the invention is aimed to provide rebaudioside d forms or compositions containing rebaudioside d with improved solubility in water . in one embodiment , highly purified crystalline rebaudioside d , which has a solubility of 0 . 05 %, was dissolved in aqueous alcohol at a concentration of 0 . 5 to 50 %, preferably 5 - 25 %, more preferably 10 - 20 %. the alcohol content used in aqueous alcohol is 0 . 1 - 100 % ( vol / vol ), preferably 20 - 70 % ( vol / vol ), more preferably 30 - 50 % ( vol / vol ). the alcohol is selected from the group consisting of alkanols , more particularly methanol , ethanol , n - propanol , 2 - propanol , 1 - butanol , 2 - butanol or combinations thereof . to dissolve the reb d , the solution is heated to 30 - 100 ° c ., preferably 50 - 100 ° c ., more preferably 60 - 100 ° c . to prevent premature crystallization , the solution is maintained at 20 - 80 ° c ., preferably 30 - 70 ° c ., more preferably 50 - 60 ° c . the solution is fed to a spray drier to obtain a powder of highly purified amorphous reb d with a solubility of 0 . 2 %. in another embodiment highly purified amorphous or crystalline rebaudioside d is combined with a polyol at a ratio of 1 : 1 to 1 : 100 ( wt / wt ), preferably 1 : 1 to 1 : 30 ( wt / wt ), more preferably 1 : 1 to 1 : 10 . the polyol is selected from group consisting of erythritol , maltitol , mannitol , sorbitol , lactitol , xylitol , inositol , isomalt , propylene glycol , glycerol ( glycerine ), threitol , galactitol , reduced isomalto - oligosaccharides , reduced xylo - oligosaccharides , reduced gentio - oligosaccharides , reduced maltose syrup , reduced glucose syrup or combinations thereof . preferably , the polyol is selected from group consisting of erythritol , maltitol , mannitol , sorbitol , lactitol , xylitol , inositol , and isomalt , and more preferably , erythritol , maltitol , sorbitol , and isomalt . when the prepared compositions containing crystalline reb d are dissolved in water at room temperature the solubility of reb d is 0 . 1 - 2 . 0 %. for compositions with amorphous rebd the solubility under the same conditions is 0 . 3 - 2 . 0 %. in another embodiment , the combination of amorphous reb d and polyol at a ratio of 1 : 1 to 1 : 100 ( w / w ), preferably 1 : 1 to 1 : 30 ( w / w ), more preferably 1 : 1 to 1 : 10 , is granulated by means of any equipment known to art suitable for granulation of fine powder into granules , preferably by means of a roll compact granulator . the roll speed was between about 5 - 20 rpm , preferably between about 7 - 10 rpm , and more preferably about 9 rpm . the roll pressure was between about 20 - 80 bar , preferably between about 40 - 50 bar , and more preferably about 45 bar . the granulator rotors were rotating at a rate of between about 50 - 2000 rpm , preferably between about 100 - 200 rpm , and more preferably at about 150 rpm . the granulators were equipped with screens which sizes were between about 0 . 5 - 6 . 0 mm , preferably between about 1 - 4 mm , and more preferably about 3 . 1 mm for the pre - granulator and about 1 . 6 mm for the fine granulator . when the prepared compositions are dissolved in water , the solubility of reb d is 0 . 1 - 2 . 5 %. in another embodiment , the non - glycosidic fraction of stevia is combined with crystalline rebaudioside d , at a ratio of 1 : 1 to 1 : 100 ( wt / wt ), preferably 1 : 2 to 1 : 20 ( wt / wt ), more preferably 1 : 3 to 1 : 10 . the mixture is dissolved in aqueous alcohol at a concentration of 0 . 5 to 50 %, preferably 5 - 25 %, more preferably 10 - 20 %. the alcohol content in used aqueous alcohol is 0 . 1 - 100 % ( vol / vol ), preferably 20 - 70 % ( vol / vol ), more preferably 30 - 50 % ( vol / vol ). the alcohol is selected from the group consisting of alkanols , more particularly methanol , ethanol , n - propanol , 2 - propanol , 1 - butanol , and 2 - butanol . to dissolve the reb d , the solution is heated to 30 - 100 ° c ., preferably 50 - 100 ° c ., more preferably 60 - 100 ° c . to prevent premature crystallization , the solution is maintained at 20 - 80 ° c ., preferably 30 - 70 ° c ., more preferably 50 - 60 ° c . the solution is fed to a spray drier to obtain a powder of highly soluble reb d composition . when the prepared compositions are dissolved in water at room temperature the solubility of reb d is 0 . 3 - 5 . 0 %, or 0 . 1 - 2 . 5 %. in another embodiment , molasses are combined with crystalline rebaudioside d , at a ratio of 1 : 1 to 1 : 100 ( w / w ), preferably 1 : 2 to 1 : 20 ( w / w ), more preferably 1 : 3 to 1 : 10 . the mixture is dissolved in aqueous alcohol at a concentration of 0 . 5 to 50 %, preferably 5 - 25 %, more preferably 10 - 20 %. the alcohol content in used aqueous alcohol is 0 . 