Method for producing protein compositions of low solubility, compositions produced, and use thereof in bread-making products

Abstract

The invention relates to a method for functionalizing a protein composition, by heating between 100 C. and 160 C. for between 0.1 s and 1 s, then cooling between 60 C. and 90 C., with a pH adjustment to a value of between 6.2 and 9 by means of calcium hydroxide. When used in the production of bread, the protein compositions thus produced allow products to be produced without any unpleasant aftertaste; these bread products are also especially large which provides them with a very pronounced soft character. Such a balance of performances has never been achieved until now for bread-making products.

Claims

1. A process comprising: providing a vegetable protein composition, a) heating said vegetable protein composition to a temperature of between 100 C. and 160 C., in one of an injection and an infusion chamber, for between 0.1 and 1 second, and b) cooling said heated vegetable protein composition to between 55 C. and 80 C., wherein the pH of the vegetable protein composition is adjusted to a value of between 6.2 and 9 before or during or after one of steps a) and b) by adding lime to said composition, to produce a processed vegetable protein composition having a solubility of less than 20%, measured according to a test of placing 2.0 g of a test sample of processed vegetable protein composition and a magnetic bar in a 400 mL beaker, adding 100.0 g of distilled water at 20 C.+/2 C. adjusting the pH to 7.5 with 1N HCl or 1N HCl or 1N NaOH and making up the mixture to 200.0 g with distilled water, stirring this mixture for 30 minutes, then centrifuging for 15 minutes at 3000g, withdrawing 25.0 g of supernatant into a pre-tared crystallizing dish after centrifugation, placing the crystallizing dish in an oven at 103 C. until the mass is constant and calculating the solubility using the following equation: $\mathrm{Solubility}=\frac{\left(m1-m2\right)200100}{m3P}$ with m1=mass in g of the crystallizing dish after drying m2=mass in g of the empty crystallizing dish m3=mass in g of supernatant taken up P=mass in g of the test sample.

2. The process according to claim 1, wherein steps a) and b) are preceded by the steps comprising: 1) suspending a vegetable flour comprising starch and fiber in water, 2) extracting the starch and the fibers from said flour so as to obtain a suspension with a solids content of between 3% and 15%, and 3) extracting from said suspension a protein extract with a solids content of greater than 15%.

3. The process according to claim 1, wherein the heating is carried out by heat exchange with water vapor in one of said chambers.

4. The process according to claim 3, wherein the heating is carried out in an infusion chamber.

5. The process according to claim 3, wherein the cooling is carried out by lowering the pressure in a pressure-reduction chamber or in an expansion vessel.

6. The process according to claim 1, wherein the processed product is homogenized using a high-pressure homogenizer or via a high-shear pump.

7. The process according to claim 1, wherein the processed product is dried by atomization, granulation or extrusion.

8. A processed vegetable protein composition prepared according to the process of claim 1.

9. A method for producing bread comprising, mixing a processed vegetable protein composition of claim 8 to baking ingredients, subjecting the obtained mixture to a bread producing process and producing bread.

10. A bread obtained by the method of claim 9.

Description

EXAMPLES

Example 1

(1) This example illustrates 4 processes for producing protein compositions: a process according to the prior art, without rapid increase in temperature, and with pH adjustment with sodium hydroxide; a process according to the prior art, without rapid increase in temperature, and with pH adjustment with lime; a process according to the prior art (as described in application No. FR 2 958 501) by rapid heating (<1 s) then cooling, and with pH adjustment with sodium hydroxide; a process according to the invention by rapid heating (<1 s) then cooling, and with pH adjustment with lime.

(2) It illustrates the protein compositions thus obtained and some of their characteristics (such as their solubility, their water adsorption capacity, their emulsifying capacity).

(3) Test No. 1 According to the Prior Art: Conventional Process without Heat Treatment and Correction with Sodium Hydroxide

(4) A pea protein composition is prepared in the following way.

