Patent Application

App. No. 13/070,466

Abstract

Claims (40)

1 .- 24 . (canceled)

25 . A method of purifying rebaudioside A from a starting material selected from the group consisting of Stevia starting material, a crude extract of Stevia plant material, and a crude extract of Stevia plant material which extract has at least 40% rebaudioside A purity, comprising:

identifying approximate rebaudioside A purity in the starting material;

formulating an aqueous alkanol solvent having an alkanol to water ratio based on the rebaudioside A purity of the starting material;

refluxing the starting material in the aqueous alkanol solvent; and

removing alkanol and water to obtain purified rebaudioside A,

wherein the water content in the aqueous alkanol solvent is between about 4% and about 15%.

26 . The method of claim 25 , wherein when the approximate rebaudioside A purity in the starting material is between about 45% and about 90%, the water content in the aqueous alkanol solvent is between about 15% and about 6%, respectively.

27 . The method of claim 25 , wherein (i) when the approximate rebaudioside A purity in the starting material is between about 80% and about 90%, the water content in the aqueous alkanol solvent is between about 8% and about 6%, respectively, or (ii) when the approximate rebaudioside A purity in the starting material is between about 70% and about 80%, the water content in the aqueous alkanol solvent is between about 10% and about 8%, respectively, or (iii) when the approximate rebaudioside A purity in the starting material is between about 60% and about 70%, the water content in the aqueous alkanol solvent is between about 12% and about 10%, respectively.

28 . The method of claim 25 , wherein the water content of the aqueous alkanol solvent is substantially inversely proportional to the rebaudioside A purity of the starting material.

29 . The method any one of claims 25 to 28 , wherein the alkanol is selected from the group consisting of methanol, ethanol, propanol, and isopropanol.

30 . The method of any one of claims 25 to 28 , wherein the method further comprises an additional reflux step.

31 . The method of any one of claims 25 to 28 , wherein the method further comprises a wash step.

32 . Purified rebaudioside A produced by the method of any one of claims 25 to 28 .

33 . The purified Rebaudioside A of any one of claims 25 to 28 , wherein the purified rebaudioside A has a purity greater than 95%.

34 . The purified Rebaudioside A of any one of claims 25 to 28 , wherein the purified rebaudioside A has a purity greater than 99%.

35 . A food composition comprising purified rebaudioside A produced by the method of any one of claims 25 to 28 .

36 . A pharmaceutical composition comprising purified rebaudioside A produced by the method of any one of claims 25 to 28 .

37 . The method of any one of claims 25 to 28 , wherein the alkanol is a denatured alkanol.

38 . The method of any one of claims 25 to 28 , wherein the alkanol is denatured ethanol.

39 . A method of purifying rebaudioside A from a starting material selected from the group consisting of Stevia starting material, a crude extract of Stevia plant material, and a crude extract of Stevia plant material which extract has at least 40% rebaudioside A purity, comprising:

identifying approximate rebaudioside A purity in the starting material;

preparing an aqueous ethanol solvent having an ethanol to water ratio based on the rebaudioside A purity of the starting material;

refluxing the starting material in the aqueous ethanol solvent to form a reflux mixture;

cooling the reflux mixture to produce a precipitate;

separating the precipitate from the mixture; and

removing ethanol and water from the precipitate to obtain purified rebaudioside A, wherein the water content in the aqueous alkanol solvent is between about 4% and about 15%.

40 . The method of claim 39 , wherein when the approximate rebaudioside A purity in the starting material is between about 45% and about 90%, the water content in the aqueous alkanol solvent is between about 15% and about 6%, respectively.

41 . The method of claim 39 , wherein (i) when the approximate rebaudioside A purity in the starting material is between about 80% and about 90%, the water content in the aqueous alkanol solvent is between about 8% and about 6%, respectively, or (ii) when the approximate rebaudioside A purity in the starting material is between about 70% and about 80%, the water content in the aqueous alkanol solvent is between about 10% and about 8%, respectively, or (iii) when the approximate rebaudioside A purity in the starting material is between about 60% and about 70%, the water content in the aqueous alkanol solvent is between about 12% and about 10%, respectively.

42 . The method of claim 39 , wherein the water content in the aqueous alkanol solvent is substantially inversely proportional to the rebaudioside A purity of the starting material.

43 . The method any one of claims 39 to 42 , wherein the alkanol is selected from the group consisting of methanol, ethanol, propanol, and isopropanol.

44 . The method of any one of claims 39 to 42 , wherein the method further comprises an additional reflux step.

45 . The method of any one of claims 39 to 42 , wherein the method further comprises a wash step.

46 . Purified rebaudioside A produced by the method of any one of claims 39 to 42 .

47 . The purified Rebaudioside A of any one of claims 39 to 42 , wherein the purified rebaudioside A has a purity greater than 95%.

48 . The purified Rebaudioside A of any one of claims 39 to 42 , wherein the purified rebaudioside A has a purity greater than 99%.

49 . A food composition comprising purified rebaudioside A produced by the method of any one of claims 39 to 42 .

50 . A pharmaceutical composition comprising purified rebaudioside A produced by the method of any one of claims 39 to 42 .

51 . The method of any one of claims 39 to 42 , wherein the alkanol is a denatured alkanol.

52 . The method of any one of claims 39 to 42 , wherein the alkanol is denatured ethanol.

Assignments (8)