WO2005094603A1

WO2005094603A1 - Phytate reduced food

Info

Publication number: WO2005094603A1
Application number: PCT/US2005/010407
Authority: WO
Inventors: Ian Purtle; Aharon Eyal; Asher Vitner
Original assignee: Cargill, Incorporated
Priority date: 2004-03-29
Filing date: 2005-03-29
Publication date: 2005-10-13

Abstract

An industrial method for the production of a protein-containing food is disclosed. The method includes providing a plant proteinous starting material comprising at least one protein, at least one sugar and at least one phytate. The method also includes extracting with about a neutral or an alkaline aqueous solution at least a fraction of the protein, at least a fraction of the sugar and at least a fraction of the phytate from the starting material to form at least one protein-containing extract and at least one residual plant material. The method also includes separating the extract from the residual plant material to form at least one separated extract containing extracted protein, extracted sugar and extracted phytate. The method also includes purifying the extracted protein in the separated extract by separating it from extracted sugar and extracted phytate by means of an ultrafiltration membrane with a MWCO of at least about 25,000 Dalton to form a purified protein-containing retentate and sugar- and phytate-containing permeate. The method also includes further purifying the protein of the purified protein-containing retentate by washing with an aqueous solution to form a further purified protein-containing stream and a wash solution. The method also includesincorporating the further purified protein-containing stream in a food. The food is characterized by at least one of: at least one of the extract during the separating and the aqueous solution is maintained at pH of between about pI+0.5 and about pI + 2.5, wherein pI is the isoelectric point of the protein and at least one of the extract during the and the aqueous solution comprises a complexant of calcium cation. A food derived from a proteinous starting material comprising at least one protein, at least one sugar and at least one phytate, the food further comprising at least about 70 percent of the protein of the starting material and less than about 60 percent of the phytate of the starting material is also disclosed.

Description

PHYTATE REDUCED FOOD

CROSS-REFERENCE TO RELATED APPLICATIONS The following patent applications are cross-referenced and are hereby incorporated by reference in their entirety: U.S. Patent Application No. 60/557,197 entitled PHYTATE REDUCED FEED SYSTEM filed March 29, 2004 as attorney docket no. CGL04/0092USP1; PCT Patent Application

No. entitled PHYTATE REDUCED FOOD filed March 29, 2005 as attorney docket no. CGL04/0091WO1 ; PCT Patent Application No. entitled ISOFLAVONE DISTRIBUTION SYTEM filed March 29, 2005 as attorney docket no. CGL04/0049WO1 ; PCT Patent Application No. entitled PROTEIN PURIFICATION SYTEM filed March 29, 2005 as attorney docket no. CGL04/0093WO1 ; PCT Patent Application No. PCT/US05/004160 entitled PHENOLIC COMPOUND PURIFICATION filed February 9, 2005 as attorney docket no. CGL04/0008WO1; PCT Patent Application No. PCT/US05/04153 entitled PHENOLIC COMPOUND PURIFICATION filed February 9, 2005 as attorney docket no. CGL04/0009WO1 ; PCT Patent Application No. PCT/US05/04166 entitled CYCLITOL SEPARATION METHOD filed February 9, 2005 as attorney docket no. CGL03/0489WO1 ; U.S. Patent Application No. 60/660807 entitled FOOD OR FEED INGREDIENT AND METHOD filed March 11 , 2005 as attorney docket no. CGL04/0293USP2.

FIELD OF THE INVENTION The present invention generally relates to a phytate reduced food. The present invention more particularly relates to a method for the production of a purified proteinous food or feed component. The present invention more particularly relates to a method for the production of such food or feed component, which is relatively low in phytate. BACKGROUND OF THE INVENTION Various plant protein sources contain phytate. Phytate is inositol hexa-phosphate. At low pH, phytate appears in a free acid form carrying 12 protons. As pH goes up, phytic acid dissociates and protons are replaced with cations. Phytic acid and its salts are strong complexants and form complexes with various metal ions, e.g. ions of transition metals. The term "phytate" as used in this disclosure means and includes any of those forms including the fully protonated and fully dissociated ones. The term "phytate" as used in this disclosure also means and includes various compositions of phytate, including its complexed forms. The term "phytate" as used in this disclosure also means and includes partially hydrolyzed phytate.

