WO2005077929A1

WO2005077929A1 - Phenolic compound purification

Info

Publication number: WO2005077929A1
Application number: PCT/US2005/004153
Authority: WO
Inventors: Ian Purtle; Aharon Eyal; Asher Vitner
Original assignee: Cargill, Incorporated
Priority date: 2004-02-09
Filing date: 2005-02-09
Publication date: 2005-08-25

Abstract

A process for the production of purified isoflavones from a starting material resulting from a biological source is disclosed. The starting material includes at least one isoflavone in its conjugate form and at least one impurity. The process includes adjusting the concentration of the starting material in an aqueous medium so that the concentration of the isoflavone conjugates therein is greater than about 20 percent (%) of saturation, but smaller than saturation, whereby there is formed an isoflavone purified solution comprising a purified isoflavone conjugate and an isoflavone-depleted precipitate containing the impurity, and wherein the isoflavone-depleted precipitate contains, after washing, less than about 20 percent (%) of the isoflavone conjugate present in the starting material. The process also includes separating the isoflavone purified solution from the isoflavone-depleted precipitate. The process also includes separating the isoflavone from the isoflavone purified solution. A purified polyphenol produced from a starting material resulting from a biological source is also disclosed. A process for the production of purified isoflavones from a starting material is also disclosed.

Description

PHENOLIC COMPOUND PURIFICATION

CROSS-REFERENCE TO RELATED APPLICATIONS

The following applications are cross-referenced and are hereby incorporated by reference in their entirety:U.S. Patent Application No. 60/543,067 titled "PHENOLIC PURIFICATION SYSTEM" filed 09-Feb-2004 and U.S. Patent Applictaion No. [To be determined] titled "PHENOLIC PURIFICATION SYSTEM", filed 09-Feb-2005 as attorney docket no. CGL04/0008 PCT U.S. Patent Application No. 60/543066 titled "PHENOLIC PURIFICATION SYSTEM" filed 09-Feb-2004; U.S. Patent Application No. 60/630137 titled "MONOSACCHARIDE

PRODUCTION SYSTEM" filed 22-Nov-2004.

FIELD OF THE INVENTION The present invention generally relates to a process for the purification of a phenolic compound. The present invention more particularly relates to the extraction of a purified phenolic compound from a starting material resulting from a biological source. More particularly, the present invention relates to a process for purifying isoflavones from plant materials such as soy bean extracts.

BACKGROUND OF THE INVENTION It is generally known to provide a method to purify a phenolic compound. However, such known methods have several disadvantages.

Accordingly, it would be desirable to provide a method for isolating isoflavones from a variety of plant materials with suitable purity, color, flavor, solubility, shelf stability, etc. to promote the incorporation of these beneficial nutrients in a variety of food, beverage, dietary supplement, and pharmaceutical products. It would be advantageous to provide a process for the purification of a phenolic compound system filling any one or more of these needs or having other advantageous features. SUMMARY OF THE INVENTION The present invention relates to a process for the production of purified isoflavones from a starting material resulting from a biological source. The starting material includes at least one isoflavone in its conjugate form and at least one impurity. The process includes adjusting the concentration of the starting material in an aqueous medium so that the concentration of the isoflavone conjugates therein is greater than about 20 percent (%) of saturation, but smaller than saturation, whereby there is formed an isoflavone purified solution comprising a purified isoflavone conjugate and an isoflavone-depleted precipitate containing the impurity, and wherein the isoflavone-depleted precipitate contains, after washing, less than about 20 percent (%) of the isoflavone conjugate present in the starting material. The process also includes separating the isoflavone purified solution from the isoflavone-depleted precipitate. The process also includes separating the isoflavone from the isoflavone purified solution. The present invention also relates to a process for the purification of a starting material resulting from a biological source. The starting material includes at least one polyphenol glycoside in its conjugate form and at least one non-phenolic compound. The process includes adjusting the concentration of the starting material in an aqueous medium so that the concentration of the polyphenol glycoside in its conjugate form is greater than about 20 percent (%) of saturation, but smaller than saturation, in order to induce the formation of a polyphenol purified solution containing the conjugate and a polyphenol-depleted precipitate containing the non-phenolic compound, wherein the polyphenol-depleted precipitate contains less than about 20 percent (%) of the conjugate present in the starting material. The process also includes separating the formed polyphenol purified solution from the polyphenol-depleted precipitate.