(5) Pea flour is prepared by milling shelled fodder peas on an Alpine hammer mill equipped with a 100 m grille. 300 kg of flour containing 87% solids are then soaked in water at a final concentration of 25% on a dry basis, at a pH of 6.5. 1044 kg of flour suspension containing 25% of solids (i.e. thus 261 kg of dry flour) are then introduced with 500 kg of water into a 14-stage hydrocyclone battery, fed with the flour suspension at stage No. 5.

(6) This separation leads to the production of a light phase which corresponds to the output of stage No. 1. It consists of the mixture of proteins, internal fibers and soluble matter. This light phase at the hydrocyclone outlet contains as a mixture (142 kg on a dry basis in total): fibers (approximately 14.8% by weight, i.e. 21 kg dry), proteins (approximately 42.8% by weight, i.e. 60.8 kg dry) and soluble matter (approximately 42.4% by weight, i.e. 60.2 kg dry). This fraction has a solids content of 10%.

(7) The fibers are separated on Westfalia centrifugal decanters. The light phase exiting the centrifugal decanter contains a mixture of proteins and soluble matter, whereas the heavy phase contains the pea fibers. The heavy phase contains 105 kg of fibers containing 20% solids. It is noted that virtually all of the fibers are indeed found in this fraction. As regards the protein and soluble matter fraction, it contains 1142 kg of a mixture in solution of soluble matter and proteins (fraction containing 6% solids).

(8) The proteins are flocculated at their isoelectric point by adjusting the light phase exiting the centrifugal decanter to a pH of 4.5 (by adding hydrochloric acid) and heating to 60 C. by passing through a nozzle. The proteins thus flocculated are left in a maturing tank for 10 minutes.

(9) Separation of the soluble matter/proteins is then carried out on a centrifugal decanter. The mixture obtained at the outlet of the maturing tank then feeds the centrifugal decanter at a flow rate of 0.5 m.sup.3/h. The heavy phase, or floc, which has a solids content of 35%, is diluted to 10% by adding water. The pH of the floc of 4.5 is corrected to a value of 7.5 by adding sodium hydroxide.

(10) Finally, atomization is carried out on a single-effect tower with a compressed air nozzle in order to dry the product, with a drying air temperature of 150 C., and a mist temperature of 85 C., the evaporation capacity being 20 I/h and the pressure being 1 bar. A protein composition in powder form, termed protein composition 1, is obtained.

(11) Test No. 2 According to the Prior Art: Conventional Process without Heat Treatment and Correction with Lime

(12) The process is identical in all respects to that described in test No. 2, the only difference being that the pH of the floc of 4.5 is corrected to a value of 7.5 by adding lime. A protein composition in powder form, termed protein composition 2, is obtained.

(13) Test No. 3 According to the Prior Art: Rapid Heating (<1 s) then Cooling and Correction with Sodium Hydroxide

(14) The process is identical here to that described in test No. 1, until the obtaining of the heavy phase. The pH of 4.5 of the protein extract is corrected to a value of 7.5 by adding sodium hydroxide.

(15) The protein extract thus obtained is subjected to a heat treatment of 122 C. for 0.2 s in a Simplex SDH infuser or infusion chamber, and it is then cooled to 45.5 C. by pressure reduction in an expansion vessel under vacuum or flash cooling.

(16) Finally, atomization is performed on an MSD (Multi Stage Dryer) tower under the following conditions. An MSD atomization tower is chosen and is fed with the pea proteins derived from the Simplex infuser. The drying air enters at 180 C. and leaves at 80 C., the static bed at the bottom of the tower being heated with air at 80 C. At the outlet of the atomization tower, the product passes onto a vibrating fluid bed where it is cooled to ambient temperature. Recycling of the fines may advantageously be performed.

(17) This set of operations makes it possible to obtain a pea protein powder according to the prior art, with an average diameter of 200 m and an average density of 0.4. A protein composition in powder form, termed protein composition 3, is obtained.

