Hybrid vegetable protein and method for obtaining same

Abstract

A hybrid vegetable protein is described, comprising a guest protein having the structure of prolamine and glutelin, and a host protein having the structure of globulin and albumin, obtained from vegetable grains, such as corn and soybean, respectively. Likewise, a method for obtaining said hybrid vegetable protein is described, which comprises the steps of extracting the guest and host proteins, carrying out an acidification thereof, and further applying a magnetic field to provoke their attachment, and finally adding an alkali to the attached proteins to obtain a hybrid vegetable protein at its isoelectric point. The protein thus produced has a value higher than 0.97 according to the PDCAAS rating.

Claims

1. A method for obtaining a hybrid vegetable protein, comprising the steps of: a) extracting and hydrolyzing at least a first protein, and at least a second protein, from a first and second vegetable source, respectively, in order to obtain hydrolyzed proteins; b) acidifying the hydrolized proteins, in order to obtain acidifed proteins; c) applying a magnetic field to the acidified proteins in order to open the amino acid chain of the first protein to be received in the amino acid chain of the second protein, thereby forming a hybrid vegetable protein at a pH value which does not correspond to the isoelectric point of said hybrid vegetable protein; and, d) adding an alkali to the hybrid protein to take it to its isoelectric point, and thus producing a stable hybrid vegetable protein.

2. The method for obtaining a hybrid vegetable protein according to claim 1, wherein step b) is carried out using sulfuric acid.

3. The method for obtaining a hybrid vegetable protein according to claim 1, wherein step b) is carried out at a temperature of between 40° and 50 ° C.

4. The method for obtaining a hybrid vegetable protein according to claim 1, wherein step b) is carried out at a temperature of between 43° and 47 ° C.

5. The method for obtaining a hybrid vegetable protein according to claim 1, wherein the magnetic field applied in step c) is in the range of between 2450 gauss and 3850 gauss.

6. The method for obtaining a hybrid vegetable protein according to claim 1, further comprising a grinding step of the first and second acidified proteins at the same time of applying the magnetic field in step c).

7. The method for obtaining a hybrid vegetable protein according to claim 6, wherein a colloidal grinder is used for grinding.

8. The method for obtaining a hybrid vegetable protein according to claim 1, wherein the magnet used in step c) is of the Nd.sub.2Fe.sub.14B type.

9. The method for obtaining a hybrid vegetable protein according to claim 1, further comprising a drying step of the hybrid protein, after step d).

10. The method for obtaining a hybrid vegetable protein according to claim 9, wherein the drying is carried out by spray-drying.

11. The method for obtaining a hybrid vegetable protein according to claim 9, wherein the drying temperature is of between 140° and 180° C.

12. The method for obtaining a hybrid vegetable protein according to claim 1, wherein the alkali added in step d) is calcium or sodium hydroxide.

13. The method for obtaining a hybrid vegetable protein according to claim 12, wherein the hydroxide is calcium hydroxide.

14. The method for obtaining a hybrid vegetable protein according to claim 1, wherein the protein having been subjected to the magnetic field is recirculated to the acidification step for 30 to 60 minutes in order to maintain the maximum ionization and to obtain the highest yielding in the hybridization of the vegetable protein.

15. The method for obtaining a hybrid vegetable protein according to claim 1, wherein the first protein is obtained from a first vegetal source selected from corn, wheat, sorghum, rye, quinoa, and amaranth.

16. The method for obtaining a hybrid vegetable protein according to claim 15, wherein the first vegetal source is corn grain.

17. The method for obtaining a hybrid vegetable protein according to claim 16, wherein the protein is produced from the germ of the corn grain.

18. The method for obtaining a hybrid vegetable protein according to claim 1, wherein the second protein is obtained from a second vegetal source selected from soybean, safflower, sunflower, olive, and canola.

19. The method for obtaining a hybrid vegetable protein according to claim 18, wherein the second vegetal source is soybean grain.

20. The method for obtaining a hybrid vegetable protein according to claim 1, wherein the first protein is obtained from corn grains and the second protein is obtained from soybean grains.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The novel aspects considered characteristic of the present invention are particularly established in the appended claims, however, the structure of the hybrid vegetable protein, as well as the integration of the method steps for the obtaining thereof, will be better understood from the following detailed description of certain embodiments when read related to the appended drawings, wherein:

(2) FIG. 1 is a block diagram showing the step sequence of a method for the hybrid vegetable proteins obtaining, developed according to the principles of a particularly specific embodiment of the present invention.