The present invention also relates to a purified polyphenol produced from a starting material resulting from a biological source. The starting material includes a mixture of at least one isoflavone in its conjugate form and at least one impurity. The purified polyphenol is made by the process including adjusting the concentration of the starting material in an aqueous medium so that the concentration of the isoflavone conjugates therein is greater than about 20 percent (%) of saturation, but smaller than saturation, whereby there is formed a purified solution containing the isoflavone conjugate and an isoflavone depleted precipitate containing the at least one impurity, wherein the isoflavone depleted precipitate contains, after washing, less than about 20 percent (%) of the isoflavone conjugate present in the starting material. The purified polyphenol is made by the process which also includes separating the formed purified solution from the isoflavone-depleted precipitate. The purified polyphenol is made by the process which also includes separating the isoflavone from the purified solution.

The present invention also relates to a process for the production of purified isoflavones from a starting material resulting from a biological source. The starting material includes a mixture of at least one isoflavone conjugate and at least one impurity. The process includes adjusting the concentration of the starting material in an aqueous medium so that the concentration of the at least one isoflavone conjugates therein is greater than about 20 percent (%) of solubility, but less than saturation, whereby there is formed a purified solution containing the isoflavone conjugate and insolubles containing the impurity, wherein the insolubles contain after washing less than about 20 percent (%) of the isoflavone conjugate present in the starting material.

The process also includes separating the formed purified solution from the insolubles. The process also includes hydrolyzing the isoflavone conjugate in the purified solution to its glycoside or aglycones form, inducing thereby precipitation of a precipitate enriched in the isoflavone in glycoside or aglycones form.

BRIEF DESCRIPTION OF THE DRAWINGS [FIGURE 1 is a flow diagram of a process for the purification of a phenolic compound according to an exemplary embodiment. DETAILED DESCRIPTION OF THE PREFERRED AND OTHER EXEMPLARY EMBODIMENTS A process for the purification or recovery of a starting material resulting from a biological source is shown in FIGURE 1 as a a process for the purification of a phenolic compound according to an exemplary embodiment. The starting material contains a phenolic compound in its malonyl glycoside (conjugated) form according to a preferred embodiment. That phenolic compound is preferably a polyphenol, more preferably a flavonoid, most preferably an isoflavone. The starting material also contains at least one non-phenolic compound according to a preferred embodiment. Preferably, the starting material is an extract of plant material, preferably an extract of soy material.

Referring to FIGURE 1, the starting material is soy solubles (22) resulting from a process for protein purification (20). In such protein purification process, a soy material (12), preferably soybean meal (SBM) or defatted and flash- desolventized soy flakes (defatted white flakes of "DFWF") is contacted with water (14) and optionally also with an organic solvent. After the contact and other treatments, purified soy proteins (24) are separated using methods such as filtration, centrifugation, precipitation, decantation, and membrane filtration, e.g. ultrafiltration according to a preferred embodiment. Impurities removed from the soy material end up in an aqueous solution, sometimes referred to as soy solubles, soy molasses or soy whey (22). Such solution contains phenolic compounds (e.g. isoflavones) and many other components, including various carbohydrates (main components), soluble proteins or peptides, saponins, mineral salts (ashes), amino acids and other solutes. The concentration of the solution depends on the method of the protein purification. In those cases where an organic solvent is used for protein purification, it is evaporated from the co-product solution along with water to reach a solution of about 50 percent (%) concentration, typically referred to as soy molasses. In cases of using no organic solvent, the solution is dilute, particularly when membrane filtration is used for separating the purified solution. In the latter case, the solutes are of relatively low molecular weight and end up in the membrane permeate. Typically, the permeate is about a few percent concentration and is concentrated by reverse osmosis (RO) and/or evaporation.