(18) Test No. 4 According to the Invention: Rapid Heating (<1 s) and Cooling then Correction with Lime

(19) The process is identical in all respects to that described in test No. 3, the only difference being that the pH of the floc of 4.5 is corrected to a value of 7.5 by adding lime. The set of operations makes it possible to obtain a pea protein powder in accordance with the invention, with an average diameter of 200 m and an average density of 0.4. A protein composition in powder form, termed protein composition 4, is obtained.

(20) Test No. 5 According to the Invention: Rapid Heating (<1 s) and Cooling then Correction with Lime

(21) The process is the one described in test No. 4, but differs therefrom in that: the heat treatment of the protein extract is carried out at 135 C. for 0.4 s, followed by cooling to 50 C.; the pH of the floc of 4.5 is corrected to a value of 6.6 by adding lime.

(22) The set of operations makes it possible to obtain a pea protein powder in accordance with the invention, with an average diameter of 200 m and an average density of 0.4. A protein composition in powder form, termed protein composition 5, is obtained.

(23) Test No. 6 According to the Invention: Rapid Heating (<1 s) and Cooling then Correction with Lime

(24) The process is the one described in test No. 4, but differs therefrom in that: the heat treatment of the protein extract is carried out at 135 C. for 0.9 s, followed by cooling to 70 C.; the pH of the floc of 4.5 is corrected to a value of 7 by adding lime.

(25) The set of operations makes it possible to obtain a pea protein powder in accordance with the invention, with an average diameter of 200 m and an average density of 0.4. A protein composition in powder form, termed protein composition 6, is obtained.

(26) Test No. 7 According to the Invention: Rapid Heating (<1 s) and Cooling then Correction with Lime

(27) The process is the one described in test No. 4, but differs therefrom in that: the heat treatment of the protein extract is carried out at 135 C. for 0.9 s, followed by cooling to 80 C.;

(28) The set of operations makes it possible to obtain a pea protein powder in accordance with the invention, with an average diameter of 200 m and an average density of 0.4. A protein composition in powder form, termed protein composition 7, is obtained.

(29) Test No. 8 According to the Invention: Rapid Heating (<1 s) and Cooling then Correction with Lime

(30) The process is the one described in test No. 4, but differs therefrom in that: the heat treatment of the protein extract is carried out at 150 C. for 0.9 s, followed by cooling to 70 C.; the pH of the floc of 4.5 is corrected to a value of 9 by adding lime.

(31) The set of operations makes it possible to obtain a pea protein powder in accordance with the invention, with an average diameter of 200 m and an average density of 0.4. A protein composition in powder form, termed protein composition 8, is obtained.

(32) Test No. 9 According to the Invention: Rapid Heating (<1 s) and Cooling then Correction with Lime

(33) The process is the one described in test No. 4, but differs therefrom in that: the heat treatment of the protein extract is carried out at 145 C. for 0.2 s, followed by cooling to 70 C.; the pH of the floc of 4.5 is corrected to a value of 7 by adding lime.

(34) The set of operations makes it possible to obtain a pea protein powder in accordance with the invention, with an average diameter of 200 m and an average density of 0.4. A protein composition in powder form, termed protein composition 9, is obtained.

(35) Test No. 10 According to the Invention: Rapid Heating (<1 s) and Cooling then Correction with Lime

(36) The process is the one described in test No. 4, but differs therefrom in that: the heat treatment of the protein extract is carried out at 122 C. for 0.3 s, followed by cooling to 55 C.; the pH of the floc of 4.5 is corrected to a value of 8 by adding lime.

(37) The set of operations makes it possible to obtain a pea protein powder in accordance with the invention, with an average diameter of 200 m and an average density of 0.4. A protein composition in powder form, termed protein composition 9, is obtained.

(38) Table 1 hereinafter recapitulates the values of the water adsorption capacity, of solubility measured according to the test A and of emulsifying capacity measured according to the test B. In addition, the values of the Brookfield viscosities measured in the test B, with regard to the second jar (pasteurized at 75 C.) and the third jar (sterilized at 120 C.) have also been revealed.

(39) This table reveals entirely singular and distinctive characteristics of the protein composition according to the invention, which, in the case in point, has: a low solubility, a low water adsorption capacity and a low emulsifying capacity.

