Method of using a low beverage soluble iron content adsorbent

Abstract

An adsorbent removes certain undesirable components from beverages, such as beer, and has a low beverage soluble iron (BSI) content. These undesirable components include contaminants which cause chill haze. The adsorbent includes two components, a silica component and a polyphosphate sequestering agent component, such as sodium tripolyphosphate (STPP). The process for using the adsorbent involves first contacting a beverage with an adsorbent to adsorb at least a portion of the undesirable components then separating the adsorbent from the beverage. The adsorbent may be formed by one of two methods or a combination of both. The first method involves adding the polyphosphate sequestering agent to a reactant, such as a sodium or potassium silicate solution, prior to or during the gelation stage. A second method involves adding the polyphosphate sequestering agent to the water wash after a hydrogel is formed. The BSI of the adsorbent is substantially reduced using the first method, but the total iron content of the adsorbent appears to increase. The second method decreases both the BSI and the total iron content of the silica gel.

What is claimed:  
     
         1 . A process for making a silica gel adsorbent having a low beverage soluble iron content, said process comprising the steps of: 
 contacting a polyphosphate sequestering agent with at least one of a reactant of said silica gel and a wash solution containing a precursor of said silica gel; and    forming said silica gel adsorbent from said precursor.    
     
     
         2 . A process in accordance with  claim 1 , wherein: 
 said reactant comprises sodium silicate or potassium silicate; and    the contacting step consists of contacting said polyphosphate sequestering agent with said sodium silicate or potassium silicate and forming a solution of said polyphosphate sequestering agent and said sodium silicate or potassium silicate to form a mixture.    
     
     
         3 . A process in accordance with  claim 2  further comprising adding an acid to said mixture to form a hydrosol.  
     
     
         4 . A process in accordance with  claim 2 , wherein said polyphosphate sequestering agent is sodium tripolyphosphate.  
     
     
         5 . A process in accordance with  claim 1 , wherein: 
 the contacting step consists of contacting said polyphosphate sequestering agent with said wash solution containing said precursor; and    said precursor comprises a hydrogel formed by mixing an acid with sodium silicate or potassium silicate.    
     
     
         6 . A process in accordance with  claim 5 , wherein said polyphosphate sequestering agent is sodium tripolyphosphate.  
     
     
         7 . A process in accordance with  claim 1 , wherein the contacting step comprises contacting said polyphosphate sequestering agent with said reactant and with said wash solution containing said precursor.  
     
     
         8 . A process for making a silica gel adsorbent having a low beverage soluble iron content, said process comprising the steps of: 
 mixing a polyphosphate sequestering agent with sodium silicate or potassium silicate to form a mixture;    adding an acid to said mixture to form a silica hydrosol having a polyphosphate component and allowing said hydrosol to set into a hydrogel;    washing said hydrogel with acidified water; and    milling said washed hydrogel to form the silica gel adsorbent.    
     
     
         9 . A process according to  claim 8 , wherein said acid is a mineral acid.  
     
     
         10 . A process according to  claim 8 , wherein said polyphosphate sequestering agent is sodium tripolyphosphate.  
     
     
         11 . A process according to  claim 10 , wherein: 
 the sodium silicate or potassium silicate has an iron content;    the sodium tripolyphosphate is added to said sodium silicate or potassium silicate in an amount to achieve a sodium tripolyphosphate:iron molar ratio of between 0.5:1 and 50:1;    the acid is added to said mixture in an amount of between 5 molar percent and 30 molar percent greater than the stoichiometrically required amount of acid to fully neutralize the sodium or potassium; and    said acidified water has a pH of between 2.5 and 4.0.    
     
     
         12 . A process according to  claim 10 , wherein: 
 the sodium silicate or potassium silicate has an iron content;    the sodium tripolyphosphate is added to said sodium silicate or potassium silicate in an amount to achieve a sodium tripolyphosphate:iron molar ratio of between 5:1 and 10:1;    the acid is added to said mixture in an amount of between 15 molar percent and 25 molar percent greater than the stoichiometrically required amount of acid to fully neutralize the sodium or potassium; and    said acidified water has a pH of between 3.2 and 3.4.    
     
     
         13 . A process for making a silica gel adsorbent having a low beverage soluble iron content, said process comprising the steps of: 
 mixing sodium or potassium silicate with an acid to form a hydrosol and allowing said hydrosol to set into a hydrogel;    washing said hydrogel with an acidified mixture of water and a polyphosphate sequestering agent; and    milling said washed hydrogel to form the silica gel adsorbent.    
     
     
         14 . A process according to  claim 13 , wherein said acid is a mineral acid.  
     
     
         15 . A process according to  claim 13 , wherein said polyphosphate sequestering agent is sodium tripolyphosphate.  
     
     
         16 . A process according to  claim 15 , wherein: 
 the sodium silicate or potassium silicate has an iron content;    the sodium tripolyphosphate is added to said acidified mixture in an amount to achieve a concentration of between 0.01 and 1 weight percent sodium tripolyphosphate based on sodium silicate;    the acid is added to said mixture in an amount of between 5 molar percent and 30 molar percent greater than the stoichiometrically required amount of acid to fully neutralize the sodium or potassium; and    said acidified water has a pH of between 2.5 and 4.0.    
     
     
         17 . A process according to  claim 15 , wherein: 
 the sodium silicate or potassium silicate has an iron content;    the sodium tripolyphosphate is added to said acidified mixture in an amount to achieve a concentration of between 0.05 and 0.5 weight percent sodium tripolyphosphate based on sodium silicate;    the acid is added to said mixture in an amount of between 15 molar percent and 25 molar percent greater than the stoichiometrically required amount of acid to fully neutralize the sodium or potassium; and    said acidified water has a pH of between 3.3 and 3.5.    
     
     
         18 . A composition for use in the removal of components from a beverage to reduce chill haze, said composition comprising an adsorbent comprising a silica component and a polyphosphate sequestering agent component.  
     
     
         19 . A composition in accordance with  claim 18 , wherein: 
 said silica component is a silica gel; and    said polyphosphate sequestering agent component is sodium tripolyphosphate.    
     
     
         20 . A process for removing components from a beverage to reduce chill haze, said process comprising the steps of: 
 contacting a beverage with an adsorbent comprising a silica component and a polyphosphate sequestering agent component to adsorb at least a portion of said components onto said adsorbent thereby leaving a component-depleted beverage; and    separating said adsorbent from said component-depleted beverage.    
     
     
         21 . A process in accordance with  claim 20 , wherein: 
 said silica component is a silica gel; and    said polyphosphate sequestering agent component is sodium tripolyphosphate.    
     
     
         22 . A process in accordance with  claim 21 , wherein said adsorbent is added to said beverage in an amount to achieve a concentration of about 100 ppm to about 1,000 ppm.  
     
     
         23 . A process in accordance with  claim 21 , wherein said adsorbent is added to said beverage in an amount to achieve a concentration of about 400 ppm to about 800 ppm.  
     
     
         24 . A process in accordance with  claim 21 , wherein the step of separating comprises filtering said adsorbent from said component-depleted beverage.  
     
     
         25 . A silica gel adsorbent formed by the process of  claim 1 .  
     
     
         26 . A silica gel adsorbent formed by the process of  claim 8 .  
     
     
         27 . A silica gel adsorbent formed by the process of  claim 13.