Soy solubles suitable for use as a starting material may be obtained by extraction of solubles from defatted soybean germ, according to a preferred embodiment.. I Typically, on a solvent-free basis, the phenolic compounds (e.g. isoflavones) concentration in soy solubles is smaller than 5 percent (%). Soy solubles contain three families of isoflavones: genistin, daidzin and glycitin. The majority of the isoflavones there are of the first family. Each family may appear in four forms: aglycones, glycosides, malonyl glycosides, and acetyl glycosides (the malonyl and acetyl glycosides are also referred to as conjugates). Most of the isoflavones in soy solubles are in the forms of malonyl glycosides and glycosides. A suitable material includes at least part of the isoflavones in solution in the form of malonyl glycosides, preferably more than 20 percent ( ), more preferably more than 40 percent (%), most preferably more than 60 percent (%).

Isoflavones may be separated from soy solubles by adjusting the solution concentration to between about 10 percent (%) and 40 percent (%), more preferably between about 15 percent (%) and 30 percent (%). Such adjustment of concentration induces the precipitation of a solid with increased isoflavones purity compared to the soy solubles, typically about 4-7 percent (%) on a solvent-free basis.

According to a preferred embodiment, the precipitate is a suitable starting material.

The process involves adjusting the concentration of the starting material in an aqueous medium so that the concentration of at least one conjugate therein is greater than about 20 percent (%) of saturation, but smaller than saturation according to a preferred embodiment. The solution concentration and temperature are such that they induce the formation of a purified solution containing the conjugate and insolubles containing at least one non-phenolic compound, wherein the insolubles contain less than about 20 percent (%) of the conjugate present in the starting material according to a preferred embodiment. (The term "insolubles" as used in this disclosure means material that does not dissolve in the solution at the selected conditions.) The formed purified solution is then separated from the insolubles. Preferably, the phenolic compound is then separated from the purified solution. A preferred method for separating the phenolic compound is hydrolyzing the conjugate form to the glycoside or aglycones form. Such hydrolysis induces the precipitation of isoflavones-enriched insolubles, while the solution is isoflavones-depleted. Preferably, the isoflavones-enriched insolubles are separated from the isoflavones- depleted solution.

Referring further to FIGURE 1, the concentration of the soy solubles solution (22) is adjusted to bring the concentration of malonyl glycosides there to between about 20 percent (%) and 100 percent (%) of saturation (see step 30). Concentration adjustment may involve dilution with water, dissolution in water or water removal, depending on the concentration of the solubles according to alternative embodiments. Water removal could use e.g. evaporation, multiple-effect evaporation, reverse osmosis and their combination. Preferably, water removal is conducted at a temperature not greater than about 60 degrees Celsius. If the starting material is solid, it is preferably introduced into water or an aqueous solution. Means for facilitating dissolution are preferably applied, e.g. mixing and ultrasound.

The total solids concentration is selected so that insolubles exist according to a preferred embodiment (when referring to concentration in solution, the term "solids" may also mean "solutes"). The preferred concentration is a matter of economic optimization based on the cost of water removal and preferred conditions for the recovery of the product. The preferred concentration is typically smaller in the case of a solid starting material than in the case of starting with a solution such as soy solubles.

The insolubles formed contain non-phenolic compounds (e.g.non- isoflavones) so that the solution is purified with regards to phenolic compounds (e.g. isoflavones) according to a preferred embodiment. The insolubles may contain less than about 20 percent (%) phenolic compounds (e.g. isoflavones), typically less than about 10 percent (%), preferably less than about 5 percent (%) and most preferably less than about 1 percent (%)phenolic compounds (e.g. isoflavones) according to a preferred embodiment.