(3) FIG. 2 is a flowchart showing the step sequence of the method for the hybrid vegetable proteins obtaining, developed according to the principles of a first alternative embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

(4) The hybrid vegetable protein 51 claimed in the present invention comprises: at least one guest protein 21 having a structure of prolamine and glutelin, obtained from a first grain 11, having an isoelectric point of between 5.2 and 6.6, and a molecular weight from 37 kD to 46 kD; and at least one host protein 22 having a structure of globulin and albumin, obtained from a second grain 12, having an isoelectric point of between 4.0 and 5.0, and a molecular weight from 100 kD to 120 kD, wherein the guest protein 21 structure opens to facilitate its attachment to the amino acid chain of the host protein 22.

(5) The first grain 11 used as a source of the guest protein 21, is selected from corn, wheat, sorghum, rye, quinoa, amaranth, among others; most preferably using corn grains.

(6) For the first corn grain 11, preferably the germ of the seed is used, since as shown in Table 2, main parts of the corn grain 11 substantially differ in its chemical composition, for example, the seed cover or pericarp is characterized by a high content of crude fiber (about 87%), which in turns is mainly formed by hemicellulose (67%), cellulose (23%) and lignin (0.1%). On the contrary, the endosperm has a high level of starch (87%), about 8% proteins and a relatively small crude fat content. Finally, the germ is characterized by a high crude fat content, with an average of 33%, and also having a relatively high level of proteins near to 20%.

(7) TABLE-US-00002 TABLE 2 Approximate chemical composition of the main parts in corn grains (%) Chemical component Pericarp Endosperm Germ Proteins 3.7 8.0 18.4 Ethereal 1.0 0.8 33.2 extract Crude fiber 86.7 2.7 8.8 Ashes 0.8 0.3 10.5 Starch 7.3 87.6 8.3 Sugar 0.34 0.62 10.8

(8) On the other hand, the second grain 12 used as the host protein 22 source is selected from soybean, safflower, sunflower, olive, canola, among others; using preferably soybean grains.

(9) Regarding the second grain 12 preferred to obtain the host protein 22, soybean is preferred to use. Soy isolated proteins are obtained by an extraction process with water and applying a minimum temperature over the soybean flakes. This product practically does not contain carbohydrates or fat, and does not have the peculiar “leguminous” flavor of the soybean grains. Soy protein isolates are 90% protein in a dry basis, the concentration of the soy protein amino acids can be seen in Table 3.

(10) TABLE-US-00003 TABLE 3 Soy protein mg/g protein Histidine 26 Isoleucine 49 Leucine 82 Lysine 63 Methionine + Cysteine 26 Phenylalanine + Tyrosine 90 Threonine 38 Tryptophan 13 Valine 50

(11) The ratio between the guest protein 21 and the host protein 22 is of between 3:1 and 4:2, and preferably is of 3:1. Likewise, the PDCAAS value in the hybrid vegetable protein 51 of the present invention is of at least 0.97.

(12) Each gram of hybrid vegetable protein has a minimum concentration value of the following amino acids: 50 mg isoleucine, 102 mg leucine; 50 mg lysine; 35 mg cysteine; 95 mg tyrosine; 42 mg threonine; 10 mg tryptophan and 56 mg valine.

(13) Now referring to FIG. 1 of the appended drawings, the method 10 for the hybrid vegetable protein obtaining 51 of the present invention starts with step 20, wherein the extraction and hydrolysis of the guest protein 21 and host protein 22 is made from the first and second grains 11 and 12, respectively.

(14) Further, the extracted guest and host proteins 21 and 22, respectively, are acidified with sulfuric acid (H.sub.2SO.sub.4) in step 30, at a pH of between 3 and 5, at a temperature of between 40 and 50° C., and more preferably, the acidification temperature is from 43° to 47° C. In this step the acidified guest and host proteins 31 and 32, respectively, are obtained.

(15) In step 40, a magnetic field is applied to the guest 31 and host 32 acidified proteins, in order to open the amino acid chain of said acidified guest protein 31 and to provoke its attachment to the acidified host protein 32, thereby obtaining a hybrid vegetable protein 41, out of its isoelectric point.

