Sweetner and use
Sweeteners on the basis of a simultaneously transglucosylated sweet glycoside mixture of Stevia rebaudiana Bertoni are prepared. The transglucosylation was developed in the presence of starch under the action of cyclodextrin glucanotransferase. The remaining maltodextrins are transformed to the fructose-terminated oligosaccharides by the addition of sucrose. The sweeteners are purified to not less than 98% content of sweet glycosides and derivatives. The preparations are almost non-caloric, non-cariogenic, non-bitter, non-lingering sweeteners, which may be advantageously applied in foods, beverages, cosmetics and milk products.
1. A sweetener comprising more than 98% of glucosylated sweet glycoside derivatives, wherein the sweetener is produced by a process of enzymatic transglucosylation from at least one sweet glycoside selected from the group consisting of stevioside, rebaudioside A, rebaudioside C, and dulcoside A;
wherein the process of enzymatic transglucosylation comprises:
dissolving starch into water to form a starch suspension;
adding a first batch of CGTase into the starch suspension and incubating for 0.5 to 2 hours at 75-80° C., resulting in the liquefaction of starch;
adding a purified Stevia extract comprising stevioside, rebaudioside A, rebaudioside C, and/or dulcoside A into the liquefied starch suspension, resulting in a reaction mixture; wherein the added Stevia extract is about equal to that of the starch;
adding a second batch of CGTase into the reaction mixture and incubating for 12 to 48 hours at 55-75° C.;
adding sucrose into the reaction mixture and incubating for 2 to 10 hours at 65-75° C. to form fructose-terminated oligosaccharides;
removing malto- or fructose-terminated oligosaccharides; and
concentrating and drying to obtain the sweetener with more than 98% of the glucosylated sweet glycoside derivatives;
wherein the sweetener is with the most superior sweetness quality and more than 170 times of relative sweetness to 5% of sucrose.
2. The sweetener of claim 1 , wherein the COTase is produced by cultures of Bacillus stearothemophilus.
3. The sweetener of claim 1 , wherein the process further comprises decolorizing and desalting.
4. The sweetener of claim 3 , wherein the decolorizing is performed using activated carbon.
5. The sweetener of claim 3 , wherein the desalting is performed by passing through ion exchange resin.
6. The sweetener of claim 1 , wherein the process further comprises removing malto- or fructose-terminated oligosaccharides through a column packed with Amberlite XAD16 HP, wherein the column is washed sequentially with water and ethanol with increased concentration; thereby monosaccharides and oligosaccharides are in the fractions of the water and low concentration of ethanol, and glycosylated and non-modified glycosides are in the fractions of high concentrations of ethanol.