Those insolubles are preferably separated (step 40 in FIGURE 1) by means such as centrifugation, filtration, decantation, etc. and various combinations of those. The separated insolubles (42) can be used for various applications, e.g. in animal feed.

The steps of adjusting the concentration and of separating the impurities-containing solids are conducted at conditions that minimize the hydrolysis of the malonyl glycoside form according to a preferred embodiment. Preferably, the pH is less than about 9.5, more preferably at neutral or acidic pH. Particularly preferable is pH of between pi minus 1 and pi plus 1, wherein pi is the isoelectric point of the protein present in the starting solution and most preferably pH is between about 3 and about 6.

Referring further to FIGURE 1, the purified solution (44) is further treated for separation of phenolic compounds (e.g. isoflavones). That is preferably done by hydrolysis of the malonyls to glycosides or to aglycones (step 50 in FIGURE 1). The hydrolysis is preferably catalyzed, chemically, enzymatically or in a combination of the two. Chemical catalysis of hydrolysis to glycosides is conducted at alkaline pH (e.g. greater than 9) according to a preferred embodiment and optionally also at elevated temperature. Typically, the higher the temperature, the lower is the pH needed and vice versa.

Alkali hydrolysis of phenolic compounds (e.g. isoflavones) may induce formation of insolubles at the pH of the alkali hydrolysis. The pH and concentration of the solution may be adjusted so that those insolubles contain less than 20 percent (%) of the phenolic compounds (e.g. isoflavones) in the starting solution, preferably less than 10 percent (%) and most preferably less than 1 percent (%). That would typically be the case at pH > 9.5. Those insolubles are preferably separated from the solution before separation of the phenolic compounds (e.g. isoflavones). In case of alkali-catalyzed hydrolysis of the malonyl glycoside, there may be a need for pH adjustment after the hydrolysis is completed (and in case of insolubles removal, after that removal). The adjusted pH is preferably at least about 0.2 pH units lower than the pH of the alkali hydrolysis. According to another embodiment, the adjusted pH is lower than about pKa minus 1, where pKa is the pKa of the isoflavone. If more than one isoflavone is present, the pKa is that of the stronger acid isoflavone.

Referring further to FIGURE 1, the hydrolysis induces the formation of phenolic compound-enriched (e.g. isoflavones-enriched) insolubles and of a phenolic compound-depleted (e.g. isoflavones-depleted) solution. Those isoflavones- enriched solids are separated from the isoflavones-depleted solution (step 60 in FIGURE 1) by methods such as centrifugation, filtration, decantation, etc. and various combinations of those. The isoflavones-enriched solid obtained is concentrated in isoflavones in glycoside and or aglycones form according to a preferred embodiment. Their concentration there is typically greater than about 30 percent (%), preferably greater than about 40 percent (%), most preferably greater than about 50 percent (%). Those solids typically contain at least about 30 percent (%) of the amount of the isoflavones in the starting material (i.e. the isoflavones recovery yield is at least about 30 percent (%)), more preferably at least 50 percent (%), most preferably at least about 60 percent (%).

If desired, the isoflavones-enriched solids can be further purified, e.g. by solvent extraction, chromatographic separation, ion-exchange, adsorption on resin of low polarity, re-crystallization, etc.

The following is a preferred method of conducting re-crystallization for further purification of the isoflavones-enriched insolubles. Water and alkali are added to the insolubles to form a solution having at least pH of about pKa minus 1.5, and a total solid concentration of between about 1 percent (%) and 40 percent (%). A purified solution is formed, containing the isoflavones, and further insolubles containing at least one impurity and a minimal content of isoflavones, if any. Those insolubles are removed by methods as suggested above. Then, the pH of the purified solution is lowered, inducing thereby precipitation of a precipitate further enriched in isoflavones. That precipitate is separated from the depleted solution, and if desired, purified again by another step of re-crystallization.

