PROCEDURE FOR REDUCING CONTAMINANTS IN VEGETABLE PROTEIN MATTER

Abstract

This invention refers to a procedure for reducing inorganic (heavy metals) and organic (aflatoxins, molds, etc.) contaminants in high-protein vegetable matter, mainly originating from rice. Applying said procedure to raw vegetable matter results in the obtainment of derivatives presenting levels of these contaminants significantly lower than the legal limits set by health authorities. Following the procedure set out in this invention, high-quality protein derivatives are obtained usable for vitamin and nutritional supplements, milk formula for babies, sports nutrition, clinical nutrition, animal feed ingredients, etc.

Claims

1. A procedure for reducing contaminants in vegetable protein which includes performing each of the following steps at least once: a) Mixing the initial vegetable matter with water and at least one type of protease enzyme, bringing the mixture to a pH of between 3 and 10 and keeping it in agitation for a period of at least 20 minutes, at a temperature of between 20 and 90 C., b) Optionally, performing a wash and a solid-liquid separation of the product obtained in the previous stage, c) Optionally, subjecting the hydrolysate obtained in the previous stage to a sterilization process.

2. A procedure according to claim 1 where the pH of the mixture obtained from stage (a) is between 5 and 8.

3. A procedure according to claim 1 where the pH of the mixture from stage (a) is 7.5.

4. A procedure according to claim 1 where the time of agitation at stage (a) is from 60 to 180 minutes.

5. A procedure according to claim 1 where the time of agitation at stage (a) is 70 minutes.

6. A procedure according to claim 1 where temperature during stage (a) is between 50 and 80 C.

7. A procedure according to claim 1 where the temperature during stage (a) is 60 C.

8. A procedure according to claim 1 where the sterilization process during stage (c) can be either UHT sterilization or pasteurization.

9. A procedure for reducing contaminants in vegetable protein which includes performing each of the following steps at least once: a1) Mixing the initial vegetable matter with water in the presence of hydrogen peroxide, bringing this mixture to a pH of above 9 and keeping it in agitation for some time, at least, 20 minutes, at a temperature of between 75 and 95 C. and b1) Optionally, performing a wash and a solid-liquid separation of the product obtained during stage a1).

10. A procedure according to claim 9 where the time of agitation of the mixture obtained from stage (a1) is 60 minutes.

11. A procedure according to claim 9 where the temperature of stage (a1) is 85 to 90 C.

12. A procedure according to claim 9 which includes carrying out stage (a1) and optionally (b1) prior to mixing the initial vegetable matter with water and at least one type of protease enzyme, bringing the mixture to a pH of between 3 and 10 and keeping it in agitation for a period of at least 20 minutes, at a temperature of between 20 and 90 C.

13. A procedure for reducing contaminants in vegetable protein which includes performing each of the following steps at least once: a2) Mixing the initial vegetable matter with water, bringing this mixture to a pH of between 6.5 and 8.5 and keeping it in agitation for a period of between 20 and 60 minutes, at a temperature of between 60 and 90 C., b2) Carrying out a wash and a solid-liquid separation

14. A procedure according to claim 13 where the pH of stage (a2) is between 7 and 8.

15. A procedure according to claim 13 where the time of agitation of stage (a2) is 30 minutes.

16. A procedure according to claim 13 where the temperature of stage (a2) is between 60 and 80 C.

17. A procedure according to claim 13 where the temperature of stage (a2) is 66 C.

18. A procedure according to claim 13, which includes carrying out stage (a2) and (b2) prior to mixing the initial vegetable matter with water and at least one type of protease enzyme, bringing the mixture to a pH of between 3 and 10 and keeping it in agitation for a period of at least 20 minutes, at a temperature of between 20 and 90 C. or mixing the initial vegetable matter with water in the presence of hydrogen peroxide, bringing this mixture to a pH of above 9 and keeping it in agitation for some time, at least, 20 minutes, at a temperature of between 75 and 95 C.

19. A procedure for reducing contaminants in vegetable protein which includes performing each of the following steps at least once: a3) Mixing the initial vegetable matter with water, bringing this mixture to a pH of between 2 and 4 and keeping it in agitation for a period of between 20 and 60 minutes, and b3) Performing a wash and a solid-liquid separation.

20. A procedure according to claim 19 where the pH of the mixture at stage (a3) is of 3.5 to 3.7.

21. A procedure according to claim 19 where the agitation time at stage (a3) is 30 minutes.

22. A procedure according to claim 19 where the temperature at stage (a3) is controlled to be between 60 C. and 95 C.

23. A procedure according to claim 19 where the temperature at stage (a3) is 80 C.

24. A procedure according to claim 19, which includes carrying out stages (a3) and (b3) and then carrying out a step selected from the group consisting of: mixing the initial vegetable matter with water and at least one type of protease enzyme, bringing the mixture to a pH of between 3 and 10 and keeping it in agitation for a period of at least 20 minutes, at a temperature of between 20 and 90 C.; mixing the initial vegetable matter with water in the presence of hydrogen peroxide, bringing this mixture to a pH of above 9 and keeping it in agitation for some time, at least, 20 minutes, at a temperature of between 75 and 95 C.; and mixing the initial vegetable matter with water, bringing this mixture to a pH of between 6.5 and 8.5 and keeping it in agitation for a period of between 20 and 60 minutes, at a temperature of between 60 and 90 C.

25. A procedure according to claim 1 where the plant matter comes from rice, wheat, soy, corn, pea, carob, sunflower, potato, cotton, lentil or chickpea.

26. A procedure according to claim 1 where the contaminant to be reduced is selected from metals, mycotoxins or microorganisms.

