Method of removing isoflavones and phytates

Abstract

Methods for sequentially removing isoflavones and phytates from an active surface by utilizing an aqueous medium for isoflavone removal and an aqueous medium for phytate removal. The aqueous medium for isoflavone removal contains at least one alcohol and at least one acid. The aqueous medium for phytate removal is either a relatively stronger acidic solution, a basic solution, or with some active surfaces may be an aqueous solution of pH 2-7, which is essentially free of alcohol and organic solvents. The use of the methods disclosed allows sequential isolation of isoflavones and phytates, compounds which may then be utilized in various foods for human consumption.

What is claimed is:  
     
         1 . A method for the sequential removal of isoflavones and phytates from one, or more, active surfaces, comprising the steps of: 
 a) providing active surfaces comprising an anion exchange resin;    b) contacting said active surfaces with an aqueous medium for isoflavone removal; and    c) contacting said active surfaces with an aqueous medium for phytate removal.    
     
     
         2 . A method as defined in  claim 1 , wherein said active surfaces are contained within a column which has at least one inlet and at least one outlet, said inlet located lower in the column than said outlet, such that said aqueous medium for isoflavone may be contacted with said active surfaces and a first eluate collected, and then said aqueous medium for phytate removal may be contacted with said active surfaces and a second eluate collected.  
     
     
         3 . A method as defined in  claim 2 , wherein said first eluate contains less than 1% (w/v) of phytate.  
     
     
         4 . A method as defined in  claim 2 , wherein said method is conducted at room temperature.  
     
     
         5 . A method as defined in  claim 2 , wherein said method is conducted at a temperature from 90° to 120° F.  
     
     
         6 . A method as defined in  claim 2 , wherein said aqueous medium for isoflavone removal comprises: 
 a) 1-40% (w/w) of at least one acid selected from the group consisting of acetic acid, citric acid, malic acid, malonic acid, lactic acid, and mixtures thereof; and    b) 10-90% (v/v) of at least one alcohol selected from the group consisting of methanol, ethanol, propanol, butanol, and mixtures thereof.    
     
     
         7 . A method as defined in  claim 2 , wherein said aqueous medium for isoflavone removal comprises 50-70% v/v of at least one alcohol selected from the group consisting of methanol, ethanol, propanol, butanol, and mixtures thereof.  
     
     
         8 . A method as defined in  claim 2 , wherein said aqueous medium for isoflavone removal comprises: 
 (a) at least one acid selected from the group consisting of acetic acid, citric acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, succinic acid, malic acid, malonic acid, tartaric acid, lactic acid, pyruvic acid, fumaric acid and mixtures thereof;    (b) 10-90% (v/v) of at least one alcohol selected from the group consisting of methanol, ethanol, propanol, butanol, and mixtures thereof;    and has a pH ranging from 1.5 to 3.5.    
     
     
         9 . A method as defined in  claim 2 , wherein said aqueous medium for phytate removal has a pH less than 1.  
     
     
         10 . A method as defined in  claim 2 , wherein said aqueous medium for phytate removal comprises at least one acid selected from the group consisting of acetic acid, citric acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, succinic acid, malic acid, malonic acid, tartaric acid, lactic acid, pyruvic acid, fumaric acid, and mixtures thereof, and has a pH less than 1.  
     
     
         11 . A method as defined in  claim 2 , wherein said aqueous medium for phytate removal has a pH between 13 and 14.  
     
     
         12 . A method as defined in  claim 2 , wherein said aqueous medium for isoflavone removal comprises at least two separate aqueous solutions.  
     
     
         13 . A method for the sequential removal of isoflavones and phytates active surfaces, comprising the steps of: 
 a) providing active surfaces comprising alkylsilane bonded phase media;    b) contacting said active surfaces with an aqueous medium for isoflavone removal; and    c) contacting said active surfaces with an aqueous medium for phytate removal.    
     
     
         14 . A method as defined in  claim 13 , wherein said alkylsilane bonded phase medium is contacted with an aqueous medium for phytate removal which comprises an aqueous solution with a pH of 2 to 7, essentially free of alcohol and organic solvents, and said alkylsilane bonded phase medium is then contacted with an aqueous medium for isoflavone removal.  
     
     
         15 . A food containing isoflavones isolated by a method as defined in  claim 2 .  
     
     
         16 . A food containing phytates isolated by a method as defined in  claim 2 .  
     
     
         17 . A method for sequentially isolating isoflavones and phytates from plant materials comprising: 
 a) providing at least one anion exchange resin;    b) providing a slurry of plant protein that contains isoflavones and phytic acid;    c) placing the anion exchange resin in a structure which has at least one inlet and at least one outlet, and said inlet is located lower in the structure than the outlet;    d) passing the slurry into the structure and over the resin by entering through the inlet and exiting through the outlet;    e) contacting said resin with an aqueous medium for isoflavone removal and collecting a first eluate; and    (f) then contacting the resin with an aqueous medium for phytate removal and collecting a second eluate.