According to another embodiment, the pH is reduced by contact with a stream (e.g. solution or a solid) that has buffering capacity. According to a preferred embodiment, the contact is with a protein, preferably a purified one. Such contact results in precipitation of isoflavones and can form an isoflavones-enriched purified protein.

Preferably, the concentration of the solution during the separation of the isoflavones-enriched solids (e.g. in step 60 of FIGURE 1) is about the same as that of the separation of impurities solids (e.g. in step 40 of FIGURE 1) or smaller. Preferably, the temperature of the solution in step 60 of FIGURE 1 is about the same as that of the solution in step 40 or higher. Most preferably, both temperature and concentration of the solution in step 60 are similar to those in step 40. As indicated, the starting material may contain solutes that may be of commercial value. For example, soy solubles/molasses contain carbohydrates, saponins, proteins, and other components. Some of those, which tend to co- precipitate with isoflavones and, in that respect are considered as impurities, could also be valuable for some applications. Preferably, the process involves separation of such valuable solutes and their commercial utilization. Such solutes can be recovered from the various streams of the process, e.g. from the starting material before the first pH adjustment, from the insolubles formed and separated at the elevated pH, from the purified solution, from the isoflavones-depleted solution and from co-products of re- crystallization. Separation of solutes from the starting material may also be introduced as a pre-treatment before step (30). For example, proteins present in the starting material can be separated by adjusting the pH of the solution to about the protein isoelectric point (pi), by membrane filtration, or by a combination of those. In many cases, such removed proteins are enriched in the Bowman-Birk tryspin inhibitor (BBI) and present a good source for the recovery of that medically important component. Thus, a preferred embodiment involves treating the starting material to remove protein at conditions such that those removed proteins are enriched in BBI. Alternatively, BBI can be recovered from other process streams, e.g. the isoflavones- depleted solution.

The process may also involve separation of other solutes from the starting material or from other process streams according to alternative embodiments. For example, ashes and amino acids may be removed by means such as ion-exchange.

Carbohydrates may also be separated from the starting material and from other process streams according to alterntive embodiments. One objective for such separation of carbohydrates may be their commercial utilization. Another objective may be improving the yield and/or the purity of isoflavones recovery. In addition to separation and/or alternatively to it, carbohydrates may be removed by degradation to other components. Such degradation may involve enzymatic hydrolysis and/or fermentation of the carbohydrates. According to a preferred embodiment, the fermentation products are ones* that are easy to separate, e.g. by distillation, by extraction, by crystallization or by known methods of solid-liquid separation. Fermentation products may be of commercial value. Optionally, carbohydrates may be fermented to form enzymes suitable for the isoflavones process, e.g. ones for the hydrolysis of the malonyl and acetyl forms.

* * *

While the invention will now be described in connection with certain embodiments in the following examples so that aspects thereof may be more fully understood and appreciated, the examples are not intended to limit the invention to these particular examples. EXAMPLES EXAMPLE 1 Defatted soy flakes were extracted with slightly basic aqueous solution. The solution was separated from the insolubles. The separated solution was treated on an ultrafiltration membrane. Most of the dissolved protein was retained in the retentate, while the rest of the protein, the lower molecular weight solutes and most of the water permeate through the membrane. The permeating solution (referred to in this disclosure as "permeate"), contained proteins, several carbohydrates, several mineral salts, amino acids and isoflavones and had a total solutes concentration of about 1.5 percent (%). The permeate was concentrated by RO to 16 percent (%) total- solutes. Its isoflavones concentration was 0.1 percent (%). The majority of the isoflavones were in their malonyl glycoside form. Precipitate was present in the concentrated solution. That precipitate was separated by centrifugation to form a clarified solution. The precipitate was washed and analyzed and was found to contain no detectable amounts of isoflavones.