1 - 100 % ( vol / vol ), preferably 20 - 70 % ( vol / vol ), more preferably 30 - 50 % ( vol / vol ). the alcohol is selected from the group consisting of alkanols , more particularly methanol , ethanol , n - propanol , 2 - propanol , 1 - butanol , 2 - butanol . the molasses are selected from the group comprising of us grade “ a ”, “ b ” and “ c ” molasses as well as substandard molasses , preferably grade “ a ” molasses . to dissolve the reb d the solution is heated to 30 - 100 ° c ., preferably 50 - 100 ° c ., more preferably 60 - 100 ° c . to prevent premature crystallization the solution is maintained at 20 - 80 ° c ., preferably 30 - 70 ° c ., more preferably 50 - 60 ° c . the solution is fed to a spray drier to obtain a powder of highly soluble reb d composition . when the prepared compositions are dissolved in water , the solubility of reb d is 0 . 1 - 3 . 5 %. in another embodiment , caramel is combined with crystalline rebaudioside d , at a ratio of 1 : 1 to 1 : 100 ( w / w ), preferably 1 : 2 to 1 : 20 ( w / w ), more preferably 1 : 3 to 1 : 10 . the mixture is dissolved in aqueous alcohol at a concentration of 0 . 5 to 50 %, preferably 5 - 25 %, more preferably 10 - 20 %. the alcohol content in used aqueous alcohol is 0 . 1 - 100 % ( vol / vol ), preferably 20 - 70 % ( vol / vol ), more preferably 30 - 50 % ( vol / vol ). the alcohol is selected from the group consisting of alkanols , more particularly methanol , ethanol , n - propanol , 2 - propanol , 1 - butanol , 2 - butanol . the caramel is selected from the group comprising of class i , class ii , class iii and class iv caramel colors , preferably , class i caramel . to dissolve the reb d the solution is heated to 30 - 100 ° c ., preferably 50 - 100 ° c ., more preferably 60 - 100 ° c . to prevent premature crystallization the solution is maintained at 20 - 80 ° c ., preferably 30 - 70 ° c ., more preferably 50 - 60 ° c . the solution is fed to a spray drier to obtain a powder of highly soluble reb d composition . when the prepared compositions are dissolved in water , the solubility of reb d is 0 . 3 - 3 . 5 %. the following examples illustrate preferred embodiments of the invention . it will be understood that the invention is not limited to the materials , proportions , conditions and procedures set forth in the examples , which are only illustrative . 100 g of crystalline rebaudioside d , produced by purecircle sdn bhd , with 98 . 1 % purity ( on anhydrous basis ) was dissolved in 500 ml aqueous ethanol , containing 50 % ( vol .) ethanol . the solution was maintained at 50 ° c . and dried using a yc - 015 laboratory spray drier ( shanghai pilotech instrument & amp ; equipment co . ltd ., china ) operating at 175 ° c . inlet and 100 ° c . outlet temperatures . the obtained amorphous powder was compared with crystalline material for solubility . 500 g of commercial stevia extract , containing rebaudioside a 41 . 2 %, stevioside 30 . 6 %, rebaudioside c 9 . 9 %, rebaudioside f 2 . 3 %, dulcoside a 0 . 5 %, rubusoside 0 . 6 %, rebaudioside d 1 . 5 %, steviolbioside 0 . 2 % and rebaudioside b 0 . 1 % were dissolved in 9 . 5 liter of ro water and passed through a column packed with 10 liter amberlite xad7hp resin . the column was washed with 10 volumes of ro water . the collected water fractions were evaporated under vacuum at 55 ° c . and spray dried to yield 45 g powder with 9 . 8 % tsg including 7 . 8 % rebaudioside d , 2 . 0 % rebaudioside a and non - detectable amounts of other steviol glycosides . 10 g of crystalline rebaudioside d , produced by purecircle sdn bhd , with 98 . 1 % purity ( on anhydrous basis ) was mixed with different amounts of erythritol ( prima inter - chem sdn bhd , malaysia ). the obtained blends were tested for solubility , and solution stability to crystallization , during storage at room temperature . ** the material was dissolved at 100 ° c . and cooled down to room temperature ( 20 ° c .). the reported concentrations are stable ( do not crystallize ) for 24 hrs storage in room temperature . 10 g of amorphous rebaudioside d prepared according to example 1 , was mixed with different amounts of erythritol ( prima inter - chem sdn bhd , malaysia ). the obtained blends were tested for solubility , and solution stability to crystallization , during storage at room temperature . ** the material was dissolved at 100 ° c . and cooled down to room temperature ( 20 ° c .). the reported concentrations are stable ( do not crystallize ) for 24 hrs storage in room temperature . 10 g of crystalline rebaudioside d , produced by purecircle sdn bhd , with 98 . 1 % purity ( on anhydrous basis ) was mixed with different amounts of erythritol ( prima inter - chem sdn bhd , malaysia ). the obtained blends were dissolved in 5 volumes of aqueous ethanol , containing 50 % ( vol .) ethanol . the solution was maintained at 50 ° c . and dried using a yc - 015 laboratory spray drier ( shanghai pilotech instrument & amp ; equipment co . ltd ., china ) operating at 175 ° c . inlet and 100 ° c . outlet temperatures . the obtained amorphous powder was tested for solubility , and solution stability to crystallization , during storage at room temperature . ** the material was dissolved at 100 ° c . and cooled down to room temperature ( 20 ° c .). the reported concentrations are stable ( do not crystallize ) for 24 hrs storage in room temperature . 