Phytate is undesired in various feed applications. Its phosphorous is not available to the animal on one hand, while its strong complexation capacity reduces the availability of essential minerals. Conventional industrial methods of plant protein purification are not sufficiently effective in separation of phytate. One known conventional industrial option uses an enzyme - typically phytase - in order to hydrolyze the phytate contained in the purified protein. However, such known enzyme system has several disadvantages including that the more phytate present in the purified protein, the greater are the costs of that enzymatic hydrolysis.

Typically, soybeans are dehulled, flaked, extracted to separate oil and desolventized to form defatted flakes containing about 45 percent protein. After toasting for deactivating some of the anti-nutritional factors (ANF), those flakes (e.g. soybean meal, SBM) are incorporated as a protein source in animal feed. Toasting does not eliminate phytate, which is considered an ANF. A fraction of defatted soybeans is further purified to higher protein concentrations for applications such as food and fish feed in aquaculture.

One criterion for protein purity is protein concentration in the product, which is important in some applications, e.g. food/feed for infants, young animals, fish, etc. Another criterion is the content of components that interfere with optimal food/feed utilization of the protein. Oligosaccharides and phytate present in defatted soybean are ANF.

There are two known conventional industrial approaches to protein purification. According to Claim one such conventional approach, sugars (mainly mono-, di-, tri- and tetra- saccharides) and other water-soluble components are washed out of SBM at conditions selected to minimize protein dissolution. Typically, those conditions are either: (i) conducting the washing at a pH of about the isoelectric point of the protein; or (ii) washing with an aqueous ethanol solution of 60-80 percent ethanol. The product is referred to in this disclosure as "protein concentrate."

The other conventional industrial method of Claim protein purification involves the following steps: (i) extraction (dissolution) of the protein and of the other soluble components (e.g. from a non-toasted source) into a slightly alkaline aqueous solution (typically, no organic solvent); (ii) separation of the extract from the insolubles (e.g. fibers and other non-protein insoluble components); and (iii) separation of the protein in the extract from other soluble components. Such separation typically uses precipitation at about the isoelectric point of the protein or ultrafiltration. The product is referred to in this disclosure as "protein isolate." Such two known conventional industrial approaches to purifications of protein are relatively efficient in removing sugars from the protein. However, such known approaches to purifications of protein have several disadvantages including that they can be inefficient in removing phytate. The components separated from the protein during purification typically end up in an aqueous solution, which is a co-product of purification. The aqueous solution (referred to, in many cases, as soy solubles, soy molasses, soy whey, etc.) also contains part of the phytate.

Accordingly, there is a need for a method that forms purified protein products with reduced phytate content suitable for use in food or feed. There is also a need for a relatively inexpensive system for reducing phytate in purified protein products. It would be advantageous to provide a phytate reduced feed system filling any one or more of these needs or having other advantageous features.

SUMMARY OF THE INVENTION The present invention provides an industrial method for the production of a protein-containing food. The method includes providing a plant proteinous starting material comprising at least one protein, at least one sugar and at least one phytate. The method also includes extracting with about a neutral or an alkaline aqueous solution at least a fraction of the protein, at least a fraction of the sugar and at least a fraction of the phytate from the starting material to form at least one protein-containing extract and at least one residual plant material. The method also includes separating the extract from the residual plant material to form at least one separated extract containing extracted protein, extracted sugar and extracted phytate. The method also includes purifying the extracted protein in the separated extract by separating it from extracted sugar and extracted phytate by means of an ultrafiltration membrane with a MWCO of at least about 25,000 Dalton to form a purified protein-containing retentate and sugar- and phytate- containing permeate. The method also includes further purifying the protein of the purified protein-containing retentate by washing with an aqueous solution to form a further purified protein-containing stream and a wash solution. The method also includesincorporating the further purified protein-containing stream in a food. The food is characterized by at least one of: at least one of the extract during the separating and the aqueous solution is maintained at pH of between about pl+0.5 and about pi + 2.5, wherein pi is the isoelectric point of the protein and at least one of the extract during the and the aqueous solution comprises a complexant of calcium cation.