(40) TABLE-US-00001 TABLE 1 Test 1 Test 2 Test 3 Test 4 Test 5 Water absorption 4.4 2.5 4.8 2.4 2.6 Solubility (g/g) 54.9 13.5 55.0 13.1 12.5 Emulsifying capacity 74 000 3000 1 000 000 1560 1280 according to test B (mPa .Math. s) Emulsion 75 C. 10 000 5200 1 000 000 4700 1720 Emulsion 120 C. 150 000 21 000 280 000 10 000 12 000 Test 6 Test 7 Test 8 Test 9 Test 10 Water absorption 2.6 2.5 3.4 4.2 2.7 Solubility (g/g) 10.5 13 19.7 14.7 12.9 Emulsifying capacity 1600 1320 1540 1440 1280 according to test B (mPa .Math. s) Emulsion 75 C. 8000 3960 3340 2560 3520 Emulsion 120 C. 9200 not done not done not done not done

Example 2

(41) This example illustrates the production of breads according to the prior art (breads A, B and C made with the protein compositions obtained according to tests No. 1 to 3) and of a bread according to the invention (bread D using the protein composition obtained according to test No. 4). The composition of each dough is indicated in the following Table 2.

(42) The various ingredients are introduced into the kneading machine, which consists of a spiral mixer. Kneading is carried out for 2 minutes at speed 1 and then for 1.8 minutes at speed 2. The dough is left to stand for 15 minutes. It is then cut up and shaped and the dough pieces are left to stand for 15 minutes. 5 different dough pieces are thus prepared for each bread A, B, C and D. Proofing is carried out in an oven for 1 h 30 at 30 C. and at 85% relative humidity. Finally, baking is carried out at 220 C. for 30 minutes.

(43) The bread volumes are then measured using a sesame seed volumeter, a device well known to those skilled in the art (reference may in particular be made to document EP 1 067 841 A1). The volumes are measured every 15 minutes. The increase in volume is finally calculated (% increase in volume of the dough piece relative to its initial volume).

(44) TABLE-US-00002 TABLE 2 Bread A Bread B Bread C Bread D Wheat flour 830 830 830 830 Gluten 70 70 70 70 Protein 100 composition 1 Protein 100 composition 2 Protein 100 composition 3 Protein 100 composition 4 Salt 18 18 18 18 Dry yeast 7 7 7 7 Ascorbic 0.2 0.2 0.2 0.2 acid Nutrilife AM17 0.2 0.2 0.2 0.2 Water (20 C.) 715 715 715 715

(45) For each bread A, B, C and D, the average of the 5 measurements of increase in volume is calculated so as to obtain an average increase in volume; this average increase in volume (%) is indicated in Table 3.

(46) TABLE-US-00003 TABLE 3 Bread A Bread B Bread C Bread D Average 155 174 165 175 increase in volume (%)

(47) Breads B and D obtained with protein compositions 2 and 3 (pH correction with lime) stand out because of a larger volume. In addition, a more pronounced soft nature is noted.

(48) Finally, 15 individuals were asked to taste breads A, B, C and D while giving them a grade, according to the aftertaste that they have: 0 for an absence of aftertaste, 2 for a pronounced aftertaste, and 1 for the presence of a slight aftertaste.

(49) Table 4 reports all of the grades obtained.

(50) TABLE-US-00004 TABLE 4 Tester Bread A Bread B Bread C Bread D 1 1 1 0 0 2 1 1 0 0 3 1 1 0 0 4 1 1 0 0 5 1 1 0 0 6 1 1 0 0 7 0 1 0 0 8 2 2 1 0 9 1 2 1 1 10 0 1 0 0 11 1 1 0 0 12 1 1 0 0 13 2 2 1 0 14 2 2 1 1 15 2 2 1 1

(51) Only breads C and D do not make reference to the notable presence of aftertaste. Consequently, only bread D, which uses protein composition 4, advantageously has a considerable volume and therefore a considerable softness, without however showing a pronounced aftertaste.