(16) Continuing with the block diagram description of FIG. 1, an alkali 55 is added in step 50, to provoke that the hybrid vegetable protein 41 reaches its isoelectric point, thereby obtaining the hybrid vegetable protein 51 in solution, which can de used in various food compositions.

(17) Now, referring to FIG. 2 of the appended drawings, and wherein a flowchart of the method for the hybrid vegetable protein 61 obtaining is shown, according to a first alternative embodiment of the present invention, wherein, particularly, in the mixing tank 130 the already extracted guest protein 21 and host protein 22 are acidified, wherein the acidification is carried out preferably at a temperature between 43 and 47° C., as mentioned above. From the mixing tank 130 bottom, the guest 31 and host 32 acidified proteins are extracted, which are subjected to a magnetic field generated by a magnet 140, wherein the generated magnetic field has a value of 2450 gauss to 3850 gauss. The magnet used is preferably made of Nd.sub.2Fe.sub.14B.

(18) In the first alternative embodiment being described, at the same time the magnetic field is applied to the guest 31 and host 32 acidified proteins, these are subjected to an additional grinding step in a colloidal grinder 145, which favors even more the attachment between both proteins.

(19) After passing through the magnet 140, the obtained product is a hybrid vegetable protein 141 out of its isoelectric point, which is then passed through a pump 101 which sends the hybrid vegetable protein 141 to the mixing tank 130 to be recirculated for 30 to 60 minutes, in order to maintain the maximum ionization, and to obtain the highest hybridization yielding, thus producing an optimized hybrid vegetable protein 141′; further the hybrid vegetable protein 141 ′ is conveyed to a filter press 102 to remove residues and impurities. From said filter press 102, the hybrid vegetable protein 141′ is fed to a second pump 103 which sends it to a neutralization tank 150, wherein an alkali 55 is added, preferably calcium or sodium hydroxide and more preferably, by using calcium hydroxide. When adding the alkali 55, a hybrid vegetable protein in solution 51 at its isoelectric point is obtained. Said hybrid vegetable protein in solution 51 is conveyed by a pump 104 to a spray-dryer 160, wherein the protein 51 is dried at a temperature of between 140° and 180° C., thereby producing the dried hybrid vegetable protein 61, which has obvious advantages, since its transportation and further processing is cheaper than keeping it in solution.

(20) The hybrid vegetable protein 61 and its obtaining method will be more clearly illustrated by means of the following description of examples, which are provided only with illustrative purposes, and not to limit the scope of the present invention.

EXAMPLE 1

Hybrid Vegetable Protein Obtaining Using Corn Germ and Soy Protein

(21) 3 kg of corn germ and 1 kg of soy protein were used, soaked for at least 3 hours at 45° C., using 3 liters of water per each kg of dry matter; then sulfuric acid (H.sub.2SO.sub.4) was added to acidify the guest and host proteins up to the required pH; immediately after, the grinding was carried out at the same time that the magnetic field was applied, recirculating to the acidification step all protein subjected to the magnetic field; then, the hybrid vegetable protein was passed through a filter press wherein all the grain was removed; the liquid was transferred to another vessel wherein the product was neutralized with calcium hydroxide (Ca(OH).sub.2); the waste materials were removed by decantation; then spray-drying was carried out at a drying temperature of between 140° and 180° C.; finally, the product was dry packaged.

(22) Table 4 shows the comparative results between the PDCAAS rating obtained for protein sources, and those achieved in this Example 1 of the present invention. Also included for reference are the FAO recommended values.

(23) TABLE-US-00004 TABLE 4 AMINO ACID PDCAAS Source Ile Leu Lys Cys Tyr Thr Trp Val rating FAO/WHO 40 70 55 35 60 40 10 50 1.00 Egg 54 86 70 57 93 47 17 66 1.00 Casein 64 101 79 34 112 44 14 72 0.97 H corn 47 132 29 32 107 40 6 52 0.53 H soy 53 77 63 32 82 40 14 52 0.91 Rice 52 86 38 36 92 38 10 66 0.69 Example 1 50 102 50 35 95 42 10 56 0.97

(24) Although in the above description certain embodiments of the present invention have been shown and described, it must be remarked that numerous modifications are possible, such as, but not limited to, the guest and host protein source, the magnet type. Therefore, the present invention shall not be restricted except for that established in the state of the art, and by the appended claims.