The present invention also provides a food derived from a proteinous starting material comprising at least one protein, at least one sugar and at least one phytate, the food further comprising at least about 70 percent of the protein of the starting material and less than about 60 percent of the phytate of the starting material. DETAILED DESCRIPTION OF THE PREFERRED AND OTHER EXEMPLARY EMBODIMENTS A system and method for reducing phytate in a protein source is disclosed as a phytate reduced feed system and method. The method involves treating a plant material that contains a protein, a sugar, and a phytate. According to an exemplary embodiment, the starting material includes at least about 30 percent by weight protein on dry basis, suitably at least about 35 percent, more suitably at least about 40 percent. According to an exemplary embodiment, the starting material includes at least about 10 percent by weight sugar on dry basis, suitably at least about 15 percent, suitably at least about 20 percent. According to an exemplary embodiment, the starting material contains a phytate content of at least about 1 percent by weight of the protein content, suitably at least about 1.5 percent, suitably at least about 2.0 percent, suitably at least about 3 percent. According to alternative embodiments, the plant material may be an oilseed, such as soybean or a defatted oilseed. Other suitable starting materials include soybean meal, defatted soybean flour, defatted soybean flakes, flash- desolventized defatted soy flakes, etc.

According to a preferred embodiment, sugars and phytate are extracted from the starting material with a neutral or alkaline aqueous solution. The term "extraction" as used in this disclosure means and includes dissolution into the solvent. Extraction can be done by contacting the starting material with the solvent. According to a preferred embodiment, a multiple-stage contacting is conducted. According to an alternative embodiment, contacting may be a single stage operation. According to a particularly preferred embodiment, the contacting includes multiple-stage extraction conducted in a counter-current mode of operation. According to other alternative embodiments, other modes may be used in cases where more than one extract is desired and when those multiple extracts are desired at different compositions.

According to a suitable embodiment, the pH of the aqueous solution used in extraction is between about 7 and about 10, more preferably between about 7.5 and about 9.5. According to an alternative embodiment, the aqueous solution may contain a salt, such as sodium chloride. According to a suitable embodiment, the temperature of the aqueous solution in the extraction step is between about 20C and about 60C, more preferably between about 30C and about 50C. The aqueous solution formed in the extraction step is referred to in this disclosure as "extract." The protein concentration in the extract is determined by at least one of the following parameters: (1) the protein concentration in the starting material; (2) the weight ratio between the aqueous solution and the starting material; and (3) extraction yield. The latter is determined, among other parameters, by the pH and the temperature of the aqueous solution, that weight ratio and the mode of contacting the starting material with the aqueous solution. According to a suitable embodiment, those parameters are adjusted so that the extraction yield is at least about 70 percent, preferably at least about 80 percent, and most preferably at least about 90 percent. According to a preferred embodiment, the ratio between the aqueous solution and the starting material is such that the protein concentration in the extract is between about 3 percent and about 15 percent, and between about 4 percent and about 10 percent according to an alternative embodiment.

Sugars and other soluble compounds of the starting material co- dissolve with the protein and are present in the extract. The same is true for phytate, at least partially. The extract contains, therefore, the extracted protein, extracted sugars, extracted phytate, and other soluble components of the starting material according to an exemplary embodiment. The protein in the extract is purified by separation from co-extracted sugars, phytate, and other solutes. According to a preferred embodiment, the purification is conducted by transfer through an ultrafiltration membrane. Co-extracted sugars, phytate and other solutes permeate through the membrane and end up in the permeate. The protein, on the other hand, is blocked (rejected) by the membrane and ends up in the retentate. The protein in the retentate is therefore purified compared with the protein in the extract, i.e. the protein/sugars and the protein/phytate weight ratios in the retentate are greater than those in the extract. According to a suitable embodiment, the ultrafiltration membrane is selected so that its molecular-weight cut-off (MWCO) is at least about 25,000 Dalton, preferably between about 25,000 Dalton and about 500,000 Dalton.

According to a particularly preferred embodiment, the ultrafiltration membrane has a hydrophilic filtering surface as determined by the contact angle, which is preferably no more than about 40 degrees, more preferably no more than about 30 degrees, and most preferably no more than about 15 degrees. The filtering surface of the membrane may contain only hydrophilic groups, such as N- alkylolamide groups, and the bulk of the polymer matrix, which forms the membrane, may be hydrophobic polymer. As used in this disclosure, the term "contact angle" refers to contact angles of surfaces measured using the Sessile Drop Method. This is an optical contact angle method used to estimate the wetting property of a localized region on a surface. The angle between the baseline of a drop of water (applied to a flat membrane surface using a syringe) and the tangent at the drop boundary is measured. An example of a suitable instrument for measuring contact angles is a model DSA 10 Drop Shape Analysis System commercially available from Kruss.

