Method for the enrichment of rebaudioside b and/or rebaudioside d in stevia-derived glycoside compositions using adsorb-desorb chromatography with a macroporous neutral adsorbent resin

Abstract

The invention relates to the use of adsorb/desorb chromatography to prepare enriched compositions comprising rebaudioside B and/or rebaudioside D. Compositions with enriched rebaudioside-B and/or rebaudioside-D components may be prepared from Stevia-derived glycoside compositions using an adsorb-desorb chromatography process where the stationary phase of the chromatography bed comprises a macroporous neutral adsorbent resin.

1 . A method of preparing an enriched composition comprising at least one of rebaudioside B, rebaudioside D, or a mixture thereof, the method comprising the steps of:
 (A) providing a pH adjusted Stevia-derived glycoside solution comprising: (i) at least one glycoside selected from the group of reb-B and reb-D, and (ii) at least one other Stevia-derived glycoside;   (B) providing a macroporous neutral adsorbent resin;   (C) contacting the macroporous neutral adsorbent resin with the Stevia-derived glycoside solution so that at least a portion of glycosides in the Stevia-derived glycoside solution are adsorbed onto the macroporous neutral adsorbent resin;   (D) providing at least one elution solvent comprising an ethanol and water mixture formulated to selectively elute reb-B, reb-D, or a mixture thereof from the adsorbent;   (E) contacting the macroporous neutral adsorbent resin with the ethanol and water elution solvent in order to elute a composition enriched with at least one glycoside selected from the group of reb-B and reb-D; and   (F) optionally, eluting at least a portion of the remaining adsorbed glycosides from the macroporous neutral adsorbent resin.   
     
     
         2 . The method according to  claim 1 , wherein the pH of the pH adjusted Stevia-derived glycoside solution ranges from a pH of about 8 to a pH of about 11. 
     
     
         3 . (canceled) 
     
     
         4 . The method according to  claim 2 , wherein the at least one elution solvent comprises from about 20-35% w/w ethanol and from about 65-80% w/w water. 
     
     
         5 . (canceled) 
     
     
         6 . The method according to  claim 4 , wherein the composition enriched with at least one glycoside is enriched with reb-B and reb-D. 
     
     
         7 . The method according to  claim 6 , wherein at least a portion of the remaining adsorbed glycosides are eluted from the macroporous neutral adsorbent resin with a subsequent elution solvent wherein the subsequent elution solvent comprises from about 36-100% w/w ethanol and about 0-64% w/w water, and the composition eluted with the subsequent elution solvent is enriched with reb-A. 
     
     
         8 . The method according to  claim 1 , wherein the pH of the pH adjusted Stevia-derived glycoside solution ranges from a pH of about 4 to a pH of about 7. 
     
     
         9 . The method according to  claim 8 , wherein the at least one elution solvent comprises from about 20-35% w/w ethanol and from about 65-80% w/w water. 
     
     
         10 . The method according to  claim 8 , wherein the at least one elution solvent comprises from about 25-33% w/w ethanol and from about 67-75% w/w water. 
     
     
         11 . The method according to  claim 10 , wherein the composition enriched with at least one glycoside is enriched with reb-D. 
     
     
         12 . The method according to  claim 11 , wherein at least a portion of the remaining adsorbed glycosides are eluted from the macroporous neutral adsorbent resin with a subsequent elution solvent wherein the subsequent elution solvent comprises from about 36-100% w/w ethanol and about 0-64% w/w water, and the composition eluted with the subsequent elution solvent is enriched with reb-A and reb-B. 
     
     
         13 . The method according to  claim 1 , wherein the pH of the pH adjusted Stevia-derived glycoside solution ranges from a pH of about 1 to a pH of about 4. 
     
     
         14 . The method according to  claim 1 , wherein the pH of the pH adjusted Stevia-derived glycoside solution ranges from a pH of about 1 to a pH of about 3. 
     
     
         15 . The method according to  claim 13 , wherein the at least one elution solvent comprises from about 20-40% w/w ethanol and from about 60-80% w/w water. 
     
     
         16 . (canceled) 
     
     
         17 . The method according to  claim 15 , wherein the composition enriched with at least one glycoside is enriched with reb-D. 
     
     
         18 . The method according to  claim 17 , wherein at least a portion of the remaining adsorbed glycosides are eluted from the macroporous neutral adsorbent resin with a subsequent elution solvent wherein the subsequent elution solvent comprises from about 36-100% w/w ethanol and about 0-64% w/w water, and the composition eluted with the subsequent elution solvent is enriched with reb-A and reb-B. 
     
     
         19 . The method according to  claim 13 , wherein the at least one elution solvent comprises from about 40-65% w/w ethanol and from about 35-60% w/w water. 
     
     
         20 . (canceled) 
     
     
         21 . The method according to  claim 19 , wherein the composition enriched with at least one glycoside is enriched with reb-A and reb-D. 
     
     
         22 . The method according to  claim 21 , wherein at least a portion of the remaining adsorbed glycosides are eluted from the macroporous neutral adsorbent resin with a subsequent elution solvent wherein the subsequent elution solvent comprises from about 61-100% w/w ethanol and about 0-39% w/w water, and the composition eluted with the subsequent elution solvent is enriched with reb-B. 
     
     
         23 . The method according to  claim 1 , wherein the macroporous neutral adsorbent resin comprises a macroporous resin of divinyl benzene. 
     
     
         24 . An enriched composition prepared according to the method of  claim 1 .