10 g of crystalline rebaudioside d , produced by purecircle sdn bhd , with 98 . 1 % purity ( on anhydrous basis ) was mixed with different amounts of stevia non - glycosidic fraction prepared according to example 2 . the obtained blends were tested for solubility , and solution stability to crystallization , during storage at room temperature . ** the material was dissolved at 100 ° c . and cooled down to room temperature ( 20 ° c .). the reported concentrations are stable ( do not crystallize ) for 24 hrs storage in room temperature . 10 g of amorphous rebaudioside d , prepared according to example 1 , was mixed with different amounts of stevia non - glycosidic fraction , prepared according to example 2 . the obtained blends were tested for solubility , and solution stability to crystallization , during storage at room temperature . ** the material was dissolved at 100 ° c . and cooled down to room temperature ( 20 ° c .). the reported concentrations are stable ( do not crystallize ) for 24 hrs storage in room temperature . 10 g of crystalline rebaudioside d was mixed with different amounts of stevia non - glycosidic fraction , prepared according to example 2 . the obtained blends were dissolved in 5 volumes of aqueous ethanol , containing 50 % ( vol .) ethanol . the solution was maintained at 50 ° c . and dried using a yc - 015 laboratory spray drier ( shanghai pilotech instrument & amp ; equipment co . ltd ., china ) operating at 175 ° c . inlet and 100 ° c . outlet temperatures . the obtained amorphous powder was tested for solubility , and solution stability to crystallization , during storage at room temperature . ** the material was dissolved at 100 ° c . and cooled down to room temperature ( 20 ° c .). the reported concentrations are stable ( do not crystallize ) for 24 hrs storage in room temperature 10 g of crystalline rebaudioside d , produced by purecircle sdn bhd , was mixed with different amounts of molasses ( chee lam trading , malaysia ). the obtained blends were dissolved in 5 volumes of aqueous ethanol , containing 50 % ( vol .) ethanol . the solution was maintained at 50 ° c . and dried using a yc - 015 laboratory spray drier ( shanghai pilotech instrument & amp ; equipment co . ltd ., china ) operating at 175 ° c . inlet and 100 ° c . outlet temperatures . the obtained amorphous powder was tested for solubility , and solution stability to crystallization , during storage at room temperature . ** the material was dissolved at 100 ° c . and cooled down to room temperature ( 20 ° c .). the reported concentrations are stable ( do not crystallize ) for 24 hrs storage in room temperature 1 kg of amorphous rebaudioside d prepared according to example 1 , was mixed with different amounts of erythritol ( prima inter - chem sdn bhd , malaysia ). the obtained blends were transferred to an alexanderwerk wp 50n / 75 roller compactor . the compactor was operating at 9 rpm and 45 bar pressure . the compacted mass was fed to a pre - granulator and a fine granulator with rotors at rotating at 150 rpm . the screen size for the pre - granulator was 3 . 1 mm and for the fine granulator was 1 . 6 mm . the “ overs ” ( particles that are too large ) and “ fines ” ( particles that are too small ) were separated by top screen having a screen size of us mesh 10 and bottom screen of us mesh 40 . the % ratio of “ overs ”:“ product ”:“ fines ” was 0 . 9 %: 78 . 2 %: 20 . 9 % respectively . the obtained products were tested for solubility , and solution stability to crystallization , during storage at room temperature . ** the material was dissolved at 100 ° c . and cooled down to room temperature ( 20 ° c .). the reported concentrations are stable ( do not crystallize ) for 24 hrs storage in room temperature while the foregoing has described one or more embodiments of the present invention , it will be understood by those skilled in the art that various changes and modifications may be made and equivalents may be substituted for elements or compositions thereof without departing from the true scope of the invention . therefore , it is intended that this invention not be limited to a particular embodiment disclosed , but that the invention will include all embodiments falling within the scope of the appended claims .
the invention relates to a process for producing highly soluble compositions containing purified steviol glycosides from stevia rebaudiana bertoni plant extract , more particularly rebaudioside d . obtained highly soluble compositions are useful as non - caloric sweeteners or in combination with sugar or high intensity sweeteners in edible and chewable compositions such as beverages , confectionaries , bakery products , chewing gums and the like .