity, determined according to a test A, of between 40 and 160%, preferably between 100 and 150%; and a viscoelastic behaviour, according to the Chopin Alveograph, determined at a P/L parameter value of between 3 and 10, preferably between 3 and 8.

Claims

1. A wheat gluten pellet, having: a water retention capacity between 100 and 140%, said water retention capacity being determined by test A, said test A comprising: (i) grinding 30 g of wheat gluten pellets in an IKA A10 mill under circulating cold water for 2 minutes to obtain ground pellets of 0 residue on 500 m, <10% of residue on 250 m, and <50% of residue on 100 m, (ii) mixing using a glass rod 10.0 g of ground pellets with 25 ml of drinking water at between 5 and 20 C., (iii) allowing the mixture to stand for 15 minutes, (iv) centrifuging the mixture in a centrifuge for 10 minutes at 4000 revolutions, (v) allowing the centrifuge to stop on its own, the centrifuged mixture comprising a supernatant and hydrated gluten, (vi) discarding the supernatant, (vii) weighing the hydrated gluten, (viii) determining the water retention capacity from the equation (P10) 10, wherein the weight in g of the hydrated gluten is P; and a viscoelastic behavior according to a Chopin alveograph equal to the ratio of deformation resistance in mm over extensibility in mm between 3.5 and 10, wherein the wheat gluten pellets are prepared by a process comprising the steps of: 1) preparing a vital wheat gluten powder of particle size such that at least 50% of the particles have a size greater than 250 m, 2) introducing the wheat gluten powder thus prepared into the blender of a pellet press, 3) conditioning the wheat gluten powder thus prepared by regulated addition of steam at the inlet of the blender in order to obtain at the outlet of the blender an air-powder mixture temperature between 30 and 45 C., 4) introducing the wheat gluten powder into the die of the pellet press in order to obtain the wheat gluten pellets, 5) cooling the pellets through a horizontal cooler, and 6) recovering the pellets thus obtained.

2. The pellet as claimed in claim 1, wherein the viscoelastic behavior according to the Chopin alveograph is determined at a value of the extensibility less than 100 mm.

3. The pellet as claimed in claim 1, wherein the pellet has a protein content of more than 80% calculated as (N6.25) on a dry weight basis, wherein N is the nitrogen content.

4. The pellet as claimed in claim 1, wherein the pellet has a water content between 6 and 12%.

5. The pellet as claimed in claim 1, wherein the pellet has a durability between 50 and 100%.

6. A process of forming an animal feed preparation comprising: preparing an animal feed preparation comprising from 5 to 50% of wheat gluten using the wheat gluten pellets according to claim 1, said animal feed preparation being selected from the group consisting of an extruded preparation, a pellet preparation and a preparation intended to be rehydrated.

7. A wheat gluten pellet consisting of: a protein content of more than 80% calculated as (N6.25) on a dry weight basis, wherein N is the nitrogen content; a water content between 6 and 12%; and a balance of phospholipids, fiber, residual starch and inorganic matter, wherein said wheat gluten pellet has a water retention capacity between 100 and 140%, said water retention capacity being determined by test A: (i) grinding 30 g of wheat gluten pellets in an IKA A10 mill under circulating cold water for 2 minutes to obtain ground pellets of 0 residue on 500 m, <10% of residue on 250 m, and <50% of residue on 100 m, (ii) mixing using a glass rod 10.0 g of ground pellets with 25 ml of drinking water at between 5 and 20 C., (iii) allowing the mixture to stand for 15 minutes, (iv) centrifuging the mixture in a centrifuge for 10 minutes at 4000 revolutions, (v) allowing the centrifuge to stop on its own, the centrifuged mixture comprising a supernatant and hydrated gluten, (vi) discarding the supernatant, (vii) weighing the hydrated gluten, (viii) determining the water retention capacity from the equation (P10) 10, wherein the weight in g of the hydrated gluten is P; and wherein said wheat gluten pellet has a viscoelastic behavior according to a Chopin alveograph equal to the ratio of deformation resistance in mm over extensibility in mm between 3.5 and 10.

Description

EXAMPLE 1

(1) There is prepared 1 tonne of wheat gluten powder having the following characteristics: at least 50% by weight of particles having a size greater than 250 m, protein content >83% by weight dry/dry water content >9% P/L value >3 according to the Chopin alveograph.

(2) The blender of a pellet press of the LYD 66/23 type marketed by the company STOLZ is fed at a throughput of 4 t/h.