NaOH solution of 1.5N was added to 128g of that clarified solution to adjust the pH there to 11. The solution was stirred at ambient temperature for 2 hours. During that time, it is believed that the malonyls and acetyl glycosides forms of the isoflavones were hydrolyzed to their glycoside form (without intending to be limited to any particularly theory). A second precipitate appeared. It was separated by centrifugation from the clarified alkaline solution, washed, and analyzed for isoflavones. It contained less than 1 percent ( ) of the initial amount of isoflavones.

About 130g of the clarified alkaline solution were mixed with HC1 in an amount suitable to bring the pH down from 11 to 7. Mixing was applied overnight at 18°C. A precipitate was formed. The precipitate was separated, washed, dried, and analyzed. Isoflavones concentration in the washed and dried precipitate was 86 percent (%). That precipitate contained about one third of the isoflavones in the starting material. EXAMPLE 2 A permeate concentrated to 16 percent (%) total solids was produced as in Example 1. HC1 solution was added to 133g concentrated permeate to adjust the pH there to 4.5. The acidulated solution was stirred at 25°C for 2 hours. A precipitate was observed. That precipitate was removed by centrifugation. NaOH was added to the supernatant to adjust its pH to 11. Stirring was applied for an hour at room temperature and then, under vacuum, for 45minutes at 35 degrees Celsius. During that treatment the concentration of the solution was increased to 22.6 percent (%) total solids, and it is believed that the isoflavone malonyls and acetyl glycosides got hydrolyzed to the glycoside form (without intending to be limited to any particularly theory) and a second precipitate appeared. That precipitate was separated by centrifugation from the clarified alkaline solution, washed, and analyzed for isoflavones. It contained less than 1 percent (%) of the initial amount of isoflavones. About 80g of the clarified alkaline solution were mixed with HC1 in an amount suitable to bring the pH down from 11 to 7. Mixing was applied overnight at 18°C.

A precipitate was formed. The precipitate was separated, washed, dried, and analyzed. Isoflavones concentrations in the washed and dried precipitate was 89 percent (%). That precipitate contained about one third of the isoflavones in the starting material. * * *

While the preferred and other exemplary embodiments illustrated in the drawings and described above 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. A process for the production of purified isoflavones from a starting material resulting from a biological source, the starting material comprising at least one isoflavone in its conjugate form and at least one impurity, the process comprising: (a) adjusting the concentration of the starting material in an aqueous medium so that the concentration of the isoflavone conjugates therein is greater than about 20 percent (%) of saturation, but smaller than saturation, whereby there is formed an isoflavone purified solution comprising a purified isoflavone conjugate and an isoflavone -depleted precipitate containing the impurity, wherein the isoflavone -depleted precipitate contains, after washing, less than about 20 percent (%) of the isoflavone conjugate present in the starting material; (b) separating the isoflavone purified solution from the isoflavone -depleted precipitate; and (c) separating the isoflavone from the isoflavone purified solution.

2. A process for the purification of a starting material resulting from a biological source, the starting material comprising at least one polyphenol glycoside in its conjugate form and at least one non-phenolic compound, comprising: (a) adjusting the concentration of the starting material in an aqueous medium so that the concentration of the polyphenol glycoside in its conjugate form is greater than about 20 percent (%) of saturation, but smaller than saturation, in order to induce the formation of a polyphenol purified solution containing the conjugate and a polyphenol-depleted precipitate containing the non- phenolic compound, wherein the polyphenol-depleted precipitate contains less than about 20 percent (%) of the conjugate present in the starting material; and (b) separating the formed polyphenol purified solution from the polyphenol-depleted precipitate.

3. The process of Claim 2 further comprising the step of: (c) separating the polyphenol from the purified solution.

4. The process of Claim 3 wherein separating the polyphenol comprises a step (c(i)) of hydrolyzing the conjugate in the polyphenol purified solution to its glycoside or aglycone form, inducing thereby formation of a polyphenol enriched precipitate enriched in the polyphenol in glycoside or aglycone form from the purified solution.

5. The process of Claim 4 comprising the further step (c(ii)) of separating the polyphenol enriched precipitate from the purified solution.