27. A procedure according to claim 26 where metals are selected from As, Cd, Pb, Hg, Mo or V.

28. A procedure according to claim 26 where the mycotoxins are selected from fumonisin B1, deoxynivalenol, ochratoxin A or aflatoxins B1, B2, G1, G2, M1 or M2.

29. A procedure according to claim 26 where the microorganism is selected from molds, yeasts or bacteria.

30. A procedure according to claim 26 where the microorganism is selected from E. coli, Salmonella, Cronobacter Sakazaaki, Bacillus cereus, Staphylococcus aerus or Lysteria.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0043] FIG. 1. Schematic description of the entire process.

[0044] FIG. 2. Detailed description of the entire process.

EXAMPLES

[0045] Below, the invention is illustrated by way of some tests carried out by the inventors, showing the effectiveness of the invention's product.

Procedure for Reducing Heavy Metals

[0046] To prepare the initial raw material for the process 150 Kg of rice protein (raw material) was suspended in 2,500 L of water.

[0047] This mixture was stabilised at 19 C. for 30 minutes and its pH was adjusted up to a value of between 3.5 and 3.7 (+/0.5) using HCl. Specifically, the mixture's initial pH was 4.76 and a final pH of 3.68 was obtained using 2.5 of HCl. This mixture was separated using a horizontal centrifuge (decanter).

[0048] The resulting heavy phase (solids from the first wash), was used for a second wash.

[0049] In order to do this, 2,500 L of water was added, it was heated while in agitation to 66 C. and its pH was adjusted to between 7.0 and 8.0 (+/0.5) using 80% potash, agitation was maintained until the pH stabilised. Specifically, 4.4 kg of potash was added to change an initial pH of 4.08 to a final pH of 7.31. Following this process, a new solid-liquid separation was carried out using a horizontal centrifuge (decanter).

[0050] The resulting heavy phase (solids from the second wash) was used as a substrate in the enzymatic hydrolysis. In order to do this, 2,500 L water was added, stabilised at 60 C. and pH was adjusted from an initial pH of 6.75 to a final pH of 7.59 by adding 1 L of NaOH 50%. 1 L of protease was added and these conditions were maintained for 70 minutes. The initial pH was 7.59 and the final pH, 6.79. The enzyme was then deactivated by raising the temperature to 85 C. and keeping it at that level for 30 minutes.

[0051] Following that, separation was performed using a basket centrifuge and further clarification of the liquid was carried out using a plate centrifuge. The resulting light phase was stabilised by evaporation and spray drying. This powder is the end product and low in contaminants (end product).

Determination of the Contaminants in the Samples Obtained During the Process.

[0052] A sample was taken of the end product powder and we proceeded to determine quantitatively, using standard methods, the heavy metals set out in table 1 (ICP-Vis). The results obtained indicate that an independent fractionation for each metal occurred during the process. The results obtained are listed below (in mg/100 g) for the product as compared to the maximum limit (LIM.):

TABLE-US-00001 TABLE 1 Raw Solid from Solid from the End Element materia the first wash second wash product LIM. Pb 0.007 0.010 0.004 0.005 0.005 Cd 0.023 0.004 0.004 0.002 0.005 As 0.006 0.002 0.002 0.005 0.01 Hg 0.002 0.001 0.002 0.001 0.005 Al 1.22 1.44 1.03 0.412 3

[0053] As can be seen from this data, an acid pH wash process significantly reduces Cd and As, a pH neutral wash significantly reduces Pb and As, and the hydrolysis and clarification process significantly reduces the amounts of Cd, Hg and Al.

Procedure for Reducing Aflatoxin B1 and Aerobic Mesophiles

[0054] To prepare the raw material for initiating the process 300 Kg of rice protein was used (raw material) and suspended in 3,100 L of water.

[0055] This mixture was stabilised at 85 C. for 60 minutes and its pH was adjusted to a value between 9 (+/0.2) using NaOH. Specifically, the mixture's initial pH was 5.42 and a final pH of 9.15 was obtained using 5 Kg of NaOH (50%), hydrogen peroxide was added up to 10 L.

[0056] The resulting mixture was used as a substrate of the hydrolysis enzyme. In order to do so, it was stabilised at 60 C. and the pH was adjusted from an initial pH of 9.15 to a final pH of 8.1 by adding 1 L of HCL 35%. 1.2 L of protease was added and conditions were maintained for 80 minutes. The initial pH was 8.1 and the final pH, 5.93. The enzyme was then deactivated by raising the temperature to 85 C. and keeping it at that level for 30 minutes.

[0057] Following that, separation was performed using a basket centrifuge and further clarification of the liquid was carried out using a plate centrifuge. The resulting light phase was concentrated by evaporation.

[0058] The resulting syrup is pasteurised in a tank heated up to 80-85 C. and kept in agitation to remove the H2O2 for a minimum of 3 hours Finally, the product was stabilised by spray drying. This powder is the final product and low in aflatoxins and microbiological species (final product).

[0059] Determining Contaminants in the Samples Obtained During the Process.

[0060] A sample of the end product powder was taken and we proceeded to determine quantitatively, using standard methods, its aflatoxin and aerobic mesophile contents. These are set out in table 2. The results obtained indicate that there has been a reduction in aflatoxin B1 and mesophilic aerobic microorganisms during the process. The results obtained (in ppb for aflatoxins and cfu/g for the aerobic mesophiles) are listed below:

TABLE-US-00002 TABLE 2 Substance Raw material End product LIM. Aflatoxin B1 2.3 0.05 0.3 Aflatoxin B2 <0.050 <0.050 0.3 Aflatoxin G1 <0.050 <0.050 0.3 Aflatoxin G2 <0.050 <0.050 0.3 Aerobic 2,500 1,800 10,000 mesophiles

[0061] As can be seen from the data, the alkali treatment significantly reduces aflatoxin B1 and the pasteurisation process reduces microbial load.