Process for manufacturing a sweetener and use thereof
Highly purified Stevioside, Rebaudioside A and a purified sweet steviol glycoside mixture were prepared from sweet glycoside extracts obtained from Stevia rebaudiana Bertoni leaves. The resulting sweeteners are suitable as non-calorie, non-cariogenic, non-bitter, non-lingering sweeteners, which may be advantageously applied in foods, beverages, and milk products.
1. A process for producing a low-calorie sweetener composition, comprising the steps of:
a) drying Stevia rebaudiana leaves;
b) treating the dried Stevia rebaudiana leaves with water to extract sweet glycosides, wherein a leaves-water mixture is formed;
c) filtering the leaves-water mixture to obtain an aqueous filtrate;
d) directly treating the aqueous filtrate with calcium hydroxide or calcium oxide to raise the pH of the aqueous filtrate to about 10;
e) directly neutralizing the treated aqueous filtrate with trivalent iron chloride; and
f) filtrating the neutralized aqueous filtrate to obtain a filtrated aqueous filtrate, and evaporating the filtrated aqueous filtrate to dryness to obtain purified sweet glycosides to provide a high intensity sweetener;
g) providing sugar granules as a low intensity sweetener;
h) adjusting a moisture content of the sugar granules to a level of about 0.5% to about 1.5%;
i) distributing the sugar granules on a vibrating surface to form a layer with thickness of about 10 to about 100 mm on the vibrating surface;
j) dissolving the high intensity sweetener in an aqueous alcohol mixture with an alcohol content of about 0.1% to about 99.9% (v/v) to obtain a solution with about 10% to about 70% (w/w) solids to make a high intensity sweetener solution;
k) dispersing the high intensity sweetener solution onto the sugar granules while maintaining an intensity of vibration at about 1 to about 2000 vpm; and
l) drying the granules to form the low-calorie sweetener composition.
2. The process of claim 1 , wherein a dry weight ratio of the low intensity sweetener to high intensity sweetener is in the range of about 50:1 to about 300:1 (w/w).
3. A process for making a low-calorie sweetener, comprising the steps of:
a) drying Stevia rebaudiana leaves;
b) treating the dried Stevia rebaudiana leaves with water to extract sweet glycosides, wherein a leaves-water mixture is formed;
c) filtering the leaves-water mixture to obtain an aqueous filtrate;
d) directly treating the aqueous filtrate with calcium hydroxide or calcium oxide to raise the pH of the aqueous filtrate to about 10;
e) directly neutralizing the treated aqueous filtrate with trivalent iron chloride; and
f) filtrating the neutralized aqueous filtrate to obtain a filtrated aqueous filtrate, and evaporating the filtrated aqueous filtrate to dryness to obtain purified sweet glycosides as a high intensity sweetener;
g) providing sugar granules as a low intensity sweetener;
h) making a sweetener blend by combining the low intensity sweetener with the high intensity sweetener in a ribbon blender;
i) compacting the sweetener blend into a sweetener sheet using a roll compaction unit; and
j) milling the sweetener sheet into granules to make the low-calorie sweetener.
4. A process for making a low-calorie sweetener, comprising the steps of:
a) drying Stevia rebaudiana leaves;
b) treating the dried Stevia rebaudiana leaves with water to extract sweet glycosides, wherein a leaves-water mixture is formed;
c) filtering the leaves-water mixture to obtain an aqueous filtrate;
d) directly treating the aqueous filtrate with calcium hydroxide or calcium oxide to raise the pH of the aqueous filtrate to about 10;
e) directly neutralizing the treated aqueous filtrate with trivalent iron chloride; and
f) filtrating the neutralized aqueous filtrate to obtain a filtrated aqueous filtrate, and evaporating the filtrated aqueous filtrate to dryness to obtain purified sweet glycosides as a high intensity sweetener;
g) providing sugar granules as a low intensity sweetener;
h) making a sweetener solution by combining the low intensity sweetener, the high intensity sweetener and water;
i) passing the sweetener solution through multiple-effect evaporators to make an evaporated sweetener solution;
j) applying a vacuum to the evaporated sweetener solution to make a super-saturated solution;
k) seeding the super-saturated solution with an additional amount of the low intensity sweetener to initiate crystal formation;
l) allowing crystal formation to continue to complete crystallization in the solution; and
m) separating the crystals from the solution to result in the low-calorie sweetener.
5. The process of claim 3 , wherein a dry weight ratio of the low intensity sweetener to high intensity sweetener is in the range of about 50:1 to about 300:1 (w/w).
6. The process of claim 4 , wherein a dry weight ratio of the low intensity sweetener to high intensity sweetener is in the range of about 50:1 to about 300:1 (w/w).
7. The process of claim 1 , wherein the purified sweet glycosides obtained in step (f) are dissolved in methanol at temperatures ranging from about 20-50° C., in an amount of 1:2-1:7 (w/v) to precipitate Stevioside from solution, filtering the solution to recover Stevioside precipitate, suspending the precipitate in an alcohol-water solution to further purify the Stevioside, and recovering the higher purity of Stevioside with a purity of at least 98% to provide the high intensity sweetener.
8. The process of claim 7 , further comprising the steps of combining remaining alcohol solutions, removing the alcohol, ultrafiltering to obtain a filtrate, recovering Rebaudioside A, mixing the Rebaudioside A with dilute alcohol, and filtering and drying to result in Rebaudioside A with a purity of at least 98% to provide the high intensity sweetener.
9. The process of claim 3 , wherein the purified sweet glycosides obtained in step (f) are dissolved in methanol at temperatures ranging from about 20-50° C., in an amount of 1:2-1:7 (w/v) to precipitate Stevioside from solution, filtering the solution to recover Stevioside precipitate, suspending the precipitate in an alcohol-water solution to further purify the Stevioside, and recovering the higher purity of Stevioside with a purity of at least 98% to provide the high intensity sweetener.
10. The process of claim 9 , further comprising the steps of combining remaining alcohol solutions, removing the alcohol, ultrafiltering to obtain a filtrate, recovering Rebaudioside A, mixing the Rebaudioside A with dilute alcohol, and filtering and drying to result in Rebaudioside A with a purity of at least 98% to provide the high intensity sweetener.
11. The process of claim 4 , wherein the purified sweet glycosides obtained in step (f) are dissolved in methanol at temperatures ranging from about 20-50° C., in an amount of 1:2-1:7 (w/v) to precipitate Stevioside from solution, filtering the solution to recover Stevioside precipitate, suspending the precipitate in an alcohol-water solution to further purify the Stevioside, and recovering the higher purity of Stevioside with a purity of at least 98% to provide the high intensity sweetener.
12. The process of claim 11 , further comprising the steps of combining remaining alcohol solutions, removing the alcohol, ultrafiltering to obtain a filtrate, recovering Rebaudioside A, mixing the Rebaudioside A with dilute alcohol, and filtering and drying to result in Rebaudioside A with a purity of at least 98% to provide the high intensity sweetener.