According to a particularly preferred embodiment, the membrane is a modified polyacrylonitrile membrane. Suitable membranes are commercially available from GE Water Technologies of Trevose, Pennsylvania, USA. Suitable membranes are disclosed in U.S. Patent No. 6,630,195, the disclosure of which is herein incorporated by reference.

According to a preferred embodiment, the pH of the extract in the ultrafiltration step is maintained between about pi + 0.5 and about pi + 2.5, wherein pi is the isoelectric point of the protein. According to a preferred embodiment, the pH of the extract is between about 4.5 and about 6.5, more preferably between about 5 and 6. This pH may be lower than the pH of the protein extraction step, which is neutral or slightly alkaline. In that case, the pH of the extract is adjusted, for example by the addition of an acid (preferably a mineral one). According to alternative embodiments, the pH adjustment is conducted after extract separation from the insolubles and prior to ultrafiltration, or substantially simultaneously with it.

According to an alternative embodiment, the extract in the ultrafiltration step contains a reagent capable of forming strong interactions with cations of alkaline earth metals such as calcium or magnesium. Such reagent is preferably a complexant, more preferably a complexant that is approved for use in feed, food or both. According to alternative embodiments, that complexant may be added at any stage prior to ultrafiltration or simultaneously with it. Suitable complexants of calcium cations approved for use in feed include citric acid, EDTA, etc.

According to still another alternative embodiment, the pH adjustment of the extract to the desired range is combined with complexant addition.

According to a particularly preferred embodiment, a trans-membrane pressure is applied in the ultrafiltration operation, but it is limited to less than about 50psig, more preferably between about 10psig and about 20psig. According to a preferred embodiment the temperature of the solution in the ultrafiltration step is maintained between about 40C and about 70C, more preferably between about 50C and about 65C, and most preferably between about 55C and about 60C.

Water transfers along with the sugar and the phytate into the ultrafiltration permeate according to an exemplary embodiment. In cases of adding no water to the retentate side of the membrane, or in case the amount of water added is smaller than the amount of permeating water, the concentration of the protein in the solution increases so that it becomes greater than in the extract. According to a preferred embodiment, the protein concentration in the purified protein-containing retentate is greater than the protein concentration in the extract by at least a factor of about 2. According to a preferred embodiment, the protein concentration in the purified protein-containing retentate is at least about 10 percent. According to a preferred embodiment, the purified protein contained in the retentate is further purified by washing with an aqueous solution to form a further purified protein-containing stream. According to a preferred embodiment, the washing is done via diafiltration, which use the ultrafiltration membrane of the previous step or a similar membrane, according to a preferred embodiment. Thus, after the ultrafiltration step, water or an aqueous solution is added to the retentate side of the ultrafiltration membrane and permeates through the membrane carrying with it impurities that were left in the retentate of the previous step. Those impurities end up in the diafiltration permeate, while the diafiltration retentate contains a further purified protein. Methods for conducting the diafiltration are disclosed in US Patent 6,630,195.

According to a preferred embodiment, the pH of the aqueous solution in the washing step, e.g. the solution used in the diafiltration step, is maintained between about pi + 0.5 and about pi + 2.5, wherein pi is the isoelectric point of the protein. According to a preferred embodiment, the pH of the solution is between about 4.5 and about 6.5, more preferably between about 5 and 6. According to an alternative embodiment, the aqueous solution contains a reagent capable of forming relatively strong interactions with cations of alkaline earth metals, such as calcium or magnesium. Such reagent is preferably a complexant, more preferably a complexant that is approved for use in feed, food or both. According to still another preferred embodiment, the washing-solution pH adjustment to the desired range is combined with complexant addition.

According to a preferred embodiment, the pH of both the extract and the washing solution is adjusted to the desired range. According to an alternative embodiment, both solutions contain a complexant of calcium. According to still another alternative embodiment, the pH of both solutions is adjusted to the desired range and a suitable complexant is added.