(3) The feeding is performed via a metering screw whose speed is set in order to obtain a throughput of the order of 4 t/h, and so as to obtain, after regulated addition of steam by means of a regulating valve, a stable blender outlet temperature of 35 C.

(4) At the outlet of the blender, the powder is directed by gravity to the die of the pelleting press whose compression ratio is 20.

(5) The pellets are then cooled to room temperature on a horizontal cooler RHS2P 20.60 marketed by the company STOLZ.

(6) After grinding the granules with the aid of the IKA mill as described above and analyzing the ground product obtained, the wheat gluten pellets in accordance with the invention have the characteristics assembled as 2 series of samples (series 1 and 2).

(7) TABLE-US-00001 TABLE 1 Series 1 Series 2 Water 130 130 retention (%) Chopin alveograph P 182 145 L 26 41 P/L 7.0 3.5 Protein 86.8 86.9 content (N6.25/dry) Water content 9.0 11.2 Durability 58 92

(8) By way of comparison, table 2 below presents the values measured on two samples of vital wheat gluten and devital wheat gluten, marketed by the applicant company under the respective trademarks VITEN and DEVITEN.

(9) TABLE-US-00002 TABLE 2 VITEN DEVITEN Water 170 No retention retention (%) Chopin Very brittle, alveograph tenacious P 70 dough which L 120 does not P/L 0.6 leave the kneading machine Protein 85.4 85.5 content (N6.25/dry) Water content 6.2 6.7

(10) The wheat gluten pellets in accordance with the invention, as set out above, therefore preserve well their water retention capacity, with however somewhat reduced elastic properties.

EXAMPLE 2

(11) The capacity of the wheat gluten pellets in accordance with the invention to preserve the free-flowing and homogeneous character of a mixture of proteins rehydrated in the hot state in a preconditioner is tested by measuring the flow of the final mixture thus obtained through a sieve with a mesh size of 1000 m.

(12) To do this, a mixture of proteins in powdered form, comprising 50% by weight of wheat gluten pellets in accordance with the invention, is introduced in the hot state and with stirring into a jacketed CUTTER STEPHAN UMC/SK5 preconditioner, marketed by the company STEPHAN, equipped with direct steam injection.

(13) Steam is thus injected in order to raise the temperature of said mixture to 90 C. and hydrate it to about 20% of water.

(14) The mixture thus obtained is then sieved on a sieve with a coarse mesh in order to recover the agglomerates and the percentage of residue is then calculated.

(15) Table 3 below presents the basic formula of the mixtures to be tested.

(16) TABLE-US-00003 TABLE 3 Nature of the Content by proteins Content as % weight (g) MILUREX 40.5 202.5 GLUTALYS 7 35 Rapeseed oil 2.5 12.5 Wheat gluten 50 250 as pellets according to the invention or not

(17) The following are tested: two control batches of vital gluten powder, three batches of wheat gluten pellets manufactured according to example 1 above, ground in a hammer mill of the trademark RETSCH equipped with a 1000 m screen, so as to have the same particle size as the control vital gluten powder (100 to 1000 m).

(18) The preconditioner is preheated by injection of steam (0.7 bar) into the jacket of the CUTTER of trademark STEPHAN and the powders are mixed as minimum speed (100 rpm) for 4 min.

(19) After 4 min of mixing, the jacket heating is stopped.

(20) Steam is injected directly into the chamber of the CUTTER at a pressure of 0.7 bar, with stirring at 100 rpm, for 30 seconds, in order to obtain a 20% hydration of the powders and a temperature of 90 C.

(21) The final mixture obtained is sieved on a sieve with square mesh of side 0.7 cm.

(22) The percentage of residue is calculated by the equation: (mass of the agglomerates/total mass of the mix)100.

(23) The results obtained are presented in table 4 below.

(24) TABLE-US-00004 TABLE 4 % by weight of residue on 0.7 cm Vital gluten 32.7% 30% Gluten pellets in 2.6% accordance with the 1.1% invention 2.8%

(25) These results clearly show that vital gluten, by forming its viscoelastic network, agglomerates during the preconditioning phase with the other proteins of the mixture, and thus forms a heterogeneous mixture composed, on the one hand, of free-flowing powders and, on the other hand, of a lump of gluten.

(26) By contrast, the wheat gluten pellets in accordance with the invention, ground, do not form networks and the mixture advantageously remains free-flowing and homogeneous.