Process for manufacturing a sweetener and use thereof

1. A process for producing a low-calorie cake, comprising:

kneading a natural sweetener; wherein the natural sweetener comprises sweet glycosides, wherein the sweet glycosides are produced from Stevia rebaudiana leaves by a method; and

wherein the method comprises the following steps:

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;

wheat flour; hen eggs; sugar; sorbitol; and sucrose fatty acid ester into a dough; and

baking the dough into the low-calorie cake.

2. The process of claim 1 , wherein the treating step (b) of the method is performed with a water content of at least 5 to 15 liters per 1 kg of dry leaves, a treating time for 0.5-24 hours, and a temperature range between 25-90° C.

3. The process of claim 1 , wherein the treating step (d) of the method is performed at a temperature range from 40 to 60° C., for 0.5-1 hours.

4. The process of claim 1 , wherein the method further comprises the following steps:

g) dissolving the purified sweet glycosides in alcohol at ambient temperatures 20-50° C. in an amount of 1:2-1:7 (w/v) to precipitate Stevioside from solution;

h) filtering the solution from step (g) to recover the precipitate of Stevioside;

i) suspending the precipitate of Stevioside obtained in step (h) in an alcohol-water solution to further purify the Stevioside; and

j) recovering the Stevioside with a purity of at least 98%.

5. The process of claim 2 , wherein the method further comprises:

combining remaining alcohol solutions;

removing the alcohol;

ultrafiltering to obtain a filtrate; and

recovering Rebaudioside A with at least 98% of purity.

6. The process of claim 3 , wherein the recovering the Rebaudioside A step comprises:

drying the ultrafiltration filtrate;

mixing the ultrafiltration filtrate with an alcohol solution;

filtering and drying to obtain a dried filtrate;

mixing the dried filtrate with dilute alcohol; and

filtering and drying to recover the Rehaudioside A;

wherein the mixing with dilute alcohol step is performed with 92% ethanol at 12° C. for 60 minutes.

7. The process of claim 1 , wherein the low-calorie cake further comprises coloring including orange red color, and flavor including vanilla.

8. The process of claim 1 , wherein

the natural sweetener in the range of 0.01-0.2% (w/w);

the wheat flour in the range of 30-50% (w/w);

the hen eggs in the range of 30-50% (w/w);

the sugar in the range of 10-20% (w/w);

the sorbitol in the range of 8-12% (w/w); and

the sucrose fatty acid ester in the range of 0.5-2% (w/w).