The further purified protein generated by washing/diafiltration is purified with regards to sugars, phytate and other components compared with the starting material, compared with the extract and compared with the ultrafiltration retentate according to an exemplary embodiment. According to a preferred embodiment, the protein/sugar weight ratio in the further purified protein- containing stream is greater than that ratio in the purified protein-containing retentate and both are greater than that ratio in the extract and in the starting material. According to a preferred embodiment, the protein/sugar weight ratio in the further purified protein-containing stream is greater than that ratio in the extract by a factor of at least about 3, more preferably at least about 5, and most preferably at least about 10. According to a preferred embodiment, the protein/phytate weight ratio in the further purified protein-containing stream is greater than that ratio in the purified protein-containing retentate and both are greater than that ratio in the extract and in the starting material. According to a preferred embodiment, the protein/phytate weight ratio in the further purified protein-containing stream is greater than that ratio in the extract by a factor of at least about 2, more preferably at least about 3, and most preferably at least about 4.

The permeates of ultrafiltration and diafiltration are relatively dilute aqueous solutions, containing sugars, phytate and other soluble components separated from the protein according to an exemplary embodiment. Water may be separated from those solutions to form separated water and concentrated solutions. Water separation could be done from either of those, from both or from a solution formed by combining those solutions according to alternative embodiments. Methods such as evaporation, multiple-stage evaporation, reverse osmosis (RO) and a combination of those are suitable for that water separation according to other alternative embodiments. The formed concentrated solutions contain sugars that present energy source, e.g. in feed according to an exemplary embodiment. Those concentrated solutions may be further concentrated to about 50 percent solutes or more and used as molasses in feed. According to an alternative embodiment, the sugars can be used as fermentation feedstock. According to another alternative embodiment, the sugars may be separated from the solution for other applications. According to another alternative embodiment, other components, such as isoflavones, could be recovered.

According to a preferred embodiment, the separated water (or highly dilute aqueous solution) is reused as process water in steps such as the protein extraction and/or wash/diafiltration.

Phytate is an ester of inositol with six phosphates (inositol hexa- phosphate). Hydrolysis cleaves phosphates off the inositol backbone. According to an exemplary embodiment, phytate is chemically or biologically hydrolyzed in the system. Chemical hydrolysis uses an acid catalysts according to a preferred embodiment. Biological hydrolysis uses enzymatic catalysis according to an alternative embodiment. Phytase is a suitable enzyme for that purpose. According to an alternative embodiment, hydrolysis does not need completion in the sense that it is sufficient to hydrolyze only a fraction of the phosphate-inositol ester bonds on a given phytate molecule. Phytate hydrolysis can be conducted on the purified proteinous material (e.g. the diafiltration retentate) prior to further treatments, such as washing and drying, simultaneously with such treatment or after it according to alternative embodiments. According to another alternative embodiment, a mixture of phytase and the purified protein may be incorporated into a feed or food. According to other alternative embodiments, hydrolysis may be conducted during the extraction of proteins, during the ultrafiltration step, during the wash step (e.g. diafiltration) or between those operations. According to another alternative embodiment, hydrolysis may be conducted in more than one of those stages. According to another alternative embodiment, hydrolyzing phytate present in recycled process streams may also be conducted.

Recycling aqueous solutions in the process may reduce the overall evaporation load. An example for that is re-using the wash solution (e.g. as such, without further treatment on RO) in protein extraction. According to a preferred embodiment, phytate contained in that or other recycled stream is at least partially hydrolyzed.

According to alterative embodiments, phytate hydrolysis may be combined with other hydrolysis reactions, e.g. hydrolysis of oligosaccharides and hydrolysis of peptides. Those other hydrolysis reactions may be conducted substantially simultaneously with phytate hydrolysis or sequentially in any desired order. Hydrolysis with immobilized enzymes in a solution, which is substantially free of solids, is particularly suitable.

According to a preferred embodiment, the further purified protein formed, e.g. the diafiltration retentate is low in sugars, phytate and other undesired components and is suitable for incorporation in feed or food products, as such or after further treatment. Such further treatment may include operations such as a additional wash and drying. In particular cases there might be a desire for other purification operations, e.g. ion-exchange or active carbon treatment. According to a preferred embodiment, the food or feed product includes at least about 70 percent of the protein of the starting material, preferably at least about 80 percent, more preferably at least about 90 percent. According to an alternative embodiment, the food or feed product includes less than about 60 percent of the phytate of the starting material, preferably less than about 50 percent, preferably less than about 40 percent, preferably less than about 30 percent.