6. The process of Claim 5 wherein the polyphenol is a flavonoid.

7. The process of Claim 6 wherein the flavonoid is an isoflavone. I

8. The process of Claim 6 wherein the flavonoid is a flavonoid glycoside in its conjugate form and comprises at least one of malonyls of genistin, daidzin and glycitin.

9. The process of Claim 7 wherein the biological source comprises at least one of a plant, an extract thereof, and a processed material derived therefrom.

10. The process of Claim 7 wherein the plant comprises the family Glycine.

11. The process of Claim 7 wherein the plant comprises Glycine max.

12. The process of Claim 7 wherein the biological source comprises at least one of soybean, non-oil products of soybean processing, defatted soy flakes, soybean meal, soy molasses, soy solubles soy whey and soy germ.

13. The process of Claim 7 wherein the biological source comprises at least one of cocoa and citrus.

14. The process of Claim 7 wherein the biological source is initially subjected to ultrafiltration processing to provide a permeate, the permeate comprising the starting material.

15. The process of Claim 14 wherein the permeate is further concentrated, the permeate concentrate comprising the starting material.

16. The process of Claim 7 wherein the starting material is a solid.

17. The process of Claim 7 wherein the solid is a product of co-precipitation of the conjugate and the non-phenolic compound.

18. The process of Claim 7 wherein the starting material also contains polyphenol in its glycoside or aglycones form.

19. The process of Claim 7 wherein the conjugate forms at least about 20 percent (%) of the total polyphenols in the starting material.

20. The process of Claim 7 wherein a total solids concentration of the solution in (c(ii)) is about the same as that of the solution in step (b) or smaller.

21. The process of Claim 7 wherein the temperature of the solution in (c(ii)) is about the same as that of the solution in step (b) or higher.

22. The process of Claim 7 wherein the concentration and the temperature of the solution in (c(ii)) are about the same as those of the solution in step (b).

23. The process of Claim 7 wherein the starting material is formed during the production of purified soy protein.

24. The process of Claim 23 wherein the production comprises extraction with a solvent.

25. The process of Claim 24 wherein the production comprises dissolution of soy protein in an aqueous solution followed by separation of dissolved protein comprising at least one of protein precipitation at about the isoelectric point, membrane separation, and a combination thereof.

26. The process of Claim 7 wherein the starting material comprises at least one of soy solubles, soy whey, soy molasses, precipitates obtained from those, and solutions obtained from those.

27. The process of Claim 7 wherein the adjusted concentration of step (a) is between about 10 percent (%) and about 40 percent (%). The process of Claim 7 wherein the hydrolyzing in (c(i)) is conducted by at least one of treatment at alkaline pH, enzymatic hydrolysis, and a combination thereof.

28. The process of Claim 7 wherein the hydrolyzing in (c(i)) is conducted at pH greater than about 9 and wherein the formation of the polyphenol enriched precipitate further comprises the step of: (d) adjusting the pH of the solution to less than that of hydrolyzing by at least about 0.2 pH units.

29. The process of Claim 28 wherein the hydrolyzing induces formation of the polyphenol depleted precipitate containing less than about 20 percent (%) of the polyphenol present in the starting material.

30. The process of Claim 28 comprising the further step of separating the polyphenol depleted precipitate from the solution before step (d).

31.The process of Claim 28 wherein the total solids concentration in the step of separating the polyphenol depleted precipitate is similar to that of step (d) or greater.

32. The process of Claim 28 wherein the temperature in the step of separating the polyphenol depleted precipitate is similar to that of step (d) or smaller

33. The process of Claim 7 wherein the starting material is a solution with total solutes concentration of less than about 3 percent (%).

34. The process of Claim 7 wherein the adjusting of concentration is conducted by water removal comprising at least one of evaporation, multiple-effect evaporation, reverse osmosis, and a combination thereof.

35. The process of Claim 7 wherein the starting material is solid, and step (a) further comprises introduction of the starting material into water and/or solution using mixing, ultrasound or combinations of those.

36. The process of Claim 7 wherein the polyphenol forms less than about 5 percent (%) of the starting material on dry basis.

37. The process of laim 7 wherein the polyphenol enriched precipitate contains at least about 30 percent (%) of the polyphenol in the starting material.

38. The process of Claim 7 further comprising re-crystallization of the polyphenol enriched precipitate according to the steps of: (e) addition of water and alkali to the polyphenol enriched precipitate to form a solution having pH of at least about pKa - 1.5, wherein pKa is that of the polyphenol and having a total solid concentration of between about 1 percent (%) and about 40 percent (%), whereby there is formed a purified solution containing the polyphenol and the polyphenol depleted precipitate containing the non- phenolic compound, wherein the polyphenol depleted precipitate contains less than 20 percent (%) of the polyphenol present in the polyphenol enriched precipitate; (f) separating the purified solution from polyphenol depleted precipitate and (g) adjusting the pH of the purified solution resulting from step (f) to smaller than that of step (e) by at least about 0.2 pH units, inducing thereby precipitation of a precipitate further enriched in the polyphenol, the further enriched precipitate comprising at least 30 percent (%) phenolic compound on a dry basis.

39. The processof Claim 38 further comprising at least one recrystallization of the precipitate further enriched in the polyphenol.

40. The processof Claim 39 wherein the recrystallizations are conducted in a counter-current mode.

41. The process of Claim 40 further comprising a step of purifying the precipitate further enriched in the polyphenolcomprising at least one of solvent extraction, chromatographic separation, ion-exchange, adsorption on resin of low polarity and a combination thereof.

42. A purified polyphenol produced from a starting material resulting from a biological source, the starting material comprising a mixture of at least one isoflavone in its conjugate form and at least one impurity, wherein the purified polyphenol is made by the process comprising: (a) adjusting the concentration of the starting material in an aqueous medium so that the concentration of the isoflavone conjugates therein is greater than about 20 percent (%) of saturation, but smaller than saturation, whereby there is formed a purified solution containing the isoflavone conjugate and an isoflavone depleted precipitate containing the at least one impurity, wherein the isoflavone-depleted precipitate contains, after washing, less than about 20 percent (%) of the isoflavone conjugate present in the starting material; (b) separating the formed purified solution from the isoflavone- depleted precipitate; and (c) separating the isoflavone from the purified solution.

43. The purified polyphenol of Claim 42 wherein the steps (a) and (b) are conducted at pH less than about 9.5.

44. The process of Claim 42 wherein the steps (a) and (b) are conducted at about neutral pH.

45. The purified polyphenol of Claim 42 >vherein the steps (a) and (b) are conducted at about acidic pH.

46. The purified polyphenol of Claim 42 wherein the starting solution comprises a protein and the steps (a) and (b) are conducted at pH of between about pi minus 1 and about pi plus 1, wherein pi is the isoelectric point of the protein present in the starting solution.

47. The purified polyphenol of Claim 42 wherein the steps (a) and (b) are conducted at pH between about 3 and about 6.

48. A process for the production of purified isoflavones from a starting material resulting from a biological source, the starting material comprising a mixture of at least one isoflavone conjugate and at least one impurity, comprising: (a) adjusting the concentration of the starting material in an aqueous medium so that the concentration of the at least one isoflavone conjugates therein is greater than about 20 percent (%) of solubility, but less than saturation, whereby there is formed a purified solution containing the isoflavone conjugate and insolubles containing the impurity, wherein the insolubles contain after washing less than about 20 percent (%) of the isoflavone conjugate present in the starting material; (b) separating the formed purified solution from the insolubles; and (c) hydrolyzing the isoflavone conjugate in the purified solution to its glycoside or aglycones form, inducing thereby precipitation of a precipitate enriched in the isoflavone in glycoside or aglycones form.