According to another preferred embodiment, a protein comprising food or feed product is formed and is characterized in that at least about 20 percent of its protein content (suitably at least about 40 percent, more suitably at least about 70 percent, results from the separated purified protein material.

While the preferred and other exemplary embodiments described in this disclosure are presently preferred, it should be understood that these embodiments are offered by way of example only. The invention is not limited to a particular embodiment, but extends to various modifications, combinations, and permutations.

Claims

CLAIMSWhat is claimed is:

1. An industrial method for the production of a protein-containing food comprising the steps of: (a) providing a plant proteinous starting material comprising at least one protein, at least one sugar and at least one phytate; (b) extracting with about a neutral or an alkaline aqueous solution at least a fraction of the protein, at least a fraction of the sugar and at least a fraction of the phytate from the starting material to form at least one protein-containing extract and at least one residual plant material; (c) separating the extract from the residual plant material to form at least one separated extract containing extracted protein, extracted sugar and extracted phytate; (d) purifying the extracted protein in the separated extract by separating it from extracted sugar and extracted phytate by means of an ultrafiltration membrane with a MWCO of at least about 25,000 Dalton to form a purified protein-containing retentate and sugar- and phytate-containing permeate; (e) further purifying the protein of the purified protein-containing retentate by washing with an aqueous solution to form a further purified protein-containing stream and a wash solution; and (f) incorporating the further purified protein- containing stream in a food, characterized by at least one of: (g) at least one of the extract during the separating of step (c) and the aqueous solution of step (e) is maintained at pH of between about pl+0.5 and about pi + 2.5, wherein pi is the isoelectric point of the protein; (h) at least one of the extract during the separating of step (c) and the aqueous solution of step (e) comprises a complexant of calcium cation.

2. The method of Claim 1 , wherein the proteinous starting material comprises between about 30 percent and about 90 percent by weight protein on dry basis.

3. The method of Claim 1 , wherein the proteinous starting material comprises at least about 10 percent by weight sugar on dry basis.

4. The method of Claim 1 , wherein the proteinous starting material comprises phytate in an amount of at least about 1 percent by weight of the protein content.

5. The method of Claim 1 , wherein the plant comprises an oilseed.

6. The method of Claim 1 , wherein the starting material comprises a defatted oilseed.

7. The method of Claim 1 , wherein the plant comprises a soybean and the plant material comprises at least one of dehulled soybean, soybean meal, defatted soybean flour, defatted soybean flakes, flash-desolventized defatted soy flakes, soy molasses, soy whey and soy solubles.

8. The method of Claim 1 , wherein the extracting of step (b) is conducted in a multiple-stage mode of operation.

9. The method of Claim 1 , wherein the extracting of step (b) is conducted in a multiple-stage and counter-current mode of operation.

10. The method of Claim 1 , wherein the conditions in step (b) are such that the separated extract of step (c) comprises at least about 70 percent of the original protein content of the starting material.

11. The method of Claim 1 , wherein the pH of the aqueous solution of step (b) is between about 7 and about 10.

12. The method of Claim 1 , wherein the temperature of the aqueous solution of step (b) is between about 20C and about 60C.

13. The method of Claim 1 , wherein in step (b) the ratio between the aqueous solution and the starting material is such that the protein concentration in the extract is between about 3 percent and about 15 percent.

14. The method of Claim 1 , wherein the separating of step (c) is conducted by at least one of decantation, centrifugation, gravimetric separation, filtration, membrane filtration, and a combination thereof.

15. The method of Claim 1 , wherein the ultrafiltration membrane of step (d) has a s filtering surface with contact angle of no more than about 40 degrees.

16. The method of Claim 1 , wherein the membrane of step (d) is a modified polyacrylonitrile membrane.

17. The method of Claim 1 , wherein the membrane of step (d) has a MWCO of between about 25,000 Dalton and about 500,000 Dalton. o

18. The method of Claim 1 , wherein a trans-membrane pressure of less than about 50psig is used in step (d).

19. The method of Claim 1 , wherein the temperature of the extract in step (d) is between about 40C and about 70C.

20. The method of Oaim 1 , wherein the protein concentration on dry basis in thes purified protein-containing retentate of step (d) is greater than the protein concentration on dry basis in the extract by at least about a factor of 2

21. The method of Claim 1 , wherein the protein concentration in the purified protein-containing retentate is at least about 10 percent by weight.

22. The method of Claim 1 , wherein the washing of step (e) uses diafiltration and wherein the washed protein-containing stream is a diafiltration retentate.

23. The method of Claim 22, wherein the diafiltration uses the ultrafiltration membrane of step (d) or a similar one.

24. The method of Claim 1 , further comprising the steps of: (f) treating at least a fraction of the permeate of step (d), at least a fraction of the wash solution of5 step (e) or both for separating water to form separated water and at least one concentrated solution; (g) using at least a fraction of the separated water in step (b), step (e) or both; and (h) using sugar of the concentrated solution as an energy source.

25. The method of Claim 24, wherein water separation is conducted by at least one of evaporation, multiple-stage evaporation, reverse osmosis, and a combination thereof.

26. The method of Claim 1 , wherein the protein/sugar weight ratio in the further purified protein-containing stream is greater than that ratio in the purified protein-containing retentate and both are greater than that ratio in the extract.

27. The method of Claim 1 , wherein the protein/sugar weight ratio in the further purified protein-containing stream is greater than that ratio in the extract by a factor of at least about 3.

28. The method of Claim 1 , wherein the protein/phytate weight ratio in the further purified protein-containing stream is greater than that ratio in the purified protein-containing retentate and both are greater than that ratio in the extract.

29. The method of Claim 1 , wherein the protein/phytate weight ratio in the further purified protein-containing stream is greater than that ratio in the extract by a factor of at least about 3.

30. The method of Claim 1 , wherein the extract during the separating of step (c) and the aqueous solution of step (e) are maintained at pH of between about pl+0.5 and about pi + 2.5.

31. The method of Claim 1 , wherein the pH of at least one of the extract during the separating of step (c) and the aqueous solution of step (e) is between about 4.5 and about 6.5.

32. The method of Claim 1, further comprising the step of: (i) catalytically hydrolyzing phytate using at least one of chemical catalysis and biological catalysis.

33. The method of Claim 32, wherein the hydrolyzing uses phytase.

34. The method of Claim 1 , wherein the extraction steps uses a recycled aqueous stream.

35. The method of Claim 34, wherein the recycled aqueous stream is the wash solution formed in step (e).

36. The method of Claim 1 , further comprising the step of: (j) hydrolyzing phytate in at least one of the aqueous solutions used in the extraction process.

37. The method of Claims 34 and 36, wherein the at least one aqueous solution is a recycled aqueous stream.

38. A food derived from a proteinous starting material comprising at least one protein, at least one sugar and at least one phytate, the food further comprising at least about 70 percent of the protein of the starting material and less than about 60 percent of the phytate of the starting material, the food produced by the process comprising: (a) providing the starting material; (b) extracting with about a neutral or an alkaline aqueous solution at least a fraction of the protein, at least a fraction of the sugar and at least a fraction of the phytate from the starting material to form at least one protein-containing extract and at least one residual plant material; (c) separating the extract from the residual plant material to form at least one separated extract containing extracted protein, extracted sugar and extracted phytate; (d) purifying the extracted protein in the separated extract by separating it from extracted sugar and extracted phytate by means of an ultrafiltration membrane with a MWCO of at least about 25,000 Dalton to form a purified protein-containing retentate and sugar- and phytate-containing permeate; (e) further purifying the protein of the purified protein-containing retentate by washing with an aqueous solution to form a further purified protein-containing stream and a wash solution; and (f) incorporating the further purified protein- containing stream in a food characterized by at least one of: (g) at least one of the extract during the separating of step (c) and the aqueous solution of step (e) is maintained at pH of between about pl+0.5 and about pi + 2.5, wherein pi is the isoelectric point of the protein; (h) at least one of the extract during the separating of step (c) and the aqueous solution of step (e) comprises a complexant of calcium cation.

39. The food of Claim 38, wherein at least 20 percent of the protein content of the food results from the separated purified protein material.